JP7635740B2 - Steering wheel - Google Patents

Description

The present invention relates to a steering wheel that is operated by a driver when steering a vehicle such as a car.

A vehicle such as a car is provided with a steering shaft as part of its steering device, which has a first axis and rotates in both forward and reverse directions around the first axis. A steering handle is attached to this steering shaft and is gripped and operated by the driver of the vehicle. Patent Document 1 describes a steering handle that does not put much strain on the driver's wrists even when it is rotated significantly, for example by 90 degrees or more, around the first axis from the position when the vehicle is traveling straight ahead.

This steering handle comprises a boss portion, a pair of spoke portions, and a pair of grip portions. The boss portion is attached to the steering shaft so as to be able to rotate integrally with the steering shaft. Both spoke portions have second axes that extend from the boss portion in opposite directions in the width direction of the vehicle when the vehicle is moving straight. Both spoke portions are supported by the boss portion so as to be able to rotate in both forward and reverse directions around the second axis. Both grip portions are fixed to the ends of both spoke portions farther from the boss portion.

In the above steering wheel, both grips can be rotated around the second axis. Therefore, the driver can maintain a natural angle of the wrists by rotating both grips around the second axis while rotating around the first axis of the steering shaft. This means that even when rotating the steering wheel more than 90 degrees around the first axis, there is no need to bend the wrists at an unnatural angle, and so strain is less likely to be placed on the wrists.

JP 2004-34849 A

However, the steering wheel of the above-mentioned Patent Document 1 does not have a mechanism for returning both grips to a neutral position when the vehicle is moving straight ahead, so there is room for improvement in terms of operability. For this reason, it is conceivable to provide the above-mentioned mechanism in the steering wheel in order to improve the operability of this steering wheel. However, for example, providing the above-mentioned mechanism in the connection portion between the spoke portion and the boss portion of the steering wheel or in the vicinity thereof would limit the design freedom of the boss portion, and there is a risk that the design of the steering wheel cannot be ensured.

This problem can occur in any vehicle equipped with the conventional steering wheel described above, and is not limited to cars.

Means for solving the above problems and their effects will be described below.
A steering wheel that solves the above problem is applied to a vehicle equipped with a steering shaft having a first axis and rotating in both forward and reverse directions around the first axis, and includes a boss portion attached to the steering shaft so as to be integrally rotatable with the steering shaft, a pair of spoke portions fixed to the boss portion and having second axes extending from the boss portion in opposite directions in the width direction of the vehicle when the vehicle travels straight, and a pair of grip portions provided on the pair of spoke portions so as to be rotatable in both forward and reverse directions around the second axis, and when the position of the grip portions around the second axis when traveling straight is set to a neutral position, the grip portions are returned to the neutral position when traveling straight. The grip portion includes a rotation control mechanism for rotating the pusher or the rotating cam toward the other side, the rotation control mechanism including a rotating cam attached to the spoke portion and having a cam surface on one side in a direction along the second axis, a pusher having a contact portion that contacts the cam surface, and a coil spring that biases one of the pusher or the rotating cam toward the other side, the cam surface having a pair of inclined surfaces formed around the second axis and inclined in opposite directions with respect to a plane perpendicular to the second axis, the pair of inclined surfaces being connected to each other via a boundary portion, the contact portion and the boundary portion coming into contact with each other during the straight movement, and the rotating cam or the pusher rotating about the second axis as the grip portion rotates.

According to this configuration, when the vehicle moves straight, the pair of spokes and the pair of gripping parts are located on both sides of the boss in the width direction of the vehicle. The pair of gripping parts are located in a neutral position in the direction of rotation about the second axis. In the rotation control mechanism, as an example, the contact part of the pusher is pressed against the boundary part of the cam surface of the rotating cam by the biasing force of the coil spring.

When the driver applies a force to the grip part in either the forward or reverse direction around the first axis from the above-mentioned state, this force is transmitted to the steering shaft via the spokes and boss. As a result, the grip part, spokes, boss, and steering shaft rotate around the first axis. In this way, the vehicle is steered and the direction of travel of the vehicle is changed. The rotation of the grip part around the first axis is accompanied by the grip part rotating in both forward and reverse directions around the second axis due to the structure of the wrist of the driver holding the grip part.

In one example of a rotation control mechanism, the grip rotates in both forward and reverse directions together with the rotating cam. As the rotating cam rotates, the cam surface rotates in both forward and reverse directions around the second axis. This causes a change in the contact position of the contact portion of the pusher on the cam surface. When this contact position moves from the boundary portion to the inclined surface, a force is generated that tries to move the pusher away from the rotating cam while elastically deforming the coil spring so as to compress it. This force increases as the contact position with the contact portion on the inclined surface moves away from the boundary portion in the circumferential direction of the rotating cam as the rotating cam rotates. In addition, the above force is transmitted to the driver through the hand holding the grip as a steering load when the grip is rotated around the second axis.

From the above-mentioned state, when the driver reduces the force applied to the grip part in the above-mentioned direction or applies a force to the grip part to return it to the straight-ahead position, the grip part, spoke part, boss part, and steering shaft rotate around the first axis in the opposite direction to the above. This returns the vehicle's traveling direction to the straight-ahead direction. The rotation of the grip part around the first axis is accompanied by the rotation of the grip part around the second axis in the opposite direction to the above.

In the rotation control mechanism, the gripping portion rotates together with the rotating cam in the opposite direction to the above. As the rotating cam rotates, the cam surface rotates around the second axis in the opposite direction to the above. As a result, the contact position of the inclined surface of the cam surface with the contact portion of the pusher approaches the boundary portion. As a result, the force that moves the pusher away from the rotating cam while elastically deforming the coil spring to compress it decreases, and the steering load transmitted to the driver decreases. The force and steering load are minimized when the boundary portion of the cam surface and the contact portion of the pusher come into contact when the vehicle is traveling straight. At this time, the gripping portion is in a neutral position.

In this way, the steering load when rotating the grip around the second axis changes depending on the amount of rotation of the grip from the neutral position. This improves the steering feel compared to when the steering load is constant regardless of the amount of rotation of the grip.

In addition, because the spokes are fixed to the boss and the grip is rotatably attached to the spokes, the spokes do not rotate even when the grip is rotated. This allows electrical components such as switches and sensors that require wiring to be attached to the spokes.

