JP4533763B2 - Vibration isolator and assembly method thereof - Google Patents

Description

  The present invention relates to a vibration isolator including a resin outer cylinder fitted into an attachment hole of an attachment member, an inner cylinder disposed on an inner peripheral side thereof, and an elastic body that couples both together, and an assembling method thereof.

  Conventionally, there has been known an anti-vibration device in which an inner cylinder is arranged in an outer cylinder and an elastic body is provided so as to connect the two, and such an anti-vibration device is mainly used for an elastic bushing on a suspension of an automobile. It is used as Such a bush is required to increase the rigidity in the direction perpendicular to the axis for improving the steering stability and to reduce the rigidity in the twisting direction for improving the riding comfort. As disclosed in FIG. 1, there is known a product obtained by reducing the outer diameter of both end portions in the axial direction of an outer cylinder coupled to a suspension.

  In this way, by reducing the diameter of both ends in the axial direction of the outer cylinder, the elastic body is held between the both ends in the axial direction, and the escape of the elastic body in the axial direction is restricted. Stiffness can be increased. In this case, the thickness of the elastic body is reduced at both ends in the axial direction and the rigidity in the twisting direction is increased. I try to lower it.

  Moreover, not only the effect of improving steering stability but also the effect of improving the durability of the elastic body can be obtained by reducing the diameter of both ends in the axial direction of the outer cylinder as described above. That is, after the elastic body is vulcanized and formed between the outer cylinder and the inner cylinder, both ends in the axial direction of the outer cylinder are reduced in diameter, so that the elastic body is formed between the outer cylinder and the inner cylinder. The wall thickness (initial wall thickness) of the elastic body can be increased, so that the strain applied to the elastic body is smaller than that in which the elastic body is molded in a state in which both end portions in the axial direction of the outer cylinder are previously reduced in diameter. Thus, the durability of the elastic body can be improved.

In the above-described vibration isolator, the outer cylinder is made of metal, but it is also known that the outer cylinder is constituted by a resin having sufficient deformability. For example, in the one disclosed in Patent Document 2, the entire outer elastic body is squeezed into a pre-compressed state by press-fitting a resin outer cylinder into the mounting hole of the mounting member, so that the durability of the elastic body is improved. I have to.
JP-A-9-203428 JP 2002-896523 A

  However, in the former conventional example, it is necessary to reduce the outer diameter of both end portions in the axial direction of the metal outer cylinder, which increases the manufacturing process and increases the manufacturing cost. Moreover, since the outer cylinder is made of metal, the weight is relatively heavy, and since the outer cylinder is integrated with an elastic body such as rubber, it cannot be reused and has a poor recyclability.

  On the other hand, if the outer cylinder is made of resin as in the latter conventional example, the outer cylinder and the elastic body can be integrally pulverized and recycled, and the weight is relatively reduced. However, in order to satisfy the above-mentioned performance required for the elastic bush of the suspension of an automobile, it is necessary to form the outer cylinder in a shape with both ends in the axial direction constricted. Thus, there arises a problem that the manufacturing cost increases.

  The present invention has been made in view of such points, and an object of the present invention is to provide a vibration isolator provided with an elastic body that connects the resin outer cylinder and the inner cylinder between the resin outer cylinder and the resin outer cylinder. An object of the present invention is to provide an inexpensive vibration isolator capable of obtaining predetermined spring characteristics by devising the configuration of the cylinder.

  In order to achieve the above object, in the vibration isolator according to the present invention, when the resin outer cylinder is fitted into the mounting hole of the mounting member, both axial end portions of the resin outer cylinder are directed radially inward. Modified.

Specifically, in the first aspect of the present invention, a resin outer cylinder fitted into the mounting hole of the mounting member connected to the supported body, an inner cylinder disposed on the inner peripheral side and connected to the supporting body, Further, an object of the present invention is to provide a vibration isolator provided with an elastic body that connects the resin outer cylinder and the inner cylinder together. Then, the resin barrel, as to deform both axial ends are radially inwardly as it is fitted into the mounting hole of the mounting member for restricting the movement in the axial direction of the elastic body, said both It is assumed that the outer diameter of the end portion and the thickness in the radial direction are formed larger than the central portion.

