Steering device and method for manufacturing steering device

Abstract

A steering device (100) comprises: an input shaft body (110); a fixed member (120); a movable member (130) that supports the input shaft body (110); an upper-side guidance mechanism (140) that is disposed at an upper position and guides the movable member (130); and a lateral-side guidance mechanism (160) that is disposed laterally from the input shaft body (110) and guides the movement of the movable member (130). The upper-side guidance mechanism (140) includes: an upper-side fixed rail (141) that is fixed to the fixed member (120) and has a first track (145) facing one side thereof and a second track (146) facing another side; an upper-side movable rail (142) that has a third track (149) opposing the first track (145) and a fourth track (150) opposing the second track (146); a first rolling-element row (143) disposed between the first track (145) and the third track (149); and a second rolling-element row (144) disposed between the second track (146) and the fourth track (150).

Description

[Technical Field]

[0001] The present invention relates to a steering device that can increase the space in front of a driver by moving an operating member, such as a steering wheel, operated by the driver in the longitudinal direction of a vehicle. [Background technology]

[0002] At autonomous driving level 4 or higher, where the system is responsible for autonomous driving of a vehicle, the driver does not need to be responsible for operating the vehicle and therefore does not need to hold the steering wheel. Therefore, if the steering wheel moves during autonomous driving and a larger space is secured in front of the driver, the driver's comfort and safety can be improved. For example, Patent Document 1 discloses a steering device that can be stored in a folded state by extending and retracting its two-stage structure to increase the stroke of the operating member. As a result, when stored, the steering wheel is no longer in the space in front of the driver, thereby expanding the space in front of the driver and improving safety. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 193956 Summary of the Invention [Problem to be solved by the invention]

[0004] 2. Description of the Related Art Conventionally, in an extendable steering device, it is desirable to suppress rattle of an operating member such as a steering wheel due to vibration of the vehicle.

[0005] The present invention has been made in consideration of the above-mentioned demand, and has as its object to provide a steering device that can stably support an operating member against vibrations of a vehicle, and a method for manufacturing the steering device. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, one steering device of the present invention is a steering device for steering a vehicle, and comprises: an input shaft to which an operating member is attached; a fixed member fixed to the vehicle; a movable member rotatably supporting the input shaft; an upper guide mechanism that is arranged at a position higher than the input shaft in the vertical direction and guides movement of the movable member in the longitudinal direction of the vehicle; and a lateral guide mechanism that is arranged on the side of the input shaft in the width direction of the vehicle and guides movement of the movable member in the longitudinal direction of the vehicle, wherein the upper guide mechanism comprises: an upper fixed rail that is fixed to the fixed member and has a first raceway facing one side in the vertical direction and a second raceway facing the other side; an upper movable rail that is slidably attached to the upper fixed rail and has a third raceway facing the first raceway and a fourth raceway facing the second raceway; a first rolling element row that is a row of rolling elements arranged between the first raceway and the third raceway; and a second rolling element row that is a row of rolling elements arranged between the second raceway and the fourth raceway.

[0007] In order to achieve the above object, another aspect of the present invention provides a method for manufacturing a steering device, the steering device for steering a vehicle, comprising: an input shaft to which an operating member is attached; a fixed member fixed to the vehicle; a movable member rotatably supporting the input shaft; an upper guide mechanism that is arranged above the input shaft in the vertical direction and guides movement of the movable member in the longitudinal direction of the vehicle; and a lateral guide mechanism that is arranged to the side of the input shaft in the width direction of the vehicle and guides movement of the movable member in the longitudinal direction of the vehicle, the upper guide mechanism comprising an upper fixed rail that is fixed to the fixed member and has a first track facing one side in the vertical direction and a second track facing the other side. and an upper movable rail slidably attached to the upper fixed rail, the upper movable rail having a third raceway facing the first raceway and a fourth raceway facing the second raceway, a first rolling element row which is a row of rolling elements arranged between the first raceway and the third raceway, and a second rolling element row which is a row of rolling elements arranged between the second raceway and the fourth raceway, wherein the upper guide mechanism is attached between the fixed member and the movable member, a load is applied to at least one of the fixed member and the movable member to apply a preload to the first rolling element row and the second rolling element row, and the lateral guide mechanism is attached between the fixed member and the movable member to leave the preload. [Effects of the Invention]

