JPH11334609A - Rack and pinion type steering system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rack and pinion type steering system which eliminates necessity for adjustment of a rack guide clearance and retains durability of a spring receiver. SOLUTION: In this rack and pinion type steering system, an energizing force of a spring 8 urges a rack shaft 3 of a rack guide 5 that is slidably fit to the inside of a cylinder 4 formed in a housing 1, against a pinion shaft 2. A part of a spring receiving member 7 is installed on a stepped portion formed in the inner peripheral face of the cylinder 4, with a displacement to the axially outward direction being restricted. A retaining member 10 for restricting a displacement of the spring receiving member 7 in the rotational direction is press-fit into the cylinder 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rack and pinion type steering device.

[0002]

2. Description of the Related Art A rack and pinion type steering device for an automobile or the like is provided with a rack shaft connected to a steering arm of a wheel via a tie rod inside a housing, and a pinion shaft meshing with rack teeth of the rack shaft. And a pinion gear shaft which is rotated by a handle is housed.

In order to eliminate backlash between the rack teeth of the rack shaft and the pinion teeth of the pinion shaft,
The rack guide is slidably fitted in a cylinder formed in the housing, and the rack guide is urged by a spring, thereby pressing the rack shaft against the pinion shaft in an engaging direction with an appropriate pressing force.

[0004] The structure is disclosed in Japanese Patent Application Laid-Open No. 8-133101.
As disclosed in this publication, a cap is screwed into a cylinder, and by adjusting the amount of screwing of the cap, a very small clearance (generally about several hundred μ) between the rack guide and the cap is adjusted to adjust the rack shaft. A rack ring that allows the rack guide to be displaced in the axial direction when it is displaced by an external force, or a snap ring having a spring seat in an annular groove in a cylinder as disclosed in Japanese Patent Application Laid-Open No. Hei 8-505527. Are provided.

[0005]

However, in the case of the former structure, adjusting the extremely small clearance by adjusting the screwing amount of the cap requires skill and increases the number of assembling steps, resulting in an increase in cost. .
In the case of the latter structure, the adjustment as in the former case is unnecessary, but the web serving as the spring seat is a circular plate connected by a snap ring and a thin neck portion or a trifurcated plate fixed by rivets, and has durability. I'm worried. In order to eliminate this concern about durability, the plate thickness of the plate may be increased, but when the snap ring is installed in the annular groove in the cylinder, it is necessary to reduce the diameter so that the plate thickness cannot be increased so much. There is a problem.

An object of the present invention is to provide a rack and pinion type steering device which does not require adjustment of a rack guide clearance and maintains durability of a spring receiver.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a housing in which a pinion shaft and a rack shaft meshing with each other are provided in a housing, and the rack shaft is engaged with a meshing portion of both shafts by the urging force of a spring. In a rack-and-pinion type steering device in which a rack guide pressing to the side is slidably fitted in a cylinder formed in the housing, an axially outer portion is formed on a step formed on an inner peripheral surface of the cylinder. The spring receiving member is provided with a spring receiving member having a part placed on the spring receiving member while restricting its displacement in the direction of rotation, and a detent member for restricting the rotational direction displacement of the spring receiving member.

The spring receiving member has a plurality of bulging portions formed by bulging a part of the outer periphery thereof, and a step in the cylinder has an annular groove with which the bulging portion is engaged. Formed on the inner peripheral surface of the cylinder, a plurality of axial grooves communicating from the open end to the annular groove are formed at positions corresponding to the plurality of bulging portions, and the detent member is It has a substantially cylindrical shape that is inserted and fixed to a cylinder, and has a rotation restricting portion protrudingly provided on the distal end side of the insertion and positioned between the bulging portions in an assembled state and engaged with the bulging portion.

