Steering device

Abstract

A steering device (100) includes a first moving unit (110) that moves together with a shaft member (118) that connects an operation member (101) in an axial direction, a second moving unit (120), a holding unit (130), a first screw mechanism (140), a second screw mechanism (150), a driving unit (160), and a transmission mechanism (170) that transmits a driving force of the driving unit (160) to the first screw mechanism (140) and the second screw mechanism (150). One of the first screw mechanism (140) and the second screw mechanism (150) is provided to operate in a forward direction when the operation member (101) moves between a retracted region and an operation region, and a reverse rate of the one screw mechanism is set so that the one screw mechanism does not operate in a reverse direction when the operation member (101) is subjected to an external force directed toward the retracted region.

Description

Background of the Invention Technical Field

[0002] The present invention relates to a steering device that can move operating components such as a steering wheel to thereby expand the space in front of the driver. Background Technology

[0004] In Level 3 or higher driving automation, where the system assumes full responsibility for the vehicle's autonomous driving, the driver is not responsible for operating the vehicle and therefore does not need to hold control components such as the steering wheel. For example, Japanese Patent Application Publication No. 2017-206153 discloses a technique that moves control components and ensures ample space in front of the driver to improve driver comfort during autonomous driving. Summary of the Invention

[0005] Steering devices such as the aforementioned steering mechanisms, which allow the operating members to retract, require a locking mechanism to lock the movement of the operating members. However, providing a dedicated locking mechanism would complicate the device accordingly.

[0006] The present invention provides a steering device that can lock the movement of the operating component without being overly complicated.

[0007] A steering device according to a first aspect of the invention includes: an operating member that steers a vehicle; a first moving unit that moves along an axial direction of a shaft member together with the operating member at a rear end, and the first moving unit rotatably supports the shaft member; a second moving unit that holds the first moving unit so as to be movable in an axial direction; a retaining unit that holds the second moving unit so as to be movable in an axial direction; a first lead screw mechanism disposed between the first moving unit and the second moving unit, and the first lead screw mechanism moves the first moving unit in an axial direction; a second lead screw mechanism disposed between the second moving unit and the retaining unit, and the second lead screw mechanism moves the second moving unit in an axial direction; a drive unit that outputs a driving force for driving the first lead screw mechanism and the second lead screw mechanism; and a transmission mechanism connected to the first lead screw mechanism, the second lead screw mechanism and the drive unit, and the transmission mechanism transmits the driving force of the drive unit to the first lead screw mechanism and the second lead screw mechanism. The steering mechanism moves the operating member between the operating area and the retracted area. One of the first and second lead screw mechanisms is configured to operate in the forward direction when the operating member moves between the retracted and operating areas, and the reverse efficiency of the lead screw mechanism is set such that when the operating member is subjected to an external force pointing towards the retracted area, the lead screw mechanism does not operate in the reverse direction due to the external force.

[0008] A steering device according to a second aspect of the invention includes: an operating member that steers a vehicle; a first moving unit that moves along an axial direction of a shaft member connected to the operating member at a rear end, and the first moving unit rotatably supports the shaft member; a second moving unit that holds the first moving unit so that it can move axially; a retaining unit that holds the second moving unit so that it can move axially; a first lead screw mechanism disposed between the first moving unit and the second moving unit, and the first lead screw mechanism moves the first moving unit axially; a second lead screw mechanism disposed between the second moving unit and the retaining unit, and the second lead screw mechanism moves the second moving unit axially; a first drive unit that outputs a driving force for driving the first lead screw mechanism; and a second drive unit that outputs a driving force for driving the second lead screw mechanism. The steering device moves the operating member between an operating region and a retracted region. Each of the first and second lead screw mechanisms is configured to operate in the positive direction when the operating member moves between the retracted region and the operating region, and the reverse efficiency of each of the first and second lead screw mechanisms is set such that when the operating member is subjected to an external force pointing toward the retracted region, each of the first and second lead screw mechanisms does not operate in the reverse direction due to the external force.

[0009] The present invention can provide a steering device that can lock the movement of the operating component without being overly complicated. Attached Figure Description

[0010] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, in which the same reference numerals denote the same elements, and in the drawings:

[0011] Figure 1 This is a perspective view showing the appearance of the steering device according to an embodiment;

[0012] Figure 2 This is a schematic view showing the structure of the steering device according to an embodiment;

[0013] Figure 3 This is a perspective view showing a structure for supporting a first nut on a shell body according to an embodiment;

[0014] Figure 4 This is a schematic diagram showing the configuration of the clearance reduction mechanism according to the embodiment;

[0015] Figure 5This is a schematic diagram illustrating a structure for joining the first nut and the engagement portion together, according to a comparative example;

[0016] Figure 6 This is an exploded perspective view showing the various parts of the alignment mechanism according to the embodiment when disassembled.

[0017] Figure 7 This is an exploded perspective view showing the various parts of the alignment mechanism according to the embodiment when disassembled.

[0018] Figure 8 This is a schematic view showing the structure of the steering device according to an embodiment;

[0019] Figure 9 This is a block diagram illustrating the functional configuration of a steering device according to an embodiment; and

[0020] Figure 10 This is a block diagram illustrating the functional configuration of the steering device according to a modified example. Detailed Implementation

[0021] Embodiments and modifications of the steering device according to the present invention will now be described in detail with reference to the accompanying drawings. Each embodiment and modification described below represents a general or specific example. The numerical values, shapes, materials, constituent elements, arrangement and connection forms of constituent elements, steps, and order of steps shown in the following embodiments and modifications are all examples and are not intended to limit the present invention. Those constituent elements in the following embodiments and modifications not described in the independent claims will be described as optional constituent elements.

[0022] The accompanying drawings are schematic diagrams, in which some parts have been exaggerated, omitted, or scaled to illustrate the invention, and the shapes, positional relationships, and scales in the drawings may differ from the actual shapes, positional relationships, and scales. Furthermore, when expressions indicating relative directions or orientations, such as "parallel" or "orthogonal," are used in the following embodiments, these expressions also cover directions or orientations that are not exactly that particular. For example, two directions being parallel to each other not only means that the two directions are completely parallel to each other, but also covers the case where the two directions are approximately parallel to each other, i.e., with an error of, for example, about a few percent.

[0023] Implementation

[0024] First, an overview of the configuration and operation of the steering device 100 according to the embodiment will be described. Figure 1 This is a perspective view showing the appearance of the steering device 100 according to an embodiment. Figure 2This is a schematic view illustrating the structure of the steering device 100 according to an embodiment. Figure 2 For clarity, the various parts of the steering device 100 are schematically shown, wherein the positional relationship of these parts is as follows: Figure 1 The positional relationships have changed compared to the previous version, and the description of some components has been omitted.

[0025] The steering device 100 according to this embodiment is, for example, a device installed in a vehicle capable of switching between manual and automatic driving, such as a car, bus, truck, construction machinery, or agricultural machinery. The steering device 100 also has the function of moving an operating member 101 for steering the vehicle between an operating area and a retractable area.

[0026] Specifically, such as Figure 1 and Figure 2 As shown, the steering device 100 includes an operating member 101, a first moving unit 110, a second moving unit 120, a holding unit 130, a first lead screw mechanism 140, a second lead screw mechanism 150, a drive unit 160, and a transmission mechanism 170.

