Steering column device

Abstract

An impact absorption mechanism (26) comprises a movable component (81) and a fixed component. The fixed component includes: a support rail (91) that guides the movement of the movable component (81) in the axial direction while restricting the movement of the movable component (81) in the first direction; an opening (93) that penetrates in the first direction; a band (94) that extends in the axial direction so as to divide the opening (93) into one side and the other side in the second direction, and bulges from the opening (93) to one side in the first direction so as to face the movable component (81) in the axial direction; at least one first rib (95) provided on the one side in the second direction with respect to the band (94); and at least one second rib (96) provided on the other side in the second direction with respect to the band (94).

Description

Steering column device

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

[0002] For example, when a vehicle traveling on a road undergoes a frontal collision, a secondary collision may occur in which the driver collides with the steering wheel due to the effect of inertia. Therefore, as described in, for example, Patent Document 1, some steering column devices are provided with an impact absorption mechanism configured to absorb the impact of a secondary collision.

[0003] The impact absorption mechanism of Patent Document 1 includes an impact absorption member curved in a J-shape. The impact absorption member has a first plate portion, a second plate portion, and a curved portion that connects the first plate portion and the second plate portion to each other. The first plate portion is fixed to a member that moves integrally with the steering wheel in the axial direction when a secondary collision occurs, and the second plate portion is fixed to a member that does not move in the axial direction when a secondary collision occurs. Therefore, when a secondary collision occurs, the impact absorption member absorbs impact by undergoing plastic deformation such that the position of the curved portion is displaced along with the axial movement of the steering wheel. The load required to move the steering wheel in the axial direction when a secondary collision occurs in this manner is referred to as an EA (Energy Absorption) load, and impact corresponding to the EA load is absorbed.

[0004] Japanese Unexamined Patent Application Publication No. 2021-41760

[0005] In recent years, it has been desired to finely adjust the impact absorption characteristics of the impact absorption mechanism according to the vehicle model or the like in which the steering column device is mounted. Such impact absorption characteristics include not only the magnitude of the EA load, but also, for example, the fluctuation of the EA load accompanying the axial movement of the steering wheel. However, when attempting to adjust the impact absorption characteristics in the impact absorption mechanism of the above-mentioned Patent Document 1, fine adjustment is difficult because the parameters that can be modified, such as changing the thickness and width of the impact absorption member, are limited.

[0006] A steering column device according to one aspect of the present disclosure comprises a column shaft to which a steering wheel is fixed, a column tube that rotatably supports the column shaft, the column tube having an upper tube and a lower tube that is movably fitted to the upper tube in the axial direction of the upper tube, a bracket fixed to the vehicle body and supporting the column tube, and an impact absorbing mechanism configured to absorb the impact of a secondary collision. The direction perpendicular to the axial direction is the first direction, and the direction perpendicular to the axial direction and the first direction is the second direction. The impact absorbing mechanism comprises a movable part configured to move in the axial direction together with the upper tube when a secondary collision occurs, and a fixed part fixed to the bracket so as not to move in the axial direction when a secondary collision occurs. The fixed component includes a support rail that guides the movable component to move in the axial direction while restricting the movable component to move in the first direction; an opening that penetrates in the first direction; a band that extends in the axial direction so as to divide the opening into one side and the other side in the second direction, the band bulging out from the opening to one side in the first direction so as to be opposite the movable component in the axial direction; at least one first rib provided on one side in the second direction relative to the band, the first rib extending in the second direction to connect the band to the edge of the opening in the fixed component; and at least one second rib provided on the other side in the second direction relative to the band, the second rib extending in the second direction to connect the band to the edge of the opening in the fixed component.

[0007] This is a perspective view of a steering column device equipped with an impact absorption mechanism according to one embodiment. This is a side view showing a part of the steering column device of Figure 1. This is a cross-sectional view of the steering column device of Figure 2 along the axial direction. This is a cross-sectional view taken along line IV-IV of Figure 2. This is a plan view of the impact absorption mechanism of Figure 1. This is a cross-sectional view of the impact absorption mechanism of Figure 1 along the axial direction. This is a plan view of a modified impact absorption mechanism. This is a plan view of another modified impact absorption mechanism.

