Rotation limiting device and steering device

Abstract

A rotation-limiting device comprises: a first member having a first protrusion; a second member that has a second protrusion disposed on one side of the first protrusion in the axial direction, and that is disposed coaxially with the first member and so as to be capable of relative rotation with respect to the first member; a side plate part disposed between the first protrusion and the second protrusion in the axial direction; and one intermediate member that has an intermediate-side first protrusion protruding from the other axial side surface of the side plate part toward the other axial side and an intermediate-side second protrusion protruding from the one axial side surface of the side plate part toward the one axial side, and that is supported so as to be capable of rotating relative to the first member and the second member.

Description

[Technical Field]

[0001] The present disclosure relates to a rotation limiting device for limiting the amount of rotation of a rotating member, and a steering device. [Background technology]

[0002] In a rack-and-pinion steering device, when the steering wheel is turned (turned) to the maximum right or left, the rack end, which is supported and fixed to the end of the rack shaft, hits the housing. In this way, in a rack-and-pinion steering device in which the steering unit and the steering unit are mechanically connected, the number of lock-to-lock rotations of the steering wheel (the number of rotations of the steering wheel when the steering wheel is turned from the maximum right or left to the maximum left or right) is limited by limiting the stroke of the rack shaft that constitutes the steering unit.

[0003] In contrast, in a steer-by-wire steering system, the steering unit and the turning unit are not mechanically connected, so it is not possible to limit the lock-to-lock rotation speed of the steering wheel that constitutes the steering unit by limiting the stroke of the rack shaft that constitutes the turning unit.

[0004] Figure 20 shows a stopper unit 100 for mechanically limiting the number of lock-to-lock rotations of a steering wheel in a steer-by-wire steering device described in Patent Document 1. However, Figure 20 is a representation where the left and right sides are reversed (left and right symmetrical) from Figure 4 of Patent Document 1. The stopper unit 100 includes a first rotating member 101, a housing 102, and a second rotating member 103.

[0005] The first rotating member 101 has a first rotating protrusion 104 that protrudes toward one axial direction on one axial side (the left side in FIG. 20). The first rotating member 101 is connected and fixed to the tip end (the other axial end) of a steering shaft (not shown) so as not to rotate relative to it. In other words, the first rotating member 101 rotates integrally with the steering shaft as the steering wheel is operated.

[0006] The housing 102 has a fixing protrusion 105 that protrudes toward the other axial direction on the other axial side (the right side in FIG. 20) and does not rotate even during use. The steering shaft is supported radially inside the housing 102 so as to be rotatable relative to the housing 102.

[0007] The second rotating member 103 has a cylindrical portion 106 and a second rotating protrusion 107 that protrudes radially outward from one circumferential position on the outer circumferential surface of the cylindrical portion 106. The second rotating member 103 is supported around the steering shaft so as to be rotatable relative to the steering shaft, the first rotating member 101, and the housing 102.

[0008] That is, the steering shaft is inserted through the housing 102 and the second rotating member 103 from one axial side to the other axial side, and the first rotating member 101 is coupled and fixed to the tip of the steering shaft that protrudes from the end face of the second rotating member 103 on the other axial side. In addition, a steering wheel is supported and fixed to the end of one axial side of the steering shaft.

[0009] In a steering device equipped with the stopper unit 100, for example, when the steering wheel is turned to the right (rotated clockwise as viewed from the left side of FIG. 20), the steering The first rotating member 101 rotates together with the rotating shaft from the top to the bottom in Fig. 20. Then, one circumferential side surface of the first rotating protrusion 104 (the bottom side surface in Fig. 20) collides with the other circumferential side surface of the other axial side portion of the second rotating protrusion 107 (the top side surface in Fig. 20).

[0010] From this state, when the steering wheel is turned further to the right, the second rotating member 103 rotates together with the steering shaft and the first rotating member 101 from the top to the bottom in Figure 20. Then, one circumferential side surface of one axial side portion of the second rotating protrusion 107 abuts against the other circumferential side surface of the fixed protrusion 105. This prevents the steering wheel from being turned further to the right.

[0011] Patent Document 2 discloses a small and lightweight multi-rotation limit mechanism that aims to detect rotation limit operation with high accuracy without using a reduction gear mechanism. This multi-rotation limit mechanism includes a rotating shaft rotatably mounted on a bearing plate and having a rotation stopper fixed thereto, a plurality of idle rotors that are loosely fitted on the rotating shaft and rotated by the rotation stopper, a stopper rotor that is loosely fitted on the rotating shaft and engages with the idle rotors, a pair of spring members that bias the stopper portion of the stopper rotor in both rotational directions, an electrical sensor for detecting the stopper portion, and engaging pieces that are provided on the rotation stopper, idle rotor, and stopper rotor for engaging with each other.

[0012] Patent Document 3 discloses a steering device designed to maintain a constant position of a striking sound generated when an operating member is rotated left or right from a neutral position. This steering device rotatably holds an operating member that is not mechanically connected to a steered wheel. The steering device also includes a shaft member that rotates in response to operation of the operating member, a holding member that rotatably holds the shaft member, a rotary engagement member attached to the shaft member and including a rotary pawl that rotates integrally with the shaft member, a fixed pawl that is positioned so as not to engage with the rotary pawl and fixed to the holding member, an intermediate engagement member that rotates about the axis of the shaft member by engaging with the rotary engagement member and includes an intermediate pawl that engages with the rotary pawl and the fixed pawl in the circumferential direction, and a biasing member that applies a biasing force to maintain the intermediate pawl at a predetermined position in the circumferential direction relative to the fixed pawl when not engaged with the rotary pawl.

[0013] Patent Document 4 discloses a steer-by-wire type power steering device. This power steering device is provided with a rotation restriction mechanism that restricts the steering angle range of the steering wheel. The rotation restriction mechanism has an integrally rotating part that rotates integrally with the second input shaft, a relative rotating part that rotates relative to the integrally rotating part, and a stopper mechanism that restricts the rotation of the relative rotating part.

[0014] Patent Document 5 discloses a steer-by-wire steering device. This steering device includes a first rotating member connected to the steering shaft and rotating in conjunction with it, a second rotating member supported on the outer periphery of the first rotating member and rotating in conjunction with the first rotating member when the steering shaft rotates, and a housing that houses the first and second rotating members, is connected to the steering column, and the outer periphery of the second rotating member is supported on the inner periphery to limit the rotation of the second rotating member. [Prior art documents] [Patent documents]

[0015] [Patent Document 1] Japanese Patent Application Publication No. 2020-69844 [Patent Document 2] Japanese Patent Publication No. 05-042437 [Patent Document 3] Japanese Patent Publication No. 2021-172231 [Patent Document 4] Japanese Patent Application Publication No. 2006-182078 [Patent Document 5] U.S. Patent Publication No. 20220266895 Summary of the Invention [Problem to be solved by the invention]

[0016] In the stopper unit 100 described in Patent Document 1, the angle through which the first rotating member 101 can rotate relative to the second rotating member 103 is smaller than 360 degrees by the sum of the circumferential width of the first rotating protrusion 104 and the circumferential width of the second rotating protrusion 107. Furthermore, the angle through which the second rotating member 103 can rotate relative to the housing 102 is smaller than 360 degrees by the sum of the circumferential width of the fixed protrusion 105 and the circumferential width of the second rotating protrusion 107. Therefore, in a steering device including the stopper unit 100, the amount of rotation (rotational angle) of the steering shaft is limited to less than ±360 degrees. This is also true for the techniques described in Patent Documents 3 to 5. Therefore, the number of lock-to-lock rotations of the steering wheel is limited to less than two rotations.

[0017] However, in steering devices for general passenger cars that have become widespread in recent years, the number of lock-to-lock rotations is greater than two. For example, in so-called family cars, it is about four rotations, and even in sports cars, it is about two to three rotations. For this reason, a rotation limiting device that allows a high degree of freedom in setting the number of lock-to-lock rotations of the steering wheel is desired.

[0018] The multiple rotation limit mechanism of Patent Document 2 is a device for detecting the rotation end of the rotating shaft, and is not intended to lock the rotation of the rotating shaft.

[0019] In view of the above circumstances, the present disclosure has an object to provide a rotation limiting device that allows a high degree of freedom in setting the amount of rotation of a rotating member. [Means for solving the problem]

[0020] A rotation limiting device according to a first aspect of the present disclosure includes a first member, a second member, and at least one intermediate member.

[0021] The first member has a first protrusion.

[0022] The second member has a second protrusion disposed on one axial side of the first protrusion, and is disposed coaxially with the first member and rotatable relative to the first member.

[0023] The at least one intermediate member has a side plate portion disposed between the first protrusion and the second protrusion in the axial direction, a first intermediate protrusion protruding from the other axial side surface of the side plate portion toward the other axial side, and a second intermediate protrusion protruding from one axial side surface of the side plate portion toward one axial side. The at least one intermediate member is supported so as to be rotatable relative to the first member and the second member.

[0024] In a rotation limiting device according to a second aspect of the present disclosure, in the rotation control device according to the first aspect, the first member can have a first side facing one axial side and the first protrusion protruding from the first side toward one axial side, and the second member can have a second side facing the other axial side and the second protrusion protruding from the second side toward the other axial side.

[0025] In a rotation limiting device according to a third aspect of the present disclosure, the first member can be fitted radially inside the second member so as to be rotatable relative to the first member, and the at least one intermediate member can be disposed between the first member and the second member in the radial direction so as to be rotatable relative to the first member and the second member. Note that the rotation limiting device according to the third aspect can also be implemented simultaneously with the rotation limiting device according to the second aspect. do.

[0026] In a rotation limiting device according to a fourth aspect of the present disclosure, in the rotation limiting device according to the third aspect, the second member can have a second cylindrical portion arranged radially outside the first member and the at least one intermediate member.

[0027] In a rotation limiting device according to a fifth aspect of the present disclosure, in the rotation limiting device according to the fourth aspect, the first member can have a first side facing one axial side and the first protrusion protruding from the first side toward one axial side, the second member can have a second side facing the other axial side and the second protrusion protruding from the second side toward the other axial side, the second member can have a second flange portion bent radially inward from an end of one axial side of the second cylindrical portion, and the second flange portion can have the second side on the other axial side.

[0028] In a rotation limiting device according to a sixth aspect of the present disclosure, in the rotation limiting device according to the fifth aspect, the second member can include a housing main body having the second cylindrical portion and the second flange portion, and a cover body covering the radially outer portion of the opening on the other axial side of the second cylindrical portion.

[0029] A seventh aspect of the present disclosure provides a rotation limiting device according to the sixth aspect, wherein the housing main body has a main body-side fastening hole and the lid has a lid-side fastening hole. In this case, one of the main body-side fastening hole and the lid-side fastening hole is configured as a threaded hole, and the other of the main body-side fastening hole and the lid-side fastening hole is configured as a threaded hole or a cylindrical hole. The rotation limiting device further includes a fastening bolt threaded into or inserted through the other fastening hole and threaded into the one fastening hole.

