Steering device

Abstract

A steering device (100) comprises: a fixed member (110); a movable member (120) that is attached so as to be linearly movable with respect to the fixed member (110); and a guide mechanism (130). The guide mechanism (130) includes: a fixed rail (131) having a fixed-side track (137); a movable rail (132) having a movable-side track (138); rolling bodies (133); a retainer (134); a fixed-side stopper (135) provided at the end section of the fixed rail (131) on the front side of a vehicle and capable of abutting on the retainer (134); and a movable-side stopper (136) that is provided at the end section of the movable rail (132) on the rear side of the vehicle and capable of abutting on the retainer (134). A deformation section that widens the gap between the fixed-side track (137) and the movable-side track (138) more than other sections and relaxes the pressurization applied to the rolling bodies (133) is provided at the end section of the fixed rail (131) on the front side and / or at the end section of the movable rail (132) on the rear side.

Description

Steering device

[0001] The present invention relates to a steering device that can move a steering member operated by a driver forward of a vehicle.

[0002] Conventionally, there have been retractable steering devices that can extend and retract in the axial direction of a steering input shaft that holds a steering member such as a steering wheel. For example, Patent Document 1 describes a steering device that includes, as a guide mechanism that guides the extension and retraction of the steering input shaft, a pair of rails that extend in the axial direction of the steering input shaft and a ball slide mechanism in which a ball held by a cage is disposed between the pair of rails.

[0003] JP 2021-45999 A JP 2020-99447 A

[0004] In the ball slide mechanism described in Patent Document 1, the cage moves by about half the amount of rail movement as the rail moves in and out. However, when the rail moves in and out repeatedly, a deviation occurs in the movement of the cage relative to the movement of the rail, resulting in a phenomenon known as ball creep, in which the amount of cage movement relative to the amount of rail movement becomes smaller.

[0005] For example, Patent Document 2 discloses a technology in which, when ball creep occurs, a contact piece provided on a rail is brought into contact with a retainer, and the rail drags the retainer along with the balls, thereby correcting (correcting) the position of the retainer.

[0006] However, correcting the position of such a cage requires a load greater than the force required to move the rail under normal circumstances. In particular, in steering devices, a preload is applied to the ball slide mechanism to ensure the rigidity required to support the steering member, which poses a problem of increased load required to correct ball creep.

[0007] The present invention has been made in view of the above-mentioned problems, and has an object to provide a steering device that can correct the misalignment of the retainer of the ball slide mechanism with a small load.

[0008] In order to achieve the above object, one aspect of the present invention is a steering device that holds a steering member movably between a first position, which is a position of the steering member that can be operated by a driver, and a second position that is further forward of the vehicle than the first position, and that includes a fixed member attached to a vehicle body, a movable member that supports the steering member and is attached to the fixed member movably in a movement direction connecting the first position and the second position, and a guide mechanism that guides movement of the movable member relative to the fixed member, and the guide mechanism includes a fixed rail that is fixed to the fixed member and has a fixed-side track, and a movable member that is fixed to the movable member and has a fixed-side track. a movable rail having a movable side track facing the fixed rail and slidable relative to the fixed rail, rolling elements arranged between the fixed side track and the movable side track, a retainer for holding the rolling elements, a fixed side stopper provided at the front end of the fixed rail with respect to the vehicle and capable of abutting against the retainer, and a movable side stopper provided at the rear end of the movable rail with respect to the vehicle and capable of abutting against the retainer, and at least one of the front end of the fixed rail and the rear end of the movable rail is provided with a deformation portion that makes the gap between the fixed side track and the movable side track wider than other portions, thereby easing the pressure applied to the rolling elements.

[0009] Since pressure is applied to the rolling elements, the rigidity of the guide mechanism is ensured and rattle can be suppressed. In addition, since the pressure applied to the rolling elements in the deformation section is suppressed, misalignment of the rolling elements can be corrected (corrected) with a low load.

