JP2003327147A - Steering gear for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a great shock from acting on a driver when steering is executed up to the maximum steering angle, in a vehicular steering gear capable of changing a ratio of a control input for an operation member to a steering quantity for wheels. <P>SOLUTION: Motion of a steering actuator 2 is transmitted to the wheels 4 to generate a steering angle change. The actuator 2 is controlled to change the ratio of the control input for the operation member 1 to the steering quantity for wheels 4. When the steering quantity for wheels 4 comes to the maximum value, a body side member 31 blocks the steering of the wheels 4. In the operation member 1, an operation to a direction for making a steering angle large is allowed not only before the steering quantity for wheels 4 reaches to the maximum value but also after reaching to the maximum value. When the operation member 1 operated to the direction for making the steering angle large after the steering quantity for wheels 4 reaches to the maximum value is inversion-operated to a direction for making the steering angle small, the steering actuator 2 is controlled considering the control input of the operation member 1 in an inversion operation start time point as the control input at the time point when the steering quantity for wheels 4 reaches to the maximum value. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle steering system capable of changing a ratio between an operation amount of an operation member and a turning amount of wheels.

[0002]

2. Description of the Related Art When transmitting the movement of a steering actuator according to the operation of an operating member to a wheel so that the steering angle changes, the ratio of the operating amount of the operating member and the turning amount of the wheel is changed. Has developed a vehicle steering system capable of changing steering characteristics. As such a steering device, there are a steering device that employs a so-called steer-by-wire system in which an operation member is not mechanically connected to a wheel and a device that is mechanically connected to the wheel. In a steering device that employs a steer-by-wire system, when the movement of the steering actuator is transmitted to the wheels so that the steering angle is changed by the steering gear, without mechanically connecting an operating member simulating a steering wheel to the wheels. In addition, the ratio between the operation amount and the steering amount is changed by controlling the steering actuator. Further, in a steering device in which an operating member is mechanically connected to a wheel, when a rotation of the steering wheel is transmitted to a steering gear through a transmission ratio variable mechanism such as a planetary gear mechanism, a ring gear that constitutes the planetary gear mechanism is used. The ratio between the operation amount and the turning amount is changed by controlling the steering actuator that drives the steering wheel and the like.

[0003]

In the steering apparatus employing the steer-by-wire system, the rotation of the operating member is not blocked even if the steering of the wheels is blocked at the maximum steering angle position. Therefore, conventionally, a stopper for preventing the operation of the operating member and an actuator for generating a torque having the same magnitude as the torque applied by the driver but the opposite direction have been provided. Therefore, the torque acting on the operating member fluctuates greatly at the maximum steering angle position, causing a large shock to the driver. In the steering device that transmits the rotation of the steering wheel to the steering gear via the variable transmission ratio mechanism, since the steering of the wheels is blocked at the maximum steering angle position, the operation of the operating member is also blocked. There was a shock.

Further, a general steering wheel has an index of a shape capable of indicating a specific direction, and the direction indicated by the index corresponds to the front-rear direction of the vehicle in a straight traveling state. However, in the above steering device, when the ratio of the turning amount to the operation amount changes during steering,
In a straight traveling state, the direction indicated by the index does not correspond to the front-back direction of the vehicle. Therefore, there is a possibility that the rudder angle midpoint is erroneously recognized or it is difficult to grasp the rudder angle midpoint. An object of the present invention is to provide a vehicle steering system that can solve the above problems.

