JP2009085260A - Vibration isolation bushing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration isolation bushing having favorable assembling properties enabling easy and quick work while keeping a structure capable of maintaining a stable connection state into a connection hole of a connection member. <P>SOLUTION: This bushing is provided with a first outside vibration isolating body 8A comprising a rubber-shaped elastic body internally fit into one end in the axial direction of the connection hole H of a connection tube 1B, a second outside vibration isolating body 8B comprising a rubber-shaped elastic body internally fit into the other end of the connection hole H, and a resin inside vibration isolating body 8C. An inner circumference surface shape of the connection hole H is formed in a curved shape of which the diameter becomes smaller as it goes to an axial direction center side in a longitudinal section. Outer circumference surface shapes of the first outside vibration isolating body 8A and the second outside vibration isolating body 8B are formed along an inner circumference surface shape of the connection hole H. Either of the first outside vibration isolating body 8A and the second outside vibration isolating body 8B, and the inside vibration isolating body 8C are connected to each other via an engagement mechanism C. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an anti-vibration bush that is mounted in a connection hole of a connection portion of a connection member that is installed between a vehicle body and an axle.

  In general, in a link suspension of an automobile, a lateral rod as the connecting member is used to receive a load in the vehicle width direction. The lateral rod has one end connected to the vehicle body and the other end connected to the axle, and a vibration isolating bush is interposed at a connection portion between the lateral rod and the vehicle body to absorb vibration.

Conventionally, the anti-vibration bush has been constituted by a cylindrical member made of only a rubber material that is mounted in a connecting hole of a boss as a connecting portion of a lateral rod (see Patent Document 1).
JP 9-175131 A (paragraph number [0003], FIG. 8)

  However, in the above-described conventional configuration, since the vibration isolating bush is made of only a rubber material, if the vibration isolating bush is configured with high flexibility giving priority to vibration absorption, the steering stability is lowered. If too much emphasis was placed on stability, there was a problem that vibration absorption decreased.

In order to solve this problem, as shown in FIG. 7, a technique that employs an anti-vibration bush B composed of three parts has been proposed.
This anti-vibration bush B
A first outer vibration isolator 8A made of a rubber-like elastic body fitted into one end of the connecting cylinder 1B;
A second outer vibration isolator 8B made of a rubber-like elastic body fitted into the other end of the connecting cylinder 1B;
A resin-made inner vibration isolator 8C is provided between the first outer vibration isolator 8A and the second outer vibration isolator 8B.
Further, the inner peripheral surface shape of the connection hole is formed in a curved shape having a smaller diameter toward the axial center in the longitudinal section, and the outer peripheral surface shape of the first outer vibration isolator and the second outer vibration isolator. Is formed in a shape along the shape of the inner peripheral surface of the connecting hole.

According to this configuration, the resin-made inner vibration isolator is sandwiched between the first outer vibration isolator made of the rubber-like elastic body and the second outer vibration isolator, so that flexibility is exhibited by the outer vibration isolator. The shape-retaining property can be maintained by the resin-made inner vibration isolator.
Further, the inner peripheral surface shape of the connection hole is formed in a curved shape having a smaller diameter toward the axial center in the longitudinal section, and the outer peripheral surface shape of the first outer vibration isolator and the second outer vibration isolator. Are formed in a shape along the inner peripheral surface shape of the connection hole, so that even when a force in the twisting direction is applied to the vibration isolating bush, the first outer vibration isolator and the second outer anti-vibration body located on both sides are formed. The vibration absorption with the vibration isolator can be improved.

However, since the inner peripheral surface of the connecting hole is formed in a curved shape having a smaller diameter toward the center in the axial direction, the first outer vibration isolator is inserted from one end side of the connecting hole, and the second outer vibration isolator is inserted. The body and the inner vibration isolator had to be inserted into the connecting hole from the other end side of the connecting hole, and the operation of inserting these three parts was complicated and time-consuming.
Therefore, the inner vibration isolator, and either the first outer vibration isolator or the second outer vibration isolator were integrated using an adhesive to simplify the work process. In the means, it was not possible to prevent the two vibration isolators from being peeled off or to be misaligned under the influence of temperature conditions, humidity conditions, etc., and there was room for improvement.

