JP2006132688A - Bush, and supporting mechanism of steering device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bush, and a supporting structure of a steering device using the same, capable of improving both of controllability and traveling stability. <P>SOLUTION: This bush comprises an inner cylinder 21 having a cylindrical portion 21a and a flange 21b radially projecting from one end of the cylindrical portion 21a, an outer cylinder 22 having a cylindrical portion 22a formed at an outer side of the cylindrical portion 21a on the same axis at a distance, and a flange 22b formed on an end portion at a side corresponding to the flange 21b of the cylindrical portion 22a, an elastic member positioned between the cylindrical portion 21a and the cylindrical portion 22a for integrally connecting the inner cylinder 21 and the outer cylinder 22, and a gouging member 24 mounted on the flange 21b and kept into contact with the flange 22b to keep a contact face in a low μ state. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a bush used for a connecting portion or the like in a support structure of a steering device for a vehicle.

In a conventional rack-and-pinion type steering device support structure, flanges are formed on the inner cylinder and the outer cylinder, respectively, as bushes used in the connecting portion that connects the housing supporting the rack and the vehicle body. A rubber member is known that is filled and bonded to the substrate (for example, see Patent Document 1). With such a structure, vibration transmitted from the road surface via the steering wheel can be prevented from being transmitted to the vehicle body, and the shaft rigidity of the bush can be increased.
Japanese Utility Model Publication No. 5-92047

However, in the above-described conventional bushing, since the rubber member is filled and bonded to the entire flange portion, the friction in the direction perpendicular to the cylinder axis (axial direction) is increased, and the rigidity in the axial direction is increased. Get higher. The bush that supports the steering rack is required to have high shaft rigidity, high twisting rigidity, low shaft rigidity, and low shaft friction in order to improve maneuverability and running stability. Therefore, when the axial rigidity of the bush is increased, the conventional bushing in which the axial rigidity and the axial friction are increased has an unsolved problem that it is impossible to improve both the maneuverability and the running stability.
Accordingly, the present invention has been made paying attention to the unsolved problems of the above-described conventional example, and an object thereof is to provide a bush capable of improving both the maneuverability and the running stability.

  In order to achieve the above object, a bush according to the present invention includes an inner cylinder having a first cylinder part and a first flange part protruding radially outward from one end of the first cylinder part, A second cylindrical portion formed on the same axial center at a distance from the outer side of the first cylindrical portion, and a second portion formed on the end of the second cylindrical portion corresponding to the first flange portion. An outer cylinder having a flange portion, an elastic member interposed between the first cylinder portion and the second cylinder portion, and integrally connecting the inner cylinder and the outer cylinder; An anti-skid member that is bonded to one of the axially opposed surfaces of the first flange portion and the second flange portion.

  According to the present invention, since the anti-adhesion member is provided on any one of the axially opposed surfaces of the flange portion of the inner cylinder and the flange portion of the outer cylinder, the axial rigidity and the rigidity of the twist can be increased. For example, the axial rigidity and axial friction can be reduced by bonding only one surface of the anti-squeeze member to the flange portion and sliding the surface opposite to the bonded surface with respect to the counterpart member. Therefore, both the steering performance and the running stability can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing a schematic configuration when the present invention is applied to a support structure for a rack-and-pinion type steering device. In FIG. 1, reference numeral 1 denotes a rack-and-pinion type steering device. The steering device 1 is a device that converts a steering torque generated by a rotation operation of the steering 2 into a displacement of the rack 3 in the left-right direction of the vehicle and transmits the displacement to the steering wheels 7.

That is, the rack 3 includes a ball joint 4 at each end, and is connected to the tie rod 5 via the ball joint 4. The tie rods 5 are connected to axles (not shown), and are configured to transmit a steering force to the steering wheels 7 that are rotatably supported by the axles.
The rack 3 is covered with a housing 8 fixed to the vehicle body, and engages with a pinion 9 connected to the steering shaft 6 inside thereof. Here, the rack 3 is formed with a tooth portion that meshes with the tooth portion of the pinion 9, and when the pinion 9 rotates together with the steering shaft 6 by the rotation operation of the steering 2, the rack 3 corresponds to the rotation angle and the rotation direction. Moves in the left-right direction of the vehicle.

