Vehicle steering system

Abstract

A stopper mechanism part in this vehicle steering device is provided with: a rotary member that has a connection part which is connected to a steering shaft, and a cylindrical part which is positioned on one side in the axial direction relative to said connection part and which has a female thread in the inner circumference thereof; a linear motion member that moves linearly in the axial direction relative to the rotary member; a first housing that is positioned on the outer circumferential side of the cylindrical part and the linear motion member; and a second housing that is positioned on the other side in the axial direction relative to the first housing and on the outer circumferential side of the connection part, and that is attached to the first housing.

Description

Technical Field

[0001] The present disclosure relates to a vehicle steering device.

Background Art

[0002] In a steer-by-wire type vehicle steering device, the steering shaft connected to the steering wheel and the steered wheels are mechanically disconnected. In this configuration, since the steering reaction force is not transmitted to the steering wheel, a steering reaction force device and a stopper mechanism portion are provided on the steering shaft.

[0003] The steering reaction force device applies a reaction force in the opposite direction to the rotation direction (steering direction) of the steering wheel to the steering wheel, so as to give the driver a natural steering operation feeling. The steering reaction force device includes, for example, a motor and a speed reduction mechanism, and the steering reaction force generated by the motor is transmitted to the steering shaft through the speed reduction mechanism. The speed reduction mechanism has, for example, a worm shaft and a worm wheel, and the shaft teeth of the worm shaft mesh with the wheel teeth of the worm wheel, so that the rotation of the motor is transmitted to the worm wheel through the worm shaft.

[0004] The stopper mechanism portion includes, for example, a cylindrical rotating member fitted on the outer periphery of the steering shaft, a nut fastened to the outer peripheral side of the rotating member and linearly moving axially with respect to the rotating member, a first stopper portion fitted on one axial side of the rotating member to stop the linear movement of the nut, a second stopper portion fitted on the other axial side of the rotating member to stop the linear movement of the nut, and a first housing and a second housing for housing these rotating member, nut, first stopper portion and second stopper portion. A male thread is provided on the outer periphery of the rotating member, and a female thread meshing with the male thread is provided on the inner periphery of the nut. When the nut abuts against the first stopper portion or the second stopper portion, the rotation of the rotating member stops, and accordingly, the rotation (steering) of the steering wheel via the steering shaft is also stopped.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] German Patent No. 102020126785 Specification [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, in Patent Document 1, the assembly of the stopper mechanism is complex and may be burdensome. Specifically, first, the first housing is attached to the outer circumference of the steering shaft. Next, a stopper unit having a rotating member, a nut, a first stopper part, and a second stopper part is assembled. Specifically, the first stopper part is fitted to one side of the rotating member in the axial direction, and the nut is fastened to the outer circumference of the rotating member. Then, the second stopper part is fitted to the other side of the rotating member in the axial direction to form the stopper unit. The stopper unit is inserted (spline fitted) toward one side of the steering shaft in the axial direction and brought into contact with the first housing. After this, the assembly of the stopper mechanism is completed by fitting the second housing from one side of the steering shaft in the axial direction.

[0007] This disclosure has been made in view of the aforementioned problems and aims to provide a vehicle steering device equipped with a stopper mechanism that is easier to assemble. [Means for solving the problem]

[0008] To achieve the above objective, a steering system for a vehicle according to one embodiment is a steering system for a vehicle in which a steering shaft to which a steering wheel is connected and a steering wheel are mechanically unconnected, and the system includes a stopper mechanism that restricts the range of rotation angle of the steering wheel when the steering wheel is rotated, the stopper mechanism is a rotating member that extends in the axial direction of the central shaft and is rotatable in the circumferential direction about the axis of the central shaft, and the rotating member has a connecting portion connected to the steering shaft and a cylindrical portion located on one side in the axial direction with respect to the connecting portion and having an internal thread on its inner circumference, The device comprises: a linear motion member provided on the inner circumference of the cylindrical portion and having a male screw on its outer circumference that engages with the female screw, and which moves linearly in the axial direction relative to the rotating member; a first housing located on the outer circumference of the cylindrical portion and the linear motion member, which holds the linear motion member in a state in which it is unable to rotate in the circumferential direction but is able to move linearly in the axial direction; a second housing located on the other axial side of the first housing and on the outer circumference of the connecting portion, which is attached to the first housing; and a first contact portion and a second contact portion to which the linear motion member abuts and stops its linear motion.

