JP2016097741A - Steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steering device capable of suppressing looseness of a fastening body.SOLUTION: A flange section 41a is formed over the peripheral direction whole area on an outer peripheral surface at one end of a ball screw nut 41. A groove section 41b is formed over the peripheral direction whole area on a peripheral surface of the flange section 41a. A driven pulley 52 is fitted to the outer peripheral surface of the ball screw nut 41 so as to cover the ball screw nut 41 corresponding to the shape of the flange section 41a of the ball screw nut 41. The driven pulley 52 includes a step section 52a corresponding to the flange section 41a, and an abutting surface 41c of the flange section 41a abuts on the step section 52a. The flange section 41a abuts on a cylindrical lock screw 44 on an abutting surface 41d to be an end face on an opposite side of the abutting surface 41c. The flange section 41a is held by the step section 52a of the driven pulley 52 and the lock screw 44 so as to fix the ball screw nut 41 integrally and rotatably to the driven pulley 52.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a steering device.

  As one of vehicle steering devices, there is known an electric power steering device (EPS) that assists a driver's steering operation by applying a rotational force of a motor to a vehicle steering mechanism.

  For example, in EPS, a rack and pinion mechanism is adopted as a steering mechanism. The rack and pinion mechanism changes the angle of the steered wheels by converting the rotational motion of the steering shaft into the linear motion of the rack shaft. The rack shaft is provided with a ball screw mechanism that converts the rotational motion of the motor into the linear motion of the rack shaft. For example, in the EPS of Patent Document 1, a ball nut cover that is connected to a ball nut so as to be integrally rotatable is connected to a driven pulley so as to be integrally rotatable, and a flange provided on the ball nut is sandwiched between the ball nut cover and the screw member. Thus, the ball nut is connected to the driven pulley so as to be integrally rotatable.

JP 2012-224191 A

  When an impact load due to the linear motion of the rack shaft is applied to the ball screw mechanism, the ball screw nut that is the fastened body and the fastening body (ball nut cover and screw member) that fastens the ball screw nut are fastened. The contact surface (seat surface) may be released. When the seating surface is released, there is a concern that the fastening is easily loosened when a force is applied in a direction in which the fastening is loosened.

  The objective of this invention is providing the steering apparatus which can suppress the loosening of a fastening body.

  A steering device that can achieve the above-described object includes a motor that is a source of assist force, a turning shaft that reciprocates in an axial direction, and screwed with the turning shaft via a large number of balls. A ball screw nut in which a flange portion is formed over the entire circumferential direction, and a driven pulley having a step portion that is in contact with the flange portion in the axial direction inside the ball screw nut inserted and fixed to the outer peripheral surface thereof A driving pulley fixed to be rotatable integrally with the rotating shaft of the motor, a belt wound between the driven pulley and the driving pulley, and the step being tightened from the opposite side of the stepped portion of the driven pulley. And a fastening body that sandwiches the flange portion with the portion. The flange portion is provided with a spring constant adjusting portion for reducing its own spring constant.

  According to this structure, the spring constant adjustment part is provided in the flange part. For this reason, the spring constant of the flange part which is a to-be-fastened body clamped by the said step part and the said fastening body is reduced. When the spring constant is reduced, the release of the seating surface (the contact surface between the flange portion and the step portion, and the contact surface between the flange portion and the fastening body) can be suppressed between the fastening body and the fastened body.

In the steering apparatus, the spring constant adjusting portion may be a groove portion provided on the outer peripheral surface of the flange portion over the entire circumferential direction.
According to this configuration, since the groove portion is provided in the flange portion, the flange portion is easily deformed, and the rigidity of the flange portion is reduced. That is, since the spring constant of the flange portion is reduced, it is possible to suppress the release of the seating surface between the fastening body and the fastened body.

  In the above steering apparatus, the stepped portion has a first stepped portion with which the fastening body abuts and a second stepped portion having a smaller diameter than the first stepped portion and spaced from the fastening body. It may be. The flange portion may be sandwiched between the first step portion and the fastening body, and the spring constant adjustment portion may be a portion facing the second step portion on the radially inner side of the flange portion. .

  According to this configuration, since the spring constant adjusting portion that is not sandwiched between the stepped portion and the fastening body is provided on the inner side in the circumferential direction of the flange portion, the flange portion is easily bent and the rigidity of the flange portion is reduced. For this reason, it can suppress that the release of the seating surface between a fastening body and a to-be-fastened body generate | occur | produces.

