JPH1149005A - Steering device - Google Patents

Abstract

(57) [Problem] To provide a steering device which is highly safe, small in size and low in cost, and which can smoothly change from an automatic steering mode to a normal steering mode. A second control valve (2) operated based on an external signal.
By the hydraulic control of the pressure oil from the pump 37 by 3 ', the auxiliary hydraulic actuator 50 generates the operating force of the first control valve 23.
Hydraulic control by the first control valve 23, which is operated based on the steering force of the driver, applies the steering assist force for normal steering to the hydraulic cylinder.
18 is generated, and the hydraulic actuator 18 generates a steering force for automatic steering by hydraulic control by the first control valve 23 that is operated based on the generated force of the auxiliary hydraulic actuator 50. By the action of the driver's steering force in the automatic steering mode, the relief oil passage connecting the pump 37 and the tank 41 is opened and closed by the opening / closing valve 11.
Switched to normal steering mode, opened by 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering device capable of automatically steering a vehicle in response to an external signal.

[0002]

2. Description of the Related Art In recent years, there has been developed a steering device that generates a steering force according to an external signal by an actuator mounted on a vehicle and automatically steers the vehicle based on the steering force. ing.

[0003] Such a steering device can select between a normal steering mode in which the vehicle is steered based on the steering force of the driver and an automatic steering mode in which the vehicle is steered based on the steering force generated by the hydraulic actuator. An actuator which generates a steering assist force in a normal steering mode by an actuator has been proposed (Japanese Patent Laid-Open No. 7-2058).
No. 24). In this conventional steering device, when disconnection occurs in the automatic steering mode, it is possible to switch to the normal steering mode, and fail-safe is achieved.

[0004] However, in the conventional steering apparatus described above, the driver cannot change the steering direction on his own will against automatic steering. For this reason, fail-safe measures against control system abnormalities other than disconnection and unexpected emergency situations have not been sufficient.

[0005] Assuming that the driver can change the steering direction by his / her own will against automatic steering, a steering device capable of switching to the normal steering mode by applying a steering force by the driver in the automatic steering mode. (JP-A-4-39167, JP-A-4-95575).

In the steering apparatus disclosed in Japanese Patent Laid-Open Publication No. 4-39167, a steering shaft is rotated by a servomotor to generate a steering force during automatic steering. Therefore, the structure becomes complicated and the device becomes large. It is also very expensive.

In the steering apparatus disclosed in Japanese Patent Application Laid-Open No. 4-95575, a hydraulic control valve for generating a steering force during automatic steering and a hydraulic control valve for generating a steering assist force during normal steering are provided. Are provided in parallel and selectively supply pressure oil sent from a pump to each hydraulic control valve by a switching valve.

As described above, when a hydraulic control valve for generating a steering force during automatic steering and a hydraulic control valve for generating a steering assist force during normal steering are provided, the structure becomes complicated and the device becomes larger. I do. Further, it is difficult to smoothly switch the flow of the pressure oil when switching from the automatic steering mode to the normal steering mode, and a shock is given to the driver at the time of switching.

Further, there is a system in which when a driver operates a steering wheel to apply a steering force during automatic steering, the operation of the steering wheel is electrically detected and an electric signal is output to cancel the automatic steering. However, there is a possibility that the operation of the steering wheel cannot be detected or an erroneous detection may occur due to a failure of the detecting means of the operation of the steering wheel, the control device, or an electric disturbance. Therefore, there is a problem that the automatic steering is not released even if the steering wheel is operated, or the automatic steering is released against the driver's intention.

An object of the present invention is to provide a steering device that can solve the above-mentioned problem.

[0011]

According to the present invention, a normal steering mode in which a vehicle is steered based on a driver's steering force and a steering assist force generated by a hydraulic actuator, and the hydraulic actuator is generated in response to an external signal. The present invention is applied to a steering device capable of selecting an automatic steering mode in which a vehicle is steered based on a steering force. The present invention provides a steering apparatus, wherein a first hydraulic oil pump, an auxiliary hydraulic actuator, a first operation that is operated based on an operation of a driver's steering force and an operation of a force generated by the auxiliary hydraulic actuator. A first control valve that includes a control valve and a second control valve that is operated based on an external signal thereof, and in a normal steering mode, hydraulic pressure of pressure oil supplied from the pump is operated based on a driver's steering force. By being controlled by the valve, a steering assist force corresponding to the operation amount is generated by the hydraulic actuator, and in the automatic steering mode, the hydraulic pressure of the pressure oil supplied from the pump is controlled by the second control valve. Thereby, a force for operating the first control valve is generated by the auxiliary hydraulic actuator, and
The hydraulic pressure of the pressure oil supplied from the pump is controlled by the first control valve that is operated based on the force generated by the auxiliary hydraulic actuator, so that a steering force corresponding to the operation amount is generated by the hydraulic actuator, In order to be able to switch to the normal steering mode by applying the steering force of the driver in the automatic steering mode, a relief oil passage for communicating the pump and the tank is provided in parallel with the second control valve, and the relief oil passage is provided. A normally open / close valve is provided so as to be opened by a driver's steering force.