[0009] As mentioned above, in Patent Document 1, the assembly of the stopper mechanism is complex and may result in a heavy workload. Specifically, the first housing is attached to the outer circumference of the steering shaft. Next, a stopper unit having a rotating member, a nut, a first stopper part, and a second stopper part is assembled. The stopper unit is inserted (spline fitted) toward one side in the axial direction of the steering shaft and brought into contact with the first housing, and then the second housing is fitted from the one side in the axial direction of the steering shaft to complete the assembly of the stopper mechanism.

[0010] In contrast, according to this disclosure, the stopper mechanism can be assembled in the following simple procedure. Specifically, first, the linear motion member is assembled to the rotating member by fastening the male thread of the linear motion member to the female thread of the rotating member from one side in the axial direction to the other. Next, the first housing is inserted into the outer circumference of the rotating member and the linear motion member from one side in the axial direction to the other, and the second housing is attached to the first housing. Thus, according to this disclosure, it is possible to provide a vehicle steering device equipped with a stopper mechanism that is easier to assemble.

[0011] In a preferred embodiment, a female spline is provided on the inner circumference of the first housing, and the linear motion member has a male threaded portion having the male thread and capable of contacting the first contact portion and the second contact portion, and a splined portion having a male spline on its outer circumference located on one side in the axial direction relative to the male threaded portion and capable of fitting into the female spline, and a through hole passing through in the axial direction is provided at one end of the first housing in the axial direction, and when the linear motion member is moving linearly toward one side in the axial direction, the splined portion of the linear motion member is capable of protruding from the through hole of the first housing toward one side in the axial direction.

[0012] When the steering wheel is rotated, the steering shaft and rotating members rotate, and the linear motion members move in the axial direction. However, if the linear motion members are housed inside the housing and not visible from the outside, it is difficult to determine the axial position of the linear motion members, and therefore it is difficult to determine the direction of rotation of the steering wheel (clockwise or counterclockwise) and the angle of rotation.

[0013] In contrast, in this disclosure, since the spline portion of the linear motion member can protrude from the through hole to one side in the axial direction, the rotation direction and rotation angle of the steering wheel can be visually determined. Therefore, the rotation direction (clockwise or counterclockwise) and rotation angle of the steering wheel are easy to understand. Furthermore, by applying markings, for example, to the outer surface of the spline portion, the rotation direction and rotation angle of the steering wheel can be recognized with even higher precision.

[0014] In a preferred embodiment, an axial gap is provided between a part of the rotating member and the inner surface of the second housing, and an elastic member is housed in this gap to reduce the impact when the linear motion member contacts the first contact portion and the impact when the linear motion member contacts the second contact portion.

[0015] Therefore, when the linear motion member moves to one side in the axial direction and contacts the first contact portion, the first and second housings also move to one side in the axial direction. This causes the elastic member to compress in the axial direction, reducing the impact when the linear motion member and the first contact portion collide.

[0016] Furthermore, when the linear motion member moves to the other side in the axial direction and contacts the second contact portion, the second housing moves to the other side in the axial direction, and the elastic member compresses in the axial direction, reducing the impact. In this way, regardless of whether the linear motion member moves to one side or the other side in the axial direction, the elastic member can reduce the impact when the rotating member or the first housing and the linear motion member come into contact.

[0017] In a preferred embodiment, at least one of the following is an interposed linear distance variable member having thickness in the axial direction and capable of contacting the linear motion member, which changes the axial distance when the linear motion member moves in a straight line: between the first contact portion and the male screw portion, and between the second contact portion and the male screw portion.

[0018] Therefore, according to the present disclosure, with a simple configuration of a linearly movable distance variable member, it is possible to change the axial distance when the linearly movable member moves linearly, and thus change the rotation angle of the steering wheel.

[0019] As a desirable aspect, on the spline portion of the linearly movable member, there is provided a protruding portion that is arranged on one axial side with respect to the axial end surface on one axial side of the first housing, protrudes in the radial direction, and abuts against the axial end surface to stop the linear movement of the linearly movable member toward one axial side.

[0020] When the linearly movable member abuts against the second abutting portion, since the non-rotating linearly movable member and the rotating second abutting portion abut against each other, friction occurs between the two, and as a result, the linearly movable member and the second abutting portion may be damaged due to wear.

[0021] Here, in the present disclosure, both the linearly movable member and the first housing are non-rotating members. Therefore, when the linearly movable member moves linearly toward the other axial side, the non-rotating protruding portion and the non-rotating first housing abut against each other. Thus, according to the present disclosure, damage to the protruding portion and the first housing can be suppressed.

Advantages of the Invention

[0022] According to the present disclosure, it is possible to provide a vehicle steering device including a stopper mechanism portion with easier assembly work.

