Steering system

Abstract

To provide a steering device that can absorb the collision load of a secondary collision while further suppressing the increase in size. [Solution] The steering device comprises a steering shaft, a steering column, a vehicle mounting bracket fixed to the steering column and having a notch that is open on the X1 side, and a detachment bracket that fits into the notch and is attached to the vehicle body. The detachment bracket has a fastening member and a load absorbing member. The fastening member has a head and a shaft portion that protrudes from the head through the notch toward the Z2 side and has male threads on its outer circumference. The load absorbing member has a plate-shaped portion having a through hole with female threads, a fixed portion fixed to the vehicle mounting bracket, and a long collision load absorbing portion connecting the plate-shaped portion and the fixed portion.

Description

Technical Field

[0001] The present disclosure relates to a steering device.

Background Art

[0002] A steering device shown in Patent Document 1 is known. In the Patent Document 1, the steering device is detachably attached to the vehicle body via a detachment bracket. Specifically, the steering device has a vehicle body attachment bracket, and a notch that opens to the rear side of the vehicle is provided in the vehicle body attachment bracket. The detachment bracket is fitted into the notch. The detachment bracket is fixed to the vehicle body via bolts.

[0003] With this configuration, when a collision load of a secondary collision is applied to the steering device via the steering wheel toward the front of the vehicle, the steering device moves forward of the vehicle. Then, the detachment bracket detaches from the notch, thereby reducing the impact applied to the driver from the steering device during the secondary collision.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Here, in order to absorb the collision load of the secondary collision, a collision load absorbing device may be separately provided in the steering device. In this case, however, the steering device may be enlarged.

[0006] The present disclosure has been made in view of the above problems, and an object thereof is to provide a steering device capable of absorbing a collision load of a secondary collision while further suppressing enlargement. [Means for solving the problem]

[0007] To achieve the above objective, a steering device according to one aspect of the present disclosure includes a steering shaft extending in a first direction and having a steering wheel connected to one end in the first direction; a steering column disposed on the outer circumference of the steering shaft and rotatably supporting the steering shaft; a vehicle body mounting bracket fixed to the steering column and having a notch that is open on one side in the first direction; and a detachment bracket fitted into the notch and attached to the vehicle body, wherein when a collision load of a secondary collision is applied, the vehicle body mounting bracket moves to the other side in the first direction. The vehicle mounting bracket includes, at times, a release bracket that releases from the notch while absorbing the collision load, and when the direction intersecting the first direction is defined as the second direction, the release bracket includes a fastening member having a head that abuts against one side of the vehicle mounting bracket in the second direction, and a shaft that protrudes from the head through the notch toward the other side in the second direction and has a male screw on its outer circumference, and a load absorbing member having a plate-like portion with a female screw on its inner circumference that engages with the male screw, a fixing portion that is fixed to the vehicle mounting bracket, and an elongated collision load absorbing portion that connects the plate-like portion and the fixing portion.

[0008] As mentioned above, in the steering device shown in Patent Document 1, when the collision load of a secondary collision is applied towards the front of the vehicle, the steering device moves forward. Then, the detachment bracket detaches from the notch in the vehicle body mounting bracket, thereby mitigating the impact transmitted to the driver from the steering device during a secondary collision. However, if a separate collision load absorption device is to be provided in the steering device to absorb the collision load of a secondary collision, the steering device may become larger.

[0009] In contrast, the detachment bracket according to this disclosure includes an elongated collision load absorbing section that absorbs the collision load in a secondary collision. Specifically, when the vehicle body mounting bracket moves to the other side in the first direction during a secondary collision, the collision load absorbing section extends in the first direction and undergoes plastic deformation, thereby absorbing at least a portion of the collision load. In this way, the detachment bracket has the function of absorbing the collision load of a secondary collision. Therefore, this disclosure makes it possible to provide a steering device that can absorb the collision load of a secondary collision while further suppressing the increase in size.

[0010] In another aspect of the present disclosure, the impact load absorbing portion has a bent portion between one end and the other end, extending from the one end toward the other in the first direction to the bent portion, being curved and bent at the bent portion, and extending toward the other end toward the one in the first direction.

[0011] During a secondary collision, the collision load absorbing section absorbs the collision load by undergoing plastic deformation such that one end and the other end move relatively far apart in the first direction. In this way, the collision load absorbing section according to this disclosure can absorb the collision load of a secondary collision with a relatively simple configuration.

[0012] In other embodiments of the present disclosure, when the third direction is defined as the direction intersecting the first and second directions, the collision load absorbing portion has a bellows-like shape that alternately bends toward one side and the other side of the third direction as it moves toward the other side of the first direction.

[0013] This allows the collision load of a secondary collision to be absorbed with a relatively simple configuration by plastically deforming the collision load absorption section so that the two ends of the collision load absorption section in the first direction move further apart during a secondary collision.

[0014] In another aspect of the present disclosure, the other end face in the second direction of the head of the fastening member has a friction-reducing layer.

