Steering device and steer-by-wire steering system

Abstract

To provide low-cost steering device that can quickly execute a tilt adjustment, a telescopic adjustment and a retractable operation by combining two actuators with a crank mechanism, and to provide a steer-by-wire type steering system.SOLUTION: A steering device includes: a fastening bracket 12 attached to a vehicle body; a steering shaft 20; and a steering jacket 30 that internally supports the steering shaft 20 so as to be freely rotatable. This steering device further includes: a first actuator 70 which is placed between the fastening bracket 12 and a lower column 32, and which displaces the lower column 32 in the axial direction; a second actuator 80 which is placed between the lower column 32 and an upper column 31, and which displaces the upper column 31 in the axial direction; and a crank mechanism 43 which is placed between the lower column 32 and a swing column 40, and which causes the swing column 40 to swing in accordance with the relative displacements of the upper column 31 and of the lower column 32 in the axial direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a steering device and a steer-by-wire steering system, and more particularly to a steering device and a steer-by-wire steering system in which the steering wheel can be adjusted in the front-rear direction, the up-down direction, and the steering wheel can be stored. [Background technology]

[0002] In conventional automobiles, mechanisms have been proposed that allow the position of the steering wheel to be adjusted in the forward / backward and vertical directions to suit each driver, in order to facilitate driving operations. Furthermore, in recent years, autonomous driving technology for automobiles has rapidly advanced, and it is believed that in the near future, the level of autonomous driving will reach levels where automobiles can drive themselves under certain conditions (Levels 3 and 4), or even fully autonomous driving (Level 5). In automobiles equipped with such autonomous driving functions, the driver will no longer need to operate the steering wheel. Therefore, with the aim of improving comfort by expanding the interior space, development is underway on steering devices with the ability to store the steering wheel inside the dashboard. In this specification, adjustment of the steering wheel in the front-to-rear direction is also referred to as "telescopic adjustment," and adjustment of the steering wheel in the up-and-down direction is also referred to as "tilt adjustment" (telescopic is a registered trademark).

[0003] Patent Document 1 discloses a steering device in which three jackets, an upper jacket, a middle jacket, and a lower jacket, are combined in a telescopic manner to ensure sufficient extension and contraction of the overall length, allowing for tilt adjustment / telescopic adjustment as well as a retractable function to store the steering wheel.

[0004] Furthermore, Patent Document 2 discloses a steering device that aims to make efficient use of an electric motor, in which a transmission rod rotated by the electric motor is moved to change the combination of a gear that is rotationally driven by the electric motor and a mating gear that meshes with that gear, thereby enabling steering operation assistance, telescopic adjustment, and tilt adjustment using a crank mechanism. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] US Patent Application Publication No. 2019 / 210632 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-199350 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in steering devices with a retractable function, the stroke in the forward and backward directions is longer than that of conventional devices, which results in a longer waiting time when moving the steering wheel from the storage position to the driving position, or vice versa. Furthermore, in a steering device with a retractable function, if the telescopic actuator breaks while the steering wheel is being stored, it may become impossible to remove the steering wheel.

[0007] Furthermore, the steering device disclosed in Patent Document 1 requires a total of three independent actuators for tilt, telescoping, and retraction, leaving room for improvement in terms of manufacturing costs and flexibility in device layout.

[0008] The steering device disclosed in Patent Document 2 requires a tilt / telescope switching operation, and tilt / telescope operations cannot be performed simultaneously. This makes it difficult to quickly move the steering wheel to a predetermined position, and furthermore, the steering wheel cannot be retracted.

[0009] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a low-cost steering device and a steer-by-wire steering system that can quickly perform tilt adjustment, telescopic adjustment, and retractable operation. [Means for solving the problem]

