Steering column device

Abstract

To provide a steering column device that is able to detect with higher accuracy a load applied to a steering wheel by a driver.SOLUTION: A steering column device includes a steering column supporting a steering shaft, the steering column has a bearing portion rotatably supporting the steering shaft on a steering wheel side, and the bearing portion has a load sensor.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] A steering column device is used that has a telescopic mechanism that adjusts the position of the steering wheel in the fore-and-aft direction and a tilt mechanism that adjusts the angle of the steering wheel in the up-and-down direction.

[0003] A steering column device has been devised that can control the telescopic mechanism and tilt mechanism by the load applied to the steering wheel by the driver. This steering column device does not require a user interface such as a joystick or operation keys, and allows the driver to intuitively adjust the position and angle of the steering wheel.

[0004] The vehicle steering column device described in Patent Document 1 includes a pressure sensor that detects the load applied to the steering wheel by the driver, and electrically adjusts the position of the steering wheel based on the detection result of the pressure sensor. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-098189 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the vehicle steering column device described in Patent Document 1, the pressure sensors that detect the load in the forward / backward direction and the pressure sensors that detect the load in the up / down direction are located far from the steering wheel, making it difficult to detect the load applied to the steering wheel by the driver.

[0007] In view of the above circumstances, an object of the present invention is to provide a steering column device that can detect the load applied to the steering wheel by the driver with higher accuracy. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention proposes the following means. A steering column device according to a first aspect of the present invention includes a steering column that supports a steering shaft, the steering column having a bearing portion on the steering wheel side that rotatably supports the steering shaft, the bearing portion having a load sensor, the steering column having a base bracket, a first column that is movable in a fore-and-aft direction relative to the base bracket, and a second column that is movable in a fore-and-aft direction relative to the first column, the second column being located closer to the steering wheel than the first column, and the bearing portion being located on the second column. The load sensor is a ring-shaped load cell that is sandwiched between the second column and the steering shaft via a bearing, and movement of the load sensor together with the bearing in the fore-and-aft direction is restricted. [Effects of the Invention]

[0009] According to the steering column device of the present invention, the load applied to the steering wheel by the driver can be detected with higher accuracy. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing a configuration of a steering device including a steering column device according to a first embodiment. [Figure 2] FIG. 2 is a perspective view showing the steering column device. [Figure 3] FIG. 2 is a perspective view showing the steering column device. [Figure 4] FIG. 2 is a cross-sectional view of the steering column device. [Figure 5] FIG. 2 is a perspective view of a column holder of the steering column device. [Figure 6]FIG. 5 is an enlarged view of the area indicated by the dashed double-dashed line in FIG. [Figure 7] FIG. 2 is an exploded perspective view of a first bearing portion of the steering column device. [Figure 8] 10A and 10B are diagrams illustrating why it is desirable to place a load sensor in a bearing portion close to the steering wheel. [Figure 9] 10A and 10B are diagrams illustrating why it is desirable to place a load sensor in a bearing portion close to the steering wheel. [Figure 10] 10A and 10B are diagrams illustrating why it is desirable to place a load sensor in a bearing portion close to the steering wheel. DETAILED DESCRIPTION OF THE INVENTION

[0011] (First embodiment) A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram showing the configuration of a steering device 300 including a steering column device 100 according to this embodiment.

[0012] [Steering device 300] As shown in FIG. 1, the steering device (steering device) 300 includes a steering wheel (input mechanism) 200, which is a steering member for steering the vehicle, a steering mechanism 210 that turns the steered wheels in conjunction with the rotation of the steering wheel 200, and a steering assist mechanism 230 that assists the driver in steering.

[0013] The steering mechanism 210 includes the steering column device 100, a steering shaft 220 connected to the steering wheel 200, a universal joint 224, an intermediate shaft 225, a pinion rack mechanism 226, tie rods 227a and 227b, and hub units 228a and 228b.

[0014] The steering shaft 220 is connected to the steered wheels via a universal joint 224, an intermediate shaft 225, a pinion rack mechanism 226, tie rods 227a and 227b, and further via hub units 228a and 228b.

