JPS595654Y2 - Rack and pinion steering gear device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a rack-and-pinion type steering gear device for a steering system of a vehicle such as an automobile.

As one of the steering gear devices in a vehicle steering system, a rack of a rack bar is engaged with a pinion at the tip of a steering gear shaft in a gear box, and the rotation of the steering shaft drives the rack bar in its axial direction. A piston-like rack guide element is slidably housed in a cylinder bore formed in the gearbox on the opposite side of the rack bar from the portion that engages with the pinion. A rack and pinion type steering gear device is known in which a compression coil spring is elastically mounted between a cover element fixed to the gearbox and the rack guide element in dynamic contact with each other.

In a rack and pinion type steering gear device having such a structure, in order for the rack guide element to be always slidably maintained in the cylinder bore without causing stick, it is a matter of course that the cylinder bore and A certain amount of clearance must be provided between the rack guide elements to account for machining tolerances and to provide adequate flexibility for the support of the rack bars by the rack guide elements. A certain clearance must also be provided between the end of the guide element and the cover element.

By the way, conventionally, when a vehicle equipped with a rack-and-pinion steering gear device having such a structure is driven at low speed on a rough road or a road surface with steps, a metal-thumping sound is generated from inside the gearbox. There was a problem.

This metal striking sound is caused by the impact and direct contact between the end surface of the rack guide element and the opposing end surface of the cover element, and the sound generated by the impact between the inner circumferential surface of the cylinder bore and the outer circumferential surface of the rack guide element. This includes sounds caused by impactful direct contact.

Among these, metal striking noise caused by direct impact contact between the end face of the rack guide element and the end face of the cover element facing it can be avoided by using a buffer material such as plastic or rubber between the cover element and the rack guide element. A structure for preventing this by providing a structure is proposed in U.S. Pat. No. 52-105956 filed by the same applicant as the present applicant.

In addition, regarding metal striking noise that occurs due to impactful direct contact between the inner circumferential surface of the cylinder bore and the outer circumferential surface of the rack guide element, it is possible to prevent A structure for preventing this by providing a cushioning member such as rubber has been proposed in Japanese Patent Application No. 140211/1983 filed by the same applicant as the present applicant.

Furthermore, regarding the generation of metallic noise due to direct impact contact between the inner circumferential surface of the cylinder bore and the outer circumferential surface of the rack guide element, the rack guide element should be placed in one plane including its axis and the axis of the rack bar. The end of the rack guide element that contacts the rack bar is shaped into an arc, so that when the rack guide element is pressed toward the rack bar, the component force exerted by the arc surface acts on the rack guide element. Drive each half of the divided rack guide element in a direction away from each other and press these halves against the inner circumferential surface of the four cylinder bores so that the outer circumferential surface of the rack guide element is always in contact with the inner circumferential surface of the cylinder bore, This prevents direct impact contact between the two.
No. 6326).

In the present invention, a rack of a rack bar is engaged with a pinion at the tip of a steering shaft in a gear box, and the rack bar is driven in the axial direction by rotation of the steering shaft, and a portion of the rack bar that engages with the pinion On the opposite side, a piston-like rack guide element slidably housed in a cylinder bore formed in the gearbox is in sliding contact with one end thereof, and a cover fixed to the gearbox. In a rack-and-pinion type steering gear device in which a compression coil spring is resiliently loaded between the rack guide element and the rack guide element, noise caused by impact direct contact between the rack guide element and the cover element can be reduced. A rack equipped with an improved noise prevention structure capable of simultaneously and reliably preventing both the generation of noise and the generation of noise due to direct impact contact between the inner peripheral surface of the cylinder bore and the outer peripheral surface of the rack guide element. The purpose of the present invention is to provide an and-pinion type steering gear device.

According to the present invention, in the rack and pinion type steering gear device having the basic structure as described above, the rack guide element is arranged along one plane including the axis of the rack guide element and the axis of the rack bar. a ring element that is divided into two parts and has a V-shaped sloped part at the dividing boundary, and has a V-shaped wedge part between the rack guide element and the force bar element that corresponds to the V-shaped sloped part; This effect is achieved by interposing a cushion sheet between the V-shaped slope portion and the V-shaped wedge portion.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail by way of example with reference to the accompanying figures below.

FIG. 1 attached herewith is a sectional view showing one embodiment of a rack and pinion type steering gear device according to the present invention.

In the figure, reference numeral 1 denotes a gearbox that constitutes the housing of the steering gear device, and inside the gearbox there is a pinion 3 provided at the tip of the steering main shaft 2, and a bearing race formed at both ends of the pinion 3. Part 4, Ball 5
, is rotatably supported around its axis by a ball bearing structure supported by a bearing race ring 6 mounted in the gearbox 1.