[0030] In a rotation limiting device according to an eighth aspect of the present disclosure, in the rotation limiting device according to the fourth aspect, the first member can have a first side surface facing one axial side and the first protrusion protruding from the first side surface toward one axial side, the second member can have a second side surface facing the other axial side and the second protrusion protruding from the second side surface toward the other axial side, and the second member can include a housing main body having the second cylindrical portion and an inward flange portion bent radially inward from an end portion of the second cylindrical portion on the other axial side, and a lid body covering a radially outer portion of an opening on one axial side of the second cylindrical portion. In this case, the lid body has the second side surface on the other axial side.

[0031] A ninth aspect of the present disclosure provides a rotation limiting device according to the eighth aspect, wherein the housing main body has a main body-side fastening hole and the lid has a lid-side fastening hole. In this case, one of the main body-side fastening hole and the lid-side fastening hole is configured as a threaded hole, and the other of the main body-side fastening hole and the lid-side fastening hole is configured as a threaded hole or a cylindrical hole. The rotation limiting device further includes a fastening bolt threaded into or inserted through the other fastening hole and threaded into the one fastening hole.

[0032] In a rotation limiting device according to a tenth aspect of the present disclosure, in the rotation limiting device according to the second aspect, the first member can have a first cylindrical portion into which the at least one intermediate member is externally fitted so as to be rotatable relative to the first member, and a first flange portion protruding radially outward from the outer peripheral surface of the first cylindrical portion. In this case, the first flange portion has the first side surface on one axial side surface. Note that the rotation limiting device according to the tenth aspect can also be implemented simultaneously with the rotation limiting device according to any one of the third to ninth aspects.

[0033] A rotation limiting device according to an eleventh aspect of the present disclosure may include a preload applying member that applies an axial preload between the first member and the second member in the rotation limiting device according to the first aspect. Note that the rotation limiting device according to the eleventh aspect may be implemented simultaneously with the rotation limiting device according to any one of the second to tenth aspects.

[0034] A steering device according to a twelfth aspect of the present disclosure includes a steering shaft and a rotation limiting device that limits the amount of rotation of the steering shaft to a predetermined value.

[0035] The rotation limiting device is configured by the rotation limiting device according to any one of the first to eleventh aspects of the present disclosure.

[0036] One of the first member and the second member is connected and fixed to the steering shaft, and the other of the first member and the second member is supported and fixed to a part that does not rotate even when in use. [Effects of the Invention]

[0037] According to a rotation limiting device according to one aspect of the present disclosure, it is possible to improve the degree of freedom in setting the amount of rotation of a rotating member. [Brief explanation of the drawings]

[0038] [Figure 1] FIG. 1 is a schematic diagram showing an example of a steer-by-wire steering system including a rotation limiting device according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view showing a rotation limiting device according to a first embodiment of the present disclosure. [Figure 3] FIG. 3 is an exploded perspective view showing a rotation limiting device according to a first embodiment of the present disclosure. [Figure 4] 4(A) to 4(C) are schematic diagrams for explaining the operation of the rotation limiting device when the steering wheel is operated from the maximum left to the maximum right. [Figure 5]5(A) to 5(C) are schematic diagrams for explaining the operation of the rotation limiting device when the steering wheel is operated from the maximum right to the maximum left. [Figure 6] FIG. 6 is a cross-sectional view showing a modification of the first example of the embodiment of the present disclosure. [Figure 7] 7(A) to 7(D) are schematic diagrams for explaining the operation of the rotation limiting device in the modified example when the steering wheel is operated from the maximum left to the maximum right. [Figure 8] 8(A) to 8(D) are schematic diagrams for explaining the operation of the rotation limiting device in the modified example when the steering wheel is turned from the maximum right to the maximum left. [Figure 9] FIG. 9 is a cross-sectional view showing a rotation limiting device according to a second embodiment of the present disclosure. [Figure 10] FIG. 10 is a cross-sectional view showing a rotation limiting device according to a third embodiment of the present disclosure. [Figure 11] FIG. 11 is a cross-sectional view showing a rotation limiting device according to a fourth embodiment of the present disclosure. [Figure 12] FIG. 12 is a cross-sectional view showing a rotation limiting device according to a fifth example of an embodiment of the present disclosure. [Figure 13] FIG. 13 is an exploded perspective view showing a rotation limiting device according to a fifth embodiment of the present disclosure. [Figure 14] FIG. 14 is a cross-sectional view showing a rotation limiting device according to a sixth embodiment of the present disclosure. [Figure 15] FIG. 15 is an exploded perspective view showing a rotation limiting device according to a sixth embodiment of the present disclosure. [Figure 16] FIG. 16 is a cross-sectional view showing a rotation limiting device according to a seventh embodiment of the present disclosure. [Figure 17] FIG. 17 is an exploded perspective view showing a rotation limiting device according to a seventh embodiment of the present disclosure. [Figure 18] FIG. 18 is a cross-sectional view showing a rotation limiting device according to an eighth example of an embodiment of the present disclosure. [Figure 19] FIG. 19 is an exploded perspective view showing a rotation limiting device according to an eighth example of an embodiment of the present disclosure. [Figure 20] FIG. 20 is an exploded view showing a stopper unit of a conventional structure. DETAILED DESCRIPTION OF THE INVENTION

[0039] [First example of embodiment] A first example of an embodiment of the present disclosure will be described with reference to Figs. 1 to 5(C). In this example, a rotation limiting device 4 is incorporated into a steering unit 3 constituting the steering device 1 in order to limit the lock-to-lock rotation speed of a steering wheel 2 of a steer-by-wire steering device 1. Below, the overall structure of the steering device 1 will be described first, and then the structure and operation of the rotation limiting device 4 will be described. In addition, in the following description, the front-rear direction means the front-rear direction of the vehicle.

[0040] <Overall structure of steering device 1> As shown in Fig. 1, the steering device 1 includes a steering unit 3 having a steering wheel 2, a steering unit 6 that applies a steering angle to a pair of steered wheels 5, and a control unit (ECU) 7. The steering device 1 has a linkless structure in which the steering unit 3 and the steering unit 6 are not mechanically connected, but are electrically connected via the control unit 7.

[0041] The steering unit 3 includes a steering column 8, a steering shaft 9, a reaction force applying device 10, and a rotation limiting device 4.

[0042] The steering column 8 has a cylindrical shape and is supported by the vehicle body.

[0043] The steering shaft 9 is rotatably supported on the radially inner side of the steering column 8. The steering wheel 2 is supported and fixed to the rear end of the steering shaft 9.

[0044] The reaction force applying device 10 is connected to the front end of the steering shaft 9. The reaction force applying device 10 includes a reaction force applying motor and a reducer such as a worm reducer, and applies the output torque of the reaction force applying motor to the steering shaft 9 after increasing it with the reducer.

[0045] The rotation limiting device 4 is provided between the steering shaft 9 and a portion that does not rotate even when in use, and limits the number of lock-to-lock rotations of the steering wheel 2. In this example, the rotation limiting device 4 is provided between the front portion of the steering shaft 9 and the front end of the steering column 8. However, the rotation limiting device 4 can be provided at any position between the steering shaft 9 and a fixed portion that does not rotate even when in use. Specifically, the rotation limiting device 4 can also be provided in a portion closer to the steering wheel 2, for example, between the rear portion of the steering shaft 9 and the rear end of the steering column 8. Alternatively, the rotation limiting device 4 can be provided between the front end of the steering shaft 9 and the housing of the reaction force applying device 10. If the rotation limiting device 4 is disposed between the front end of the steering shaft 9 and the housing of the reaction force applying device 10, the rotation limiting device 4 can be attached and detached relatively easily. The specific configuration of the rotation limiting device 4 will be described later.

[0046] The steering unit 3 further includes sensors such as a torque sensor and a steering angle sensor that measure the operation of the steering wheel 2 by the driver.

[0047] The steering unit 6 includes a gear housing 11 supported and fixed to the vehicle body, a linear motion member, and a steering actuator 12 that linearly drives the linear motion member.

[0048] The linear motion member is composed of a rack shaft, a screw shaft, etc. The linear motion member has its axial direction oriented in the width direction of the vehicle body and is supported inside the gear housing 11 so as to be able to move linearly in the axial direction. Base ends of a pair of tie rods 13 are connected to both axial ends of the linear motion member via spherical joints (not shown), and a pair of steered wheels 5 are supported at the tip ends of the pair of tie rods 13.

[0049] When the linear motion member is constituted by a rack shaft, the steering actuator 12 includes a pinion shaft that meshes with the rack shaft, a steering motor, and a reducer, and the output torque of the steering motor is increased by the reducer and then input to the pinion shaft, which is then rotationally driven to cause linear movement of the rack shaft.

[0050] When the linear motion member is formed by a screw shaft, steering actuator 12 includes a nut supported around the screw shaft so as to be rotatable relative to the screw shaft, a steering motor, and a reducer. Steering actuator 12 linearly moves the screw shaft by increasing the output torque of the steering motor using the reducer and then inputting it to the nut, which rotates and drives the nut. The feed screw mechanism including the screw shaft and the nut can be formed by a slide screw type feed screw mechanism in which a male threaded portion on the outer peripheral surface of the screw shaft is directly threadedly engaged with a female threaded portion on the inner peripheral surface of the nut, or by a ball screw type feed screw mechanism in which a plurality of balls are freely rollably arranged between an inner diameter side ball screw groove on the outer peripheral surface of the screw shaft and an outer diameter side ball screw groove on the inner peripheral surface of the nut.

[0051] In the steering device 1 of this example, when the driver operates the steering wheel 2, the operation of the steering wheel 2 is measured by a sensor in the steering unit 3, and the measurement results are output to the control unit 7. Various signals indicating the driving situation, such as the steering torque measured by a torque sensor, the steering angle measured by a steering angle sensor, the vehicle speed, the yaw rate, and the acceleration, are input to the control unit 7. The control unit 7 drives the steering actuator 12 provided in the steering unit 6 based on the various signals indicating the driving situation. As a result, the linearly moving member is displaced in the width direction of the vehicle body, and the pair of tie rods 13 are pushed and pulled, thereby applying a steering angle to the pair of steered wheels 5.

[0052] <Structure of rotation limiting device 4> The rotation limiting device 4 of this example is provided between the front portion of the steering shaft 9 and the steering column 8, which does not rotate even when in use, and limits the lock-to-lock rotation speed of the steering wheel 2 by limiting the amount of rotation of the steering shaft 9 to a predetermined value. The rotation limiting device 4 includes a first member 14, a second member 15, and one intermediate member 16.

[0053] In the first to sixth embodiments, the one axial side refers to the front side of the vehicle. 2 to 15, and the other axial side refers to the rear side of the vehicle, that is, the right side in FIGS.

[0054] The first member 14 has a first protrusion 17 .

[0055] In this example, the first member 14 has a cylindrical first tubular portion 18 and a hollow circular plate-shaped first flange portion 19 that protrudes radially outward from the outer peripheral surface of the other axial end of the first tubular portion 18.

[0056] The first cylindrical portion 18 is fitted and fixed to the front portion of the steering shaft 9 so as not to rotate relative to the steering shaft 9. That is, the first member 14 rotates together with the steering shaft 9.

[0057] The first flange portion 19 has a first side surface 20 on one axial side surface, and a first protrusion 17 protruding toward one axial side at one circumferential position on the radially outer side of the first side surface 20. The radially inner surface of the first protrusion 17 faces the outer peripheral surface of the end portion on the other axial side of the first cylindrical portion 18 via a gap.

