WO2015030362A1

WO2015030362A1 - Bellows structure of vehicle steering system

Info

Publication number: WO2015030362A1
Application number: PCT/KR2014/006063
Authority: WO
Inventors: 신종훈; 정진형; 맹성재
Original assignee: 주식회사 현대포리텍
Priority date: 2013-08-27
Filing date: 2014-07-07
Publication date: 2015-03-05
Also published as: KR101476705B1

Abstract

The present invention relates to a bellows structure of a vehicle steering system, in which a known vehicle steering system comprises: a hollow rack-housing having both ends opened; a rack-bar inserted in the rack-housing so as to extend to the outside of both ends of the rack-housing; a pair of tie rods connected to both leading ends of the rack-bar; and a bellows which has a predetermined width and size to be axially extendable, has a hollow cylindrical shape, has corrugation ridges and corrugation valleys repeatedly formed to continue a corrugated part to thereby cover between both leading ends of the rack-bar and the middle-end of the tie rods, and is formed of rubber or a synthetic resin, wherein the corrugated part in the larger-diameter portion of the bellows is formed in a jar shape where the inner and outer diameters of the corrugation ridges and corrugation valleys gradually increase from the first corrugation ridge toward the center of the axial direction, and the corrugated part in the smaller-diameter portion of the bellows is formed in a cone shape where the inner and outer diameters of the corrugation ridges and corrugation valleys gradually decrease toward the smaller-diameter portion, or is formed in a cylindrical shape where the inner and outer diameters of the corrugation ridges and corrugation valleys are uniformly formed toward the smaller-diameter portion.

Description

Bellows Structure of Vehicle Steering System

The present invention relates to a bellows structure of a vehicle steering system, and more particularly, to improve the bellows structure of a vehicle steering system to prevent the deformation of the bellows from high temperature and high pressure gas generated inside the bellows by engine heat, thereby improving durability and reliability. It relates to a bellows structure of a vehicle steering system for improving.

BACKGROUND ART In general, a vehicle steering device includes a steering wheel provided in a driver's seat, a steering shaft provided at a lower side thereof, and a gear box connected to the steering shaft to reduce the rotational force transmitted from the steering wheel and to change the power transmission direction. It is done by

Here, the gearbox is a rack bar in the interior of the hollow housing provided in the axial direction is configured to switch the rotational force from the steering shaft to the horizontal movement, the tie bar is provided at both ends of the rack bar to be linked to this The inner ball joint is connected to the tire wheels on both sides of the vehicle so as to change the wheels.

At this time, the inner side of the inner ball joint portion in which the tie rod and the rack bar interlocked in the axial direction are covered with bellows to prevent penetration of moisture and dust from the outside.

1 is a cross-sectional view showing a state in which a bellows is installed on the outside of the tie rod and the rack bar in the steering system for a vehicle according to the prior art as described above.

As shown in FIG. 1, the rack bar 2 and the tie rod 3 which are moved in the axial direction are covered outside the front end of the rack housing 1 and the middle end of the tie rod 3 of the rack housing 1. A bellows 5 is installed to prevent foreign matter such as moisture or dust from penetrating inside.

Such bellows (5) is located around the engine of the vehicle is provided in the form of corrugated pipe so that the rack bar (2) and tie rods (3) can be stretched as they move in the left and right axial direction, a relatively large diameter of both ends The large diameter portion 52 is fixed by a steel band 6 wrapped around and fastened from the outside in a state of being fitted to the outer peripheral surface of the front end of the rack housing 1, the small diameter portion 54 of the other end of the relatively small diameter is a tie rod ( 3) It is fixed by the clip 7 which wraps and fastens it from the outside in the state fitted in the groove formed on the outer peripheral surface of the intermediate end.

Here, in order to increase the watertightness between the bellows 5, the rack housing 1, and the tie rods 3, which are to be assembled when the bellows 5 is assembled as described above, the bellows assembly part, that is, the large diameter part 52 or the small diameter part (54) An o-ring (not shown) was installed between the inner diameter and the outer diameter of the assembly by using a sealing adhesive 8 or a groove was made in the assembly portion to allow the bellows 5 to be fitted to the outside thereof.

