JP7549341B2 - Cam device and steering device - Google Patents

Description

The present invention relates to a cam device and a steering device.

Automobile steering systems incorporate a steering wheel position adjustment device that allows the steering wheel to be adjusted up and down and fore and aft depending on the driver's physique and driving posture.

11 and 12 show an example of a steering device equipped with a steering wheel position adjustment device described in JP 2016-94950 A (Patent Document 1). A steering shaft 1, to the rear end of which a steering wheel is fixed, is supported rotatably inside a steering column 2. A column side bracket 4 consisting of a pair of clamped plate parts 3 is provided at the axial middle part of the steering column 2. The column side bracket 4 is clamped from both sides in the width direction by a pair of support plate parts 6 provided on a vehicle body side bracket 5 supported by the vehicle body. An adjustment rod 9 is inserted in the width direction through a column side through hole 7 that passes through each of the pair of clamped plate parts 3 in the width direction and a vehicle body side through hole 8 that passes through each of the pair of support plate parts 6 in the width direction. An anchor part 10 is provided at the base end of the adjustment rod 9, and a nut 13 is screwed to the tip end of the adjustment rod 9. A cam device 11 and an adjustment lever 12 are provided between the nut 13 and one of the support plate parts 6 (the left side in Figure 12).

The cam device 11 consists of a movable cam 14 and a fixed cam 15. The movable cam 14 is fitted and supported by the adjustment rod 9, and has a movable cam surface 16, which is a circumferentially uneven surface, on one axial side (right side in FIG. 12). The fixed cam 15 is supported on one of the support plates 6 so as not to rotate relative to it, and has a fixed cam surface 17, which is a circumferentially uneven surface, on the other axial side (left side in FIG. 12) opposite the movable cam surface 16. The adjustment lever 12 has its base fixed to the movable cam 14 so as not to rotate relative to it. The cam device 11 rotates the movable cam 14 relative to the fixed cam 15 based on the operation of the adjustment lever 12, thereby changing the rotation phase between the movable cam surface 16 and the fixed cam surface 17, thereby expanding and contracting the axial dimension. This allows the distance between the pair of support plate parts 6 to be increased or decreased, adjusting the amount of force that clamps the pair of clamped plate parts 3.

In the unlocked state, where the axial dimension of the cam device 11 is reduced and the force with which the pair of support plate parts 6 clamp the pair of clamped plate parts 3 is reduced, the position of the steering wheel can be adjusted within the range in which the adjustment rod 9 can be displaced inside the column side through hole 7 and the vehicle side through hole 8. In contrast, in the locked state, where the axial dimension of the cam device 11 is expanded and the force with which the pair of support plate parts 6 clamp the pair of clamped plate parts 3 is increased, the steering wheel can be held in the adjusted position.

JP 2016-94950 A International Publication No. 2016/114327

However, when the adjustment lever is operated to expand and contract the cam device, snagging may occur between the movable cam surface and the fixed cam surface. Such snagging can reduce the operability of the adjustment lever. Snaggling between the movable cam surface and the fixed cam surface is more likely to occur when a circumferentially protruding portion or a notch is provided on the convex portion constituting the fixed cam surface or the movable cam surface, as in the structure described in International Publication No. 2016/114327 (Patent Document 2).

The present invention has been made to solve the above problems, and aims to provide a cam device that can prevent snagging between the movable cam surface and the fixed cam surface.

The cam device of the present invention includes a movable cam and a fixed cam.
The movable cam has a movable cam surface on one axial side thereof, which is formed by alternatingly arranging movable reference surfaces and movable convex portions that protrude further toward one axial side than the movable reference surface in the circumferential direction.
The fixed side cam has a fixed side cam surface on its other axial side that faces the movable side cam surface in the axial direction, in which fixed side reference surfaces in the same number as the movable side convex portions and fixed side convex portions in the same number as the movable side reference surfaces that protrude toward the other axial direction beyond the fixed side reference surfaces are arranged alternately in the circumferential direction.
By rotating the movable side cam relative to the fixed side cam, it is possible to switch between a locked state in which the tip faces of the movable side convex portion and the fixed side convex portion are butted together to increase the axial dimension, and an unlocked state in which the movable side convex portion and the fixed side convex portion are arranged alternately in the circumferential direction to reduce the axial dimension.
Either the fixed side convex portion or the movable side convex portion (e.g., the movable side convex portion) has a protrusion portion that protrudes circumferentially on the radially inner part of a circumferential first side portion, which is the side on which the other of the fixed side convex portion or the movable side convex portion (e.g., the fixed side convex portion) rides on when switching from the unlocked state to the locked state.
The protruding portion has a substantially triangular chamfered surface at a radially outer end of a connection portion that connects the side surface on the first circumferential side and the tip surface.
The chamfered surface is inclined in a direction such that the circumferential width increases toward the radially outer side and the axial height decreases toward the first circumferential side.

When the chamfered surface is provided on the movable side convex portion, the chamfered surface can be provided on at least one movable side convex portion, or on all movable side convex portions. When the chamfered surface is provided on the fixed side convex portion, the chamfered surface can be provided on at least one fixed side convex portion, or on all fixed side convex portions.

In one aspect of the cam device of the present invention, the ridge of the connection portion connecting the side surface on the first circumferential side and the tip surface of the one of the convex portions located radially outward from the protruding portion can be arranged in the radial direction.

The steering device of the present invention includes a steering column, a column side bracket, a column side through hole, a vehicle body side bracket, a pair of vehicle body side through holes, an adjustment rod, a cam device, and an adjustment lever.
The steering column rotatably supports, on the inside, a steering shaft having a steering wheel fixed to its rear end.
The column side bracket is provided at a portion of the steering column in the axial direction.
The column-side through-hole is provided so as to penetrate the column-side bracket in the width direction.
The vehicle body side bracket has a pair of support plate portions arranged to sandwich the column side bracket from both sides in the width direction, and is supported by the vehicle body.
The pair of vehicle body side through holes are provided so as to penetrate each of the pair of support plate portions in the width direction.
The adjustment rod is inserted in the width direction through the column side through hole and the pair of vehicle body side through holes.
The cam device has a movable cam that is externally supported on the adjustment rod, and a fixed cam that is non-rotatably supported on one of the pair of support plate portions, and the axial dimension is expanded or contracted by rotating the movable cam relative to the fixed cam.
The adjustment lever is fixed to the movable cam and rotates the movable cam.
In the steering device according to one aspect of the present invention, the cam device is the cam device according to one aspect of the present invention.

The cam device of the present invention can prevent snagging between the movable cam surface and the fixed cam surface.

