Steering device

Abstract

To provide a steering assemblage capable of suppressing an increase in the number of components or man-hour for assembling, inhibiting a backlash of a rod, and performing a smooth tilt movement.SOLUTION: A steering assemblage in accordance with an embodiment of the present invention includes a column unit, a front bracket, a rear bracket, and a rock mechanism. The rock mechanism includes a rod supported by the column unit so that the rod can move in a vertical direction in a tilt guide hole in an unlocked condition, and a manipulation part that is fixed to a first lateral end in a horizontal direction of the rod and used to manipulate the rod. A first through hole includes a first straight part and first tapered part. A second through hole includes a second straight part and second tapered part.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention 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 that restricts the rotation of the column unit relative to the front bracket and an unlocked state that allows the column unit to rotate relative to the front bracket (see, for example, Patent Document 1 below). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2019 / 189473 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, an operating lever for operating the rod is attached to a first side end of the rod in the left-right direction. Therefore, the weight of the operating lever causes the first side end of the rod to tilt downward by the amount of the gap between the rod and the through-hole. In particular, the through-hole formed in the column unit generally has a draft angle set to improve mold releasability during molding of the column unit. That is, the through-hole is formed in a tapered shape, with the inner diameter gradually increasing from the inside to the outside in the left-right direction. Therefore, a gap is likely to occur between the inner circumferential surface of the through-hole and the outer circumferential surface of the rod. Performing a tilting operation in this state poses a problem of rattle in the rod, and the rattle can easily cause vibrations and abnormal noises.

[0006] For example, Patent Document 1 discloses a configuration in which a rod is supported by a sleeve provided in a through-hole. However, the configuration in Patent Document 1 requires a separate sleeve to be provided on the column unit, which may lead to an increase in the number of parts and assembly steps.

[0007] The present disclosure provides a steering device that can suppress rod rattle and perform smooth tilting operations while suppressing an increase in the number of parts and an increase in assembly man-hours. [Means for solving the problem]

[0008] In order to solve the above problems, the present disclosure employs the following aspects. A steering device according to one aspect of the present disclosure includes: a column unit that supports a steering shaft rotatably about a first axis along a front-rear direction; a front bracket that supports the column unit rotatably about a second axis along a left-right direction and is attached to a vehicle body; a rear bracket that has side plate portions located on both left-right sides of the column unit, with tilt guide holes extending in a vertical direction formed in the side plate portions and is attached to the vehicle body behind the front bracket; and a lock mechanism that switches between a locked state that restricts movement of the column unit about the second axis relative to the front bracket and an unlocked state that allows movement of the column unit about the second axis relative to the front bracket, wherein the column unit has a first through hole that penetrates in the left-right direction and a first tightening portion that is provided on a first side in the left-right direction with respect to the first axis, and a second through hole that penetrates in the left-right direction and is provided on a second side in the left-right direction with respect to the first axis, and the lock mechanism and a second tightening portion that moves toward or away from the first tightening portion as the locking mechanism transitions between the locked state and the unlocked state, the locking mechanism comprising: a rod that passes through the first through hole, the second through hole, and the tilt guide hole in the left-right direction and is supported by the column unit so as to be movable up and down within the tilt guide hole in the unlocked state; and an operating portion that is fixed to a first side end of the rod in the left-right direction and for operating the rod, the first through hole comprising: a first straight portion that extends linearly along the left-right direction at least in a portion located below the rod; and a first tapered portion that is a portion other than the first straight portion and that gradually increases the inner diameter of the first through hole toward a first side in the left-right direction, the second through hole comprising: a second straight portion that extends linearly along the left-right direction at least in a portion located above the rod; and a second tapered portion that is a portion other than the second straight portion and that gradually increases the inner diameter of the second through hole toward a second side in the left-right direction.

[0009] According to this aspect, even if the first side end of the rod in the left-right direction tends to tilt downward due to the weight of the operating part in the unlocked state, the tilt of the rod can be restricted between the first straight portion and the second straight portion. This makes it possible to suppress rattling of the rod, for example, and to suppress vibration of the rod during tilting operation and abnormal noises that may occur when the rod comes into contact with the rear bracket or the like due to vibration. As a result, a smooth tilting operation can be achieved. Furthermore, in this embodiment, the above-mentioned effects are achieved by the shape of the through hole of the column unit, so that an increase in the number of parts and an increase in the number of assembly steps can be suppressed compared to the conventional case in which a separate sleeve is provided inside the through hole.

[0010] In the steering device of the above aspect, it is preferable that the locking mechanism comprises a drive cam having a cam portion and fixed to a first side end portion of the rod in the left-right direction, and a cam follower portion that has a sliding contact with the cam portion as the rod rotates and faces the drive cam in the left-right direction outside the side plate portion that is arranged on the first side of the side plate portion in the left-right direction relative to the first tightening portion. According to this aspect, the tilt angle of the rod (the angle formed by the axis of the rod relative to the left-right direction) can be reduced compared to conventional devices, thereby reducing the load acting between the driven cam and the side plate. As a result, frictional resistance when the driven cam slides on the outer surface of the side plate during tilting can be reduced, resulting in smoother tilting.

[0011] In the steering device of the above aspect, it is preferable that the first straight portion is formed around the entire circumference of a second side end portion of the first through hole in the left-right direction, and the second straight portion is formed around the entire circumference of a first side end portion of the second through hole in the left-right direction. According to this aspect, the inner end of each through-hole in the left-right direction is formed as a straight portion over the entire circumference. Therefore, when molding the column unit, it is possible to reduce variations in the circumferential range of the straight portion between each steering device. Also, it becomes easier to suppress rattle of the rod in the up-down direction.

[0012] In the steering device of the above aspect, it is preferable that the column unit comprises a cylindrical outer column having the first fastening portion and the second fastening portion, and an inner column that is inserted into the outer column so as to be movable forward and backward and that rotatably supports the steering shaft, a hanger bracket is provided on a portion of the inner column that is located between the first fastening portion and the second fastening portion, the hanger bracket has a telescopic guide hole through which the rod is inserted and that extends in the forward and backward directions, and the rod is fitted with a slide guide that has buffer portions located within the telescopic guide hole at least on both forward and backward sides of the rod. According to this aspect, direct contact between the lock bolt and the hanger bracket can be prevented when the column unit is in the fully retracted or fully extended position, thereby preventing abnormal noise from being generated during telescopic movement.