Brief Description of the Drawings

[0023] [Figure 1] FIG. 1 is a schematic diagram showing the overall configuration of a vehicle steering device according to the first embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing a part of FIG. 1. [Figure 3] FIG. 3 is a cross-sectional view showing a part of FIG. 2. [Figure 4] FIG. 4 is an enlarged cross-sectional view showing a part of FIG. 3. [Figure 5] FIG. 5 is an exploded perspective view of a stopper mechanism portion according to the first embodiment. [Figure 6] Figure 6 is a cross-sectional view of the stopper mechanism according to the second embodiment. [Figure 7] Figure 7 is an enlarged cross-sectional view of section A in Figure 6. [Figure 8] Figure 8 is a perspective view of a wave washer. [Figure 9] Figure 9 is a cross-sectional view of the stopper mechanism according to the third embodiment. [Figure 10] Figure 10 is a cross-sectional view of the stopper mechanism according to the fourth embodiment. [Figure 11] Figure 11 is a schematic diagram of Figure 10 as seen from the X1 side. [Figure 12] Figure 12 is a perspective view of the wheel chock. [Figure 13] Figure 13 is a schematic diagram of a modified example in which a pin is applied as a protruding part. [Modes for carrying out the invention]

[0024] Embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by those skilled in the art and those that are substantially the same. Furthermore, the components described below can be combined as appropriate. Furthermore, parts with the same structure are given the same reference numerals and their descriptions are omitted. In the coordinate system, the X direction indicates the axial direction of the rotating member, the X1 side is one side in the axial direction, and the X2 side is the other side in the axial direction.

[0025] [First Embodiment] The first embodiment will be described below. Figure 1 is a schematic diagram showing the overall configuration of the vehicle steering device of the first embodiment. Figure 2 is a cross-sectional view showing a part of Figure 1. Figure 3 is a cross-sectional view showing a part of Figure 2. Figure 4 is an enlarged cross-sectional view showing a part of Figure 3. Figure 5 is an exploded perspective view of the stopper mechanism according to the first embodiment.

[0026] The vehicle steering system 100 according to this embodiment is a steer-by-wire type vehicle steering system in which the steering wheel 10 and the steering wheels 22 are not mechanically connected. As shown in Figure 1, the vehicle steering system 100 comprises a steering unit 4, a control unit (ECU) 14, and a steering unit 20.

[0027] As shown in Figures 1 to 3, the steering unit 4 is equipped with a steering reaction force device 13. When steering the steering wheel 10, the steering reaction force device 13 applies a steering reaction force to the steering wheel 10 in the opposite direction to the steering direction of the steering wheel 10. Based on the operation information, the control unit (ECU) 14 calculates the reaction force torque according to the vehicle's driving state, adjusts the power value supplied to the motor 110 of the steering reaction force device 13 based on the reaction force torque, and the motor 110 operates according to the power value, thereby transmitting the steering reaction force of the steering wheel 10 to the operator. The control unit (ECU) 14 also calculates a current command value based on the operation information and controls the current supplied to the steering motor 21 of the steering unit 20. In the steering unit 20, the steering wheels 22 are steered via various gears connected to the steering motor 21. The configurations of each part of the vehicle steering system 100 will be described in detail below. In the steer-by-wire type vehicle steering system 100, the steering wheel 10 and the steering wheels 22 are mechanically disconnected. However, in the present invention, "disconnected" also includes a configuration in which the steering wheel 10 and the steering wheels 22 can be connected by a clutch device or the like, for example, in an emergency.

[0028] As shown in Figure 1, the steering unit 4 comprises a steering wheel 10, a steering shaft 11, a steering housing 12, and a steering reaction force device 13.

[0029] As shown in Figures 2 and 3, the steering shaft 11 extends in the X direction (axial direction). The steering wheel 10 is rotatably connected to the steering shaft 11. The steering shaft 11 is housed inside the steering housing 12. The steering shaft 11 includes a column shaft 15, an output shaft 16, and a torsion bar 17.

[0030] The column shaft 15 and the output shaft 16 are connected via a torsion bar 17. Specifically, an insertion hole is provided axially at the X1 end of the column shaft 15, and the torsion bar 17 is inserted into this insertion hole. The column shaft 15 and the torsion bar 17 are connected via a pin 122 so that they cannot rotate relative to each other. The output shaft 16 is provided with a through hole that penetrates axially, and the X1 end of the torsion bar 17 is fitted into this through hole. As a result, the output shaft 16 and the torsion bar 17 are connected so that they cannot rotate relative to each other. Therefore, when the steering wheel 10 is rotated, the steering shaft 11 rotates in conjunction with it.

[0031] Furthermore, the steering housing 12 includes a shaft holding member 121, rotation support members 123 and 124, and a sub-housing 127.