[0015] The pinion rack mechanism 226 has a pinion and a rack (not shown). The pinion is connected to the intermediate shaft 225 and rotates in conjunction with the rotation of the intermediate shaft 225 . The rack extends linearly in the left-right direction of the vehicle (a direction perpendicular to the vehicle's forward travel). The rack meshes with the pinion near the center of the rack's axial direction. The pinion and rack convert the rotation of the pinion into axial movement of the rack. By moving the rack in the axial direction, the steered wheels are turned.

[0016] When the driver steers (rotates) steering wheel 200, the rotation of steering wheel 200 is transmitted to the pinion via steering shaft 220 and intermediate shaft 225. The rotation of the pinion is then converted into axial movement of the rack. Tie rods 227a, 227b and hub units 228a, 228b connected to both ends of pinion rack mechanism 226 move in the axial direction of the rack, and the steered wheels connected to hub units 228a, 228b are turned.

[0017] The steering mechanism 210 may be of a steer-by-wire type in which the steering shaft 220 and tie rods 227a, 227b that steer the steered wheels are electrically connected to each other.

[0018] In the following description, when the steering device 300 is attached to a vehicle, the direction toward the front of the vehicle along the axial direction A of the steering shaft 220 is defined as the "forward direction FR." The opposite direction is defined as the "rear direction RR." The direction toward the forward direction FR or the rear direction RR is defined as the "forward / rearward direction."

[0019] In the direction perpendicular to the longitudinal direction, the direction toward the top of the vehicle is defined as "upward UP." The opposite direction is defined as "downward LWR." The direction toward upward UP or downward LWR is defined as "vertical direction."

[0020] In the direction perpendicular to the front-to-back and left-to-right directions, the direction toward the right as you face backward is defined as the "right RH." The opposite direction is defined as the "left LH." The direction toward the right RH or left LH is defined as the "left-to-right direction" or "width direction."

[0021] 2 and 3 are perspective views showing the steering column device 100. FIG. The steering assist mechanism 230 includes a speed reduction mechanism 231, an electric motor (not shown), an ECU (not shown), and a housing 240.

[0022] The speed reduction mechanism 231 has, for example, a worm gear mechanism. A worm of the worm gear mechanism is rotationally driven by an electric motor. A worm wheel of the worm gear mechanism is connected to the steering shaft 220 so as to be rotatable integrally therewith.

[0023] The electric motor is an electric motor, such as a three-phase brushless motor, that assists the steering force of the steering shaft 220. The electric motor is connected to the steering shaft 220 via a reduction mechanism 231.

[0024] The ECU (control unit) includes a programmable device (computer) and drives the electric motor to control the reduction mechanism 231.

[0025] [Steering column device 100] The steering column device 100 is a device that supports the steering wheel 200, and has a telescopic mechanism that adjusts the position of the steering wheel 200 in the fore-and-aft direction, and a tilt mechanism that adjusts the angle of the steering wheel 200 in the up-and-down direction. The steering column device 100 includes a steering column 10 that supports a steering shaft 220, a lower telescopic actuator 6, an upper telescopic actuator 7, a tilt actuator 8, and a control device 9.

[0026] The lower telescopic actuator 6 and the upper telescopic actuator 7 constitute a part of a telescopic mechanism that extends and retracts in two stages. The tilt actuator 8 constitutes a part of a tilt mechanism. The lower telescopic actuator 6, the upper telescopic actuator 7, and the tilt actuator 8 are controlled by a control device 9.

[0027] FIG. 4 is a cross-sectional view of the steering column device 100. The steering shaft 220 has an inner shaft 221 and an outer shaft 222. The inner shaft 221 and the outer shaft 222 are connected so as to be unable to rotate relative to each other about an axis along the axial direction A, but are able to move relative to each other in the front-rear direction. In this embodiment, the inner shaft 221 of the front FR and the outer shaft 222 of the rear RR are connected by spline engagement.

[0028] A steering wheel 200 is attached to the rear RR end of the steering shaft 220, i.e., the rear RR end of the outer shaft 222. In addition, a steering assist mechanism 230 that assists the driver in steering is provided to the front FR end of the steering shaft 220, i.e., the front FR end of the inner shaft 221.

[0029] [Steering column 10] The steering column 10 is an axial tube member that supports a steering shaft 220. The steering column 10 has a base bracket 1 that is attached to the vehicle body, a column holder 2, a lower column 3 (first column), an inner column 4, and an upper column 5 (second column).

