Steering device

Abstract

To provide a steering unit capable of upgrade maneuverability at a time of adjusting the position of a steering wheel.SOLUTION: A steering unit 1 includes a cylindrical lower tube 17 that rotatively supports a steering shaft 2, and an upper jacket 16 that has an insertion hole 16C externally engaged with the lower tube 17 so that the insertion hole can slide along the axial direction of the lower tube, and is fixed to the lower tube 17 when the diameter of the insertion hole 16C is elastically contracted. The upper jacket 16 has a first lateral wall 16A and second lateral wall 16B which are located on mutually opposite sides with the insertion hole 16C between them. The second lateral wall 16B has a slit 16D that, when the second lateral wall 16B is tightened toward a direction of approaching the first lateral wall 16A by manipulating a lock lever 54, allows part of the second lateral wall 16B to elastically deform inward so as to contract the diameter of the insertion hole 16C.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Conventionally, there have been steering devices that allow the position of a steering wheel to be adjusted. These steering devices have, for example, a tilt mechanism and a telescopic mechanism. The tilt mechanism is a mechanism for adjusting the tilt position of the steering wheel in the vertical direction. The telescopic mechanism is a mechanism for adjusting the axial position of the steering wheel. A driver can adjust the position of the steering wheel to their preferred position by moving the steering wheel in the vertical direction or axial direction.

[0003] For example, the steering device in Patent Document 1 has a steering shaft to which a steering wheel is attached and a steering column that rotatably supports the steering shaft. The steering shaft is made up of a wheel shaft and a telescopic shaft connected to each other via a universal joint. The telescopic shaft has a double-tube structure and is capable of extending and retracting in its axial direction. The steering column is supported on the vehicle body in a state that allows movement in the direction of adjusting the position of the steering wheel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-197054 Summary of the Invention [Problem to be solved by the invention]

[0005] The steering device of Patent Document 1 has the following concerns: When adjusting the axial position of the steering wheel, the steering column, wheel shaft, and universal joint move axially as a unit as the telescopic shaft extends and retracts. This is one factor that reduces operability when adjusting the steering wheel position. [Means for solving the problem]

[0006] A steering device that can solve the above problem includes a steering shaft to which a steering wheel is connected and which is axially extendable and contractible, a cylindrical lower tube that rotatably supports the steering shaft, and an upper jacket that has an insertion hole that is slidably fitted onto the lower tube along the axial direction and is fixed to the lower tube by elastically reducing the diameter of the insertion hole. The upper jacket has a first side wall and a second side wall located opposite each other with the insertion hole in between. At least one of the first side wall and the second side wall has a slit that elastically deforms a portion of at least one of the first side wall and the second side wall inward to reduce the diameter of the insertion hole when the first side wall and the second side wall are tightened in a direction toward each other by operating a lock lever.

[0007] According to this configuration, the insertion hole elastically expands in diameter when the lock lever is operated to release the clamping force that moves the first side wall and the second side wall toward each other. This allows the upper jacket to move axially relative to the lower tube. The axial position of the steering wheel can be adjusted simply by sliding the upper jacket axially relative to the lower tube via the steering wheel. This improves operability when adjusting the position of the steering wheel, particularly when adjusting the axial position of the steering wheel.

[0008] In the above steering device, the slit may have a first slit portion extending along the axial direction of the upper jacket, and a second slit portion connected to an end of the first slit portion and extending along a direction intersecting the first slit portion.

[0009] With this configuration, when the first side wall and the second side wall are tightened toward each other by operating the lock lever, the portion of at least one of the first side wall and the second side wall separated by the slit is likely to elastically deform inward, thereby making it possible to hold the lower tube in an appropriate position.

[0010] The steering device may further include a tightening shaft for tightening the first side wall and the second side wall in a direction toward each other through operation of the lock lever. The first side wall and the second side wall may also include an elongated hole through which the tightening shaft is inserted and which extends along the first slit. The elongated hole may be provided at an inner angle between the first slit and the second slit, and a distance between an end of the elongated hole opposite the second slit and an end of the upper jacket opposite the second slit relative to the elongated hole may be set to a distance narrower than a width of the first slit or the second slit.

[0011] Depending on the product specifications, the distance between the end of the slot opposite the second slit and the end of the upper jacket opposite the second slit relative to the slot may be set to a distance narrower than the width of the first slit or the second slit. In this case, a slit having a first slit and a second slit is preferable.

[0019] In the above steering device, the inner surface of the insertion hole may have a plurality of recesses, which may be spaced apart along the circumferential direction of the insertion hole and may extend over the entire axial length of the insertion hole.

[0020] With this configuration, the contact area between the inner surface of the insertion hole and the outer surface of the lower tube can be secured, while reducing the contact resistance between the inner surface of the insertion hole and the outer surface of the lower tube when adjusting the axial position of the steering wheel. [Effects of the Invention]

[0021] According to the steering device of the present invention, it is possible to improve the operability when adjusting the position of the steering wheel. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a schematic diagram showing the configuration of a steering device according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 1 is a perspective view of a steering column according to a first embodiment. [Figure 4] FIG. 2 is an exploded perspective view of the steering column according to the first embodiment. [Figure 5] FIG. 2 is a perspective view of the upper jacket of the first embodiment, seen from the first jacket portion side. [Figure 6] 3 is a side view of the upper jacket of the first embodiment as viewed in the axial direction from the first jacket portion side. FIG. [Figure 7] FIG. 3 is a side view of the upper jacket of the first embodiment as viewed from the second side wall side. [Figure 8] FIG. 10 is a perspective view of an upper jacket according to a second embodiment, seen from the first jacket portion side. [Figure 9] FIG. 11 is a side view of the upper jacket of the third embodiment, seen from the second side wall side. [Figure 10] FIG. 10 is a side view of the upper jacket of the fourth embodiment, viewed from the second side wall side. [Figure 11] FIG. 11 is a side view of the upper jacket of the fifth embodiment, seen from the second side wall side. [Figure 12] FIG. 13 is a side view of the upper jacket of the sixth embodiment, seen from the second side wall side. DETAILED DESCRIPTION OF THE INVENTION