  The present invention has been made in view of the above circumstances, and its purpose is to provide a stable connection state of the connection member into the connection hole by applying a simple connection structure to the vibration isolation body constituting the vibration isolation bush. An object of the present invention is to provide a vibration isolating bush that has a structure that can be maintained, has good assemblability, and can perform work easily and quickly.

[Configuration, Action and Effect of Claim 1]
〔Constitution〕
The characteristic configuration of the invention according to claim 1 is:
An anti-vibration bush mounted in a connecting hole of a connecting portion in a connecting member installed between a vehicle body and an axle,
A first outer vibration isolator made of a rubber-like elastic body fitted into one end of the connecting hole in the axial direction;
A second outer vibration isolator made of a rubber-like elastic body fitted inside the other end of the connection hole;
A resin inner vibration isolator positioned between the first outer vibration isolator and the second outer vibration isolator,
The inner peripheral surface shape of the connection hole is formed in a curved shape having a smaller diameter toward the axial center in the longitudinal section, and the outer peripheral surface shape of the first outer vibration isolator and the second outer vibration isolator, Formed along the inner peripheral surface shape of the connecting hole in the longitudinal section,
One of the first outer vibration isolator and the second outer vibration isolator is connected to the inner vibration isolator via an engagement mechanism, and the function and effect thereof are as follows. It is.

[Action]
That is, by integrating the inner vibration isolator and one outer vibration isolator via the engagement mechanism, the component parts as the vibration isolating bush are substantially two parts, and the anti-vibration bush is connected to the connecting member. When inserting into the connecting hole, it is only necessary to insert the vibration isolator connected by the engaging mechanism and insert the remaining outer vibration isolator.
Moreover, since the inner vibration isolator and one outer vibration isolator are integrated through an engagement mechanism, there is no misalignment or peeling compared to the case where the inner vibration isolator is fixed through an adhesive or the like, and stable connection is achieved. The state can be maintained.

〔effect〕
Therefore, the structure can maintain a stable connection state with respect to the inside of the connection hole of the connection member, but the work burden for the assembly can be reduced, the assembly performance is good, and the mounting work of the connection member into the connection hole can be easily and quickly performed. It was possible to provide an anti-vibration bush that could be performed.

[Configuration, Action and Effect of Invention of Claim 2]
〔Constitution〕
The characteristic configuration of the invention according to claim 2 is the configuration of the invention according to claim 1,
The outer diameter of the inner vibration isolator is set so that a gap is formed between the outer peripheral surface of the inner vibration isolator and the inner peripheral surface of the connection hole of the connecting portion.

[Action]
With this configuration, the first outer vibration isolator and the second outer vibration isolator on both sides of the inner vibration isolator come into contact with the inner peripheral surface of the coupling hole of the coupling portion and support the coupling portion. On the other hand, the inner vibration isolator is not in contact with the connecting cylinder in the assembled state.
Thereby, at the initial stage of input of the load, only the vibration isolator portions made of rubber elastic bodies on both sides support the connecting portion, and when the load increases, the resin-made inner vibration isolator also supports the connecting portion, It can be made easier to demonstrate.
That is, in the initial stage of load input, the support function by the first outer vibration isolator and the second outer vibration isolator can be exhibited. When the load increases, the resin inner vibration isolator also exhibits the support function. As a result, the spring constant of the anti-vibration bush is increased, and the effect of ensuring the stability of the vehicle body and ensuring the steering stability can be more easily obtained.

[Configuration, Action and Effect of Invention of Claim 3]
〔Constitution〕
The characteristic configuration of the invention according to claim 3 is the configuration of the invention according to claim 1 or 2,
The connecting member is a lateral rod.

[Action]
That is, when a lateral rod is installed between the vehicle body and the axle, the same effect as the effect of the configuration of the first or second aspect can be obtained.

  As shown in FIG. 1, a description will be given of a vibration isolating bush used for a three-link suspension that supports a rear wheel W of an automobile. A pair of left and right trailing arms 2 is supported on a vehicle body (not shown) so as to be swingable up and down about a lateral axis P, and a bracket 3 is attached and fixed to the tip of the trailing arm 2. An axle case 4 on the axle side is spanned. In the figure, W is a rear wheel.

A holding member 5 supported by the vehicle body is provided in the vicinity of one bracket 3, and a connecting rod 6 is attached to the holding member 5. An attachment structure between the connecting rod 6 and the lateral rod 1 as a connecting member will be described.

