KR20100088850A - Rack bush, and rack and pinion type steering apparatus for vehicle having the same - Google Patents

Abstract

PURPOSE: A rack bush and a steering apparatus of a rack pinion type of a vehicle comprising the same is provided to reduce the rattle noise caused by the external force transferred through a rack bar and the abnormal abrasion of a rack bush by supporting the load in the axial and vertical directions of the rack bar. CONSTITUTION: A rack bush(200) comprises an external slot groove(220), an internal slot groove(230), and an O ring groove(240). The number of the external slot groove is plural, the external slot grooves are spaced from each other and are formed along the axial direction. The O ring groove is connected and formed in the outer circumferential direction. The rack bush is coupled to the inner side of a rack housing. The rack bush has a hollow pipe shape, a rack bar is inserted into the inner circumference of the rack bush and the rack bush transfers the rack bar in a straight line. The internal slot groove is formed on the inner circumference between the external slot grooves adjacent. The rack bush comprises a slit(250) cut the outer circumference and the inner circumference of the rack bush in the axial direction.

Description

Rack Bush, and Rack and Pinion Type Steering Apparatus for Vehicle having The Same}

The present invention relates to a rack bush and a rack pinion type steering apparatus of a vehicle having the same. More specifically, it can smoothly support the load in the axial and vertical direction of the rack bar to reduce abnormal wear of the rack bush, reduce the rattle noise due to the external force transmitted through the rack bar during the movement of the rack bar, and reduce the load caused by external impact. The present invention relates to a rack bush and a rack pinion type steering apparatus of a vehicle having the same, which may be distributed to prevent breakage of the rack bar and the pinion shaft.

In general, the steering device is provided between the driver's seat and the wheel to move the wheel by the driver, the steering shaft provided under the steering wheel of the driver's seat, the gear box connected to the steering shaft, and the wheel according to the operation of the gear box It is configured to include a rack bar extending to the left and right sides so as to operate directly to the wheel.

1 is a partial cross-sectional view showing a rack pinion type steering apparatus of a vehicle according to the prior art.

As shown in FIG. 1, a gear box 125 connected to the rack housing is provided on the side of the steering wheel 110 and the steering shaft 115.

The gear box 125 is provided with an input shaft 120 connected to the steering shaft 115 at an upper side thereof so as to receive a rotational force generated from the steering wheel 110.

The inner lower side of the gear box 125 is rotated by the rotational force transmitted through the input shaft 120 is provided with a pinion (not shown) formed on the outer peripheral end of the gear box 125 and the gear box 125 and the lower outer side of the gear box 125 and A rack housing 137 formed integrally and extending to both sides is provided.

The rack housing 137 is formed as a hollow tube, both sides of which are opened, and a rack bush 160, a rack stopper 165, and the like are installed at one side of the opened inlet, and a bellows 150 is provided at the outer circumferential side thereof.

A rack bar 140 having a rack formed therein is provided inside the rack housing 137 so as to be engaged with the pinion provided in the gear box 125.

The rack bar 140 is provided to be linearly moved in the axial direction inside the rack housing 137, and a rack is formed in the middle thereof so as to be engaged with the pinion of the gearbox 125. Left and right sides are connected to the tie rod 155 through the inner ball joint to which the ball is inserted into the ball housing 175 to be coupled to steer the wheels.

On the other hand, one side of the rack housing 137 formed to be opened is provided with a rack bush 160 to guide the movement of the rack bar 140 while supporting the rack bar 140.

The rack bush 160 is provided in a hollow and the outer circumferential surface is tightly fixed to the inner circumferential surface of the rack housing 137 and the step portion 135, and the inner circumferential surface of the rack bush 160 is closely attached to the outer circumferential surface of the rack bar 140 inserted. The sliding of the rack bar 140 is guided, and the other end of the rack stopper 165 is pressed into the rack housing 137.

That is, at the end of the rack bush 160 is provided in a hollow to seal the rack housing 137 while being in close contact with the rack bush 160, the rack stopper 165 is tightly fixed to the inner circumferential surface of the rack housing 137 is installed This prevents the departure of the rack bush 160.