[0008] According to the present invention, preload is applied to the rolling elements to prevent rattle from occurring in the rail mechanism, and the operating member can be stably supported. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing a configuration of a steering system including a steering device according to an embodiment; [Figure 2] 1 is a perspective view showing the appearance of a steering device according to an embodiment; [Figure 3] FIG. 10 is a front view showing the fixed member, the movable member, the upper guide mechanism, and the lateral guide mechanism. [Figure 4] FIG. 2 is a front view showing a first step of a manufacturing method for the steering device. [Figure 5] FIG. 10 is a front view showing a second stage of the manufacturing method of the steering device. [Figure 6] FIG. 10 is a front view showing a third stage of the manufacturing method of the steering device. [Figure 7] FIG. 10 is a front view showing a first modified example of the upper guide mechanism. [Figure 8] FIG. 10 is a front view showing a second modified example of the upper guide mechanism. [Figure 9] FIG. 10 is a front view showing a third modified example of the upper guide mechanism. [Figure 10] FIG. 10 is a front view showing a fourth modified example of the upper guide mechanism. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of a steering device and a steering device manufacturing method according to the present invention will be described with reference to the drawings. Note that the following embodiments are presented as examples for explaining the present invention and are not intended to limit the present invention. For example, the shapes, structures, materials, components, relative positional relationships, connection states, numerical values, mathematical formulas, the content of each step in the method, and the order of each step shown in the following embodiments are merely examples and may include content not described below. Furthermore, while geometric expressions such as parallel and orthogonal may be used, these expressions do not indicate mathematical precision and include substantially allowable errors and deviations. Furthermore, expressions such as simultaneous and identical also include substantially allowable ranges.

[0011] The drawings are schematic diagrams in which emphasis, omission, or adjustment of proportions is appropriately made for the purpose of explaining the present invention, and differ from the actual shapes, positional relationships, and proportions. The X-axis, Y-axis, and Z-axis shown in the drawings represent Cartesian coordinates arbitrarily set for the purpose of explaining the drawings. In other words, the Z-axis is not necessarily an axis along the vertical direction, and the X-axis and Y-axis are not necessarily located within a horizontal plane.

[0012] In addition, in the following, multiple inventions may be collectively described as one embodiment, and some of the contents described below may be described as optional components related to the present invention.

[0013] 1 is a schematic diagram showing an outline of the configuration of a steering system 200 according to an embodiment. The steering system 200 according to this embodiment is a device mounted on a vehicle such as a passenger car, bus, truck, construction machine, or agricultural machine that can switch between a manual driving mode and an automatic driving mode.

[0014] 1, steering system 200 includes steering device 100 having an operation member 210 operated by the driver, and a steering mechanism unit 230 that steers steerable wheels 220. Steering system 200 is a system that, in a manual driving mode, for example, reads the rotation angle of operation member 210 with a sensor or the like, and steers steerable wheels 220 by causing rack shaft 231 to reciprocate left and right based on a signal from the sensor or the like. Such a system is called, for example, a steer-by-wire (SBW) system.

[0015] In steering mechanism 230, movement of rack shaft 231 in the width direction of the vehicle (left and right direction in FIG. 1 ) causes steerable wheels 220 connected to rack shaft 231 via tie rod 232 to turn. Specifically, in manual driving mode, steering actuator 233 operates based on a signal indicating the rotation angle of operating member 210, etc., transmitted from steering device 100. This causes rack shaft 231 to move in the width direction of the vehicle, and steers steerable wheels 220. In other words, steerable wheels 220 are turned in accordance with the operation of operating member 210. In autonomous driving mode, steering actuator 233 operates based on a signal, etc., transmitted from an ECU (Electronic Control Unit) for autonomous driving provided in the vehicle, and thereby steers steerable wheels 220 regardless of the operation of operating member 210. 1 illustrates a configuration in which the driving force of steering actuator 233 is transmitted to rack shaft 231 using a belt, but there are no particular limitations on the method of transmitting the driving force of steering actuator 233 to rack shaft 231. For example, the driving force of steering actuator 233 may be transmitted to rack shaft 231 via a pinion gear fixed to the rotation shaft of steering actuator 233.

[0016] Fig. 2 is a perspective view showing the appearance of the steering device 100 according to the embodiment. Fig. 2 shows the steering device 100 when the movable member 130 is in a protruding position protruding from the fixed member 120. The "protruding position" is a position where the driver can operate the operating member 210 during manual driving.

[0017] The steering device 100 according to this embodiment includes an input shaft 110 , a fixed member 120 , a movable member 130 , an upper guide mechanism 140 , and a lateral guide mechanism 160 .