[0008] An embodiment of the steering column device will be described below with reference to the drawings. (Overall configuration) As shown in Figures 1 to 3, the steering column device 1 comprises a column shaft 2 and a steering column 3 that rotatably houses the column shaft 2. The steering column device 1 is mounted on the vehicle such that the axis L of the column shaft 2 is generally aligned with the longitudinal direction of the vehicle.

[0009] In the following explanation, the left side of Figure 1 is considered the front of the vehicle, and the right side of Figure 1 is considered the rear of the vehicle. Directions expressed using terms such as "front," "rear," "up," "down," "left," and "right" are defined relative to the vehicle. The direction along the axis L is called the axial direction, the direction perpendicular to the axial direction and generally along the vertical direction of the vehicle is called the height direction, and the direction perpendicular to the axial and height directions and generally along the left-right direction of the vehicle is called the width direction. In the width direction, the direction toward the axis L is called the inward direction, and the direction away from the axis L is called the outward direction. In this embodiment, the height direction corresponds to the first direction, and the width direction corresponds to the second direction.

[0010] A steering wheel 4 is connected to the rear end of the column shaft 2. An intermediate shaft (not shown) is connected to the front end of the column shaft 2. The intermediate shaft is connected to the steering wheels via a rack and pinion mechanism (not shown). As a result, the steering wheels steer in response to the driver's steering input. In other words, the steering column device 1 of this embodiment constitutes part of a steering system that mechanically transmits the driver's operation of the steering wheel 4 to the steering wheels.

[0011] As shown in Figure 1, the steering column device 1 of this embodiment is equipped with an electric actuator 5 that provides an assist force to help the driver operate the steering wheel 4. The electric actuator 5 comprises a motor 6, which is a drive source, and a reduction mechanism (not shown) that reduces the rotation of the motor 6. The electric actuator 5 then provides an assist force by reducing the rotation of the motor 6 and transmitting it to the column shaft 2.

[0012] The steering column device 1 is configured to allow adjustment of the vertical position of the steering wheel 4 (hereinafter referred to as the tilt position) and the front-to-back position of the steering wheel 4 (hereinafter referred to as the telescopic position).

[0013] More specifically, as shown in Figure 3, the column shaft 2 comprises an upper shaft 11, a lower shaft 12, and an output shaft (not shown). The upper shaft 11 is, for example, a long cylindrical shape. A steering wheel 4 is connected to the rear end of the upper shaft 11. The lower shaft 12 is, for example, a long cylindrical shape. The lower shaft 12 is fitted to the inner circumference of the upper shaft 11 through a spline engagement. As a result, the upper shaft 11 is connected to the lower shaft 12 so that it can rotate integrally with the lower shaft 12 and move axially relative to the lower shaft 12. The output shaft is connected to the lower shaft 12 so that it can rotate integrally with the lower shaft 12. The rotation of the motor 6 is transmitted to the output shaft via a reduction mechanism.

[0014] As shown in Figure 1, the steering column 3 comprises a bracket 21, a housing 22, a column tube 23, a clamp 24, a locking mechanism 25, and a shock absorption mechanism 26.

[0015] As shown in Figures 1 to 4, the bracket 21 has an upper wall portion 31, a rear wall portion 32, a pair of side wall portions 33, and a pair of extension wall portions 34. In this embodiment, the bracket 21 is a single piece in which the upper wall portion 31, the rear wall portion 32, the pair of side wall portions 33, and the pair of extension wall portions 34 are continuous without any breaks.

[0016] The upper wall portion 31 is a rectangular plate shape parallel to the axial and width directions. The rear wall portion 32 extends downward from the rear edge of the upper wall portion 31. The rear wall portion 32 is a rectangular plate shape parallel to the height and width directions. The rear wall portion 32 is provided with one or more engagement holes 35 that penetrate in the axial direction. In the illustrated example, the rear wall portion 32 has two engagement holes 35. A pair of side wall portions 33 extend downward from both side edges in the width direction of the upper wall portion 31. Each side wall portion 33 is a rectangular plate shape parallel to the axial and height directions. Each side wall portion 33 extends axially so as to protrude forward from the upper wall portion 31. Bolt holes 36 (see Figure 2) that penetrate in the width direction are provided in the portion of each side wall portion 33 that protrudes forward from the upper wall portion 31. A pair of extension wall portions 34 extend outward in the width direction from the lower edges of the pair of side wall portions 33. Mounting holes 37 are provided at the front end of each extension wall portion 34. The bracket 21 is fixed immovably to the vehicle body via fastening bolts (not shown) inserted through the mounting holes 37. Each extension wall portion 34 in this embodiment constitutes part of the shock absorption mechanism 26 and corresponds to a fixing component. Details of each extension wall portion 34 will be described later.