[0032] A rotational support member 123 is located on the X1 side of the shaft holding member 121, and a rotational support member 124 is located on the X1 side of the rotational support member 123. A sub-housing 127 is located on the X1 side of the rotational support member 124. A bearing 125 is provided on the radially inner side of the rotational support member 124, and a bearing 126 is provided on the radially inner side of the sub-housing 127. The output shaft 16 is rotatably supported via the bearings 125 and 126. A torque sensor 128 is provided between the rotational support member 123 and the rotational support member 124. The torque sensor 128 detects the rotational torque transmitted between the column shaft 15 and the output shaft 16.

[0033] Here, the steering reaction device 13 includes a steering shaft 11, a worm wheel 18, a worm shaft 19, and a motor 110.

[0034] A worm wheel 18 is mounted on the outer circumference of the output shaft 16 of the steering shaft 11. The worm wheel 18 has a core metal portion 18a and a wheel tooth portion 18b. The wheel tooth portion 18b is provided on the outer circumference of the core metal portion 18a. A worm shaft 19 and a motor 110 are located on the Y2 side (see Figure 6) of the worm wheel 18. The worm shaft 19 is mounted on the output shaft of the motor 110. The worm shaft 19 has a shaft tooth portion 19a. The shaft tooth portion 19a meshes with the wheel tooth portion 18b.

[0035] The motor 110 is the source of the steering reaction force. That is, the output of the motor 110 becomes a reaction torque, and this reaction torque is transmitted from the steering shaft 11 to the steering wheel 10 via the worm wheel 18 and worm shaft 19.

[0036] As shown in Figures 2 and 3, a stopper mechanism 3 is provided on the X1 side of the output shaft 16 of the steering shaft 11. The stopper mechanism 3 will be described in detail below.

[0037] As shown in Figures 2 and 3, the rotating member 32 has a central axis AX, and the axial direction of the central axis AX coincides with the X direction. The rotating member 32, which is included in the stopper mechanism 3, is spline-fitted to the X1-side end of the output shaft 16 of the steering shaft 11. Specifically, a female spline 321a extending in the X direction is provided on the inner circumference of the rotating member 32, and a male spline extending in the X direction is provided on the outer circumference of the X1-side end of the output shaft 16. The male spline of the output shaft 16 is fitted into the female spline 321a of the rotating member 32. As a result, the rotating member 32 is movable in the X direction relative to the output shaft 16, but cannot rotate in the circumferential direction around the axis of the central axis AX. That is, the rotating member 32 rotates integrally with the output shaft 16 in the direction around the axis of the central axis AX.

[0038] As shown in Figure 4, the stopper mechanism 3 comprises a rotating member 32, a linear motion member 31, a first housing 351, and a second housing 352.

[0039] The rotating member 32 has a central axis AX. The axial direction of the central axis AX is the X direction. The direction around the central axis AX is the circumferential direction. The direction perpendicular to the central axis AX is the radial direction. The rotating member 32 is a cylindrical member extending in the circumferential direction. The rotating member 32 comprises a connecting portion 321 and a cylindrical portion 322.

[0040] The connecting portion 321 is located on the X2 side of the rotating member 32. The connecting portion 321 has a female spline 321a on its inner circumference. A second contact portion 326 is provided on the inner surface of the connecting portion 321. The X2 side end face 311b of the male threaded portion 311 can contact the second contact portion 326.

[0041] The cylindrical portion 322 is adjacent to the connecting portion 321 on the X1 side. The cylindrical portion 322 has a plurality of female threads 323 on its inner circumference. The rotating member 32 has end faces 327 and 328. The end faces 327 and 328 are sandwiched between the first housing 351 and the second housing 352 in the X direction, thereby positioning the rotating member 32 in the X direction. The rotating member 32 also has an outer circumferential surface 325. A radial gap is provided between the outer circumferential surface 325 and the large diameter portion 351c of the first housing 351.

[0042] The linear motion member 31 has a male threaded portion 311 and a splined portion 313. The linear motion member 31 extends in the X direction. The male threaded portion 311 has a plurality of male threads 312 on its outer circumference. The male threads 312 mesh with the female threads 323. The splined portion 313 is located on the X1 side relative to the male threaded portion 311. A male spline 314 is provided on the outer circumference of the splined portion 313. The splined portion 313 has an axial end 313a at the end on the X1 side. A large diameter hole 315 is provided inside the male threaded portion 311. A small diameter hole 316 is provided inside the splined portion 313. The inner diameter of the large diameter hole 315 is larger than the inner diameter of the small diameter hole 316.

