JPS621011Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a rack-and-pinion type steering device. In particular, the structure is simplified by using a bearing for the rack shaft or pinion shaft arranged in the gear housing. It is an object of the present invention to provide a steering device that eliminates backlash with a pinion shaft.

In general, a rack-and-pinion type steering device has a rack shaft 2 suspended horizontally within a gear housing 1, with both ends protruding through the gear housing 1, as shown in FIGS. 1 and 2. The gear housing 1 is supported movably left and right by rack bearings 3 mounted on both ends.
The tip of a pinion shaft 4 is inserted perpendicularly to the rack shaft 2, and is rotatably supported by pinion bearings 5, 5 mounted on the upper and lower ends of the gear housing 1. A tooth surface 6 carved on the lower surface of the center of the rack shaft 2 and a gear 7 carved on the peripheral surface of the tip of the pinion shaft 4 are meshed with each other. Both ends of the rack shaft 2 are connected to tie rods (not shown) that are connected to the wheel, and the protruding end of the pinion shaft 4 is
It is connected to a steering shaft (not shown) that is connected to a steering wheel.

The rotation from the handle is transmitted to the rack shaft 2 via the pinion shaft 4, and the rack shaft 2 is moved left and right to operate the wheel. by the way,
In the steering device with the above configuration, when the steering wheel is steered, the tooth surface 6 of the rack shaft 2 and the gear 7 of the pinion shaft 4 are in sufficient meshing contact and do not cause backlash, but when driving straight ahead, ,
There was a problem in that the rack shaft 2 and pinion shaft 4 did not mesh sufficiently, causing some backlash, which caused noise due to running vibrations.

Therefore, conventionally, as shown in Fig. 3, the rack shaft 2
A spring case 8 is integrally formed with the gear housing 1 along an axis passing through the center of the rack shaft 2 in a plane orthogonal to
A pressing member 9 is slidably inserted therein, and a spring 10 compressed and interposed between the pressing member 9 and a screw rod 8a screwed into the spring case 8 is used to push the rack shaft 2 through the pressing member 9. is pressed against the pinion shaft 4, but the structure is complicated, there are many components, the cost is high, and the adjustment of the spring 10 is difficult, and backlash cannot be completely eliminated.

This invention was developed by improving and eliminating the above-mentioned problems of the conventional steering device, and using the bearing of the rack shaft or pinion shaft to displace the rack shaft or pinion shaft to prevent backlash. It is something.

Hereinafter, a case where the configuration of this invention is applied to a rack shaft bearing will be explained with reference to the drawings.

In Fig. 4, 11 is a gear housing, 12
Reference numeral 13 indicates a rack shaft which is movably inserted into the gear housing 11 in a floating manner, and 13 is a rack bearing which supports the rack shaft 12 in a predetermined arrangement relation with respect to the gear housing 11 in a slidable manner. The rack bearing 13 includes an inner cylinder 14 that is slidably fitted to the outer peripheral surface of the rack shaft 12, an outer cylinder 15 that is fitted and fixed to the inner peripheral surface of the gear housing 11, and the inner cylinder 14 and the outer cylinder. It is composed of a rubber bush 16 which is interposed between the inner cylinder 14 and the outer cylinder 15 and which is connected to the inner cylinder 14 and the outer cylinder 15 by flanges 17 and 18 formed on the inner and outer peripheral edges of both ends,
Through holes 19 and 20 are formed in a portion of the outer cylinder 15 and the rubber bush 16, respectively. On the other hand, a bolt hole 21 is formed on the peripheral surface of the end portion of the gear housing 11 on the side opposite to the pinion shaft (not shown).