However, the bellows 5 of the conventional vehicle steering system has a constant pitch interval of the pleated peaks on the large diameter portion 52 side, and the outer diameters of the pleated peaks and the pleated bones are constant so that the engine (not shown) vibrates or runs. As a means for limiting the displacement of tensile compression, bending, and torsion due to steering system vibrations received from the road including steering wheels, there was a problem.

In addition, since the large diameter portion 52 and the small diameter portion 54 of the bellows 5 are sealed and the inside of the bellows 5 is sealed, the gas existing inside the bellows 5 located around the engine (not shown). That is, the air receives the engine heat during driving of the vehicle to maintain the high temperature and high pressure. At this time, since the height of the pleat peak of the center portion in the axial direction among the pleats of the bellows 5 is formed to be the same as the height of the pleat peak on the large diameter portion 52 side, the expansion length of the pleats is increased. When the wheel is variable at steering angle neutral or vehicle steering angle neutral, the wrinkles in the central portion in the axial direction are severely bent by the high-temperature, high-pressure gas present in the bellows 5 when the wheels are variable in the wheels. When the wrinkles are brought into contact with the rack bar 2 and the tie rods 3 due to the generation, there is a problem that the durability and reliability of the bellows 5 are deteriorated due to the occurrence of breakage in which the wrinkles of the bellows 5 burst.

The present invention has been devised to solve the above problems, the bellows on the large diameter side of the bellows in the form of a jar, and the wrinkles on the small diameter side in the form of a cone (cone) or cylindrical form to the engine vibration and running Wrinkles and wrinkles on the small diameter side of the bellows from the high temperature and high pressure gas present inside the bellows by the engine heat during operation of the vehicle by distributing the stress concentrated by the steering system vibration generated during the operation of the vehicle. Improves the durability and reliability of the bellows by preventing deformation due to deterioration of the material of the bone and concentration of stress, and the bellows pleat of the rack bar and tie rod of the steering system for vehicles The purpose is to provide a bellows structure for a steering system for vehicles that allows the new operation to be stable. All.

In addition, another object of the present invention is to form the height of the pleated peak of the central portion in the axial direction lower than the height of the pleated peak on the large diameter side and the small diameter side to reduce the internal volume increase and the expansion length of the pleated portion than the conventional bellows, The present invention provides a bellows structure of a steering system for a vehicle that prevents deformation caused by creases to be broken or bent from high temperature and high pressure gas present inside the bellows.

The bellows structure of the vehicle steering system according to the present invention for solving the above problems is a hollow rack housing having both ends of the opening is formed, the rack bar is inserted therein so as to extend outside the both ends of the rack housing; A pair of tie rods connected to both ends of the rack bar, and the wrinkles and the corrugated bone is formed repeatedly in a hollow cylindrical shape having a predetermined width and size so as to be axially stretchable in a hollow cylindrical shape and both ends of the rack bar and In a known vehicle steering system comprising a bellows formed of rubber or synthetic resin so as to cover an intermediate end of the tie rod, the wrinkles on the large diameter side of the bellows are wrinkles and wrinkles from the first wrinkles toward the center in the axial direction. It is formed in the form of a jar to gradually increase the outer diameter of the bone, the wrinkle portion of the small diameter side toward the small diameter side It is characterized in that it is formed in any one of a cone (cone) form that is gradually reduced in the inner and outer diameter of the wrinkle acid and wrinkle bone or the cylindrical form in which the inner and outer diameter of the wrinkle acid and wrinkle bone is constantly formed toward the side of the small diameter portion It is done.

The wrinkles pitch of the small diameter portion is formed at a predetermined interval smaller than the pitch of the diameter of the large diameter side.

The wrinkles pitch of the small diameter portion side is characterized in that it is formed to gradually decrease toward the small diameter portion side than the large diameter portion side wrinkle pitch.

It is characterized in that at least one or more wrinkles pitch of the small diameter portion side is formed smaller than the large diameter portion side wrinkle pitch.

The height of the pleated peak is characterized in that the central portion in the axial direction is formed lower than the height of the pleated peak on the large diameter side and the small diameter side.

The corrugated acid is characterized in that formed in a square (square) shape.

The shape of the corrugated bone is characterized in that formed in any one of a square (square), U-type, round.

