JP2013177069A - Rack guide mechanism and vehicle steering device having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rack guide mechanism in which a support yoke can be suppressed from being largely inclined to a housing, and also to provide a vehicle steering device with the mechanism.SOLUTION: A rack guide mechanism 50 is accommodated in the hole 42 of a housing 40 and slidably guides a rack shaft 20, and includes: a support yoke 51 which has a yoke sidewall portion 51B corresponding to the inner wall portion 42C of the hole 42, and has a yoke outer groove 51D formed on the yoke sidewall portion 51B; a plug 55 in which a plug sidewall portion 55B is fitted to the inner wall portion 42C of the housing hole 42, and the plug sidewall portion 55B faces the yoke sidewall portion 51B with a gap, and a plug inner groove 55C is formed on the plug sidewall portion 55B, and the plug inner groove 55C faces a yoke outer groove 51D; and an elastic member 54 which is disposed across the yoke outer groove 51D and the plug inner groove 55C.

Description

  The present invention relates to a rack guide mechanism that guides movement of a rack shaft by a support yoke, and a vehicle steering apparatus having the rack guide mechanism.

  The vehicle steering apparatus includes a housing, a rack shaft, and a rack guide mechanism. The rack guide mechanism has a support yoke, a plug, and an elastic member. The support yoke is accommodated in the housing together with the rack shaft. In general, the outer peripheral portion of the support yoke faces the inner peripheral portion of the housing through a gap. The plug is fitted into an opening formed in the housing. The elastic member is attached to a groove formed in the outer peripheral portion of the support yoke.

  The rack support device of Patent Document 1 corresponds to a rack guide mechanism. The rack support device has a rack guide corresponding to a support yoke. A gap is formed between the rack guide and the housing.

JP 2010-47148 A

  In the rack guide mechanism, since the gap is formed between the support yoke and the housing, the support yoke may be inclined with respect to the housing. When the support yoke is largely inclined with respect to the housing, contact noise may be generated due to the support yoke coming into contact with the housing.

  In order to solve the above-described problems, an object of the present invention is to provide a rack guide mechanism capable of suppressing a tilt of a support yoke with respect to a housing, and a vehicle steering apparatus having the mechanism.

  (1) The first means is the rack guide mechanism that supports the rack shaft that meshes with the pinion shaft and moves axially in the housing in the invention according to claim 1, and is housed in a housing hole of the housing. The rack shaft is slidably guided, has a yoke side wall portion corresponding to the inner wall portion of the receiving hole, and has a yoke yoke groove formed in the yoke side wall portion, and the receiving hole A plug side wall portion that is fitted to the inner wall portion of the plug, the plug side wall portion is opposed to the yoke side wall portion through a gap, a plug inner groove is formed in the plug side wall portion, and the plug inner groove is the yoke The gist of the invention is to have a plug facing the outer groove, and an elastic member disposed across the yoke outer groove and the plug inner groove.

  In the rack guide mechanism, when a force for tilting the support yoke with respect to the housing acts on the support yoke, the elastic member is compressed by the plug inner groove and the yoke outer groove as the position of the yoke outer groove changes with respect to the plug inner groove. . At this time, a restoring force is generated in each of the portion of the elastic member positioned in the plug inner groove and the portion of the elastic member positioned in the outer yoke groove. For this reason, the restoring force generated in the elastic member is larger than the configuration in which the plug inner groove is not formed in the plug, that is, the configuration in which the elastic member is fitted only in the yoke outer groove of the support yoke and the plug. For this reason, it can suppress that a support yoke inclines largely with respect to a housing.

  (2) The second means is the rack guide mechanism according to the invention described in claim 2, ie, the rack guide mechanism according to claim 1, wherein the rack guide mechanism includes a biasing member that pushes the support yoke toward the rack shaft. And the elastic member is arranged in the yoke outer groove and the plug inner groove in a state in which the biasing member is compressed in a biasing direction which is a direction of pushing the support yoke.

  In the rack guide mechanism, since the elastic member disposed across the yoke outer groove and the plug inner groove is compressed in advance in the biasing direction, it is possible to further suppress the support yoke from being greatly inclined with respect to the housing. it can.

  (3) The third means is the rack guide mechanism according to the invention described in claim 3, ie, the rack guide mechanism according to claim 1 or 2, wherein the elastic member has an annular shape, and the groove in the plug The gist is to have an annular shape corresponding to the shape of the elastic member.