[0030] The steering column 10 is extendable and retractable in its entire length in the front-to-rear direction. Specifically, in the steering column 10, the base bracket 1 and the column holder 2 are connected so as to be movable relative to each other in the front-to-rear direction. Also, in the steering column 10, the column holder 2 and the upper column 5 are connected so as to be movable relative to each other in the front-to-rear direction.

[0031] FIG. 5 is a perspective view of the column holder 2. As shown in FIG. The column holder 2 is connected to the base bracket 1 so as to be relatively movable in the front-to-rear direction. The column holder 2 has a displacement plate portion 21, a pair of hanging plate portions (right hanging plate portion 22a, left hanging plate portion 22b), and a swing support bracket portion 23 that supports the lower column 3 so as to be swingable in the up-and-down direction.

[0032] The displacement plate portion 21 has a rectangular shape extending in the front-rear direction when viewed from the top-bottom direction. A pair of hanging plate portions (right hanging plate portion 22a and left hanging plate portion 22b) hang down from both widthwise end portions of the displacement plate portion 21 toward the lower left side (LWR).

[0033] The swing support bracket portion 23 is formed in a substantially U-shape when viewed from the front-to-rear direction, and is fixed to the end portion of the rear RR of the displacement plate portion 21. The swing support bracket portion 23 is provided with a tilt feed screw device 81 that supports the lower column 3 so that the lower column 3 is swingable in the up-and-down direction relative to the swing support bracket portion 23. The supported lower column 3 passes through a space surrounded by the displacement plate portion 21 and the swing support bracket portion 23.

[0034] The lower column 3 (first column) has a substantially cylindrical shape and is supported by the swing support bracket portion 23 of the column holder 2 so as to be swingable in the up-and-down direction but not to allow relative movement in the front-to-rear direction. As shown in FIG. 4, the lower column 3 has a large diameter portion 32 arranged at the front FR and a small diameter portion 33 arranged at the rear RR. The inner diameter dimension of the small diameter portion 33 is smaller than the inner diameter dimension of the large diameter portion 32. In addition, the lower column 3 has a slit 34 extending in the axial direction on the lower surface.

[0035] The large diameter portion 32 has a threaded hole 35a on the upper surface of the end portion of the front FR. A screw plug 37a having a pad 36a made of a material with a low friction coefficient such as polyacetal (POM) adhesively fixed to the tip end thereof is screwed into the threaded hole 35a.

[0036] The small diameter portion 33 has a threaded hole 35b on the upper surface of the end portion of the front FR. A screw plug 37b having a pad 36b made of a material with a low friction coefficient such as polyacetal (POM) adhesively fixed to the tip end thereof is screwed into the threaded hole 35b.

[0037] 2 to 4, the inner column 4 has a cylindrical portion 45 and a flange portion 46 that is bent radially outward from the front FR end of the cylindrical portion 45. The flange portion 46 is rotatably supported on the base bracket 1 via a housing 240 by a pivot bolt 49 that passes through the base bracket 1 in the left-right direction.

[0038] The inner column 4 and the lower column 3 are connected to be able to move relatively in the front-to-rear direction. Specifically, the rear portion of the cylindrical portion 45 of the inner column 4 is clearance-fitted into the large diameter portion 32 of the lower column 3. The pad 36a of the screw plug 37a that is threaded into the threaded hole 35a on the front side of the lower column 3 abuts against the outer peripheral surface of the rear portion of the cylindrical portion 45.

[0039] As shown in Figure 4, the upper column 5 (second column) is formed in a substantially cylindrical shape. The lower column 3 and the upper column 5 are connected to be able to move relative to each other in the front-to-rear direction. Specifically, the front portion of the upper column 5 is internally fitted in the small diameter portion 33 of the lower column 3 with a clearance fit. Pad 36b of screw plug 37b that is threaded into threaded hole 35b on the rear side of the lower column 3 abuts against the outer peripheral surface of the front portion of the upper column 5.

[0040] The upper column 5 has a first bearing portion 51 (bearing portion) and a second bearing portion 52. The first bearing portion 51 is provided at the end portion of the front side FR of the upper column 5, and rotatably supports the outer shaft 222. The second bearing portion 52 is provided at the end portion of the rear side RR of the upper column 5, and rotatably supports the outer shaft 222.

