JP2002321630A - Rack and pinion steering system - Google Patents

Abstract

(57) [Problem] To provide a rack and pinion type steering device capable of suppressing generation of abnormal noise due to contact noise of a support yoke, rattling noise due to rattling between a rack and a pinion, and the like. An auxiliary member (12) is fitted in a groove (7d) of a support yoke (7) so as to be selectively protruded and retracted from an outer peripheral surface of the support yoke (7) and a recess (7a). In a state where the support yoke is mounted in the support yoke receiving hole, the auxiliary member 12 projects from the outer peripheral surface of the support yoke 7 into the gap S and abuts on the inner peripheral surface of the support yoke receiving hole 1a. The O-ring 11 is interposed in a space surrounded by the support yoke 7, the inner peripheral surface of the support yoke receiving hole 1a, and the yoke plug 9.

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 used for a vehicle such as an automobile.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view showing a main part of a conventional rack and pinion type steering device. As shown in FIG. 4, the conventional rack and pinion type steering device is provided with a pinion shaft 53 having a pinion 53a formed at a tip end thereof, which is rotatably supported by bearings 51 and 52 with respect to a housing 50, and the pinion shaft 53. And a rack shaft 54 formed with a rack 54a engaged with the pinion 53a. The pinion shaft 53 is connected to a steering wheel (handle) (not shown), and the rack shaft 54 is connected to steered wheels (not shown). The rear side of the rack 54a of the rack shaft 54 is formed in an arc shape, for example, as shown in FIG.

The housing 50 is provided with a cylindrical support yoke receiving hole 50a orthogonal to the rack shaft 54. Inside the support yoke receiving hole 50a, a support yoke 55 that supports the rack shaft 54 via a support yoke sheet 56 that is in direct sliding contact with the rack shaft 54, a back side of the support yoke 55 Yoke plug 57, and the support yoke 55 and the yoke plug 5
7 and a spring 58 arranged in a compressed state.
Is housed. The yoke plug 57 is screwed to an end of the support yoke receiving hole 50a, and
9 is fixed at a predetermined position.

The entire circumference between the outer periphery of the support yoke 55 and the inner periphery of the support yoke receiving hole 50a has a radial direction (in FIG. 4, vertical and vertical directions) to absorb the thermal expansion of the support yoke 55. ) Is provided. The support yoke 55 is held in the support yoke receiving hole 50a so as to be slidable in a small range in the axial direction (the horizontal direction in FIG. 4).
The support yoke 55 is pressed against the rack shaft 54 by a spring 58, and the rack 54a and the pinion 53
A preload is applied between the preload and a.

[0005]

However, in the conventional rack and pinion type steering apparatus, since the above-mentioned gap S is provided, for example, a load is applied to the rack shaft by operation of the steering wheel or vibration transmitted from the steered wheels. When the support yoke acts on the support yoke 55 from the support yoke 55, the support yoke 55 not only moves toward the yoke plug 57 in a direction parallel to the axial direction of the support yoke receiving hole 50a, but also attempts to move in the radial direction. For this reason, the outer periphery of the end of the rack shaft 54 of the support yoke 55 particularly hits the inner peripheral surface of the support yoke receiving hole 50a, and a contact noise may be generated. Further, the engagement of the rack 54a with the pinion 53a is deteriorated due to the outer periphery of the end portion of the support yoke 55 hitting the inner peripheral surface of the support yoke receiving hole 50a, and the play between the rack 54a and the pinion 53a is reduced. In some cases, rattling noise due to sticking was produced. As a result, in the conventional rack and pinion type steering device, there is a problem in that the contact sound and the rattle sound are transmitted to the driver as abnormal noise, and the driver feels discomfort.