[0010] The above object of the present invention can be achieved by the following configuration. (1) a fixing bracket attached to the vehicle body; a steering shaft to which a steering wheel is connected; a steering jacket that is held by the fixed bracket and that rotatably supports the steering shaft inside, the steering jacket includes an upper column, a lower column, and a fixed column, which are arranged in this order from the steering wheel side and which are combined to allow relative displacement in the axial direction, and a swinging column which is swingably supported by the upper column, a first actuator disposed between the fixed bracket or the fixed column and the lower column, and configured to displace the lower column in the axial direction relative to the fixed column; a second actuator disposed between the lower column and the upper column and configured to displace the upper column in the axial direction relative to the lower column; a crank mechanism that is disposed between the lower column and the swing column and swings the swing column relative to the upper column in response to relative displacement between the upper column and the lower column in the axial direction; A steering device comprising: (2) The crank mechanism is a first arm portion fixed to the lower column and extending radially outward; a second arm portion fixed to the swing column and extending radially outward; The steering device according to (1), further comprising: a connecting rod whose both ends are rotatably connected to the first arm portion and the second arm portion. (3) A steering device as described in (2), wherein the second arm portion has a pair of steel plates with one end fixed to both the left and right sides of the oscillating column, and the pair of steel plates are integrally connected to each other between the one end and the other end that pivotally supports the end of the connecting rod. (4) The first actuator has a first motor disposed on the fixed bracket, and moves the lower column in the axial direction relative to the fixed column attached to the fixed bracket, The steering device according to any one of (1) to (3), wherein the second actuator has a second motor disposed in the lower column and moves the upper column in the axial direction relative to the lower column. (5) The steering device according to any one of (1) to (4), wherein the second actuator is operable simultaneously with the first actuator. (6) A steering device according to any one of (1) to (5), a sensor for measuring the steering amount of the steering wheel; a steering device having an actuator driven based on an output signal from the sensor, for applying a steering angle to a pair of steering wheels; A steer-by-wire steering system. [Effects of the Invention]

[0011] According to the steering device and steer-by-wire steering system of the present invention, by combining two actuators and a crank mechanism, the number of actuators is reduced to two, reducing costs, and tilt adjustment, telescopic adjustment, and retractable operation can be performed quickly. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram of a steer-by-wire steering system incorporating a steering device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of the steering device shown in FIG. [Figure 3] FIG. 3 is a left side view of the steering device shown in FIG. [Figure 4] 4 is a right side view of the steering device shown in FIG. 2. FIG. [Figure 5] FIG. 5 is a view taken along the arrow V in FIG. 3 with the steering wheel removed. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] FIG. 8 is an explanatory diagram for explaining the telescopic operation, where (a) is a left side view of the steering device in the telescopic reference position, (b) is a left side view of the steering device with the steering wheel moved upward, and (c) is a left side view of the steering device with the steering wheel moved downward. [Figure 9] FIG. 9 is an explanatory diagram for explaining tilt operation, where (a) is a left side view of the steering device with the steering wheel in the reference position, (b) is a left side view of the steering device with the steering wheel tilted upward, and (c) is a left side view of the steering device with the steering wheel tilted downward. [Figure 10] FIG. 10 is a left side view of the steering device in the stored state. [Figure 11] FIG. 11 is a perspective view of a steering device according to a second embodiment of the present invention. [Figure 12] FIG. 12 is a left side view of the steering device shown in FIG. [Figure 13] FIG. 13 is a left side view of the steering device in the stored state. [Figure 14] FIG. 14 is a perspective view of a steering device according to a third embodiment of the present invention. [Figure 15] FIG. 15 is a left side view of the steering device shown in FIG. [Figure 16] FIG. 16 is a right side view of the steering device shown in FIG. [Figure 17] FIG. 17 is a bottom view of the steering device shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a steering device according to the present invention and a steer-by-wire steering system incorporating the steering device will be described in detail with reference to the accompanying drawings.

[0014] (First embodiment) As shown in Fig. 1, a steer-by-wire steering system 1 incorporating the steering device of the present invention comprises a steering device 3 having a steering wheel 2 and a sensor (not shown) for measuring the steering amount of the steering wheel 2, and a steering device 6 for applying a steering angle to a pair of steered wheels 5, which are electrically connected to each other. That is, in the steer-by-wire steering system 1, the amount of operation of the steering wheel 2 by the driver is measured by a sensor in the steering device 3. Then, based on the output signal of the sensor, an actuator 7 of the steering device 6 is driven to displace a linear shaft such as a rack shaft or a screw shaft arranged in the width direction of the vehicle in the width direction of the vehicle, thereby pushing and pulling a pair of tie rods 8 and applying a steering angle to the pair of steered wheels 5.

[0015] The steering device 3 includes a steering device 10, a steering shaft 20, and a reaction force applying device 60. Note that the front-to-rear direction, the up-to-down direction, and the width direction (left-to-right direction) of the steering device 3 refer to the front-to-rear direction, the up-to-down direction, and the width direction of the vehicle when the steering device 3 is attached to the vehicle.

[0016] As shown in FIGS. 2 to 7, the steering device 10 includes a steering column 11, a first actuator 70, and a second actuator 80.