[0005]

SUMMARY OF THE INVENTION A vehicle steering system according to the present invention comprises an operating member, a means for detecting the amount of operation of the operating member, a steering actuator, and a movement of the steering actuator with a change in steering angle. The steering actuator can be controlled so that the means for transmitting to the wheels so as to generate, the means for detecting the turning amount of the wheels, and the ratio of the operation amount of the operating member and the turning amount of the wheels change. Control system, a means for determining whether or not the steering amount of the wheels has reached the maximum value, and a vehicle body side that prevents the steering of the wheels when the steering amount of the wheels reaches the maximum value. The operation member is allowed to operate in the direction of increasing the operation angle not only before the wheel steering amount reaches the maximum value but also after the wheel steering amount reaches the maximum value, and the wheel steering amount reaches the maximum value. Operation that is operated to increase the operating angle after reaching When the material is inverted in the direction of decreasing the operation angle, the operation amount of the operation member at the start of the inversion operation is regarded as the operation amount at the time when the wheel steering amount reaches the maximum value, and the steering actuator Is controlled. According to the present invention, the operation member can be operated in the direction of increasing the operation angle even after the turning of the wheels is blocked by the turning amount of the wheels reaching the maximum value. Therefore, it is possible to prevent the torque acting on the operation member from largely changing at the maximum steering angle position.

It is preferable that the operation amount of the operating member at the time of starting the engine of the vehicle is regarded as corresponding to the turning amount of the wheels at the time of starting the engine. Accordingly, regardless of the steering amount of the wheels when the vehicle is parked, the operation amount of the operating member when the engine is started is considered to correspond to the steering amount of the wheels when the engine is started. Therefore, it is possible to prevent the wheels from being steered just by starting the engine.

An operating actuator and a control system capable of controlling the operating actuator so as to generate a torque acting on the operating member are provided, and the magnitude of the torque generated by the operating actuator is determined by the rotation of the wheel. It is preferable that the steering amount changes according to the operation amount of the operating member until the steering amount reaches the maximum value, and it is preferably fixed after the steering amount reaches the maximum value. As a result, the torque that acts on the operating member does not fluctuate when the turning amount of the wheels reaches the maximum value, and when the operating angle is increased after reaching the maximum value, the operating member does not change. Since the acting torque does not change, the driver can be made aware that the turning amount of the wheels has reached the maximum value.

It is preferable that the operating member is rotated and the shape visually recognized by the driver does not change even if the operating position changes. As a result, even if the ratio of the amount of steering to the amount of operation changes during steering, the visible shape of the operating member does not change, so it is possible to prevent erroneous recognition of the midpoint of the steering angle.

An index indicating a reference direction is attached to the operating member so as to be relatively displaceable with respect to the gripping member, and a mechanism is provided for switching between a state in which the relative displacement of the index with respect to the gripping member is allowed and a state in which the index is prevented. Is provided for determining whether the vehicle is in a straight traveling state, the relative displacement of the index with respect to the gripping member is permitted when the vehicle is determined to be in a straight traveling state, and is blocked when it is determined to be in a state other than the straight traveling state. It is preferable that the index in which the relative displacement with respect to the grip member is allowed is relatively displaced by gravity so that the reference direction corresponds to the front-back direction of the vehicle. As a result, even if the ratio of the turning amount to the operation amount changes during steering, the reference direction indicated by the index is corrected so as to correspond to the front-back direction of the vehicle, so the midpoint of the steering angle can be easily grasped. You can

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A vehicle steering system according to an embodiment shown in FIG. 1 includes an operating member 1 imitating a steering wheel,
The steering actuator 2 and the steering gear 3 that transmits the movement of the steering actuator 2 to the wheels 4 so as to change the steering angle without mechanically connecting the operating member 1 to the wheels 4.

The operating member 1 is connected to an input side rotating shaft 10 rotatably supported by the vehicle body so as to rotate together. The output shaft of the operation actuator 19 is integrated with the input side rotation shaft 10. The operating actuator 19 can generate a torque that acts on the operating member. The operating actuator 19 can be configured by an electric motor such as a brushless motor.

The steering actuator 2 can be composed of an electric motor such as a brushless motor. The steering gear 3 has a motion conversion mechanism that converts the rotational motion of the output shaft of the steering actuator 2 into the linear motion of the steering rod 7. The toe angle of the wheel 4 is changed by transmitting the movement of the steering rod 7 to the wheel 4 via the tie rod 8 and the knuckle arm 9. A known steering gear 3 can be used, and the configuration is not limited as long as the movement of the steering actuator 2 can be transmitted to the wheels 4 so that the steering angle changes. In this embodiment, the steering rod 7 is formed with a rack 7a that meshes with the pinion 2a attached to the output shaft of the steering actuator 2. When the steering actuator 2 is not driven, the wheel alignment is set so that the wheels 4 can return to the straight-ahead position by the self-aligning torque.