[0010] 1 is a perspective view showing a steering device with a steering member disposed at a first position; FIG. 2 is a perspective view showing a steering device with a steering member disposed at a second position; FIG. 3 is an exploded perspective view showing a guide mechanism with the steering member disposed at the second position; FIG. 4 is an exploded side view showing a guide mechanism with the steering member disposed at the second position; FIG. 5 is a side view showing a state of the guide mechanism with the steering member disposed at the first position; FIG. 6 is a side view showing a state of the guide mechanism with the steering member disposed at the second position; FIG. 7 is a side view showing an example of a method for forming a fixed-side deformation portion; FIG. 8 is a side view showing an example of a method for forming a movable-side deformation portion.

[0011] Hereinafter, an embodiment of a steering device according to the present invention will be described with reference to the drawings. Note that the following embodiment is an example for explaining the present invention and is 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 a method, and the order of each step shown in the following embodiment are 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, deviations, etc. Furthermore, expressions such as simultaneous and identical also include substantially allowable ranges.

[0012] 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.

[0013] 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.

[0014] FIG. 1 is a perspective view showing a steering device 100 in which a steering member 200 is disposed in a first position. FIG. 2 is a perspective view showing the steering device 100 in which the steering member 200 is disposed in a second position. The steering device 100 is a device used in a steer-by-wire system that holds the steering member 200 movably between a first position (see FIG. 1 ), which is a position of the steering member 200 that can be operated by a driver, and a second position (see FIG. 2 ), which is further forward of the vehicle than the first position. In the present embodiment, the second position is a position where at least a portion of the steering member 200 is stored (contained) in a dashboard, instrument panel, or the like provided in the vehicle. The steering device 100 reciprocates the steering member 200 in a linear movement direction (the X-axis direction in the figure) between the first position and the second position. Steer-by-wire (SBW) refers to an electronically controlled device in which a steering member 200 and the steered wheels of a vehicle are not mechanically connected, and the steered wheels are steered based on information from the driver operating the steering member 200. Note that steer-by-wire also includes a device in which the steering member 200 and the steered wheels are mechanically connected, and when autonomous driving is performed, the mechanical connection between the steering member 200 and the steered wheels is severed and the device is electronically controlled. The steering device 100 includes a fixed member 110 and a movable member 120. The direction of movement coincides with the fore-and-aft direction of the vehicle in a horizontal plane or intersects with it at a predetermined angle, but the predetermined angle is less than 90 degrees in a vertical plane, and the front side in the fore-and-aft direction (the front side of the vehicle) coincides with the front side of the direction of movement, and the rear side in the fore-and-aft direction (the rear side of the vehicle) coincides with the rear side of the direction of movement.

[0015] The steering member 200 is attached to an end of a column shaft 210 that is attached to the movable member 120. Also, attached to the end of the column shaft 210 opposite to the end to which the steering member 200 is attached are a sensor box 220 that houses sensors that detect the rotation angle at which the driver rotates the steering member 200, the torque applied to the column shaft 210, and the like, and a reaction force device 230 that gives the driver a steering feel when the driver operates the steering member 200.

[0016] The fixing member 110 is a member fixedly attached to a part of the vehicle body, for example, a structural member such as a reinforcement. The manner in which the fixing member 110 is attached to the vehicle body is not limited, but for example, it is attached in a state in which it is suspended from a reinforcement that is stretched across the width direction of the vehicle body. The shape of the fixing member 110 is not limited, and can be selected arbitrarily depending on the shape of the vehicle body, etc. In addition, in the drawings, the fixing member 110 is shown in a simplified shape in order to show the guide mechanism 130, etc.

[0017] The movable member 120 is a member that supports the steering member 200 and is attached to the fixed member 110 so that the supported steering member 200 can move linearly between a first position that is a position rearward of the vehicle (X+ side in the figure) and a second position that is a position frontward of the vehicle (X- side in the figure). The shape of the movable member 120 is not limited and can be arbitrarily selected depending on the shape of the vehicle body, etc. In the figures, the movable member 120 is shown in a simplified shape.

[0018] Fig. 3 is an exploded perspective view of the guide mechanism 130 when the steering member 200 is disposed at the second position. Fig. 4 is an exploded side view of the guide mechanism 130 when the steering member 200 is disposed at the second position. The guide mechanism 130 is a mechanism that guides the reciprocating movement of the movable member 120 in the movement direction relative to the fixed member 110, and includes a fixed rail 131, a movable rail 132, a rolling element 133, a cage 134, a fixed-side stopper 135, and a movable-side stopper 136.