[0058] In this example, the first projection 17 has a fan-shaped end face shape when viewed from one axial side. That is, the radially inner surface and the radially outer surface of the first projection 17 have an arc-shaped outline shape centered on the central axis O of the first member 14 when viewed from one axial side. The radially outer surface of the first projection 17 exists within the same cylindrical surface as the outer circumferential surface of the first flange portion 19. That is, the first projection 17 does not protrude radially outward beyond the first flange portion 19. The side surfaces on both circumferential sides of the first projection 17 have a linear outline shape extending in the radial direction centered on the central axis O of the first member 14 when viewed from one axial side, and extend linearly in the axial direction when viewed from the radially outer side. That is, the side surfaces on both circumferential sides of the first projection 17 exist within an imaginary plane including the central axis O of the first member 14. Furthermore, in this example, the circumferential width of the first projection 17, i.e., the angle formed by the side surfaces on both circumferential sides, is 45 degrees.

[0059] The second member 15 has a second protrusion 21 disposed on one axial side of the first protrusion 17, and is disposed coaxially with the first member 14 and capable of rotating relative to the first member 14.

[0060] In this example, the second member 15 includes a housing main body 22 and a lid body 23.

[0061] The housing body 22 has a cylindrical second tubular portion 24 and a hollow circular plate-like second flange portion 25 bent radially inward from one axial end of the second tubular portion 24.

[0062] The second flange portion 25 has a second side surface 26 on the other side surface in the axial direction, and has a second protrusion 21 at one circumferential position on the radially outer portion of the second side surface 26. The radially outer end of the second protrusion 21 is connected to one axial end of the inner peripheral surface of the second cylindrical portion 24.

[0063] In this example, the second projection 21 has a fan-shaped end face shape when viewed from the other axial side. That is, the radially inner and outer surfaces of the second projection 21 have an arc-shaped outline shape centered on the central axis O of the second member 15 when viewed from the other axial side. The side surfaces on both circumferential sides of the second projection 21 have a linear outline shape extending in the radial direction centered on the central axis O of the second member 15 when viewed from the other axial side, and extend linearly in the axial direction when viewed from the radially inner side. That is, the side surfaces on both circumferential sides of the second projection 21 exist within an imaginary plane including the central axis O of the second member 15. Furthermore, in this example, the circumferential width of the second projection 21 is 45 degrees.

[0064] The housing body 22 further has a pair of body ears 27 that protrude radially outward from two radially opposite positions on the other axial end of the second cylindrical portion 24. 27 has a main body side coupling hole 28 that penetrates in the axial direction. In this example, the main body side coupling hole 28 is configured as a cylindrical hole whose inner diameter does not change in the axial direction.

[0065] In this example, the housing main body 22 is configured as a single unit, including the second protrusion 21. However, when implementing the present disclosure, the second protrusion can also be provided by supporting and fixing a separately configured pin to the second side surface of the second flange portion.

[0066] The cover 23 covers (blocks) the radially outer portion of the opening on the other axial side of the second cylindrical portion 24 of the housing main body 22. In this example, the cover 23 has a hollow circular plate-shaped blocking plate 29 and a pair of cover ears 30 that protrude radially outward from two radially opposite positions of the blocking plate 29. Each of the cover ears 30 has a cover-side connecting hole 31 that penetrates in the axial direction. In this example, the cover-side connecting holes 31 are configured as screw holes.

[0067] In this example, the housing body 22 and the lid 23 are joined and fixed together by overlapping a pair of cover lugs 30 on the other axial side of the pair of main body lugs 27, inserting joining bolts (not shown) into a pair of main body-side joining holes 28, and screwing the joining bolts into a pair of cover-side joining holes 31. The rotation limiting device 4 in this example is supported and fixed to the steering column 8, which does not rotate even during use, by screwing the joining bolts into column-side threaded holes that open on the front side of the steering column 8.

[0068] The intermediate member 16 has a side plate portion 32 that is arranged between the first projection 17 and the second projection 21 in the axial direction, a first intermediate projection 33 that protrudes from the other axial side surface of the side plate portion 32 toward the other axial side, and a second intermediate projection 34 that protrudes from one axial side surface of the side plate portion 32 toward one axial side. The intermediate member 16 is supported coaxially with the first member 14 and the second member 15 and capable of relative rotation with respect to the first member 14 and the second member 15.

[0069] In this example, the intermediate member 16 has a cylindrical intermediate tubular portion 35 that is externally fitted onto the first tubular portion 18 of the first member 14 so as to be rotatable relative to the first tubular portion 18, and a hollow circular plate-shaped side plate portion 32 that protrudes radially outward from the outer peripheral surface of the axial middle portion of the intermediate tubular portion 35.

[0070] Furthermore, the intermediate member 16 has a first intermediate-side protrusion 33 that protrudes toward the other axial side from one circumferential position on the other axial side surface of the side plate portion 32, and has a second intermediate-side protrusion 34 that protrudes toward one axial side from one position on one axial side surface of the side plate portion 32 that is radially opposite to the first intermediate-side protrusion 33 (one position that is 180 degrees out of phase with the first intermediate-side protrusion 33 in the circumferential direction). A radially inner end of the first intermediate-side protrusion 33 is connected to the other axial side portion of the outer circumferential surface of the intermediate tubular portion 35, and a radially inner end of the second intermediate-side protrusion 34 is connected to one axial side portion of the outer circumferential surface of the intermediate tubular portion 35.

[0071] In this example, the intermediate-side first protrusion 33 has a fan-shaped end face shape when viewed from the other axial side. That is, the radially inner surface and the radially outer surface of the intermediate-side first protrusion 33 have an arc-shaped contour centered on the central axis O of the intermediate member 16 when viewed from the other axial side. The radially outer surface of the intermediate-side first protrusion 33 is located within the same cylindrical plane as the outer peripheral surface of the side plate portion 32. That is, the intermediate-side first protrusion 33 is formed integrally with the side plate portion 32 and does not protrude radially outward beyond the side plate portion 32. That is, the intermediate-side first protrusion 33 is located radially inward beyond the outer peripheral surface of the side plate portion 32. Note that the radially outer surface of the intermediate-side first protrusion 33 does not necessarily have to be located within the same cylindrical plane as the outer peripheral surface of the side plate portion 32, as long as it is located radially inward beyond the outer peripheral surface of the side plate portion 32. The side surfaces on both sides in the circumferential direction of the intermediate side first projection 33 have a linear outline shape extending in the radial direction centered on the central axis O of the intermediate member 16 when viewed from the other axial side, and extend linearly in the axial direction when viewed from the radially outer side. In other words, the side surfaces on both sides in the circumferential direction of the intermediate side first projection 33 exist within an imaginary plane including the central axis O of the intermediate member 16. In this example, the circumferential width of the intermediate first projection 33 is set to 45 degrees.

[0072] In this example, the intermediate-side second protrusion 34 has a fan-shaped end face shape when viewed from one axial side. That is, the radially inner surface and the radially outer surface of the intermediate-side second protrusion 34 have an arc-shaped contour centered on the central axis O of the intermediate member 16 when viewed from one axial side. The radially outer surface of the intermediate-side second protrusion 34 is located within the same cylindrical plane as the outer peripheral surface of the side plate portion 32. That is, the intermediate-side second protrusion 34 is formed integrally with the side plate portion 32 and does not protrude radially outward beyond the side plate portion 32. That is, the intermediate-side second protrusion 34 is located radially inward beyond the outer peripheral surface of the side plate portion 32. Note that the radially outer surface of the intermediate-side second protrusion 34 does not necessarily have to be located within the same cylindrical plane as the outer peripheral surface of the side plate portion 32, as long as it is located radially inward beyond the outer peripheral surface of the side plate portion 32. The side surfaces on both circumferential sides of the intermediate-side second projection 34 have a linear outline shape extending in a radial direction centered on the central axis O of the intermediate member 16 when viewed from one axial side, and extend linearly in the axial direction when viewed from the radially outer side. In other words, the side surfaces on both circumferential sides of the intermediate-side second projection 34 exist within an imaginary plane including the central axis O of the intermediate member 16. In this example, the circumferential width of the intermediate-side second projection 34 is 45 degrees.

[0073] The rotation limiting device 4 of this example is formed by combining the first member 14 and the intermediate member 16 inside the second member 15 so as to be rotatable relative to each other. Specifically, the intermediate cylindrical portion 35 of the intermediate member 16 is externally fitted onto the other axial side portion of the first cylindrical portion 18 of the first member 14 without any rattle so as to be rotatable relative to each other, and one axial end of the first cylindrical portion 18 is internally fitted into the second flange portion 25 of the housing main body 22 without any rattle so as to be rotatable relative to each other. In addition, the radially inner portion of the other axial side surface of the second flange portion 25 is in sliding contact with or closely faces the end surface of one axial side of the intermediate cylindrical portion 35, and the radially inner portion of one axial side surface of the closing plate portion 29 of the cover 23 is in sliding contact with or closely faces the other axial side surface of the first flange portion 19 of the first member 14. With the rotation limiting device 4 assembled in this manner, one axial side surface of the first protrusion 17 faces the other axial side surface of the side plate portion 32 across a gap, and the other axial side surface of the second protrusion 21 faces the other axial side surface of the side plate portion 32 across a gap. Furthermore, the other axial side surface of the intermediate-side first protrusion 33 faces the other axial side surface of the first flange portion 19 across a gap, and the one axial side surface of the intermediate-side second protrusion 34 faces the other axial side surface of the second flange portion 25 across a gap.

[0074] <Operation of rotation limiting device 4> The operation of the rotation limiting device 4 of this example will be described with reference to Figures 4(A) to 5(C). Figures 4(A) to 5(C) are diagrams that schematically show the first protrusion 17 of the first member 14, the second protrusion 21 of the second member 15, and the intermediate member 16 as viewed from the radial outside. In the following description, "one circumferential side" refers to the counterclockwise front side as viewed from the driver seated in the driver's seat, and refers to the lower side in Figures 4(A) to 5(C), and "the other circumferential side" refers to the clockwise front side as viewed from the driver seated in the driver's seat, and refers to the upper side in Figures 4(A) to 5(C).

[0075] First, when the steering wheel 2 is operated from its maximum left position (counterclockwise as seen by the driver sitting in the driver's seat) to its maximum right position (clockwise as seen by the driver sitting in the driver's seat), the rotation limiting device 4 operates in the order shown in Figure 4(A) → Figure 4(B) → Figure 4(C).

[0076] That is, when the steering wheel 2 is turned to the maximum left, as shown in Figure 4(A), one circumferential side of the first protrusion 17 abuts against the other circumferential side of the intermediate first protrusion 33, and the other circumferential side of the second protrusion 21 abuts against one circumferential side of the intermediate second protrusion 34.

