Steering device

Abstract

Provided is a steering device comprising a cylindrical steering column extending in an axial direction. The steering column includes an upper column, a lower column, and a fixing member. The fixing member comprises a cylindrical part, the cylindrical part including a small-diameter part fitted to the lower column, a curved part having an outer circumferential surface with the outer diameter being increased toward the other end in the axial direction, and a large-diameter part with the outer diameter being larger than the outer diameter of the small-diameter part. The difference between the radius of the large-diameter part and the radius of the small-diameter part is a first length, and in a cross section including the central axis, the outer circumferential surface of the curved part is a circular arc having a radius of curvature that is greater than the first length, and a tangent at the end of the circular arc on one side in the axial direction is aligned with the outer circumferential surface of the small-diameter part. The outer diameter of the large-diameter part is smaller than the outer diameter of the lower column.

Description

[Technical Field]

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

[0002] The steering device of Patent Document 1 includes a steering shaft connected to a steering wheel and extending in the axial direction, and a cylindrical steering column supported via a bearing on the outer periphery of the steering shaft. The steering column includes an upper column disposed on the steering wheel side, a lower column disposed forward of the upper column and partially fitted into the inner periphery of the upper column, and a sensor housing disposed forward of the lower column and partially fitted into the inner periphery of the lower column. The sensor housing includes a cylindrical portion that includes a small diameter portion, a medium diameter portion, and a large diameter portion. The front end of the lower column is fitted into the small diameter portion. The outer diameters of the medium diameter portion and the large diameter portion are larger than the outer diameter of the lower column. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-276591 Summary of the Invention [Problem to be solved by the invention]

[0004] During a secondary collision, the driver applies a force to the steering wheel toward the front of the vehicle, causing the upper column to slide forward along the outer periphery of the lower column. Here, because the outer diameters of the medium-diameter portion and the large-diameter portion are larger than the outer diameter of the lower column, there is a possibility that the front end of the upper column will interfere with the medium-diameter portion or the large-diameter portion as the upper column slides. Therefore, there is a demand for a steering device that allows the upper column to move a longer distance during a secondary collision.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and has an object to provide a steering device in which the movement length of an upper column is longer in the event of a secondary collision. [Means for solving the problem]

[0006] In order to achieve the above object, a steering device according to one aspect of the present disclosure includes: a steering shaft extending along a central axis and having a steering wheel coupled to one side in the axial direction; a cylindrical steering column arranged on the outer periphery of the steering shaft and extending in the axial direction; and a gearbox arranged on the other side in the axial direction of the steering column and fixed to the steering column, wherein the steering column includes an upper column, a lower column arranged on the other side in the axial direction of the upper column and a portion of the lower column fitted to the inner periphery of the upper column, and a gearbox arranged on the other side in the axial direction of the lower column and fixed to the front and a fixed member fixed to the gearbox, the fixed member having a cylindrical portion extending in the axial direction, the cylindrical portion including: a small diameter portion fitted to the inner peripheral side of the lower column; a curved portion adjacent to the other axial side of the small diameter portion and having an outer peripheral surface whose outer diameter increases toward the other axial side; and a large diameter portion adjacent to the other axial side of the curved portion and whose outer diameter is larger than the outer diameter of the small diameter portion, in a cross section including the central axis, the outer peripheral surface of the curved portion is an arc, and a tangent to the arc at one end on the axial side coincides with the outer peripheral surface of the small diameter portion, and the outer diameter of the large diameter portion is smaller than the outer diameter of the lower column.

[0007] During a secondary collision, the driver applies force to the steering wheel toward the front of the vehicle. In this case, the force is transmitted from the steering wheel via the steering shaft to the upper column. The upper column is fitted to the outer periphery of the lower column, but if the force transmitted to the upper column becomes greater than the fitting force with the lower column, the upper column will slide forward along the outer periphery of the lower column.

[0008] Here, if the outer diameter of the large diameter portion is smaller than the outer diameter of the lower column, when the upper column moves forward, it can move up to the vicinity of the disc portion without interfering with the large diameter portion. Therefore, the movement length (stroke amount) of the upper column during a secondary collision is greater than when the outer diameter of the large diameter portion is larger than the outer diameter of the lower column.

[0009] In a preferred aspect of the above steering device, the difference between the radius of the large diameter portion and the radius of the small diameter portion is a first length, and in a cross section including the central axis, the radius of curvature of the arc of the outer peripheral surface at the curved portion is greater than the first length.