According to the bellows structure of the vehicular steering system according to the present invention, the bellows on the large diameter side of the bellows is formed in the form of a jar, and the bellows on the small diameter side is formed in the shape of a cone or a cylinder to prevent engine vibration and vibration generated during driving. Decentralization and stress concentration of wrinkles and corrugated bones on the small diameter side of the bellows from the high temperature and high pressure gas present inside the bellows by the engine heat during operation of the vehicle by transmitting and dispersing the stress concentrated on the small diameter side of the bellows. To improve the durability and reliability of the bellows by preventing deformation and to make the bellows wrinkles stretch stably during the left and right axial movement of the rack bar and tie rod of the steering system and forward and backward movement of the tie rod. It is effective.

In addition, by forming the height of the wrinkles of the central portion in the axial direction lower than the heights of the wrinkles on the large diameter side and the small diameter side to increase the internal volume and reduce the expansion length of the wrinkle portion than the conventional bellows, the presence of the inside of the bellows by the engine heat There is an effect to prevent the deformation that the wrinkles are broken or bent from the gas of high temperature, high pressure.

1 is a cross-sectional view showing a state in which the bellows is installed on the outside of the tie rod and the rack bar in the steering device for a vehicle according to a conventional embodiment;

2 is a perspective view showing a bellows structure of a vehicle steering system according to an embodiment of the present invention;

3 is a left side view of FIG. 2;

4 is a front view of FIG. 3;

5 is a longitudinal sectional view of FIG. 3;

6 is an enlarged view of a portion G of FIG. 5;

7 is a longitudinal sectional view showing the excavation of the bellows bellows according to another embodiment of the present invention,

8 is a longitudinal sectional view showing the excavation of the bellows bellows according to another embodiment of the present invention,

9 is a cross-sectional view showing a state in which the bellows is installed on the outside of the tie rod and the rack bar in the steering device for a vehicle according to an embodiment of the present invention;

Figure 10 (a) is a schematic diagram showing the heat deformation shape of the conventional bellows at the steering angle neutral of the vehicle, (b) is a schematic diagram showing the heat deformation shape of the bellows according to an embodiment of the present invention at the steering angle neutral of the vehicle Drawing,

Figure 11 (a) is a schematic diagram showing a conventional bellows heat deformation shape when the wheel is variable at the steering angle neutral of the vehicle, (b) is a heat deformation of the bellows according to an embodiment of the present invention when the wheel is variable at the steering angle neutral of the vehicle Schematic illustration showing the shape.

Hereinafter, a preferred embodiment of the bellows structure of the vehicle steering system according to the present invention will be described in detail with reference to the accompanying drawings.

Embodiment of the present invention can be modified in various forms, the scope of the invention should not be construed as limited to the embodiments described in detail below.

In addition, the shape and the like of the elements in the drawings may be exaggerated to emphasize a more clear description, the same members in each of the drawings may be represented by the same reference numerals, it may unnecessarily obscure the subject matter of the present invention Detailed descriptions of known functions and configurations will be omitted.

2 is a perspective view showing a bellows structure of a vehicle steering system according to an embodiment of the present invention, FIG. 3 is a left side view of FIG. 2, FIG. 4 is a front view of FIG. 3, and FIG. 5 is a longitudinal cross-sectional view of FIG. 3. 6 is an enlarged view of a portion G of FIG. 5, FIG. 7 is a longitudinal cross-sectional view illustrating a main portion of a bellows wrinkle according to another embodiment of the present invention, and FIG. 8 is a view illustrating a bellows according to another embodiment of the present invention. 9 is a cross-sectional view showing the main portion of the corrugated bone, Figure 9 is a cross-sectional view showing a state in which the bellows is installed on the outside of the tie rod and the rack bar in the vehicle steering apparatus according to an embodiment of the present invention.