[0027] The operating member 101 is, for example, a ring-shaped member referred to as a steering wheel, and is connected to the rear end of the shaft member 118. Specifically, the operating member 101 is connected to the operating support portion 103 via a support member 102. The operating support portion 103 is a member that rotates with the operating member 101 as it rotates by the driver's operation, and is positioned between the operating member 101 and the shaft member 118. Thus, the shaft member 118 is connected to the operating member 101 via the operating support portion 103, and rotation of the operating member 101 about the steering axis Aa is transmitted to the shaft member 118 via the operating support portion 103. Alternatively, the operating member 101 may be directly fixed to the shaft member 118.

[0028] exist Figure 1 In the steering system 100, the axial direction of the shaft member 118 (the direction parallel to the steering axis Aa) corresponds to the X-axis direction. The forward direction in the steering system 100 is the forward direction in the vehicle on which the steering system 100 is installed and is the negative X-axis direction. The rearward direction in the steering system 100 is the opposite direction to the forward direction and is the positive X-axis direction. Figure 1 In the diagram, the steering axis Aa, which serves as the axis of rotation of the shaft member 118, is represented by a dashed line. In the following text, the term "axial direction" used alone refers to the axial direction of the shaft member 118 (i.e., the direction parallel to the steering axis Aa). In this embodiment, the axial direction and the longitudinal direction are consistent with each other.

[0029] The operating member 101 rotates about the steering axis Aa by the driver's operation, and one or more tires of the vehicle rotate based on the amount of rotation, etc. Specifically, the steering device 100 is a device integrated into a so-called steer-by-wire system, and the operating member 101 and the tires are not mechanically connected to each other. A rotary motor drives one or more tires based on information such as the steering angle of the operating member 101, which is output from the steering device 100. Although the steering device 100 also includes a reaction force device that applies a torque to the operating member 110 opposite to the force applied by the driver, a description of this device will be omitted.

[0030] In this embodiment, an airbag housing 104 is fixed to the driver's side (positive X-axis side) of the operating support portion 103, and when viewed from the driver's side, the airbag housing 104 is located at the central portion of the operating member 101. An airbag is housed in the airbag housing 104 in a deployable manner (see...). Figure 9 Furthermore, the airbag 200 deploys, for example, by pushing and breaching the airbag housing 104 in the event of a vehicle collision.

[0031] The first moving unit 110 is a portion that moves axially together with the shaft member 118 and rotatably supports the shaft member 118. Specifically, the first moving unit 110 has a housing 111 that rotatably supports the shaft member 118. The housing 111, for example, houses a switch for activating a direction indicator.

[0032] The second moving unit 120 has a guide mechanism 121 that allows the housing 111 of the first moving unit 110 to slide. The guide mechanism 121 includes a pair of guide rails 122 and a pair of movable parts 123, the sliding movement of the pair of movable parts 123 in the axial direction being guided by the guide rails 122.

[0033] The guide rail 122 is a guide rail body that extends in the axial direction, and the guide rail 122 holds the movable part 123 so that it can slide in the axial direction. The guide rails 122 are arranged to face each other at predetermined intervals in the left-right direction (Y-axis direction). The movable part 123 is fixed to the left outer surface and the right outer surface of the housing 111. The housing 111 and the movable part 123 can slide back and forth in the axial direction by being guided by the guide rail 122. Therefore, the first moving unit 110 is held by the second moving unit 120 so that it can move in the axial direction.

[0034] The pair of guide rails 122 are connected together by a connecting member 124. Specifically, the connecting member 124 is a metal plate extending in the left-right direction, and its two ends are fixed to the upper ends of the respective guide rails 122. Therefore, the connecting member 124 supports the guide rails 122 while being suspended between them. Thus, the integral connection of the guide rails 122 by the connecting member 124 improves the rigidity of the guide rails 122 and the connecting member 124 as a whole. Therefore, the gap can be reduced when the first moving unit 110 slides relative to the second moving unit 120 or when the second moving unit 120 slides relative to the holding unit 130.

[0035] One of the pair of guide rails 122 (in this embodiment, the guide rail 122 located on the negative side of the Y-axis) is provided with a frame 125, which holds the drive unit 160 and the transmission mechanism 170. The frame 125 is integrally connected to the guide rail 122 and moves together with the guide rail 122.

[0036] The holding unit 130 has a guide mechanism 131 that allows the second moving unit 120 to slide in the axial direction and a base member 134 that supports the guide mechanism 131.

[0037] The guiding mechanism 131 includes a pair of guide rails 132 and a pair of movable portions 133, the sliding movement of which is guided in the axial direction by the guide rails 132. The guide rails 132 are guide rail bodies extending in the axial direction, and hold the movable portions 133 so that they can slide in the axial direction. The guide rails 132 are arranged to face each other at a predetermined interval in the left-right direction. The movable portions 133 are fixed to the left and right outer surfaces of the guide rails 122. The guide rails 122 and the movable portions 133 can slide back and forth in the axial direction by being guided by the guide rails 132. Therefore, the second moving unit 120 is held by the holding unit 130 so that it can move in the axial direction.

[0038] The base member 134 connects the pair of guide rails 132 together. Specifically, the base member 134 is a generally box-shaped metal member that is open on its lower side. The upper ends of each guide rail 132 are fixed to the two ends of the base member 134 in the left-right direction. Therefore, the base member 134 supports the guide rails 132 while being suspended between them. Thus, by integrally joining the guide rails 132 through the base member 134, the rigidity of the guide rails 132 and the base member 134 as a whole can be improved. Therefore, the gap can be reduced when the first moving unit 110 slides relative to the second moving unit 120 or when the second moving unit 120 slides relative to the holding unit 130.

[0039] The base member 134 is provided with a first fixing portion 135 and a second fixing portion 136 for fixing to the vehicle body 50. The first fixing portion 135 is arranged at the rear relative to the second fixing portion 136, and the first fixing portion 135 connects the base member 134 and the vehicle body 50 together to fix the base member 134 to the vehicle body 50. The second fixing portion 136 is arranged at the front relative to the first fixing portion 135, and the second fixing portion 136 connects the base member 134 and the vehicle body 50 together to fix the base member 134 to the vehicle body 50.

[0040] The rigidity of the second fixing part 136 is lower than that of the first fixing part 135. Specifically, the first fixing part 135 is merely a fastening tool such as a bolt, while the second fixing part 136 is composed of a bent metal plate and bolts. The base member 134 and the vehicle body 50 are fixed to each other via the second fixing part 136. Since the bent portion in the metal plate is more vulnerable than the first fixing part 135, in the event of a frontal collision, the impact of the collision can be absorbed by the deformation of the vulnerable portion. Therefore, it can be said that the second fixing part 136 has a higher impact absorption characteristic than the first fixing part 135. The second fixing part 136 can have any structure with a higher impact absorption characteristic than the structure of the first fixing part 135. Specifically, it can be formed into a vulnerable portion as described above, or, for example, by incorporating an elastic material such as rubber as part of the second fixing part.