[0019] The fixed rail 131 is a component fixed to the fixed member 110 and extends in the movement direction, and has a pair of fixed-side tracks 137 extending in the movement direction. The shape of the fixed rail 131 is not limited, but in this embodiment, the fixed rail 131 has a pair of fixed-side tracks 137 facing each other at a predetermined fixed-side distance D1 (see FIG. 1 ). The fixed-side distance D1 is the distance when the guide mechanism 130 is not assembled, i.e., when the fixed rail 131 exists alone. The fixed rail 131 may have the fixed-side tracks 137 back-to-back (opposite to facing each other). The method for forming the fixed rail 131 is not limited, but in this embodiment, the fixed rail 131 is formed by plastically deforming a metal plate. The pair of fixed-side tracks 137 are groove-shaped extending in the movement direction of the movable member 120 and are formed to make two-point contact with the rolling elements 133.

[0020] The movable rail 132 is fixed to the movable member 120 and has a pair of movable track sections 138 facing the pair of fixed track sections 137, respectively. The movable rail 132 is a member that can slide in the movement direction relative to the fixed rail 131. The shape of the movable rail 132 is not limited, but in this embodiment, the movable rail 132 has a pair of movable track sections 138 back-to-back with a predetermined movable distance D2 (see FIG. 2 ). The movable distance D2 is the distance when the guide mechanism 130 is not assembled, i.e., when the movable rail 132 exists alone. The movable rail 132 may have the movable track sections 138 facing each other (opposite to back-to-back). The method for forming the movable rail 132 is not limited, but in this embodiment, the movable rail 132 is formed by plastically deforming a metal plate, similar to the fixed rail 131. The pair of movable track sections 138 are groove-shaped extending in the movement direction of the movable member 120 and are formed to make two-point contact with the rolling elements 133.

[0021] The rolling elements 133 are arranged between the pair of fixed-side raceways 137 and the pair of movable-side raceways 138, and are components that rotate as the movable-side raceways 138 move relative to the fixed-side raceways 137. The multiple rolling elements 133 are arranged side by side at predetermined intervals in the movement direction, and form the rolling element row 103. In the present embodiment, the guide mechanism 130 includes a pair of rolling element rows 103.

[0022] When the guide mechanism 130 is assembled, the rolling elements 133 are in a state where a predetermined load is applied between the opposing fixed track 137 and movable track 138, i.e., a pre-pressurized state. This pre-pressurization is due to elastic forces created by the materials and structures of the fixed rail 131 and the movable rail 132. In other words, the rolling elements 133 are pre-pressurized by being press-fitted between the opposing fixed track 137 and movable track 138.

[0023] The cage 134 is a member that holds the rolling elements 133 so that they can roll on the fixed-side raceway 137 and the movable-side raceway 138. In this embodiment, the cage 134 holds a pair of rolling element rows 103 at a predetermined interval.

[0024] The fixed-side stopper 135 is provided at the end of the fixed rail 131 on the front side of the vehicle (X-side in the figure), and is a member that restricts movement of the retainer 134 toward the front side of the vehicle by abutting against the retainer 134. The shape and structure of the fixed-side stopper 135 are not limited. For example, the fixed-side stopper 135 may be formed by bending a portion of the fixed rail 131. In the present embodiment, the fixed-side stopper 135 is a bolt, and also functions as a fastening member for fixing the fixed rail 131 to the fixed member 110.

[0025] The movable side stopper 136 is provided at the end of the movable rail 132 on the vehicle rear side (X+ side in the figure), and is a member that abuts against the retainer 134 to restrict movement of the movable member 120 toward the vehicle front side via the retainer 134. The shape and structure of the movable side stopper 136 are not limited. For example, the movable side stopper 136 may be formed by bending a portion of the movable rail 132. In the present embodiment, the movable side stopper 136 is a bolt, and also functions as a fastening member for fixing the movable rail 132 to the movable member 120.

