JP6729116B2 - Steer-by-wire steering system - Google Patents

Description

The present invention relates to a steering device for a vehicle by a steer-by-wire system.

In recent years, a steer-by-wire steering device in which a steering wheel and a steering gear mechanism are electrically connected has been developed. That is, it is a system that steers the wheels by converting the steering intention of the driver into an electric signal and transmitting the electric signal to a steering motor via a wire. The steering device of the steer-by-wire system is provided with a mechanism that mechanically connects the steering wheel and the steering gear mechanism only when the system is abnormal. For example, a clutch or a planetary gear is used for this connecting mechanism (see Patent Document 1).

JP, 2005-189346, A

By the way, a shaft (so-called intermediate shaft) connecting the steering wheel and the steering gear mechanism has a function of absorbing a shock by being deformed when the vehicle collides with the front surface. However, in the steering device of the steer-by-wire system as described in Patent Document 1, compared with the steering device that is not the steer-by-wire system, the length of the intermediate shaft is equal to the length of the coupling mechanism provided on the intermediate shaft. Since the length is shortened, there is a concern that the ability to absorb a shock at the time of a vehicle collision (deformation amount at the time of collision) becomes small.

The present invention has been devised in view of such a problem, and an object thereof is to improve the safety at the time of a vehicle collision in a steer-by-wire type steering device. Note that the present invention is not limited to this purpose, and it is also for the other purpose of the present invention to provide operational effects that are obtained by the respective configurations shown in the modes for carrying out the invention to be described later and that cannot be obtained by the conventional technology. is there.

(1) The steer-by-wire type steering device disclosed herein is a steer-by-wire type steering device in which torque transmission between a steering wheel and a steering gear mechanism is cut off, and is interlocked with rotation of the steering wheel. A sleeve connected to a lower end of a rotating shaft; a pinion gear included in the steering gear mechanism, which is radially outside of the sleeve and coaxial with the sleeve; A connecting portion that is arranged on a torque transmission path to the pinion gear and that can mechanically connect and disconnect the sleeve and the pinion gear. The connecting portion cuts off or transmits the rotation (torque) of the sleeve to the pinion gear, and includes, for example, a clutch, a planetary gear, a cam, and the like.

(2) It is preferable that the connecting portion is arranged adjacent to the pinion gear.
(3) At this time, it is preferable that the connecting portion is arranged below the pinion gear.
(4) Further, the coupling portion has a first engagement element fixed to the sleeve and a second engagement element fixed to the pinion gear and arranged above the first engagement element. And a drive source for switching the connection/disconnection state of the clutch.

(5) It is preferable that the steering gear box that houses the steering gear mechanism has a housing part that houses the coupling part.
(6) The steering device is a torque sensor that detects a twist amount of the torsion bar when the torsion bar that connects the shaft and the sleeve and the sleeve and the pinion gear are connected by the connecting portion. And a control device that controls the motor based on the amount of twist detected by the torque sensor to reduce the steering torque with respect to the steering wheel.

When a vehicle collides, an external force can be absorbed by the gap (play) in the connecting portion. Further, since the pinion gear is free to rotate with respect to the sleeve, they can move relative to each other in the axial direction. Therefore, when the pinion gear enters the rear of the vehicle at the time of a vehicle collision, the backward movement amount of the sleeve and the steering wheel connected thereto can be reduced by the relative movement amount of the sleeve and the pinion gear. By these, the safety at the time of a vehicle collision can be improved.

FIG. 1 is a schematic front view illustrating a steer-by-wire type steering device according to an embodiment. It is a figure which shows the path|route of the torque transmitted to a wheel. FIG. 2 is a schematic vertical cross-sectional view (cross-sectional view taken along the line AA of FIG. 1) taken in the front-rear direction through the axis of the pinion gear in the steering device of FIG. 1. It is a longitudinal cross-sectional view (cross-sectional view corresponding to FIG. 3) showing a steering device according to a modification.

A steer-by-wire steering apparatus as an embodiment will be described with reference to the drawings. The embodiments described below are merely examples, and there is no intention to exclude various modifications and application of techniques that are not explicitly shown in the following embodiments. Each configuration of the present embodiment can be variously modified and implemented without departing from the spirit thereof. In addition, they can be selected or combined as needed.