An angle sensor 11 for detecting an operation angle δh as an operation amount of the operation member 1 is provided. A steering angle sensor 13 that detects a steering angle δ as a steering amount of the wheels 4 is provided. In the present embodiment, the steering angle sensor 13 detects the amount of movement of the steering rod 7 from the steering angle midpoint as the steering angle δ. A speed sensor 14 that detects the vehicle speed V is provided. Operation torque T applied by the driver to the operation member 1
A torque sensor 12 for detecting the torque transmitted by the input side rotation shaft 10 as h is provided. The angle sensor 11, the torque sensor 12, the steering angle sensor 13,
The speed sensor 14 is connected to the control device 20 that is configured by a computer.

The control device 20 constitutes a control system for controlling the steering actuator 2 so that the ratio between the operation amount of the operation member 1 and the turning amount of the wheels 4 changes. For example, control device 2
0 is the operation angle δh of the operation member 1, the vehicle speed V, and the target steering angle δ ^*.
Is stored in advance and the steering actuator 2 is arranged so as to eliminate the deviation between the target steering angle δ ^* and the detected steering angle δ.
Drive signal is output. The relationship between the operation angle δh, the vehicle speed V, and the target steering angle δ ^* is that, for example, turning performance is improved at low vehicle speed and traveling stability at high vehicle speed until the steering amount of the wheels 4 reaches a maximum value. In order to improve, the ratio δ ^* / δh of the target steering angle δ ^* to the operation angle δh becomes smaller as the vehicle speed V increases. As a result, the steering actuator 2 is controlled so that the ratio between the operation angle δh and the steering angle δ, that is, the ratio between the operation amount of the operation member 1 and the turning amount of the wheels 4 changes. It should be noted that the ratio δ ^* / δh is not limited to that which changes according to the vehicle speed V, and may change according to other operating conditions such as operating speed and operating angle. It suffices if the steering actuator 2 can be controlled.

The control device 20 constitutes a control system for controlling the operating actuator 19 so as to generate a torque acting on the operating member 1. The magnitude of the torque is changed according to the driving condition, for example, until the turning amount of the wheels 4 reaches the maximum value. The operating condition is, for example, the operation angle δh, and the control device 20 stores the relationship that the target operation torque Th ^* increases as the operation angle δh increases, and the target operation torque Th ^* is stored based on the relationship and the detected operation angle δh ^. Is calculated and the drive signal of the operation actuator 19 is output so as to eliminate the deviation between the target operation torque Th ^* and the detected operation torque Th, thereby generating the torque acting in the neutral position returning direction of the operation member 1. The vehicle operating condition is not limited to the operation angle δh, and the target operation torque Th ^* may be correlated with the operation angle δh and the vehicle speed V as long as the operation actuator 19 can generate an appropriate torque.

The output side rotating shaft 15 is mechanically connected to the wheel 4 so as to rotate in response to the movement of the wheel 4 due to the change in the steering angle. For example, the output side rotation shaft 15 is coupled to the pinion 15a meshing with the rack 7a so as to rotate together. The output-side rotary shaft 15 and the input-side rotary shaft 10 normally rotate relative to each other, and are connected via a connecting mechanism 30 so that steering can be performed when an abnormality such as a failure of the steering actuator 2 or the control system occurs. The connecting mechanism 30 is composed of, for example, an electromagnetic clutch that connects the input side rotating shaft 10 and the output side rotating shaft 15 when an abnormality occurs due to a signal from the control device 20.