[0013] In the steering device of the above aspect, it is preferable that the slide guide has an insertion hole through which the rod is inserted, and the inner diameter of the insertion hole gradually decreases from the first tightening portion toward the second tightening portion. According to this aspect, rattle between the rod and the slide guide can be suppressed, which makes it easier to suppress tilt of the rod in the unlocked state.

[0014] In the steering device of the above aspect, it is preferable that the slide guide has an insertion hole through which the rod is inserted, and that the insertion hole is formed with a support portion that supports the rod from below. According to this aspect, the rod is supported from below by the inner peripheral edge of the insertion hole, which makes it easier to prevent the rod from tilting in the unlocked state.

[0015] In the steering device of the above aspect, it is preferable that the central axis of the insertion hole is offset upward with respect to the central axis of the rod, and that a portion of the inner peripheral edge of the insertion hole that is located below the rod constitutes the support portion. According to this aspect, since the central axis of the insertion hole is offset upward with respect to the central axis of the rod, the portion of the inner periphery of the insertion hole that is positioned below the rod can function as a support portion, which reduces dimensional variation of the support portion between steering devices when molding the slide guide.

[0016] In the steering device of the above aspect, it is preferable that the hanger bracket includes a bracket side wall in which the telescopic guide hole is formed, and a bracket bottom wall extending in the left-right direction from the lower end edge of the bracket side wall, the slide guide includes a guide side wall having the insertion hole and arranged on a first side in the left-right direction with respect to the bracket side wall, and a guide bottom wall extending in the left-right direction from the lower end edge of the guide side wall and arranged below the bracket bottom wall, and that a biasing member is provided between the rear bracket and the column unit to bias the column unit upward via the guide bottom wall. According to this aspect, since the slide guide is biased upward together with the column unit, rattle between the slide guide and the hanger bracket can be suppressed, which in turn suppresses rattle of the rod relative to the hanger bracket and makes it easier to suppress tilt of the rod in the unlocked state. [Effects of the Invention]

[0017] According to each of the above aspects, it is possible to perform a smooth tilting operation while suppressing an increase in the number of parts and an increase in the number of assembly steps. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a perspective view of a steering device according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view corresponding to line II-II in FIG. [Figure 3] FIG. 3 is a cross-sectional view corresponding to line III-III in FIG. 2. [Figure 4] FIG. [Figure 5] FIG. 4 is a cross-sectional view corresponding to the line VV in FIG. [Figure 6] FIG. [Figure 7] FIG. 4 is an enlarged view of FIG. [Figure 8] FIG. 8 is a cross-sectional view corresponding to line VIII-VIII in FIG. [Figure 9] FIG. 10 is a schematic diagram of a steering device according to a modified example. [Figure 10] FIG. 10 is a side view of the periphery of a slide guide according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0019] Next, an embodiment of the present invention will be described with reference to the drawings. In the embodiments and modifications described below, corresponding components will be designated by the same reference numerals, and their description may be omitted. In the following description, expressions indicating relative or absolute arrangements, such as "parallel," "orthogonal," "center," and "coaxial," not only strictly indicate such arrangements, but also indicate a state in which the components are relatively displaced by an angle or distance to such an extent that tolerances or the same functions are obtained.

[0020] [Steering device 1] 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.

[0021] The steering device 1 includes a column unit 11, a steering shaft 12, brackets (a front bracket 13 and a rear bracket 14), and an adjustment mechanism 15. The column unit 11 and the steering shaft 12 are each formed into a cylindrical shape and disposed on a first axis O1. Therefore, in the following description, the direction in which the first 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 first axis O1 may be referred to as the shaft radial direction, and the direction around the first axis O1 may be referred to as the shaft circumferential direction.

[0022] The steering device 1 of this embodiment is mounted on a vehicle with the first axis O1 inclined with respect to the front-to-rear direction. Specifically, the first axis O1 of the steering device 1 extends upward as it approaches the rear. However, for convenience, in the following description, the shaft axial direction will be referred to as the front-to-rear direction. In the steering device 1, the direction toward the steering wheel 2 in the front-to-rear direction will simply be referred to as the rear, and the direction toward the opposite side of the steering wheel 2 will simply be referred to as the front (arrow FR). Furthermore, among 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-to-right direction will simply be referred to as the left-to-right direction.

[0023] <Column Unit 11> Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 2. As shown in FIGS. 1 to 3, the column unit 11 has an outer column 21 and an inner column 22. 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, and a second fastening portion .

[0024] The retaining cylindrical portion 24 is formed in a cylindrical shape extending along the first axis O1. A slit 28 is formed in a part of the rear portion of the retaining cylindrical portion 24 in the circumferential direction of the shaft (in this embodiment, the lower part of the outer column 21). The slit 28 passes through the outer column 21 in the vertical direction and is open at the rear end surface of the outer column 21.

[0025] 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. A first through-hole 31 is formed in the first tightening portion 25, penetrating the first tightening portion 25 in the left-right direction. A second through-hole 32 is formed in the second tightening portion 26, penetrating the second tightening portion 26 in the left-right direction. The shapes of the through-holes 31, 32 will be described later.

[0026] As shown in Fig. 2, the inner column 22 is formed in a cylindrical shape extending along the first axis O1. 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. The inner column 22 is configured to be movable in the front-rear direction relative to the retaining cylindrical portion 24. Within the inner column 22, bearings 34 are attached to the front end and rear end, respectively, by press fitting or the like.

[0027] <Steering shaft 12> The steering shaft 12 includes a rear shaft 40 and a front shaft 41. The rear shaft 40 is inserted into the inner column 22. The rear shaft 40 is supported within the inner column 22 via a bearing 34 so as to be rotatable about a first axis O1. The rear end of the rear shaft 40 protrudes rearward through a rear end opening of the inner column 22. The steering wheel 2 (see FIG. 1) is connected to the rear end of the rear shaft 40.