The movement of the rack 3 in the left-right direction of the vehicle turns the axle in the pulling direction or the pushing direction through the tie rod 5, thereby turning the steering wheel 7 to steer the vehicle. It is configured as follows.
Further, in order to support the steering device 1 on the vehicle body, at least two through holes (attachment holes) (not shown) are formed in the housing 8, and the through holes are formed with shafts along the vertical direction of the vehicle. A cylindrical bush 20 is press-fitted. A bolt (mounting bolt) 10 inserted into the bush 20 from above the vehicle is screwed to a nut welded to the vehicle body side member. In this way, the housing 8 and the vehicle body are connected.

  2A and 2B are diagrams showing details of the bush 20, FIG. 2A is a plan view, and FIG. 2B is a cross-sectional view taken along line A-A ′ in FIG. 1. The bush 20 has an inner cylinder 21 and an outer cylinder 22. The inner cylinder 21 includes a cylindrical portion 21a made of a cylindrical metal member as a first cylindrical portion, and a flange 21b as a first flange portion extending radially outward from one end of the cylindrical portion 21a. It is configured. The outer cylinder 22 includes a cylindrical portion 22a made of a cylindrical metal member as a second cylindrical portion, and a second flange portion formed at an end of the cylindrical portion 22a on the side corresponding to the flange 21b. And the flange 22b.

Further, the outer diameter of the flange 22 b of the outer cylinder 22 is formed larger than the outer diameter of the flange 21 b of the inner cylinder 21.
An elastic member 23 made of cylindrical rubber, resin, or the like is filled between the tube portion 21a of the inner tube 21 and the tube portion 22a of the outer tube 22. The elastic member 23 is formed of the tube portion 21a. Are vulcanized and bonded to the outer peripheral surface of the tube and the inner peripheral surface of the cylindrical portion 22a. That is, the inner cylinder 21 and the outer cylinder 22 are integrally connected by the elastic member 23.

  Further, an anti-squeeze member 24 made of a member having rigidity higher than that of the elastic member 23 is bonded to the axially facing surface of the flange 21b of the inner tube 21 with the flange 22b of the outer tube 22. The opposite surface is configured to be in contact with the flange 22b of the outer cylinder 22, that is, in a non-bonded state. With this configuration, the structure is such that the anti-squeeze member 24 and the flange 22b slide, and the contact surface of the anti-squeeze member 24 with the flange 22b is in a low μ state.

  Further, as shown in FIG. 2 (a), the anti-squeeze member 24 is arranged only at a part of the outer peripheral portion of the flange 21b, and the arrangement direction thereof coincides with the input direction of the tampering force of the bush 20. ing. In this embodiment, the input direction of the twisting force of the bush 20 coincides with the vehicle front-rear direction. That is, the kink preventing member 24 is disposed at the front end portion and the rear end portion in the vehicle front-rear direction of the outer peripheral portion of the flange 21b.

By the way, the bush supporting the steering device is required to have high axial rigidity, high twisting rigidity, low axial rigidity, and low axial friction in order to improve maneuverability and running stability.
In general, the rigidity in the axial direction and the twisting direction affects the maneuverability. The higher the stiffness, the more stable the steered wheels are steered for the driver's steering, and the maneuverability becomes better. In addition, the rigidity in the direction perpendicular to the axis affects the running stability. If the rigidity is low and soft, the tendency to oversteer is suppressed and the running stability is improved.

In the bush of the present invention, high axial rigidity is provided by the elastic member 23 formed integrally with the inner cylinder 21 and the outer cylinder 22 and the anti-torsion member 24 having higher rigidity than the elastic member 23 with respect to displacement in the axial direction. Can be secured.
Further, with respect to the displacement in the prying direction, the moment preventing member 24 is disposed as far as possible from the outer peripheral portion of the flange 21b of the inner cylinder 21, that is, the cylinder axis of the bush 20, so that the moment length is increased. Therefore, high rigidity can be secured with a small area. Further, since the twist-preventing member 24 is disposed so as to coincide with the input direction of the twisting force at the outer peripheral portion of the flange 21b, it can play a role to stop the movement in the twisting direction more effectively.

