JP2022164999A - Rotation restriction device and steering device - Google Patents

Abstract

To provide a rotation restriction device which has a small radial dimension and can make a load, acting on a member whose rotation amount is limited, almost equal regardless of a rotation direction of a rotary shaft.SOLUTION: A rotation restriction device includes: a rotary shaft 28 having a spiral groove 36 on an outer peripheral surface; a guide member 29 having a guide groove 38, which is provided over an entire length of a range in which the spiral groove 36 exists with respect to an axial direction of the rotary shaft 28, at a position facing the outer peripheral surface of the rotary shaft 28; a ball 30 disposed between the spiral groove 36 and the guide groove 38 and serving as a movable member; and a case 31 which has a holding hole 43 extending in a radial direction of the rotary shaft 28 and holds the guide member 29 at the inner side of the holding hole 43. An outer peripheral surface of the guide member 29 and an inner peripheral surface of the holding hole 43 are fitted in a non-circular form.SELECTED DRAWING: Figure 5

Description

The present invention relates to a rotation limiting device for limiting the amount of rotation of a rotating member, and a steering device.

2. Description of the Related Art In various mechanical devices having a rotating member, a rotation limiting device may be incorporated in order to limit the amount of rotation of the rotating member to a predetermined amount or less.

For example, in Japanese Patent Laying-Open Nos. 2007-106245 (Patent Document 1) and 2014-210524 (Patent Document 2), a steering device is incorporated in a steer-by-wire steering device, and a steering member is rotated by a predetermined amount. A rotation limiting device is described, limiting to: In particular, the rotation limiting device described in Japanese Patent Application Laid-Open No. 2014-210524 has the advantage that it can be configured with a smaller number of parts and can be easily assembled than the rotation limiting device described in Japanese Patent Application Laid-Open No. 2007-106245. be.

The rotation limiting device disclosed in Japanese Patent Laying-Open No. 2014-210524 includes a disk-shaped first plate, a disk-shaped second plate, and balls. The first plate is coaxially fixed to a steering shaft that is connected to the steering member and rotates integrally with the steering member. The second plate is arranged coaxially with the first plate at a position facing the first plate in the axial direction of the steering shaft, and does not rotate during use. The first plate has a radially extending linear first rolling path on a side surface facing the second plate. The second plate has a second spiral rolling path on the side facing the first plate. A ball is arranged between the first rolling path and the second rolling path. When the steering member is in the neutral rotational position, i.e., in the rotational position in which the vehicle is traveling straight ahead, the balls are positioned at the radial center portions of the first rolling path and the second rolling path. located in

In the rotation limiting device having such a configuration, when the steering member is rotated from the neutral rotation position to one side, the balls roll along the first rolling path and the second rolling path, respectively. Move inward. When the ball contacts the radially inner end of the spiral second rolling path, further rotation of the steering member to one side is restricted. On the other hand, when the steering member is rotated from the neutral rotation position to the other side, the ball moves radially outward while rolling along the first rolling path and the second rolling path. Further, when the ball contacts the radially outer end of the spiral second rolling path, the steering member is restricted from further rotating to the other side.

JP 2007-106245 A JP 2014-210524 A

In the rotation limiting device disclosed in JP-A-2014-210524, since the first plate and the second plate are disk-shaped members arranged coaxially with the steering shaft, the radial dimension tends to be bulky. Therefore, it is difficult to adopt when the installation space in the radial direction is limited.

Further, in the rotation limiting device disclosed in Japanese Patent Application Laid-Open No. 2014-210524, when the steering member is rotated to one side to bring the ball into contact with the radial inner end of the second rolling path, the steering member is rotated. The radial distance from the center of rotation of the steering shaft to the center of the ball is shorter than when the ball is brought into contact with the radially outer end of the second rolling path by rotating to the other side. Therefore, when the steering member is rotated in one direction to bring the ball into contact with the radially inner end of the second rolling path, the contact load rotates the steering member in the other direction to cause the ball to undergo the second rolling motion. The contact load becomes larger than the contact load when contacting the radially outer end of the road, and there is a possibility that the driver may feel uncomfortable.

The present invention provides a rotation restricting device capable of keeping the radial dimension small and making the load acting on a member that restricts the amount of rotation substantially equal regardless of the direction of rotation of a rotating shaft, and the rotation restricting device. An object of the present invention is to provide a steering device with

A rotation limiting device of one aspect of the present invention includes a rotating shaft, a guide member, a moving member, and a case.
The rotating shaft has a spiral groove on its outer peripheral surface.
The guide member has a guide groove provided over the entire length of the range where the spiral groove exists in the axial direction of the rotating shaft, at a position facing the outer peripheral surface of the rotating shaft.
The moving member is disposed between the helical groove and the guide groove, and moves along the helical groove as the rotating shaft rotates with respect to the guide member. and is capable of contacting each of the opposite ends of said helical groove.
The case has a holding hole extending in the radial direction of the rotating shaft, and holds the guide member inside the holding hole.
The outer peripheral surface of the guide member and the inner peripheral surface of the holding hole are non-circularly fitted.

In the rotation restricting device of one aspect of the present invention, the outer peripheral surface of the guide member is non-circularly fitted to the inner peripheral surface of the holding hole only at the inner portion in the radial direction of the rotating shaft.

In the rotation restricting device according to one aspect of the present invention, the inner portion of the holding hole in the radial direction of the rotating shaft is larger than the width dimension in the axial direction of the rotating shaft in the axial direction of the rotating shaft and the holding hole. The width dimension in the direction orthogonal to the extension direction of the is smaller.

In one aspect of the rotation restricting device of the present invention, the guide member includes a concave portion that curves along the outer peripheral surface of the rotating shaft and faces the outer peripheral surface of the rotating shaft, and the guide groove includes the It is provided so as to be recessed radially outward from the concave portion.

In the rotation restricting device of one aspect of the present invention, the case is held inside the holding hole so as to be movable in the radial direction of the rotating shaft, and the guide member is arranged radially inward of the rotating shaft. and a first resilient member biasing toward.

In the rotation limiting device of one aspect of the present invention, the radial width between the bottom portion of the spiral groove and the bottom portion of the guide groove decreases from the central portion toward both sides in the axial direction of the rotating shaft. .

In the rotation restricting device of one aspect of the present invention, the depth of the spiral groove becomes shallower toward both sides from the central portion in the axial direction of the rotating shaft.

In the rotation restricting device of one aspect of the present invention, the depth of the guide groove becomes shallower toward both sides from the central portion in the axial direction of the rotating shaft.

In the rotation restricting device of one aspect of the present invention, the first elastic member has an elastic modulus larger than that of the first elastic member, and is elastically deformed when the moving member comes into contact with the end of the spiral groove. It further comprises two elastic members.

In one aspect of the rotation restricting device of the present invention, a portion of the guide member that contacts the moving member is made of metal.

In the rotation restricting device of one aspect of the present invention, a portion of the guide member including a portion that contacts the moving member is made of metal, and the remaining portion is made of synthetic resin.

In the rotation restricting device of one aspect of the present invention, the cross-sectional shape of each of the spiral groove and the guide groove is a Gothic arch shape.

In one aspect of the rotation restricting device of the present invention, the moving member is configured by a ball.

A steering device according to one aspect of the present invention includes a rotation limiting device that limits the amount of rotation of a steering member to a predetermined amount or less, and the rotation limiting device is the rotation limiting device of the present invention.

ADVANTAGE OF THE INVENTION According to the present invention, there is provided a rotation restricting device capable of suppressing the radial dimension and making the load acting on a member restricting the amount of rotation substantially equal regardless of the direction of rotation of the rotating shaft, and the rotation restricting device. A steering device with a limiting device can be provided.

