Note: Descriptions are shown in the official language in which they were submitted.
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HEAT EXCHANGER ELEMENT AND HEAT EXCHANGER MEMBER FOR A
STIRLING CYCLE REFRIGERATOR AND METHOD OF MANUFACTURING SUCH
A HEAT EXCHANGER MEMBER
Technical field
The present invention relates to a heat exchanger member, such as a heat
absorber or heat rejector, provided in a Stirling cycle refrigerator, to a
heat exchanger
element for use in such a heat exchanger member, and to a method of
manufacturing
such a heat exchanger member.
Background art
First, a typical configuration of a free-piston-type Stirling cycle
refrigerator
exploiting a Stirling cycle will be described. Fig. 29 is a diagram
schematically showing
a section, as seen from the side, of a free-piston-type Stirling cycle
refrigerator. Inside
a cylinder 1, a heat absorber (heat sink) 2 acting as a low-temperature
portion, a
regenerator 3, and a heat rejector (radiator) 4 acting as a high-temperature
portion are
arranged in this order. The heat absorber 2 and the heat rejector 4 are each
built as
a heat exchanger member composed of a tubular body 21 or 41 having a heat
exchanger element 22 or 42 fitted on the inner surface thereof at one end.
Inside the
cylinder 1, the heat exchanger elements 22 and 42 are each contiguous to the
regenerator 3.
Inside the cylinder 1 are also arranged a displacer 6 firmly fitted to one end
of
a displacer rod 5, and a piston 7 through which the displacer rod 5 is placed.
The other
end of the displacer rod 5 is connected to a spring 8. Inside the cylinder 1,
the
displacer 6 and the piston 7 create an expansion space 9 in the heat absorber
2 and
a compression space 10 in the heat rejector 4. The expansion space 9 and the
compression space 10 communicate with each other through the regenerator 3,
and
thereby form a closed circuit.
The operation of the free-piston-type Stirling cycle refrigerator will now be
described. The piston 7 is made to reciprocate along the axis of the cylinder
1 with a
predetermined period by an external power source, such as a linear motor (not
shown).
The compression space 10 is filled with working gas, such as helium,
beforehand.
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As the piston 7 moves, the working gas in the compression space 10 is
compressed. This causes the working gas to flow through the heat exchanger
element
42 then through the regenerator 3 into the expansion space 9 (as indicated by
broken-
line arrows A in the figure). Meanwhile, the working gas first releases heat
in the heat
rejector 4, by exchanging the heat produced therein as a result of compression
with the
air outside, and is then precooled as it passes through the regenerator 3, by
receiving
the cold accumulated in the regenerator 3 beforehand.
When the working gas flows into the expansion space 9, it presses the
displaces
6 rightward against the spring 8. Thus, the working gas expands, and produces
cold
therein. When the working gas expands to a certain degree, the resilience of
the spring
8 presses the displaces 6 back in the opposite direction.
As a result, the working gas in the expansion space 9 flows through the heat
exchanger element 22 of the heat absorber 2 and then through the regenerator 3
back
to the compression space 10 (as indicated by solid-line arrows A'). Meanwhile,
the
working gas first absorbs heat in the heat exchanger element 22, by exchanging
heat
with the air outside, and is then preheated as it passes through the
regenerator 3, by
receiving the heat accumulated in the regenerator 3 beforehand. The working
gas back
in the compression space 10 is then compressed again by the piston 7.
Through the repetition of this cycle of events, cryogenic cold is obtained in
the
heat absorber 2. Here, the larger the amount of heat absorbed in the heat
exchanger
element 22 of the heat absorber 2 and the amount of heat released in the heat
exchanger element 42 of the heat rejector 4, the better. This helps increase
the
efficiency with which the regenerator 3 precools and preheats the working gas,
and
thus helps reduce the burden on the regenerator 3, leading to better chilling
performance of the Stirling cycle refrigerator.
Next, the heat rejector 4 acting as the high-temperature-side heat exchanger
member of the Stirling cycle refrigerator described above will be described
with
reference to Fig. 30. It is to be understood that, although the following
description
deals only with the heat rejector 4 and its heat exchanger element 42, the
heat
absorber 2 acting as the low-temperature-side heat exchanger member and its
heat
exchanger element 22 are configured in the same manner.
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As Fig. 30 shows, this heat exchanger element 42 is built as an annular
corrugated fin 421 produced by forming a corrugated sheet material into a
cylindrical
shape. Thus, the heat exchanger element 42 has a rugged surface, with a large
number of axially-extending straight V-shaped grooves 421 a formed at regular
intervals.
Here, the portions of the heat exchanger element 42 which protrude toward the
center of the body 41 of the heat rejector 4 are referred to as the bottoms
421 b of the
individual grooves 421 a, and the portions of the heat exchanger element 42
which
protrude toward the inner surface of the body 41 are referred to as the tops
421 c
between every two adjacent grooves 421 a. The diameter of the circle formed by
smoothly connecting all the tops 421 c together (i.e. the external diameter of
the annular
corrugated fin 421 ) is substantially equal to the internal diameter of the
body 41 . The
body 41 and the annular corrugated fin 421 are arranged so as to be coaxial
with each
other.
The inner surface of the body 41 and the tops 421c of the annular corrugated
fin 421 are firmly fixed together with adhesive or solder. Fig. 31 is an
enlarged view of
a portion of the annular corrugated fin 421 as seen axially, and shows how it
is fixed
with adhesive. In this case, first, adhesive 11 is applied thinly to the inner
surface of
the body 41, and then the annular corrugated fin 421 is inserted into the body
41.
Then, with the annular corrugated fin 421 held in the desired position for a
while, the
adhesive 11 is dried.
On the other hand, Fig. 32 shows how the annular corrugated fin 421 is fixed
with solder. In this case, first, the annular corrugated fin 421 is inserted
into the body
41. Then, with the annular corrugated fin 421 held in the desired position,
solder 12 is
applied to where the inner surface of the body 41 makes contact with or comes
close
to the tops 421c of the annular corrugated fin 421.
However, with this conventional heat exchanger member described above, the
fixing together of its components with adhesive or solder is performed by
hand. Thus,
this process takes too much trouble and time, hindering the improvement of
productivity
and the reduction of manufacturing costs. Moreover, the heat exchanger member
thus
manufactured is prone to variations in quality, specifically in heat exchange
performance, and thus tends to lack in stability and reliability.
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Furthermore, as the Stirling cycle refrigerator is used for an extended
period, if
the annular corrugated fin 421 is damaged, it is impossible to simply remove
and
replace it. This adds to the economic burden on the user in the event of
repair, and is
contrary to the general trend toward recycling of resources in view of the
global
environment.
Disclosure of the invention
The present invention has been made to solve the problems mentioned above.
Specifically, according to one aspect of the present invention, a heat
exchanger
element for a Stirling cycle refrigerator comprises: an annular corrugated fin
produced
by forming a sheet material, corrugated so as to have a large number of
grooves, into
a cylindrical shape with the grooves parallel to an axis of the cylindrical
shape; and an
inner ring-shaped member placed in contact with an inner periphery of the
annular
corrugated fin, wherein the annular corrugated fin and the inner ring-shaped
member
are formed integrally.
Integrally forming the annular corrugated fin and the inner ring-shaped member
helps increase the area of contact between them and thereby enhance heat
conductivity. Moreover, their integration makes the handling of the heat
exchanger
element easy, and makes the repair, by replacement, of the heat exchanger
element
possible. This makes the heat exchanger element very economical and
recyclable.
The integration is achieved by a bonding means, such as brazing or soldering.
A heat exchanger member according to the present invention is produced by
inserting the above-described heat exchanger element for a Stirling cycle
refrigerator
into a hollow portion of a tubular body. In this case, the internal diameter
of the body
may be made slightly smaller than the external diameter of the heat exchanger
element. This makes it possible to fit the heat exchanger element into the
body by
press fitting, i.e. without bonding or welding. Moreover, at least one end of
the body
may be tapered so that the wall thickness of the body decreases toward that
end along
the axis. This permits easy insertion of the heat exchanger element into the
body.
Moreover, around the annular corrugated fin, wave-shaped projections may be
formed so as to be in close contact with one another and at regular intervals
overall,
with wave-shaped depressions formed in the inner surface of the body so as to
extend
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axially and correspond to the wave-shaped projections, so that, when the heat
exchanger element is inserted into the body, the wave-shaped projections fit
into the
wave-shaped depressions. This prevents the heat exchanger element from
rotating out
of position inside the body.
