KR20030033839A - Gear box of steering system for vehicle - Google Patents

Abstract

PURPOSE: A gearbox of a steering device for a vehicle is provided to prevent the rotation of a rack piston installed in a housing and keep the adhesion of a rack gear and a sector gear by installing an elastic support part on the outside of the rack piston. CONSTITUTION: A gearbox of a steering device for a vehicle is composed of a rack piston(40) installed inside a housing(10), to reciprocate in an axial direction, and one side of the rack piston formed with a rack gear(42), a sector shaft(50) throttled with the rack piston by having a sector gear(51) to engage with the rack gear in one side, and an elastic support part(100) supporting elastically the rack piston to the sector shaft and to hold the adhesion of the rack gear and the sector gear.

Description

GEAR BOX OF STEERING SYSTEM FOR VEHICLE}

The present invention relates to a gear box of a steering device for a vehicle, and more particularly, to prevent rotation of a rack piston installed inside a housing, and to maintain a close contact between a rack gear and a sector gear that are interleaved with each other. It relates to a gearbox of a vehicle steering apparatus having an elastic support portion on the outside.

In general, the steering device for a vehicle is provided to adjust the steering wheel rotation angle of the vehicle to change the traveling direction of the vehicle, the steering wheel provided in the driver's seat, the steering shaft provided on the lower side, and is connected to the steering shaft It is provided with a gear box for reducing the rotational force and at the same time switching the power transmission direction.

Meanwhile, the gearbox includes a worm sector type, a worm sector roller type, a ball and nut type, a rack and pinion type, and transmits the steering force of the steering wheel to the steering wheel through a link mechanism. It is provided with a hydraulic generator for generating.

1 is a cross-sectional view showing a ball-and-nut type gearbox. As shown in the figure, the housing 1 is formed inside the gear box and has a cylinder 1a formed therein.

One side of the housing 1 is provided with a rotary valve 2 having an input shaft 2a provided therein so as to be rotatable.

In addition, a ball screw 3 is connected to the front end of the input shaft 2a extending into the housing 1, and an outer groove 3a of a hemispherical cross section is spirally extended on the outer surface of the ball screw 3. Is formed.

In addition, the outer side of the ball screw (3), the inner groove (4a) is formed on the inner surface so as to correspond to the outer groove (3a), the rack piston (4) so as to slide in the axial direction inside the cylinder (1a) To be prepared.

Meanwhile, a plurality of balls 6 are inserted into the outer grooves 3a and the inner grooves 4a so that the rack piston 4 is slid when the ballscrew 3 rotates. Rack gear 4b is formed on one side of the outer surface of the rack piston 4 so as to be possible.

In addition, in the rack gear 4b, a sector shaft 5 having a sector gear 5a formed at one end thereof is interlocked with the rack piston 4 so that the ball screw 3 and the rack piston 4 can be engaged with the rack gear 4b. Receives the deceleration steering force by) and transmits it to the link mechanism side again.

At this time, the sector shaft 5 is inclined about 6 ° based on the rack gear 4b, and the contact area therebetween varies according to the height of the sector shaft 5, so that the rack gear 4b and the sector gear are inclined. The height of the torque transmitted through 5a is determined.

However, the gear box of the conventional vehicle steering apparatus configured as described above has a play formed at a predetermined value in and out of the rack piston for smooth sliding of the rack piston, and wears between the rack gear and the sector gear to be engaged for a long time. Due to the generated play, when the ball screw and the ball rotate to move the rack piston in the axial direction, the rack piston rotates in the radial direction.

That is, since the rack piston rotates in a linear motion, a change in the engagement point occurs, and the change in the engagement point changes the torque between the rack gear and the sector gear, which reduces the steering feeling felt by the driver, and the rack gear and the sector gear. There is a problem that the power transmission between the unstable, noise and vibration is generated to reduce the reliability of the product.