The lateral rod 1 is composed of a pipe-shaped rod main body 1A extending over the left and right sides, and a connecting cylinder 1B (corresponding to a connecting portion) attached to both ends of the rod main body 1A. As shown in FIGS. 2 (a) and 2 (b), the connecting cylinder 1B is configured by forming a pipe-like member into a curved shape having a smaller diameter toward the center side in the axial direction J. That is, the inner peripheral surface shape of the connection hole H of the connection cylinder 1B is formed in a curved shape having a smaller diameter toward the center side in the axial direction J in the longitudinal section.

  With this configuration, even when the connecting cylinder 1B of the lateral rod 1 is twisted, the first outer vibration isolator 8A and the second outer vibration isolator 8B located at both ends are connected to the connecting hole of the connecting cylinder 1B as will be described later. The connecting cylinder 1B is supported by contacting the inner peripheral surface of H.

As shown in FIGS. 2 (a) and 2 (b), the connecting rod 6 includes a rod base end portion 6A, an intermediate flange portion 6B provided on the tip end side of the rod base end portion 6A, and an intermediate flange. The anti-vibration bush connection part 6C provided in the front end side of the part 6B and the male screw part 6D having a smaller diameter than the anti-vibration bush connection part 6C are provided. Washers 7A and 7B are provided at a connection portion between the intermediate flange portion 6B and the vibration isolating bush connection portion 6C and a connection portion between the vibration isolation bush connection portion 6C and the male screw portion 6D.

As shown in FIGS. 2 (a), 2 (b), and 3, the anti-vibration bush B is fitted into the anti-vibration bush connecting portion 6C to absorb the vibration with the connecting cylinder 1B. Yes.
The anti-vibration bush B includes a first outer anti-vibration body 8A made of a rubber-like elastic body that is fitted into one end t1 that is the inner end in the axial direction J of the connection hole H of the connection cylinder 1B, and the connection cylinder 1B. A second outer vibration isolator 8B made of a rubber-like elastic body fitted into the other end t2 which is the front end side end of the connection hole H, a first outer vibration isolator 8A, and a second outer vibration isolator 8B. It consists of a resin-made inner vibration isolator 8C located between them.

The first outer vibration isolator 8A is formed in a substantially truncated cone shape, and its outer peripheral surface follows a tapered surface shape having a smaller diameter toward the center side in the axial direction J of the inner peripheral surface of the connecting cylinder 1B. In addition, the diameter is smaller on the tip side. That is, the outer peripheral surface shape of the first outer vibration isolator 8A is formed so as to follow the inner peripheral surface shape of the connecting hole H in the longitudinal section. As the material of the first outer vibration isolator 8A, a synthetic rubber such as natural rubber or NBR (acrylonitrile butadiene rubber) is used.

  As shown in FIGS. 2 (a), 2 (b), and 3, the second outer vibration isolator 8B is formed in substantially the same shape as the first outer vibration isolator 8A and is made of the same material. The outer peripheral surface shape of the second outer vibration isolator 8B is formed so as to follow the inner peripheral surface shape of the connecting hole H in the longitudinal section, but the engagement mechanism C is formed on the surface facing the inner vibration isolator 8C. It differs in that it is provided. This point will be described later.

Since the inner vibration isolator 8C is located on the center side in the axial direction of the connecting cylinder 1B, the inner vibration isolator 8C is formed into a drum-shaped outer shape along a shape that becomes smaller in diameter toward the center like the inner peripheral surface of the connecting cylinder 1B. ing. The material used is an engineering resin such as nylon, polyethylene, or PET. It also has self-lubricating properties. Then, the outer side of the inner vibration isolator 8C is formed so that a gap is formed between the outer peripheral surface h4 of the inner vibration isolator 8C and the inner peripheral surface h1 of the connection hole H of the connection cylinder 1B (see FIG. 2A). The diameter is set.
In each of the vibration isolators 8A, 8B, 8C as described above, a through hole through which the connecting rod 6 passes is formed at the axial position. As described above, by introducing not only rubber but also a resin vibration isolator as the structure of the vibration isolating bush B, the following effects are obtained.