[0017] The steering column 11 includes a fixed bracket 12, a displacement bracket 13, a linear guide 14, and a steering jacket 30, and is configured so that its overall length can be extended or contracted. The steering jacket 30 is held by the fixed bracket 12 and includes an upper column 31, a lower column 32, and a fixed column 33, which are arranged in this order from the steering wheel 2 side and are combined to allow relative displacement in the axial direction, and a swinging column 40, which is located on the opposite side of the upper column 31 from the lower column 32 in the axial direction and is supported by the upper column 31 so as to be swingable.

[0018] Specifically, the fixed bracket 12 is supported and fixed to a vehicle body (not shown) by a plurality of mounting bolts 15. The displacement bracket 13 is integrally attached to the lower column 32 by a plurality of bolts 16 (see FIG. 4). The displacement bracket 13 is combined with the fixed bracket 12 via a linear guide 14 so as to be capable of relative displacement in the axial direction, and is displaced in the axial direction together with the lower column 32. The displacement bracket 13 may be supported by another guide device, instead of the linear guide 14, so as to be displaceable relative to the fixed bracket 12.

[0019] 6, the lower column 32 is formed in a substantially cylindrical shape and has a large diameter portion 34 in its front portion, and a small diameter portion 35 in its rear portion, the inside diameter of which is smaller than that of the large diameter portion 34. The lower column 32 also has a slit 36 ​​extending in the axial direction on the underside of an axially intermediate portion (the portion from the rear portion of the large diameter portion 34 to the front end portion of the small diameter portion 35), and screw plugs 37a, 37b, to which pads made of a material with a low friction coefficient such as polyacetal (POM) are adhesively fixed, are provided at the front end portion of the large diameter portion 34 and the front end portion of the small diameter portion 35 so as to be adjustable in position in the radial direction of the lower column 32. A first arm portion 38 extending downward in a direction substantially perpendicular to the axis of the lower column 32 is fixedly provided at the rear portion of the lower column 32.

[0020] Furthermore, the fixed column 33 includes a cylindrical portion 33a and a flange portion 33b bent radially outward from the front end of the cylindrical portion 33a, with the rear portion of the cylindrical portion 33a being fitted into the large diameter portion 34 of the lower column 32 with a clearance fit, and the pad of the screw plug 37a on the front side of the lower column 32 abutting against the outer circumferential surface of the front portion of the cylindrical portion 33a. In this way, the fixed column 33 is fitted into the lower column 32 so that the lower column 32 is capable of relative displacement in the axial direction with respect to the fixed column 33. Furthermore, when the fixed column 33 and the lower column 32 are displaced relative to each other in the axial direction, the sliding friction force between the pad of the screw plug 37a and the outer circumferential surface of the cylindrical portion 33a can be adjusted.

[0021] The housing 61 of the reaction force applying device 60 is fixed to the flange portion 33b of the fixed column 33 by fixing bolts, and is also fixed to the fixed bracket 12. In other words, the fixed column 33 is fixed to the fixed bracket 12 via the housing 61 of the reaction force applying device 60.

[0022] The upper column 31 has a generally cylindrical shape, and is assembled to the lower column 32 so as to be able to move relative to the lower column 32 in the axial direction. Specifically, the front portion of the upper column 31 is clearance-fitted into the small diameter portion 35 of the lower column 32, and the pad of the screw plug 37b provided on the rear side of the lower column 32 abuts against the outer circumferential surface of the front portion of the upper column 31. In this way, the upper column 31 is fitted into the lower column 32 so as to be able to move relative to the lower column 32 in the axial direction. The inner diameter of the fixed column 33 is equal to or larger than the outer diameter of the upper column 31, so that they do not interfere with each other when displaced in the axial direction.

[0023] Furthermore, the upper column 31 rotatably supports the second steering shaft 23, which will be described later, via a pair of rolling bearings 39 disposed inside. By adjusting the position of the pad of the screw plug 37b in the radial direction, the upper column 31 can adjust the sliding friction force between the pad of the screw plug 37b and the outer peripheral surface of the upper column 31 when the upper column 31 and the lower column 32 are displaced relative to each other in the axial direction.