[0077] From this state, when the steering wheel 2 is turned to the right and the steering shaft 9 is rotated clockwise, the other circumferential side surface of the second protrusion 21 moves in the clockwise direction as shown by the arrow in FIG. Only the first member 14 rotates clockwise (towards the other circumferential side) while remaining in contact with one circumferential side surface of the intermediate-side second protrusion 34. Then, when the first member 14 rotates an angle smaller than 360 degrees by the sum of the circumferential width of the first protrusion 17 and the circumferential width of the intermediate-side first protrusion 33, that is, 270 degrees in this example, the other circumferential side surface of the first protrusion 17 comes into contact with one circumferential side surface of the intermediate-side first protrusion 33, as shown in FIG. 4(B). In this state, the steering wheel 2 is positioned at the center, and the pair of steered wheels 5 are facing in a straight-ahead direction.

[0078] When the steering wheel 2 is further turned to the right from the state shown in FIG. 4(B), the other circumferential side surface of the first protrusion 17 presses one circumferential side surface of the middle-side first protrusion 33 toward the other circumferential side, as shown by the arrow in FIG. 4(B). As a result, the first member 14 and the intermediate member 16 rotate together in the clockwise direction (toward the other circumferential side). When the first member 14 and the intermediate member 16 rotate clockwise by an angle smaller than 360 degrees by the sum of the circumferential width of the second protrusion 21 and the circumferential width of the middle-side second protrusion 34, that is, 270 degrees in this example, the other circumferential side surface of the middle-side second protrusion 34 abuts against one circumferential side surface of the second protrusion 21, as shown in FIG. 4(C). When the other circumferential side surface of the middle-side second protrusion 34 abuts against one circumferential side surface of the second protrusion 21, the intermediate member 16 is prevented from rotating further clockwise relative to the second member 15. When the clockwise rotation of the intermediate member 16 is prevented, the first member 14 is prevented from rotating further in the clockwise direction.

[0079] Alternatively, when the steering wheel 2 is turned right from the state shown in FIG. 4(A), the first member 14 rotates clockwise. Due to the frictional force acting between the outer peripheral surface of the first cylindrical portion 18 and the inner peripheral surface of the intermediate cylindrical portion 35, the intermediate member 16 is rotated along with the first member 14, and the first member 14 and the intermediate member 16 rotate together. Then, the other circumferential side surface of the intermediate-side second protrusion 34 abuts against one circumferential side surface of the second protrusion 21, preventing the intermediate member 16 from rotating further clockwise relative to the second member 15. When the steering wheel 2 is turned further right from this state, only the first member 14 rotates clockwise. Then, the other circumferential side surface of the first protrusion 17 abuts against one circumferential side surface of the intermediate-side first protrusion 33, preventing the first member 14 from rotating further clockwise relative to the intermediate member 16.

[0080] In either case, when the first member 14 is prevented from rotating further in the clockwise direction, the steering shaft 9 and the steering wheel 2 supported and fixed to the steering shaft 9 are prevented from rotating further in the clockwise direction.

[0081] Next, when the steering wheel 2 is operated from the maximum right position to the maximum left position, the rotation limiting device 4 operates in the order shown in Figure 5(A) → Figure 5(B) → Figure 5(C).

[0082] That is, when the steering wheel 2 is turned to the maximum right, as shown in Figure 5(A), the other circumferential side of the first protrusion 17 abuts against one circumferential side of the intermediate first protrusion 33, and one circumferential side of the second protrusion 21 abuts against the other circumferential side of the intermediate second protrusion 34.

[0083] From this state, when the steering wheel 2 is turned to the left and the steering shaft 9 is rotated counterclockwise, as shown by the arrow in Fig. 5(A), only the first member 14 rotates counterclockwise (toward one circumferential side) while one circumferential side of the second protrusion 21 remains in contact with the other circumferential side of the intermediate-side second protrusion 34. Then, when the first member 14 rotates an angle smaller than 360 degrees by the sum of the circumferential width of the first protrusion 17 and the circumferential width of the intermediate-side first protrusion 33, that is, 270 degrees in this example, one circumferential side of the first protrusion 17 comes into contact with the other circumferential side of the intermediate-side first protrusion 33, as shown in Fig. 5(B). In this state, the steering wheel 2 is positioned at the center, and the pair of steered wheels 5 are facing straight ahead.

[0084] When the steering wheel 2 is further turned to the left from the state shown in FIG. 5(B), one circumferential side surface of the first protrusion 17 presses the other circumferential side surface of the intermediate-side first protrusion 33 toward one circumferential side, as shown by the arrow in FIG. 5(B). As a result, the first member 14 and the intermediate member 16 rotate together counterclockwise (toward one circumferential side). When the first member 14 and the intermediate member 16 rotate counterclockwise an angle smaller than 360 degrees by the sum of the circumferential width of the second protrusion 21 and the circumferential width of the intermediate-side second protrusion 34, that is, 270 degrees in this example, as shown in FIG. 5(C). When one circumferential side surface of the intermediate-side second projection 34 abuts against the other circumferential side surface of the second projection 21, the intermediate member 16 is prevented from rotating further counterclockwise relative to the second member 15. When the counterclockwise rotation of the intermediate member 16 is prevented, the first member 14 is prevented from rotating further counterclockwise.

[0085] Alternatively, when the steering wheel 2 is turned left from the state shown in FIG. 5(A), the first member 14 rotates counterclockwise. Due to the frictional force acting between the outer circumferential surface of the first cylindrical portion 18 and the inner circumferential surface of the intermediate cylindrical portion 35, the intermediate member 16 is rotated together with the first member 14, and the first member 14 and the intermediate member 16 rotate together. Then, one circumferential side surface of the intermediate-side second protrusion 34 abuts against the other circumferential side surface of the second protrusion 21, preventing the intermediate member 16 from rotating further counterclockwise relative to the second member 15. When the steering wheel 2 is turned further left from this state, only the first member 14 rotates counterclockwise. Then, one circumferential side surface of the first protrusion 17 abuts against the other circumferential side surface of the intermediate-side first protrusion 33, preventing the first member 14 from rotating further counterclockwise relative to the intermediate member 16.

[0086] In either case, when the first member 14 is prevented from rotating further counterclockwise, the steering shaft 9 and the steering wheel 2 supported and fixed to the steering shaft 9 are prevented from rotating further counterclockwise.

[0087] The rotation limiting device 4 of this example can adjust the amount of rotation of the steering shaft 9 that is fixedly coupled to the first member 14 by changing the number of intermediate members 16 that are arranged between the first protrusion 17 and the second protrusion 21 in the axial direction. Therefore, the rotation limiting device 4 of this example can improve the degree of freedom in setting the amount of rotation of the steering shaft 9. Specifically, the more the number of intermediate members 16 is increased, the greater the amount of rotation of the steering shaft 9 can be.

[0088] 6 to 8(D) show a rotation limiting device 4a including two intermediate members 16a, 16b. The intermediate members 16a, 16b each include a hollow, circular, plate-like side plate 32a, 32b, a first intermediate projection 33a, 33b projecting toward the other axial direction from a single circumferential position on the other axial side surface of the side plate 32a, 32b, and a second intermediate projection 34a, 34b projecting toward the one axial direction from a single position on one axial side surface that is radially opposite the first intermediate projection 33a, 33b. That is, the intermediate members 16a, 16b do not include the intermediate cylindrical portion 35 included in the intermediate member 16 according to the first embodiment. The two intermediate members 16a, 16b are arranged in series in the axial direction and fitted around the first cylindrical portion 18 of the first member 14 so as to be rotatable relative to each other. The intermediate member 16a on the other axial side and the intermediate member 16b on one axial side are given different reference numerals for ease of explanation, but have the same shape. The axial lengths of the first tubular portion 18 and the second tubular portion 24 are longer than those of the structure according to the first example embodiment by the amount of the additional intermediate member 16a, 16b.

[0089] In the steering unit 3 (see FIG. 1) equipped with the rotation limiting device 4a of this modified example, when the steering wheel 2 is operated from the state in which it is operated to the maximum left to the state in which it is operated to the maximum right, the rotation limiting device 4a operates in the order shown in FIG. 7(A) → FIG. 7(B) → FIG. 7(C) → FIG. 7(D). Make.

[0090] When the steering wheel 2 is turned to the maximum left, as shown in FIG. 7(A), one circumferential side surface of the first protrusion 17 abuts against the other circumferential side surface of the intermediate-side first protrusion 33a of the intermediate member 16a on the other axial side, one circumferential side surface of the intermediate-side second protrusion 34a of the intermediate member 16a on the other axial side abuts against the other circumferential side surface of the intermediate-side first protrusion 33b of the intermediate member 16b on one axial side, and one circumferential side surface of the intermediate-side second protrusion 34b of the intermediate member 16b on one axial side abuts against the other circumferential side surface of the second protrusion 21.

[0091] From this state, when the steering wheel 2 is turned to the right and the steering shaft 9 is rotated clockwise, as shown by the arrow in Figure 7(A), one circumferential side surface of the intermediate-side second protrusion 34a of the intermediate member 16a on the other axial side abuts against the other circumferential side surface of the intermediate-side first protrusion 33b of the intermediate member 16b on one axial side, and one circumferential side surface of the intermediate-side second protrusion 34b of the intermediate member 16b on one axial side remains in contact with the other circumferential side surface of the second protrusion 21, and only the first member 14 rotates clockwise (towards the other circumferential side). Then, when the first member 14 rotates clockwise by an angle that is smaller than 360 degrees by the sum of the circumferential width of the first protrusion 17 and the circumferential width of the intermediate side first protrusion 33a, as shown in Figure 7(B), the other circumferential side surface of the first protrusion 17 abuts against one circumferential side surface of the intermediate side first protrusion 33a of the intermediate member 16a on the other axial side.

[0092] 7(B), when the steering wheel 2 is further turned to the right, one circumferential side surface of the intermediate-side first protrusion 33a of the intermediate member 16a on the other axial side is pushed toward the other circumferential side by the other circumferential side surface of the first protrusion 17, as shown by the arrow in FIG. 7(B). As a result, one circumferential side surface of the intermediate-side second protrusion 34b of the intermediate member 16b on one axial side remains in contact with the other circumferential side surface of the second protrusion 21, and the first member 14 and the intermediate member 16a on the other axial side rotate clockwise (toward the other circumferential side) together. Then, when the first member 14 and the intermediate member 16a on the other axial side rotate clockwise by an angle that is smaller than 360 degrees by the sum of the circumferential width of the intermediate-side second protrusion 34a of the intermediate member 16a on the other axial side and the circumferential width of the intermediate-side first protrusion 33b of the intermediate member 16b on one axial side, as shown in Figure 7(C) , the other circumferential side surface of the intermediate-side second protrusion 34a of the intermediate member 16a on the other axial side abuts against one circumferential side surface of the intermediate-side first protrusion 33b of the intermediate member 16b on one axial side.