Bellows structure of the steering system for a vehicle according to the present invention, as shown in Figures 2 to 9, the hollow rack housing (1) having both sides opening is formed, and extends outside the both ends of the rack housing (1) A rack bar (2) inserted therein, a pair of tie rods (3) connected to both ends of the rack bar (2), and a hollow cylinder having a predetermined width and size to be axially stretchable In the known vehicle steering system comprising a bellows that is formed so that the corrugated portion and the corrugated bone is continuously molded to cover between the both ends of the rack bar (2) and the intermediate end of the tie rod (3), the bellows The wrinkle portion on the large diameter portion 52 side of the (100) is the inner and outer diameters d1 (d2) (D1) of the wrinkle peak 110 and the corrugated bone 120 toward the center in the axial direction from the first wrinkle peak 110. It is formed in the form of a jar gradually increasing (D2), the small diameter portion 54 The wrinkle part on the side is formed to decrease the inner and outer diameters d1, d2, D1, D2 of the wrinkles 110 and the corrugated bone 120 toward the small diameter part 54 side. Cylindrical form (shown as the inner or outer diameter (d1) (d2) (D1) (D2) of the corrugated mountain 110 and the corrugated bone 120 toward the small diameter portion 54 side as shown in the form or conventional Omission). This is caused by the engine (not shown) vibration of the vehicle and vibration generated during driving to transmit and disperse the stress concentrated on the small diameter portion 54 side of the bellows 100 and exist inside the bellows 100 by the engine heat of the vehicle. To prevent deformation of the bellows 100 and the corrugated bone 120 from material degradation and stress concentration of the bellows 100, the small diameter portion 54, from the gas at high temperature and high pressure, the durability of the bellows 100 and the Improved reliability and stable expansion and contraction of the bellows 100 creases in the left and right axial movements of the rack bar 2 and tie rods 3 of the vehicle steering system and forward and backward movements of the tie rods 3. To make it happen.

The corrugated acid 110 is formed in a square shape, and the shape of the corrugated bone 120 is most preferably formed in a square shape as shown in FIG. 6, but is illustrated in FIG. 7. It may be formed in a U-shape as shown, or a round shape as shown in FIG.

In this case, it is preferable that the bellows 100 is integrally molded using a TPEE material which is a thermoplastic polyester elastomer. In addition, the bellows 100 of the synthetic resin material can be formed by integrally molding using a TPE, TPV material having the physical properties of the thermoplastic rubber as conventional.

And the bellows 100 is fixed by a steel band (6) wrapped around it from the outside in a state in which the large diameter portion 52 of a relatively large diameter of both ends is fitted to the outer peripheral surface of the front end of the rack housing (1), The relatively small diameter portion 54 is fixed by a clip 7 that wraps around and fastens on the outside thereof in a state of being fitted on a groove formed on the outer circumferential surface of the middle rod of the tie rod 3.

As described above, in order to increase the watertightness between the bellows 100, the rack housing 1, and the tie rod 3, which is the assembly, the bellows 100 assembly part, that is, the large diameter part 52, is assembled. Or a sealing adhesive is used between the inner diameter of the small diameter portion 54 and the outer diameter of the rack housing 1 and the tie rod 3, or a groove is formed in the assembly portion to install an O-ring (not shown). It is desirable to allow 100) to be fitted.

The bellows 100, the small diameter portion 54 side of the wrinkles (110) pitch P is formed at regular intervals smaller than the large diameter portion 52 side wrinkles (110) pitch (P) or toward the small diameter portion 54 side It is formed to decrease gradually. This causes the creases on the small diameter portion 54 side, which is the most stretchable operation of the bellows 100, to be quickly folded first during driving of the vehicle, so that the high temperature and high pressure present inside the bellows 100 by the engine heat. This is to prevent the deformation of the wrinkles on the side of the small diameter portion 54 from the base.

In addition, the pitch P of the wrinkles 110 on the side of the small diameter portion 54 is larger than the pitch P of the wrinkles 110 on the side of the large diameter portion 52 so that the wrinkle portion on the small diameter portion 54 side is quickly folded. It can be configured by forming at least one or more small.

In addition, the height h of the corrugated peak 110 is formed so that the central portion in the axial direction is lower than the height of the corrugated peak 110 on the large diameter portion 52 side and the small diameter portion 54 side. This lowers the height h of the pleated peak 110 in the axial center portion of the bellows 100, thereby making the inner volume smaller than the conventional bellows 5 with respect to the pleated inner diameter d1 and the pleated bone inner diameter d2. Since it increases and decreases the expansion length of the wrinkles, the deformation of the wrinkles is bent due to the generation of high temperature heat present inside the bellows 100 by the engine heat of the vehicle.

