Steering device

Abstract

To provide a steering device which can obtain required tightening force and operation torque.SOLUTION: In a steering device, a lock mechanism comprises a rod, a drive cam, and a follower cam. The lock mechanism causes a pair of side plate parts to approach in a longitudinal direction in such a manner that a drive base and a follower base are separated from each other in a longitudinal direction in association with sliding of a cam part toward a first side of a cam follower part in a circumferential direction, and causes the pair of side plate parts to separate from each other in the longitudinal direction in such a manner that the drive base and the follower base approach each other in the longitudinal direction in association with sliding of the cam part toward a second side of the cam follower part in the circumferential direction. A first portion of the cam part and the cam follower part comprises a first apex of the cam part and the cam follower part contacting a second portion, and a first relief part extending in a direction separating the second portion in the longitudinal direction as approaching from the first apex toward an outer side in a radial direction crossing a second axis.SELECTED DRAWING: Figure 7

Description

[Technical Field]

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

[0002] Some steering devices are equipped with a tilt function that adjusts the vertical position of the steering shaft according to differences in the driver's physique and driving posture. In the steering device, a column unit holds the steering shaft rotatably about an axis along the front-to-rear direction. The front end of the column unit is supported by a front bracket so as to be rotatable about an axis along the left-to-right direction. The rear end of the column unit is supported by a rear bracket via a rod. Specifically, a tilt guide hole extending in the vertical direction is formed in the rear bracket. The rod is inserted into the tilt guide hole through a through hole in the column unit. In the steering device, as the steering device rotates relative to the front bracket, the rod moves up and down within the tilt guide hole, changing the vertical position of the column unit (steering shaft).

[0003] A steering device with a tilt function is equipped with a locking mechanism that switches between a locked state, which restricts the rotation of the column unit relative to the front bracket, and an unlocked state, which allows the column unit to rotate relative to the front bracket. For example, the locking mechanism includes a drive cam fixed to a rod and a driven cam held by the rear bracket. In the locking mechanism, as the rod rotates, the cam portion of the drive cam and the cam follower portion of the driven cam slide against each other, expanding or contracting the distance between the drive cam and the driven cam. As the distance between the drive cam and the driven cam expands, the rear bracket tightens the column unit, resulting in the locked state. Meanwhile, as the distance between the drive cam and the driven cam contracts, the rear bracket loosens the tightening of the column unit, resulting in the unlocked state.

[0004] Here, Patent Document 1 below discloses a configuration in which the radius of curvature of the cam portion decreases toward the inside in the radial direction of the drive cam. With this configuration, it is said that the operating torque of the rod can be reduced by bringing the contact point between the cam portion and the cam follower portion closer to the rotation center of the rod. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-129411 Summary of the Invention [Problem to be solved by the invention]

[0006] In the locking mechanism, a component of the load acting in the normal direction of the cam portion between the drive cam and the driven cam along the rotational direction of the drive cam acts as a frictional force (resistance force) that occurs when the drive cam and the driven cam rotate relative to each other. Meanwhile, a component of the load acting in the normal direction of the cam portion along the left-right direction acts as an axial force that presses the rear bracket in the left-right direction via the cam follower. In the locked state, the axial force functions as a tightening force that tightens the column unit via the rear bracket.

[0007] However, when the radius of curvature of the cam portion is reduced as in the above-described conventional technology, the component of the load acting in the normal direction of the cam portion along the rotational direction of the drive cam tends to be large, while the component along the left-right direction tends to be small. Therefore, in the conventional technology, the frictional force between the drive cam and the driven cam tends to be large, and the desired tightening force may not be obtained. Furthermore, if dimensional errors occur due to manufacturing variations, the cam portion and the cam follower may not be able to contact each other at the desired position. This not only makes it impossible to ensure the desired tightening force, but also makes it impossible to obtain the desired operating torque.

[0008] The present disclosure provides a steering device that can ensure a desired tightening force while reducing the operating torque. [Means for solving the problem]

[0009] In order to solve the above problems, the present disclosure employs the following aspects. a locking mechanism that switches between a locked state in which the pair of side plates are brought close to each other in the left-right direction to restrict the vertical movement of the column unit relative to the bracket, and an unlocked state in which the pair of side plates are moved apart in the left-right direction to allow the vertical movement of the column unit relative to the bracket, and a second state in which the pair of side plates are moved apart in the left-right direction to allow the column unit to move up and down relative to the bracket, wherein the locking mechanism has a rod that penetrates the column unit and the tilt guide hole in the left-right direction and is supported by the column unit to be rotatable in a circumferential direction about a second axis that is also in the left-right direction, a drive base, and a cam portion that bulges out in the left-right direction from the drive base, The locking mechanism comprises a drive cam that rotates integrally with the rod, a driven base, and a driven cam that bulges out in the left-right direction from the driven base and has a cam follower that slides against the cam as the rod rotates, and as the cam slides against the cam follower toward a first side in the circumferential direction, the drive base and the driven base move apart in the left-right direction, bringing the pair of side plate portions closer together in the left-right direction, and as the cam slides against the cam follower toward a second side in the circumferential direction, the drive base and the driven base move closer together in the left-right direction, causing the pair of side plate portions to move apart in the left-right direction, and a first portion of the cam portion and the cam follower has a first apex that contacts a second portion of the cam portion and the cam follower, and a first recess that extends from the first apex toward the outside in a radial direction intersecting the second axis, away from the second portion in the left-right direction.

[0010] According to this aspect, when the drive cam and the driven cam rotate relative to each other, the apex located on the inner periphery can slide while the recesses located on the outer periphery are spaced apart. This allows the contact position between the first portion and the second portion to be set radially inward, thereby reducing the torque about the second axis when the rod rotates. This reduces the operating torque when rotating the rod, providing excellent operability. Furthermore, when the contact position on the first portion with the second portion is set radially inward, the radius of curvature of the first portion can be set relatively large compared to a configuration in which the radius of curvature of the first portion is small. This ensures that, of the load acting between the cam portion and the cam follower along the normal direction of the first portion, the component along the rotational direction of the drive cam is small and the component along the left-right direction is large. By reducing the component along the rotational direction of the drive cam, the frictional force during relative rotation between the drive cam and the follower cam can be reduced, further improving operability. By increasing the component along the left-right direction, it is easy to ensure an axial force that presses the side plate portion in the left-right direction via the cam follower. As a result, it is easy to ensure the desired tightening force in the locked state. Furthermore, compared to a configuration in which the radius of curvature of the cam portion is small, manufacturing variations can be reduced, so variations in the contact position of the cam portion and cam follower portion between products can be reduced, and a steering device with excellent reliability can be provided.

[0011] In the steering device of the above aspect, it is preferable that the first apex portion is formed at an inner end portion of the first portion in the radial direction. According to this aspect, the contact position on the first portion with the second portion can be set to the innermost position in the radial direction, so that the torque about the second axis when the rod rotates can be more reliably reduced.

[0012] In the steering device of the above aspect, it is preferable that the first recess is formed as an inclined surface that extends in a direction away from the second portion in the left-right direction as it moves radially outward from the first apex. According to this aspect, it is easier to ensure the strength of the first portion compared to, for example, a configuration in which the first relief portion is formed as a curved surface or a stepped shape.

[0013] In the steering device of the above aspect, it is preferable that the second portion has a second apex that contacts the first apex, and a second recess that extends in a direction away from the first portion in the left-right direction as it moves radially outward from the second apex. According to this aspect, since it is easy to set the contact position between the first part and the second part, it is possible to reduce the variation in the contact position between the first part and the second part between products, and it is possible to provide a steering device with excellent reliability.