[0017] As shown in Figure 1, the motor 6 is mounted in the housing 22. The reduction gear mechanism and output shaft described above are housed inside the housing 22. The housing 22 has a pair of support parts 41 positioned between the side wall portions 33 of the bracket 21. Each support part 41 is provided with a through hole 42 that penetrates in the width direction. The housing 22 is positioned relative to the bracket 21 such that the through holes 42 are aligned in the width direction with the bolt holes 36 of the bracket 21. Hinge bolts 43 are inserted through the bolt holes 36 and the through holes 42. As a result, the housing 22 is rotatably supported relative to the bracket 21 around the hinge bolts 43.

[0018] The column tube 23 comprises a cylindrical upper tube 51 and a lower tube 52 that rotatably house the column shaft 2. The upper tube 51 and the lower tube 52 are arranged coaxially with the column shaft 2. In other words, the axes of the upper tube 51 and the lower tube 52 coincide with the axis L of the column shaft 2.

[0019] As shown in Figure 3, the upper tube 51 rotatably supports the upper shaft 11 via a bearing 53. The upper tube 51 is fitted to the lower tube 52 so as to be axially movable relative to the lower tube 52. As the upper tube 51 moves axially relative to the lower tube 52, the column tube 23 expands and contracts. At this time, as the upper tube 51 moves, the upper shaft 11 moves axially relative to the lower shaft 12, causing the column shaft 2 to expand and contract as well. The telescopic position of the steering wheel 4 is changed by the expansion and contraction of the column tube 23.

[0020] As shown in Figure 1, the front end of the lower tube 52 is fixed to the housing 22. This allows the column shaft 2, supported by the upper tube 51 and the lower tube 52, to rotate together with the housing 22 around the hinge bolt 43. The tilt position of the steering wheel 4 is changed by the rotation of the column tube 23 and the housing 22 together with the column shaft 2 around the hinge bolt 43.

[0021] As shown in Figures 3 and 4, the column tube 23 of this embodiment further comprises a connecting member 54 fixed to the lower part of the upper tube 51. The connecting member 54 has a lower plate portion 55 and a pair of side plate portions 56. The lower plate portion 55 is a rectangular plate parallel to the axial and width directions. The pair of side plate portions 56 extend upward from both side edges in the width direction of the lower plate portion 55. Each side plate portion 56 is a rectangular plate parallel to the axial and height directions. Each side plate portion 56 has an elongated hole 57 that penetrates in the width direction and extends in the axial direction. The connecting member 54 is fixed immovably to the upper tube 51, for example, by welding the upper edges of each side plate portion 56 to the outer circumferential surface of the upper tube 51.

[0022] The clamp 24 has an upper plate portion 61 and a pair of side plate portions 62. The upper plate portion 61 is a rectangular plate parallel to the axial and width directions. The upper plate portion 61 has one or more engaging projections 63 that protrude rearward from its rear edge. The engaging projections 63 are inserted into engaging holes 35 of the bracket 21. The engaging projections 63 are crimped in the engaging holes 35 so that they can be disengaged from the engaging holes 35 when an axial load exceeding a predetermined load is applied to the clamp 24. In this way, the clamp 24 is detachably connected to the bracket 21. The pair of side plate portions 62 extend downward from both side edges in the width direction of the upper plate portion 61. Each side plate portion 62 is a plate parallel to the axial and height directions. Each side plate portion 62 has an elongated hole 64 that penetrates in the width direction and extends in the height direction.

[0023] The locking mechanism 25 comprises a clamping shaft 71, an operating lever 72 rotatable around the clamping shaft 71, one or more friction plates 73 fixed to the connecting member 54, and one or more friction plates 74 fixed to the clamp 24. The clamping shaft 71 is inserted through the elongated hole 57 of the connecting member 54 and the elongated hole 64 of the clamp 24. The operating lever 72 is rotatable between a locked position and an unlocked position. The friction plates 73 and 74 are in contact with each other.

