WO2024157422A1 - Steering column device - Google Patents

Abstract

A steering column device (1) rotatably supports a steering shaft (2) of a vehicle. The steering column device includes: an inner tube (17); an outer tube (16) fitted to the outer circumferential surface of the inner tube; and a cylindrical retainer (18) interposed between the outer circumferential surface of the inner tube and the inner circumferential surface of the outer tube. The retainer is formed such that movement in the circumferential direction and movement in the axial direction with respect to the outer tube are restricted. The outer tube is movable in the axial direction relative to the inner tube via the retainer. The outer tube includes a first slit (16A) extending in the axial direction. The retainer includes a second slit (18A) which extends in the axial direction and of which the circumferential position is different from the circumferential position of the first slit. The first slit is blocked from the inside of the outer tube by the retainer.

Description

Steering column device

This disclosure relates to a steering column device.

A vehicle's steering column device rotatably supports the steering shaft. Some steering column devices have a telescopic function. The telescopic function is a function that adjusts the position of the steering wheel in the fore-and-aft direction of the vehicle.

For example, the steering column device of Patent Document 1 has an inner tube, an outer tube, and a retainer. The outer tube is fitted onto the outer peripheral surface of the inner tube via the retainer. The retainer is restricted in axial and circumferential movement relative to the outer tube. The inner tube and the outer tube are relatively movable in the axial direction via the retainer. The outer tube has a first slit extending in the axial direction. The retainer has a second slit extending in the axial direction. The outer tube and the retainer are assembled so that the circumferential position of the first slit and the circumferential position of the second slit coincide with each other.

JP 2021-112959 A

The following concerns exist regarding steering column devices with slits, including the one in Patent Document 1. That is, there is a risk that foreign matter such as water or dust may enter the inside of the steering column device through the slit.

A steering column device according to one aspect of the present disclosure rotatably supports a steering shaft of a vehicle. The steering column device includes an inner tube, an outer tube fitted to the outer peripheral surface of the inner tube, and a cylindrical retainer interposed between the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube, the retainer being configured to restrict circumferential and axial movement with respect to the outer tube. The outer tube and the inner tube are relatively movable in the axial direction via the retainer. The outer tube has a first slit extending in the axial direction. The retainer has a second slit extending in the axial direction and whose circumferential position is different from that of the first slit. The first slit is blocked from the inside of the outer tube by the retainer.

FIG. 1 is a schematic diagram of an embodiment of a steering column device. FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. FIG. 2 is a perspective view showing a main part of a comparative example of the steering column of FIG. 1 . FIG. 2 is a perspective view of an embodiment of the steering column of FIG. FIG. 5 is a cross-sectional view showing a range in which the circumferential position of the second slit in FIG. 4 is set. FIG. 5 is a cross-sectional view showing a first circumferential position of the second slit in FIG. 4 . FIG. 5 is a cross-sectional view showing a second circumferential position of the second slit in FIG. 4 . FIG. 5 is a cross-sectional view showing a third circumferential position of the second slit in FIG. 4 . FIG. 5 is a cross-sectional view showing a fourth circumferential position of the second slit in FIG. 4 .

A steering column device according to an embodiment will be described.
<Overall configuration of steering column device 1>
As shown in Fig. 1, a vehicle steering column device 1 rotatably supports a steering shaft 2. A first end of the steering shaft 2 is connected to a steering wheel 3. A second end of the steering shaft 2 is meshed with a rack shaft via an intermediate shaft and a pinion shaft. The rack shaft extends in the left-right direction of the vehicle body. Both ends of the rack shaft are connected to steered wheels via tie rods. The direction of the steered wheels is changed by operating the steering wheel 3.

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, for example, by a spline connection. The outer shaft 11 and the inner shaft 12 can rotate together. Furthermore, the outer shaft 11 and the inner shaft 12 can move relative to each other in the axial direction. The steering shaft 2 is disposed at an angle to the front-to-rear direction X1 of the vehicle so that the steering wheel 3 is located on the upper side.

The steering column device 1 has a steering column 15. The steering column 15 is fixed to a fixed part 13 such as a frame of a vehicle body. The steering shaft 2 is inserted axially through the steering column 15. The steering shaft 2 is rotatably supported by the steering column 15 via a bearing.

The steering column 15 has an outer tube 16 , an inner tube 17 , and a retainer 18 .
The outer tube 16 is made of metal and has a cylindrical shape with a circular cross section. The outer tube 16 has a first end and a second end. The first end is the axial end of the outer tube 16 that is closer to the steering wheel 3. The second end is the axial end of the outer tube 16 that is farther from the steering wheel 3.

