JP2005249022A - Suspension bush - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suspension bush, attaining compatibility between a longitudinal compliance of a wheel and the lateral force rigidity of the wheel. <P>SOLUTION: When the wheel gets over the uneven part of a road surface or suddenly braked so that load at the back of a car body is applied to a lower arm 12, a hollow part 30a is formed in a part of an elastic body 30 of the front suspension bush 22 that is compressed by an outer cylinder 29, whereby the spring constant of the elastic body 30 is decreased by the hollow part 30a and the longitudinal compliance is increased to heighten the riding comfortableness performance. When the inward lateral force in the width direction is applied to the revolving outer wheel increased in vertical load when a vehicle revolves, a solid part 30f is formed on a part of the elastic body 30 that is compressed by the outer cylinder, whereby the spring constant of the elastic body to the lateral force is increased to increase the lateral force rigidity and heighten the steering performance. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention includes an inner cylinder fixed to a vehicle body, an outer cylinder arranged to surround the inner cylinder and fixed to an inner end in the vehicle width direction of a suspension arm, an outer peripheral surface of the inner cylinder, and an inner peripheral surface of the outer cylinder The present invention relates to a suspension bush that includes an elastic body that buffers a load input from a suspension arm by connecting the, and a tick formed on the elastic body.

  Of the front and rear suspension bushes that elastically support the front and rear ends of the bifurcated lower arm of the suspension device, the front suspension bush includes an inner cylinder fixed to the vehicle body with a vertically extending bolt, and a lower arm Consists of an outer cylinder that is fixed by press-fitting into a mounting hole formed at the front end, and an elastic body that connects the inner cylinder and the outer cylinder, and a spring (space portion) for reducing the spring constant is formed in the elastic body. This is known from the following patent document 1.

By the way, if the front and rear ends of a bifurcated lower arm are supported by the vehicle body via suspension bushes, the vehicle's rearward overload when the wheel gets over the road surface unevenness and the vehicle's rearward braking load when the wheel is braked Acts on the outer end of the lower arm in the vehicle width direction, so that the front suspension bush tends to swing outward in the vehicle width direction with the rear suspension bush as a fulcrum. Therefore, in the above-mentioned conventional one, a pair of curls are formed on both sides in the vehicle width direction sandwiching the inner cylinder of the elastic body of the front suspension bush, and the spring in the vehicle width direction of the elastic body when the overcoming load or the braking load is applied. The ride comfort performance of the vehicle is improved by reducing the constant and increasing the front-rear compliance of the wheels.
JP 2002-337527 A

  When the vehicle turns at a high speed, lateral force inward in the vehicle width direction acts on the turning outer wheel whose ground load increases, and therefore, the load inward in the vehicle width direction is input to the suspension bush that supports the lower arm on the vehicle body. In such a case, since the elastic body of the front suspension bush described in Patent Document 1 has a pair of curls on both sides in the vehicle width direction across the inner cylinder, these curls may be crushed. There was a problem that the lateral force rigidity against the lateral force at the time of turning would be low. In other words, it has been difficult to improve both the front-rear compliance of the wheels to improve the ride comfort performance and the lateral force rigidity of the wheels at the time of turning to improve the steering performance.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a suspension bush that can achieve both front-rear compliance of the wheel and lateral force rigidity of the wheel.

  In order to achieve the above object, according to the first aspect of the present invention, the inner cylinder fixed to the vehicle body and the inner cylinder are arranged so as to surround the inner cylinder and fixed to the inner end in the vehicle width direction of the suspension arm. In a suspension bush including an outer cylinder, an elastic body that connects the outer peripheral surface of the inner cylinder and the inner peripheral surface of the outer cylinder to buffer the load input from the suspension arm, and a tick formed on the elastic body, The elastic body has a straight portion in a portion that is compressed when a load to the rear of the vehicle body is applied to the suspension arm, and a solid portion in a portion that is compressed when a lateral force from the road surface is applied during turning. A suspension bush characterized by the above is proposed.

  The lower arm 12 of the embodiment corresponds to the suspension arm of the present invention, and the first curl 30a of the embodiment corresponds to the curl of the present invention.

  According to the configuration of the first aspect, when the wheel gets over the road surface unevenness or is suddenly braked and a load to the rear of the vehicle body acts on the suspension arm, the elastic body is compressed by the outer cylinder fixed to the suspension arm. Since the curl is formed in the portion to be formed, the curling can reduce the spring constant of the elastic body, increase the front-rear compliance, and improve the riding comfort performance. In addition, when a lateral force inward in the vehicle width direction acts on the turning outer wheel whose ground load increases when the vehicle turns, a solid part is formed in a portion of the elastic body that is compressed by the outer cylinder fixed to the suspension arm. Therefore, the spring constant of the elastic body with respect to the lateral force can be increased, and the lateral force rigidity can be increased to improve the steering performance. In this way, by specifying the position of the elastic body of the suspension bush, the riding comfort performance and the steering performance of the vehicle can both be achieved.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples of the present invention shown in the accompanying drawings.

  1 and 2 show an embodiment of the present invention. FIG. 1 is a perspective view of a double wishbone suspension of a left rear wheel, and FIG. 2 is an enlarged view in the two directions of FIG.

  As shown in FIG. 1, the double wishbone suspension device S includes a knuckle 13 supported by a vehicle body by an upper arm 11 and a lower arm 12. The knuckle 13 includes a knuckle main body 14 and a lower arm support bracket 15 fastened to the lower part thereof. The knuckle body 14 includes an axle support portion 14a that rotatably supports the axle of the wheel W, and an upper arm support portion 14b that extends upward from the axle support portion 14a, and a ball joint at the upper end of the upper arm support portion 14b. 16, the outer end of the upper arm 11 in the vehicle width direction is pivotally supported. Further, the outer end in the vehicle width direction of the lower arm 12 is pivotally supported by the lower arm support bracket 15 via the ball joint 17.