[0018] The input shaft 110 is a rod-shaped member to which an operating member 210, which is operated by the driver to steer the vehicle, is attached at its tip, and is rotatably supported by the movable member 130. A reaction force generator, a rotation angle sensor, etc. are attached to the input shaft 110, and a reaction force is applied to the operating member 210 when the driver operates the operating member 210. In addition, the rotation angle sensor outputs a signal for synchronizing the rotation position of the operating member 210 with the steering angle of the steered wheels 220.

[0019] The fixed member 120 is a member that is fixedly attached to a reinforcement, which is one of the structural members of the vehicle body. The manner in which the fixed member 120 is attached to the vehicle body is not limited, but in this embodiment, the fixed member 120 is attached in a suspended state to a reinforcement that is stretched across the width direction of the vehicle body. The cross-sectional shape of the fixed member 120 perpendicular to the movement direction of the movable member 130 (the Y-axis direction in the figure) is an L-shape rotated 90 degrees to the right, and the fixed member 120 includes a plate-like fixed top panel portion 121 and a fixed wall portion 122 that extends downward on one side (the X-side in the figure) of the fixed top panel portion 121 in the width direction (the X-axis direction in the figure).

[0020] A moving device 125 for moving movable member 130 is attached below fixed member 120 (on the Z-side in the drawing). The type of moving device 125 is not particularly limited, but in this embodiment, it includes a feed screw 127 rotatably attached to fixed member 120 via fixed bracket 126 so as to extend in the movement direction of movable member 130 (the Y-axis direction in the drawing), a movable nut 138 that meshes with feed screw 127 and reciprocates in the movement direction of movable member 130 as the feed screw 127 rotates, and a rotation drive device 128 that includes a motor that rotates feed screw 127.

[0021] The movable member 130 is attached to the fixed member 120 so as to be reciprocable between an advanced position and a retracted position by the upper guide mechanism 140, the lateral guide mechanism 160, and the moving device 125. An input shaft 110 that holds an operating member 210 is rotatably attached to the movable member 130. In this embodiment, the cross-sectional shape of the movable member 130 perpendicular to the direction of movement (the Y-axis direction in the figure) is an L-shape rotated 90 degrees to the right, and the movable member 130 includes a plate-like movable top panel 131 and a movable wall portion 132 that extends downward from one side (the X-side in the figure) of the movable top panel 131 in the width direction (the X-axis direction in the figure). The movable wall portion 132 is thicker than the fixed wall portion 122 in the width direction, and is provided with a through-hole 135 therein through which a harness or the like connected to an operating switch or the like can be inserted.

[0022] FIG. 3 is a front view showing the fixed member 120, the movable member 130, the upper guide mechanism 140, and the lateral guide mechanism 160. FIG.

[0023] The upper guide mechanism 140 is positioned above (on the Z+ side in the figure) the input shaft 110 in the vertical direction (Z-axis direction in the figure), and is a mechanism that guides the movement of the movable member 130 in the fore-and-aft direction of the vehicle (Y-axis direction in the figure), and is equipped with an upper fixed rail 141, an upper movable rail 142, a first rolling body row 143, and a second rolling body row 144.

[0024] The upper fixed rail 141 is fixed to the fixed member 120 and includes a first track 145 facing one side in the vertical direction and a second track 146 facing the other side. In this embodiment, the upper fixed rail 141 is formed of a plate-like member including a first fixed portion 147 fixed to the underside of the fixed top plate portion 121 and a first spaced portion 148 extending from the first fixed portion 147 so as to move away from the fixed top plate portion 121 as it moves away from the lateral guide mechanism 160. The first track 145 is located at the tip end of the first spaced portion 148, on the surface of the first spaced portion 148 facing the fixed member 120. The second track 146 is located at the base end of the first spaced portion 148, on the surface of the first spaced portion 148 facing the movable member 130. In this embodiment, the one side faces upward and the other side faces downward in the vertical direction. The first separation portion 148 is gradually spaced away from the fixing member 120, and the first track 145 is spaced farther from the fixing member 120 than the second track 146. The first track 145 and the second track 146 are planar, and the first track 145 and the second track 146 are arranged in parallel.