FIG. 1 is a partially cutaway side view showing a steering device incorporating a rotation limiting device according to a first embodiment of the invention. FIG. 2 is a cross-sectional view taken along line AA of FIG. 3 is a cross-sectional view taken along the line BB of FIG. 2. FIG. FIG. 4 is an exploded perspective view of the rotation limiting device of the first example. FIG. 5 is a cross-sectional view of the rotation limiting device of the first example, corresponding to section C in FIG. FIG. 6 is a cross-sectional view taken along line DD of FIG. 7 is a plan view seen from above in FIG. 6. FIG. 8 is a cross-sectional view taken along line EE of FIG. 6. FIG. FIG. 9(a) shows a state in which only the guide member, the rotating shaft, and the ball that constitute the rotation limiting device of the first example are taken out, and the state in which the ball has moved to the end of the spiral groove is seen from the axial direction of the rotating shaft. Fig. 9(b) is a view of the guide member and the ball viewed from below Fig. 9(a); It is the figure seen from above. FIG. 10 is a perspective view of a guide member that constitutes the rotation limiting device of the first example. 11 shows a guide member that constitutes the rotation limiting device of the first example, FIG. 9(a) is a view of the guide member viewed from the axial direction of the rotation shaft, and FIG. 9A and 9B are views of the guide member viewed from the right side of FIG. 9A, and FIG. 9C is a view of the guide member viewed from the bottom side of FIG. 9A. 12 is a plan view of the case constituting the rotation limiting device of the first example, viewed from above in FIG. 6. FIG. FIG. 13 is a diagram corresponding to FIG. 6 regarding the second example of the embodiment of the present invention. FIG. 14 is a perspective view of a guide member that constitutes the rotation restricting device of the second example. 15A and 15B show a guide member constituting a second example of a rotation restricting device, FIG. 15A and 15B are views of the guide member viewed from the right side of FIG. 15A, and FIG. 15C is a view of the guide member viewed from the bottom side of FIG. FIG. 16 is a diagram corresponding to FIG. 6 regarding the third example of the embodiment of the present invention. 17 is a cross-sectional view taken along the line FF of FIG. 16. FIG. FIG. 18 is a perspective view of a guide member that constitutes the rotation limiting device of the third example. 19A and 19B show a guide member that constitutes a rotation restricting device of the third example, FIG. 19(a), and FIG. 19(c) is a view of the guide member viewed from the bottom of FIG. 19(a). FIG. 20 is a diagram corresponding to FIG. 6 regarding the fourth example of the embodiment of the present invention. 21(a) is a cross-sectional view along GG in FIG. 20, and FIG. 21(b) is a cross-sectional view along HH in FIG. FIG. 22 is a perspective view of a guide member that constitutes the rotation limiting device of the fourth example. FIGS. 23A and 23B show a guide member that constitutes a rotation limiting device of a fourth example, FIG. 23A and 23B are views of the guide member viewed from the right side of FIG. 23A, and FIG. 23C is a view of the guide member viewed from the bottom side of FIG. FIG. 24 is a diagram corresponding to FIG. 6 regarding the fifth example of the embodiment of the present invention. 25(a) is a cross-sectional view taken along line II in FIG. 24, and FIG. 25(b) is a cross-sectional view taken along line JJ in FIG. FIG. 26 is a perspective view of a guide member that constitutes the rotation limiting device of the fifth example. 27A and 27B show a guide member that constitutes a rotation restricting device of the fifth example, FIG. 27(a) is a view of the guide member viewed from the right side of FIG. 27(a), and FIG. 27(c) is a view of the guide member viewed from the bottom side of FIG. 27(a). FIG. 28 is a diagram corresponding to FIG. 6 regarding the sixth example of the embodiment of the present invention. FIG. 29(a) is an exploded perspective view of a guide member fitted with an O-ring, which constitutes the rotation restricting device of the sixth example. FIG. 30 is a diagram corresponding to FIG. 6 regarding the seventh example of the embodiment of the present invention. FIG. 31 is an exploded perspective view of a guide member that constitutes the rotation limiting device of the seventh example. FIG. 32 is a diagram corresponding to FIG. 6 regarding an eighth embodiment of the present invention. FIG. 33 is a diagram corresponding to FIG. 6 regarding the ninth example of the embodiment of the present invention. FIG. 34 is a diagram showing cross-sectional shapes of a spiral groove and guide grooves in a tenth embodiment of the present invention. FIG. 35 is a diagram showing cross-sectional shapes of a spiral groove and guide grooves in an eleventh embodiment of the present invention. FIG. 36 is a schematic side view showing a steering device according to a twelfth embodiment of the invention.

[First example of embodiment]
A rotation limiting device according to a first embodiment of the present invention and a steering apparatus to which the rotation limiting device is applied will be described with reference to FIGS. 1 to 12. FIG. Note that the rotation limiting device according to one aspect of the present invention, including this example, will be described below as an example in which the rotation limiting device is applied to a steering device, but the application of the rotation limiting device is limited to the steering device. It is widely applicable to various mechanical devices.

1 to 3 show a steering device 1 of this example. The steering device 1 includes a rotation limiting device 10 that limits the amount of rotation of a steering wheel 2, which is a steering member, to a predetermined amount or less.

More specifically, the steering device 1 of this example includes a steering wheel 2, a steering shaft 3, a steering column 4, an electric assist device 5, a pair of universal joints 6a and 6b, an intermediate shaft 7, A steering gear unit 8 , a pair of tie rods 9 and a rotation limiter 10 are provided.

Regarding the steering device 1, the front-rear direction and the width direction refer to the front-rear direction and the width direction of the vehicle in which the steering device 1 is assembled. be.

The steering shaft 3 is rotatably supported inside a steering column 4 supported by the vehicle body. A steering wheel 2 is supported and fixed to the rear end of the steering shaft 3 . A front end portion of the steering shaft 3 is connected to a pinion shaft 11 of a steering gear unit 8 via an electric assist device 5, a rear universal joint 6a, an intermediate shaft 7, and a front universal joint 6b. ing. Therefore, when the driver rotates the steering wheel 2 , the rotation of the steering wheel 2 is transmitted to the pinion shaft 11 of the steering gear unit 8 . The rotation of the pinion shaft 11 is converted into linear motion of a rack shaft (not shown) meshed with the pinion shaft 11 to push and pull the pair of tie rods 9 . As a result, a steering angle corresponding to the amount of rotation of the steering wheel 2 is applied to the pair of steered wheels.

The steering device 1 of this example includes a telescopic mechanism for adjusting the longitudinal position of the steering wheel 2 . For this reason, the steering column 4 is formed by fitting the front end of a tubular outer column 13 onto the rear end of the tubular inner column 12 so as to allow relative displacement in the axial direction. is configured to be extendable. In addition, the steering shaft 3 is configured by spline-engaging the inner peripheral surface of the front end portion of the cylindrical outer shaft 15 with the outer peripheral surface of the rear end portion of the inner shaft 14 , so that the inner shaft 14 and the outer shaft 3 are connected. 15, and the entire length can be expanded and contracted. The outer shaft 15 is rotatably supported inside the outer column 13 by a rolling bearing (not shown) with its rear end projecting rearward from the outer column 13 . Therefore, when adjusting the longitudinal position of the steering wheel 2 supported and fixed to the rear end portion of the outer shaft 15 , the outer column 13 together with the outer shaft 15 moves in the longitudinal direction with respect to the inner column 12 and the inner shaft 14 . , the steering shaft 3 and the steering column 4 expand and contract.

The electric assist device 5 includes a housing 16 , an electric motor 17 , a torsion bar 18 , an output shaft 19 , a pair of ball bearings 20 a and 20 b , a worm speed reducer 21 and a torque sensor 22 .