The inner tube 17 is made of metal and is cylindrical with a circular cross-sectional shape. The inner tube 17 has a first end and a second end. The first end is the axial end of the inner tube 17 that is closer to the steering wheel 3. The second end is the axial end of the inner tube 17 that is farther from the steering wheel 3.

The retainer 18 is made of resin and is cylindrical with a circular cross-sectional shape. The axial length of the retainer 18 is shorter than the axial length of the outer tube 16. The first end of the retainer 18 is inserted into the interior of the outer tube 16 from the second end of the outer tube 16. The outer peripheral surface of the retainer 18 is fitted into the inner peripheral surface of the outer tube 16.

The retainer 18 has a flange portion 18B that protrudes radially outward. The flange portion 18B is provided on the outer peripheral surface of the second end of the retainer 18. The flange portion 18B abuts against the second end of the outer tube 16 in the axial direction, thereby restricting movement of the retainer 18 in the direction from the second end to the first end of the outer tube 16.

The retainer 18 is configured so that circumferential and axial movement is restricted relative to the outer tube 16. The retainer 18 has, for example, a positioning protrusion. The positioning protrusion is provided on the outer peripheral surface of the retainer 18. The outer tube 16 has a fitting recess or a fitting hole. The fitting recess is provided on the inner peripheral surface of the outer tube 16. The fitting hole is provided so as to penetrate radially through the peripheral wall of the outer tube 16. The positioning protrusion fits into the fitting recess or fitting hole of the outer tube. This restricts circumferential and axial movement of the retainer 18 relative to the outer tube 16.

The first end of the inner tube 17 is inserted into the retainer 18 from the second end of the retainer 18. The outer peripheral surface of the inner tube 17 is fitted into the inner peripheral surface of the retainer 18. That is, the inner peripheral surface of the outer tube 16 is fitted into the outer peripheral surface of the inner tube 17 via the retainer 18. The retainer 18 is interposed between the inner peripheral surface of the outer tube 16 and the outer peripheral surface of the inner tube 17. The outer tube 16 and the inner tube 17 can move relatively in the axial direction via the retainer 18. The outer tube 16 is fixed to the fixed part 13 of the vehicle body via a column bracket 21.

<Column bracket 21>
As shown in FIG. 2, the column bracket 21 has an upper bracket 22, a tilt bracket 23, a first clamp bracket 24A, and a second clamp bracket 24B.

The upper bracket 22 is made of metal and has a flat plate shape extending in the left-right direction of the vehicle body. A mounting seat 22A is provided at each of a first end and a second end of the upper bracket 22. The first end is the end of the upper bracket 22 on the left side in the direction of travel of the vehicle. The second end is the end of the upper bracket 22 on the right side in the direction of travel of the vehicle. The upper bracket 22 is fixed to the fixing part 13 of the vehicle body via the mounting seat 22A.

Two bolts 31 protrude from the fixing portion 13. The axial direction Z1 of the bolts 31 is a direction that intersects with the vertical direction. When viewed from the axial direction of the steering shaft 2, the bolts 31 are provided on the left and right sides of the vehicle body with the steering shaft 2 as a reference. The bolts 31 are stud bolts with male threads on both ends. A first end of the bolt 31 is screwed into the fixing portion 13. A second end of the bolt 31 passes through the mounting seat 22A. The mounting seat 22A is fixed to the fixing portion 13 by tightening a nut 32 on the second end of the bolt 31. A washer 33 is interposed between the nut 32 and the mounting seat 22A.

The tilt bracket 23 is fixed to the upper bracket 22. The tilt bracket 23 is made of metal and has a rectangular U-shaped cross section. The tilt bracket 23 is open on the side opposite the fixed part 13. The tilt bracket 23 has a first side plate 23A, a second side plate 23B, and a connecting plate 23C.

The connecting plate 23C is flat and fixed to the surface of the upper bracket 22 opposite the fixed portion 13. The first side plate 23A is connected to a first side edge of the connecting plate 23C when viewed from the axial direction of the steering shaft 2. The first side edge is the side edge of the connecting plate 23C on the left side in the direction of travel of the vehicle. The second side plate 23B is connected to a second side edge of the connecting plate 23C when viewed from the axial direction of the steering shaft 2. The second side edge is the side edge of the connecting plate 23C on the right side in the direction of travel of the vehicle. The first side plate 23A and the second side plate 23B each extend in the opposite direction to the fixed portion 13 along the axial direction Z1 of the bolt 31. The first side plate 23A and the second side plate 23B are parallel to each other. The first side plate 23A and the second side plate 23B each have a first long hole extending in the axial direction Z1 of the bolt 31. The rigidity of the first side plate 23A is equal to the rigidity of the second side plate 23B.

