Note: Descriptions are shown in the official language in which they were submitted.
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TITLE
MOUNTING DEVICE AND PROCESS FOR
MANUFACTURE THEREOF
,. 5 BACKGROUND OF THE INVENTION
1. Field of The Invention
The present invention relates to a mounting device which supports
and secures an engine, a transmission, a suspension, or the like, to the body
of a vehicle, at the same time damping out engine- or suspension-generated
vibrations, as well as a process for the manufacture thereof.
2. Description of the Related Art
Mounting devices which support and secure an engine, a
is transmission, a suspension, or the like, to the body of a vehicle which
have
been long used previously have comprised rubber and like insulators held
between a lame and small metal cylinder.
However, to reduce the weight of an automobile and also to reduce
cost, the use of a resin has been attempted so as to replace the metal in the
20 outer cylinder with a resin.
Such a mounting device having an insulator placed between such a
resin outer cylinder is manufactured by molding the insulator part from
rubber and then injection molding a resin using the insulator part and the
metal inner cylinder as the insert.
2s However, the conventional manufacturing process has faced
problems in that injection molding using rubber which is a very elastic
material, if earned out under high pressure, deformed the insulator part
while molding even under a relatively low pressure not only providing
molded articles with poor appearance, but also leading to a failure to obtain
so the mechanical properties with a resin.
Molding a resin insert has also faced problems in that for
manufacturing a metal cylinder as an outer cylinder, the insulator part is
subjected to sufficient compression behavior to increase its strength by
annularly tensioning drawing the metal. But molding an insert from a resin
3s requires providing the insulator part with compression behavior based only
on the resin-characteristic shrinkage so that a molded article or an outer
cylinder obtained by using a special insulator material had to become a very
thick-walled molded article.
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It is an object of this invention to provide a mounting device
which is light weight, excellent in durability and good in appearance and a
process for the manufacture thereof.
SUMMARY OF THE INVENTION
A mounting device includes an outer cylinder, an inner cylinder, and
an elastic insulator part positioned between said outer cylinder and inner .
cylinder to connect the outer cylinder and inner cylinder. The outer
cylinder is made of a resin and includes a first outer cylinder molded into
1o an annular form having at least one opening therein, and a second outer
cylinder molded on the outer circumference of the first outer cylinder and
covering the opening in the first outer cylinder.
BRIEF DESCRIPTION OF THE DRAWINGS
1s Figure 1 is a plan view showing an embodiment for the
manufacturing stage of Example 1 of a mounting device of this invention.
Figure 2 is a plan view showing an embodiment for the
manufacturing stage of Example 2 of a mounting device of this invention.
Figure 3 is a plan view showing the final embodiment of Example 1
20 of the mounting device of this invention.
DETAILED DESCRIPTION
The present invention relates to a mounting device that supports and
secures an engine, a transmission, a suspension, or the like, to the body of a
2s vehicle while at the same time damping out engine- or suspension
generated vibrations, and a process for the manufacture thereof.
Specifically the invention relates to a mounting device having an insulator
part placed between a resin outer cylinder and a metal or resin inner
cylinder and a process for the manufacture thereof.
3o The process for manufacturing a mounting device by other
embodiments of this invention is characterized in that in a process for
manufacturing a mounting device comprising an outer cylinder, an inner
cylinder, an insulator part which is located between said outer cylinder and
inner cylinder, and having an outer annular part which is contact with an '
3s inner circumferential face of said outer cylinder, an inner annular part in
contact with an outer circumferential surface of said inner cylinder, an '
insulator part having at least one connector for connecting said outer
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annular part and said inner annular part, the process of manufacturing the
mounting de~~ice comprises
Step 1 of molding, using said inner cylinder as an insert, the
insulator part which has at least one opening in said outer annular part;
Step 2 of molding, using the molded above insulator part and the
inner cylinder as the insert, a first outer cylinder which has an opening at a
' position corresponding to the opening; and
Step 3 of molding, wherein the opening of the said first outer
cylinder and the opening of the outer annular part of said insulator part are
closed, using said first outer cylinder, insulator part, and inner cylinder as
the insert, a second outer cylinder from a resin at least on an outer
circumference of said first outer cylinder.