[0028] The front shaft 41 is connected to the front end of the rear shaft 40 via a first universal joint 43. That is, the front shaft 41 is configured to be able to swing relative to the rear shaft 40. The front end of the front shaft 41 is connected to a steering gear box (not shown) via a second universal joint (not shown). In the steering device 1, the rotational force of the steering shaft 12 is transmitted to the steering gear box, thereby steering the wheels.

[0029] <Bracket 13, 14> As shown in Figure 1, the front bracket 13 connects the outer column 21 and the vehicle body via the pivot shaft 50. The front bracket 13 is formed in a U-shape that opens downwards when viewed from the front in the front-to-rear direction. The front bracket 13 surrounds the rear end of the outer column 21 from above and on both sides in the left-to-right direction. The outer column 21 is supported by the front bracket 13 so as to be rotatable about a second axis O2 that extends in the left-to-right direction with the pivot shaft 50 as the center.

[0030] As shown in Figure 3, the rear bracket 14 connects the outer column 21 and the vehicle body via a lock bolt (rod) 80, which will be described later. The rear bracket 14 is formed in a U-shape that opens downwards when viewed from the front in the front-to-rear direction. The rear bracket 14 surrounds the outer column 21 from above and on both sides in the left-right direction. Specifically, the rear bracket 14 includes a first side plate portion 54 that is arranged on a first side in the left-right direction with respect to the column unit 11, a second side plate portion 55 that is arranged on a second side in the left-right direction with respect to the column unit 11, and a bridge portion 56 that connects the side plate portions 54, 55 together.

[0031] FIG. 4 is an enlarged perspective view of the lock bolt 80 and its surroundings. As shown in Figures 3 and 4, each side plate portion 54, 55 has a tilt guide hole 57 formed therein that penetrates the side plate portion 54, 55 in the left-right direction. The tilt guide hole 57 is an elongated hole that extends in the up-down direction. Specifically, the tilt guide hole 57 is formed in the shape of a circular arc that convex rearward with the second axis O2 as its center of curvature. A lock bolt 80 penetrates the tilt guide hole 57 in the left-right direction. That is, the lock bolt 80 moves up and down within the tilt guide hole 57 during tilting of the column unit 11 (adjusting the up-down position of the column unit 11 about the second axis O2).

[0032] As shown in Fig. 2, the bridge portion 56 connects the upper ends of the side plate portions 54, 55. The bridge portion 56 is formed in an arch shape that protrudes upward. The bridge portion 56 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 56 from below.

[0033] <Adjustment mechanism 15> 3 and 4, the adjustment mechanism 15 adjusts the longitudinal position (telescopic position) of the inner column 22 (and the steering shaft 12) relative to the outer column 21, and the vertical position (tilt position) of the column unit 11 about the second axis O2 relative to the front bracket 13. Specifically, the adjustment mechanism 15 includes a hanger bracket 60, a locking mechanism 61, a slide guide 62, and a biasing member 63.

[0034] The hanger bracket 60 guides the forward and backward movement of the inner column 22 relative to the outer column 21. The hanger bracket 60 is fixed to the outer peripheral surface of the inner column 22 facing downward. The hanger bracket 60 is formed, for example, by pressing a metal plate. The hanger bracket 60 is formed in a U-shape that opens upward when viewed from the front. The hanger bracket 60 includes a first opposing wall portion (bracket side wall) 71 and a second opposing wall portion (bracket side wall) 72 that face each other in the left-right direction, and a bracket bottom wall 73 that connects the lower end edges of the opposing wall portions 71, 72. The upper end edges of the opposing wall portions 71, 72 are fixed to the inner column 22 by welding or the like.

[0035] The hanger bracket 60 is exposed to the outside of the outer column 21 through the slit 28. A first telescopic guide hole 74 is formed in the first opposing wall portion 71, penetrating the first opposing wall portion 71 in the left-right direction. A second telescopic guide hole 75 is formed in the second opposing wall portion 72, penetrating the second opposing wall portion 72 in the left-right direction. The guide holes 74, 75 are arranged facing each other in the left-right direction. The guide holes 74, 75 are elongated holes whose major axis direction is the front-rear direction. When viewed from the left-right direction, part of the guide holes 74, 75 overlap with the through holes 31, 32 in the front-rear direction.

[0036] FIG. 5 is a cross-sectional view taken along line VV in FIG. As shown in FIG. 5, the first telescopic guide hole 74 has a telescopic region 74a and a load absorbing region 74b that is connected to the rear of the telescopic region 74a. The telescopic region 74a is formed so that its width in the vertical direction is uniform. Within the telescopic region 74a, the lock bolt 80 moves back and forth as the inner column 22 moves relative to the outer column 21.

[0037] A protruding piece 74c is formed at the lower edge of the first telescopic guide hole 74, at the boundary between the telescopic region 74a and the load absorbing region 74b. The protruding piece 74c is located on the movement path of the lock bolt 80 in the front-to-rear direction. During telescopic movement, the lock bolt 80 abuts against the protruding piece 74c, thereby restricting the telescopic range. The protruding piece 74c is configured to tilt rearward with its lower end serving as a fulcrum when an impact during, for example, a secondary collision is transmitted via the lock bolt 80. That is, in the load absorbing region 74b, the protruding piece 74c tilts as the hanger bracket 60 moves forward relative to the lock bolt 80, thereby absorbing the impact load during the secondary collision. Note that the protruding piece 74c may protrude downward from the upper edge of the first telescopic guide hole 74.

[0038] 2, the second telescopic guide hole 75 has a length equal to that of the first telescopic guide hole 74 (the telescopic region 74a and the load absorbing region 74b). The second telescopic guide hole 75 is formed so that its width in the up-down direction is uniform over its entire length.

