JP7230995B2 - Electric vehicle steering system - Google Patents

Description

The present invention relates to a steering system for an electric vehicle.

In Patent Document 1, one operation mode is set from a plurality of operation modes according to the speed of an obstacle, and an electric motor is controlled in this set operation mode, thereby driving assistance according to the state of the obstacle. A travel support method for a small electric vehicle that performs control is disclosed. Also, for small electric vehicles such as electric wheelchairs, there is known a driving support device that detects an obstacle with an onboard camera, a laser, or the like, and supports driving to avoid the obstacle.

JP 2006-110207 A

In the driving support device according to the background art, as one method of avoiding an obstacle when it is detected, it is conceivable to use automatic steering control in which the vehicle travels while automatically steering in a direction in which the obstacle can be avoided. However, when an obstacle is detected and automatic steering control is executed, the operating handle may rotate against the driver's intention, causing the driver to feel uncomfortable.

SUMMARY OF THE INVENTION An object of the present invention is to prevent an operation handle from rotating against the driver's intention during automatic steering control for avoiding obstacles. To provide a steering device for an electric vehicle capable of relieving a sense of incongruity associated with steering wheel operation by a person.

A steering apparatus for an electric vehicle according to the present invention comprises an operation handle operated by a driver, obstacle detection means for detecting an obstacle, and when the obstacle is detected by the obstacle detection means, the obstacle is detected. A steering apparatus for an electric vehicle, comprising: a first shaft connected to the operating handle; a second shaft connected to a steering wheel ; The steering wheel further includes first rotation angle detection means for detecting the rotation angle of the first shaft and second rotation angle detection means for detecting the rotation angle of the second shaft, wherein the control means controls the automatic steering. , the rotation of the first shaft is prevented by a lock mechanism, and the rotation angle of the first shaft and the second rotation angle detected by the first rotation angle detection means are detected when automatic steering cancellation is determined. driving the electric motor for steering to rotate the second shaft with the locking mechanism preventing rotation of the first shaft so that the rotation angle of the second shaft detected by the means matches ; It is characterized in that the rotation angle of the first shaft and the rotation angle of the second shaft are made to match and the prevention of rotation of the first shaft is released to enable normal steering by a driver. is.

According to the present invention, the steering shaft is composed of the first shaft connected to the operating handle and the second shaft connected to the steered wheels. During automatic steering control, the second shaft rotates to rotate the steered wheels. and the first shaft and the operating handle are not rotated. As a result, it is possible to prevent the steering wheel from turning against the driver's intention during automatic steering control for avoiding obstacles, thereby eliminating the driver's sense of incongruity in handling the steering wheel.

1 is a left side view of an electric vehicle to which an electric vehicle steering apparatus according to an embodiment of the present invention is applied; FIG. FIG. 2 is a left side view showing the periphery of the steering shaft in FIG. 1; III arrow directional view of FIG. IV arrow directional view of FIG. FIG. 5 is an enlarged cross-sectional view showing the state of the electromagnetic solenoid mechanism, which is part A in FIG. 4 , during normal steering; FIG. 5 is an enlarged cross-sectional view showing the state of the lock mechanism, which is part B in FIG. 4 , during normal steering; FIG. 5 is an enlarged cross-sectional view showing the state of the fitting portion, which is the portion C in FIG. 4 , during normal steering; FIG. 5 is an enlarged cross-sectional view showing the state of the electromagnetic solenoid mechanism at the time of automatic steering control, which is part A of FIG. 4 ; FIG. 5 is an enlarged cross-sectional view showing the state of the lock mechanism during automatic steering control, which is part B of FIG. 4 ; FIG. 5 is an enlarged cross-sectional view showing a state of the fitting portion, which is a portion C in FIG. 4 , during automatic steering control; FIG. 2 is a block diagram showing the system configuration of the steering device mounted in FIG. 1; FIG. 12 is a flow chart showing a procedure relating to automatic steering control executed by control means in FIG. 11; FIG.

