Note: Descriptions are shown in the official language in which they were submitted.
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I BLOW MOLDED FAN SHROUD
2 This invention relates generally to a fan shroud assembly for an automotive
3 coolant fan, and more particularly to a blow molded automotive coolant fan
shroud
4 which integrates a motor mount into the fan shroud body, wherein said
integrated
motor mount comprises single-wall or double-wall construction and which
attenuates
6 motor vibration transmission. In addition, the present invention relates to
a fan
7 shroud that is simultaneously prepared with a separate bottle or container
positioned
8 in the center waste-area of the shroud, wherein the precursor parison used
to prepare
9 such shroud/bottle combination in a blow-molding operation can be programmed
to
. form selected thicker wall sections as may be required for selected
locations in the
11 shroud construction. Furthermore, the present invention relates to the
novel use of a
12 die-trimming procedure as applied to a fan shroud blow-molded assembly
which
13 provides improved tolerances in the final product.
14 U.S. Patent No. 5,649,587 discloses a blow-molded radiator fan shroud which
provides an improved, compact and efficient blow-molded radiator fan shroud
with
16 integral fluid receptacles. Oppositely disposed recesses are formed in the
front and
I7 rear faces to form a wall for dividing the hollow body into two or more
internal
18 chambers.
19 In addition, attention is directed to Tangue et al U.S. Pat. No. 3,692,004
which
discloses a fan shroud and fluid receptacle arrangement including a
cylindrical band
21 or collar extending away from a radiator, and a radiator fluid receptacle
and a
22 windshield washer fluid receptacle integrally molded on opposite side
surfaces of the
23 cylindrical band or collar. Furthermore, attention is also directed to the
following
24 U.S. Patents: 3,833,054; 4,030,541; 4,709,757; 4,762,244; 4,763,724;
4,947,931 and
5,107,924.
26 Finally, attention is also directed to U.S. Appln. Serial No. 09/177,458,
filed
27 October 22, 1998, owned by the assignee herein, which relates to the use of
a fan
28 shroud with an air intake arrangement.
29 In a fan shroud and receptacle arrangement for use adjacent a vehicle
radiator
and around one or more engine cooling fans, the improvement which comprises an
31 integrated motor mount in the fan shroud body, wherein said integrated
motor mount
32 comprises double-wall construction, optionally compressed into a single
layer, and
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1 wherein said double-wall construction can be adjusted by programmed parison
2 formation in a corresponding blow-molding operation. In alternative
embodiment,
3 the present invention relates to the preparation of a fan-shroud assembly
wherein the
4 center waste-area of the shroud is simultaneously prepared with a separate
bottle/container which bottle/container is not part of the final fan shroud,
and which
6 bottle may contain ribs or weirs to ultimately assist in dissolved gas
removal to
7 thereby improve the heat-transfer efficiency of the fluid to be contained
therein.
8 Finally, in alternative embodiment, the present invention relates to the use
of
9 additives in the plastic of the shroud which additives are designed to
change
color/shape based upon liquid temperature to thereby indicate coolant levels.
Finally,
11 the present invention also relates to all of the above embodiments, wherein
the shroud
12 is simultaneously designed to contain engine coolant liquid, and wherein
the shroud
13 contains air flow-through ducting, to thereby channel air for engine
combustion and
14 to improve the cooling of the engine coolant contained therein.
FIG. 1 illustrates a perspective view of the blow molded fan shroud of the
16 present invention.
17 FIG. 2 illustrates in perspective view a second embodiment of the present
18 invention.
19 FIG. 3 illustrates in exploded view the blow molded fan shroud and a
reinforcing member.
21 FIG. 4 illustrates in cross-section high section modulus profiles of
spiders.
22 FIG. 5 illustrates in perspective view a separate spider assembly.
23 FIG. 6 is a cross-sectional view of a collapsible post and socket
attachment
24 means.
FIG. 7 is a cross-sectional view of the dovetail-twist lock attachment means.