[0039] As shown in FIG. 4, the locking mechanism 61 includes a locking bolt 80, an operating lever 81, and a cam mechanism 82. The lock bolt 80 passes through the side plate portions 54, 55, the tightening portions 25, 26, and the hanger bracket 60 in the left-right direction via the tilt guide hole 57, the through holes 31, 32, and the telescopic guide holes 74, 75. During telescopic operation, the lock bolt 80 moves back and forth within the telescopic guide holes 74, 75 as the inner column 22 moves back and forth relative to the outer column 21. During tilt operation, the lock bolt 80 moves up and down within the tilt guide hole 57, thereby moving up and down together with the column unit 11. In the following description, the axis of the lock bolt 80 is referred to as a third axis O3, and the direction perpendicular to the third axis O3 may be referred to as the bolt radial direction, and the direction around the third axis O3 may be referred to as the bolt circumferential direction.

[0040] The operating lever 81 extends in a cantilever fashion rearward from the lock bolt 80. Specifically, the base end (front end) of the operating lever 81 is connected to the left end (first side end in the left-right direction) of the lock bolt 80. The operating lever 81 is configured to be rotatable around the third axis O3 together with the lock bolt 80 by pushing down or pulling up via the tip end (rear end).

[0041] The cam mechanism 82 is disposed between the operating lever 81 and the first side plate portion 54. The cam mechanism 82 includes a drive cam 90 and a driven cam 91. The drive cam 90 is formed in a disk shape and is arranged coaxially with the third axis O3. The drive cam 90 is fixed to the operating lever 81. That is, the drive cam 90 rotates integrally with the operating lever 81 around the axis O3 as the operating lever 81 is operated. The drive cam 90 includes a drive base 90a and a cam portion 90b.

[0042] The drive base 90a is formed in a disk shape and is arranged coaxially with the third axis O3. The lock bolt 80 passes through the center of the drive base 90a in the bolt radial direction in the left-right direction. The cam portion 90b protrudes inward in the left-right direction (toward the driven cam 91) from the drive base 90a. A plurality of cam portions 90b are formed at intervals in the bolt circumferential direction.

[0043] The driven cam 91 is disposed between the first side plate portion 54 and the drive cam 90. The driven cam 91 is formed in a disk shape and is disposed coaxially with the axis O3. The driven cam 91 is supported by the first side plate portion 54 with the lock bolt 80 passing through it. The driven cam 91 includes a driven base 91a, a rotation prevention portion 91b (see FIG. 7), and a cam follower portion 91c.

[0044] The driven base 91a is formed in a disk shape and is arranged coaxially with the third axis O3. The lock bolt 80 passes through the center of the driven base 91a in the bolt radial direction in the left-right direction. 7, the anti-rotation portion 91b protrudes inward in the left-right direction from the driven base 91a. The anti-rotation portion 91b is housed in the tilt guide hole 57. The anti-rotation portion 91b comes into contact with the inner peripheral edge of the tilt guide hole 57, thereby restricting the rotation of the driven cam 91 about the third axis O3 relative to the first side plate portion 54. As shown in Fig. 4, a plurality of cam follower portions 91c are formed at intervals around the bolt circumference to correspond to the cam portion 90b. The cam follower portions 91c form a sliding surface along which the cam portion 90b slides as the operating lever 81 rotates. The cam follower portions 91c of the cam portion 90b gradually increase in the amount of protrusion from the follower base 91a toward one side in the bolt circumference direction.

[0045] The cam mechanism 82 is configured so that its thickness in the left-right direction changes as the cam portion 90b slides on the cam follower portion 91c in response to the rotation of the operating lever 81. In the steering device 1, the change in thickness of the cam mechanism 82 causes the tightening portions 25, 26 to move closer to or farther away from each other in the left-right direction via the side plate portions 54, 55 (so that the left-right dimension of the slit 28 expands or contracts). Specifically, by rotating the operating lever 81 toward one side in the bolt circumferential direction, the thickness of the cam mechanism 82 increases. Then, the tightening portions 25, 26 approach each other together with the side plate portions 54, 55, and the diameter of the retaining tube portion 24 contracts. As a result, the inner column 22 is tightened by the retaining tube portion 24, and the telescopic movement and tilt movement are restricted (locked state). Meanwhile, in the locked state, the thickness of the cam mechanism 82 decreases when the operating lever 81 is rotated toward the other side in the bolt circumferential direction. Then, the fastening portions 25, 26 move away from each other together with the side plate portions 54, 55, expanding the diameter of the retaining cylindrical portion 24. This releases the fastening of the inner column 22 by the retaining cylindrical portion 24, allowing telescopic movement and tilting movement.

[0046] FIG. 6 is a perspective view of the slide guide 62 and its surroundings. As shown in Fig. 6, the slide guide 62 is mounted between the lock bolt 80 and the hanger bracket 60. The slide guide 62 is made of a material (e.g., a resin material) that is elastically deformable and has a smaller coefficient of friction than the lock bolt 80. The slide guide 62 is formed in an L-shape when viewed from the front. The slide guide 62 includes a guide bottom wall 100, a rising piece 101, a guide side wall 102, a front buffer portion 103, and a rear buffer portion 104.

[0047] The guide bottom wall 100 extends in the left-right direction below the bracket bottom wall 73. The guide bottom wall 100 abuts against the bracket bottom wall 73 from below. Downwardly protruding ribs 100a are formed on both front and rear end edges of the guide bottom wall 100. Each rib 100a extends in the left-right direction from both front and rear end edges of the guide bottom wall 100.

[0048] The rising piece 101 extends upward from a second side edge in the left-right direction of the guide bottom wall 100. The rising piece 101 is close to or abuts against the second opposing wall portion 72 from the outside in the left-right direction. The upper edge of the rising piece 101 is located below the lower edge of the second telescopic guide hole 75.

[0049] Fig. 7 is an enlarged view of a main part of Fig. 3. Fig. 8 is a cross-sectional view corresponding to the line VIII-VIII of Fig. 3. 7 and 8, the guide side wall 102 extends upward from a first side edge in the left-right direction of the guide bottom wall 100. The guide side wall 102 is close to or abuts against the first opposing wall portion 71 from the outside in the left-right direction. In other words, the guide bottom wall 100, the rising piece 101, and the guide side wall 102 surround the hanger bracket 60 from below and both the left and right sides. The upper edge of the guide side wall 102 is located above the upper edge of the first telescopic guide hole 74.