  In the rack guide mechanism, since the groove in the plug has an annular shape, a restoring force generated in the elastic member is large when a force for tilting the support yoke is applied. For this reason, it can suppress further that a support yoke inclines largely with respect to a housing.

  (4) The fourth means is the rack guide mechanism according to any one of claims 1 to 3, that is, the plug inner groove is a depth direction of the plug inner groove. The first inclined surface and the second inclined surface are inclined with respect to each other, and the first inclined surface and the second inclined surface have shapes that approach each other in the width direction of the groove in the plug, and the elastic member is The gist is that the yoke outer groove and the plug inner groove are disposed in a compressed state in contact with the first inclined surface and the second inclined surface.

  According to this invention, since the first inclined surface and the second inclined surface compress the elastic member, the vertical surface perpendicular to the width direction of the groove in the plug is generated in the elastic member as compared with the case where the elastic member is compressed. Shear force can be reduced.

  (5) A fifth means is characterized by having the rack guide mechanism according to any one of claims 1 to 4, that is, the invention according to claim 5.

  The present invention provides a rack guide mechanism capable of suppressing a tilt of a support yoke with respect to a housing, and a vehicle steering apparatus having the mechanism.

The block diagram which shows the whole structure of the steering apparatus for vehicles in embodiment of this invention. It is sectional drawing regarding the steering apparatus for vehicles of embodiment, and sectional drawing which shows a cross-sectional structure perpendicular | vertical to the axial direction of the rack shaft in FIG. It is sectional drawing regarding the steering apparatus for vehicles of embodiment, and sectional drawing which shows the sectional structure of the periphery of the rack shaft in FIG. 2, a rack guide mechanism, and the mechanism. It is sectional drawing regarding the steering apparatus for vehicles in other embodiment of this invention, and sectional drawing which shows a cross-sectional structure perpendicular | vertical to the axial direction of a rack shaft. It is sectional drawing regarding the steering apparatus for vehicles of a comparative example, and sectional drawing which shows a cross-sectional structure perpendicular | vertical to the axial direction of a rack shaft.

With reference to FIG. 1, the structure of the steering apparatus 1 for vehicles is demonstrated.
The vehicle steering apparatus 1 includes a steering shaft 10, a rack shaft 20, an assist device 30, a housing 40, and a rack guide mechanism 50.

The steering shaft 10 includes a column shaft 11, an intermediate shaft 12, and a pinion shaft 13.
A steering wheel 2 is fixed to the column shaft 11. The column shaft 11 transmits the rotation of the steering wheel 2 to the pinion shaft 13 via the intermediate shaft 12. The intermediate shaft 12 connects the column shaft 11 and the pinion shaft 13 to each other. The pinion shaft 13 has a pinion 14. The pinion 14 constitutes the rack and pinion mechanism 1A.

  The rack shaft 20 has a rack 21. The rack 21 constitutes a rack and pinion mechanism 1A. The rack shaft 20 moves according to the rotation of the pinion shaft 13 when the rack 21 meshes with the pinion 14. The steered wheels 3 are connected to the rack shaft 20.

The assist device 30 includes an electric motor 31, a worm shaft 32, and a worm wheel 33.
The worm shaft 32 is rotated by the output of the electric motor 31. The worm wheel 33 rotates integrally with the column shaft 11. The worm wheel 33 meshes with the worm shaft 32. The worm shaft 32 and the worm wheel 33 constitute a speed reduction mechanism 1B.

The operation of the vehicle steering apparatus 1 will be described.
The steering shaft 10 rotates as the steering wheel 2 rotates. The rack and pinion mechanism 1 </ b> A converts the rotational motion of the pinion shaft 13 into linear motion of the rack shaft 20. The rack shaft 20 meshes with the pinion shaft 13 and moves in the housing 40 in the axial direction indicated by an arrow X in the drawing. As the rack shaft 20 moves in the axial direction X, the direction of the steered wheels 3 changes. When the steering shaft 10 is rotating, the assist device 30 drives the electric motor 31 based on the output of a torque sensor (not shown) that detects the torque applied to the steering shaft 10 to move the rack shaft 20. An assist torque to assist is applied to the steering shaft 10.