[0043] The first housing 351 has a small diameter portion 351a, a medium diameter portion 351b, and a large diameter portion 351c. The medium diameter portion 351b is adjacent to the large diameter portion 351c on the X1 side, and the small diameter portion 351a is adjacent to the medium diameter portion 351b on the X1 side. A female spline 351f is provided on the inner circumference of the small diameter portion 351a. The female spline 351f spline-fits with the male spline 314 of the linear motion member 31. As a result, the first housing 351 holds the linear motion member 31 in a state where it cannot rotate in the circumferential direction but can move linearly in the X direction. As a result, the linear motion member 31 moves linearly in the X direction relative to the rotating member 32 in a non-rotating state. The first housing 351 is also located on the outer circumference side of the cylindrical portion 322 of the rotating member 32 and the linear motion member 31. A through hole 351g extending in the X direction is provided in the small diameter portion 351a. The axial end 313a of the linear motion member 31 can protrude towards X1 beyond the axial end face 351d of the small diameter portion 351a. A first contact portion 351i is provided on the inner surface of the small diameter portion 351a. The first contact portion 351i can contact the end face 311a of the male screw portion 311.

[0044] The second housing 352 is located on the X2 side relative to the first housing 351. The second housing 352 is located on the outer circumference side of the connecting portion 321. The mating portion 352a of the second housing 352 abuts against the end face 328 of the rotating member 32. A vertical wall portion 352c is provided at the X2 side end of the second housing 352. The inner circumferential surface 352e of the vertical wall portion 352c supports the rotation of the connecting portion 321 on the rotating member 32. In addition, the axial end face 351e of the first housing 351 abuts against the axial end face 352d of the second housing 352. Here, the axial end face 351e and the axial end face 352d are the dividing portion 300 between the first housing 351 and the second housing 352. This dividing portion can be provided at various locations such as the dividing portion 300A and dividing portion 300B shown in Figure 4. In other words, the first housing 351 and the second housing 352 can be divided at various points, not limited to the divided sections 300, 300A, and 300B shown in the diagram.

[0045] As shown in Figure 5, the second housing 352 has flanges 351h that protrude to the Y1 and Y2 sides. A first bolt hole H1 is provided in the flange 351h. The male threaded portion of bolt BL passes through the first bolt hole H1. The first housing 351 has flanges 352b that protrude to the Y1 and Y2 sides. A second bolt hole H2 is provided in the flange 352b. The second bolt hole H2 has a female threaded portion on its inner circumference, and the male threaded portion of bolt BL engages with this female threaded portion.

[0046] Next, the assembly procedure for the stopper mechanism 3 will be briefly explained. First, the linear motion member 31 is assembled to the rotating member 32 from the X1 side to the X2 side. Specifically, the male thread 312 of the linear motion member 31 is fastened to the female thread 323 of the rotating member 32 from the X1 side to the X2 side.

[0047] Next, the first housing 351 is inserted into the outer circumference of the rotating member 32 and the linear member 31 from the X1 side to the X2 side. Then, the second housing 352 is moved from the X2 side to the X1 side and attached to the first housing 351. Specifically, with the first bolt hole H1 and the second bolt hole H2 aligned, the flange 351h and flange 352b are butted together. Bolt BL is inserted into the first bolt hole H1 and engaged with the female thread portion of the second bolt hole H2. This completes the assembly of the stopper mechanism 3.

[0048] The first contact portion 351i is located at the X1 side end when the linear motion member 31 is moving in a straight line. The second contact portion 326 is located at the X2 side end when the linear motion member 31 is moving in a straight line. That is, when the steering wheel 10 is rotated, for example in a clockwise direction, the linear motion member 31 contacts the first contact portion 351i at the end contact position. When the steering wheel 10 is rotated, for example in a counterclockwise direction, the linear motion member 31 contacts the second contact portion 326 at the end contact position. In other words, the steering wheel 10 can be rotated within the range from the position where the linear motion member 31 contacts the first contact portion 351i to the position where it contacts the second contact portion 326.

[0049] As described above, in the first embodiment, the stopper mechanism 3 comprises a rotating member 32 having a connecting portion 321 and a cylindrical portion 322, a linear motion member 31, a first housing 351 located on the outer circumference side of the cylindrical portion 322 and the linear motion member 31, and a second housing 352 located on the X2 side relative to the first housing 351 and on the outer circumference side of the connecting portion 321.

[0050] As mentioned above, in Patent Document 1, the assembly of the stopper mechanism is complex and may result in a heavy workload. Specifically, the first housing is attached to the outer circumference of the steering shaft. Next, a stopper unit having a rotating member, a nut, a first stopper part, and a second stopper part is assembled. The stopper unit is inserted (spline fitted) toward one side in the axial direction of the steering shaft and brought into contact with the first housing, and then the second housing is fitted from the one side in the axial direction of the steering shaft to complete the assembly of the stopper mechanism.