[0041] FIG. 6 is an enlarged view of the area indicated by the two-dot dashed line in FIG. The first bearing portion 51 (bearing portion) is sandwiched between the upper column 5 and the outer shaft 222 in the radial direction R. The first bearing portion 51 has a bearing 54, a load sensor 55, a first fastener 56, and a second fastener 57.

[0042] FIG. 7 is an exploded perspective view of the first bearing portion 51. FIG. The bearing 54 is a known ball bearing that can support not only radial loads but also axial loads. The inner peripheral surface of the bearing 54 abuts against the outer peripheral surface 222c of the outer shaft 222. The bearing 54 is not limited to a ball bearing, and may be any bearing that can support radial and axial loads.

[0043] The load sensor 55 is a ring-shaped load cell. The outer peripheral surface of the load sensor 55 abuts against the inner peripheral surface 5i of the upper column 5. A recess 55a extending in the circumferential direction is formed in the inner peripheral surface of the load sensor 55. A bearing 54 is fitted into the recess 55a. The load sensor 55 is connected to the steering shaft 220 via the bearing 54. In other words, the load sensor 55 is sandwiched between the upper column 5 and the bearing 54 in the radial direction R. The load sensor 55 may also be a load washer, a strain gauge, or the like.

[0044] An end portion of the load sensor 55 on the front FR abuts against an engaging protrusion 5t that protrudes inward from the inner circumferential surface 5i of the upper column 5. Therefore, movement of the load sensor 55 in the front FR is restricted.

[0045] An end portion of the load sensor 55 on the rear RR abuts against a first fastener 56. The first fastener 56 engages with an engaging recess 5a formed on the inner circumferential surface 5i of the upper column 5. Therefore, movement of the load sensor 55 toward the rear RR is restricted.

[0046] The front FR end of the bearing 54 abuts against an engaging protrusion 222t that protrudes outward from the outer circumferential surface 222c of the outer shaft 222. Therefore, movement of the bearing 54 in the front FR is restricted.

[0047] The rear end RR of the bearing 54 abuts against the second fastener 57. The second fastener 57 engages with an engaging recess 222a formed in the outer circumferential surface 222c of the outer shaft 222. Therefore, movement of the bearing 54 toward the rear RR is restricted.

[0048] The load sensor 55 is sandwiched between the upper column 5 and the outer shaft 222 in the radial direction R via a bearing 54, and can detect relative loads acting on the upper column 5 and the outer shaft 222 in the vertical and horizontal directions. For example, when a load is applied to the handle in the UP direction, the UP side of the load sensor 55 is compressed and distorted, and the load in the UP direction can be detected by detecting this compressive strain. The strain generated in the load sensor 55 can be detected by a known strain detection method such as a strain gauge or magnetostrictive sensor.

[0049] Since the load sensor 55 has its movement in the front-to-rear direction restricted by the engaging protrusion 5t of the upper column 5 and the engaging recess 222a of the outer shaft 222, it can also detect the relative load acting on the upper column 5 and the outer shaft 222 in the front-to-rear direction. For example, when a load is applied to the handle in the FR direction, the area sandwiched between the FR side engaging protrusion 5t of the load sensor 55 and the bearing 54 is compressed and distorted, and by detecting this distortion, the load in the FR direction can be detected. Alternatively, the load in the FR direction may be detected by detecting shear strain occurring in the region sandwiched between the outer periphery of the bearing 54 and the inner periphery of the upper column 5. The strain occurring in the load sensor 55 can be detected by a known strain detection method such as a strain sensor or a magnetostrictive sensor.

[0050] The load detected by the load sensor 55 is acquired by the control device 9 via a cable 59 .

[0051] [Lower telescopic actuator 6] The lower telescopic actuator 6 has a lower telescopic motor 60 and a lower feed screw device 61. The lower telescopic actuator 6 uses the lower telescopic motor 60 as a drive source to move the column holder 2 in the front-to-rear direction relative to the base bracket 1.

[0052] 2, the lower-side feed screw device 61 has a first screw shaft 62 having a male thread portion on its outer circumferential surface, and a first nut 63 having a female thread portion on its inner circumferential surface. The male thread portion of the first screw shaft 62 and the female thread portion of the first nut 63 are threadedly engaged with each other. The first screw shaft 62 is rotated by a lower-side telescopic motor 60, with an axis of rotation extending along the front-rear direction.