  The housing 40 and the rack guide mechanism 50 will be described with reference to FIG. FIG. 2 shows a cross section of the housing 40 and the like that is perpendicular to the axial direction X (FIG. 1) of the rack shaft 20 and along the axial direction Y of the pinion shaft 13.

The housing 40 includes a rack housing part 41, a housing hole 42, a seal member 43, a ball bearing 44, and a needle bearing 45.
The rack accommodating portion 41 accommodates a portion including the rack 21 of the rack shaft 20, a portion including the pinion 14 of the pinion shaft 13, a seal member 43, a ball bearing 44, and a needle bearing 45. The rack accommodating portion 41 has an opening 41A that serves as an insertion port for the pinion shaft 13.

  The accommodation hole 42 accommodates the support yoke 51, the elastic members 53 and 54, a part of the plug 55, and the urging member 56. The accommodation hole 42 has an opening 42 </ b> A that serves as an insertion opening for the support yoke 51.

  The seal member 43 is located between the pinion shaft 13 and the housing 40 in the opening 41 </ b> A of the rack housing portion 41. The seal member 43 suppresses entry of foreign matter into the housing 40 from the opening 41A.

  The ball bearing 44 supports a portion of the pinion shaft 13 above the pinion 14. The needle bearing 45 supports a portion of the pinion shaft 13 below the pinion 14. The ball bearing 44 and the needle bearing 45 are located at locations spaced apart from each other in the axial direction Y of the pinion shaft 13.

  The rack guide mechanism 50 includes a support yoke 51, a seat member 52, an O-ring as an elastic member 53, an O-ring as an elastic member 54, a plug 55, and a coil spring as an urging member 56. The rack guide mechanism 50 supports the rack shaft 20.

  The support yoke 51 is located between the rack shaft 20 and the biasing member 56. The support yoke 51 can move in the movement direction Z within the housing 40. The support yoke 51 guides the movement of the rack shaft 20 in the axial direction X (see FIG. 1). The support yoke 51 supports the rack shaft 20 through the sheet member 52 so as to be slidable.

The sheet member 52 is formed of a resin excellent in wear resistance and slidability. The seat member 52 is worn by the movement of the rack shaft 20 in the axial direction X (see FIG. 1).
The elastic member 53 and the elastic member 54 are located between the support yoke 51 and the plug 55 in the direction perpendicular to the moving direction Z. The elastic member 53 and the elastic member 54 are located at locations spaced from each other in the movement direction Z. The elastic member 53 and the elastic member 54 are formed of an elastic resin.

  The plug 55 is located in the opening 42 </ b> A of the accommodation hole 42. The plug 55 has a male screw 55A. The plug 55 is fixed to the housing 40 by screwing the screw 55 </ b> A into the female screw 42 </ b> B formed in the accommodation hole 42. The plug 55 closes the opening 42 </ b> A of the accommodation hole 42.

  The urging member 56 is located between the support yoke 51 and the plug 55 in the movement direction Z. The biasing member 56 presses the support yoke 51 toward the rack shaft 20 by applying a force acting in the biasing direction in the figure to the support yoke 51.

The operation of the rack guide mechanism 50 will be described.
The biasing member 56 presses the support yoke 51 toward the rack shaft 20, so that the support yoke 51 supports the rack shaft 20 slidably. When the seat member 52 is worn, the rack guide mechanism 50 maintains the state in which the support yoke 51 slidably supports the rack shaft 20 by the urging member 56 moving the support yoke 51 in the urging direction. .

With reference to FIG. 3, the structure of the accommodation hole 42 and the structure of the rack guide mechanism 50 will be described in more detail. FIG. 3 is an enlarged cross-sectional view of a part of FIG. 2 including the rack guide mechanism 50.
The accommodation hole 42 has an inner wall portion 42C. The inner wall portion 42C is formed with a female screw 42B, and has an inner peripheral surface with a one-dot chain line C in the figure as a central axis.

The support yoke 51 includes a guide groove 51A, a yoke side wall portion 51B, a yoke outer groove 51C, and a yoke outer groove 51D.
The rack shaft 20 is fitted into the guide groove 51 </ b> A via the sheet member 52.