[0015] As a result, during a secondary collision, when the vehicle mounting bracket moves to the other side in the first direction, the peripheral edge of the notch in the vehicle mounting bracket and the other end face in the second direction of the head of the fastening member slide against each other. If the frictional resistance between the peripheral edge and the other end face in the second direction of the head is too high, or if the release load of the release bracket varies, the release bracket may become difficult to detach from the notch, potentially increasing the impact transmitted to the driver from the steering system. Therefore, a friction-reducing layer is formed on the other end face in the second direction of the head to facilitate the release of the release bracket from the notch during a secondary collision.

[0016] In another aspect of the present disclosure, one end face of the plate-like portion in the second direction has a friction-reducing layer.

[0017] As a result, when the vehicle mounting bracket moves to the other side in the first direction during a secondary collision, the peripheral edge of the notch in the vehicle mounting bracket and the end face on one side in the second direction of the plate-like portion slide against each other. If the frictional resistance between the peripheral edge and the end face of the plate-like portion is too high, or if the release load of the release bracket varies, the release bracket may become difficult to detach from the notch, potentially increasing the impact transmitted to the driver from the steering device. Therefore, a friction-reducing layer is formed on the end face on one side in the second direction of the plate-like portion to facilitate the release of the release bracket from the notch during a secondary collision.

[0018] In other embodiments of the present disclosure, the head of the fastening member is provided with a through hole in the radial central portion that penetrates in the second direction, and the through hole has a polygonal shape when viewed from the second direction.

[0019] If the through-hole is, for example, hexagonal, a tool such as a hex wrench can be inserted into the through-hole and the head rotated to fasten the fastening member to the plate-like part. Therefore, compared to a method in which a large spanner is fitted around the outer circumference of the head and rotated when the outer circumference of the head is, for example, hexagonal, this disclosure allows work to be performed in a narrower space. [Effects of the Invention]

[0020] According to the present disclosure, it is possible to provide a steering device capable of absorbing a collision load of a secondary collision while further suppressing an increase in size.

Brief Description of the Drawings

[0021] [Figure 1] FIG. 1 is a perspective view of a steering device according to a first embodiment. [Figure 2] FIG. 2 is a perspective view showing a part of FIG. 1. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2. [Figure 4] FIG. 4 is an enlarged cross-sectional view of a part of FIG. 3. <00QQ090> [Figure 5] FIG. 5 is a perspective view showing a fastening member according to the first embodiment. [Figure 6] FIG. 6 is a perspective view showing a load absorbing member according to the first embodiment. [Figure 7] FIG. 7 is a perspective view showing a load absorbing member according to the first embodiment. [Figure 8] FIG. 8 is a perspective view showing a state in which a friction reducing layer is provided on the surface of the plate-shaped portion of FIG. 6. [Figure 9] FIG. 9 is an enlarged perspective view of a part of FIG. 2. [Figure 10] FIG. 10 is a cross-sectional view taken along line X-X of FIG. 9. [Figure 11A] FIG. 11A is a bottom view of a vehicle body mounting member as viewed from below, showing a state before a secondary collision. [Figure 11B] FIG. 11B is a perspective view showing a load absorbing member before a secondary collision. [Figure 11C] FIG. 11C is a side view showing a load absorbing member before a secondary collision. [Figure 12A] FIG. 12A is a bottom view of a vehicle body mounting member as viewed from below, showing a state after a secondary collision. <000Q0111>FIG. 12B is a perspective view showing a load absorbing member after a secondary collision. [Figure 12C]Figure 12C is a side view showing the load-absorbing member after the secondary collision. [Figure 13] Figure 13 is a perspective view of the detachable bracket according to the second embodiment, seen from below. [Figure 14A] Figure 14A is a bottom view of the detachable bracket according to the second embodiment, viewed from below. [Figure 14B] Figure 14B is a perspective view of a portion of Figure 14A. [Figure 14C] Figure 14C is a side view of Figure 14B. [Figure 15A] Figure 15A is a bottom view of the vehicle body mounting member, seen from below, and shows the state before the secondary collision. [Figure 15B] Figure 15B is a bottom view showing the load-absorbing member before the secondary collision. [Figure 16A] Figure 16A is a bottom view of the vehicle body mounting member, seen from below, and shows the state after a secondary collision. [Figure 16B] Figure 16B is a bottom view showing the load-absorbing member after the secondary collision. [Figure 17] Figure 17 is a perspective view showing a detachable bracket according to the third embodiment. [Figure 18] Figure 18 is a perspective view showing a fastening member according to the third embodiment. [Modes for carrying out the invention]

[0022] The present invention will now be described in detail with reference to the drawings. The present invention is not limited to the embodiments described below. Furthermore, the components in the embodiments below include those easily conceivable by those skilled in the art, those substantially identical, and those within the so-called equivalence range. In addition, the components disclosed in the embodiments below can be combined as appropriate. Also, components with the same configuration are given the same reference numerals and their descriptions are omitted. In the XYZ Cartesian coordinate system, the Y direction is perpendicular (intersects) the X direction. The Z direction is perpendicular (intersects) both the X and Y directions. The X1 side is opposite the X2 side, the Y1 side is opposite the Y2 side, and the Z1 side is opposite the Z2 side. In the following description, the X direction corresponds to the first direction, the Z direction to the second direction, and the Y direction to the third direction. X1 is one side of the first direction, X2 is the other side of the first direction, Z1 is one side of the second direction, Z2 is the other side of the second direction, Y1 is one side of the third direction, and Y2 is the other side of the third direction.