[0023] First Embodiment A first embodiment of the steering device will be described below. As shown in FIG. 1, the steering device 1 has a steering shaft 2, an intermediate shaft 3, a pinion shaft 4, and a rack shaft 5. A steering wheel 6 is connected to a first end of the steering shaft 2. A first end of the intermediate shaft 3 is connected to a second end of the steering shaft 2 via a universal joint 7. A first end of the pinion shaft 4 is connected to the second end of the intermediate shaft 3 via a universal joint 8. A pinion 4a is provided at the second end of the pinion shaft 4. The pinion 4a meshes with a rack 5a provided on a rack shaft 5. The rack shaft 5 is supported inside a housing 10 fixed to a frame 9 of the vehicle body. The rack shaft 5 is movable left or right relative to the traveling direction of the vehicle. Both ends of the rack shaft 5 are connected to left and right steered wheels (not shown) via tie rods (not shown).

[0024] The steering shaft 2 has an outer shaft 11 and an inner shaft 12. The outer shaft 11 and the inner shaft 12 are connected to each other by, for example, a spline connection. The outer shaft 11 and the inner shaft 12 are rotatable together and are capable of relative movement along the axial direction. The steering shaft 2 is disposed obliquely with respect to the longitudinal direction X1 of the vehicle, with the steering wheel 6 facing upward.

[0025] The steering device 1 has a steering column 15. A steering shaft 2 is inserted through the steering column 15. The steering shaft 2 is rotatably supported by the steering column 15 via a bearing (not shown).

[0026] The steering column 15 has an upper jacket 16, a lower tube 17, and a housing 18. The upper jacket 16 is attached to the vehicle body frame 13. The upper jacket 16 has a cylindrical portion. The upper jacket 16 rotatably supports the outer shaft 11. The lower tube 17 is cylindrical. The lower tube 17 rotatably supports the inner shaft 12. The upper jacket 16 and the lower tube 17 are fitted together. As an example, a first end of the lower tube 17 is inserted into a second end of the upper jacket 16. The second end is an end opposite to the first end, which is closer to the steering wheel 6. The upper jacket 16 and the lower tube 17 are movable relative to each other in the axial direction of the steering shaft 2.

[0027] The housing 18 is connected to a second end of the lower tube 17. A steering assist motor 19 is provided outside the housing 18. A reducer 20 is accommodated inside the housing 18. The reducer 20 reduces the rotation speed of the motor 19 and transmits the reduced rotation to the inner shaft 12. The reducer 20 is a worm reducer having a worm 21 and a worm wheel 22. The worm 21 is connected to an output shaft (not shown) of the motor 19 so as to be rotatable together with the motor 19. The axis of the worm 21 and the axis of the output shaft of the motor 19 are located on the same straight line. The worm wheel 22 is engaged with the worm 21. The worm wheel 22 is provided so as to be rotatable together with the inner shaft 12. The axis of the worm wheel 22 and the axis of the inner shaft 12 are located on the same straight line.

[0028] <Steering column support structure> Next, the support structure of the steering column 15 will be described in detail. As shown in Fig. 1, the upper jacket 16 has a column bracket 30. The upper jacket 16 is attached to the frame 13 of the vehicle body via the column bracket 30. The column bracket 30 extends along the axial direction of the steering shaft 2. A first end of the column bracket 30 is fixed to the frame 13 of the vehicle body.

[0029] The column bracket 30 has two support portions 31 (only one is shown in FIG. 1) and a support shaft 32. The two support portions 31 are provided at a second end portion of the column bracket 30. The two support portions 31 face each other in the width direction of the vehicle body. The support shaft 32 extends between the two support portions 31. The support shaft 32 is rotatably connected to a support bracket 33, which is shown by a two-dot chain line in FIG. 1. The support bracket 33 is fixed to the vehicle body.

[0030] As shown in FIG. 2, the column bracket 30 has an upper bracket 34 and a tilt bracket 35. The upper bracket 34 is a flat plate extending in the left-right direction of the vehicle body (left-right direction in FIG. 2). Mounting seats 34A are provided on both ends of the upper bracket 34. The upper bracket 34 is fixed to the frame 13 of the vehicle body via these mounting seats 34A, 34A. Specifically, this is as follows.

[0031] That is, two bolts 41 are provided protruding from the frame 13. These bolts 41 extend such that their axial direction Z1 intersects the vertical direction. When viewed from the axial direction of the steering shaft 2, these bolts 41 are provided on the left and right sides of the vehicle body relative to the steering shaft 2. The bolts 41 are stud bolts having male threads on both ends. A first end of the bolt 41 is threadedly engaged with the frame 13. A second end of the bolt 41 passes through the mounting seat 34A. The mounting seat 34A is fixed to the frame 13 by tightening a nut 42 onto the second end of the bolt 41. A washer 43 is interposed between the nut 42 and the mounting seat 34A.

[0032] Tilt bracket 35 is fixed to upper bracket 34. Tilt bracket 35 has a square U-shape when viewed in the axial direction of steering shaft 2. Tilt bracket 35 is made by bending a metal plate that has been punched into a predetermined shape. Tilt bracket 35 is open on the side opposite upper bracket 34.