The housing 16 is coupled and fixed to the front end of the inner column 12 . The electric motor 17 is supported and fixed to the housing 16 . A front end of the inner shaft 14 is inserted inside the housing 16 . A front end of the inner shaft 14 is connected to an output shaft 19 via a torsion bar 18 . A front end portion of the output shaft 19 protrudes forward from the front end surface of the housing 16 . A rear universal joint 6 a is coupled to the front end of the output shaft 19 . The output shaft 19 is rotatably supported inside the housing 16 by a pair of ball bearings 20a and 20b. A worm wheel 23 constituting a worm speed reducer 21 is externally fitted and fixed between portions of the output shaft 19 supported by a pair of ball bearings 20a and 20b. Wheel teeth 24 provided on the outer peripheral surface of the worm wheel 23 mesh with worm teeth 26 provided on the outer peripheral surface of the axially intermediate portion of the worm 25 that constitutes the worm reduction gear 21 . An output shaft 27 of the electric motor 17 is coupled to the worm 25 so as to transmit torque.

A torque sensor 22 is arranged around the rear end of the output shaft 19 . The torque sensor 22 detects the direction and magnitude of torque applied from the steering wheel 2 to the steering shaft 3 based on the twist amount of the torsion bar 18 caused by rotating the steering wheel 2 . The electric assist device 5 drives the electric motor 17 with a current corresponding to the torque detected by the torque sensor 22 . By applying the assist torque generated by the electric motor 17 to the output shaft 19 via the worm speed reducer 21, the force required for the driver to rotate the steering wheel 2 is reduced.

The rotation limiting device 10 is installed at a location where the front portion of the steering shaft 3 is located. When carrying out the present invention, the rotation limiting device 10 can be installed at any position on any one of the steering force transmission shafts between the steering wheel 2 and the pair of steered wheels. That is, the rotation limiting device 10 can be installed closer to the steering wheel 2 than the torsion bar 18 as in this example, or it can be installed closer to the pair of steering wheels than the torsion bar 18. can also In addition, in the structure of this example, each of the steering shaft 3, the output shaft 19, the intermediate shaft 7, and the pinion shaft 11 corresponds to a steering force transmission shaft.

In this example, as shown in FIGS. 4 to 7, the rotation limiting device 10 includes a rotating shaft 28, a guide member 29, a ball 30 as a moving member, a case 31, and a coil as a first elastic member. and a spring 32 .

In the following description of the rotation restricting device 10, axial direction, radial direction, and circumferential direction refer to the axial direction, radial direction, and circumferential direction of the rotating shaft 28 unless otherwise specified.

The rotary shaft 28 is a member that rotates together with the steering wheel 2 that is rotated, and has a spiral groove 36 on its outer peripheral surface. In this example, the rotary shaft 28 constitutes the front portion of the inner shaft 14 and is made of metal such as rolled steel for general structure (SS material) or carbon steel for machine structure (SC material). However, when carrying out the present invention, the material of the rotating shaft 28 is not particularly limited as long as the mechanical properties such as strength and rigidity required for the rotating shaft 28 can be ensured. The outer diameter of the rotating shaft 28 is constant over the entire length in the axial direction at the portion outside the spiral groove 36 .

The spiral groove 36 is a portion for engaging the radial inner portion of the ball 30 . The helical groove 36 has a shape like a groove of a single-start screw, that is, a three-dimensional curvilinear shape formed as a whole. In this example, the depth of the spiral groove 36 is constant over the entire axial range. The depth of the spiral groove can ensure the strength of the ball 30 and the end portion 37 of the spiral groove 36 when the ball 30 contacts the end portion 37 of the spiral groove 36 as described later, and Any depth can be used as long as the ball 30 does not drop out of the spiral groove 36 .

In this example, the cross-sectional shape of the spiral groove 36 when cut along a virtual plane perpendicular to the spiral direction, which is the extending direction of the spiral groove 36, is a single circular arc. The radius of curvature of the cross-sectional shape of the spiral groove 36 is slightly larger than the radius of curvature of the surface of the ball 30 , that is, the radius of the ball 30 .

The end portion 37 of the spiral groove 36 has a concave curved surface as shown in FIG. It is composed of an inclined concave curved surface. However, the end portion 37 of the spiral groove 36 can ensure the strength of the ball 30 and the end portion 37 of the spiral groove 36 when the ball 30 contacts the end portion 37 of the spiral groove 36 as described later. Moreover, as long as the ball 30 does not drop out of the spiral groove 36, it can be configured with a surface having an arbitrary shape. For example, the end portion 37 of the spiral groove 36 can be configured by a surface having a cut-up shape or a plane perpendicular to the extending direction of the spiral groove 36 . Also, in order to reduce the collision noise between the balls and the ends of the spiral grooves, the ends of the spiral grooves can be made of synthetic resin such as polyacetal (POM) or MC nylon.

The number of turns of the spiral groove 36 on the outer peripheral surface of the rotating shaft 28 substantially corresponds to the maximum number of rotations of the steering wheel 2 limited by the rotation limiting device 10 . Here, the maximum number of rotations of the steering wheel 2 is the number of rotations when the steering wheel 2 is rotated from one rotation limit position to the other rotation limit position. In the illustrated example (see FIG. 4), the spiral groove 36 has substantially two turns. However, when carrying out the present invention, the number of turns of the spiral groove can be set to any number according to the desired maximum number of revolutions of the steering wheel 2 .

In addition, since the spiral groove 36 only needs to have the function of guiding the ball 30, it is not necessary to form it with excessive precision. Such a spiral groove 36 can be formed by an appropriate processing method such as cutting or rolling.

The guide member 29 has a guide groove 38 provided at a position facing the outer peripheral surface of the rotating shaft 28 over the entire length of the range where the spiral groove 36 exists in the axial direction of the rotating shaft 28 .

In this example, as shown in FIGS. 4, 10, and 11(a) to 11(c), the guide member 29 as a whole is configured in a substantially elliptical cylindrical shape extending in the radial direction of the rotating shaft 28. ing. Such a guide member 29 has a non-circular elliptical outline shape as shown in FIG. In this example, the longitudinal direction of the contour shape (vertical direction in FIG. 11(c)) coincides with the axial direction of the rotating shaft 28 when the rotation limiting device 10 is assembled. In this example, the guide member 29 is made of a metal such as general structural rolled steel (SS material) or machine structural carbon steel (SC material). However, when carrying out the present invention, the material of the guide member 29 is not particularly limited as long as the mechanical properties such as strength and rigidity required for the guide member 29 can be ensured.

The guide member 29 has a radial inner surface (lower surface in FIGS. 4 to 6, 9A, 10, 11A, and 11B) facing the outer peripheral surface of the rotating shaft 28. , a flat portion 39 . The plane portion 39 is formed of a plane orthogonal to the central axis of the guide member 29 extending in the radial direction of the rotating shaft 28 .

The guide groove 38 is formed so as to be recessed radially outward from the flat portion 39 . As shown in FIG. 11(c), when viewed from the inside in the radial direction, the guide groove 38 extends in the longitudinal direction ( 11(c)). That is, the guide groove 38 extends in the longitudinal direction, that is, in the axial direction of the rotating shaft 28 , and both ends of the guide groove 38 are open to the outer peripheral surface of the guide member 29 .

Such a guide groove 38 engages the outer portion of the ball 30 in the radial direction and guides the ball 30 to move in the axial direction as the steering wheel 2 and the rotary shaft 28 rotate. is the part of The guide groove 38 is provided over the entire length of the range where the spiral groove 36 exists in the axial direction of the rotating shaft 28 .