The yoke side wall portion 51B corresponds to the inner wall portion 42C. The yoke side wall portion 51B has a cylindrical outer peripheral surface whose center axis is a one-dot chain line C in the drawing.
The yoke outer groove 51C and the yoke outer groove 51D are formed in an annular shape on the outer periphery of the yoke side wall portion 51B, and have a rectangular cross section. The yoke outer groove 51C and the yoke outer groove 51D are located at locations spaced from each other in the movement direction Z. The elastic member 53 is fitted in the yoke outer groove 51C. An elastic member 54 is fitted into the yoke outer groove 51D.

  The plug 55 has a cup shape. The plug 55 accommodates the end of the support yoke 51 on the side opposite to the biasing direction, the elastic member 53, the elastic member 54, and the biasing member 56. The plug 55 has a plug side wall portion 55B and a plug inner groove 55C.

  The plug side wall portion 55B is fitted into the inner wall portion 42C of the accommodation hole 42 by screwing the male screw 55A into the female screw 42B. Plug side wall portion 55B is opposed to yoke side wall portion 51B through a gap, and has a cylindrical inner peripheral surface having a one-dot chain line C in the figure as a central axis.

  The plug inner groove 55C is formed in an annular shape on the inner periphery of the plug side wall portion 55B, and has a V-shaped cross section. The plug inner groove 55C has a first inclined surface 55D and a second inclined surface 55E.

  The first inclined surface 55D and the second inclined surface 55E are inclined with respect to the depth direction of the plug inner groove 55C and have shapes that approach each other in the width direction of the plug inner groove 55C. The depth direction of the plug inner groove 55C corresponds to a direction perpendicular to the inner peripheral surface of the plug side wall portion 55B and a direction in which the plug inner groove 55C is recessed with respect to the inner peripheral surface of the plug side wall portion 55B. The width direction of the plug inner groove 55C corresponds to a direction perpendicular to the depth direction of the plug inner groove 55C. The direction perpendicular to the depth direction of the plug inner groove 55C corresponds to a direction parallel to the urging direction. The elastic member 54 is fitted into the plug inner groove 55C. The first inclined surface 55D and the second inclined surface 55E sandwich the elastic member 54, thereby compressing the elastic member 54 in a direction parallel to the biasing direction.

  The elastic member 53 is located between the yoke side wall portion 51B and the plug side wall portion 55B, and is fitted in the yoke outer groove 51C. The elastic member 53 holds the elastic member 53 in a state in which the yoke side wall portion 51B and the plug side wall portion 55B are compressed in a direction perpendicular to the urging direction. It is compressed.

  The elastic member 54 is located between the yoke side wall portion 51B and the plug side wall portion 55B, and is fitted into both the yoke outer groove 51D and the plug inner groove 55C. The elastic member 54 is compressed in a direction parallel to the urging direction by holding the elastic member 54 in a state in which the yoke side wall portion 51B and the plug side wall portion 55B are compressed in a direction parallel to the urging direction. Has been.

The operation of the elastic member 54 will be described with reference to FIG.
When the support yoke 51 moves so as to incline in the direction indicated by the arrow R1 or the arrow R2 with respect to the point P in the drawing, the portion of the elastic member 54 located in the plug inner groove 55C and the elastic member 54 A restoring force is generated in each of the portions located in the yoke outer groove 51D. When the support yoke 51 moves so as to incline in the direction indicated by the arrow R1 with respect to the point P in the drawing, the elastic member 54 applies a force including the components indicated by the arrows F1 and F2 to the yoke outer groove 51D. Further, when the support yoke 51 moves so as to tilt in the direction indicated by the arrow R2 with respect to the point P in the drawing, the elastic member 54 applies a force including the components indicated by the arrows F3 and F4 to the yoke outer groove 51D. . Thus, the restoring force of the elastic member 54 restricts the rotation of the support yoke 51 around the point P in the figure.

