Steering device

Abstract

A steering device (100) according to a first aspect of the present invention is for steering a vehicle and has: a steering shaft body (110) to which a steering member (210) is attached; a movable member (130) that rotatably holds the steering shaft body (110); and at least a pair of rail mechanisms (140) that guide the movement of the movable member (130) in the front-rear direction of the vehicle. In a cross section orthogonal to the guide direction of the pair of rail mechanisms (140), the rail mechanisms (140) are disposed obliquely with respect to the sides of a rectangle (300), which is a virtual rectangle (300) in which the movable member (130) is inscribed and one side of which is parallel to a horizontal plane, in a state in which at least parts of the mechanisms (140) are included in a pair of corners of the rectangle (300) in which the movable member (130) is not included.

Description

Steering device

[0001] The present invention relates to a steering device that holds a steering member steered by a driver in a vehicle or the like.

[0002] There is known a retractable steering device that moves a steering member steered by a driver to the front side of a vehicle to improve the driver's habitability during autonomous driving. The retractable steering device may store the steering member at a predetermined position by sliding the entire steering shaft body that holds the steering member using rails. In such a retractable steering device, Patent Document 1 describes rails disposed above the steering shaft body. Further, Patent Document 2 describes rails disposed above and laterally of the steering shaft body.

[0003] Japanese Patent Application Laid-Open No. 2019-182041, WO2023 / 119365

[0004] However, when the rails are disposed above the steering shaft body, there is a risk of interfering with meters or the like disposed within the instrument panel, or the dashboard through which the steering shaft body passes becoming larger in the upward direction, which may obstruct the driver's view. Also, when the rails are disposed laterally of the steering shaft body, there is concern about interference with brakes, air conditioners, etc. disposed laterally of the steering device, and there is a risk that the entire steering device may become larger in order to ensure rigidity against vertical loads.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a steering device capable of achieving compactness in a plane perpendicular to the movable direction.

[0006] One steering device according to the present invention is a steering device for steering a vehicle, comprising: a steering shaft to which a steering member is attached; a movable member that rotatably holds the steering shaft; and at least a pair of rail mechanisms that guide the movement of the movable member in the longitudinal direction of the vehicle, wherein the pair of rail mechanisms are arranged diagonally with respect to the sides of a hypothetical rectangle in which the movable member is inscribed, and at least a portion of the pair of corners other than the movable member within the rectangle, with one side parallel to the horizontal plane, in a cross section perpendicular to the guiding direction of the rail mechanisms.

[0007] According to the present invention, a compact steering device can be provided by arranging at least a portion of a pair of rail mechanisms in the dead space generated by the movable member, and by arranging the rail mechanisms diagonally.

[0008] Figure 1 is a schematic diagram showing the configuration of the steering system. Figure 2 is a perspective view showing the external appearance of the steering device with the steering member moved to the rear position of the vehicle. Figure 3 is a plan view showing the shape of the movable member and column unit as seen from the direction of movement of the movable member. Figure 4 is a cross-sectional view showing the fastening portion between the movable member and the rail mechanism.

[0009] The following describes embodiments of the steering device according to the present invention with reference to the drawings. Note that the following embodiments are examples provided to illustrate the present invention and are not intended to limit it. For example, the shapes, structures, materials, components, relative positional relationships, connection states, numerical values, formulas, the content of each step in the method, and the order of each step shown in the following embodiments are examples and may include content not described below. Furthermore, geometric expressions such as parallel and orthogonal may be used, but these expressions do not indicate mathematical rigor and include substantially acceptable errors and deviations. Similarly, expressions such as simultaneous and identical also include substantially acceptable ranges.

[0010] Furthermore, the drawings are schematic diagrams that have been appropriately emphasized, omitted, or had their proportions adjusted to illustrate the present invention, and therefore differ from the actual shapes, positional relationships, and proportions. Also, the X, Y, and Z axes shown in the drawings represent orthogonal 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 and Y axes are not necessarily located in the horizontal plane.

[0011] Furthermore, in the following, multiple inventions may be described comprehensively as a single embodiment. Also, some of the content described below is described as an optional component relating to the present invention.

[0012] Figure 1 is a schematic diagram showing the configuration of the steering system 200. The steering system 200 according to this embodiment is a device that can be mounted on vehicles such as passenger cars, buses, trucks, construction machinery, or agricultural machinery, and can switch between manual driving mode and automatic driving mode.