According to the configuration of the present invention, in the normal steering mode, the first operation is performed based on the steering force of the driver.
The hydraulic actuator generates a steering assist force for normal steering by controlling the hydraulic pressure of the pressure oil supplied from the pump by the control valve. In the automatic steering mode, the hydraulic pressure of the pressure oil supplied from the pump is controlled by the second control valve that operates based on an external signal, so that the auxiliary hydraulic actuator generates a force that operates the first control valve. The hydraulic actuator generates a steering force for automatic steering by controlling the hydraulic pressure of the pressure oil supplied from the pump by the first control valve that operates based on the force generated by the auxiliary hydraulic actuator. When the driver applies a steering force in the automatic steering mode, the second
A relief oil passage provided in parallel with the control valve and communicating the pump and the tank is opened by the on-off valve.
Thus, the auxiliary hydraulic actuator does not generate a force for operating the first control valve. Therefore, the hydraulic pressure of the hydraulic oil supplied from the pump is controlled by the first control valve that is operated only by the steering force of the driver, and the hydraulic actuator generates a steering assist force for normal steering. That is, by applying the steering force of the driver in the automatic steering mode, the automatic steering mode is released and switched to the normal steering mode. Thus, the driver can surely change the steering direction by his / her own will against automatic steering, and can achieve a sufficient fail-safe function.

Further, according to the configuration of the present invention, the first control valve controls the hydraulic pressure of the pressure oil supplied from the pump, thereby generating a steering force during automatic steering and generating a steering assist force during normal steering. Can be done. That is, since a hydraulic control valve for generating a steering force during automatic steering and a hydraulic control valve for generating a steering assist force during normal steering are not separately required, the structure can be simplified and the device can be downsized. .

A steering device according to the present invention includes an input shaft and an output shaft for a driver's steering force, and both shafts are connected to be elastically relatively rotatable in accordance with the driver's steering force. The valve has a first valve member and a second valve member, and one of the two valve members is connected to one of the two shafts elastically and relatively rotatably in response to a force generated by the auxiliary hydraulic actuator. The other of the two valve members is rotatable with the other of the two shafts, and the relative rotation amount of the two valve members is set as the operation amount of the first control valve. The working hydraulic pressure is controllable, and the auxiliary hydraulic actuator is provided so as to be displaceable on one of both shafts to which one of both valve members is elastically connected to be relatively rotatable. Moving member, a left and right steering oil chamber partitioned by the moving member, and a connecting member for connecting the moving member to one of the two valve members, and the right steering oil chamber and the left steering oil chamber are controlled by the second control valve. It is possible to selectively apply hydraulic pressure to the steering oil chamber, and the displacement of the moving member due to the differential pressure between the hydraulic pressure of the right steering hydraulic chamber and the hydraulic pressure of the left steering hydraulic chamber is changed via the connecting member. It is preferable that the transmission to one of the two valve members enables relative rotation of the two valve members. Thereby, during the automatic steering, one of the two valve members resiliently rotates relative to one of the two shafts by the action of the force generated by the auxiliary hydraulic actuator, and the two valve members relatively rotate by the relative rotation. Thus, the first control valve is operated. A steering force corresponding to the operation amount of the first control valve is generated by a hydraulic actuator.

The input shaft has a first shaft portion on the steering wheel side and a second shaft portion on the output shaft side, and both shaft portions are elastically rotatable relative to each other according to the steering force of the driver. The second shaft portion of the input shaft and the output shaft are connected to be elastically and relatively rotatable according to the steering force of the driver. One of the two valve members is connected to the output shaft by the auxiliary hydraulic actuator. The other of the two valve members is rotatable together with the second shaft portion of the input shaft, and the opening and closing valve is a first rotating member and a second rotating member. One of the two rotating members is rotatable with one of the two shaft portions of the input shaft, and the other of the two rotating members is rotatable with the other of the two shaft portions. Is, the relief oil path by relative rotation of the two rotary members by the steering force of the driver preferably is opened. Thereby, during the automatic steering, when the first shaft portion and the second shaft portion of the input shaft are relatively elastically rotated by the action of the driver's steering force,
The two rotating members of the open / close valve rotate relative to each other to open the relief oil passage. Therefore, the automatic steering can be canceled by the action of the driver's steering force as described above. That is, with a simple configuration, it is possible to smoothly switch from the automatic steering mode to the normal steering mode. Further, since the opening / closing valve can be arranged between the steering wheel and the first control valve, the radial size of the device can be reduced.