[0041] The first lead screw mechanism 140 is arranged between the first moving unit 110 and the second moving unit 120, and the first lead screw mechanism 140 causes the first moving unit 110 to move in the axial direction. Specifically, the first lead screw mechanism 140 has a housing body 141, a first nut 142, a sliding lead screw 143, and a backlash reduction mechanism 144.

[0042] Figure 3 This is a perspective view showing a structure for supporting a first nut 142 on a housing body 141 according to an embodiment. Figure 3 In the middle, the outline of the shell body 141 is indicated by dashed lines.

[0043] like Figure 3 As shown, the housing body 141 is a housing that houses the sliding lead screw 143 and holds the sliding lead screw 143 in a rotatable manner in this state. The housing body 141 extends in the axial direction, and the sliding lead screw 143 is arranged axially inside the housing body 141. A first nut 142 is also housed inside the housing body 141, and the sliding lead screw 143 is screwed into the first nut 142.

[0044] The first nut 142 is secured to the housing 111 of the first moving unit 110 by the shock-absorbing member 180, which will be described later. The axial movement of the first nut 142 is guided by a pair of bushings 175. Specifically, the pair of bushings 175 are resin-made members that extend in the X-axis direction. The pair of bushings 175 are held at the upper edge of the housing body 141 so that they face each other in the Y-axis direction. The first nut 142 is positioned between the pair of bushings 175. The first nut 142 contacts the inner surface of each bushing 175. Therefore, the posture of the first nut 142 is stabilized. The inner surface of each bushing 175 serves as a guide surface and guides the axial movement of the first nut 142.

[0045] A plunger 176 is provided on the lower surface of the first nut 142. The plunger 176 extends in the Z-axis direction, and a ball 177 protrudes retractably from the lower end surface of the plunger 176. The ball 177 is pushed in the protruding direction by a spring disposed inside the plunger 176. The ball 177 contacts the inner bottom surface of the housing body 141. Therefore, the tilting of the first nut 142 can be absorbed by the ball 177, thereby stabilizing the posture of the first nut 142. Furthermore, when the first nut 142 moves in the axial direction, the ball 177 guides the movement of the first nut 142 by rolling on the inner bottom surface of the housing body 141.

[0046] The sliding lead screw 143 is arranged axially inside the housing body 141. The front end of the sliding lead screw 143 is connected to the transmission mechanism 170, while the other end of the sliding lead screw 143 is rotatably supported by the housing body 141.

[0047] The gap reduction mechanism 144 is the part that reduces the gap between the first nut 142 and the sliding screw 143. Figure 4 This is a schematic diagram showing the configuration of the clearance reduction mechanism according to an embodiment. Figure 4 As shown, the gap-reducing mechanism 144 includes an elastomer 145, a fastening portion 146, and a washer 147. The elastomer 145 is a rubber member disposed between the first nut 142 and the engagement portion 181 as part of an impact-absorbing member 180, and is clamped between the first nut 142 and the engagement portion 181. The engagement portion 181 and the elastomer 145 do not obstruct the sliding screw 143, nor do they impede the movement of the first nut 142 relative to the sliding screw 143. The engagement portion 181 and the elastomer 145 each have, for example, holes through which the sliding screw 143 passes.

[0048] The fastening portion 146 is a threaded body that fastens the engaging portion 181 and the first nut 142 together. The fastening portion 146 extends through the first nut 142 and the elastic body 145, and in this state, the fastening portion 146 is screwed onto the internal thread formed in the engaging portion 181. The washer 147 is a spring washer placed between the screw head of the fastening portion 146 and the first nut 142.

[0049] Figure 5 This is a schematic diagram illustrating a structure for joining the first nut 142 and the engagement portion 181 together, according to a comparative example. Figure 5 As shown, the difference between the comparative example and the embodiment is the absence of the elastomer 145 and washer 147. Without the elastomer 145 and washer 147, when the first nut 142 and the engaging portion 181 are fastened together by the fastening portion 146, the first nut 142 and the engaging portion 181 may be fixed in an inclined state relative to the sliding screw 143 due to the gap between the sliding screw 143 and the first nut 142. Specifically, the engaging portion 181 and the sliding screw 143 may be inclined due to the gap in the first moving unit 110 on which the engaging portion 181 is mounted and the gap in the second moving unit 120 on which the sliding screw 143 is mounted. In this case, when the engaging portion 181 and the first nut 142 are fixed, the first nut 142 will be inclined relative to the sliding screw 143 (see [link to relevant documentation]). Figure 5 This results in an increase in torque as the first nut 142 and the sliding screw 143 move relative to each other.

[0050] In this embodiment, the orientation of the first nut 142 is stabilized by the pair of bushings 175 and plunger 176, thereby reducing the gap of the first nut 142.

[0051] Furthermore, in this embodiment, the aforementioned tilt is as follows: Figure 4 The elastomer 145 and washer 147 shown absorb the impact, thus preventing the formation of gaps and the increase of torque. Specifically, in this embodiment, due to the washer 147, loosening of the fastening portion 146 can be suppressed when the elastomer 145 undergoes permanent deformation. The gap reduction mechanism 144 illustrated in this embodiment includes the elastomer 145 and the washer 147. However, the gap reduction mechanism can have any structure capable of reducing the gap between the first nut 142 and the sliding screw 143. For example, a gap reduction mechanism including an elastomer or a washer can be employed.

[0052] The second lead screw mechanism 150 is arranged between the second moving unit 120 and the holding unit 130, and the second lead screw mechanism 150 causes the second moving unit 120 to move in the axial direction. Specifically, the second lead screw mechanism 150 includes a second nut 152, a ball screw 153, and an alignment mechanism 154.

[0053] The second nut 152 is a component that is rotated by the drive unit 160 and connected to the transmission mechanism 170. The ball screw 153 is screwed into the second nut 152. The front end of the ball screw 153 is rotatably supported and fixed to a guide rail 132 of the retaining unit 130 (in this embodiment, the guide rail 132 located on the negative side of the Y-axis). This means that the ball screw 153 is fixed so as not to rotate relative to the retaining unit 130. Specifically, a downwardly protruding shaft support portion 138 is provided at the front end of the guide rail 132. The front end of the ball screw 153 is connected to the shaft support portion 138 via an alignment mechanism 154.

[0054] The alignment mechanism 154 will be described here. The alignment mechanism 154 is a mechanism for adjusting the position of the axis of the ball screw 153 relative to the second nut 152. Figure 6 and Figure 7 This is an exploded perspective view showing the various parts of the alignment mechanism 154 according to the embodiment during disassembly. Specifically, Figure 6 This is a perspective view of the various parts of the alignment mechanism 154 as viewed from the rear. Figure 7 This is a perspective view of the various parts of the alignment mechanism 154 when viewed from the front.

[0055] First, the shaft support portion 138 will be described. The shaft support portion 138 has a through-hole 381 through which the front end of the ball screw 153 extends. As... Figure 7 As shown, the front surface of the shaft support portion 138 is a planar surface parallel to the YZ plane. On the other hand, as... Figure 6 As shown, the rear surface of the shaft support portion 138 has a pair of recesses 382, ​​383 formed on each side of the through hole 381 in the vertical direction. The recess 382 is located on the upper side of the through hole 381 and is recessed in a rectangular shape extending in the Y-axis direction. The recess 383 is located on the lower side of the through hole 381 and is a groove extending in the Y-axis direction. The portion between the pair of recesses 382, ​​383 will be referred to as the base portion 384. The base portion 384 has a shape extending in the Y-axis direction, and its upper surface 384a and lower surface 384b are planar surfaces parallel to the XY plane. The upper surface 384a and lower surface 384b facilitate adjustment of the position of the ball screw 153's axis. Therefore, the shaft support portion 138 is part of the alignment mechanism 154.