The first clamp bracket 24A and the second clamp bracket 24B are each made of metal and have a square U-shaped cross section. The first clamp bracket 24A and the second clamp bracket 24B are each fixed to the outer peripheral surface of the outer tube 16. The first clamp bracket 24A and the second clamp bracket 24B are located on opposite sides of each other in a direction perpendicular to the axial direction of the outer tube 16. The first clamp bracket 24A and the second clamp bracket 24B face each other in the left-right direction of the vehicle body.

The first clamp bracket 24A and the second clamp bracket 24B each extend in a direction approaching the fixed portion 13 along the axial direction Z1 of the bolt 31. The first end of the first clamp bracket 24A and the first end of the second clamp bracket 24B are each fixed ends that are fixed to the outer peripheral surface of the outer tube 16. The second end of the first clamp bracket 24A and the second end of the second clamp bracket 24B are each free ends that are not fixed to other members.

The first clamp bracket 24A is located inside the first side plate 23A of the tilt bracket 23 when viewed from the axial direction of the steering shaft 2. The outer surface of the first clamp bracket 24A is in contact with the inner surface of the first side plate 23A. The second clamp bracket 24B is located inside the second side plate 23B of the tilt bracket 23 when viewed from the axial direction of the steering shaft 2. The outer surface of the second clamp bracket 24B is in contact with the inner surface of the second side plate 23B. The first clamp bracket 24A and the second clamp bracket 24B each have a second long hole extending in the axial direction of the steering shaft 2. The first clamp bracket 24A and the second clamp bracket 24B are each movable relative to the tilt bracket 23.

The first clamp bracket 24A and the second clamp bracket 24B are each connected to the tilt bracket 23 via a fastening shaft 51. The fastening shaft 51 is, for example, a bolt. When viewed from the axial direction of the steering shaft 2, the fastening shaft 51 is, for example, located between the connecting plate 23C and the outer tube 16. The fastening shaft 51 extends in a direction intersecting with the axial direction of the steering shaft 2.

The tightening shaft 51 has a head 52. The head 52 is provided at a first end of the tightening shaft 51. The tightening shaft 51 is disposed to pass through the first long holes of the two side plates (23A, 23B) and the second long holes of the two clamp brackets (24A, 24B). The second end of the tightening shaft 51 protrudes outside the second side plate 23B. A nut 53 is fastened to the second end of the tightening shaft 51. A lever 54 is rotatably supported between the head 52 and the first side plate 23A. Movement of the lever 54 in a direction along the tightening shaft 51 is restricted.

The lever 54 has a first cam 55. The first cam 55 is integrally provided at the base end of the lever 54. The base end is the end of the lever 54 that is supported by the tightening shaft 51. The first cam 55 is disposed on the opposite side of the head 52 with respect to the lever 54. A second cam 56 is provided on the outer surface of the first side plate 23A. The second cam 56 is restricted from rotating relative to the first side plate 23A.

The first cam 55 has a first cam surface. The first cam surface is the surface of the first cam 55 that faces the second cam 56. A plurality of protrusions are provided at intervals in the circumferential direction on the peripheral edge of the first cam surface. The second cam 56 has a second cam surface. The second cam surface is the surface of the second cam 56 that faces the first cam 55. A plurality of protrusions are provided at intervals in the circumferential direction on the peripheral edge of the second cam surface.

The rotational position of the first cam 55 is switched between a first rotational position and a second rotational position by operating the lever 54. The first rotational position is a position where the protrusion of the first cam 55 fits between the two protrusions of the second cam 56. The second rotational position is a 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 operation of the lever 54, the first cam 55 rotates relative to the second cam 56. As the first cam 55 rotates, the protrusion of the first cam 55 rides on the protrusion of the second cam 56. The axial movement of the tightening shaft 51 of the lever 54 is restricted. Therefore, when the protrusion of the first cam 55 rides on the protrusion of the second cam 56, the second cam 56 exerts a force in a direction approaching the nut 53. The force is a force in the axial direction of the tightening shaft 51. Therefore, between the second cam 56 and the nut 53, the first side plate 23A and the second side plate 23B elastically deform in a direction approaching each other.