[0051] In contrast, according to this embodiment, the stopper mechanism 3 can be assembled in the following simple procedure.

[0052] Specifically, first, the male thread 312 of the linear motion member 31 is fastened to the female thread 323 of the rotating member 32 from the X1 side to the X2 side, and the linear motion member 31 is assembled to the rotating member 32 from the X1 side to the X2 side. Next, the first housing 351 is inserted into the outer circumference of the rotating member 32 and the linear motion member 31 from the X1 side to the X2 side, and the second housing 352 is attached to the first housing 351.

[0053] Thus, according to this embodiment, it is possible to provide a vehicle steering device 100 equipped with a stopper mechanism 3 that is easier to assemble.

[0054] Furthermore, a through hole 351g is provided at the X1-side end of the first housing 351, allowing the spline portion 313 of the linear motion member 31 to protrude from the through hole 351g toward the X1 side.

[0055] When the steering wheel 10 is rotated, the steering shaft 11 and the rotating member 32 rotate, and the linear motion member 31 moves in the X direction. However, if the linear motion member 31 is housed inside the housing and not visible from the outside, the position of the linear motion member 31 in the X direction cannot be determined, and therefore the direction of rotation of the steering wheel 10 (clockwise or counterclockwise) cannot be determined, nor can the angle of rotation be determined.

[0056] In contrast, in this embodiment, since the spline portion 313 of the linear motion member 31 can protrude from the through hole 351g toward X1, the rotation direction and rotation angle of the steering wheel 10 can be visually confirmed. Furthermore, by applying, for example, a marking to the outer circumferential surface of the spline portion 313, the rotation direction and rotation angle of the steering wheel 10 can be recognized with even higher accuracy.

[0057] [Second Embodiment] A second embodiment will be described below. Figure 6 is a cross-sectional view of the stopper mechanism according to the second embodiment. Figure 7 is an enlarged cross-sectional view of part A in Figure 6. Figure 8 is a perspective view of the wave washer.

[0058] The second embodiment differs from the first embodiment in that a wave washer 341 (elastic member 34) is added. The following will focus on explaining this difference.

[0059] As shown in Figure 6, the stopper mechanism 3A according to the second embodiment includes a rotating member 32A. The rotating member 32A has a protruding portion 320 on the connecting portion 321. The protruding portion 320 protrudes toward the X2 side. The second housing 352A is provided with a recess 352Ad. The recess 352Ad is recessed toward the X2 side. A wave washer 341 (elastic member 34) is housed inside the recess 352Ad.

[0060] As shown in Figure 8, the wave washer 341 has an inner peripheral edge 345 on the radially inward side and an outer peripheral edge 344 on the radially outward side. In addition, bent portions 342 and bent portions 343 are arranged alternately along the circumferential direction. The bent portion 342 is convex towards X2, and the bent portion 343 is convex towards X1. Note that the wave washer 341 is an example of an elastic member 34, and various other elastic members such as disc springs can be applied in addition to the wave washer 341. Next, the effect of the wave washer 341 in the stopper mechanism 3A will be briefly explained.

[0061] First, as shown by arrow D1 in Figure 6, when the linear motion member 31 moves linearly toward X1 and its end face 311a comes into contact with the first contact portion 351i, the first housing 351 moves toward X1, as shown by arrow D2.

[0062] Since the second housing 352A is fixed to the first housing 351, the second housing 352A also moves towards X1, as shown by arrow D3 in Figures 6 and 7. This causes the wave washer 341 to compress in the X direction, reducing the impact.

[0063] Furthermore, when the linear motion member 31 moves linearly toward the X2 side and its end face 311b comes into contact with the second contact portion 326, the second housing 352A moves toward the X2 side. As a result, the wave washer 341 compresses in the X direction, reducing the impact.

[0064] As described above, in the second embodiment, in the stopper mechanism 3A, the wave washer 341 (elastic member 34) is housed in the recess 352Ad of the second housing 352A.

[0065] Therefore, when the linear motion member 31 moves toward X1 and contacts the first contact portion 351i, the first housing 351 and the second housing 352A move toward X1. As a result, the wave washer 341 compresses in the X direction, reducing the impact.

[0066] Furthermore, when the linear motion member 31 moves toward the X2 side and its end face 311b comes into contact with the second contact portion 326, the connecting portion 321 moves toward the X2 side, causing the wave washer 341 to contract in the X direction and reduce the impact.

[0067] In this way, regardless of whether the linear motion member 31 moves towards the X1 side or the X2 side, the wave washer 341 can reduce the impact when the rotating member 32 or the first housing 351 comes into contact with the linear motion member 31.