[1. overall structure]
FIG. 1 is a schematic front view showing a steering device 1 of the present embodiment. The steering device 1 is a steer-by-wire type steering device in which the steering wheel 2 and the steering gear mechanism 10 are not mechanically connected in the steering gear box 13 and torque transmission between them is cut off. In a vehicle equipped with the steering device 1, the steering intention of the driver is detected as a steering angle, and an electric signal corresponding to the steering angle is transmitted to the steering motor 5 via a wire, whereby the wheels 9 are steered. At the same time, by being transmitted to the reaction force motor 6 through the wire, the reaction force (feeling) related to steering is given to the driver.

Further, in the present steering device 1, when the power supply from the vehicle-mounted battery that is the power source of the motors 5 and 6 is interrupted (when the power is lost), when the wire is broken, or when the motors 5 and 6 are broken, In the case where an abnormality that makes steering by control impossible is generated in the steering device 1 or the vehicle (hereinafter referred to as “at the time of abnormality”), the coupling mechanism 20 that exhibits the function is provided. In the steering device 1, the motors 5 and 6 are controlled in accordance with the steering angle as described above during normal times other than abnormal times. On the other hand, when an abnormality occurs, the steering wheel 2 and the steering gear mechanism 10 are mechanically coupled by the coupling mechanism 20, and the rotational movement of the pinion gear 12 included in the steering gear mechanism 10 is converted into the linear movement of the rack shaft 11. The wheels 9 are steered. That is, the coupling mechanism 20 has a function of enabling torque transmission between the steering wheel 2 and the steering gear mechanism 10 when an abnormality occurs.

The steering gear mechanism 10 is a rack and pinion type gear mechanism in which a rack shaft 11 and a pinion gear 12 meshing with the rack shaft 11 are housed in a steering gear box 13. However, as described above, the steering device 1 is configured so that the rotational movement of the pinion gear 12 is converted into the linear movement of the rack shaft 11 only when an abnormality occurs. This structure will be described later.

The steering device 1 includes a steering motor 5 for steering the wheels 9, a reaction force motor 6 for applying a steering reaction force to the steering wheel 2, and a steering angle of the steering wheel 2 (the steering intention of the driver). It has a steering angle sensor 7 for detecting, and a control device 8 for controlling the motors 5, 6 in accordance with the steering angle detected by the steering angle sensor 7. The steered motor 5 is an electric motor for moving the rack shaft 11 in the axial direction, and is connected to the rack shaft 11 via a reduction gear 14 and the like. A pair of left and right wheels 9 are connected to the rack shaft 11 via tie rods 17, and the torque of the steering motor 5 amplified by the reduction gear 14 is transmitted to the rack shaft 11, so that the wheels 9 are connected. Steered.

The reaction force motor 6 is an electric motor for rotating the steering shaft 3 connected to the steering wheel 2, and is connected to the steering shaft 3 via the reduction gear 15 and the like. The reaction force motor 6 normally gives a steering reaction force by generating a torque on the steering shaft 3 in response to an input applied to the rack shaft 11 from the road surface. The steering angle sensor 7 is provided, for example, on the steering shaft 3 or the steering column 4, and transmits the detected steering angle to the control device 8.

The control device 8 is a computer (electronic control device) that controls various controls of the steering device 1, and is, for example, an LSI device or a built-in electronic device in which a microprocessor, ROM, RAM and the like are integrated. As described above, the control device 8 normally controls the motors 5 and 6 according to the steering angle. On the other hand, when an abnormality occurs, the coupling mechanism 20 is controlled to mechanically couple the steering wheel 2 and the steering gear mechanism 10. At this time, if at least one of the motors 5 and 6 is controllable, the motors 5 and 6 are controlled to reduce the steering torque on the steering wheel 2 and assist the steering of the driver.

For example, when the steering motor 5 is out of order and the reaction force motor 6 is normal (controllable), the control device 8 rotates the steering shaft 3 in the same direction as the steering wheel 2 is steered. Thus, an electric signal is sent to the reaction force motor 6. When the reaction force motor 6 is out of order and the steering motor 5 is normal (controllable), the control device 8 moves the rack shaft 11 in the same direction as the movement direction of the pinion gear 12. An electric signal is sent to the steering motor 5.

The connecting mechanism 20 includes a connecting portion 21 for mechanically connecting the steering wheel 2 and the steering gear mechanism 10, and members 22 to 25 for transmitting steering torque (rotational force) to the steering wheel 2 to the steering gear mechanism 10. Have and. Further, the steering device 1 has a torque sensor 26 for obtaining the torque (assist amount) of the motors 5 and 6 capable of assisting the steering of the driver at the time of abnormality.

