JPS624058Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a mounting structure for a steering gear box, and more specifically, the invention relates to a mounting structure for a steering gear box.More specifically, the invention relates to a mounting structure for a steering gear box. This relates to a mounting structure for a steering gear box which is supported under pressure by a steering gear box.

[Conventional technology]

Generally, in a rack-and-pinion type steering gear, as shown in FIG. 5, a rack (not shown) is fitted into a steering gear box 1 so as to be movable in the axial direction, and a steering pinion shaft 2 is provided with a pinion that meshes with the rack. It is arranged approximately perpendicular to the rack. The steering pinion shaft 2 is connected to a steering shaft via a joint (not shown). Further, left and right tie rods 3, 3 are connected to the rack via a ball joint (not shown). and,
The rotational movement of the steering pinion shaft 2, which is linked to the rotational operation of the steering handle, is converted into the axial movement of the rack that meshes with the pinion, and the left and right tie rods 3, 3 move the tire through the knuckle arm (not shown). It is designed to change the cutting angle. 4 is boots.

By the way, the steering gear box 1 is normally attached to a fixing member on the vehicle body side such as a cross member using brackets 5, 5 through cushioning material such as rubber, and fixing means 6, 6 such as bolts and nuts. (For example, Japanese Utility Model Application No. 55-37721).

This conventional structure will be explained below based on FIGS. 6 and 7.

The entire circumference of the steering gear box 1, which is attached to the vehicle body, is covered with a cushioning material 7 such as rubber. As shown in FIG. 6, this cushioning material 7 has a substantially semi-cylindrical cross-sectional shape, and one side (left side in FIG. 6) and bottom surface are approximately L-shaped, fixed to the cross member 8 of the vehicle body. The reinforcing member 9 is disposed so as to come into contact with the reinforcing member 9 . Further, a single bracket 5 having a substantially semicircular cross section is placed over the cushioning material 7 from above so as to cover its upper surface and the other side surface (the right side surface in FIG. 6). Parts 5a, 5b
The gearbox 1 is supported under pressure by being attached to vehicle body side fixing members such as a cross member 8 and a reinforcing member 9 using fixing means 6, 6 such as bolts and nuts, respectively.

As is clear from FIG. 7, the gearbox 1 is integrally formed with a pair of radially outwardly protruding flanges 1a, 1a spaced apart from each other in the axial direction and in contact with both ends of the buffer material 7. There is. The pair of flanges 1a, 1a prevents the cushioning material 7 from shifting in the axial direction (lateral shifting), and improves the mounting rigidity in the axial direction. In this way, with the gearbox 1 attached to the vehicle body side fixing member, the bracket 5 and the flange 1 sandwiching the cushioning material 7 are connected.
1a and 1a, the gearbox 1 is prevented from being displaced in the axial direction. Note that the racks are omitted from the cross-sectional views of FIGS. 6 and 7.

[Problem that the invention attempts to solve]

However, in the conventional steering gear box mounting structure having the above configuration, when an axial force is applied to the gear box 1 due to friction between the rack and pinion when the steering wheel is turned, this force is mainly reduced by about half. It is adapted to be handled by a circular bracket 5.

That is, the axial force acting on the gearbox 1 is transmitted to the bracket 5 via the buffer material 7 by the collar 1a. Then, a plane C-C connecting the left and right vehicle body side mounting surfaces of the bracket 5 shown in FIG.
The above axial force (lateral force) is received only on the upper side.
That is, as shown in FIG. 8, a lateral force acts on one end surface of the bracket 5 in the direction of the arrow. Therefore, the bracket 5 has left and right mounting portions 5 as shown in FIG.
A bending moment _M1 is generated in only one direction approximately centered on the axis DD connecting the centers of a and 5b (however, in FIGS. 8 and 9, the brackets are The mounting portions 5a and 5b are depicted as being located on the same plane C).

As a result, the bending moment _M1 causes the bracket 5 to tilt, causing cracks at the bases A and B of the mounting portion of the bracket 5, resulting in damage to the bracket 5.

Although it is possible to prevent damage by increasing the wall thickness of the bracket 5, it brings about a new drawback of increased weight. There is also a method of directly attaching the gearbox to the vehicle body side fixing member using bolts and nuts, etc. without using a bracket, but this is not the best method because various vibrations of the vehicle are easily transmitted to the steering wheel.

Therefore, the purpose of the present invention is to reduce the bending moment acting on the bracket.
The objective is to improve the durability of gearbox mounting brackets.

[Means for solving problems]

Therefore, the present invention employs the following configuration as a means for solving the above-mentioned problems.