In addition, because the rotation control mechanism is located within the grip and not in the boss, it can be made invisible from the outside and does not limit the design freedom of the boss. This improves the design of steering wheels equipped with a rotation control mechanism.

In the above steering handle, the coil spring is preferably disposed outside the pusher.
According to this configuration, the coil spring can be made larger without making the pusher larger. Therefore, the spring constant of the coil spring can be secured while suppressing the size increase of the rotation control mechanism. Incidentally, if the coil spring is arranged inside the pusher, for example, making the coil spring larger requires the pusher to be made larger by the amount of the coil spring, which results in an increase in the size of the rotation control mechanism.

In the above steering wheel, it is preferable that the rotation control mechanism includes a holding portion that holds the position of the coil spring so that the central axis of the coil spring coincides with the second axis.

With this configuration, when the coil spring biases one of the pusher and the rotating cam toward the other, the biasing force of the coil spring can be applied to the pusher or the rotating cam in a balanced manner. Therefore, it is possible to prevent the pusher or the rotating cam from being deformed by the biasing force of the coil spring. Incidentally, if the position of the coil spring is shifted and the biasing force of the coil spring is biasedly applied to the pusher or the rotating cam, there is a risk that the pusher or the rotating cam will be deformed by the biasing force of the coil spring.

In the above steering handle, the rotation control mechanism includes a support part that supports the coil spring from the side opposite to the pusher side or the rotating cam side, and a non-metallic inclusion is interposed between the coil spring and the support part, and the surface of the inclusion is preferably embossed.

With this configuration, fine irregularities are formed on the surface of the inclusion with which one end of the coil spring comes into contact, increasing the coefficient of friction of the surface, making it difficult for the coil spring to slide on the surface of the inclusion. This makes it possible to prevent the coil spring from shifting out of position relative to the inclusion.

In the above steering wheel, it is preferable that an engagement recess capable of engaging with the contact portion is formed in the boundary portion of the cam surface.
According to this configuration, when the contact portion and the boundary portion come into contact with each other while driving straight, the contact portion engages with the engagement recess. Therefore, when the grip portion is returned to the neutral position while driving straight, the driver can feel a sense of moderation. In addition, by the contact portion engaging with the engagement recess, rattling of the contact portion can be suppressed.

This invention has the effect of improving design.

FIG. 2 is a perspective view of a framework of a steering handle according to an embodiment. FIG. 2 is a front view showing a main part of FIG. 1 . FIG. 2 is a cross-sectional view showing a main part of FIG. 1 . FIG. 2 is an exploded perspective view showing a main part of FIG. 1 . FIG. 4 is a perspective view of a rotating cam as viewed from the pusher side. 4 is a perspective view of the rotating cam as viewed from the rotating portion side. FIG. 11 is a perspective view of the rotating portion as viewed from the rotating cam side. FIG. FIG. 4 is a side view of the rotating cam as viewed from the pusher side. FIG. FIG. 4 is a front view of the grip when in a neutral position. 1 is a front view showing a main part of a steering wheel when a grip portion is rotated forward from a neutral position by a maximum rotation angle. FIG. 12 is a side view of the rotating cam in FIG. 11 as viewed from the pusher side. FIG. FIG. 12 is a side view of FIG. 1 is a front view showing a main part of a steering handle when a grip portion is rotated from a neutral position toward the rear by a maximum rotation angle. FIG. 15 is a side view of the rotating cam in FIG. 14 as viewed from the pusher side. FIG. FIG. 15 is a side view of FIG. FIG. 11 is a cross-sectional view showing a main part of a framework of a steering wheel according to a modified example. FIG. 11 is a cross-sectional view showing a main part of a framework of a steering wheel according to another modified example. FIG. 11 is a perspective view of a rotating cam according to a modified example. FIG. 13 is a perspective view of a rotating cam according to another modified example.

Hereinafter, an embodiment of a steering wheel used in a steering device of a vehicle to which a steer-by-wire system is applied will be described with reference to the drawings.
A steer-by-wire system is a system in which steering is performed via an actuator using an electric signal rather than a mechanical connection. In a vehicle to which this system is applied, the steering wheel may be rotated around the steering shaft by a large amount, for example, up to about 150°.

In the following description, the forward direction of the vehicle is referred to as the front, and the reverse direction as the rear. The up-down direction refers to the up-down direction of the vehicle, and the left-right direction refers to the vehicle width direction (the width direction of the vehicle), which coincides with the left-right direction when the vehicle is moving forward.

As shown in FIG. 1, a steering device 10 is provided in front of the driver's seat inside a vehicle, which is an example of a vehicle, and is operated by a driver (not shown) when steering the vehicle. The steering device 10 includes a steering shaft 11 having a first axis L1 and a steering handle 12. The steering shaft 11 is configured to be rotatable in both forward and reverse directions about the first axis L1. The steering shaft 11 is disposed at an angle relative to the front-to-rear direction of the vehicle so that it is higher toward the rear.

In this embodiment, when describing each part of the steering wheel 12, the first axis L1 is used as a reference. The direction along this first axis L1 is simply referred to as the "forward/rearward direction." Additionally, the forward direction along the first axis L1 is simply referred to as the "forward" or "front," and the rearward direction along the first axis L1 is simply referred to as the "rear" or "rear."

1 shows only the framework of the steering wheel 12. The steering wheel 12 includes a boss portion 13, a pair of spoke portions 14, and a pair of grip portions 15.
<Boss portion 13>
As shown in Fig. 1, the boss portion 13 includes a cylindrical portion 16 and a case portion 17. The cylindrical portion 16 is attached to the rear end portion of the steering shaft 11 so as to be integrally rotatable therewith. The case portion 17 includes a front wall 18, a lower wall 19, a right wall 20, and a left wall 21. The front wall 18 of the case portion 17 is fixed to the rear end portion of the cylindrical portion 16. For example, an airbag device (not shown) is accommodated inside the case portion 17.

<Spoke portion 14>
1 and 2, each of the pair of spoke portions 14 is formed by a shaft having a second axis L2. The base ends of both spoke portions 14 are supported by the left wall 21 and the right wall 20 of the case portion 17, respectively. In this case, when the vehicle is traveling straight, both second axes L2 extend in opposite directions in the left-right direction from the boss portion 13. In other words, both second axes L2 extend radially from the boss portion 13 to both sides in the left-right direction.