[0010] If the outer diameter of the large diameter portion is smaller than the outer diameter of the lower column, the radial thickness of the large diameter portion will be thin, and the rigidity of the large diameter portion will be reduced. As a result, when the lower column is fitted to the fixed member, or when force is applied to the fixed member via the lower column while the vehicle is running, force will be concentrated on the curved portion located between the large diameter portion and the small diameter portion. Therefore, the outer peripheral surface of the curved portion is made into an arc shape with a large radius of curvature, and the step at the boundary between the curved portion and the small diameter portion is made as small as possible. This makes it possible to minimize deformation and damage to the curved portion even if force is concentrated on it.

[0011] In a preferred aspect of the above steering device, the other axial end of the lower column is located on one axial side of the one axial end of the curved portion.

[0012] When fitting the lower column into the cylindrical portion of the fixing member during manufacturing of the steering device, fitting the lower column up to the curved portion will deform the shape of the curved portion. Therefore, by positioning the lower column at a position axially separated from the curved portion, it is possible to suppress deformation of the curved portion during manufacturing of the steering device.

[0013] In a preferred aspect of the steering device, the fixing member has a radially extending disk portion provided on the other axial side of the cylindrical portion, and the disk portion has a rib protruding from one axial surface to one axial side and fixed to the cylindrical portion. In this configuration, the rib is formed across the disk portion and the cylindrical portion, thereby improving the rigidity of the disk portion and the cylindrical portion.

[0014] In a preferred aspect of the above steering device, the upper column has a protrusion at the other axial end thereof that can accommodate the rib. This makes it possible to suppress interference between the upper column and the rib when the upper column moves forward relative to the lower column during a secondary collision. [Effects of the Invention]

[0015] According to the present disclosure, it is possible to provide a steering device in which the movement length of the upper column in the event of a secondary collision is longer. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic side view of a steering device according to a first embodiment. [Figure 2] FIG. 2 is a front view of the lower column and the fixed member according to the first embodiment, viewed from the -X direction toward the +X direction. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a schematic cross-sectional view showing an enlarged portion A of FIG. [Figure 5] FIG. 5 is a perspective view of the fixing member according to the first embodiment, as viewed from the -X direction toward the +X direction. [Figure 6] FIG. 6 is a perspective view of the fixing member according to the first embodiment, as viewed from the -X direction toward the +X direction. [Figure 7] FIG. 7 is a perspective view of the fixing member according to the first embodiment, as viewed from the +X direction toward the −X direction. [Figure 8] FIG. 8 is a perspective view of a fixing member according to the second embodiment, as viewed from the -X direction toward the +X direction. [Figure 9] FIG. 9 is a perspective view of the periphery of the fixed member according to the second embodiment, viewed from the -Z direction toward the +Z direction, showing a state in which the upper column has moved in the +X direction during a secondary collision. [Figure 10] 10 is a front view of the lower column, upper column, and fixed member in the state of FIG. 9, viewed from the -X direction toward the +X direction. [Figure 11] FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. [Figure 12] FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be described in detail below with reference to the drawings. Note that the present invention is not limited to the following detailed description of the invention (hereinafter referred to as the embodiment). Furthermore, the components in the following embodiment include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the components disclosed in the following embodiment can be combined as appropriate. Note that the following description uses an XYZ Cartesian coordinate system. The X axis is parallel to the axis of the steering shaft. The Y axis is parallel to the width direction of the vehicle in which the steering device is installed. The Z axis is perpendicular to both the X axis and the Y axis. The direction parallel to the X axis is referred to as the X direction, the direction parallel to the Y axis is referred to as the Y direction, and the direction parallel to the Z axis is referred to as the Z direction. Within the X direction, the direction toward the front of the vehicle is referred to as the +X direction, and the direction toward the rear is referred to as the -X direction. When the operator faces the +X direction, the right direction is referred to as the +Y direction, and the left direction is referred to as the -Y direction. Within the Z direction, the upward direction is referred to as the +Z direction, and the downward direction is referred to as the -Z direction. Moreover, the X direction is referred to as the "axial direction", the -X direction side is referred to as "one side in the axial direction", and the +X direction side is referred to as "the other side in the axial direction".

[0018] [First embodiment] FIG. 1 is a schematic side view of a steering device according to a first embodiment.

[0019] First, we will explain the basic configuration of the steering device 1. As shown in Fig. 1, the steering device 1 includes a steering wheel 2, a steering shaft 3, a steering column 4, a gear box 5, a tilt bracket 6, a tightening mechanism 7, and a motor 50.