[0013] The type of steering system 200 equipped with the steering device 100 is not limited. In this embodiment, as shown in Figure 1, the steering system 200 includes a steering device 100 to which a steering member 210 operated by the driver is attached, and a steering mechanism 230 that steers the steering wheels 220. The steering system 200 is a system that, for example in manual driving mode, reads the rotation angle of the steering member 210 with a sensor or the like, and steers the steering wheels 220 by having the rack shaft 231 reciprocate from side to side based on the signal from the sensor or the like. Such a system is called, for example, an SBW (Steer By Wire) system. In this embodiment, the steering system 200 is a linkless SBW system that does not have mechanical elements such as links connecting the steering member 210 and the steering wheels 220.

[0014] In the steering mechanism 230, the movement of the rack shaft 231 in the vehicle's width direction (left-right direction in Figure 1) steers the steering wheels 220 connected to the rack shaft 231 via the tie rods 232. Specifically, in manual driving mode, the steering actuator 233 operates based on signals from the steering device 100 indicating the rotation angle of the steering member 210, etc. This causes the rack shaft 231 to move in the vehicle's width direction, steering the steering wheels 220. In other words, the steering wheels 220 steer in response to the operation of the steering member 210. In automatic driving mode, the steering actuator 233 operates based on signals from the vehicle's ECU (Electronic Control Unit) for automatic driving, etc., causing the steering wheels 220 to steer independently of the operation of the steering member 210. Figure 1 illustrates a configuration in which the driving force of the steering actuator 233 is transmitted to the rack shaft 231 using a belt, but there are no particular limitations on the method of transmitting the driving force of the steering actuator 233 to the rack shaft 231. For example, the driving force of the steering actuator 233 may be transmitted to the rack shaft 231 via a pinion gear fixed to the rotation axis of the steering actuator 233.

[0015] Figure 2 is a perspective view showing the external appearance of the steering device 100 with the steering member moved to a rear position of the vehicle. Figure 3 is a plan view showing the shape of the movable member 130 as seen from the direction of movement. The steering device 100 is a device for steering a vehicle, and is a device that can move the steering member 210 (not shown in Figure 2) in at least one predetermined axial direction (Y-axis direction in the figure). In this embodiment, the steering device 100 moves the steering member 210 between a rear position where the driver can operate the steering member 210 for driving, and a front position which is a position in front of the vehicle that is out of reach of the driver in a driving position. The steering device 100 comprises a steering shaft 110, a movable member 130, and a rail mechanism 140. In this embodiment, the steering device 100 comprises a fixed member 120, a reaction motor 111, and a coaxial reducer 112.

[0016] The steering shaft 110 is a rod-shaped member to which a steering member 210, operated by the driver for steering the vehicle, is attached, and is rotatably held by a movable member 130. In this embodiment, the steering shaft 110 is connected to a coaxial reduction gear 112, which is arranged coaxially. The coaxial reduction gear 112 is connected to a reaction motor 111, which is also arranged coaxially. By arranging the steering shaft 110, the reaction motor 111, and the coaxial reduction gear 112 coaxially, the column unit 113, consisting of the steering shaft 110, the reaction motor 111, and the coaxial reduction gear 112, is made smaller (slimmer). The column unit 113 is also equipped with a rotation angle sensor (not shown) and a torque sensor (not shown), and a reaction force is applied to the steering member 210 when the driver operates the steering member 210. The rotation angle sensor outputs a signal to synchronize the rotational position of the steering member 210 with the steering angle of the steering wheel 220.

[0017] The movable member 130 is a member that rotatably holds the steering shaft 110 and moves relative to the fixed member 120 in the direction of movement (Y-axis direction in the figure) connecting the rear and front positions of the vehicle. Note that the direction of movement of the movable member 130 in the longitudinal direction of the vehicle does not necessarily coincide with the direction of movement of the movable member 130 in the longitudinal direction of the vehicle. In this embodiment, the movable member 130 holds a reaction motor 111 and a coaxial reduction gear 112 coaxially with the steering shaft 110. The movable member 130 holds the steering shaft 110 via the reaction motor 111 and the coaxial reduction gear 112. The shape of the movable member 130 is not limited. In this embodiment, the movable member 130 is formed by bending sheet metal. The movable member 130 includes a pair of rail holding parts 131, which are attached to a virtual rectangle 300 in which the movable member 130 is inscribed in a cross section (ZX plane in the figure) perpendicular to the direction of movement of the movable member 130 (Y axis direction in the figure), and one side of the rectangle 300 is positioned diagonally to the side of the rectangle 300 which is parallel to the horizontal plane (XY plane in the figure). The movable member 130 also includes a beam part 132 that holds the pair of rail holding parts 131 at both ends in the width direction, and a shaft holding part 133 that extends downward from the lower end of the rail holding parts 131 and holds the steering shaft 110 via a reaction motor 111 and a coaxial reducer 112.