Note that the "radially extending state" here includes a state in which the wheels extend along a plane perpendicular to the first axis L1, as well as a state in which the wheels extend along a plane that intersects the first axis L1 at a nearly perpendicular angle. For example, the "radially extending state" includes a state in which the wheels extend along a plane that intersects the first axis L1 at a nearly perpendicular angle, so that the wheels get closer to the driver as they move away from the first axis L1 radially outward.

The pair of spokes 14 are shaped to be plane-symmetrical with respect to the first axis L1, so only the right spoke 14 will be described here.
1 and 4 , a portion of the spoke portion 14 is formed by a cylindrical general portion 22. A portion of the spoke portion 14 that is farther from the first axis L1 than the general portion 22 is formed by a first shank portion 23 and a second shank portion 24, each of which has a cylindrical shape smaller in outer diameter than the general portion 22.

The outer diameter of the first shaft portion 23 is larger than the outer diameter of the second shaft portion 24. A screw hole 24a is formed in the tip surface of the second shaft portion 24. A flat portion 23a is formed on part of the peripheral surface of the tip portion of the first shaft portion 23. In other words, the tip portion of the first shaft portion 23 is D-shaped in cross section.

A protrusion 25 having a D-shaped cross section is formed in the center of the end face of the general portion 22 on the first axis L1 side. The protrusion 25 constitutes the base end of the spoke portion 14. The protrusion 25 is formed in the right wall 20 of the case portion 17 and is fixed in a state where it is fitted into a D-shaped through hole (not shown) that corresponds to the protrusion 25. Therefore, the spoke portion 14 is fixed to the right wall 20 of the case portion 17 in a state where it does not rotate around the second axis L2 at the protrusion 25.

<Grip portion 15>
1 and 3, the pair of grip portions 15 are gripped by the driver's hands and are shaped to be plane-symmetrical with respect to each other across the first axis L1. Each grip portion 15 is provided to cover the first shaft portion 23 and the second shaft portion 24 with respect to the spoke portion 14. Each grip portion 15 is provided to be rotatable in both forward and reverse directions with respect to the spoke portion 14 about the second axis L2. In other words, each grip portion 15 is configured to be rotatable in both forward and reverse directions around the spoke portion 14 with the non-rotating spoke portion 14 as the rotation center.

As shown in Figures 2 and 10, the position of each gripping portion 15 around the second axis L2 when the vehicle is traveling straight is defined as the "neutral position." The direction in which the portion of each gripping portion 15 above the second axis L2 in Figure 2 rotates toward the driver is defined as the "forward direction." The direction in which the portion of each gripping portion 15 above the second axis L2 in Figure 2 rotates away from the driver is defined as the "rearward direction."

As shown in Figures 2 and 3, a rotation control mechanism 26 is provided within each gripping portion 15. That is, each gripping portion 15 is provided with an accommodation recess 27 that accommodates the rotation control mechanism 26 attached to the first shaft portion 23 and the second shaft portion 24 of the spoke portion 14. The accommodation recess 27 extends along the second axis L2 and has a substantially hexagonal shape when viewed from the case portion 17 side. The structures of the rotation control mechanisms 26 are plane-symmetrical with respect to each other across the first axis L1. For this reason, only the right-side rotation control mechanism 26 will be described here.

<Rotation control mechanism 26>
The rotation control mechanism 26 has the following three functions (see FIG. 8).
The maximum rotation angle θ2 of the grip portion 15 from the neutral position toward the front is specified.

The maximum rotation angle θ1 of the grip portion 15 in the rear direction from the neutral position is specified.
The grip portion 15 is returned to the neutral position when the vehicle is traveling straight.
2 to 4, the rotation control mechanism 26 includes a plurality of components arranged in order from the tip end (the side farther from the case portion 17) of the spoke portion 14 toward the base end (the side closer to the case portion 17) as follows. That is, the rotation control mechanism 26 includes, as its main components, a rotating portion 28, a rotating cam 29, a pusher 30, a coil spring 31, and a support portion 32. Next, each of the components constituting the rotation control mechanism 26 will be described. Note that the base end and tip end sides of each of the components constituting the rotation control mechanism 26 correspond to the tip end and base end sides of the spoke portion 14.

<Rotating portion 28>
As shown in Figures 3, 4 and 7, the rotating part 28 is cylindrical with a circular hole 33 in the center. The contour of the rotating part 28 when viewed from the second axis L2 direction is a substantially hexagonal shape corresponding to the accommodation recess 27 of the grip part 15. An annular protrusion 34 surrounding the hole 33 is provided on the end face on the base end side of the rotating part 28. Planar parts 34a are formed by making the outer surface of the peripheral wall flat at two locations facing each other across the center of the peripheral wall constituting the protrusion 34. Therefore, the contour of the protrusion 34 when viewed from the second axis L2 direction is non-circular.

A first bearing 35 and a second bearing 36 are fitted into both ends of the hole 33 of the rotating part 28. The base end face of the first bearing 35 located on the base end side is flush with the end face of the protrusion 34. The tip end face of the second bearing 36 located on the tip end side is flush with the tip end face of the rotating part 28 and the end face of the second shaft part 24 inserted into the hole 33.

The first bearing 35 and the second bearing 36 have the same configuration. Each bearing 35, 36 has an annular outer ring 37, an annular inner ring 38, and a number of rolling elements 39 arranged between the outer ring 37 and the inner ring 38. The rolling elements 39 are balls or rollers. A bolt 41 is screwed into the threaded hole 24a of the second shaft portion 24 via a washer 40.

The outer diameter of the washer 40 is approximately the same as the outer diameter of the inner ring 38 of the second bearing 36. Therefore, the inner ring 38 of the second bearing 36 is held down by the washer 40, so that it does not come out of the hole 33 of the rotating part 28. The hole 33 of the rotating part 28 is formed with a first step surface 42 against which the tip end of the outer ring 37 of the first bearing 35 abuts, and a second step surface 43 against which the base end of the outer ring 37 of the second bearing 36 abuts.

The first step surface 42 and the second step surface 43 respectively position the first bearing 35 and the second bearing 36 in the direction of the second axis L2. The inner ring 38 of each bearing 35, 36 is fitted into the second shaft portion 24 of the spoke portion 14. The outer ring 37 of each bearing 35, 36 is fitted into the hole 33 of the rotating portion 28.