[0020] As shown in Fig. 1, the steering wheel 2 is connected to the -X direction end of the steering shaft 3. When the driver operates the steering wheel 2, the steering shaft 3 rotates around the central axis Ax, and an operating torque is applied to the steering shaft 3.

[0021] A gearbox 5 is provided at the end of the steering column 4 in the +X direction. A motor 50 is attached to the gearbox 5. The motor 50 is an ECU (Electronic Control Unit) integrated motor. Therefore, the steering device 1 according to this embodiment is an electric power steering device that uses the motor 50 to assist the driver in steering.

[0022] The steering shaft 3 includes an upper shaft 31 and a lower shaft 32. The upper shaft 31 and the lower shaft 32 are cylindrical shafts. The steering wheel 2 is attached to the −X direction end of the upper shaft 31. In other words, the steering wheel 2 is connected to one axial side of the steering shaft 3. The +X direction end of the upper shaft 31 is fitted onto the lower shaft 32. Furthermore, the +X direction end of the upper shaft 31 and the −X direction end of the lower shaft 32 are spline-fitted. Therefore, the upper shaft 31 is slidable in the X direction relative to the lower shaft 32.

[0023] As shown in FIG. 1 , the steering column 4 is an outer cylinder that extends in the X direction and is disposed on the outer circumferential side of the steering shaft 3. The steering column 4 includes an upper column 41, a lower column 42, and a fixing member 8. The upper column 41 is a column that is disposed closer to the steering wheel 2. The lower column 42 is a column that is disposed in the +X direction relative to the upper column 41 and is spaced apart from the steering wheel 2. The upper column 41 and the lower column 42 are cylindrical, and the +X direction end of the upper column 41 is fitted into the -X direction end of the lower column 42. In the event of a secondary collision, the upper column 41 is movable in the +X direction relative to the lower column 42. The +X direction end of the lower column 42 is fixed to the gearbox 5 via the fixing member 8. As described above, in FIG. 1 , the fixing member 8 and the gearbox 5 are shown as separate bodies, but the present disclosure is not limited thereto, and the fixing member 8 and the gearbox 5 may be integrated.

[0024] The gearbox 5 includes a plate 51 and a main body 52. ​​The main body 52 houses a plurality of gears therein. The plate 51 seals the opening of the main body 52 in the -X direction. That is, the plate 51 is fixed to the fixed member 8 and the main body 52 while being sandwiched between the fixed member 8 and the main body 52. ​​The fixed member 8 will be described in detail later.

[0025] A tilt bracket 6 is provided on the outer periphery of the steering column 4. A tightening mechanism 7 is provided on the tilt bracket 6. The tightening mechanism 7 includes an operating lever 71 and a tightening shaft 72 that supports the end of the operating lever 71. Operation of the operating lever 71 allows or restricts movement of the upper column 41 in the Z direction, and fixes the position of the steering wheel 2 in the Z direction. In this way, the steering device 1 according to this embodiment has a tilt function. The tilt bracket 6 is fixed to a vehicle body member 70. The tilt spring 61 is, for example, a torsion coil spring. The tilt spring 61 applies an upward force (+Z direction) to the steering column 4. This makes it difficult for the steering column 4 to fall downward (-Z direction) even if the fixed tilt position is released by rotating the operating lever 71. The pivot bracket 62 is fixed to a vehicle body member and supports the steering column 4 so that it can swing around the swing center axis 300. As a result, the steering column 4 is supported so as to be swingable in the tilt direction.

[0026] Fig. 2 is a front view of a lower column and a fixed member according to the first embodiment, viewed from the -X direction toward the +X direction. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 2. Fig. 4 is a schematic cross-sectional view enlarging a portion A in Fig. 3. Fig. 5 is a perspective view of a fixed member according to the first embodiment, viewed from the -X direction toward the +X direction. Fig. 6 is a perspective view of a fixed member according to the first embodiment, viewed from the -X direction toward the +X direction. Fig. 7 is a perspective view of a fixed member according to the first embodiment, viewed from the +X direction toward the -X direction.

[0027] 2 and 3, the lower column 42 is a cylindrical member having a cylindrical shape that extends in the circumferential direction around the central axis Ax. An end 42a of the lower column 42 in the +X direction is fitted onto the outer circumferential side of the cylindrical portion 81 of the fixed member 8.