  In the above steering apparatus, a housing that houses the steered shaft, rack ends that are respectively attached to both ends of the steered shaft and connected to steered wheels, the housing in the moving direction of the steered shaft, It is preferable to include an impact absorbing member that is provided between the rack end and absorbs an impact when they abut.

  According to this structure, the external force input into a fastening body is reduced by providing the impact-absorbing member. For this reason, it is possible to reduce the occurrence of liberation of the seating surface.

  According to the steering device of the present invention, the looseness of the fastening body can be suppressed.

The block diagram which shows the structure of an electric power steering apparatus. Sectional drawing which shows schematic structure of an assist mechanism about the electric power steering apparatus of embodiment. The fastening diagram of the fastening body of the embodiment and the fastened body. (A)-(d) is sectional drawing which shows schematic structure of a fastening body and a to-be-fastened body. Sectional drawing which shows schematic structure of the rack end vicinity.

  Hereinafter, an embodiment of the steering device will be described. The steering device of this embodiment is a so-called rack parallel type electric power steering device (RP-EPS).

  As shown in FIG. 1, the EPS 1 includes a steering mechanism 2 that steers the steered wheels 16 based on the driver's operation of the steering wheel 10 and an assist mechanism 3 that assists the driver's steering operation.

  The steering mechanism 2 includes a steering wheel 10 and a steering shaft 11 that rotates integrally with the steering wheel 10. The steering shaft 11 includes a column shaft 11a connected to the steering wheel 10, an intermediate shaft 11b connected to the lower end portion of the column shaft 11a, and a pinion shaft 11c connected to the lower end portion of the intermediate shaft 11b. Yes. A lower end portion of the pinion shaft 11 c is connected to the rack shaft 12 via a rack and pinion mechanism 13. Therefore, in the steering mechanism 2, the rotational motion of the steering shaft 11 is converted into a reciprocating linear motion in the direction of the axis m of the rack shaft 12 (left and right in FIG. 1) via the rack and pinion mechanism 13 including the pinion shaft 11c and the rack shaft 12. Converted. The reciprocating linear motion is transmitted to the tie rod 15 via the rack ends 14 respectively connected to both ends of the rack shaft 12. The movement of these tie rods 15 is transmitted to the left and right steered wheels 16, whereby the steered angle of the steered wheels 16 changes.

  The assist mechanism 3 is provided on the rack shaft 12. The assist mechanism 3 transmits to the ball screw mechanism 40 the rotational force of the rotating shaft 31 of the motor 30 that is a source of the assist force, the ball screw mechanism 40 that is integrally attached around the rack shaft 12, and the motor 30. It consists of the reduction gear 50 which carries out. The assist mechanism 3 converts the rotational force of the rotating shaft 31 of the motor 30 into a reciprocating linear motion in the axis m direction of the rack shaft 12 via the speed reducer 50 and the ball screw mechanism 40. The driver's steering operation is assisted by the force applied to the rack shaft 12 from the reciprocating linear motion thus converted.

  The ball screw mechanism 40, the speed reducer 50, the pinion shaft 11c, and the rack shaft 12 are accommodated in the housing 17. The housing 17 includes a first housing 17a and a second housing 17b that are divided in the axis m direction of the rack shaft 12 in the vicinity of the assist mechanism 3, and is configured by connecting them together. The housing 17 has a portion protruding in a direction intersecting with the direction in which the rack shaft 12 extends (downward in the drawing), and a part of the speed reducer 50 is accommodated in the protruding portion. A through hole 32 is provided in the outer wall (right side wall in the figure) of the housing 17 protruding downward in the vertical direction. A rotation shaft 31 of the motor 30 extends into the housing 17 through a through hole 32 formed in the housing 17. The motor 30 is fixed to the housing 17 by bolts 33 so that the rotating shaft 31 is parallel to the rack shaft 12. A slight gap is provided between the housing 17 and the rack shaft 12. At the end of the housing 17, a rack boot 18 having a bellows cylindrical shape is arranged. One end of the rack boot 18 is connected to the end of the housing 17, and the other end of the rack boot 18 is connected to the tie rod 15.