Then, the through holes 19 and 20 of the outer cylinder 15 of the easy bearing 13 and the rubber bush 16 are connected to the gear housing 1.
The inner cylinder 14 is aligned with the bolt hole 21 of 1.
is fitted onto the outer peripheral surface of the rack shaft 12, and the outer cylinder 15 is fitted and fixed onto the inner peripheral surface of the gear housing 15.
The through holes 19 and 20 and the bolt hole 21 are aligned. After that, screw the bolt 22 into the bolt hole 21 of the gear housing 11 from the outside, and
Press the inner cylinder 14 of the easy bearing 13 with the tip of the
The rubber bush 16 is elastically deformed to displace the center of the inner cylinder 14 from the center of the gear housing 11 by a predetermined amount, and then the nut 23 screwed onto the bolt 22 is tightened to fix the bolt 22. The rack bearing mounted on the other end (not shown) of the gear housing 11 to support the rack shaft 12 is the same as a conventional bearing.

With the above configuration, one of the rack bearings 13 mounted on the gear housing 11 allows the rack shaft 12
The center of the inner cylinder 14 that fits into the gear housing 11
The center of the support point of the rack shaft 12, which is supported by the rack shaft 12, is displaced with respect to the center of the rack shaft 1.
2 is elastically pressed into contact with the pinion shaft side, each tooth surface is in constant contact, and backlash is eliminated. Further, the meshing state between the rack shaft and the pinion shaft can be adjusted by adjusting the amount of tightening of the bolt 22 screwed into the gear housing 11, and by appropriately setting the displacement position of the inner cylinder 14 of the rack bearing 13. Easy to adjust.

In the above explanation, the case where the present invention is applied to a rack bearing that supports a rack shaft has been explained, but the present invention is not limited to this, and the same effect can be obtained even if it is applied to a pinion bearing that supports a pinion shaft. .

As explained above, this invention is applicable to rack-and-pinion type steering devices, including an inner cylinder that is fitted onto a rack shaft or a pinion shaft and supports the shaft in a slidable and rotatable manner; It is integrally fixed to the outer peripheral surface and has a through hole in a direction perpendicular to the axis of the shaft in a part thereof, so that the shaft can be elastically displaced in the direction perpendicular to the axis within the gear housing integrally with the inner cylinder. This is because the gear housing is provided with a rubber bushing that can be supported on the shaft, and a bolt that is screwed into the gear housing so that it can move forward and backward in a direction perpendicular to the axis of the shaft, and whose tip abuts on the outer peripheral surface of the inner cylinder through the through hole of the rubber bushing. If you directly push the rack shaft or pinion shaft together with the inner cylinder with a bolt, you can obtain sufficient axis movement by the amount of push with the bolt.In this case, the bearing itself is an elastic bearing called a rubber bush with an inner cylinder, so Since this bearing does not require any special members such as springs and uses the elasticity of the bearing itself (i.e., the rubber bushing), it is structurally simple and inexpensive, and is especially easy to use with bolts. Since it can be directly forcibly displaced and maintained in this state, it does not cause resonance phenomena such as those caused by displacement with a spring even in response to running vibrations, and rationally eliminates backlash in the meshing part of the rack and pinion. Can be done.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view showing the meshing state of the rack shaft and pinion shaft of a general steering device, Fig. 2 is a cross-sectional bottom view thereof, and Fig. 3 shows a configuration for preventing backlash of a conventional steering device. FIG. 4 is a sectional view of essential parts showing the structure of the steering device according to the present invention. 1. Gear housing, 12. Rack shaft, 1
3..Rack bearing, 14..Inner cylinder, 15..Outer cylinder, 16..Rubber bushing, 22..Bolt.

Claims (1)

[Scope of utility model registration request] In a rack and pinion type steering device, it is fitted to the rack shaft or pinion shaft,
an inner cylinder that slidably and rotatably supports the shaft; and an inner cylinder that is integrally fixed to the outer peripheral surface of the inner cylinder and has a through hole in a part thereof in a direction perpendicular to the axis of the shaft; and a rubber bush which integrally supports the shaft in a gear housing so as to be elastically displaceable in a direction orthogonal to the axis; A steering device comprising: a bolt that abuts the outer circumferential surface of the inner cylinder through the through hole.