Alternatively, the annular corrugated fin may be produced by forming a linear
corrugated fin, of which the endmost sides of the inverted-V-shaped grooves at
both
ends are longer than the slant sides of the V-shaped grooves in between, into
a
cylindrical shape, then holding the endmost sides together so that the
surfaces of those
endmost sides are kept in contact with each other, and then fitting the
resulting
protruding portion that is formed at the tip of the endmost sides so as to
protrude
radially out of the outer periphery of the annular corrugated fin into a
groove that is
formed in the inner surface of the body so as to extend axially. This also
prevents the
heat exchanger element from rotating out of position inside the body.
This heat exchanger member can be manufactured, for example, by removably
attaching to the body one end of a tubular guide member tapered so that the
internal
diameter thereof at one end is substantially equal to the internal diameter of
the body
and that the wall thickness thereof decreases toward another end, and then
inserting
the heat exchanger element for a Stirling cycle refrigerator into the body by
guiding it
through the guide member axially from the other end thereof. In the heat
exchanger
member manufactured in this way, when the annular corrugated fin is guided
through
the guide member, its peripheral shape changes, increasing the area of contact
with
the inner surface of the body. This enhances the heat conduction efficiency of
the
annular corrugated fin, and thus makes it possible to realize a heat exchanger
member
with excellent heat exchange performance.
According to another aspect of the present invention, a heat exchanger element
for a Stirling cycle refrigerator comprises: an annular corrugated fin
produced by
forming a sheet material, corrugated so as to have a large number of grooves,
into a
cylindrical shape with the grooves parallel to an axis of the cylindrical
shape; and an
outer ring-shaped member placed in contact with an outer periphery of the
annular
corrugated fin, wherein the annular corrugated fin and the outer ring-shaped
member
are formed integrally.
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Integrally forming the annular corrugated fin and the outer ring-shaped member
helps increase the area of contact between them and thereby enhance heat
conductivity. Moreover, their integration makes the handling of the heat
exchanger
element easy, and makes the repair, by replacement, of the heat exchanger
element
possible. This makes the heat exchanger element very economical and
recyclable.
The integration is achieved by a bonding means, such as brazing or soldering.
A heat exchanger member according to the present invention is produced by
inserting the above-described heat exchanger element for a Stirling cycle
refrigerator
into a hollow portion of a tubular body. In this case, the internal diameter
of the body
may be made slightly smaller than the external diameter of the heat exchanger
element. This makes it possible to fit the heat exchanger element into the
body by
press fitting, i.e. without bonding or welding. Moreover, at least one end of
the body
may be tapered so that the wall thickness of the body decreases toward that
end along
the axis. This permits easy insertion of the heat exchanger element into the
body.
The aforementioned annular corrugated fin is produced easily by forming a
linear
corrugated fin, having contiguous V-shaped grooves, into a cylindrical shape,
and then
engaging the endmost side of the V-shaped groove at one end of the linear
corrugated
fin with the endmost side of the inverted-V-shaped groove at the other end
thereof.
Alternatively, the annular corrugated fin is produced by forming a linear
corrugated fin, having contiguous V-shaped grooves, into a cylindrical shape,
and then
coupling together the endmost side of the V-shaped groove at one end of the
linear
corrugated fin and the endmost side of the inverted-V-shaped groove at the
other end
thereof by performing spot welding on the surfaces of those endmost sides.
Alternatively, the annular corrugated fin is produced by forming a linear
corrugated fin, having contiguous V-shaped grooves, into a cylindrical shape,
and then
coupling together the endmost side of the V-shaped groove at one end of the
linear
corrugated fin and the endmost side of the inverted-V-shaped groove at the
other end
thereof by bonding the surfaces of those endmost sides together.
Alternatively, the annular corrugated fin is produced by forming a linear
corrugated fin, having contiguous V-shaped grooves, into a cylindrical shape,
and then
coupling together the endmost side of the V-shaped groove at one end of the
linear
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corrugated fin and the endmost side of the inverted-V-shaped groove at the
other end
thereof by brazing the surfaces of those endmost sides together.
Alternatively, the annular corrugated fin is produced by forming a linear
corrugated fin, having contiguous V-shaped grooves, into a cylindrical shape,
then
holding the endmost sides of the inverted-V-shaped grooves at both ends of the
linear
corrugated fin together so that the surfaces of those endmost sides are kept
in contact
with each other, and then fitting a coupling member having a C-shaped section
on the
tip of those endmost sides of which the surfaces are kept in contact with each
other.
Alternatively, the annular corrugated fin is produced by forming a linear
corrugated fin, having contiguous V-shaped grooves, into a cylindrical shape,
and then
coupling together the endmost sides of the inverted-V-shaped grooves at both
ends of
the linear corrugated fin by engaging together a slit that is formed in the
endmost side
at one end of the linear corrugated fin so as to extend from one flank halfway
inward
and a slit that is formed in the endmost side at the other end of the linear
corrugated
fin so as to extend from another flank halfway inward.
Brief description of drawings
Fig. 1 is an external perspective view of the heat rejector of a first
embodiment
of the invention.
' Fig. 2A is an external perspective view of the heat exchanger element of the
heat rejector.
Fig. 2B is an exploded perspective view of the heat exchanger element.
Fig. 3 is an enlarged plan view of a portion of the heat exchanger element, as
seen axially.
Fig. 4 is a vertical sectional outline of the body and the heat exchanger
element
of the heat rejector.
Fig. 5 is an enlarged plan view of a portion of the heat rejector, as seen
axially.
Fig. 6A is a plan view of the linear corrugated fin.
Fig. 6B is an enlarged plan view of the linear corrugated fin in a rounded
state
with both ends brought close together.
Fig. 6C is an enlarged plan view of a portion of the annular corrugated fin in
its
finished state.
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Fig. 7 is an enlarged plan view of a portion of the heat rejector of a second
embodiment of the invention, as seen axially.
Fig. 8A is a plan view of the linear corrugated fin.
Fig. 8B is an enlarged plan view of the linear corrugated fin in a rounded
state
with both ends brought close together.
Fig. 8C is an enlarged plan view of a portion of the annular corrugated fin in
its
finished state.
Fig. 9 is an enlarged plan view of a portion of the heat rejector of a third
embodiment of the invention, as seen axially.
Fig. 10A is a plan view of the linear corrugated fin.
Fig. IOB is an enlarged plan view of the linear corrugated fin in a rounded
state
with both ends brought close together.
Fig. 10C is an enlarged plan view of a portion of the annular corrugated fin
in its
finished state.
Fig. 11 is an enlarged plan view of the heat rejector of a fourth embodiment
of
the invention, as seen axially.
Fig. 12A is a plan view of the linear corrugated fin.
Fig. 12B is an enlarged plan view of the linear corrugated fin in a rounded
state
with both ends brought close together.
Fig. 12C is an enlarged plan view of a portion of the annular corrugated fin
in its
finished state.
Fig. 13 is an enlarged plan view of a portion of the heat rejector of a fifth
embodiment of the invention, as seen axially.
Fig. 14A is a plan view of the linear corrugated fin.
Fig. 14B is an enlarged plan view of the linear corrugated fin in a rounded
state
with both ends brought close together.
Fig. 14C is an enlarged plan view of a portion of the annular corrugated fin
in its
finished state.
Fig. 15 is an enlarged plan view of a portion of the heat rejector of a sixth
embodiment of the invention, as seen axially.
Fig. 16A is a plan view of the linear corrugated fin.
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Fig. 16B is an enlarged plan view of the linear corrugated fin in a rounded
state
with both ends brought close together.
Fig. 16C is an enlarged plan view of a portion of the annular corrugated fin
in its
finished state.
Fig. 17 is an enlarged perspective view of a principal portion of Fig. 16B.
Fig. 18 is an enlarged plan view of the heat rejector of a seventh embodiment
of the invention, as seen axially.
Fig. 19A is a plan view of the linear corrugated fin.
Fig. 19B is a plan view of the annular corrugated fin formed by rounding the
linear corrugated fin and putting both ends thereof together.
Fig. 19C is a top view of the cylindrical body.
Fig. 20 is an external perspective view of a portion of the heat rejector of
an
eighth embodiment of the invention.
Fig. 21A is an external perspective view of the heat exchanger element of the
heat rejector.
Fig. 21 B is an exploded perspective view of the heat exchanger element.
Fig. 22 is an enlarged plan view of a portion of the heat exchanger element,
as
seen axially.
Fig. 23 is a vertical sectional outline of the body and the heat exchanger
element
of the heat rejector.
Fig. 24 is an enlarged plan view of a portion of the heat rejector of a ninth
embodiment of the invention, as seen axially.
