JPH05294248A - Power steering - Google Patents

Abstract

PURPOSE:To prevent the generation of noise by forming a pair of elongated holes at a front and a rear parts in the axial direction of a pinion shaft, and providing cushioning material at the whole periphery of the elongated hole so as to ease a shock with this cushioning material even when a bearing moves in the elongated hole and collides with the end part. CONSTITUTION:A pinion shaft 5 is inserted into a gear box 1, and a pair of elongated holes 8, 9 are formed in the gear box 1, at the front and rear parts in the axial direction of the pinion shaft 5. A bearing 7 is integrated into the elongated holes 8, 9. The bearing 7 is movable in the major axis direction of the elongated holes 8, 9, and when the pinion shaft 5 is oscillated in the elongated holes 8, 9, a braking valve is switched to put a power cylinder in action. A groove 15 is formed at the whole periphery of the braking valve side elongated hole 9 between both elongated holes 8, 9, and cushioning material 16 is fitted into the groove 15. The bearing 7 therefore comes in contact with the elongated hole 9 side while compressing the cushioning material 16 by surface contact, so that the impact of contact is eased to prevent the generation of noise.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power steering system in which a switching valve is switched in association with the swing of a pinion shaft.

[0002]

2. Description of the Related Art In the conventional apparatus shown in FIGS. 3 to 6, a gear box 1 is connected to a valve case 2. In the gear box 1, a rack shaft 3a having a rack 3 formed therein is slidably mounted, and a pinion shaft 5 having a pinion 4 meshing with the rack 3 is provided.
The pinion shaft 5 is rotatably supported by a pair of bearings 6 and 7. A pair of elongated holes 8 and 9 are formed in the gear box 1, and the bearings 6 and 7 are inserted into the elongated holes 8 and 9. Therefore, the pinion shaft 5 is rotatably supported by the bearings 6 and 7, and can be rocked by the amount by which the bearings 6 and 7 can move in the long axis direction of the long holes 8 and 9.

Further, one end of the pinion shaft 5 is connected to the gear box 1 side via a spring pin 10. Moreover, the other end of the pinion shaft 5 penetrates the gear box 1 and projects outward. The valve case 2 is internally provided with a control valve V. The control valve V has a slidable spool 11 and the spool 11.
And a spring 12 for centering. A through hole 13 is formed in the spool 11 at right angles to its axis, and an action point portion 14a, which is the tip of the swing lever 14, is inserted into the through hole 13. In the swing lever 14, a fulcrum portion 14b opposite to the action point portion 14a is swingably attached to the valve case 2, and the action point portion 14a is provided.
An annular force point portion 14c is formed in an intermediate portion between the fulcrum portion 14b and the fulcrum portion 14b, and the pinion shaft 5 is passed through the annular force point portion 14c.

Now, if a handle (not shown) is rotated, the pinion shaft 5 also rotates accordingly. Then, even if the pinion 4 rotates together with the pinion shaft 5, the ground resistance on the wheel side is large, so that the rack shaft 3a does not move. Therefore, the pinion 4 rolls on the rack 3, and the pinion shaft 5 moves the bearings 6 and 7 in the long axis directions of the long holes 8 and 9 and swings.
When the pinion shaft 5 swings, the lever 14 also swings accordingly. Therefore, the spool 11 of the control valve V
Also moves to switch the control valve V in a predetermined direction. When the control valve V is switched in this way, the oil discharged from the pump (not shown) is supplied to the power cylinder, so that the power cylinder (not shown) operates to exert the desired assist force.

[0005]

In the conventional device as described above, when the bearings 6 and 7 move in the elongated holes 8 and 9 and collide with the ends in the axial direction, abnormal noise is generated. . In particular,
When the control shaft V is switched and hydraulic pressure is generated, the bearings 6 and 7 have the ends of the long holes 8 and 9 in the long axis direction because the external force is applied to the rack shaft 3a, such as when traveling on a jagged road or a wasteland. They often collide with other parts and generate abnormal noise. Of course, even during normal operation, at full stroke,
This abnormal noise is generated. The abnormal noise generated in this way is
There was the problem of giving the driver anxiety that could lead to a breakdown. An object of the present invention is to provide a device that does not generate abnormal noise even when the bearing and both ends of the long hole collide with each other.

[0006]

According to the present invention, a pinion shaft having a pinion that engages with a rack is inserted into a gear box, and a pair of long holes are formed in the gear box in the axial front and rear direction of the pinion shaft. Then, the bearing of the pinion shaft is installed in this long hole, the pinion shaft is rotatably supported by this bearing, and this bearing is movable in the long axis direction of the long hole. It is premised on a power steering device configured to operate a power cylinder by switching a control valve when rocking. While assuming the above device, the present invention provides a pair of elongated holes,
The feature is that a cushion material is provided on the entire circumference of at least one of the long holes.

[0007]

According to the present invention, since the cushion material is provided on the entire circumference of the elongated hole as described above, even if the bearing moves in the elongated hole and collides with the end portion thereof, the cushion material reduces the impact. Was
No abnormal noise is generated.

According to the apparatus of the present invention, no abnormal noise is generated even if the bearing and the end of the long hole collide with each other. Therefore, the driver may feel uncomfortable due to the abnormal noise. lost.

[0008]

1 and 2 show an embodiment of the present invention. Here, of the pair of long holes 8 and 9, a groove 15 is formed on the entire circumference of the long hole 9 on the control valve V side, and a cushion material 16 such as rubber is fitted and fixed in the groove 15. Other configurations are the same as the above-mentioned conventional example. Since the cushion material 16 is fitted in this way, the bearing 7 contacts the elongated hole 9 side while compressing the cushion material 16 in a surface contact state. Therefore, when they come into contact with each other, the cushioning material 16 cushions them, so that abnormal noise does not occur. Since no abnormal noise is generated in this way, the driver does not feel uncomfortable.

[Brief description of drawings]

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

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a conventional cross-sectional view.

FIG. 4 is a sectional view of a conventional control valve portion.

5 is a sectional view taken along line VV of FIG.

6 is a sectional view taken along line VI-VI of FIG.

[Explanation of symbols]

 1 Gear Box 3 Rack 4 Pinion 5 Pinion Shaft 6 Bearing 7 Bearing 8 Long Hole 9 Long Hole V Control Valve 16 Cushion Material

Claims (1)

[Claims] 1. A pinion shaft having a pinion that engages with a rack is inserted into a gear box, and a pair of long holes are formed in the gear box in the axial front and rear direction of the pinion shaft. When the pinion shaft oscillates in the long hole together with this bearing, the pinion shaft is rotatably supported by this bearing, and this bearing is movable in the long axis direction of the long hole. A power steering device configured to switch and operate a power cylinder, wherein a cushion material is provided on the entire circumference of at least one of the pair of long holes.