  Furthermore, since the contact surface with the flange 22b of the anti-slip member 24 is in a low μ state with respect to the displacement in the axial direction, the bush 20 slips when displaced in the axial direction. Low axial rigidity and low axial friction can be realized with respect to axial rigidity and twist rigidity. Further, since the anti-squeeze member 24 is disposed only in the outer peripheral portion of the flange 21b and in the direction in which the twisting force is input, the contact area with the flange 22b is reduced, thereby further reducing the axial rigidity and the axial friction. be able to.

  As described above, in the first embodiment, the inner cylinder, the outer cylinder, the elastic member interposed between the inner cylinder and the outer cylinder, and the anti-adhesion that adheres to the flange of the inner cylinder and contacts the flange of the outer cylinder. Therefore, it is possible to arbitrarily set the shaft stiffness, the torsional stiffness, the shaft straight stiffness and the shaft straight friction by setting the rigidity and arrangement of each member, which can improve both maneuverability and running stability. it can.

Further, the anti-squeeze member has a structure in which one surface is bonded to the flange of the inner cylinder and the surface opposite to the bonding surface is in contact with the flange of the outer cylinder, so that it is in a low μ state compared to the bonded state. Therefore, when the bushing is displaced in the axial direction, a low axial friction can be realized by sliding the anti-squeeze member and the outer cylinder flange.
Further, since the anti-squeeze member is disposed only on the outer peripheral portion of the flange of the inner cylinder, the moment length can be increased to greatly increase the rigidity of the squeeze, and the contact area with the flange of the outer cylinder can be reduced. As a result, axial rigidity and axial friction can be reduced.

Further, since the rigidity of the anti-squeeze member is set higher than the rigidity of the elastic member, it can play a role to stop the movement in the axial direction and the anti-squeeze direction more effectively.
Furthermore, since the anti-squeeze member is disposed so as to coincide with the input direction of the twisting force at the outer peripheral portion of the inner cylinder flange, it can play a more effective role in stopping the movement in the twisting direction.

Next, a second embodiment of the present invention will be described.
In the second embodiment, in the first embodiment described above, the anti-squeeze member has a separate structure for the adhesive portion and the contact portion with the flange, and a low μ material is applied to the contact portion. It is.
FIG. 3 is an enlarged view of the tamper-proof member 24 in the second embodiment. The anti-squeeze member 24 includes an adhesive portion 24a with the flange 21b of the inner cylinder 21 and a contact portion 24b with the flange 22b of the outer cylinder 22.

The bonding portion 24 a is made of a material such as rubber or resin, and its rigidity is set higher than that of the elastic member 23. The contact portion 24b is made of a low μ material such as Teflon (registered trademark), and is more slidable with the flange 21b of the inner cylinder 21 which is a contact partner.
As described above, in the second embodiment, the anti-squeeze member is constituted by different members for the adhesive portion and the contact portion, and the low μ material is applied to the contact portion. Therefore, when the bush is displaced in the axial direction, A lower axial direct friction can be realized by making the anti-squeeze member and the outer cylinder flange more slippery.

In the second embodiment, the description has been given of the case where the anti-squeeze member has a separate structure for the adhesive portion and the contact portion, and the low μ material is applied to the contact portion. However, the present invention is not limited to this. Alternatively, the adhesive portion and the contact portion may be made of the same material and made of a low μ material.
In each of the above embodiments, the description has been given of the case where the anti-squeeze member is arranged in accordance with the input direction of the prying force and is arranged only in a part of the outer peripheral portion of the flange of the outer cylinder. However, when a twisting force is applied in all directions, the flange may be arranged over the entire circumference.