In other words, the first clamp bracket 24A and the second clamp bracket 24B are sandwiched between the first side plate 23A and the second side plate 23B in a direction in which they approach each other. The inner surface of the first side plate 23A is pressed against the outer surface of the first clamp bracket 24A. The inner surface of the second side plate 23B is pressed against the outer surface of the second clamp bracket 24B. This restricts the relative movement of the first clamp bracket 24A and the second clamp bracket 24B with respect to the tilt bracket 23. In addition, by being sandwiched between the first side plate 23A and the second side plate 23B, the first clamp bracket 24A and the second clamp bracket 24B elastically deform in a direction in which they approach each other.

The outer tube 16 has a first slit 16A. The first slit 16A is located between the first clamp bracket 24A and the second clamp bracket 24B. The first slit 16A extends from the second end of the outer tube 16 toward the first end. The first slit 16A is provided over a predetermined range in the axial direction. The first slit 16A opens toward the connecting plate 23C of the tilt bracket 23. When the steering column device 1 is mounted on the vehicle body, the first slit 16A faces upward.

The retainer 18 has a second slit 18A. The second slit 18A is located between the first clamp bracket 24A and the second clamp bracket 24B. The second slit 18A extends from the second end of the retainer 18 toward the first end. The second slit 18A is provided over a predetermined range in the axial direction. This predetermined range includes the entire axial length of the retainer 18.

The circumferential position of the second slit 18A may be aligned with the circumferential position of the first slit 16A, for example. In this case, the second slit 18A opens toward the connecting plate 23C of the tilt bracket 23 through the first slit 16A. When the steering column device 1 is mounted on the vehicle body, the second slit 18A faces upward.

Therefore, as the first clamp bracket 24A and the second clamp bracket 24B elastically deform in a direction approaching each other, the outer tube 16 elastically deforms so that the spacing of the first slits 16A narrows and the inner diameter becomes smaller. As the outer tube 16 contracts in diameter, the retainer 18 elastically deforms so that the spacing of the second slits 18A narrows and the inner diameter becomes smaller. As the retainer 18 contracts in diameter, it tightens the outer peripheral surface of the inner tube 17. That is, the outer tube 16 tightens the outer peripheral surface of the inner tube 17 via the retainer 18. This restricts the relative axial movement between the outer tube 16 and the inner tube 17 via the retainer 18.

When changing the position of the steering wheel 3, the rotational position of the first cam 55 is switched from the second rotational position to the first rotational position by operating the lever 54. In the first rotational position, the protrusion of the first cam 55 fits between the two protrusions of the second cam 56. This releases the clamping of the first side plate 23A and the second side plate 23B in the direction in which they approach each other. Also, the clamping of the first clamp bracket 24A and the second clamp bracket 24B in the direction in which they approach each other is released. Therefore, the first side plate 23A and the second side plate 23B each elastically return to their original positions, and the distance between the first side plate 23A and the second side plate 23B increases. Also, the first clamp bracket 24A and the second clamp bracket 24B each elastically return to their original positions, and the distance between the first clamp bracket 24A and the second clamp bracket 24B increases.

By increasing the distance between the first side plate 23A and the second side plate 23B, the force with which the first side plate 23A and the second side plate 23B clamp the first clamp bracket 24A and the second clamp bracket 24B is weakened. This allows the outer tube 16 to move up and down relative to the tilt bracket 23. By moving the steering wheel 3 up and down, it is possible to adjust the vertical position of the steering wheel 3.

In addition, as the gap between the first clamp bracket 24A and the second clamp bracket 24B widens, the outer tube 16 elastically returns to its original shape so that the gap between the first slits 16A widens and the inner diameter increases. Accordingly, the retainer 18 elastically returns to its original shape so that the gap between the second slits 18A widens and the inner diameter increases. In other words, the outer tube 16 and the retainer 18 release the clamping of the outer peripheral surface of the inner tube 17. This allows relative axial movement between the outer tube 16 and the inner tube 17 via the retainer 18. By moving the steering wheel 3 axially, the axial position of the steering wheel 3 can be adjusted.

<About intrusion of foreign objects>
If the circumferential position of the first slit 16A and the circumferential position of the second slit 18A coincide with each other, the following concern arises: When adjusting the axial position of the steering wheel 3, the fitting length between the outer tube 16 and the inner tube 17 changes as the steering wheel 3 moves in the axial direction.