FIG. 1 is a side view of a steering device showing an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line II of FIG. 3A and 3B are views showing the movable cam, in which FIG. 3A is a front view seen from one side in the width direction, and FIG. 3B is a perspective view. 4A and 4B are views showing the fixed cam, in which (A) is a front view seen from the other side in the width direction, and (B) is a perspective view. FIG. 5 is a partially enlarged view of FIG. FIG. 6 is a partially enlarged view of FIG. Figure 7 shows the cam device taken out, where (A)-(X) is a side view of the cam device in the unlocked state as seen from the radial outside, (A)-(Y) is a front view of the cam device in the unlocked state as seen from the other widthwise side, (B)-(X) is a side view of the cam device in the locked state as seen from the radial outside, and (B)-(Y) is a front view of the cam device in the locked state as seen from the other widthwise side. 8A and 8B are perspective views showing the cam device, in which (A) shows the unlocked state and (B) shows the locked state. FIG. 9 is a diagram showing a comparative example of the structure of the movable cam, and corresponds to FIG. FIG. 10 is a schematic diagram showing a state in which the cam device is in an unlocked state and the adjustment lever is tilted. FIG. 11 is a side view showing a steering device equipped with a cam device of a conventional structure. FIG. 12 is a cross-sectional view taken along line II-II of FIG.

[One Example of the Embodiment]
An example of an embodiment will be described with reference to Figures 1 to 10. In this example, the cam device of the present invention is applied to a steering device. In the following description, the front-rear direction means the front-rear direction of the vehicle body to which the steering device is attached, the up-down direction means the up-down direction of the vehicle body, and the width direction means the width direction of the vehicle body.

Overall structure of the steering device
The steering device of this example is equipped with a position adjustment mechanism (tilt mechanism and telescopic mechanism) for adjusting the vertical position and the front-rear position of the steering wheel according to the driver's physique and driving posture. The steering device includes a steering shaft 1a, a steering column 2a, a column side bracket 4a, a vehicle body side bracket 5a, a cam device 11a, and an adjustment lever 12a.

The steering shaft 1a is supported rotatably inside the steering column 2a, which is supported on the vehicle body. A steering wheel is fixed to the rear end of the steering shaft 1a. The front end of the steering shaft 1a is connected to the pinion shaft of the steering gear unit via a universal joint and an intermediate shaft. With this configuration, the rotation of the steering wheel is transmitted to the pinion shaft, and a pair of tie rods are pushed and pulled in accordance with the rotation of the pinion shaft, thereby applying a steering angle to the steered wheels.

The steering shaft 1a is configured to combine an inner shaft 18 located at the front and an outer shaft 19 located at the rear, which are splined for example to enable torque transmission and expansion/contraction, in order to allow the fore-aft position of the steering wheel to be adjusted. The inner shaft 18 and the outer shaft 19 are each made of a metal such as an iron alloy or an aluminum alloy.

The steering column 2a has a generally cylindrical shape and is supported by the vehicle body. In order to allow the fore-aft position of the steering wheel to be adjusted, the steering column 2a is configured such that the rear end of the inner column 20 located at the front is loosely fitted with the front end of the outer column 21 located at the rear to allow relative displacement in the axial direction, making the entire length extendable. The inner column 20 and the outer column 21 are each made of a metal such as an iron alloy or an aluminum alloy.

The steering column 2a supports a gear housing 22 fixed to the front end of the steering column 2a so that it can swing relative to the vehicle body around a tilt shaft 23 arranged in the width direction, allowing the vertical position of the steering wheel to be adjusted. A worm reduction gear is housed inside the gear housing 22, and the worm reduction gear increases the torque of an electric motor 24 fixed to the gear housing 22 and transmits it to the steering shaft 1a.

The steering device of this example allows the vertical position of the steering wheel to be adjusted based on the swinging displacement of the steering column 2a around the tilt axis 23, and also allows the front-rear position of the steering wheel to be adjusted by making the steering shaft 1a and the steering column 2a each have an extendable structure. In order to hold the steering wheel in the adjusted position, a column side bracket 4a is provided at the axial middle of the steering column 2a, and a vehicle side bracket 5a is supported on the vehicle body.

The column side bracket 4a is provided integrally with the outer column 21 at the top of the front end of the outer column 21 and is composed of a pair of clamped plate parts 3a arranged at a distance in the width direction. The pair of clamped plate parts 3a are configured in a substantially flat plate shape, and each clamped plate part 3a has a column side through hole 7a penetrating in the width direction. The column side through hole 7a is an elongated hole extending in the axial direction (front-rear direction) of the outer column 21. A spacer 25 made of synthetic resin is attached to the column side through hole 7a. The outer column 21 has a slit 26 extending in the axial direction between the base ends (lower ends) of the pair of clamped plate parts 3a. This makes it possible to elastically expand and contract the inner diameter of the front end of the outer column 21. Note that if no telescopic mechanism is provided, the column side through hole is simply a circular hole.

The vehicle body side bracket 5a is made of a metal plate having sufficient rigidity, such as steel or an aluminum alloy, and includes a top plate portion 27 and a pair of support plate portions 6a. The top plate portion 27 is configured in a flat plate shape and is normally supported by the vehicle body, but in the event of a secondary collision, it detaches forward, allowing the outer column 21 to be displaced forward. For this reason, the top plate portion 27 has a pair of locking notches that open to the rear end edge, and a locking capsule 28 fixed to the vehicle body is releasably locked to each of the pair of locking notches.

The pair of support plate portions 6a are arranged substantially parallel to each other and spaced apart in the width direction, and the upper ends of each are fixed to the underside of the top plate portion 27 by welding or the like. The pair of support plate portions 6a are arranged on the widthwise outer sides of the pair of clamped plate portions 3a so as to sandwich the column side bracket 4a from both sides in the width direction. Each of the pair of support plate portions 6a has a vehicle body side through hole 8a that penetrates in the width direction. The vehicle body side through hole 8a is an elongated hole that extends in the vertical direction and curves in an arc shape around the tilt axis 23. Note that if no tilt mechanism is provided, the vehicle body side through hole is simply a circular hole.

In order to make it possible to adjust the force with which the pair of support plate portions 6a fasten the pair of clamped plate portions 3a, an adjustment rod 9a is arranged to pass through each of the column side through holes 7a and the vehicle body side through holes 8a in the width direction. The adjustment rod 9a has a total length longer than the distance between the pair of support plate portions 6a. The adjustment rod 9a has a male threaded portion 29 at its tip end (end on one side in the width direction, end on the right side in FIG. 2) and a head-like anchor portion 10a at its base end (end on the other side in the width direction, end on the left side in FIG. 2). A nut 13a is screwed onto the male threaded portion 29.