[0024] When the operating lever 72 is operated to the locked position, the friction plates 73 and 74 are pressed together and rubbed into each other, engaging in friction. As a result, the locking mechanism 25 restricts the movement of the upper tube 51 relative to the clamp 24, i.e., the movement of the upper tube 51 relative to the bracket 21, thereby maintaining the position of the steering wheel 4. In other words, the clamp 24 supports the upper tube 51 via the locking mechanism 25, and the bracket 21 supports the upper tube 51 via the clamp 24.

[0025] The holding force of the steering wheel 4 by the locking mechanism 25 is set so that the upper tube 51 does not move relative to the clamp 24 even if a load exceeding a predetermined load is applied to the upper tube 51. Therefore, if an axial load exceeding a predetermined load is applied to the upper tube 51 via the steering wheel 4 due to a secondary collision, the clamp 24 will detach from the bracket 21 and move axially together with the upper tube 51.

[0026] On the other hand, when the operating lever 72 is moved to the unlock position, the frictional engagement of the friction plates 73 and 74 is released, allowing the column tube 23 to move relative to the clamp 24. This allows for adjustment of the position of the steering wheel 4.

[0027] (Shock Absorption Mechanism 26) Next, the configuration of the shock absorption mechanism 26 will be described. As shown in Figures 1 and 4, the steering column device 1 of this embodiment has shock absorption mechanisms 26 on both sides in the width direction of the axis L. The two shock absorption mechanisms 26 have a substantially symmetrical structure with respect to the axis L. Therefore, the shock absorption mechanism 26 provided on the left will be described below, and the description of the shock absorption mechanism 26 provided on the right will be omitted as appropriate.

[0028] The impact absorption mechanism 26 includes a movable part 81 fixed to the clamp 24 and an extended wall portion 34 of the bracket 21. As described above, the clamp 24 is configured to move axially together with the upper tube 51 when a secondary collision occurs, so the movable part 81 moves axially together with the upper tube 51 when a secondary collision occurs. The extended wall portion 34 is part of the bracket 21 fixed to the vehicle body, so it does not move axially together with the upper tube 51 when a secondary collision occurs.

[0029] As shown in Figures 4 to 6, the movable part 81 has a mounting portion 82, a front contact portion 83, and an upper contact portion 84. The mounting portion 82 is plate-shaped and parallel to the axial and height directions. The mounting portion 82 is fixed to the outer side surface in the width direction of the side plate portion 62 of the clamp 24, for example, by welding. The front contact portion 83 extends outward in the width direction from the front edge of the mounting portion 82. The front contact portion 83 is plate-shaped and parallel to the height and width directions. The upper contact portion 84 extends rearward along the axial direction from the upper edge of the front contact portion 83. The upper contact portion 84 is plate-shaped and parallel to the axial and width directions. The upper contact portion 84 is also continuous with the upper edge of the mounting portion 82. The connection portion between the front contact portion 83 and the upper contact portion 84 of the movable part 81 is curved in an arc shape when viewed from the width direction. The upper contact portion 84 has a projection 85 that protrudes outward in the width direction compared to the front contact portion 83.

[0030] The extension wall 34 has a support rail 91 and a hook 92. The support rail 91 extends outward in the width direction from the side edge located outward in the width direction of the extension wall 34, and then curves inward in the width direction as it goes downward. The support rail 91 extends over most of the axial region of the extension wall 34, excluding both axial ends. The support rail 91 defines a groove-shaped space that opens forward, backward, and inward in the width direction. The support rail 91 is positioned axially opposite to the protrusion 85 so that when the movable part 81 moves forward due to a secondary collision, the protrusion 85 enters the groove-shaped space within the support rail 91. When the protrusion 85 enters the groove-shaped space within the support rail 91, the support rail 91 comes into contact with the protrusion 85, restricting the movement of the movable part 81 in the height direction.

[0031] The hook 92 is positioned behind the support rail 91 on the extension wall 34. The hook 92 extends outward in the width direction from the rear end of the extension wall 34, and then folds back to face inward. When the clamp 24 is connected to the bracket 21, the hook 92 grips the protruding portion 85 of the movable part 81.