[0026] In this embodiment, the guide mechanism 130 includes a first stopper 141 and a second stopper 142. The first stopper 141 is provided at the end of the fixed rail 131 on the rear side of the vehicle (the X+ side in the figure) and is a member that abuts against the retainer 134 to restrict movement of the retainer 134 toward the rear of the vehicle. Although not limited to, in this embodiment, the first stopper 141 is a bolt and also functions as a fastening member for fixing the fixed rail 131 to the fixed member 110. The second stopper 142 is provided at the end of the movable rail 132 on the front side of the vehicle (the X- side in the figure) and is a member that abuts against the retainer 134 to restrict movement of the movable member 120 toward the rear of the vehicle via the retainer 134. Although not limited to, in this embodiment, the second stopper 142 is a bolt and also functions as a fastening member for fixing the movable rail 132 to the movable member 120.

[0027] The deformation portion is a portion provided on at least one of the front end portion of the fixed rail 131 and the rear end portion of the movable rail 132, and is a portion that makes the gap between the opposing fixed-side track 137 and movable-side track 138 wider than other portions, thereby easing the pressure applied to the rolling elements 133. In the case of this embodiment, the deformation portion includes a fixed-side deformation portion 151 provided on the fixed rail 131 and a movable-side deformation portion 152 provided on the movable rail 132.

[0028] The fixed-side deformation portion 151 is provided at the end of the fixed rail 131 on the front side of the vehicle, and is a portion where the fixed-side track 137 facing the movable-side track 138 is deformed in a direction away from the movable-side track 138 when the guide mechanism 130 is assembled. In the present embodiment, the spacing between the pair of fixed-side tracks 137 in the fixed-side deformation portion 151 is wider than the fixed-side spacing D1 in the portion other than the fixed-side deformation portion 151. Furthermore, the spacing between the pair of fixed-side tracks 137 in the fixed-side deformation portion 151 gradually widens toward the front of the vehicle.

[0029] The movable side deformation section 152 is provided at the rear end of the movable rail 132, and is a section where the movable side track 138 facing the fixed side track 137 is deformed in a direction away from the fixed side track 137 when the guide mechanism 130 is assembled. In this embodiment, the distance between the pair of movable side tracks 138 in the movable side deformation section 152 is narrower than the movable side distance D2 in the portion other than the movable side deformation section 152. Furthermore, the distance between the pair of movable side tracks 138 in the movable side deformation section 152 gradually narrows toward the rear of the vehicle.

[0030] In this embodiment, the length of the deformation portion in the movement direction, which is the sum of the length L1 of the fixed-side deformation portion 151 (see FIG. 4 ) and the length L2 of the movable-side deformation portion 152, is shorter than the length of the rolling element array 103 by at least the length L3 of two rolling elements 133. The length of two rolling elements 133 is the center-to-center distance between two adjacent rolling elements 133 in the rolling element array 103. By setting the length L3 in this manner, at least two of the multiple rolling elements 133 in the rolling element array 103 are not located in the deformation portion. In other words, there are two or more rolling elements 133 that are not located in the fixed-side deformation portion 151 or the movable-side deformation portion 152. This means that there are two or more rolling elements 133 to which pressure is applied by the opposing tracks in the portions other than the deformation portion. This ensures the rigidity of the guide mechanism 130 even when the steering member 200 is located in the second position.

[0031] Next, the operation of the steering device 100 will be described. FIG. 5 is a side view showing the state of the guide mechanism 130 when the steering member 200 is placed in the first position. The first position of the steering member 200 varies depending on the driver's physique and the state of the seat in which the driver sits. The guide mechanism 130 is designed with a certain amount of leeway, so that at the first position, at least one of the first stopper 141 and the second stopper 142 does not abut against the retainer 134. Therefore, when the steering device 100 moves the steering member 200 from the second position to the first position, the second stopper 142 abuts against the retainer 134 and hardly drags the retainer 134 together with the rolling elements 133.