A thrust needle bearing 30 is fitted to the portion of the adjustment rod 9a located between the nut 13a and the support plate portion 6a on one side in the width direction (right side in Fig. 2), and a cam device 11a and adjustment lever 12a are fitted to the portion located between the anchor portion 10a and the support plate portion 6a on the other side in the width direction (left side in Fig. 2). The axial dimension of the cam device 11a can be expanded or contracted based on the swing operation of the adjustment lever 12a, making it possible to adjust the force with which the pair of support plate portions 6a tighten the pair of clamped plate portions 3a. The structure of the cam device 11a will be described in detail below.

<Cam device>
The cam device 11a is composed of a movable cam 14a and a fixed cam 15a. The movable cam 14a is fitted and supported on the base end of the adjustment rod 9a, and rotates around the central axis of the adjustment rod 9a based on the swing operation of the adjustment lever 12a. The fixed cam 15a is arranged coaxially with the movable cam 14a and supported non-rotatably with respect to the support plate portion 6a on the other side in the width direction. Grease (not shown) is filled between the movable cam surface 16a of the movable cam 14a and the fixed cam surface 17a of the fixed cam 15a. When the adjustment lever 12a is swung, the rotation phase between the movable cam surface 16a and the fixed cam surface 17a changes, so that the cam device 11a can be switched between a locked state in which the axial dimension is expanded and an unlocked state in which the axial dimension is reduced. Hereinafter, the rotation direction (locking direction) of the movable cam 14a when the cam device 11a is switched to the locked state is taken to be in one circumferential direction and is indicated by arrow α in each figure, and the rotation direction (unlocking direction) of the movable cam 14a when the cam device 11a is switched to the unlocked state is taken to be in the other circumferential direction and is indicated by arrow β in each figure.

[Movable cam]
The movable cam 14a is made of sintered metal, and has a central hole 31 for inserting the adjustment rod 9a in the center, as shown in FIG. 3. The movable cam 14a is composed of a movable cam body 32 having a substantially circular ring plate shape and a movable engagement portion 33 having a substantially rectangular plate shape. The movable cam body 32 has a movable cam surface 16a, which is a circumferentially uneven surface, on a side surface on one axial side (one width direction side, right side in FIG. 2, front side in FIG. 3A). The movable engagement portion 33 is a portion that fits the base 63 of the adjustment lever 12a, and is provided on a side surface on the other axial side (other width direction side, left side in FIG. 2) of the movable cam body 32. In this example, the movable engagement portion 33 has a substantially rectangular end face shape when viewed from the other axial side. However, the end face shape of the movable engagement portion 33 is not limited to a substantially rectangular shape, and is not particularly limited as long as it has a shape that can be non-circularly fitted into a mounting hole 64 of the adjustment lever 12a described later.

The movable side cam surface 16a is composed of flat movable side reference surfaces 34a, 34b and movable side protrusions 35a, 35b that protrude from the movable side reference surfaces 34a, 34b to one side in the axial direction, which are arranged alternately in the circumferential direction. In this example, there are four movable side reference surfaces 34a, 34b and four movable side protrusions 35a, 35b, but the number of movable side reference surfaces and movable side protrusions is not limited to four as long as there is more than one.

Each of the movable side reference surfaces 34a, 34b is a flat surface existing on a virtual plane perpendicular to the central axis of the movable side cam 14a, and has a fan shape when viewed in the axial direction. In this example, of the four movable side reference surfaces 34a, 34b, the circumferential width of the movable side reference surfaces 34a existing at two diametrically opposite locations is wider than the circumferential width of the remaining two movable side reference surfaces 34b. In other words, the movable side reference surface 34a with a wider circumferential width (larger central angle) and the movable side reference surface 34b with a narrower circumferential width (smaller central angle) are alternately arranged at a distance in the circumferential direction. The outer diameter of the movable side reference surface 34a and the outer diameter of the movable side reference surface 34b are the same.

Each of the movable side protrusions 35a, 35b has a tip surface 36a, 36b that exists on an imaginary plane perpendicular to the central axis of the movable side cam 14a. The movable side protrusions 35a, 35b have a substantially trapezoidal cross-sectional shape with respect to the imaginary plane perpendicular to the radial direction of the movable side cam 14a.

In this example, of the four movable side protrusions 35a, 35b, the circumferential width of the movable side protrusions 35a present at two diametrically opposite locations is wider than the circumferential width of the remaining two movable side protrusions 35b. That is, the movable side protrusions 35a with a wider circumferential width (larger central angle) and the movable side protrusions 35b with a narrower circumferential width (smaller central angle) are alternately arranged at a distance in the circumferential direction. The movable side protrusions 35a, 35b and the movable side reference surfaces 34a, 34b are arranged in one circumferential direction in the following order: movable side protrusion 35a → movable side reference surface 34a → movable side protrusion 35b → movable side reference surface 34b → movable side protrusion 35a → ....

Each of the movable side protrusions 35a, 35b has a protrusion 37a, 37b that protrudes further toward one side in the circumferential direction than the radially outer end in a range from the radially inner part to the middle part of one circumferential side portion. In other words, each of the movable side protrusions 35a, 35b has a notch 38a, 38b that is approximately rectangular when viewed in the axial direction at the radially outer end of one circumferential side portion. In this example, the movable side protrusions 35a, 35b correspond to one protrusion, and the fixed side protrusions 49a, 49b described later correspond to the other protrusion. Also, the one circumferential side corresponds to the first circumferential side.

The outer diameter of each of the movable side protrusions 35a, 35b at the protrusions 37a, 37b is slightly larger than the outer diameter of the movable side reference surfaces 34a, 34b, and the outer diameter of the parts other than the protrusions 37a, 37b is sufficiently larger than the outer diameter of the movable side reference surfaces 34a, 34b. Therefore, the outer diameter of the movable side cam surface 16a is not constant in the circumferential direction, and the phase in the circumferential direction is larger at the parts that match the movable side protrusions 35a, 35b, and is particularly large at the parts that match the parts other than the protrusions 37a, 37b. The parts of the movable side protrusions 35a, 35b that are located radially outward from the movable side reference surfaces 34a, 34b are connected in the circumferential direction by a thin plate-shaped connecting portion 39 that does not constitute the movable side cam surface 16a.