[0024] A swing column 40 is supported by a support shaft 49 on the rear portion of the upper column 31 so as to be swingable up and down. The rear portion of the upper column 31 has flat, plate-shaped connected portions 31b that branch off to the left and right sides from a cylindrical portion 31a and extend rearward. The swing column 40 includes a main body 40a formed in a substantially cylindrical shape, and flat, plate-shaped connecting portions 40b that extend forward from both the left and right sides of the main body 40a and cover the connected portions 31b of the upper column 31 from the left and right. A second arm 42 is fixed integrally to the connecting portion 40b, and extends further downward from the connecting portion 40b in a direction perpendicular to the axis of the swing column 40. The main body 40a rotatably supports a first steering shaft 21 (described later) via a pair of rolling bearings 41 arranged inside.

[0025] The lower column 32 and the oscillating column 40 are connected by a crank mechanism 43. The crank mechanism 43 includes a first arm 38 fixed to the lower column 32 and extending radially outward, a second arm 42 fixed to the oscillating column 40 and extending radially outward, and a connecting rod 44 of a predetermined length, both ends of which are rotatably connected to the first arm 38 and the second arm 42. An end 44a of the connecting rod 44 on the first arm 38 side is rotatably connected to the first arm 38 by a pin 46, and an end 44b of the connecting rod 44 on the second arm 42 side is rotatably connected to the second arm 42 by a shaft 47.

[0026] As shown in FIG. 5, the second arm 42 is formed by a pair of steel plates 48a, 48b. One end (upper end) of the pair of steel plates 48a, 48b is fixed to the left and right side surfaces of the connecting portion 40b of the oscillating column 40, respectively, and the other end (lower end) covers the left and right side surfaces of the end 44b of the connecting rod 44 on the second arm 42 side and pivotally supports the shaft 47 formed on the end 44b on the second arm 42 side. The pair of steel plates 48a, 48b are bent so that one end and the other end come into contact with each other and are integrally joined to each other by welding or the like. This eliminates misalignment of the pair of steel plates 48a, 48b relative to each other, facilitating assembly of the shaft 47 of the end 44b on the second arm 42 side and ensuring smooth cranking. In this embodiment, the shaft portion 47 is configured by an actuator nut attached to the end portion 44b on the second arm portion 42 side.

[0027] 4 and 5 , the first actuator 70 has a first motor 71, and uses the first motor 71 as a drive source to axially displace the displacement bracket 13 and the lower column 32 fixed to the displacement bracket 13 relative to the fixed bracket 12. The first motor 71 is supported and fixed to the right side surface of the fixed bracket 12 with the axis of the rotation shaft of the first motor 71 facing in the vertical direction perpendicular to the axis of the steering jacket 30.

[0028] The first actuator 70 further includes a feed screw device 72 for converting the rotational motion of the output shaft of the first motor 71 into linear motion. The feed screw device 72 includes a screw shaft 73 having a male thread on its outer circumferential surface and being driven to rotate by the first motor 71, and a nut 74 having a female thread on its inner circumferential surface that screws into the male thread.

[0029] The screw shaft 73 is supported only rotatably relative to the fixed bracket 12, and the nut 74 is supported and fixed to the displacement bracket 13. Therefore, when the first motor 71 drives and rotates the screw shaft 73 via a reduction mechanism such as a worm reducer, the nut 74 is displaced in the front-to-rear direction along the screw shaft 73, and the displacement bracket 13, together with the lower column 32 fixed to the displacement bracket 13, is displaced in the axial direction of the fixed bracket 12, i.e., in the front-to-rear direction, relative to the fixed bracket 12.

[0030] 2 and 6, the second actuator 80 has a second motor 81, and uses the second motor 81 as a drive source to displace the upper column 31 in the axial direction relative to the displacement bracket 13. The second motor 81 is supported and fixed to the underside of the lower column 32 with the axis of the rotation shaft of the second motor 81 facing in the left-right direction, perpendicular to the axis of the steering jacket 30.

[0031] The second actuator 80 further has a feed screw device 82 for converting the rotational motion of the output shaft of the second motor 81 into linear motion. The feed screw device 82 includes a screw shaft 83 having a male thread portion on its outer circumferential surface and being rotationally driven by the second motor 81, and a nut 84 having a female thread portion on its inner circumferential surface that screws into the male thread portion.

[0032] The screw shaft 83 is supported so as to be rotatable only relative to the lower column 32, and the nut 84 is supported and fixed to the upper column 31. Specifically, the screw shaft 83 is supported so as to be rotatable only by the underside of the front portion of the large diameter portion 34 of the lower column 32 and the underside of the rear portion of the displacement bracket 13, and the nut 84 is attached to the underside of the front portion of the upper column 31, and is supported and fixed to the upper column 31 via a support portion 85 that protrudes downward from a slit 36 ​​formed in the underside of the lower column 32.

