JP2010064577A - Gear housing support structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gear housing support structure capable of reducing the working noise of an electric power actuator to be transmitted to a vehicle body via a gear housing of a vehicular steering device, and enhancing the steering stability of a vehicle. <P>SOLUTION: A gear housing 11 is installed to a vehicle body (a suspension member) via a support device having a bolt 31, a collar 33 and a rubber elastic body 36. A pair of flat parts 11a1 extending in the vertical direction and in the longitudinal direction of a vehicle and parallel to each other are formed in a fitting hole part 11a of the gear housing 11. In the circumference of the collar 33, a pair of right and left engagement projecting parts 33a passing through the rubber elastic body 36 and extending in the right-to-left direction of the vehicle, and engaged with the flat parts 11a1 of the gear housing 11 movably in the vertical direction and in the longitudinal direction of the vehicle, and non-movably in the right-to-left direction of the vehicle. A scooped portion 36a1 as a rigidity-reducing means for reducing the rigidity in the vertical direction of the vehicle is provided above and below the rubber elastic body 36. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a support structure for a gear housing in a vehicle steering device, and more particularly, to a vehicle body, a gear housing that supports a rack bar that extends in the left-right direction of the vehicle and moves to the left and right according to a handle operation so as to move in the left-right direction. The present invention also relates to a support structure for connecting and supporting.

The above-described support structure for the gear housing is described in, for example, Patent Document 1 below, and extends in the vertical direction of the vehicle and is integrally assembled with the vehicle body. A bolt that penetrates a mounting hole provided in the housing, a cylindrical collar (inner cylinder bracket) that is coaxially assembled to the outer periphery of the shaft portion of the bolt, and the bolt at both axial ends of the collar. A pair of stopper plates that are respectively assembled to the outer periphery of the shaft portion to restrict movement of the collar in the bolt axis direction, and the mounting holes of the gear housing that are provided on the outer periphery of the collar between these stopper plates A rubber elastic body fitted to the portion is provided. In Patent Document 1 having such a configuration, the shape of the rubber elastic body is devised to ensure vehicle driving stability, to realize weak under-steering performance, and to feel shock when an excessive load is input in the lateral direction of the vehicle. Is reduced.
JP 2002-160647 A

By the way, in the above-mentioned Patent Document 1, a configuration is employed in which the left and right movement of the rack bar assembled to the gear housing is assisted by a hydraulic actuator. However, in the electric power steering device described in Patent Document 2 below, A configuration is employed in which the left and right movement of the rack bar assembled to the gear housing is assisted by an electric actuator (equipped with an electric motor and a ball screw mechanism).
JP 2006-76541 A

  Like the electric power steering apparatus described in Patent Document 2 described above, the gear housing supports a rack bar that extends in the left-right direction of the vehicle and moves to the left and right in response to a handle operation so as to be movable in the left-right direction. In the configuration in which the electric actuator for assisting the left and right movement of the rack bar is housed inside, the operation sound of the electric actuator may be transmitted from the gear housing to the vehicle body via the structural member of the support structure. .

  Paying attention to such a problem, the inventor has attached the mounting hole provided in the gear housing at the shaft portion between the head portion and the leg portion, which extends in the longitudinal direction of the vehicle and is integrally assembled to the vehicle body at the leg portion. A bolt that penetrates the shaft, a cylindrical collar that is coaxially and rotatably assembled to the outer periphery of the shaft portion of the bolt, and an outer periphery of the shaft portion of the bolt at both axial ends of the collar. An annular pair of washers that are assembled to restrict movement of the collar in the bolt axis direction, and fitted between the two washers and fitted on the mounting hole of the gear housing provided on the outer periphery of the collar. Various experiments and analyzes were performed on the support structure of the gear housing having a rubber elastic body having a flange portion interposed between the joint portion, the washer, and the gear housing. And backward stiffness and lateral rigidity and vertical rigidity, to verify the relationship between the transmissibility to the vehicle body of the steering stability and the electric actuator operating noise of the vehicle.