In this example, the depth of the guide groove 38 is constant over the entire range in the extending direction of the guide groove 38 . The depth of the guide groove 38 can ensure the strength of the ball 30 and the guide groove 38 when the ball 30 contacts the end portion 37 of the spiral groove 36 as will be described later. The depth can be arbitrarily set as long as it does not drop out of the guide groove 38 .

When carrying out the present invention, at the end of the guide groove, the shape of the bottom of the guide groove is tapered or concavely curved in a direction in which the depth of the guide groove becomes shallower toward the edge of the guide groove. can be shaped. By adopting such a configuration, it is possible to make it difficult for the ball 30 to ride up the edge of the spiral groove 36 when the ball 30 contacts the end portion 37 of the spiral groove 36 .

In this example, the cross-sectional shape of the guide groove 38 when cut along an imaginary plane perpendicular to the extending direction of the guide groove 38 is a single circular arc shape. The radius of curvature of the cross-sectional shape of the guide groove 38 is slightly larger than the radius of curvature of the surface of the ball 30 .

In this example, the guide member 29 has a pair of locking grooves 40 on its outer peripheral surface. The pair of locking grooves 40 are spaced apart from each other in the radial direction of the rotating shaft 28 , and are provided along the entire circumference of the outer peripheral surface of the guide member 29 .

In this example, the guide member 29 has a radial outer surface (FIGS. 4 to 6, FIG. 9A, FIG. 10, FIG. 11A, FIG. 11(b)) has a bottomed recessed hole 41 that is recessed radially inward, and a guide member 29 is provided around the recessed hole 41 on the radially outer surface. has a seat surface portion 42 formed of an annular plane perpendicular to the central axis of the .

Ball 30 is arranged between spiral groove 36 and guide groove 38 . More specifically, the ball 30 is in rolling contact with the spiral groove 36 so as to be able to roll along the spiral groove 36 , and is in rolling contact with the guide groove 38 to move along the guide groove 38 . are in rolling contact. As the rotating shaft 28 rotates with respect to the guide member 29 , the ball 30 moves along the spiral groove 36 , i.e., rolls, while moving along the guide groove 38 in the axial direction of the rotating shaft 28 . It is possible and possible to contact each of the ends 37 on either side of the spiral groove 36 . Also, when the steering wheel 2 is in the neutral rotational position, the ball 30 is positioned at the center of the axial range in which the spiral groove 36 exists, as shown in FIG.

In this example, balls are used as moving members, but members other than balls can also be used as moving members when implementing the present invention. That is, the moving member can move in the axial direction of the rotating shaft along the guide groove while moving along the spiral groove as the rotating shaft rotates with respect to the guide member, and It suffices if it is possible to contact each of the ends on both sides.

In this example, the balls 30 are made of metal, such as high carbon chromium bearing steel (SUJ2), or ceramic. However, when carrying out the present invention, the material of the balls 30 is not particularly limited as long as the mechanical properties such as the strength and rigidity required for the balls 30 can be ensured. In this example, grease for lubrication is applied to the surface of the ball 30 and the surface of the spiral groove 36 and the surface of the guide groove 38 which are the mating surfaces thereof. However, the grease can be omitted.

Further, in this example, when the ball 30 contacts the end portion 37 of the spiral groove 36, the guide member 29 is pushed by the ball 30 and displaced radially outward (upward in FIGS. 5 and 6). Including, the gap between the opening edge of the spiral groove 36 and the opening edge of the guide groove 38 is always regulated to be smaller than the diameter of the ball 30 . This prevents the ball 30 from entering between the portion of the outer peripheral surface of the rotary shaft 28 that is outside the spiral groove 36 and the plane portion 39 of the guide member 29 , thereby preventing the ball 30 from entering between the spiral groove 36 and the guide groove 38 . The state in which the ball 30 is arranged between them is maintained.

The case 31 has a holding hole 43 extending in the radial direction of the rotating shaft 28 , and has a guide member 29 inside the holding hole 43 so as to move in the radial direction of the rotating shaft 28 , that is, in the extending direction of the holding hole 43 . holds possible.

In this example, the case 31 has a T-tube shape as a whole, and includes a first tubular portion 44 and a second tubular portion 45 having a holding hole 43 . In this example, the case 31 constitutes the front portion of the inner column 12 .

The first cylindrical portion 44 is configured in a cylindrical shape, and the rotating shaft 28 is inserted radially inwardly.

The second cylindrical portion 45 is formed in a substantially cylindrical shape extending radially outward from one circumferential portion (upper portion in the illustrated example) of the axially intermediate portion of the first cylindrical portion 44 . there is The center hole (inner space) of the second cylindrical portion 45 communicates with the center hole (inner space) of the first cylindrical portion 44 . The center hole of the second tubular portion 45 has a radially inner portion (lower portion in FIGS. 5 and 6) formed by the holding hole 43, and a radially outer portion (upper portion in FIGS. 5 and 6). part) is constituted by a female screw hole 46 having a diameter larger than that of the holding hole 43 . In this example, the case 31 constitutes the front portion of the inner column 12 . Therefore, even when a load generated when the ball 30 contacts the end portion 37 of the spiral groove 36 is applied to the case 31 via the guide member 29 or the like, as will be described later, the case 31 does not support the inner column 12. are not rotated or displaced with respect to other parts of the

In this example, the holding hole 43 has an elliptical cylindrical inner peripheral surface. Such a holding hole 43 has a non-circular elliptical profile when viewed from the radial direction of the rotating shaft 28, as shown in FIG. In this example, the long axis direction, which is the longitudinal direction of the contour shape, coincides with the axial direction of the rotating shaft 28 (horizontal direction in FIG. 5 and vertical direction in FIGS. 8 and 12). Therefore, the width of the holding hole 43 is greater than the width dimension Wa of the rotating shaft 28 in the axial direction (Fig. 8, and the lateral direction in FIG. 12) is smaller.

In this example, as shown in FIGS. 5 and 6, the guide member 29 is arranged inside the holding hole 43 with the O-ring 33 engaged with each of the pair of engagement grooves 40. It is held so as to be movable in the radial direction. For this reason, in this example, the outer peripheral surface of the guide member 29 and the inner peripheral surface of the holding hole 43, which are each configured in an elliptical cylindrical shape, are elliptical fit, which is a non-circular fit, with a clearance fit. . Also, in this state, the O-ring 33 is elastically compressed between the bottom surface of the locking groove 40 and the inner peripheral surface of the holding hole 43 , thereby allowing the O-ring 33 to move between the outer peripheral surface of the guide member 29 and the inner peripheral surface of the holding hole 43 . It seals with the surrounding surface. As a result, the grease that lubricates the contact portions between the balls 30 and the spiral grooves 36 and the guide grooves 38 flows out into the external space through the space between the outer peripheral surface of the guide member 29 and the inner peripheral surface of the holding hole 43. Foreign matter such as dust is prevented from entering the installation portion of the hollow ball 30.例文帳に追加

When carrying out the present invention, the number of O-rings 33 that seal between the outer peripheral surface of the guide member 29 and the inner peripheral surface of the holding hole 43 can be one or three or more. However, if the number of the O-rings 33 is two or more, these O-rings 33 support the guide member 29 with respect to the inner peripheral surface of the holding hole 43 at a plurality of locations spaced apart in the radial direction over the entire circumference. be able to. Therefore, inclination of the central axis of the guide member 29 with respect to the central axis of the holding hole 43 can be suppressed.