As shown in FIG. 3, depending on the axial position of the steering wheel 3, an area A0 occurs where the outer tube 16 and the inner tube 17 do not overlap radially. In area A0, the inside of the steering column 15 is connected to the outside of the steering column 15 via the first slit 16A and the second slit 18A. For this reason, there is a risk that foreign matter such as water or dust may enter the inside of the steering column 15 via the first slit 16A and the second slit 18A.

Therefore, in this embodiment, the circumferential position of the second slits 18A is set as follows.
<Circumferential Position of Second Slit 18A>
As shown in Fig. 4, the circumferential position of the second slit 18A is different from the circumferential position of the first slit 16A. That is, the circumferential position of the second slit 18A does not match the circumferential position of the first slit 16A. The first slit 16A is blocked from the inside of the outer tube 16 by the circumferential wall of the retainer 18. The second slit 18A is blocked from the outside of the retainer 18 by the circumferential wall of the outer tube 16. For this reason, even if an area A0 occurs where the outer tube 16 and the inner tube 17 do not overlap in the radial direction, the inside of the steering column 15 and the outside of the steering column 15 do not communicate with each other through the first slit 16A and the second slit 18A.

As indicated by a large number of dots in FIG. 5, the circumferential positions of the second slits 18A are set in a circumferential range excluding the first to fourth circumferential ranges A1 to A4 when viewed from the axial direction.
The first slit 16A is disposed at the 12 o'clock position as viewed from the axial direction, which is the upper position when the steering column device 1 is mounted on the vehicle body.

The first circumferential range A1 is a circumferential range that includes the 12 o'clock position when viewed from the axial direction, and is a circumferential range that corresponds to the first slit 16A and the peripheral portion of the first slit 16A. The peripheral portion includes a first peripheral portion and a second peripheral portion. The first peripheral portion and the second peripheral portion are parts of the outer tube 16 that face each other in the circumferential direction, sandwiching the first slit 16A therebetween.

When the outer tube 16 is elastically deformed through the operation of the lever 54 so that the spacing of the first slits 16A narrows and the inner diameter decreases, the first peripheral portion applies a first holding force F1 to the inner tube 17 via the retainer 18. The first holding force F1 is an inward force. The first holding force F1 is applied to the first holding portion P11 of the inner tube 17 via the retainer 18. The first holding portion P11 is a portion of the inner tube 17 that holds the outer tube 16, and is a portion of the inner tube 17 to which the first holding force F1 is applied via the retainer 18. In FIG. 5, the first holding portion P11 is indicated by a single dot when viewed from the axial direction.

When the outer tube 16 is elastically deformed through the operation of the lever 54 so that the spacing of the first slits 16A narrows and the inner diameter decreases, the second peripheral portion applies a second holding force F2 to the inner tube 17 via the retainer 18. The second holding force F2 is an inward force that is a force in a direction intersecting with the first holding force F1. The second holding force F2 is applied, for example, to the second holding portion P12 of the inner tube 17 via the retainer 18. The second holding portion P12 is a portion of the inner tube 17 that holds the outer tube 16, and is a portion of the inner tube 17 to which the second holding force F2 is applied via the retainer 18. In FIG. 5, the second holding portion P12 is indicated by a single dot when viewed from the axial direction.

The second circumferential range A2 is a circumferential range including the 6 o'clock position when viewed from the axial direction. The 6 o'clock position is a lower position when the steering column device 1 is mounted on the vehicle body. When the outer tube 16 is elastically deformed through the operation of the lever 54 so that the interval of the first slits 16A narrows and the inner diameter decreases, the portion of the outer tube 16 opposite the first slits 16A in the radial direction applies a third holding force F3 to the inner tube 17 via the retainer 18. The third holding force F3 is an inward force, and includes a force in the radial direction from the 6 o'clock position to the 12 o'clock position. The third holding force F3 is applied to, for example, the third holding portion P13 of the inner tube 17 via the retainer 18. The third holding portion P13 is a portion of the inner tube 17 that holds the outer tube 16, and is a portion of the inner tube 17 to which the third holding force F3 is applied via the retainer 18. In FIG. 5, the third holding portion P13 is shown as a single dot when viewed in the axial direction.