[0023] [First Embodiment] First, the steering device according to the first embodiment will be described. Figure 1 is a perspective view of the steering device according to the first embodiment.

[0024] The steering device 100 has, for example, a telescopic function that extends and retracts in the vehicle's longitudinal direction (the axial direction of the steering shaft) and a tilt function that moves in the vehicle's vertical direction. However, in the present invention, embodiments without the telescopic and tilt functions are also applicable.

[0025] As shown in Figure 1, the steering device 100 comprises a steering shaft 1, a steering column 2, a vehicle body mounting member 3, and a gearbox 120.

[0026] The steering shaft 1 extends in the axial direction of the central axis AX1. The axial direction of the central axis AX1 extends along the longitudinal direction of the vehicle. The steering wheel 101 is connected to the X1-side end 1a of the steering shaft 1. When the driver operates the steering wheel 101, the steering shaft 1 rotates around the central axis AX1, and an operating torque is applied to the steering shaft 1. In this way, the steering shaft 1 is connected to the steering wheel 101 and extends in the X direction (first direction, axial direction).

[0027] A steering shaft 1 is inserted into the inner circumference of the steering column 2. In other words, the cylindrical steering column 2 is positioned outside the steering shaft 1. The steering shaft 1 is rotatably supported relative to the steering column 2 via bearings (not shown). The steering column 2 has an outer column 21 and an inner column 22. The outer column 21 is located on the X1 side relative to the inner column 22. The X1 side end of the inner column 22 is fitted to the inner circumference side of the X2 side end of the outer column 21.

[0028] A vehicle body mounting member 3 is fixed to the steering column 2. The vehicle body mounting member 3 includes a vehicle body mounting bracket 31, which is attached to the vehicle body 140 via a detachment bracket 4. The vehicle body mounting bracket 31 and the detachment bracket 4 will be described later.

[0029] A gearbox 120 is located on the X2 side of the steering column 2. Inside the gearbox 120, although not shown, is a worm gear mechanism in which a worm shaft and worm wheel, provided on the output shaft of the motor, mesh. The ECU 121 controls the operation of the motor. A support bracket 122 is fixed to the gearbox 120, and a vehicle body support bracket 123 is attached to the X2 side end of the support bracket 122. The vehicle body support bracket 123 is provided with a through hole 123a, and the shaft of a bolt (not shown) passes through the through hole 123a and is fastened to the vehicle body. In this way, the X2 side end of the steering device 100 is attached to the vehicle body.

[0030] Figure 2 is a perspective view showing a part of Figure 1. Figure 3 is a cross-sectional view taken along line III-III in Figure 2. As shown in Figure 2, a load-absorbing member holding bracket 133 is fixed to the lower surface of the vehicle body mounting bracket 31. The load-absorbing member holding bracket 133 has a vertical plate portion 133a, a horizontal plate portion 133b, and a support portion 133c. The vertical plate portion 133a protrudes from the lower surface of the vehicle body mounting bracket 31 toward the Z2 side (downward side). The vertical plate portion 133a extends in the X direction. The horizontal plate portion 133b bends at the Z2 side end of the vertical plate portion 133a and extends toward the Y2 side. The support portion 133c bends at the X1 side end of the horizontal plate portion 133b and extends toward the Z1 side. An opening 133e is provided at the corner between the vertical plate portion 133a and the horizontal plate portion 133b, and an opening 133d is provided at the corner between the horizontal plate portion 133b and the support portion 133c.

[0031] Furthermore, a pair of left and right side plates 131 extend towards the Z2 direction from the lower side of the vehicle body mounting bracket 31. The side plates 131 are provided with tilt holes 131a, which are elongated holes extending in the vertical direction (Z direction). A pivot shaft 130b is provided through the tilt holes 131a. The pivot shaft 130b is movable in the Z direction of the tilt holes 131a. The pivot shaft 130b extends in the Y direction. When the lever 130 shown in Figure 3 is rotated downward, for example, the pair of left and right side plates 131 move outward to the left and right, enabling tilt and telescopic movement. When the lever 130 is rotated upward, for example, the pair of left and right side plates 131 move inward to the left and right, preventing tilt and telescopic movement. As shown in Figure 3, the lever 130 is biased by a spring 130a.

