JP4626990B2 - Steering device - Google Patents

Description

  The present invention relates to a rack and pinion type steering device for a vehicle, and more particularly to a support structure for a rack shaft in a steering device, and the steering device is, for example, a power steering device.

  In a rack and pinion type steering device, when an external force such as a reaction force from the road surface or curb acts on the rack shaft, if the external force is large, the rack shaft bends, and the teeth of the teeth at the meshing portion of the pinion and the rack The meshing state changes and a rattling sound is generated. For this reason, a rack shaft support structure for reducing the rattling noise has been proposed.

For example, in the electric power steering apparatus disclosed in Patent Document 1, the rack shaft disposed in the rack housing is supported by first, second, and third support means disposed at intervals in the axial direction. The The first support means is formed by meshing of a rack tooth provided on one end side of the rack shaft and a pinion, and the second support means is constituted by a support bearing provided on the other end side of the rack shaft, The three support means is constituted by a support bearing provided on the rack shaft between the first and second support means in the axial direction. In the electric power steering device disclosed in Patent Document 2, the pinion and the rack guide support one end of the rack shaft housed in the steering gear box, and the ball screw nut is the other end of the rack shaft. The flat bearing (bush) supports the middle part of the rack shaft.
JP 2002-321632 A Japanese Patent Laid-Open No. 11-20717

  By the way, if the bearing or bush that supports the rack shaft is not held at or near a predetermined position set from the viewpoint of suppressing the deflection of the rack shaft, the effect of reducing rattling noise is reduced. However, in order to restrict the movement of the bush having a closed cross section in the insertion direction and the anti-insertion direction, it is necessary to reduce the diameter of the bush in order to mount the bush in the annular groove provided on the inner peripheral surface of the housing. Therefore, its assemblability is reduced. Therefore, if a slit is formed in the bush in order to improve the assembling property of the bush, the support rigidity is lowered and the effect of suppressing the deflection of the rack shaft is lowered. On the other hand, when the bush is inserted so as to come into contact with the step provided in the housing, the bush can be easily inserted into the housing, but the movement of the bush in the anti-insertion direction cannot be restricted. Further, when the movement in the insertion direction and the non-insertion direction is performed by the pressing force in the radial direction of the bush, the pressing force by the bush against the rack shaft also increases, so that the sliding resistance of the rack shaft increases and the steering feeling is increased. Decreases.

  The present invention has been made in view of such circumstances, and the invention according to claims 1 to 5 is a steering device in which the bush inserted into the housing can be easily positioned in the insertion direction and the anti-insertion direction. The purpose is to provide. The invention described in claims 2 to 4 further aims to improve the movement restricting function of the stopper means for restricting the movement of the bush in the anti-insertion direction and to improve the assembling property in the housing. A further object of the present invention is to facilitate positioning of an intermediate support member in a steering apparatus in which a rack shaft is supported by three support members.

  The invention according to claim 1 includes a housing that houses a rack shaft provided with a rack portion that meshes with a pinion to which a steering force is input, and a support means that supports the rack shaft so as to be movable in the axial direction. The support means is a steering device including a bush inserted in the housing in the axial direction and held in the housing, and slidably supports the rack shaft, and the position of the bush in the axial direction is determined. The stopper means includes a step portion provided in the housing for restricting the movement of the bush in the insertion direction, and the stopper means inserted in the insertion direction in the insertion direction and the anti-insertion direction in the anti-insertion direction. A ring for restricting the movement of the bush, and the ring forms an insertion port through which the rack shaft is inserted and can contact the bush. A main body portion, a locking portion that is provided integrally with the main body portion and restricts movement of the ring in the anti-insertion direction, and is provided integrally with the main body portion and protrudes in the axial direction from the main body portion. A steering device having a guide portion that prevents the ring from falling over by contacting an inner peripheral surface of the housing.