[0018] The rail mechanism 140 is interposed between the fixed member 120 and the movable member 130, and is a mechanism that guides the movement of the movable member 130 in the longitudinal direction of the vehicle. Each of the pair of rail mechanisms 140 is positioned such that, in a cross section (XZ plane in the figure) perpendicular to the guidance direction of the rail mechanism 140 (Y axis direction in the figure), the movable member 130 is inscribed in a virtual rectangle 300, and one side of the rectangle 300 is parallel to the horizontal plane (XY plane in the figure), with at least a portion of each of the pair of corners other than the movable member 130 within the rectangle 300. Furthermore, each of the pair of rail mechanisms 140 is positioned diagonally with respect to the sides of the rectangle 300. In this embodiment, the rail mechanism 140 is positioned diagonally with respect to the sides of the rectangle 300 by being attached to the mounting surface 135 of the rail holding portion 131 of the movable member 130, which is positioned diagonally with respect to the rectangle 300. Diagonal with respect to the sides of the rectangle 300 means in the range of approximately 25 degrees or more and 65 degrees or less with respect to the sides of the rectangle 300. The pair of mounting surfaces 135, each provided on the upper side of the pair of rail holding portions 131, are inclined such that the distance between them decreases as you move upward (towards the Z+ side in the figure). The pair of rail mechanisms 140, each attached to the pair of mounting surfaces 135, are also inclined such that the distance between them decreases as you move upward (towards the Z+ side in the figure).

[0019] The type of rail mechanism 140 is not limited. Examples of rail mechanisms 140 include those that allow a pair of rails to slide relative to each other, and those that arrange rolling elements 143 between a pair of rails. In this embodiment, the rail mechanism 140 is a so-called ball slide rail. The rail mechanism 140 comprises a first rail 141, a second rail 142, a plurality of rolling elements 143, and a retainer 144 that holds the rolling elements 143. The rolling elements 143 form rolling element rows aligned in the extending direction of the rail mechanism 140, and there are two rows of rolling element rows between the first rail 141 and the second rail 142. Preferably, the rolling elements 143 contact at least one of the first rail 141 and the second rail 142 at multiple points, and the other at one or more points. The rail mechanism 140 in this embodiment is a so-called angular type slide rail, and the first rail 141 and the second rail 142 and the rolling element 143 are in contact at four points.

[0020] In this embodiment, the column unit 113 has an overall cylindrical shape when viewed from the direction of movement of the movable member 130, as shown in Figure 3. If we draw a hypothetical second rectangle 310 in which the column unit 113 is inscribed, with one side parallel to the horizontal plane (XY plane in the figure), then at least a part of the movable member 130, particularly at least a part of the rail holding part 131, and at least a part of the rail mechanism 140 are included in each of the pair of corners of the second rectangle 310 other than the column unit 113. In other words, at least a part of the rail holding part 131 and the rail mechanism 140 are arranged in the dead space created by the column unit 113. This makes it possible to miniaturize (slim down) the steering device 100.

[0021] Figure 4 is a cross-sectional view showing the fastening portion between the movable member 130 and the rail mechanism 140. In this embodiment, each of the pair of rail mechanisms 140 and each of the pair of rail holding portions 131 of the movable member 130 are fastened together by fastening members 160. Each of the pair of rail holding portions 131 of the movable member 130 is provided with a through hole 134 through which the fastening member 160 is inserted. In a cross-section perpendicular to the direction of movement of the movable member 130, one of the through holes 134 (right side in Figure 4) is longer than the other through hole (left side in Figure 4). In this embodiment, one of the through holes 134 is an elongated hole with a width through which the fastening member 160 is inserted, and the other through hole 134 is a round hole with a diameter through which the fastening member 160 is inserted. The pair of rail mechanisms 140 and the pair of rail holding portions 131 are connected in the direction of extension of the rail mechanism 140 by a plurality of fastening members 160, a plurality of through holes 134, etc., which are aligned in the direction of extension of the rail mechanism 140. According to this, even if the movable member 130 contains dimensional errors, the extending directions of the pair of rail mechanisms 140 can be easily made parallel.