  That is, when the vibration isolating bush B is composed of only rubber, if the vibration absorbing property is prioritized and the vibration isolating bush is configured with high flexibility, the steering stability is lowered, while the steering stability is too important. As described above, the resin-made inner vibration isolator 8C is configured to be sandwiched between the first outer vibration isolator 8A and the second outer vibration isolator 8B made of a rubber-like elastic body. The steering stability is maintained by the resin-made inner vibration isolator 8C while the flexibility is exhibited by the first outer vibration isolator 8A and the second outer vibration isolator 8B.

Next, an engagement mechanism C between the inner vibration isolator 8C and the second outer vibration isolator 8B will be described.
[Structure of engagement mechanism C]
As shown in FIG. 4 (a), an annular recess 8a having an arc-shaped cross section is formed on the outer peripheral surface of one end of the inner vibration isolator 8C facing the second outer vibration isolator 8B, and the shaft of the annular recess 8a is formed. On the outer side in the direction, a first annular convex portion 8b having an arcuate cross section projecting radially outward is formed, and the annular recessed portion 8a and the first annular convex portion 8b are smoothly connected.

On the other hand, in the portion of the second outer vibration isolator 8B facing the inner vibration isolator 8C, as shown in FIG. 4 (b), a second annular convex portion having an arcuate cross section projecting radially inward. 8f is formed. The second annular convex portion 8f forms a retaining structure.

The engagement mechanism C is formed as described above, and when the inner vibration isolator 8C and the second outer vibration isolator 8B are relatively moved in the axial direction during assembly, the second outer vibration isolator 8B The second annular convex portion 8f gets over the first annular convex portion 8b having an arc-shaped cross section of the inner vibration isolator 8C and enters the annular recessed portion 8a so that the second annular convex portion 8f engages with the annular recessed portion 8a. . Therefore, the inner vibration isolator 8C and the second outer vibration isolator 8B are not peeled off compared to the case where the adhesive is used to connect, and the core misalignment or the like does not occur.

  The anti-vibration bush B has the following configuration. That is, the outer diameters of the first outer vibration isolator 8A and the second outer vibration isolator 8B are set to the same diameter, and the outer diameter of the inner vibration isolator 8C is set to the first outer vibration isolator 8A and the second outer vibration isolator 8C. The vibration isolator 8A, 8B is set to a smaller diameter than the outer diameter. Further, as described above (see FIG. 2 (a)), the inner anti-vibration is formed so that a gap is formed between the outer peripheral surface h4 of the inner vibration isolator 8C and the inner peripheral surface h1 of the connecting hole H of the connecting cylinder 1B. The outer diameter of the vibrator 8C is set.

With such a configuration, the first outer vibration isolator 8A and the second outer vibration isolator 8B located at both ends come into contact with the inner peripheral surface h1 of the connection hole H of the connection cylinder 1B to support the connection cylinder 1B. become. On the other hand, the inner vibration isolator 8C is not in contact with the connecting cylinder 1B in the assembled state. Thus, at the initial stage of load input, only the vibration isolator portions made of rubber elastic bodies on both sides support the connecting cylinder 1B, and when the load increases, the resin inner vibration isolator 8C also exhibits a support function. To do.
That is, at the initial stage of input of the load, the support function by the first outer vibration isolator 8A and the second outer vibration isolator 8B can be exhibited, and when the load increases, the resin inner vibration isolator 8C is also supported. The function is exerted, and the spring constant as the vibration-proof bushing B is increased, so that the stability of the vehicle body is good and the steering stability can be ensured.

In order to assemble the anti-vibration bush B having the above configuration, the following steps are taken.
(1) The connecting rod 6 is attached and fixed to the holding member 5.
(2) Insert the washer 7A into the connecting rod 6.
(3) The first outer vibration isolator 8A is externally fitted to the vibration isolating bush connecting portion 6C of the connecting rod 6.
(4) The connecting cylinder 1B of the lateral rod 1 is externally fitted to the first outer vibration isolator 8A.
(5) A combined body of the inner vibration isolator 8C and the second outer vibration isolator 8B is externally fitted to the vibration isolating bush connecting portion 6C and inserted into the connecting cylinder 1B.
(6) The washer 7B is inserted, and the nut 6E is screwed into the male screw portion 6D to complete the connecting operation.