Therefore, the rack shaft 5 of the support yoke 55
It is conceivable that the four-side end can be slidably engaged with the support yoke receiving hole 50a without any gap. However, in this case, it is necessary to form the support yoke 55 and the support yoke receiving hole 50a with high accuracy. This causes problems such as an increase in manufacturing cost and difficulty in assembling. In addition, since there is no gap at the end of the support yoke 55 on the rack shaft 54 side where thermal expansion is particularly likely to occur, there is a problem that the thermal expansion of the support yoke 55 cannot be absorbed. The present invention has been proposed in view of the above circumstances, and a rack and pinion type steering that can suppress generation of abnormal noise due to contact noise of a support yoke and rattling noise due to rattling between a rack and a pinion. It is intended to provide a device.

[0007]

The present invention employs the following means to achieve the above object. That is, a pinion shaft rotatably supported by the housing and having a pinion at the tip, a rack shaft provided on a side surface with a rack meshing with the pinion, and a cylindrical support yoke receiving hole formed in the housing. A support yoke which is accommodated in the support yoke receiving hole with a predetermined gap provided over the entire circumference between the support yoke receiving hole and a recess for supporting the rack shaft on the rear side of the rack; And a yoke plug that closes the support yoke receiving hole, and selectively protrudes and retracts from the outer peripheral surface and the recess of the support yoke at an end of the support yoke on the rack shaft side. The support yoke is fitted so as to protrude from the outer peripheral surface of the support yoke into the gap, and accommodates the support yoke. To the inner peripheral surface while contacting with the support yoke employs the means of an auxiliary member for supporting the rack shaft (claim 1).

[0008] In the rack and pinion type steering apparatus thus configured, the support member is brought into contact with the inner peripheral surface of the support yoke receiving hole while the support yoke is mounted in the support yoke receiving hole. The movement of the yoke in the radial direction can be restricted. Also,
Since a gap is provided between the outer circumference of the support yoke and the inner circumference of the support yoke receiving hole, it is not necessary to form these with high precision. Further, since the auxiliary member can be selectively protruded and retracted with respect to the outer peripheral surface and the concave portion of the support yoke, the work can be easily performed when the support yoke is mounted in the support yoke receiving hole. That is, by making the concave side of the auxiliary member protrude from the concave part of the support yoke,
By mounting the support yoke in the support yoke receiving hole in a state where the outer peripheral surface of the support yoke is flush with the outer peripheral surface of the auxiliary member or the outer peripheral surface of the auxiliary member is retracted from the outer peripheral surface of the support yoke, it is easily mounted. It is possible.

Preferably, the auxiliary member is made of an elastic material. In this case, the auxiliary member is elastically deformed such that the inner peripheral surface and the concave end surface of the support yoke are flush with each other in a state where the auxiliary member is pressed by the rack shaft and abuts on the inner peripheral surface of the support yoke receiving hole. It is not necessary to form this auxiliary member with high precision. It is preferable that a ring-shaped elastic member is interposed in a space surrounded by the support yoke, the support yoke receiving hole, and the yoke plug. In this case, the ring-shaped elastic member can simultaneously absorb the axial and radial vibrations of the support yoke.

[0010]

FIG. 1 is a sectional view showing a main part of an embodiment of a rack and pinion type steering apparatus according to the present invention. Hereinafter, the rack and pinion type steering device will be described with reference to the drawings. As shown in FIG. 1, a rack-and-pinion type steering device is rotatably supported on a housing 1 by bearings 2 and 3, and has a pinion 5 a formed at a tip end thereof, and a pinion shaft 5 orthogonal to the pinion shaft 5. And a rack shaft 6 formed on a side surface of a rack 6a that is supported in a direction in which the rack 6a engages with the pinion 5a. An oil seal 4 is mounted between the upper end of the housing 1 and the pinion shaft 5. A steering wheel (handle) (not shown) is connected to the other end of the pinion shaft 5. The rack shaft 6 is
The left and right steered wheels (not shown) are connected to both ends thereof, and are configured to be rotatable by the steering wheel.