[0033] The tilt bracket 35 has a connecting portion 35A, a first clamp portion 35B, and a second clamp portion 35C. The connecting portion 35A is fixed to the surface of the upper bracket 34 opposite the frame 13 (the lower surface in FIG. 2). The first clamp portion 35B is connected to a first side edge portion of the connecting portion 35A in the left-right direction of the vehicle body when viewed in the axial direction of the steering shaft 2. The second clamp portion 35C is connected to a second side edge portion of the connecting portion 35A in the left-right direction of the vehicle body when viewed in the axial direction of the steering shaft 2. The first clamp portion 35B and the second clamp portion 35C extend toward the side opposite the frame 13 of the vehicle body (downward in FIG. 2).

[0034] As shown in FIG. 3, the first clamp portion 35B and the second clamp portion 35C each have an elongated hole 35D extending along the axial direction Z1 of the bolt 41 for tilt adjustment. As shown in FIG. 2, the upper jacket 16 is positioned between the first clamp portion 35B and the second clamp portion 35C. The upper jacket 16 has a first side wall 16A and a second side wall 16B. The first side wall 16A and the second side wall 16B are positioned on opposite sides of each other in the left-right direction of the vehicle body. The outer surface of the first side wall 16A is maintained in contact with the inner surface of the second clamp portion 35C. The outer surface of the second side wall 16B is maintained in contact with the inner surface of the first clamp portion 35B.

[0035] The upper jacket 16 has an insertion hole 16C and a slit 16D. The insertion hole 16C and the slit 16D are in communication with each other. The insertion hole 16C penetrates the upper jacket 16 in the axial direction of the steering shaft 2. The lower tube 17 is inserted into the insertion hole 16C. The slit 16D is provided in the second side wall 16B. The slit 16D is provided in the second side wall 16B at a position closer to the connecting portion 35A. The slit 16D penetrates the second side wall 16B in the left-right direction of the vehicle body. The slit 16D has a portion that extends along the axial direction of the steering shaft 2. The slit 16D is open at the end face of the upper jacket 16 on the side where the lower tube 17 is inserted. The interior and exterior of the upper jacket 16 are in communication via the slit 16D. The slit 16D is intended to elastically deform a portion of the second side wall 16B separated by the slit 16D inward, i.e., toward the first side wall 16A, when an external force is applied to the second side wall 16B in a direction toward the first side wall 16A.

[0036] The upper jacket 16 has two elongated holes 16E, 16F for telescopic adjustment. The two elongated holes 16E, 16F are located between the insertion hole 16C and the slit 16D when viewed in the axial direction of the steering shaft 2. One elongated hole 16E is provided in the first side wall 16A, and the other elongated hole 16F is provided in the second side wall 16B. One elongated hole 16E penetrates the first side wall 16A in the width direction of the vehicle body, while the other elongated hole 16F penetrates the second side wall 16B in the width direction of the vehicle body. The two elongated holes 16E, 16F extend along the axial direction of the steering shaft 2. The two elongated holes 16E, 16F face each other in the width direction of the vehicle body.

[0037] The tilt bracket 35 and the upper jacket 16 are connected via a fastening shaft 51 made of a bolt. The upper jacket 16 is supported by the fastening shaft 51 so that its position can be adjusted relative to the tilt bracket 35. The fastening shaft 51 extends along the width direction of the vehicle body (the left-right direction in FIG. 2). The fastening shaft 51 passes through two elongated holes 35D, 35D of the tilt bracket 35 and two elongated holes 16E, 16F of the upper jacket 16. A nut 53 is threadedly engaged with the end of the passed-through fastening shaft 51 opposite the head 52. A lock lever 54 is rotatably supported on the fastening shaft 51 between the head 52 and the second side wall 16B.

[0038] A first cam 55 is integrally provided at the base end of the lock lever 54. A second cam 56 is provided between the first cam 55 and the second side wall 16B. The second cam 56 is provided in a state in which its rotation relative to the first clamp portion 35B is restricted. A plurality of protrusions are provided at intervals on the peripheral edge of the side surface of the first cam 55 facing the second cam 56. A plurality of protrusions are also provided at intervals on the peripheral edge of the side surface of the second cam 56 facing the first cam 55. The rotational position of the first cam 55 is switched between a first rotational position and a second rotational position by rotating the lock lever 54. The first rotational position is a position in which the protrusions of the first cam 55 engage with the protrusions of the second cam 56 in a meshing manner. The second rotation position refers to a position where the protrusion of the first cam 55 rides on the protrusion of the second cam 56 .

[0039] When the rotational position of the first cam 55 is switched from the first rotational position to the second rotational position through the rotational operation (locking operation) of the lock lever 54, the first cam 55 rotates relative to the second cam 56, and this rotation causes the protrusion of the first cam 55 to ride up on the protrusion of the second cam 56. Because movement of the lock lever 54 in the direction along the fastening shaft 51 is restricted, the second cam 56 attempts to move in a direction approaching the nut 53 by the amount that the protrusion of the first cam 55 rides up on the protrusion of the second cam 56. As a result, the first clamp portion 35B and the second clamp portion 35C of the tilt bracket 35 elastically deform in directions approaching each other between the second cam 56 and the nut 53. As a result, the inner surface of the first clamp portion 35B is pressed against the outer surface of the second side wall 16B, while the inner surface of the second clamp portion 35C is pressed against the outer surface of the first side wall 16A. That is, the first side wall 16A and the second side wall 16B are sandwiched between the first clamp portion 35B and the second clamp portion 35C in a direction in which they approach each other. This restricts movement of the upper jacket 16 relative to the tilt bracket 35.