Each of the movable side protrusions 35a, 35b has a movable side guide slope 40a, 40b rising from the movable side reference surface 34a, 34b on the side surface on one circumferential side of the protrusions 37a, 37b. The side surface on the other circumferential side of the movable side protrusions 35a, 35b has a larger inclination angle with respect to the movable side reference surface 34a, 34b than the movable side guide slope 40a, 40b. The inclination of the side surface on the other circumferential side of the movable side protrusions 35a, 35b corresponds to the draft angle required to remove the movable side cam 14a from the mold.

The movable cam 14a has a movable stopper portion 41 on the radial outside of the movable convex portion 35a, which has a wide circumferential width. The movable stopper portion 41 is provided integrally with the movable convex portion 35a. The movable stopper portion 41 is configured in a partially cylindrical shape and protrudes to one side in the axial direction beyond the tip surface 36a of the movable convex portion 35a. The side surface on one circumferential side of the movable stopper portion 41 coincides in circumferential position with the radially outer end of the side surface on one circumferential side of the movable convex portion 35a, and the side surface on the other circumferential side of the movable stopper portion 41 coincides in circumferential position with the side surface on the other circumferential side of the movable convex portion 35a.

The protrusions 37a, 37b on the movable side protrusions 35a, 35b each have a movable side first connection portion 42a, 42b that connects the movable side guide slopes 40a, 40b to the tip surfaces 36a, 36b. The movable side first connection portions 42a, 42b have an R-chamfered portion (or corner portion) with a cross-sectional arc shape having a linear ridgeline (S1a described later) in the range from the radially inner end to the radially middle portion, while the radially outer end has a chamfered surface 43a, 43b that is a flat surface with a substantially triangular shape (isosceles triangle shape in the illustrated example).

Each of the chamfered surfaces 43a, 43b is inclined in such a direction that the circumferential width increases toward the radial outside and the axial height decreases toward one side in the circumferential direction (toward the other axial direction). Therefore, each of the overhanging portions 37a, 37b has a shape in which the radially outer corner of one side in the circumferential direction is cut into a substantially triangular pyramid shape. Also, as shown in FIG. 5, the ratio (B/A) of the radial width dimension B of the chamfered surface 43b (43a) to the radial width dimension A of the overhanging portion 37b (37a) is about 15% to 50%. Also, the apex angle θ of the chamfered surface 43b (43a) (the angle between the ridge line S1b and the ridge line S1c described later) is about 10° to 30°. In addition, the ratio (D/H) of the axial depth (drop amount) D from the tip surface 36b (36a) to the edge on one circumferential side of the chamfered surface 43b (43a) to the axial height (lift amount) H from the movable side reference surface 34b (34a) to the tip surface 36b (36a) of the protruding portion 37b (37a) is approximately 5% to 15%.

In this example, the radially outer ends of the movable side first connection parts 42a, 42b are provided with the chamfered surfaces 43a, 43b as described above, so that the ridge line (edge line) S1 of the movable side first connection part 42b (42a) is bifurcated at the radially outer end as shown in FIG. 5. In other words, the ridge line S1 is provided in a range from the radially inner part to the middle part, and is composed of a ridge line S1a arranged in the radial direction R passing through the center axis of the movable side cam 14a, a ridge line S1b that constitutes one side of the circumferential direction of the chamfered surface 43b (43a) and extends in a direction toward the other axial direction as it moves radially outward, and a ridge line S1c that constitutes the other side of the circumferential direction of the chamfered surface 43b (43a) and is inclined in a direction toward the other circumferential direction as it moves radially outward with respect to the radial direction R.

As shown in FIG. 5, the portion of the movable-side protrusion 35b (35a) that is located radially outward from the protrusion 37b (37a) has the ridge line S2 of the movable-side second connection portion 44 that connects the side surface on one circumferential side to the tip surface 36b (36a) aligned in the radial direction R that passes through the central axis of the movable-side cam 14a.

[Fixed cam]
The fixed cam 15a is made of sintered metal, and has a central hole 45 for inserting the adjustment rod 9a in the center, as shown in Fig. 4. The fixed cam 15a is composed of a fixed cam body 46 having a substantially circular plate shape and a fixed engagement portion 47 having a substantially rectangular plate shape. The fixed cam body 46 has a fixed cam surface 17a, which is a circumferentially uneven surface, on a side surface on the other axial side (the other width side, the left side in Fig. 2, the front side in Fig. 4A) facing the movable cam surface 16a. The fixed engagement portion 47 is a portion that engages with the vehicle body through hole 8a provided in the support plate portion 6a on the other width side so as not to rotate relative to the vehicle body through hole 8a and so as to be displaceable only along the vehicle body through hole 8a, and is provided on a side surface on one axial side of the fixed cam body 46.

The fixed-side cam surface 17a is formed by alternately arranging flat fixed-side reference surfaces 48a, 48b and fixed-side protrusions 49a, 49b that protrude from the fixed-side reference surfaces 48a, 48b to the other axial side. In this example, there are four fixed-side reference surfaces 48a, 48b and four fixed-side protrusions 49a, 49b, but the number of fixed-side reference surfaces and fixed-side protrusions is not limited to four as long as it is the same as the number of movable-side reference surfaces and movable-side protrusions.

The fixed-side reference surfaces 48a, 48b are flat surfaces that exist on an imaginary plane perpendicular to the central axis of the fixed-side cam 15a, and are generally L-shaped when viewed in the axial direction. The fixed-side reference surfaces 48a, 48b have a wide portion on the other circumferential side, and a narrow portion with a smaller radial width than the wide portion in the range from one circumferential side to the circumferential middle portion. In this example, the four fixed-side reference surfaces 48a, 48b have the same circumferential length (central angle) and are arranged at equal intervals in the circumferential direction.

A retraction surface 50 is provided radially inward of each of the fixed side reference surfaces 48a, 48b, which is slightly recessed toward one side of the axial direction from the fixed side reference surfaces 48a, 48b and has a roughly fan-shaped configuration when viewed in the axial direction.

Each of the fixed side protrusions 49a, 49b has a tip surface 51a, 51b that exists on an imaginary plane perpendicular to the central axis of the fixed side cam 15a, except for the portion where the tip recess 62 described later is provided. The fixed side protrusions 49a, 49b have a substantially trapezoidal cross-sectional shape with respect to the imaginary plane perpendicular to the radial direction of the fixed side cam 15a.

Of the four fixed side protrusions 49a, 49b, the outer diameter of the fixed side protrusions 49a that are located at two diametrically opposite locations is smaller than the outer diameter of the remaining two fixed side protrusions 49b. In other words, the fixed side protrusions 49a with the smaller outer diameter and the fixed side protrusions 49b with the larger outer diameter are alternately arranged at a distance in the circumferential direction.