[0050] An insertion hole 102a is formed in the guide side wall 102 at a position overlapping the first telescopic guide hole 74 when viewed in the left-right direction. The insertion hole 102a is formed in a tapered shape such that the inner diameter gradually decreases from the outer side toward the inner side in the left-right direction. A center axis O4 of the insertion hole 102a is offset upward with respect to the third axis O3. The bottom end of the insertion hole 102a is located above the lower edge of the first telescopic guide hole 74 and above the bottom ends of the through holes 31 and 32. A lock bolt 80 passes through the insertion hole 102a between the first through hole 31 and the first telescopic guide hole 74. The lock bolt 80 is supported from below within the insertion hole 102a by the lower edge (a portion including the bottom end) of the insertion hole 102a.

[0051] As shown in Figures 5 and 8, when the column unit 11 moves to the most retracted position during telescopic operation, the lock bolt 80 comes into contact with the front edge of the first telescopic guide hole 74 via the front buffer portion 103, thereby mitigating the load at the time of contact. The front buffer portion 103 protrudes inward in the left-right direction from a portion of the guide side wall 102 that is positioned forward of the insertion hole 102a. The front buffer portion 103 is interposed within the first telescopic guide hole 74 between the front edge of the first telescopic guide hole 74 and the lock bolt 80. Each front buffer portion 103 is formed in a crescent shape when viewed from the left-right direction.

[0052] The surface of the front buffer portion 103 facing rearward (hereinafter referred to as the inner peripheral surface 103a) is formed in an arc shape that convex forward about the central axis O4 when viewed from the left-right direction. In this embodiment, the inner peripheral surface 103a of the front buffer portion 103 smoothly connects to the inner peripheral surface of the insertion hole 102a. That is, the inner peripheral surface 103a of the front buffer portion 103 is formed in a tapered shape that extends in a direction approaching the central axis O4 as it moves inward in the left-right direction. The surface of the front buffer portion 103 facing forward (hereinafter referred to as the outer peripheral surface 103b) is formed in an arc shape that extends in line with the front end edge of the first telescopic guide hole 74 when viewed from the left-right direction.

[0053] The upper end surface of the front buffer portion 103 connects the upper ends of the inner circumferential surface 103a and the outer circumferential surface 103b of the front buffer portion 103. The upper end surface of the front buffer portion 103 is formed into a flat surface that is perpendicular to the up-down direction. It is preferable that the upper end surface of the front buffer portion 103 is spaced downward from the upper edge of the first telescopic guide hole 74. The lower end surface of the front buffer portion 103 connects the lower ends of the inner circumferential surface 103a and the outer circumferential surface 103b of the front buffer portion 103. The lower end surface of the front buffer portion 103 is formed into a flat surface that is perpendicular to the up-down direction. It is preferable that the lower end surface of the front buffer portion 103 is spaced upward from the lower edge of the first telescopic guide hole 74.

[0054] When the column unit 11 moves to the most extended position during telescopic movement, the lock bolt 80 hits the protruding piece 74c via the rear buffer portion 104, thereby mitigating the load at the time of collision. The rear buffer portion 104 is formed symmetrically with respect to a line of symmetry that passes through the central axis O4 and runs along the up-down direction when viewed from the left-right direction. However, the buffer portions 103, 104 may be formed asymmetrically.

[0055] The rear buffer portion 104 protrudes inward in the left-right direction from a portion of the guide side wall 102 that is located rearward with respect to the insertion hole 102a. The rear buffer portion 104 is interposed within the first telescopic guide hole 74 between the protruding piece 74c and the lock bolt 80. The surface of the rear buffer portion 104 facing forward (hereinafter referred to as the inner peripheral surface 104a) is formed in an arc shape that protrudes forward about the central axis O4 when viewed from the left-right direction. In this embodiment, the inner peripheral surface 104a of the rear buffer portion 104 smoothly connects to the inner peripheral surface of the insertion hole 102a. That is, the inner peripheral surface 104a of the rear buffer portion 104 is formed in a tapered shape that extends inward in the left-right direction and approaches the central axis O4. Therefore, the inner peripheral surface 103a of the front buffer portion 103 and the inner peripheral surface 104a of the rear buffer portion 104 approach the outer peripheral surface of the lock bolt 80 as they move inward in the left-right direction. In this embodiment, the inner peripheral surface 103a of the front buffer portion 103 and the inner peripheral surface 104a of the rear buffer portion 104 are formed to have the same radius of curvature.

[0056] The rearward-facing surface of the rear buffer portion 104 (hereinafter referred to as the outer peripheral surface 104b) is formed in an arc shape that extends along the rear end edge of the first telescopic guide hole 74 when viewed from the left-right direction. In this embodiment, the outer peripheral surface 103b of the front buffer portion 103 and the outer peripheral surface 104bb of the rear buffer portion 104 are formed to have the same radius of curvature.

[0057] The upper end surface of the rear buffer portion 104 connects the upper ends of the inner circumferential surface and the outer circumferential surface of the rear buffer portion 104. The upper end surface of the rear buffer portion 104 is formed into a flat surface that is perpendicular to the up-down direction. It is preferable that the upper end surface of the rear buffer portion 104 is spaced downward from the upper edge of the first telescopic guide hole 74. The lower end surface of the rear buffer portion 104 connects the lower ends of the inner and outer circumferential surfaces of the rear buffer portion 104. The lower end surface of the rear buffer portion 104 is formed into a flat surface that is perpendicular to the up-down direction. It is preferable that the lower end surface of the rear buffer portion 104 is spaced upward from the lower edge of the first telescopic guide hole 74.

[0058] As shown in FIGS. 2 to 4, the biasing member 63 is interposed between the rear bracket 14 and the slide guide 62. The biasing member 63 biases the column unit 11 upward via the slide guide 62. The biasing member 63 is, for example, a double torsion spring. That is, the biasing member 63 includes a first coil portion 63a and a second coil portion 63b (see FIG. 2), a first connecting portion 63c, a second connecting portion 63d, and an intermediate portion 63e.