A stepped screw hole 44 is formed in the gripping portion 15 at a position corresponding to the rotating portion 28, penetrating the inside and outside of the gripping portion 15. The stepped screw hole 44 extends so as to be approximately perpendicular to the second axis L2. A bolt 45 is screwed into the stepped screw hole 44 from the outside of the gripping portion 15. By tightening the bolt 45, the rotating portion 28 is pressed by the bolt 45 in a direction approximately perpendicular to the second axis L2, and is pressed against the side of the storage recess 27.

As a result, the rotating part 28 is clamped between the inner surface of the storage recess 27 and the bolt 45, so that the rotating part 28 does not come out of the storage recess 27. Therefore, the rotating part 28 rotates together with the grip part 15 around the second axis L2.

After the bolt 45 is tightened, the blind member 46 is fitted into the stepped screw hole 44 from above the bolt 45, making the bolt 45 invisible from the outside. If it is desired to allow the rotating part 28 to be removed from the accommodation recess 27, the blind member 46 can be removed from the stepped screw hole 44 and then the bolt 45 can be loosened. The blind member 46 is made of, for example, an elastomer.

<Rotating cam 29>
3 to 6, the rotating cam 29 has a circular insertion hole 47 extending in a direction along the second axis L2 and has an overall annular shape. The second shaft portion 24 is inserted into the insertion hole 47. With this insertion, the rotating cam 29 is rotatably supported by the second shaft portion 24. A recess 48 having a shape corresponding to the outline of the protrusion 34 of the rotating portion 28 is formed on the surface of the tip side of the rotating cam 29.

Two flat surfaces 48a corresponding to the two flat surfaces 34a of the protrusion 34 are formed on the circumferential surface of the recess 48. The protrusion 34 is inserted into the recess 48 so that the two flat surfaces 48a face the two flat surfaces 34a of the protrusion 34 of the rotating part 28, respectively. This type of insertion connects the rotating part 28 and the rotating cam 29 so that they can rotate together. Therefore, the rotating cam 29 rotates together with the rotating part 28 around the second axis L2 as the gripping part 15 rotates.

As shown in Figures 5, 8 and 9, the rotating cam 29 has a cam surface 49 on the base end surface (the surface closer to the case portion 17), which is an example of one of the two surfaces in the direction along the second axis L2. The cam surface 49 is formed over the entire circumference of the rotating cam 29. The cam surface 49 has two sets of combinations of inclined surfaces 50, 51. The inclined surfaces 50, 51 in each set are formed in an area of half the angle (180°) around the second axis L2. The inclined surfaces 50, 51 each have an arc shape that bulges outward in the radial direction of the rotating cam 29.

The inclined surface 50 in each set is the surface that contacts the contact portion 56 of the pusher body 53 (described later) when the gripping portion 15 is rotated toward the front. The inclined surface 51 in each set is the surface that contacts the contact portion 56 when the gripping portion 15 is rotated toward the rear. The inclined surfaces 50, 51 in each set are inclined in opposite directions with respect to the plane P1 perpendicular to the second axis L2.

The inclination angles of the inclined surfaces 50, 51 are set to be the same regardless of the position around the second axis L2. In other words, each inclined surface 50, 51 is inclined at a single angle with respect to the plane P1. The inclination angles that the inclined surfaces 50, 51 in each set make with respect to the plane P1 are set to be the same. The inclined surfaces 50, 51 in each set are adjacent to each other around the second axis L2.

The inclined surfaces 50, 51 are connected to each other via a boundary portion 52 at the end on the tip side (the side farther from the case portion 17). Each boundary portion 52 is located at the position furthest from the case portion 17 on each inclined surface 50, 51 in the direction along the second axis L2. As each inclined surface 50, 51 moves away from the boundary portion 52 around the second axis L2, it moves away from the rotating portion 28 in the direction along the second axis L2. The inclined surfaces 50 in one set and the inclined surfaces 51 in the other set are adjacent to each other around the second axis L2.

<Pusher 30>
As shown in Figures 3, 4 and 9, the pusher 30 includes a pusher body 53 and a holding portion 54. The pusher body 53 has an insertion hole 55 extending in a direction along the second axis L2 and is generally annular. The pusher body 53 is made of a synthetic resin such as polyacetal (POM). Most of the insertion hole 55 is curved in an arc shape centered on the second axis L2. The insertion hole 55 has a flat portion 55a in part. In other words, the insertion hole 55 is D-shaped.

The first shaft portion 23 is inserted into the insertion hole 55 so that its flat surface portion 23a faces the flat surface portion 55a of the insertion hole 55 of the pusher body 53. By inserting in this manner, the pusher body 53 is attached to the first shaft portion 23 (spoke portion 14) so as to be non-rotatable. In this case, the pusher body 53 is attached to the first shaft portion 23 so as to be slidable in the direction along the second axis line L2 while its rotation is restricted.

The pusher body 53 has a pair of contact portions 56. The pair of contact portions 56 are located at positions on the pusher body 53 facing each other across the second axis L2. Each contact portion 56 protrudes toward the rotating cam 29 along the second axis L2. The tip surface of each contact portion 56 is spherical. Each contact portion 56 contacts the cam surface 49 of the rotating cam 29 at its spherical tip surface. Each contact portion 56 contacts the boundary portion 52 of the cam surface 49 of the rotating cam 29 when the vehicle is traveling straight.

<Holding portion 54>
3 and 4, the holding portion 54 is made of a synthetic resin such as polyacetal (POM). The holding portion 54 includes a cylindrical main body 57 and an annular flange 58 that is provided at the tip of the main body 57 and has an outer diameter larger than that of the main body 57. The first shaft 23 is inserted into the holding portion 54.

That is, the holding portion 54 is attached to the first shaft portion 23 so as to be slidable in a direction along the second axis L2 while being permitted to rotate. The outer diameter of the flange portion 58 is the same as the outer diameter of the pusher body 53. The flange portion 58 is in contact with the base end surface of the pusher body 53.

<Coil spring 31>
3 and 4, the coil spring 31 is made of metal. The first shaft portion 23 and the main body portion 57 of the holding portion 54 are inserted into the coil spring 31. The coil spring 31 is disposed outside the pusher 30. In other words, the coil spring 31 is disposed outside the pusher main body 53 and radially outside the main body portion 57 of the holding portion 54. In this case, the main body portion 57 of the holding portion 54 holds the position of the coil spring 31 such that the central axis of the coil spring 31 coincides with the second axis L2.