[0056] Next, the alignment mechanism 154 will be described in detail. For example... Figure 6 and Figure 7 As shown, the alignment mechanism 154 includes, in addition to the shaft support portion 138, a first alignment member 51, a second alignment member 52, a first washer 53, a second washer 54, and a nut 55.

[0057] The first alignment member 51 is a generally annular member. A protrusion 511 extending in the Z-axis direction is formed on the front surface of the first alignment member 51. A pair of outer surfaces of the protrusion 511 are planar surfaces parallel to the XZ plane. The protrusion 511 extends through the central portion of the first alignment member 51. A through hole 512 is formed at the central portion of the first alignment member 51, through which the front end of the ball screw 153 extends. The through hole 512 is located within the protrusion 511. At a predetermined position in the front end of the ball screw 153 extending through the through hole 512, the axial movement of the first alignment member 51 relative to the ball screw 153 is restricted.

[0058] The second alignment member 52 is a generally annular member. A first recess 521 extending in the Z-axis direction is formed in the rear surface of the second alignment member 52. The first recess 521 extends through the central portion of the second alignment member 52. A through hole 525 is formed at the central portion of the second alignment member 52, through which the front end of the ball screw 153 extends. The through hole 525 is located inside the first recess 521. A pair of inner surfaces of the first recess 521 are planar surfaces parallel to the XZ plane. A protrusion 511 of the first alignment member 51 is fitted into the first recess 521. The pair of outer surfaces of the protrusion 511 are slidable on the pair of inner surfaces of the first recess 521, and thus the first alignment member 51 and the second alignment member 52 are able to move relative to each other in the Z-axis direction while being restricted from rotating relative to each other. Therefore, when the ball screw 153 extending through the first alignment member 51 and the second alignment member 52 moves or tilts in the Z-axis direction, the positional offset is permitted due to the movement of the first alignment member 51 and the second alignment member 52 relative to each other.

[0059] A second recess 522 extending in the Y-axis direction is formed in the front surface of the second alignment member 52. A through hole 525 is located inside the second recess 522. The second recess 522 extends through the central portion of the second alignment member 52. A pair of inner surfaces of the second recess 522 are planar surfaces parallel to the XY plane. The base portion 384 of the shaft support portion 138 is fitted into the second recess 522. The pair of outer surfaces of the base portion 384 are slidable on the pair of inner surfaces of the second recess 522, and thus the second alignment member 52 and the shaft support portion 138 are able to move relative to each other in the Y-axis direction while being restricted from rotating relative to each other. Therefore, when the ball screw 153 extending through the second alignment member 52 and the shaft support portion 138 moves or tilts in the Y-axis direction, this positional offset is allowed due to the movement of the second alignment member 52 and the shaft support portion 138 relative to each other.

[0060] The first washer 53 is positioned directly in front of the shaft support portion 138, and in this state, the front end of the ball screw 153 extends through the first washer 53. The front surface of the first washer 53 is a spherical surface convex towards the front. The second washer 54 is positioned directly in front of the first washer 53. The rear surface of the second washer 54 is a spherical surface convex towards the front. When the front surfaces of the first washer and the rear surfaces of the second washer 54 slide against each other, the positional offsets allowed by the first alignment member 51, the second alignment member 52, and the shaft support portion 138 can be absorbed. Therefore, during assembly, the position of the axis of the ball screw 153 relative to the second nut 152 can be adjusted.

[0061] Nut 55 is tightened to an external thread formed at the front end of ball screw 153. Specifically, nut 55 is tightened to this external thread, and nut 55 clamps other components (second alignment member 52, shaft support portion 138, first washer 53 and second washer 54) between nut 55 and first alignment member 51, thereby fixing ball screw 153—whose axis of position has been adjusted—to shaft support portion 138. Thus, once these parts are assembled, the position and orientation of ball screw 153 are fixed.

[0062] like Figure 1 and Figure 2 As shown, the impact absorbing member 180 is arranged between the first moving unit 110 and the first lead screw mechanism 140, and thereby can absorb the impact of the collision (secondary collision) between the driver and the operating member 101 caused by the collision between the vehicle and other objects.

[0063] The impact-absorbing member 180 is a metal component and has a joining portion 181, a mounting portion 182, and a deformable portion 183. Specifically, the joining portion 181 is the lower end portion of the impact-absorbing member 180, and is fixed to the first nut 142 as the sliding screw 143 extends through the joining portion 181. The mounting portion 182 is the upper end portion of the impact-absorbing member 180, and is mounted and fixed to the housing 111 of the first moving unit 110. The deformable portion 183 is a portion disposed between the joining portion 181 and the mounting portion 182 and bent into a U-shape, and deforms in a secondary impact to absorb impact energy. The deformable portion 183 is configured, for example, such that the bent portion (with a U-shaped bottom portion) faces forward.

[0064] like Figure 2 As shown, an energy absorption (EA) space 166 is formed inside the housing 111 of the first moving unit 110. This energy absorption (EA) space 166 is an example of a space that allows the shaft member 118 to move forward. In a secondary collision, while the impact absorbing member 180 deforms under the compressive force from the first moving unit 110, the shaft member 118 moves forward within the EA space 166. Therefore, the impact energy of the secondary collision is absorbed, ensuring the safety of the driver. The axial length of the EA space 166 is determined, for example, based on the required impact absorption performance of the steering device 100 and the characteristics of the impact absorbing member 180.

[0065] There are no particular limitations on the technology used to absorb impacts through the impact absorbing member 180. The impact absorbing member 180 can absorb impacts using displacement (friction) between two components in contact with each other, rather than deformation of a single component. Furthermore, resin components and the impact absorbing member 180 can be used in combination to absorb impact energy in two stages: first, through the fracture of the resin component, and then through deformation of the metal impact absorbing member 180, etc. For example, suppose a resin pin is arranged vertically on the impact absorbing member 180, extending through a U-shaped impact absorbing member 180 (see...). Figure 1 In this case, when a secondary impact occurs, a portion of the impact energy is absorbed when the resin pin breaks, and the impact energy is further absorbed when the impact absorbing member 180 deforms.

[0066] like Figure 1 and Figure 2 As shown, the drive unit 160 is the drive source that synchronously drives the first lead screw mechanism 140 and the second lead screw mechanism 150. The drive unit 160 is held by the frame 125. Although the drive unit 160 is not particularly limited, in this embodiment, an electric motor is used as the drive unit 160.

[0067] The transmission mechanism 170 is connected to the first lead screw mechanism 140, the second lead screw mechanism 150, and the drive unit 160, and transmits the driving force of the drive unit 160 to the first lead screw mechanism 140 and the second lead screw mechanism 150. Specifically, the transmission mechanism 170 is held by the frame 125. The transmission mechanism 170 is not particularly limited and can be any mechanism capable of transmitting the driving force of the drive unit 160 to the sliding lead screw 143 of the first lead screw mechanism 140 and the second nut 152 of the second lead screw mechanism 150. Belt drives, gear combinations, etc., can be used arbitrarily. In this embodiment, a gear combination is used.