The third circumferential range A3 is a circumferential range that includes the 3 o'clock position when viewed from the axial direction, and the fourth circumferential range A4 is a circumferential range that includes the 9 o'clock position when viewed from the axial direction.
Note that a structure may be provided between the outer peripheral surface of the inner tube 17 and the inner peripheral surface of the outer tube 16 to suppress rattling between the outer tube 16 and the retainer 18, or between the retainer 18 and the inner tube 17. This structure is provided, for example, at positions corresponding to the third circumferential range A3 and the fourth circumferential range A4.

The first to fourth circumferential ranges A1 to A4 correspond to the areas of the outer tube 16 and the inner tube 17 that are functionally important in holding the outer tube 16.

As shown by the two-dot chain line in FIG. 5, when viewed from the axial direction, an isosceles triangle is formed by connecting the first holding portion P11, the second holding portion P12, and the third holding portion P13. The line segment connecting the first holding portion P11 and the third holding portion P13 is the first side of the isosceles triangle. The line segment connecting the second holding portion P12 and the third holding portion P13 is the second side of the isosceles triangle. The line segment connecting the first holding portion P11 and the second holding portion P12 is the third side of the isosceles triangle. The first side and the second side are equilateral and have the same length. The third side is the base. The intersection of the first side and the second side is the apex of the isosceles triangle.

The rigidity of the first side plate 23A is equal to that of the second side plate 23B. In addition, the peripheral wall of the retainer 18 is appropriately interposed between the inner tube 17 and the three portions of the outer tube 16 that impart three holding forces (F1 to F3) to the inner tube 17. The three portions are a first peripheral portion corresponding to the first slit 16A of the outer tube 16, a second peripheral portion corresponding to the first slit 16A of the outer tube 16, and a portion of the outer tube 16 on the radial side opposite the first slit 16A.

In this case, when viewed from the axial direction, connecting the first holding portion P11, the second holding portion P12, and the third holding portion P13 forms an ideal isosceles triangle that is symmetrical from the left to right. "Symmetrical" means, for example, that when viewed from the axial direction, the perpendicular bisector of the base of the isosceles triangle coincides with the center line of the first slit 16A. When viewed from the axial direction, the center line is a straight line that passes through the circumferential center of the first slit 16A and the center of the outer tube 16.

<Specific examples of circumferential positions>
The circumferential position of the second slit 18A is set to any one of first to fourth circumferential positions P1 to P4 shown in Figures 6 to 9. In Figures 6 to 9, the circumferential position of the second slit 18A is the position of the center line of the second slit 18A as viewed from the axial direction. The center line is a straight line that passes through the circumferential center of the second slit 18A and the center of the retainer 18 as viewed from the axial direction.

As shown in FIG. 6, the first circumferential position P1 is, for example, a circumferential position between the 10 o'clock position and the 11 o'clock position when viewed from the axial direction. The first slit 16A is blocked from the inside of the outer tube 16 by the peripheral wall of the retainer 18. The second slit 18A is blocked from the outside of the retainer 18 by the peripheral wall of the outer tube 16. When viewed from the axial direction, the first retaining portion P11, the second retaining portion P12, and the third retaining portion P13 are connected to form an ideal, left-right symmetrical isosceles triangle.

As shown in FIG. 7, the second circumferential position P2 is, for example, a circumferential position between the 7 o'clock position and the 8 o'clock position when viewed from the axial direction. The first slit 16A is blocked from the inside of the outer tube 16 by the peripheral wall of the retainer 18. The second slit 18A is blocked from the outside of the retainer 18 by the peripheral wall of the outer tube 16. When viewed from the axial direction, the first retaining portion P11, the second retaining portion P12, and the third retaining portion P13 are connected to form an ideal, left-right symmetrical isosceles triangle.

As shown in FIG. 8, the third circumferential position P3 is, for example, a circumferential position between the 4 o'clock position and the 5 o'clock position when viewed from the axial direction. The first slit 16A is blocked from the inside of the outer tube 16 by the peripheral wall of the retainer 18. The second slit 18A is blocked from the outside of the retainer 18 by the peripheral wall of the outer tube 16. When viewed from the axial direction, the first retaining portion P11, the second retaining portion P12, and the third retaining portion P13 are connected to form an ideal, left-right symmetrical isosceles triangle.

As shown in FIG. 9, the fourth circumferential position P4 is, for example, a circumferential position between the 1 o'clock position and the 2 o'clock position when viewed from the axial direction. The first slit 16A is blocked from the inside of the outer tube 16 by the peripheral wall of the retainer 18. The second slit 18A is blocked from the outside of the retainer 18 by the peripheral wall of the outer tube 16. When viewed from the axial direction, the first retaining portion P11, the second retaining portion P12, and the third retaining portion P13 are connected to form an ideal, left-right symmetrical isosceles triangle.