[0059] The first coil portion 63a is disposed in front of the first side plate portion 54, with the left-right direction as its axial direction. The second coil portion 63b is disposed with its axial direction aligned in the left-right direction in front of the second side plate portion 55. That is, the coil portions 63a and 63b are disposed on both sides in the left-right direction with the slit 28 therebetween.

[0060] The first connecting portion 63c extends upward from the outer end of the first coil portion 63a in the left-right direction, and the tip of the first connecting portion 63c is connected to the upper part of the first side plate portion . The second connecting portion 63d extends upward from the outer end of the second coil portion 63b in the left-right direction.

[0061] The intermediate portion 63e connects the inner ends of the first coil portion 63a and the second coil portion 63b in the left-right direction. The intermediate portion 63e is formed in a U-shape that opens forward when viewed from the top-bottom direction. The rear end of the intermediate portion 63e abuts against the guide bottom wall 100 from below. In this way, the biasing member 63 connects the first side plate portion 54 and the second side plate portion 55 in a state where it abuts against the guide bottom wall 100 from below, thereby biasing the slide guide 62 upward and biasing the column unit 11 upward.

[0062] 7 and 8, the first through hole 31 is disposed coaxially with the third axis O3. The first through hole 31 includes a first straight portion 31a and a first tapered portion 31b. The first straight portion 31a constitutes the inner end portion of the first through hole 31 in the left-right direction. The first straight portion 31a is a portion of the first through hole 31 that has a uniform inner diameter (gradient angle (the angle between the third axis O3 and the inner peripheral surface of the first through hole 31 is 0°)). In other words, the first straight portion 31a extends linearly in the left-right direction in both front and plan views. The inner diameter of the first through hole 31 is formed to be slightly larger than the lock bolt 80. The inner edge of the first straight portion 31a in the left-right direction coincides with the inner edge of the first through hole 31 in the left-right direction.

[0063] The first tapered portion 31b is a portion of the first through hole 31 other than the first straight portion 31a. In the example shown, the first tapered portion 31b configures the first through hole 31 from a portion located more inward than the center in the left-right direction to the outer edge in the left-right direction. The inner diameter of the first tapered portion 31b gradually increases as it moves outward in the left-right direction. The inner end of the first tapered portion 31b in the left-right direction is continuous with the first straight portion 31a. The first tapered portion 31b functions as a draft angle when molding the outer column 21, and also functions as a guide when inserting the lock bolt 80 into the first through hole 31. In the example shown, the gradient angle of the first tapered portion 31b is uniform over the entire circumferential direction of the bolt.

[0064] The second through hole 32 overlaps with the first through hole 31 when viewed from the left-right direction, and is formed plane-symmetrically in the left-right direction with respect to the first through hole 31. Specifically, the second through hole 32 includes a second straight portion 32a and a second tapered portion 32b. The second straight portion 32a constitutes an inner end portion in the left-right direction of the second through-hole 32. The second straight portion 32a extends linearly in the left-right direction in both a front view and a plan view. The second tapered portion 32b is the portion of the second through hole 32 other than the second straight portion 32a. The inner end of the second tapered portion 32b in the left-right direction is continuous with the second straight portion 32a. The second tapered portion 32b functions as a draft angle when molding the outer column 21. Note that in the through holes 31, 32, the straight portions 31a, 32a and the tapered portions 31b, 32b may have different dimensions.

[0065] Next, a description will be given of the operation (telescopic operation and tilt operation) of the above-mentioned steering device 1. In the following description, the initial state is when the steering device 1 is in a locked state. To perform telescopic or tilting operations, the steering device 1 is first placed in an unlocked state. To place the steering device 1 in an unlocked state, the operating lever 81 is pushed down in a direction in which the thickness of the cam mechanism 82 decreases (for example, downward). This causes the fastening portions 25, 26 to move apart together with the side plate portions 54, 55, and the inner diameter of the retaining tube portion 24 (the width of the slit 28) is expanded. This releases the fastening of the inner column 22 by the retaining tube portion 24, and also releases the fastening of the outer column 21 by the side plate portions 54, 55. As a result, telescopic and tilting operations become possible.

[0066] <Telescopic movement> To change the position of the steering wheel 2 forward, in the unlocked state, the steering wheel 2 is pushed forward. This causes the steering wheel 2 to move forward relative to the outer column 21 together with the inner column 22 and the steering shaft 12. In the steering device 1, the front buffer portion 103 abuts against the front edge of the first telescopic guide hole 74 from behind, thereby defining the most retracted position (forwardmost position) of the column unit 11. On the other hand, to change the telescopic position of the steering wheel 2 rearward, the steering wheel 2 is retracted in the unlocked state. This causes the steering wheel 2 to move rearward relative to the outer column 21 together with the inner column 22 and the steering shaft 12. In the steering device 1, the rear buffer section 104 abuts against the protruding piece 74c from the front, thereby defining the most extended position (rearmost end position) of the column unit 11. In this way, the fore-and-aft position of the steering wheel 2 can be adjusted as desired between the most retracted position and the most extended position of the column unit 11.

[0067] <Tilt operation> To change the position of the steering wheel 2 upward, in the unlocked state, the steering wheel 2 is pushed upward. Then, the lock bolt 80 moves upward within the tilt guide hole 57, and the steering wheel 2 rotates upward together with the column unit 11 and the steering shaft 12 about the second axis O2. On the other hand, to change the tilt position of the steering wheel 2 downward, in the unlocked state, the steering wheel 2 is pulled downward. This causes the lock bolt 80 to move downward within the tilt guide hole 57, causing the steering wheel 2 to rotate downward around the second axis O2 together with the column unit 11 and steering shaft 12. This allows the vertical position of the steering wheel 2 to be adjusted to any position.