In this example, the radially outer opening of the center hole of the second tubular portion 45 is closed by the cap 34 . The cap 34 has a disk shape as a whole. The cap 34 has a male threaded portion 47 on its outer peripheral surface, and a cylindrical projection 48 protruding radially inward at the central portion of its radial inner surface (lower surface in FIG. 4). The outer diameter of the convex portion 48 is larger than the inner diameter of the concave hole 41 of the guide member 29 and smaller than the outer diameter of the seat portion 42 of the guide member 29 . The cap 34 is attached to the case 31 by screwing the male threaded portion 47 into the female threaded hole 46 , and closes the radially outer opening of the center hole of the second tubular portion 45 .

In this example, the cap 34 is attached to the case 31 by screwing the male threaded portion 47 into the female threaded hole 46 , so that the cap 34 can be attached to and detached from the case 31 . Therefore, for example, by removing the cap 34 during maintenance, it is possible to replace the parts arranged in the case 31 or replenish the grease. When carrying out the present invention, the method of attaching the cap to the case is different from that in this example, such as screwing using a double nut, bonding (including bonding of the threaded portion), crimping, and the like. can also be adopted. However, whichever method is adopted, it is necessary that the cap can support the load applied when the ball 30 contacts the end 37 of the spiral groove 36 .

A coil spring 32 that is a first elastic member urges the guide member 29 inward in the radial direction of the rotating shaft 28 . That is, in this example, the coil spring 32 is arranged inside the concave hole 41 of the guide member 29 with its central axis aligned in the radial direction (the vertical direction in FIGS. 4 to 6). In addition, the bottom surface of the concave hole 41 and the radial inner surface of the projection 48 of the cap 34 are radially compressed. As a result, the coil spring 32 elastically urges the guide member 29 radially inward and applies preload to the ball 30 . When carrying out the present invention, various springs other than the coil spring, rubber members, and the like can be used as the first elastic member.

The structure of this example further comprises a second elastic member, disc spring 35 , which elastically deforms when ball 30 contacts end 37 of spiral groove 36 . The disc spring 35 has an elastic modulus (spring constant) k2 that is larger than the elastic modulus (spring constant) k1 of the coil spring 32 (k2>k1). The disk spring 35 is arranged coaxially with the coil spring 32 around the coil spring 32, and is positioned so that the seating surface portion 42 of the guide member 29 and the cap 34 are aligned in the radial direction (the vertical direction in FIGS. 4 to 6). It is arranged between the radial inner surface of the convex portion 48 .

When the ball 30 is not in contact with the end portion 37 of the spiral groove 36, the disc spring 35 is radially (Fig. 4 to 6), but as the ball 30 contacts the end 37 of the spiral groove 36, the guide member 29 is pushed by the ball 30 and radially outward (in FIGS. 4 to 6). When displacing upward), the disc spring 35 itself is axially compressed between the bearing surface portion 42 of the guide member 29 and the radially inner surface of the convex portion 48 of the cap 34 so as to be elastically deformed. Directional dimensions are restricted. When carrying out the present invention, various springs other than disc springs, rubber members, and the like can be used as the second elastic member.

It should be noted that the second elastic member (in this example, the disk spring 35) can be omitted when implementing the present invention.

In the steering device 1 of this example having the configuration described above, when the rotating shaft 28 is rotated together with the steering wheel 2 by rotating the steering wheel 2 from the neutral rotation position, the ball 30 moves along the spiral groove 36. It moves in the axial direction along the guide groove 38 while rolling. Here, the directions in which the balls 30 move along the guide grooves 38 are opposite to each other when the steering wheel 2 rotates in one direction and in the other direction.

Then, when the ball 30 moves to the end of the guide groove 38 and comes into contact with the end 37 of the spiral groove 36 as indicated by the imaginary line (two-dot chain line) in FIG. , the ball 30 cannot move along the spiral groove 36. As a result, the steering wheel 2 is restricted from further turning to one side or the other. In this example, when the steering wheel 2 is in the neutral rotation position, the ball 30 is positioned at the center of the axial range in which the spiral groove 36 exists, as shown in FIG. Therefore, when the steering wheel 2 rotates to one side from the neutral rotation position and when the steering wheel 2 rotates to the other side, the rotation limit amount of the steering wheel 2 is the same. becomes 1/2.

According to the rotation limiting device 10 of the present embodiment incorporated in the steering device 1 as described above, the radial dimension can be kept small, and the rotation amount can be limited regardless of the rotation direction of the rotating shaft 28. The acting loads can be made approximately equal.

That is, in the rotation restricting device 10 of this example, the engaging portion of the ball 30 faces the spiral groove 36 provided on the outer peripheral surface of the rotating shaft 28 and the outer peripheral surface of the rotating shaft 28 in the guide member 29. Since the guide groove 38 is provided at the position, the radial dimension of the rotation restricting device 10 can be kept small. Therefore, even when the installation space in the radial direction is limited, it is easy to install the rotation limiting device 10 .

Also, the radial distance from the center of rotation of the rotating shaft 28 to the center of the ball 30 when the steering wheel 2 is rotated to one side to bring the ball 30 into contact with the end 37 of the spiral groove 36 on one side , the radial distance from the rotation center of the rotary shaft 28 to the center of the ball 30 when the steering wheel 2 is rotated to the other side to bring the ball 30 into contact with the end 37 of the spiral groove 36 on the other side. , can be the same size. Therefore, the contact load when the ball 30 contacts the one end 37 of the spiral groove 36 and the contact load when the ball 30 contacts the other end 37 of the spiral groove 36 are substantially equal. can do. Therefore, it is possible to prevent the driver from feeling uncomfortable when rotating the steering wheel 2 .

In the structure of this example, the outer peripheral surface of the guide member 29 and the inner peripheral surface of the holding hole 43 are fitted in an elliptical fit, which is a non-circular fit, that is, in a non-rotatable relationship. Therefore, as shown in FIGS. 9A and 9B, as the ball 30 comes into contact with the end 37 of the spiral groove 36, the ball 30 rotates with respect to the end of the guide groove 38. Even when a load F is applied in a direction perpendicular to the axial direction of the shaft 28 , that is, in a direction that rotates the guide member 29 around its own central axis, the guide member 29 is positioned inside the holding hole 43 so that the guide member 29 rotates around its own central axis. can be prevented from rotating around Therefore, it is possible to effectively prevent the inconvenience that the guide member 29 rotates and the rotation limit amount of the steering wheel 2 increases.

The width dimension Wb of the holding hole 43 in the width direction is smaller than the width dimension Wa in the axial direction of the rotating shaft 28 . Therefore, when assembling the rotation restricting device 10 of this embodiment, the balls 30 engaged with the spiral grooves 36 are moved to the center in the width direction in the inner portion of the holding hole 43 in the radial direction of the rotating shaft 28 . You can reduce the trouble of assembling it. Therefore, it is easy to ensure the assemblability of the rotation limiting device 10 .

A preload is applied to the ball 30 by elastically biasing the guide member 29 radially inward with the coil spring 32 . Therefore, when the steering wheel 2 is rotated, the balls 30 are prevented from rattling. Therefore, it is possible to prevent the vibration due to rattling of the balls 30 from being transmitted to the steering wheel 2 and giving the driver a sense of discomfort.

Based on the preload applied to the ball 30 , a moderate rotational resistance can be generated in the rotating shaft 28 , that is, the steering wheel 2 . Therefore, the driver's steering feeling can be improved.

As the ball 30 contacts the end 37 of the spiral groove 36, when the guide member 29 is pushed by the ball 30 and displaced radially outward (upward in FIGS. 4 to 6), the guide member 29 Between the bottom surface of the concave hole 41 and the radial inner surface of the projection 48 of the cap 34, the coil spring 32 is further compressed in the radial direction (vertical direction in FIGS. 4 to 6). Therefore, the elastic force of the coil spring 32 can reduce the impact and hitting sound when the ball 30 collides with the end 37 of the spiral groove 36 .