[0040] Additionally, a slit 16D is formed in the second side wall 16B of the upper jacket 16. As a result, the first side wall 16A and the second side wall 16B are sandwiched between the first clamp portion 35B and the second clamp portion 35C in a direction toward each other, and a portion of the second side wall 16B separated by the slit 16D elastically deforms toward the first side wall 16A. As the second side wall 16B elastically deforms, the gap between the first side wall 16A and the second side wall 16B narrows, and the inner diameter of the insertion hole 16C elastically decreases. The inner peripheral surface of the insertion hole 16C clamps the outer peripheral surface of the lower tube 17, thereby restricting relative axial movement of the upper jacket 16 with respect to the lower tube 17.

[0041] When changing the position of the steering wheel 6, the rotational position of the first cam 55 is switched from the second rotational position to the first rotational position by rotating the lock lever 54 (unlocking operation). The protrusions of the first cam 55 fit between the protrusions of the second cam 56, releasing the clamping between the first clamp portion 35B and the second clamp portion 35C of the tilt bracket 35 in the direction toward each other and the clamping between the first side wall 16A and the second side wall 16B of the upper jacket 16 in the direction toward each other. The first clamp portion 35B and the second clamp portion 35C, and the second side wall 16B, respectively, elastically return to their original positions, thereby widening the gap between the first clamp portion 35B and the second clamp portion 35C and the gap between the first side wall 16A and the second side wall 16B. Accordingly, the diameter of the insertion hole 16C elastically expands.

[0042] This weakens the clamping force between the first clamp portion 35B and the second clamp portion 35C and the first side wall 16A and the second side wall 16B. This also weakens the clamping force of the upper jacket 16 on the outer circumferential surface of the lower tube 17. This allows the upper jacket 16 to move vertically relative to the first clamp portion 35B and the second clamp portion 35C of the tilt bracket 35. By moving the steering wheel 6 vertically, the vertical position of the steering wheel 6 can be adjusted. Furthermore, by releasing the clamping force of the lower tube 17 by the upper jacket 16, the upper jacket 16 can move axially relative to the lower tube 17. By moving the steering wheel 6 axially, the axial position of the steering wheel 6 can be adjusted.

[0043] <Upper jacket detailed configuration> Next, the configuration of the upper jacket will be described in detail. 4 and 5, the upper jacket 16 has a rectangular parallelepiped first jacket portion 61 and a cylindrical second jacket portion 62. The insertion hole 16C is provided over a range from the end face of the first jacket portion 61 opposite the second jacket portion 62 to the boundary between the first jacket portion 61 and the second jacket portion 62. The lower tube 17 is inserted into the insertion hole 16C from the side of the first jacket portion 61 opposite the second jacket portion 62. The two elongated holes 16E, 16F and the slit 16D for telescopic adjustment are all provided in the first jacket portion 61.

[0044] As shown in FIG. 6, the inner diameter φ1 of the insertion hole 16C is longer than the inner diameter φ2 of the second jacket portion 62. The inner diameter φ1 of the insertion hole 16C is basically set to be approximately the same length as the outer diameter of the lower tube 17. Three recesses 61A, 61B, and 61C are provided on the inner peripheral surface of the insertion hole 16C. The three recesses 61A, 61B, and 61C extend over the entire axial length of the insertion hole 16C. The three recesses 61A, 61B, and 61C are provided at intervals along the circumferential direction of the insertion hole 16C. The three recesses 61A, 61B, and 61C are provided at the 9 o'clock position, the 3 o'clock position, and the 6 o'clock position when viewed from the axial direction of the insertion hole 16C. As shown by the two-dot chain lines in FIG. 6, when the lower tube 17 is inserted into the insertion hole 16C, gaps are formed between the outer circumferential surface of the lower tube 17 and the three recesses 61A, 61B, 61C.

[0045] 7, the slit 16D is L-shaped as a whole when viewed from a direction perpendicular to the axial direction of the upper jacket 16. The slit 16D has a first slit portion 16D1 and a second slit portion 16D2. The first slit portion 16D1 and the second slit portion 16D2 are continuous with each other.

[0046] The first slit portion 16D1 extends along the axial direction of the upper jacket 16. A first end of the first slit portion 16D1 is open on the side opposite the second jacket portion 62. A second end of the first slit portion 16D1 is located in a position, in the axial direction of the upper jacket 16, closer to the second jacket portion 62 than the elongated hole 16F for telescopic adjustment.

[0047] The second slit portion 16D2 extends in a direction perpendicular to the first slit portion 16D1. A first end of the second slit portion 16D2 is connected to a second end of the first slit portion 16D1. The second end of the second slit portion 16D2 is located in an area opposite the first slit portion 16D1 with respect to the axis of the upper jacket 16.

[0048] The first end (the left end in FIG. 7) of the elongated hole 16F for telescopic adjustment is close to the end of the upper jacket 16 opposite the second jacket portion 62. When viewed from a direction perpendicular to the axial direction of the upper jacket 16, the distance W3 between the first end of the elongated hole 16F and the end of the upper jacket 16 opposite the second jacket portion 62 is set to be approximately the same as or narrower than the width W1 of the first slit portion 16D1 or the width W2 of the second slit portion 16D2.