Fig. 25A is a sectional view of the heat rejector before the heat exchanger
element is inserted into it from the guide member side thereof.
Fig. 25B is a sectional view of the heat rejector after the heat exchanger
element
is inserted into it.
Fig. 26 is a plan view of the heat rejector of a tenth embodiment of the
invention.
Fig. 27 is a plan view of the heat exchanger element of the heat rejector.
Fig. 28 is a plan view of the cylindrical body.
Fig. 29 (prior art) is a sectional outline of a conventional free-piston-type
Stirling
cycle refrigerator.
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Fig. 30 (prior art) is an external perspective view of a heat rejector as a
conventional example of a heat exchanger member.
Fig. 31 (prior art) is an enlarged plan view of a portion of an example of a
conventional heat exchanger element, as seen axially.
Fig. 32 (prior art) is an enlarged plan view of a portion of an example of
another
conventional heat exchanger element, as seen axially.
Hereinafter, embodiments of the present invention will be described with
reference to the drawings. In the following description, same elements as in
the
conventional examples shown in Figs. 29 to 32 are identified with the same
reference
numerals. Moreover, in the following description, although only the heat
rejector 4 and
its heat exchanger element 42 are dealt with, the explanations given as to
their
configurations, selection of materials for the members constituting them,
possible
design changes in them, and other aspects of them apply also to the heat
absorber 2
and its heat exchanger element 22. Therefore, unless otherwise stated, in the
following
description, the heat rejector 4 and its heat exchanger element 42 are used
interchangeably with the heat absorber 2 and its heat exchanger element 22.
A first embodiment of the invention will be described below. Fig. 1 is an
external
perspective view of the heat rejector 4 serving as a heat exchanger member in
this
embodiment. Figs. 2A and 2B are an external perspective view and an exploded
perspective view, respectively, of the heat exchanger element 42 of the heat
rejector
4. Fig. 3 is an enlarged plan view of a portion of the heat rejector, as seen
axially.
This heat exchanger element 42 is composed of an annular corrugated fin 421
and an inner ring-shaped member 422. The annular corrugated fin 421 is
produced by
forming a corrugated sheet material into a cylindrical shape with the
individual grooves
421 a thereof parallel to the axis of the cylindrical shape. The inner ring-
shaped
member 422 is a cylindrical member made of a material having good thermal
conductivity.
First, the manufacturing method of the annular corrugated fin 421 used in this
embodiment will be described. Figs. 6A to 6C show the manufacturing procedure
of
the annular corrugated fin 421. Fig. 6A is a plan view of a linear corrugated
fin 420,
Fig. 6B is an enlarged plan view of the linear corrugated fin 420 in a rounded
state with
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both ends thereof brought close together, and Fig. 6C is an enlarged plan view
of the
annular corrugated fin 421 in its finished state.
As Fig. 6A shows, the linear corrugated fin 420 has contiguous grooves 420e
each having a V-shaped section. At one end of the linear corrugated fin 420 is
a V-
shaped groove 420a, and at the other end thereof is an inverted-V-shaped
groove 420b.
The endmost side 420c of the groove 420a and the endmost side 420d of the
groove
420b are so formed that their length L1 is shorter than the length L of the
slant sides
between the tops and bottoms 420f and 420f of the grooves 420e in between.
The linear corrugated fin 420 is bent in the directions indicated by arrows FI
and
F2 in Fig. 6A so as to be formed into a cylindrical shape. With the endmost
sides 420c
and 420d brought close together as shown in Fig. 6B, those endmost sides 420c
and
420d are hooked on each other as shown in Fig. 6C, and thereby the annular
corrugated fin 421 is formed. Thus, as the annular corrugated fin 421 tends to
return
to its original linear state, the endmost sides 420c and 420d so hooked on
each other
pull against each other, and thereby the annular shape of the annular
corrugated fin 421
is maintained. Reference numeral 421 d represents the coupled portion.
As Figs. 2A and 5 show, the inner ring-shaped member 422 is placed in contact
with the inner periphery of the annular corrugated fin 421 so that they are
coaxial with
each other (i.e. so that their axes coincide with each other). Here, the
diameter of the
circle formed by smoothly connecting all the bottoms 421 b of the annular
corrugated fin
421 (i.e. the internal diameter of the annular corrugated fin 421 ) is
substantially equal
to the external diameter of the inner ring-shaped member 422.
The annular corrugated fin 421 and the inner ring-shaped member 422 are joined
together with a brazing metal ring 13. Specifically, as Fig. 2B shows, the
brazing metal
ring 13 is placed where the annular corrugated fin 421 and the inner ring-
shaped
member 422 make contact with each other and is heated so that the molten
brazing
metal flows down along the bottoms 421 b of the annular corrugated fin 421.
As a result, as Fig. 3 shows, the brazing metal of the ring 13 is applied
substantially evenly to where the annular corrugated fin 421 and the inner
ring-shaped
member 422 make contact with each other. When the brazing metal hardens, the
annular corrugated fin 421 and the inner ring-shaped member 422 are joined
together
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and thereby integrated together. Instead of brazing specifically mentioned
above,
soldering or the like may be used.
The heat exchanger element 42 described above is inserted into a body 41
shown in Fig. 1 so that they are coaxial with each other, and thereby the heat
rejector
4 is produced. The heat exchanger element 42 is inserted into the body 41 by
the
following mechanism. As shown in Fig. 4, which is a sectional outline of the
body 41
and the heat exchanger element 42, both ends of the body 41 are tapered so
that the
wall thickness thereof decreases towards the ends along the axis thereof
(these
portions are referred to as the tapered portions 41 a).
Moreover, the external diameter of the heat exchanger element 42 (i.e. the
external diameter of the annular corrugated fin 421 ) R1 (_ ~8) is made
slightly smaller
than the maximum internal diameter R2 (_ ~8 + a, ) of the body 41 at both ends
thereof,
and slightly greater than the internal diameter R3 (_ ~8 - a2) of the body 41
in the
portion thereof between the tapered portions 41 a.
Thus, when the heat exchanger element 42 is inserted into the heat exchanger
element 42 from one end thereof, the insertion requires a small force at
first. Since the
internal diameter of the body 41 gradually becomes smaller until it eventually
becomes
smaller than the external diameter R1 of the heat exchanger element 42, as the
heat
exchanger element 42 is inserted, the force required to do so gradually
increases. In
this way, the heat exchanger element 42 can be inserted into the body 41
easily.
Here, since the bottoms 421 b of the annular corrugated fin 421 are fixed to
the
inner ring-shaped member 422, the annular corrugated fin 421 thus fitted into
the body
41, of which the internal diameter R3 is smaller than the external diameter R1
of the
annular corrugated fin 421, is brought into a state in which the grooves 421 a
are so
pressed as to be wider open, and this produces a resilient force acting
radially outward.
Moreover, since the external diameter R1 of the annular corrugated fin 421 and
the depth of the grooves 421 a are constant along the axis, the aforementioned
resilient
force presses the heat exchanger element 42 onto the inner surface of the body
41 with
a uniform force all around and thereby keeps it in position. Here, the annular
corrugated
fin 421 and the inner ring-shaped member 422 are firmly fixed together, and
thus are
not deformed.
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As described above, in this embodiment, the inner ring-shaped member422 can
be fixed in the desired position inside the body 41 without the use of
adhesive or solder.
This helps simplify the manufacturing procedure and reduce the manufacturing
cost,
and also stabilize the heat exchange performance of the heat exchanger member.
Moreover, when the annular corrugated fin 421 is damaged, the heat exchanger
element 42 can be taken out of and removed from the body 41. This permits easy
replacement as required, and thus helps alleviate the economic burden on the
user in
the event of repair and solve recycling problems.
Furthermore, in the heat exchanger element 42 used in this embodiment, the
annular corrugated fin 421 and the inner ring-shaped member 422 are integrated
together by brazing, soldering, or the like, and thus exhibit better thermal
conductivity
than where they are left unintegrated. This helps increase heat exchange
efficiency.
Next, a second embodiment of the invention will be described. Fig. 7 is an
enlarged plan view of the heat rejector 4 of this embodiment, as seen axially.
The heat
rejector 4 of this embodiment, like that of the first embodiment described
above, is
composed of a heat exchanger element 42, consisting of an annular corrugated
fin 421
and an inner ring-shaped member 422 brazed inside it, and a body 41 into which
the
heat exchanger element 42 is fitted.
The manufacturing method of the annular corrugated fin 421 used in the second
embodiment will now be described. Figs. 8A to 8C show the manufacturing
procedure
of the annular corrugated fin 421. Fig. 8A is a plan view of the linear
corrugated fin 420,
Fig. 8B is an enlarged plan view of the linear corrugated fin 420 in a rounded
state with
both ends thereof brought close together, and Fig. 8C is an enlarged plan view
of a
portion of the annular corrugated fin 421 in its finished state.