[0053] A rear end RR of the first screw shaft 62 is rotatably supported by a lower telescopic motor 60. In addition, the first nut 63 is fixed to the left LH side surface of the left hanging plate portion 22b of the column holder 2. In addition, the lower telescopic motor 60 is fixed to the left LH side surface of the base bracket 1.

[0054] As the lower telescopic motor 60 rotates and drives the first screw shaft 62 via a reduction mechanism such as a worm reducer, the first nut 63 moves in the front-to-rear direction along the first screw shaft 62, and the column holder 2 and the lower column 3 supported by the column holder 2 move in the front-to-rear direction relative to the base bracket 1.

[0055] [Upper telescopic actuator 7] The upper telescopic actuator 7 has an upper telescopic motor 70 and an upper feed screw device 71. The upper telescopic actuator 7 uses the upper telescopic motor 70 as a drive source to move the upper column 5 in the front-to-rear direction relative to the column holder 2.

[0056] 2, the upper feed screw device 71 has a second screw shaft 72 having a male threaded portion on its outer circumferential surface, and a second nut 73 having a female threaded portion on its inner circumferential surface. The male threaded portion of the second screw shaft 72 and the female threaded portion of the second nut 73 are threadedly engaged with each other. The second screw shaft 72 is rotated by an upper telescopic motor 70, with an axis extending in the front-to-rear direction as its rotation axis.

[0057] An end portion of the rear RR of the second screw shaft 72 is supported so as to be rotatable by an upper telescopic motor 70. In addition, the second nut 73 is fixed to the lower surface of the upper column 5. As shown in FIG. 4, the second nut 73 passes through a slit 34 formed in the lower column 3. In addition, the upper telescopic motor 70 is fixed to the lower surface of the large diameter portion 32 of the lower column 3.

[0058] As the upper telescopic motor 70 rotates and drives the second screw shaft 72 via a reduction mechanism such as a worm reducer, the second nut 73 moves in the front-to-rear direction along the second screw shaft 72, and the upper column 5 moves in the front-to-rear direction relative to the lower column 3.

[0059] [Tilt Actuator 8] The tilt actuator 8 has a tilt motor 80 and a tilt feed screw device 81. The tilt actuator 8 moves the lower column 3 relative to the column holder 2 in the up and down direction using the tilt motor 80 as a drive source.

[0060] As shown in Fig. 5, tilt feed screw device 81 has a third screw shaft 82 having a male thread portion on its outer circumferential surface, and a third nut 83 having a female thread portion on its inner circumferential surface. The male thread portion of third screw shaft 82 and the female thread portion of third nut 83 are threadedly engaged with each other. Third screw shaft 82 is driven to rotate by tilt motor 80. Third nut 83 has a cylindrical pivot shaft portion 84 on its outer circumferential surface.

[0061] The third screw shaft 82 is supported by the swing support bracket portion 23 so as to be rotatable about an axis extending in the vertical direction. A pivot shaft portion 84 of the third nut 83 is fixed to the lower column 3.

[0062] As the tilt motor 80 rotates and drives the third screw shaft 82 via a reduction mechanism such as a worm reducer, the third nut 83 moves up and down along the third screw shaft 82, and the connected lower column 3 moves up and down relative to the column holder 2.

[0063] [Control device 9] The control device 9 is a programmable device (computer) that includes a processor, a memory, a storage unit, and an input / output control unit. By executing a predetermined program, the control device 9 controls the lower telescopic actuator 6, the upper telescopic actuator 7, and the tilt actuator 8. At least some of the functions of the control device 9 may be configured using a dedicated logic circuit or the like. The control device 9 may also be integrated into an ECU for the steering assist mechanism 230.

[0064] [Operation of the steering column device 100 (1)] When the driver wants to adjust the fore-and-aft position of the steering wheel 200, the driver sets the control device 9 from the normal mode to the adjustment mode, and applies force to the steering wheel 200 in the direction in which the driver wants to move the steering wheel 200 (forward FR or backward RR). The transition between the normal mode and the adjustment mode can be performed by pressing a switch (not shown). Alternatively, the normal mode and the adjustment mode may be switched via an input / output device arranged on the dashboard of the vehicle. An example of the input / output device is a touch panel type information display.