The manufacturing process of a mounting device by other further
embodiments of this invention is characterized in that in the process for
is manufacture of a mounting device comprising an outer cylinder, an
cylinder, an insulator part which is located between said outer cylinder and
i_n_n_er cylinder, and having an outer annular part which is contact with an
inner circumferential face of said outer cylinder, an inner annular part in
contact with an outer circumferential surface of said inner cylinder, an
2o insulator part having at least one connector for connecting said outer
annular part and said inner annular part, the process of manufacturing the
mounting device which comprises
Step 1 of molding a first outer cylinder having at least one opening
from a resin;
25 Step .2 of molding, using said molded first outer cylinder and the the
inner cylinder as the insert, an insulator part having an outer annular part
with an opelvng at a position corresponding to the opening provided on the
first outer cylinder; and
Step 3 of molding, wherein the opening of the said first outer
3o cylinder and the opening of the outer annular part of said insulator part
are
closed, using said first outer cylinder, W sulator part, and inner cylinder as
the insert, a second outer cylinder from a resin at least on an outer
circumference of said first outer cylinder.
The mounting device manufacture by this invention comprises
ss molding the outer cylinder separately into a first outer cylinder and a
second outer cylinder so as to have it provided with excellent strength and
good appearance. A thin walled first outer cylinder is molded under
relatively low pressure, and an insulator part is preconnected to the first
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outer cylinder to secure the insulator part, which allows molding the second
outer cylinder under high pressure, resulting in a mounting device with
good appearance.
Since the openings provided on the first outer cylinder, the outer
annular section of the insulator are closed off when the second outer
cylinder is molded, compression behavior can be applied to the insulator
part without depending on the resin-inherent shrinkage alone, so as to
permit manufacturing a high strength mounting device. This construction
does not require the outer cylinder to be thicker walled than necessary.
to Since a resin is used instead of metal, the device is light weight and uses
an
outer cylinder which is not thick walled to make it even lighter weight than
the conventional mounting devices made of a resin.
Preferred embodiments for this invention are described in detail by
referring to the examples described in the attached drawings. These
15 examples are used to explain this invention and in no way do they limit the
scope of this invention.
EXAMPLES
Examples of this invention are described by referring to Figures 1-3.
In the figures, 10 is an outer cylinder comprising a first outer
cylinder 11 and a second outer cylinder 12 and is molded from a glass fiber
reinforced thermoplastic resin. Preferred thermoplastic resins which meet
the heat resistance and strength requirements are polyamides, polyesters, or
2s polyphthalamides, and the like.
20 is a metal inner cylinder which can be obtained by machining a
steel pipe. The inner cylinder 20 may be an article molded from a resin,
such as a polyamide, if excellent sliding properties and high strength are
assured.
30 is an insulator part which is molded from a natural rubber, a
synthetic rubber, or the like elastomer, preferably molded from a blended
rubber based on natural rubber with a dime rubber, such as styrene
butadiene rubber, butadiene rubber, and the like, because they are
outstanding in vibration isolation, preferably one molded from an
ss ethylene-propylene-dime terpolymer (EPDM rubber) owing to outstanding
heat resistance, as well as one molded from a chloroprene rubber owing to
its combination of excellent vibration isolation and heat resistance.
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The insulator part 30 comprises an outer annular part 31 which is
bound to the inner circumferential face of the first outer cylinder ll of
outer
cylinder 10, inner annular part 33 bound to the outer circumferential face of
inner cylinder 20, link 32 which links the outer annular part 31 to the inner
' s annular part 33. There should be one or more links 32 and their shape,
size,
and position are arbitrary within the range of not causing any problems in
' strength as illustrated in Figure 1 or Figure 2 with no particular
limitation.