26 FIG. 8 illustrates in perspective a third embodiment of the present
invention.
27 With reference to FIG. 1, the present invention comprises a fan shroud 10
for
28 use with an automotive cooling system. The fan shroud IO comprises a
hollow,
29 double walled body of generally rectangular shape having a generally planar
front
face 12 and an opposed generally planar rear face. The fan shroud 10 contains
an
31 opening 14 through the body of the fan shroud 10 defined by a cylindrical
wall.
32 Alternately, the opening 14 may have a rectangular geometry on the front
face that
2
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1 transitions to a circular opening on the rear face. The double walled
construction of
2 fan shroud 10 attenuates vibration transmission from the fan assembly. In
the context
3 of the present invention, vibration attenuation has reached levels of about
40%.
4 As shown in FIG. 2, preferably, the hollow, double-walled body of the fan
shroud 10 is configured as a chamber, as for holding fluid. Alternately, the
body of
6 fan shroud 10 may be configured into multiple chambers through the use of
pinch
7 lines 16 sealing opposed walls together. Each chamber preferably includes
8 appropriate openings and fittings necessary for filling, draining, and/or
plumbing
9 requirements depending upon the end use application of the chamber.
The opening 14 in fan shroud 10 may be configured to direct the flow of air
11 from the fan 26 to the engine, to be employed, for example, for additional
engine
12 cooling or forced induction feed for engine combustion. The air stream from
opening
13 14 maybe directed by means of diffusers or deflectors positioned about the
periphery
14 of the opening 14. Alternately, the opening 14 may be Etted with ducting to
communicate the air flow to appropriate secondary uses.
16 As illustrated in FIGS. 2-3, the fan shroud 10 further contains spiders 18
17 extending radially from the circumference of the opening 14 toward the
normal axis
18 of the opening 14. Spiders 18 are connected to a fan motor mounting ring or
plate 20
19 that is positioned concentrically with opening 14. The fan motor mounting
ring 20
preferably includes a reinforcing member 40. The reinforcing member may be
21 disposed on the forward face of the fan motor mounting ring 20, on the
rearward face
22 of the fan motor mounting ring 20 as illustrated in FIG. 3, or it may be an
insert-
23 molded, integral component of the fan motor mounting ring 20. Preferably,
24 reinforcing member 40 comprises a metallic member. Alternately, reinforcing
member 40 may comprise a reinforcing structure, such as fiber reinforced
plastic.
26 Preferably, spiders 18 are integral with fan shroud 10 as shown in FIG. 1,
and
27 are formed in the same blow molding operation as fan shroud 10. The concept
of
28 parison programming, i.e. forming the parison for the part with varying,
and
29 controlled, thickness about the length and circumference of the parison, is
herein used
to control the final thickness of the fan shroud 10 and of the spiders 18
formed
31 therewith.
3
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1 When spiders 18 are integrally molded with the fan shroud 10, spiders 18 may
2 be formed as solid, or single walled members. Alternately, the strength of
spiders 18
3 may be increased by forming the spiders 18 as hollow, double-walled members
4 having at least one longitudinal hollow chamber 22 extending at least a
portion of the
length of the spider 18 by modifying the blow molding process. The structural
6 integrity of spiders 18 may be further improved by molding spiders 18 in a
high
7 section modulus profile, for example a "V" or "I" cross-section, as shown in
FIGS.
8 4A-4C. The high modulus profiles may therefore comprise a single continuous
9 hollow chamber 22, or a plurality of hollow chambers 22 joined by regions of
a pinch
off 24, Preferably the profile or shape of spiders 18 is also configured to
provide
11 maximum aerodynamic flow through fan shroud 10.
12 When spiders 18 are formed integrally with fan shroud 10, the region
defined
13 by the perimeter of the opening 14 and adjacent spiders 18 will comprise a
plurality
14 of webs of material. To ensure proper removal of the webs, and concentric
placement
of fan assembly 26 within opening 14, it is preferred that all of the webs be
removed
16 in a single step trimming operation using a V-die trimming process. This
trimming
17 process allows exact placement of the fan within opening 14, therein
allowing
18 minimal clearance between the tip of the fan and the wall of opening 14,
The reduced
19 clearance achievable through die trimming provides overall increased
efficiency of
the cooling fan.