[0065] The load sensor 55 detects the magnitude and direction of the relative load in the front-rear direction acting on the upper column 5 and the outer shaft 222. The control device 9 acquires the magnitude and direction of the load detected by the load sensor 55.

[0066] Based on the magnitude and direction of the load detected by the load sensor 55, the control device 9 drives the lower telescopic motor 60 to move the column holder 2 in the front-to-rear direction relative to the base bracket 1. The control device 9 also controls the upper telescopic motor 70 to move the upper column 5 in the front-to-rear direction relative to the lower column 3. As a result, the steering column 10 extends and contracts in the front-to-rear direction.

[0067] When the direction of the load detected by the load sensor 55 is forward FR, the control device 9 moves the column holder 2 forward FR relative to the base bracket 1, and moves the upper column 5 forward FR relative to the lower column 3.

[0068] When the direction of the load detected by the load sensor 55 is rearward RR, the control device 9 moves the column holder 2 rearward RR relative to the base bracket 1, and moves the upper column 5 rearward RR relative to the lower column 3.

[0069] The control device 9 may drive either the lower telescopic motor 60 or the upper telescopic motor 70, or may drive both. By driving both, the steering column device 100 can quickly adjust the position of the steering wheel 200 in the fore-and-aft direction.

[0070] The steering shaft 220 expands and contracts together with the steering column 10 as the inner shaft 221 and the outer shaft 222 move relative to each other in the front-to-rear direction. As a result, the position of the steering wheel 200 in the front-to-rear direction is adjusted.

[0071] The control device 9 adjusts the position of the steering wheel 200 in the front-to-rear direction until the load sensor 55 no longer detects a load. After the position of the steering wheel 200 has been adjusted, the driver sets the operation mode of the control device 9 from the adjustment mode to the normal mode. When the operation mode of the control device 9 is set to the normal mode, the control device 9 does not adjust the position of the steering wheel 200.

[0072] [Operation of the steering column device 100 (2)] When the driver wants to adjust the up-down angle of the steering wheel 200, he sets the control device 9 from normal mode to adjustment mode and applies force to the steering wheel 200 in the direction he wants to move the steering wheel 200 (upward UP or downward LWR).

[0073] The load sensor 55 detects the magnitude and direction of the relative load in the vertical direction acting on the upper column 5 and the outer shaft 222. The control device 9 obtains the magnitude and direction of the load detected by the load sensor 55.

[0074] The control device 9 drives the tilt motor 80 to move the lower column 3 in the up and down direction based on the magnitude and direction of the load detected by the load sensor 55. As a result, the angle of the steering wheel 200 in the up and down direction is adjusted.

[0075] When the direction of the load detected by the load sensor 55 is upward UP, the control device 9 moves the lower column 3 upward UP relative to the column holder 2.

[0076] When the direction of the load detected by the load sensor 55 is the downward LWR, the control device 9 moves the lower column 3 downward LWR relative to the column holder 2.

[0077] The control device 9 adjusts the angle of the steering wheel 200 in the vertical direction until the load sensor 55 no longer detects a load. After the angle of the steering wheel 200 has been adjusted, the driver sets the operation mode of the control device 9 from the adjustment mode to the normal mode. When the operation mode of the control device 9 is set to the normal mode, the control device 9 does not adjust the angle of the steering wheel 200.

[0078] The control device 9 can adjust the position of the steering wheel 200 in the front-rear direction and the angle of the steering wheel 200 in the up-down direction simultaneously or separately.

[0079] According to the steering column device 100 of this embodiment, the load sensor 55 is disposed in a position close to the steering wheel 200, and therefore can detect the load applied to the steering wheel 200 by the driver with higher accuracy. The load sensor 55 can detect loads in the front-rear direction as well as loads in the up-down direction. Furthermore, the load sensor 55 is not provided on the second threaded shaft 72, and there is no need to make the length of the second threaded shaft 72 longer than is necessary for functionality.

[0080] According to the steering column device 100 of this embodiment, it is desirable to place the load sensor 55 in a bearing portion that supports the steering shaft 220 connected to the steering wheel 200. Furthermore, if there are multiple bearing portions that support the steering shaft 220, it is desirable to place the load sensor 55 in a bearing portion that is closest to the steering wheel 200. The reason for this will be explained using Figs. 8 to 10.