Alternatively, the opening / closing valve has an opening / closing spool that can be displaced so as to open and close the relief oil passage on one of the shafts, and the relief is performed by the relative rotation of the shafts in accordance with the driver's steering force. Preferably, the open / close spool and both shafts are linked so that the oil passage is opened. As a result, during the automatic steering, when the shafts are elastically rotated relative to each other by the action of the driver's steering force, the spool of the on-off valve is displaced to open the relief oil passage. Thereby, the automatic steering can be released by the action of the driver's steering force as described above. That is, with a simple configuration, it is possible to smoothly switch from the automatic steering mode to the normal steering mode. Further, since the open / close valve can be provided on one of the input and output shafts, the axial dimension of the device can be reduced.

In the steering device of the present invention, the input shaft and the output shaft are coaxially connected, the first valve member is cylindrical, and the second valve member is coaxially opposed to the first valve member. The first valve member is rotatably inserted, and recesses along the axial direction are formed on the inner periphery of the first valve member and the outer periphery of the second valve member at intervals in the circumferential direction. A portion between the edge along the axis and the edge along the axial direction of the second valve member-side concave portion is a throttle portion provided in an oil passage between the hydraulic actuator and the pump, and the opening degree of the throttle portion is determined by the two valve members. It is preferable that the hydraulic pressure of the pressure oil supplied to the hydraulic actuator is controlled according to the change due to the relative rotation. Thereby, the auxiliary actuator can be configured compactly in the transmission system of the steering force.

In the steering apparatus according to the present invention, the first
Preferably, a second control valve is provided between the control valve and the tank. Thus, the hydraulic control system for automatic steering can be arranged downstream of the hydraulic control system for normal steering, so that when the automatic steering mode is changed to the normal steering mode, the flow of the pressure oil is smoothly changed. Can prevent the driver from being shocked. Further, the configuration of the hydraulic circuit is simplified.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.

The rack and pinion type steering apparatus 1 shown in FIGS. 1 and 7 is coaxially connected to an input shaft 2 connected to a steering wheel (not shown) via a torsion bar 3. And an output shaft 4. The input shaft 2 has a first shaft portion 2a on the steering wheel side and a second shaft portion 2b on the output shaft 4 side. The torsion bar 3 is connected to the first shaft portion 2a of the input shaft 2 via the first pin 5a, and connected to the second shaft portion 2b of the input shaft 2 via the second pin 5b.
And the output shaft 4. This allows
The first shaft portion 2a and the second shaft portion 2b of the input shaft 2 are connected to the torsion bar 3 according to the steering force of the driver.
Are elastically twisted between the first pin 5a and the second pin 5b, so that they can be relatively rotated relative to each other. Further, the second shaft portion 2b of the input shaft 2 and the output shaft 4 are steered by the driver. The torsion bar 3 is moved to the second pin 5 according to the force.
By being elastically twisted between b and the serration 6, it is possible to elastically rotate relatively.

A pinion 7 is formed on the output shaft 4, and steering wheels (not shown) are connected to each end of the rack 8 meshing with the pinion 7. The first shaft 2a of the input shaft 2 is supported by the valve housing 10a via the bearing 9, and is supported by the second shaft 2b via the bush 11a. The second shaft 2b
Is supported by the output shaft 4 via a bush 11b. The output shaft 4 is supported by the rack housing 10b via bearings 12 and 13.

In a normal steering mode in which the vehicle is steered based on a driver's steering force and a steering assist force generated by a hydraulic cylinder 18 described later, the first shaft of the input shaft 2 is driven by a steering torque based on the driver's steering force. The part 2a rotates. The rotation of the first shaft portion 2a is
The power is transmitted to the second shaft portion 2b through the space between the first pin 5a and the second pin 5b of the torsion bar 3. The rotation of the second shaft portion 2b is performed by the second pin 5b of the torsion bar 3.
Is transmitted to the pinion 7 of the output shaft 4 through the space between the shaft and the serration 6. The rack 8 moves in the axial direction by the rotation of the pinion 7. The wheels are steered by the movement of the rack 8. Between the input shaft 2 and the valve housing 10a, between the output shaft 4 and the rack housing 10
b, oil seals 14 and 15 are provided.
A support yoke 16 for supporting the rack 8 is provided. The support yoke 16 is pressed against the rack 8 by the elastic force of a spring 17.