<Effects of the embodiment>
This embodiment provides the following advantages.
(1) The circumferential position of the first slit 16A and the circumferential position of the second slit 18A are different from each other. The first slit 16A is blocked from the inside of the outer tube 16 by the peripheral wall of the retainer 18. The second slit 18A is blocked from the outside of the retainer 18 by the peripheral wall of the outer tube 16. Therefore, even if an area A0 occurs where the outer tube 16 and the inner tube 17 do not overlap in the radial direction, it is possible to suppress the intrusion of foreign matter from the first slit 16A. The foreign matter includes water, dust, etc. Therefore, waterproofness or dustproofness is improved.

(2) When the outer tube 16 is mounted on the vehicle body, the first slit 16A faces upward. Therefore, foreign objects from above the outer tube 16 can easily enter the first slit 16A. In this regard, the first slit 16A is blocked by the peripheral wall of the retainer 18. Therefore, it is possible to prevent foreign objects from above the steering column 15 from entering the inside of the steering column 15 through the first slit 16A.

(3) When the position of the first slit 16A as viewed from the axial direction is the 12 o'clock position, the circumferential position of the second slit 18A is set to a range that does not include the first circumferential range A1, the second circumferential range A2, the third circumferential range A3, and the fourth circumferential range A4. The four circumferential ranges (A1 to A4) are ranges that correspond to parts of the outer tube 16 and the inner tube 17 that are functionally important in holding the outer tube 16. Therefore, by setting the circumferential position of the second slit 18A to a range that does not include the four circumferential ranges (A1 to A4), the second slit 18A can be positioned in an appropriate circumferential position without impeding the function of the steering column device 1.

(4) The rigidity of the first side plate 23A is equal to that of the second side plate 23B. In addition, the peripheral wall of the retainer 18 is interposed between the three portions of the outer tube 16 that impart the three holding forces (F1 to F3) and the inner tube 17. Therefore, the three holding forces (F1 to F3) are appropriately imparted to the inner tube 17 via the retainer 18. Therefore, when viewed from the axial direction, the first holding portion P11, the second holding portion P12, and the third holding portion P13 are linked to form an ideal, left-right symmetrical isosceles triangle. This state is the most efficient for holding the outer tube 16. Therefore, the outer tube 16 is stably held relative to the inner tube 17.

<Other embodiments>
This embodiment may be modified as follows.
Depending on the product specifications, the tightening shaft 51 may be disposed on the opposite side of the connecting plate 23C with respect to the steering column 15. In this case, the first slit 16A is provided in a portion of the outer tube 16 on the same side as the tightening shaft 51. When the outer tube 16 is mounted on the vehicle body, the first slit 16A faces downward. The circumferential position of the second slit 18A is set in a circumferential range excluding the first to fourth circumferential ranges A1 to A4 shown in FIG. 5. Therefore, the first slit 16A is blocked by the circumferential wall of the retainer 18. This makes it possible to prevent foreign matter from entering the inside of the steering column 15 from below through the first slit 16A.

- Depending on the product specifications, the rigidity of the first side plate 23A and the rigidity of the second side plate 23B may differ. This is to ensure operability during tightening while ensuring the rigidity of the entire tilt bracket 23. For example, if the rigidity of the first side plate 23A is higher than the rigidity of the second side plate 23B, the first side plate 23A with higher rigidity receives the axial force of the tightening shaft 51. The second side plate 23B with lower rigidity receives the axial force of the tightening shaft 51 and tightens the outer tube 16. In other words, when the relative movement between the outer tube 16 and the inner tube 17 is restricted through the operation of the lever 54, the second side plate 23B elastically deforms to approach the first side plate 23A.

For this reason, when viewed from the axial direction, the first retaining portion P11, the second retaining portion P12, and the third retaining portion P13 are connected, and do not form an ideal isosceles triangle that is symmetrical on the left and right. Due to the difference in rigidity between the first side plate 23A and the second side plate 23B, the first retaining portion P11 and the second retaining portion P12 move in a direction toward the first side plate 23A, which has a slightly higher rigidity. In addition, the position of the third retaining portion P13 moves in a direction away from the first side plate 23A, which has a slightly higher rigidity. In other words, the first retaining portion P11, the second retaining portion P12, and the third retaining portion P13 move counterclockwise. The isosceles triangle connecting the first holding portion P11, the second holding portion P12, and the third holding portion P13 is the isosceles triangle shown by the two-dot chain line in FIG. 5 rotated slightly counterclockwise.