[0081] 8 is a diagram that schematically shows a steering column device 100 equipped with a telescopic mechanism. One end of a lower column 3 is fixed to the vehicle body via a base bracket 1. A front side FR of an upper column 5 is connected to a rear side RR of the lower column 3 so as to be movable in the front-rear direction. Specifically, the upper column 5 is supported by a pad 36a and a pad 36b that are fixed to the upper column 3 so as to be movable in the front-rear direction.

[0082] A steering shaft 220 is connected to the rear RR side of the upper column 5 so as to be rotatable but not movable in the front-to-rear direction. Specifically, the steering shaft 220 is rotatably supported by the upper column 5 by a first bearing portion 51 and a second bearing portion 52. Rotary bearings such as ball bearings and needle bearings can be used as the first bearing portion 51 and the second bearing portion 52.

[0083] An upper telescopic actuator 7 is disposed on the outer periphery of the lower column 3 and the outer periphery of the upper column 5. Fig. 8 is a schematic diagram showing the upper telescopic actuator 7 in a contracted state, and Fig. 9 is a schematic diagram showing the upper telescopic actuator 7 in an extended state. As shown in Fig. 9, the upper column 5 moves relative to the lower column 3 as the upper telescopic actuator 7 expands and contracts.

[0084] In other words, the load sensor 55 in the present disclosure is a sensor that detects a force in the radial direction R that occurs in a shaft-like member and the support portions (pads 36a, 36b, first bearing portion 51, and second bearing portion 52) that support the shaft-like member. That is, the load sensor 55 can be disposed at any position in the support portions (pads 36a, 36b, first bearing portion 51, and second bearing portion 52). However, as described above, it is desirable to dispose the load sensor 55 in a support portion that is closest to the steering wheel 200 among the support portions that support the space between the steering shaft 220 and the steering wheel 200. That is, it is desirable to dispose the load sensor 55 in the first bearing portion 51.

[0085] The reasons for this will be explained separately: (1) why it is desirable to place the load sensor between the steering shaft 220 and the upper column 5, and (2) why it is desirable to place the load sensor in a position close to the steering wheel 200.

[0086] (1) Why it is desirable to place the load sensor 55 between the steering shaft 220 and the upper column 5 In Figure 10, the distance from pad 36a to pad 36b is L34, the distance from pad 36a to steering wheel 220 is L3h, the distance from second bearing portion 52 to first bearing portion 51 is L21, and the distance from second bearing portion 52 to steering wheel 220 is L2h.

[0087] 10 shows the forces generated in the upper column 5 and steering shaft 220 when a downward force Fh is applied to the steering wheel 200. In Fig. 10, arrows F3 and F4 indicate forces acting on the upper column 5, and arrows F1 and F2 indicate forces acting on the steering shaft 220. Between the upper column 5 and the steering shaft 220, a compressive force F2 is generated above the second bearing portion 52, and a compressive force F1 is generated below the first bearing portion 51. Between the lower column 3 and the upper column 5, a compressive force F3 is generated above the pad 36a, and a compressive force F4 is generated below the pad 36b.

[0088] In FIG. 10, when the balance between the forces and moments acting on the upper column 5 is taken into consideration, the following relationship holds between the force Fh applied to the steering wheel, the compressive force F3 acting above the pad 36a, and the compressive force F4 acting below the pad 36b.

[0089]

number

[0090]

number

[0091] By solving equations 1 and 2 for Fh, the following equation 3 is derived.

[0092]

number

[0093] Here, in Equation 3, the coefficients by which F3 and F4 are multiplied include L3h, which is the distance from the pad 36a to the steering wheel 200, and therefore change depending on the position of the steering wheel 200. In other words, if the load sensor 55 is disposed between the lower column 3 and the upper column 5, the amount of expansion and contraction of the upper telescopic actuator 7 will affect the detected value of the load Fh.

[0094] In Figure 10, when considering the balance of forces and moments acting on the steering shaft 220, the following relationship holds between the force Fh applied to the steering wheel, the compressive force F1 acting above the second bearing portion 52, and the compressive force F2 acting below the first bearing portion 51.

[0095]

number

[0096]

number

[0097] By solving equations 1 and 2 for Fh, the following equation 6 is derived.