Hereinafter, a state in which the steering wheel 2 and the steering gear mechanism 10 are mechanically connected by the connecting portion 21 is referred to as a “connected state”, and a state in which these are not mechanically connected is referred to as a “separated state”. The steering device 1 is basically in a separated state and is in a connected state only when an abnormality occurs. In the separated state, the four members 22 to 25 rotate integrally with the rotation of the steering wheel 2. Hereinafter, these members 22 to 25 are referred to as an intermediate shaft 22, an input shaft 23, a torsion bar 24, and a sleeve 25.

The intermediate shaft 22 is a member that connects the steering shaft 3 and the steering gear mechanism 10, and also has a function of absorbing a shock by deforming when the vehicle collides with the front surface. A shaft coupling 27 is provided on the intermediate shaft 22. The input shaft 23 is a member connected to the intermediate shaft 22 via a shaft joint 28, and inputs steering torque to the steering gear mechanism 10. The torsion bar 24 (see FIG. 3) is a member that twists when the steering wheel 2 is steered during an abnormality (that is, in a connected state), and the sleeve 25 is a member that transmits steering torque to the pinion gear 12 during an abnormality. ..

Here, the path of the torque transmitted to the wheels 9 will be described with reference to FIG. The black arrow in the drawing indicates the torque transmission path in the normal state, and the broken white arrow indicates the torque transmission path in the abnormal state. The connecting portion 21 is arranged on the torque transmission path from the sleeve 25 to the pinion gear 12, and is provided so that the sleeve 25 and the pinion gear 12 can be mechanically connected and disconnected. When the connecting portion 21 is in the open state, the sleeve 25 and the pinion gear 12 are mechanically disconnected (not connected), and the torque transmission is cut off (that is, the separated state). On the contrary, when the connecting portion 21 is in the engaged state, the sleeve 25 and the pinion gear 12 are mechanically connected to each other, and the torque can be transmitted (that is, the connected state).

Since the vehicle is normally in the separated state, even if the steering torque is input to the steering wheel 2, the torque is not transmitted to the pinion gear 12. In this case, the torque of the steering motor 5 is transmitted to the rack shaft 11 to steer the wheels 9. On the other hand, in the abnormal state, the steering wheel 2 is brought into the connected state, so that the steering torque input to the steering wheel 2 is transmitted from the sleeve 25 to the pinion gear 12, the rotational movement of the pinion gear 12 is converted into the linear movement of the rack shaft 11, and the wheel is rotated. 9 is steered.

[2. Main composition]
FIG. 3 is a schematic vertical cross-sectional view (cross-sectional view taken along the line AA of FIG. 1) cut in the front-rear direction through the axis of the pinion gear 12. Note that hatching is omitted in FIG. As shown in FIG. 3, a sleeve 25 is coaxially connected to the lower end of the input shaft 23 via a torsion bar 24. The lower end surface of the input shaft 23 is formed with a recess into which the torsion bar 24 is fitted, and the upper end surface of the sleeve 25 is formed with a stepped recess into which the torsion bar 24 and the input shaft 23 are fitted. ing. A torque sensor 26 is provided at the upper end of the sleeve 25.

The torsion bar 24 is a round bar member having a thin central portion for easy twisting, and serrations (not shown) are formed at both upper and lower ends thereof. The upper portion of the torsion bar 24 is fitted into and fixed to the recess of the input shaft 23, and rotates together with the input shaft 23. The lower portion of the torsion bar 24 is press-fitted and fixed in the concave portion of the sleeve 25, and the rotation of the torsion bar 24 is transmitted to the sleeve 25 via serration. The lower end of the input shaft 23 is rotatably fitted in the recess of the sleeve 25.

The sleeve 25 of the present embodiment is a stepped rod-shaped member having an inclined outer peripheral surface at an intermediate portion in the axial direction, and extends in the vertical direction. The sleeve 25 has a large diameter portion 25a, an inclined portion 25c, and a small diameter portion 25b in order from above. The sleeve 25 is rotatably supported with respect to the steering gear box 13 by bearings 29 provided at two upper and lower positions. The reduction gear 15 is fixed to the outer peripheral surface of the large diameter portion 25 a of the sleeve 25. A worm shaft 16 connected to the output shaft of the reaction force motor 6 meshes with the reduction gear 15.