[0014] In the steering device of the above aspect, it is preferable that the drive cam has a first regulating portion that bulges outward in the left-right direction from the drive base at a portion of the drive base that is located radially outward from the cam portion, and the driven cam has a second regulating portion that bulges outward in the left-right direction from the driven base at a portion of the driven base that is located radially outward from the cam follower portion, and that the first regulating portion and the second regulating portion abut in the circumferential direction in the locked state to regulate rotation of the cam portion toward the first side in the circumferential direction relative to the cam follower portion. According to this aspect, the outer diameters of the drive cam and the driven cam can be reduced compared to when the first restricting portion and the cam portion, and the second restricting portion and the cam follower portion are disposed on the same circumference. Furthermore, by disposing the cam portion and the cam follower portion radially inward of the restricting portion, it is easy to reduce the torque about the second axis when the rod rotates.

[0015] In the steering device of the above aspect, it is preferable that a biasing member be disposed between the driven cam and the side plate portion, for biasing the cam follower portion toward the cam portion. According to this aspect, it is easy to ensure a lateral load acting between the drive cam and the driven cam. Therefore, it is easy to ensure a frictional force (static frictional force) acting in the circumferential direction between the drive cam and the driven cam, especially when the locking mechanism is in the unlocked state. This makes it possible to prevent the locking mechanism from accidentally transitioning to the locked state when in the unlocked state. As a result, the axial force acting by the locking mechanism in the unlocked state is reduced, improving operability. [Effects of the Invention]

[0016] According to one aspect of the present disclosure, a desired tightening force and operating torque can be obtained. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a perspective view of a steering device according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 2 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a cross-sectional view corresponding to the line IV-IV in FIG. [Figure 5] FIG. 3 is an enlarged view of the hanger bracket and its surroundings in FIG. 2. [Figure 6] FIG. [Figure 7] FIG. 4 is an enlarged view of a main part of FIG. 3. [Figure 8] FIG. [Figure 9] FIG. 2 is a development view of the fastening cam developed around an axis. [Figure 10] 10 is a development view illustrating the operation of the locking mechanism, corresponding to FIG. 9. FIG. [Figure 11] 10 is a development view illustrating the operation of the locking mechanism, corresponding to FIG. 9. FIG. [Figure 12] 8 is a cross-sectional view corresponding to FIG. 7, illustrating the operation of the locking mechanism. FIG. [Figure 13] FIG. 8 is a cross-sectional view corresponding to FIG. 7 according to a modified example. [Figure 14] FIG. 8 is a cross-sectional view corresponding to FIG. 7 according to a modified example. [Figure 15] FIG. 13 is a cross-sectional view corresponding to FIG. 12 according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0018] Next, an embodiment of the present disclosure will be described with reference to the drawings. [Steering device] FIG. 1 is a perspective view of a steering device 1. FIG. As shown in Fig. 1, a steering device 1 is mounted on a vehicle. The steering device 1 adjusts the steering angle of wheels in accordance with the rotation of a steering wheel 2.

[0019] The steering device 1 includes a column unit 11, a steering shaft 12, a front bracket 13, a rear bracket (bracket) 14, and a locking mechanism 15. The column unit 11 and the steering shaft 12 are each formed along an axis (first axis) O1. Therefore, in the following description, the direction in which the axis O1 of the column unit 11 and the steering shaft 12 extends may be simply referred to as the shaft axial direction, the direction perpendicular to the axis O1 may be referred to as the shaft radial direction, and the direction around the axis O1 may be referred to as the shaft circumferential direction.

[0020] The steering device 1 of this embodiment is mounted on a vehicle with its axis O1 intersecting the front-rear direction. Specifically, the axis O1 of the steering device 1 extends upward as it moves rearward. However, for convenience in the following description, the shaft axial direction of the steering device 1 will be referred to as the front-rear direction. In this case, in the steering device 1, the direction toward the steering wheel 2 will simply be referred to as the rearward direction, and the direction toward the opposite side of the steering wheel 2 will simply be referred to as the forward direction (arrow FR). Of the shaft radial directions, the up-down direction when the steering device 1 is mounted on a vehicle will simply be referred to as the up-down direction (arrow UP indicates upward), and the left-right direction will simply be referred to as the left-right direction.

[0021] <Column Unit 11> FIG. 2 is a cross-sectional view taken along line II-II in FIG. As shown in FIGS. 1 and 2, the column unit 11 has an outer column 21, an inner column 22, and a hanger bracket 23. The outer column 21 is attached to the vehicle body via brackets 13, 14. The outer column 21 includes a retaining cylindrical portion 24, a first fastening portion 25 (see FIG. 3), and a second fastening portion .

[0022] The retaining cylindrical portion 24 is formed in a cylindrical shape extending in the front-rear direction. A front bearing 27 is fitted (press-fitted) into the front end portion of the retaining cylindrical portion 24. A slit 28 is formed in a part of the rear portion of the retaining cylindrical portion 24 in the shaft circumferential direction (in this embodiment, the lower part of the outer column 21). The slit 28 passes through the outer column 21 in the shaft radial direction and is open at the rear end face of the outer column 21.

[0023] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 3, the tightening portions 25, 26 extend downward from positions on the holding tube portion 24 that face each other in the left-right direction with the slit 28 therebetween. The first tightening portion 25 is formed with a first through-hole 31 that penetrates the first tightening portion 25 in the left-right direction.

[0024] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3 and 4, the first through hole 31 is formed as a stepped hole. Specifically, the first through hole 31 includes a bolt support hole 31a and a cam support hole 31b located outside the bolt support hole 31a in the left-right direction. The bolt support hole 31a constitutes the inner portion in the left-right direction of the first through hole 31. The bolt support hole 31a is a circular hole centered on an axis (second axis) O2 that extends along the left-right direction in a side view. The bolt support hole 31a opens on the inner end surface in the left-right direction of the first tightening portion 25. In the following description, the direction that intersects with the axis O2 in a side view may be referred to as the bolt radial direction (radial direction), and the direction around the axis O2 may be referred to as the bolt circumferential direction (circumferential direction).

[0025] In a side view, the cam support hole 31b is formed in the shape of a parallelogram with the axis O2 as the intersection of the diagonals. Of the two pairs of diagonals that make up the cam support hole 31b, the radius of curvature of one diagonal is smaller than the radius of curvature of the other diagonal. The inner left-right end of the cam support hole 31b is connected to the bolt support hole 31a via a stepped surface 31c. The outer left-right end of the bolt support hole 31a opens on the stepped surface 31c. The outer left-right end of the cam support hole 31b opens at the outer left-right end surface of the first tightening portion 25.

[0026] 3, a second through hole 32 is formed in the second fastening portion 26, penetrating the second fastening portion 26 in the left-right direction. The second through hole 32 is a circular hole formed coaxially with the axis O2 and with the same diameter as the bolt support hole 31a.

[0027] As shown in Fig. 2, the inner column 22 is formed in a cylindrical shape extending in the front-rear direction. The outer diameter of the inner column 22 is smaller than the inner diameter of the retaining cylindrical portion 24. The inner column 22 is inserted into the retaining cylindrical portion 24 from the rear. The inner column 22 is configured to be movable in the front-rear direction relative to the outer column 21. A rear bearing 30 is fitted (press-fitted) into the rear end portion of the inner column 22.

[0028] FIG. 5 is an enlarged view of the hanger bracket 23 and its surroundings in FIG. As shown in Figures 3 and 5, the hanger bracket 23 is fixed facing downward to the lower part of the inner column 22. The hanger bracket 23 is formed, for example, by pressing a metal plate. The hanger bracket 23 is exposed to the outside of the retaining cylindrical portion 24 through a slit 28 in the retaining cylindrical portion 24. The hanger bracket 23 is formed in a U-shape that opens downward when viewed from the front in the front-rear direction.