Next, the assist mechanism 3 will be described in detail.
As shown in FIG. 2, the ball screw mechanism 40 supports a ball screw nut 41, a lock screw 44 as a fastening body for fastening the ball screw nut 41, and the ball screw nut 41 rotatably with respect to the housing 17. And a bearing 45. The speed reducer 50 includes a drive pulley 51 that is integrally attached to the rotating shaft 31 of the motor 30, a driven pulley 52 that is integrally attached to the outer periphery of the ball screw nut 41, and the drive pulley 51 and the driven pulley 52. The belt 53 is wound around.

  A spiral thread groove 12 a is formed on the outer peripheral surface of the rack shaft 12. The ball screw mechanism 40 includes a cylindrical ball screw nut 41 having a screw groove 43 on the inner peripheral surface, which is screwed into the screw groove 12a of the rack shaft 12 via a ball. That is, the ball screw nut 41 is formed with a helical thread groove 43 corresponding to the thread groove 12a. A ball 42 is arranged in a spiral space surrounded by the screw groove 43 of the ball screw nut 41 and the screw groove 12a of the rack shaft 12, and a rolling path R on which the ball 42 rolls is formed. Although not shown, the ball screw nut 41 is formed with a circulation path that opens at two locations on the rolling path R and short-circuits the two locations. Therefore, the ball 42 can circulate infinitely in the rolling path R through the circulation path in the ball screw nut 41.

  A flange portion 41 a is formed on the outer peripheral surface of one end of the ball screw nut 41 over the entire circumferential direction. Grooves 41b are formed in the circumferential surface of the flange portion 41a over the entire circumferential direction. A driven pulley 52 is fitted to the outer peripheral surface of the ball screw nut 41 so as to cover the ball screw nut 41 corresponding to the shape of the flange portion 41 a of the ball screw nut 41. That is, the driven pulley 52 is provided with a step portion 52a corresponding to the flange portion 41a, and the contact surface 41c of the flange portion 41a and the step portion 52a abut. The flange portion 41a is in contact with the cylindrical lock screw 44 on the contact surface 41d which is the end surface opposite to the contact surface 41c. The outer peripheral surface of the flange portion 41 a is in contact with the inner peripheral surface of the driven pulley 52. A screw groove 44 a is formed on the outer peripheral surface of the lock screw 44, and a screw groove 52 b is formed on the inner peripheral surface of the driven pulley 52. By locking the screw groove 44a and the screw groove 52b, the lock screw 44 moves in the direction of the axis m. The ball screw nut 41 is fixed to the driven pulley 52 so as to be integrally rotatable by sandwiching the flange portion 41 a between the stepped portion 52 a of the driven pulley 52 and the lock screw 44. The driven pulley 52 is rotatably supported with respect to the inner peripheral surface of the housing 17 through a cylindrical bearing 45. The bearing 45 is fixed to the housing 17 so as not to move in either the axial m direction or the circumferential direction.

  In the assist mechanism 3 having such a configuration, when the rotation shaft 31 of the motor 30 rotates, the drive pulley 51 rotates together with the rotation shaft 31. The rotation of the driving pulley 51 is transmitted to the driven pulley 52 via the belt 53, whereby the driven pulley 52 rotates. For this reason, the ball screw nut 41 attached integrally with the driven pulley 52 also rotates. Since the ball screw nut 41 rotates relative to the rack shaft 12, a large number of balls 42 interposed between the ball screw nut 41 and the rack shaft 12 receive an infinite load in the rolling path R from both sides. Circulate. As the ball 42 circulates infinitely, the torque applied to the ball screw nut 41 is converted into a force in the direction of the axis m of the rack shaft 12. For this reason, the rack shaft 12 moves relative to the ball screw nut 41 in the direction of the axis m. The axial force applied to the rack shaft 12 becomes an assist force, and assists the driver's steering operation.

  By the way, in order to sufficiently apply the assist force, it is necessary that the lock screw 44 as the fastening body sufficiently fastens the flange portion 41a of the ball screw nut 41 as the fastened body. If the fastening is insufficient, the ball screw nut 41 may not rotate sufficiently even if the driven pulley 52 rotates. For this reason, even if the motor 30 is driven to assist the driver's steering operation, the assisting force smaller than the target assisting force is applied to the steering mechanism, thereby sufficiently assisting the driver's steering operation. It may not be possible.