Further, the pinion gear 12 is provided outside the small diameter portion 25b of the sleeve 25 in the radial direction via a bearing 18. The pinion gear 12 is arranged coaxially with the sleeve 25 so as to rotate freely with respect to the sleeve 25. That is, the inner diameter dp of the pinion gear 12 is larger than the outer diameter Ds of the small diameter portion 25b of the sleeve 25, and a gap is provided between the inner peripheral surface of the pinion gear 12 and the outer peripheral surface of the sleeve 25. The pinion gear 12 of the present embodiment is supported by the bearing 18 interposed in this gap so as to rotate freely with respect to the sleeve 25. The pinion gear 12 of the present embodiment is arranged with a gap G from the boundary line between the inclined portion 25c of the sleeve 25 and the small diameter portion 25b.

In the small diameter portion 25b of the sleeve 25, the connecting portion 21 is arranged adjacent to the pinion gear 12. The connecting portion 21 of the present embodiment is located below the pinion gear 12. The coupling portion 21 blocks or transmits the steering torque transmitted to the sleeve 25 to the pinion gear 12, and is accommodated in the accommodation portion 13A provided in the steering gear box 13. The connecting portion 21 is composed of, for example, a transmission mechanism such as a clutch, a planetary gear, a cam, and the like, and a drive source (actuator) that switches the connection/disconnection state of the transmission mechanism.

The coupling portion 21 of the present embodiment includes a clutch having a first engagement element 21A fixed to the sleeve 25 and a second engagement element 21B fixed to the pinion gear 12, and a drive source for switching the clutch on/off state. Have. In the clutch of this embodiment, the second engagement element 21B is arranged above the first engagement element 21A, and a gap (play) is provided between these elements 21A and 21B. The drive source drives the two engagement elements 21A and 21B in the directions of separating (cutting) and approaching (engaging), and is, for example, a hydraulic pressure or an electric actuator. The connection/disconnection state of the engagement elements 21A and 21B is controlled by the control device 8.

The connecting portion 21 does not transmit the steering torque to the pinion gear 12 in the open state in which the two engagement elements 21A and 21B are disconnected. That is, in this case, the sleeve 25 idles with respect to the pinion gear 12 by the steering torque input to the steering wheel 2 and the torque of the reaction force motor 6. On the other hand, the connecting portion 21 transmits the steering torque to the pinion gear 12 in the engaged state in which the two engaging elements 21A and 21B are engaged. That is, in this case, the pinion gear 12 also rotates in conjunction with the rotation of the sleeve 25. Further, in this case, since the resistance force against the rotation of the sleeve 25 is increased by the rack shaft 11 and the pinion gear 12, the torsion bar 24 is twisted.

The torque sensor 26 detects the twist amount of the torsion bar 24 when the connecting portion 21 is in the engaged state, and transmits the detected twist amount to the control device 8. The control device 8 controls the controllable motors 5 and 6 so that the steering torque with respect to the steering wheel 2 is reduced based on this twist amount. As a result, the steering of the driver is assisted, and the safety at the time of abnormality is improved.

[3. Action, effect]
(1) In the steering device 1 described above, since the pinion gear 12 is arranged so as to rotate freely with respect to the sleeve 25, the steering torque input to the steering wheel 2 at normal times is not transmitted to the pinion gear 12, and the steer-by-wire is not provided. Steering by the method is possible. Further, since the pinion gear 12 and the sleeve 25 are mechanically connected by the connecting portion 21 at the time of abnormality and the steering torque is transmitted to the wheels 9, safety at the time of abnormality can be ensured.

Further, in the steering device 1 described above, when an external force is applied to the pinion gear 12 via the rack shaft 11, the tie rod 17, etc. (for example, at the time of a vehicle collision), the external force is absorbed by the gap (play) in the connecting portion 21. You can Further, since the pinion gear 12 and the sleeve 25 are separated in the radial direction and the pinion gear 12 can freely rotate with respect to the sleeve 25, they can relatively move in the axial direction. Therefore, for example, when the vehicle collides with the front surface and the pinion gear 12 enters the rear of the vehicle together with the rack shaft 11, the backward movement amount of the sleeve 25 and the steering wheel 2 connected thereto is determined by the relative movement of the sleeve 25 and the pinion gear 12. It can be reduced depending on the amount. By these, the safety at the time of a vehicle collision can be improved.