[0029] The hanger bracket 23 includes a mounting plate portion 35 and guide walls 36 extending downward from both left and right end portions of the mounting plate portion 35 . The mounting plate portion 35 has a thickness direction in the up-down direction and extends in the front-rear direction along the outer circumferential surface of the inner column 22. An EA (Energy Absorbing) elongated hole 35a is formed in the mounting plate portion 35, penetrating the mounting plate portion 35 in the up-down direction. The EA elongated hole 35a is formed in the shape of a slit extending in the front-rear direction.

[0030] The hanger bracket 23 is fixed to the inner column 22 by a bolt 39. The bolt 39 is inserted into the rear end of the EA elongated hole 35a from below and fastened to the inner column 22. This restricts the movement of the hanger bracket 23 in the front-to-rear direction relative to the inner column 22 during telescopic movement (the hanger bracket 23 moves integrally with the inner column 22).

[0031] The guide wall 36 is formed over the entire length of the mounting plate portion 35. The guide wall 36 includes a telescopic guide portion 36a and telescopic stoppers 36b and 36c. The telescopic guide portion 36a is formed at a position other than both front and rear end portions of the guide wall 36. The lower end edge of the telescopic guide portion 36a is formed linearly along the front-rear direction.

[0032] As shown in FIG. 5, the telescopic stoppers 36b, 36c are a front telescopic stopper 36b located at the front end of the guide wall 36, and a rear telescopic stopper 36c located at the rear end of the guide wall 36. The front telescopic stopper 36b protrudes downward with respect to the telescopic guide portion 36a. The front telescopic stopper 36b restricts the forward movement of the inner column 22 relative to the outer column 21 during telescopic operation. The rear telescopic stopper 36c protrudes downward with respect to the telescopic guide portion 36a. The rear telescopic stopper 36c restricts the rearward movement of the inner column 22 relative to the outer column 21 during telescopic operation.

[0033] <Steering shaft 12> As shown in FIG. 2, the steering shaft 12 includes an outer shaft 37 and an inner shaft . The outer shaft 37 is formed in the shape of a hollow cylinder extending in the front-rear direction. The outer shaft 37 is inserted into the column unit 11. The front end of the outer shaft 37 is press-fitted into the front bearing 27 inside the outer column 21. As a result, the outer shaft 37 is supported by the outer column 21 so as to be rotatable about the axis O1. The front end of the outer shaft 37 (the portion that protrudes forward beyond the front bearing 27) is connected to, for example, a steering gear box (not shown) or the like via a universal joint (not shown) or the like.

[0034] The inner shaft 38 extends in the front-rear direction. The inner shaft 38 is inserted into the inner column 22. The rear end of the inner shaft 38 is press-fitted into the rear bearing 30 inside the inner column 22. As a result, the inner shaft 38 is supported by the inner column 22 so as to be rotatable about the axis O1. The steering wheel 2 (see FIG. 1) is connected to a portion of the inner shaft 38 that protrudes rearward beyond the inner column 22.

[0035] The front end of the inner shaft 38 is inserted into the outer shaft 37 inside the inner column 22. The inner shaft 38 is configured to be able to move in the front-rear direction relative to the outer shaft 37 together with the inner column 22 as the inner column 22 moves in the front-rear direction relative to the outer column 21.

[0036] In this embodiment, a female spline is formed on the inner peripheral surface of the outer shaft 37. The female spline engages with a male spline formed on the outer peripheral surface of the inner shaft 38. As a result, the inner shaft 38 is restricted from rotating relative to the outer shaft 37, and is allowed to move in the front-to-rear direction relative to the outer shaft 37. However, the telescopic structure of the steering shaft 12 and the structure for restricting rotation can be modified as appropriate. Note that, although this embodiment has been described as having a configuration in which the outer shaft 37 is disposed forward of the inner shaft 38, the present invention is not limited to this configuration, and the outer shaft 37 may also be disposed rearward of the inner shaft 38.

[0037] <Bracket 13, 14> As shown in FIG. 1, the front bracket 13 connects the vehicle body and the outer column 21. The front bracket 13 is formed in a U-shape that opens downwards when viewed from the front. The front bracket 13 surrounds the rear end of the outer column 21 from above and on both sides in the left and right directions. The front bracket 13 is connected to the outer column 21 by a pivot shaft 40 that extends in the left and right direction. As a result, the outer column 21 is supported by the front bracket 13 so as to be rotatable about an axis O3 that extends in the left and right direction.

[0038] The rear bracket 14 connects the vehicle body and the outer column 21 rearward of the front bracket 13. The rear bracket 14 is formed in a U-shape that opens downward when viewed from the front. The rear bracket 14 surrounds the outer column 21 from above and on both sides in the left and right directions.

[0039] The rear bracket 14 includes a first side plate portion 41 disposed on a first side (left side) in the left-right direction relative to the column unit 11, a second side plate portion 42 disposed on a second side (right side) in the left-right direction relative to the column unit 11, and a bridge portion 43 connecting the side plate portions 41, 42 to each other. As shown in FIG. 3, a tilt guide hole 45 is formed in each side plate portion 41, 42, penetrating each side plate portion 41, 42 in the left-right direction. The tilt guide hole 45 is an elongated hole extending in the up-down direction. Specifically, the tilt guide hole 45 is formed in an arc shape that convex rearward with the axis O3 as the center of curvature (see FIG. 4).

[0040] The bridge portion 43 connects the upper ends of the side plate portions 41, 42. The bridge portion 43 is formed in an arch shape that protrudes upward. The bridge portion 43 is located on the rotation trajectory of the column unit 11 when the column unit 11 tilts. When the column unit 11 tilts, the column unit 11 approaches or moves away from the bridge portion 43 from below. The front bracket 13 and the rear bracket 14 are connected by a connecting piece 48 (see Figure 1). The connecting piece 48 has a thickness direction in the left-right direction and extends in the front-rear direction. The connecting piece 48 restricts the movement (rotation) of the front bracket 13 relative to the rear bracket 14. However, the connecting piece 48 is not an essential component.

[0041] <Lock mechanism 15> As shown in FIG. 3, the locking mechanism 15 includes a lock bolt (rod) 53, an operating lever 54, a fastening cam 55, a first biasing member 56, a second biasing member 57, and a cam biasing member (biasing member) 58.

[0042] The lock bolt 53 is disposed coaxially with the axis O2. The lock bolt 53 passes through the side plate portions 41, 42 and the fastening portions 25, 26 in the left-right direction via the tilt guide hole 45 and the through holes 31, 32. During telescopic operation, the lock bolt 53 moves back and forth along the telescopic guide portion 36a as the inner column 22 and the like move back and forth. During tilt operation, the lock bolt 53 moves up and down within the tilt guide hole 45, and therefore moves up and down together with the column unit 11.

[0043] A collar 59 is attached to the center of the lock bolt 53 (the portion located between the tightening portions 25, 26). The collar 59 is formed in a cylindrical shape coaxial with the lock bolt 53. The collar 59 is formed from a material softer than the lock bolt 53 (for example, an elastically deformable material such as rubber or resin). As shown in FIG. 5 , during telescoping operation, when the inner column 22 is in the frontmost position (the column unit 11 is in the most retracted position P1), the collar 59 abuts against the front telescoping stopper 36b from the rear. On the other hand, during telescoping operation, when the inner column 22 is in the rearmost position (the column unit 11 is in the most extended position P2), the collar 59 abuts against the rear telescoping stopper 36c from the front. That is, the lock bolt 53 abuts against the telescoping stoppers 36b, 36c via the collar 59. However, the lock mechanism 15 may be configured such that the lock bolt 53 directly contacts the telescopic stoppers 36b and 36c.

[0044] FIG. 6 is an exploded perspective view of the fastening cam 55. As shown in FIG. 1, 4, and 6, the operating lever 54 is connected to the left end of the lock bolt 53. The operating lever 54 includes a connecting portion 54a and a transmission portion 54b. As shown in Fig. 6, the connecting portion 54a is formed in a disk shape that is coaxial with the axis O2. As shown in Fig. 5, the connecting portion 54a is formed with a positioning hole 54c that penetrates the connecting portion 54a in the left-right direction. The positioning hole 54c is formed in a rectangular shape in side view. The lock bolt 53 penetrates the positioning hole 54c in the left-right direction. A locking piece 54d is formed at the lower rear end of the connecting portion 54a. The locking piece 54d protrudes outward in the left-right direction from the connecting portion 54a.