Further, the surface of the detent member opposite to the insertion tip side has a bottomed shape.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a housing. The housing 1 accommodates a pinion shaft 2 rotated by a handle and a rack shaft 3 connected to a steering arm of a wheel via a tie rod. The pinion teeth of the pinion shaft 2 and the rack teeth of the rack shaft 3 are housed. And are engaged.

Further, in order to eliminate the backlash between the pinion teeth of the pinion shaft 2 and the rack teeth of the rack shaft 3, the rack shaft 3 is inserted into a cylinder 4 formed in the housing 1 via a sliding member 6. A rack guide 5 that is in contact with the rack guide 5 is slidably fitted thereto, and is urged by a spring 8 to press the rack shaft 3 toward the pinion shaft 2 with an appropriate pressing force.

A spring receiving member 7 serving as a seat for receiving the spring 8 is detachably mounted in the cylinder 4. The spring receiving member 7 has a disk shape as shown in FIG. 4, and has a plurality of bulging portions 7 a (ear portions) formed at predetermined intervals on an outer periphery thereof to allow the inside of the cylinder 4 to breathe. Is provided with a plurality of small holes 9.

As shown in FIGS. 2 and 3, the spring receiving member 7 is mounted in the cylinder 4 on the inner peripheral surface of the cylinder 4. As shown in FIGS.
a which engages with the annular groove 11 to regulate the displacement outward in the axial direction.
(Step) and the annular groove 11 from the opening side of the cylinder 4.
And a plurality of axial grooves 12 communicating therewith. The axial groove 12 is provided on the bulging portion 7 of the spring receiving member 7.
a, and has a groove width through which the bulging portion 7a is inserted. The size of the inner diameter E at the bottom of the annular groove 11 and the outer diameter F of the bulging portion 7a of the spring receiving member 7
Are almost the same.

Further, the bulging portion 7a is formed in the annular groove 11.
Engage with each other to restrict the axial displacement of the spring receiving member 7 in the rotation direction, which is restricted by the detent member 10 (cap). As shown in FIGS. 5 and 6, the detent member 10 has a bottom 10 c and is a cylindrical body having an outer diameter slightly larger than the inner diameter of the cylinder 4. Has a structure in which a plurality of claw portions 10a are formed by notches 10a. The plurality of claw portions 10a are formed at positions corresponding to the gaps between the bulging portions 7a of the spring receiving member 7 and have substantially the same width as the width of the gaps.

Since the present invention has the structure described above, the rack guide 5 and the spring 8 are loaded in the cylinder 4. Next, the bulging portion 7a of the spring receiving member 7 is
To the axial groove 12. The spring receiving member 7 can be easily inserted by using a jig having a projection fitted into the small hole 9.

When the spring receiving member 7 inserted with the axial groove 12 as a guide reaches the annular groove 11, the bulging portion 7a rotates the spring receiving member 7 to a position where the phase is shifted from the axial groove 12 to expand. The protrusion 7a is engaged with the annular groove 11.

As a result, the spring receiving member 7 regulates the displacement of the cylinder 4 to the outside in the axial direction, presses the spring 8 to urge the rack guide 5 by the spring 8, and moves the rack shaft 3 to the pinion shaft. 2, the backlash is removed by pressing in a meshing direction with an appropriate pressing force. And
As shown in FIG. 3, a clearance D between the rack guide 5 and the spring receiving member 7 is determined by the position of the annular groove 11, and when the rack shaft 3 is displaced by an external force, the axial direction of the rack guide 5 is changed. Is allowed.

Further, the rotation stopping member 10 regulates the displacement of the spring receiving member 7 engaged with the annular groove 11 in the rotation direction. When the spring receiving member 7 is rotated to a position where the swelling portion 7a is out of phase with the axial groove 12 and the swelling portion 7a is engaged with the annular groove 11, the gap between the swelling portions 7a is shown in FIG. As shown in the figure, the state coincides with the axial groove 12. Then, the claw portion 10a of the rotation preventing member 10 is press-fitted in accordance with the axial groove 12, so that the claw portion 10a enters the gap between the bulging portions 7a and regulates the rotation of the spring receiving member 7. The detent member 10 press-fitted into the cylinder 4 has the bottom 10c thereof.
To prevent the entry of dust and the like into the cylinder 4.