The control device 20 determines whether or not the vehicle is in a straight traveling state. In the present embodiment, the detected vehicle speed V exceeds the set value,
Further, when the duration of the state in which the magnitude of the operation speed d (δh) / dt of the operation member 1 is less than the set value exceeds the set value, it is determined that the vehicle is in the straight traveling state. The set value of the vehicle speed V is set to, for example, 40 km / hour so as to prevent the state where the cornering is continued from being erroneously determined to be the straight running state. The set value of the operation speed indicates whether the operation is performed or not. For example, it is set to 30 degrees / second so that it can be determined, and the set value of the duration is set to a time at which it can be determined that the straight traveling state is maintained, for example, 10 seconds.

An index M indicating a reference direction is attached to the operating member 1 so as to be capable of relative displacement. As shown in FIG. 2, the operating member 1 of the present embodiment includes a disc portion 1a and the disc portion 1a.
And an annular grip 1b (grip member) around the
The index M of the present embodiment is substantially T-shaped, and has a connecting portion M1 having substantially the same size as the diameter of the disc portion 1a and an indicating portion M2 having substantially the same diameter as the radius.
And is rotatably attached to the disc portion 1a about the axis O of the input-side rotary shaft 10 via a bearing (not shown), so that relative displacement occurs. Annular grip 1b
A pair of clutches 41 is provided as a mechanism for switching between a state in which the relative displacement of the index M with respect to is allowed and a state in which the relative displacement is prevented. Each clutch 41 has a pusher 41a which is built in at the end of the connecting portion M1 and is pressed against the annular grip 1b by the elastic force of a spring, for example, and the pressing from the control device 20 when the vehicle is judged to be straight ahead. It is configured by a device that is released by a solenoid that is excited by a signal. When the pusher 41a is pressed against the annular grip 1b, relative displacement of the index M with respect to the annular grip 1b is blocked by friction, and when the pusher 41a is released, relative displacement is allowed. Accordingly, the relative displacement of the index M with respect to the annular grip 1b is
It is allowed when it is determined that the vehicle is in the straight traveling state, and is blocked when it is determined that the vehicle is not in the straight traveling state. The indicating portion M2 indicates the reference direction by the longitudinal direction,
A weight 42 is built in at its end, and the rotation axis of the operation member 1 is inclined with respect to the vertical direction. As a result, the annular grip 1
The index M in which the relative displacement with respect to b is allowed is relatively displaced by gravity so that the reference direction corresponds to the vehicle front-rear direction.

A vehicle body side member 31 for preventing the movement of the steering rod 7 is attached to the vehicle body side when the turning amount of the wheels 4 reaches the maximum value and the size of the steering angle becomes maximum. The structure of the vehicle body side member is not particularly limited as long as it can prevent the turning of the wheels 4 when the turning amount of the wheels 4 reaches the maximum value.

The control device 20 determines from the steering angle δ detected by the steering angle sensor 13 whether or not the turning amount of the wheels 4 has reached the maximum value. The operation member 1 is allowed to be operated in a direction in which the operation angle is increased not only before the steering amount of the wheels 4 reaches the maximum value but also after the steering amount reaches the maximum value. Therefore, the operating member 1
Is rotatable over 360 degrees, and the torque generated by the operating actuator 19 is smaller than the operating torque applied by the driver. In the present embodiment, the magnitude of the torque generated by the operation actuator 19 changes according to the operation angle δh as described above until the turning amount of the wheels 4 reaches the maximum value, and reaches the maximum value. After that, it will be constant. The constant value is, for example, the wheel 4
The steering amount may be equal to the value immediately before reaching the maximum value, or may be a different value. After the turning amount of the wheels 4 reaches the maximum value, the generated torque of the operation actuator 19 may be gradually decreased as the operation angle δh increases, or within a range that does not prevent the operation of the operation member 1. It may be increased gradually.