Hereinafter, embodiments for carrying out the present invention will be described based on the drawings.
FIG. 1 is a left side view showing an electric vehicle to which an embodiment of an electric vehicle steering system according to the present invention is applied. As shown in FIG. 1, in an electric vehicle 10 such as a steering wheel type electric wheelchair, a pair of left and right front wheels 12 and rear wheels 13 are supported by a body frame 11 via suspensions (not shown). The vehicle body frame 11 is covered with a resin cover including a front cover 14, a leg shield 15, a floor panel 16, a rear cover 17, and the like, except for a portion thereof.

The substantially box-shaped rear cover 17 at the rear portion of the vehicle body is protruded upward. Inside the rear cover 17, a driving electric motor 18 for driving the rear wheels 13 is provided. 19 and a battery (both not shown) are accommodated. The traveling electric motor 18 applies a driving force to the rear wheels 13 as drive wheels to cause the electric vehicle 10 to travel, and is controlled by the control means 20 .

A seat 22 on which the driver sits is mounted above the rear cover 17 via a bracket (not shown) rising from the vehicle body frame 11 . This seat 22 includes a seat cushion 23 and a seat back (backrest) 24 . Furthermore, armrests 26 are provided on both sides of the seat back 24 , and each armrest 26 is rotatably supported around a fulcrum 27 .

The leg shield 15 is arranged vertically in the front part of the vehicle body and protects the legs of the driver seated on the seat 22 from the wind. A steering shaft 29 for steering the front wheels 12 is erected inside the leg shield 15 , and a handle unit 30 is attached to the upper end of the steering shaft 29 . During normal steering, the driver sits on the seat 22 and rotates the steering wheel unit 30 to steer the front wheels 12 as steered wheels left and right.

As shown in FIGS. 2 and 3 , the handle unit 30 has semicircular operation handles 32 attached to the left and right sides of a main plate 31 , and an accelerator lever 33 rotatably provided on the main plate 31 . The main plate 31 is accommodated in a switch box 34, and the switch box 34 is provided with a power switch (not shown), a maximum speed setting switch, and the like.

The accelerator lever 33 extends in the width direction of the vehicle by bending in a crank shape to both sides from a rotation shaft portion 33A at the central portion in the axial direction, and has an operation portion 33B at both ends thereof. When the driver of the electric vehicle 10 places his palm on the grip portion 32A of the operating handle 32 and pushes down the operation portion 33B of the accelerator lever 33 with his finger, the control means 20 controls the electric motor 18 for traveling based on the amount of depression. is controlled to control the running speed of the electric vehicle 10 .

By the way, the electric vehicle 10 of the present embodiment automatically steers the front wheels 12 to avoid the obstacle when the distance between the electric vehicle 10 and an obstacle such as a step or a groove reaches a dangerous distance. A steering device 35 is provided for performing automatic steering control in addition to normal steering in which the driver manually rotates the steering wheel unit 30 as described above. As shown in FIGS. 2 to 4, the steering device 35 includes a handle unit 30 having an operating handle 32, a steering shaft 29 having a fitting portion 36 as connecting means, and an electromagnetic solenoid mechanism as moving means. 37, a lock mechanism 38 as a fixing means, an electric motor for steering 39, an obstacle detection means 40 (FIG. 1), a first rotation angle detection means 41 and a second rotation angle detection means 42, and a control means 20. (FIG. 1).

As shown in FIGS. 2 and 4, the steering shaft 29 is configured such that an upper steering shaft 29A as a first shaft and a lower steering shaft 29B as a second shaft are releasably fitted by a fitting portion 36 ( are splined or serrated; The upper portion of the upper steering shaft 29A is connected to the main plate 31 of the handle unit 30 via an electromagnetic solenoid mechanism 37, and is connected to the operation handle 32 attached to the main plate 31. As shown in FIG.