Each of the fixed side protrusions 49a, 49b has a protrusion 52a, 52b that protrudes further toward the other circumferential direction than the radially outer end in a range from the radially inner part to the middle part of the other circumferential direction part on which the movable side protrusions 35a, 35b ride when the cam device 11a is switched from the unlocked state to the locked state. In other words, each of the fixed side protrusions 49a, 49b has a notch 53a, 53b that is approximately rectangular in axial view at the radially outer end of the other circumferential direction part.

The outer diameter of the protruding portions 52a, 52b of the fixed side convex portions 49a, 49b is approximately the same as the outer diameter of the narrow portions of the fixed side reference surfaces 48a, 48b, and the outer diameter of the portions other than the protruding portions 52a, 52b is approximately the same as the outer diameter of the wide portions of the fixed side reference surfaces 48a, 48b. Therefore, the outer diameter of the fixed side cam surface 17a is not constant in the circumferential direction.

The fixed-side protrusions 49a, 49b each have a fixed-side guide slope 54a, 54b that rises from the fixed-side reference surface 48a, 48b on the side surface on the other circumferential side of the protrusions 52a, 52b, on which the movable-side protrusions 35a, 35b ride (slide down). The side surface on one circumferential side of the fixed-side protrusions 49a, 49b has a larger inclination angle with respect to the fixed-side reference surface 48a, 48b than the fixed-side guide slope 54a, 54b. The inclination of the side surface on one circumferential side of the fixed-side protrusions 49a, 49b corresponds to the draft angle required to remove the fixed-side cam 15a from the mold.

The fixed-side cam 15a has a fixed-side first stopper portion 55 on the radial outside of the fixed-side convex portion 49a having a small outer diameter. The fixed-side first stopper portion 55 is integrally provided with the fixed-side convex portion 49a and protrudes in the other axial direction from the tip surface 51a of the fixed-side convex portion 49a. The fixed-side first stopper portion 55 is configured in a partially cylindrical shape and is arranged with a phase shift in the circumferential direction relative to the fixed-side convex portion 49a. Specifically, the other circumferential side half of the fixed-side first stopper portion 55 is arranged radially outside the one circumferential side half of the fixed-side convex portion 49a, while the one circumferential side half of the fixed-side first stopper portion 55 is arranged to protrude to one circumferential side from the fixed-side convex portion 49a. Therefore, the side surface on the other circumferential side of the fixed-side first stopper portion 55 is located on one circumferential side from the fixed-side guide slope 54a.

The fixed-side cam 15a has a fixed-side second stopper portion 56 on the radial outside of the fixed-side convex portion 49b having a large outer diameter. The fixed-side second stopper portion 56 is integrally provided with the fixed-side convex portion 49b and protrudes in the other axial direction from the tip surface 51b of the fixed-side convex portion 49b. The fixed-side second stopper portion 56 is configured in a partially cylindrical shape and is arranged with a phase shift in the circumferential direction relative to the fixed-side convex portion 49b. Specifically, the other circumferential half of the fixed-side second stopper portion 56 is arranged radially outside the one circumferential half of the fixed-side convex portion 49b, while the one circumferential half of the fixed-side second stopper portion 56 is arranged to protrude to one circumferential side from the fixed-side convex portion 49b. Therefore, the side surface on one circumferential side of the fixed side second stopper portion 56 is located on one circumferential side of the side surface on one circumferential side of the fixed side protrusion portion 49b.

The fixed side first stopper portion 55 and the fixed side second stopper portion 56, which are adjacent in the circumferential direction, are connected in the circumferential direction by a thin plate-like connecting portion 57a that does not constitute the fixed side cam surface 17a. In addition, the fixed side first stopper portion 55 and the radially outer portion of the fixed side protrusion 49b, which are adjacent in the circumferential direction, are connected in the circumferential direction by a thin plate-like connecting portion 57b that does not constitute the fixed side cam surface 17a.

The fixed-side cam 15a has side recesses 58a, 58b in the radially inner half of the side surface on the other circumferential side, where the movable-side protrusions 35a, 35b (movable-side guide slopes 40a, 40b) slide down when the cam device 11a is switched to the unlocked state, among the overhangs 52a, 52b provided on the fixed-side protrusions 49a, 49b. The side recesses 58a, 58b are recessed toward one circumferential side, and are provided in the lower portion (other circumferential side portion) with a low axial height among the side surfaces on the other circumferential side of the overhangs 52a, 52b. The side recesses 58a, 58b have a substantially rectangular shape when viewed in the circumferential direction.

The radially outer ends of the side recesses 58a, 58b and the radially outer end of the retreat surface 50 are aligned in the radial direction (located on the same concentric circle). For this reason, as shown in FIG. 6, the fixed-side first slope 54x, which constitutes the lower portion of the fixed-side guide slope 54b (54a) and is present radially outside the side recess 58b (58a) on the other circumferential side of the protrusion 52b (52a), has the same radial width as the fixed-side reference surface 48b (48a) and is provided to rise in the axial direction from the fixed-side reference surface 48b (48a).

The side surface on the other circumferential side of the overhanging portions 52a, 52b has outer diameter side recesses 59a, 59b at the radially outer end. The outer diameter side recesses 59a, 59b are recessed toward one circumferential side and are arranged in a range from the upper part with a high axial height to the middle part of the side surface on the other circumferential side of the overhanging portions 52a, 52b. Therefore, as shown in FIG. 6, the fixed side second slope 54y constituting the middle part of the fixed side guide slope 54b (54a) existing radially inside the outer diameter side recess 59b (59a) of the side surface on the other circumferential side of the overhanging portion 52b (52a) has a larger radial width than the fixed side first slope 54x and is arranged so as to overhang radially inward from the fixed side first slope 54x (offset radially inward).

In this example, the fixed side connecting portion (corner, chamfered portion) 60, which connects the other circumferential side of the portion of the fixed side convex portion 49a, 49b located radially outward from the protrusions 52a, 52b to the tip faces 51a, 51b, has the relief recesses 61a, 61b formed. As shown in FIG. 6, the ridge line S3 of the fixed side connecting portion 60 is disposed in the radial direction R passing through the central axis of the fixed side cam 15a.