As a result, the center line of the spirally wound wire that forms the coil spring 31 and the center line of the pair of contact portions 56 of the pusher body 53 are perpendicular to each other. In other words, the spirally wound wire that forms the coil spring 31 and the pair of contact portions 56 face each other in the direction in which the second axis L2 extends.

A circular inclusion 59 is interposed between the tip of the coil spring 31 and the flange portion 58 of the holding portion 54. The inclusion 59 is made of a non-metallic material such as rubber or synthetic resin. The main body portion 57 of the holding portion 54 is inserted into the inclusion 59. The entire surface of the inclusion 59 is embossed.

The tip of the coil spring 31 is in contact with the intermediate member 59. The coil spring 31 is configured to be able to bias the pusher 30 toward the rotating cam 29 via the intermediate member 59. In other words, the coil spring 31 is configured to be able to bias the pusher body 53 toward the rotating cam 29 via the intermediate member 59 and the flange portion 58 of the holding portion 54.

<Support portion 32>
3 and 4, the support portion 32 is configured by a metal flanged washer. That is, the support portion 32 includes a cylindrical washer portion 60 and an annular flange portion 61 that is provided at the base end of the washer portion 60 and has an outer diameter larger than that of the washer portion 60. The first shaft portion 23 is inserted into the support portion 32. The outer diameter of the washer portion 60 is the same as the outer diameter of the main body portion 57 of the holding portion 54.

A circular inclusion 62 is interposed between the base end of the coil spring 31 and the flange portion 61 of the support portion 32. This inclusion 62 has exactly the same configuration as the inclusion 59 described above. The washer portion 60 of the support portion 32 is inserted into the inclusion 62. The step between the washer portion 60 and the flange portion 61 is the same as the thickness of the inclusion 62. Therefore, the end face on the tip side of the washer portion 60 and the surface on the tip side of the inclusion 62 are flush with each other.

The base end of the coil spring 31 is in contact with the inclusion 62. A gap is formed between the washer portion 60 of the support portion 32 and the main body portion 57 of the retaining portion 54. The base end surface of the support portion 32 is in contact with the tip end surface of the general portion 22 of the spoke portion 14. The support portion 32 supports the coil spring 31 from the side opposite the pusher 30 via the inclusion 62.

The rotation control mechanism 26 further includes a regulating section that determines the maximum rotation angles θ1 and θ2 in the forward and reverse directions of the gripping section 15 when it is in the neutral position. The regulating section is made up of a first regulating section 63 and a second regulating section 64.

<First restriction portion 63>
3 and 14 to 16, the first restricting portion 63 has a function of defining a maximum rotation angle θ1 when the gripping portion 15 is rotated in the rear direction from the neutral position. The first restricting portion 63 realizes the above function by restricting the sliding of the holding portion 54.

The first restricting portion 63 is composed of the main body portion 57 of the holding portion 54 and the washer portion 60 of the support portion 32. The first restricting portion 63 restricts the sliding of the holding portion 54 in the direction toward the support portion 32 by contacting the main body portion 57 with the washer portion 60 as the holding portion 54 slides in that direction. By restricting the sliding of the holding portion 54, the first restricting portion 63 restricts the gripping portion 15 from rotating in the depth direction beyond the maximum rotation angle θ1. In this case, there is no gap between the washer portion 60 of the support portion 32 and the main body portion 57 of the holding portion 54.

<Second restriction portion 64>
11 to 13, the second restricting portion 64 has a function of defining a maximum rotation angle θ2 when the grip portion 15 is rotated toward the user from the neutral position. The second restricting portion 64 realizes the above function by restricting the rotation of the rotating cam 29 toward the user.

As shown in Figures 5, 8 and 9, the second regulating portion 64 has two flat regulating wall surfaces 65 formed on the rotating cam 29. Each regulating wall surface 65 starts from the edge of each set of inclined surfaces 50 opposite the boundary portion 52 and extends along the second axis L2 toward the side away from the rotating portion 28. In this embodiment, in which two sets of inclined surfaces 50, 51 are provided and the inclined surfaces 50 of one set are adjacent to the inclined surfaces 51 of the other set, the regulating wall surface 65 is formed by the surface between the inclined surfaces 50 of one set and the inclined surfaces 51 of the other set.

As shown in FIG. 12, the second restricting portion 64 restricts the gripping portion 15 from rotating toward the front beyond the maximum rotation angle θ2 by contacting each restricting wall surface 65 with the corresponding contact portion 56 as the rotating cam 29 rotates.

Furthermore, as shown in FIG. 8, the maximum rotation angle θ1 of the gripping portion 15 in the rear direction restricted by the first restricting portion 63 is set to be larger than the maximum rotation angle θ2 of the gripping portion 15 in the front direction restricted by the second restricting portion 64. In this embodiment, the maximum rotation angle θ1 is set to approximately 130° and the maximum rotation angle θ2 is set to approximately 50°, but the maximum rotation angles θ1 and θ2 may be changed as appropriate. Therefore, if the length of each inclined surface 50, 51 around the second axis L2 is taken as the circumferential length, the circumferential length of the inclined surface 51 is set to be longer than the circumferential length of the inclined surface 50.

As shown in Figures 1 and 4, the rotation control mechanism 26 having the above-mentioned configuration includes the support 32, coil spring 31, pusher 30, and rotating cam 29, which constitute the rotation torque generating mechanism 66. The rotation torque generating mechanism 66 has the function of generating rotation torque acting on the gripping portion 15 when the gripping portion 15 is rotated in the forward and reverse directions around the second axis L2.

As shown in Figures 8 and 9, the rotational torque generating mechanism 66 minimizes the rotational torque when the gripping portion 15 is in the neutral position, i.e., when the contact portion 56 contacts the boundary portion 52. When the gripping portion 15 is rotated in the rearward direction, the rotational torque generating mechanism 66 gradually increases the rotational torque as the rotation angle from the neutral position increases, i.e., as the contact position of the inclined surface 51 with the contact portion 56 moves away from the boundary portion 52. Then, as shown in Figures 14 to 16, the rotational torque generating mechanism 66 maximizes the rotational torque when the gripping portion 15 is rotated in the rearward direction by the maximum rotational angle θ1, i.e., when the rotation is restricted by the first restricting portion 63.