[0093] When the steering wheel 2 is further turned to the right from the state shown in Fig. 7(C), the first member 14 and the intermediate member 16a on the other axial side rotate clockwise together, and as shown by the arrow in Fig. 7(C), one circumferential side surface of the intermediate-side first protrusion 33b of the intermediate member 16b on one axial side is pushed toward the other circumferential side by the other circumferential side surface of the intermediate-side second protrusion 34a of the intermediate member 16a on the other axial side. As a result, the first member 14 and the two intermediate members 16a, 16b rotate clockwise (toward the other circumferential side) together. When the first member 14 and the two intermediate members 16a, 16b rotate clockwise by an angle smaller than 360 degrees by the sum of the circumferential width of the intermediate-side second protrusion 34b of the intermediate member 16b on one axial side and the circumferential width of the second protrusion 21, as shown in FIG. 7(D), the other circumferential side surface of the intermediate-side second protrusion 34b of the intermediate member 16b on one axial side abuts against one circumferential side surface of the second protrusion 21. As a result, the intermediate member 16b on one axial side is prevented from rotating in the clockwise direction further relative to the second member 15. When the clockwise rotation of the intermediate member 16b on one axial side is prevented, the intermediate member 16a on the other axial side is prevented from rotating in the clockwise direction further. When the clockwise rotation of the intermediate member 16a on the other axial side is prevented, the first member 14 is prevented from rotating in the clockwise direction further, and the steering shaft 9 and the steering wheel 2 supported and fixed to the steering shaft 9 are prevented from rotating in the clockwise direction further.

[0094] In contrast, when the steering wheel 2 is turned from the maximum right position to the maximum left position, the rotation limiting device 4a operates in the order shown in Figure 8(A) → Figure 8(B) → Figure 8(C) → Figure 8(D).

[0095] That is, when the steering wheel 2 is turned to the maximum right, as shown in FIG. 8(A), the other circumferential side surface of the first protrusion 17 abuts against one circumferential side surface of the intermediate-side first protrusion 33a of the intermediate member 16a on the other axial side, the other circumferential side surface of the intermediate-side second protrusion 34a of the intermediate member 16a on the other axial side abuts against one circumferential side surface of the intermediate-side first protrusion 33b of the intermediate member 16b on one axial side, and the other circumferential side surface of the intermediate-side second protrusion 34b of the intermediate member 16b on one axial side abuts against one circumferential side surface of the second protrusion 21.

[0096] From this state, when the steering wheel 2 is turned to the left and the steering shaft 9 is rotated counterclockwise, as shown by the arrow in Figure 8 (A), the other circumferential side of the intermediate-side second protrusion 34a of the intermediate member 16a on the other axial side abuts against one circumferential side of the intermediate-side first protrusion 33b of the intermediate member 16b on one axial side, and the other circumferential side of the intermediate-side second protrusion 34b of the intermediate member 16b on one axial side remains in contact with one circumferential side of the second protrusion 21, and only the first member 14 rotates counterclockwise (towards one circumferential side). Then, when the first member 14 rotates counterclockwise by an angle that is smaller than 360 degrees by the sum of the circumferential width of the first protrusion 17 and the circumferential width of the intermediate side first protrusion 33a, one circumferential side surface of the first protrusion 17 abuts against the other circumferential side surface of the intermediate side first protrusion 33a of the intermediate member 16a on the other axial side, as shown in Figure 8(B).

[0097] 8(B), when the steering wheel 2 is further turned to the left, the other circumferential side surface of the intermediate-side first protrusion 33a of the intermediate member 16a on the other axial side is pushed toward one circumferential side by one circumferential side surface of the first protrusion 17, as shown by the arrow in FIG. 8(B). As a result, the first member 14 and the intermediate member 16a on the other axial side rotate counterclockwise (to one circumferential side) together while the other circumferential side surface of the intermediate-side second protrusion 34b of the intermediate member 16b on one axial side remains in contact with one circumferential side surface of the second protrusion 21. Then, when the first member 14 and the intermediate member 16a on the other axial side rotate counterclockwise by an angle that is smaller than 360 degrees by the sum of the circumferential width of the intermediate-side second protrusion 34a of the intermediate member 16a on the other axial side and the circumferential width of the intermediate-side first protrusion 33b of the intermediate member 16b on one axial side, one circumferential side surface of the intermediate-side second protrusion 34a of the intermediate member 16a on the other axial side comes into contact with the other circumferential side surface of the intermediate-side first protrusion 33b of the intermediate member 16b on one axial side, as shown in Figure 8(C).

[0098] When the steering wheel 2 is further turned to the left from the state shown in Fig. 8(C), the first member 14 and the intermediate member 16a on the other axial side rotate counterclockwise together, and as shown by the arrow in Fig. 8(C), one circumferential side surface of the intermediate-side second protrusion 34a of the intermediate member 16a on the other axial side presses the other circumferential side surface of the intermediate-side first protrusion 33b of the intermediate member 16b on one axial side toward one circumferential side, thereby causing the first member 14 and the two intermediate members 16a, 16b to rotate counterclockwise (to one circumferential side) together. When the first member 14 and the two intermediate members 16a, 16b rotate counterclockwise by an angle smaller than 360 degrees by the sum of the circumferential width of the intermediate-side second protrusion 34b of the intermediate member 16b on one axial side and the circumferential width of the second protrusion 21, one circumferential side surface of the intermediate-side second protrusion 34b of the intermediate member 16b on one axial side abuts against the other circumferential side surface of the second protrusion 21, as shown in FIG. 8(D). As a result, the intermediate member 16b on one axial side is prevented from rotating counterclockwise further relative to the second member 15. When the counterclockwise rotation of the intermediate member 16b on one axial side is prevented, the intermediate member 16a on the other axial side is prevented from rotating counterclockwise further. When the counterclockwise rotation of the intermediate member 16a on the other axial side is prevented, the first member 14 is prevented from rotating counterclockwise further, and the steering shaft 9 and the steering wheel 2 supported and fixed to the steering shaft 9 are prevented from rotating counterclockwise further. Further counterclockwise rotation is prevented.

[0099] In this modified example, too, based on the frictional force acting between the outer peripheral surface of the first cylindrical portion 18 of the first member 14 and the inner peripheral surface of the side plate portion 32a of the intermediate member 16a on the other axial side and / or the inner peripheral surface of the side plate portion 32b of the intermediate member 16b on one axial side, the intermediate member 16a on one axial side and / or the intermediate member 16b on the other axial side may rotate so as to be rotated by the first member 14. In this case, the operating sequence of the rotation limiting device 4a may differ from the example shown in FIGS. 7 and 8.

[0100] In any event, as described above, the rotation limiting device 4 (4a) of this example can increase the amount of rotation of the steering shaft 9 by increasing the number of intermediate members 16 (16a, 16b) having the intermediate first protrusions 33 (33a, 33b) protruding toward the other axial side and the intermediate second protrusions 34 (34a, 34b) protruding toward one axial side, and arranging the intermediate members 16 (16a, 16b) in series in the axial direction. Specifically, assuming that the circumferential widths W of the first protrusions 17, the second protrusions 21, the intermediate first protrusions 33 (33a, 33b), and the intermediate second protrusions 34 (34a, 34b) are all the same, each increase in the number of intermediate members 16 can increase the amount of rotation of the steering shaft 9 by an angle that is smaller than 360 degrees by twice the circumferential width W (2W).

[0101] When the circumferential width W is 45 degrees, the amount of rotation of the steering shaft 9 can be increased by 270 degrees for each additional intermediate member 16 (16a, 16b), and the number of lock-to-lock rotations of the steering wheel 2 can be increased by 0.75. For example, in a rotation limiting device 4 that includes only one intermediate member 16 as in the first example of the embodiment, the amount of rotation of the steering shaft 9 is 540 degrees (the number of lock-to-lock rotations of the steering wheel 2 is 1.5), but in a rotation limiting device 4a that includes two intermediate members 16a, 16b as in the modified example, the amount of rotation of the steering shaft 9 can be increased to 810 degrees (the number of lock-to-lock rotations of the steering wheel 2 is 2.25).

[0102] In the rotation limiting device 4a of this modified example, the two intermediate members 16a, 16b have the same shape. That is, in the rotation limiting device of the present disclosure, the amount of rotation of the rotatable member can be adjusted by increasing or decreasing the number of intermediate members having the same shape. Therefore, the rotation limiting device of the present disclosure can prevent unnecessary increases in the manufacturing costs, management costs, and assembly costs of parts, and can suppress increases in the manufacturing costs of the rotation limiting device.

[0103] In the rotation limiting device 4 of this example, the first member 14 and the intermediate member 16 are sandwiched in the axial direction between the housing main body 22 and the lid body 23 that constitute the second member 15, and are disposed radially inside the second cylindrical portion 24, with the housing main body 22 and the lid body 23 being fastened together with fastening bolts. Therefore, even before the first member 14 is fastened to the steering shaft 9 and the second member 15 is supported and fastened to the steering column 8, the rotation limiting device 4 can be pre-assembled (assembled). This improves the ease of handling of the rotation limiting device 4.

[0104] In this example, the housing body 22 and the lid 23 are connected and fixed by threading a fastening bolt inserted through the cylindrical body-side fastening hole 28 into the threaded lid-side fastening hole 31, but the fastening bolt inserted through the cylindrical lid-side fastening hole can also be threaded into the threaded body-side fastening hole. Alternatively, both the body-side fastening hole and the lid-side fastening hole can be threaded holes.

[0105] Alternatively, before the rotation limiting device 4 is supported and fixed to the steering column 8, the housing body 22 and the cover 23 may be connected and fixed by another means such as a clip. In this case, or when there is no need to assemble them in advance, both the body-side joining hole and the cover-side joining hole may be cylindrical holes.

[0106] Furthermore, with the rotation limiting device 4 of this example, the axial connection strength of the first member 14 to the steering shaft 9 and the axial connection strength of the second member 15 to the steering column 8 do not need to be increased unnecessarily.

[0107] 20 described above, both circumferential side surfaces of the first rotation protrusion 104, both circumferential side surfaces of the fixed protrusion 105, and both circumferential side surfaces of the second rotation protrusion 107 are inclined with respect to the axial direction when viewed from the radial outside. Therefore, when the first rotation member 101 rotates, a force is applied between the first rotation member 101 and the second rotation member 103 and / or between the second rotation member 103 and the housing 102 in a direction that moves them away from each other in the axial direction. Therefore, it is necessary to sufficiently increase the axial connection strength of the first rotation member 101 to the steering shaft and the axial connection strength of the housing 102 to the vehicle body.

[0108] In contrast, in this example, the circumferentially opposite side surfaces of the first protrusion 17, the circumferentially opposite side surfaces of the second protrusion 21, the circumferentially opposite side surfaces of the intermediate-side first protrusion 33, and the circumferentially opposite side surfaces of the intermediate-side second protrusion 34 each extend linearly in the axial direction when viewed from the radial direction. Therefore, even when the first member 14 rotates in conjunction with the rotation of the steering shaft 9, no axial force acts between the first member 14 and the intermediate member 16, and between the intermediate member 16 and the second member 15. Therefore, there is no need to unnecessarily increase the axial connection strength of the first member 14 to the steering shaft 9 and the axial connection strength of the second member 15 to the steering column 8, and this prevents an unnecessarily high manufacturing cost for the steering device 1 including the rotation limiting device 4.

[0109] In this example, the circumferential widths of the first protrusions 17, the second protrusions 21, the intermediate-side first protrusions 33, and the intermediate-side second protrusions 34 are all 45 degrees. However, when implementing this disclosure, the circumferential widths of the first protrusions, the second protrusions, the intermediate-side first protrusions, and the intermediate-side second protrusions are not particularly limited and can be set to any desired size. However, if these circumferential widths are excessively small, the strength of the protrusions cannot be sufficiently ensured. On the other hand, if these circumferential widths are excessively large, the amount of rotation of the rotating member will be unnecessarily reduced. Taking these factors into consideration, the circumferential widths of the first protrusions, the second protrusions, the intermediate-side first protrusions, and the intermediate-side second protrusions can each be 90 degrees or less, and preferably between 30 degrees and 60 degrees.