  According to this, when the bush is inserted, positioning in the insertion direction is performed by the step portion, and after insertion of the bush, movement in the insertion direction is restricted by the step portion, and movement in the anti-insertion direction is performed by the ring. The bush is held at a predetermined position in the axial direction or in the vicinity thereof. In addition, the movement of the ring in the direction opposite to the insertion direction is restricted by the locking portion, and when the ring is inserted into the housing, the guide portion prevents the body from falling down, which facilitates the insertion of the ring into the housing. Assembling becomes easy.

  According to a second aspect of the present invention, in the steering apparatus according to the first aspect, the locking portion is provided to be bent in the anti-insertion direction radially outward in a part of the main body portion in the circumferential direction. When the force in the anti-insertion direction acts on the main body portion, the distal end portion can be elastically deformed so as to press the inner peripheral surface of the housing in the radial direction, and the guide portion is circumferentially moved from the locking portion. It is provided in the main body part apart from the direction, protrudes in the anti-insertion direction from the main body part, and can be elastically deformed by contact with the inner peripheral surface of the housing.

  According to this, the locking portion bends in the anti-insertion direction and elastically deforms when it comes into contact with the inner peripheral surface, so that it does not hinder the movement of the ring in the insertion direction, while the force in the anti-insertion direction is applied to the main body. When acting on the part, the inner peripheral surface of the housing is pressed so that the engaging part bent in the anti-insertion direction is stretched against the main body part, so that the movement of the bush in the anti-insertion direction is restricted. Moreover, since the guide part protrudes in the anti-insertion direction from the main body part and elastically deforms when it comes into contact with the inner peripheral surface, the guide part is not caught by the housing when the ring is inserted.

  According to a third aspect of the present invention, in the steering device according to the second aspect, the length of the guide portion in the axial direction is longer than the length of the locking portion in the axial direction.

  According to this, since a guide part is longer than a latching | locking part, the degree of the fall of a ring can be made small at the time of ring insertion. Further, since the bend angle can be reduced due to the short locking portion, the pressing force radially outward can be increased, and the movement of the ring in the anti-insertion direction is restricted.

  According to a fourth aspect of the present invention, in the steering apparatus according to the second or third aspect, the plurality of locking portions and the plurality of guide portions are alternately provided in the circumferential direction.

  According to this, since the locking portions and the guide portions are alternately arranged in the circumferential direction, the ring is locked and guided in a state where there is little bias in the circumferential direction.

  According to a fifth aspect of the present invention, in the steering apparatus according to any one of the first to fourth aspects, the support means includes first and second support members and the first and second support members in the axial direction. It is comprised from the said bush arrange | positioned between members.

  According to this, since the rack shaft is supported by the three support members arranged in the axial direction, the deflection of the rack shaft is suppressed, and the rack shaft is arranged between the first and second support members in the axial direction. Bushing is easy to assemble and positioning is easy.

  According to invention of Claim 1, the following effect is show | played. In other words, the bushing is positioned by the stepped portion and the ring, and the ring is provided with a steering device in which the ease of assembly into the housing is improved by the guide portion, and the bushing can be easily positioned in the insertion direction and the anti-insertion direction. can get.

  According to invention of Claim 2, in addition to the effect of the invention of the cited claim, there exists the following effect. That is, since the locking portion and the guide portion are bent in the anti-insertion direction and are elastically deformed, the function of restricting the movement of the bush by the ring is improved, and the assembling property of the ring into the housing is improved.

  According to invention of Claim 3, in addition to the effect of the invention of the cited claim, there exist the following effects. That is, since the pressing force by the locking portion can be increased and the degree of the ring falling by the guide portion can be reduced, the function of restricting the movement of the bush by the ring is improved, and the assembling property of the ring in the housing is improved.

  According to invention of Claim 4, in addition to the effect of the invention of the cited claim, there exists the following effect. That is, since the ring is locked and guided in a state where there is little bias in the circumferential direction, the function of restricting the movement of the bush by the ring is improved, and the assembling property of the ring in the housing is improved.