  As a cause of insufficient fastening of the lock screw 44 and the ball screw nut 41, it is assumed that the lock screw 44 is loosened. For example, when the rack shaft 12 moves in the direction of the axis m, if the lock screw 44 is separated from the flange portion 41a due to insufficient fastening, the lock screw 44 is immediately locked only by applying a force in the direction in which the lock screw 44 is loosened. The screw 44 may be loosened. Even when an external force is applied to the lock screw 44, in order to suppress loosening of the fastening, the release of the lock screw 44 and the contact surface 41d is suppressed, and the stepped portion 52a of the driven pulley 52 and the contact surface It is necessary to suppress release from 41c. For this reason, in this embodiment, in order to suppress the release of the fastening body (the lock screw 44) and the fastened body (the flange portion 41a of the ball screw nut 41), the flange portion 41a is provided in the groove portion 41b.

  The operation when the flange portion 41a is fastened by the lock screw 44 will be described using the tightening diagram of FIG. The tightening diagram of FIG. 3 is a diagram in which one horizontal axis is the amount of expansion of the fastening body and the other horizontal axis is the amount of contraction of the fastened body, and both are placed back to back. When the flange portion 41 a is fastened by the lock screw 44, an axial force (expansion force) F that stretches itself is applied to the lock screw 44. For this reason, the lock screw 44 expands by an expansion amount dB. At this time, the relationship between the axial force F acting on the lock screw 44 and the expansion amount dB is a proportional relationship in which the spring constant kB of the lock screw 44 is inclined. On the other hand, by being fastened by the lock screw 44, a contracting axial force (compression force) F equivalent to the axial force F for extending the lock screw 44 itself acts on the flange portion 41 a that is the fastened body. For this reason, the flange portion 41a contracts by the compression amount dC. At this time, the relationship between the axial force F acting on the lock screw 44 and the compression amount dC is a proportional relationship in which the spring constant kC of the lock screw 44 is inclined. Here, there is an ideal relationship between the following formulas (1) and (2) between the axial force F and the expansion amount dB, and the axial force F and the compression amount dC.

kB = F / dB (1)
kC = F / dC (2)
Here, in the initial state in which the flange portion 41a is fastened by the lock screw 44, the force is balanced by the axial force F0. At this time, since the compression force of the axial force F0 acts on the flange portion 41a, the stepped portion 52a contacts the contact surface 41c of the flange portion 41a, and the lock screw 44 contacts the contact surface 41d of the flange portion 41a. Abut. Therefore, the separation of the seat surface (the contact surface between the lock screw 44 and the contact surface 41d and the contact surface between the stepped portion 52a and the contact surface 41d) does not occur. The triangle formed by connecting the axial force F0 in the initial state, the point B that is the origin of the expansion amount of the lock screw 44, and the point C that is the origin of the compression amount of the flange portion 41a is the lock screw 44 and the flange. Within the range of elastic deformation of the part 41a, it is similar to the axial force F0.

  Next, when an external force W is applied in the direction in which the lock screw 44 is fastened, that is, in the direction of the axis m, an axial force F greater than the initial axial force F0 can be applied to the lock screw 44. For example, as shown in FIG. 3, since the axial force F larger than the axial force F0 acts on the lock screw 44 by the amount of the axial force increase due to the external force, the expansion force of the lock screw 44 increases. For this reason, when external force acts, the compressive force which acts on the flange part 41a is weakened. At the point C where the external force W is applied, the compressive force is not applied to the flange portion 41a. When the compression force does not act on the flange portion 41a, the expansion force of the lock screw 44 does not act on the flange portion 41a, so the seat surface (the contact surface of the lock screw 44 and the contact surface 41d or the step portion 52a abuts). The contact surface 41d of the surface 41d is released. For this reason, when the lock screw 44 has the spring constant kB and the flange portion 41a has the spring constant kC, the seating surface is released when the external force W is applied.

Next, the operation of the groove 41b provided in the flange 41a will be described.
As shown in FIG. 4A, the provision of the groove 41b makes it easier for the flange 41a to deform in the direction of the axis m than when the groove 41b is not provided. In other words, it can be said that the rigidity of the flange portion 41a is reduced. For this reason, the spring constant kC ′ of the flange portion 41a provided with the groove portion 41b is smaller than the spring constant kC of the flange portion 41a provided with no groove portion 41b.