  With this configuration, by inserting the resin outer cylinder into the mounting hole of the mounting member, both axial ends thereof are deformed radially inward by the inner peripheral surface of the mounting hole. It is possible to obtain the same operation and effect as those of the conventional structure in which the diameter is reduced in advance and fitted into the mounting hole. That is, when the resin outer cylinder is fitted into the mounting hole, the axial movement of the elastic body is restricted by deforming both ends in the axial direction of the resin outer cylinder in the radially inward direction. Since the rigidity of the elastic body can be increased and the initial thickness of the elastic body can be increased, the strain acting upon deformation of the elastic body can be relatively reduced, and the durability of the elastic body can be improved. be able to.

  Therefore, since the diameter reduction process can be omitted by simultaneously performing the diameter reduction of both ends in the axial direction of the outer cylinder and the fitting operation of the attachment member into the attachment hole, the same as the case of diameter reduction processing. The production cost can be reduced while obtaining the effects of the above.

  As described above, the outer diameter of the axial end portion of the resin outer cylinder and the thickness in the radial direction are larger than those of the central portion. It is preferable that a groove is formed over the entire circumference between the axial end and the center (invention of claim 2). As a result, the rigidity of the resin outer cylinder is reduced at the groove, so that when the resin outer cylinder is fitted into the mounting hole of the mounting member, the axial end is large and easily deformed radially inward. become. Therefore, when the resin outer cylinder is fitted into the mounting hole of the mounting member, the axial end portion of the resin outer cylinder more reliably compresses the axial end portion of the elastic body, thereby reducing the diameter. It is possible to obtain the same effect as that of the above case more reliably.

  The invention of claim 3 relates to a method of assembling the vibration isolator having the above-described configuration to the mounting member. Specifically, a resin outer cylinder connected to the supported body via the mounting member, and An anti-vibration device comprising an inner cylinder disposed on the inner peripheral side and connected to the support and an elastic body connecting the resin outer cylinder and the inner cylinder to each other is fitted into the mounting hole of the mounting member. Targeting the assembly method.

Then, the resin outer cylinder is formed such that the outer diameter and the radial thickness at both axial end portions are larger than the central portion, and the outer diameter of the resin outer cylinder is set at both axial end portions from the central portion. There it is then largely deformed radially inward to reduce the so that to regulate the movement in the axial direction of the elastic body, shall be fitted in the mounting hole of the mounting member.

  By fitting the resin outer cylinder into the mounting hole of the mounting member by this method, the outer diameter of both ends in the axial direction of the resin outer cylinder can be reduced at the same time. Cost can be reduced.

  As described above, according to the vibration isolator according to the present invention, when the resin outer cylinder is fitted into the mounting hole of the mounting member, the both ends in the axial direction of the resin outer cylinder are deformed radially inward. By making the outer diameter and radial thickness of both ends in the axial direction of the resin outer cylinder larger than the central portion, it is not necessary to reduce the diameter in the axial ends in order to obtain the predetermined spring characteristics as in the past. The manufacturing cost can be reduced. In particular, by providing grooves between the axial end portions and the central portion of the outer peripheral surface of the resin outer cylinder, the axial end portions can be greatly and easily deformed, and when the diameter is reduced. The same effect can be obtained more reliably.

  Further, by fitting the vibration isolator having the above-described configuration into the mounting hole of the mounting member, it is not necessary to reduce the diameter of the vibration isolator, so that the vibration isolator can be assembled at low cost.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following description of the embodiment is merely illustrative in nature, and does not mean that the present invention, its application, or its use is limited.