The housing 1 has a cylindrical support yoke receiving hole 1a orthogonal to the rack shaft 6. Inside the support yoke receiving hole 1a, a substantially columnar support yoke 7 for supporting the rack shaft 6 on the rear surface 6b side of the rack 6a, and a yoke plug 9 attached to the housing 1 to close the support yoke receiving hole 1a. , A compression coil spring 10 disposed between the support yoke 7 and the yoke plug 9, and O as a ring-shaped elastic member.
A ring 11 is provided.

A radial gap (vertical and vertical in FIG. 1) is provided between the outer periphery of the support yoke 7 and the inner periphery of the support yoke receiving hole 1a to absorb the thermal expansion of the support yoke 7. S is provided. The support yoke 7 is held in the support yoke accommodating hole 1a so as to be slidable in a slight range in the axial direction (the horizontal direction in FIG. 1). 6 is urged.

As shown in FIG. 2A, an arc-shaped (radius of curvature r) concave portion 7a is formed on the rack shaft 6 side of the support yoke 7 so as to correspond to the shape of the rear surface 6b of the rack 6a.
Is provided. The recess 7a is provided with a sheet groove 7f in a direction perpendicular to the rack shaft 6, and both ends of the sheet groove 7f (ends of the support yoke 7 on the rack shaft 6 side) are provided with grooves 7d. ing. further,
The support yoke 7 has a notch groove 7e on the outer periphery of the end opposite to the concave portion 7a, a spring receiving hole 7b inside the notch groove 7e, and a concave portion 7a and a spring receiving hole 7b at a substantially cylindrical central portion. Are provided respectively. In the groove 7d, an auxiliary member 12 having substantially the same shape as the groove 7d is provided with an outer peripheral surface of the support yoke 7 and a recess 7a.
Are fitted so that they can selectively appear and disappear. The auxiliary member 12 is made of, for example, a metal, a resin having elasticity, rubber, or the like. The outer peripheral surface 12b is formed in a state where the inner peripheral surface 12a of the auxiliary member 12 and the end surface of the concave portion 7a of the support yoke 7 are flush. The support yoke 7 is formed so as to protrude from the outer peripheral surface into the gap S and to contact the inner peripheral surface of the support yoke receiving hole 1a.

A support yoke sheet 8 which is in sliding contact with the rack shaft 6 is mounted in the seat groove 7f. The support yoke sheet 8, for example, is obtained by further coating a fluorocarbon resin laminated plate obtained by laminating copper plate on a steel plate, it is formed in a curved shape having radius of curvature R smaller than the radius of curvature R ₁ of the rack to the back 6b ing. Thereby, the support yoke 7 is moved to the support yoke receiving hole 1a.
Before mounting on the auxiliary member 12, as shown in FIG.
The outer peripheral surface of the support yoke 7 and the outer peripheral surface 12b of the auxiliary member 12 are aligned (at this time, the concave portion 7 of the support yoke 7).
The inner peripheral portion 12c of the auxiliary member 12 protrudes from (a), and can be fitted into the groove 7d of the support yoke 7. In this state, the support yoke 7 is
When the support yoke is mounted on the support y, the support yoke sheet 8 is pressed by the rack shaft 6 so as to bend toward the concave portion 7a and press the auxiliary member 12 as shown in FIG. By being pressed in this manner, the auxiliary member 12 slides in the groove 7 d, and the outer peripheral portion 12 d projects from the outer peripheral surface of the support yoke 7 into the gap S and contacts the inner peripheral surface of the support yoke receiving hole 1 a. . At the same time, the inner peripheral surface 12a of the auxiliary member 12 is flush with the seat groove 7f on the end face of the concave portion 7a of the support yoke 7.

The support yoke sheet 8 is provided with a projection 8a.
Into the through hole 7c. As a result, the support yoke sheet 8 is integrally attached to the support yoke 7 and is fitted into the seat groove 7f, so that even when a load is applied from the rack shaft 6, the position of the support yoke sheet 8 is shifted. It is possible to maintain the state of being mounted in the concave portion 7a without occurrence. As described above, by interposing the support yoke sheet 8 between the rack shaft 6 and the support yoke 7, it is possible to reduce friction against the friction with the rack shaft 6 and improve wear resistance.