The fixed side cam 15a has a tip recess 62 on the tip surfaces 51a and 51b of the fixed side convex parts 49a and 49b. The tip recess 62 is a recess recessed on one axial side and is arranged on the radial inner side of the tip surfaces 51a and 51b of the fixed side convex parts 49a and 49b. Each tip recess 62 is approximately L-shaped when viewed from the axial direction, and is arranged on the radial inner side and consists of a circumferential recess 62a extending in the circumferential direction and a radial recess 62b extending from one circumferential side portion of the circumferential recess 62a toward the radial outside. The circumferential recess 62a is provided in a range covering the entire width of the tip surfaces 51a and 51b of the fixed side convex parts 49a and 49b in the circumferential direction. The radial recess 62b is provided in a range from the radial inner side to the radial middle part of the tip surfaces 51a and 51b of the fixed side convex parts 49a and 49b. The tip recess 62 opens on both the radially inner side and the circumferential side, except the radially outer side. Therefore, the other circumferential side portion of the circumferential recess 62a opens at the radially inner end of the upper part with a higher axial height among the side surfaces of the other circumferential side of the overhanging portion 52a, 52b. Therefore, as shown in FIG. 6, the fixed side third slope 54z constituting the upper part of the fixed side guide slope 54b (54a), which exists radially outside the opening of the circumferential recess 62a among the side surfaces of the other circumferential side of the overhanging portion 52b (52a), is arranged so as to retreat radially outward from the fixed side second slope 54y (offset radially outward).

As shown in FIG. 7A and FIG. 8A, in the unlocked state in which the steering wheel position can be adjusted, the cam device 11a has the movable side protrusions 35a, 35b of the movable side cam 14a and the fixed side protrusions 49a, 49b of the fixed side cam 15a arranged alternately in the circumferential direction. As a result, the tip surfaces 36a, 36b of the movable side protrusions 35a, 35b abut against the fixed side reference surfaces 48a, 48b. In addition, the tip surfaces 51a, 51b of the fixed side protrusions 49a, 49b abut against the movable side reference surfaces 34a, 34b. As a result, the axial dimension of the cam device 11a is reduced.

When the movable cam 14a is rotated relative to the fixed cam 15a in one circumferential direction by the swing operation of the adjustment lever 12a from the unlocked state of the cam device 11a described above, the movable guide slopes 40a, 40b provided on the movable convex parts 35a, 35b are guided by and slide against the fixed guide slopes 54a, 54b provided on the fixed convex parts 49a, 49b, and ride up on the fixed guide slopes 54a, 54b. This causes the axial dimension of the cam device 11a to expand. At this time, the contact position between the movable convex parts 35a, 35b and the fixed convex parts 49a, 49b changes from the radial outside to the radial inside, and then changes from the radial inside to the radial outside, depending on the radial positions of the fixed first slope 54x, the fixed second slope 54y, and the fixed third slope 54z. After that, the radially outer halves of the tip faces 36a, 36b of the movable side convex parts 35a, 35b come into contact with the parts of the tip faces 51a, 51b of the fixed side convex parts 49a, 49b that are not in the tip recess 62. As a result, as shown in Figures 7B and 8B, the axial dimension of the cam device 11a becomes maximum, and the steering wheel is locked in the adjusted position.

On the other hand, when the movable cam 14a is rotated relative to the fixed cam 15a in the other circumferential direction by the swing operation of the adjustment lever 12a from the locked state of the cam device 11a described above, the movable guide slopes 40a, 40b provided on the movable convex parts 35a, 35b slide down the fixed guide slopes 54a, 54b provided on the fixed convex parts 49a, 49b. As a result, the axial dimension of the cam device 11a is reduced. At this time, the contact positions of the movable convex parts 35a, 35b and the fixed convex parts 49a, 49b change from the radially outer side to the radially inner side, and then change from the radially inner side to the radially outer side, depending on the radial positions of the fixed side third slope 54z, the fixed side second slope 54y, and the fixed side first slope 54x. Then, the tip surfaces 36a, 36b of the movable side convex parts 35a, 35b come into contact with the fixed side reference surfaces 48a, 48b, and the parts of the tip surfaces 51a, 51b of the fixed side convex parts 49a, 49b that are not in contact with the tip recess 62 come into contact with the movable side reference surfaces 34a, 34b.

In the locked state, after the tip surfaces 36a, 36b of the movable convex parts 35a, 35b hit against the tip surfaces 51a, 51b of the fixed convex parts 49a, 49b, as shown in FIG. 7B and FIG. 8B, the side surface on one circumferential side of the movable stopper part 41 abuts against the side surface on the other circumferential side of the fixed first stopper part 55, preventing the movable cam 14a from rotating further relative to the fixed cam 15a in one circumferential direction. On the other hand, in the unlocked state, as shown in FIG. 7A and FIG. 8A, the side surface on the other circumferential side of the movable stopper part 41 abuts against the side surface on one circumferential side of the fixed second stopper part 56, preventing the movable cam 14a from rotating further relative to the fixed cam 15a in the other circumferential direction.

The adjustment lever 12a is for rotating the movable cam 14a to change the axial dimension of the cam device 11a. The adjustment lever 12a is made of a metal plate and has a shape that is bent into an approximately crank shape, and extends rearward (toward the driver's seat) and downward toward the tip end where a grip part (not shown) is provided. A base 63 provided at the front end (upper end) of the adjustment lever 12a is provided with a substantially rectangular mounting hole 64 that penetrates in the width direction. The adjustment lever 12a is fixed to the movable cam 14a so that it cannot rotate relative to the movable cam 14a by non-circularly fitting the mounting hole 64 into the movable engagement part 33 provided on the movable cam 14a. With this configuration, it is possible to rotate the movable cam 14a relative to the fixed cam 15a by swinging the adjustment lever 12a. In the structure of this example, when the adjustment lever 12a is swung, not only the movable cam 14a but also the adjustment rod 9a rotates in sync, but it is also possible to adopt a configuration in which only the movable cam rotates (without rotating the adjustment rod).

The thrust needle bearing 30 has a pair of raceways and a number of needles. The dimensions of each part of the thrust needle bearing 30 are set so that an internal gap exists when the cam device 11a is switched from the unlocked state to the locked state. Therefore, when the cam device 11a is switched from the unlocked state to the locked state (when the movable guide slopes 40a, 40b and the fixed guide slopes 54a, 54b are in sliding contact with each other), the internal gap of the thrust needle bearing 30 gradually decreases and each needle starts to roll, and the rolling of each needle continues until the locked state is reached. Therefore, by providing the thrust needle bearing 30, the frictional force generated when the cam device 11a is switched from the unlocked state to the locked state can be reduced, and the swinging operation of the adjustment lever 12a can be made smooth.