[0098]

number

[0099] Here, in equation 6, the coefficients by which F1 and F2 are multiplied are constant regardless of the position of the steering wheel 200. In other words, when the load sensor 55 is disposed between the upper column 5 and the steering shaft 220, the amount of extension and contraction of the upper telescopic actuator 7 does not affect the detection of the load Fh. Therefore, it is desirable to dispose the load sensor 55 between the upper column 5 and the steering shaft 220.

[0100] (2) Why it is desirable to place the load sensor close to the steering wheel 200 Equation 6 is rearranged for F1 to derive equation 7.

[0101]

number

[0102] Equation 6 is rearranged for F2 to derive equation 8.

[0103]

number

[0104] Comparing the coefficients by which Fh is multiplied in Equation 7 and Equation 8, the coefficient in Equation 8 is smaller. This means that the fluctuation in F2 when the same steering load Fh is applied is smaller than the fluctuation in F1. In other words, when using a load sensor 55 with the same resolution (ratio of output to load), detecting F1 allows the steering load Fh to be detected with higher accuracy than detecting F2. Therefore, it is desirable to arrange the load sensor 55 in the first bearing portion 51 closer to the steering wheel 200.

[0105] Although the first embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the present invention. Furthermore, the components shown in the above-described embodiment and modifications can be configured by appropriately combining them.

[0106] (Variation 1) In the above embodiment, the steering column device 100 has a telescopic mechanism that extends and retracts in two stages. However, the form of the telescopic mechanism is not limited to this. The steering column device 100 may also have a telescopic mechanism that extends and retracts in one stage.

[0107] (Variation 2) In the above embodiment, the first bearing portion 51 (bearing portion) has a bearing 54 and a load sensor 55. However, the aspect of the first bearing portion 51 (bearing portion) is not limited to this. If the outer shaft 222 can be rotatably supported by the load sensor 55 formed in a ring shape, the load sensor 55 does not need to be connected to the outer shaft 222 via the bearing 54.

[0108] (Variation 3) In the above embodiment, the movement of the load sensor 55 in the forward FR direction is limited by the engaging protrusion 5t formed on the upper column 5, and the movement of the load sensor 55 in the rearward RR direction is limited by the engaging recess 222a formed on the outer shaft 222. However, the manner in which the movement of the load sensor 55 in the front-to-rear direction is limited is not limited to this. The movement of the load sensor 55 in the forward FR direction may be limited by the engaging recess 222a formed on the outer shaft 222, and the movement of the load sensor 55 in the rearward RR may be limited by the engaging protrusion 5t formed on the upper column 5. [Industrial Applicability]

[0109] The present invention can be applied to a steering column device. [Explanation of symbols]

[0110] 300 Steering device (steering device) 220 steering shaft 200 Steering wheel (input mechanism) 100 Steering column device 10. Steering column 1 base bracket 2 Column holder 3 Lower Column (First Column) 4 Innacolumn 5 Upper Column (Second Column) 51 First bearing part (bearing part) 52 Second bearing part 54 bearings 55 Load sensor 6 Lower telescopic actuator 7 Upper telescopic actuator 8 Tilt actuator 9 Control Device

Claims

1. A steering column supporting a steering shaft is provided. the steering column has a bearing portion on the steering wheel side that rotatably supports the steering shaft, the bearing portion has a load sensor, the steering column includes a base bracket, a first column movable in a front-to-rear direction relative to the base bracket, and a second column movable in a front-to-rear direction relative to the first column, the second column is provided closer to the steering wheel than the first column, the bearing portion is provided on the second column, the load sensor is a ring-shaped load cell, and is sandwiched between the second column and the steering shaft via a bearing, and movement of the load sensor together with the bearing in the forward / backward direction is limited; Steering column device.

2. The bearing portion is disposed between the steering shaft and the steering column in the radial direction. The steering column device according to claim 1 .

3. The bearing portion further includes a bearing, The load sensor is connected to the steering shaft via a bearing. The steering column device according to claim 2 .

4. The load sensor is Forward movement is limited by one of the steering column and the steering shaft, Rearward movement is limited by the other of the steering column and the steering shaft.

4. The steering column device according to claim 2 or 3.

5. a second bearing portion different from the bearing portion is provided between the second column and the steering shaft, the bearing portion and the second bearing portion support the second column and the steering shaft, 5. The steering column device according to claim 1, wherein the bearing portion is disposed closer to the steering wheel than the second bearing portion.

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