[0033] Therefore, when the second motor 81 drives the screw shaft 83 to rotate via a reduction mechanism such as a worm reducer, the nut 84 is displaced in the front-to-rear direction along the screw shaft 83, and the upper column 31 is displaced in the axial direction of the lower column 32, i.e., in the front-to-rear direction, relative to the lower column 32.

[0034] The steering shaft 20 has a first steering shaft 21 connected to the steering wheel 2 from the steering wheel 2 side, a second steering shaft 23 connected to the first steering shaft 21 via a universal joint 22, and an inner shaft 24 combined with the second steering shaft 23 so as to allow relative axial displacement but not relative rotation. That is, the second steering shaft 23 is fitted onto the inner shaft 24, and the rear portion of the inner shaft 24 and the front portion of the second steering shaft 23 are spline-fitted.

[0035] As described above, the first steering shaft 21 is rotatably supported inside the main body 40a of the oscillating column 40 via a pair of rolling bearings 41. In addition, the second steering shaft 23 is rotatably supported inside the upper column 31 via a pair of rolling bearings 39. Therefore, the steering shaft 20 expands and contracts in accordance with the expansion and contraction of the steering column 11.

[0036] Furthermore, the shaft portion extending to the left and right of the universal joint 22 is disposed coaxially with support shafts 49 provided on the left and right side surfaces of the swing column 40. Therefore, the first steering shaft 21 swings relative to the second steering shaft 23 in accordance with the swing of the swing column 40 relative to the upper column 31.

[0037] The steering wheel 2 is supported on the rear end of the steering shaft 20, i.e., the rear end of the first steering shaft 21. A reaction force imparting device 60 for imparting an operation reaction force to the steering wheel 2 is connected to the front end of the steering shaft 20, i.e., the front end of the inner shaft 24.

[0038] The reaction force application device 60 includes a housing 61, a reaction force application motor (not shown), and a reducer. When the driver operates the steering wheel 2, the reaction force application device 60 drives the reaction force application motor, and the torque of the reaction force application motor is increased by the reducer housed inside the housing 61 and then applied to the steering shaft 20. In this way, an operation reaction force is applied to the steering wheel 2. The magnitude of the reaction force applied to the steering wheel 2 is determined depending on the steering angle of the steering wheel 2 acquired by a sensor, the torque applied to the steering shaft 20, and other factors. The reducer is configured by, for example, a worm reducer.

[0039] Next, the operation of the steering device 10 will be described in detail with reference to Figures 8 to 10. Figures 8(a) to 8(c) are explanatory views for explaining the telescopic operation of the steering device 10, where Figure 8(a) is a left side view of the steering device 10 with the steering wheel 2 in the reference position (neutral position), Figure 8(b) is a left side view of the steering device 10 with the steering wheel 2 moved rearward, and Figure 8(c) is a left side view of the steering device 10 with the steering wheel 2 moved forward.

[0040] As shown in (a) of Figure 8, when the steering device 10 is in the reference position, the lower column 32 and the upper column 31 are each in a neutral position so that the lower column 32 can extend and retract relative to the fixed column 33, and the upper column 31 can extend and retract relative to the lower column 32.

[0041] In this reference position, if the mounting position of the reaction force applying device 60 is taken as reference point P, the length from reference point P to the rear end P1 of the lower column 32 is taken as A, the length from the rear end P1 to the support shaft 49 of the oscillating column 40 is taken as B, and the length from reference point P to the steering wheel 2 is taken as E.

[0042] When moving the steering wheel 2 in the above-mentioned reference position rearward (telescopic adjustment), as shown in FIG. 8(b), the second motor 81 is not energized, that is, the length B from the rear end P1 to the support shaft 49 of the oscillating column 40 is kept constant, and the first motor 71 is energized to rotate the screw shaft 73 of the feed screw device 72, thereby displacing the nut 74 rearward, and thereby moving the lower column 32 axially rearward relative to the fixed bracket 12.

[0043] As a result, the length A from the reference point P to the rear end P1 changes from length A to A1, and extends rearward by length C. Accordingly, the steering wheel 2 also moves rearward by length C. In other words, the steering wheel 2 is telescopically adjusted rearward. After the fore-and-aft position of the steering wheel 2 has been adjusted to the desired position, power to the first motor 71 is stopped.