  According to the invention described in claim 5, in addition to the effect of the invention described in the cited claim, the following effect is produced. That is, the rack shaft is restrained from bending, and the rattling noise caused by the engagement between the pinion and the rack portion is reduced. Further, the bushing disposed between the first and second support members is inserted in the opposite direction. A steering device that can be easily positioned in the direction can be obtained.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
Referring to FIG. 1, a steering device 1 to which the present invention is applied includes a gear box 3 into which a steering force applied to a steering wheel 2 by a driver is input via an interlocking mechanism (not shown), and an output from the gear box 3. A transmission mechanism including a pair of tie rods 4a and 4b that transmits the steering force to the steered wheels, and an auxiliary steering force generation mechanism 5 having an electric motor 25 that generates an auxiliary steering force that reduces the steering force by the driver. This is a rack and pinion type electric power steering apparatus.

  The gear box 3 includes a housing 6 attached to the vehicle body, an input unit 10 having an input shaft 11 to which a steering force from the handle 2 is transmitted, and a steering force from the input unit 10 housed in the housing 6 to transmit the steering force. A rack and pinion mechanism including a rack shaft 22 that outputs to the mechanism.

  The housing 6 has a first end housing 7 as a first housing that rotatably supports the input shaft 11, and a cylinder having an end 9 a that is coupled to the end 7 b of the first end housing 7 in the axial direction. An intermediate housing 9 as a second housing having a cylindrical shape, and a second end housing 8 as a cylindrical third housing having an end 8 a coupled to another end 9 b of the intermediate housing 9. The rack shaft 22 is accommodated across the three housings 7-9.

  Referring also to FIG. 2, the first end housing 7 includes a first housing portion 7 c having a cylindrical portion 7 e extending along the rack shaft 22, and a first housing portion 7 c coupled to the first housing portion 7 c by a bolt B 1. The second housing portion 7d that forms the gear chamber G in cooperation with the housing portion 7c. The cylindrical tubular portion 7e has an end portion 7b and another end portion 7a to which a dustproof boot D that covers a joint portion between the end portion 22a of the rack shaft 22 and the tie rod 4a is attached. The second end housing 8 has an end portion 8a and another end portion 8b to which a dustproof boot D covering between the other end portion 22b of the rack shaft 22 and the tie rod 4b is attached. The intermediate housing 9 is constituted by a thin cylindrical member as compared with the cylindrical portion 7e and the cylindrical second end housing 8, and has a substantially uniform diameter small portion 9c having an end portion 9a, and an end portion. And a large-diameter portion 9d having an inner diameter and an outer diameter larger than the small-diameter portion 9c and a substantially uniform diameter.

  The first housing portion 7c, the intermediate housing 9, and the second end housing 8 form an insertion hole H through which the rack shaft 22 is inserted. A pair of end openings Ha and Hb of the insertion hole H are formed in both end portions 7a and 8b, respectively.

  In the specification or claims, the axial direction, the radial direction, and the circumferential direction are respectively the direction in which the central axis L2 of the rack shaft 22 extends, the radial direction centered on the central axis L2, and the central axis L2. The cross section is a cross section in a plane perpendicular to the central axis L2.

  The input portion 10 is relatively connected to the input shaft 11 rotatably supported by the second housing portion 7d via a bearing 15 held by a torque sensor 14 to be described later, coaxially with the input shaft 11 and via a torsion bar 13. An output shaft 12 that is rotatably coupled and a torque sensor 14 that detects a steering torque based on the amount of twist of the torsion bar 13 are provided. An output shaft 12 to which the torsion bar 13 is coupled at a serration portion 13a as a coupling portion thereof is rotatably supported by the first housing portion 7c via bearings 16 and 17 including a pair of ball bearings in a gear chamber G. The

  The torque sensor 14 attached to the second housing portion 7d outside the gear chamber G is in proportion to the direction A1 of the rotation center line L1 of the input shaft 11 in proportion to the amount of twist of the torsion bar 13 (hereinafter referred to as “rotation center line direction A1”). And a pair of coils 14b and 14c as a detector for detecting the position of the core 14a. The torque sensor 14 is partially covered with a protective cover 19 for preventing a collision with a foreign object during traveling of the vehicle.