  As a result, in the above-described gear housing support structure, if the vehicle has a high longitudinal rigidity, it is advantageous for the steering stability of the vehicle, but it is disadvantageous for the degree of transmission of the electric actuator operating sound to the vehicle body. If the vehicle's left-right rigidity is high, it is advantageous for the steering stability of the vehicle, and the influence of the electric actuator operation sound on the vehicle body is small. If the vehicle's vertical rigidity is low, the electric actuator operation sound It has been found that it is advantageous to the degree of transmission to the vehicle body and has little effect on the steering stability of the vehicle.

  The present invention has been made on the basis of the above-mentioned known matters, and supports a rack bar that extends in the left-right direction of the vehicle and moves to the left and right in response to a handle operation so as to be movable in the left-right direction. It is a support structure for connecting and supporting the gear housing that accommodates the electric actuator that assists left and right movement with respect to the vehicle body, and extends in the front-rear direction of the vehicle, and is assembled to the vehicle body integrally with the leg part A bolt that passes through a mounting hole provided in the gear housing at a shaft portion between the head portion and the leg portion, and a cylindrical collar that is coaxially and rotatably assembled to the outer periphery of the shaft portion of the bolt. An annular pair of washers that are assembled to the outer periphery of the shaft of the bolt at both ends of the collar in the axial direction to restrict the movement of the collar in the bolt axial direction, A rubber elastic body is provided between the washers on the outer periphery of the collar and fitted into the mounting hole portion of the gear housing. The mounting hole portion of the gear housing extends in the vertical direction and the front-rear direction of the vehicle. A pair of plane portions extending to be parallel to each other is formed, and the collar penetrates the rubber elastic body and extends in the left-right direction of the vehicle, and moves in the vehicle vertical direction and the front-rear direction with respect to the plane portion of the gear housing. A pair of left and right engaging protrusions are provided that engage with each other so as to be immovable in the left and right direction of the vehicle, and the rubber elastic body is provided with a low rigidity means for reducing the vertical rigidity of the vehicle. There is a feature. In this case, the low rigidity means may be a straight portion or a hollow portion provided above and below the rubber elastic body.

  In the support structure of the gear housing according to the present invention, it extends in the left-right direction of the vehicle through the rubber elastic body and is movable in the up-down direction and the front-rear direction of the vehicle with respect to the plane portion of the gear housing and moves in the left-right direction of the vehicle Since the collar is provided with a pair of left and right engaging projections that are impossiblely engaged, the collar is supported by the gear housing so as not to move in the left-right direction of the vehicle. Therefore, in the gear housing support structure according to the present invention, a part of the rubber elastic body is interposed between the collar and the gear housing in the left-right direction of the vehicle so that the collar can move in the left-right direction of the vehicle with respect to the gear housing. Compared to the support structure, the vehicle lateral rigidity of the support structure can be increased, and the control of the vehicle can be performed with less influence on the degree of transmission of the electric actuator operating sound to the vehicle body. Stability can be improved.

  In the gear housing support structure according to the present invention, the rubber elastic body is provided with a low rigidity means (for example, a straight portion or a hollow portion) for reducing the vertical rigidity of the vehicle. For this reason, the vertical rigidity of the vehicle in the support structure can be reduced compared to the support structure in which the rubber elastic body is not provided with the low-rigidity means described above, and the vehicle handling stability is improved. It is possible to reduce the degree of transmission of the electric actuator operating sound to the vehicle body while suppressing the influence. As a result, in the gear housing support structure according to the present invention, it is possible to reduce the operation noise of the electric actuator transmitted to the vehicle body via the gear housing of the vehicle steering device and to improve the steering stability of the vehicle. Is possible.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a vehicle steering device 10 and a known suspension member 20 assembled to a vehicle body (not shown). The gear housing 11 of the vehicle steering device 10 is connected and supported to the support portions a and b of the suspension member 20 by the pair of left and right attachment portions A and B via the support device 30 shown in FIG. It is configured as follows.

  The vehicle steering device 10 includes a gear housing 11 that extends in the left-right direction of the vehicle, and is supported by the gear housing 11 so as to be movable in the left-right direction of the vehicle and non-rotatable. A rack bar 13 (see FIG. 2) that moves in response to the left and right is provided, and a known electric actuator (not shown) that is housed in the gear housing 11 and assists the left and right movement of the rack bar 13 is provided.