That is, the present invention, in the above-mentioned steering gear box mounting structure, includes a clamp member having a substantially inverted U-shaped cross section that covers the upper surface and both side surfaces of the cushioning material, and a clamp member that is integrally provided with the clamp member and fixed thereto. and a mounting member having a substantially L-shaped cross section that is attached to the vehicle body side fixing member by a means, and both side surfaces of the clamp member are formed to extend downward from the vehicle body side mounting surface of the mounting member. Features.

Specifically, using FIG. 1 as an example,
The steering gear box 1 is supported by a bracket 10 under pressure against vehicle body side fixing members 8 and 9 via a cushioning material 7 covering its entire circumference.

The bracket 10 is fixed to the vehicle body side by a clamp member 11 having a substantially inverted U-shaped cross section that covers the upper surface and both side surfaces of the cushioning material 7, and fixing means 6, which are integrally provided with the clamp member 11. It is composed of mounting members 14 and 15 that are attached to the members 8 and 9 and have a substantially L-shaped cross section.

Furthermore, both side surfaces 12 and 13 of the clamp member 11 are formed to extend downward from the vehicle body side mounting surfaces (mounting plane C-C) of the mounting members 14 and 15.

[Effect]

According to the above-described means, when an axial force is applied to the gearbox 1, a force (lateral force) in the direction of the arrow is applied to one end surface of the bracket 10 via the buffer material 7, as shown in FIGS. 3 and 4. do.

That is, lateral force acts on the clamp member 11 of the bracket 10 not only on the upper side of the plane C connecting the mounting surfaces of the mounting members 14 and 15 on the vehicle body side, but also on both side surfaces 12 and 13 extending downward.

Therefore, the bracket 1 is approximately centered on the axis D-D connecting the centers of the left and right mounting members 14 and 15.
0, a bending moment _M1 is generated due to a lateral force acting above the mounting plane C. at the same time,
A lateral force acting below the mounting plane C generates a bending moment _M2 in the opposite direction to the bending moment _M1 .

Therefore, the bending moment M ₁ and the bending moment
M ₂ cancel each other out, the moment acting on the bracket 10 becomes smaller, and the mounting member 1
The bending stress generated at the bases A and B of parts 4 and 15 is reduced.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

1 and 2 show a mounting structure for a steering gear box according to an embodiment of the present invention. Note that in FIGS. 1 and 2, parts corresponding to those in FIGS. 6 and 7 are indicated using the same reference numerals as in FIGS. 6 and 7.

On the outer periphery of the steering gear box 1, there is a second
As shown in the figure, in the attachment area to the vehicle body, a pair of flanges 1a, 1a are integrally molded at intervals in the axial direction (separate parts may be fixed integrally), and both flanges 1a , 1a are covered with a cushioning material 7 such as rubber. As shown in FIG. 1, this cushioning material 7 has a substantially semicylindrical cross-sectional shape. The cushioning member 7 is disposed so that the lower surface thereof is in contact with the bottom surface of a recess of a reinforcing member 9 fixed to a cross member 8, which is a fixing member on the vehicle body side.

Now, the bracket 10 for clamping and supporting the gearbox 1 on the vehicle body side fixing member is composed of a clamp member 11 and left and right mounting members 14 and 15. The clamp member 11 has a substantially inverted U-shaped cross section that covers the semi-cylindrical upper surface and both planar side surfaces of the buffer material 7. left and right mounting members 14,
Each of the bolts 15 has a substantially L-shaped cross section with a bolt hole, and is integrally fixed to the clamp member 11 by welding or the like.

The fixing positions of both the mounting members 14 and 15 are not at the lower end of the clamp member 11 but at an intermediate position thereof, and are fixed at the both side surfaces 12 and 15 of the clamp member.
13 extends below the mounting surfaces of the mounting members 14 and 15 on the vehicle body side. And this fixed position is
It is desirable to select the mounting surface so that the vehicle body side mounting surface is located at a position where the cross-sectional length of each of the left and right halves of the clamp member 11 is further divided into approximately two halves. That is, the plane C-C connecting the vehicle body side mounting surfaces of the left and right mounting members 14 and 15 shown in FIG.
1 is divided into left and right halves by the central plane E, and the respective cross-sectional lengths are set at positions where the respective cross-sectional lengths are approximately equally divided into two. For this purpose, the right end of the reinforcing member 9 in the figure has a substantially L-shaped cross section, and its mounting surface is formed to protrude close to the axis of the gearbox 1.

Then, as in the conventional case, the bracket 10 is placed over the cushioning material 7 from above, and the mounting members 14 and 15 are attached to the vehicle body side fixing members such as the cross member 8 and the reinforcing member 9 using fixing means 6 and 6 such as bolts and nuts. , so as to support the gearbox 1 under pressure.