  The rack and pinion mechanism includes a pinion 21 that is formed on the output shaft 12 and rotates integrally with the output shaft 12, and a rack shaft 22 on which a rack portion 23 that meshes with the pinion 21 is formed. The pair of bearings 16 and 17 support a pair of journal portions 12c and 12d respectively provided at both end portions 12a and 12b located on the output shaft 12 with the pinion 21 in the rotation center line direction A1. The rotation center line of the output shaft 12 and the pinion 21 coincides with the rotation center line L1.

  A rack shaft 22 arranged to extend in the left-right direction in a state where the steering device 1 is mounted on a vehicle has an outer peripheral surface that is substantially a cylindrical surface except for the rack portion 23, and is provided on the steering device 1 to be described later. The structure is supported by the housing 6 so as to be capable of reciprocating in the axial direction. The rack portion 23 having a tooth portion 23a formed in a notch portion in which a part of the rack shaft 22 is cut out in parallel with the central axis L2 over a predetermined range in the axial direction is the outer peripheral surface of the rack shaft 22. The rack 23 is pressed against the pinion 21 by a rack guide 31 that presses the rack 23 against the back 23b.

  The transmission mechanism includes a pair of tie rods 4a and 4b connected to both end portions 22a and 22b of the rack shaft 22 via ball joints 24a and 24b as coupling portions, and each tie rod 4a and 4b and a steering wheel. And a link mechanism (not shown) for connecting the two.

  The auxiliary steering force generating mechanism 5 that adds an auxiliary steering force to the rack shaft 22 at the time of turning is electrically operated as an actuator controlled by an electronic control unit (not shown) to which the steering torque detected by the torque sensor 14 is input. A motor 25 and a worm gear 26 as a transmission mechanism that transmits the rotational force of the electric motor 25 to the rack shaft 22 are provided. The worm gear 26 housed in the gear chamber G is coupled to the worm 26a that rotates integrally with the rotating shaft of the electric motor 25 attached to the first housing portion 7c, and rotates together with the output shaft 12 by being coupled to the output shaft 12. Worm wheel 26b.

  Therefore, in the steering device 1, when the steering force applied by the driver to the steering wheel 2 to be steered is transmitted to the input shaft 11, the input shaft 11 causes the torsion bar 13 to twist and the output shaft 12 and the pinion. 21 is rotated, and the rack shaft 22 driven by the pinion 21 moves in the axial direction. At the same time, the electric motor 25 that operates in proportion to the steering torque detected by the torque sensor 14 moves the rack shaft 22 in the axial direction via the worm gear 26, the output shaft 12, and the pinion 21. For this reason, the auxiliary steering force generated by the electric motor 25 is transmitted to the rack shaft 22, and the driver's steering force is reduced.

The support structure of the rack shaft 22 will be described with reference to FIG.
The support structure includes support means that is held by the housing 6 and supports the rack shaft 22 so as to be movable in the axial direction, and stopper means that restricts movement of the support means with respect to the housing 6.

  The support means includes a rack guide 31 held in the first housing portion 7c, a first end bush 41 as a first support member, and a second support member as a second support member held in the second end housing 8. It comprises an end bush 51 and an intermediate bush 61 as a third support member that is held in the intermediate housing 9 and disposed between the end bushes 41 and 51 in the axial direction. After the bushes 41, 51, 61 are held in the corresponding housings 7, 8, 9, the rack shaft 22 is inserted into the annular bushes 41, 51, 61.

  2 and 3, the cylindrical rack guide 31 formed in the first housing part 7c and inserted into the insertion hole 30a of the holding part 30 protruding from the cylindrical part 7e is provided on the rack part 23. It has a sheet member 31a made of a low friction member in surface contact with the back surface 23b. The rack guide 31 slides the rack shaft 22 in the axial direction by pressing the rack portion 23 against the pinion 21 by the elastic force of the spring 33 disposed between the cap 32 screwed to the holding portion 30. Support movably.