[0022] The fixing 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 fixing member 120 is attached to the vehicle body is not limited. In this embodiment, the fixing member 120 is attached in a suspended state from a reinforcement that is stretched in the width direction of the vehicle body. The shape of the fixing member 120 is not limited. In this embodiment, the fixing member 120 is formed by bending and joining sheet metal. The fixing member 120 has a fixed-side holding portion 122 having a pair of fixed-side mounting surfaces 121 that are parallel to and opposite to a pair of mounting surfaces 135 of the movable member 130. A rail mechanism 140 is attached between the fixed-side mounting surfaces 121 and the mounting surfaces 135.

[0023] A moving device 150 for moving the movable member 130 is attached below the fixed member 120 (towards the Z-side in the figure). The type of moving device 150 is not particularly limited. In this embodiment, the moving device 150 includes a lead screw 152 that is rotatably attached to the fixed member 120 via a fixed bracket 151 so as to extend in the direction of movement of the movable member 130 (in the Y-axis direction in the figure), a movable nut 153 that meshes with the lead screw 152 and reciprocates in the direction of movement of the movable member 130 by the rotation of the lead screw 152, a motor 154 that rotates the lead screw 152, and a reduction gear 155.

[0024] It should be noted that the present invention is not limited to the embodiments described above. For example, other embodiments of the present invention may be realized by arbitrarily combining the components described herein, or by excluding some of the components. Furthermore, modifications obtained by applying various modifications to the above embodiments that a person skilled in the art could conceive of without departing from the spirit of the present invention, that is, the meaning indicated by the wording in the claims, are also included in the present invention.

[0025] For example, the extension direction of the rail mechanism 140 is shown parallel to the Y-axis direction in the figure, but the Y-axis direction in the figure does not necessarily coincide with the longitudinal direction of the vehicle. Generally, the extension direction of the rail mechanism 140, that is, the direction of movement of the movable member 130, is inclined to become higher as it moves from the front to the rear of the vehicle.

[0026] Furthermore, the rail mechanism 140 is not limited to having a first rail 141 and a second rail 142, but may also be a multi-stage rail having three or more rails.

[0027] Furthermore, the steering device 100 may also include a tilt mechanism that changes the angle of the steering shaft 110 and the column unit relative to the movable member 130 in a vertical plane that includes the direction of movement of the movable member 130.

[0028] Furthermore, although we have described a steering device 100 that is installed in a vehicle capable of autonomous driving and moves the steering member 210 to the front of the vehicle where the driver cannot operate it during autonomous driving, the steering device 100 may also be installed in a vehicle that does not have an autonomous driving function. For example, the steering device 100 may change the position of the steering member 210 depending on the driver's physique.

[0029] Furthermore, instead of ball bearings, roller bearings may be used as the rolling elements 143. The material forming the rolling elements 143 is not limited to metal. The rolling elements 143 may be formed from, for example, resin.

[0030] Furthermore, instead of four-point contact, there may be two-point contact. That is, the rolling element 143 may be in contact with the first rail 141 and the second rail 142 at a single point.

[0031] Furthermore, the rail mechanism 140 of the steering device 100 may not include rolling elements 143, and the rail may be guided by sliding. For example, a low-friction resin member may be placed between the first rail 141 and the second rail 142.

[0032] The moving device 150 is not limited to a lead screw system; a ball screw may also be used. Furthermore, the movable member 130 may be moved by a link mechanism or the like.

[0033] (Summary) The steering device 100 of the first embodiment is a steering device 100 for steering a vehicle, comprising a steering shaft 110 to which a steering member 210 is attached, a movable member 130 that rotatably holds the steering shaft 110, and at least a pair of rail mechanisms 140 that guide the movement of the movable member 130 in the longitudinal direction of the vehicle, wherein the pair of rail mechanisms 140 are arranged diagonally with respect to the sides of a hypothetical rectangle 300 in which the movable member 130 is inscribed, and at least a portion of the pair of corners other than the movable member 130 within the rectangle 300, which has one side parallel to the horizontal plane, in a cross section perpendicular to the guiding direction of the rail mechanism 140.