[0032] As shown in Figures 5 and 6, the extension wall portion 34 further has an opening 93 that penetrates in the height direction, a band 94, a plurality of first ribs 95, and a plurality of second ribs 96. The opening 93 is axially elongated and rectangular in shape. The band 94 is axially extending and band-shaped. The band 94 extends axially so as to divide the opening 93 into the right and left sides in the width direction, and bulges downward from the opening 93 so as to face the movable part 81 in the axial direction. In other words, the band 94 extends axially so as to traverse (longitudinally) the opening 93, and bulges downward from the opening 93 so as to face the movable part 81 in the axial direction. In the illustrated example, the rear end of the band 94 extends so as to be positioned downward from the rear edge of the opening 93 in the extension wall portion 34 toward the front, so as to face the movable part 81 in the axial direction. The middle portion of the band 94 extends linearly so as to not change its position in the height direction. The front end of the band 94 extends upward as it moves forward, so as to connect to the front edge of the opening 93 in the extension wall 34. The band 94 is positioned in the widthwise center of the opening 93. In other words, the distance between the band 94 and the inner edge of the opening 93 in the extension wall 34 is equal to the distance between the band 94 and the outer edge of the opening 93 in the extension wall 34.

[0033] The dimensions of the band 94 along the width direction are substantially constant throughout the entire axial region, and the dimensions (thickness) of the band 94 along the height direction are substantially constant throughout the entire axial region. In other embodiments, at least one of the dimensions of the band 94 along the width direction and the dimensions along the height direction may not be substantially constant in the axial region.

[0034] Each first rib 95 is positioned inward in the width direction relative to the band 94. Each first rib 95 extends in the width direction and connects the band 94 to the inner edge of the opening 93 in the extended wall portion 34. Specifically, each first rib 95 extends diagonally downward outward in the width direction from the inner edge of the opening 93 in the extended wall portion 34 and connects to the band 94. Multiple first ribs 95 are arranged at equal intervals in the axial direction.

[0035] The axial dimension of the first rib 95 is substantially constant throughout the width direction, and the height dimension of the first rib 95 is substantially constant throughout the width direction. In other embodiments, at least one of the axial dimension and the height dimension of the first rib 95 may not be substantially constant in the width direction.

[0036] Each second rib 96 is positioned outward in the width direction relative to the band 94. Each second rib 96 extends in the width direction and connects the band 94 to the outer edge of the opening 93 in the extended wall portion 34. Specifically, each second rib 96 extends diagonally downward inward in the width direction from the outer edge of the opening 93 in the extended wall portion 34 and connects to the band 94. The second ribs 96 are arranged at equal intervals in the axial direction so as not to overlap with the first ribs 95. In the illustrated example, multiple second ribs 96 are arranged alternately with multiple first ribs 95 such that the axial distance between adjacent first ribs 95 and second ribs 96 is equal.

[0037] The axial dimension of the second rib 96 is substantially constant throughout the width direction, and the height dimension of the second rib 96 is substantially constant throughout the width direction. In other embodiments, at least one of the axial dimension and the height dimension of the second rib 96 may not be substantially constant in the width direction.

[0038] Thus, the band 94 is supported by a plurality of first ribs 95 and a plurality of second ribs 96. In the following description, the support structure of the band 94 by the first ribs 95 will be referred to as the first support structure, and the support structure of the band 94 by the second ribs 96 will be referred to as the second support structure. In this embodiment, since the plurality of second ribs 96 are arranged alternately with respect to the plurality of first ribs 95, the first support structure is asymmetrical with respect to a straight line along the band 94 with respect to the second support structure.

[0039] The bracket 21 in this embodiment is formed by punching and pressing a metal plate. The band 94, the first rib 95, and the second rib 96 are formed by punching a metal plate so that the portion corresponding to the band 94, the first rib 95, and the second rib 96 remains after the portion corresponding to the extended wall portion 34 remains, and then bending them downwards by pressing. The movable part 81 in this embodiment is formed by pressing a metal plate.