[0049] <Operation of the First Embodiment> Next, the operation of the first embodiment will be described. After completing the adjustment of the position of the steering wheel 6, the rotational position of the first cam 55 is switched from the first rotational position to the second rotational position by rotating the lock lever 54. This operation tightens the first clamp portion 35B and the second clamp portion 35C of the tilt bracket 35 toward each other, thereby restricting the relative movement of the upper jacket 16 with respect to the first clamp portion 35B and the second clamp portion 35C. Furthermore, as the portion of the second side wall 16B of the upper jacket 16 separated by the slit 16D elastically deforms toward the first side wall 16A, the insertion hole 16C elastically contracts in diameter and tightens the outer peripheral surface of the lower tube 17. This restricts the relative axial movement of the upper jacket 16 with respect to the lower tube 17.

[0050] Here, the slit 16D has not only a first slit portion 16D1 extending along the axial direction of the upper jacket 16, but also a second slit portion 16D2 extending along a direction perpendicular to the axial direction of the upper jacket 16. Therefore, the rigidity of the portion of the second side wall 16B divided by the slit 16D, i.e., the portion of the second side wall 16B on the inner angle side between the first slit portion 16D1 and the second slit portion 16D2, is lower than the rigidity of the other portions. The rigidity here refers to the rigidity against deformation in a direction approaching the first side wall 16A. The portion of the second side wall 16B divided by the slit 16D is more likely to elastically deform in a direction approaching the first side wall 16A. Therefore, the portion of second side wall 16B separated by slit 16D is elastically deformed in a direction approaching first side wall 16A, and thus the operating force of lock lever 54 required to reduce the diameter of insertion hole 16C is reduced, thereby improving the operability of lock lever 54.

[0051] Furthermore, as the portion of the second side wall 16B separated by the slit 16D elastically deforms toward the first side wall 16A, the insertion hole 16C contracts in diameter and the lower tube 17 is pressed against a portion of the inner circumferential surface of the insertion hole 16C that is provided on the first side wall 16A. As a result, the lower tube 17 is positioned relative to the first side wall 16A. In this state, the portion of the inner circumferential surface of the insertion hole 16C that is provided on the second side wall 16B is pressed against the outer circumferential surface of the lower tube 17, thereby fixing the lower tube 17 to the upper jacket 16. As the outer circumferential surface of the lower tube 17 is tightened with the lower tube 17 positioned relative to the first side wall 16A, axial misalignment between the lower tube 17 and the upper jacket 16 is suppressed.

[0052] Incidentally, the inner circumferential surface of the insertion hole 16C is provided with a plurality of recesses 61A, 61B, and 61C. The size and arrangement of these recesses 61A, 61B, and 61C are set based on the viewpoint of reducing contact resistance between the inner circumferential surface of the insertion hole 16C and the outer circumferential surface of the lower tube 17 while ensuring a contact area between the inner circumferential surface of the insertion hole 16C and the outer circumferential surface of the lower tube 17. Therefore, when the outer circumferential surface of the lower tube 17 is fastened, no rattle occurs between the inner circumferential surface of the insertion hole 16C and the outer circumferential surface of the lower tube 17, and the lower tube 17 is suitably held by the upper jacket 16. Furthermore, the contact area between the inner circumferential surface of the insertion hole 16C and the outer circumferential surface of the lower tube 17 is reduced by the amount of the plurality of recesses 61A, 61B, and 61C provided in the inner circumferential surface of the insertion hole 16C. Therefore, contact resistance between the inner circumferential surface of the insertion hole 16C and the outer circumferential surface of the lower tube 17 when adjusting the axial position of the steering wheel 6 is reduced.

[0053] <Advantages of the First Embodiment> Therefore, according to the first embodiment, the following effects can be obtained. (1-1) The lower tube 17 is connected to a housing 18 in which a motor 19 and a reducer 20 are provided. The upper jacket 16 is movable in the axial direction relative to the lower tube 17. When adjusting the axial position of the steering wheel 6, it is only necessary to slide the upper jacket 16 in the axial direction relative to the lower tube 17 via the steering wheel 6. In other words, when adjusting the axial position of the steering wheel 6, it is not necessary to move components located downstream of the outer shaft 11, such as the inner shaft 12, the housing 18, the motor 19, the reducer 20, and the universal joint 7. Therefore, it is possible to improve operability when adjusting the position of the steering wheel 6, particularly when adjusting the axial position of the steering wheel 6.

[0054] (1-2) The upper jacket 16 has a first side wall 16A and a second side wall 16B that face each other. A slit 16D is formed in the second side wall 16B. Therefore, the portion of the second side wall 16B separated by the slit 16D is more likely to bend toward the first side wall 16A. Furthermore, the insertion hole 16C of the upper jacket 16 is more likely to contract in diameter. Therefore, when the lock lever 54 is locked, the inner circumferential surface of the insertion hole 16C effectively clamps the outer circumferential surface of the lower tube 17. Therefore, the upper jacket 16 can effectively hold the lower tube 17.

[0055] (1-3) The slit 16D is provided only in the second side wall 16B of the first side wall 16A and the second side wall 16B of the upper jacket 16. Therefore, when the lock lever 54 is locked, the portion of the second side wall 16B separated by the slit 16D elastically deforms toward the first side wall 16A, pressing the lower tube 17 against the portion of the inner circumferential surface of the insertion hole 16C that is provided in the first side wall 16A. This positions the lower tube 17 relative to the first side wall 16A. Therefore, axial misalignment between the lower tube 17 and the upper jacket 16 can be suppressed.

