JP7632169B2 - Steering device - Google Patents

Description

The present invention relates to a steering device.

Conventionally, there are steering devices that allow the position of the 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 up and down direction. The telescopic mechanism is a mechanism for adjusting the axial position of the steering wheel. The driver can adjust the position of the steering wheel to a desired position by moving the steering wheel in the up and down direction or axial direction.

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 that are 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 by the vehicle body in a state in which movement in the direction of adjusting the position of the steering wheel is permitted.

JP 2017-197054 A

The steering device of Patent Document 1 has the following concerns. That is, when adjusting the axial position of the steering wheel, the steering column, wheel shaft, and universal joint move together in the axial direction as the telescopic shaft extends and retracts. This is one of the factors that reduces operability when adjusting the position of the steering wheel.

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 retractable, 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 its 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 that are located on opposite sides of the insertion hole. 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 approaching each other through the operation of a lock lever.

According to this configuration, the insertion hole elastically expands in diameter by releasing the tightening of the first side wall and the second side wall in the direction toward each other through the operation of the lock lever. 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.

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.

With this configuration, when the first side wall and the second side wall are tightened in a direction approaching each other through the operation of the lock lever, the portion of at least one of the first side wall and the second side wall separated by the slit tends to elastically deform inward. This makes it possible to hold the lower tube in an appropriate position.

In the above steering device, a tightening shaft may be provided for tightening the first side wall and the second side wall in a direction approaching each other through the operation of the lock lever. The first side wall and the second side wall may have a long hole through which the tightening shaft is inserted and which extends along the first slit portion. The long hole may be provided in an inner angle portion between the first slit portion and the second slit portion, and the distance between the end of the long hole opposite the second slit portion and the end of the upper jacket opposite the second slit portion based on the long hole may be set to a distance narrower than the width of the first slit portion or the second slit portion.

Depending on the product specifications, etc., with this configuration, the distance between the end of the long hole opposite the second slit portion and the end of the long hole opposite the second slit portion based on the long hole of the upper jacket may be set to a distance narrower than the width of the first slit portion or the second slit portion. In this case, a slit having a first slit portion and a second slit portion is preferable.

In the above steering device, the inner peripheral 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.

This configuration ensures a sufficient contact area between the inner circumferential surface of the insertion hole and the outer circumferential surface of the lower tube, while reducing the contact resistance between the inner circumferential surface of the insertion hole and the outer circumferential surface of the lower tube when adjusting the axial position of the steering wheel.

The steering device of the present invention can improve operability when adjusting the position of the steering wheel.

1 is a schematic diagram showing a configuration of a steering device according to a first embodiment; FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. FIG. 2 is a perspective view of the steering column according to the first embodiment. FIG. 2 is an exploded perspective view of the steering column according to the first embodiment. FIG. 2 is a perspective view of the upper jacket according to the first embodiment, as viewed from the first jacket portion side. 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. FIG. 4 is a side view of the upper jacket according to the first embodiment, as viewed from the second side wall side. FIG. 11 is a perspective view of an upper jacket according to a second embodiment, as viewed from a first jacket portion side. FIG. 13 is a side view of the upper jacket according to the third embodiment, as viewed from the second side wall side. FIG. 13 is a side view of the upper jacket according to the fourth embodiment, as viewed from the second side wall side. FIG. 13 is a side view of the upper jacket according to the fifth embodiment, as viewed from the second side wall side. FIG. 23 is a side view of the upper jacket of the sixth embodiment, as viewed from the second side wall side.

First Embodiment
A first embodiment of a 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 a second end of the intermediate shaft 3 via a universal joint 8. A pinion 4a is provided on 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 a vehicle body. The rack shaft 5 can move leftward or rightward 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).

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, for example, by a spline connection. The outer shaft 11 and the inner shaft 12 are integrally rotatable and relatively movable along the axial direction. The steering shaft 2 is disposed at an angle to the front-rear direction X1 of the vehicle, with the steering wheel 6 facing upward.

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).

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 frame 13 of the vehicle body. 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 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.

The housing 18 is connected to the second end of the lower tube 17. A steering assist motor 19 is provided outside the housing 18. A reduction gear 20 is accommodated inside the housing 18. The reduction gear 20 reduces the rotation of the motor 19 and transmits the reduced rotation to the inner shaft 12. The reduction gear 20 is a worm reduction gear having a worm 21 and a worm wheel 22. The worm 21 is connected to the 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.

<Steering column support structure>
Next, the support structure of the steering column 15 will be described in detail.
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.

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

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, it is as follows.

That is, two bolts 41 are provided protruding from the frame 13. These bolts 41 extend such that their axial direction Z1 intersects with 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 with male threads on both ends. A first end of the bolt 41 is screwed into 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 on the second end of the bolt 41. A washer 43 is interposed between the nut 42 and the mounting seat 34A.