The rack and pinion type steering apparatus of the vehicle according to the prior art has an abnormal wear and noise of the rack bush as the load in the axial and vertical directions of the rack bar is transmitted through the rack bar, the rack bush and the rack housing when the steering wheel is steered by the driver. There was a problem that occurred.

In addition, the rack bush does not support the load in the axial and vertical direction of the rack bar smoothly, there was a problem that the rack bar and pinion shaft is damaged by the impact transmitted from the outside through the road surface.

In order to solve this problem, the present invention can smoothly support the load in the axial and vertical direction of the rack bar to reduce abnormal wear of the rack bush, reduce the rattle noise due to external force transmitted through the rack bar during the movement of the rack bar and the outside It is an object of the present invention to provide a rack bush and a rack pinion type steering apparatus of a vehicle having the same, which can prevent the damage of the rack bar and the pinion shaft by distributing the load due to the impact.

In order to achieve the above object, the present invention is a hollow tube shape coupled to the inside of the rack housing and the rack bar is inserted into the inner circumferential surface to move the rack bar linearly, the outer circumferential surface is spaced apart from each other and formed in the axial direction of the long outer slot groove One or more O-ring grooves are connected to each other, and the inner circumferential surface is provided with a rack bush having a plurality of inner slot grooves formed in an axial direction and spaced apart from each other, and a rack pinion type steering apparatus for a vehicle having the same. do.

In addition, the present invention is a hollow tube shape coupled to the inside of the rack housing and the rack bar is inserted into the inner circumferential surface to move the rack bar linearly, both ends are provided with an annular fixing portion and the center is formed of a cylindrical support portion, these fixing portion and the support portion It is formed of an elastic deformation guide portion for connecting the support portion of the rack bush is provided with a plurality of slot holes spaced apart from each other and formed in the circumferential direction and at least one O-ring groove formed in the circumferential direction and the vehicle having the same Provides a rack pinion type steering system.

According to the present invention, it is possible to smoothly support the load in the axial and vertical directions of the rack bar to reduce abnormal wear of the rack bush, to reduce the rattle noise due to the external force transmitted through the rack bar during the movement of the rack bar, and the load due to external impact. By dispersing the rack bar and pinion shaft can be prevented from being damaged.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In addition, in describing the component of this invention, terms, such as 1st, 2nd, A, B, (a), (b), can be used. These terms are only for distinguishing the components from other components, and the nature, order or order of the components are not limited by the terms. If a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected to or connected to that other component, but there may be another configuration between each component. It is to be understood that the elements may be "connected", "coupled" or "connected".

The rack bush according to the first and second embodiments of the present invention to be described later is required to be formed of a material having excellent abrasion resistance and low friction resistance, having a predetermined warpage and rigidity, and having low elasticity due to heat. Engineering plastics such as polyacetal (POM), polyamide (PA), polycarbonate (PC), polyimide (PI), polybutylene terephthalate (PBT), or natural rubber or polyester It is formed of a synthetic resin such as stormer (PE) or the like.

FIG. 2A is an exploded perspective view showing a rack bush according to a first embodiment of the present invention, FIG. 2B is a cross-sectional view showing a rack bush according to a first embodiment of the present invention, and FIG. 2C is a cross-sectional view of a portion AA in FIG. 2B. .

2A to 2C, the rack bush 200 according to the first embodiment of the present invention is coupled to the inner side of the rack housing 137 and the rack bar 140 is inserted into the inner circumferential surface of the rack bar 140. Hollow tube shape to move in a straight line, the outer peripheral surface is provided with a plurality of outer slot grooves 220 formed in the axial direction spaced apart from each other and one or more O-ring grooves 240 formed in the outer peripheral direction, the inner peripheral surface A plurality of inner slot grooves 230 are formed to be spaced apart in the axial direction.

The rack bar 140 converts the rotational movement of the steering shaft into a linear motion. The rack bar 140 reciprocates axially in the rack housing 137. The left and right ends of the rack bar 140 are ball housings (see 175 of FIG. 1). It is connected to the tie rods (155 of FIG. 1) via the inner ball joint to which the ball is inserted and coupled to the steering wheel.