(Embodiment 1)
<Overall configuration>
FIG. 1 shows a schematic configuration of a rubber mount device A according to an embodiment of the present invention. In this rubber mount device A, reference numeral 1 denotes a metal bracket (attachment member) in which a small attachment hole 1a and a large attachment hole 1b (attachment hole) are provided in parallel. An inner cylinder 2 connected to a power plant (engine or transmission), suspension arm or the like (supported body) is inserted into the small mounting hole 1a, and the inner peripheral surface of the small mounting hole 1a and the inner cylinder 2 The outer peripheral surface is coupled with a vibration isolating rubber 3. An anti-vibration bush 4 (anti-vibration device) is fitted in the large mounting hole 1b. The anti-vibration bush 4 includes a resin-made outer cylinder 11, an inner cylinder 12 inserted into the outer cylinder 11, and an anti-vibration rubber 13 (elastic body) that couples the outer cylinder 11 and the inner cylinder 12. It is configured. And the said inner cylinder 12 is connected with the vehicle body (support body) of a motor vehicle.

  The outer cylinder 11 is formed by a mold or the like using a resin material such as nylon, for example. As shown in FIG. 2, the inner diameter is substantially constant in the axial direction, and the outer diameter is at both end portions in the axial direction. 11a, 11a is formed to be larger than the large mounting hole 1b of the bracket 1. Further, the outer diameters of the axial end portions 11a and 11a are larger than the central portion 11b, that is, the axial end portion 11a is thicker (larger in the radial direction) than the central portion 11b. It is molded into.

  As will be described in detail later, when the outer cylinder 11 is fitted into the large attachment hole 1b of the bracket 1, the axially opposite ends 11a and 11a of the outer cylinder 11 are formed by the inner peripheral surface of the large attachment hole 1b. Deforms inward in the direction. Then, both ends in the axial direction of the anti-vibration rubber 13 are compressed as shown in FIG.

  By doing so, the anti-vibration rubber 13 is held between the axial ends 11a, 11a of the outer cylinder 11 and the inner cylinder 12, and the deformation in the axial direction is restricted to some extent. The rigidity in the direction perpendicular to the axis is increased. Therefore, when the rubber cloak apparatus A is used for an automobile suspension, the steering stability can be improved. The shafts 13a and 13a are provided at both ends in the axial direction of the anti-vibration rubber 13, and both ends in the axial direction of the anti-vibration rubber 13 by the deformation of the both end portions 11a and 11a in the axial direction of the outer cylinder 11 as described above. Even if the wall thickness of the portion is reduced, the rigidity in the direction of bending is reduced, and the ride comfort is improved.

  The outer cylinder 11 may be formed using a resin material containing short fibers. Thus, when using a resin containing short fibers, various synthetic resins such as nylon resin can be adopted as the matrix resin, and various organic or inorganic short fibers such as short glass fibers can be used for the short fibers. Fiber can be employed. And the compounding quantity of a short fiber should just be about 10-40 mass% of the quantity of a matrix resin, and the short fiber from the one end vicinity of the said outer cylinder 11 to an other end is the axial direction of this outer cylinder 11 ( (Cylinder length direction).

  The short fibers as described above function to reinforce the outer cylinder 11 and, in the case of short glass fibers, function to reduce the water absorption rate of the outer cylinder 11. That is, when the outer cylinder 11 is placed in a high humidity environment or comes into contact with rainwater or salt water, the outer cylinder 11 absorbs water and deteriorates, and the adhesive force with the vibration isolating rubber 13 decreases. For example, in the case of nylon resin, the water absorption is about 7%. On the other hand, when the short glass fiber is contained in the outer cylinder 11, the water absorption rate of the outer cylinder 11 is lowered according to the content, and when the short glass fiber content is about 30%, the water resistance of the outer cylinder 11 is reduced. And adhesion with rubber are improved.

The inner cylinder 12 is a metallic cylindrical member, and as shown in FIGS. 1 and 2, a spherical bulging portion 12a is integrally provided at the central portion in the axial direction. By providing such a bulging portion 12a, the thickness of the anti-vibration rubber 13 near the center in the axial direction is reduced, and the rigidity in the direction perpendicular to the axis is further increased. The bulging portion 12a may be formed of resin and fixed integrally to the inner cylinder 12, or may not be provided on the inner cylinder 12.
<Method of manufacturing rubber mount device>
Below, the manufacturing method of the said rubber mount apparatus A is demonstrated.