[0025] Upper movable rail 142 is a member slidably attached to upper fixed rail 141 and includes third track 149 opposite first track 145 and fourth track 150 opposite second track 146. In this embodiment, upper movable rail 142 is formed of a plate-like member including second fixed portion 151 fixed to the top surface of movable top plate portion 131 and second spaced portion 152 extending from second fixed portion 151 away from movable top plate portion 131 and positioned between first spaced portion 148 and fixed top plate portion 121. Third track 149 is positioned at the tip of second spaced portion 152, between first spaced portion 148 and fixed top plate portion 121, by bending the tip of second spaced portion 152. The bent portion of second spaced portion 152 is positioned so as to bypass the tip of first spaced portion 148. The third track 149 and the fourth track 150 are arranged on the same plane of the second spaced apart portion 152. The portion of the second spaced apart portion 152 where the fourth track 150 is arranged bulges out toward the second track 146. The third track 149 and the fourth track 150 are planar and arranged parallel to the first track 145 and the second track 146.

[0026] The first rolling element row 143 is a row of multiple rolling elements arranged between the first raceway 145 and the third raceway 149, and is held by the first retainer 153 so as to extend along the direction of movement of the movable member 130. The second rolling element row 144 is a row of multiple rolling elements arranged between the second raceway 146 and the fourth raceway 150, and is held by the first retainer 153 so as to extend along the direction of movement of the movable member 130.

[0027] The lateral guide mechanism 160 is a mechanism that is arranged to the side of the input shaft 110 in the width direction of the vehicle (X-axis direction in the figure) and guides the movement of the movable member 130 in the fore-and-aft direction of the vehicle (Y-axis direction in the figure), and is equipped with a lateral fixed rail 161, a lateral movable rail 162, a third rolling body row 163, and a fourth rolling body row 164.

[0028] The lateral fixed rail 161 is fixed to the fixed member 120 and includes a fifth track 165 facing upward in the vertical direction and a sixth track 166 facing downward. In this embodiment, the lateral fixed rail 161 is formed of a plate-like member including a third fixed portion 167 fixed to the surface of the fixed wall portion 122 facing the movable member 130, and a first protrusion 168 and a second protrusion 169 protruding from both upper and lower ends of the third fixed portion 167. The fifth track 165 is disposed on the upper surface of the tip of the first protrusion 168. The sixth track 166 is disposed on the lower surface of the tip of the second protrusion 169. The fifth track 165 and the sixth track 166 are groove-shaped and extend in the direction of movement of the movable member 130, and make two-point contact with the rolling elements constituting the third rolling element row 163.

[0029] The lateral movable rail 162 is fixed to the movable member 130 and includes a seventh track 170 facing downward in the vertical direction and an eighth track 171 facing upward. In this embodiment, the lateral movable rail 162 is formed of a plate-like member including a fourth fixed portion 172 fixed to the surface of the movable wall portion 132 facing the fixed member 120, and a third protrusion 173 and a fourth protrusion 174 protruding from both upper and lower ends of the fourth fixed portion 172. The seventh track 170 is disposed on the lower surface of the tip of the third protrusion 173. The eighth track 171 is disposed on the upper surface of the tip of the fourth protrusion 174. The seventh track 170 and the eighth track 171 are groove-shaped extending in the movement direction of the movable member 130 and make two-point contact with the rolling elements constituting the fourth rolling element row 164.

[0030] The third rolling element row 163 is a row of multiple rolling elements arranged between the fifth raceway 165 and the seventh raceway 170, and is held by the second retainer 175 so as to align with the movement direction of the movable member 130. The fourth rolling element row 164 is a row of multiple rolling elements arranged between the sixth raceway 166 and the eighth raceway 171, and is held by the second retainer 175 so as to align with the movement direction of the movable member 130.

[0031] As a result, the lateral guide mechanism 160 has two pairs of fifth track 165 and seventh track 170, and sixth track 166 and eighth track 171 that face each other in the vertical direction (Z-axis direction in the drawing).

[0032] The positional relationship between the upper guide mechanism 140 and the lateral guide mechanism 160, which are respectively attached between the fixed member 120 and the movable member 130, is such that a compressive preload is applied to the first rolling element row 143 and the second rolling element row 144 from the upper fixed rail 141 and the upper movable rail 142. In other words, by attaching the lateral guide mechanism 160 between the fixed member 120 and the movable member 130, it is possible to determine the distance between the fixed top plate portion 121 and the movable top plate portion 131. The determined distance is a distance that allows a compressive preload to be applied to the first rolling element row 143 and the second rolling element row 144.

[0033] In this embodiment, the normals to the contact points between the rolling elements and the first raceway 145, the second raceway 146, the third raceway 149, and the fourth raceway 150 in the upper guide mechanism 140 each extend in the vertical direction (the Z-axis direction in the figure). In other words, the contact angle of the rolling elements in the upper guide mechanism 140 is 0 degrees.