[0032] Next, the detachable bracket 4 will be described. Figure 4 is an enlarged cross-sectional view of a part of Figure 3. Figure 5 is a perspective view showing the fastening member according to the first embodiment. Figure 6 is a perspective view showing the load absorbing member according to the first embodiment. Figure 7 is a perspective view showing the load absorbing member according to the first embodiment. Figure 8 is a perspective view showing the plate-shaped portion of Figure 6 with a friction reduction layer provided on its surface.

[0033] As shown in Figures 4 to 10, the detachable bracket 4 has a fastening member 5 and a load-absorbing member 6. As shown in Figures 4 and 5, the fastening member 5 has a head 51 and a shaft 52. The head 51 has a through hole 51a. The head 51 has a first portion 511 and a second portion 512. The first portion 511 is located closer to Z1 than the second portion 512. The first portion 511 has the shape of a polygonal prism, such as a hexagonal prism. This allows the outer circumference of the first portion 511 to be gripped with a tool such as a wrench and rotated. The outer circumference of the second portion 512 is a circle with a larger diameter than the outer circumference of the first portion 511 when viewed from the Z direction. In other words, the second portion 512 is an annular shape extending along the axis of the central axis AX2 shown in Figure 4. As shown in Figure 5, a friction-reducing layer 110 is provided on the back surface (end surface on the Z2 side, and the other end surface in the second direction) 512a of the second part 512, indicated by dot hatching. The friction-reducing layer 110 can be, for example, a fluorine coating layer or a plating layer. That is, a fluorine coating layer or a plating layer is formed on the back surface 512a of the second part 512. When applying a fluorine coating, it is preferable to mask the male thread 52b of the shaft part 52. The shaft part 52 is a cylindrical member that protrudes from the second part 512 toward the Z2 side. The shaft part 52 has a through hole 52a. A male thread 52b is formed on the outer circumference of the shaft part 52.

[0034] As shown in Figures 4, 6, and 7, the load-absorbing member 6 extends from one end 6a to the other end 6b. The load-absorbing member 6 has a plate-shaped portion 61, a fixing portion 62, and an impact load absorbing portion 63.

[0035] The plate-like portion 61 has an annular projection 61a. The annular projection 61a has a through hole 61e that penetrates in the Z direction, and an internal thread is formed on its inner circumferential surface 61b. This internal thread engages with the male thread 52b of the shaft portion 52.

[0036] Here, as shown in Figure 4, the male thread 52b of the shaft portion 52 and the female thread of the plate-shaped portion 61 engage, so that the peripheral edge 31a of the notch 32 in the vehicle body mounting bracket 31 is clamped in the Z direction by the back surface 512a of the second portion 512 and the front surface 61c of the plate-shaped portion 61. Also, the Z2 side end face 52c of the shaft portion 52 is located on the Z2 side relative to the back surface 61d of the plate-shaped portion 61. The Z-direction separation distance between the end face 52c and the back surface 61d is distance D. The fastening member 5 is provided with a through hole 5a that penetrates in the Z direction. The fastening member 5 and the plate-shaped portion 61 are attached to the vehicle body 140 via a bolt member 141. In detail, the bolt member 141 has a head 141a and a shaft portion 141b. The back surface of the head 141a abuts against the end face 52c of the shaft portion 52. A male thread is formed on the outer circumference of the shaft portion 141b. A screw hole 140a recessed to the Z1 side is formed in the vehicle body 140. A female thread is formed on the inner circumference of the screw hole 140a. The male thread of the shaft portion 141b engages with the female thread of the screw hole 140a. In this way, the fastening member 5 and the plate-shaped portion 61 are attached to the vehicle body 140 via the bolt member 141. Here, since the head 141a of the bolt member 141 abuts against the end face 52c, when the bolt member 141 is rotated and fastened to the vehicle body 140, contact between the bolt member 141 and the back surface 61d of the plate-shaped portion 61 is suppressed. As shown in Figure 8, a friction-reducing layer 111, indicated by dot hatching, is provided on the surface (end face on the Z1 side, one end face on the second direction) 61c of the plate-shaped portion 61. The friction-reducing layer 111 can be, for example, a fluorine coating layer or a plating layer. Alternatively, the fastening member 5 and the plate-shaped portion 61 may be attached to the vehicle body 140 via a stud bolt and a nut. Specifically, a stud bolt is provided on the vehicle body 140, and one side of the stud bolt protrudes from the vehicle body 140 toward the Z2 side. A male thread is formed on the outer circumference of one side of the stud bolt. Then, one side of the stud bolt is passed through the through hole 5a of the fastening member 5, and the female thread on the inner circumference of the nut is fastened to the portion that protrudes from the through hole 5a toward the Z2 side. In this way, the fastening member 5 and the plate-shaped portion 61 are attached to the vehicle body 140 via the stud bolt.

[0037] The fixing portion 62 has a T-shape, as shown in Figures 6 and 7. More specifically, the fixing portion 62 has a first projection 621 and a second projection 622. The first projection 621 protrudes toward the Y1 side and the Y2 side. The second projection 622 protrudes toward the X1 side.