[0044] Furthermore, when the steering wheel 2 in the reference position is moved forward (telescopic adjustment), as shown in FIG. 8(c), the second motor 81 is not energized, that is, the length B from the rear end P1 to the support shaft 49 of the oscillating column 40 is kept constant, and the first motor 71 is energized to rotate the screw shaft 73 of the feed screw device 72, thereby displacing the nut 74 forward and moving the lower column 32 axially forward relative to the fixed bracket 12.

[0045] As a result, the length A from the reference point P to the rear end P1 changes from length A to A2, shortening by length D. Accordingly, the steering wheel 2 also moves forward by length D. In other words, the steering wheel 2 is telescopically adjusted forward. After the fore-and-aft position of the steering wheel 2 has been adjusted to the desired position, power supply to the first motor 71 is stopped. Therefore, by driving only the first actuator 70, only the telescopic adjustment can be performed.

[0046] Next, tilt adjustment will be described. Figures 9(a) to 9(c) are explanatory views for explaining the tilt operation of the steering device 10. Figure 9(a) is the same as Figure 8(a) and is a left side view of the steering device 10 with the steering wheel 2 in the reference position, Figure 9(b) is a left side view of the steering device 10 with the steering wheel 2 tilted upward, and Figure 9(c) is a left side view of the steering device 10 with the steering wheel 2 tilted downward.

[0047] When tilting the steering wheel 2 in the reference position shown in (a) of Figure 9 upward (tilt adjustment), as shown in (b) of Figure 9, the second motor 81 is energized to rotate the screw shaft 83 of the feed screw device 82, displacing the nut 84 forward, thereby moving the upper column 31 axially forward relative to the lower column 32. As a result, the length B is shortened to the length F.

[0048] When the distance between the lower column 32 and the upper column 31 is shortened, the second arm 42 rotates counterclockwise in the figure about the support shaft 49 due to the action of the crank mechanism 43, which has a connecting rod 44 of a fixed length, thereby tilting the steering wheel 2 upward. Then, after the vertical position of the steering wheel 2 has been adjusted to the desired position, the power supply to the second motor 81 is stopped.

[0049] Furthermore, this tilt adjustment causes the upper column 31 to move forward in the axial direction relative to the lower column 32, and as a result the position of the steering wheel 2 moves forward by that movement length, shortening the distance from the reference point P. In other words, the second motor 81 simultaneously performs telescopic adjustment and tilt adjustment. Therefore, the first motor 71 is energized to correct this by moving the lower column 32 rearward in the axial direction relative to the fixed bracket 12 by the shortened length G (G = BF), and the steering wheel 2 is maintained in its original position. Of course, this correction may be performed only when necessary, and may also be omitted.

[0050] 9(a) to tilt downward (tilt adjustment), the second motor 81 is energized to rotate the screw shaft 83 of the feed screw device 82, displacing the nut 84 rearward, thereby moving the upper column 31 axially rearward relative to the lower column 32, as shown in FIG. 9(c). This increases the length B to a length H.

[0051] When the length between the lower column 32 and the upper column 31 that form one side of the crank mechanism 43 becomes longer, the second arm 42 rotates clockwise in the figure around the support shaft 49 due to the action of the crank mechanism 43, which has a connecting rod 44 of a fixed length, and the steering wheel 2 tilts downward. Then, after the vertical position of the steering wheel 2 has been adjusted to the desired position, the power supply to the second motor 81 is stopped.

[0052] Furthermore, this tilt adjustment causes the upper column 31 to move rearward in the axial direction relative to the lower column 32, which in turn moves the position of the steering wheel 2 rearward by that amount, increasing the distance from the reference point P. Therefore, by energizing the first motor 71 and moving the lower column 32 forward in the axial direction relative to the fixed bracket 12 by a length J (J = HB), the increased length is corrected and the steering wheel 2 is maintained in its original position. Of course, this correction work may be performed only when necessary and may also be omitted.

[0053] Next, stowing of the steering wheel 2 will be described with reference to Figure 10. When stowing the steering wheel 2 inside the dashboard or the like, the first motor 71 is energized to move the lower column 32 axially forward to its maximum extent relative to the fixed bracket 12, and the second motor 81 is energized to move the upper column 31 axially forward to its maximum extent relative to the lower column 32. As a result, the steering wheel 2 moves forward (telescopically) by the total length of the axial forward movement of the lower column 32 and the upper column 31. At the same time, the steering wheel 2 is rotated counterclockwise in the figure by a maximum angle due to the action of the crank mechanism 43, and reaches the stowing state shown in Figure 10. Note that in the figure, the dashed-dotted line X represents, as an example, a portion of the front position of the dashboard.