The present invention is to solve such a conventional problem, an object of the present invention, to prevent the rotation of the rack pistons installed in the interior of the housing, so as to maintain a close contact between the rack gears and the sector gears that are interdigitated with each other. It is to provide a gear box of a vehicle steering apparatus having an elastic support portion on the outside of the rack piston.

1 is a cross-sectional view showing a gear box of a conventional vehicle steering apparatus.

2 is a cross-sectional view showing a gearbox of a vehicle steering apparatus according to the present invention.

3 is a partial cross-sectional view taken along line A-A of FIG.

<Explanation of symbols for main parts of drawing>

10 housing 20 rotary valve

30: ball screw 40: rack piston

42: rack gear 50: sector axis

51: sector gear 100: elastic support

110: guide hole 120: end cover

130: pressure member 140: spring

Gear box of the present invention vehicle steering apparatus for achieving the above object, is installed inside the housing to be reciprocated in the axial direction and the rack piston is formed on one side and the rack gear so as to be separated from the rack gear In a gearbox of a vehicle steering apparatus having a sector shaft formed on one side to be throttled with the rack piston, the rack piston is elastically supported to the sector shaft side so as to maintain close contact between the rack gear and the sector gear. It characterized in that the elastic support is provided.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of the gearbox of the vehicle steering apparatus according to the present invention.

As shown in FIG. 2, a housing 10 having an outer shape of a gear box and an installation space for various components, a cylinder 11, and a flow path are formed therein.

And, one side of the housing 10 is provided with an input shaft 21 therein to be rotated by receiving a steering force generated by the driver, is connected to an external hydraulic pump rotary valve 20 for supplying hydraulic pressure into the housing 10 ) Is installed.

In addition, a ball screw 30 is provided at the front end of the input shaft 21 extending into the housing 10 so as to be interlocked with the ball screw 30. An outer groove 31 having a hemispherical cross section is provided on the outer surface of the ball screw 30. It is formed extending spirally.

In addition, the outer side of the ball screw 30, the inner groove 41 of the hemispherical cross section is formed spirally extending on the inner surface so as to correspond to this, the rack piston 40 is to be sliding in the axial direction in the interior of the cylinder (11) To be prepared.

In addition, a plurality of balls 32 are inserted into the outer grooves 31 and the inner grooves 41 formed in the ball screw 30 and the rack piston 40 to install the rack pistons when the ball screw 30 rotates. 40 is sliding, the rack gear 42 is formed on one side of the outer surface of the rack piston 40 so as to transfer this operation to the outside.

In addition, in the rack gear 42, the sector shaft 50 having the sector gear 51 formed at one end thereof so as to be engaged with the rack gear 42 is orthogonal to the rack piston 40, so that the ball screw 30 and the rack piston 40 Receives the deceleration steering force by) and transfers it to the link mechanism side again.

On the other hand, one side of the housing 10, the elastic support portion 100 to elastically support the rack piston 40 to the sector axis 50 side to maintain the close contact between the rack gear 42 and the sector gear 51 which are meshed with each other ) Is provided.

The elastic support portion 100 is formed on the side opposite to the rack gear 42 of the rack piston 40, the guide hole 110 formed in the housing 10, and the opening and closing the guide hole 110 The pressing member 130 is provided to push the rack piston 40 while being guided by the end cover 120 and the guide hole 110, and is installed between the pressing member 130 and the end cover 120. The pressing member 130 is provided with a spring 140 for pushing the rack piston 40 side.

First, the guide hole 110 is provided with a smaller inner diameter into which the pressing member 130 of a smaller diameter than the end cover 120 is inserted, compared to the outer diameter into which the end cover 120 is inserted, and between the outer and inner sides. It is formed with a diameter smaller than the diameter of the inner side, stepped to form the inner side.

At this time, the end cover 120 installed on the outside of the guide hole 110 extends inwardly through the intermediate side formed with the smallest diameter of the guide hole 110 with the insertion end 121 projecting downward on the center side. do.