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

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 from 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 from the axial direction of the steering shaft 2. The first clamp portion 35B and the second clamp portion 35C extend toward the opposite side of the vehicle body from the frame 13 (downward in FIG. 2).

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 adjusting the tilt.
As shown in Fig. 2, the upper jacket 16 is located 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 located on opposite sides 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.

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 a position near the connecting portion 35A in the second side wall 16B. 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 on the end face of the upper jacket 16 on the side where the lower tube 17 is inserted. The inside and outside of the upper jacket 16 are in communication with each other 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.

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

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 (left and right direction in FIG. 2). The fastening shaft 51 penetrates the two long holes 35D, 35D of the tilt bracket 35 and the two long holes 16E, 16F of the upper jacket 16. A nut 53 is screwed onto the end of the fastening shaft 51 opposite the head 52. A lock lever 54 is supported rotatably between the head 52 and the second side wall 16B of the fastening shaft 51.

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 relative rotation with respect to the first clamp portion 35B is restricted. A plurality of protrusions are provided at intervals on the peripheral portion 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 portion 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 through the rotational operation of the lock lever 54. The first rotational position refers to a position in which the protrusions of the first cam 55 engage with the protrusions of the second cam 56 in a meshed manner. The second rotation position is the position where the protrusion of the first cam 55 rides on the protrusion of the second cam 56.

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 the protrusion of the first cam 55 rides on the protrusion of the second cam 56 due to this rotation. Since the movement of the lock lever 54 in the direction along the tightening shaft 51 is restricted, the second cam 56 tries to move in a direction approaching the nut 53 by the amount that the protrusion of the first cam 55 rides 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 a direction 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. In other words, the first side wall 16A and the second side wall 16B are sandwiched by the first clamp portion 35B and the second clamp portion 35C in a direction approaching each other. This restricts the upper jacket 16 from moving relative to the tilt bracket 35.

In addition, the second side wall 16B of the upper jacket 16 is provided with a slit 16D. Therefore, the first side wall 16A and the second side wall 16B are sandwiched by the first clamp portion 35B and the second clamp portion 35C in a direction approaching each other, and a portion of the second side wall 16B separated by the slit 16D elastically deforms in a direction approaching the first side wall 16A. With this elastic deformation of the second side wall 16B, the distance 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 outer peripheral surface of the lower tube 17 is clamped by the inner peripheral surface of the insertion hole 16C, thereby restricting the relative axial movement of the upper jacket 16 with respect to the lower tube 17.

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 through the rotational operation (unlock operation) of the lock lever 54. The protrusion of the first cam 55 fits between the protrusions of the second cam 56, and the clamping of the first clamp portion 35B and the second clamp portion 35C in the tilt bracket 35 in the direction of approaching each other, and the clamping of the first side wall 16A and the second side wall 16B in the direction of approaching each other in the upper jacket 16 are released. The first clamp portion 35B and the second clamp portion 35C, and the second side wall 16B each elastically return to their original positions, and the distance between the first clamp portion 35B and the second clamp portion 35C, and the distance between the first side wall 16A and the second side wall 16B are increased. Accordingly, the insertion hole 16C elastically expands in diameter.

This weakens the force with which the first clamp portion 35B and the second clamp portion 35C clamp the first side wall 16A and the second side wall 16B. Also, the force with which the upper jacket 16 clamps the outer circumferential surface of the lower tube 17 is weakened. 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. Also, by releasing the clamping 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 position of the steering wheel 6 in the axial direction can be adjusted.

<Details of upper jacket structure>
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 long holes 16E, 16F and the slit 16D for telescopic adjustment are all provided in the first jacket portion 61.

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 a length approximately equal to the outer diameter of the lower tube 17. Three recesses 61A, 61B, 61C are provided on the inner peripheral surface of the insertion hole 16C. The three recesses 61A, 61B, 61C extend over the entire axial length of the insertion hole 16C. The three recesses 61A, 61B, 61C are provided at intervals along the circumferential direction of the insertion hole 16C. The three recesses 61A, 61B, 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, and 61C.

As shown in FIG. 7, the slit 16D is generally L-shaped 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.

The first slit portion 16D1 extends along the axial direction of the upper jacket 16. The first end of the first slit portion 16D1 is open on the side opposite the second jacket portion 62. The second end of the first slit portion 16D1 is located closer to the second jacket portion 62 in the axial direction of the upper jacket 16 than the long hole 16F for telescopic adjustment.

The second slit portion 16D2 extends in a direction perpendicular to the first slit portion 16D1. The first end of the second slit portion 16D2 is connected to the 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 the axis of the upper jacket 16 as the boundary.