In the automatic steering mode, a steering force is generated,
A hydraulic cylinder 18 is provided as a hydraulic actuator that generates a steering assist force in a normal steering mode.
The hydraulic cylinder 18 has a cylinder tube constituted by a rack housing 10b and a piston 20 integrated with the rack 8, and a first oil chamber 21 and a second oil chamber 22 partitioned by the piston 20. Have.

Each of the oil chambers 21 and 22 is connected to a rotary hydraulic first control valve 23 which is operated based on both the operation of a driver's steering force and the operation of a force generated by an auxiliary hydraulic actuator 50 described later. Is done. The first control valve 23
The hydraulic pressure of the pressure oil supplied from the pump 37 is controlled in accordance with the operation amount of.

That is, the first control valve 23 includes a cylindrical first valve member 24 and a second valve member 25 which is coaxially rotatably inserted into the first valve member 24. The first valve member 24 is inserted into the valve housing 10a so as to be relatively rotatable, and is coaxially and elastically connected to the output shaft 4 so as to be relatively rotatable as described later. The second valve member 25 is integrally formed on the outer periphery of the second shaft portion 2b of the input shaft 2, and rotates together with the second shaft portion 2b. Thereby, the torsion bar 3 is twisted between the second pin 5b and the serration 6 by the steering torque based on the driver's steering force, and the second shaft portion 2b of the input shaft 2 and the output shaft 4 elastically rotate relative to each other. Thus, the first valve member 24 and the second valve member 25 rotate relatively. In addition, due to the relative rotation of the first valve member 24 with respect to the output shaft 4 by the force generated by the auxiliary hydraulic actuator 50 described later, the two valve members 24 and 25 rotate relatively. Both valve members 2
The relative rotation amounts of 4 and 25 are set as the operation amounts of the first control valve 23.

The hydraulic pressure acting on the hydraulic cylinder 18 is controlled according to the relative rotation amount between the two valve members 24 and 25. That is, as shown in FIG. 2, a plurality of concave portions along the axial direction are formed at equal intervals in the circumferential direction on the inner periphery of the first valve member 24 and the outer periphery of the second valve member 25. The first valve member-side concave portion includes a right steering concave portion 27 and a left steering concave portion 28 which are located at equal intervals in the circumferential direction. The second valve member side recess is composed of a pressure oil supply recess 29 and a pressure oil discharge recess 30 which are located at equal intervals in the circumferential direction. Each right steering recess 27 and each left steering recess 28 are alternately arranged in the circumferential direction, and each pressure oil supply recess 29 and each pressure oil discharge recess 30 are alternately arranged in the circumferential direction.

Each right steering recess 27 is provided with a first valve member 2.
Oil passage 31 and valve housing 1 formed in valve 4
0a from the first port 32 formed in the hydraulic cylinder 1
8 to the first oil chamber 21.

Each left steering recess 28 is provided with the first valve member 2.
Oil passage 33 formed in valve housing 4 and valve housing 1
0a from the second port 34 formed in the hydraulic cylinder 1
8 to the second oil chamber 22.

Each of the recesses 29 for supplying pressure oil is formed between a third oil passage 35 formed in the first valve member 24 and the valve housing 1.
It communicates with a pump 37 via an inlet port 36 formed at 0a.

Each of the recesses 30 for discharging pressure oil includes a first discharge path 38 formed in the second valve member 25, an oil path 47 between the input shaft 2 and the inner and outer circumferences of the torsion bar 3, and an input shaft 2.
Through a second discharge passage 39 formed in the second shaft portion 2b and a second control valve 23 'described later.

Thus, the oil chambers 21 and 22 of the hydraulic cylinder 18 and the pump 37 are connected via the inter-valve oil passage 42 formed between the inner and outer circumferences of the first valve member 24 and the second valve member 25. Connected. In the inter-valve oil passage 42, between the first valve member-side concave portion and the second valve member-side concave portion, there are throttle portions A, B, C, and D whose opening degree changes due to the relative rotation of the two valve members 24 and 25. Is done. Each of the apertures A, B, C,
By changing the opening of D, the hydraulic pressure acting on the hydraulic cylinder 18 is controlled.

FIG. 2 shows the relative positions of the two valve members 24 and 25 in the straight steering position where steering is not performed. In this state, the openings of the throttle portions A, B, C, and D between the pressurized oil supply recesses 29 and the pressurized oil discharge recesses 30 are constant, and the pressurized oil flows through the respective throttle portions A, B, C and D return to the tank 41 from the second discharge path 39 via the second control valve 23 '.