As Fig. 8A shows, the linear corrugated fin 420 has contiguous grooves 420e
each having a V-shaped section. At one end of the linear corrugated fin 420 is
a V-
shaped groove 420a, and at the other end thereof is an inverted-V-shaped
groove 420b.
The endmost side 420c of the groove 420a and the endmost side 420d of the
groove
420b are so formed that their length L2 is shorter than the length L of the
slant sides
between the tops and bottoms 420f and 420f of the grooves 420e in between.
The linear corrugated fin 420 is bent in the directions indicated by arrows FI
and
F2 in Fig. 8A so as to be formed into a cylindrical shape. With the endmost
sides 420c
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and 420d brought close together as shown in Fig. 8B, spot welding is performed
on
parts of the surfaces of those endmost sides 420c and 420d so that these
surfaces are
joined together while they are kept in contact with each other. In this way,
the annular
corrugated fin 421 as shown in Fig. 8C is produced. Reference numeral 421e
represents the brazed or welded portion.
As Figs. 2A and 7 show, the inner ring-shaped member 422 is placed in contact
with the inner periphery of the annular corrugated fin 421 so that they are
coaxial with
each other. Here, the diameter of the circle formed by smoothly connecting all
the
bottoms 421 b of the annular corrugated fin 421 (i.e. the internal diameter of
the annular
corrugated fin 421 ) is made substantially equal to the external diameter of
the inner ring-
shaped member 422.
The annular corrugated fin 421 and the inner ring-shaped member 422 arejoined
together with a ring-shaped brazing metal element 13. Specifically, as Fig. 2B
shows,
the brazing metal element 13 is placed where the annular corrugated fin 421
and the
inner ring-shaped member 422 make contact with each other and is heated so
that the
molten brazing metal flows down along the bottoms 421 b of the annular
corrugated fin
421.
As a result, as Fig. 3 shows, the brazing metal of the ring 13 is applied
substantially evenly to where the annular corrugated fin 421 and the inner
ring-shaped
member 422 make contact with each other. When the brazing metal hardens, the
annular corrugated fin 421 and the inner ring-shaped member 422 are joined
together
and thereby integrated together. Instead of brazing specifically mentioned
above,
soldering or the like may be used.
The heat exchanger element 42 described above is inserted into a body 41
shown in Fig. 1 so that they are coaxial with each other, and thereby the heat
rejector
4 is produced. The heat exchanger element 42 is inserted into the body 41 by
the
following mechanism. As shown in Fig. 4, which is a sectional outline of the
body 41
and the heat exchanger element 42, both ends of the body 41 are tapered so
that the
wall thickness thereof becomes smaller towards the ends along the axis thereof
(these
portions are referred to as the tapered portions 41 a).
Moreover, the external diameter of the heat exchanger element 42 (i.e. the
external diameter of the annular corrugated fin 421 ) R1 (_ ~8) is made
slightly smaller
CA 02419724 2005-03-11
-15-
than the maximum internal diameter R2 (_ ~8 + a, ) of the body 41 at both ends
thereof,
and slightly greater than the internal diameter R3 (_ ~8 - cr2) of the body 41
in the
portion thereof between the tapered portions 41 a.
Thus, when the heat exchanger element 42 is inserted into the heat exchanger
element 42 from one end thereof, the insertion requires a small force at
first. Since the
internal diameter of the body 41 gradually becomes smaller until it eventually
becomes
smaller than the external diameter R1 of the heat exchanger element 42, as the
heat
exchanger element 42 is inserted, the force required to do so gradually
increases. In
this way, the heat exchanger element 42 can be inserted into the body 41
easily.
Here, since the bottoms 421 b of the annular corrugated fin 421 are fixed to
the
inner ring-shaped member 422, the annular corrugated fin 421 thus fitted into
the body
41, of which the internal diameter R3 is smaller than the external diameter R1
of the
annular corrugated fin 421, is brought into a state in which the grooves 421 a
are so
pressed as to be wider open, and this produces a resilient force acting
radially outward.
Moreover, since the external diameter R1 of the annular corrugated fin 421 and
the depth of the grooves 421 a are constant along the axis, the aforementioned
resilient
force presses the heat exchanger element 42 onto the inner surface of the body
41 with
a uniform force all around and thereby keeps it in position. Here, the annular
corrugated
fin 421 and the inner ring-shaped member 422 are firmly fixed together, and
thus are
not deformed.
As described above, in this embodiment, the inner ring-shaped member 422 can
be fixed in the desired position inside the body 41 without the use of
adhesive or solder.
This helps simplify the manufacturing procedure and reduce the manufacturing
cost,
and also stabilize the heat exchange performance of the heat exchanger member.
Moreover, when the annular corrugated fin 421 is damaged, the heat exchanger
element 42 can be taken out of and removed from the body 41. This permits easy
replacement as required, and thus helps alleviate the economic burden on the
user in
the event of repair and solve recycling problems.
Furthermore, in the heat exchanger element 42 used in this embodiment, the
annular corrugated fin 421 and the inner ring-shaped member 422 are integrated
together by brazing, soldering, or the like, and thus exhibit better thermal
conductivity
than where they are left unintegrated. This helps increase heat exchange
efficiency.
CA 02419724 2005-03-11
-16-
Next, a third embodiment of the invention will be described. Fig. 9 is a plan
view
of a portion of the heat rejector 4 of this embodiment, as seen axially. The
heat rejector
4 of this embodiment, like that of the first embodiment described earlier, is
composed
of a heat exchanger element 42, consisting of an annular corrugated fin 421
and an
inner ring-shaped member 422 brazed inside it, and a body 41 into which the
heat
exchanger element 42 is fitted.
The manufacturing method of the annular corrugated fin 421 used in the third
embodiment will now be described. Figs. 10A and 10B show the manufacturing
procedure of the annular corrugated fin 421. Fig. 10A is a plan view of the
linear
corrugated fin 420, Fig. 10B is an enlarged plan view of the linear corrugated
fin 420 in
a rounded state with both ends thereof brought close together, and Fig. 10C is
an
enlarged plan view of a portion of the annular corrugated fin 421 in its
finished state.
As Fig. 10A shows, the linear corrugated fin 420 has contiguous grooves 420e
each having a V-shaped section. At one end of the linear corrugated fin 420 is
a V-
shaped groove 420a, and at the other end thereof is an inverted-V-shaped
groove 420b.
The endmost side 420c of the groove 420a and the endmost side 420d of the
groove
420b are so formed that their length L3 is shorter than the length L of the
slant sides
between the tops and bottoms 420f and 420f of the grooves 420e in between.
The linear corrugated fin 420 is bent in the directions indicated by arrows FI
and
F2 in Fig. 10A so as to be formed into a cylindrical shape so that the endmost
sides
420c and 420d are put together (Fig. 1 OB). Then, the surfaces of those
endmost sides
420c and 420d, to which adhesive 16 such as instant adhesive has been applied
beforehand, are held in contact with each other for a while so that they are
bonded
together. In this way, the annular corrugated fin 421 as shown in Fig. 10C is
produced.
Reference numeral 421f represents the bonded portion.
As Figs. 2A and 9 show, the inner ring-shaped member 422 is placed in contact
with the inner periphery of the annular corrugated fin 421 so that they are
coaxial with
each other. Here, the diameter of the circle formed by smoothly connecting all
the
bottoms 421 b of the annular corrugated fin 421 (i.e. the internal diameter of
the annular
corrugated fin 421 ) is made substantially equal to the external diameter of
the inner ring-
shaped member 422.
CA 02419724 2005-03-11
-17-
The annular corrugated fin 421 and the inner ring-shaped member 422 are joined
together with a ring-shaped brazing metal element 13. Specifically, as Fig. 2B
shows,
the brazing metal element 13 is placed where the annular corrugated fin 421
and the
inner ring-shaped member 422 make contact with each other and is heated so
that the
molten brazing metal flows down along the bottoms 421 b of the annular
corrugated fin
421.
As a result, as Fig. 3 shows, the brazing metal of the element 13 is applied
substantially evenly to where the annular corrugated fin 421 and the inner
ring-shaped
member 422 make contact with each other. When the brazing metal hardens, the
annular corrugated fin 421 and the inner ring-shaped member 422 are joined
together
and thereby integrated together. Instead of brazing specifically mentioned
above,
soldering or the like may be used.