[0028] 3, 5, 6, and 7, the fixing member 8 includes a cylindrical portion 81, a disk portion 82, and a flange portion 83. The fixing member 8 has an annular shape that extends in the circumferential direction around the central axis Ax.

[0029] The cylindrical portion 81 has a small diameter portion 811, a curved portion 812, and a large diameter portion 813. As shown in FIGS. 3 and 4 , the small diameter portion 811 is located in the −X direction of the cylindrical portion 81. In a cross section including the central axis Ax, the outer circumferential surface of the small diameter portion 811 is a straight line along the axial direction. The curved portion 812 is adjacent to the small diameter portion 811 in the +X direction. The outer diameter of the outer circumferential surface of the curved portion 812 increases toward the +X direction. That is, in a cross section including the central axis Ax, the outer circumferential surface of the curved portion 812 has an arc shape. Specifically, in a cross section including the central axis Ax, the outer circumferential surface of the curved portion 812 is an arc of a radius of curvature r centered on the center C of the radius of curvature. The outer circumferential surface of the curved portion 812 extends from an end 812a to an end 812b. The end 812a and the center C are located at the same position in the X direction. In a cross section including the central axis Ax, a line connecting the end 812a and the center C is perpendicular to the outer peripheral surface of the small diameter portion 811. Therefore, a tangent to the end 812a on the outer peripheral surface of the curved portion 812 coincides with the outer peripheral surface of the small diameter portion 811. The large diameter portion 813 is adjacent to the curved portion 812 in the +X direction. In a cross section including the central axis Ax, the outer peripheral surface of the large diameter portion 813 is a straight line along the axial direction.

[0030] Here, the radius of curvature r is larger than the difference H1 in the radial direction between the outer circumferential surface of the large diameter portion 813 and the small diameter portion 811. The difference H1 is the difference between the radius of the large diameter portion 813 and the radius of the small diameter portion 811, and is also referred to as the first length. For example, the radius of curvature r is four times the difference H1. Furthermore, the +X direction end 421 of the lower column 42 is located in the -X direction further than the end 812a. In other words, the +X direction end 421 of the lower column 42 is disposed in the small diameter portion 811 in the X direction. Note that the outer circumferential surface 422 of the lower column 42 is located radially outward of the outer circumferential surface of the large diameter portion 813, and in a cross section including the central axis Ax, there is a difference H2 in the radial direction between the outer circumferential surface 422 of the lower column 42 and the outer circumferential surface of the large diameter portion 813. The difference H2 is the difference between the radius of the outer circumferential surface 422 of the lower column 42 and the radius of the outer circumferential surface of the large diameter portion 813, and is also referred to as a second length.

[0031] The disk portion 82 has an annular shape that extends radially outward about the central axis Ax. Specifically, the −X direction surface of the disk portion 82 has a flat surface 822 that extends radially outward from an end 814 of the cylindrical portion 81 in the +X direction to an end 821, and a cylindrical surface 824 that extends from the end 821 to an end 823.

[0032] The collar portion 83 extends radially outward. As shown in FIGS. 5 to 7 , the collar portion 83 has protrusions 831, 832, and 833 that protrude radially outward. The protrusions 831, 832, and 833 are provided at three locations equally spaced apart in the circumferential direction about the central axis Ax. Through holes 831H, 832H, and 833H are provided in the protrusions 831, 832, and 833. Bolts can be inserted into the through holes 831H, 832H, and 833H, and the collar portion 83 is fixed to the gearbox 5 via these bolts.

[0033] As described above, in the steering device 1 according to the first embodiment, the fixed member 8 includes a cylindrical portion 81 extending in the axial direction. The cylindrical portion 81 includes a small diameter portion 811 that is fitted onto the inner peripheral side of the lower column 42, a curved portion 812 that is adjacent to the other axial side of the small diameter portion 811 and has an outer peripheral surface whose outer diameter increases toward the other axial side, and a large diameter portion 813 that is adjacent to the other axial side of the curved portion 812 and has an outer diameter larger than that of the small diameter portion 811. The difference between the radius of the large diameter portion 813 and the radius of the small diameter portion 811 is difference H1 (first length). In a cross section including the central axis Ax, the outer peripheral surface of the curved portion 812 is an arc having a radius of curvature r that is larger than difference H1 (first length), and a tangent to the arc at one end on one axial side coincides with the outer peripheral surface of the small diameter portion 811. The outer diameter of the large diameter portion 813 is smaller than the outer diameter of the lower column 42.