The rack guide mechanism 50 of the vehicle steering apparatus 1 of the present embodiment has the following effects.
(1) The rack guide mechanism 50 includes a support yoke 51 in which a yoke outer groove 51D is formed in the yoke side wall portion 51B, a plug inner groove 55C in the plug side wall portion 55B, and the plug inner groove 55C in the yoke outer groove 51D. It has the plug 55 which opposes, and the elastic member 54 arrange | positioned ranging over yoke outer groove | channel 51D and plug inner groove | channel 55C. For this reason, when the force for tilting the support yoke 51 with respect to the housing 40 acts on the support yoke 51, the elastic member 54 is caused to change by the change in the position of the yoke outer groove 51D with respect to the plug inner groove 55C. Compressed by 51D. At this time, a restoring force is generated in each of the portion of the elastic member 54 located in the plug inner groove 55C and the portion of the elastic member 54 located in the yoke outer groove 51D. For this reason, the restoring force generated in the elastic member 54 is larger than the configuration in which the plug inner groove 55 </ b> C is not formed in the plug 55, that is, the configuration in which the elastic member 54 is fitted only in the yoke outer groove 51 </ b> D of the support yoke 51. For this reason, it is possible to suppress the support yoke 51 from being largely inclined with respect to the housing 40.

  (2) The elastic member 54 can be positioned by the plug inner groove 55C. Further, since the plug inner groove 55C is formed in the plug 55, the plug inner groove 55C can be moved along with the movement of the plug 55 when the amount of screw 55A screwed into the female screw 42B is changed. it can.

  (3) The rack guide mechanism 50 can stably suppress the tilting of the support yoke 51 as compared with the rack guide mechanism 150 of the comparative example of FIG. 5 and occurs when the pinion shaft 13 is rotated. The steering feeling can be improved.

  The effect of the rack guide mechanism 50 on the rack guide mechanism 150 will be described with reference to FIG. In addition, about the structure similar to the rack guide mechanism 50, the code | symbol same as the code | symbol of embodiment is attached | subjected and the description is abbreviate | omitted.

  The rack guide mechanism 150 includes a housing 140, an O-ring as the elastic member 153, a square ring as the tilt suppressing member 154, and a plug 155. The housing 140 has a receiving hole 142. The accommodation hole 142 has a cylindrical inner peripheral surface with a one-dot chain line C in the figure as a central axis. The accommodation hole 142 faces the yoke side wall portion 51B.

  The elastic member 153 is located between the support yoke 51 and the plug 155 in the direction perpendicular to the moving direction Z. The elastic member 53 and the elastic member 153 are located at locations spaced from each other in the movement direction Z. The elastic member 153 is formed of an elastic resin.

  The tilt suppression member 154 is located between the support yoke 51 and the plug 155 in the movement direction Z, that is, the direction parallel to the biasing direction. The tilt suppressing member 154 is made of an elastic resin. The tilt suppression member 154 is compressed in a direction parallel to the biasing direction. That is, the support yoke 51 and the plug 155 hold the tilt suppressing member 154 in a compressed state in a direction parallel to the biasing direction.

  The plug 155 is located in the opening 142 </ b> A of the accommodation hole 142. Plug 155 has a male screw 155A. The male screw 155A is screwed into a female screw 142B formed in the opening 142A of the accommodation hole 142.

The operation of the tilt suppression member 154 will be described.
When the support yoke 51 moves so as to incline in the direction indicated by the arrow R1 with respect to the point P in the figure, the tilt suppressing member 154 compressed in the direction parallel to the urging direction includes the force including the component indicated by the arrow G1. Is applied to the support yoke 51. Further, when the support yoke 51 moves so as to tilt in the direction indicated by the arrow R2 with respect to the point P in the figure, the tilt suppression member 154 compressed in the direction parallel to the biasing direction has the component indicated by the arrow G2. The included force is applied to the support yoke 51. That is, the restoring force of the tilt suppression member 154 restricts the rotation of the support yoke 51 around the point P in the drawing.

  However, when the tilt suppression member 154 is positioned between the support yoke 51 and the plug 155 in the movement direction Z, the support yoke 51 is excessively pressed against the rack shaft 20 and the pinion shaft 13 is rotated. There is a possibility that the steering feeling generated in the vehicle will deteriorate. Further, when the support yoke 51 is tilted in the direction indicated by the arrow R1, the force indicated by the arrows F1 and F2 is applied to the support yoke 51 in the rack guide mechanism 50, whereas in the rack guide mechanism 150, the force is indicated by the arrow G1. The indicated force is applied to the support yoke 51. Therefore, there is a possibility that the tilting of the support yoke 51 cannot be stably regulated.