As the ball 30 contacts the end 37 of the spiral groove 36, when the guide member 29 is pushed by the ball 30 and displaced radially outward (upward in FIGS. 4 to 6), the guide member 29 Between the seat surface portion 42 and the radial inner surface of the convex portion 48 of the cap 34, the disc spring 35 is compressed in the radial direction (vertical direction in FIGS. 4 to 6) and elastically deformed. Therefore, the impact and hammering sound when the ball 30 collides with the end portion 37 of the spiral groove 36 can be reduced not only by the elasticity of the coil spring 32 but also by the elasticity of the disc spring 35 . That is, in the structure of this example, the disc spring 35 can improve the effect of reducing the impact and hammering sound when the ball 30 collides with the end portion 37 of the spiral groove 36 .

Note that if the elastic modulus k1 of the coil spring 32 is too large, the movement of the ball 30, that is, the turning operation of the steering wheel 2 becomes excessively heavy or cannot be performed smoothly. Therefore, in the structure of this example, the elastic modulus k1 of the coil spring 32 is made smaller than the elastic modulus k2 of the disk spring 35 (k1<k2).

[Second example of embodiment]
A second example of the embodiment of the invention will be described with reference to FIGS. 13 to 15. FIG.

In the structure of this example, the guide member 29a is curved along the outer peripheral surface of the rotating shaft 28 and has a concave surface facing the outer peripheral surface of the rotating shaft 28 on the radial inner surface facing the outer peripheral surface of the rotating shaft 28. It has a part 49 . The concave portion 49 is formed of a partially cylindrical concave surface having a radius of curvature slightly larger than the radius of curvature of the outer peripheral surface of the rotating shaft 28 , and is arranged close to the outer peripheral surface of the rotating shaft 28 . The guide groove 38 is provided so as to be recessed radially outward from the concave portion 49 .

In the structure of this example, when assembling the rotation restricting device 10, the ball 30 engaged with the spiral groove 36 in the inner portion of the holding hole 43 in the radial direction of the rotating shaft 28 is inserted into the concave portion of the guide member 29a. It is assembled while being guided by 49 and moved to the center in the width direction. Therefore, it is easy to ensure the assemblability of the rotation limiting device 10 .
Other configurations and effects are the same as those of the first embodiment.

[Third example of embodiment]
A third example of the embodiment of the invention will be described with reference to FIGS. 16 to 19. FIG.

In the structure of this example, the entire guide member 29b is configured in a substantially rectangular columnar shape extending in the radial direction of the rotating shaft 28. As shown in FIG. Further, the holding hole 43a of the case 31a has a substantially rectangular cylindrical inner peripheral surface. 16 and 17, the outer peripheral surface of the guide member 29b and the inner peripheral surface of the holding hole 43a are non-circularly fitted with clearance. Therefore, even when the ball 30 contacts the end portion 37 of the spiral groove 36, the guide member 29b can be prevented from rotating about its central axis inside the holding hole 43a.

In addition, in the structure of this example, each of the guide member 29b and the holding hole 43a has a substantially rectangular contour shape with the axial direction of the rotating shaft 28 as the longitudinal direction when viewed from the radial direction of the rotating shaft 28 . That is, in the structure of this example as well, the width dimension Wb in the width direction of the holding hole 43a is smaller than the width dimension Wa in the axial direction of the rotating shaft 28 . Therefore, for the same reason as in the case of the first embodiment, it is easy to ensure the ease of assembly of the rotation restricting device 10 .
Other configurations and effects are the same as those of the first embodiment.

[Fourth example of embodiment]
A fourth example of the embodiment of the invention will be described with reference to FIGS. 20 to 23. FIG.

In the structure of this example, the outer peripheral surface of the guide member 29c is non-circularly fitted to the inner peripheral surface of the holding hole 43b of the case 31b only at the inner portion in the radial direction of the rotating shaft 28 .

That is, in the structure of this example, the guide member 29c has the inner guide portion 50 at the inner end portion in the radial direction of the rotating shaft 28, and the outer guide portion 50 at the outer end portion and intermediate portion in the radial direction of the rotating shaft 28. It has a part 51 . The inner guide portion 50 is bifurcated as a whole by the guide groove 38 penetrating the middle portion in the width direction in the axial direction. The inner guide portion 50 has a substantially elliptical cylindrical outer peripheral surface. The outer guide portion 51 has a cylindrical outer peripheral surface. In this example, the pair of locking grooves 40 are provided on the outer peripheral surface of the outer guide portion 51 .

In the structure of this example, the holding hole 43b has an inner hole portion 52 formed by a substantially elliptical hole extending in the radial direction of the rotating shaft 28 at the inner end portion in the radial direction of the rotating shaft 28. An outer hole portion 53 formed by a circular hole extending in the radial direction of the rotating shaft 28 is provided at the outer end portion and intermediate portion of the rotating shaft 28 in the radial direction.

In the structure of this example, the outer peripheral surface of the inner guide portion 50 and the inner peripheral surface of the inner hole portion 52 are non-circularly fitted with clearance as shown in FIGS. 20 and 21(b), and 20 and 21(a), the outer peripheral surface of the outer guide portion 51 and the inner peripheral surface of the outer hole portion 53 are circularly fitted with a clearance fit. Also, in this state, the O-rings 33 locked in the respective locking grooves 40 are elastically compressed between the bottom surface of the locking grooves 40 and the inner peripheral surface of the outer hole portion 53 .

In the structure of this example, since the outer peripheral surface of the inner guide portion 50 and the inner peripheral surface of the inner hole portion 52 are non-circularly fitted, even when the ball 30 contacts the end 37 of the spiral groove 36, It is possible to prevent the guide member 29b from rotating about its central axis inside the holding hole 43a.

In the structure of this example, the inner hole portion 52, which is the inner portion in the radial direction of the rotating shaft 28, of the holding hole 43b has a width dimension Wb in the width direction rather than the width dimension Wa in the axial direction of the rotating shaft 28. is small. Therefore, for the same reason as in the case of the first embodiment, it is easy to ensure the ease of assembly of the rotation restricting device 10 .
Other configurations and effects are the same as those of the first and second examples of the embodiment.

[Fifth example of embodiment]
A fifth example of the embodiment of the present invention will be described with reference to FIGS. 24 to 27. FIG.

In the structure of this example, the outer peripheral surface of the inner guide portion 50a of the guide member 29d and the inner peripheral surface of the inner hole portion 52a of the holding hole 43c forming the case 31c, which are non-circularly fitted with a clearance fit, are shown in FIG. As shown in 24 and FIG. 25(b), it is configured in a substantially rectangular tubular shape.
Other configurations and effects are the same as those of the fourth example of the embodiment.

[Sixth example of embodiment]
A sixth example of the embodiment of the present invention will be described with reference to FIGS. 28 and 29. FIG.

In the structure of this example, at least the portion of the guide member 29e that contacts the ball 30 is made of metal. Specifically, a portion of the guide member 29e including the guide groove 38, which is the portion that contacts the ball 30, is made of metal, and the remaining portion is made of synthetic resin. More specifically, in the guide member 29e, the surface layer portion of the guide groove 38, which corresponds to the above-described portion, is made of a metal portion 54, and the remaining portion is made of a resin portion 55 made of synthetic resin. ing.

The metal portion 54 is made of metal such as steel and has a partially cylindrical shape, and has a guide groove 38 on its radial inner surface.

The resin portion 55 has a holding recessed portion 56 on its radially inner side surface. The surface of the holding recess 56 has a shape that matches the radial outer surface of the metal portion 54 . The metal portion 54 and the resin portion 55 are joined and fixed to each other by fusing, gluing, or press-fitting the radial outer surface of the metal portion 54 and the surface of the holding recess 56 of the resin portion 55 . .

