JPH0692243A - Rack bar support device - Google Patents

Abstract

PURPOSE:To prevent a rack guide from abutting against a cap by constitution in which a spacer is provided between a spring and a rack guide and a clearance is formed between the projection of the spacer and a cap to regulate the axial movement of the rack guide and prevent the clearance from being changed by the inclination of the rack guide. CONSTITUTION:Rack guides 21A, 21B are incorporated slidably in a cylindrical part 11a formed in a housing 11. Both rack guides 21A, 21B are provided in the rear recesses with spacer 22 and a spring 23 for energizing the spacer 22. A clearance A is formed between a projection 22a formed in the axial part of the spacer 22 and a cap 24 to regulate the axial movement of the rack guides 21A, 21B. Thus, even if the rack guides 21A, 21B are inclined even for a time in the cylindrical part 11a, the clearance A is hardly changed and the rack guides 21A, 21B do not abut against the cap 24 even if the clearance A is set small.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art As one of rack bar supporting devices, for example, as disclosed in Japanese Utility Model Laid-Open No. 61-176064, a rack guide is slidably mounted in a cylindrical portion formed in a housing. The amount of axial movement of the rack is defined by a cap that is screwed into the cylindrical portion so as to be able to move forward and backward, and the rack guide is pressed toward the rack bar by a spring interposed between the rack guide and the cap, and the rack Some bars are slidably supported in the rack axis direction.

[0003]

In the rack bar supporting device proposed in the above publication, the cap for supporting one end of the spring defines the axial movement amount of the rack guide. Although there is an advantage that it is simple and can be implemented at low cost, the axial clearance formed between the outer peripheral end of the rack guide and the cap (after tightening the cap to zero to loosen the cap, loosen the cap a predetermined amount The amount of movement of the rack guide in the axial direction is regulated by (returning the rack guide). Therefore, when the rack guide tilts due to the sliding gap in the cylindrical portion of the housing, the clearance changes greatly, which is unexpected. In this state, the rack guide may come into contact with the cap and generate abnormal noise. In addition,
Although such a problem can be solved by setting the clearance to a large value, when the clearance is set to a large value, new problems such as abnormal noise and deterioration of steering feeling occur. The present invention has been made to address the above problems,
It is an object of the present invention to provide a rack bar supporting device having a simple structure in which the clearance that defines the amount of movement of the rack guide in the axial direction hardly changes even when the rack guide tilts.

[0004]

In order to achieve the above-mentioned object, in the present invention, the axial movement amount of a rack guide assembled slidably in an axial direction in a cylindrical portion formed in a housing is set to the cylindrical portion. It is defined by a cap that is screwed into the rack so that it can move forward and backward, and a spring interposed between the rack guide and the cap pushes the rack guide toward the rack bar and slides the rack bar in the rack axial direction. In a rack bar supporting device that is supported so that it can be supported, it is formed between a spacer that is coaxially interposed between the spring and the rack guide or a projection formed at the axial center of the rack guide itself and the cap. Axial clearance, or axial clearance formed between the protrusion formed on the axial center of the cap itself and the rack guide Axial movement amount of the serial rack guide has to be defined.

[0005]

In the rack bar supporting apparatus according to the present invention, the spacer is coaxially interposed between the spring and the rack guide, or is formed between the cap formed on the shaft center of the rack guide itself and the cap. Since the axial movement of the rack guide is regulated by the axial clearance or the axial clearance formed between the rack guide and the projection formed on the axial center of the cap itself, the axial movement of the rack guide is regulated within the cylindrical portion of the housing. Even if the rack guide tilts due to the sliding clearance, the clearance hardly changes, and even if the clearance is set to a small value, the rack guide does not come into contact with the cap in an unexpected state. Also,
In the rack bar supporting device according to the present invention, since the basic configuration is the same as the conventional configuration, the configuration is simple,
It can be implemented at low cost.

[0006]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a vehicle rack and pinion type steering device which adopts a rack bar supporting device according to the present invention. In this steering device, a steering device is rotatably assembled to a housing 11 via bearings 12 and 13. Torsion bar 1 on shaft 14
Pinion 16a of the pinion shaft 16 connected via 5
A rack 17a formed on one side of the rack bar 17 is meshed with. The rack bar 17 is attached to the housing 11 so as to be slidable in the rack axial direction (vertical direction in the plane of FIG. 1), and the rack bar supporting device 20 is used to mount the pinion 16 a.
It is supported slidably in the rack axis direction while being pressed toward.