  An annular bush 41 made of synthetic resin is arranged on the opposite side of the bush 61 in the axial direction between the meshing part of the pinion 21 and the rack part 23 or the rack guide 31. It is inserted. The bush 41 is held between the rack guide 31 and the end opening Ha by a holding portion 40 which is a part of the cylindrical portion 7e, and supports the rack shaft 22 slidably on the back surface 23b.

  Referring to FIG. 3, the holding portion 40 includes a first insertion hole 40a that is a part of the insertion hole H and has a larger diameter than the insertion hole portion H1 provided in the cylindrical portion 7e, and a first insertion hole 40a. And a second insertion hole 40b having a large diameter. These insertion holes 40a and 40b are part of the insertion hole H. The insertion hole portion H1 is radially inward with respect to the first insertion hole 40a, the first insertion hole 40a is radially inward with respect to the second insertion hole 40b, and the second insertion hole 40b is the third insertion hole H2. Are located radially inward. The third insertion hole H2 provided in the end portion 7a and having the end opening Ha is a ball joint as a contact portion provided in the rack shaft 22 that defines a rack stroke in one axial direction in the insertion hole H. 24a (refer FIG. 1) is a part which can approach. A bush 41 inserted in a light press-fit state from the end opening Ha through the third and second insertion holes H2 and 40b into the first insertion hole 40a is inserted into the insertion hole portion H1 and the first insertion hole 40a in the holding portion 40. The movement in the insertion direction is restricted by contact with the stepped portion 40c formed by the metal ring, and the metal annular ring 49 as a stopper that is press-fitted and fixed in the second insertion hole 40b is used to move the anti-insertion direction. The movement in the direction (that is, the direction opposite to the insertion direction) is restricted, and the retaining portion 40 is prevented from being removed. In the holding portion 40, the ring 49, which is in contact with the stepped portion 40d formed by the first insertion hole 40a and the second insertion hole 40b and whose movement in the insertion direction is restricted, is contacted by the ball joint 24a. Since it comes into contact, it also serves as a stopper that defines the rack stroke. Therefore, as for the bush 41, the step portion 40c and the ring 49 constitute the stopper means.

  Referring to FIG. 1, an annular bush 51 made of synthetic resin serves as a stopper that comes into contact with a ball joint 24b as a contact portion provided on the rack shaft 22 so as to define a rack stroke in the other direction in the axial direction. It is held by a holding portion 50 which is a part of the end portion 8b. The bush 51 supports the rack shaft 22 so as to be slidable on the entire inner peripheral surface thereof. The holding portion 50 is inserted with a diameter larger than that of the insertion hole portion H3 with a portion of the insertion hole H between the end opening Hb and an insertion hole portion H3 provided in the second end housing 8. A hole 50a is provided. The bush 51, which has been reduced in diameter and inserted into the insertion hole 50a from the end opening Hb through the insertion hole portion H3, has a pair of step portions 50b formed by the insertion hole H and the insertion hole 50a in the holding portion 50. Abutting on 50c, the movement in the insertion direction and the anti-insertion direction is restricted. Therefore, for the bush 51, the stopper means is constituted by both step portions 50b and 50c. Note that the bush 51 may be provided with a slit in order to easily reduce the diameter.

  Referring to FIGS. 1 and 4, the synthetic resin annular bush 61 is located between the holding portions 40 and 50 or between the holding portions 30 and 50 at a position where the rack portion 23 is not inserted in the rack stroke range. The rack shaft 22 is slidably supported by a curved portion 61c convex inward in the radial direction by being held by a holding portion 60 that is a part of the large-diameter portion 9d positioned therebetween. Therefore, the bush 61 is positioned between the bushes 41 and 51 or between the rack guide 31 and the bush 51 in the axial direction. The stopper means for restricting the movement of the bush 61 in the axial direction includes a step portion 60 c and a ring 62.

  The bush 61 and the ring 62 are part of the insertion hole H before the intermediate housing 9 is coupled to the second end housing 8, and are formed in the opening H4a of the insertion hole portion H4 provided in the end 9b (see FIG. 1). To the insertion hole portion H4 in the axial direction. In the holding portion 60, the step portion 60c is provided in the intermediate housing 9, and the end portion 61a of the bush 61 in the insertion direction restricts the movement of the bush 61 in the insertion direction. The end 61b of the bush 61 in the opposite insertion direction is inserted in the same insertion direction as the bush 61, and the movement of the bush 61 in the opposite insertion direction is restricted.