[0068] [Third Embodiment] A third embodiment will be described below. Figure 9 is a cross-sectional view of the stopper mechanism according to the third embodiment.

[0069] The third embodiment differs from the first embodiment in that it adds a variable linear distance member. The following will focus on explaining this difference.

[0070] As shown in Figure 9, in the stopper mechanism 3B according to the third embodiment, a linear distance variable member 51 is positioned between the first contact portion 351i and the end face 311a. The linear distance variable member 51 is an annular member extending in the direction of the axis of the central axis AX and has thickness in the axial direction. The linear motion member 31 can contact the linear distance variable member 51. The rigidity of the linear distance variable member 51 is, for example, greater than or equal to the rigidity of the linear motion member 31. The linear distance variable member 51 is, for example, made of resin. The linear distance variable member 51 changes the axial distance of the linear motion member 31 when it moves linearly by contacting the linear motion member 31. The axial distance of the linear motion member 31 is reduced by the thickness of the linear distance variable member 51.

[0071] Furthermore, a linear motion distance variable member 52 is positioned between the second contact portion 326 and the end face 311a. The linear motion distance variable member 52 is an annular member extending in the direction of the axis of the central axis AX and has thickness in the axial direction. The linear motion member 31 can contact the linear motion distance variable member 52. The linear motion distance variable member 52 comprises a disc portion 522 and a flange portion 521. The flange portion 521 protrudes from the peripheral edge of the disc portion 522 toward the X2 side. The flange portion 521 extends in the circumferential direction. The rigidity of the linear motion distance variable member 52 is, for example, greater than or equal to the rigidity of the linear motion member 31. The linear motion distance variable member 52 is, for example, made of resin. The linear motion distance variable member 52 changes the axial distance of the linear motion member 31 when it moves linearly by contacting the linear motion member 31. The axial distance of the linear motion member 31 is reduced by the thickness of the linear motion distance variable member 52.

[0072] Furthermore, both the linear distance variable member 5 and the linear distance variable member 52 may be provided, or only one of them may be provided.

[0073] As described above, in the third embodiment, the stopper mechanism 3B is provided with a linear distance variable member 5. The linear distance variable member 5 is, for example, linear distance variable members 51 and 52.

[0074] Therefore, according to this embodiment, with a simple configuration of a variable linear motion distance member 5, it is possible to change the axial distance when the linear motion member 31 moves in a straight line, and consequently, to change the rotation angle of the steering wheel 10.

[0075] [Fourth Embodiment] A fourth embodiment will be described below. Figure 10 is a cross-sectional view of the stopper mechanism according to the fourth embodiment. Figure 11 is a schematic view of Figure 10 as seen from the X1 side. Figure 12 is a perspective view of the wheel stopper. Figure 13 is a schematic view of a modified example in which a pin is applied as a protruding part. Note that Figure 13 is a view of Figure 10 as seen from the X1 side.

[0076] The fourth embodiment differs from the first embodiment in that it adds a wheel chock 61 or a pin 62. The following will focus on explaining these differences.

[0077] As shown in Figures 10 to 12, in the stopper mechanism 3C according to the fourth embodiment, a wheel stopper 61 (projection 6) projecting radially is provided on the spline portion 313 of the linear motion member 31. The wheel stopper 61 is an example of the projection 6. Specifically, the wheel stopper 61 is attached to the X1 side end of the spline portion 313. A groove is provided in the spline portion 313 along the circumferential direction, and the wheel stopper 61 is fitted into this groove. The wheel stopper 61 is located on the X1 side with respect to the axial end face 351d of the first housing 351 and faces the axial end face 351d. The wheel stopper 61 acts as a stopper to stop the linear motion of the linear motion member 31 toward the X2 side.

[0078] In addition, the pin 62 shown in Figure 13 can also be used as the protruding portion 6. Specifically, the pin 62 is attached to the X1-side end of the spline portion 313. A groove is provided in the spline portion 313, and the pin 62 is fitted into this groove. The pin 62 is located on the X1 side with respect to the axial end face 351d of the first housing 351 and faces the axial end face 351d. The pin 62 acts as a stopper to stop the linear motion of the linear motion member 31 toward the X2 side.

[0079] As described above, in the fourth embodiment, in the stopper mechanism 3C, a projection 6 is provided on the spline portion 313 of the linear motion member 31. The projection 6 is, for example, a wheel stopper 61 or a pin 62. The projection 6 protrudes radially and abuts against the axial end face 351d to stop the linear motion of the linear motion member toward X1.