When the rigidity of the first side plate 23A is higher than that of the second side plate 23B, the circumferential position of the second slit 18A is set within a range of half the circumference of the retainer 18 facing the first side plate 23A with higher rigidity. Specifically, the circumferential position of the second slit 18A is set, for example, to the first circumferential position P1 in FIG. 6 or the second circumferential position P2 in FIG. 7. When viewed from the axial direction, of the outer peripheral surface of the inner tube 17, about half of the inner tube 17 facing the second side plate 23B with lower rigidity is in contact with the inner peripheral surface of the outer tube 16 via the retainer 18. Therefore, when the outer tube 16 is tightened from the side facing the second side plate 23B with lower rigidity, this tightening force is easily transmitted to the inner tube 17 via the retainer 18. Therefore, the holding force of the outer tube 16 against the inner tube 17 can be secured.

If the rigidity of the second side plate 23B is higher than the rigidity of the first side plate 23A, the circumferential position of the second slit 18A is set within a range of half the circumference of the retainer 18 facing the second side plate 23b with higher rigidity. Specifically, the circumferential position of the second slit 18A is set, for example, to the third circumferential position P3 in FIG. 8 or the fourth circumferential position P4 in FIG. 9.

Claims (6)

A steering column device that rotatably supports a steering shaft of a vehicle,
Inner tube and
an outer tube fitted onto an outer peripheral surface of the inner tube;
a cylindrical retainer interposed between an outer peripheral surface of the inner tube and an inner peripheral surface of the outer tube, the retainer being configured to be restricted in circumferential and axial movement with respect to the outer tube,
the outer tube and the inner tube are relatively movable in the axial direction via the retainer,
The outer tube has a first slit extending in an axial direction,
the retainer has a second slit extending in an axial direction and having a circumferential position different from a circumferential position of the first slit,
A steering column device, wherein the first slit is blocked from the inside of the outer tube by the retainer. When the position of the first slit as viewed from the axial direction is the 12 o'clock position,
2. The steering column device according to claim 1, wherein the circumferential position of the second slit is set in a circumferential range that does not include a first circumferential range including the 12 o'clock position, a second circumferential range including the 6 o'clock position, a third circumferential range including the 3 o'clock position, or a fourth circumferential range including the 9 o'clock position. a tilt bracket that supports the outer tube on a vehicle body, the tilt bracket having a first side plate and a second side plate that face each other via the outer tube;
a fastening shaft configured to be able to fasten the first side plate and the second side plate in a direction in which they approach each other,
the outer tube and the retainer are configured to be elastically contracted in diameter as the first side plate and the second side plate are fastened in a direction in which they approach each other by the fastening shaft, thereby restricting relative movement between the outer tube and the inner tube,
3. The steering column device according to claim 1, wherein the first side plate and the second side plate have an equal rigidity. a tilt bracket that supports the outer tube on a vehicle body, the tilt bracket having a first side plate and a second side plate that face each other via the outer tube;
a fastening shaft configured to be able to fasten the first side plate and the second side plate in a direction in which they approach each other,
the outer tube and the retainer are configured to be elastically contracted in diameter as the first side plate and the second side plate are fastened in a direction in which they approach each other by the fastening shaft, thereby restricting relative movement between the outer tube and the inner tube,
The rigidity of the first side plate is higher than the rigidity of the second side plate,
3. The steering column device according to claim 1, wherein the second slit is positioned in a circumferential direction within a range of half the circumference of the retainer facing the first side plate. a tilt bracket that supports the outer tube on a vehicle body, the tilt bracket having a first side plate and a second side plate that face each other via the outer tube;
a fastening shaft configured to be able to fasten the first side plate and the second side plate in a direction in which they approach each other,
the outer tube and the retainer are configured to be elastically contracted in diameter as the first side plate and the second side plate are fastened in a direction in which they approach each other by the fastening shaft, thereby restricting relative movement between the outer tube and the inner tube,
The rigidity of the second side plate is higher than the rigidity of the first side plate,
3. The steering column device according to claim 1, wherein the second slit is positioned in a circumferential direction within a range of half the circumference of the retainer facing the second side plate. The steering column device according to claim 1 or 2, wherein the outer tube is configured so that the first slit faces upward or downward when the outer tube is mounted on the vehicle body.

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