  First, in a state where the inner cylinder 2 is concentrically inserted into the small mounting hole 1a of the metal bracket 1, the raw rubber of the vibration isolating rubber 3 is placed between the inner peripheral surface of the small mounting hole 1a and the inner cylinder 2. It is injected and vulcanized into a predetermined shape. At this time, an adhesive is applied to the inner peripheral surface of the small mounting hole 1 a and the outer peripheral surface of the inner cylinder 2. In this way, instead of directly coupling the small mounting hole 1a and the inner cylinder 2 with the vibration isolating rubber 3, a vibration isolating bush as described later may be fitted into the small mounting hole 1a. .

  Then, a separately manufactured anti-vibration bush 4 is fitted into the large mounting hole 1b of the bracket 1. The method of manufacturing the vibration isolating bush 4 is manufactured in the same manner as the case where the inner cylinder 2 and the vibration isolating rubber 3 are disposed in the small mounting hole 1a. That is, with the metal inner cylinder 12 inserted concentrically into the resin outer cylinder 11 formed by a mold or the like, the raw rubber is injected between the outer cylinder 11 and the inner cylinder 12. And vulcanized. In the present embodiment, since the outer cylinder 11 is made of resin, surface treatment before bonding is unnecessary.

Fitted to large mounting hole 1b of the above said vibration damping bushing 4, as shown in FIG. 3, carried out using a metal die 22.

  Specifically, the outer cylinder 11 of the anti-vibration bushing 4 has an outer diameter at both axial ends larger than a diameter of the large mounting hole 1b of the bracket 1 in a free state (a state where no external force is applied). Therefore, the outer diameter of the outer cylinder 11 of the vibration isolating bush 4 is reduced using the die 22 so as to be fitted into the large mounting hole 1b. Here, the diameter of the inlet 23 of the die 22 is larger than the outer diameter of the outer cylinder 11, the diameter of the outlet 24 is smaller than the diameter of the large mounting hole 1b, and the diameter gradually increases from the inlet toward the outlet. It is getting smaller.

  In the fitting, as shown in FIG. 3A, the die 22 and the bracket 1 are opposed so that the outlet 24 of the die 22 is concentric with the large mounting hole 1b. In this embodiment, both are made to contact. Then, as shown in FIG. 3B, the vibration isolating bush 4 is inserted from the inlet 23 of the die 22 and pushed toward the outlet 24.

  The outer cylinder 11 of the anti-vibration bush 4 is reduced in outer diameter so as to be tapered by passing through the die 22. Then, the portion of the vibration isolating bush 4 that has passed through the outlet 24 of the die 22 is inserted into the large mounting hole 1b as it is.

  When the outer cylinder 11 is passed through the die 22, the outer diameter is reduced. However, since the outer cylinder 11 gradually decreases from the tip of the outer cylinder 11, the outer diameter is rapidly reduced. Therefore, the cracking of the outer cylinder 11 can be avoided. Further, the tip of the outer cylinder 11 is first squeezed, but since the orientation of the short fibers is aligned in the axial direction at the tip, the short fibers do not become a great resistance of the squeezing, It is avoided that the outer cylinder 11 is cracked.

  Since the diameter of the outlet 24 of the die 22 is smaller than the diameter of the large mounting hole 3, the outer cylinder 11 enters the large mounting hole 3 without resistance as shown in FIG. As shown in FIG. 3D, the outer cylinder 11 of the vibration-isolating bushing 4 has its outer diameter expanded by its elastic restoring force because the external force due to the die 22 does not act when its entire length passes through the die 22. Then, the large attachment hole 3 is tightly fitted. However, the outer diameter of the outer cylinder 11 is smaller than that in the free state. As a result, the anti-vibration rubber 13 of the anti-vibration bush 4 is pre-compressed to obtain a predetermined anti-vibration characteristic.