A rack par 7, which is also supported by the gear box 1 so as to be slidable in the axial direction, is engaged with the pinion 3 at its rack teeth 8, and when the steering main shaft 2 is rotated, the rack par 7 is engaged with the pinion 3. The rack bar is adapted to be driven in the direction of its axis.

A piston-shaped rack guide element 10, slidably housed in a cylinder bore 9 formed in the gearbox on the side opposite the rack teeth 8 of the rack par 7, is provided at one arc-shaped end thereof. and are slidably engaged.

The other end of the rack guide element 10 is connected via a compression coil spring 14 interposed therebetween by a cover element 13 screwed into the threaded part 12 corresponding to the threaded part 11 formed at the outer end of the cylinder bore 9. Supported.

The rack guide element 10 is divided into two rack guide element halves 10a and 10b along a plane including its axis, and the dividing boundary has a ■-shaped slope as shown in FIG. 15.

In this part, the rack guide element 10 is a compression coil spring 1
Since the recess 16 for receiving the rack guide element 4 is formed into an annular shape, the square square portion 15 is formed at two locations facing each other in the diametrical direction of the rack guide element.

Between the rack guide element 10 and the cover element 13, the V
A ring element 18 having a ■-shaped wedge portion 17 corresponding to the letter-shaped slope portion 15 is interposed.

The ■-shaped wedge portions 17 are also provided at two diametrically opposed locations of the ring element 1B, corresponding to the V-shaped slope portions 15 at the cut locations.

As shown in FIG. 1, the ■-shaped wedge part 17 of the ring element 18 is engaged in the V-shaped slope part 15 of the rack guide element 10, and there is a cushioning material such as rubber or plastic between them. A cushion sheet 19 made of material is interposed.

According to this structure, the two rack guide element halves 10a and 10b constituting the rack guide element 10 have their outer peripheral surfaces aligned with the cylinder bore 9 due to the wedge engagement between the ■-shaped slope portion 15 and the V-shaped wedge portion 17. Since it is held in close contact with the wall surface, when the vehicle is driving on a rough or uneven road surface, even if impact forces are applied to it, there will be no impact contact between the rack guide element and the cylinder bore. There is no fear;
Furthermore, there is no risk of metal striking noise caused by this.

Both halves 10a and 10b of the rack guide element are also cushioningly supported with respect to their axial movement towards the cover element 13 via a cushion seat 19, and are therefore subject to axial shocks. Even if force acts,
There is no risk of a direct impact contact between the rack guide element and the cover element or the ring element 1B made of metal, resulting in metal striking sounds.

Thus, according to the present invention, both the impact direct contact between the rack guide element and the cylinder bore and the impact direct contact between the rack guide element and the cover element are effectively avoided, and these impact direct contacts are avoided. It will be understood that the occurrence of metal welding due to this method is effectively prevented.

Although one embodiment of the present invention has been described in detail above, it will be obvious to those skilled in the art that various modifications can be made to this embodiment within the scope of the present invention.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the rack and pinion steering gear device according to the present invention, and FIG. 2 shows the rack guide element incorporated in the rack and pinion steering gear device shown in FIG. FIG. 2 is an enlarged perspective view showing a related member. DESCRIPTION OF SYMBOLS 1... Gear box, 2... Steering shaft, 3... Pinion, 4... Bearing race part, 5...
Ball, 6...Bearing race ring, 7...Rack bar, 8...Rack tooth, 9...Cylinder bore, 10...
...Rack guide element, 10a, 10b...Rack guide element half piece, 11.12...Threaded part, 13.
...Cover element, 14...Compression coil spring, 15...
・■-shaped slope part, 16... Depression, 17... V-shaped wedge part, 1B... Annular element, 19... Cushion seat.

Claims (1)

[Scope of utility model registration request] A rack of a rack bar is engaged with a pinion at the tip of a steering shaft in a gear box so that rotation of the steering shaft drives the rack bar in its axial direction, and a side of the rack bar opposite to a portion of the rack bar that engages with the pinion is configured. A piston-like rack guide element slidably housed in a cylinder bore formed in the gearbox is in sliding contact at one end with a cover element fixed to the gearbox and the rack. In a rack and pinion type steering gear device in which a compression coil spring is elastically mounted between the rack guide element and the rack guide element, the rack guide element is divided into two along a plane including the axis of the rack guide element and the axis of the rack bar. and a ring element having a V-shaped slope portion at the dividing boundary portion, and a ring element having a V-shaped wedge portion corresponding to the V-shaped slope portion is interposed between the rack guide element and the cover element. A rack and pinion type steering gear device further comprising a cushion seat interposed between the V-shaped slope portion and the V-shaped wedge portion.