[0038] The collision load absorbing section 63 extends from one end 631 to the other end 632. The collision load absorbing section 63 has a bent portion 633 between the one end 631 and the other end 632. In the collision load absorbing section 63, it extends from end 631 toward the X2 side to the bent portion 633, and then curves and bends at the bent portion 633 to extend toward the X1 side to end 632. That is, when the collision load absorbing section 63 is viewed from the side (Y direction), it has a roughly U-shape that is convex toward the X2 side. In this way, the collision load absorbing section 63 is a long member that connects the plate-like portion 61 and the fixing portion 62.

[0039] Figure 9 is an enlarged perspective view of a portion of Figure 2. Figure 10 is a cross-sectional view taken along line XX in Figure 9. As shown in Figure 9, the support portion 133c has a pair of support portions 133c1 and 133c2 that are separated in the Y direction. Support portion 133c1 is separated from support portion 133c2 on the Y1 side. The connecting portion 133c3 extends in the Y direction and connects the pair of support portions 133c1 and 133c2. As shown in Figures 9 and 10, a second projection 622 is inserted into the opening 133d. A pair of first projections 621 are arranged on the X2 side of support portions 133c1 and 133c2, respectively. When the fastening member 5 in Figure 5 is rotated to engage the male thread 52b of the shaft portion 52 with the female thread on the inner circumferential surface 61b of the annular projection 61a in Figure 8, a rotational force indicated by the arrow in Figure 10 is applied to the plate-shaped portion 61. In particular, since the load-absorbing member 6 has an elongated impact load-absorbing portion 63, there is a possibility that the plate-shaped portion 61 may rotate when the fastening member 5 in Figure 5 is rotated. However, since each of the pair of first projections 621 abuts against the support portions 133c1 and 133c2, the rotation of the plate-shaped portion 61 is suppressed even when the rotational force shown in Figure 10 is applied. It is also possible to apply a configuration in which a tool 150 is placed on the flat portion 31b shown in Figure 10, and the plate-shaped portion 61 is held down from the Y1 side and the Y2 side. This further suppresses the rotation of the plate-shaped portion 61 even when the rotational force shown in Figure 10 is applied.

[0040] Next, the deformation behavior of the load-absorbing member 6 when a collision load from a secondary collision directed toward the X2 side is applied to the steering device 100 will be explained. Figure 11A is a bottom view of the vehicle body mounting member viewed from below, showing the state before the secondary collision. Figure 11B is a perspective view showing the load-absorbing member before the secondary collision. Figure 11C is a side view showing the load-absorbing member before the secondary collision. Figure 12A is a bottom view of the vehicle body mounting member viewed from below, showing the state after the secondary collision. Figure 12B is a perspective view showing the load-absorbing member after the secondary collision. Figure 12C is a side view showing the load-absorbing member after the secondary collision.

[0041] First, as shown in Figures 11A and 12A, a U-shaped notch 32 extending toward the X2 side is provided on the X1 side end face of the vehicle body mounting bracket 31. The X1 side of the notch 32 is open. Then, as explained with reference to Figure 4, the fastening member 5 and plate-shaped portion 61 of the detachable bracket 4 are attached to the vehicle body 140 via bolt members 141 through the notch 32. At this time, as shown in Figure 11C, the distance in the X direction between one end 6a and the other end 6b of the load absorbing member 6 is distance L1.

[0042] Then, when a collision load from a secondary collision directed towards X2 is applied to the steering device 100, as shown in Figure 12A, the steering device 100 moves towards X2 relative to the release bracket 4, and each of the pair of first projections 621 comes into contact with the support parts 133c1 and 133c2, causing the fastening member 5 and plate-shaped part 61 of the release bracket 4 to detach from the notch 32. At this time, as is clear from comparing Figures 11B and 11C with Figures 12B and 12C, the fixing part 62 moves towards X2 relative to the plate-shaped part 61. At this time, as shown in Figure 12C, the distance in the X direction between one end 6a and the other end 6b of the load absorbing member 6 is distance L2. That is, due to the secondary collision, the distance between one end 6a and the other end 6b of the load absorbing member 6 changes by distance (L1-L2). In this way, the collision load absorbing part 63 undergoes plastic deformation due to the movement of the fixing part 62 and absorbs a portion of the collision load of the secondary collision.

[0043] As described above, the steering device 100 according to the first embodiment includes a steering shaft 1, a steering column 2, a vehicle body mounting bracket 31 fixed to the steering column 2 and having a notch 32 that is open on the X1 side, and a detachment bracket 4 that fits into the notch 32 and is attached to the vehicle body 140. The detachment bracket 4 includes a fastening member 5 and a load absorbing member 6. The fastening member 5 has a head 51 and a shaft portion 52 that protrudes from the head 51 through the notch 32 toward the Z2 side and has a male screw 52b on its outer circumference. The load absorbing member 6 has a plate-shaped portion 61 having a through hole 61e with a female screw, a fixing portion 62 fixed to the vehicle body mounting bracket 31, and an elongated collision load absorbing portion 63 connecting the plate-shaped portion 61 and the fixing portion 62. The collision load absorbing section 63 absorbs at least a portion of the collision load by extending in the X direction and undergoing plastic deformation when the vehicle body mounting bracket 31 moves toward the X2 side during a secondary collision.