[0056] (1-4) The inner peripheral surface of the insertion hole 16C is provided with a plurality of recesses 61A, 61B, and 61C. This ensures a sufficient contact area between the inner peripheral surface of the insertion hole 16C and the outer peripheral surface of the lower tube 17, while reducing contact resistance between the inner peripheral surface of the insertion hole 16C and the outer peripheral surface of the lower tube 17 when adjusting the axial position of the steering wheel 6. Furthermore, since the contact area between the inner peripheral surface of the insertion hole 16C and the outer peripheral surface of the lower tube 17 is ensured, the following effect is also achieved. Specifically, when the relative movement between the upper jacket 16 and the lower tube 17 in the axial direction is restricted, rattle is prevented from occurring between the inner peripheral surface of the insertion hole 16C and the outer peripheral surface of the lower tube 17. This allows the upper jacket 16 to properly hold the lower tube 17.

[0057] (1-5) Depending on product specifications, the first end (left end in FIG. 7) of the elongated hole 16F for telescopic adjustment may be provided close to the end of the upper jacket 16 opposite the second jacket portion 62. In this case, it is difficult to provide a slit having a width similar to that of the first slit portion 16D1 or the second slit portion 16D2 in the second side wall 16B between the first end of the elongated hole 16F and the end of the upper jacket 16 opposite the second jacket portion 62. When such a configuration of the elongated hole 16F is adopted, an L-shaped slit 16D having the first slit portion 16D1 and the second slit portion 16D2 is preferable.

[0058] <Second embodiment> Next, a second embodiment of the steering device will be described. This embodiment basically has the same configuration as the first embodiment shown in FIGS. 1 to 6. However, this embodiment differs from the first embodiment in part of the configuration of the upper jacket 16. Therefore, the same members and configurations as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0059] 8, the upper jacket 16 has a rectangular parallelepiped first jacket portion 61 and a cylindrical second jacket portion 62. The first jacket portion 61 has a first side wall 16A and a second side wall 16B located on opposite sides of each other. The first side wall 16A and the second side wall 16B each have a slit 16G.

[0060] The slit 16G has a U-shape as a whole when viewed from a direction perpendicular to the axial direction of the upper jacket 16. The slit 16G has a third slit portion 16D3 in addition to the first slit portion 16D1 and the second slit portion 16D2. The first slit portion 16D1, the second slit portion 16D2, and the third slit portion 16D3 are continuous with one another.

[0061] The first end of the first slit portion 16D1, i.e., the end opposite to the end to which the second slit portion 16D2 is connected, is not open. The third slit portion 16D3 is connected to the first end of the first slit portion 16D1. The third slit portion 16D3 is parallel to the second slit portion 16D2. The first slit portion 16D1 also functions as an elongated hole for telescopic adjustment. A tightening shaft 51 is inserted through the first slit portion 16D1. The two elongated holes 16E and 16F of the first embodiment shown in Figures 4 and 5 are omitted.

[0062] The portion of first side wall 16A separated by slit 16G and the portion of second side wall 16B separated by slit 16G can elastically deform toward each other. The portion separated by slit 16G refers to the inner portion of first side wall 16A and second side wall 16B surrounded by first slit portion 16D1, second slit portion 16D2, and third slit portion 16D3.

[0063] When the lock lever 54 is locked, the portions of the first side wall 16A and the second side wall 16B separated by the slit 16G are sandwiched between the first clamp 35B and the second clamp 35C in a direction toward each other, causing the portions of the first side wall 16A and the second side wall 16B separated by the slit 16G to elastically deform in a direction toward each other. Due to this elastic deformation, the insertion hole 16C contracts in diameter, clamping the outer peripheral surface of the lower tube 17. This restricts the axial movement of the upper jacket 16 relative to the lower tube 17.

[0064] <Advantages of the second embodiment> Therefore, according to the second embodiment, in addition to the effects (1-1) and (1-4) of the first embodiment, the following effects can be obtained.

[0065] (2-1) When the lock lever 54 is locked, the lower tube 17 is held by being held from both sides by the portions of the first side wall 16A and the second side wall 16B separated by the slit 16G. The outer peripheral surface of the lower tube 17 is clamped by being held from both sides by the inner peripheral surface of the insertion hole 16C. Therefore, the lower tube 17 can be held in an appropriate position by the upper jacket 16.

[0066] (2-2) The first slit portion 16D1 also functions as a long hole for telescopic adjustment, so there is no need to provide a long hole for telescopic adjustment separately from the slit 16G.

[0067] <Third embodiment> Next, a third embodiment of the steering device will be described. This embodiment differs from the second embodiment in the shape of the slit 16G. Therefore, the same members and configurations as those in the second embodiment are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

[0068] As shown in FIG. 9, the slit 16G of the second side wall 16B has a fourth slit 16D4 as a stress relief portion in addition to the first slit 16D1, second slit 16D2, and third slit 16D3. The fourth slit 16D4 is connected to the second end of the second slit 16D2, i.e., the end opposite the end connected to the first slit 16D1. The fourth slit 16D4 extends toward the third slit 16D3 when viewed from a direction perpendicular to the axial direction of the upper jacket 16. The fourth slit 16D4 is parallel to the first slit 16D1.

[0069] The second side wall 16B has an opening 16H. When viewed from a direction perpendicular to the axial direction of the upper jacket 16, the opening 16H is provided in an area surrounded by the first slit portion 16D1, the second slit portion 16D2, and the third slit portion 16D3 in the second side wall 16B. The opening 16H penetrates the second side wall 16B. When viewed from a direction perpendicular to the axial direction of the upper jacket 16, the opening 16H has, for example, a parallelogram shape.

[0070] The first side wall 16A also has a slit 16G and an opening 16H similar to those of the second side wall 16B. <Advantages of the third embodiment> Therefore, according to the third embodiment, in addition to the effects (1-1) and (1-4) of the first embodiment and the effects (2-1) and (2-2) of the second embodiment, the following effects can be obtained.