  Referring to FIGS. 4 and 5, the stepped portion 60c is constituted by a stepped portion of a small diameter portion 9c and a large diameter portion 9d. On the other hand, the ring 62 is formed by pressing from a thin plate material made of metal, for example, steel. The bush 61 and the ring 62 are part of the insertion hole H in the holding part 60 and are part of the insertion hole part H4 having a larger diameter than the insertion hole part H5 provided in the small diameter part 9c. Inserted and held.

  Referring to the ring 62, a ring portion 63a is formed in the anti-insertion direction so as to form an insertion port 63a through which the rack shaft 22 is inserted and the bushing 61 can be contacted in the axial direction. A locking part 64 that restricts the movement of 62 and an integral part of the main body part 63, and project from the main body part 63 in the axial direction to contact the inner peripheral surface 60 e of the holding part 60 to prevent the ring 62 from falling down. And a guide portion 65.

  In the main body 63, an inner peripheral edge 63b that defines a circular insertion port 63a is formed by an annular wall protruding in the anti-insertion direction over the entire periphery. The inner peripheral edge 63b forms a gap in the radial direction over the entire circumference with the rack shaft 22 when no load is applied, and the rack shaft 22 bends by the action of the external force on the rack shaft 22 and comes into contact with the inner peripheral edge 63b. When the bending is suppressed.

  A plurality of, in this embodiment, six locking portions 64 are provided at equal intervals in the circumferential direction in a part of the main body portion 63 in the circumferential direction. Each locking portion 64 is bent from the outer peripheral edge 63c of the main body portion 63 in the radially outward direction at a bending angle θ in the anti-insertion direction and defines an insertion hole 60a at the distal end portion 64a in the radial direction. 60e is pressed in the radial direction. Each locking portion 64 is formed of an elastically deformable protruding piece, and when the bush 61 applies a force in the anti-insertion direction to the main body portion 63, the tip portion 64a contacts the inner peripheral surface 60e. In order to push out the engaging portions 64 that are in the radially outward direction, the engaging portions 64 are elastically deformed so as to increase the pressing force applied to the inner peripheral surface 60e.

  A plurality of, in this embodiment, six guide portions 65 are provided in the main body portion 63 at equal intervals in the circumferential direction so as to be spaced apart from the locking portion 64 in the circumferential direction. Each guide portion 65 protrudes from the main body portion 63 in the anti-insertion direction, and the length of the guide portion 65 in the axial direction is longer than the length of the locking portion 64 in the axial direction. The locking portions 64 and the guide portions 65 are alternately provided in the circumferential direction one by one in this embodiment, but may be alternately provided in a state where one or a plurality are mixed or a plurality are all mixed. .

  To form the ring 62, first, a flat plate material is punched to form a material in which the annular main body 63, the locking portion 64, and the guide portion 65 extend in a flat plate shape. Is done. Next, the inner peripheral edge 63a, the guide portion 65, and the locking portion 64 that are bent with respect to the main body portion 63 are formed by bending the material by pressing from the same direction as the anti-insertion direction. 4 is obtained.

  Therefore, the rack shaft 22 is supported at three points by the three bushes 41, 51, 61 with respect to the housing 6 (see FIG. 1), and further supported by the rack guide 31, so that the external force is applied. The steering device 1 is obtained in which the deflection of the rack shaft 22 is suppressed and the rattling noise is reduced.