The heat exchanger element 42 described above is inserted into a body 41
shown in Fig. 1 so that they are coaxial with each other, and thereby the heat
rejector
4 is produced. The heat exchanger element 42 is inserted into the body 41 by
the
following mechanism. As shown in Fig. 4, which is a sectional outline of the
body 41
and the heat exchanger element 42, both ends of the body 41 are tapered so
that the
wall thickness thereof becomes smaller towards the ends along the axis thereof
(these
portions are referred to as the tapered portions 41 a).
Moreover, the external diameter of the heat exchanger element 42 (i.e. the
external diameter of the annular corrugated fin 421 ) R1 (_ ~B) is made
slightly smaller
than the maximum internal diameter R2 (_ ~8 + a,) of the body 41 at both ends
thereof
and slightly greater than the internal diameter R3 (_ ~8 - a2) of the body 41
in the
portion thereof between the tapered portions 41 a.
Thus, when the heat exchanger element 42 is inserted into the heat exchanger
element 42 from one end thereof, the insertion requires a small force at
first. Since the
internal diameter of the body 41 gradually decreases until it eventually
becomes smaller
than the external diameter R1 of the heat exchanger element 42, as the heat
exchanger
element 42 is inserted, the force required to do so gradually increases. In
this way, the
heat exchanger element 42 can be inserted into the body 41 easily.
Here, since the bottoms 421 b of the annular corrugated fin 421 are fixed to
the
inner ring-shaped member 422, the annular corrugated fin 421 thus fitted into
the body
CA 02419724 2005-03-11
-18-
41, of which the internal diameter R3 is smaller than the external diameter R1
of the
annular corrugated fin 421, is brought into a state in which the grooves 421 a
are so
pressed as to be wider open, and this produces a resilient force acting
radially outward.
Moreover, since the external diameter R1 of the annular corrugated fin 421 and
the depth of the grooves 421 a are constant along the axis, the aforementioned
resilient
force presses the heat exchanger element 42 onto the inner surface of the body
41 with
a uniform force all around and thereby keeps it in position. Here, the annular
corrugated
fin 421 and the inner ring-shaped member 422 are firmly fixed together, and
thus are
not deformed.
As described above, in this embodiment, the inner ring-shaped member 422 can
be fixed in the desired position inside the body 41 without the use of
adhesive or solder.
This helps simplify the manufacturing procedure and reduce the manufacturing
cost,
and also stabilize the heat exchange performance of the heat exchanger member.
Moreover; when the annular corrugated fin 421 is damaged, the heat exchanger
element 42 can be taken out of and removed from the body 41. This permits easy
replacement as required, and thus helps alleviate the economic burden on the
user in
the event of repair and solve recycling problems.
Furthermore, in the heat exchanger element 42 used in this embodiment, the
annular corrugated fin 421 and the inner ring-shaped member 422 are integrated
together by brazing, soldering, or the like, and thus exhibit better thermal
conductivity
than where they are left unintegrated. This helps increase heat exchange
efficiency.
Next, a fourth embodiment of the invention will be described. Fig. 11 is a
plan
view of a portion of the heat rejector 4 of this embodiment, as seen axially.
The heat
rejector 4 of this embodiment, like that of the first embodiment described
earlier, is
composed of a heat exchanger element 42, consisting of an annular corrugated
fin 421
and an inner ring-shaped member 422 brazed inside it, and a body 41 into which
the
heat exchanger element 42 is fitted.
The manufacturing method of the annular corrugated fin 421 used in the fourth
embodiment will now be described. Figs. 12A to 12C show the manufacturing
procedure of the annular corrugated fin 421. Fig. 12A is a plan view of the
linear
corrugated fin 420, Fig. 12B is an enlarged plan view of the linear corrugated
fin 420 in
CA 02419724 2005-03-11
-19-
a rounded state with both ends thereof brought close together, and Fig. 12C is
an
enlarged plan view of a portion of the annular corrugated fin 421 in its
finished state.
As Fig. 12A shows, the linear corrugated fin 420 has contiguous grooves 420e
each having a V-shaped section. At one end of the linear corrugated fin 420 is
a V-
shaped groove 420a, and at the other end thereof is an inverted-V-shaped
groove 420b.
The endmost side 420c of the groove 420a and the endmost side 420d of the
groove
420b are so formed that their length L4 is shorter than the length L of the
slant sides
between the tops and bottoms 420f and 420f of the grooves 420e in between.
The linear corrugated fin 420 is bent in the directions indicated by arrows F1
and
F2 in Fig. 12A so as to be formed into a cylindrical shape so that the endmost
sides
420c and 420d are put together (Fig. 12B). Then, the surfaces of those endmost
sides
420c and 420d, to which solder in the form of paste has been applied uniformly
beforehand, are held in contact with each other and heated for a while so that
they are
soldered together. In this way, the annular corrugated fin 421 as shown in
Fig. 12C is
produced. Reference numeral 421 g represents the soldered or welded portion.
As Figs. 2A and 11 show, the inner ring-shaped member 422 is placed in contact
with the inner periphery of the annular corrugated fin 421 so that they are
coaxial with
each other. Here, the diameter of the circle formed by smoothly connecting all
the
bottoms 421 b of the annular corrugated fin 421 (i.e. the internal diameter of
the annular
corrugated fin 421 ) is made substantially equal to the external diameter of
the inner ring-
shaped member 422.
The annular corrugated fin 421 and the inner ring-shaped member 422 are joined
together with a ring-shaped brazing metal element 13. Specifically, as Fig. 2B
shows,
the brazing metal element 13 is placed where the annular corrugated fin 421
and the
inner ring-shaped member 422 make contact with each other and is heated so
that the
molten brazing metal flows down along the bottoms 421 b of the annular
corrugated fin
421.
As a result, as Fig. 3 shows, the brazing metal of the element 13 is applied
substantially evenly to where the annular corrugated fin 421 and the inner
ring-shaped
member 422 make contact with each other. When the brazing metal hardens, the
annular corrugated fin 421 and the inner ring-shaped member 422 are joined
together
CA 02419724 2005-03-11
-20-
and thereby integrated together. Instead of brazing specifically mentioned
above,
soldering or the like may be used.
The heat exchanger element 42 described above is inserted into a body 41
shown in Fig. I so that they are coaxial with each other, and thereby the heat
rejector
4 is produced. The heat exchanger element 42 is inserted into the body 41 by
the
following mechanism. As shown in Fig. 4, which is a sectional outline of the
body 41
and the heat exchanger element 42, both ends of the body 41 are tapered so
that the
wall thickness thereof decreases towards the ends along the axis thereof
(these
portions are referred to as the tapered portions 41 a).
Moreover, the external diameter of the heat exchanger element 42 (i.e. the
external diameter of the annular corrugated fin 421 ) R1 (_ ~B) is made
slightly smaller
than the maximum internal diameter R2 (_ ~8 + a, ) of the body 41 at both ends
thereof,
and slightly greater than the internal diameter R3 (_ ~B - a2) of the body 41
in the
portion thereof between the tapered portions 41a.
Thus, when the heat exchanger element 42 is inserted into the heat exchanger
element 42 from one end thereof, the insertion requires a small force at
first. Since the
internal diameter of the body 41 gradually decreases until it eventually
becomes smaller
than the external diameter R1 of the heat exchanger element 42, as the heat
exchanger
element 42 is inserted, the force required to do so gradually increases. In
this way, the
heat exchanger element 42 can be inserted into the body 41 easily.
Here, since the bottoms 421 b of the annular corrugated fin 421 are fixed to
the
inner ring-shaped member 422, the annular corrugated fin 421 thus fitted into
the body
41, of which the internal diameter R3 is smaller than the external diameter R1
of the
annular corrugated fin 421, is brought into a state in which the grooves 421a
are so
pressed as to be wider open, and this produces a resilient force acting
radially outward.
Moreover, since the external diameter RI of the annular corrugated fin 421 and
the depth of the grooves 421 a are constant along the axis, the aforementioned
resilient
force presses the heat exchanger element 42 onto the inner surface of the body
41 with
a uniform force all around and thereby keeps it in position. Here, the annular
corrugated
fin 421 and the inner ring-shaped member 422 are firmly fixed together, and
thus are
not deformed.
CA 02419724 2005-03-11
-21-
As described above, in this embodiment, the inner ring-shaped member 422 can
be fixed in the desired position inside the body 41 without the use of
adhesive or solder.
This helps simplify the manufacturing procedure and reduce the manufacturing
cost,
and also stabilize the heat exchange performance of the heat exchanger member.
Moreover, when the annular corrugated fin 421 is damaged, the heat exchanger
element 42 can be taken out of and removed from the body 41. This permits easy
replacement as required, and thus helps alleviate the economic burden on the
user in
the event of repair and solve recycling problems.