[0034] There are two contact points between the rolling elements and the fifth raceway 165, the sixth raceway 166, the seventh raceway 170, and the eighth raceway 171 in the side guide mechanism 160, and the normal to each contact point is inclined with respect to the vertical direction. In other words, the contact angle of the rolling elements in the side guide mechanism 160 is greater than 0 degrees, and in this embodiment, it is 45 degrees. By attaching the side guide mechanism 160 to the fixed member 120 and the movable member 130, the vertical and widthwise positions of the movable member 130 relative to the fixed member 120 are determined.

[0035] Due to the relationship between the structure of the lateral guide mechanism 160 and the structure of the upper guide mechanism 140, the upper fixed rail 141 and the upper movable rail 142 of the upper guide mechanism 140 can be shifted to accommodate the widthwise positional relationship between the fixed member 120 and the movable member 130 determined by the lateral guide mechanism 160. Therefore, even if the upper guide mechanism 140 and the lateral guide mechanism 160 are not arranged strictly parallel to the moving direction of the movable member 130, for example, an increase in the slide load is suppressed by the structure that allows the upper fixed rail 141 and the upper movable rail 142 of the upper guide mechanism 140 to move (displace) in the width direction of the vehicle. Furthermore, because strict parallel arrangement of the lateral guide mechanism 160 and the upper guide mechanism 140 to the moving direction of the movable member 130 is not required, the installation work of the lateral guide mechanism 160 and the upper guide mechanism 140 is made more efficient. As a result, the manufacturing efficiency of the steering device 100 is improved and manufacturing costs are reduced.

[0036] Furthermore, the vertical positional relationship between the fixed member 120 and the movable member 130 determined by the lateral guide mechanism 160 can generate a compressive preload that is applied in the vertical direction to the first rolling element row 143 and the second rolling element row 144 of the upper guide mechanism 140. As a result, even if the dimensional tolerance of the upper guide mechanism 140 is large, the upper movable rail 142 can be tightly attached to the upper fixed rail 141 via the rolling elements, making it possible to suppress rattle of the movable member 130 relative to the fixed member 120. Furthermore, because strict dimensional tolerances are not required for the upper guide mechanism 140, the upper guide mechanism 140 can be easily manufactured. As a result, the manufacturing efficiency of the steering device 100 can be improved and manufacturing costs can be reduced.

[0037] Next, a method for manufacturing the steering device 100 will be described. FIG. 4 is a front view showing a first stage of the method for manufacturing the steering device 100. As shown in the figure, first, the upper guide mechanism 140 is attached between the fixed member 120 and the movable member 130. The attachment method is not particularly limited, and examples include fastening and welding. Furthermore, the posture for attaching the upper guide mechanism 140 between the fixed member 120 and the movable member 130 is not limited to the posture shown in FIG. 4, and any posture that provides good work efficiency can be adopted.

[0038] Next, a force is applied to the fixed member 120 and the movable member 130 to apply a preload to the first rolling element row 143 and the second rolling element row 144. The method of applying the preload is not particularly limited. For example, as shown in FIG. 5 , the steering device 100 is arranged on a workbench 300 so that the fixed member 120 is below the movable member 130. Then, a load (indicated by the hollow arrow in the drawing) may be applied to the movable member 130 toward the fixed member 120 at a position on the fixed wall portion 122 side of the second rolling element row 144, thereby applying a preload (indicated by the arrow in the drawing) to the first rolling element row 143 and the second rolling element row 144. Specifically, the application of the load narrows the gap between the second raceway 146 and the fourth raceway 150, thereby applying a preload to the second rolling element row 144. This creates a lever-like effect with the load-applied position of the movable member 130 as the force point, the second rolling element row 144 as the fulcrum, and the first rolling element row 143 as the point of action, and a moment is generated in the second spaced portion 152 around the second rolling element row 144, causing the third raceway 149, which is located at the tip of the second spaced portion 152, to approach the first raceway 145. As a result, a preload in the compressive direction is also applied to the first rolling element row 143.