A steering plate 44 is fixed to the lower portion of the lower steering shaft 29B, and the steering plate 44 is connected to a knuckle arm that supports the front wheel 12 via tie rods (both not shown). As a result, the lower steering shaft 29B is connected to the front wheel 12 side. Accordingly, by fitting the upper steering shaft 29A with the lower steering shaft 29B through the fitting portion 36, the operating force from the operating handle 32 of the handle unit 30 is transmitted to the front wheels 12. As shown in FIG.

The fitting portion 36 described above will be described with reference to FIGS. 7 and 10. FIG. A bearing 45 is fixed by, for example, press fitting in the vicinity of the lower end of the upper steering shaft 29A. An upper end plug 46 is fixed to the upper end of the lower steering shaft 29B, and the engaging portion 46A of the upper end plug 46 is engaged with the inner side of the bearing 45 so as to be relatively movable along the axial direction of the steering shaft 29B. be. Further, a spline 47 is formed at the lower end of the upper steering shaft 29A, and a spline 48 is formed at the trunk portion 46B of the upper end plug 46. These splines 47, 48 are coupled to the steering shaft 29 so as to be relatively movable along the axial direction. be.

A relationship of A>B is established between the dimension A of the engaging portion 46A along the axial direction of the steering shaft 29 and the dimension B of the splines 47, 48 along the axial direction of the steering shaft 29. FIG. By establishing this relationship, the upper steering shaft 29A rises from the state shown in FIG. 7 to the state shown in FIG. Even when the fitting portion 36 with the lower steering shaft 29B is released, the separation of the upper steering shaft 29A and the lower steering shaft 29B is prevented.

The electromagnetic solenoid mechanism 37 shown in FIG. 2 moves the upper steering shaft 29A with respect to the lower steering shaft 29B in the axial direction of the steering shaft 29, thereby moving the upper steering shaft 29A using the fitting portion 36 described above. It is engaged with or disengaged from the lower steering shaft 29B. 5 and 8, the electromagnetic solenoid mechanism 37 includes a fixed iron core 49, a movable iron core 50, a copper wire (coil) 51 and a return spring 52, which are housed in a casing 53. be accommodated. The casing 53 is attached to the main plate 31 of the handle unit 30 using bolts 54 or the like.

The fixed core 49 and the movable core 50 are arranged to face each other in the axial direction of the upper steering shaft 29A (steering shaft 29), and the fixed core 49 is fixed to the casing 53. As shown in FIG. The movable iron core 50 is screwed or pressed (in this embodiment, screwed) to an upper end plug 55 welded to the upper end of the upper steering shaft 29A. Also, the copper wire 51 is installed around the fixed core 49 and the movable core 50 , and the return spring 52 is interposed between the fixed core 49 and the movable core 50 .

When the energization of the copper wire 51 is stopped (during normal steering), the biasing force of the return spring 52 maintains the upper steering shaft 29A at the lowered position, as shown in FIG. At this time, as shown in FIG. 7, the spline 47 of the upper steering shaft 29A and the spline 48 of the upper end plug 46 of the lower steering shaft 29B are held in a coupled state at the fitting portion 36. As shown in FIG. Therefore, the upper steering shaft 29A and the lower steering shaft 29B are fitted together by the fitting portion 36, and are provided so as to be integrally rotatable about the axis of the steering shaft 29. As shown in FIG.

When the copper wire 51 is energized (during automatic steering control), as shown in FIG. As a result, the upper steering shaft 29A rises toward the handle unit 30 with respect to the lower steering shaft 29B. At this time, as shown in FIG. 10, at the fitting portion 36, the spline 47 of the upper steering shaft 29A and the spline 48 of the upper end plug 46 of the lower steering shaft 29B are disconnected, and the upper steering shaft 29A and the lower steering shaft 29A are separated from each other. The fitting by the fitting portion 36 with the steering shaft 29B is released. Therefore, the upper steering shaft 29A and the lower steering shaft 29B are separately provided so as to be rotatable around the axis of the steering shaft 29. As shown in FIG.