[0110] If the circumferential width of the first projection, the circumferential width of the second projection, the circumferential width of the intermediate first projection, and the circumferential width of the intermediate second projection are all W [deg], and the number of intermediate members is n, then the amount of rotation α [deg] of the rotating member coupled and fixed to the first member 14 is α = (360 - 2W)(n + 1). Therefore, if W is set to 90 degrees or less, preferably between 30 and 60 degrees, the lock-to-lock rotation speed of the steering wheel set in a typical automobile (approximately 1 to 4.167) can be achieved with a minimum number of intermediate members (four or less).

[0111] Furthermore, when implementing the present disclosure, the circumferential width of the first protrusion, the circumferential width of the second protrusion, the circumferential width of the intermediate first protrusion, and the circumferential width of the intermediate second protrusion do not all need to be the same, and some or all of them can be different.

[0112] In this example, the circle between the first intermediate protrusion 33 and the second intermediate protrusion 34 provided on the intermediate member 16 is The phases of the intermediate member 16 in the circumferential direction are shifted by 180 degrees. This allows the center of gravity of the intermediate member 16 to be positioned on the central axis O of the intermediate member 16. This prevents the intermediate member 16 from rotating due to the action of gravity even when no torque is applied to the steering shaft 9. However, when implementing the present disclosure, the phases of the intermediate first protrusions and the intermediate second protrusions in the circumferential direction can be set arbitrarily. Specifically, for example, as shown in a sixth example of an embodiment shown in FIGS. 14 and 15 (described later), the phases of the intermediate first protrusions and the intermediate second protrusions in the circumferential direction can be made to match, or the phases of the intermediate first protrusions and the intermediate second protrusions in the circumferential direction can be shifted by 90 degrees.

[0113] In this example, the first protrusion 17, the second protrusion 21, the intermediate first protrusion 33, and the intermediate second protrusion 34 all have a fan-shaped end face shape when viewed in the axial direction. This increases the contact area between the first protrusion 17 and the intermediate first protrusion 33, and the contact area between the second protrusion 21 and the intermediate second protrusion 34, thereby reducing the contact surface pressure. In contrast, Patent Document 2 neither describes nor suggests the specific shapes of the engagement pieces 13a to 16a, 14b to 17b.

[0114] In this example, the first member 14 is connected and fixed to the steering shaft 9, which rotates when in use, and the second member 15 is connected and fixed to the steering column 8, which does not rotate when in use. However, when implementing this disclosure, it is also possible to connect and fix the second member to a rotating member that rotates when in use, and the first member to a fixed member that does not rotate when in use.

[0115] When implementing the present disclosure, the materials constituting the first member, the second member, and the intermediate member are not particularly limited as long as they are capable of relative rotation (sliding) with respect to one another, and can be made of, for example, synthetic resin or metal material. Furthermore, the first member, the second member, and the intermediate member can be integrally formed as a whole, or can be formed by combining multiple components. When combining multiple components, for example, the protrusions and the portions other than the protrusions can be made of different materials. If the first protrusions and the intermediate-side first protrusions are made of different metal materials, adhesion between the first protrusions and the intermediate-side first protrusions can be prevented, and if the second protrusions and the intermediate-side second protrusions are made of different metal materials, adhesion between the second protrusions and the intermediate-side second protrusions can be prevented. Furthermore, if the protrusions are made of synthetic resin, impact noise can be reduced.

[0116] To prevent adhesion and seizure among the first member, the second member, and the intermediate member, it is desirable to fill the cylindrical space between the outer peripheral surface of the first cylindrical portion of the first member and the inner peripheral surface of the second cylindrical portion of the second member with a lubricant such as grease. In this case, an oil seal may be provided between the first cylindrical portion of the first member and the second flange portion and / or closing plate portion of the second member.

[0117] Furthermore, in this example, an example has been described in which the rotation limiting device 4 is incorporated into the steering unit 3 that constitutes the steer-by-wire steering device 1, but the rotation limiting device of the present disclosure is not limited to steer-by-wire steering devices, and can be incorporated and used to limit the amount of rotation of the rotating member of any rotating mechanical device, including a steering device in which a steering unit and a turning unit are mechanically connected.

[0118] In addition, in the rotation limiting device 4 of this example, the intermediate member 16 has a first intermediate side protrusion 33 that protrudes from the other axial side surface of the side plate portion 32 toward the other axial side, and a second intermediate side protrusion 34 that protrudes from one axial side surface of the side plate portion 32 toward one axial side.

[0119] In contrast to this, Patent Document 2 discloses that the idle rotors 14 to 16 have engagement pieces 14a to 16a and 14b to 16b, but the multi-rotation limit mechanism of Patent Document 2 is a device for detecting the rotation end of the rotary shaft, and does not lock the rotation of the rotary shaft. However, the configuration and function are different from the intermediate side first protrusion 33 and the intermediate side second protrusion 34 of the present disclosure.

[0120] Patent Document 3 discloses a first engagement member 141 that is formed integrally with the intermediate engagement member 150 and extends in the axial direction, but the first engagement member 141 prevents the generation of impact sounds by coming into contact with the first and second arms 161, 162 of the biasing member 160, and its function is different from that of the intermediate side first protrusion 33 and the intermediate side second protrusion 34 of the present disclosure.

[0121] Patent document 4 discloses that a first abutment portion 412 is provided that protrudes from the integrally rotating portion 410 on only one axial side, but does not disclose a member that protrudes from the integrally rotating portion 410 on the other axial side.

[0122] FIG. 8 of Patent Document 5 discloses an outer peripheral support portion 175 formed to protrude on both axial sides of the second rotating member 170. However, the outer peripheral support portion 175 protrudes radially outward from the outer periphery of the second rotating member 170. That is, the outer peripheral support portion 175 is not located radially inward from the outer periphery of the second rotating member 170, which is disadvantageous in terms of compactness and strength. In other words, repeated contact of the outer peripheral support portion 175 with the first support portion 161 of the first rotating member 160 or the inner periphery support portion 189 of the housing 180 may cause the outer peripheral support portion 175 to deform or rotate as viewed radially. In contrast, in the presently disclosed invention, the intermediate-side first protrusion 33 and the intermediate-side second protrusion 34 are formed integrally with the side plate portion 37 and do not protrude radially outward beyond the side plate portion 37, making the above-described problem less likely to occur. Note that the third support portion 173 of the second rotating member 170 shown in Figure 3 of Patent Document 5 protrudes only on one axial side, and is therefore different from the intermediate side first protrusion 33 and intermediate side second protrusion 34 of the present disclosure, which protrude on both axial sides.

[0123] [Second example of embodiment] 9 shows a second example of an embodiment of the present disclosure. In the rotation limiting device 4b of this example, the first member 14a has a first cylindrical portion 18a and a first flange portion 19a that protrudes radially outward from the outer peripheral surface of the axially middle portion of the first cylindrical portion 18a.

[0124] The intermediate cylindrical portion 35 of the intermediate member 16 is externally fitted onto one axial side portion of the first cylindrical portion 18a without any rattle and rotatable relative to the first cylindrical portion 18a, and the other axial side portion of the first cylindrical portion 18a is internally fitted into the closing plate portion 29 of the cover body 23 constituting the second member 15 without any rattle and rotatable relative to the first cylindrical portion 18a. That is, in this example, the first member 14 is radially positioned with respect to the second member 15 by internally fitting the other axial side portion of the first cylindrical portion 18a into the closing plate portion 29 without any rattle and rotatable relative to the first cylindrical portion 18a. Furthermore, one axial end face of the intermediate cylindrical portion 35 and one axial end face of the first cylindrical portion 18a are in sliding contact with or closely opposed to a radially inner portion of the other axial side surface of the second flange portion 25 of the housing main body 22 constituting the second member 15. That is, in this example, the first member 14 is positioned axially relative to the second member 15 by sliding the end face of one axial side of the first cylindrical portion 18a against or closely opposing the radially inner portion of the other axial side surface of the second flange portion 25.

[0125] Preferably, rotation limiting device 4b includes a centering means for ensuring coaxiality between housing body 22a and lid 23. For example, the centering means is configured by fitting a convex portion provided on one of the housing body and the lid with a concave portion provided on the other. The configuration and effects of other parts are the same as those of the first example embodiment.

[0126] [Third example of embodiment] 10 shows a third example of an embodiment of the present disclosure. A rotation limiting device 4c of this example includes a preload applying member 36 that applies a preload in the axial direction between the first member 14 and the second member 15. The preload applying member 36 has an annular shape and is arranged to apply a preload in the axial direction of the first flange portion 19 of the first member 14. The preload applying member 36 is elastically sandwiched between the side surface of the first member 14 and one axial side surface of the closing plate portion 29 of the cover 23 that constitutes the second member 15. This applies a preload between the first member 14 and the second member 15 in a direction that brings the first protrusion 17 and the second protrusion 21 closer to each other in the axial direction, i.e., in a direction that presses the first member 14 toward one axial side relative to the second member 15. The preload applying member 36 can be configured, for example, by a disc spring or a spacer made of synthetic resin, or a combination of these.

[0127] The rotation limiting device 4c of this example can suppress axial rattle of the first member 14 relative to the second member 15, thereby preventing the generation of abnormal noise. The configuration and effects of other parts are the same as those of the first example of the embodiment.

[0128] [Fourth Example of Embodiment] 11 shows a fourth embodiment of the present disclosure. Similar to the rotation limiting device 4c of the third embodiment, a rotation limiting device 4d of this embodiment also includes a preload applying member 36 that applies an axial preload between the first member 14 and the second member 15. In this embodiment, the preload applying member 36 is formed of a disc spring and is elastically sandwiched between the other axial side surface of the first flange portion 19 and one axial side surface of the closing plate portion 29. This applies a preload between the first member 14 and the second member 15 in a direction that moves the first protrusion 17 and the second protrusion 21 toward each other in the axial direction.

[0129] In this example, the intermediate member 16c has a hollow circular plate-shaped side plate portion 32c, a first intermediate protrusion 33c protruding from one circumferential position on the other axial side surface of the side plate portion 32c toward the other axial side, and a second intermediate protrusion 34c protruding from one axial side surface on the other axial side surface that is radially opposite to the first intermediate protrusion 33c toward the one axial side. The side plate portion 32c of the intermediate member 16c is fitted onto the first cylindrical portion 18 of the first member 14 without rattle and rotatable relative to the first cylindrical portion 18.

[0130] The rotation limiting device 4d has annular spacers 37a, 37b in a portion between the other axial side surface of the side plate portion 32c and one axial side surface of the first flange portion 19 of the first member 14, and in a portion between one axial side surface of the side plate portion 32c and the other axial side surface of the second flange portion 25 of the second member 15. This prevents axial rattle of the intermediate member 16c relative to the first member 14 and the second member 15, suppressing the generation of abnormal noise and suppressing an increase in steering force due to increased frictional resistance. Each of the spacers 37a, 37b is made of a material with a low coefficient of friction relative to one axial side surface of the first flange portion 19 and the other axial side surface of the second flange portion 25, and / or the side plate portion 32c. Specifically, each of the spacers 37a, 37b can be made of a resin washer, an oil-impregnated metal, or the like.