[0032] FIG. 6 is a side view showing the state of the guide mechanism 130 when the steering member 200 is disposed in the second position. The second position of the steering member 200 is determined by the vehicle structure and is constant. The guide mechanism 130 is configured so that the fixed-side stopper 135 and the movable-side stopper 136 sandwich the retainer 134 when the steering member 200 is disposed in the second position. When the fixed-side stopper 135 and the movable-side stopper 136 abut against the retainer 134, the fixed-side deformation portion 151 and the movable-side deformation portion 152 are spaced apart in the movement direction. The separation distance is preferably equal to or greater than the center-to-center distance between adjacent rolling elements 133 in the rolling element array 103 and is preferably equal to or less than twice the center-to-center distance. If the separation distance is less than the center-to-center distance between the rolling elements 133, it becomes difficult to ensure the rigidity of the steering member 200 when disposed in the second position, and rattle of the steering member 200 cannot be suppressed. On the other hand, if the distance is longer than twice the center distance, the load when dragging the rolling elements 133 and the cage 134 increases, and the burden on the steering device 100 increases.

[0033] Next, a method for providing the deformation portions will be described. For example, when the fixed rail 131 and the movable rail 132 are manufactured by bending a metal sheet, the fixed-side deformation portion 151 and the movable-side deformation portion 152 may be formed during the bending process. Alternatively, the fixed rail 131 and the movable rail 132 may be formed so that the entire fixed-side raceway 137 and the entire movable-side raceway 138 are parallel, and then the fixed-side deformation portion 151 and the movable-side deformation portion 152 may be simultaneously formed by burnishing the fixed-side raceway 137 and the movable-side raceway 138 by the length of the fixed-side deformation portion 151 (and the same length for the movable-side deformation portion 152) using a processing ball with a larger diameter than the rolling elements 133.

[0034] 7 , the fixed rail 131 is formed so that the entire fixed-side track 137 is parallel. Meanwhile, the surface of the fixed member 110 corresponding to the fixed-side deformation portion 151 that abuts against the fixed rail 131 is curved so as to protrude toward the fixed rail 131. When fastening the fixed rail 131 to the fixed member 110 using the fixed-side stopper 135, a fixed-side deformation member 153, which is a plate-like member that is long in the width direction of the fixed rail 131 (the Z-axis direction in the figure), and which protrudes toward the fixed member 110 on both ends in the width direction and has protrusions extending in the movement direction, may be pressed against the fixed rail 131 to curve the front end of the fixed rail 131, thereby forming the fixed-side deformation portion 151.

[0035] 8, the movable rail 132 is formed so that the entire movable-side track 138 is parallel. Meanwhile, the surface of the movable member 120 that corresponds to the movable-side deformation portion 152 and that abuts against the movable rail 132 is curved so as to be recessed on the opposite side from the movable rail 132. When fastening the movable rail 132 to the movable member 120 using the movable-side stopper 136, the movable rail 132 may be pressed against the movable member 120 using the movable-side stopper 136, thereby curving the rear end of the movable rail 132 and forming the movable-side deformation portion 152.

[0036] 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.

[0037] For example, the shape of the fixed rail 131 and the shape of the movable rail 132 may be interchanged. In other words, the pair of fixed tracks 137 may be disposed inside the pair of movable tracks 138.

[0038] The steering device 100 of a first aspect included in the above-described embodiment is a steering device 100 that holds the steering member 200 movably between a first position, which is a position of the steering member 200 that can be operated by a driver, and a second position that is further forward of the vehicle than the first position, and is provided with a fixed member 110 attached to a vehicle body, a movable member 120 that supports the steering member 200 and is attached to the fixed member 110 so as to be movable in a movement direction connecting the first position and the second position, and a guide mechanism 130 that guides the movement of the movable member 120 relative to the fixed member 110, and the guide mechanism 130 includes a fixed rail 131 fixed to the fixed member 110 and having a fixed-side track 137, and a movable member 120 fixed to the movable member 120 and having a fixed-side track 137. the movable rail 132 having a movable track 138 facing the fixed rail 131 and slidable relative to the fixed rail 131; rolling elements 133 arranged between the fixed track 137 and the movable track 138; a retainer 134 for holding the rolling elements 133; a fixed stopper 135 provided at the front end of the fixed rail 131 of the vehicle and capable of abutting against the retainer 134; and a movable stopper 136 provided at the rear end of the movable rail 132 of the vehicle and capable of abutting against the retainer 134. At least one of the front end of the fixed rail 131 and the rear end of the movable rail 132 is provided with a deformation portion that makes the gap between the fixed track 137 and the movable track 138 wider than in other portions, thereby alleviating the pressure applied to the rolling elements 133.