(2) In the steering device 1 described above, since the coupling portion 21 is arranged adjacent to the pinion gear 12, the reaction force motor 6 can be arranged close to the rack shaft 11. Since the reaction force motor 6 normally rotates the steering shaft 3, the reaction force motor 6 needs to be disposed above the connecting portion 21, but as the reaction force motor 6 is closer to the steering wheel 2, the reaction force motor 6 is closer to the steering wheel 2. The operating noise of 6 easily reaches the vehicle interior. On the other hand, in the steering apparatus 1 described above, since the connecting portion 21 is provided at the position adjacent to the pinion gear 12, the position of the reaction force motor 6 can be lowered to near the rack shaft 11. As a result, the distance between the reaction force motor 6 and the steering wheel 2 (that is, the vehicle interior) becomes long, so that the quietness in the vehicle interior can be improved. Further, since the position of the connecting portion 21 is also far from the steering wheel 2, the rattle noise of the connecting portion 21 does not easily reach the vehicle interior, which also improves the quietness of the vehicle interior.

(3) Further, in the above-described steering device 1, since the connecting portion 21 is arranged below the pinion gear 12, the length of the intermediate shaft 22 is smaller than that of the conventional configuration in which a clutch or the like is arranged on the intermediate shaft. Can be long. As a result, the contraction amount (deformation amount) of the intermediate shaft 22 at the time of a vehicle collision can be increased, so that a larger impact (external force) can be absorbed by the intermediate shaft 22 and the safety at the time of collision is improved. be able to. By disposing the connecting portion 21 below the pinion gear 12 and the rack shaft 11, the position of the reaction motor 6 can be brought closer to the rack shaft 11. Further, since the position of the connecting portion 21 is farthest from the steering wheel 2, it is possible to further improve the quietness of the vehicle interior.

(4) In the steering device 1 described above, the connecting portion 21 has a clutch composed of two engagement elements 21A and 21B, and therefore the configuration can be simplified. Further, since the second engagement element 21B fixed to the pinion gear 12 is arranged above the first engagement element 21A fixed to the sleeve 25, the pinion gear 12 is moved upward with respect to the sleeve 25 in the event of a vehicle collision. Can move relative to each other. As a result, the amount of backward movement of the steering wheel 2 can be reduced, and the safety at the time of a vehicle collision can be improved.

Further, in the steering device 1 of the present embodiment, as shown in FIG. 3, the pinion gear 12 is arranged with a gap G from the boundary line between the inclined portion 25c of the sleeve 25 and the small diameter portion 25b, so that the pinion gear 12 is It can move relative to the sleeve 25 by a length G. If the amount of relative movement between the pinion gear 12 and the sleeve 25 can be increased, it is expected that the safety will be improved in the event of a vehicle collision.

(5) In the steering device 1 described above, the steering gear box 13 that houses the steering gear mechanism 10 has the housing portion 13A that houses the coupling portion 21. That is, a housing for housing the connecting portion 21 is provided integrally with the steering gear box 13. Therefore, the number of parts can be reduced and the steering device 1 can be made lighter than in the case where a dedicated housing is provided. Thereby, the cost can be reduced.

(6) In the steering device 1 described above, the torsion bar 24 is twisted due to the connected state when an abnormality occurs. The control device 8 controls the normal motors 5 and 6 based on this twist amount to reduce the steering torque for the steering wheel 2, so that the steering of the driver can be appropriately assisted, and safety in the event of an abnormality It is possible to improve the sex.

[4. Modification]
Although the embodiments and modifications of the present invention have been described above, the present invention is not limited to the above-described embodiments and the like, and various modifications can be made without departing from the spirit of the present invention.
The steering device 1 described above exemplifies the one in which the connecting portion 21 is arranged below the pinion gear 12, but the position of the connecting portion 21 is not limited to this. For example, as shown in FIG. 4, the above-mentioned connecting portion 21 may be arranged adjacent to the upper side of the pinion gear 12. Even in this case, the same effect can be obtained from the configuration similar to that of the above-described embodiment. In the steering apparatus 1 shown in FIG. 4, the pinion gear 12 is rotatably supported with respect to the steering gear box 13 by a bearing 18' provided on the outer side in the radial direction. It may be provided similarly to. On the contrary, the bearing 18' shown in FIG. 4 may be provided instead of the bearing 18 of the above-described embodiment.