[0045] 1, the transmission part 54b extends rearward from the connecting part 54a. The operating lever 54 is configured to be rotatable around the axis O2 together with the lock bolt 53 by pushing down or pulling up the rear end of the transmission part 54b.

[0046] As shown in FIG. 3 , the fastening cam 55 is disposed between the operating lever 54 and the rear bracket 14 (first side plate portion 41). The fastening cam 55 is configured so that its thickness in the left-right direction changes as the operating lever 54 is rotated. In the steering device 1, the change in thickness of the fastening cam 55 causes the fastening portions 25, 26 to move closer to or farther away from each other in the left-right direction via the first side plate portion 41 (so that the left-right width (interval) of the slit 28 increases or decreases). Specifically, by rotating the operating lever 54 so that the thickness of the fastening cam 55 increases, the fastening portions 25, 26 move closer to each other together with the side plate portions 41, 42, and the diameter of the retaining tube portion 24 decreases. As a result, the inner column 22 is clamped by the retaining tube portion 24, and the telescopic movement and tilt movement are restricted (locked state). On the other hand, in the locked state, by rotating the operating lever 54 so that the thickness of the fastening cam 55 decreases, the fastening portions 25, 26 move away from each other together with the side plate portions 41, 42, and the diameter of the holding cylinder portion 24 is expanded. This releases the clamping of the inner column 22 by the holding cylinder portion 24, and allows telescopic movement and tilt movement (unlocked state).

[0047] Fig. 7 is an enlarged view of the main part of Fig. 3. Fig. 8 is a plan view of the drive cam 60. As shown in FIGS. 6 to 9, the fastening cam 55 includes a drive cam 60 and a driven cam 61. As shown in FIGS. The drive cam 60 is connected to the operating lever 54 so as to be non-rotatable relative to the operating lever 54 (but can rotate integrally with the operating lever 54). The drive cam 60 is made of a material harder than the side plate portions 41, 42 (for example, a sintered iron-based material).

[0048] The drive cam 60 includes a drive base 71, a holding portion 72, a cam portion (first portion) 73, and a plurality of restricting portions (first restricting portions) 74. The drive base 71 is formed in a disk shape and is disposed coaxially with the axis O2. The drive base 71 is disposed inside the connecting portion 54a in the left-right direction and overlaps the connecting portion 54a.

[0049] The holding portion 72 bulges outward in the left-right direction from a portion of the drive base 71 that includes the axis O2. A through hole 60a through which the lock bolt 53 passes is formed in the holding portion 72 and the drive base 71. The drive cam 60 is supported so as to be rotatable about the axis O2 relative to the lock bolt 53. The holding portion 72 is formed in a rectangular shape corresponding to the positioning hole 54c in a side view. The holding portion 72 is fitted into the positioning hole 54c. This restricts the rotation of the drive cam 60 relative to the operating lever 54 about the axis O2.

[0050] The cam portion 73 surrounds the passage hole 70a in the bolt circumferential direction on the inner circumferential portion of the drive base 71. The cam portion 73 includes a seat portion 73a and a plurality of cam protrusions 73b. The pedestal portion 73a bulges inward in the left-right direction from the drive base 71. The pedestal portion 73a is formed in an annular shape surrounding the periphery of the passage hole 70a. A plurality of (for example, four) cam protrusions 73b are formed on the base portion 73a at intervals in the bolt circumferential direction. Each cam protrusion 73b has the same shape. Therefore, in the following explanation, the details of the cam protrusions 73b will be explained using one cam protrusion 73b as an example.

[0051] FIG. 9 is a development view of the fastening cam 55 in the locked state, developed around the axis O2. 8 and 9, the cam projection 73b bulges inward in the left-right direction from the base portion 73a. In a side view, the cam projection 73b is formed in a fan shape whose width in the bolt circumferential direction gradually increases as it extends radially outward in the bolt radial direction. When viewed radially from the bolt, the peripheral surface of the cam projection 73b includes a first side surface 81, a locking surface 83, and a second side surface 84.

[0052] The first side surface 81 extends inward in the left-right direction toward one side (second side) in the bolt circumferential direction. When viewed radially from the bolt, the first side surface 81 is formed in a linear shape or in an arc shape that convex toward the other side (first side) in the bolt circumferential direction.

[0053] The locking surface 83 is a surface of the cam projection 73b facing outward in the left-right direction. The locking surface 83 is continuous with one end of the first side surface 81 in the bolt circumferential direction. The locking surface 83 includes a transition surface 83a and a pressing surface 83b. The transition surface 83a smoothly connects to the first side surface 81. In the illustrated example, the boundary between the first side surface 81 and the transition surface 83a is a curved surface. The transition surface 83a extends inward in the left-right direction as it moves toward one side in the bolt circumferential direction. The transition surface 83a is formed in an arc shape or a straight line that convex toward the inside in the left-right direction when viewed from the bolt radial direction. When viewed from the bolt radial direction, the angle between the transition surface 83a and an imaginary line L perpendicular to the axis O2 is smaller than the angle between the imaginary line L and the first side surface 81.

[0054] The pressing surface 83b is continuous with one side of the transition surface 83a in the bolt circumferential direction. When viewed radially of the bolt, the pressing surface 83b extends linearly (flat) along the bolt circumferential direction. However, when viewed radially of the bolt, the locking surface 83 may be formed as a flat surface entirely or as an arc convex inward in the left-right direction.

[0055] The second side surface 84 is continuous with one side of the pressing surface 83b in the bolt circumferential direction. The second side surface 84 extends outward in the left-right direction as it approaches one side in the bolt circumferential direction. When viewed from the bolt radial direction, the second side surface 84 is formed in a straight line. When viewed from the bolt radial direction, the angle formed between the imaginary line L and the second side surface 84 is larger than the angle formed between the imaginary line L and the first side surface 81.

[0056] The portion of the base portion 73a located between adjacent cam projections 73b in the bolt circumferential direction constitutes a release surface 85. The release surface 85 is formed as a flat surface perpendicular to the left-right direction. In a side view, the outer shape of the release surface 85 is formed to be the same as the outer shape of the cam projections 73b.

[0057] The restricting portions 74 are formed at intervals around the bolt in portions of the drive base 71 that are located radially outward of the cam portion 73 in the bolt radial direction. A corresponding restricting portion 74 and a portion of the cam protrusion 73b overlap each other when viewed radially of the bolt. All of the restricting portions 74 have the same shape. Therefore, in the following description, the details of the restricting portions 74 will be described using one restricting portion 74 as an example.

[0058] The restricting portion 74 bulges inward in the left-right direction from the drive base 71. When viewed in the bolt radial direction, the circumferential surface of the restricting portion 74 includes a lock position restricting surface 74a, a top surface 74b, and a release position restricting surface 74c. When viewed radially from the bolt, the lock position restriction surface 74a extends inward in the left-right direction from a portion located on one side of the transition surface 83a in the bolt circumferential direction while moving toward one side in the bolt circumferential direction. When viewed radially from the bolt, the lock position restriction surface 74a is formed in a straight line. The angle between the imaginary line L and the lock position restriction surface 74a is equal to or greater than the angle between the imaginary line L and the first side surface 81.