The rack bar support device 20 has a rack guide 21A, which is slidably mounted in the axial direction (left and right direction in the drawing) in a cylindrical portion 11a formed in the housing 11 in such a manner that the rack bar support device 20 is divided into two in the axial direction. 21B and both rack guides 2
A spring 23 that is coaxially arranged with a spacer 22 having a convex spherical surface facing the rack guides in the back recesses of 1A and 21B, and biases the rack guides 21A and 21B toward the rack bar 17, and a housing. Cap 24 with hexagonal hole screwed to the cylindrical portion 11a of 11 so as to be able to advance and retreat
And a nut 25 that locks the rotation of the cap 24. Both rack guides 21A, 2
The shape of the rear recess in 1B is a concave conical surface,
Each rack guide 21A, 21B is generated by the radial component force of the force applied from the spacer 22 to both rack guides 21A, 21B.
Is pushed open to come into pressure contact with the cylindrical portion 11a.

By the way, in the rack bar supporting apparatus 20 of the present embodiment, the axial clearance A formed between the projection 22a formed on the axial center portion of the spacer 22 and the cap 24 (the cap 24 is fully filled as in the conventional case). Is formed by loosening and returning the cap 24 by a predetermined amount after tightening it to zero to eliminate the clearance A) from the axial clearance B formed between the outer peripheral ends of the rack guides 21A and 21B and the cap 24. Since the axial movement amount of the rack guides 21A and 21B is regulated by the clearance A so that the rack guide 2 has a small value, the rack guide 2 is formed in the cylindrical portion 11a of the housing 11 due to the sliding gap.
Even if the 1A and 21B are tilted, the clearance A hardly changes, and even if the clearance A is set to a small value, the rack guides 21A and 21B are capped by the cap 24 in an unexpected state.
Never touches. Further, in the rack bar supporting device 20 of the present embodiment, the basic structure is the same as the conventional structure, so that the structure is simple and can be implemented at low cost. In order to prevent the rack guides 21A and 21B from tilting, it is effective to lengthen the rack guides 21A and 21B in the axial direction. Therefore, it is desirable to set the clearance B to a small value.

In the above embodiment, the two divided rack guides 21A and 21B are used as the rack guide and the spacer 22 is used. However, as shown in FIG. 2, the rack guide 121 is a single member as the rack guide.
And the projection 121a is formed on the axial center of the rack guide 121 itself, and the projection 121a and the cap 24
The present invention is carried out such that the axial movement amount of the rack guide 121 is defined by the axial clearance A formed therebetween, or, as shown in FIG. 3, the axial center of the cap 124 itself. It is also possible to carry out the present invention such that the axial movement amount of the rack guide 221 is regulated by the axial clearance A formed between the projection 124a formed on the portion and the rack guide 221.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a rack bar supporting device according to the present invention.

FIG. 2 is a sectional view showing a modified example of the rack bar supporting device according to the present invention.

FIG. 3 is a sectional view showing another modification of the rack bar supporting device according to the present invention.

[Explanation of symbols]

11 ... Housing, 11a ... Cylindrical part, 17 ... Rack bar, 20 ... Rack bar support device, 21A, 21B ... Divided rack guide, 22 ... Spacer, 22a ... Protrusion,
23 ... Spring, 24 ... Cap, 121 ... Rack guide, 121a ... Protrusion, 124 ... Cap, 124a ...
Protrusion, A ... Clearance.

Claims (1)

[Claims] 1. An axial movement amount of a rack guide assembled slidably in an axial direction in a cylindrical portion formed in a housing is defined by a cap screwed to the cylindrical portion so as to advance and retreat, and the rack guide is also provided. A rack bar supporting device configured to press the rack guide toward a rack bar by a spring interposed between the cap and the cap so as to slidably support the rack bar in the rack axial direction. A spacer that is coaxially interposed between the guides, a projection formed on the axial center portion of the rack guide itself and an axial clearance formed between the cap, or a projection formed on the axial center portion of the cap itself. An axial movement amount of the rack guide is defined by an axial clearance formed between the rack guides. Rack bar support device.