JPH07137643A - Steering gear box mounting structure - Google Patents

Abstract

(57) [Abstract] [Purpose] A mounting structure of a steering gear box for mounting a gear box in a rack-and-pinion type steering device to a subframe to which a suspension arm is assembled, and to improve mounting rigidity and steering stability. [Structure] First and second mounting portions (bolts 13 and 14) on a bracket upper portion 15 of a steering gear box 11
Intersection (C) of a first straight line I connecting the first and second attachment points A and A'in FIG. 2 and a second straight line II passing through the center position C of the steering gear box and orthogonal to the first straight line.
Through a third straight line III connecting the first connecting point B on the first connecting portion (mounting piece 1a) and the second connecting point B'on the second connecting portion (mounting piece 2a). Constitution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering gear box mounting structure, and more particularly to a steering gear for mounting a gear box in a rack and pinion type steering device to a subframe (also referred to as a suspension member) to which a suspension arm is assembled. Regarding the mounting structure of the box.

[0002]

2. Description of the Related Art Conventionally, as a mounting structure of a steering gear box, for example, one disclosed in Japanese Utility Model Laid-Open No. 2-85667 is known.

In such a mounting structure of a steering gear box, brackets are provided on both horizontal frames of a subframe which is formed into a substantially quadrilateral shape by both vertical frames and both horizontal frames so as to be positioned at the apexes of a triangle. The steering gear box is attached to the sub-frame via each bracket by rigidly connecting the attachment piece provided on the steering gear box corresponding to each bracket to each bracket with a bolt and a nut.

[0004]

However, the mounting structure of the steering gear box described above does not consider the axial force input to the steering gear box.

Therefore, when the steering gear box is fixed by bolting the mounting piece and the bracket via a rubber bush, for example, a moment for rotating the steering gear box is generated by the axial force, and the mounting rigidity and the steering stability are improved. There was a problem in that it was not preferable.

Therefore, according to the present invention, the intersection of the first straight line connecting the front and rear mounting points of the steering gear box and the second straight line passing through the center position of the steering gear box and orthogonal to the first straight line is attached to the bracket. The third straight line connecting the first connecting point and the second connecting point is configured to pass therethrough, thereby reducing the rotational moment input to the bracket by the axial force and solving the above problems. To do.

[0007]

[Means for Solving the Problems] The above problems can be solved by the following constitution.

That is, in the steering gear box mounting structure in which the steering gear box is mounted on the first and second lateral frames which are spaced apart from each other in the vehicle front-rear direction, the front and rear of the steering gear box are mounted with the elastic body interposed. A bracket to which a steering gear box is attached by at least one first and a second attachment portion, and a first bracket that is disposed on the first horizontal frame and has one end of the bracket joined thereto. The steering gear box includes a coupling portion and a second coupling portion disposed on the second lateral frame and coupled to the other end of the bracket. The steering gear box includes first and second mounting portions on the bracket. The intersection of a first straight line connecting the first and second attachment points and a second straight line that passes through the center position of the steering gear box and is orthogonal to the first straight line. And it is solved by a configuration as a third straight line connecting a first point of attachment on the first coupling part and a second coupling point on the second coupling part passes.

[0009]

The axial force acting on the steering gear box acts on the intersection of the first straight line connecting the front and rear mounting points of the steering gear box and the second straight line passing through the center position of the steering gear box and orthogonal to the first straight line. However, according to the present invention having the above-described configuration, the first connection point and the second connection point are located in front of and behind the application point of the axial force, and
A third straight line connecting the connection point of No. 2 and the second connection point acts so as to pass through the above-mentioned intersection point which is the point of application of the axial force.

[0010]

An embodiment of the present invention will now be described with reference to the drawings. 1 is a vertical sectional view showing an embodiment of the present invention, and FIG. 2 is a plan view showing an embodiment of the present invention.
FIG. 3 is a vertical sectional view taken along line I-I in FIG. 2.

In FIG. 2, with respect to the horizontal frame portions 1 and 2 in the left-right direction having a predetermined distance in the front-rear direction, the vertical frame portion 3 in the front-rear direction substantially orthogonal to the horizontal frame portions 1 and 2, and the vertical frame portion 3. And left and right with a predetermined interval, both horizontal frame parts 1
And a vertical frame portion (not shown) in the front-rear direction that is substantially orthogonal to 2 and 2 form a substantially quadrilateral subframe 4.

The sub-frame 4 is provided at two positions, namely, at the front part and the rear part of the vertical frame part 3, and at the front part and the rear part of the vertical frame part, which are not shown in the figure, for a total of four positions. , Is mounted on a vehicle body (not shown) by a mounting mechanism 5 such as a rubber bush.

A suspension arm (lower arm) 6 is supported by a base portion of the vertical frame portion 3 of the subframe 4 in a substantially central portion in the front-rear direction so as to be vertically swingable. A suspension arm (not shown) is also supported on the vertical frame portion, which is not shown in the figure.

Further, the right end of the suspension arm 6 which is not shown in the drawing is connected to the other end of the suspension arm 7 which is connected to the rear end of the vertical frame portion 3 at one end thereof which is not shown in the drawing. A strut bar (not shown) is similarly connected to the suspension arm not shown.

In the figure, 8 is an intermediate rod, 9 is a tie rod end, 10 is a steering pinion housing,
The steering gear box 11 of the rack-and-pinion type steering is attached to the subframe 4 in the left-right direction at an intermediate position between the lateral frames 1 and 2 of the subframe 4.