  Further, since the anti-vibration bush 4 fitted in the large mounting hole 1b of the bracket 1 is restricted from being deformed outward in the radial direction by the inner peripheral surface of the large mounting hole 1b, the vibration isolating bush 4 is more than the axial center portion 11b. Also, both axial ends 11a, 11a having a large outer diameter are deformed radially inward. That is, as shown in FIG. 1, in the state where the vibration isolating bush 4 is fitted in the large mounting hole 1b, the inner peripheral side of the axial end portions 11a and 11a of the outer cylinder 11 compresses the vibration isolating rubber 13. Thus, the deformation of the anti-vibration rubber 13 in the axial direction can be restricted to some extent, and the rigidity in the direction perpendicular to the axis can be increased.

  Moreover, the anti-vibration rubber was molded with the thickness (initial thickness) of the anti-vibration rubber 13 before the outer cylinder 11 was fitted into the large mounting hole 1b reduced in diameter at both axial ends of the outer cylinder 11. Since the thickness can be increased as compared with the case, the strain applied to the anti-vibration rubber 13 becomes relatively small, and the durability of the anti-vibration rubber 13 can be improved.

As described above, according to the present embodiment, the anti-vibration bush 4 is inserted into the large mounting hole 1b of the bracket 1 by inserting the anti-vibration bush 4 in which the outer diameter and thickness of the axial end portions 11a and 11a are larger than the central portion 11b. The rigidity of the rubber 13 in the direction perpendicular to the axis can be increased, the steering stability can be improved, the initial thickness of the anti-vibration rubber 13 can be increased, and the durability of the anti-vibration rubber 13 is also improved. be able to. In other words, it is possible to obtain the same effect as that obtained by reducing the diameter of both ends in the axial direction of the outer cylinder as in the prior art, and the manufacturing cost of the rubber mount device A is reduced by the amount that does not require this diameter reduction. can do.
(Embodiment 2)
In the second embodiment, groove portions are provided between the axial end portions and the central portion so that the axial end portions of the vibration-isolating bushing are easily deformed. Since only the shape of the outer cylinder is different as shown in FIG. 5, only the parts different from the first embodiment will be described in detail below.

  That is, as shown in FIG. 5, the outer cylinder 31 of the anti-vibration bush 5 is formed so that the inner diameter thereof is substantially the same in the axial direction, while the outer peripheral surface has a substantially semicircular shape in a cross-sectional view. The groove portions 31c and 31c are formed in the circumferential direction. Thus, the outer cylinder 31 has axial end portions 31a and 31a formed so that the outer diameter gradually increases from the bottom of the grooves 31c and 31c toward both axial ends of the outer cylinder 31; The groove portions 31c and 31c are divided into a central portion 31b on the axially central side. The outer diameters at both ends in the axial direction are formed to be larger than the outer diameter of the central portion 31b.

  By forming the outer cylinder 31 as described above, as shown in FIG. 4, when the outer cylinder 31 is fitted into the large mounting hole 1 b of the bracket 1, both axial ends 31 a and 31 a of the outer cylinder 31 are A force is received inward in the radial direction by the inner peripheral surface of the large mounting hole 1b, and the rigidity of the grooves 31c and 31c is small. Therefore, the grooves 31c and 31c are easily deformed. As a result, as in the first embodiment, the initial thickness of the anti-vibration rubber 13 can be increased, the durability of the anti-vibration rubber 13 can be improved, and the axial end portions 31a and 31a are provided with the anti-vibration rubber. Since both ends in the axial direction of 13 are more reliably compressed and the movement of the anti-vibration rubber 13 in the axial direction is more reliably regulated, the rigidity in the direction perpendicular to the axis can be reliably increased.