When the vehicle is steered to the right from the straight steering position, the relative rotation of the first valve member 24 with respect to the output shaft 4 due to the torsion of the torsion bar 3 according to the steering torque of the driver or the force generated by the auxiliary hydraulic actuator 50 described later. Accordingly, the two valve members 24 and 25 rotate relative to each other. In accordance with the relative rotation amount, each right steering recess 27
The opening degree of the throttle portion A between the pressure oil supply concave portion 29 and the throttle portion B between the left steering concave portion 28 and the pressure oil discharge concave portion 30 increases, and the left steering angle increases. Of the throttle portion C between the pressure recess 28 and each pressure oil supply recess 29 and the throttle portion D between each right steering recess 27 and each pressure oil discharge recess 30.
Is smaller. As a result, the first
The pressurized oil is supplied to the oil chamber 21 and the tank 4
The oil is returned to the rack 1 and the steering assist force to the right of the vehicle is applied to the rack 8 during normal steering, and the steering force to the right of the vehicle is applied to the rack 8 during automatic steering.

When the vehicle is steered to the left from the straight steering position, the degree of opening of each of the throttles A, B, C, and D changes in the opposite direction as when the vehicle is steered to the right. Therefore, during normal steering, the vehicle is steered to the left. At the time of automatic steering, the steering force to the left of the vehicle acts on the rack 8 during automatic steering.

As shown in FIGS. 1, 3 to 5, an auxiliary hydraulic actuator 50 is provided. The auxiliary hydraulic actuator 50 includes a moving member 53 provided to be displaceable on the output shaft 4, a right steering oil chamber 51 and a left steering oil chamber 52 partitioned by the moving member 53, and a moving member 53 including a first valve. It has a connecting member 54 connected to the member 24. In the present embodiment, a pair of recesses 4a is provided on the outer periphery of one end (the upper end in FIG. 1) of the output shaft 4.
4b is formed, and annular member 55 covering both recesses 4a, 4b
Are fitted to the output shaft 4. As a result, the interior of both recesses 4a and 4b is used as the oil chambers 51 and 52. Further, two oil chambers 51 and 52 are provided at one end of the output shaft 4.
Is formed, and the substantially cylindrical moving member 53 is inserted into the through hole 56 so as to be movable in the axial direction.
The moving member 53 has a circumferential groove 53a formed on the outer periphery, and each end faces the pressing plate 53b. Each holding plate 53b
Needle 53c is attached to the end, and each oil chamber 51, 5
By being fitted into the guide grooves 51a and 52a formed on the inner surface of the second member 2, the movable member 53 can be moved in the axial direction.

In this embodiment, the first valve member 24 is elastically connected to the output shaft 4 via the moving member 53 so as to be relatively rotatable. That is, each oil chamber 51,
The leaf springs 58 and 59 are provided on the inner surface of the
3 are attached so as to be in contact with both ends via a needle 53c and a pressing plate 53b. The connecting member 54 has a round bar shape, one end of which is fixed to the center of the outer periphery of the moving member 53, and the other end of which is inserted into a notch 24 a formed at the lower end of the first valve member 24. The moving direction of the moving member 53 is parallel to the tangential direction of the peripheral surface of the first valve member 24 in a plane perpendicular to the axis of the output shaft 4. When the torsion bar 3 is twisted according to the steering torque based on the steering force of the driver, the friction between the first valve member 24 and the second valve member 25 and the first valve member 2
The rotation of the first valve member 24 following the second valve member 25 in response to the friction between the valve member 4 and the valve housing 10a is prevented by the preload of the leaf springs 58 and 59. Thus, the two valve members 24 and 25 are relatively rotated in accordance with the steering force of the driver, and the moving member 53 is prevented from accidentally moving in the normal steering mode. In the automatic steering mode, the moving member 53
, The first valve member 24 rotates relative to the output shaft 4, and the moving member 53 moves in one direction, whereby the leaf spring 58 of the right steering oil chamber 51 elastically deforms and moves in the other direction. As a result, the leaf spring 59 of the left steering oil chamber 52 is elastically deformed. That is, by the movement of the moving member 53,
The two valve members 24 and 25 can be elastically rotated relative to each other. The first valve member 24 and the output shaft 4
May be connected via a spring joined to the first valve member 24 and the output shaft 4, for example, so as to be elastically relatively rotatable without using the moving member 53.

The right steering oil chamber 51 and the left steering oil chamber 52 are described.
Is connected to the second control valve 23 'as shown in FIGS. The second control valve 23 'is connected to the first control valve 2
3 and is provided between the tank 41 and controls the hydraulic pressure acting on the auxiliary hydraulic actuator 50.