21 Stated another way, it has been found that die-cutting has a primary
advantage
22 in "relative" rather than "absolute" dimensioning. In the case of a fan-
shroud, what is
23 important is that the tip clearance of the fan be minimized to maximize
cooling.
24 Accordingly, it is more important to center the fan in the shroud than to
consider
where the fan is in space. This is best accomplished by referencing off the
center of
26 the fan motor mount for trimming. With water jet or laser, the trimming is
relative to
27 an absolute locator somewhere on the holding fixture (all indirect
referencing subject
28 to variation).
29 In an alternative embodiment, illustrated in FIG. 5, spiders 18 may
comprise a
separately molded component 28 attached to fan shroud 10 during a secondary
31 operation. Preferably, separately molded component 28 is injection molded
from a
32 reinforced plastic material, such as glass fiber reinforced nylon. In the
interest of
4
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1 minimizing assembly parts, separately molded component 28 may be attached to
fan
2 shroud 10 using molded in securement means, for example collapsible post 30
and
3 socket 32, or dovetail twist lock 34 fastening, as illustrated in cross-
sectional views in
4 FIG. 6 and FIG. 7 respectively. Corresponding male and female components of
the
molded in securement means are molded to the spiders 18 and the fan shroud 10
6 respectively. The joint may be further strengthened by assembling spiders 18
to the
7 fan shroud 10 promptly after the fan shroud 10 is removed from the mold. As
the fan
8 shroud 10 shrinks during cooling the molded in securement means will tighten
9 together providing a secure joint.
When the fan shroud 10 is to be provided with separately molded spider
11 component 28 a web, or waste area, of material will be molded over opening
14 of fan
12 shroud 10 as a natural product of the blow molding operation. The waste
inherent in
13 blow molding the fan shroud 10 may be reduced by molding a separate bottle
36 or
14 reservoir, preferable a hot or pressurized bottle, in the center of the
waste area or the
fan shroud 10, as illustrated in FIG. 8. The size and shape of the bottle 36
is
16 constrained only by the dimensions of opening 14, as illustrated in broken
lines in
17 FIG. 8. Furthermore, the thickness of the bottle 36 can be controlled using
parison
18 programming as described above. As an additional feature, if desired the
bottle 36
19 may be molded with flow disrupters, such as ribs or weirs, to assist
deaeration of the
fluid in the bottle, and thereby increase the heat transfer efficiency of the
fluid. After
21 the fan shroud 10, containing the bottle 36, has been molded, the bottle 36
will be
22 removed, as by V-die trimming, as a secondary process.
23 A final aspect of the present invention is the incorporation of a fluid
level
24 indicator integrated into at least one of the chambers of the fan shroud 10
or into the
bottle 36 molded into the waste area of the fan shroud 10. The level of a
fluid above
26 ambient temperature, such as coolant, can be indicated using a reversible
heat
27 activated colorant. When the temperature of the coolant, and therefore the
plastic,
28 exceeds a predetermined magnitude the colorant is activated and the color
of the
29 plastic changes. The reversible nature of the colorant is such that when
the coolant,
and therefore the plastic, falls below the predetermined level the coloration
reverses.
31 In this manner, when the chamber or bottle is partially filled with fluid
above the
32 predetermined temperature, the portion of the chamber or bottle in contact
with the
5
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1 fluid will appear as a different color than the portion of the chamber or
bottle not in
2 contact with the fluid above the predetermined temperature.
3 Although the present invention has been described in relation to particular
4 embodiments thereof, many other variations and modifications and other uses
will
become apparent to those skilled in the art. It is preferred, therefore, that
the present
6 invention be limited not by the specific disclosure herein, but only by the
appended
7 claims.
8
6