The lock mechanism 38 shown in FIG. 2 includes a lock plate 58 attached to a brace 57 fixed to the vehicle body frame 11 side, and a disk plate 59 fixed, for example, to the upper steering shaft 29A. As shown in FIGS. 6 and 9, one of the lock plate 58 and the disc plate 59 (the lock plate 58 in this embodiment) has a lock claw 60, and the other (the disc plate 59 in this embodiment) has a lock claw 60. A plurality of lock holes 61 are formed in the lock plate 58 and disc plate 59 in the circumferential direction. By engaging the lock claw 60 with the lock hole 61, the upper steering shaft 29A and the handle unit 30 are fixed (locked), and the upper steering shaft 29A is rotated by the operating force from the operation handle 32 of the handle unit 30. is blocked.

As shown in FIGS. 5 and 6, the lock claw 60 and the lock hole 61 are closed when the upper steering shaft 29A is lowered when the copper wire 51 of the electromagnetic solenoid mechanism 37 is de-energized (during normal steering). is in the disengaged state. At this time, as shown in FIGS. 2 and 7, the upper steering shaft 29A is in a fitted state with the lower steering shaft 29B through the fitting portion 36, so that when the operating handle 32 of the handle unit 30 is operated, The upper steering shaft 29A and the lower steering shaft 29B are integrally rotated around the axis of the steering shaft 29, and the front wheels 12 are steered.

As shown in FIGS. 8 and 10, when the copper wire 51 of the electromagnetic solenoid mechanism 37 is energized (during automatic steering control), the upper steering shaft 29A moves relative to the lower steering shaft 29B. As a result, the fitting portion 36 is disengaged from the lower steering shaft 29B. As shown in FIGS. 2 and 9, the lock claw 60 and the lock hole 61 are engaged in conjunction with the upward movement of the upper steering shaft 29A for disengagement. As a result, rotation of the upper steering shaft 29A and the handle unit 30 (operating handle 32) is prevented during automatic steering control.

The steering electric motor 39 shown in FIG. 2 is attached via a motor bracket 64 to a frame bracket 63 fixed to the body frame 11 . A pinion gear 65 is fixed to the motor shaft of the steering electric motor 39, and the pinion gear 65 meshes with a counter gear 66 fixed to the lower steering shaft 29B. Accordingly, driving the steering electric motor 39 causes the lower steering shaft 29B to rotate about the steering shaft 29 via the pinion gear 65 and the counter gear 66, thereby steering the front wheels 12. As shown in FIG. The steering electric motor 39 is driven not only during automatic steering control, but also when matching the rotation angle of the lower steering shaft 29B with the rotation angle of the upper steering shaft 29A as will be described later.

The obstacle detection means 40 shown in FIGS. 1 and 11 are installed at the front and rear of the electric vehicle 10, that is, at the front end of the front cover 14 and the rear end of the rear cover 17, respectively. These obstacle detection means 40 are cameras, optical (for example, laser) distance sensors, ultrasonic distance sensors, etc., and detect obstacles such as steps and grooves, and detect obstacles and the electric vehicle 10. Detect the distance of A detection signal detected by the obstacle detection means 40 is transmitted to the control means 20 .

The first rotation angle detection means 41 shown in FIGS. 2 and 11 includes a first gear plate 67 fixed to the upper steering shaft 29A and a first rotation angle sensor 68 installed on the brace 57. be. As the first gear plate 67 meshes with the detection portion of the first rotation angle sensor 68, the first rotation angle sensor 68 detects the rotation angle (steering angle) of the upper steering shaft 29A. Also, the second rotation angle detection means 42 comprises a second gear plate 69 fixed to the lower steering shaft 29B and a second rotation angle sensor 70 installed on the frame bracket 63 . The rotation angle (steering angle) of the lower steering shaft 29B is detected by the second rotation angle sensor 70 by the second gear plate 69 meshing with the detection portion of the second rotation angle sensor 70 . The rotation angles detected by the first rotation angle detection means 41 and the second rotation angle detection means 42 are transmitted to the control means 20 .