As shown in Figures 8 and 9, when the grip portion 15 is rotated toward the user, the rotational torque generating mechanism 66 gradually increases the rotational torque as the rotation angle from the neutral position increases, i.e., as the contact position with the contact portion 56 of the inclined surface 50 moves away from the boundary portion 52. Then, as shown in Figures 11 to 13, the rotational torque generating mechanism 66 maximizes the rotational torque when the grip portion 15 is rotated toward the user by the maximum rotational angle θ2, i.e., when the rotation is restricted by the second restricting portion 64.

The rotation torque is preferably set to have characteristics that increase in the range of 0.1 [N·m] to 1.5 [N·m] as the rotation angle increases, whether the grip portion 15 is rotated toward the user or away from the user. When the rotation torque is in the above range, the grip portion 15 is less likely to rotate with a small amount of force, and the grip portion 15 can be rotated stably. In addition, when the rotation torque is in the above range, excessive force does not need to be applied to rotate the grip portion 15, and excessive strain on the wrist can be suppressed.

<Function of the Steering Handle 12>
1 and 2, when the vehicle is traveling straight, the spoke portions 14 and the grip portions 15 are located on both the left and right sides of the case portion 17 of the boss portion 13. Also, as shown in Figures 2, 3 and 10, each grip portion 15 is located in a neutral position in the rotation direction about the second axis L2. In each rotation control mechanism 26, each contact portion 56 of the pusher body 53, which is biased toward the rotating cam 29 by the coil spring 31, is pressed against the corresponding boundary portion 52 of the cam surface 49 (see the two-dot chain lines in Figures 8 and 9).

At this time, the rotational torque acting on each grip portion 15 is at a minimum. This rotational torque is transmitted to the driver through the hand holding each grip portion 15 as a steering load when rotating each grip portion 15 around the second axis L2. The steering load felt by the driver is at a minimum.

From the above state, when the driver applies a force to each grip part 15 that tries to rotate it in either the forward or reverse direction around the first axis L1 against the above rotational torque, i.e., a force in the clockwise or counterclockwise direction, each rotation control mechanism 26 acts as follows.

As shown in FIG. 1, the force applied by the driver to each grip 15 is transmitted to the steering shaft 11 via each spoke 14 and boss 13. This transmission causes each grip 15, each spoke 14, boss 13, and steering shaft 11 to rotate around the first axis L1. This causes the steering device 10 to operate and steer the vehicle, changing the direction of travel of the vehicle.

The rotation of each grip part 15 around the first axis L1 is accompanied by forward and reverse rotation of each grip part 15 around the second axis L2 due to the structure of the wrist of the driver holding the grip part 15. In this way, because each grip part 15 rotates around the second axis L2, the driver can rotate the steering wheel 12 much more (90° or more) around the first axis L1 while holding each grip part 15, compared to a non-rotating grip part.

For example, if we look at the right-side grip 15, when the grip 15 is rotated counterclockwise around the first axis L1, as shown in Figures 11 to 13, the grip 15 is rotated toward the front against the rotational torque. In the rotation control mechanism 26, the rotating cam 29 rotates toward the front, which is the same direction as the grip 15, as the grip 15 rotates. As the rotating cam 29 rotates, the cam surface 49 rotates toward the front around the second axis L2.

As a result, the position at which the cam surface 49 contacts each contact portion 56 of the pusher body 53 changes. When the contact position of each contact portion 56 on the cam surface 49 moves from each boundary portion 52 to each inclined surface 50, a force is generated that pushes the pusher body 53 back toward the support portion 32 while elastically compressing and deforming the coil spring 31. This force causes the pusher body 53 and the holding portion 54, i.e., the pusher 30, to slide toward the support portion 32 along the second axis L2.

The above force increases as the contact position of each inclined surface 50 with each contact portion 56 moves away from each boundary portion 52 in the circumferential direction with the rotation of the rotating cam 29. In addition, when the amount of compression of the coil spring 31 increases with the rotation of the rotating cam 29, the rotation torque increases. Therefore, the rotation torque has a characteristic that changes according to the rotation angle of the grip portion 15. The steering load increases as the rotation angle of the grip portion 15 from the neutral position toward the front increases.

When the rotating cam 29 rotates by the maximum rotation angle θ2 in conjunction with the rotation of the gripper 15 around the second axis L2, each of the restricting wall surfaces 65 comes into contact with the corresponding contact portion 56 of the pusher body 53 (see FIG. 12). This contact restricts the rotating cam 29 from rotating further forward.

This prevents the grip 15 from rotating beyond the maximum rotation angle θ2. At this time, the amount of compression of the coil spring 31 is at its maximum, so the rotational torque and steering load are at their maximum. Furthermore, at this time, a gap is formed between the main body 57 of the holding part 54 and the washer part 60 of the support part 32.

On the other hand, when the right-side gripping portion 15 is rotated clockwise around the first axis L1, as shown in Figures 14 to 16, the gripping portion 15 rotates in the rearward direction against the rotational torque. In the rotation control mechanism 26, the rotating cam 29 rotates in the rearward direction, which is the same direction as the gripping portion 15, as the gripping portion 15 rotates. As the rotating cam 29 rotates, the cam surface 49 rotates in the rearward direction around the second axis L2.

As a result, the position at which the cam surface 49 contacts each contact portion 56 of the pusher body 53 changes. When the contact position of each contact portion 56 on the cam surface 49 moves from each boundary portion 52 to each inclined surface 51, a force is generated that pushes the pusher body 53 back toward the support portion 32 while elastically compressing and deforming the coil spring 31. This force causes the pusher body 53 and the holding portion 54, i.e., the pusher 30, to slide toward the support portion 32 along the second axis L2.

The above force increases as the contact position of each inclined surface 51 with each contact portion 56 moves away from each boundary portion 52 in the circumferential direction with the rotation of the rotating cam 29. In addition, when the amount of compression of the coil spring 31 increases with the rotation of the rotating cam 29, the rotation torque increases. Therefore, the rotation torque has a characteristic that changes according to the rotation angle of the grip portion 15. The steering load increases as the rotation angle of the grip portion 15 from the neutral position toward the rear increases.

When the rotating cam 29 rotates in conjunction with the rotation of the gripping portion 15 in the rearward direction, the pusher body 53 and the holding portion 54, i.e., the pusher 30, are pushed by the rotating cam 29 and approach the support portion 32. When the gripping portion 15 rotates with the rotating cam 29 through the maximum rotation angle θ1, the main body portion 57 of the holding portion 54 comes into contact with the washer portion 60 of the support portion 32. This contact restricts the rotating cam 29 from rotating further in the rearward direction. This restricts the gripping portion 15 from rotating beyond the maximum rotation angle θ1. At this time, the compression amount of the coil spring 31 is maximized, and therefore the rotational torque and steering load are maximized.