[0080] When the end face 311b of the linear motion member 31 comes into contact with the second contact portion 326, friction occurs between the non-rotating end face 311b and the rotating second contact portion 326, which can lead to wear and potentially damage to both the end face 311b and the second contact portion 326.

[0081] In this embodiment, both the linear motion member 31 and the first housing 351 are non-rotating members. Therefore, when the linear motion member 31 moves linearly toward the X2 side, the non-rotating projection 6 and the axial end face 351d of the non-rotating first housing 351 come into contact. Thus, according to this embodiment, damage to the projection 6 and the axial end face 351d can be suppressed. [Explanation of Symbols]

[0082] 3, 3A, 3B, 3C Stopper mechanism 4. Steering Unit 5. Variable linear motion distance member 6 Protrusion 10 Steering Wheel 11 Steering shaft 12 Steering Housing 13. Steering reaction device 14 Control Unit (ECU) 15 Column axis 16 Output shaft 17 Torsion bar 18 Worm Wheel 18a Core metal part 18b Wheel teeth 19 Worm shaft 19a Shaft teeth 20 Snake Unit 21 Steering motor 22 steering wheels 31 Linear motion member 32, 32A Rotating member 34 Elastic members 51 Variable linear motion distance member 52 Variable linear motion distance member 61 Wheel chock (protruding part) 62 pins (protruding part) 100 Vehicle steering systems 311 Male threaded section 311a End face 311b End face 312 Male screw 313 Spline section 313a Axial end 314 Male spline 315 Large diameter hole 316 Small diameter hole 320 Protrusion 321 Connecting part 321a Female spline 322 Cylindrical part 323 Female thread 325 Outer surface 326 Second contact part 327, 328 end face 341 Wave Washer 342, 343 Folded section 344 Outer edge 345 Inner periphery 351 Housing No. 1 351a Small diameter section 351b Medium diameter section 351c Large diameter section 351d Axial end face 351e Axial end face 351f Female spline 351g through hole 351h Flange 351i 1st contact part 352 Second Housing 352a Joint 352b Flange 352d Axial end face 352A Second Housing 352Ad recess 521 Flange section 522 Disc section BL Bolt H1 First bolt hole H2 Second bolt hole

Claims

1. A steering system for a vehicle in which the steering shaft to which the steering wheel is connected and the steering wheels are not mechanically connected, The steering wheel is equipped with a stopper mechanism that restricts the range of rotation angle of the steering wheel when it is rotated, The stopper mechanism is, A rotating member that extends in the axial direction of a central axis and is rotatable in the circumferential direction about the axis of the central axis, comprising a connecting portion connected to the steering shaft and a cylindrical portion located on one side in the axial direction relative to the connecting portion and having an internal thread on its inner circumference, A linear motion member is provided on the inner circumference of the cylindrical portion and has a male thread on its outer circumference that engages with the female thread, and moves linearly in the axial direction relative to the rotating member, A first housing located on the outer circumference of the cylindrical portion and the linear motion member, and holding the linear motion member in a state where it is unable to rotate in the circumferential direction but is capable of linear motion in the axial direction, A second housing is located on the other axial side of the first housing and on the outer circumference side of the connecting portion, and is attached to the first housing, The linear motion member comprises a first contact portion and a second contact portion that come into contact with the linear motion member and stop its linear motion, Steering device for vehicles.

2. A female spline is provided on the inner circumference of the first housing. The linear motion member has a male screw portion having the male screw and capable of contacting the first contact portion and the second contact portion, and a spline portion located on one side in the axial direction with respect to the male screw portion and having a male spline on its outer circumference that can be fitted into the female spline, A through hole is provided at one end of the first housing in the axial direction, In a state in which the linear motion member is moving linearly toward one side in the axial direction, The spline portion of the linear motion member is capable of protruding from the through hole of the first housing to one side in the axial direction. The steering device for a vehicle according to claim 1.

3. A gap is provided in the axial direction between a part of the rotating member and the inner surface of the second housing, and in this gap, An elastic member is housed therein to reduce the impact when the linear motion member contacts the first contact portion and the impact when the linear motion member contacts the second contact portion. The steering device for a vehicle according to claim 1 or 2.

4. Between the first contact portion and the male thread portion, and between the second contact portion and the male thread portion, A linear motion distance variable member is interposed, which has thickness in the axial direction and is capable of contacting the linear motion member, and which changes the axial distance when the linear motion member moves in a straight line. The steering device for a vehicle according to claim 2.

5. The spline portion of the linear motion member includes: A projection is provided which is positioned on one side in the axial direction relative to the axial end face on one side in the axial direction of the first housing, protruding radially, and contacting the axial end face to stop the linear motion of the linear motion member toward one side in the axial direction. The steering device for a vehicle according to claim 4.

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