  As shown in FIG. 3, when the flange portion 41a provided with the groove portion 41b has a spring constant kC ', the flange portion 41a contracts by the contraction amount dC' due to the contracting axial force F (compression force). At this time, the relationship between the axial force F acting on the lock screw 44 and the contraction amount dC ′ is a proportional relationship in which the spring constant kC ′ of the flange portion 41 a is inclined. For this reason, the relationship of following Formula (3) is ideally formed.

kC ′ = F / dC ′ (3)
Even if the spring constant is changed, in the initial state in which the flange portion 41a is fastened by the lock screw 44, the force balance can be obtained by the axial force F0. When the flange portion 41a provided with the groove portion 41b has a spring constant kC ', the seat surface is released when an external force W' larger than the external force W acts in the direction of the axis m. That is, if the external force W ′ acts in the direction of the axis m when the flange portion 41a has the spring constant kC ′, the compressive force on the flange portion 41a does not act at the point C ′. On the other hand, even if the external force W acts in the direction of the axis m when the flange portion 41a has the spring constant kC ′, the compressive force on the flange portion 41a is not lost at the point C ′, so that the seating surface is released. do not do. For this reason, the release of the seating surface can be suppressed by reducing the spring constant of the flange portion 41a from the spring constant kC to the spring constant kC ′.

The effect of this embodiment will be described.
(1) The spring constant of the flange part 41a is reduced by providing the groove part 41b in the flange part 41a which is a to-be-fastened body. By reducing the spring constant of the flange portion 41a from the spring constant kC to the spring constant kC ′, it is possible to suppress the seating surface from being released until an external force W ′ larger than the external force W acts in the direction of the axis m. Since the release of the seating surface can be suppressed, the ball screw nut 41 and the driven pulley 52 can be more reliably fixed.

In addition, you may change this embodiment as follows. The following other embodiments can be combined with each other within a technically consistent range.
In the present embodiment, the external force is assumed to be in the direction of the axis m, and the lock screw 44 is also fastened in the direction of the axis m. However, the present invention is not limited to this. For example, it can be assumed that vibration is applied in a direction perpendicular to the axis m due to reverse input during traveling.

  In the present embodiment, the configuration of the rack end 14 has not been described in detail. However, as shown in FIG. Since the impact load or the like due to reverse input is absorbed by the impact absorbing member 60, the external force acting on the lock screw 44 is reduced. For this reason, it can suppress that a seat surface loosens more. When the impact absorbing member 60 is not provided, the impact load or the like due to reverse input directly acts on the lock screw 44. Therefore, by providing the groove 41b in the flange 41a, the spring constant is reduced and the seat is reduced. It is particularly effective to suppress surface release.

  -In this embodiment, although the flange part 41a was fastened by the lock screw 44 and the driven pulley 52, it is not restricted to this. For example, the ball screw nut 41 may be fixed to the driven pulley 52 so as to be integrally rotatable by screwing a bolt into screw holes provided in the flange portion 41 a and the driven pulley 52. For example, when a ball screw nut cover that covers the ball screw nut 41 is employed, the flange portion 41 a may be fastened by the ball screw nut cover and the lock screw 44 instead of the driven pulley 52.

  -In this embodiment, although the spring part of the flange part 41a was reduced by providing the groove part 41b in the flange part 41a, it is not restricted to this. For example, as shown in FIG. 4B, the radially outer portion of the flange portion 41a is fastened by the lock screw 44 and the driven pulley 52, and the spring constant adjusting portion 41e is provided on the radially inner portion. May be. The spring constant adjusting portion 41e is a portion that is not fastened by the lock screw 44 and the driven pulley 52 in order to adjust the spring constant of the flange portion 41a. Further, the stepped portion 52a of the driven pulley 52 includes a first stepped portion 52c on the outer peripheral side and a second stepped portion 52d on the inner peripheral side. The first step 52c comes into contact with the contact surface 41c. The second step portion 52d is provided corresponding to the spring constant adjusting portion 41e, but does not contact the spring constant adjusting portion 41e. By providing the spring constant adjusting part 41e, the spring constant adjusting part 41e is easily bent in the direction of the axis m, as exaggerated in FIG. 4C. For this reason, since the flange part 41a becomes easy to deform | transform into the axis | shaft m direction, the spring constant (rigidity) of the flange part 41a is reduced. Further, as shown in FIG. 4D, in order to make the spring constant adjusting portion 41e more easily deformed in the axis m direction, groove portions 41f are provided over the entire circumferential direction of both end surfaces in the axis m direction of the spring constant adjusting portion 41e. May be. Accordingly, the flange portion 41a is further easily deformed in the direction of the axis m, so that the spring constant of the flange portion 41a can be further reduced.