The second control valve 23 'is inserted into an auxiliary valve housing 61 connected to the valve housing 10a and an insertion hole 66 of the auxiliary valve housing 61 so as to be movable in the axial direction (vertical direction in FIG. 1). Spool 62 and a screw member 6 screwed to the spool 62
And 4. The axis of the spool 62 and the screw member 64
Are parallel to the relative rotation axes of the two valve members 24 and 25 and are eccentric to each other. One end of the insertion hole 66 is closed by a plug 68, and the other end is closed by a cover 94. A compression coil spring 90 is arranged between the spool 62 and the plug 68. The output shaft of the stepping motor 80 is connected to the screw member 64.

The stepping motor 80 is connected to the controller 8
In the automatic steering mode, the screw member 64 is driven to rotate in one direction during right steering and is driven to rotate in the other direction during left steering. The rotation of the screw member 64 during right steering causes the spool 62 to be displaced downward in the drawing, and the rotation during left steering causes the spool 62 to be displaced upward in the drawing. The spool 6
The decentering of the axis of the second member and the axis of the screw member 64 prevents the rotation of the spool 62.

The control device 81 is constituted by a computer, and is connected to an external signal receiver 85 and a steering amount sensor 86. The external signal may be, for example, a vehicle guidance signal transmitted from a transmitter provided on a traveling road or a guardrail, or an alarm signal which notifies a collision danger transmitted from a transmitter provided in another vehicle. Can be. The steering amount sensor 86 detects an amount corresponding to the actual steering amount, such as the amount of movement of the rack 8 and the rotation angle of the steering wheel.

The control device 81 outputs the following control signal in the automatic steering mode, and the output of the control signal is released in the normal steering mode. Switching between the automatic steering mode and the normal steering mode is performed by operating a switch (not shown).

First and second circumferential grooves 62a and 62b are formed at two locations on the outer circumference of the spool 62, and third, fourth and fifth circumferential grooves 66a, 66b and 66 are provided at three locations on the inner circumference of the insertion hole 66.
c is formed. The second circumferential groove 62b and the fifth circumferential groove 66c
Between the first circumferential groove 62a and the fourth
A second constricted portion B 'is defined between the peripheral groove 66b and the third constricted portion C' is defined between the first peripheral groove 62a and the third peripheral groove 66a. The gap between the peripheral groove 66b is the fourth
The aperture portion is D '.

The first circumferential groove 62a is provided between the auxiliary valve housing 61 and the oil passage 7 formed in the valve housing 10a.
0, 71, a circumferential groove 4d formed on the outer periphery of the output shaft 4, and an oil passage 72 formed in the output shaft 4 to the left steering oil chamber 52 of the auxiliary hydraulic actuator 50. . The second circumferential groove 62b is provided with oil passages 73 and 74 formed in the auxiliary valve housing 61 and the valve housing 10a, a space 4e formed between the output shaft 4 and the oil seal 16, and the output shaft The oil passage 75 communicates with the right hydraulic oil chamber 51 of the auxiliary hydraulic actuator 50 through the oil passage 75 formed in the auxiliary hydraulic actuator 50. The third and fifth circumferential grooves 66a and 66c are provided in the oil passage 7 formed in the auxiliary valve housing 61 and the valve housing 10a.
6, 77, 78 and the second discharge path 39 of the first control valve 23, and the pump 37 through the first control valve 23.
Lead to. The fourth circumferential groove 66b is connected to the tank 41 via a discharge port 79 formed in the auxiliary valve housing 61.
Lead to. As a result, each of the oil chambers 51 and 52 of the auxiliary hydraulic actuator 50 is connected to the pump 3 via the second control valve 23 '.
7 are connected to form the hydraulic circuit shown in FIG.

The degree of opening of the first to fourth throttle portions A ', B', C ', D' of the second control valve 23 'is determined based on an external signal input via the receiver 85. Reference numeral 81 outputs a control signal for the motor 80, and changes when the second control valve 23 'is operated. The pressure oil supplied from the pump 37 is controlled by the second control valve 23 'by the change in the opening degree.
As a result, the hydraulic pressure is applied to the right steering oil chamber 51 and the left steering oil chamber 52 of the auxiliary hydraulic actuator 50, and a force for operating the first control valve 23 is generated by the auxiliary hydraulic actuator 50. You.