[0071] (3-1) When the lock lever 54 is locked, the portions of the first side wall 16A and the second side wall 16B separated by the slit 16G elastically deform toward each other, potentially concentrating stress at the tip of the second slit 16D2. To address this issue, the tip of the second slit 16D2 is provided with a fourth slit 16D4 as a stress relief portion extending perpendicular to the second slit 16D2. Therefore, when the portions of the first side wall 16A and the second side wall 16B separated by the slit 16G elastically deform toward each other, stress is less likely to concentrate at the tip of the second slit 16D2, including the fourth slit 16D4 as a stress relief portion. The tip of the second slit 16D2 is the end of the second slit 16D2 opposite the first slit 16D1.

[0072] Incidentally, a fifth slit portion (not shown) similar to the fourth slit portion 16D4 may be provided at the tip of the third slit portion 16D3. In this case, the fifth slit portion extends in the axial direction of the upper jacket 16 in a direction approaching the fourth slit portion 16D4.

[0073] (3-2) The first side wall 16A and the second side wall 16B each have an opening 16H. The rigidity of the first side wall 16A and the second side wall 16B is reduced by the amount of the opening 16H. Therefore, when the lock lever 54 is operated to lock, the first side wall 16A and the second side wall 16B are more likely to elastically deform toward each other.

[0074] <Fourth embodiment> Next, a fourth embodiment of the steering device will be described. This embodiment differs from the third embodiment in the shape of the slit 16G. Therefore, the same members and configurations as those in the third embodiment are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

[0075] As shown in FIG. 10, the slit 16G of the second side wall 16B has a first slit portion 16D1, a second slit portion 16D2, and a third slit portion 16D3. The tip of the second slit portion 16D2 is provided with an expanded hole portion 16D5 as a stress relief portion. The expanded hole portion 16D5 has a teardrop-shaped contour. The width of the expanded hole portion 16D5 gradually increases toward the tip of the second slit portion 16D2. The expanded hole portion 16D5 and the second slit portion 16D2 are connected via a smoothly curved surface. The tip of the expanded hole portion 16D5 has a smoothly arcuate or curved surface. The expanded hole portion 16D5 is expanded in the axial direction of the upper jacket 16 toward the third slit portion 16D3. That is, the widened hole portion 16D5 is widened so as not to protrude from the side edge of the second slit portion 16D2 on the side opposite to the third slit portion 16D3 (the right side in FIG. 10).

[0076] Incidentally, a widened hole similar to the widened hole 16D5 may be provided at the tip of the third slit 16D3. In this case, the widened hole of the third slit 16D3 is widened so as not to protrude from the side edge of the third slit 16D3 opposite to the second slit 16D2 (the left side in FIG. 10).

[0077] The first side wall 16A also has a slit 16G and an opening 16H similar to those of the second side wall 16B. <Advantages of the Fourth Embodiment> Therefore, according to the fourth embodiment, it is possible to obtain the same effects as those of (1-1) and (1-4) of the first embodiment, (2-1) and (2-2) of the second embodiment, and (3-1) and (3-2) of the third embodiment.

[0078] <Fifth embodiment> Next, a fifth embodiment of the steering device will be described. This embodiment differs from the second embodiment in the configuration of the upper jacket 16. Therefore, the same members and configurations as those in the second embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0079] 11, a slit 16G is provided in each second side wall 16B. The slit 16G is U-shaped as a whole when viewed from a direction perpendicular to the axial direction of the upper jacket 16. The slit 16G has a first slit portion 16D1, a second slit portion 16D2, and a third slit portion 16D3.

[0080] The second side wall 16B has a first opening 16H1. When viewed from a direction perpendicular to the axial direction of the upper jacket 16, the first opening 16H1 is provided in an area surrounded by the first slit portion 16D1, the second slit portion 16D2, and the third slit portion 16D3 in the second side wall 16B. The first opening 16H1 penetrates the second side wall 16B. When viewed from a direction perpendicular to the axial direction of the upper jacket 16, the first opening 16H1 has, for example, a parallelogram shape.

[0081] The second side wall 16B has a second opening 16H2. The second opening 16H2 extends linearly along the axial direction of the upper jacket 16. The second opening 16H2 is located between the tip of the second slit portion 16D2 and the tip of the third slit portion 16D3. The first opening 16H1 is located between the second opening 16H2 and the first slit portion 16D1.

[0082] The first side wall 16A is provided with a slit 16G, a first opening 16H1 and a second opening 16H2 similar to those of the second side wall 16B. <Advantages of the Fifth Embodiment> Therefore, according to the fifth embodiment, in addition to the effects (1-1) and (1-4) of the first embodiment and the effects (2-1) and (2-2) of the second embodiment, the following effects can be obtained.

[0083] (5-1) The first side wall 16A and the second side wall 16B have a first opening 16H1 and a second opening 16H2, respectively. The rigidity of the portions of the first side wall 16A and the second side wall 16B separated by the slit 16G is reduced by the provision of the first opening 16H1 and the second opening 16H2. The rigidity of the distal ends (ends closer to the first slit portion 16D1) of the portions of the first side wall 16A and the second side wall 16B separated by the slit 16G is reduced by the provision of the first opening 16H1. The rigidity of the proximal ends (ends farther from the first slit portion 16D1) of the portions of the first side wall 16A and the second side wall 16B separated by the slit 16G is reduced by the provision of the second opening 16H2. That is, the portions of the first side wall 16A and the second side wall 16B separated by the slits 16G have reduced rigidity from their base ends to their tips, which makes the portions of the first side wall 16A and the second side wall 16B separated by the slits 16G more likely to elastically deform toward each other when the lock lever 54 is locked.