[0059] The top surface 74b extends linearly from the inner end of the lock position restriction surface 74a in the left-right direction toward one side in the bolt circumferential direction. The top surface 74b is located inside the pressing surface 83b in the left-right direction. The release position limiting surface 74c is continuous with one end of the top surface 74b in the bolt circumferential direction. The release position limiting surface 74c extends outward in the left-right direction as it moves toward one side in the bolt circumferential direction. When viewed in the bolt radial direction, the release position limiting surface 74c is formed in a straight line. In the illustrated example, the angle between the imaginary line L and the release position limiting surface 74c is equal to the angle between the imaginary line L and the lock position limiting surface 74a. The release position limiting surface 74c is located on the same plane in the bolt radial direction as the second side surface 84 of the corresponding cam protrusion 73b.

[0060] 4, 6, and 7, the driven cam 61 is movable up and down along the tilt guide hole 45, and is supported by the first side plate portion 41 and the outer column 21 so as not to be rotatable relative to each other. Similar to the drive cam 60, the driven cam 61 is made of a material that is harder than the side plate portions 41, 42.

[0061] The driven cam 61 includes a driven base 91, a holding portion 92, a cam follower portion (second portion) 93, and a plurality of restricting portions (second restricting portions) 94. The surfaces of the drive cam 60 and the driven cam 61 that face each other in the left-right direction (the surfaces of the drive base 71 and the driven base 91, the cam portion 73 and the cam follower portion 93, and the restricting portions 74, 94) have the same shape.

[0062] The driven base 91 is formed in a disk shape and is arranged coaxially with the axis O2. The driven base 91 is arranged on the outer side in the left-right direction of the first side plate portion 41, overlapping the tilt guide hole 45. A through hole 91a is formed in a portion of the driven base 91 that is located on the axis O2. The through hole 91a is a circular hole through which the lock bolt 53 can be inserted.

[0063] The retaining portion 92 bulges inward in the left-right direction from a portion of the driven base 91 that includes the axis O2. In a side view, the retaining portion 92 is formed in the shape of a parallelogram imitating the cam support hole 31b. The retaining portion 92 is housed in the cam support hole 31b through the tilt guide hole 45 of the first side plate portion 41. This holds the driven cam 61 so that it cannot rotate relative to the first side plate portion 41 and the outer column 21.

[0064] A spring receiving portion 92a is formed in the holding portion 92. The spring receiving portion 92a is a circular hole formed with a larger diameter than the through hole 91a. The spring receiving portion 92a opens on the inner end surface of the holding portion 92 in the left-right direction. The inner end of the spring receiving portion 92a in the left-right direction is connected to the through hole 91a via a stepped surface 92b (see FIG. 7). The through hole 91a opens at a portion of the stepped surface 92b that is located on the axis O2. The lock bolt 53 passes through the driven cam 61 in the left-right direction via the through hole 91a and the spring receiving portion 92a. As a result, the driven cam 61 is supported so as to be movable in the left-right direction relative to the lock bolt 53.

[0065] The cam follower portion 93 surrounds the through hole 91a in the bolt circumferential direction on the inner circumferential portion of the follower base 91. The cam follower portion 93 includes a seat portion 93a and a plurality of follower protrusions 93b. The pedestal portion 93a bulges outward in the left-right direction from the driven base 91. The pedestal portion 93a is formed in an annular shape surrounding the periphery of the through hole 91a. A plurality of (for example, four) follower protrusions 93b are formed on the base portion 93a at intervals in the bolt circumferential direction. Each follower protrusion 93b has the same shape. Therefore, in the following explanation, the details of the follower protrusion 93b will be explained using one follower protrusion 93b as an example.

[0066] The follower protrusion 93b bulges outward in the left-right direction from the base portion 93a. In a side view, the follower protrusion 93b is formed in a fan shape whose width in the bolt circumferential direction gradually increases as it extends radially outward in the bolt radial direction. In the locked state, the follower protrusion 93b faces the cam protrusions 73b of the drive cam 60 in the left-right direction (see FIG. 9), and is located between adjacent cam protrusions 73b in the unlocked state (see FIG. 11). When viewed radially of the bolt, the peripheral surface of the follower protrusion 93b has a first side surface 101, a locking surface 103, and a second side surface 104.

[0067] The first side surface 101 extends outward in the left-right direction as it moves toward the other side in the bolt circumferential direction. In the unlocked state, the first side surface 101 faces the first side surface 81 in the bolt circumferential direction (see FIG. 11). The first side surface 101 slides on the first side surface 81 as the operating lever 54 is rotated.

[0068] The locking surface 103 is a surface of the follower projection 93b facing inward in the left-right direction. The locking surface 103 is continuous with the other end of the first side surface 101 in the bolt circumferential direction. The locking surface 103 includes a transition surface 103a and a pressing surface 103b. The transition surface 103a smoothly connects to the other end of the first side surface 101 in the bolt circumferential direction. The transition surface 103a extends outward in the left-right direction as it approaches the other side in the bolt circumferential direction. The transition surface 103a slides on the transition surface 83a of the drive cam 60 as the operating lever 54 is rotated.

[0069] The pressing surface 103b is continuous with the other side of the transition surface 103a in the bolt circumferential direction. When viewed in the bolt radial direction, the pressing surface 103b extends linearly (flat) along the bolt circumferential direction. In the unlocked state, the pressing surface 103b faces the release surface 85 in the left-right direction (see FIG. 11), and in the locked state, faces the pressing surface 83b in the left-right direction (see FIG. 9). Note that the locking surface 103 may be formed as a flat surface as a whole or as an arc convex inward in the left-right direction when viewed in the bolt radial direction.

[0070] The second side surface 104 is continuous with the pressing surface 103b on the other side in the bolt circumferential direction. The second side surface 104 extends inward in the left-right direction as it approaches the other side in the bolt circumferential direction. In the unlocked state, the second side surface 104 approaches or abuts against the second side surface 84 from one side in the bolt circumferential direction.

[0071] The portion of the base portion 93a located between adjacent follower projections 93b in the bolt circumferential direction constitutes a release surface 105. The release surface 105 is formed as a flat surface perpendicular to the left-right direction. In the unlocked state, the release surface 105 faces the pressing surface 83b in the left-right direction.

[0072] The restricting portions 94 are formed at intervals in the bolt circumferential direction on portions of the driven base 91 that are positioned radially outward of the cam follower portions 93. Corresponding restricting portions 94 and follower projections 93b overlap each other when viewed radially of the bolt. The restricting portion 94 bulges outward in the left-right direction from the driven base 91. When viewed in the bolt radial direction, the circumferential surface of the restricting portion 94 includes a lock position restricting surface 94a, a top surface 94b, and a release position restricting surface 94c. When viewed radially from the bolt, the lock position limiting surface 94a extends outward in the left-right direction from a portion located on the other side of the second transition surface 102 in the bolt circumferential direction as it moves toward the other side in the bolt circumferential direction. In the locked state, the lock position limiting surfaces 74a, 94a of the drive cam 60 and the driven cam 61 face each other in the bolt circumferential direction. In the locked state, the lock position limiting surfaces 74a, 94a abut against each other in the bolt circumferential direction, thereby restricting rotation of the drive cam 60 relative to the driven cam 61 toward the other side in the bolt circumferential direction.

[0073] The top surface 94b extends linearly from the outer end of the lock position restriction surface 94a in the left-right direction toward the other side in the bolt circumferential direction. The top surface 94b is located outward in the left-right direction from the pressing surface 103b. The release position restriction surface 94c is continuous with the other end of the top surface 94b in the bolt circumferential direction. The release position restriction surface 94c extends inward in the left-right direction as it approaches the other side in the bolt circumferential direction. The release position restriction surface 94c is located on the same plane as the second side surface 104 of the corresponding follower protrusion 93b in the bolt radial direction. In the unlocked state, the release position restriction surfaces 74c, 94c or the second side surfaces 84, 104 abut against each other in the bolt circumferential direction, thereby restricting rotation of the drive cam 60 relative to the follower cam 61 to one side in the bolt circumferential direction.