The control means 20 shown in FIGS. 1 and 11 has a running speed control function for controlling the running speed of the electric vehicle 10 by controlling the running electric motor 18 based on the depression operation of the operating portion 33B of the accelerator lever 33, and a fault detection function. It also has an automatic steering control function for avoiding an obstacle when the obstacle is detected by the object detection means 40 . The latter automatic steering control function will be described below.

When an obstacle such as a step or a groove is detected by the obstacle detection means 40 and the distance between the obstacle and the electric vehicle 10 reaches a distance judged to be dangerous (at the time of automatic steering start determination). Then, by energizing the copper wire 51 of the electromagnetic solenoid mechanism 37, the upper steering shaft 29A shown in FIG. 2 is raised with respect to the lower steering shaft 29B. Due to this upward movement of the upper steering shaft 29A, the fitting portion 36 between the upper steering shaft 29A and the lower steering shaft 29B is released, and the upper steering shaft 29A and the lower steering shaft 29B are aligned with each other. Relative rotation is possible around. At the same time, the lock claws 60 (FIG. 9) of the lock plate 58 attached to the brace 57 are engaged with the lock holes 61 of the disk plate 59 attached to the upper steering shaft 29A, thereby locking the upper steering shaft 29A and the handle unit. 30 (operating handle 32) are fixed (locked) to prevent their rotation.

After that, the control means 20 drives the steering electric motor 39 to rotate the lower steering shaft 29B and executes automatic steering control to steer the front wheels 12 to avoid obstacles.

1 and 11, when the obstacle is avoided by the execution of the automatic steering control and the obstacle is no longer detected by the obstacle detection means 40 (at the time of automatic steering cancellation determination), The rotation angle (steering angle) of the upper steering shaft 29A detected by the first rotation angle detection means 41 and the rotation angle (steering angle) of the lower steering shaft 29B detected by the second rotation angle detection means 42 match. The steering electric motor 39 is driven to rotate the lower steering shaft 29B around its axis. Then, when the rotation angles detected by the first rotation angle detection means 41 and the second rotation angle detection means 42 match, the steering electric motor 39 is stopped.

In this state, the control means 20 stops energizing the copper wire 51 of the electromagnetic solenoid mechanism 37, lowers the upper steering shaft 29A shown in FIG. They are fitted and connected by the joining portion 36, and the automatic steering control ends. As a result, the upper steering shaft 29A and the lower steering shaft 29B become rotatable together about the axis of the steering shaft 29, preparing for normal steering by the driver.

The above automatic steering control by the control means 20 will be further described with reference to the flow chart of FIG.
The control means 20 detects an obstacle by the obstacle detection means 40, and determines whether or not the distance between the obstacle and the electric vehicle 10 has reached a dangerous distance (S1). In this step S1, if it is determined that the distance between the obstacle and the electric vehicle 10 has reached a dangerous distance, the control means 20 starts energizing the copper wire 51 of the electromagnetic solenoid mechanism 37, The upper steering shaft 29A is lifted with respect to the lower steering shaft 29B to release the fitting portion 36 between the upper steering shaft 29A and the lower steering shaft 29B (S2).

After step S2, the control means 20 drives the steering electric motor 39 to execute automatic steering control to steer the front wheels 12 (S3). The control means 20 determines whether or not the obstacle has been avoided by executing the automatic steering control in step S3 based on the detection signal from the obstacle detection means 40 (S4), and continues the automatic steering control until the obstacle is avoided. continue.