In the steering device of this example, to adjust the vertical and front-rear positions of the steering wheel, the adjustment lever 12a is swung downward (clockwise in FIG. 1) to rotate the movable cam 14a in the other circumferential direction. Then, the movable convex parts 35a, 35b and the fixed convex parts 49a, 49b are arranged alternately in the circumferential direction to reduce the axial dimension of the cam device 11a and to set the cam device 11a in an unlocked state. This reduces (releases) the force with which the pair of support plate parts 6a clamp the pair of clamped plate parts 3a from both sides in the width direction. As a result, the vertical position of the steering wheel can be adjusted within the range in which the adjustment rod 9a can be displaced inside the vehicle body side through hole 8a, and the front-rear position of the steering wheel can be adjusted within the range in which the adjustment rod 9a can be displaced inside the column side through hole 7a.

In contrast, to hold the steering wheel in the adjusted position, after moving the steering wheel to the desired position, the adjustment lever 12a is swung upward (counterclockwise in FIG. 1) to rotate the movable cam 14a in one circumferential direction. Then, the tip faces 36a, 36b of the movable convex parts 35a, 35b and the tip faces 51a, 51b of the fixed convex parts 49a, 49a are butted against each other to expand the axial dimension of the cam device 11a and lock the cam device 11a. This increases the force with which the pair of support plate parts 6a clamps the pair of clamped plate parts 3a from both sides in the width direction. As a result, the contact pressure between the pair of support plate parts 6a and the pair of clamped plate parts 3a increases, and the contact pressure between the inner peripheral surface of the front end of the outer column 21 and the outer peripheral surface of the rear end of the inner column 20 increases, making it possible to hold the steering wheel in the adjusted position.

In particular, according to the steering device of this embodiment, it is possible to prevent the occurrence of jamming between the movable cam surface 16a and the fixed cam surface 17a.
That is, as in the structure of the comparative example shown in Fig. 9, when the ridge Sx of the movable-side first connection part 42x is arranged in the radial direction R over the entire width in the radial direction without providing a chamfered surface on the radially outer end of the protruding part 37x of the movable-side convex part 35x, the movable-side first connection part 42x is likely to be caught by the fixed-side connection part 60 of the fixed-side convex parts 49a, 49b. The reason for this is that since the ridge S3 of the fixed-side connection part 60 is also arranged in the radial direction R, when the movable-side guide slope 40x rides on the fixed-side guide slopes 54a, 54b and the axial force is applied to the cam device 11a, if the two ridges Sx, S3 arranged in the radial direction coincide with each other (the phase in the circumferential direction and the height in the axial direction coincide), the two ridges Sx, S3 are likely to be caught by each other (the edges are caught by each other).

In contrast, the movable-side protrusions 35a, 35b of this example are provided with chamfered surfaces 43a, 43b at the radially outer ends of the movable-side first connection parts 42a, 42b. Therefore, even when the movable-side guide inclined surfaces 40a, 40b ride up onto the fixed-side guide inclined surfaces 54a, 54b and the axial force of the cam device 11a is applied, the chamfered surfaces 43a, 43b (other than the ridge line S1c) provided on the movable-side first connection parts 42a, 42b and retreated to the other axial side do not come into contact with the fixed-side connection part 60. In addition, the ridge line S1c constituting the other circumferential side side of the chamfered surfaces 43a, 43b among the ridge lines S1 of the movable-side first connection parts 42a, 42b intersects with the ridge line S3 of the fixed-side connection part 60 without coinciding with each other. Therefore, the fixed-side connection portion 60 (the ridge line S3) and the movable-side first connection portions 42a, 42b (the ridge lines S1) can be prevented from getting caught. As a result, the occurrence of getting caught between the movable-side cam surface 16a and the fixed-side cam surface 17a can be suppressed, and the operability of the adjustment lever 12a can be prevented from decreasing.

In addition, in the unlocked state in which the axial dimension of the cam device 11a is reduced to adjust the position of the steering wheel, the axial force acting between the movable cam 14a and the fixed cam 15a is lost, and as shown in FIG. 10, the adjustment lever 12a is likely to tilt in the width direction due to its own weight. In this way, when the adjustment lever 12a is operated in a state in which the adjustment lever 12a is tilted in the width direction, snagging is likely to occur between the fixed side connection part 60 and the radially outer parts of the movable side first connection parts 42a, 42b. However, in this example, the radially outer ends of the movable side first connection parts 42a, 42b are provided with chamfered surfaces 43a, 43b, so that snagging can be effectively prevented.

Furthermore, according to the steering device of this embodiment, the rotational speed of the movable cam 14a when switching to the unlocked state can be reduced without increasing the number of parts.
In other words, when the cam device 11a is switched to the unlocked state to adjust the position of the steering wheel, the movable cam 14a tends to be biased in the other circumferential direction due to the influence of the inertial force acting on the movable cam 14a, the elastic restoring force of the clamped plate portion 3a (and the support plate portion 6a), and the weight of the adjustment lever 12a.

Therefore, in this example, the side recesses 58a, 58b are provided in the radially inner half of the lower part of the side surface on the other circumferential side, where the movable side protrusions 35a, 35b (movable side guide slopes 40a, 40b) slide down when the cam device 11a is switched to the unlocked state, among the protrusions 52a, 52b of the fixed side protrusions 49a, 49b. As a result, the radial center position of the fixed side first slope 54x constituting the lower part of the fixed side guide slopes 54a, 54b is moved radially outward compared to the case where the side recesses are not provided. Therefore, when the cam device 11a is switched from the locked state to the unlocked state, the sliding contact position between the movable side guide slopes 40a, 40b and the fixed side first slope 54x, which slide in the final stage, can be moved radially outward. Therefore, when the cam device 11a is switched to the unlocked state and the movable guide slopes 40a, 40b slide down (come into contact with) the fixed guide slopes 54a, 54b, the friction torque (braking force) applied to the movable cam 14a can be increased in a state in which the movable guide slopes 40a, 40b and the fixed first slope 54x are in sliding contact with each other. As a result, it is possible to reduce the rotation speed of the movable cam 14a without providing a new part such as a friction plate. This makes it possible to prevent the adjustment lever 12a from rotating too vigorously when the cam device 11a is switched to the unlocked state, and to prevent the operator of the adjustment lever 12a from feeling uncomfortable. In addition, the tip surfaces 36a, 36b of the movable side convex parts 35a, 35b and the fixed side reference surfaces 48a, 48b, and the tip surfaces 51a, 51b of the fixed side convex parts 49a, 49b and the movable side reference surfaces 34a, 34b can be prevented from colliding forcefully, thereby preventing abnormal noise (metallic hammering) that occurs due to the collision.