When the operating member 1 operated to increase the operation angle after the turning amount of the wheel 4 reaches the maximum value is inverted to decrease the operation angle, the operation at the start of the inversion operation is performed. The steering actuator 2 is controlled by regarding the operation angle of the member 1 as the operation angle at the time when the turning amount of the wheel 4 reaches the maximum value. FIG. 3 shows the steering angle δ and the operation when the operating member 1 is operated in a direction to increase the operating angle δh even after the steering angle δ reaches the maximum value δmax, and then to a direction in which the operating angle δh is decreased. An example of the relationship between the angle δh and time is shown. In the figure, the solid line shows the change over time of the steering angle δ, and the broken line shows the change over time of the operating angle δh. Here, it is assumed that the time t is zero and the operation angle δh and the steering angle δ are zero. Further, by keeping the vehicle speed constant, the ratio between the operation angle δh and the steering angle δ is made constant. In this case, when the operation angle δh becomes δha and the steering angle δ reaches the maximum value δmax at the time ta, even if the operation member 1 is subsequently operated in a direction to increase the operation angle δh, the maximum steering angle δ is δmax. It does not change as it is. After the operating angle δh becomes δhb at time tb, the operating member 1 moves the operating angle δh.
When the steering angle is decreased, the operation angle δhb at the start of the reversing operation is regarded as the operation angle at the time when the steering angle δ reaches the maximum value δmax. Therefore, the operating angle δh is (δh
b-δha), the steering angle δ becomes zero.

The operating angle δh of the operating member 1 when the engine of the vehicle is started is considered to correspond to the turning amount of the wheels 4 when the engine is started. That is, the control device 20 calculates an operation angle at which the detected steering angle δ at the time of engine start becomes the target steering angle δ ^*, and the calculated operation angle is the detected operation angle δh.
Then, the steering actuator 2 is controlled. As a result, the steering actuator 2 is not driven when the engine is started.

The control procedure of the steering actuator 2 and the operation actuator 19 by the control device 20 of the embodiment will be described with reference to the flowchart of FIG. First, the value detected by each sensor is read (step S1), and it is determined whether or not the engine has just been started depending on whether or not the ignition switch is switched from off to on (step S).
2). If not immediately after the engine is started, it is determined whether or not the magnitude of the detected steering angle δ is less than the maximum value δmax (step S
3). If the magnitude of the detected steering angle δ has not reached the maximum value δmax, the target steering angle δ ^* is obtained from the detected operation angle δh and the detected vehicle speed V as described above (step S4).
^The steering actuator 2 is controlled so as to eliminate the deviation between ^* and the detected steering angle δ (step S5). Further, the target operation torque Th ^* is obtained from the detected operation angle δh as described above (step S6), and the operation actuator 19 is controlled so as to eliminate the deviation between the target operation torque Th ^* and the detected operation torque Th (step S6). S7). Then, it is determined whether or not the control is ended, for example, by whether or not the ignition switch is off (step S8), and if not ended, the process returns to step S1. If the magnitude of the detected steering angle δ reaches the maximum value δmax in step S3, the operation angle δha at the time when the maximum value δmax is reached is stored (step S9), and the operation member 1 increases the operation angle. It is determined whether or not is operated (step S10). For example, it is determined whether or not the absolute value of the detected operation angle δh is equal to or greater than the value when the magnitude of the detected steering angle δ reaches the maximum value δmax. If the operation member 1 is operated in the direction to increase the operation angle in step S10, the target steering angle δ ^* is set to the maximum steering angle value δmax (step S11), and the steering actuator 2 is controlled (step S12). Further, the target operation torque Th ^* is set to a constant value immediately before the steering angle δ reaches the maximum value δmax (step S13), and the operation actuator 19 is controlled (step S14). After that, it is determined whether or not to end the control (step S8). When the operation member 1 is not operated in the direction to increase the operation angle in step S10, the detected operation angle δh at that time
Is regarded as the stored operation angle δha when the detected steering angle δ reaches the maximum value δmax (step S15), and the steering actuator 2 is controlled by returning to step S4. If the detected steering angle δ matches the target steering angle δ ^* immediately after the engine is started in step S2, the operation angle δho
Is calculated (step S16), the operation angle δho is regarded as the detected operation angle δh, and the process proceeds to step S3.