The yoke plug 9 is screwed to the open end of the support yoke receiving hole 1a so as to crush the O-ring 11 mounted on the notch groove 7e of the support yoke 7 (see FIG. 3). 14 fixed at a predetermined position. In this manner, the support yoke 7 and the support yoke receiving hole 1 are in a state where the O-ring 11 is crushed.
By being interposed in a space surrounded by the inner peripheral surface of a and the yoke plug 9, the axial and radial vibrations of the support yoke 7 can be simultaneously absorbed.

The compression coil spring 10 has one end in contact with the bottom surface of the spring receiving hole 7b of the support yoke 7 and the other end in contact with the yoke plug 9, so that the compression yoke 7 and the support yoke 7 are compressed. It is arranged between the yoke plug 9. By the urging force of the compression coil spring 10,
The support yoke 7 is pressed against the rack shaft 6 via the support yoke sheet 8, and the rack 6a and the pinion 5a
Are engaged at a predetermined pressure.

In the rack and pinion type steering device configured as described above, the outer peripheral surface 12b of the auxiliary member 12
However, the auxiliary member 12 protrudes from the outer peripheral surface of the support yoke 7 and abuts against the inner peripheral surface of the support yoke receiving hole 1a, so that the movement of the rack shaft 6 in the radial direction can be restricted by the auxiliary member 12. Thereby, especially the support yoke 7
The outer periphery of the end on the rack shaft 6 side is the support yoke receiving hole 1a.
Contact noise can be prevented from being generated, and the outer circumference of the end of the support yoke 7 on the rack shaft 6 side hits the inner circumference of the support yoke receiving hole 1a. The meshing state between the pinion 6a and the pinion 5a deteriorates, and the rattling noise caused by the rattling between the rack 6a and the pinion 5a can be suppressed.

When the auxiliary member 12 is made of an elastic material, the auxiliary member 12 is pressed by the rack shaft 6 via the support yoke sheet 8 and abuts on the inner peripheral surface of the support yoke receiving hole 1a. In this state, the inner peripheral surface 12a and the end surface of the seat groove 7f of the concave portion 7a of the support yoke 7 are elastically deformed so as to be flush, so that it is not necessary to form the auxiliary member 12 with high precision. Further, the O-ring 11 can simultaneously absorb vibration (movement) in the axial direction and the radial direction of the support yoke 7. Thereby, especially, the outer periphery of the end of the support yoke 7 on the yoke plug 9 side hits the inner peripheral surface of the support yoke receiving hole 1a, and it is possible to suppress the generation of contact noise.

Further, the auxiliary member 12 is provided with the support yoke 7.
The support yoke 7 can be selectively protruded and retracted with respect to the outer peripheral surface of the support yoke and the concave portion 7a.
The work can be easily performed when the device is mounted on the device. That is, the auxiliary member 12 is projected toward the concave portion 7a from the seat groove 7f of the concave portion 7a of the support yoke so that the outer peripheral surface of the support yoke 7 and the outer peripheral surface 12b of the auxiliary member 12 are flush with each other or the outer peripheral surface of the support yoke is smaller than the outer peripheral surface. By mounting the support yoke 7 in the support yoke receiving hole 1a while the outer peripheral surface 12b of the member 12 is retracted, the support yoke 7 can be easily mounted.

In the present embodiment, the rack shaft 6 having an arc-shaped cross section has been described, but the present invention is not limited to this. For example, a rack shaft having a Y-shaped cross section may be used. . In this case, the support yoke sheet may be formed in a Y-shape having an angle smaller than the angle of the Y-shape of the support yoke.