The rack housing 137 linearly reciprocates the rack bar 140 left and right in the rack housing 137 when the steering wheel is engaged with the pinion of the steering shaft.

At this time, the rack bar 140 is supported by the rack bush 200 coupled to the inside of the rack housing 137 and is a linear reciprocating motion, the rack bush 200 according to the first embodiment of the present invention is the outer slot The groove 220 and the inner slot groove 230 and the O-ring groove 240 is formed, so that the O-ring 210 coupled to the O-ring groove 240 is contracted between the rack housing 137 and the rack bar 140. While reducing the noise by reducing the impact energy input through the rack bar 140 while the elastic deformation, elastic deformation of the rack bush 200 and close contact with the rack bar 140 to prevent noise due to play with the rack bar 140. There is a feature that makes it possible.

That is, the rack bush 200 according to the first embodiment of the present invention is coupled to the inner side of the rack housing 137 and the rack bar 140 is inserted into the inner circumferential surface so that the rack bar 140 can be linearly moved in a hollow tube shape. Is formed.

In addition, several outer slot grooves 220 are formed on the outer circumferential surface of the rack bush, and the outer slot grooves 220 are formed to be long in the axial direction and are spaced apart from each other.

In addition, the outer circumferential surface of the rack bush 200 is provided with at least one O-ring groove 240 formed perpendicular to the outer slot groove 220, the O-ring groove 240 has an annular shape connected in the circumferential direction in the outer peripheral surface It is formed by being recessed and combined with the O-ring 210.

Meanwhile, several inner slot grooves 230 are formed on the inner circumferential surface of the rack bush 200. The inner slot grooves 230 are formed to be long in the axial direction and are spaced apart from each other, and are adjacent to each other. It is formed between the grooves 220, the outer slot groove 220 and the inner slot groove 230 is formed alternately (or staggered) on the inner peripheral surface and the outer peripheral surface.

Therefore, the thickness between the outermost outer circumferential surface and the innermost inner circumferential surface of the rack bush 200 becomes thinner, and the inner diameter is contracted by the elastic force of the O-ring 210, thereby allowing close contact with the rack bar 140 and contacting the rack bar 140. The area is also reduced, thereby reducing the sliding resistance.

In addition, the rack bush 200 according to the first embodiment of the present invention has a slit 250 formed by cutting the outer circumferential surface and the inner circumferential surface in the axial direction, and the inner diameter due to the elastic force of the O-ring coupled to the O-ring groove 240. This shrinkage deformation can be reduced to compensate for the play with the rack bar 140.

Further, both ends of the inner circumferential surface of the rack bush 200 are formed with an inclined portion 270 that extends the inner diameter from both ends to the center, so that the rack bar 140 can be easily assembled and the rack bar 140 can be manufactured due to the manufacture or durability of the rack bar 140. Even if bending deformation occurs, it is possible to prevent the sliding resistance of the rack bar 140 and the rack bush 200 from being increased.

On the other hand, one end of the rack bush 200 is supported by the step portion 135 of the rack housing 137 is formed in the diameter from the outer peripheral surface to be fixed to the rack housing 137 without being interlocked during linear movement of the rack bar 140 Being caught 260 may be further provided.

Figure 3a is an exploded perspective view showing a rack bush according to a second embodiment of the present invention, Figure 3b is a cross-sectional view showing a rack bush according to a second embodiment of the present invention, Figure 3c is a cross-sectional view of the BB portion of Figure 3b. .

3A to 3C, the rack bush 300 according to the second embodiment of the present invention is coupled to the inner side of the rack housing 137 and the rack bar 140 is inserted into the inner circumferential surface thereof so as to provide the rack bar 140. Hollow tube shape to move in a straight line, both ends are provided with an annular fixing portion 310 and a cylindrical support portion 320 is formed in the center and the elastic deformation guide portion connecting the fixing portion 310 and the support portion 320 ( 330 is formed, the support 320 is provided with a plurality of slot holes 340 spaced apart from each other and formed in the circumferential direction and at least one O-ring groove 350 is formed in the circumferential direction.