Furthermore, in the heat exchanger element 42 used in this embodiment, the
annular corrugated fin 421 and the inner ring-shaped member 422 are integrated
together by brazing, soldering, or the like, and thus exhibit better thermal
conductivity
than where they are left unintegrated. This helps increase heat exchange
efficiency.
Next, a fifth embodiment of the invention will be described. Fig. 13 is a plan
view
of a portion of the heat rejector 4 of this embodiment, as seen axially. The
heat rejector
4 of this embodiment, like that of the first embodiment described earlier, is
composed
of a heat exchanger element 42, consisting of an annular corrugated fin 421
and an
inner ring-shaped member 422 brazed inside it, and a body 41 into which the
heat
exchanger element 42 is fitted.
The manufacturing method of the annular corrugated fin 421 used in the fifth
embodiment will now be described. Figs. 14A to 14C show the manufacturing
procedure of the annular corrugated fin 421. Fig. 14A is a plan view of the
linear
corrugated fin 420, Fig. 14B is an enlarged plan view of the linear corrugated
fin 420 in
a rounded state with both ends thereof brought close together, and Fig. 14C is
an
enlarged plan view of a portion of the annular corrugated fin 421 in its
finished state.
As Fig. 14A shows, the linear corrugated fin 420 has contiguous grooves 420e
each having a V-shaped section. At both ends of the linear corrugated fin 420
are
inverted-V-shaped grooves 420b. The endmost side 420c of the groove 420a and
the
endmost side 420d of the groove 420b are so formed that their length L5 is
shorter than
the length L of the slant sides between the tops and bottoms 420f and 420f of
the
grooves 420e in between.
The linear corrugated fin 420 is bent in the directions indicated by arrows FI
and
F2 in Fig. 14A so as to be formed into a cylindrical shape so that the endmost
sides
CA 02419724 2005-03-11
-22-
420c and 420d are put together (Fig. 14B). Then, the endmost sides 420c and
420d
are, with the surfaces thereof held in contact with each other over their
entire surfaces,
coupled together with a coupling member 18 made of a highly resilient material
and
having a C-shaped section. In this way, the annular corrugated fin 421 as
shown in Fig.
14C is produced.
As Figs. 2A and 13 show, the inner ring-shaped member 422 is placed in contact
with the inner periphery of the annular corrugated fin 421 so that they are
coaxial with
each other. Here, the diameter of the circle formed by smoothly connecting all
the
bottoms 421 b of the annular corrugated fin 421 (i.e. the internal diameter of
the annular
corrugated fin 421 ) is made substantially equal to the external diameter of
the inner ring-
shaped member 422.
The annular corrugated fin 421 and the inner ring-shaped member422 are joined
together with a ring-shaped brazing metal element 13. Specifically, as Fig. 2B
shows,
the brazing metal element 13 is placed where the annular corrugated fin 421
and the
inner ring-shaped member 422 make contact with each other and is heated so
that the
molten brazing metal flows down along the bottoms 421 b of the annular
corrugated fin
421.
As a result, as Fig. 3 shows, the brazing metal of the element 13 is applied
substantially evenly to where the annular corrugated fin 421 and the inner
ring-shaped
member 422 make contact with each other. When the brazing metal hardens, the
annular corrugated fin 421 and the inner ring-shaped member 422 are joined
together
and thereby integrated together. Instead of brazing specifically mentioned
above,
soldering or the like may be used.
The heat exchanger element 42 described above is inserted into a body 41
shown in Fig. 1 so that they are coaxial with each other, and thereby the heat
rejector
4 is produced. The heat exchanger element 42 is inserted into the body 41 by
the
following mechanism. As shown in Fig. 4, which is a sectional outline of the
body 41
and the heat exchanger element 42, both ends of the body 41 are tapered so
that the
wall thickness thereof decreases towards the ends along the axis thereof
(these
portions are referred to as the tapered portions 41 a).
Moreover, the external diameter of the heat exchanger element 42 (i.e. the
external diameter of the annular corrugated fin 421 ) R1 (_ ~8) is made
slightly smaller
CA 02419724 2005-03-11
-23-
than the maximum internal diameter R2 (_ ~8 + a,) of the body 41 at both ends
thereof,
and slightly greater than the internal diameter R3 (_ ~8 - a2) of the body 41
in the
portion thereof between the tapered portions 41 a.
Thus, when the heat exchanger element 42 is inserted into the heat exchanger
element 42 from one end thereof the insertion requires a small force at first.
Since the
internal diameter of the body 41 gradually decreases until it eventually
becomes smaller
than the external diameter R1 of the heat exchanger element 42, as the heat
exchanger
element 42 is inserted, the force required to do so gradually increases. In
this way, the
heat exchanger element 42 can be inserted into the body 41 easily.
Here, since the bottoms 421 b of the annular corrugated fin 421 are fixed to
the
inner ring-shaped member 422, the annular corrugated fin 421 thus fitted into
the body
41, of which the internal diameter R3 is smaller than the external diameter R1
of the
annular corrugated fin 421, is brought into a state in which the grooves 421 a
are so
pressed as to be wider open, and this produces a resilient force acting
radially outward.
Moreover, since the external diameter R1 of the annular corrugated fin 421 and
the depth of the grooves 421 a are constant along the axis, the aforementioned
resilient
force presses the heat exchanger element 42 onto the inner surface of the body
41 with
a uniform force all around and thereby keeps it in position. Here, the annular
corrugated
fin 421 and the inner ring-shaped member 422 are firmly fixed together, and
thus are
not deformed.
As described above, in this embodiment, the inner ring-shaped member 422 can
be fixed in the desired position inside the body 41 without the use of
adhesive or solder.
This helps simplify the manufacturing procedure and reduce the manufacturing
cost,
and also stabilize the heat exchange performance of the heat exchanger member.
Moreover, when the annular corrugated fin 421 is damaged, the heat exchanger
element 42 can be taken out of and removed from the body 41. This permits easy
replacement as required, and thus helps alleviate the economic burden on the
user in
the event of repair and solve recycling problems.
Furthermore, in the heat exchanger element 42 used in this embodiment, the
annular corrugated fin 421 and the inner ring-shaped member 422 are integrated
together by brazing, soldering, or the like, and thus exhibit better thermal
conductivity
than where they are left unintegrated. This helps increase heat exchange
efficiency.
CA 02419724 2005-03-11
-24-
Next, a sixth embodiment of the invention will be described. Fig. 15 is a plan
view of a portion of the heat rejector 4 of this embodiment, as seen axially.
The heat
rejector 4 of this embodiment, like that of the first embodiment described
earlier, is
composed of a heat exchanger element 42, consisting of an annular corrugated
fin 421
and an inner ring-shaped member 422 brazed inside it, and a body 41 into which
the
heat exchanger element 42 is fitted.
The manufacturing method of the annular corrugated fin 421 used in the sixth
embodiment will now be described. Fig. 16 shows the manufacturing procedure of
the
annular corrugated fin 421. Fig. 16A is a plan view of the linear corrugated
fin 420, Fig.
16B is an enlarged plan view of the linear corrugated fin 420 in a rounded
state with
both ends thereof brought close together, and Fig. 14C is an enlarged plan
view of the
annular corrugated fin 421 in its finished state. Fig. 17 is a perspective
view of a
principal portion of Fig. 16B.
As Fig. 16A shows, the linear corrugated fin 420 has contiguous grooves 420e
each having a V-shaped section. At both ends of the linear corrugated fin 420
are
inverted-Vshaped grooves 420b. The endmost side 420c of the groove 420a and
the
endmost side 420d of the groove 420b are so formed that their length L6 is
shorter than
the length L of the slant sides between the tops and bottoms 420f and 420f of
the
grooves 420e in between. Moreover, as Fig. 17 shows, in the endmost sides 420c
and
420d, slits 19 are respectively formed in such a way that one slit extends
from one flank
420g of the linear corrugated fin 420 halfway inward and the other slit
extends from the
other flank 420h of linear corrugated fin 420 halfway inward.
The linear corrugated fin 420 is bent in the directions indicated by arrows FI
and
F2 in Fig. 16A so as to be formed into a cylindrical shape so that the endmost
sides
420c and 420d are put together (Fig. 16B). Then, the endmost sides 420c and
420d
are coupled together by engaging together the slit 19 formed in the endmost
side 420c
and the slit 19 formed in the endmost side 420d. In this way, the annular
corrugated fin
421 as shown in Fig. 16C is produced.