When the control means 20 determines in step S4 that the obstacle has been avoided, the upper steering shaft 29A and the lower steering shaft 29B detected by the first rotation angle detection means 41 and the second rotation angle detection means 42, respectively. (S5). When the rotation angles of the upper steering shaft 29A and the lower steering shaft 29B do not match, the control means 20 drives the steering electric motor 39 to rotate the lower steering shaft 29B. The rotation angle of the lower steering shaft 29B is matched with the rotation angle of the upper steering shaft 29A (S6).

In step S5, if the rotation angles of the upper steering shaft 29A and the lower steering shaft 29B are the same (Yes), the control means 20 stops energizing the copper wire 51 of the electromagnetic solenoid mechanism 37 and rotates the upper steering shaft. 29A is lowered, and the upper steering shaft 29A is fitted to the lower steering shaft 29B through the fitting portion 36 (S7). By executing step 7, the automatic steering control is completed, and preparations are made for normal steering by the driver (S8). If no obstacle is detected in step S1, automatic steering control is not performed, and normal steering by the driver is performed.

With the configuration as described above, the present embodiment has the following effects (1) to (5).
(1) As shown in FIGS. 1 and 2, the steering shaft 29 includes an upper steering shaft 29A connected to a handle unit 30 having an operation handle 32, and a lower steering shaft 29B connected to the front wheel 12 side. are connected by being releasably fitted by the fitting portion 36 . When executing the automatic steering control, the control means 20 causes the electromagnetic solenoid mechanism 37 to release the fitting portion 36 between the upper steering shaft 29A and the lower steering shaft 29B, and the steering electric motor 39 is operated. The front wheels 12 are steered by driving and rotating the lower steering shaft 29B.

Therefore, the upper steering shaft 29A and the handle unit 30 (operating handle 32) are not rotated during automatic steering control. As a result, it is possible to prevent the steering wheel unit 30 (the steering wheel 32) from rotating against the intention of the driver holding the steering wheel 32 of the steering wheel unit 30 when the automatic steering control for avoiding obstacles is executed. It is possible to eliminate the sense of incongruity associated with the steering wheel operation of the driver.

(2) As shown in FIGS. 2, 6 and 9, the upper steering shaft 29A and the handle unit 30 are fixed (locked) by engaging the lock claw 60 with the lock hole 61 of the upper steering shaft 29A. A lock mechanism 38 is provided to prevent the rotation of these parts. During automatic steering control in which the upper steering shaft 29A and the lower steering shaft 29B are disengaged and the lower steering shaft 29B is rotated by the steering electric motor 39, the lock mechanism 38 locks the upper steering shaft 29A. And the rotation of the handle unit 30 is blocked.

Therefore, the upper steering shaft 29A is prevented from rotating unintentionally during automatic steering control, and the driver's posture can be prevented from becoming unstable by gripping the operation handle 32 of the handle unit 30. FIG. Therefore, the front wheels 12 can be steered at the maximum steering angle during automatic steering control.

(3) As shown in FIGS. 2, 8 and 9, the upper steering shaft 29A is raised by energizing the copper wire 51 of the electromagnetic solenoid mechanism 37, and the fitting portion 36 is engaged with the lower steering shaft 29B. When the engagement is released, the lock mechanism 38 engages the lock pawl 60 with the lock hole 61 in conjunction with the upward movement of the upper steering shaft 29A, thereby fixing (locking) the upper steering shaft 29A and the handle unit 30. . In this manner, the actuation (locking) of the lock mechanism 38 and the disengagement of the fitting portion 36 can be performed by the electromagnetic solenoid mechanism 37, which is the same drive source. As a result, the drive source for the lock mechanism 38 and the fitting portion 36 can be shared, and the system configuration of the steering device 35 can be simplified.