  As shown in FIG. 2, the lower arm 12 is a so-called A-type arm in which a rear arm 12a and a front arm 12b are arranged in a bifurcated manner, and the rear arm 12a is supported by the vehicle body via a first suspension bush 21. The front arm 12 b is supported on the vehicle body via the second suspension bush 22.

  The first suspension bush 21 is formed by connecting the outer peripheral surface of the inner cylinder 23 and the inner peripheral surface of the outer cylinder 24 with an elastic body 25, and a bolt 26 extending in the longitudinal direction of the vehicle body is a fork-like shape of the rear arm 12 a of the lower arm 12. The support portion 12 c and the inner cylinder 23 are passed through and fastened with a nut 27. The outer cylinder 24 is fixed by press-fitting into an annular mounting hole formed in a bracket (not shown) on the vehicle body side.

  The second suspension bush 22 is formed by connecting the outer peripheral surface of the inner cylinder 28 and the inner peripheral surface of the outer cylinder 29 with an elastic body 30, and the outer cylinder 29 is press-fitted into the annular support portion 12 d of the front arm 12 b of the lower arm 12. The bolt 31 extending in the vertical direction passes through the inner cylinder 28 and is fixed to a bracket (not shown) on the vehicle body side with a nut.

  The elastic body 30 of the second suspension bush 22 is formed with a first curl 30a to a fifth curl 30e, the first curl 30a is provided alone, and the second curl 30b to the fifth curl 30e are adjacent to each other. Are provided so as to constitute a tick group.

  When the wheel W gets over the unevenness of the road surface, if a load Fr facing the rear of the vehicle body acts on the outer end in the vehicle width direction of the lower arm 12, a counterclockwise moment M is applied to the lower arm 12 with the first suspension bush 21 as a fulcrum. Therefore, a load (see arrow A) that faces the rear side of the vehicle body acts on the second suspension bush 22. The first curl 30a is disposed in a portion of the elastic body 30 of the second suspension bush 22 that is compressed by the load in the direction of arrow A, that is, a portion of the elastic body 30 on the front side inside the vehicle body, and the first curl 30a is crushed. By reducing the spring constant, the compliance in the front-rear direction of the wheel W can be increased, and the riding comfort performance can be improved.

  Also, when the wheel W is braked, the load Fr facing the rear of the vehicle body acts on the wheel W due to the frictional force generated between the road surface and the tire. Riding comfort performance can be improved by increasing the longitudinal compliance of the vehicle.

  When the height of the unevenness on the road surface and the braking force are extremely large, the load for overcoming the unevenness and the braking load change from the direction of the arrow A to the direction of the arrow A ′ that is substantially rearward of the vehicle body. At this time, since a group of scoops including the second curb 30b to the fifth curb 30e is arranged in a portion of the elastic body 30 that is pulled by the load in the arrow A 'direction, the curb group is expanded and the spring constant is increased. By lowering, the compliance in the front-rear direction of the wheel W can be further increased, and the riding comfort performance can be further improved.

  Further, when the vehicle turns right at a high speed, the vehicle body tilts to the left side, which is the outside of the turn, due to the centrifugal force caused by the turn, so the ground load on the turn outer wheel (left wheel W) increases. As a result, an inward (rightward) lateral force Fi acts on the left wheel W from the road surface, and the lateral force Fi causes the second suspension bush 22 to be directed substantially inward in the vehicle width direction (see arrow B). ) Acts. At this time, the portion compressed by the load in the direction of the arrow B in the elastic body 30 is a solid part 30f that is not straight, so the spring constant of the elastic body 30 with respect to the lateral force Fi during turning is increased, The rigidity for the lateral force Fi can be increased to improve the vehicle stability.

  As described above, paying attention to the fact that the direction of the overloading load Fr (or braking load) of the road surface unevenness acting on the second suspension bush 22 of the lower arm 12 and the direction of the turning lateral force Fi differ, The first straight 30a is formed in the vehicle width direction outer side portion compressed by the overcoming load Fr of 30, and the solid portion 30f is formed in the vehicle width direction inner portion compressed by the turning lateral force Fi. It is possible to effectively achieve both performance and steering performance.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. It is.

  For example, in the embodiment, the double wishbone type suspension apparatus S is illustrated, but the present invention can be applied to any other type of suspension apparatus.

Perspective view of left wish wheel double wishbone suspension 2 direction enlarged view of FIG.

Explanation of symbols

12 Lower arm (suspension arm)
28 Inner cylinder 29 Outer cylinder 30 Elastic body 30a First curl (straight)
30f Solid part

Claims (1)

An inner cylinder (28) fixed to the vehicle body;
An outer cylinder (29) disposed so as to surround the inner cylinder (28) and fixed to the inner end in the vehicle width direction of the suspension arm (12);
An elastic body (30) for connecting the outer peripheral surface of the inner cylinder (28) and the inner peripheral surface of the outer cylinder (29) to buffer the load input from the suspension arm (12);
Tickling (30a) formed on the elastic body (30);
Suspension bush with
The elastic body (30) has an edge (30a) at a portion compressed when a load to the rear of the vehicle body is applied to the suspension arm (12), and is compressed when a lateral force from the road surface is applied during turning. Suspension bushing characterized by having a solid part (30f) in the part to be made.

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