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

<Operation of the First Embodiment>
Next, the operation of the first embodiment will be described.
After the adjustment of the position of the steering wheel 6 is completed, 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. With this operation, the first clamp portion 35B and the second clamp portion 35C of the tilt bracket 35 are tightened in a direction approaching 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. In addition, as the portion of the second side wall 16B of the upper jacket 16 separated by the slit 16D elastically deforms in a direction approaching the first side wall 16A, the insertion hole 16C elastically contracts in diameter and tightens the outer circumferential surface of the lower tube 17. This restricts the relative movement of the upper jacket 16 with respect to the lower tube 17 in the axial direction.

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 on the inner angle side between the first slit portion 16D1 and the second slit portion 16D2 in the second side wall 16B, is lower than the rigidity of the other portions. The rigidity here is the rigidity against deformation in the 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 the direction approaching the first side wall 16A. As a result, the portion of the second side wall 16B separated by the slit 16D is elastically deformed in a direction approaching the first side wall 16A, and thus the operating force of the lock lever 54 required to reduce the diameter of the insertion hole 16C is reduced. This improves the operability of the lock lever 54.

In addition, 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 the portion of the first side wall 16A on the inner circumferential surface of the insertion hole 16C. This positions the lower tube 17 relative to the first side wall 16A. In this state, the portion of the inner circumferential surface of the second side wall 16B is pressed against the outer circumferential surface of the lower tube 17, so that the lower tube 17 is fixed to the upper jacket 16. With the lower tube 17 positioned relative to the first side wall 16A, the outer circumferential surface of the lower tube 17 is tightened, suppressing axial misalignment between the lower tube 17 and the upper jacket 16.

Incidentally, a plurality of recesses 61A, 61B, 61C are provided on the inner peripheral surface of the insertion hole 16C. The size and arrangement of these recesses 61A, 61B, 61C are set based on the viewpoint of reducing the contact resistance between the inner peripheral surface of the insertion hole 16C and the outer peripheral surface of the lower tube 17 while ensuring the contact area between the inner peripheral surface of the insertion hole 16C and the outer peripheral surface of the lower tube 17. Therefore, when the outer peripheral surface of the lower tube 17 is tightened, there is no rattling between the inner peripheral surface of the insertion hole 16C and the outer peripheral surface of the lower tube 17, and the lower tube 17 is suitably held by the upper jacket 16. In addition, the contact area between the inner peripheral surface of the insertion hole 16C and the outer peripheral surface of the lower tube 17 is reduced by the amount of the plurality of recesses 61A, 61B, 61C provided on the inner peripheral surface of the insertion hole 16C. Therefore, the 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 is reduced.

Effects 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. That is, when adjusting the axial position of the steering wheel 6, it is not necessary to move the 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.

(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 provided 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 in the direction toward the first side wall 16A. Also, 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 adequately tightens the outer circumferential surface of the lower tube 17. Therefore, the upper jacket 16 can adequately hold the lower tube 17.

(1-3) The slit 16D is provided only in the second side wall 16B of the first side wall 16A and second side wall 16B of the upper jacket 16. Therefore, when the lock lever 54 is operated to lock, the portion of the second side wall 16B separated by the slit 16D elastically deforms toward the first side wall 16A, and the lower tube 17 is pressed against the portion of the inner 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.

(1-4) The inner peripheral surface of the insertion hole 16C is provided with a plurality of recesses 61A, 61B, 61C. Therefore, while ensuring the contact area between the inner peripheral surface of the insertion hole 16C and the outer peripheral surface of the lower tube 17, the 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 can be reduced. In addition, 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 obtained. That is, when the relative movement between the upper jacket 16 and the lower tube 17 in the axial direction is restricted, the occurrence of rattle between the inner peripheral surface of the insertion hole 16C and the outer peripheral surface of the lower tube 17 is suppressed. Therefore, the lower tube 17 can be favorably held by the upper jacket 16.

(1-5) Depending on the product specifications, the first end (left end in FIG. 7) of the long hole 16F for telescopic adjustment may be provided close to the end opposite the second jacket portion 62 of the upper jacket 16. 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 portion of the second side wall 16B between the first end of the long hole 16F and the end opposite the second jacket portion 62 of the upper jacket 16. When such a long hole 16F configuration is adopted, an L-shaped slit 16D having the first slit portion 16D1 and the second slit portion 16D2 is preferable.

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 Figures 1 to 6. However, this embodiment differs from the first embodiment in a portion of the configuration of the upper jacket 16. Therefore, the same members and configurations as those in the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 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. The first side wall 16A and the second side wall 16B each have a slit 16G.

The slit 16G is generally U-shaped when viewed from a direction perpendicular to the axial direction of the upper jacket 16. In addition to the first slit portion 16D1 and the second slit portion 16D2, the slit 16G has a third slit portion 16D3. The first slit portion 16D1, the second slit portion 16D2, and the third slit portion 16D3 are continuous with each other.