Next, operations and effects of the embodiment configured as described above will be described.
In the steering device 1, the stopper means for defining the position of the bush 61 in the axial direction is composed of a step portion 60 c provided in the holding portion 60 and a ring 62 inserted in the holding portion 60. 62 includes a main body portion 63 capable of contacting the bush 61, a locking portion 64 that restricts the movement of the ring 62 in the anti-insertion direction, and a guide portion 65 that prevents the ring 62 from falling down. When the 61 is inserted, positioning in the insertion direction is performed by the step portion 60c. After the bush 61 is inserted, movement in the insertion direction is restricted by the step portion 60c, and movement in the anti-insertion direction is restricted by the ring 62. Thus, the bush 61 is held at or near a predetermined position in the axial direction. In addition, the ring 62 is restricted from moving in the anti-insertion direction by the locking portion 64, and when inserted into the intermediate housing 9, the guide portion 65 prevents a fall, so that the insertion becomes smooth, Assembling of the ring 62 to the intermediate housing 9 is facilitated. As a result, the bush 61 is positioned by the step portion 60c and the ring 62, and the ring 62 is smoothly inserted into the intermediate housing 9 by the guide portion 65. Therefore, the bush 61 is positioned in the insertion direction and the anti-insertion direction. Can be obtained.

  The locking portion 64 is provided to be bent in the anti-insertion direction radially outward from the main body portion 63, and when the force in the anti-insertion direction acts on the main body portion 63, the inside of the holding portion 60 is The circumferential surface 60e can be elastically deformed so as to press outward in the radial direction. The guide portion 65 is spaced apart from the locking portion 64 in the circumferential direction and protrudes from the main body portion 63 in the anti-insertion direction. By being elastically deformable by contact with the surface 60e, the locking portion 64 is bent in the anti-insertion direction and elastically deforms when in contact with the inner peripheral surface 60e. On the other hand, when the force in the anti-insertion direction acts on the main body portion 63, the inner peripheral surface 60e is pressed so that the locking portion 64 is stretched, so that the movement of the bush 61 in the anti-insertion direction is restricted. Is done. Further, since the guide portion 65 protrudes in the anti-insertion direction from the main body portion 63 and elastically deforms when coming into contact with the inner peripheral surface 60e, the guide portion 65 is caught by the intermediate housing 9 when the ring 62 is inserted. There is no. As a result, the function of restricting the movement of the bush 61 by the ring 62 is improved, and the assembling property of the ring 62 into the intermediate housing 9 is improved.

  Since the length of the guide portion 65 in the axial direction is longer than the length of the locking portion 64 in the axial direction, it is possible to reduce the degree of collapse of the ring 62 when the ring 62 is inserted. In addition, since the bend angle θ can be reduced because the locking portion 64 is short, the pressing force radially outward can be increased, and the movement of the ring 62 in the anti-insertion direction is restricted. The As a result, the degree of tilting of the ring 62 at the time of insertion can be reduced, so that the function of restricting the movement of the bush 61 by the ring 62 is improved, and the assembling property of the ring 62 into the intermediate housing 9 is improved.

  Since the plurality of locking portions 64 and the plurality of guide portions 65 are alternately provided in the circumferential direction, the locking portions 64 and the guide portions 65 are alternately arranged in the circumferential direction. Since the ring 62 is locked and guided, the function of restricting the movement of the bush 61 by the ring 62 is improved, and the assembling property of the ring 62 into the intermediate housing 9 is improved. Further, since the plurality of locking portions 64 and the plurality of guide portions 65 are alternately provided at equal intervals in the circumferential direction and one by one, the bias in the circumferential direction is further reduced. Restriction of movement and prevention of falling by the guide unit 65 are made more effective.

  In addition to being supported by the rack guide 31, the rack shaft 22 is disposed between the bushes 41 and 51 held by the first and second end housings 7 and 8 and the bushes 41 and 51 in the axial direction, respectively. By comprising the bush 61 held by the housing 9, the rack shaft 22 is supported by three support members arranged in the axial direction, so that the deflection of the rack shaft 22 due to the application of the external force is suppressed. In addition, the assembly of the bush 61 disposed between the bushes 41 and 51 in the axial direction is facilitated, and positioning is facilitated. As a result, the deflection of the rack shaft 22 is suppressed, the rattling noise caused by the meshing of the pinion 21 and the rack portion 23 is reduced, and the insertion direction of the bush 61 disposed between the bushes 41 and 51 and A steering device 1 that can be easily positioned in the anti-insertion direction is obtained.