(4) As shown in FIG. 2, when the automatic steering control ends, the rotation angle of the upper steering shaft 29A detected by the first rotation angle detection means 41 and the lower steering shaft angle detected by the second rotation angle detection means 42 When the rotation angle of the steering shaft 29B coincides with the rotation angle of the steering shaft 29B, the power supply to the copper wire 51 of the electromagnetic solenoid mechanism 37 is stopped to lower the upper steering shaft 29A. It is configured to fit and connect to the steering shaft 29B. Therefore, in the normal steering by the driver after the automatic steering control ends, the positional relationship between the operating handle 32 of the steering wheel unit 30 and the front wheel 12 becomes appropriate, and the normal steering can be performed properly.

(5) As shown in FIGS. 2 and 7, the upper steering shaft 29A and the lower steering shaft 29B are releasably fitted and connected by the spline connection or serration connection of the fitting portion 36. FIG. Therefore, compared to the case where the upper steering shaft 29A and the lower steering shaft 29B are connected using frictional force, it is possible to reliably transmit the rotational force (operating force) between the upper steering shaft 29A and the lower steering shaft 29B. . Moreover, since the fitting portion 36 has a small number of parts, and is lightweight and small, it is possible to reduce the operating force applied to the operating handle 32 by the driver, and the steering electric motor 39 can be made compact. Furthermore, the degree of freedom in designing around the steering shaft 29 can be increased.

Although the embodiment of the present invention has been described above, this embodiment is presented as an example and is not intended to limit the scope of the invention. This embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. , is included in the scope and gist of the invention, and is included in the scope of the invention described in the claims and its equivalents.

REFERENCE SIGNS LIST 12 Front wheel (steering wheel) 20 Control means 29 Steering shaft 29A Upper steering shaft 29B Lower steering shaft 30 Handle unit 32 Operation handle 35 Steering device 36 Fitting Parts (connecting means) 37 Electromagnetic solenoid mechanism (moving means) 38 Locking mechanism (fixing means) 39 Steering electric motor 40 Obstacle detecting means 41 First rotation angle detecting means 42 Second rotation angle detection means 47, 48 Spline 58 Lock plate 59 Disk plate 60 Lock claw 61 Lock hole 67 First gear plate 68 First rotation angle sensor 69 ... second gear plate, 70 ... second rotation angle sensor.

Claims (5)

An operation handle operated by a driver, an obstacle detection means for detecting an obstacle, and automatic steering control to avoid the obstacle when the obstacle is detected by the obstacle detection means. A steering device for an electric vehicle, comprising a control means,
a first shaft connected to the operating handle; a second shaft connected to the steering wheel ; first rotation angle detection means for detecting the rotation angle of the first shaft; and a second rotation angle detection means for detecting,
The control means prevents rotation of the first shaft by a lock mechanism when executing the automatic steering control,
so that the rotation angle of the first shaft detected by the first rotation angle detection means and the rotation angle of the second shaft detected by the second rotation angle detection means match when automatic steering cancellation is determined; driving the steering electric motor to rotate the second shaft in a state in which the lock mechanism prevents rotation of the first shaft ;
An electric power steering wheel according to claim 1, characterized in that the rotation angle of the first shaft and the rotation angle of the second shaft are made to coincide with each other, and the prevention of rotation of the first shaft is released to enable normal steering by a driver. Vehicle steering system. 2. The steering apparatus for an electric vehicle according to claim 1, wherein the lock mechanism is configured to prevent rotation of the first shaft by engaging the lock pawl with the lock hole by the action of an electromagnetic solenoid mechanism. . 3. The steering apparatus for an electric vehicle according to claim 1, wherein the steering electric motor is installed on the vehicle body frame and connected to the second shaft via a gear mechanism. 4. The apparatus according to any one of claims 1 to 3, wherein the first shaft and the second shaft are connected by a connecting means when the automatic steering is determined to be canceled, and are disconnected when the automatic steering is controlled. A steering system for an electric vehicle as described. It is characterized in that the blocking of rotation of the first shaft by the lock mechanism and the release of the blocking of rotation of the first shaft are performed in conjunction with the disconnection and coupling of the first shaft and the second shaft by the coupling means, respectively. The steering system for an electric vehicle according to claim 4.

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