[0022]

As described above, in the rack and pinion type steering apparatus according to the present invention, the auxiliary member is brought into contact with the inner peripheral surface of the support yoke receiving hole while the support yoke is mounted in the support yoke receiving hole. Therefore, the movement of the support yoke in the radial direction can be restricted. Thereby, especially, the outer periphery of the end of the support yoke on the rack shaft side hits the inner peripheral surface of the support yoke receiving hole, and it is possible to suppress the occurrence of contact noise. It is possible to suppress the generation of rattling noise due to rattling between the rack and the pinion caused by hitting the inner peripheral surface of the support yoke receiving hole. Further, since a gap is provided between the outer circumference of the support yoke and the inner circumference of the support yoke receiving hole, it is not necessary to form these with high precision.

Further, since the auxiliary member can be selectively protruded and retracted with respect to the outer peripheral surface and the concave portion of the support yoke, when the support yoke is mounted in the support yoke receiving hole,
Work can be done easily. That is, with the concave side of the auxiliary member protruding from the concave part of the support yoke, the outer peripheral surface of the support yoke and the outer peripheral surface of the auxiliary member are flush or the outer peripheral surface of the auxiliary member is retracted from the outer peripheral surface of the support yoke, By mounting the support yoke in the support yoke receiving hole, the support yoke can be easily mounted.

In the case where the auxiliary member is made of an elastic material, the auxiliary member is pressed by the rack shaft and abuts on the inner peripheral surface of the support yoke receiving hole. Since the elastic member is elastically deformed so as to be flush with the end surface, it is not necessary to form the auxiliary member with high accuracy. In the case where a ring-shaped elastic member is interposed in a space surrounded by the support yoke, the support yoke receiving hole, and the yoke plug, the ring-shaped elastic member is interposed to allow the support yoke to move in the axial and radial directions. Vibration can be absorbed at the same time. Thus, it is possible to suppress the occurrence of contact noise, particularly when the outer circumference of the end of the support yoke on the yoke plug side hits the inner circumference of the support yoke receiving hole. In addition, there is also an effect of simultaneously suppressing the sound of the support yoke contacting the yoke plug and the sound generated when the yoke plug is pushed by the rack shaft in the support yoke axis direction and the engagement between the rack and the pinion deteriorates.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part showing an embodiment of a rack and pinion type steering device according to the present invention.

FIGS. 2A and 2B are views showing a support yoke portion used in an embodiment of a rack and pinion type steering device according to the present invention, wherein FIG. 2A is a perspective view thereof, and FIG. FIG. 4C is a cross-sectional view before mounting the support yoke in the support yoke receiving hole.

FIG. 3 is an enlarged sectional view of a main part showing a support yoke used in the rack and pinion type steering apparatus according to one embodiment of the present invention.

FIG. 4 is a sectional view of a main part showing a conventional rack and pinion type steering device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 1a Support yoke accommodation hole 5 Pinion shaft 5a Pinion 6 Rack shaft 6a Rack 7 Support yoke 8 Support yoke sheet 9 Yoke plug 11 O-ring (ring-shaped elastic member) 12 Auxiliary member

Claims (3)

[Claims] A first housing rotatably supported by the housing;
A pinion shaft provided with a pinion at the tip, a rack shaft provided on a side surface with a rack that meshes with the pinion, a cylindrical support yoke receiving hole formed in the housing,
A support yoke which is accommodated in the support yoke receiving hole with a predetermined gap provided between the support yoke and the inner peripheral surface thereof and is provided with a concave portion for supporting the rack shaft on the rear side of the rack; A rack and pinion type steering device having a yoke plug for closing the support yoke receiving hole, wherein the support yoke can be selectively protruded and retracted with respect to the outer peripheral surface and the concave portion of the support yoke at the rack shaft side end of the support yoke. An auxiliary member that is fitted, protrudes into the gap from the outer peripheral surface of the support yoke, and supports the rack shaft together with the support yoke in a state of being in contact with the inner peripheral surface of the support yoke receiving hole. Rack and pinion steering system. 2. A rack and pinion type steering apparatus according to claim 1, wherein said auxiliary member is made of an elastic material. 3. The rack and pinion type steering apparatus according to claim 1, wherein a ring-shaped elastic member is interposed in a space surrounded by the support yoke, the support yoke receiving hole, and the yoke plug.