[0034] During a secondary collision, the driver applies a force to the steering wheel 2 toward the front of the vehicle (+X direction). In this case, the force is transmitted from the steering wheel 2 to the upper column 41 via the steering shaft 3. The upper column 41 is fitted to the outer periphery of the lower column 42, and when the force transmitted to the upper column 41 becomes greater than the fitting force with the lower column 42, the upper column 41 slides forward (+X direction) on the outer periphery of the lower column 42.

[0035] 4, if the outer diameter of large diameter portion 813 is smaller than the outer diameter of lower column 42, when upper column 41 moves forward, it can move up to the vicinity of disc portion 82 without interfering with large diameter portion 813. Therefore, the amount of movement (stroke amount) of upper column 41 during a secondary collision is greater than when the outer diameter of large diameter portion 813 is larger than the outer diameter of lower column 42.

[0036] If the outer diameter of large diameter portion 813 is smaller than the outer diameter of lower column 42, the radial thickness of large diameter portion 813 will be thin, and the rigidity of large diameter portion 813 will decrease. As a result, when fitting lower column 42 to fixed member 8, or when force is applied to fixed member 8 via lower column 42 while the vehicle is running, force will be concentrated on curved portion 812 located between large diameter portion 813 and small diameter portion 811. Therefore, the outer peripheral surface of curved portion 812 is made into an arc shape with a large radius of curvature, and the step at the boundary between curved portion 812 and small diameter portion 811 is made as small as possible. As a result, even if force is concentrated on curved portion 812, it is possible to minimize deformation and damage to curved portion 812.

[0037] An end 421 on the other axial side of the lower column 42 is located on one axial side of an end 812a on one axial side of the curved portion 812.

[0038] When fitting the lower column 42 into the cylindrical portion 81 of the fixed member 8 during manufacturing of the steering device 1, if the lower column 42 is fitted up to the area of ​​the curved portion 812, the shape of the curved portion 812 will be deformed. Therefore, by arranging the lower column 42 in a position that is separated from the curved portion 812 in the axial direction, it is possible to suppress deformation of the curved portion 812 during manufacturing of the steering device 1.

[0039] [Second embodiment] Next, a second embodiment will be described. Note that parts having the same structure as in the first embodiment are given the same reference numerals and their description will be omitted. Fig. 8 is a perspective view of a fixed member according to the second embodiment, viewed from the -X direction toward the +X direction. Fig. 9 is a perspective view of the peripheral portion of the fixed member according to the second embodiment, viewed from the -Z direction toward the +Z direction, showing a state in which the upper column has moved in the +X direction during a secondary collision. Fig. 10 is a front view of the lower column, upper column, and fixed member in the state of Fig. 9, viewed from the -X direction toward the +X direction. Fig. 11 is a cross-sectional view taken along line XI-XI in Fig. 10. Fig. 12 is a cross-sectional view taken along line XII-XII in Fig. 11.

[0040] The second embodiment differs from the first embodiment in that a rib is provided on the surface side (the side in the -X direction) of the fixing member, as will be described in detail below.

[0041] The disc portion 82 of the fixing member 8A of the steering column 4A according to the second embodiment has a rib 200 on its front surface (one axial side, the -X direction side). The rib 200 has a triangular shape when viewed from the side. The rib 200 protrudes from the flat surface 822 in the -X direction. The rib 200 extends radially outward from the disc portion 82. The rib 200 is fixed to the cylindrical portion 81. The height of the rib 200 is highest at the end 201 on the large diameter portion 813 side of the cylindrical portion 81 and lowest at the radially outer end 202. Therefore, the upper surface 210 of the rib 200 becomes lower from the end 201 on the large diameter portion 813 side toward the radially outer side.

[0042] 9 to 12 show a state in which, during a secondary collision, the upper column 41 has moved in the +X direction to the fixed member 8A. That is, during a secondary collision, the driver applies a force to the steering wheel 2 toward the front of the vehicle. In this case, the force is transmitted from the steering wheel 2 to the upper column 41 via the steering shaft 3. Normally, the upper column 41 is fitted into the lower column 42, but when the force transmitted to the upper column 41 becomes greater than the fitting force with the lower column 42, the upper column 41 slides along the outer periphery of the lower column 42. In this way, during a secondary collision, the front end of the upper column 41 may be located near the fixed member 8A, as shown in FIG. 11.