Note that racks are also omitted in FIGS. 1 and 2. Further, the height of the flanges 1a, 1a is at least as large as that of the cushioning material 7 and the clamp member 1.
The size is set such that force can be applied to the gearbox 1 in the axial direction.

In the steering gear box mounting structure configured as described above, when an axial force is applied to the gear box 1 due to friction between the rack and pinion when the steering wheel is turned, the flange 1a and the buffer material 7 are As shown in FIGS. 3 and 4, a force (lateral force) in the direction of the arrow acts on one end surface of the bracket 10 through the bracket 10. Similar to FIGS. 8 and 9, the left and right mounting members 14 and 15 are shown aligned on a unified plane C).

That is, lateral force acts on the clamp portion 11 of the bracket 10 not only on the upper side of the plane C connecting the vehicle body side mounting surfaces of the left and right mounting members 14 and 15, but also on both side surfaces 12 and 13 extending downward. .

Therefore, a lateral force (P ₁ to P in FIG. ₃ ) causes a counterclockwise bending moment _M1 . At the same time, the lateral force acting below the mounting plane C (P ₄ ~
P ₆ ) causes a clockwise bending moment M ₂ . The bending moments M ₁ and M ₂ are approximately equal in size because the cross-sectional lengths of the upper and lower clamp members 11 are approximately equal with respect to the vehicle body side mounting plane C as a boundary.

Therefore, the bending moment _M1 and the bending moment _M2 , which act in opposite directions, cancel each other out,
The bending moment acting on the bracket 10 is extremely small. As a result, the bending stress generated at the bases A and B of the mounting members 14 and 15 in the bracket 10 is reduced, and the occurrence of cracks can be prevented, so that the durability of the bracket 10 can be improved.

Furthermore, since the contact area between the cushioning material 7 and the clamp member 11 increases, it helps to prevent the cushioning material 7 from shifting laterally and from being worn out.

Furthermore, since the bracket 10 is divided into three parts, the clamping member 11 and the mounting members 14 and 15, it is possible to achieve weight reduction by setting the optimum wall thickness for each in consideration of the load stress, and also to reduce the weight by press forming. Since they can be manufactured separately, even complex shapes can be manufactured easily.

Although the present invention has been described above with reference to specific embodiments, the present invention is not limited to the above-mentioned embodiments, but includes various embodiments within the scope of the claims for utility model registration. For example, the clamp member and the mounting member of the bracket may be integrally molded.

[Effect of idea]

As described above, according to the present invention, it is possible to reduce the bending moment that acts on the bracket when an axial force acts on the gearbox.

Therefore, it is possible to reduce the bending stress acting on the base of the mounting member in the bracket and prevent the occurrence of cracks. Therefore, the durability of the bracket can be improved.

Furthermore, since the contact area between the clamp member of the bracket and the cushioning material is increased, it is possible to prevent the cushioning material from lateral displacement and wear, and it is also possible to improve the durability of the cushioning material.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of the main parts including the bracket showing the mounting structure of a steering gear box according to an embodiment of the present invention, Fig. 2 is a cross-sectional view taken along the - line of Fig. 1, and Fig. 3 is a main part of the mounting structure of the steering gear box according to an embodiment of the present invention. Fig. 4 is a schematic side view of Fig. 3, and Fig. 5 shows the entire conventional rack-and-pinion type steering gear. Schematic plan view, Fig. 6 is - of Fig. 5.
An enlarged cross-sectional view along the line, FIG. 7 is the − of FIG.
8 is a schematic perspective view for explaining a state in which a lateral force is applied to a conventional bracket, and FIG. 9 is a schematic side view of FIG. 8. Explanation of symbols, 1... Steering gear box, 1a, 1a... Flange, 6, 6... Fixing means,
7... Cushioning material, 8... Cross member (vehicle body side fixing member), 9... Reinforcement member (vehicle body side fixing member), 10
... Bracket, 11 ... Clamp member, 12,
13... Side part of the clamp member, 14, 15...
Mounting member, C-C: mounting plane of the bracket on the vehicle body side, D-D: axis connecting the center of the mounting member.

Claims (1)

[Claims for Utility Model Registration] In a mounting structure for a steering gear box in which a steering gear box is supported by a bracket under pressure against a fixed member on the vehicle body side through a cushioning material covering the entire circumference thereof, the bracket is configured to a clamp member having a generally inverted U-shape in cross section that covers the top and both side surfaces of the material, and a mounting having a roughly L-shape in cross-section that is integrally provided with the clamp member and is attached to the vehicle body side fixing member by a fixing means. A mounting structure for a steering gear box, characterized in that both side surfaces of the clamp member are formed to extend downward from a mounting surface of the mounting member on the vehicle body side.