FIGS. 1 and 7 show the position of the spool 62 of the second control valve 23 'in the straight steering position where steering is not performed. In this state, the first to fourth
The openings of the throttle portions A ', B', C ', and D' are constant, and the second control valve 23 'is supplied from the pump 37 via the first control valve 23.
Is supplied to each of the throttle portions A ', B', C ', D'
The auxiliary hydraulic actuator 50 does not generate any force.

In the automatic steering mode, when an external signal is input to the control device 81 via the receiver 85, the control device 81 determines whether the actual steering amount input from the steering amount sensor 86 and the steering based on the external signal. The control signal is output to the motor 80 so that the actual steering amount becomes the steering amount based on the external signal.

When the control device 81 outputs a control signal for steering rightward from the straight steering position to the motor 80, the motor 80 rotates the screw member 64 to rotate the spool 62.
Are displaced downward in FIG. Due to this displacement, the first
The opening of the throttle A 'and the opening of the second throttle B' increase, and the opening of the third throttle C 'and the opening of the fourth throttle D' decrease. As a result, pressure oil according to the external signal is supplied from the pump 37 to the right steering oil chamber 51 of the auxiliary hydraulic actuator 50, and the oil is returned from the left steering oil chamber 52 to the tank 41.

When pressure oil is supplied to the right steering oil chamber 51 of the auxiliary hydraulic actuator 50, its movement is caused by the pressure difference between the right steering oil chamber 51 and the left steering oil chamber 52. The member 53 is a leaf spring 59 of the left steering oil chamber 52.
Is displaced so as to be elastically deformed. This displacement is transmitted to the first valve member 24 via the connecting member 54, and the force for relatively rotating the first valve member 24 and the second valve member 25 elastically so that a right steering force is generated. Occur. That is, the first control valve 23 is operated based on the force generated by the auxiliary hydraulic actuator 50, and the hydraulic pressure of the pressure oil supplied from the pump 37 is controlled by the first control valve 23 as described above. Pressure oil is supplied from 37 to the first oil chamber 21 of the hydraulic cylinder 18, and a rightward steering force of the vehicle acts on the rack 8.

When the control device 81 outputs a control signal for steering leftward from the straight steering position to the motor 80, the motor 80 rotates the screw member 64 to rotate the spool 62.
Are displaced upward in FIG. Due to this displacement, the first
The opening of the throttle A 'and the opening of the second throttle B' are reduced, and the opening of the third throttle C 'and the opening of the fourth throttle D' are increased. As a result, pressure oil corresponding to the external signal is supplied from the pump 37 to the left steering oil chamber 52 of the auxiliary hydraulic actuator 50, and the oil is recirculated from the right steering oil chamber 51 to the tank 41.

When pressure oil is supplied to the left steering oil chamber 52 of the auxiliary hydraulic actuator 50, its movement is caused by the pressure difference between the right steering oil chamber 51 and the left steering oil chamber 52. The member 53 is a leaf spring 58 of the right steering oil chamber 51.
Is displaced so as to be elastically deformed. When this displacement is transmitted to the first valve member 24 via the connecting member 54, a force for relatively rotating the first valve member 24 and the second valve member 25 relatively to generate a left steering force is generated. Occur. That is, the first control valve 23 is operated based on the force generated by the auxiliary hydraulic actuator 50, and the hydraulic pressure of the pressure oil supplied from the pump 37 is controlled by the first control valve 23 as described above. Pressure oil is supplied from 37 to the second oil chamber 22 of the hydraulic cylinder 18, and a steering force to the left of the vehicle acts on the rack 8.

Thus, while the control signal is being output by the control device 81, the automatic steering mode is set in which the vehicle is steered based on the steering force generated by the hydraulic cylinder 18 in response to the external signal.

FIGS. 1, 6, 7, and 8 (1) and (2)
As shown in the figure, the relief oil passage 111 that connects the pump 37 and the tank 41 is connected to the second control valve 23 so that the normal steering mode can be switched by applying the steering force of the driver in the automatic steering mode. ′ And a normally closed on-off valve 1
12 is provided so as to be opened by the steering force of the driver.

That is, the opening / closing valve 112 has a cylindrical first rotating member 113 and a second rotating member 114 inserted into the first rotating member 113 so as to be relatively rotatable coaxially. The first rotating member 113 is rotatably inserted into the valve housing 10a, and is connected to the first shaft portion 2a of the input shaft 2 via a pin 115 so as to be rotatable therewith. The second rotating member 114 is integrally formed on the outer periphery of the second shaft portion 2b of the input shaft 2, and rotates together with the second shaft portion 2b. Thereby, the torsion bar 3 is twisted between the first pin 5a and the second pin 5b by the steering torque based on the steering force of the driver, and the first shaft portion 2a and the second shaft portion 2b elastically rotate relative to each other. Thus, the first rotating member 113 and the second
It rotates relative to the rotating member 114.