The flowchart of FIG. 5 shows the control procedure of the clutch 41 by the control device 20. The control of the clutch 41 may be performed by interrupting the control of the steering actuator 2 and the operation actuator 19 or in parallel. First, it is determined whether the vehicle is in the straight traveling state as described above (step S101), and if it is the straight traveling state, the solenoid of the clutch 41 is excited (step S102). As a result, the index M is displaced relative to the annular grip 1b, and the reference direction indicated by the index M corresponds to the front-back direction of the vehicle. If the vehicle is not in the straight traveling state in step S101, the solenoid is demagnetized (step S
103). As a result, relative displacement of the index M with respect to the annular grip 1b is prevented. This is repeated until the control ends.

According to the above-described embodiment, even after the turning amount of the wheels 4 reaches the maximum value and the turning of the wheels 4 is blocked, the operating member 1 can be operated in the direction of increasing the operating angle. Therefore, it is possible to prevent the torque acting on the operation member 1 from changing greatly at the maximum steering angle position. Further, regardless of the turning amount of the wheels 4 when the vehicle is parked, the operation amount of the operating member 1 at the engine start is regarded as corresponding to the turning amount of the wheels 4 at the engine start. Therefore, it is possible to prevent the wheels 4 from being steered just by starting the engine. Further, since the magnitude of the torque generated by the operating actuator 19 is constant after the turning amount of the wheels 4 reaches the maximum value, the torque acting on the operating member 1 does not fluctuate, and moreover, the driver is not affected. It can be recognized that the turning amount of the wheels 4 has reached the maximum value. further,
Even if the ratio of the turning amount to the operation amount changes during steering, the reference direction indicated by the index M is corrected so as to correspond to the front-back direction of the vehicle, so that the midpoint of the steering angle can be easily grasped. .

The present invention is not limited to the above embodiment. For example, the operation member 1 may be rotated and the shape visually recognized by the driver may not change even if the operation position changes. For example, the operating member 1 is composed of only the disc portion 1a and the grip 1b in the embodiment. As a result, even if the ratio of the amount of steering to the amount of operation changes during steering, the visible shape of the operating member 1 does not change, and therefore the misidentification of the midpoint of the steering angle can be prevented.

Further, as shown in the modified example of FIG. 6, the steering wheel H, which is the operating member, is mechanically connected to the wheels, and the ratio between the operating amount of the operating member and the turning amount of the wheels is changed. The present invention may be applied to the steering device 101 that can be used. That is, the rotation of the input shaft 102 according to the operation of the steering wheel H is generated by the rotation transmission mechanism 1.
30 is transmitted to the output shaft 111, and the rotation of the output shaft 111 is transmitted to the wheels by a steering gear (not shown) so that the steering angle changes. As the steering gear, known gears such as a rack and pinion type steering gear and a ball screw type steering gear can be used. Input shaft 102 and output shaft 11
1 are arranged coaxially with each other with a gap therebetween, and the housing 1 is provided with bearings 107, 108, 112 and 113.
Supported by 10. The rotation transmission mechanism 130
Is a planetary gear mechanism in this modification, and the sun gear 131
The planet gear 133 meshing with the ring gear 132 is held by the carrier 134. The sun gear 131 is connected to the end of the input shaft 102 so as to rotate together. The carrier 134 is connected to the output shaft 111 so as to rotate together. The ring gear 132 is fixed to a holder 136 surrounding the input shaft 102 via bolts 362. The holder 136 is supported via a bearing 109 by a tubular member 135 fixed to the housing 110 so as to surround the input shaft 102. A worm wheel 137 is fitted on the outer periphery of the holder 136 so as to rotate together. A worm 138 that meshes with the worm wheel 137 is supported by the housing 110. The worm 138 is driven by a steering actuator 139 attached to the housing 110. As a result, the ratio between the operation amount of the steering wheel H and the turning amount of the wheels can be changed by controlling the steering actuator 139. Further, an operating actuator 119 that generates a torque that acts on the steering wheel H is provided. The control system of the steering actuator 139 and the control system of the operation actuator 119 are composed of the same control device and sensors as those in the above-described embodiment. The wheels 4
When allowing the operation of the operating member 1 to increase the operation angle even after the steering amount of the steering wheel reaches the maximum value, the steering amount of the wheels 4 reaches the maximum value regardless of the operation amount of the steering wheel H. Steering actuator 13 so that
9 is controlled.