[0043] 9 to 12, a protruding portion 410 that protrudes downward is provided on the lower side (-Z direction) of the upper column 41. The protruding portion 410 has a U-shape in a cross section perpendicular to the central axis Ax. The protruding portion 410 includes a pair of left and right plates, a first plate portion 411 and a second plate portion 412, that extend in the Z direction, and a connecting plate 413 that connects the lower end of the first plate portion 411 and the lower end of the second plate portion 412. A recessed portion 414 that is surrounded by the first plate portion 411, the second plate portion 412, and the connecting plate 413 has a height that is greater than the maximum height of the rib 200 (i.e., the height at the end 201 of the cylindrical portion 81 on the large diameter portion 813 side).

[0044] 10 and 11, three protrusions 415 that protrude radially outward are provided on the outer peripheral surface of the end portion in the −X direction of the upper column 41. Each protrusion 415 has a through-hole 415H that penetrates in the plate thickness direction.

[0045] As described above, in the steering device according to the second embodiment, the fixed member 8A is provided on the other axial side of the cylindrical portion 81 and has the radially extending disk portion 82. The disk portion 82 has the rib 200 that protrudes from one axial surface toward one axial side and is fixed to the cylindrical portion 81.

[0046] The ribs 200 extend from the disk portion 82 in the −X direction and radially outward, and therefore the ribs 200 improve the rigidity of the disk portion 82 and the cylindrical portion 81.

[0047] The upper column 41 has a protrusion 410 at the other end in the axial direction that can accommodate the rib 200. This makes it possible to suppress interference between the upper column 41 and the rib 200 when the upper column 41 moves forward relative to the lower column 42 during a secondary collision. [Explanation of symbols]

[0048] 1 Steering device 2 steering wheels 3 Steering shaft 4, 4A steering column 5 Gearbox 6 Tilt bracket 7. Clamping mechanism 8, 8A Fixing member 31 Upper shaft 32 Lower shaft 41 Upper Column 42 Roar Column 42a end 50 motor 51 Plate 52 Main body 61 Tilt spring 62 Pivot bracket 70 Body parts 71 Operating lever 72 Fastening shaft 81 Cylindrical part 82 Disc 83 Brim 200 ribs 201 edge 202 edge 210 Top 300 Swing central axis 410 Protrusion 411 1st plate part 412 2nd plate part 413 Connecting plate 414 recess 415H Through hole 421 Edge 811 Small diameter section 812 curved section 812a edge 812b end 813 Large diameter section 814 edge 821 edge 822 Flat surface 823 edge 824 Cylindrical Surface 831, 832, 833 protrusion 831H, 832H, 833H through hole Ax center axis C center H1 Difference (first length) H2 Difference (second length) r radius of curvature

Claims

1. a steering shaft extending along a central axis and having a steering wheel connected to one side in the axial direction; a cylindrical steering column disposed on the outer circumferential side of the steering shaft and extending in the axial direction; a gear box disposed on the other axial side of the steering column and fixed to the steering column, The steering column Upper column and a lower column that is disposed on the other axial side of the upper column and has a portion that fits into an inner peripheral side of the upper column; a fixing member provided on the other axial side of the lower column and fixed to the gear box, the fixing member includes a cylindrical portion extending in an axial direction; The cylindrical portion is a small diameter portion fitted to an inner circumferential side of the lower column; a curved portion adjacent to the other axial side of the small diameter portion and having an outer circumferential surface whose outer diameter increases toward the other axial side; a large diameter portion adjacent to the other axial side of the curved portion and having an outer diameter larger than the outer diameter of the small diameter portion, In a cross section including the central axis, the outer circumferential surface of the curved portion is an arc, The outer diameter of the large diameter portion is smaller than the outer diameter of the lower column. Steering device.

2. In a cross section including the central axis, a tangent at one end of the axial direction of the arc on the outer peripheral surface of the curved portion coincides with the outer peripheral surface of the small diameter portion. The steering device according to claim 1 .

3. a difference between a radius of the large diameter portion and a radius of the small diameter portion is a first length; In a cross section including the central axis, a radius of curvature of the arc of the outer peripheral surface of the curved portion is greater than the first length.

3. A steering device according to claim 1 or 2.

4. the other axial end of the lower column is located on one axial side of the one axial end of the curved portion, A steering device according to any one of claims 1 to 3.

5. The fixing member is a disk portion provided on the other axial side of the cylindrical portion and extending in the radial direction, The disk portion has a rib that protrudes from a surface on one side in the axial direction toward one side in the axial direction and radially outward. A steering device according to any one of claims 1 to 4.

6. The upper column is The other end in the axial direction has a protrusion that can accommodate the rib. The steering device according to claim 5.

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