[0068] Next, the operation of each part when moving the operating member 101 between the operating area and the retracted area will be described. Figure 8 This is a schematic view showing the structure of the steering device 100 according to an embodiment. Specifically, Figure 8 Is with Figure 2 The corresponding view. Figure 2 The diagram shows the state in which the operating component 101 is arranged in the operating area, while Figure 8 The diagram illustrates the state in which the operating member 101 is arranged in the retracted region. Here, the operating region is the area where a user can operate the operating member 101 to drive the vehicle, and the operating region corresponds to the position of the operating member 101 when the first moving unit 110, the second moving unit 120, and the holding unit 130 have been extended. The retracted region is the area where the operating member 101 is retracted during autonomous driving and user operation is not permitted, and the retracted region corresponds to the position of the operating member 101 when the first moving unit 110, the second moving unit 120, and the holding unit 130 have been retracted. For each of the operating region and the retracted region, a certain allowable range is provided in the axial direction.

[0069] In this embodiment, the rotation direction of the drive unit 160 (i.e., the electric motor), the rotation direction of the sliding lead screw 143, and the rotation direction of the second nut 152 will be referred to as the forward rotation direction when the operating member 101 moves from the operating area to the retracted area. On the other hand, the rotation direction of the drive unit 160, the rotation direction of the sliding lead screw 143, and the rotation direction of the second nut 152 will be referred to as the reverse rotation direction when the operating member 101 moves from the retracted area to the operating area.

[0070] Although the rotation direction of each part is referred to here as the "forward rotation direction" and the "reverse rotation direction," there may be cases where, for example, the forward rotation direction of one part is not the same as that of another part. Specifically, the drive unit 160, the sliding lead screw 143, and the second nut 152 are connected together via a transmission mechanism 170. Depending on the configuration of the transmission mechanism 170, it is possible that at least one of the sliding lead screw 143 and the second nut 152 rotates in a direction opposite to the rotation direction of the drive unit 160. Again, in this case, the rotation direction of each part will be referred to as the forward rotation direction. The same applies to the reverse rotation direction.

[0071] When the drive unit 160, i.e., the electric motor, is arranged in the operating member 101 as follows: Figure 2 When rotating in the forward direction in the operating area shown, the sliding screw 143 of the first lead screw mechanism 140 rotates in the forward direction through the transmission mechanism 170, and the second nut 152 of the second lead screw mechanism 150 also rotates in the forward direction.

[0072] Therefore, the first lead screw mechanism 140 operates in the positive direction when the rotational motion of the sliding lead screw 143 is converted into the linear motion of the first nut 142. The first nut 142 moves along the sliding lead screw 143 in the negative X-axis direction, causing the first moving unit 110 to also move in the negative X-axis direction and get closer to the second moving unit 120.

[0073] Simultaneously, the second lead screw mechanism 150 operates in the positive direction when the rotational motion of the second nut 152 is converted into the linear motion of the ball screw 153. The ball screw 153 moves relative to the second nut 152 in the positive X-axis direction, causing the second moving unit 120 to move closer to the holding unit 130.

[0074] Therefore, the first moving unit 110, the second moving unit 120, and the holding unit 130 retract, and the operating member 101 is arranged in the retracted area, as... Figure 8 As shown in the diagram. When the operating member 101 is arranged in the retracted area, the space in front of the driver is expanded, which, for example, improves the driver's comfort.

[0075] Next, when the drive unit 160, i.e. the electric motor, rotates in the opposite direction with the operating member 101 arranged in the retracted area, the sliding screw 143 of the first lead screw mechanism 140 rotates in the opposite direction via the transmission mechanism 170, and the second nut 152 of the second lead screw mechanism 150 also rotates in the opposite direction.

[0076] Therefore, the first lead screw mechanism 140 operates in the positive direction when the rotational motion of the sliding lead screw 143 is converted into the linear motion of the first nut 142. The first nut 142 moves along the sliding lead screw 143 in the positive X-axis direction, causing the first moving unit 110 to also move in the positive X-axis direction and move further away from the second moving unit 120.

[0077] Simultaneously, the second lead screw mechanism 150 operates in the positive direction when the rotational motion of the second nut 152 is converted into the linear motion of the ball screw 153. The ball screw 153 moves relative to the second nut 152 in the negative X-axis direction, causing the second moving unit 120 to move further away from the holding unit 130.

[0078] Therefore, the first moving unit 110, the second moving unit 120, and the holding unit 130 extend and the operating member 101 is arranged in the operating area, such as Figure 2 As shown in the diagram. Within the operating area, the position of the operating member 101 can also be adjusted by controlling the forward and reverse rotation of the drive unit 160. Specifically, the driver can change the position of the operating member 101 in the forward and backward directions when he or she intends to. Therefore, the driver can adjust the position of the operating member 101 to a specific location based on his or her body type, preferences, etc.

[0079] As already described, each of the first lead screw mechanism 140 and the second lead screw mechanism 150 is configured to operate in the positive direction when the operating member 101 moves between the retracted region and the operating region.

[0080] exist Figure 8 In this diagram, the respective movement amounts of the first lead screw mechanism 140 and the second lead screw mechanism 150 are represented by L1 and L2. The movement amount L1 of the first lead screw mechanism 140 refers to the relative movable range of the first nut 142 relative to the sliding lead screw 143. The movement amount L2 of the second lead screw mechanism 150 refers to the relative movable range of the ball screw 153 relative to the second nut 152. When the first lead screw mechanism 140 and the second lead screw mechanism 150 are synchronously driven by the drive unit 160 to move the operating member 101 from the operating area to the retracted area (retraction action) or from the retracted area to the operating area (expansion action), the movement amount L2 of the second lead screw mechanism 150 is greater than the movement amount L1 of the first lead screw mechanism 140.

[0081] Specifically, for example, the forward efficiency of the second lead screw mechanism 150 is set to be higher than that of the first lead screw mechanism 140, so that the movement L2 is greater than the movement L1. Here, forward efficiency is the ratio of output to input when converting rotary motion into linear motion. Specifically, the forward efficiency of the first lead screw mechanism 140 is the ratio of output to input when the sliding lead screw 143 is rotated to linearly move the first nut 142. The forward efficiency of the second lead screw mechanism 150 is the ratio of output to input when the second nut 152 is rotated to linearly move the ball screw 153. The forward efficiency can be adjusted by adjusting the lead, lead angle, forward friction angle, static friction coefficient, etc. of each of the first lead screw mechanism 140 and the second lead screw mechanism 150.

[0082] As already described, the movement L2 of the second lead screw mechanism 150 is greater than the movement L1 of the first lead screw mechanism 140, and the forward efficiency of the second lead screw mechanism 150 is higher than that of the first lead screw mechanism 140. Therefore, even when the first lead screw mechanism 140 and the second lead screw mechanism 150, in which the movement L1 is less than the movement L2, are driven synchronously by the drive unit 160, the first nut 142 and the ball screw 153 can move at the same time, and the movement of the first nut 142 and the ball screw 153 can be completed at the same time.