Openings 34 and 14 are provided, respectively, on the outer annular part 31
and the first cylinder 11 without any restrictions as to the their numbers and
i0 positions, which may be provided at syixlmetrical positions 180 degrees
apart from each other as given in Figure 1 or may be at a single position as
shown in Figure 2. Openings are preferably provided as given in Figure 1
or Figure 2 considering the ease of molding and assembling and the
strength limitations.
1s In Example 1, for the process for manufacturing a mounting device
of this invention, in Step 1, insulator part 30 is molded from a rubber blend
of a natural h-ubber base with a styrene butadiene rubber using a metal inner
cylinder 20 as an insert, into a configuration as shown in Figure 1 or Figure
2 so as to have an outer annular part 31 provided with an opening 34.
2o The molding is carried out by compression molding under conditions
of a mold temperature of 145-165°C and 20-60 minutes.
Molding can also be carried out by injection molding under
conditions of a flow temperature of 175-185°C for 60 seconds -15
minutes
The molding conditions vary soxnewhat depending on parts, shapes,
25 gate positions, etc.
If a metal inner cylinder 20 is used, the surface of the inner cylinder
20, that face of the inner cylinder 20 coming in contact with the inner
annular part: 33, is preferably pretreated with an adhesive, such as a
phenolic adhesive or the like, so as to >Jncrease the adhesion of the cylinder
3o to the insulator part 30.
Next, in step 2, the insulator part 30 molded in step 1, along with the
metal inner cylinder 20, are placed as an insert into a mold followed by
injection molding an outer cylinder 11 having an opening 14 at a position
corresponding to the opening 34 of the insulator part 30. Molding is
ss carried out in this case so as to mold at the same time on the first outer
cylinder 11 lugs 15 which project outward in the radial direction at both ends
adjacent to openings) 14.
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Injection molding is carried out under conditions of injection
pressure of 400-450 kgf/cm2 and a mold temperature of 100-120°C. The
first outer cylinder is 2-3 mm in wall thickness. In order to increase the
adhesion of the insulator part 30 to the first outer cylinder ll, the face
which
s comes in contact with the outer annular part 31 of the first outer cylinder
is
preferably pretreated with an adhesive, such as a phenolic adhesive, or the
like.
In steps l and 2, the first outer cylinder 11 and inner cylinder 20 are
linked and integrated via insulator part 30. In step 3, a second outer
o cylinder 12 is molded using the integrated first cylinder 11, insulator part
30,
and inner cylinder 20 as an insert; the integrated first outer cylinder Il,
insulator part 30, and inner cylinder 20 are placed, with the two lugs being
gripped, into a mold for molding the second outer cylinder 12. This is
slightly larger in size than the first outer cylinder 11 with its opening 14
is closed and the insulator part 30 with its opening 34 of the outer annular
part
31 being closed, thereby injection molding the second outer cylinder 12 by
applying compression to the insulator part with openings 14 and 34 being
closed. The injection molding is carried out under conditions of an
injection pressure of 800-1,000 kgf/cm2 and a mold temperature of
20 110-120°C. The first outer cylinder is 2-3 mm in wall thickness.
The resultant molded mounting device is illustrated by Figure 3.
In this example, the second outer cylinder 12 is molded not only to
envelop the outer circumference of the first outer cylinder 11 including lugs
I5, but also to extend around the side face of the first outer cylinder 1I. In
2s terms of the viewpoint of the strength alone, it should be sufficient if
the
second outer cylinder I2 is at least present on the outer circumference side
of the first outer cylinder 11.
In another example, in the above first step, the first outer cylinder 11
is molded and then in the second step, insulator part 30 may be molded
3o with the first outer cylinder 11 which has been molded and with the metal
inner cylinder 20 as the insert. Step 3 is the same as the above.
As described above, the present invention can provide a resin-rubber
mounting device which is lighter in weight than the conventional
resin-rubber mounting devices, is good in appearance, and is durable as a
ss metal-rubber mounting device.
The use of the manufacturing process of this invention makes it
possible to mold the first outer cylinder and second outer cylinder from
different resin materials, for example, using a high flow resin for the first
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outer cylinder, and a second cylinder may be molded from a resin with
more emphasis on chemical resistance, appearance, and heat resistance.
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