[0039] Next, as shown in FIG. 6 , while maintaining the preload applied to the first rolling element row 143 and the second rolling element row 144, the lateral guide mechanism 160 is attached between the fixed member 120 and the movable member 130, thereby maintaining the preload applied to the first rolling element row 143 and the second rolling element row 144. The attachment method is not particularly limited, and examples include fastening and welding. For example, when attaching the lateral guide mechanism 160 by fastening, holes through which fastening members pass are provided in the fixed member 120 and the movable member 130. These holes are preferably elongated holes aligned with the direction of the preload applied to the first rolling element row 143 and the second rolling element row 144. This allows the lateral guide mechanism 160 to be attached between the fixed member 120 and the movable member 130 at a position that maintains the predetermined preload by adjusting the fastening position relative to the elongated holes, even when the dimensional tolerance of the upper guide mechanism 140 is wide. Note that as a result of adjusting the distance between movable member 130 and fixed member 120, the position of the through hole of movable member 130 relative to lateral guide mechanism 160 may be slightly misaligned from the position of the through hole of the fixed member, causing movable member 130 to tilt slightly when attached by fastening lateral guide mechanism 160, but since this tilt is small, it can be absorbed by elastic deformation of upper fixed rail 141, upper movable rail 142, fixed member 120, and movable member 130. Therefore, lateral guide mechanism 160 can connect fixed member 120 and movable member 130 without any gaps.

[0040] Finally, the force that was being applied in the direction narrowing the gap between fixed member 120 and movable member 130 is released. Even after the force is released, fixed member 120 and movable member 130 are connected by lateral guide mechanism 160, whose contact angle is inclined with respect to the preload direction, so that the gap between fixed top plate portion 121 and movable top plate portion 131 can be maintained, and the preload can be maintained.

[0041] The present invention is not limited to the above-described embodiments. For example, the present invention may be embodied in another embodiment by arbitrarily combining the components described in this specification or by excluding some of the components. Furthermore, the present invention also includes various modifications that would occur to a person skilled in the art without departing from the spirit of the present invention, i.e., the meaning of the wording of the claims.

[0042] For example, instead of the upper guide mechanism 140 applying a compressive preload to the first rolling element row 143 and the second rolling element row 144 by shortening the distance between the fixed top plate portion 121 and the movable top plate portion 131, as a first variant, as shown in Figure 7, the upper guide mechanism 140 may apply a compressive preload to the first rolling element row 143 and the second rolling element row 144 by widening the distance between the fixed top plate portion 121 and the movable top plate portion 131.

[0043] Specifically, the upper fixed rail 141 is formed of a plate-like member including a first fixed portion 147 fixed to the underside of the fixed top panel portion 121 and a first spaced portion 148 extending from the first fixed portion 147 so as to be spaced apart from the fixed top panel portion 121. The first spaced portion 148 is bent to bypass the tip of the second spaced portion 152 and is disposed between the second spaced portion 152 and the movable top panel portion 131. The first track 145 is disposed at the base end of the first spaced portion 148 on the surface facing the movable member 130. In the first modified example, one of the first track 145 faces downward and the other faces upward in the vertical direction. The second track 146 is disposed at the tip of the first spaced portion 148 on the same surface as the first track 145 of the first spaced portion 148. The second track 146 is disposed on the surface of the first spaced portion 148 facing the fixed member 120. The first track 145 and the second track 146 are respectively arranged on mutually opposing surfaces of the curved first spacing portion 148. The second spacing portion 152 of the upper movable rail 142 extends from the second fixed portion 151 so as to move away from the movable top plate portion 131 as it moves away from the lateral guide mechanism 160, with its tip approaching the movable top plate portion 131. As a result, by applying a tensile load in a direction away from the fixed member 120 to a position on the movable member 130 closer to the fixed wall portion 122 than the second rolling element row 144, the distance between the fixed top plate portion 121 and the movable top plate portion 131 widens, and a compressive preload is applied to the second rolling element row 144. This creates a lever-like effect with the tensile load position of the movable member 130 as the force point, the second rolling element row 144 as the fulcrum, and the first rolling element row 143 as the point of action, and a moment is generated in the second separating portion 152 in a direction in which the tip of the second separating portion 152 approaches the fixed top plate portion 121. This also applies a preload in the compression direction to the first rolling element row 143.

[0044] Furthermore, as a second modified example, the shapes of the upper fixed rail 141 and the upper movable rail 142 may be such that a fastening portion 181 is provided so that the upper fixed rail 141 and the upper movable rail 142 do not interfere with each other in the vertical direction, as shown in Figure 8, making it easier for tools to reach the fastening member 180.