In the above embodiment, the step on which the spring receiving member 7 is mounted is formed as the annular groove 11, but the inside of the cylinder 4 is formed into a small diameter section and a large diameter section from the opening side, and the step between the two sections is formed. The spring receiving member 7 may be placed on the portion.

Although the small hole 9 is provided in the spring receiving member 7, the present invention is not limited to this. A jig provided with a projection in the spring receiving member 7 and a small hole fitted in the projection is used. Alternatively, any configuration may be used as long as the spring receiving member 7 is loaded into the cylinder 4 and rotated.

Further, although the slide guide 6 is used to guide the rear surface of the rack shaft 3 by the rack guide 5, the slide guide is used. However, a rolling guide using a roller type rack guide may be used.

[0022]

As described above, according to the present invention, the clearance between the rack guide and the spring receiving member is set on the step on the inner peripheral surface of the cylinder or is engaged with the annular groove. Therefore, if the processing accuracy of the step portion or the annular groove is managed, it is not necessary to adjust the clearance which requires skill at the time of assembly. Therefore, if a plurality of types of spring receiving members having different plate thicknesses are prepared in advance, appropriate fine adjustment of the rack guide clearance can be easily performed.

Further, since the spring receiving member is not attached with a reduced diameter unlike a conventional snap ring, it is possible to obtain a sufficient thickness in consideration of durability.

Further, since the spring receiving member is firmly restricted in the axial displacement by the step portion or the annular groove, and is also restricted in the rotational direction by the detent member, there is no possibility of falling off during use. Also, the disassembling operation for maintenance or the like is easy.

In addition, the detent member is attached to the cylinder by, for example, press-fitting, but the urging force of the spring is received by a step or an annular groove via a spring receiving member. Since no force is applied, there is no risk that the detent member will fall off. If the detent member has a bottomed shape, there is an advantage that dust and the like can be prevented from entering the cylinder.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a device of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG. 1;

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a plan view of a spring receiving member.

FIG. 5 is a side view of a detent member.

FIG. 6 is a view taken in the direction of arrow C in FIG. 5;

[Description of Signs] 1 housing 2 pinion shaft 3 rack shaft 4 cylinder 5 rack guide 7 spring receiving member 7a bulging portion 8 spring 10 detent member 10a claw portion 10b notch 10c bottom 11 annular groove 12 axial groove

Claims (3)

[Claims] 1. A housing in which a pinion shaft and a rack shaft that mesh with each other are provided in a housing, and a rack guide that presses the rack shaft toward a meshing portion of both shafts by the urging force of a spring is provided in a cylinder formed in the housing. In a rack and pinion type steering device fitted slidably, a spring receiver is provided in which a portion is placed on a step formed on an inner peripheral surface of the cylinder while restricting displacement in an axially outward direction. A rack and pinion type steering device comprising: a member; and a detent member that restricts a displacement of the spring receiving member in a rotation direction. 2. The spring receiving member has a plurality of bulging portions formed by bulging a part of an outer periphery thereof, and a step in the cylinder has an annular groove with which the bulging portion is engaged. Formed on the inner peripheral surface of the cylinder, a plurality of axial grooves communicating from the open end to the annular groove are formed at positions corresponding to the plurality of bulging portions, and the detent member is A substantially cylindrical shape inserted into and fixed to the cylinder, and a rotation restricting portion which is located between the bulging portions in an assembled state and is engaged with the bulging portion in a mounted state protrudes from the insertion tip side. Item 2. A rack and pinion type steering device according to Item 1. 3. The rack and pinion type steering device according to claim 1, wherein a surface of the detent member opposite to the insertion tip side has a bottomed shape.