[0054] The first motor 71 and the second motor 81 can be operated simultaneously or independently. By operating the first motor 71 and the second motor 81 simultaneously, tilt adjustment and telescopic adjustment by the second motor 81 and telescopic adjustment by the first motor 71 can be performed simultaneously, allowing the retraction of the steering wheel 2 to be performed quickly and shortening the waiting time for retracting the steering wheel. Similarly, the movement of the steering wheel 2 from the retracted position to the driving position can also be performed quickly. The steering wheel 2 is not limited to the circular shape shown in the figure, and may be of any size and shape that is easy to store. Furthermore, the connecting rod 44 does not expand or contract when operated by either the first motor 71 or the second motor 81, and has a fixed length.

[0055] As described above, according to the steering device 10 of this embodiment, whereas conventional mechanisms require a total of three actuators, two actuators for telescoping and one actuator for tilting, by combining two actuators with a crank mechanism, it is possible to configure the steering device 10 with tilt adjustment, telescoping adjustment, and retractable operation, thereby significantly reducing the cost of the steering device 10. Furthermore, the telescoping adjustment length is the total length of the adjustment lengths of the two actuators (first actuator and second actuator), and the telescoping adjustment length can be longer compared to a steering device 10 with one telescoping actuator.

[0056] Furthermore, by operating the two actuators simultaneously to perform telescopic adjustment and tilt adjustment simultaneously, the position of the steering wheel 2 can be adjusted quickly and in a short time. The telescopic adjustment (adjustment of the front-to-rear position) and tilt adjustment (adjustment of the up-to-down position) of the steering wheel 2 can be performed simultaneously or independently. Furthermore, even if a malfunction such as a breakdown occurs in either the first actuator 70 or the second actuator 80, the telescopic adjustment of the steering wheel 2 can be performed by the other actuator.

[0057] (Second embodiment) Next, a steering device 10A according to a second embodiment of the present invention will be described with reference to Figures 11 to 13. The steering device 10A according to this embodiment differs from the steering device 10 of the first embodiment in that a crank mechanism 43 that connects the lower column 32 and the swing column 40 is disposed above the steering jacket 30. Note that parts that are the same as or equivalent to those in the first embodiment will be given the same or equivalent reference numerals, and descriptions thereof will be simplified or omitted.

[0058] Specifically, a first arm 38 is fixed to the rear portion of the lower column 32, extending upward in a direction approximately perpendicular to the axis of the lower column 32. Furthermore, a second arm 42 is fixed integrally to a connecting portion 40b of the oscillating column 40, extending upward in a direction perpendicular to the axis of the oscillating column 40. The tips of the first arm 38 and the second arm 42 are connected to each other by a connecting rod 44 so as to be able to swing freely.

[0059] 13, according to the steering device 10 of this embodiment, the first motor 71 is energized to move the lower column 32 axially forward to its maximum extent relative to the fixed bracket 12, and the second motor 81 is energized to move the upper column 31 axially forward to its maximum extent relative to the lower column 32. As a result, the steering wheel 2 is rotated by a maximum angle in the clockwise direction in the drawing, which is the opposite direction to the first embodiment, by the action of the crank mechanism 43, and moves axially forward to enter a stored state of the steering wheel 2. In this way, the steering wheel 2 is rotated downward by a maximum angle in the clockwise direction, and thus enters a state in which the steering wheel 2 can be easily stored in the dashboard. Other configurations and operations are the same as those of the steering device 10 of the first embodiment of the present invention.

[0060] (Third embodiment) Next, a steering device 10B according to a third embodiment of the present invention will be described with reference to Figures 14 to 17. The steering device 10B according to this embodiment differs from the steering device 10 according to the first embodiment in the layout of the first motor 71 and the second motor 81. Note that parts that are the same as or equivalent to those in the first embodiment are given the same or equivalent reference numerals, and descriptions thereof will be simplified or omitted.

[0061] Specifically, in the steering device 10 according to the first embodiment, the axes of the rotation shafts of the first motor 71 and the second motor 81 are both supported and fixed to the fixed bracket 12 and the lower column 32 so that they are perpendicular to the axis of the steering jacket 30. On the other hand, in the steering device 10B of the present embodiment, the axes of the rotation shafts of both the first motor 71 and the second motor 81 are arranged parallel to the axis of the steering jacket 30.