  Therefore, the elastic member 54 of the rack guide mechanism 50 can be stably restricted from tilting the support yoke 51 by being fitted into both the yoke outer groove 51D and the plug inner groove 55C. Further, since the tilt suppression member 154 is not provided between the support yoke 51 and the plug 155 in the movement direction Z, it is possible to improve the steering feeling that occurs when the pinion shaft 13 is rotated.

  (4) The rack guide mechanism 50 has a biasing member 56 that pushes the support yoke 51 toward the rack shaft 20, and the elastic member 54 is in a biasing direction in which the biasing member 56 pushes the support yoke 51. In a compressed state, it is disposed in the yoke outer groove 51D and the plug inner groove 55C. For this reason, since the elastic member 54 is compressed in advance in the biasing direction, the support yoke 51 can be further prevented from being largely inclined with respect to the housing 40.

  (5) Since the elastic member 54 has an annular shape and the plug inner groove 55C has an annular shape corresponding to the shape of the elastic member 54, the elastic member 54 is applied when a force for tilting the support yoke 51 is applied. The resilience generated in is great. For this reason, it is possible to further suppress the support yoke 51 from being largely inclined with respect to the housing 40.

  (6) The plug inner groove 55C has a first inclined surface 55D and a second inclined surface 55E that are inclined with respect to the depth direction of the plug inner groove 55C, and the first inclined surface 55D and the second inclined surface 55E are The plug inner grooves 55C have shapes that approach each other in the width direction. The elastic member 54 is disposed in the yoke outer groove 51D and the plug inner groove 55C in a compressed state in contact with the first inclined surface 55D and the second inclined surface 55E. Therefore, since the first inclined surface 55D and the second inclined surface 55E compress the elastic member 54, the elastic member 54 is more elastic than the case where the vertical surface perpendicular to the width direction of the plug inner groove 55C compresses the elastic member 54. The generated shear force can be reduced.

  The present invention includes embodiments other than the above-described embodiment. Hereinafter, the modification of the said embodiment as other embodiment of this invention is shown. The following modifications can be combined with each other.

  The plug inner groove 55C of the embodiment has a first inclined surface 55D and a second inclined surface 55E that are inclined with respect to the depth direction of the plug inner groove 55C. On the other hand, as shown in FIG. 4, the plug inner groove 55F of the modification has a first vertical surface 55G and a second vertical surface 55H that are not inclined with respect to the depth direction of the plug inner groove 55F. The first vertical surface 55G and the second vertical surface 55H are perpendicular to the width direction of the plug inner groove 55F. In this way, the shape of the plug inner groove can be changed.

  The elastic member 53 of the embodiment is compressed in a direction perpendicular to the biasing direction. On the other hand, the elastic member 53 of the modified example is compressed in two directions, a direction perpendicular to the urging direction and a direction parallel to the urging direction. That is, the elastic member 53 can be compressed in two directions. In such a configuration, the plug side wall portion 55B has a groove (not shown) into which the elastic member 53 is fitted.

  The elastic member 54 of the embodiment is compressed in a direction parallel to the biasing direction. On the other hand, the elastic member 54 of the modified example is compressed in two directions, a direction parallel to the urging direction and a direction perpendicular to the urging direction. That is, the elastic member 54 can be compressed in two directions.

  In the rack guide mechanism 50 of the embodiment, the elastic member 54 that is one of the elastic member 53 and the elastic member 54 is compressed in a direction parallel to the biasing direction. On the other hand, in the modified rack guide mechanism 50, the elastic member 54 or both the elastic member 53 and the elastic member 54 are compressed in a direction parallel to the urging direction. That is, if at least one of the plurality of elastic members positioned on the yoke side wall portion 51B is compressed in a direction parallel to the urging direction, the effect according to the above (4) is obtained.

  In the rack guide mechanism 50 of the embodiment, the yoke side wall portion 51B and the plug side wall portion 55B hold the elastic member 54 in a compressed state in a direction parallel to the urging direction. On the other hand, in the rack guide mechanism of the modified example, the yoke side wall portion 51B and the plug side wall portion 55B hold the elastic member 54 in a state where the elastic member 54 is not compressed in a direction parallel to the urging direction. Thus, even when the elastic member 54 is not compressed in advance, the effect (1) is achieved when the support yoke 51 moves so as to tilt.