Rack bush 300 according to a second embodiment of the present invention is coupled to the inside of the rack housing 137 and the rack bar 140 is inserted into the inner circumferential surface is formed in a hollow tube shape so as to linearly move the rack bar 140 A plurality of slot holes 340, elastic deformation guide portion 330 and the O-ring groove 350 is formed, the O-ring 210 is coupled to the O-ring groove 350, the rack housing 137 and the rack bar 140 The elastic deformation that is contracted between the while reducing the impact energy input through the rack bar 140 to reduce noise, elastically deform the rack bush 300 and close contact with the rack bar 140 to the play with the rack bar 140 There is a feature that can prevent the noise caused by.

Rack bush 300 according to the second embodiment of the present invention is formed of a fixed portion 310 and the support portion 320 and the elastic deformation guide portion 330 connecting the fixed portion 310 and the support portion 320, O-ring 210 is coupled to the outside of the support 320 is configured.

That is, the rack bush 300 according to the second embodiment of the present invention is provided with an annular fixing portion 310 at both ends, and a cylindrical support portion 320 is formed at the center thereof, and these fixing portions 310 and the support portion ( It is formed of an elastic deformation guide portion 330 connecting 320.

The support 320 has a plurality of slot holes 340 formed by cutting an inner circumferential surface and an outer circumferential surface thereof. The slot holes 340 are formed long in the axial direction and spaced apart from each other, and are formed perpendicular to the slot holes 340. One or more o-ring grooves 350 are provided, and the o-ring grooves 350 are formed by being recessed in the outer circumferential surface of the support part 320 in an annular shape connected in the circumferential direction and coupled with the O-ring 210.

On the other hand, the elastic deformation induction part 330 connecting the fixing part 310 and the support part 320 is formed by reducing the diameter from the outer peripheral surface of the fixing part 310 and the support part 320 so that the thickness of the inner peripheral surface is thin, O-ring The elastic deformation inducing portion 330 is elastically deformed by the elastic force of the O-ring 210 coupled to the groove 350 to allow shrinkage deformation to reduce the inner diameter, thereby compensating play with the rack bar 140.

In addition, the slot hole 340 may be formed to be wider and wider from both ends of the support 320 to the elastic deformation induction part 330. Thus, the width of the slot hole 340 is extended and formed to extend the elastic deformation induction part. The elastic deformation of 330 is facilitated.

And, both ends of the inner circumferential surface of the rack bush 300 is formed with an inclined portion 270 that extends the inner diameter from the both ends of the fixing portion 310 to the support 320, the assembly with the rack bar 140 is easy Even if bending deformation occurs due to manufacturing or durability of the 140, the sliding resistance of the rack bar 140 and the rack bush can be prevented from increasing.

In addition, any one of the fixing portion 310 of the fixing portion 310 provided on both sides of the rack bush 300 is supported by the step portion 135 of the rack housing 137 is interlocked during the linear movement of the rack bar 140 The diameter may be enlarged from the outer peripheral surface so as to be fixed to the rack housing 137.

As described above, the rack bushes 200 and 300 according to the first and second embodiments of the present invention include a rack housing 137 to which the rack bushes 200 and 300 are coupled to an inner side, and a pinion and tooth coupling. And is supported on the inner peripheral surface of the rack bush reciprocating the rack housing 137 constitutes a rack pinion type steering apparatus of a vehicle including a rack bar 140 for converting the rotational movement of the steering shaft to linear movement.

According to the present invention having such a structure and shape can smoothly support the load in the axial and vertical direction of the rack bar to reduce abnormal wear of the rack bush, and to reduce the rattle noise due to external force transmitted through the rack bar during the movement of the rack bar. In addition, by distributing the load due to external impact, the rack bar and pinion shaft can be prevented from being damaged.

In the above description, all elements constituting the embodiments of the present invention are described as being combined or operating in combination, but the present invention is not necessarily limited to the embodiments. In other words, within the scope of the present invention, all of the components may be selectively operated in combination with one or more.