[0131] According to the rotation limiting device 4d of this example, it is possible to suppress axial rattle of the first member 14 relative to the second member 15, while preventing the rotational resistance between the first member 14 and the intermediate member 16c and the rotational resistance between the second member 15 and the intermediate member 16c from becoming unnecessarily large.

[0132] That is, in the rotation limiting device 4c according to the third example embodiment, the preload applying member 36 applies a preload in a direction that presses the first member 14 toward one side in the axial direction relative to the second member 15. Therefore, the intermediate cylindrical portion 35 of the intermediate member 16 is elastically sandwiched in the axial direction between the first flange portion 19 of the first member 14 and the second flange portion 25 of the second member 15, which may increase the rotational resistance between the first member 14 and the intermediate member 16 and between the second member 15 and the intermediate member 16.

[0133] In contrast, in the rotation limiting device 4d of this example, the first flange portion 19 and the second flange portion Spacers 37a, 37b made of a material with a low coefficient of friction with respect to first flange portion 19, second flange portion 25, and / or side plate portion 32c are disposed between first member 14 and intermediate member 16 and second member 15 and intermediate member 16c. This prevents the rotational resistance between first member 14 and intermediate member 16 and the rotational resistance between second member 15 and intermediate member 16c from becoming unnecessarily large, thereby enabling smooth relative rotation between first member 14 and intermediate member 16c and between second member 15 and intermediate member 16c.

[0134] The positions of the preload applying member 36 and the spacers 37a and 37b can be interchanged. For example, a spacer can be disposed between the first flange and the cover (closure plate), and preload applying members exerting axial elasticity can be disposed between the first flange and the side plate and between the second flange and the side plate. In this case, for example, the preload applying member disposed between the first flange and the side plate can be formed by disposing a disc spring between a pair of resin washers. Furthermore, the preload applying member disposed between the second flange and the side plate can be formed by disposing a disc spring between a metal washer on one axial side and a resin washer on the other axial side. This prevents unnecessary increase in rotational resistance between the first and second members and the intermediate member while providing the function of applying preload between the first and second members. The configurations, functions, and effects of other parts are the same as those of the first and third embodiments.

[0135] [Fifth Example of Embodiment] 12 and 13 illustrate a fifth embodiment of the present disclosure. A rotation limiting device 4e of this embodiment includes a first member 14, a second member 15, and three intermediate members 16c. The intermediate members 16c all have the same shape. In this embodiment, each intermediate member 16c includes a hollow, circular, plate-like side plate 32c, a first intermediate protrusion 33c protruding toward the other axial direction from a single circumferential position on the other axial side surface of the side plate 32c, and a second intermediate protrusion 34c protruding toward one axial direction from a single position on one axial side surface that is radially opposite the first intermediate protrusion 33c. The three intermediate members 16c are arranged in series in the axial direction and fitted onto the first cylindrical portion 18 of the first member 14 so as to be rotatable relative to each other. The axial length of the first cylindrical portion 18 and the axial length of the second cylindrical portion 24 are longer than those of the structure according to the first example of the embodiment by the amount of the two additional intermediate members 16c.

[0136] Furthermore, the rotation limiting device 4e of this example is provided with four spacers 37c in the portions between the three intermediate members 16c, the portion between the intermediate member 16c on the other axial side and the first flange portion 19, and the portion between the intermediate member 16c on one axial side and the second flange portion 25. This prevents axial rattle of the three intermediate members 16c relative to the first member 14 and the second member 15, suppressing the generation of abnormal noise and suppressing an increase in steering force due to increased frictional resistance. Each spacer 37c is made of a material with a low coefficient of friction with one axial side surface of the first flange portion 19 and the other axial side surface of the second flange portion 25, and / or the side plate portion 32c.

[0137] Because the rotation limiting device 4e of this example includes three intermediate members 16c, if the circumferential widths of the first protrusion, the second protrusion, the intermediate first protrusion, and the intermediate second protrusion are all 45 degrees, the amount of rotation of the steering shaft 9 (see FIG. 1 ) coupled and fixed to the first member 14 can be doubled compared to the structure including only one intermediate member 16, such as the rotation limiting device 4 of the first example embodiment. Specifically, in the rotation limiting device 4e of this example, if the circumferential widths W of the first protrusion 17, the second protrusion 21, the intermediate first protrusion 33c, and the intermediate second protrusion 34c are all 45 degrees, the amount of rotation of the steering shaft 9 can be 1080 degrees.

[0138] In the rotation limiting device 4e of this example, the three intermediate members 16c have the same shape. Therefore, unnecessary increases in the manufacturing costs, management costs, and assembly costs of the parts can be prevented, and increases in the manufacturing costs of the rotation limiting device 4e can be suppressed. The configurations and effects of other parts are the same as those of the first embodiment, its modified example, and the third embodiment.

[0139] [Sixth Example of Embodiment] 14 and 15 show a sixth embodiment of the present disclosure. A rotation limiting device 4f of this embodiment includes a first member 14, a second member 15, and three intermediate members 16d. All of the intermediate members 16d have the same shape. In this embodiment, each intermediate member 16d includes a hollow, circular, plate-like side plate 32d, a first intermediate protrusion 33d protruding toward the other axial direction from a single circumferential position on the other axial side surface of the side plate 32d, and a second intermediate protrusion 34d protruding toward one axial side from a single position on one axial side surface that is in phase with the first intermediate protrusion 33d in the circumferential direction. The three intermediate members 16d are arranged in series in the axial direction and fitted externally to the first cylindrical portion 18 of the first member 14 so as to be rotatable relative to each other.

[0140] The rotation limiting device 4f of this embodiment can prevent a large force from acting in the circumferential direction on the side plate portions 32d of the respective intermediate members 16d.

[0141] That is, for example, in a structure such as rotation limiting device 4e according to a fifth example embodiment in which the intermediate first protrusion 33c and the intermediate second protrusion 34c are out of phase with each other in the circumferential direction by 180 degrees, the circumferential force applied from the first protrusion 17 to the intermediate first protrusion 33c is transmitted in the circumferential direction through side plate portion 32c and applied from the intermediate second protrusion 34c to the second protrusion 21. Therefore, since a large circumferential force may be applied to side plate portion 32c, it is necessary to ensure that side plate portion 32c has sufficient strength.

[0142] In contrast, in the rotation limiting device 4f of this embodiment, the circumferential phases of the intermediate-side first protrusion 33d and the intermediate-side second protrusion 34d are aligned. Therefore, most of the circumferential force applied from the first protrusion 17 to the intermediate-side first protrusion 33d is transmitted directly to the intermediate-side second protrusion 34d without acting on the side plate portion 32d, and is then applied from the intermediate-side second protrusion 34d to the second protrusion 21. This prevents a large circumferential force from acting on the side plate portion 32d. This allows the axial thickness of the side plate portion 32d to be reduced, or the intermediate-side first protrusion 33d and the intermediate-side second protrusion 34d to be made of a metal material and the side plate portion 32d to be made of a synthetic resin, thereby facilitating a reduction in the weight of the intermediate member 16d. The remaining configurations, functions, and effects are similar to those of the first embodiment, its modified example, third embodiment, and fifth embodiment.

[0143] [Seventh Example of Embodiment] 16 and 17 show a seventh example of an embodiment of the present disclosure. The rotation limiting device 4g of this example includes a first member 14, a second member 15a, and three intermediate members 16c. The second member 15a includes a housing main body 22a and a cover 23a.

[0144] The housing body 22a has a cylindrical second tubular portion 24a and an inward flange portion 38 in the shape of a hollow circular plate that is bent radially inward from the other axial end of the second tubular portion 24a.

[0145] The housing body 22a further has a pair of body ears 27a that protrude radially outward from two radially opposite positions on one axial end of the second tubular portion 24a. Each of the body ears 27a has a body-side coupling hole 28a that penetrates it in the axial direction. In this example, the body-side coupling hole 28a is a cylindrical hole whose inner diameter does not change in the axial direction.

[0146] The lid 23a covers (closes) the radially outer side of an opening on one axial side of the second tubular portion 24a of the housing main body 22a. In this example, the lid 23a has a cylindrical lid tubular portion 39 and a hollow circular plate-like closing plate portion 29a that protrudes radially inward from one axial side portion of the inner circumferential surface of the lid tubular portion 39.

[0147] The axial length of the lid cylindrical portion 39 is sufficiently shorter than the axial length of the second cylindrical portion 24a because there is no need to arrange multiple intermediate members 16c in series radially inward. For example, the axial length of the lid cylindrical portion 39 is preferably 1 / 5 to 1 / 7 of the axial length of the second cylindrical portion 24a.

[0148] The closing plate portion 29a has a second side surface 26 on the other axial side surface, and has a second protrusion 21 at one circumferential position on the radially outer portion of the second side surface 26. The radially outer end of the second protrusion 21 is connected to the other axial side portion of the inner peripheral surface of the lid cylindrical portion 39. In this example, the other axial side surface of the second protrusion 21 is flush with the other axial side surface of the lid cylindrical portion 39.

[0149] The lid 23a has a pair of lid lugs 30a that protrude radially outward from two radially opposite positions on the outer peripheral surface of the lid tubular portion 39. Each of the lid lugs 30a has a lid-side connecting hole 31a that penetrates in the axial direction. In this example, the lid-side connecting hole 31a is configured as a screw hole.

[0150] The housing body 22a and the lid body 23a are joined and fixed together by overlapping a pair of lid body ears 30a on one axial side of a pair of body ears 27a, inserting connecting bolts (not shown) into a pair of body side connecting holes 28a, and screwing the connecting bolts into a pair of lid side connecting holes 31a.

[0151] The rotation limiting device 4g of this example is supported and fixed to the steering column 8, which does not rotate even when in use, by threading the connecting bolt into a column-side threaded hole that opens on the front side of the steering column 8. That is, in this example, one axial side (the left side in FIGS. 16 and 17) corresponds to the rear side of the vehicle, and the other axial side (the right side in FIGS. 16 and 17) corresponds to the front side of the vehicle. However, the rotation limiting device 4g of this example can also be supported and fixed to the vehicle so that one axial side faces the front side of the vehicle and the other axial side faces the rear side of the vehicle.

[0152] Each intermediate member 16c has a hollow circular plate-shaped side plate portion 32c, a first intermediate protrusion 33c protruding from one circumferential position on the other axial side surface of the side plate portion 32c toward the other axial side, and a second intermediate protrusion 34c protruding from one axial side surface at one position radially opposite to the first intermediate protrusion 33c.

[0153] The rotation limiting device 4g of this example is formed by combining the first member 14 and three intermediate members 16c inside the second member 15a so as to be relatively rotatable. Specifically, the three intermediate members 16c are arranged in series and fitted onto the other axial side portion of the first cylindrical portion 18 of the first member 14 without rattle so as to be relatively rotatable, and one axial end of the first cylindrical portion 18 is fitted into the closing plate portion 29a of the cover body 23a without rattle so as to be relatively rotatable.