[0083] High forward efficiency can be described as low reduction ratio or large lead. Since the first lead screw mechanism 140 and the second lead screw mechanism 150 differ from each other in efficiency (reduction ratio or lead), when the first lead screw mechanism 140 and the second lead screw mechanism 150 are driven synchronously, the movement of the first lead screw mechanism 140 and the movement of the second lead screw mechanism 150, which differ from each other in the amount of movement, can be completed at the same time.

[0084] The reversing efficiency of the first lead screw mechanism 140 is set such that when the operating member 101 is subjected to an external force F1 pointing toward the retraction region, the first lead screw mechanism 140 does not operate in the reverse direction due to the external force F1. Specifically, the external force F1 can be set, for example, as the force applied to the operating member 101 when a person pushes or pulls the operating member 101. The external force F1 can also be set as the force applied to the operating member 101 in a secondary collision. Here, the reversing efficiency is the ratio of output to input when converting linear motion into rotational motion. Specifically, the reversing efficiency of the first lead screw mechanism 140 is the ratio of output to input when the first nut 142 is moved linearly to rotate the sliding lead screw 143. The reversing efficiency can be adjusted by adjusting the lead, lead angle, reverse friction angle, reverse friction coefficient, etc. of the first lead screw mechanism 140.

[0085] Assuming an external force F1 directed toward the retraction area is applied to the operating member 101, such as Figure 2As shown in the diagram, since the reversing efficiency of the first lead screw mechanism 140 is set such that the first lead screw mechanism 140 does not operate in the reverse direction under the external force F1, the linear movement of the first nut 142 relative to the sliding lead screw 143 is restricted. Therefore, the axial movement of the first moving unit 110 relative to the second moving unit 120 is also restricted.

[0086] Simultaneously, the external force F1 also acts on the second moving unit 120 through the first moving unit 110. Here, the second ball screw 153 has a high reverse efficiency due to its use. Therefore, the ball screw 153 can move linearly through the second nut 152 due to the external force F1. The second nut 152 is connected to the sliding screw 143 of the first screw mechanism 140 via the transmission mechanism 170. Since the reverse efficiency of the first screw mechanism 140 is set as described above so that the first screw mechanism 140 does not operate in the reverse direction, the sliding screw 143 is restricted from rotating even under the external force F1. Therefore, the transmission mechanism 170 connected to the restricted sliding screw 143 is also restricted from moving, so that the second nut 152 connected to the transmission mechanism 170 is also restricted from rotating. Therefore, in the second screw mechanism 150, the ball screw 153 is restricted to move linearly relative to the second nut 152.

[0087] This limitation is affected by the friction between the first nut 142 and the sliding screw 143. This friction is generated when the reverse input F2 acts on the first nut 142 due to the external force F1, causing the tooth surface of the first nut 142 to press against the tooth surface of the sliding screw 143. If the force F3 used by the second nut 152 to attempt to rotate becomes greater than this friction, the limitation on the second nut 152 is released and the second screw mechanism 150 operates in the reverse direction. It is desirable that the gear specifications of the first screw mechanism 140 are set such that the second screw mechanism 150 does not operate in the reverse direction in the event of a secondary impact in which an excessive force F3 may be generated.

[0088] The steering device 100 may further include a tilting mechanism that changes the tilt angle of the operating member 101 in the vertical direction. The tilting mechanism, for example, involves causing the first moving unit 110 to rotate around a direction parallel to the left-right direction. Figure 1 The tilt angle of the operating member 101 in the vertical direction is changed by rotating it about an axis parallel to the Y-axis. Therefore, the position of the operating member 101 in the vertical direction can be adjusted, for example, according to the driver's intention. The tilting mechanism can be configured to change the tilt angle by rotating the second moving unit 120 about an axis parallel to the left-right direction. Figure 1 The tilt of the operating component 101 in the vertical direction is changed by rotating the axis (Y-axis direction) of the component.

[0089] The operation of the drive unit 160 described above is controlled by the control unit 190 of the steering device 100 (see above). Figure 9 )control. Figure 9 This is a block diagram illustrating the functional configuration of the steering device 100 according to an embodiment.

[0090] The control unit 190 acquires various information and controls the drive unit 160, etc., based on the acquired information. For example, the control unit 190 acquires a predetermined command given by the driver or by the detection results of various sensors. The control unit 190 controls the drive unit 160 based on the acquired predetermined command or detection results, thereby moving the operating member 101 in the axial direction. The control unit 190 acquires information from the drive unit 160 indicating the positions of the first moving unit 110 and the second moving unit 120 as needed. Therefore, the control unit 190 can identify the position of the operating member 101, which is indirectly supported on the first moving unit 110, relative to a predetermined reference as needed.

[0091] The control unit 190 that performs the above control is implemented, for example, by a computer including a central processing unit (CPU), a storage device such as a memory, and an interface for inputting and outputting information. For example, when the CPU executes a predetermined program stored in the storage device, the control unit 190 can control the operation of the steering device 100 based on control signals sent from the superior control unit 300, the detection results of sensors, etc.

[0092] The airbag 200, housed in the airbag housing 104 of the steering mechanism 100, is activated according to a command from the airbag control unit 210 installed in the vehicle. The airbag control unit 210 determines whether to deploy the airbag 200, for example, based on acceleration information received from the acceleration sensor 250. When a rapid change in acceleration rate equal to or greater than a threshold occurs, such as during a collision between the vehicle and an object, the airbag control unit 210 issues a deployment command to the airbag 200, and the airbag 200 deploys when the inflator is activated. Therefore, the airbag 200 inflates immediately.

[0093] As described above, the airbag 200 inflates essentially upon a collision between the vehicle and another object. However, if the airbag housing 104, along with the operating member 101, retracts to a position away from the driver, the airbag 200 cannot be expected to provide adequate impact absorption due to factors such as the long distance between the airbag 200 and the driver, and the dashboard's proximity to the airbag 200. In short, the airbag 200 fails to perform its intended function. Therefore, based on the positions of the operating member 101, the airbag housing 104, etc., obtained from the steering system 100, the upper-level control unit 300, for example, controls the airbag control unit 210 to prevent it from deploying the airbag. In this case, driver safety is ensured by other airbags (not shown) located in positions other than the front side of the driver's seat (e.g., in the ceiling).

[0094] In the event of a collision, an excessive force F3 may occur. Even if the reversing efficiency of the first lead screw mechanism 140 is set so that the second lead screw mechanism 150 does not operate in the reverse direction in the event of a collision as described above, this setting may not work in all cases. Therefore, when an excessive reversing input is detected to either the first lead screw mechanism 140 or the second lead screw mechanism 150, the control unit 190 controls the drive unit 160 to limit the reversing operation. Specifically, the control unit 190 causes the drive unit 160 to rotate in the direction opposite to the rotational direction of the reversing operation or prevents the drive unit 160 from rotating itself. Thus, the reversing operation can be reliably limited.

[0095] To detect excessive reverse input, a sensor that directly detects the reverse input can be provided. Alternatively, control unit 190 can infer a collision based on acceleration information received from acceleration sensor 250, and thereby detect excessive reverse input. Furthermore, control unit 190 can detect excessive reverse input based on a sudden increase in load on drive unit 160. Therefore, any configuration that allows detection of excessive reverse input in either the first lead screw mechanism 140 or the second lead screw mechanism 150 can be employed.