[0044] As mentioned above, in the steering device shown in Patent Document 1, when the collision load of a secondary collision is applied towards the front of the vehicle, the steering device moves forward. Then, the detachment bracket detaches from the notch in the vehicle body mounting bracket, thereby mitigating the impact transmitted to the driver from the steering device during a secondary collision. However, if a separate collision load absorption device is to be provided in the steering device to absorb the collision load of a secondary collision, the steering device may become larger.

[0045] In contrast, the detachment bracket 4 according to the first embodiment includes an elongated collision load absorbing section 63 that absorbs the collision load in a secondary collision. Specifically, the collision load absorbing section 63 extends in the X direction and plastically deforms when the vehicle body mounting bracket 31 moves toward the X2 side relative to the detachment bracket 4 during a secondary collision, thereby absorbing at least a portion of the collision load. In this way, the detachment bracket 4 has the function of absorbing the collision load of a secondary collision. Therefore, in the first embodiment, it is possible to provide a steering device 100 that can absorb the collision load of a secondary collision while further suppressing the increase in size.

[0046] The collision load absorbing section 63 has a bent portion 633 between one end 631 and the other end 632. The collision load absorbing section 63 extends from one end 631 toward the X2 side to the bent portion 633, is bent in a curved manner at the bent portion 633, and extends toward the other end toward the X1 side.

[0047] In other words, when viewed from the Y direction, the collision load absorbing section 63 has a U-shape that is convex towards the X2 side. The collision load is absorbed by plastic deformation that causes one end 631 and the other end 632 to separate relative to each other in the X direction. Thus, the collision load absorbing section 63 according to the first embodiment can absorb the collision load of a secondary collision with a simple configuration.

[0048] The back surface 512a (end face on the Z2 side) of the head 51 of the fastening member 5 has a friction-reducing layer 110.

[0049] When the vehicle mounting bracket 31 moves toward the X2 side during a secondary collision, the peripheral edge 31a of the notch 32 in the vehicle mounting bracket 31 and the back surface 512a (end surface on the Z2 side) of the head 51 of the fastening member 5 slide against each other. If the frictional resistance between the peripheral edge 31a and the back surface 512a (end surface on the Z2 side) is too high, or if the release load of the release bracket 4 varies, the release bracket 4 may become difficult to detach from the notch 32, potentially increasing the impact on the driver from the steering device 100. Therefore, a friction-reducing layer 110 is formed on the back surface 512a (end surface on the Z2 side) to facilitate the release of the release bracket 4 from the notch 32 during a secondary collision.

[0050] The surface 61c (end face on the Z1 side) of the plate-shaped portion 61 has a friction-reducing layer 111.

[0051] When the vehicle mounting bracket 31 moves toward the X2 side during a secondary collision, the peripheral edge 31a of the notch 32 in the vehicle mounting bracket 31 and the surface 61c (end face on the Z1 side) of the plate-shaped portion 61 slide against each other. If the frictional resistance between the peripheral edge 31a and the surface 61c (end face on the Z1 side) is too high, or if the release load of the release bracket 4 varies, the release bracket 4 may become difficult to detach from the notch 32, potentially increasing the impact on the driver from the steering device 100. Therefore, a friction-reducing layer 111 is formed on the surface 61c (end face on the Z1 side) to facilitate the release of the release bracket 4 from the notch 32 during a secondary collision.

[0052] [Second Embodiment] Next, a second embodiment will be described. Figure 13 is a perspective view of the detachable bracket according to the second embodiment, viewed from below. Figure 14A is a bottom view of the detachable bracket according to the second embodiment, viewed from below. Figure 14B is a perspective view of a part of Figure 14A. Figure 14C is a side view of Figure 14B.

[0053] As shown in Figures 13 to 14C, the vehicle body mounting member 3A has a vehicle body mounting bracket 31A. The vehicle body mounting brackets 31A are arranged in pairs on the left and right sides of the steering column 2. The vehicle body mounting bracket 31A shown in Figure 13 is positioned on the Y1 side. The vehicle body mounting bracket 31A is rectangular in shape and extends long in the X direction when viewed from the Z direction. A notch 32 is provided at the X1 side end of the vehicle body mounting bracket 31A, and a support portion 133Ac is provided at the X2 side end. The support portion 133Ac has support portions 133Ac1 and 133Ac2. Support portion 133Ac1 is separated from support portion 133Ac2 on the Y1 side. Each of the support portions 133Ac1 and 133Ac2 is bent and extends on the Z2 side.

[0054] The detachment bracket 4A differs from the detachment bracket 4 according to the first embodiment in the configuration of the load-absorbing member 6A. This will be explained in detail below.