[0068] In the steering device 1, the operating lever 81 is attached to a first side end of the lock bolt 80 in the left-right direction. Therefore, in conventional steering devices, the weight of the operating lever may cause the first side end of the lock bolt in the left-right direction to tilt downward compared to the second side end, particularly in the unlocked state. In this case, the driven cam is pressed against the first side plate, which tends to increase the load acting between the driven cam and the first side plate. As a result, frictional resistance may increase when the driven cam slides on the outer surface of the first side plate during tilting.

[0069] Therefore, in the steering device 1 of this embodiment, the first through hole 31 and the second through hole 32 are configured so that straight portions 31a, 32a are formed on the inside in the left-right direction and tapered portions 31b, 32b are formed on the outside in the left-right direction. With this configuration, even if the first side end of the lock bolt 80 in the left-right direction tries to tilt downward in the unlocked state, the tilt of the lock bolt 80 can be restricted between the lower edge of the first straight portion 31a and the upper edge of the second straight portion 32a. This reduces rattling of the lock bolt 80, and suppresses vibration of the lock bolt 80 during tilting, for example, and abnormal noises that may occur when the lock bolt 80 comes into contact with the rear bracket 14 or the like due to vibration. As a result, smooth tilting can be achieved. Furthermore, in this embodiment, the above-mentioned effects are achieved by the shape of the through holes 31, 32 of the outer column 21, so it is possible to suppress an increase in the number of parts and assembly man-hours compared to the conventional case in which a separate sleeve is provided inside the through hole.

[0070] In this embodiment, the locking mechanism 61 is configured to include a drive cam 90 fixed to the first side end of the locking bolt 80 in the left-right direction, and a driven cam 91 facing the drive cam 90 in the left-right direction outside the first side plate portion 54. With this configuration, the inclination angle of the lock bolt 80 (the angle formed by the third axis O3 with respect to the left-right direction) can be reduced compared to conventional configurations, thereby reducing the load acting between the driven cam 91 and the first side plate portion 54. As a result, during tilting, the frictional resistance when the driven cam 91 slides on the outer surface of the first side plate portion 54 can be reduced. As a result, a smoother tilting operation can be achieved.

[0071] In this embodiment, the first straight portion 31a is formed around the entire circumference of the inner end portion of the first through hole 31 in the left-right direction, and the second straight portion 32a is formed around the entire circumference of the inner end portion of the second through hole 32 in the left-right direction. According to this configuration, the inner ends in the left-right direction of each through-hole 31, 32 are formed into straight portions 31a, 32a over the entire circumference. Therefore, when molding the outer column 21, it is possible to reduce variations in the circumferential range of the straight portions 31a, 32a between each steering device 1. Also, it becomes easier to suppress rattle of the lock bolt 80 in the up-and-down direction.

[0072] In this embodiment, the lock bolt 80 is configured to be fitted with a slide guide 62 having buffer portions 103, 104 located in the first telescopic guide hole 74 on at least both sides of the lock bolt 80 in the front-rear direction. This configuration can prevent direct contact between the lock bolt 80 and the hanger bracket 60 when the column unit 11 is in the most retracted or most extended position, thereby preventing abnormal noise from being generated during telescopic movement.

[0073] In this embodiment, the slide guide 62 has an insertion hole 102a through which the lock bolt 80 is inserted, and the inner diameter of the insertion hole 102a gradually decreases inward in the left-right direction. This configuration can reduce rattle between the lock bolt 80 and the slide guide 62. Therefore, tilting of the lock bolt 80 in the unlocked state can be more easily prevented.

[0074] In this embodiment, a support portion that supports the lock bolt 80 from below is formed in a portion of the insertion hole 102a that is located below the third axis O3. According to this configuration, the lock bolt 80 is supported from below by a portion of the inner circumferential edge of the insertion hole 102a that is located below the third axis O3, making it easier to prevent the lock bolt 80 from tilting in the unlocked state. In particular, in this embodiment, the central axis O4 of the insertion hole 102a is offset upward with respect to the third axis O3, so that the portion of the inner periphery of the insertion hole 102a that is positioned below the third axis O3 can function as a support portion. Therefore, when molding the slide guide 62, dimensional variations in the support portion between steering devices 1 can be reduced.

[0075] In this embodiment, a biasing member 63 is provided between the rear bracket 14 and the column unit 11 to bias the column unit 11 upward via the guide bottom wall 100. With this configuration, the slide guide 62 is biased upward together with the column unit 11, which reduces rattle between the slide guide 62 and the hanger bracket 60. Also, the outer peripheral surface of the lock bolt 80 is easily supported by the lower edge (support portion) of the insertion hole 102a. This makes it easier to prevent the lock bolt 80 from tilting in the unlocked state.

[0076] Although the preferred embodiments of the present invention have been described above, the present invention 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 invention. The present invention is not limited by the above description, but is limited only by the appended claims. For example, in the above-described embodiment, the first axis O1 intersects with the front-rear direction, but the present invention is not limited to this configuration. The first axis O1 may coincide with the front-rear direction of the vehicle.

[0077] In the above-described embodiment, a configuration has been described in which each straight portion 31a, 32a is provided around the entire circumference of the corresponding through hole 31, 32, but this configuration is not limited to this. For example, as shown in Fig. 9, only a portion of the first through hole 31 located below the lock bolt 80 (a portion overlapping the lock bolt 80 when viewed from above) and only a portion of the second through hole 32 located above the lock bolt 80 (a portion overlapping the lock bolt 80 when viewed from below) may be the straight portion 31a, 32a, respectively. In this case, the straight portions 31a, 32a may be formed over the entire through hole 31, 32 in the left-right direction, or may be formed only in a portion of the through hole 31, 32.

[0078] In the above-described embodiment, a configuration has been described in which the locked state and the unlocked state are switched by the operation of the cam mechanism 82 in accordance with the rotation of the lock bolt 80, but the present invention is not limited to this configuration. The lock mechanism may be switched between the locked state and the unlocked state by a mechanism other than a cam mechanism (for example, a gear or a link). Furthermore, the lock bolt 80 may be slid by an operating unit. In the above-described embodiment, the slide guide 62 is configured to be L-shaped and attached to the lock bolt 80 and the hanger bracket 60, but the configuration is not limited to this. The slide guide 62 may have buffer portions 103, 104 and may be configured to be attached only to the lock bolt 80. In the above-described embodiment, a configuration has been described in which rattle of the lock bolt 80 is suppressed by both the shape of the through holes 31, 32 and the slide guide 62, but this configuration is not limited to this. In the steering device, it is sufficient if rattle of the lock bolt 80 can be suppressed by at least one of the shape of the through holes 31, 32 and the slide guide 62.