Further, in the above-described embodiment, the sleeve 25 has a stepped rod shape, and the pinion gear 12 is arranged with a gap G from the boundary line between the small diameter portion 25b and the inclined portion 25c. May be zero. Further, the inner diameter dp of the pinion gear 12 may be made larger than the outer diameter of the large diameter portion 25a, and the pinion gear 12 may be arranged so as to overlap the inclined portion 25c and the large diameter portion 25a. The sleeve 25 may have a cylindrical shape.

Further, the configuration of the connecting portion 21 is not limited to the above. For example, the clutch included in the connecting portion 21 may be a multi-plate type, or may include a planetary gear or a cam instead of the clutch.
When the connecting portion has a planetary gear having three elements of a sun gear, a carrier, and a ring gear, one of the three elements is fixed to the sleeve 25, another element is fixed to the pinion gear 12, and the remaining elements are fixed. A drive source is provided to enable braking. With the connecting portion having such a configuration, it is possible to bring the connected state when the brake is released and the connected state when the brake is applied. Further, by using the planetary gear, since the steering torque can be amplified and transmitted to the pinion gear 12, the steerability of the steering wheel 2 at the time of abnormality can be improved.

When the connecting portion has a cam, for example, a ring member fixed to the pinion gear 12 is provided outside the sleeve 25 in the radial direction, and cam grooves are formed on the inner peripheral surface of the ring member and the outer peripheral surface of the sleeve 25, respectively. .. Further, a roller is arranged between the cam grooves, and a drive source for moving the ring member or the roller in the circumferential direction is provided. With the connecting portion having such a configuration, when the roller is in a position where torque is not transmitted, the roller is in a separated state, and when the roller is moved to a position in which torque is transmitted, the roller can be in a connected state. Further, by using the cam, the element on the pinion gear 12 side and the sleeve 25 can be separated from each other in the radial direction even at the connecting portion, so that the amount of relative displacement in the axial direction between the pinion gear 12 and the sleeve 25 can be increased. You can As a result, the amount of backward movement of the steering wheel 2 at the time of a vehicle collision can be reduced, and safety can be improved.

1 Steering device 2 Steering wheel 3 Steering shaft 5 Steering motor
6 Reaction force motor
7 Steering Angle Sensor 8 Control Device 10 Steering Gear Mechanism 11 Rack Shaft 12 Pinion Gear 13 Steering Gear Box 13A Housing 20 Coupling Mechanism 21 Coupling 21A First Engaging Element 21B Second Engaging Element 22 Intermediate Axis (Shaft)
23 Input axis (axis)
24 Torsion Bar 25 Sleeve 25a Large Diameter Part 25b Small Diameter Part 25c Inclined Part 26 Torque Sensor

Claims (6)

A steer-by-wire type steering device in which torque transmission between a steering wheel and a steering gear mechanism is cut off,
A sleeve connected to the lower end of the shaft that rotates in conjunction with the rotation of the steering wheel;
A pinion gear included in the steering gear mechanism, which is radially outer side of the sleeve and is coaxial with the sleeve and is arranged so as to rotate freely with respect to the sleeve;
A steering device of a steer-by-wire system, which is arranged on a torque transmission path from the sleeve to the pinion gear, and includes a connecting portion capable of mechanically connecting and disconnecting the sleeve and the pinion gear. .. The steer-by-wire type steering device according to claim 1, wherein the connecting portion is disposed adjacent to the pinion gear. The steer-by-wire type steering device according to claim 2, wherein the connecting portion is disposed below the pinion gear. The connecting portion is
A clutch having a first engagement element fixed to the sleeve and a second engagement element fixed to the pinion gear and arranged above the first engagement element,
The steer-by-wire type steering device according to claim 3, further comprising: a drive source that switches a connection/disconnection state of the clutch. The steer-by-wire type steering device according to claim 1, wherein a steering gear box that houses the steering gear mechanism has a housing part that houses the connecting part. A torsion bar connecting the shaft and the sleeve,
A torque sensor that detects the amount of twist of the torsion bar when the sleeve and the pinion gear are connected by the connecting portion,
6. A control device that controls a motor based on the amount of twist detected by the torque sensor to reduce a steering torque with respect to the steering wheel. The steer-by-wire type steering device described in 1.

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