  Further, in each of the above embodiments, the case has been described in which the anti-squeeze member is bonded to the flange of the inner cylinder and is configured to slide in contact with the flange of the outer cylinder. However, the present invention is not limited to this. You may make it adhere | attach on any one of the axial direction opposing surfaces of a flange and the flange of an outer cylinder. That is, it is good also as a structure which adhere | attaches on the flange of an outer cylinder, contacts with the flange of an inner cylinder, and slides.

Furthermore, in each said embodiment, it is good also as a structure which adhere | attaches a kink prevention member to the flange of an outer cylinder, contacts an attachment bracket, and slides.
In each of the above embodiments, the case where the present invention is applied to the support portion of the steering apparatus has been described. However, the present invention is not limited to this, and the present invention can also be applied to a suspension connection portion or the like.

  For example, in an H-type torsion beam type suspension, the present invention can be applied to a connecting portion between a front end portion of a trailing arm and a vehicle body side member. When a lateral force is applied to this type of suspension during turning, the turning outer wheel tends to toe out, and the tendency of oversteering as a vehicle becomes strong, so that traveling stability is lowered. Therefore, it is necessary to increase the rigidity of the bush against such a lateral force. However, if the rigidity of the bush is simply increased, the input from the wheel is transmitted to the vehicle body side member, and the riding comfort deteriorates. If the bush is softened to improve the lateral force, there is a problem that the lateral force rigidity is lowered.

  Therefore, the bush of the present invention is applied to the front end portion of the trailing arm, and this bush is arranged so that the cylinder shaft extends in the vehicle width direction, so that an axial direction and a twisting direction are applied to the lateral force. The rigidity becomes high, and the toe-out tendency of the turning outer wheel can be suppressed during turning, thereby improving the running stability. Further, the rigidity of the bush in the direction perpendicular to the axis is lowered, and it is difficult for vibration from the wheels to be transmitted to the vehicle body, thereby improving riding comfort.

It is a schematic structure figure showing an embodiment of the present invention. It is a block diagram which shows the detail of a bush. It is an enlarged view of a kink prevention member in a 2nd embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steering device 2 Steering 3 Rack 4 Ball joint 5 Tie rod 6 Steering shaft 7 Steering wheel 8 Housing 9 Pinion 10 Bolt 20 Bush 21 Inner cylinder 22 Outer cylinder 23 Elastic member 24 Tightening prevention member

Claims (7)

  An inner cylinder having a first cylindrical portion and a first flange portion projecting radially outward from one end of the first cylindrical portion, and the same axial center with a distance to the outside of the first cylindrical portion An outer cylinder having a second cylinder part to be formed and a second flange part formed at an end of the second cylinder part corresponding to the first flange part; and the first cylinder An elastic member that is interposed between the first tube portion and the second tube portion and integrally connects the inner tube and the outer tube, and an axial direction of the first flange portion and the second flange portion A bush comprising an anti-squeeze member adhered to either one of the opposing surfaces.   2. The bush according to claim 1, wherein a surface of the anti-squeeze member that is opposite to a surface bonded to one of the axially opposed surfaces is in a non-bonded state with the counterpart member.   3. The bush according to claim 1, wherein the twist-preventing member is disposed on an outer peripheral portion of one of the axially opposed surfaces.   The bush according to any one of claims 1 to 3, wherein the rigidity of the kink preventing member is set higher than the rigidity of the elastic member.   The bush according to any one of claims 1 to 4, wherein the anti-squeeze member is disposed so as to coincide with or substantially coincide with an input direction of any one of the axially opposing surfaces. . A support structure for a steering device that uses a bush according to any one of claims 1 to 5 to connect a housing that supports a steering rack to a vehicle body.
The housing has a mounting hole having a shaft formed in the vertical direction of the vehicle, the bush is press-fitted into the mounting hole, and the housing is connected to the vehicle body via a mounting bolt that penetrates the inner cylinder of the bush. A support structure for a steering device.   The steering device support structure according to claim 6, wherein the anti-squeeze member is disposed at a position that coincides with or substantially coincides with any one of the axially opposed surfaces in the vehicle front-rear direction.

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