[0074] As shown in FIG. 7 , when viewed from the circumferential direction of the bolt, the locking surfaces 83, 103 are formed as inclined surfaces that extend toward each other in the left-right direction as they move from the outside to the inside in the bolt radial direction. Specifically, the locking surface 83 of the drive cam 60 gradually extends inward in the left-right direction as it moves from the outside to the inside in the bolt radial direction. The locking surface 103 of the driven cam 61 gradually extends outward in the left-right direction as it moves from the outside to the inside in the bolt radial direction. Therefore, the inner peripheral edges of the locking surfaces 83, 103 form peaks (first peak, second peak) 83c, 103c that abut against each other in the locked state. Meanwhile, portions of the locking surfaces 83, 103 located outside the peaks 83c, 103c in the bolt radial direction form outer recesses (first recess, second recess) 83d, 103d that are spaced apart from each other in the locked state. The outer recesses 83d, 103d are formed as inclined surfaces that gradually extend in the left-right direction as they extend radially outward in the bolt direction. The angle of the locking surfaces 83, 103 (outer recesses 83d, 103d) relative to the bolt radial direction can be changed as appropriate.

[0075] 1, the first biasing member 56 connects the locking piece 54d and the upper end of the first side plate portion 41. The first biasing member 56 is, for example, a coil spring. The first biasing member 56 biases the operating lever 54 toward the other side in the bolt circumferential direction via the locking piece 54d, and also biases the column unit 11 upward via the locking piece 54d.

[0076] The second biasing member 57 connects the right end of the lock bolt 53 and the upper end of the second side plate portion 42. The second biasing member 57 is, for example, a coil spring. The second biasing member 57 biases the column unit 11 upward via the lock bolt 53.

[0077] 7, cam biasing member 58 is housed in spring receiving portion 72a with lock bolt 53 inserted therein. Cam biasing member 58 is, for example, a coil spring. Both left and right ends of cam biasing member 58 contact step surfaces 31c and 92b, respectively, thereby biasing driven cam 61 outward in the left and right direction (toward drive cam 60).

[0078] [Effect] Next, the operation of the above-described steering device 1 will be described. In the following explanation, the method of operating the lock mechanism 15 will be mainly described. Figures 10 to 12 are explanatory views of the operation of the lock mechanism 15, with Figures 10 and 11 being development views corresponding to Figure 9, and Figure 12 being a cross-sectional view corresponding to Figure 7. 9, the fastening cam 55 restricts the drive cam 60 and the driven cam 61 from moving closer together in the left-right direction because the pressing surfaces 83b, 103b of the drive cam 60 abut against each other in the left-right direction. In particular, the pressing surfaces 83b, 103b contact each other at their tops 83c, 103c, leaving gaps in the left-right direction at the outer circumferential portions (outer relief portions 83d, 103d) of the pressing surfaces 83b, 103b. Furthermore, the lock position restriction surfaces 74a, 94a of the drive cam 60 and the driven cam 61 abut against each other in the bolt circumferential direction, restricting rotation of the drive cam 60 relative to the driven cam 61 to the other side in the bolt circumferential direction.

[0079] In this state, to set the fastening cam 55 to the unlocked state, the operating lever 54 is rotated to one side in the bolt circumferential direction. As the operating lever 54 rotates, the drive cam 60 rotates to one side in the bolt circumferential direction relative to the driven cam 61. Then, the peripheral surfaces of the cam protrusion 73b of the drive cam 60 and the follower protrusion 93b of the driven cam 61 slide against each other, and the driven cam 61 moves outward in the left-right direction due to the biasing force of the cam biasing member 58. Specifically, as shown in FIG. 10 , the drive cam 60 rotates to one side in the bolt circumferential direction relative to the driven cam 61 while the pressing surfaces 83b, 103b slide against each other, the transition surfaces 83a, 103a slide against each other, and the first side surfaces 81, 101 slide against each other in this order. Then, as the drive cam 60 rotates to one side in the bolt circumferential direction relative to the driven cam 61, the driven cam 61 is displaced outward in the left-right direction due to the biasing force of the cam biasing member 58. As a result, as the drive cam 60 rotates to one side in the bolt circumferential direction, the thickness of the fastening cam 55 gradually decreases (the drive base 71 and the driven base 91 move closer to each other).

[0080] As the thickness of the fastening cam 55 decreases, the fastening portions 25, 26 move away from each other together with the side plate portions 41, 42, and the diameter of the retaining tube portion 24 increases. Thereafter, as shown in FIGS. 11 and 12 , the cam projection 73b reaches between the follower projections 93b that are adjacent to each other in the bolt circumferential direction of the driven cam 61, and the thickness of the fastening cam 55 becomes minimum. In this state, the clamping of the inner column 22 by the retaining tube portion 24 is released, and telescopic movement and tilt movement are permitted (the lock is released). In the unlocked state, the locking surface 83 of the drive cam 60 faces the release surface 105 of the driven cam 61 in the left-right direction, and the pressing surface 103b of the driven cam 61 faces the release surface 85 of the drive cam 60 in the left-right direction. In addition, in the unlocked state, the drive cam 60 is restricted from rotating in one direction around the bolt relative to the driven cam 61 because the release position control surface 74c of the drive cam 60 and the release position control surface 94c of the driven cam 61 abut in the circumferential direction of the bolt.

[0081] In the unlocked state, telescoping can be performed by moving the steering wheel 2 forward or backward. For example, by pushing the steering wheel 2 forward, the steering wheel 2 moves forward relative to the outer column 21 together with the inner column 22 and the steering shaft 12. On the other hand, by pulling the steering wheel 2 rearward, the steering wheel 2 moves rearward relative to the outer column 21 together with the inner column 22 and the steering shaft 12. This makes it possible to adjust the fore-and-aft position of the steering wheel 2 to any position. Note that, as shown in FIG. 4 , when the column unit 11 is in the most retracted position P1, the lock bolt 53 abuts against the front telescoping stopper 36b from the rear via the collar 59, thereby restricting the forward movement of the inner column 22, etc. On the other hand, when the column unit 11 is in the most extended position P2, the lock bolt 53 abuts against the rear telescoping stopper 36c from the front via the collar 59, thereby restricting the rearward movement of the inner column 22, etc.

[0082] In the unlocked state, tilting can be performed by moving the steering wheel 2 up and down. For example, to adjust the steering wheel 2 upward, the steering wheel 2 is pushed upward. This moves the lock bolt 53 upward within the tilt guide hole 45, causing the steering wheel 2 to move upward together with the column unit 11 and steering shaft 12 around the axis O3. On the other hand, to adjust the steering wheel 2 downward, the steering wheel 2 is pulled downward. This moves the steering wheel 2 downward together with the column unit 11 and steering shaft 12 around the axis O3 along the tilt guide hole 45. This allows the angle of the steering wheel 2 to be adjusted to any position.

[0083] After the telescopic movement or tilt movement is completed, the fastening cam 55 is returned to the locked state. Specifically, the operating lever 54 is rotated toward the other side in the bolt circumferential direction. As the operating lever 54 rotates, the drive cam 60 rotates relative to the driven cam 61 toward the other side in the bolt circumferential direction. Then, as shown in FIGS. 9 and 10 , the peripheral surfaces of the cam protrusion 73b and the follower protrusion 93b slide against each other, and the driven cam 61 moves inward in the left-right direction against the biasing force of the cam biasing member 58. Specifically, the drive cam 60 rotates relative to the driven cam 61 toward the other side in the bolt circumferential direction while the first side surfaces 81, 101 slide against each other, the transition surfaces 83a, 103a slide against each other, and the pressing surfaces 83b, 103b slide against each other in this order. Then, as the drive cam 60 rotates relative to the driven cam 61 toward the other side in the bolt circumferential direction, the driven cam 61 is displaced inward in the left-right direction against the biasing force of the cam biasing member 58. As a result, as the drive cam 60 rotates toward the other side in the bolt circumferential direction, the thickness of the fastening cam 55 gradually increases (the drive base 71 and the driven base 91 move apart).