[0045] Specifically, the upper fixed rail 141 is formed of a plate-like member including a first fixed portion 147 fixed to the underside of the fixed top panel portion 121, a first spaced portion 148 extending from the first fixed portion 147 away from the fixed top panel portion 121 and disposed between the second spaced portion 152 and the movable top panel portion 131, and a fastening portion 181 extending from the first fixed portion 147 toward the other widthwise side (the X+ side in the figure) and fixed to the fixed top panel portion 121. The first track 145 is located at the tip of the first spaced portion 148 and is disposed on the surface facing the fixed member 120. The second track 146 is located on the same surface of the upper fixed rail 141 as the first track 145 and is disposed on the surface of the first fixed portion 147 facing the movable member 130. In the second modified example, one of the first and second track 146 faces upward and the other faces downward in the vertical direction. The portion of the first fixed portion 147 where the second track 146 is disposed is spaced from the fixed top panel portion 121.

[0046] In the second variant, as in the embodiment, a preload can be applied to the first rolling element row 143 and the second rolling element row 144 by applying a load toward the fixed element 120 to a position on the movable element 130 closer to the fixed wall portion 122 than the second rolling element row 144.

[0047] Specifically, when a load is applied, the gap between the second raceway 146 and the fourth raceway 150 narrows, and a preload is applied to the second rolling element row 144. This creates a lever with the load position of the movable member 130 as the force point, the second rolling element row 144 as the fulcrum, and the first rolling element row 143 as the point of action, and a moment is generated in the second spaced portion 152 around the second rolling element row 144, and the third raceway 149, which is located at the tip of the second spaced portion 152, approaches the first raceway 145. As a result, a preload in the compressive direction is also applied to the first rolling element row 143.

[0048] Furthermore, as shown in Figure 9, as a third modified example, in order to generate a strong moment in the second separation portion 152, the portion of the upper fixed rail 141 where the second track 146 of the first fixed portion 147 is provided may have a structure that makes it difficult to bend when it abuts against the fixed top plate portion 121.

[0049] Furthermore, the shapes of the upper fixed rail 141 and the upper movable rail 142 may be interchanged, and the shapes of the lateral fixed rail 161 and the lateral movable rail 162 may be interchanged. For example, as shown in FIG. 10 , in a fourth modified example, the second spaced portion 152 is bent to bypass the tip of the first spaced portion 148 and is disposed between the first spaced portion 148 and the fixed top plate portion 121. The third track 149 is disposed at the base end of the second spaced portion 152. In the fourth modified example, one of the second spaced portion 152 faces downward and the other faces upward in the vertical direction. The fourth track 150 is disposed at the tip of the second spaced portion 152, on the same surface as the third track 149 of the second spaced portion 152. The third track 149 and the fourth track 150 are disposed on opposing surfaces of the curved second spaced portion 152. The first separating portion 148 of the upper fixed rail 141 extends from the first fixed portion 147 so as to move away from the fixed top plate portion 121 as it moves away from the lateral guide mechanism 160, with its tip approaching the fixed top plate portion 121. As a result, when a tensile load in a direction away from the fixed member 121 is applied to a position on the movable member closer to the fixed wall portion 122 than the second rolling element row 144, the gap between the fixed top plate portion 121 and the movable top plate portion 131 widens, and a compressive preload is applied to the second rolling element row 144. Then, the tip end of the second spaced portion 152 presses the base end of the first spaced portion 148 via the second rolling element row 144, and the first spaced portion 148 moves away from the fixed member 120 with the first fixed portion 147 as a fulcrum, causing the tip end of the first spaced portion 148 to press the base end of the second spaced portion 152 against the movable member 130 via the first rolling element row 143, generating a moment. This applies a preload in the compression direction to the first rolling element row 143 as well.

[0050] The steering device 100 may also be provided with a tilt mechanism that tilts the moving direction of the movable member 130. In this case, the fixed member 120 may be attached to the vehicle body so as to be swingable, or the movable member 130 may be attached to the fixed member 120 so as to be swingable. [Industrial Applicability]

[0051] The present invention is useful as a steering device that can expand the space ahead of the driver, and can therefore be used in vehicles equipped with wheels or caterpillars, such as manually and automatically driven passenger cars, buses, trucks, agricultural machinery, and construction machinery. [Explanation of symbols]

