JPS6040387Y2 - Power steering device - Google Patents

Description

[Detailed description of the invention] This invention relates to a rack and pinion type power steering device, and its purpose is to easily and reliably eliminate backlash between the rack and pinion. It is.

In rack-and-pinion type steering devices, in order to eliminate backlash between the rack and pinion, the rack shaft is usually pressed against the pinion shaft by a spring force via a half bearing, but such a structure In this case, proper meshing between the rack and pinion cannot be obtained.

In such a case, by using a tapered pinion and moving the pinion in the axial direction, the backlash between the rack and the pinion can be accurately removed.

However, a rack-and-pinion type power steering device is equipped with a servo valve consisting of a pair of valve members that can move relative to each other in order to control the power cylinder, and the pinion shaft is integrally attached to one valve member of the servo valve. Therefore, in order to move the pinion in the axial direction as described above, it is necessary to move the entire servo valve, resulting in a problem that the structure of the power steering device becomes complicated and large.

The present invention was developed in view of the above-mentioned problems, and a pinion shaft having tapered pinion teeth is rotatably connected to one valve member of a servo valve so as to be relatively movable in the axial direction, and the servo valve is moved. This allows only the pinion shaft to be moved in the axial direction without any backlash between the rack and pinion.

Embodiments of the present invention will be described below with reference to the drawings.

Reference numeral 10 indicates a housing forming the main body of the power steering device, and the housing 10 has two holes 11 that intersect at a predetermined angle.
．． 12 is penetrated.

One hole 11 has a rack shaft 14 with rack teeth 13.
is slidably inserted through the rack shaft 14, and both ends of the rack shaft 14 are connected to steering wheels via a required steering linkage, and a power cylinder of the enclosure is operatively connected to the rack shaft 14. .

A pinion shaft 16 having tapered pinion teeth 15 that mesh with the rack teeth 13 is housed in the other hole 12, and one end of the pinion shaft 16 is screwed into the open end of the hole 12 so that its position can be adjusted. The adjusting nut 17 is rotatably supported via a ball bearing 18, and the other end is rotatably supported on the housing 10 by a roller bearing 19 so as to be movable in the axial direction.

As a result, by rotating the adjustment nut 17, the pinion shaft 16 is moved in the axial direction, and the pinion teeth 15 and the rack teeth 1 are
The adjustment nut 17 is normally fixed to the housing 10 by a lock nut 20.

A servo valve 23 consisting of a pair of valve members 21 and 22 that are movable relative to each other is also housed in the other hole 12 on the same axis as the pinion shaft 16.

One valve member 21 of the servo valve 23 is rotatably fitted into the housing 10, and has an engaging shaft 2 chamfered on one end thereof.
4 is provided in a protruding manner, and this engagement shaft 24 is engaged with an engagement hole 25 formed in the pinion shaft 16 so as to be able to move only in the relative axial direction.

A steering shaft 26 connected to a steering handle is integrally formed on the other valve member 22 of the servo valve 23.
6 is flexibly connected to the one valve member 21 via a torsion bar 27.

As a result, when the pair of valve members 21 and 22 of the servo valve 23 are moved relative to each other by the manual steering torque applied to the steering shaft 26, the pressure oil supply port 29 connected to the pump communicates with both chambers of the power cylinder. supply/discharge port) 30.3
1, and the other supply/discharge port communicates with a discharge port 32 connected to the reservoir.

As described above, the present invention has a configuration in which the pinion shaft 16 on which the tapered pinion teeth 15 are formed is moved in the axial direction to eliminate backlash between the rack teeth 13 and the pinion teeth 15. Rack axis 1 due to processing
Even if there is an error in the pitch between the pinion shaft 16 and the rack and pinion shaft 16, this error can be easily absorbed, and proper meshing of the rack and pinion can always be ensured.

Moreover, according to the present invention, the pinion shaft 16 and the servo valve 23
The valve member 21 is divided so that only the pinion shaft 16 can be adjusted in the axial direction, and
Since the valve member 21 and the valve member 21 are rotatably connected so as to be relatively movable only in the axial direction, there is no need to move the servo valve 23 in the axial direction together with the pinion shaft 16, thereby simplifying the configuration of the power steering device. It also has the advantage of being compact and durable.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a power steering device showing an embodiment of the present invention;
FIG. 2 is a sectional view taken along the line ■--■ in FIG. 1. 10...Housing, 13...Rack teeth, 14...Rack shaft, 15...Zenion teeth, 16...Zenion shaft, 17... ...Adjusting nut, 21.22...Valve member, 23...
...servo valve.

Claims (2)

[Scope of utility model registration request] (1) A rack shaft with rack teeth operatively connected to a power cylinder is slidably provided in a housing, a servo valve consisting of a pair of valve members movable relative to each other is housed in the housing, and A pinion shaft with tapered pinion teeth meshing with the rack teeth is rotatably and axially movably supported, and this pinion shaft is rotatably connected to one valve member of the servo valve so as to be relatively movable only in the axial direction. A rack-and-pinion type power steering device, further comprising an adjustment member for adjusting the position of the pinion shaft in the axial direction. (2) The power steering device according to claim 1, wherein the adjusting member is screwed into the housing so that its position can be adjusted, and a pinion shaft is rotatably supported on the adjusting member.