  The rack bar 13 passes through the gear housing 11 in the left-right direction of the vehicle, and can be connected to the knuckle arm 15 (see FIG. 1) via the tie rods 14 at both left and right ends. (Not shown) is configured to be steerable. The electric actuator includes a motor (not shown) whose operation is controlled by an electric control device (not shown), and a ball that decelerates the rotation of the rotation shaft of the electric motor and converts it into an axial displacement of the rack bar 13 for transmission. A screw mechanism (not shown) is provided.

  The support device 30 shown in FIG. 2 includes a bolt 31 and a nut 32, a cylindrical collar 33, a pair of annular washers 34 and 35, and a rubber elastic body 36. The bolt 31 has a head portion 31a, a shaft portion 31b, and a leg portion 31c, and a male screw 31c1 is formed at a tip portion of the leg portion 31c. The bolt 31 extends in the front-rear direction of the vehicle, and is integrally assembled to the support portion a (b) of the suspension member 20 (vehicle body) at the leg portion 31c, between the head portion 31a and the leg portion 31c. The shaft portion 31b passes through the mounting hole portion 11a provided in the mounting portion A (B) of the gear housing 11. The nut 32 is screwed onto the male screw 31 c 1 of the bolt 31.

  The collar 33 is coaxially and rotatably assembled to the outer periphery of the shaft portion 31 b of the bolt 31. The pair of washers 34 and 35 are assembled to the outer periphery of the shaft portion 31b of the bolt 31 at both ends in the axial direction of the collar 33, and restrict the movement of the collar 33 in the bolt shaft direction. The rubber elastic body 36 is provided on the outer periphery of the collar 33 between both washers 34, 35, and is fitted with a fitting portion 36a fitted into the mounting hole portion 11a of the gear housing 11, and the washers 34, 35 and the gear. There are annular flange portions 36b, 36c interposed between the attachment portions A (B) of the housing 11.

  By the way, in this embodiment, as shown in FIG. 3, a pair of plane portions 11a1 extending in the vertical direction and the front-rear direction of the vehicle and parallel to each other are formed in the mounting hole portion 11a of the gear housing 11. Further, the outer periphery of the collar 33 excluding both front and rear end portions extends through the rubber elastic body 36 in the left-right direction of the vehicle and is movable in the vertical direction and the front-rear direction of the vehicle with respect to the flat portion 11a1 of the gear housing 11. In addition, a pair of left and right engaging protrusions 33a that are immovably engaged in the left and right direction of the vehicle (that is, in direct metal contact) are provided. Further, a straight portion 36a1 as a rigidity reducing means for reducing the rigidity in the vertical direction of the vehicle is provided above and below the portion (fitting portion 36a) excluding both front and rear end portions of the rubber elastic body 36, respectively. Yes.

  Each engagement protrusion 33a has a pair of upper and lower protrusions 33a1 and is slidably engaged (metal contact) with the flat surface part 11a1 at the tip of each protrusion 33a1. Each projection 33a1 is formed in a triangular shape with a sharp point to reduce the contact area with the flat portion 11a1, and the tip thereof has a friction such as grease to reduce the sliding resistance with the flat portion 11a1. A reducing agent is applied. For this reason, each protrusion 33a1 is easy to move in the vertical direction and the front-rear direction of the vehicle with respect to the flat portion 11a1.

  As shown in FIG. 2 and FIG. 3, each of the straight portions 36 a 1 is formed on the outer periphery of the fitting portion 36 a of the rubber elastic body 36 by forming a recessed portion having a predetermined shape to reduce the thickness of the corresponding portion. Directional rigidity has been lowered. In place of or in addition to such a configuration, the rubber hardness in the fitting portion 36a of the rubber elastic body 36 is lowered (specifically, compared with the rubber material used in other portions, It is also possible to reduce the rigidity of the vehicle in the vertical direction of the vehicle by adopting a rubber material having a low hardness for the portion. It should be noted that a hollow portion (not shown) may be employed instead of each of the straight portions 36a1.