[0096] As described above, in this embodiment, the first lead screw mechanism 140 is configured to operate in the forward direction when the operating member 101 moves between the retracted region and the operating region, and the reverse efficiency of the first lead screw mechanism 140 is set such that when the operating member 101 is subjected to an external force F1 pointing toward the retracted region, the first lead screw mechanism 140 does not operate in the reverse direction due to the external force F1. Therefore, even when the operating member 101 is subjected to an external force F1, the first lead screw mechanism 140 does not convert the linear motion attributable to the external force F1 into rotational motion. Therefore, the movement of the first moving unit 110 is restricted.

[0097] The second lead screw mechanism 150 is connected to the first lead screw mechanism 140 via a transmission mechanism 170. Since the reverse efficiency of the first lead screw mechanism 140 is set such that it does not operate in the reverse direction, the first lead screw mechanism 140 is restricted from rotating under an external force F1. Therefore, the transmission mechanism 170 connected to the restricted-rotation first lead screw mechanism 140 is also restricted from moving, thus restricting the rotation of the second lead screw mechanism 150 connected to the transmission mechanism 170. Consequently, the second lead screw mechanism 150 is also restricted from linear movement, i.e., the second moving unit 120 is restricted from moving. As already described, a simple setting of the reverse efficiency of the first lead screw mechanism 140 can restrict the movement of the first moving unit 110 and the second moving unit 120 due to the external force F1. This means that the first lead screw mechanism 140 can be used as a locking mechanism. Therefore, without a dedicated locking mechanism, the steering device 100 can restrict the movement of the first moving unit 110 and the second moving unit 120 due to the external force F1. Compared to having a dedicated locking mechanism, this reduces the total number of parts, shrinks the size of the device, and improves the efficiency of installing the device in a vehicle.

[0098] Here, the second lead screw mechanism 150 can also be used as a locking mechanism. In this case, the reversing efficiency of the second lead screw mechanism 150 is set such that when the operating member 101 is subjected to an external force F1, the second lead screw mechanism 150 does not operate in the reverse direction due to the external force F1. However, the second lead screw mechanism 150 is arranged at the front of the vehicle relative to the first lead screw mechanism 140, and is located away from the side where the external force F1 is input. Therefore, reliably limiting the operation of the first lead screw mechanism 140 may involve complicating the structure of the transmission mechanism 170 (increasing the number of gears). This complexity may lead to backlash, reduced rigidity, and deterioration of the locking function, etc. In contrast, using the first lead screw mechanism 140 as a locking mechanism as described above does not complicate the structure of the transmission mechanism 170, and is therefore preferred.

[0099] Since the movement amount L2 of the second lead screw mechanism 150 is greater than the movement amount L1 of the first lead screw mechanism 140, the movement amount of the operating member 101 can be increased by increasing only the movement amount L2 of the second lead screw mechanism 150.

[0100] Here, if the movement L1 of the first lead screw mechanism 140 is large, then when the parts extend (when the operating member 101 is arranged in the operating area), there is a long distance between the first moving unit 110 and the holding unit 130, which leads to a reduction in the rigidity of the steering device 100 as a whole. Furthermore, when the torque applied to the first moving unit 110 increases, the effect on the reduction in the rigidity of the steering device 100 as a whole is significant. However, in this embodiment, since the movement L1 of the first lead screw mechanism 140 is smaller than the movement L2 of the second lead screw mechanism 150, a reduction in the rigidity of the steering device 100 as a whole can be avoided.

[0101] Since the forward efficiency of the second lead screw mechanism 150 is higher than that of the first lead screw mechanism 140, even when the first lead screw mechanism 140 and the second lead screw mechanism 150, in which the movement amount L1 is less than the movement amount L2, are driven synchronously by the drive unit 160, the first nut 142 and the ball screw 153 can move at the same time and the movement of the first nut 142 and the ball screw 153 can be completed at the same time.

[0102] This allows us to avoid reducing the rigidity of the device itself while increasing the amount of movement of the operating component 101.

[0103] Since the ball screw 153 of the second lead screw mechanism 150, which has a large amount of movement, is fixed to the retaining unit 130 supported on the vehicle body 50, the rigidity of the steering device 100 can be further improved.

[0104] The position of the axis of the ball screw 153 relative to the second nut 152 can be adjusted by the alignment mechanism 154, and thus the position of the axis of the ball screw 153 can be adjusted during assembly. This allows for smooth rotational movement of the second nut 152 relative to the ball screw 153.

[0105] Because the backlash reduction mechanism 144 reduces the backlash between the first nut 142 and the sliding screw 143, it can prevent the generation of backlash or increased torque between the sliding screw 143 and the first nut 142. This makes the rotational movement of the sliding screw 143 relative to the first nut 142 smoother.

[0106] Because the second fixed portion 136 is positioned at the front relative to the first fixed portion 135 and has higher impact absorption performance than the first fixed portion 135, the impact of a frontal collision can be absorbed by the second fixed portion 136. This impact can be absorbed when the vulnerable portion of the second fixed portion 136 deforms.

[0107] The impact-absorbing member 180, connected to the first moving unit 110, absorbs impacts when the front end of at least one of the shaft member 118 and the first moving unit 110 moves forward in the axial direction. Here, the retaining unit 130 not only retains the second moving unit 120 but also retains the first moving unit 110 through the second moving unit 120, and therefore the retaining unit 130 needs to have a certain rigidity. In this embodiment, the impact-absorbing member 180 is connected to the first moving unit 110. Therefore, compared to the case where the impact-absorbing member 180 is connected to the retaining unit 130, a reduction in the rigidity of the retaining unit 130 can be avoided.

[0108] When an excessive reverse input is detected to the first lead screw mechanism 140 or the second lead screw mechanism 150, the control unit 190 controls the drive unit 160 to limit reverse operation. Therefore, when a situation arises where mechanical limitation alone cannot eliminate the possibility of reverse operation, the control unit 190 can reliably control the operation of the drive unit 160 to limit reverse operation.

[0109] Since the guiding mechanism 121 guides the movement of the first moving unit 110 relative to the second moving unit 120, the first moving unit 110 can move smoothly.

[0110] Other implementation methods

[0111] The steering device according to the present invention has been described above based on embodiments. However, the present invention is not limited to the above embodiments. Embodiments that can be conceived by those skilled in the art, including various modifications to the above embodiments, as well as embodiments established by combining some of the above-described constituent elements without departing from the spirit of the invention, are also included within the scope of the present invention.

[0112] For example, Figure 1 The appearance and configuration of the steering device 100 shown are illustrative, and the shape, size, and position of each constituent element are not limited to those described above. Figure 1 The shapes, sizes, and positions shown. The configuration of each constituent element does not necessarily have to be... Figure 1 The configuration shown in the figure.