[0055] The detachable bracket 4A extends along the X direction from one end 6A1 to the other end 6A2. The detachable bracket 4A has a fastening member 5 and a load absorbing member 6A. The load absorbing member 6A has a plate-shaped portion 61, a fixing portion 62A, and an impact load absorbing portion 63A.

[0056] As shown in Figures 13 and 14A, the fixing portion 62A has a third projection 623 and a fourth projection 624. The third projection 623 protrudes toward the Y1 side, and the fourth projection 624 protrudes toward the Y2 side. The third projection 623 and the fourth projection 624 are positioned toward the X2 side relative to the support portions 133Ac1 and 133Ac2. The third projection 623 and the fourth projection 624 abut against the support portions 133Ac1 and 133Ac2.

[0057] The collision load absorbing section 63A extends from one end 631 to the other end 632. The collision load absorbing section 63A has a collision load absorbing section 63A1 and a collision load absorbing section 63A2. The collision load absorbing sections 63A1 and 63A2 are aligned in the Y direction. The collision load absorbing section 63A1 is located on the Y1 side relative to the collision load absorbing section 63A2. Each of the collision load absorbing sections 63A1 and 63A2 has a bellows-like shape that bends alternately towards the Y1 side and towards the Y2 side as it moves towards the X2 side. In other words, it is formed by alternately connecting U-shaped bends that are convex towards the Y1 side and U-shaped bends that are convex towards the Y2 side to form a bellows shape. The collision load absorbing sections 63A1 and 63A2 are symmetrical in shape. In other words, the U-shaped bent portion of the collision load absorbing portion 63A1 that is convex to the Y1 side and the U-shaped bent portion of the collision load absorbing portion 63A2 that is convex to the Y2 side are positioned at the same location in the X direction. In the second embodiment, two collision load absorbing portions 63A1 and 63A2 are shown side by side in the Y direction, but in the present invention, there may be one or three or more collision load absorbing portions. As shown in Figure 14A, in the second embodiment as well, the third projection 623 and the fourth projection 624 abut against the support portions 133Ac1 and 133Ac2, so that the rotation of the plate-shaped portion 61 is suppressed even when a rotational force indicated by the arrow in Figure 14A is applied.

[0058] Next, we will explain the deformation behavior of the load-absorbing member 6A when a collision load from a secondary collision directed toward the X2 side is applied to the steering device 100A. Figure 15A is a bottom view of the vehicle body mounting member viewed from below, showing the state before the secondary collision. Figure 15B is a bottom view of the load-absorbing member before the secondary collision. Figure 16A is a bottom view of the vehicle body mounting member viewed from below, showing the state after the secondary collision. Figure 16B is a bottom view of the load-absorbing member after the secondary collision.

[0059] First, as shown in Figure 15A, the fastening member 5 and plate-shaped portion 61 of the detachable bracket 4A are attached to the vehicle body 140 via the bolt member 141 in the notch 32. At this time, as shown in Figure 15B, the distance in the X direction between one end 6A1 and the other end 6A2 of the load-absorbing member 6A is distance LA1.

[0060] Then, when a collision load from a secondary collision directed towards X2 is applied to the steering device 100A, as shown in Figure 16A, the steering device 100A moves towards X2 relative to the release bracket 4A, and the fastening member 5 and plate-shaped portion 61 of the release bracket 4A detach from the notch 32. At this time, as is clear from comparing Figure 15B and Figure 16B, the fixing portion 62A moves towards X2 relative to the plate-shaped portion 61. At this time, as shown in Figure 16B, the distance in the X direction between one end 6A1 and the other end 6A2 of the load-absorbing member 6A is distance LA2. That is, due to the secondary collision, the distance between one end 6A1 and the other end 6A2 of the load-absorbing member 6A changes by distance (LA2-LA1). In this way, the collision load-absorbing portion 63A undergoes plastic deformation due to the movement of the fixing portion 62A and absorbs a portion of the collision load of the secondary collision. In particular, in the second embodiment, since the collision load absorbing section 63A has a bellows shape, the amount of load absorbed when the collision load absorbing section 63A is stretched becomes larger.

[0061] As described above, in the second embodiment, the collision load absorbing section 63A has a bellows-like shape that bends alternately towards the Y1 side and the Y2 side as it moves towards the X2 side.

[0062] Therefore, by plastically deforming the collision load absorbing section 63A so that its ends in the X direction are separated, the collision load of a secondary collision can be absorbed with a relatively simple configuration. Furthermore, although a load absorbing member holding bracket 133 was provided in the first embodiment, the load absorbing member holding bracket 133 is unnecessary in the second embodiment, so the steering device of the second embodiment is more compact.

[0063] [Third Embodiment] Next, a third embodiment will be described. Figure 17 is a perspective view showing a detachable bracket according to the third embodiment. Figure 18 is a perspective view showing a fastening member according to the third embodiment.

[0064] The detachable bracket 4B according to the third embodiment includes a fastening member 5B. The fastening member 5B differs from the fastening member 5 according to the first embodiment in its head portion 51B.