[0052] 100...Steering device, 110...Input shaft body, 120...Fixed member, 121...Fixed top plate portion, 122...Fixed wall portion, 125...Moving device, 126...Fixed bracket, 127...Feed screw, 128...Rotation drive device, 130...Moving member, 131...Moving top plate portion, 132...Moving wall portion, 135...Through hole, 138...Moving nut, 140...Upper guide mechanism, 141...Upper fixed rail, 142...Upper movable rail, 143...First rolling element row, 144...Second rolling element row, 145...First raceway, 146...Second raceway, 147...First fixed portion, 148...First separation portion, 149...Third raceway, 150...Fourth raceway, 151...Second fixed portion, 152...Second separation portion, 153 ...First retainer, 160...side guide mechanism, 161...side fixed rail, 162...side movable rail, 163...third rolling element row, 164...fourth rolling element row, 165...fifth raceway, 166...sixth raceway, 167...third fixed portion, 168...first protrusion, 169...second protrusion, 170...seventh raceway, 171...eighth raceway, 172...fourth fixed portion, 173...third protrusion, 174...fourth protrusion, 175...second retainer, 180...fastening member, 181...fastening portion, 200...steering system, 210...operating member, 220...steered wheel, 230...steering mechanism portion, 231...rack shaft, 232...tie rod, 233...steering actuator, 300...work platform

Claims

1. A steering device for steering a vehicle, an input shaft to which an operating member is attached; a fixing member fixed to the vehicle; a movable member that rotatably supports the input shaft; an upper guide mechanism that is disposed at a position higher than the input shaft in the vertical direction and that guides movement of the movable member in the front-rear direction of the vehicle; a lateral guide mechanism that is arranged on a side of the input shaft in the width direction of the vehicle and that guides movement of the movable member in the front-rear direction of the vehicle, The upper guide mechanism is an upper fixed rail fixed to the fixed member and having a first track facing one side in the vertical direction and a second track facing the other side; an upper movable rail slidably attached to the upper fixed rail and having a third track opposite the first track and a fourth track opposite the second track; a first rolling element row which is a row of a plurality of rolling elements arranged between the first raceway and the third raceway, and a second rolling element row which is a row of a plurality of rolling elements arranged between the second raceway and the fourth raceway, Steering device.

2. The positional relationship between the upper guide mechanism and the lateral guide mechanism, which are respectively attached between the fixed member and the movable member, is such that a preload in a compression direction is applied to the first rolling element row and the second rolling element row. The steering device according to claim 1 .

3. The upper fixed rail is a first fixed portion fixed to a surface of the fixed member facing the movable member; a first spaced portion extending from the first fixed portion in the width direction of the vehicle and spaced apart from the fixed member, The upper movable rail is a second fixed portion fixed to a surface of the movable member facing the fixed member; a second spaced portion extending from the second fixed portion in the width direction of the vehicle and spaced apart from the movable member, the first spaced portion is disposed between the second spaced portion and the movable member, The first track is disposed at a tip end of the first spaced apart portion, and the third track is disposed at a tip end of the second spaced apart portion.

3. A steering device according to claim 1 or 2.

4. The upper fixed rail is a first fixed portion fixed to a surface of the fixed member facing the movable member; a first spaced portion extending from the first fixed portion in the width direction of the vehicle and spaced apart from the fixed member, The upper movable rail is a second fixed portion fixed to a surface of the movable member facing the fixed member; a second spaced portion extending from the second fixed portion in the width direction of the vehicle and spaced apart from the movable member, the first spaced portion is disposed between the second spaced portion and the movable member, The first track is disposed at a distal end of the first spaced apart section and the third track is disposed at a proximal end of the second spaced apart section, or the first track is disposed at a proximal end of the first spaced apart section and the third track is disposed at a distal end of the second spaced apart section.

3. A steering device according to claim 1 or 2.

5. the first orbit, the second orbit, the third orbit, and the fourth orbit are planar; The lateral guide mechanism is a lateral fixed rail fixed to the fixed member and having a fifth track and a sixth track; a movable lateral rail slidably attached to the fixed lateral rail and having a seventh track opposite the fifth track and an eighth track opposite the sixth track; a third rolling element row which is a row of a plurality of rolling elements arranged between the fifth raceway and the seventh raceway, and a fourth rolling element row which is a row of a plurality of rolling elements arranged between the sixth raceway and the eighth raceway, The contact angles of each of the plurality of rolling elements in the third rolling element row with respect to the fifth raceway and the seventh raceway, and the contact angles of each of the plurality of rolling elements in the fourth rolling element row with respect to the sixth raceway and the eighth raceway are both greater than 0°. A steering device according to any one of claims 1 to 4.

6. A method for manufacturing a steering device according to any one of claims 1 to 5, comprising: the upper guide mechanism is attached between the fixed member and the movable member; applying a force to the fixed member and the movable member to preload the first rolling element row and the second rolling element row; The lateral guide mechanism is attached between the fixed member and the movable member to maintain the preload. A method for manufacturing a steering device.

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