  In this embodiment configured as described above, the rubber elastic body 36 extends in the left-right direction of the vehicle and is movable in the vertical direction and the front-rear direction of the vehicle relative to the flat portion 11a1 of the gear housing 11, and is Since the pair of left and right engaging protrusions 33 a that are immovably engaged in the direction are provided on the collar 33, the collar 33 is supported by the gear housing 11 so as to be immovable in the left and right direction of the vehicle. Therefore, in the support structure of this embodiment, a part of the rubber elastic body is interposed between the collar 33 and the gear housing 11 in the left-right direction of the vehicle, and the collar 33 extends in the left-right direction of the vehicle with respect to the gear housing 11. Compared with a support structure that can be moved, the vehicle can be provided with higher rigidity in the left-right direction with the support structure, and in a state where the influence of the electric actuator operating sound on the degree of transmission to the vehicle body is reduced. It is possible to improve the steering stability of the vehicle.

  Further, in the support structure of this embodiment, the rubber elastic body 36 is provided with a means for reducing rigidity (the straight portion 36a1) for reducing the vertical rigidity of the vehicle. For this reason, compared to the support structure in which the rubber elastic body 36 is not provided with the above-described lower rigidity means, the vertical rigidity of the vehicle in the support structure can be reduced, and the steering stability of the vehicle can be improved. It is possible to reduce the degree of transmission of the electric actuator operating sound to the vehicle body in a state where the influence of the above is suppressed. As a result, in the support structure of this embodiment, it is possible to reduce the operating noise of the electric actuator transmitted to the vehicle body via the gear housing 11 of the vehicle steering device 10 and to improve the steering stability of the vehicle. Is possible.

  In the above-described embodiment, the present invention is implemented in an embodiment in which the gear housing 11 is assembled to the vehicle body via the suspension member 20. However, the present invention is an embodiment in which the gear housing (11) is directly assembled to the vehicle body. Can also be implemented in the same manner as in the above embodiment or with appropriate modifications.

1 is an exploded perspective view of a vehicle steering device and a suspension member that can implement a gear housing support structure according to the present invention. FIG. 2 is an enlarged vertical side view of a connection support portion between a gear housing and a suspension member shown in FIG. 1. FIG. 3 is a longitudinal front view taken along line 3-3 in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Vehicle steering device, 11 ... Gear housing, 11a ... Mounting hole part, 11a1 ... A pair of plane part, 12 ... Steering wheel, 13 ... Rack bar, 20 ... Suspension member, 30 ... Supporting device, 31 ... Bolt, 31a ... head, 31b ... shaft, 31c ... leg, 32 ... nut, 33 ... collar, 33a ... pair of left and right engaging protrusions, 34, 35 ... washers, 36 ... rubber elastic body, 36a ... fitting part, 36a1 ... Turning part (lower rigidity means), 36b, 36c ... Flange part

Claims (2)

A gear housing that supports a rack bar that extends in the left-right direction of the vehicle and moves to the left and right in response to a handle operation so as to be movable in the left-right direction and accommodates an electric actuator that assists the left-right movement of the rack bar is provided in the vehicle body. It is a support structure for connecting and supporting
A bolt that extends in the front-rear direction of the vehicle and that is integrally assembled to the vehicle body at a leg portion and that passes through a mounting hole provided in the gear housing at a shaft portion between a head portion and a leg portion; A cylindrical collar that is coaxially and rotatably assembled to the outer periphery of the shaft portion, and the bolt axial direction of the collar that is assembled to the outer periphery of the shaft portion of the bolt at both axial end portions of the collar. A pair of annular washers that restrict movement of the collar, a fitting portion that is provided on the outer periphery of the collar between the washers and is fitted into the mounting hole of the gear housing, and between the washer and the gear housing A rubber elastic body having a flange portion interposed therebetween,
The mounting hole of the gear housing is formed with a pair of parallel flat portions extending in the vertical direction and the front-rear direction of the vehicle, and the collar extends in the left-right direction of the vehicle through the rubber elastic body. A pair of left and right engaging projections that are movable in the vertical and longitudinal directions of the vehicle and immovable in the horizontal direction of the vehicle are provided with respect to the flat portion of the gear housing. A gear housing support structure, characterized in that low rigidity means for reducing the vertical rigidity of the vehicle is provided.   2. The support structure for a gear housing according to claim 1, wherein the low rigidity means is a straight portion or a hollow portion provided above and below the rubber elastic body.

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