  -In this embodiment, although concretely shown to RP-EPS, it is not restricted to this. For example, a column assist type EPS or a rack assist type EPS may be used.

  In the present embodiment, the electric power steering device that assists the linear motion of the rack shaft 12 interlocked with the steering operation by using the rotational force of the motor 30 is taken as an example, but applied to the steer-by-wire (SBW). Also good. In addition, when it materializes to a steer-by-wire, it can also materialize not only as a front-wheel steering apparatus but as a rear-wheel steering apparatus or a 4-wheel steering apparatus (4WS).

Next, the technical idea that can be grasped from the above embodiment will be added below.
(A) A groove portion is provided over the entire circumferential direction on at least one axial end surface of the flange portion where the spring constant adjusting portion is provided.

  According to this configuration, the spring constant adjuster is more easily bent and deformed by the groove provided in the spring constant adjuster. For this reason, the spring constant of a flange part is reduced and it can suppress that isolation | separation of a seat surface generate | occur | produces.

  DESCRIPTION OF SYMBOLS 1 ... EPS, 2 ... Steering mechanism, 3 ... Assist mechanism, 10 ... Steering wheel, 11 ... Steering shaft, 11a ... Column shaft, 11b ... Intermediate shaft, 11c ... Pinion shaft, 12 ... Rack shaft (steering shaft), 12a ... thread groove, 13 ... rack and pinion mechanism, 14 ... rack end, 15 ... tie rod, 16 ... steered wheel, 17 ... housing, 18 ... rack boot, 30 ... motor, 31 ... rotating shaft, 32 ... through hole, 33 DESCRIPTION OF SYMBOLS ... Bolt, 40 ... Ball screw mechanism, 41 ... Ball screw nut, 41a ... Flange part, 41b ... Groove part (spring constant adjustment part), 41c ... Contact surface (1st end surface), 41d ... Contact surface (2nd ), 41e... Spring constant adjuster, 41f... Groove (spring constant adjuster), 42... Ball, 43. Lock screw (fastened body), 44a ... thread groove, 45 ... bearing, 50 ... speed reducer, 51 ... driving pulley, 52 ... driven pulley, 52a ... step portion, 52b ... screw groove, 52c ... first step portion, 52d ... 2nd step part, 53 ... Belt, 60 ... Shock absorption member.

Claims (4)

A motor that is a source of assist force;
A steering shaft that reciprocates in the axial direction;
A ball screw nut that is threadedly engaged with the steered shaft via a large number of balls and in which a flange portion is formed over the entire circumferential direction of the outer peripheral surface;
The ball screw nut is inserted and fixed to the outer peripheral surface thereof, and a driven pulley having a step portion that contacts the flange portion in the axial direction inside,
A drive pulley fixed to be rotatable integrally with a rotating shaft of the motor;
A belt wound between the driven pulley and the driving pulley;
A fastening body that is tightened from the side opposite to the stepped portion of the driven pulley and sandwiches the flange portion between the stepped portion, and
A steering device in which the flange portion is provided with a spring constant adjusting portion for reducing its own spring constant. The steering apparatus according to claim 1, wherein
The steering device, wherein the spring constant adjuster is a groove provided on the outer peripheral surface of the flange portion over the entire circumferential direction. The steering apparatus according to claim 1, wherein
The step portion has a first step portion with which the fastening body abuts, and a second step portion having a smaller diameter than the first step portion and spaced apart from the fastening body,
The flange portion is sandwiched between the first step portion and the fastening body,
The spring constant adjusting portion is a steering device that is a portion facing the second step portion on the radially inner side of the flange portion. In the steering device according to any one of claims 1 to 3,
A housing that houses the steered shaft;
Rack ends respectively attached to both ends of the steered shaft and connected to steered wheels;
A steering device comprising: an impact absorbing member that is provided between the housing and the rack end in the moving direction of the steered shaft and absorbs an impact when they abut.