In the structure of this example as described above, the guide member 29e is partially made of metal, including the surface of the guide groove 38, and the rest is made of synthetic resin. It is possible to ensure durability and reduce the weight of the guide member 29e.
Other configurations and effects are the same as those of the first embodiment.

[Seventh example of embodiment]
A seventh example of the embodiment of the present invention will be described with reference to FIGS. 30 and 31. FIG.

In the structure of this example, the outer peripheral surface of the guide member 29f is formed of a cylindrical surface having no locking groove. In the structure of this example, no O-ring is assembled between the outer peripheral surface of the guide member 29f and the inner peripheral surface of the holding hole 43. As shown in FIG. Instead, in the structure of this example, the outer peripheral surface of the guide member 29f is fitted to the inner peripheral surface of the holding hole 43 with a clearance that eliminates rattling in the radial direction of the holding hole 43, or the inside of the holding hole 43 is fitted. The guide member 29f is internally fitted by light press-fitting so as not to hinder the movement of the guide member 29f in the radial direction (vertical direction in FIG. 30). Thereby, the sealability between the outer peripheral surface of the guide member 29f and the inner peripheral surface of the holding hole 43 is ensured.

In the structure of this example as described above, since the O-ring to be assembled between the outer peripheral surface of the guide member 29f and the inner peripheral surface of the holding hole 43 is omitted, the number of parts can be reduced. Further, since the outer peripheral surface of the resin portion 55a constituting the guide member 29d is not provided with a locking groove for locking the O-ring, the molding cost of the resin portion 55a can be suppressed.
Other configurations and effects are the same as those of the sixth example of the embodiment.

[Eighth example of embodiment]
An eighth example of the embodiment of the invention will be described with reference to FIG.

In the structure of this example, the radial width between the bottom portion of the spiral groove 36a of the rotary shaft 28a and the bottom portion of the guide groove 38 of the guide member 29 decreases from the central portion toward both sides in the axial direction of the rotary shaft 28a. It's becoming In order to employ such a configuration, in this example, the depth of the spiral groove 36a becomes shallower toward both sides from the central portion in the axial direction of the rotating shaft 28a.

In the structure of this example having the above configuration, when the steering wheel 2 (see FIG. 1) is rotated from the neutral rotation position, the balls 30 are moved from the central portion of the guide groove 38 toward the end portion. On the ball 30, a pressing force having a component in the direction of returning from the bottom of the spiral groove 36a to the central portion of the guide groove 38 acts on the ball 30 based on the elasticity of the coil spring 32. As shown in FIG. Therefore, the steering wheel 2 can be easily returned to the neutral rotation position by the pressing force having such a component.
Other configurations and effects are the same as those of the first embodiment.

[Ninth example of embodiment]
A ninth example of the embodiment of the present invention will be described with reference to FIG.

In the structure of this example as well, the radial width between the bottom of the spiral groove 36 of the rotary shaft 28 and the bottom of the guide groove 38a of the guide member 29g decreases from the central portion toward both sides in the axial direction of the rotary shaft 28. It's becoming In order to adopt such a configuration, in this example, the depth of the guide groove 38a becomes shallower toward both sides from the central portion in the axial direction of the rotating shaft 28. As shown in FIG.

In the structure of the present example having the configuration described above, when the steering wheel 2 (see FIG. 1) is rotated from the neutral rotational position, the ball 30 is moved from the central portion toward the end portion of the guide groove 38a. On the ball 30, a pressing force having a component in the direction of returning from the end of the guide groove 38a to the center of the guide groove 38a acts on the ball 30 based on the elasticity of the coil spring 32. As shown in FIG. Therefore, the steering wheel 2 can be easily returned to the neutral rotation position by the pressing force having such a component.
Other configurations and effects are the same as those of the first embodiment.

[Tenth example of embodiment]
A tenth example of the embodiment of the present invention will be described with reference to FIG.

In the structure of this example, the cross-sectional shape of the spiral groove 36b when cut by a virtual plane orthogonal to the spiral direction, which is the extending direction of the spiral groove 36b, and the cross-sectional shape of the spiral groove 36b when cut by a virtual plane orthogonal to the extending direction of the guide groove 38b As the cross-sectional shape of the guide groove 38b, a V-shaped cross-sectional shape as shown is adopted. In such a spiral groove 36b and guide groove 38b, the ball 30 contacts the groove surface at two points (two P portions) separated in the groove width direction. Therefore, the surface pressure at each contact portion can be kept small, and the durability of the spiral groove 36b, the guide groove 38b, and the ball 30 can be improved accordingly.
Other configurations and effects are the same as those of the first embodiment.

[Eleventh example of embodiment]
An eleventh example of the embodiment of the invention will be described with reference to FIG.

In the structure of this example, the cross-sectional shape of the spiral groove 36c when cut by a virtual plane orthogonal to the spiral direction, which is the extending direction of the spiral groove 36c, and the shape of the spiral groove 36c when cut by a virtual plane orthogonal to the extending direction of the guide groove 38c As the cross-sectional shape of the guide groove 38c, a Gothic arch-shaped cross-sectional shape as shown in the drawing is adopted. That is, this cross-sectional shape is formed by combining two circular arcs whose centers of curvature O _a and O _b exist at different positions into a substantially V shape. The respective radii of curvature r of these two arcs are equal to each other and larger than the radius of curvature of the surface of ball 30 . Even with such a spiral groove 36c and guide groove 38c, the ball 30 contacts the groove surface at two points (two Q portions) separated in the axial direction. Further, the contact area of each of these two locations (two Q portions) is larger than the contact area of each of the two locations (two P portions) in FIG. Therefore, the durability of the spiral groove 36c, the guide groove 38c, and the ball 30 can be further improved. When carrying out the present invention, it is most preferable that the cross-sectional shape of each of the spiral groove and the guide groove is a Gothic arch shape from the viewpoint of ensuring the durability of the rotation restricting device.
Other configurations and effects are the same as those of the first embodiment.

[Twelfth example of embodiment]
A twelfth example of the embodiment of the present invention will be described with reference to FIG.

In this example, a rotation limiting device 10 (see FIGS. 4 to 12 relating to the first embodiment) for limiting the amount of rotation of the steering wheel 2 to a predetermined amount or less is provided for the steering device 1a of the steer-by-wire system. This is an applied example. The rotation restricting device of the present invention can be applied more preferably to a steer-by-wire steering device than to a steering device in which a steering wheel and a pair of steered wheels are mechanically connected. .

The steering device 1a of this example includes a steering device 57 having a steering wheel 2 and a steering device 58 for imparting a steering angle to a pair of steered wheels (not shown). are electrically connected. When the automobile is driven, the amount of rotational operation of the steering wheel 2 is detected by a sensor (not shown) that constitutes the steering device 57, and the actuator that constitutes the steering device 58 is driven based on the output signal of the sensor. , a steering angle is given to a pair of steering wheels.

The steering device 57 includes a steering shaft 59 , a steering column 60 , a locking mechanism (not shown), a reaction force applying device 61 , and a rotation limiting device 10 in addition to the steering wheel 2 and the sensor.

The steering wheel 2 is supported and fixed to the rear end of the steering shaft 59 . The steering shaft 59 is rotatably supported inside a steering column 60 supported by the vehicle body.