A steering pinion (not shown) is operated by rotating a steering wheel (not shown).
Is rotated, and the rack meshing with the steering pinion reciprocates in the steering rack housing 12 in the left-right direction. As a result, the tie rod end 9 is driven via the intermediate rod 8 and the knuckle arm (not shown) is driven to steer the front wheel.

The steering rack housing 12 of the steering gear box 11 is provided with bolts 13 and 14 (first and second mounting portions) to form a bracket 1 in the shape of a arm.
5 (see FIG. 1). The bolt 13 is interposed by a cylindrical interposition member 16, and the interposition member 1
A cylindrical bush 17 is arranged around the circumference of the bush 6.

Similarly, the bolt 14 is a cylindrical interposition member 1.
The cylindrical bush 19 is disposed around the interposing member 18. The rubber bushes 17 and 19 are arranged to absorb low-frequency vibrations such as flutter.

On the other hand, a mounting piece 1a, which is a first connecting portion, is provided so as to project from the rear portion of the horizontal frame 1, and a mounting piece 2a, which is a second connecting portion, projects from the front portion of the horizontal frame 2. Is provided. The front end of the bracket 15 is rigidly coupled to the mounting piece 1a by being fastened and fixed to the mounting piece 1a by a bolt 20 and a nut 21. Further, the rear end portion of the bracket 15 is attached to the mounting piece 2a by the bolt 22 and the nut 23.
It is fastened to and rigidly connected to.

Here, the attachment points of the bolts 13 on the bracket 15 are the line segment in the axial center of the bolts 13 and the bush 1.
A point A intersects with a line segment of 1/2 in the height direction 7. Further, the mounting point of the bolt 14 on the bracket 15 is 1 / in the height direction of the bush 19 and the axial center line of the bolt 14.
It is defined as a point A'that intersects the line segment of 2.

A straight line I (first straight line) connecting these mounting points A and A'passes through the central position C of the steering rack housing 12 of the steering gear box 11. In addition, the center position C is a midpoint position between the mounting point A and the mounting point A '. The straight line II orthogonal to the straight line I at the center position C is the second
Is a straight line.

On the other hand, the connecting point of the bolt 20 on the mounting piece 1a is a point B where the line segment in the axial center of the bolt 20 and the line segment in the thickness direction ½ of the mounting piece 1a intersect. The connecting point of the bolt 22 on the mounting piece 2a is a point B'where the line segment in the axial center direction of the bolt 22 and the line segment in the thickness direction 1/2 of the mounting piece 2a intersect. A straight line III (third straight line) connecting these connecting points B and B'also passes through the central position C of the steering rack housing 12 of the steering gear box 11.

By the way, the steering gear box 11
The axial force input to the steering rack housing 12
It acts on the center position C of. Therefore, the connecting point B and the connecting point B ′ are located before and after the operating point of the axial force, and the straight line III connecting the connecting point B and the connecting point B ′ passes through the operating point of the axial force.

Therefore, even if an axial force is input to the steering gear box, the rotational moment for rotating the bracket 15 is reduced. That is, the rotational moment for rotating the steering gear box 11 is reduced, sufficient mounting rigidity can be obtained, and good steering stability can be obtained.

Further, since the bracket 15 and the lateral frames 1 and 2 are rigidly connected to each other, the bracket 15 functions as a structural member of the sub-frame 4. Therefore, the rigidity of the sub-frame 4 is increased and the effect of suppressing vibration is also obtained.

Further, in the present embodiment, since the straight line I passes through the center position C of the steering rack housing 12 of the steering gear box 11, there is no deviation of the center position C from the straight line I, and the bushing. A rotation moment for rotating the steering gear box 11 with respect to 17 and 19 is not generated. Further, since the center position C is the midpoint position of the mounting points A and A'of the bolts 13 and 14, no horizontal rotation moment is generated. Therefore, the mountability is further improved, and good steering stability can be obtained.

[0027]

As described above, according to the present invention, the first connecting point and the second connecting point are located in front of and behind the operating point of the axial force, and the first connecting point and Since the third straight line connecting the second coupling points passes through the axial force application point, the rotational moments of the first and second lateral frames are reduced even if the axial force acts, so that the steering gear box rotates. Without this, sufficient mounting rigidity can be obtained and good steering stability can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a plan view showing an embodiment of the present invention.

[Explanation of symbols]

 1, 2 Horizontal frames 1a, 2a Mounting piece 4 Subframe 11 Steering gear box 12 Bracket A, A'Mounting point B, B 'Coupling point C Center position

Claims (1)

[Claims] 1. A first device, which is arranged in a vehicle front-rear direction at a distance from each other.
And a steering gear box mounting structure for mounting a steering gear box on a second horizontal frame, wherein at least one mounting portion is provided in front of and behind the steering gear box with an elastic body interposed. A bracket to which the steering gear box is attached, and a first connecting portion to which one end of the bracket is connected, and a second horizontal frame. And a second coupling part to which the other end of the bracket is coupled, the first part on the bracket of the steering gear box.
And an intersection of a first straight line connecting the first and second mounting points of the second mounting portion and a second straight line passing through the center position of the steering gear box and orthogonal to the first straight line, A steering gear box mounting structure comprising a third straight line connecting a first connecting point on the first connecting portion and a second connecting point on the second connecting portion.