[0084] Sixth Embodiment Next, a sixth embodiment of the steering device will be described. This embodiment differs from the second embodiment in the configuration of the upper jacket 16. Therefore, the same members and configurations as those in the second embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0085] 12, the slit 16G of the second side wall 16B has a first slit portion 16D1, a second slit portion 16D2, and a third slit portion 16D3. However, the second slit portion 16D2 and the third slit portion 16D3 are extended to the opposite side of the first slit portion 16D1 compared to the second embodiment.

[0086] The second side wall 16B has an opening 16H3. When viewed from a direction perpendicular to the axial direction of the upper jacket 16, the opening 16H3 is provided in an area of ​​the second side wall 16B surrounded by the first slit portion 16D1, the second slit portion 16D2, and the third slit portion 16D3. The opening 16H3 penetrates the second side wall 16B. The opening 16H3 extends linearly along the axial direction of the upper jacket 16. Both ends of the opening 16H3 are rounded. A first end of the opening 16H3 is adjacent to the second slit portion 16D2. A second end of the opening 16H3 is adjacent to the third slit portion 16D3.

[0087] The first side wall 16A is provided with a slit 16G and an opening 16H3 similar to those of the second side wall 16B. <Advantages of the Sixth Embodiment> Therefore, according to the sixth embodiment, in addition to the effects (1-1) and (1-4) of the first embodiment and the effects (2-1) and (2-2) of the second embodiment, the following effects can be obtained.

[0088] (6-1) The second slit portion 16D2 and the third slit portion 16D3 extend in the direction opposite to the first slit portion 16D1. Therefore, when the lock lever 54 is locked, the portions of the first side wall 16A and the second side wall 16B separated by the slit 16G are more likely to elastically deform toward each other.

[0089] (6-2) The first side wall 16A and the second side wall 16B each have an opening 16H3. The rigidity of the portions of the first side wall 16A and the second side wall 16B separated by the slit 16G is reduced by the amount of the first opening 16H1 and the second opening 16H2. Therefore, when the lock lever 54 is locked, the portions of the first side wall 16A and the second side wall 16B separated by the slit 16G are more likely to elastically deform toward each other.

[0090] <Other embodiments> The first to sixth embodiments may be modified as follows. In the first embodiment, the slit 16D may be provided only in the first side wall 16A, not in the second side wall 16B. Alternatively, the slit 16D may be provided in both the first side wall 16A and the second side wall 16B.

[0091] In the second to sixth embodiments, the slit 16G may be provided in only one of the first side wall 16A and the second side wall 16B. The opening 16H in the third and fourth embodiments, the first opening 16H1 and the second opening 16H2 in the fifth embodiment, and the opening 16H3 in the sixth embodiment are provided in only the first side wall 16A or the second side wall 16B in which the slit 16G is provided.

[0092] In the second to sixth embodiments, the first side wall 16A and the second side wall 16B of the upper jacket 16 may be provided with elongated holes for telescopic adjustment separately from the slits 16G.

[0093] In the third to sixth embodiments, the openings (16H, 16H1, 16H2, 16H3) may also function as elongated holes for telescopic adjustment. In the first to sixth embodiments, three recesses 61A, 61B, and 61C are provided on the inner circumferential surface of the insertion hole 16C, but the number of recesses may be changed as appropriate. For example, the number of recesses may be two, or four or more.

[0094] In the first to sixth embodiments, the structure for adjusting the vertical position of the steering wheel 6 may be omitted. The vehicle on which the steering device 1 is mounted may be a cab-over truck, a passenger car, or a light vehicle. [Explanation of symbols]

[0095] 1...Steering device 2...Steering shaft 6...Steering wheel 16...Upper jacket 16A...first side wall 16B...Second side wall 16C...insertion hole 17...Lower tube 54...Lock lever 16D, 16G...Slit 16D1...First slit section 16D2...Second slit section 16D3...Third slit section 16D4...Fourth slit section (stress relief section) 16D5... Widened hole section (stress relief section) 16E,16F…Long hole 16H…Opening 16H1...First opening 16H2...Second opening 16H3…Opening 54...Tightening shaft 61A, 61B, 61C...recesses

Claims

1. A cylindrical lower tube that rotatably supports a steering shaft; an upper jacket having an insertion hole that is slidably fitted onto the lower tube along the axial direction thereof and is fixed to the lower tube by elastically reducing the diameter of the insertion hole; the upper jacket has a first side wall and a second side wall positioned opposite each other with the insertion hole therebetween, at least one of the first side wall and the second side wall has a slit for elastically deforming a portion of at least one of the first side wall and the second side wall inward to reduce a diameter of the insertion hole when the first side wall and the second side wall are tightened in a direction approaching each other through an operation of a lock lever, The slit includes a first slit portion extending along the axial direction of the upper jacket, A steering device having a second slit portion connected to an end of the first slit portion and extending along a direction intersecting the first slit portion, a fastening shaft for fastening the first side wall and the second side wall in a direction toward each other through operation of the lock lever; the first side wall and the second side wall have an elongated hole through which the fastening shaft is inserted and which extends along the first slit portion, A steering device in which the long hole is provided in a portion on the inner angle side between the first slit portion and the second slit portion, and a distance between an end of the long hole opposite the second slit portion and an end of the upper jacket opposite the second slit portion based on the long hole is narrower than a width of the first slit portion or the second slit portion.

2. The inner circumferential surface of the insertion hole has a plurality of recesses, 2. The steering device according to claim 1, wherein the recesses are provided at intervals along a circumferential direction of the insertion hole and over an entire length of the insertion hole in an axial direction.

Images