[0034] According to the first embodiment, at least a portion of the rail mechanism 140 is positioned in the so-called dead space formed by the movable member 130, thus reducing the volume of the rail mechanism 140 that protrudes outside the virtual rectangle 300. This makes it possible to miniaturize the steering device 100 and reduce interference with other components such as brakes and air conditioners that are mounted near the steering device 100. Furthermore, by positioning the rail mechanism 140 diagonally with respect to the sides of the rectangle 300, it is possible to have a wider base surface for the rails than when they are positioned parallel to the sides of the rectangle 300, thus enabling miniaturization of the steering device 100 while ensuring high rigidity.

[0035] The steering device 100 of the second embodiment includes the first embodiment, wherein each pair of rail mechanisms 140 comprises a first rail 141, a second rail 142, and a pair of rolling element rows having a plurality of rolling elements 143 arranged in the guiding direction, and the movable member 130 comprises a pair of rail holding parts 131 having through holes 134 through which a fastening member 160 fastened to one of the pair of rail mechanisms 140 is inserted, and in a cross section perpendicular to the direction of movement of the movable member 130, one of the through holes 134 is longer than the other.

[0036] According to the second embodiment, even if tolerance deviations occur in the through holes 134 of the movable member 130 or the rail holding portion 131, the tolerance deviations can be absorbed by sliding the rail mechanism 140 relative to the movable member 130 through a hole in one of the pair of rail holding portions 131 that is longer than the other. Furthermore, since the surfaces to which the rail mechanism 140 is attached are arranged at an angle, it is also possible to adjust the distance between the pair of rail mechanisms 140.

[0037] The steering device 100 of the third embodiment includes the first or second embodiment, wherein the movable member 130 holds a reaction motor 111 and a coaxial reduction gear 112 coaxially with the steering shaft 110.

[0038] According to the third embodiment, the column unit 113, which includes the reaction motor 111 and the coaxial reducer 112, can be miniaturized, and interference between the steering device 100 and other components can be suppressed. Furthermore, at least a portion of the pair of rail mechanisms 140 and at least a portion of the movable member 130 can be arranged in the smallest second rectangle 310 inscribed within the column unit 113, allowing the steering device 100 to be made even smaller.

[0039] The present invention is useful as a steering device that allows the operation member to be moved, and can be used in vehicles equipped with wheels or tracks, such as passenger cars, buses, trucks, agricultural machinery, and construction machinery.

[0040] 100... Steering device, 110... Steering shaft, 111... Reaction motor, 112... Coaxial reducer, 113... Column unit, 120... Fixing member, 121... Fixed side mounting surface, 122... Fixed side holding part, 130... Movable member, 131... Rail holding part, 132... Beam part, 133... Shaft holding part, 134... Through hole, 135... Mounting surface, 140... Rail mechanism, 141... First rail, 142... Second rail, 143... Rolling element, 144... Retainer, 150... Moving device, 151... Fixed bracket, 152... Screw, 153... Movable nut, 154... Motor, 155... Reducer, 160... Fastening member, 200... Steering system, 210... Steering member, 220... Steering wheel, 230... Steering mechanism, 231... Rack shaft, 232... Tie rod, 233... Steering actuator, 300... Rectangle, 310... Second rectangle

Claims

1. A steering device for steering a vehicle, comprising: a steering shaft to which a steering member is attached; a movable member that rotatably holds the steering shaft; and at least one pair of rail mechanisms that guide the movement of the movable member in the longitudinal direction of the vehicle, wherein the pair of rail mechanisms are arranged diagonally to the sides of a hypothetical rectangle in which the movable member is inscribed, with at least a portion of each rail mechanism included in each of the pair of corners other than the movable member within the rectangle, in a cross section perpendicular to the guiding direction of the rail mechanisms.

2. The steering device according to claim 1, wherein each pair of rail mechanisms comprises a first rail, a second rail, and a pair of rolling element rows having a plurality of rolling elements arranged in the guiding direction, and the movable member comprises a pair of rail holding portions having through holes through which fastening members fastened to each of the pair of rail mechanisms are inserted, and in a cross section perpendicular to the direction of movement of the movable member, one of the through holes is longer than the other.

3. The steering device according to claim 1 or 2, wherein the movable member holds a reaction motor and a coaxial reduction gear coaxially with the steering shaft.

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