[0113] In the above embodiments, the following situation has been described: the drive unit 160 is a single electric motor, and this electric motor is connected to the first lead screw mechanism 140 and the second lead screw mechanism 150 via the transmission mechanism 170. However, the drive unit may have two electric motors if it can synchronously drive the first lead screw mechanism 140 and the second lead screw mechanism 150. Specifically, one electric motor is connected to the sliding lead screw 143 of the first lead screw mechanism 140, while the other electric motor is connected to the second nut 152 of the second lead screw mechanism 150. In this case, the transmission mechanism 170 may be omitted.

[0114] When the transmission mechanism 170 is omitted, the reverse efficiency of each of the first lead screw mechanism 140 and the second lead screw mechanism 150 can be set such that the lead screw mechanism does not operate in the reverse direction due to the external force F1. In this respect, the steering device 100 includes: a first moving unit 110 that moves along the axial direction of a shaft member 118 connected to an operating member 101 at its rear end, and the first moving unit 110 rotatably supports the shaft member 118; a second moving unit 120 that holds the first moving unit 110 so as to be movable in the axial direction; a holding unit 130 that holds the second moving unit 120 so as to be movable in the axial direction; a first lead screw mechanism 140 that is disposed between the first moving unit 110 and the second moving unit 120 and moves the first moving unit 110 in the axial direction; a second lead screw mechanism 150 that is disposed between the second moving unit 120 and the holding unit 130 and moves the second moving unit 120 in the axial direction; and a first drive unit 160a (see...). Figure 10 The first drive unit 160a outputs a driving force for driving the first lead screw mechanism 140; and the second drive unit 160b (see...) Figure 10 The second drive unit 160b outputs a driving force for driving the second lead screw mechanism 150.

[0115] Figure 10 This is a block diagram illustrating the functional configuration of the steering device 100 according to a modified example. (See diagram below.) Figure 10 As shown, the first drive unit 160a and the second drive unit 160b are electrically connected to the control unit 190. The first drive unit 160a is configured to output drive force only to the first lead screw mechanism 140. The second drive unit 160b is configured to output drive force only to the second lead screw mechanism 150. The control unit 190 acquires various information and controls the first drive unit 160a and the second drive unit 160b based on the acquired information.

[0116] Each of the first lead screw mechanism 140 and the second lead screw mechanism 150 is configured to operate in the forward direction when the operating member 101 moves between the retracted region and the operating region, and the reverse efficiency of each of the first lead screw mechanism 140 and the second lead screw mechanism 150 is set such that when the operating member 101 is subjected to an external force F1 pointing toward the retracted region, neither the first lead screw mechanism 140 nor the second lead screw mechanism 150 operates in the reverse direction due to the external force F1. Therefore, a certain locking function can be achieved even by omitting the steering device 100, which omits the transmission mechanism.

[0117] In the above embodiments, the posture of the first nut 142 has been stabilized by the plunger 176 and the pair of bushings 175. However, the steering device may only have either the pair of bushings 175 or the plunger 176. In this case, the posture of the first nut 142 can be stabilized to a certain extent, and a certain clearance reduction effect can be achieved on the first nut 142.

[0118] This invention serves as a steering device that expands the space in front of the driver and improves collision safety. Therefore, this invention is applicable to vehicles equipped with wheels, tracks, etc., and capable of manual and automatic driving, such as automobiles, buses, trucks, agricultural machinery, and construction machinery.

Claims

1. A steering device (100), characterized in that comprises: an operation member (101) that steers a vehicle; a first moving unit (110) that moves along an axial direction of a shaft member (118) to which the operation member (101) is connected at a rear end portion, and rotatably supports the shaft member (118); a second moving unit (120) that holds the first moving unit (110) so as to be movable in the axial direction; a holding unit (130) that holds the second moving unit (120) so as to be movable in the axial direction; a first lead screw mechanism (140) that is arranged between the first moving unit (110) and the second moving unit (120), and moves the first moving unit (110) in the axial direction; a second lead screw mechanism (150) that is arranged between the second moving unit (120) and the holding unit (130), and moves the second moving unit (120) in the axial direction; a drive unit (160) that outputs a drive force for driving the first lead screw mechanism (140) and the second lead screw mechanism (150); and a transmission mechanism (170) that is coupled to the first lead screw mechanism (140), the second lead screw mechanism (150), and the drive unit (160), and transmits the drive force of the drive unit (160) to the first lead screw mechanism (140) and the second lead screw mechanism (150), wherein: the steering device (100) moves the operation member (101) between an operation region and a retracted region; and the first lead screw mechanism (140) is provided so as to operate in a forward direction when the operation member (101) moves between the retracted region and the operation region, and a reverse efficiency of the first lead screw mechanism (140) is set so that the first lead screw mechanism (140) does not operate in a reverse direction due to an external force directed toward the retracted region when the operation member (101) is subjected to the external force, a reverse efficiency of the second lead screw mechanism (150) is set so as to be higher than that of the first lead screw mechanism (140), and is capable of operating in the reverse direction due to the external force, the first lead screw mechanism (140) functions as a locking mechanism when the operation member (101) is subjected to the external force directed toward the retracted region, the second lead screw mechanism (150) does not function as a locking mechanism, and is locked via the transmission mechanism (170).

2. The steering device (100) according to claim 1, characterized in that: The first lead screw mechanism (140) has a first nut (142) fixed to the first moving unit (110) and a sliding lead screw (143) screwed into the first nut (142) in a state of extending in the axial direction, and the sliding lead screw (143) is rotated by the drive unit (160) through the transmission mechanism (170), and The second lead screw mechanism (150) has a second nut (152) rotated by the drive unit (160) through the transmission mechanism (170) and a ball screw (153) screwed into the second nut (152) and fixed to the holding unit (130) so as to extend in the axial direction with respect to the holding unit (130).

3. The steering device (100) according to claim 2, characterized in that The second lead screw mechanism (150) includes an alignment mechanism (154) that adjusts the position of the axis of the ball screw (153) with respect to the second nut (152).

4. The steering device (100) according to claim 2 or 3, characterized in that The first lead screw mechanism (140) includes a gap reduction mechanism (144) that reduces the gap of the first nut (142) with respect to the sliding lead screw (143).

5. The steering device (100) according to any one of claims 1 to 3, characterized in that A control unit (190) that controls the drive unit (160) is further included, wherein the control unit (190) controls the drive unit (160) to limit the reverse operation when an excessive reverse input to the first lead screw mechanism (140) or the second lead screw mechanism (150) is detected.

6. The steering device (100) according to any one of claims 1 to 3, characterized in that An impact absorbing member (180) connected to the first moving unit (110) and absorbing an impact when the front end portion of at least one of the shaft member (118) and the first moving unit (110) moves in the axial direction toward the front side is further included.

7. The steering device (100) according to any one of claims 1 to 3, characterized in that The second lead screw mechanism (150) has a larger moving amount and a higher forward efficiency than the first lead screw mechanism (140).

8. The steering device (100) according to any one of claims 1 to 3, characterized in that The second moving unit (120) has a guide mechanism (121) that guides the movement of the first moving unit (110) with respect to the second moving unit (120).

9. The steering device (100) according to any one of claims 1 to 3, characterized in that: The holding unit (130) has a first fixed portion (135) and a second fixed portion (136) fixed to a vehicle body; and The second fixed portion (136) is arranged on the front side of the vehicle with respect to the first fixed portion (135), and the second fixed portion (136) has a higher impact absorbing property than the first fixed portion (135).

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