Figure 10 (a) is a schematic diagram showing the heat deformation shape of the conventional bellows at the steering angle neutral of the vehicle, (b) is a schematic diagram showing the heat deformation shape of the bellows according to an embodiment of the present invention at the steering angle neutral of the vehicle 11 (a) is a schematic diagram showing a conventional bellows heat deformation shape when the wheel is variable at the steering angle neutral of the vehicle, (b) is a variable according to an embodiment of the present invention when the wheel is variable at the steering angle neutral of the vehicle This is a schematic diagram showing the heat deformation shape of the bellows.

As shown in FIG. 10 and FIG. 11, a heat deformation test was performed on the bellows 5 according to the embodiment of the present invention and the bellows 100 under the same conditions using the same TPEE material. The bellows 5 is a vehicle in which the wheel angle is variable at the steering angle neutral of the vehicle or at the steering angle neutral of the vehicle (when the bellows 5 is compressed about 28 mm). Deformation that is severely bent by the gas of high pressure occurred, but the bellows 100 according to an embodiment of the present invention, when the wheel is variable at the steering angle neutral of the vehicle or the steering angle neutral of the vehicle (wrinkle of the bellows 100 about 28 At the time of the mm compression), the fold of the central portion of the bellows 100 in the axial direction was not bent from the gas of the high temperature and the high pressure even at an internal temperature of 120 ° C of the bellows 100.

As described above with reference to the accompanying drawings for the preferred embodiment of the present invention, the present invention is not limited by the above-described specific embodiments, those of ordinary skill in the art to which the present invention belongs It is apparent that various modifications and changes can be made without departing from the spirit and scope of the appended claims.

Claims

A hollow rack housing (1) having both ends formed with an opening, a rack bar (2) inserted therein so as to extend outward from both ends of the rack housing (1), and connected to both ends of the rack bar (2) A pair of tie rods 3 and a predetermined width and size to be stretchable in the axial direction are formed in a hollow cylindrical form, and the wrinkles and the corrugations are continuously formed in the form of a pleated portion, so that both ends of the rack bar 2 and the tie are formed. In a known vehicle steering system comprising a bellows formed of rubber or synthetic resin so as to cover between the intermediate ends of the rod 3,

The bellows portion of the bellows 100 on the large diameter portion 52 side of the bellows 100 from the first wrinkles 110 toward the center in the axial direction, the inner and outer diameters d1 and d2 of the wrinkles 110 and the corrugated bone 120 ( D1) (D2) is formed in the shape of a jar gradually increasing, the wrinkle portion of the small diameter portion 54 side toward the small diameter portion 54 toward the inner and outer diameter (d1) of the wrinkles 110 and the corrugated bone (120) (d2) (D1) (D2) is formed in a cone (cone) is formed to gradually decrease or the inner and outer diameter (d1) of the wrinkles 110 and the corrugated bone 120 toward the small diameter portion 54 side ( d2) (D1) (D2) is a bellows structure of a vehicular steering system, characterized in that formed in any one of the cylindrical form is formed.
The method of claim 1,

Bellows structure of the steering system for a vehicle, characterized in that formed on the small diameter portion 54 side wrinkles 110 pitch P is smaller than the large diameter portion 52 side wrinkles 110 pitch P at regular intervals. .
The method of claim 1,

The small diameter portion 54 side wrinkles 110 pitch P is formed to be gradually reduced toward the small diameter portion 54 side than the large diameter portion 52 side wrinkles 110 pitch (P) Bellows structure of vehicle steering system.
The method of claim 1,

Bellows structure of the vehicle steering system, characterized in that at least one of the wrinkles (110) pitch (P) of the small diameter portion 54 side is formed smaller than the pitch (P) of the large diameter portion (52) side wrinkles (110). .
The method of claim 1,

The height h of the corrugated peak 110 is a center portion in the axial direction is formed lower than the height of the corrugated peak 110 on the large diameter portion 52 side and the small diameter portion 54 side. Bellows structure.
The method according to any one of claims 1 to 5,

The bellows structure 110 is a bellows structure of a vehicle steering system, characterized in that formed in a square (square) shape.
The method of claim 1,

The bellows structure 120 is a bellows structure of the vehicle steering system, characterized in that formed in any one of a square (square), U-type, round.