[Another embodiment]
(1) The engagement mechanism C may be as follows. That is, as shown in FIGS. 5 (a) and 5 (b), an annular engagement edge 8h having an arcuate cross section is formed on the surface of the inner vibration isolator 8C facing the second outer vibration isolator 8B. .
On the other hand, on the side surface of the second outer vibration isolator 8B facing the inner vibration isolator 8C, an annular engaging recess 8j having an arc cross section is formed. By engaging the annular engagement edge 8h with the annular engagement recess 8j, the inner vibration isolator 8C and the second outer vibration isolator 8B can be connected and fixed. The annular engagement edge 8h and the annular engagement recess 8j constitute an engagement mechanism C.

(2) The engagement mechanism C may be as follows. As shown in FIG. 6, the inner vibration isolator 8 </ b> C is divided into two at the axial center position to provide two inner vibration isolator 8 </ b> C, and each inner vibration isolator 8 </ b> C is a first outer vibration isolator. By connecting to 8A and the second outer vibration isolator 8B via the engagement mechanism C, two parts are formed. As a result, the two parts fitted into the connecting cylinder 1B of the lateral rod 1 are the first outer vibration isolator 8A and the inner vibration isolator 8C, and the second outer vibration isolator 8B and the inner vibration isolator 8C. It becomes two parts.

(3) Although the form used as the anti-vibration bush B of the lateral rod 1 was demonstrated in the above embodiment, you may use as the anti-vibration bush B of another suspension member.

Perspective view showing a 3-link suspension (A) is a longitudinal side view showing a state before the lateral rod is attached to the connecting rod, and (B) is a longitudinal side view showing a state where the connecting hole of the lateral rod is attached to the connecting rod. Exploded side view showing anti-vibration bush FIG. 2 shows a vibration isolating bush, wherein (A) is a vertical side view showing a first annular convex portion provided on the inner vibration isolator, and (B) a vertical side view showing a second annular convex portion provided on a second outer vibration isolator. Fig. 4 shows another embodiment of the vibration isolating bush, wherein (a) is a vertical side view showing an engagement edge provided on the inner vibration isolator, and (b) is a vertical side view showing an engagement recess provided on the second outer vibration isolator. Figure Longitudinal side view showing another embodiment of the anti-vibration bush Vertical side view showing a conventional anti-vibration bush

Explanation of symbols

1 Lateral rod (connecting member)
1A Rod body 1B Connecting cylinder (connecting part)
2 Trailing arm 3 Bracket 4 Axle case (axle)
5 Holding member (car body)
6 connecting rod 6A rod base end portion 6B intermediate flange portion 6C anti-vibration bush connecting portion 6D male screw portion 7A, 7B washer 8A first outer anti-vibration body 8B second outer anti-vibration body 8C inner anti-vibration body 8a annular recess 8b First annular projection (engagement mechanism)
8f 2nd annular convex part (engagement mechanism)
8h Engagement edge (engagement mechanism)
8j Engaging recess (engaging mechanism)
A Three-link suspension B Anti-vibration bush C Engaging mechanism H Connection hole h1 Inner peripheral surface h4 of the connection hole Outer peripheral surface J of the inner vibration isolator J Axial direction P Horizontal axis t1 One end t2 in the axial direction of the connection hole The other end W of the hole Rear wheel

Claims (3)

An anti-vibration bush mounted in a connecting hole of a connecting portion in a connecting member installed between a vehicle body and an axle,
A first outer vibration isolator made of a rubber-like elastic body fitted into one end of the connecting hole in the axial direction;
A second outer vibration isolator made of a rubber-like elastic body fitted inside the other end of the connection hole;
A resin inner vibration isolator positioned between the first outer vibration isolator and the second outer vibration isolator,
The inner peripheral surface shape of the connection hole is formed in a curved shape having a smaller diameter toward the axial center in the longitudinal section, and the outer peripheral surface shape of the first outer vibration isolator and the second outer vibration isolator, Formed along the inner peripheral surface shape of the connecting hole in the longitudinal section,
An anti-vibration bush in which one of the first outer anti-vibration member and the second outer anti-vibration member is connected to the inner anti-vibration member via an engagement mechanism.   The anti-vibration device according to claim 1, wherein an outer diameter of the inner anti-vibration member is set so that a gap is formed between an outer peripheral surface of the inner anti-vibration member and an inner peripheral surface of the connecting hole of the connecting portion. bush. The vibration isolating bush according to claim 1 or 2, wherein the connecting member is a lateral rod.

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