[0062] According to the steering device 10B of this embodiment, the first motor 71 and the second motor 81 of the two actuators 70, 80 are both arranged with the axis of the rotation shaft parallel to the axis of the steering jacket 30, so that the radial dimensions of the steering device 10, i.e., the dimensions in the vehicle width direction and the vertical direction, are reduced, improving layout flexibility. Other configurations and operations are the same as those of the steering device 10 of the first embodiment of the present invention.

[0063] The present invention is not limited to the above-described embodiments, and modifications and improvements are possible as appropriate. For example, in each of the above embodiments, an example has been described in which the steering device 10 is applied to the steering device 3 of a steer-by-wire steering system 1, but the steering device 10 of the present invention is not limited to this and can also be applied to a mechanical steering system in which the front end of the steering shaft 20 is mechanically connected to the input shaft (pinion shaft) of a steering gear unit via a universal joint or an intermediate shaft. Note that the mechanical steering system can be equipped with an assist device for reducing the force required for the driver to operate the steering wheel. In other words, the steering device 10 of the present invention can be applied to a power steering system such as an electric power steering system.

[0064] Furthermore, in the above embodiment, the connecting rod is connected to a first arm extending from the lower column and a second arm extending from the oscillating column, but the connecting rod may be connected directly to the lower column or the oscillating column as long as the connecting rod can be supported so as to be able to oscillate freely at a position offset in the vertical direction from the axial center of the lower column or the oscillating column.

[0065] In addition, in the above embodiment, the fixed column 33 is arranged on the inner peripheral side of the lower column 32, but the present invention is not limited to this, and the fixed column 33 may be arranged on the outer peripheral side of the lower column 32. Furthermore, in the above embodiment, the first actuator 70 is arranged between the fixed bracket 12 and the lower column 32, but the present invention is not limited to this, and the first actuator 70 may be arranged between the fixed column 33 and the lower column 32. [Explanation of symbols]

[0066] 1 Steer-by-wire steering system 2 steering wheels 5 steering wheel 6 Steering device 7 Steering device actuator 10, 10A, 10B Steering device 12 Fixing bracket 20 Steering shaft 30 Steering Jacket 31 Upper Column 32 Roar Column 33 Fixed Column 38 1st arm 40 Swinging column 42 Second arm 43 Crank mechanism 44 Connecting rod 48a, 48b steel plate 70 First Actuator 71 First motor 80 Second Actuator 81 Second motor

Claims

1. a fixing bracket attached to the vehicle body; a steering shaft to which a steering wheel is connected; a steering jacket that is held by the fixed bracket and that rotatably supports the steering shaft inside, the steering jacket includes an upper column, a lower column, and a fixed column, which are arranged in this order from the steering wheel side and which are combined to allow relative displacement in the axial direction, and a swinging column which is swingably supported by the upper column, a first actuator disposed between the fixed bracket or the fixed column and the lower column, and configured to displace the lower column in the axial direction relative to the fixed column; a second actuator disposed between the lower column and the upper column and configured to displace the upper column in the axial direction relative to the lower column; a crank mechanism that is disposed between the lower column and the swing column and swings the swing column relative to the upper column in response to relative displacement between the upper column and the lower column in the axial direction; A steering device comprising:

2. The crank mechanism includes: a first arm portion fixed to the lower column and extending radially outward; a second arm portion fixed to the swing column and extending radially outward; The steering device according to claim 1 , further comprising: a connecting rod whose opposite ends are rotatably connected to the first arm portion and the second arm portion.

3. 3. The steering device according to claim 2, wherein the second arm portion comprises a pair of steel plates having one end fixed to both left and right side surfaces of the oscillating column, and the pair of steel plates are integrally joined to each other between the one end and the other end that pivotally supports the end of the connecting rod.

4. the first actuator has a first motor disposed on the fixed bracket, and moves the lower column in the axial direction relative to the fixed column attached to the fixed bracket; 4. The steering device according to claim 1, wherein the second actuator has a second motor disposed in the lower column, and moves the upper column in the axial direction relative to the lower column.

5. 5. The steering device according to claim 1, wherein the second actuator is operable simultaneously with the first actuator.

6. A steering device according to any one of claims 1 to 5; a sensor for measuring the steering amount of the steering wheel; a steering device having an actuator driven based on an output signal from the sensor, for applying a steering angle to a pair of steering wheels; A steer-by-wire steering system.

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