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 a long hole for telescopic adjustment. A tightening shaft 51 is inserted into the first slit portion 16D1. The two long holes 16E, 16F of the first embodiment shown in Figures 4 and 5 above are omitted.

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

Now, when the lock lever 54 is operated to lock, the portions of the first side wall 16A and the second side wall 16B separated by the slit 16G are clamped by the first clamp portion 35B and the second clamp portion 35C in a direction approaching each other, and the portions of the first side wall 16A and the second side wall 16B separated by the slit 16G elastically deform in a direction approaching each other. As a result of this elastic deformation, the insertion hole 16C contracts in diameter and the outer peripheral surface of the lower tube 17 is tightened. This restricts the relative axial movement of the upper jacket 16 with respect to the lower tube 17.

<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.

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

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

Third Embodiment
Next, a third embodiment of the steering device will be described. In this embodiment, the shape of the slit 16G is different from that of the second embodiment. Therefore, the same members and configurations as those in the second embodiment are given the same reference numerals, and detailed description thereof will be omitted.

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

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 is, for example, in the shape of a parallelogram.

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.

(3-1) When the lock lever 54 is operated to lock, the portions of the first side wall 16A and the second side wall 16B separated by the slit 16G elastically deform toward each other, and there is a concern that stress will be concentrated at the tip of the second slit portion 16D2. In this regard, the tip of the second slit portion 16D2 is provided with a fourth slit portion 16D4 as a stress relief portion extending in a direction perpendicular to the second slit portion 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 be concentrated at the tip of the second slit portion 16D2 including the fourth slit portion 16D4 as a stress relief portion. The tip of the second slit portion 16D2 is the end of the second slit portion 16D2 opposite the first slit portion 16D1.

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.

(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 in the direction of approaching each other.

<Fourth embodiment>
Next, a fourth embodiment of the steering device will be described. In this embodiment, the shape of the slit 16G is different from that of the third embodiment. Therefore, the same members and configurations as those in the third embodiment are given the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 10, the slit 16G of the second side wall 16B has the first slit portion 16D1, the second slit portion 16D2, and the 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 so-called teardrop-shaped contour shape. 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 continuous with each other via a smooth curved surface. The tip of the expanded hole portion 16D5 is a smooth arc surface 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 extend beyond the side edge of the second slit portion 16D2 opposite the third slit portion 16D3 (the right side in FIG. 10).

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

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) in the first embodiment, (2-1) and (2-2) in the second embodiment, and (3-1) and (3-2) in the third embodiment.

Fifth embodiment
Next, a fifth embodiment of the steering system 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.

As shown in FIG. 11, the second side walls 16B each have a slit 16G. The slit 16G is generally U-shaped 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.

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 is, for example, in the shape of a parallelogram when viewed from a direction perpendicular to the axial direction of the upper jacket 16.

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.

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.

(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 portion 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 tip (end close to the first slit portion 16D1) of the portion of the first side wall 16A and the second side wall 16B separated by the slit 16G is reduced by providing the first opening 16H1. The rigidity of the base end (end far from the first slit portion 16D1) of the portion of the first side wall 16A and the second side wall 16B separated by the slit 16G is reduced by providing the second opening 16H2. That is, the portions of the first side wall 16A and the second side wall 16B separated by the slit 16G have a reduced rigidity overall from their base end to their tip. 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 in the direction of approaching each other.

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.

As shown in FIG. 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.

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 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 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. The first end of the opening 16H3 is close to the second slit portion 16D2. The second end of the opening 16H3 is close to the third slit portion 16D3.

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.

(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 operated to lock, 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 in the direction toward each other.

(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 slits 16G is reduced by the amount of the first opening 16H1 and the second opening 16H2. Therefore, when the lock lever 54 is operated to lock, the portions of the first side wall 16A and the second side wall 16B separated by the slits 16G are more likely to elastically deform in the direction of approaching each other.

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

- 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 only in the first side wall 16A or the second side wall 16B in which the slit 16G is provided.

- In the second to sixth embodiments, long holes for telescopic adjustment may be provided in the first side wall 16A and the second side wall 16B of the upper jacket 16 separately from the slits 16G.

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, the 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.

In the first to sixth embodiments, the configuration 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.

REFERENCE SIGNS LIST 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 portion 16D2... Second slit portion 16D3... Third slit portion 16D4... Fourth slit portion (stress relaxation portion)
16D5... Widened hole portion (stress relief portion)
16E, 16F... oblong holes 16H... opening 16H1... first opening 16H2... second opening 16H3... opening 54... fastening shaft 61A, 61B, 61C... recesses

Claims (2)

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. 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.

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