As Figs. 2A and 15 show, the inner ring-shaped member 422 is placed in contact
with the inner periphery of the annular corrugated fin 421 so that they are
coaxial with
each other. Here, the diameter of the circle formed by smoothly connecting all
the
bottoms 421 b of the annular corrugated fin 421 (i.e. the internal diameter of
the annular
CA 02419724 2005-03-11
-25-
corrugated fin 421 ) is made substantially equal to the external diameter of
the inner ring-
shaped member 422.
The annular corrugated fin 421 and the inner ring-shaped member 422 are joined
together with a ring-shaped brazing metal element 13 . Specifically, as Fig.
2B shows,
the brazing metal element 13 is placed where the annular corrugated fin 421
and the
inner ring-shaped member 422 make contact with each other and is heated so
that the
molten brazing metal flows down along the bottoms 421 b of the annular
corrugated fin
421.
As a result, as Fig. 3 shows, the brazing metal of the element 13 is applied
substantially evenly to where the annular corrugated fin 421 and the inner
ring-shaped
member 422 make contact with each other. When the brazing metal hardens, the
annular corrugated fin 421 and the inner ring-shaped member 422 are joined
together
and thereby integrated together. Instead of brazing specifically mentioned
above,
soldering or the like may be used.
The heat exchanger element 42 described above is inserted into a body 41
shown in Fig. 1 so that they are coaxial with each other, and thereby the heat
rejector
4 is produced. The heat exchanger element 42 is inserted into the body 41 by
the
following mechanism. As shown in Fig. 4, which is a sectional outline of the
body 41
and the heat exchanger element 42, both ends of the body 41 are tapered so
that the
wall thickness thereof decreases towards the ends along the axis thereof
(these
portions are referred to as the tapered portions 41 a).
Moreover, the external diameter of the heat exchanger element 42 (i.e. the
external diameter of the annular corrugated fin 421 ) R1 (_ ~8) is slightly
smaller than
the maximum internal diameter R2 (_ ~8 + a,) of the body 41 at both ends
thereof, and
slightly greater than the internal diameter R3 (_ ~8 - a2) of the body 41 in
the portion
thereof between the tapered portions 41 a.
Thus, when the heat exchanger element 42 is inserted into the heat exchanger
element 42 from one end thereof, the insertion requires a small force at
first. Since the
internal diameter of the body 41 gradually decreases until it eventually
becomes smaller
than the external diameter R1 of the heat exchanger element 42, as the heat
exchanger
element 42 is inserted, the force required to do so gradually increases. In
this way, the
heat exchanger element 42 can be inserted into the body 41 easily.
CA 02419724 2005-03-11
-26-
Here, since the bottoms 421b of the annular corrugated fin 421 are fixed to
the
inner ring-shaped member 422, the annular corrugated fin 421 thus fitted into
the body
41, of which the internal diameter R3 is smaller than the external diameter R1
of the
annular corrugated fin 421, is brought into a state in which the grooves 421 a
are so
pressed as to be wider open, and this produces a resilient force acting
radially outward.
Moreover, since the external diameter RI of the annular corrugated fin 421 and
the depth of the grooves 421 a are constant along the axis, the aforementioned
resilient
force presses the heat exchanger element 42 onto the inner surface of the body
41 with
a uniform force all around and thereby keeps it in position. Here, the annular
corrugated
fin 421 and the inner ring-shaped member 422 are firmly fixed together, and
thus are
not deformed.
As described above, in this embodiment, the inner ring-shaped member 422 can
be fixed in the desired position inside the body 41 without the use of
adhesive or solder.
This helps simplify the manufacturing procedure and reduce the manufacturing
cost,
and also stabilize the heat exchange performance of the heat exchanger member.
Moreover, when the annular corrugated fin 421 is damaged, the heat exchanger
element 42 can be taken out of and removed from the body 41. This permits easy
replacement as required, and thus helps alleviate the economic burden on the
user in
the event of repair and solve recycling problems.
Furthermore, in the heat exchanger element 42 used in this embodiment, the
annular corrugated fin 421 and the inner ring-shaped member 422 are integrated
together by brazing, soldering, or the like, and thus exhibit better thermal
conductivity
than when they are left unintegrated. This helps increase heat exchange
efficiency.
Next, a seventh embodiment of the invention will be described. Fig. 18 is a
plan
view of the heat rejector 4 of this embodiment, as seen axially. The heat
rejector 4 of
this embodiment, like that of the first embodiment described earlier, is
composed of a
heat exchanger element 42, consisting of an annular corrugated fin 421 and an
inner
ring-shaped member 422 brazed inside it, and a body 41 into which the heat
exchanger
element 42 is fitted.
The manufacturing method of the annular corrugated fin 421 used in the seventh
embodiment will now be described. Figs. 19A to 19C show the manufacturing
procedure
of the annular corrugated fin 421. Fig. 19A is a plan view of the linear
corrugated fin
CA 02419724 2005-03-11
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420, Fig. 19B is a plan view of the annular corrugated fin formed by rounding
the linear
corrugated fin and putting both ends of thereof together, and Fig. 19C is a
top view of
the cylindrical body 41.
As Fig. 19A shows, the linear corrugated fin 420 has contiguous grooves 420e
each having a V-shaped section. At both ends of the linear corrugated fin 420
are
inverted-V-shaped grooves 420b. The endmost side 420c of the groove 420a and
the
endmost side 420d of the groove 420b are so formed that their length L7 is
shorter than
the length L of the slant sides between the tops and bottoms 420f and 420f of
the
grooves 420e in between.
The linear corrugated fin 420 is bent in the directions indicated by arrows FI
and
F2 in Fig. 19A so as to be formed into a cylindrical shape so that the endmost
sides
420c and 420d are put together. Then, the linear corrugated fin 420 is held in
a state
in which the endmost sides 420c and 420d are kept in contact with each other
at least
at their tips. In this way, the annular corrugated fin 421 as shown in Fig.
19B is
produced. As a result, the tip portions of the endmost sides 420c and 420d
form a
protruding portion 421 h that protrudes radially out of the outer periphery of
the annular
corrugated fin 421 (i.e. the circle formed by smoothly connecting all the tops
421 c).
The internal diameter of the cylindrical body 41 is made substantially equal
to the
external diameter of the annular corrugated fin 421. Moreover, as Fig. 19C
shows, in
one position in the inner surface of the body 41, a groove 41 a into which to
fit the
protruding portion 421 h of the annular corrugated fin 421 is formed so as to
extend
axially.
The annular corrugated fin 421 is then inserted axially into the body 41 with
the
center of the former aligned with the center axis of the latter and with the
protruding
portion 421 h of the former fit into the groove 41 a of the latter. Here, as
Fig. 1 shows,
the annular corrugated fin 421 is inserted until one end thereof becomes flush
with the
open end of the body 41.
On the protruding portion 421 h of the annular corrugated fin 421 acts a force
that
tends to bring the annular corrugated fin 421 back into the original state of
the linear
corrugated fin 420. However, since the protruding portion 421 h is trapped in
the groove
41 a, the force converts to a force that tends to expand the annular
corrugated fin 421
radially. Thus, the annular corrugated fin 421 expands radially, and is
thereby pressed
CA 02419724 2005-03-11
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onto the inner surface of the body 41. This makes it possible to keep the
annular
corrugated fin 421 in the desired position while maintaining its shape.
On the other hand, the external diameter of the cylindrical inner ring-shaped
member 422 is made substantially equal to the internal diameter of the annular
corrugated fin 421 (i.e. the diameter of the circle formed by smoothly
connecting all the
bottoms 2b). The inner ring-shaped member 422 is inserted axially into the
annular
corrugated fin 421 with the center of the former aligned with the center axis
of the latter.
Then, the annular corrugated fin 421 and the inner ring-shaped member 422 are
integrated together by brazing them together at where the inner periphery of
the former
makes contact with the outer surface of the inner ring-shaped member 422. In
this way,
the heat exchanger element 42 is fitted into the body 41, and thereby the heat
rejector
4 is obtained as shown in Fig. 18.
Thus, it is possible to eliminate the process of bonding or welding the
annular
corrugated fin 421 to the body 41. This enhances productivity. Moreover, it is
possible
to fix the annular corrugated fin 421 securely by press fitting, and achieve
uniform
contact all around the annular corrugated fin 421. This helps manufacture the
heat
rejector 4 stably with excellent performance.
Next, an eighth embodiment of the invention will be described. Fig. 20 is an
external perspective view of the heat rejector 4 serving as a heat exchanger
member
in this embodiment. Fig. 21A is an external perspective view and an exploded
perspective view, respectively, of the heat exchanger element 42' incorporated
in the
heat rejector 4.