[0040] Next, the operation of the impact absorption mechanism 26 during a secondary collision will be described. When an axial load exceeding a predetermined load is applied to the clamp 24 via the upper tube 51 due to the secondary collision, the clamp 24 detaches from the bracket 21. Then, the movable part 81 moves axially together with the clamp 24, the upper tube 51, and the steering wheel 4, etc. Subsequently, the protruding portion 85 of the movable part 81 enters the groove-shaped space within the support rail 91, and the front contact portion 83 comes into contact with the band 94. As described above, the movement of the movable part 81 in the height direction is restricted when the protruding portion 85 enters the groove-shaped space within the support rail 91, so the movable part 81 moves forward along the axial direction while plastically deforming to push the band 94 upward. This absorbs the impact of the secondary collision.

[0041] (Functions and Effects of the Present Embodiment) Next, the functions and effects of the present embodiment will be described. (1) The extended wall portion 34 has a band 94 extending in the axial direction so as to divide the opening 93 into the right side and the left side in the width direction, at least one first rib 95 provided inward in the width direction with respect to the band 94, and at least one second rib 96 provided outward in the width direction with respect to the band 94. Therefore, the ease of plastic deformation of the band 94, that is, the EA load, depends not only on the dimensions of the band 94 in the width direction and the height direction, but also on, for example, the number of the first ribs 95 and the second ribs 96, the dimensions of the first ribs 95 and the second ribs 96 in the width direction and the height direction, the interval (pitch) between adjacent first ribs 95, the interval between adjacent second ribs 96, or the relative position between the first rib 95 and the second rib 96, and the like. Accordingly, since the shock absorption characteristics of the shock absorption mechanism 26 can be changed by various parameters, fine adjustments can be easily performed.

[0042] (2) In a comparative example in which the extended wall portion 34 does not have the second rib 96, when the movable component 81 plastically deforms the band 94 so as to push it upward, the band 94 may be plastically deformed so as to shift outward in the width direction. As a result, the band 94 is plastically deformed at a load lower than the designed load, and there is a risk that the shock cannot be sufficiently absorbed.

[0043] In this regard, in the present embodiment, the ribs 95 and 96 are arranged on both sides in the width direction with respect to the band 94. Therefore, when the movable component 81 plastically deforms the band 94 so as to push it upward, deformation of the band 94 that shifts in the width direction can be suppressed.

[0044] (3) The load required to plastically deform the band 94 varies according to the axial position of the band 94. Specifically, the load required to plastically deform the portion of the band 94 to which the first rib 95 or the second rib 96 is connected is larger than the load required to plastically deform the other portions. Therefore, when the axial position of the first rib 95 overlaps with the axial position of the second rib 96, the fluctuation of the EA load accompanying the axial movement of the movable component 81 tends to increase.

[0045] In this respect, in the present embodiment, the first support structure, which is the support structure for the band 94 by the first rib 95, is asymmetric with respect to the second support structure, which is the support structure for the band 94 by the second rib 96, with respect to a straight line along the band 94. Therefore, variation in EA load accompanying the movement of the movable component 81 in the axial direction can be suppressed.

[0046] The present embodiment can be implemented with modifications as described below. The present embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range. - In the above embodiment, the band 94 is disposed at the center in the width direction of the opening 93, but the arrangement is not limited thereto. For example, as shown in FIG. 7, the band 94 may be disposed closer to the outer side in the width direction of the opening 93. In this case, the dimension of the first rib 95 along the width direction is larger than the dimension of the second rib 96 along the width direction. Although not illustrated, the band 94 may be disposed closer to the inner side in the width direction of the opening 93. In this case, the dimension of the first rib 95 along the width direction is smaller than the dimension of the second rib 96 along the width direction.

[0047] Further, for example, as shown in FIG. 8, the extended wall portion 34 may have a notch 101 provided at the outer edge of the opening 93. In this example, the band 94 is disposed closer to the outer side in the width direction of the opening 93. The second rib 96 is disposed in the notch 101 such that its axial position overlaps with that of the first rib 95. The dimension of the second rib 96 along the width direction may be equal to the dimension of the first rib 95 along the width direction.

[0048] The plurality of first ribs 95 may be arranged at unequal intervals in the axial direction. Similarly, the plurality of second ribs 96 may be arranged at unequal intervals in the axial direction. The number of the first ribs 95 can be changed as appropriate. For example, the extended wall portion 34 may have only one first rib 95. Similarly, the number of the second ribs 96 can be changed as appropriate. For example, the extended wall portion 34 may have only one second rib 96.