  In the rack guide mechanism 50 of the embodiment, the plug inner groove 55C is formed in an annular shape in the plug side wall portion 55B. On the other hand, in the rack guide mechanism of the modified example, the plug inner groove is formed in a part of the entire circumference of the plug side wall portion 55B. That is, as long as a restoring force acting in a direction parallel to the urging direction can be generated, the shape of the plug inner groove can be changed.

  The rack guide mechanism 50 of the embodiment has an O-ring as the elastic member 54. On the other hand, in the rack guide mechanism of the modified example, the elastic member 54 may not be formed in an annular shape. That is, as long as a restoring force that acts in a direction parallel to the urging direction can be generated, the shape and forming material of the elastic member can be changed.

  The rack guide mechanism 50 according to the embodiment includes an elastic member 53 and an elastic member 54. On the other hand, in the rack guide mechanism according to the modified example, the elastic member 54 can be omitted. That is, the number of elastic members can be changed as long as a restoring force acting in a direction parallel to the urging direction can be generated.

  The vehicle steering apparatus 1 according to the embodiment is a column assist type power steering apparatus that applies the output of the electric motor 31 to the column shaft 11. On the other hand, the vehicle steering apparatus of the modified example is a rack assist type power steering apparatus that applies the output of the electric motor to the rack shaft as a force for translating the rack shaft, or a pinion assist type power steering that is applied to the pinion shaft. Device.

  The vehicle steering apparatus 1 according to the embodiment includes an electric assist device 30. On the other hand, the vehicle steering apparatus according to the modification has a hydraulic assist device (not shown).

  DESCRIPTION OF SYMBOLS 1 ... Vehicle steering device, 1A ... Rack and pinion mechanism, 1B ... Deceleration mechanism, 2 ... Steering wheel, 3 ... Steering wheel, 10 ... Steering shaft, 11 ... Column shaft, 12 ... Intermediate shaft, 13 ... Pinion shaft, DESCRIPTION OF SYMBOLS 14 ... Pinion, 20 ... Rack shaft, 21 ... Rack, 30 ... Assist device, 31 ... Electric motor, 32 ... Worm shaft, 33 ... Worm wheel, 40 ... Housing, 41 ... Rack accommodating part, 41A ... Opening part, 42 ... Housing hole, 42A ... opening, 42B ... female screw, 42C ... inner wall portion, 43 ... seal member, 44 ... ball bearing, 45 ... needle bearing, 50 ... rack guide mechanism, 51 ... support yoke, 51A ... guide groove, 51B ... Yoke side wall portion, 51C, 51D ... Yoke outer groove, 52 ... Sheet member, 53,54 ... 55 ... plug inner wall, 55C ... plug inner groove, 55D ... first inclined surface, 55E ... second inclined surface, 55F ... plug inner groove, 55D ... first vertical surface , 55E, second vertical surface, 56, biasing member.

Claims (5)

In the rack guide mechanism that supports the rack shaft that meshes with the pinion shaft and moves in the housing in the axial direction,
The housing is housed in a housing hole and slidably guides the rack shaft, and has a yoke side wall portion corresponding to an inner wall portion of the housing hole, and a yoke outer groove is formed in the yoke side wall portion. A supported yoke,
A plug side wall portion that fits into an inner wall portion of the receiving hole; the plug side wall portion faces the yoke side wall portion through a gap; a plug inner groove is formed in the plug side wall portion; Is a plug facing the yoke outer groove,
A rack guide mechanism comprising: an elastic member disposed across the yoke outer groove and the plug inner groove. The rack guide mechanism has a biasing member that pushes the support yoke toward the rack shaft,
The rack guide mechanism according to claim 1, wherein the elastic member is disposed in the yoke outer groove and the plug inner groove in a state in which the biasing member is compressed in a biasing direction in which the biasing member pushes the support yoke. The elastic member has an annular shape,
The rack guide mechanism according to claim 1, wherein the plug inner groove has an annular shape corresponding to a shape of the elastic member. The plug inner groove has a first inclined surface and a second inclined surface inclined with respect to the depth direction of the plug inner groove,
The first inclined surface and the second inclined surface have shapes that approach each other in the width direction of the plug inner groove,
The elastic member is disposed in the yoke outer groove and the plug inner groove in a compressed state in contact with the first inclined surface and the second inclined surface. Rack guide mechanism. A vehicle steering apparatus comprising the rack guide mechanism according to any one of claims 1 to 4.