In addition, in this example, when the cam device 11a is switched to the locked state, the movable guide slopes 40a and 40b slide against the fixed side first slope 54x and then slide against the fixed side second slope 54y, so that the sliding contact position changes from the radially outer side to the radially inner side. Therefore, when the movable guide slopes 40a and 40b slide against the fixed side second slope 54y, the friction torque acting on the movable cam 14a can be kept small. Therefore, it is possible to prevent the force required to operate the adjustment lever 12a from becoming excessive. Next, the movable guide slopes 40a and 40b slide against the fixed side second slope 54y and then slide against the fixed side third slope 54z, so that the sliding contact position changes from the radially inner side to the radially outer side. Finally, the tip surfaces 36a, 36b of the movable-side convex parts 35a, 35b and the parts of the tip surfaces 51a, 51b of the fixed-side convex parts 49a, 49b that are not in the tip recess 62 come into contact with the radially outer parts of the movable-side cam surface 16a and the fixed-side cam surface 17a. This makes it possible to increase the operating force (release load) of the adjustment lever 12a required to switch the cam device 11a from the locked state to the unlocked state. This prevents the adjustment lever 12a from rotating (swinging downward ) against the driver's will, and prevents the position of the steering wheel from changing from the adjusted position.

The above describes an embodiment of the present invention, but the present invention is not limited to this and can be modified as appropriate without departing from the technical concept of the invention.

The cam device of the present invention can be applied to various devices other than steering devices. In the above embodiment, the connection part with a chamfered surface is provided on the movable side convex part, but when implementing the present invention, the connection part with a chamfered surface can also be provided on the fixed side convex part.

In the embodiment, a structure equipped with both a tilt mechanism and a telescopic mechanism has been described as a steering wheel position adjustment device, but when implementing the present invention, the target can be a structure equipped with only a tilt mechanism or only a telescopic mechanism.

LIST OF SYMBOLS 1, 1a Steering shaft 2, 2a Steering column 3, 3a Clamped plate portion 4, 4a Column side bracket 5, 5a Vehicle body side bracket 6, 6a Support plate portion 7, 7a Column side through hole 8, 8a Vehicle body side through hole 9, 9a Adjusting rod 10, 10a Anchor portion 11, 11a Cam device 12, 12a Adjusting lever 13, 13a Nut 14, 14a Movable side cam 15, 15a Fixed side cam 16, 16a Movable side cam surface 17, 17a Fixed side cam surface 18 Inner shaft 19 Outer shaft 20 Inner column 21 Outer column 22 Gear housing 23 Tilt shaft 24 Electric motor 25 Spacer 26 Slit 27 Top plate portion 28 Locking capsule 29 Male thread portion Description of the Reference Signs 30 Thrust needle bearing 31 Central hole 32 Movable cam body 33 Movable engagement portion 34a, 34b Movable reference surface 35a, 35b, 35x Movable convex portion 36a, 36b Tip surface 37a, 37b, 37x Protruding portion 38a, 38b Notch 39 Connecting portion 40a, 40b, 40x Movable guide inclined surface 41 Movable stopper portion 42a, 42b, 42x Movable first connection portion 43a, 43b Chamfered surface 44 Movable second connection portion 45 Central hole 46 Fixed cam body 47 Fixed engagement portion 48a, 48b Fixed reference surface 49a, 49b Fixed convex portion 50 Retraction surface 51a, 51b Tip surface 52a, 52b Protruding portion 53a, 53b Cutout 54a, 54b Fixed-side guide inclined surface 54x Fixed-side first inclined surface 54y Fixed-side second inclined surface 54z Fixed-side third inclined surface 55 Fixed-side first stopper portion 56 Fixed-side second stopper portion 57a, 57b Connecting portion 58a, 58b Side recess 59a, 59b Outer diameter side recess 60 Fixed-side connecting portion 61a, 61b Relief recess 62 Tip recess 62a Circumferential recess 62b Radial recess 63 Base 64 Mounting hole

Claims (4)

The movable cam is rotatably supported, and the fixed cam is non-rotatably supported.
the movable cam has a movable cam surface on one axial side thereof, the movable cam surface being formed by alternately arranging movable reference surfaces and movable protrusions protruding from the movable reference surface to one axial side, in a circumferential direction;
the fixed-side cam has a fixed-side cam surface on a side surface on the other axial direction, the fixed-side reference surfaces being the same in number as the movable-side convex portions, and the fixed-side convex portions protruding further toward the other axial direction than the fixed-side reference surfaces and the same in number as the movable-side reference surfaces being alternately arranged in a circumferential direction,
A cam device that can switch between a locked state in which a tip surface of the movable-side convex portion and a tip surface of the fixed-side convex portion are butted against each other to increase an axial dimension, and an unlocked state in which the movable-side convex portion and the fixed-side convex portion are alternately arranged in a circumferential direction to reduce an axial dimension, by rotating the movable-side cam relative to the fixed-side cam,
one of the fixed-side convex portion and the movable-side convex portion has a protruding portion that protrudes in a circumferential direction on a radially inner side of a circumferential first side portion on which the other of the fixed-side convex portion and the movable-side convex portion rides when switching from the unlocked state to the locked state,
the protruding portion has a substantially triangular chamfered surface at a radially outer end of a connection portion connecting a side surface on a first circumferential side and a tip surface,
The chamfered surface is inclined in a direction such that the circumferential width increases toward the radially outer side and the axial height decreases toward the first circumferential side.
Cam device. The cam device according to claim 1, wherein the portion of the one of the protrusions located radially outward from the protruding portion has a ridge line of a connection portion connecting the side surface on the first circumferential side and the tip surface arranged in a radial direction. A cam device according to any one of claims 1 to 2, in which the one convex portion is the movable convex portion and the other convex portion is the fixed convex portion. A steering column that rotatably supports a steering shaft having a steering wheel fixed to a rear end thereof on an inner side;
a column side bracket provided at a portion of the steering column in the axial direction;
a column side through hole penetrating the column side bracket in a width direction;
a vehicle body side bracket that has a pair of support plate portions arranged to sandwich the column side bracket from both sides in a width direction and is supported by a vehicle body;
a pair of vehicle body side through holes penetrating the pair of support plate portions in a width direction,
an adjustment rod that is inserted in a width direction through each of the column-side through hole and the pair of vehicle-body-side through holes;
a cam device including a movable cam that is fitted and supported on the adjustment rod, and a fixed cam that is supported non-rotatably on one of the pair of support plates, and which expands and contracts an axial dimension by rotating the movable cam relative to the fixed cam;
an adjustment lever fixed to the movable cam and rotating the movable cam;
A steering device, wherein the cam device is the cam device according to any one of claims 1 to 3.

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