This heat exchanger element 42' is composed of an annular corrugated fin 421
and an outer ring-shaped member 422'. The annular corrugated fin 421 is
produced by
the same procedure as described earlier in connection with the first to
seventh
embodiments. The outer ring-shaped member 422' is a cylindrical member made of
a
material having good thermal conductivity and resilience.
As Fig. 21 A shows, the outer ring-shaped member 422' is placed in contact
with
the outer periphery of the annular corrugated fin 421 so that they are coaxial
with each
other. Here, the external diameter of the annular corrugated fin 421 is made
substantially equal to the internal diameter of the outer ring-shaped member
422'.
Moreover, as Fig. 22 shows, the annular corrugated fin 421 and the outer ring-
shaped
CA 02419724 2005-03-11
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member 422' are, like the annular corrugated fin 421 and the inner ring-shaped
member
422 of the first embodiment, bonded together and fixed together with a brazing
metal
or solder.
The heat exchanger element 42' described above is inserted into a body 41
shown in Fig. 20 so that they are coaxial with each other, and thereby the
heat rejector
4 is produced. The heat exchanger element 42' is inserted into the body 41 by
the
following mechanism. As shown in Fig. 23, which is a sectional outline of the
body 41
and the heat exchanger element 42', both ends of the body 41 are tapered in
the same
way as in the first embodiment (these portions are referred to as the tapered
portions
41 a).
Moreover, the external diameter of the heat exchanger element 42' (i.e. the
external diameter of the outer ring-shaped member 422') R1' (_ ~B') is made
slightly
smaller than the maximum internal diameter R2' (_ ~8' + a,') of the body 41 at
both
ends thereof, and slightly greater than the internal diameter R3' (_ ~8'- a2')
of the body
41 in the portion thereof between the tapered portions 41 a.
Thus, as in the first embodiment described earlier, the tapered portions 41 a
permit the heat exchanger element 42' to be inserted into the body 41 easily.
Moreover,
the heat exchanger element 42' thus fitted into the body 41 is pressed onto
the inner
surface of the body 41 and is thereby kept in position by the resilience that
occurs in the
annular corrugated fin 421 and the outer ring-shaped member 422'. Here, the
annular
corrugated fin 421 and the outer ring-shaped member 422' are firmly fixed
together, and
thus are not deformed.
As described above, in this embodiment also, the heat exchanger element 42'
can be fixed in the desired position inside the body 41 without the use of
adhesive or
solder. Moreover, since the heat exchanger element 42' and the body 41 are not
fixed
together, the former can be taken out of the latter freely. Moreover, since
the annular
corrugated fin 421 and the outer ring-shaped member 422' are integrated
together, they
exhibit still better thermal conductivity.
Next, a ninth embodiment of the invention will be described with reference to
the
drawings. Fig. 24 is an enlarged plan view of a portion of the heat rejector 4
of the
embodiment, as seen axially. Fig. 25 shows part of the manufacturing procedure
of the
heat rejector 4, specifically, Figs. 25A and 25B are respectively sectional
views of the
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heat rejector before and after the heat exchanger element 42 is inserted into
it from the
guide member side thereof.
As Figs. 25A and 25B show, a cylindrical body 41 is fixed, together with a
guide
member 14, to a jig 15, with the axis of the body 41 kept substantially
horizontal. The
guide member 14 is provided so as to abut the body 41, and has an external
diameter
substantially equal to that of the body 41. The guide member 14 is so formed
as to
have a tapered cross section inside, forming a tapered portion 14a, so that
its internal
diameter is equal to the internal diameter of the body 41 at the joint and
increases away
therefrom.
The manufacturing procedure of the heat rejector 4 of the ninth embodiment
will
now be described with reference to Figs. 25A and 25B. An annular corrugated
fin 421
is produced in the same manner as described earlier in connection with the
first to sixth
embodiments, i.e. by forming a linear corrugated fin 420 into a cylindrical
shape and
putting both ends thereof together. The annular corrugated fin 421 is made of
a highly
flexible material that is easily deformed when an external force is applied
thereto.
In advance, an inner ring-shaped member 422, of which the external diameter
is made slightly greater than the external diameter of the annular corrugated
fin 421,
has been inserted axially into the annular corrugated fin 421 to produce the
heat
exchanger element 42. Then, as Fig. 25A shows, the heat exchanger element 42
is
inserted axially into the guide member 14 from the open end thereof. Thus, the
annular
corrugated fin 421 is pushed gradually in through the tapered portion 14a of
the body
41, i.e. from the portion thereof having a greater internal diameter to the
portion thereof
having a smaller internal diameter.
Then, as Fig. 25B shows, the insertion is stopped when one end surface of the
annular corrugated fin 421 becomes flush with the joint between the body 41
and the
guide member 14. Meanwhile, the tops 421 c of the annular corrugated fin 421
rub
against the inner surface of the guide member 14, and they are thereby
deformed from
arc-shaped to flat. The degree of this deformation is commensurate with how
much the
material of the guide member 14 is harder than the material of the annular
corrugated
fin 421. As Fig. 24 shows, this increases the area of contact between the
annular
corrugated fin 421 and the inner surface of the body 41. This helps enhance
the
CA 02419724 2005-03-11
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efficiency with which heat is transmitted from the annular corrugated fin 421
to the body
41 and thereby enhance the heat exchange performance of the heat rejector 4.
Next, a tenth embodiment of the invention will be described with reference to
the
drawings. Fig. 26 is a plan view of the heat rejector 42 of this embodiment,
Fig. 27 is
a plan view of the heat exchanger element 42, and Fig. 28 is a plan view of
the
cylindrical body.
Around the outer periphery of an annular corrugated fin 421', round, wave-
shaped projections 421 k are formed so as to be in close contact with one
another and
at regular intervals overall. On the other hand, a body 41 is produced by
pouring a
molten metal into a mold and then cooling it. As Fig. 28 shows, the body 41
has wave-
shaped depressions 41 m formed at regular intervals all around its inner
surface so as
to extend axially. These depressions 41 m are so shaped that the
aforementioned
wave-shaped projections 421 k of the annular corrugated fin 421' fit into
them.
As Fig. 2A shows, in advance, an inner ring-shaped member 422, of which the
external diameter is made slightly substantially equal to the internal
diameter of the
annular corrugated fin 421', has been inserted into the annular corrugated fin
421', and
they have been brazed together at where they make contact with each other, in
order
to produce the heat exchanger element 42 shown in Fig. 27. Then, as Fig. 4
shows, the
heat exchanger element 42 is inserted axially into the body 41, with the
center of the
former aligned with the center axis of the latter. Here, as Fig. 26 shows, the
projections
421 k of the annular corrugated fin 421' fit into the depressions 421 m of the
body 41.
This ensures that, in the heat rejector 4, the heat exchanger element 42 is
kept securely
in position circumferentially inside the body 41. Thus, in this embodiment, it
is possible
to keep the annular corrugated fin 421' in firm and close contact with the
inner surface
of the body 41, and thereby secure a sufficiently large area of contact all
around the
annular corrugated fin 421'. This helps manufacture the heat rejector 4 stably
with
excellent performance.
As described hereinbefore, according to the present invention, a heat
exchanger
element does not require bonding by hand when fitted into a body. This helps
enhance
the productivity of a heat exchanger member and reduce its manufacturing cost.
Moreover, the heat exchanger member thus manufactured is less prone to
variations
in quality, and therefore offers stable heat exchange performance.
CA 02419724 2005-03-11
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Moreover, in a heat exchanger element, a corrugated fin and an inner or outer
ring-shaped member are integrated together. This enhances heat conductivity
and thus
heat exchange efficiency.
Moreover, a heat exchanger element is kept in position inside the body of a
heat
exchanger member by press fitting. This makes it possible to take the heat
exchanger
element out of the body and remove it therefrom. Thus, even if the corrugated
fin is
damaged, lowering the quality of the heat exchanger element, it is possible to
replace
the corrugated fin easily as required. This makes the heat exchanger element
very
economical and recyclable.
In particular, in an arrangement in which the body of a heat exchanger member
is tapered at an end, a heat exchanger element can be inserted into it
smoothly even
when the external diameter of the heat exchanger element is greater than the
internal
diameter of the body.
Moreover, an annular corrugated fin need not be fitted into a cylindrical body
by
hand by means of bonding or welding, but can be securely kept in position by
press
fitting simply by inserting the former into the latter. This helps enhance the
productivity
of the heat exchanger member. Moreover, uniform contact is achieved all around
the
annular corrugated fin. This makes it possible to manufacture the heat
exchanger
member stably with excellent performance.