Hereinafter, an embodiment in which a part of the configuration of the above-described embodiment is changed will be described with respect to the changed configuration.
The guide portion 65 may be a ring 62 that also serves as a locking portion by the distal end portion of the guide portion 65 in the radial direction pressing the inner peripheral surface 60e radially outward.
The bush 41 can be omitted.
The steering device to which the present invention is applied may be a power steering device in which the auxiliary steering force generation mechanism includes an actuator other than the electric motor, and the auxiliary steering force generation mechanism applies the auxiliary steering force to the rack shaft. May be. Furthermore, the steering apparatus to which the present invention is applied may not include an auxiliary steering force generation mechanism.

1 is a schematic overall view showing a part of a steering device to which the present invention is applied in cross section. FIG. 2 is a cross-sectional view of a cross section including a rotation center line of an input shaft in the steering device of FIG. 1. It is the III-III sectional view taken on the line of FIG. 1 when a rack axis | shaft moves. (A) is the principal part enlarged view of FIG. 1 by which a ring is shown by an external appearance, (B) is the BB sectional drawing of (A). It is the VV sectional view taken on the line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Steering device, 2 ... Steering wheel, 3 ... Gear box, 5 ... Auxiliary steering force generation mechanism, 6-9 housing, 10 ... Input part, 11 ... Input shaft, 12 ... Output shaft, 13 ... Torsion bar, 14 ... Torque Sensor, 15 to 17 ... Bearing, 18 ... Pin, 19 ... Protective cover, 21 ... Pinion, 22 ... Rack shaft, 23 ... Rack part, 25 ... Electric motor, 26 ... Worm gear, 30 ... Holding part, 31 ... Rack guide, 32 ... Cap, 33 ... Spring, 40 ... Holding part, 41 ... Bush, 49 ... Ring, 50 ... Holding part, 51 ... Bushing, 60 ... Holding part, 60c ... Step part, 61 ... Bushing, 62 ... Ring, 63 ... Main body part, 64 ... locking part, 65 ... guide part,
B1, B2 ... bolts, G ... gear chamber, D ... dustproof boot, H ... insertion hole, θ ... bending angle.

Claims (5)

A housing that houses a rack shaft provided with a rack portion that meshes with a pinion to which a steering force is input; and a support means that supports the rack shaft so as to be movable in the axial direction. A steering device configured by a bush inserted in the axial direction and held by the housing and slidably supporting the rack shaft;
Stopper means for defining the position of the bush in the axial direction is provided, and the stopper means is provided in the housing to restrict the movement of the bush in the insertion direction, and in the insertion direction in the housing. A ring that is inserted and restricts the movement of the bush in the anti-insertion direction, the ring forming an insertion port through which the rack shaft is inserted, and a main body that can contact the bush; and the main body A locking portion that is provided integrally with the portion and restricts movement of the ring in the anti-insertion direction, and is provided integrally with the main body portion and protrudes axially from the main body portion to contact the inner peripheral surface of the housing And a guide portion that prevents the ring from falling over.   The locking portion is provided at a distal end portion when a force in the anti-insertion direction acts on the main body portion while being provided in a part of the main body portion in the circumferential direction and bent in the anti-insertion direction radially outward. The inner peripheral surface of the housing can be elastically deformed so as to press in a radial direction, and the guide portion is provided in the main body portion so as to be spaced apart from the locking portion in the circumferential direction and counteracts from the main body portion. The steering apparatus according to claim 1, wherein the steering apparatus protrudes in an insertion direction and is elastically deformable by contact with the inner peripheral surface of the housing.   The steering device according to claim 2, wherein the length of the guide portion in the axial direction is longer than the length of the locking portion in the axial direction.   The steering device according to claim 2 or 3, wherein the plurality of locking portions and the plurality of guide portions are alternately provided in a circumferential direction. The said support means is comprised from the 1st, 2nd support member, and the said bush arrange | positioned between the said 1st, 2nd support member in the axial direction. The steering device according to any one of the above.

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