In addition, the terms "comprise", "comprise" or "having" described above mean that the corresponding component may be included, unless otherwise stated, and thus excludes other components. It should be construed that it may further include other components instead. All terms, including technical and scientific terms, have the same meanings as commonly understood by one of ordinary skill in the art unless otherwise defined. Terms commonly used, such as terms defined in a dictionary, should be interpreted to coincide with the contextual meaning of the related art, and shall not be construed in an ideal or excessively formal sense unless explicitly defined in the present invention.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 is a partial cross-sectional view showing a rack pinion type steering apparatus of a vehicle according to the prior art;

Figure 2a is an exploded perspective view showing a rack bush according to the first embodiment of the present invention;

2B is a cross-sectional view showing the rack bush according to the first embodiment of the present invention;

2C is a cross-sectional view of the A-A portion of FIG. 2B;

Figure 3a is an exploded perspective view showing a rack bush according to a second embodiment of the present invention;

3B is a cross-sectional view illustrating a rack bush according to a second embodiment of the present invention;

3C is a cross-sectional view of the portion B-B in FIG. 3B.

<Description of the symbols for the main parts of the drawings>

137: rack housing 140: rack bar

200: rack bush according to the first embodiment of the present invention

210: O-ring 220: outer slot groove

230: inner slot groove 240: O-ring groove (first embodiment)

250: slit 260: engaging portion

270: slope

300: rack bush according to the second embodiment of the present invention

310: fixed portion 320: support portion

330: elastic deformation guide portion 340: slot hole

350: O-ring groove (second embodiment)

Claims (11)

One or more O-rings coupled to the inner side of the rack housing and inserted into the inner circumferential surface of the hollow tube to linearly move the rack bar, the outer circumferential surface is connected to the outer circumferential direction and several outer slot grooves are formed long in the axial direction The rack is provided with a groove, the inner circumferential surface of the rack bush is formed with a plurality of inner slot grooves are formed long in the axial direction. The method of claim 1, The inner slot groove is a rack bushing, characterized in that formed on the inner peripheral surface between the adjacent outer slot groove. The method of claim 1, The rack bush is a rack bush, characterized in that the slit formed by cutting the outer peripheral surface and the inner peripheral surface in the axial direction is formed elastically deformed by the O-ring coupled to the O-ring groove and the play with the rack bar is compensated. The method of claim 1, Rack bushes, characterized in that the inclined portion is formed at both ends of the inner peripheral surface of the rack bush to extend the inner diameter from both ends to the center. The method of claim 1, One end of the rack bush is a rack bush characterized in that the support is provided with a step portion of the rack housing is provided with a locking portion is formed to expand the diameter from the outer circumferential surface to be fixed without being interlocked during linear movement of the rack bar. A hollow tube shape coupled to the inside of the rack housing and the rack bar is inserted into the inner circumferential surface to move the rack bar linearly. Both ends are provided with an annular fixing part, a cylindrical support part is formed at the center, and an elastic deformation connecting these fixing parts and the supporting part. The rack bush is formed as an induction part, the support part is provided with one or more O-ring grooves are formed in the circumferential direction and several slot holes are formed long in the axial direction spaced apart from each other. The method of claim 6, The elastic deformation guide portion is formed to be reduced in diameter from the outer peripheral surfaces of the fixing portion and the support portion so as to have a thinner thickness with the inner circumferential surface, and the elastic deformation guide portion is elastically deformed by an O-ring coupled to the O-ring groove to compensate for the play with the rack bar. Rack bushes characterized in that the. The method of claim 6, The slot hole is a rack bush, characterized in that the width is extended and extended from the both ends of the support portion to the elastic deformation guide portion. The method of claim 6, Rack bushes, characterized in that the inclined portion is formed on both ends of the inner peripheral surface of the rack bush to extend the inner diameter from both ends of the fixing portion to the support portion. The method of claim 6, One side fixing portion of the rack bush is supported by the step of the rack housing rack bush, characterized in that the diameter is formed from the outer circumferential surface to be fixed without being interlocked during linear movement of the rack bar. A rack bush according to any one of claims 1 to 10; A rack housing to which the rack bush is coupled inside; And A rack bar engaged with the pinion and supported on the inner circumferential surface of the rack bush to convert the rotational movement of the steering shaft into linear movement while reciprocating the rack housing; Rack pinion steering system of a vehicle comprising a.

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