[0039] According to the steering device 100 of the first aspect, when the steering member 200 is moved between the first position and the second position, a preload is applied to the rolling elements 133, ensuring the rigidity of the guide mechanism 130 and suppressing rattle of the steering member 200. When the steering member 200 is moved between the first position and the second position, the position of the rolling elements 133, including the retainer 134, deviates from its normal position. By moving the movable rail 132 forward relative to the fixed rail, the rolling elements 133 and the retainer 134 are dragged along the deformation portion where the preload applied to the rolling elements 133 is absent or weakened, thereby resetting the positions of the rolling elements 133 and the retainer 134. This prevents the load required to reset the positions of the rolling elements 133 and the retainer 134 from becoming too large. Furthermore, the burden on the rolling elements 133, the fixed-side track 137, and the movable-side track 138 is also limited.

[0040] The steering device 100 of the second aspect according to the above embodiment includes the first aspect, and forms a rolling element row 103 in which a plurality of rolling elements 133 are arranged in the moving direction by a retainer 134, and the length of the deformation portion in the moving direction is shorter than the length of the rolling element row 103 by more than two rolling elements 133.

[0041] The steering device 100 of the third aspect according to the above embodiment includes the first aspect or the second aspect, and the deformation portion is provided at the front end of the fixed rail 131 and the rear end of the movable rail 132, and when the fixed side stopper 135 and the movable side stopper 136 are in contact with the retainer 134, the deformation portion on the fixed rail 131 side and the deformation portion on the movable rail 132 side are separated by two rolling bodies 133 in the movement direction.

[0042] According to the steering device 100 of the second and third aspects, at least two of the multiple rolling elements 133 in the rolling element row 103 do not lose pressure due to the deformation portion, so the rigidity of the guide mechanism 130 can be ensured even in the second position.

[0043] 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.

[0044] 100...Steering device, 103...Rolling element row, 110...Fixed member, 120...Movable member, 130...Guide mechanism, 131...Fixed rail, 132...Movable rail, 133...Rolling element, 134...Cage, 135...Fixed side stopper, 136...Movable side stopper, 137...Fixed side track, 138...Movable side track, 141...First stopper, 142...Second stopper, 151...Fixed side deformation portion, 152...Movable side deformation portion, 153...Fixed side deformation member, 200...Steering member, 210...Column shaft, 220...Sensor box, 230...Reaction force device

Claims

1. A steering device that holds a steering member so that it can be moved between a first position, which is a position of the steering member that can be operated by a driver, and a second position that is further forward of the first position on the vehicle, comprising: a fixed member attached to a vehicle body; a movable member that supports the steering member and is attached to the fixed member so as to be movable in a moving direction connecting the first position and the second position; and a guide mechanism that guides the movement of the movable member relative to the fixed member, wherein the guide mechanism comprises: a fixed rail fixed to the fixed member and having a fixed side track; a movable rail fixed to the movable member, having a movable side track facing the fixed side track and being slidable relative to the fixed rail; a rolling element disposed between the fixed side track and the movable side track; a retainer that holds the rolling element; a fixed side stopper provided at a front end of the fixed rail with respect to the vehicle and capable of abutting against the retainer; and a movable side stopper provided at a rear end of the movable rail with respect to the vehicle and capable of abutting against the retainer, A steering device in which a deformation portion is provided on at least one of a front end portion of the fixed rail and a rear end portion of the movable rail, the deformation portion making a gap between the fixed track and the movable track wider than other portions to relieve the pressure applied to the rolling elements.

2. A steering device as set forth in claim 1, wherein a plurality of said rolling elements are arranged in a rolling element row in the moving direction by said cage, and the length of said deformation portion in the moving direction is shorter than the length of said rolling element row by the length of two or more of said rolling elements.

3. A steering device as claimed in claim 1 or 2, wherein the deformation portion is provided at the front end of the fixed rail and at the rear end of the movable rail, and when the fixed side stopper and the movable side stopper are in contact with the retainer, the deformation portion on the fixed rail side and the deformation portion on the movable rail side are separated by two of the rolling elements in the direction of movement.

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