[0028]

According to the present invention, in the vehicle steering system capable of changing the ratio between the operation amount of the operation member and the turning amount of the wheels, a large shock is applied to the driver when the steering angle is steered to the maximum steering angle. It is possible to prevent the difficulty of grasping the midpoint of the steering angle.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of a vehicle steering system according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of an operation member and an index in the vehicle steering system according to the embodiment of the present invention.

FIG. 3 is a diagram showing a relationship between a steering angle δ, an operation angle δh, and time in the vehicle steering system according to the embodiment of the present invention.

FIG. 4 is a flowchart showing a control procedure of the steering actuator and the operation actuator in the vehicle steering system according to the embodiment of the present invention.

FIG. 5 is a flowchart showing a control procedure of an index clutch in the vehicle steering system according to the embodiment of the present invention.

FIG. 6 is a structural explanatory view of a vehicle steering system of a modified example of the invention.

[Explanation of symbols]

1, H operation member 2,139 Steering actuator 3 steering gear Four wheels 11 Angle sensor 13 Rudder angle sensor 19 Operation actuator 20 Control device 31 Body side member 41 clutch M index

Claims (5)

[Claims] 1. An operating member, a means for detecting an operation amount of the operating member, a steering actuator, a means for transmitting a movement of the steering actuator to a wheel so as to change a steering angle, and a wheel. A means for detecting the turning amount, and a control system capable of controlling the steering actuator so that the ratio between the operation amount of the operating member and the turning amount of the wheels changes.
A means for determining whether or not the turning amount of the wheel has reached the maximum value, and a vehicle body side member that prevents the turning of the wheel when the turning amount of the wheel reaches the maximum value, The operation member is allowed to operate in a direction to increase the operation angle not only before the wheel steering amount reaches the maximum value but also after the wheel steering amount reaches the maximum value, and is operated after the wheel steering amount reaches the maximum value. When the operating member operated in the direction of increasing the angle is inverted in the direction of decreasing the operating angle, the operation amount of the operating member at the start of the inversion operation is set to the value when the steering amount of the wheel reaches the maximum value. A vehicle steering system in which the steering actuator is controlled by regarding it as an operation amount. 2. The vehicle steering system according to claim 1, wherein the operation amount of the operating member when the engine of the vehicle is started is considered to correspond to the amount of turning of the wheels when the engine is started. 3. An operating actuator, and a control system capable of controlling the operating actuator so as to generate a torque that acts on the operating member. The magnitude of the generated torque of the operating actuator depends on a wheel. The steering apparatus for a vehicle according to claim 1 or 2, wherein the steering amount changes according to the operation amount of the operation member until the steering amount reaches the maximum value, and is constant after reaching the maximum value. 4. The vehicle steering system according to claim 1, wherein the operating member is rotated and the shape visually recognized by the driver does not change even if the operating position changes. 5. An index indicating a reference direction is attached to the operating member so as to be relatively displaceable with respect to the gripping member, and a mechanism is provided for switching between a state in which the relative displacement of the index with respect to the gripping member is allowed and a state in which the index is prevented. A means for determining whether the vehicle is in a straight traveling state is provided, and the relative displacement of the index with respect to the gripping member is allowed when the vehicle is determined to be in the straight traveling state, and is determined when the vehicle is not in the straight traveling state. The vehicle steering system according to any one of claims 1 to 3, wherein the index that is blocked and is allowed to be displaced relative to the gripping member is relatively displaced by gravity so that the reference direction corresponds to the front-rear direction of the vehicle. .