[0084] 7, in the process in which the locking surface 83 (transition surface 83a and pressing surface 83b) of the driving cam 60 slides on the locking surface 103 (transition surface 103a and pressing surface 103b) of the driven cam 61, the locking surfaces 83, 103 slide against each other via the peaks 83c, 103c. In other words, the driving cam 60 and the driven cam 61 always slide against each other at the peaks 83c, 103c located on the inner peripheries, with the outer relief portions 83d, 103d located on the outer peripheries separated from each other.

[0085] As the thickness of the fastening cam 55 increases, the tightening portions 25, 26 approach each other together with the side plate portions 41, 42, and the diameter of the retaining tube portion 24 is reduced. Thereafter, the pressing surface 83b of the drive cam 60 and the pressing surface 103b of the driven cam 61 come into contact with each other in the left-right direction, and the thickness of the fastening cam 55 reaches its maximum. In this state, the inner column 22 is clamped by the retaining tube portion 24, and the telescopic movement and tilt movement are restricted (the fastening cam 55 enters a locked state). In the locked state, the lock position restriction surface 74a of the drive cam 60 and the lock position restriction surface 74a of the driven cam 61 come into contact with each other in the bolt circumferential direction, and therefore rotation of the fastening cam 55 to the other side in the bolt circumferential direction relative to the driven cam 61 is restricted.

[0086] As described above, in the steering device 1 of this embodiment, the locking surface 83 of the drive cam 60 (cam portion 73) is configured to include an apex 83c that contacts the locking surface 103 of the driven cam 61 (cam follower portion 93), and an outer escape portion 83d that extends in the left-right direction away from the locking surface 103 as it moves from the apex 83c outward in the bolt radial direction. With this configuration, when the drive cam 60 and the driven cam 61 rotate relative to each other, the apexes 83c, 103c located on the inner periphery can always slide with the outer reliefs 83d, 103d located on the outer periphery separated from each other. This allows the contact positions on the locking surfaces 83, 103 to be set on the inner side in the bolt radial direction, thereby reducing the torque about the axis O2 when the operating lever 54 is rotated. This reduces the operating torque when rotating the operating lever 54, ensuring excellent operability. Furthermore, when the contact position on the locking surfaces 83, 103 is set radially inward of the bolt, the radius of curvature of the locking surfaces 83, 103 can be set relatively large compared to a configuration in which the radius of curvature of the cam portion is small. As a result, of the load acting between the locking surfaces 83, 103 in the normal direction of the locking surfaces 83, 103, the component force along the rotational direction of the drive cam 60 can be reduced and the component force along the left-right direction can be increased. By reducing the component force along the rotational direction of the drive cam 60, the frictional force during relative rotation between the drive cam 60 and the driven cam 61 can be reduced, further improving operability. By increasing the component force along the left-right direction, it is easier to ensure an axial force that presses the side plate portion 41 in the left-right direction via the cam follower portion 93. As a result, the desired tightening force can be easily achieved in the locked state. Furthermore, compared to a configuration in which the radius of curvature of the cam portion is small, manufacturing variations can be reduced, so variations in the contact position of the locking surfaces 83, 103 between products can be reduced, and a high-quality steering device 1 can be provided.

[0087] In this embodiment, the apexes 83c and 103c are configured to be formed at the inner ends of the locking surfaces 83 and 103 in the bolt radial direction. According to this configuration, the contact position on the locking surfaces 83, 103 can be set to the innermost position in the bolt radial direction, so that the torque about the axis O2 when the operating lever 54 is rotated can be more reliably reduced.

[0088] In this embodiment, the outer relief portions 83d, 103d are configured to be formed as inclined surfaces that gradually become more spaced apart in the left-right direction as they move from the top portions 83c, 103c outward in the bolt radial direction. According to this configuration, it is easier to ensure the strength of the cam projection 73b and the follower projection 93b compared to a configuration in which the outer relief portions 83d, 103d are formed into a curved surface or a stepped shape, for example.

[0089] In this embodiment, the locking surfaces 83, 103 of the driving cam 60 and the driven cam 61 are both configured to have apexes 83c, 103c formed thereon. According to this configuration, it is easy to set the contact position on the locking surfaces 83, 103, so that the variation in the contact position of the locking surfaces 83, 103 between products can be reduced, and a steering device 1 with excellent reliability can be provided.

[0090] In this embodiment, the drive cam 60 is provided with a regulating portion 74 that bulges outward in the left-right direction from the drive base 71 at a portion of the drive base 71 that is located radially outward from the cam portion 73 in the bolt diameter direction, and the driven cam 61 is provided with a regulating portion 94 that bulges outward in the left-right direction from the driven base 91 at a portion of the drive base 91 that is located radially outward from the cam follower portion 93 in the bolt diameter direction. This configuration allows the outer diameters of the drive cam 60 and the driven cam 61 to be reduced compared to when the restricting portion 74 and the cam protrusion 73b, and the restricting portion 94 and the follower protrusion 93b are arranged on the same circumference. Furthermore, by arranging the cam protrusion 73b and the follower protrusion 93b radially inward of the restricting portions 74, 94, it is easier to reduce the torque centered on the axis O2.

[0091] In this embodiment, a cam biasing member 58 that biases the cam follower portion 93 toward the cam portion 73 is disposed between the driven cam 61 and the first side plate portion 41. This configuration makes it easy to ensure a lateral load acting between the drive cam 60 and the driven cam 61. Therefore, it makes it easy to ensure a frictional force (static frictional force) acting in the bolt circumferential direction between the drive cam 60 and the driven cam 61, particularly when the fastening cam 55 is in the unlocked state. As a result, when the fastening cam 55 is in the unlocked state, even if the lock bolt 53 (operating lever 54) is urged toward the other side in the bolt circumferential direction by the urging force of the first urging member 56 or the like, the fastening cam 55 can be prevented from rotating toward the locked state. As a result, in the unlocked state, the axial force acting by the fastening cam 55 is reduced, enabling smooth telescopic movement or tilting movement.

[0092] Although preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to these embodiments. Addition, omission, substitution, and other modifications of the configuration are possible without departing from the spirit of the present disclosure. The present disclosure is not limited by the above description, but is limited only by the scope of the appended claims. For example, in the above-described embodiment, the axis O1 intersects with the shaft axial direction, but the present invention is not limited to this configuration. The axis O1 may coincide with the shaft axial direction of the vehicle.

[0093] In the above-described embodiment, the apex 83c, 103c and the outer recess 83d, 103d are formed on the locking surfaces 83, 103 of the drive cam 60 and the driven cam 61, respectively, but the present invention is not limited to this configuration. It is sufficient that the apex (first apex) and the outer recess (first recess) are formed on a portion (first portion) of either the cam protrusion 73b or the follower protrusion 93b. In the above-described embodiment, a configuration in which the apex 83c, 103c is formed at the inner end of the locking surface 83, 103 in the bolt radial direction has been described, but this configuration is not limited thereto. For example, as shown in FIG. 13 , the locking surface 83, 103 may have the apex 83c, 103c in the center of the bolt radial direction. In this case, an outer relief portion 83d, 103d is formed in a portion of the locking surface 83, 103 that is positioned outer in the bolt radial direction relative to the apex 83c, 103c. An inner relief portion 83e, 103e is formed in a portion of the locking surface 83, 103 that is positioned inner in the bolt radial direction relative to the apex 83c, 103c. In this way, the position of the apex 83c, 103c of the locking surface 83, 103 in the bolt radial direction can be adjusted as needed, as long as it is located inside the outer relief portion 83d, 103d.