[0154] The rotation limiting device 4g includes four spacers 37c in the spaces between the three intermediate members 16c, between the intermediate member 16c on the other axial side and the first flange portion 19, and between the intermediate member 16c on one axial side and the closing plate portion 29a, thereby preventing axial rattle of the three intermediate members 16c relative to the first member 14 and the second member 15a.

[0155] The rotation limiting device 4g of this example can reduce weight and costs.

[0156] For example, in a rotation limiting device 4e according to a fifth example of the embodiment shown in Figures 12 and 13, a second protrusion 21 to which a circumferential force is applied in response to steering wheel operation by the driver is provided on the housing main body 22 of the second member 15. The circumferential force applied to the second protrusion 21 is transmitted to the steering column 8 via the second flange portion 25, the second tubular portion 24, and the main body ear portion 27. For this reason, in the rotation limiting device 4e according to the fifth example, it is necessary to ensure that the housing main body 22 having the second tubular portion 24 has sufficient strength.

[0157] Here, since the second tubular portion 24 is arranged so as to cover the periphery of the multiple intermediate members 16c arranged in series, it is necessary to make the axial length longer to some extent. Therefore, if the thickness of the housing body 22 is ensured to ensure the strength of the housing body 22, the weight of the second member 15 increases, which in turn increases the weight of the rotation limiting device 4e.

[0158] Furthermore, in the rotation limiting device 4e of the fifth example, the second protrusion 21 is provided on the second side surface 26, which is the other axial side surface of the second flange portion 25 that is bent radially inward from one axial end of the second cylindrical portion 24. In other words, the second protrusion 21 is provided on the second side surface 26 that exists at the inner end of the cylindrical space that exists radially inward of the second cylindrical portion 24. For this reason, processing the second protrusion 21 is cumbersome and costly.

[0159] In contrast, in the rotation limiting device 4g of this example, the second protrusion 21 is provided on the cover 23a of the second member 15a. The circumferential force applied to the second protrusion 21 in response to the driver's operation of the steering wheel is transmitted to the steering column 8 via the closing plate 29a, the cover tubular portion 39, and the cover ear 30a. Unlike the second tubular portion 24, the cover tubular portion 39 does not need to cover the periphery of the multiple intermediate members 16c arranged in series. Therefore, the axial length of the cover tubular portion 39 is sufficiently shorter than the axial length of the second tubular portion 24a. Therefore, even if the thickness of the cover 23a is secured to ensure the strength of the cover 23a, the weight of the second member 15a can be prevented from increasing excessively.

[0160] Furthermore, because no circumferential force is applied to the housing body 22a, the housing body 22a can be made of a lightweight material such as synthetic resin, or even if made of a metal material, the thickness of the housing body 22a can be reduced. Therefore, according to this example, it is easy to reduce the weight of the second member 15a, and therefore the weight of the rotation limiting device 4g.

[0161] Furthermore, in this example, the second protrusion 21 is provided on the other axial side surface of the blocking plate portion 29a that protrudes radially inward from one axial side portion of the inner peripheral surface of the lid cylindrical portion 39. The axial length of the lid cylindrical portion 39 is sufficiently shorter than the axial length of the second tubular portion 24a. Therefore, the axial distance between the other axial side surface of the lid cylindrical portion 39 and the other axial side surface of the second protrusion 21 can be kept small. Specifically, in this example, the other axial side surface of the second protrusion 21 is flush with the other axial side surface of the lid cylindrical portion 39. Therefore, in the rotation limiting device 4g of this example, the lid 23a having the second protrusion 21 can be easily manufactured by press working or the like, thereby keeping costs low.

[0162] The configuration and effects of other parts are the same as those of the first embodiment, its modified example, and the fifth embodiment.

[0163] [Eighth Example of Embodiment] Figures 18 and 19 show an eighth example of an embodiment of the present disclosure. A rotation limiting device 4h of this example has a structure that combines the structure of the sixth example of an embodiment shown in Figures 14 and 15 with the structure of the seventh example of an embodiment shown in Figures 16 and 17. That is, the rotation limiting device 4h of this example includes a first member 14, a second member 15a, and three intermediate members 16d.

[0164] That is, the second member 15a is formed by joining and fixing a cover 23a having a second projection 21 to a housing main body 22a.

[0165] Each intermediate member 16d has a hollow circular plate-shaped side plate portion 32d, a first intermediate protrusion 33d protruding from one circumferential position on the other axial side surface of the side plate portion 32d toward the other axial side, and a second intermediate protrusion 34d protruding from one axial side surface at a position that coincides with the first intermediate protrusion 33d in phase with respect to the circumferential direction. The three intermediate members 16d are arranged in series in the axial direction and fitted externally onto the first cylindrical portion 18 of the first member 14 so as to be rotatable relative to each other.

[0166] The configuration and effects of other parts are the same as those of the first embodiment and its modified example, the sixth embodiment, and the seventh embodiment.

[0167] This application is based on Japanese Patent Application No. 2022-015858 filed on February 3, 2022 and Japanese Patent Application No. 2022-064765 filed on April 8, 2022, the contents of which are incorporated herein by reference. [Explanation of symbols]

[0168] 1 Steering device 2 steering wheels 3 Steering unit 4, 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h rotation limiter 5 steering wheel 6. Steering unit 7. Control Unit 8. Steering column 9. Steering shaft 10. Reaction force application device 11 Gear housing 12 Steering actuator 13 Tie rod 14, 14a First member 15 Second member 16, 16a, 16b, 16c, 16d Intermediate members 17 1st protrusion 18, 18a 1st cylinder part 19, 19a First flange part 20 First aspect 21 2nd protrusion 22, 22a Housing body 23, 23a Lid body 24, 24a 2nd cylinder part 25 Second flange 26 Second aspect 27, 27a Main body ear 28, 28a Body side connection hole 29, 29a Closure plate 30, 30a Lid ear 31, 31a Lid body side connection hole 32, 32a, 32b, 32c, 32d side plate part 33, 33a, 33b, 33c, 33d Middle side first protrusion 34, 34a, 34b, 34c, 34d 2nd protrusion on middle side 35 Intermediate cylinder part 36 Preloading member 37a, 37b, 37c spacers 38 Inward flange 39 Lid cylindrical part 100 Stopper unit 101 first rotating member 102 Housing 103 Second rotating member 104 First rotating protrusion 105 Fixed protrusion 106 Cylindrical part 107 Second rotating protrusion

Claims

1. a first member having a first projection; a second member having a second protrusion disposed on one axial side of the first protrusion, the second member being disposed coaxially with the first member and capable of rotating relative to the first member; at least one intermediate member having a side plate portion disposed between the first projection and the second projection in the axial direction, a first intermediate projection protruding from the other axial side surface of the side plate portion toward the other axial side, and a second intermediate projection protruding from one axial side surface of the side plate portion toward one axial side, the intermediate member being supported so as to be rotatable relative to the first member and the second member; the first member has a first side surface facing one side in the axial direction, and the first protrusion protruding from the first side surface toward one side in the axial direction, the second member has a second side surface facing the other axial side, and the second protrusion protruding from the second side surface toward the other axial side, the first member has a first cylindrical portion into which the at least one intermediate member is externally fitted so as to be relatively rotatable, and a first flange portion protruding radially outward from an outer circumferential surface of the first cylindrical portion, the first flange portion has the first side surface on one side surface in the axial direction, the second member has a second cylindrical portion disposed radially outward of the first member and the at least one intermediate member, the second member has a second flange portion bent radially inward from one axial end of the second cylindrical portion, the second flange portion has the second side surface on the other side surface in the axial direction, the second member includes a cover that covers a radially outer portion of an opening on the other axial side of the second cylindrical portion, the first flange portion and the intermediate member are axially sandwiched between the second flange portion and the lid body, thereby restricting the axial positions of the first flange portion and the intermediate member; The other axial side surface of the first flange portion is in sliding contact with or closely opposed to the lid body. Rotation limiter.

2. the first member is fitted radially inside the second member so as to be rotatable relative to the second member, the at least one intermediate member is disposed between the first member and the second member in a radial direction so as to be rotatable relative to the first member and the second member; The rotation limiting device of claim 1 .

3. The second member is a housing body having the second cylindrical portion and the second flange portion; The rotation limiting device of claim 1 .

4. The housing main body has a main body side coupling hole, The lid has a lid-side connection hole, one of the body-side fastening hole and the lid-side fastening hole is configured as a threaded hole, and the other of the body-side fastening hole and the lid-side fastening hole is configured as a threaded hole or a cylindrical hole, a connecting bolt that is threaded or inserted into the other connecting hole and that is threaded into the one connecting hole; The rotation limiting device of claim 3.

5. A first member having a first protrusion; a second member having a second protrusion disposed on one axial side of the first protrusion, the second member being disposed coaxially with the first member and capable of rotating relative to the first member; at least one intermediate member having a side plate portion disposed between the first projection and the second projection in the axial direction, a first intermediate projection protruding from the other axial side surface of the side plate portion toward the other axial side, and a second intermediate projection protruding from one axial side surface of the side plate portion toward one axial side, the intermediate member being supported so as to be rotatable relative to the first member and the second member; the first member has a first side surface facing one side in the axial direction, and the first protrusion protruding from the first side surface toward one side in the axial direction, the second member has a second side surface facing the other axial side, and the second protrusion protruding from the second side surface toward the other axial side, the first member has a first cylindrical portion into which the at least one intermediate member is externally fitted so as to be relatively rotatable, and a first flange portion protruding radially outward from an outer circumferential surface of the first cylindrical portion, the first flange portion has the first side surface on one side surface in the axial direction, the second member has a second cylindrical portion disposed radially outward of the first member and the at least one intermediate member, The second member is a housing main body having the second cylindrical portion and an inward flange portion bent radially inward from the other axial end of the second cylindrical portion; a cover body for covering a radially outer portion of an opening on one axial side of the second cylindrical portion, The cover has the second side surface on the other side surface in the axial direction, the first flange portion and the intermediate member are axially sandwiched between the inward flange portion and the lid body, thereby restricting the axial positions of the first flange portion and the intermediate member; The other axial side surface of the first flange portion is in sliding contact with or closely opposed to the inward flange portion. Rotation limiter.

6. The housing main body has a main body side coupling hole, The lid has a lid-side connection hole, one of the body-side fastening hole and the lid-side fastening hole is configured as a threaded hole, and the other of the body-side fastening hole and the lid-side fastening hole is configured as a threaded hole or a cylindrical hole, a connecting bolt that is threaded or inserted into the other connecting hole and that is threaded into the one connecting hole; 6. The rotation limiting device of claim 5.

7. the first cylindrical portion extends from a radially inner end of the first flange portion to at least one side in the axial direction, the intermediate member is disposed between the first side surface of the first member and the second side surface of the second member in the axial direction.

6. The rotation limiting device according to claim 1 or 5.

8. a preload applying member that applies a preload in the axial direction between the first member and the second member; 6. The rotation limiting device according to claim 1 or 5.

9. a steering shaft; and a rotation limiting device that limits the amount of rotation of the steering shaft to a predetermined value; The rotation limiting device is configured as the rotation limiting device according to claim 1 or 5, One of the first member and the second member is coupled and fixed to the steering shaft, and the other of the first member and the second member is supported and fixed to a portion that does not rotate even during use. Steering device.

Images