[0049] Furthermore, the first support structure may be symmetrical to the second support structure with respect to a straight line along the band 94, and the shape of the opening 93, the arrangement of the band 94 with respect to the opening 93, and the number and arrangement of the first rib 95 and the second rib 96 can be changed as appropriate.

[0050] In the above embodiment, the intermediate portion of the band 94 extended in a straight line so that its position in the height direction did not change. However, the band 94 is not limited to this and may be curved so that its position in the height direction changes.

[0051] In the above embodiment, the extension wall portion 34 may be a separate component from the bracket 21. In this case, the separate extension wall portion 34 corresponds to a fixing component and is fixed to the bracket 21 by, for example, welding.

[0052] In the above embodiment, the extended wall portion 34 was plate-shaped parallel to the axial and width directions, but it is not limited to this, and may be plate-shaped parallel to the axial and height directions, for example. In this case, the opening 93 penetrates in the width direction, the first rib 95 is provided above the band 94, and the second rib 96 is provided below the band 94. In this case, the height direction corresponds to the second direction, and the width direction corresponds to the first direction.

[0053] - In the above embodiment, the extended wall portion 34 does not need to have a hook 92. - In the above embodiment, the locking mechanism 25 was of a type that utilized the frictional force between the friction plates 73 and 74, but it is not limited to this, and other types may be used as long as they can maintain the position of the steering wheel 4.

[0054] In the above embodiment, the movable part 81 is fixed to the clamp 24, but this is not limited to this. The movable part 81 may be fixed to another member if it moves axially together with the upper tube 51 when a secondary collision occurs, for example, it may be fixed directly to the upper tube 51.

[0055] - In the above embodiment, the shock absorption mechanism 26 is provided on both sides in the width direction with respect to the axis L, but it is not limited to this, and the shock absorption mechanism 26 may be provided only on the inside or outside in the width direction. - In the above embodiment, the steering column device 1 does not need to be equipped with an electric actuator 5.

[0056] In the above embodiment, the steering column device 1 may be an operating unit for a steer-by-wire type steering system in which the power transmission path between the operating unit operated by the driver and the steering unit that steers the steering wheels in response to the driver's operation of the steering wheel 4 is separated.

[0057] Next, the technical ideas that can be understood from the above embodiments and modified examples are added below. (Note) The steering device further comprises a clamp connected to the bracket and supporting the upper tube, which is configured to detach from the bracket together with the upper tube when a load of a predetermined load or more along the axial direction is applied to the clamp, and the impact absorption mechanism may be configured to absorb the impact of a secondary collision by the clamp detached from the bracket moving in the axial direction.

Claims

1. A steering column device comprising: a column shaft to which a steering wheel is fixed; a column tube that rotatably supports the column shaft, the column tube having an upper tube and a lower tube that is movably fitted to the upper tube in the axial direction of the upper tube; a bracket fixed to the vehicle body and supporting the column tube; and an impact absorbing mechanism configured to absorb the impact of a secondary collision, wherein the direction perpendicular to the axial direction is a first direction, and the direction perpendicular to the axial direction and the first direction is a second direction, and the impact absorbing mechanism comprises: a movable part configured to move in the axial direction together with the upper tube when a secondary collision occurs, and a fixed part fixed to the bracket so as not to move in the axial direction when a secondary collision occurs, the fixed part comprising: a support rail that guides the movable part to move in the axial direction while restricting the movable part from moving in the first direction, and an opening that penetrates in the first direction, A steering column device comprising: a band extending in the axial direction such as to divide the opening into one side in the second direction and the other side, the band bulging out from the opening to one side in the first direction so as to be opposite the movable part in the axial direction; at least one first rib provided on one side of the band in the second direction, the first rib extending in the second direction to connect the band to the edge of the opening in the fixed part; and at least one second rib provided on the other side of the band in the second direction, the second rib extending in the second direction to connect the band to the edge of the opening in the fixed part.

2. A steering column device according to claim 1, wherein the support structure for the band by at least one first rib is a first support structure, and the support structure for the band by at least one second rib is a second support structure, wherein the first support structure is asymmetrical with respect to a straight line along the band with respect to the second support structure.

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