[0079] In the above-described embodiment, a configuration has been described in which the central axis O4 of the insertion hole 102a is offset from the third axis O3 of the lock bolt 80, but the configuration is not limited to this. As shown in Fig. 10, a support portion 102b that supports the lock bolt 80 from below may be formed on the lower edge of the insertion hole 102a that is arranged coaxially with the third axis O3. In the above-described embodiment, a configuration in which the unlocked state is transitioned to the locked state by pulling up the operating lever 81 (a so-called pull lock type) has been described, but a configuration in which the unlocked state is transitioned to the locked state by pushing down the operating lever 81 (a so-called push lock type) may also be employed.

[0080] In addition, within the scope of the spirit of the present invention, 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]

[0081] 1: Steering device 11: Column unit 12: Steering shaft 13: Front bracket 14: Rear bracket 21: Outer Column 22: Inner Column 25: First tightening part 26: Second tightening part 31: First through hole 31a: First straight section 31b: First tapered section 32: Second through hole 32a: Second straight section 32b: Second tapered section 54:First side plate part (side plate part) 55:Second side plate part (side plate part) 57: Tilt guide hole 60: Hanger bracket 61: Locking mechanism 62: Slide guide 63: biasing member 73: Bottom wall of bracket 74: First telescopic guide hole (telescopic guide hole) 75: Second telescopic guide hole (telescopic guide hole) 80: Rock bolt (rod) 90: Drive cam 90b: Cam section 91: Follower cam 91c: Cam follower 100: Guide bottom wall 102: Guide side wall 102a: Insertion hole 102b: Support part 103:Buffer section 104:Buffer section O1: 1st axis O2: 2nd axis O3: Third axis (center axis of the rod) O4: Central axis

Claims

1. a column unit that supports a steering shaft rotatably about a first axis that extends along the front-rear direction; a front bracket that supports the column unit so as to be rotatable about a second axis that extends along the left-right direction and is attached to a vehicle body; a rear bracket having side plate portions located on both left and right sides of the column unit, with tilt guide holes extending in the up and down direction formed in the side plate portions, and attached to the vehicle body behind the front bracket; a locking mechanism that switches between a locked state that restricts movement of the column unit relative to the front bracket about the second axis and an unlocked state that allows movement of the column unit relative to the front bracket about the second axis, The column unit includes: a first tightening portion having a first through hole penetrating in the left-right direction and provided on a first side in the left-right direction with respect to the first axis; a second tightening portion having a second through hole penetrating in the left-right direction, the second tightening portion being provided on a second side in the left-right direction with respect to the first axis, and moving toward or away from the first tightening portion as the locking mechanism transitions between the locked state and the unlocked state, The locking mechanism is a rod that passes through the first through hole, the second through hole, and the tilt guide hole in the left-right direction and is supported by the column unit so as to be movable up and down within the tilt guide hole in the unlocked state; an operating portion fixed to a first side end portion of the rod in the left-right direction and for operating the rod; The first through hole is a first straight portion extending linearly along the left-right direction at least in a portion located below the rod; a first tapered portion that is a portion other than the first straight portion and that gradually increases the inner diameter of the first through hole toward a first side in the left-right direction, The second through hole is a second straight portion extending linearly along the left-right direction at least in a portion located above the rod; a second tapered portion other than the second straight portion, the second tapered portion gradually increasing the inner diameter of the second through hole toward a second side in the left-right direction.

2. The locking mechanism is a drive cam having a cam portion and fixed to a first side end portion of the rod in the left-right direction; 2. The steering device according to claim 1, further comprising: a cam follower portion that slides on the cam portion as the rod rotates; and a driven cam that faces the drive cam in the left-right direction on the outside of the side plate portion that is arranged on a first side of the side plate portion in the left-right direction relative to the first tightening portion.

3. the first straight portion is formed around the entire periphery of a second side end portion of the first through hole in the left-right direction, 3. The steering device according to claim 1, wherein the second straight portion is formed around the entire periphery of a first side end portion of the second through hole in the left-right direction.

4. The column unit includes: a cylindrical outer column having the first fastening portion and the second fastening portion; an inner column that is inserted into the outer column so as to be movable forward and backward and that rotatably supports the steering shaft, a hanger bracket is provided on a portion of the inner column located between the first fastening portion and the second fastening portion, The hanger bracket has a telescopic guide hole through which the rod is inserted and which extends in the front-rear direction.

4. The steering device according to claim 1, wherein the rod is fitted with a slide guide having buffer portions located in the telescopic guide hole at least on both sides of the rod in the front-rear direction.

5. The slide guide has an insertion hole through which the rod is inserted, 5. The steering device according to claim 4, wherein the inner diameter of the insertion hole gradually decreases from the first fastening portion toward the second fastening portion.

6. The slide guide has an insertion hole through which the rod is inserted, 6. The steering device according to claim 4, wherein the insertion hole is formed with a support portion that supports the rod from below.

7. The central axis of the insertion hole is offset upward with respect to the central axis of the rod, The steering device according to claim 6, wherein a portion of the inner periphery of the insertion hole that is positioned below the rod constitutes the support portion.

8. The hanger bracket is a bracket side wall in which the telescopic guide hole is formed; a bracket bottom wall extending in the left-right direction from the lower end edge of the bracket side wall, The slide guide is a guide side wall having the insertion hole and disposed on a first side in the left-right direction with respect to the bracket side wall; a guide bottom wall extending in the left-right direction from a lower end edge of the guide side wall and disposed below the bracket bottom wall, 8. The steering device according to claim 5, further comprising a biasing member provided between the rear bracket and the column unit, the biasing member biasing the column unit upward via the guide bottom wall.

Images