The steering device 1a of this example includes a swing-type tilt mechanism for enabling adjustment of the height position of the steering wheel 2. As shown in FIG. For this reason, the steering column 60 includes a tubular front column 62 arranged on the front side, a tubular rear column 63 arranged on the rear side, and a rear end portion of the front column 62 and the rear column 63. It has a rocking shaft 64 in the vehicle width direction that rockably connects the front end portion. That is, the rear column 63 can swing relative to the front column 62 about a swing shaft 64 extending in the vehicle width direction. The front column 62 is arranged horizontally by aligning its axial direction with the longitudinal direction, and is supported and fixed to the vehicle body using a support bracket (not shown) or the like. In the steering device 1a of the present embodiment, since the front column 62 is arranged horizontally in this way, it is possible to ensure a wide foot space for the driver's seat in the vertical direction. However, the front column 62 can also be arranged in a state of being inclined downward toward the front.

The steering shaft 59 has a front shaft 65 arranged on the front side, a rear shaft 66 arranged on the rear side, and a rear end portion of the front shaft 65 and a front end portion of the rear shaft 66 so as to swing and torque. and a universal joint 67 communicatively connected. The front shaft 65 is rotatably supported inside the front column 62 by rolling bearings (not shown). The rear shaft 66 is rotatably supported inside the rear column 63 by rolling bearings (not shown). The swing center of the universal joint 67 is positioned on the central axis of the swing shaft 64 . Therefore, the rocking of the rear column 63 with respect to the front column 62 and the rocking of the rear shaft 66 with respect to the front shaft 65 can be performed smoothly in synchronization with each other.

The steering wheel 2 is supported and fixed to the rear end of the rear shaft 66 . The height position of the steering wheel 2 can be adjusted within a range in which the rear column 63 can be pivotally displaced with respect to the front column 62 . In addition, the locking mechanism allows the rear column 63 to swing with respect to the front column 62, thereby enabling adjustment of the height position of the steering wheel 2, and the swinging of the rear column 63 with respect to the front column 62. It is possible to switch between a state in which displacement is disabled and the height position of the steering wheel 2 is held at the adjusted position.

The reaction force application device 61 is supported at the front end of the front column 62 . The reaction force applying device 61 has an electric motor as a power source and a speed reducer, and drives the electric motor as the steering wheel 2 is rotated by the driver. The torque of the electric motor is increased by the speed reducer and then transmitted to the front shaft 65 as reverse torque, which is torque in the direction opposite to the rotational operation direction of the steering wheel 2 . As a result, an operation reaction force based on the reverse torque is applied to the steering wheel 2 . The magnitude of the operation reaction force applied to the steering wheel 2 basically depends on the amount of rotational operation of the steering wheel 2 acquired by the sensor, the torque input from the steering wheel 2 to the steering shaft 59, and the like. determined accordingly.

In this example, the rotating shaft 28 provided in the rotation limiting device 10 (see FIGS. 4 to 12) constitutes an axially intermediate portion of the front shaft 65 . A case 31 included in the rotation limiting device 10 constitutes an axially intermediate portion of the front column 62 . Also in the steering device 1a of this embodiment, the amount of rotation of the steering wheel 2 can be limited to a predetermined amount or less by such a rotation limiting device 10. FIG.

The present invention can be carried out by appropriately combining the configurations of the respective embodiments described above as long as there is no contradiction. For example, the rotation limiting devices of the second to eleventh embodiments can also be applied to a steer-by-wire steering system.

Reference Signs List 1, 1a steering device 2 steering wheel 3 steering shaft 4 steering column 5 electric assist device 6a, 6b universal joint 7 intermediate shaft 8 steering gear unit 9 tie rod 10 rotation limiting device 11 pinion shaft 12 inner column 13 outer column 14 inner shaft 15 outer Shaft 16 housing 17 electric motor 18 torsion bar 19 output shaft 20a, 20b ball bearing 21 worm reduction gear 22 torque sensor 23 worm wheel 24 wheel tooth 25 worm 26 worm tooth 27 output shaft 28, 28a rotating shaft 29, 29a, 29b, 29c , 29d, 29e, 29f, 29g Guide member 30 Ball 31, 31a, 31b, 31c Case 32 Coil spring 33 O-ring 34 Cap 35 Disc spring 36, 36a, 36b, 36c Spiral groove 37 End 38, 38a, 38b, 38c Guide groove 39 Plane portion 40 Locking groove 41 Concave hole 42 Seat surface portion 43, 43a, 43b, 43c Holding hole 44 First cylindrical portion 45 Second cylindrical portion 46 Female screw hole 47 Male screw portion 48 Convex portion 49 Concave portion 50, 50a inner guide portion 51 outer guide portion 52, 52a inner hole portion 53 outer hole portion 54 metal portion 55, 55a resin portion 56 holding recess 57 steering device 58 steering device 59 steering shaft 60 steering column 61 reaction force applying device 62 front column 63 rear column 64 rocking shaft 65 front shaft 66 rear shaft 67 universal joint

Claims (14)

a rotating shaft having a spiral groove on its outer peripheral surface;
a guide member having a guide groove provided at a position facing the outer peripheral surface of the rotating shaft over the entire length of the range in which the spiral groove exists in the axial direction of the rotating shaft;
It is disposed between the spiral groove and the guide groove, and moves along the guide groove in the axial direction of the rotation shaft while moving along the spiral groove as the rotation shaft rotates with respect to the guide member. and a moving member capable of contacting each of opposite ends of the spiral groove;
a case having a holding hole extending in the radial direction of the rotating shaft and holding the guide member inside the holding hole;
The outer peripheral surface of the guide member and the inner peripheral surface of the holding hole are non-circularly fitted.
rotation limiter. The outer peripheral surface of the guide member is non-circularly fitted to the inner peripheral surface of the holding hole only at the inner portion in the radial direction of the rotating shaft.
The rotation limiting device according to claim 1. In the holding hole, the inner portion in the radial direction of the rotating shaft is in the direction orthogonal to the axial direction of the rotating shaft and the extending direction of the holding hole, rather than the width dimension in the axial direction of the rotating shaft. width dimension is smaller,
The rotation limiting device according to claim 1 or 2. The guide member has a concave portion that curves along the outer peripheral surface of the rotating shaft and faces the outer peripheral surface of the rotating shaft,
The guide groove is provided so as to be recessed radially outward from the concave portion.
A rotation limiting device according to any one of claims 1 to 3. the case is held inside the holding hole so as to be movable in the radial direction of the rotating shaft;
A first elastic member that biases the guide member inward with respect to the radial direction of the rotating shaft,
A rotation limiting device according to any one of claims 1 to 4. A radial width between the bottom portion of the spiral groove and the bottom portion of the guide groove decreases from the central portion toward both sides in the axial direction of the rotating shaft.
The rotation limiting device according to claim 5. The depth of the spiral groove becomes shallower toward both sides from the center with respect to the axial direction of the rotating shaft.
A rotation limiting device according to claim 6. The depth of the guide groove becomes shallower toward both sides from the central portion in the axial direction of the rotating shaft.
A rotation limiting device according to claim 6 or 7. Further comprising a second elastic member that has an elastic modulus greater than that of the first elastic member and elastically deforms when the moving member contacts the end of the spiral groove,
The rotation limiting device according to any one of claims 5-8. A portion of the guide member that contacts the moving member is made of metal,
A rotation limiting device according to any one of claims 1 to 9. A portion of the guide member including a portion that contacts the moving member is made of metal, and the remaining portion is made of synthetic resin.
The rotation limiting device according to claim 10. The cross-sectional shape of each of the spiral groove and the guide groove is a Gothic arch shape,
A rotation limiting device according to any one of claims 1 to 11. wherein the moving member is composed of a ball;
A rotation limiting device according to any one of claims 1-12. A steering device comprising a rotation limiting device for limiting the amount of rotation of a steering member to a predetermined amount or less, wherein the rotation limiting device is the rotation limiting device according to any one of claims 1 to 13.

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