As described above, the amount of elastic compression deformation of the coil spring 31 changes each time the rotating cam 29 rotates in conjunction with the rotation of the gripping portion 15, so the coil spring 31 repeatedly expands and contracts. At this time, if the position of the coil spring 31 shifts, for example, in a direction perpendicular to the second axis L2, the biasing force of the coil spring 31 is applied unevenly to the pusher 30, and there is a risk that the pusher 30 will be deformed by the biasing force of the coil spring 31.

In this regard, in the rotation control mechanism 26 of this embodiment, the main body 57 of the holding part 54 holds the position of the coil spring 31 in a direction perpendicular to the second axis L2 so that the central axis of the coil spring 31 coincides with the second axis L2. As a result, the spirally wound wire that constitutes the coil spring 31 and the pair of contact parts 56 face each other in the direction in which the second axis L2 extends.

As a result, when the coil spring 31 biases the pusher 30 toward the rotating cam 29, the biasing force of the coil spring 31 is applied to the pusher 30 in a well-balanced and stable manner. This prevents the pusher 30 from being deformed by the biasing force of the coil spring 31.

In addition, for example, if the support portion 32 and the coil spring 31 are in direct contact with each other, repeated expansion and contraction of the coil spring 31 may cause the coil spring 31 to slip on the support portion 32, causing the position of the coil spring 31 to shift.

In this regard, in the rotation control mechanism 26 of this embodiment, a non-metallic inclusion 62 with an embossed surface is interposed between the coil spring 31 and the support portion 32. This increases the frictional force between the inclusion 62 and the coil spring 31, effectively suppressing misalignment of the coil spring 31 relative to the inclusion 62. This contributes to maintaining the position of the coil spring 31 in a direction perpendicular to the second axis L2.

According to the embodiment described above in detail, the following effects are achieved.
(1) In the steering wheel 12 , the rotation control mechanism 26 is disposed within the grip portion 15 .

With this configuration, the rotation control mechanism 26 is disposed within the grip portion 15 and not in the boss portion 13, making it invisible from the outside and not restricting the design freedom of the boss portion 13. This improves the design of the steering wheel 12 equipped with the rotation control mechanism 26.

(2) In the steering wheel 12 , the spokes 14 are fixed to the bosses 13 , and the grips 15 are rotatably attached to the spokes 14 .
According to this configuration, the spokes 14 do not rotate even when the grip portion 15 is rotated, so that electrical components such as switches and sensors that require wiring can be attached to the spokes 14 .

(3) In the rotation control mechanism 26 of the steering handle 12 , the coil spring 31 is disposed outside the pusher 30 .
According to this configuration, the coil spring 31 can be made larger without making the pusher 30 larger. Therefore, the spring constant of the coil spring 31 can be ensured while suppressing an increase in the size of the rotation control mechanism 26. Incidentally, for example, in a configuration in which the coil spring 31 is disposed inside the pusher 30, making the coil spring 31 larger requires that the pusher 30 be made larger by the amount of the increase in the coil spring 31, which results in an increase in the size of the rotation control mechanism 26.

(4) The rotation control mechanism 26 of the steering wheel 12 is provided with a holding portion 54 that holds the position of the coil spring 31 so that the central axis of the coil spring 31 coincides with the second axis L2.

With this configuration, when the coil spring 31 biases the pusher 30 toward the rotating cam 29, the biasing force of the coil spring 31 can be applied to the pusher 30 in a well-balanced manner. Therefore, it is possible to prevent the pusher 30 from being deformed by the biasing force of the coil spring 31. Incidentally, if the position of the coil spring 31 is shifted and the biasing force of the coil spring 31 is biasedly applied to the pusher 30, there is a risk that the pusher 30 will be deformed by the biasing force of the coil spring 31.

(5) The rotation control mechanism 26 of the steering handle 12 includes a support portion 32 that supports the coil spring 31 from the side opposite the pusher 30. A non-metallic inclusion 62 with an embossed surface is interposed between the coil spring 31 and the support portion 32.

With this configuration, fine irregularities are formed on the surface of the inclusion 62 with which the base end of the coil spring 31 comes into contact, increasing the coefficient of friction of the surface, making it difficult for the coil spring 31 to slide on the surface of the inclusion 62. This makes it possible to prevent the position of the coil spring 31 from shifting relative to the inclusion 62.

(Example of change)
The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other as long as they are not technically inconsistent.

- As shown in FIG. 17, the positions of the pusher body 53 and the rotating cam 29 may be interchanged in the rotation control mechanism 26. In this case, the pusher body 53 rotates together with the rotating part 28 relative to the spoke part 14 as the gripper part 15 rotates, but the rotating cam 29 is configured to slide without rotating relative to the spoke part 14.

- As shown in FIG. 18, the orientation of the rotation control mechanism 26 may be reversed. In other words, the order of the components constituting the rotation control mechanism 26 may be reversed. In this case, the rotating cam 29 rotates together with the rotating part 28 relative to the spoke part 14 as the grip part 15 rotates, but the pusher body 53 is configured to slide without rotating relative to the spoke part 14.

- As shown in FIG. 19, a U-shaped first groove 67 as an example of an engagement recess that can engage with the contact portion 56 may be formed in the boundary portion 52 of the cam surface 49 of the rotating cam 29. The first groove 67 extends in the radial direction of the rotating cam 29. The first groove 67 extends from the inner peripheral surface to the outer peripheral surface of the rotating cam 29. The width of the first groove 67 in the circumferential direction of the rotating cam 29 gradually increases toward the outer peripheral surface of the rotating cam 29. The radius of curvature of the first groove 67 in the circumferential direction of the rotating cam 29 is slightly larger than the radius of curvature of the contact portion 56 in the circumferential direction of the rotating cam 29.

In this way, when the contact portion 56 and the boundary portion 52 come into contact while the vehicle is traveling straight, the contact portion 56 engages with the first groove 67. This provides the driver with a sense of moderation when the grip portion 15 is returned to the neutral position while the vehicle is traveling straight. In addition, by engaging the contact portion 56 with the first groove 67, the position of the contact portion 56 at the boundary portion 52 is stably maintained, thereby suppressing rattling of the contact portion 56 at the boundary portion 52.