In addition, an O-ring 122 (“O” Ring) is installed at an outer step of the guide hole 110 to prevent oil from leaking to the outside by being compressed between the end cover 120 and the outside of the housing 10. The inner circumferential surface of the guide hole 110 and the outer circumferential surface of the end cover 120 are formed with screws to be coupled to each other.

In addition, the other end of the pressing member 130, one end of which is installed in close contact with the rack piston 40 is inserted into the guide hole 110 so as to be movable in a direction crossing with the reciprocating direction of the rack piston 40. .

At this time, one end of the pressing member 130 is rounded so as to be in close contact with the rack piston 40 facing this, as shown in FIG. 3 to surround the outer surface of the rack piston 40.

Then, the other end of the pressing member 130 is provided with an installation groove 131 having a diameter enough to be inserted into the insertion end 121 formed on the center side of the end cover 120, this installation groove 131 The spring 140 is installed in compression.

One end of the spring 140 is installed outside the insertion end 121 of the end cover 120 and is supported by the end cover 120, and the other end is inserted into the installation groove 131 so as to expand therebetween. Generates.

That is, one end is supported by the end cover 120 fixed to the housing 10 to generate an elastic force for pushing the pressure member 130 provided to be movable toward the rack piston 40.

In addition, the tool insertion groove 123 is installed on the outside of the end cover 120 to rotate it using a tool or the like.

Gear box of the vehicle steering apparatus of the present invention configured as described above, when installing the rack piston 40 in the housing 10, the pressing member 130 is installed to the outside of the rack piston 40.

At this time, the pressing member 130 is installed inside the guide hole 110 in a state in which the spring 140 is pressed and inserted therein.

Then, the end cover 120 through the O-ring 122 is inserted into the outside of the guide hole 110 and rotated thereto to be screwed with the guide hole 110.

As a result, the elastic support part 100 has a clearance formed at a predetermined value in and out of the rack piston 40 for smooth sliding of the rack piston 40, and between the rack gear 42 and the sector gear 51 to be engaged. It will compensate for play caused by wear.

That is, since the rack piston 40 is pressed in the direction of the sector axis 50 by the spring 140 supported by the end cover 120, the rack gear 42 and the sector axis ( The engagement state with the sector gear 51 formed at 50 is always kept constant, and the rack piston 40 is prevented from rotating.

As described in detail above, the gear box of the vehicle steering apparatus according to the present invention, by providing an elastic support on the outside of the housing, to prevent the rack piston from rotating outside of the ball screw, as well as the rack gear and the sector gear It is possible to maintain a close contact between them.

As a result, it is possible to maintain an engagement point between the rack gear and the sector gear, thereby improving the steering feeling felt by the driver, achieving stable power transmission between the rack gear and the sector gear, and reducing noise and vibration, thereby improving product reliability. There is an advantage.

Claims (3)

It is installed inside the housing so as to reciprocate in the axial direction and has a rack piston formed on one side, and a sector shaft formed on one side so as to be bite with the rack gear and a sector shaft installed to throttle the rack piston In a vehicle gearbox, A vehicle steering apparatus, characterized in that an elastic support portion 100 is provided to elastically support the rack piston 40 toward the sector shaft 50 so as to maintain a close contact between the rack gear 42 and the sector gear 51. Gearbox. The method of claim 1, The elastic support part 100 is formed through the outer side of the housing 10 so that one end of the pressing member 130 in close contact with the rack piston 40 and the other end of the pressing member 130 is inserted. Guide hole 110 for guiding the movement of the rack piston 40, the end cover 120 provided to open and close the guide hole 110, the end cover 120 and the pressing member 130 of Gear box of the steering device for a vehicle, characterized in that provided between the other end is provided with a spring 140 for generating an elastic force. The method of claim 2, An installation groove 131 is provided at the other end of the pressing member 130 to allow the spring 140 to be inserted, and one end of the end cover 120 installed into the housing 10 is the installation groove. Gear box of the steering device for a vehicle, characterized in that the portion is provided to be inserted into the (131).