Further, by changing the shape and depth of the grooves 31c, 31c provided on the outer peripheral surface of the outer cylinder 31, the deformation amount of the axial end portions 31a, 31a can be controlled. Thereby, the spring constant of the anti-vibration rubber | gum 13 can be changed according to the steering stability requested | required, and the freedom degree of design can be expanded.
(Other embodiments)
The configuration of the present invention is not limited to the above embodiment, but includes various other configurations. That is, in each said embodiment, although the inner cylinder 12 and the vibration isolator 13 are adhere | attached, it is not restricted to this, It is good also as non-adhesion. In this case, since the inner cylinder 12 is press-fitted into the vibration isolating rubber 13, it is necessary to form the vibration isolating rubber 13 in the outer cylinders 11 and 31 first. In this way, by making the inner cylinder 12 and the vibration isolating rubber 13 non-bonded, the spring constant in the twisting direction and the twisting direction can be reduced, and the metal inner cylinder 12 can be disposed when discarded. Can be extracted from the anti-vibration rubber 13, and the anti-vibration rubber 13 and the resin outer cylinders 11 and 31 can be pulverized as one body, and the recyclability can be improved.

  In each of the above embodiments, the axially opposite ends 11a, 11a, 31a, 31a of the outer cylinders 11, 31 are radially inward with the outer cylinders 11, 31 fitted in the large mounting holes 1b of the bracket 1. However, the present invention is not limited to this, and only one of the axial ends 11a, 11a, 31a, 31a may be deformed. In this case, in order to ensure the function as an elastic bush used for the suspension, it is necessary to mold the axial end portions 11a and 31a which are not deformed into a reduced diameter state.

  Furthermore, in each said embodiment, although the internal diameter of the outer cylinders 11 and 31 and the hole diameter of the large attachment hole 1b of the bracket 1 are made substantially constant in an axial direction, you may make it a diameter change in an axial direction. However, in this case, the inner diameters of the outer cylinders 11 and 31 and the hole diameters of the large mounting holes 1b of the bracket 1 are the same as the outer cylinders 11 and 31 with the outer cylinders 11 and 31 fitted in the large mounting holes 1b. The end portions 11a, 11a, 31a, 31a of the 31 in the axial direction are deformed inward in the radial direction so that the end portions in the axial direction of the anti-vibration rubber 13 are compressed.

It is the perspective view which represented a part of rubber mount device concerning Embodiment 1 of the present invention in section. It is the perspective view which represented a part of vibration proof bush by the cross section. It is explanatory drawing which shows each step which inserts a vibration isolating bush in the large attachment hole of a bracket. It is the perspective view which represented a part of rubber mount device concerning Embodiment 2 of the present invention in section. It is the perspective view which represented a part of vibration proof bush by the cross section.

A Rubber mount device 1 Bracket (Mounting member)
3 Large mounting holes (mounting holes)
4, 5 Anti-vibration bush (vibration isolator)
11, 31 Outer cylinder 11a Axial end portion 11b Central portion 12 Inner tube 12a Swelling portion 13 Anti-vibration rubber (elastic body)
13a Straight 31a Axial end 31b Center 31c Groove

Claims (3)

A resin outer cylinder fitted into an attachment hole of an attachment member connected to the supported body, an inner cylinder disposed on the inner peripheral side thereof and connected to the support, and the resin outer cylinder and the inner cylinder are coupled to each other. An anti-vibration device comprising an elastic body,
The resin outer tube, as by modifying the axial direction end portions radially inwardly as it is fitted into the mounting hole of the mounting member for restricting the movement in the axial direction of the elastic body, the both ends The vibration isolator is characterized in that the outer diameter and the thickness in the radial direction are formed larger than the central portion. In claim 1,
An anti-vibration device characterized in that a groove is formed on the outer peripheral surface of the resin outer cylinder over the entire circumference between the at least one axial end and the center. A resin outer cylinder connected to the supported body via an attachment member, an inner cylinder disposed on the inner peripheral side of the resin outer cylinder and connected to the support, and an elastic body connecting the resin outer cylinder and the inner cylinder to each other A vibration isolator comprising: a method of fitting into a mounting hole of the mounting member and assembling;
The resin outer cylinder is formed such that the outer diameter and the radial thickness at both ends in the axial direction are larger than the central portion,
Wherein the outer diameter of the resin sheath, by shrinking the so that to regulate the movement in the axial direction of the elastic body is largely deformed in the axial direction both end portions radially inward than the center portion, said mounting member A method of assembling the vibration isolator, wherein the vibration isolator is fitted into the mounting hole.

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