In the rotating cam 29 of FIG. 19 , the width of the first groove 67 in the circumferential direction of the rotating cam 29 may be constant over the entire first groove 67 .
20 , a V-shaped second groove 68 as an example of an engagement recess that can engage with the contact portion 56 may be formed in the boundary portion 52 of the cam surface 49 of the rotating cam 29. The second groove 68 extends in the radial direction of the rotating cam 29. The second groove 68 extends from the inner peripheral surface to the outer peripheral surface of the rotating cam 29. The width of the second groove 68 in the circumferential direction of the rotating cam 29 gradually increases toward the outer peripheral surface of the rotating cam 29.

In this way, when the contact portion 56 and the boundary portion 52 come into contact while the vehicle is traveling straight, the contact portion 56 engages with the second groove 68. This provides the driver with a sense of moderation when the grip portion 15 is returned to the neutral position while the vehicle is traveling straight. In addition, by engaging the contact portion 56 with the second groove 68, the position of the contact portion 56 at the boundary portion 52 is stably maintained, thereby suppressing rattling of the contact portion 56 at the boundary portion 52.

In the rotating cam 29 of FIG. 20 , the width of the second groove 68 in the circumferential direction of the rotating cam 29 may be constant throughout the entire second groove 68 .
19 and 20, the first groove 67 and the second groove 68 do not necessarily need to extend from the inner peripheral surface to the outer peripheral surface of the rotating cam 29. In other words, the first groove 67 and the second groove 68 may have at least one of both radial ends of the rotating cam 29 blocked. In other words, it is sufficient that the first groove 67 and the second groove 68 are formed in at least a portion of the rotating cam 29 that corresponds to the contact portion 56 in the radial direction.

The support portion 32 may be omitted. In this case, it is preferable that the outer diameter of the general portion 22 of the spoke portion 14 is larger than the outer diameter of the coil spring 31.
The inclusions 59 and 62 may be omitted.

The surfaces of the inclusions 59 and 62 do not necessarily need to be textured.
The holding portion 54 may be omitted.
The coil spring 31 does not necessarily have to be disposed outside the pusher 30. In other words, the structure of the pusher 30 may be modified to one that can accommodate the coil spring 31, and the coil spring 31 may be disposed inside the pusher 30.

The pusher 30 does not necessarily have to be made of synthetic resin. That is, the pusher 30 may be made of, for example, metal.
The pusher 30 may have a configuration in which the pusher body 53 and the holding portion 54 are integrally formed.

The step between the washer portion 60 and the flange portion 61 in the support portion 32 may be made larger than the thickness of the inclusion 62. In this way, the tip portion of the washer portion 60 is inserted into the base end portion of the coil spring 31, so that the washer portion 60 can prevent the coil spring 31 from shifting out of position.

- The steering wheel 12 may also be applied to steering wheels of steering devices in vehicles other than automobiles, such as aircraft and ships.

LIST OF SYMBOLS 10...Steering device 11...Steering shaft 12...Steering handle 13...Boss portion 14...Spoke portion 15...Grip portion 16...Cylindrical portion 17...Case portion 18...Front wall 19...Lower wall 20...Right wall 21...Left wall 22...General portion 23...First shaft portion 23a, 34a, 48a, 55a...Flat portion 24...Second shaft portion 24a...Threaded hole 25...Protruding portion 26...Rotation control mechanism 27...Accommodating recess 28...Rotating portion 29...Rotating cam 30...Pusher 31...Coil spring 32...Support portion 33...Hole 34...Protrusion 35...First bearing 36...Second bearing 37...Outer ring 38...Inner ring 39...Rolling element 40...Washer 41, 45...Bolt 42...First step surface 43...Second step surface 44...Step screw hole 46...Blinding member 47, 55...Through hole 48...Recess 49...Cam surface 50, 51...Inclined surface 52...Boundary 53...Pusher body 54...Retaining portion 56...Contact portion 57...Main body 58, 61...Flange portion 59, 62...Intermediate object 60...Washer portion 63...First restricting portion 64...Second restricting portion 65...Restricting wall surface 66...Rotational torque generating mechanism 67...First groove as an example of an engaging recess 68...Second groove as an example of an engaging recess θ1...Maximum rotation angle θ2...Maximum rotation angle L1...First axis L2...Second axis P1...Surface perpendicular to second axis L2

Claims (5)

A steering handle for use in a vehicle having a steering shaft which has a first axis and rotates in both forward and reverse directions about the first axis, the steering handle comprising: a boss portion attached to the steering shaft so as to be integrally rotatable with the steering shaft; a pair of spoke portions fixed to the boss portion and having second axes which extend from the boss portion in opposite directions in the width direction of the vehicle when the vehicle travels straight; and a pair of grip portions provided on the pair of spoke portions so as to be rotatable in both forward and reverse directions about the second axes,
A rotation control mechanism is provided in the gripping portion to return the gripping portion to the neutral position when the gripping portion moves straight ahead when the position of the gripping portion around the second axis when the gripping portion moves straight ahead is defined as a neutral position,
the rotation control mechanism includes a rotating cam attached to the spoke portion and having a cam surface on one side in a direction along the second axis, a pusher having a contact portion that contacts the cam surface, and a coil spring that biases one of the pusher and the rotating cam toward the other side,
the cam surface has a pair of inclined surfaces formed around the second axis and inclined in opposite directions relative to a plane perpendicular to the second axis, the pair of inclined surfaces are connected to each other via a boundary portion, and the contact portion and the boundary portion come into contact with each other during the straight movement,
A steering handle characterized in that the rotating cam or the pusher rotates about the second axis in association with rotation of the grip portion. The steering handle of claim 1, characterized in that the coil spring is disposed outside the pusher. The steering handle according to claim 1 or 2, characterized in that the rotation control mechanism includes a holding part that holds the position of the coil spring so that the central axis of the coil spring coincides with the second axis. the rotation control mechanism includes a support portion that supports the coil spring from a side opposite to the pusher side or the rotating cam side,
a non-metallic inclusion is interposed between the coil spring and the support portion,
4. The steering wheel according to claim 1, wherein the surface of the intermediate member is textured. The steering handle according to any one of claims 1 to 4, characterized in that an engagement recess capable of engaging with the contact portion is formed in the boundary portion of the cam surface.

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