[0065] In other words, in the fastening member 5, the outer circumference of the first part 511 has the shape of a polygonal prism, such as a hexagonal prism. This allows the outer circumference of the first part 511 to be gripped with a tool such as a wrench and rotated.

[0066] In contrast, in the fastening member 5B, the outer circumference of the head 51B is cylindrical, and the through hole 5Ba formed in the radial center of the fastening member 5B has the shape of a polygonal prism, such as a hexagonal prism, when viewed from the Z direction. This makes it possible to insert a tool such as a hex wrench into the through hole 5Ba and rotate the fastening member 5B.

[0067] As described above, in the third embodiment, the head 51B of the fastening member 5B is provided with a through hole 5Ba that penetrates in the Z direction in the central part of the radial direction. The through hole 5Ba has a hexagonal (polygonal) shape when viewed from the Z direction.

[0068] If the through-hole 5Ba is, for example, hexagonal, a tool such as a hex wrench can be inserted into the through-hole 5Ba and the head 51B can be rotated to fasten the fastening member 5B to the plate-shaped part 61. Therefore, compared to the method of fitting a large spanner around the outer circumference of the head and rotating the head when the outer circumference of the head is hexagonal, this embodiment allows work to be performed in a narrower space. [Explanation of Symbols]

[0069] 1. Steering shaft 1a end 2. Steering column 21 Outer Column 22 Inner Column 3. Body mounting components 3A Body mounting component 31. Vehicle mounting bracket 31A Vehicle mounting bracket 31a Peripheral area 31b Plane part 32 Notches 4. Detachable bracket 4A Detachable Bracket 4B Detachable Bracket 5 Fastening members 5B Fastening Member 5a through hole 5Ba through hole 51 Head 51B Head 51a Through hole 511 Part 1 512 Part 2 512a Back surface (the other end face in the second direction) 52 Shaft 52a Through hole 52b Male screw 52c end face 6. Load-absorbing member 6a one end 6b Other end 6A Load-absorbing member 6A1 One end 6A2 Other end 61 Plate-like part 61a Annular projection 61b Inner surface 61c Surface (end face on one side in the second direction) 61d Reverse side 61e Through hole 62 Fixed part 62A Fixed part 621 1st protrusion 622 2nd protrusion 623 Third protrusion 624 4th protrusion 63. Collision load absorption section 63A Collision load absorption section 63A1 Collision load absorption section 63A2 Collision load absorption section 631 edge 632 edge 633 Folding section 100 Steering System 101 Steering Wheel 110 Friction Reduction Layer 111 Friction reduction layer 120 Gearbox 121 ECU 122 Support bracket 123 Vehicle body support bracket 123a Through hole 130 Lever 130a spring 130b Rotary shaft 131 Side panel 131a Tilt hole 133 Bracket for holding load-absorbing member 133a Vertical plate section 133b Horizontal plate part 133c Support part 133c1, 133c2 Support part 133Ac Support part 133Ac1, 133Ac2 Support part 133c3 Connecting part 133d opening 133e opening 140 car bodies 140a Screw hole (female thread) 141 Bolt Member 141a Head 141b Shaft 150 tools

Claims

1. A steering shaft extending in a first direction and having a steering wheel connected to one end in the first direction, A steering column is positioned on the outer circumference of the steering shaft and rotatably supports the steering shaft, A vehicle body mounting bracket fixed to the steering column and having a notch that is open on one side in the first direction, A detachable bracket that fits into the notch and is attached to the vehicle body, wherein when a collision load of a secondary collision is applied and the vehicle body mounting bracket moves to the other side in the first direction, the detachable bracket absorbs the collision load and detaches from the notch, If the direction intersecting the first direction is defined as the second direction, The aforementioned detachable bracket is A fastening member having a head that abuts against one side of the vehicle body mounting bracket in the second direction, and a shaft that protrudes from the head through the notch toward the other side in the second direction and has a male thread on its outer circumference, A load-absorbing member having a plate-shaped portion with an internal thread that engages with the external thread, a fixing portion that is fixed to the vehicle body mounting bracket, and a long, elongated collision load absorbing portion that connects the plate-shaped portion and the fixing portion. Steering system.

2. The collision load absorbing portion has a bent portion between one end and the other end. It extends from one end toward the other side in the first direction to the bent portion, is bent in a curved manner at the bent portion, and extends toward the other end toward the one side in the first direction, The steering device according to claim 1.

3. If the direction intersecting the first and second directions is defined as the third direction, The collision load absorbing portion has a bellows-like shape that alternately bends towards one side and the other side of the third direction as it moves toward the other side of the first direction. The steering device according to claim 1.

4. The other end face in the second direction of the head of the fastening member has a friction-reducing layer. The steering device according to claim 1.

5. The end face on one side of the plate-like portion in the second direction has a friction-reducing layer. The steering device according to claim 1 or 4.

6. The head of the fastening member is provided with a through hole in the central radial portion that penetrates in the second direction, and the through hole has a polygonal shape when viewed from the second direction. The steering device according to claim 1.

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