[0094] The range of the apex 83c, 103c in the bolt radial direction can be changed as appropriate. For example, as shown in Fig. 14, the apex 83c, 103c is not limited to being linear along the bolt circumferential direction, but may be formed in a planar shape. In this case, the locking surface 83, 103 is formed in a trapezoidal shape when viewed from the bolt circumferential direction. In the above-described embodiment, the release surfaces 85, 105 are formed as flat surfaces, but the present invention is not limited to this configuration. For example, as shown in Fig. 15, the release surfaces 85, 105 may be formed to follow the shape of the locking surfaces 83, 103, such as inclined surfaces that move away from each other in the left-right direction as they move radially inward of the bolt. In this case, the release surfaces 85, 105 and the locking surfaces 83, 103 are more likely to come into surface contact with each other in the unlocked position, thereby reducing the surface pressure acting between the locking surfaces 83, 103 and the release surfaces 85, 105. As a result, the axial force in the unlocked state can be reduced.

[0095] In the above-described embodiment, the restricting portions 74, 94 are provided radially outward of the cam portion 73 and the cam follower portion 93, respectively, but the present invention is not limited to this configuration. The cam portion 73 and the restricting portion 74, and the cam follower portion 93 and the restricting portion 94 may be provided on the same circumference. In the above-described embodiment, the pair of side plate portions 41, 42 are sandwiched from both left and right sides by both ends of the lock bolt 53. However, the present invention is not limited to this configuration. The pair of side plate portions 41, 42 may be sandwiched from both left and right sides by rod-shaped members other than the lock bolt 53.

[0096] In the above-described embodiment, a configuration has been described in which the entire locking surface 83, 103 in the bolt circumferential direction (the transition surface 83a, 103a and the pressing surface 83b, 103b) has the apex 83c, 103c, but this configuration is not limited to this. A configuration in which the apex 83c, 103c may be provided on only a portion of the locking surface 83, 103 in the bolt circumferential direction (for example, only the pressing surface 83b, 103b) may also be provided. Furthermore, in addition to the locking surface 83, 103, a configuration in which the first side surface 81, 101 (the entire cam protrusion 73b or the follower protrusion 93b) has a apex may also be provided. In the above-described embodiment, the outer relief portions 83d, 103d are formed as inclined surfaces that gradually extend in the left-right direction as they extend radially outward in the bolt direction, but the present invention is not limited to this configuration. The outer relief portions 83d, 103d may be curved surfaces, stepped surfaces, or the like, as long as they extend in directions that separate them in the left-right direction as they extend radially outward from the tops 83c, 103d.

[0097] In addition, within the scope of the present disclosure, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described modified examples may be combined as appropriate. [Explanation of symbols]

[0098] 1: Steering device 11: Column unit 12: Steering shaft 14: Rear bracket (bracket) 15: Locking mechanism 41:First side plate part (side plate part) 42:Second side plate part (side plate part) 45: Tilt guide hole 53: Rock bolt (rod) 58: Cam biasing member (biasing member) 60: Drive cam 61: Follower cam 71: Driving base 73: Cam section (first part, second part) 74: Regulatory unit (first regulator) 81: First side (crossing surface) 83c: Top (first top, second top) 83d: Outer relief portion (first relief portion, second relief portion) 91: Driven base 93: Cam follower part (second part, first part) 94: Regulatory Department (Second Regulatory Department) 101: First side (crossing surface) 103c: Top (second top, first top) 103d: Outer relief portion (second relief portion, first relief portion) O1: Axis (First Axis) O2: Axis (Second Axis)

Claims

1. a column unit that supports a steering shaft rotatably about a first axis that extends along the front-rear direction; a bracket having a pair of side plate portions on both left and right sides of the column unit, each having a tilt guide hole extending in a vertical direction, and supporting the column unit so that the column unit is movable up and down along the tilt guide hole; a locking mechanism that switches between a locked state in which the pair of side plate portions are brought closer to each other in the left-right direction to restrict vertical movement of the column unit relative to the bracket, and an unlocked state in which the pair of side plate portions are separated from each other in the left-right direction to allow vertical movement of the column unit relative to the bracket, The locking mechanism is a rod that penetrates the column unit and the tilt guide hole in the left-right direction and is supported by the column unit so as to be rotatable in a circumferential direction about a second axis that extends along the left-right direction; a drive cam having a drive base and a cam portion that bulges out in the left-right direction from the drive base and rotates integrally with the rod; a driven base; and a driven cam having a cam follower portion that bulges out in the left-right direction from the driven base and slides against the cam portion as the rod rotates, the locking mechanism moves the pair of side plate portions closer to each other in the left-right direction as the cam portion slides on the cam follower portion toward the first side in the circumferential direction, thereby moving the drive base and the driven base apart in the left-right direction; and moves the pair of side plate portions closer to each other in the left-right direction as the cam portion slides on the cam follower portion toward the second side in the circumferential direction as the drive base and the driven base approach each other in the left-right direction, thereby moving the pair of side plate portions closer to each other in the left-right direction; a first portion of the cam portion and the cam follower portion; a first apex contacting a second portion of the cam portion and the cam follower; a first relief portion extending in a direction away from the second portion in the left-right direction while moving from the first apex portion toward the outside in a radial direction intersecting the second axis, The second portion is a second apex contacting the first apex; a second recess portion extending from the second apex portion toward the outside in the radial direction and away from the first portion in the left-right direction.

2. The steering device according to claim 1 , wherein the first apex is formed at an inner end of the first portion in the radial direction.

3. 3. The steering device according to claim 1, wherein the first recess is formed as an inclined surface that extends in a direction away from the second portion in the left-right direction as it moves radially outward from the first apex.

4. A column unit that supports a steering shaft rotatably around a first axis along the fore-and-aft direction; a bracket having a pair of side plate portions on both left and right sides of the column unit, each having a tilt guide hole extending in a vertical direction, and supporting the column unit so that the column unit is movable up and down along the tilt guide hole; a locking mechanism that switches between a locked state in which the pair of side plate portions are brought closer to each other in the left-right direction to restrict vertical movement of the column unit relative to the bracket, and an unlocked state in which the pair of side plate portions are separated from each other in the left-right direction to allow vertical movement of the column unit relative to the bracket, The locking mechanism is a rod that penetrates the column unit and the tilt guide hole in the left-right direction and is supported by the column unit so as to be rotatable in a circumferential direction about a second axis that extends along the left-right direction; a drive cam having a drive base and a cam portion that bulges out in the left-right direction from the drive base and rotates integrally with the rod; a driven base; and a driven cam having a cam follower portion that bulges out in the left-right direction from the driven base and slides against the cam portion as the rod rotates, the locking mechanism moves the pair of side plate portions closer to each other in the left-right direction as the cam portion slides on the cam follower portion toward the first side in the circumferential direction, thereby moving the drive base and the driven base apart in the left-right direction; and moves the pair of side plate portions closer to each other in the left-right direction as the cam portion slides on the cam follower portion toward the second side in the circumferential direction as the drive base and the driven base approach each other in the left-right direction, thereby moving the pair of side plate portions closer to each other in the left-right direction; a first portion of the cam portion and the cam follower portion; a first apex contacting a second portion of the cam portion and the cam follower; a first relief portion extending in a direction away from the second portion in the left-right direction while moving from the first apex portion toward the outside in a radial direction intersecting the second axis, the drive cam includes a first restriction portion that bulges outward in the left-right direction from the drive base at a portion of the drive base that is positioned radially outward from the cam portion, the driven cam includes a second restriction portion that bulges outward in the left-right direction from the driven base at a portion of the driven base that is positioned radially outward from the cam follower portion, A steering device in which the first regulating portion and the second regulating portion abut in the circumferential direction in the locked state to regulate rotation of the cam portion toward the first side in the circumferential direction relative to the cam follower portion.

5. 5. The steering device according to claim 1, wherein a biasing member is disposed between the driven cam and the side plate portion to bias the cam follower portion toward the cam portion.

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