A plurality of concave portions along the axial direction are formed at equal intervals in the circumferential direction on the inner periphery of the first rotating member 113 and the outer periphery of the second rotating member 114. The first rotating member side recess 11
6 and the second rotating member-side concave portions 117 are alternately arranged in the circumferential direction. Each first rotating member side recess 116 is provided with the first rotating member 1.
An oil passage 118 formed in the passage 13 and a second discharge port 119 formed in the valve housing 10 a communicate with the tank 41. Each of the second rotating member-side recesses 117 is provided with an oil passage 120 formed in the second shaft portion 2b and the input shaft 2.
Between the first control valve 23 and the second control valve 23 'via an oil passage 47' between the inner and outer circumferences of the torsion bar 3 and an oil passage 121 formed in the second shaft portion 2b of the input shaft 2. It communicates with a passage 78 and through its first control valve 23 to a pump 37. As a result, the second discharge port 119, the first
The rotary member-side concave portion 116, the second rotary member-side concave portion 117, and the oil passages 118, 120, 47 ', and 121 constitute a relief oil passage 111 that connects the pump 37 and the tank 41.

In the relief oil passage 111, the space between the first rotary member side concave portion 116 and the second rotary member side concave portion 117 is
It is opened and closed by the relative rotation of both rotating members 113 and 114.
FIG. 8A shows a state in which the driver's steering force is not acting. In this state, the relief oil passage 111 is closed. When the steering force of the driver is applied, the torsion bar 3 is elastically twisted between the first pin 5a and the second pin 5b, so that the two rotating members 113 and 114 rotate relatively. By this relative rotation, as shown in FIG.
The relief oil passage 111 is opened.

According to the above configuration, in the normal steering mode, the hydraulic pressure of the hydraulic oil supplied from the pump 37 is controlled by the first control valve 23 which is operated based on the steering force of the driver. Reference numeral 18 generates a steering assist force for normal steering. In the automatic steering mode,
The hydraulic pressure of the pressure oil supplied from the pump 37 is controlled by the second control valve 23 ′ that operates based on an external signal,
The auxiliary hydraulic actuator 50 controls the first control valve 2 according to the pressure difference between the oil pressure in the right steering oil chamber 51 and the oil pressure in the left steering oil chamber 52.
3 to generate a force. The first control valve 2 operated based on the force generated by the auxiliary hydraulic actuator 50
By 3, the hydraulic pressure of the pressure oil supplied from the pump 37 is controlled, and the hydraulic cylinder 18 generates a steering force for automatic steering. In other words, the first valve member 24 is elastically relatively rotated with respect to the output shaft 4 by the action of the force generated by the auxiliary hydraulic actuator 50, and the two valve members 24 and 25 are relatively rotated by the relative rotation. The first control valve 23 is operated. A steering force corresponding to the operation amount of the first control valve 23 is generated by the hydraulic cylinder 18. When the driver applies a steering force in the automatic steering mode, the first shaft portion 2 of the input shaft 2 is moved.
a and the second shaft portion 2b elastically rotate relative to each other. Due to this relative rotation, both rotating members 11 of the on-off valve 112
The relief oil passage 111 is opened by relative rotation of the relief oil passages 3 and 114. As a result, the differential pressure between the hydraulic pressure in the right steering oil chamber 51 and the hydraulic pressure in the left steering oil chamber 52 of the auxiliary hydraulic actuator 50 becomes zero, so that the auxiliary hydraulic actuator 50 has a force for operating the first control valve 23. Does not occur.
Therefore, the first type that operates only by the steering force of the driver
Since the hydraulic pressure of the hydraulic oil supplied from the pump 37 is controlled by the control valve 23, the hydraulic cylinder 18 generates a steering assist force for normal steering. In other words, by applying the driver's steering force in the automatic steering mode,
The automatic steering can be released, and the mode is switched to the normal steering mode. Thus, the driver can surely change the steering direction by his / her own will against automatic steering, and can achieve a sufficient fail-safe function. Further, it is possible to smoothly switch from the automatic steering mode to the normal steering mode with a simple configuration. Further, since the opening / closing valve 112 can be disposed between the steering wheel and the first control valve 23, the radial size of the steering device can be reduced.

By controlling the hydraulic pressure of the pressure oil supplied from the pump 37 by the first control valve 23, a steering force can be generated during automatic steering and a steering assist force can be generated during normal steering. That is, since a hydraulic control valve for generating a steering force during automatic steering and a hydraulic control valve for generating a steering assist force during normal steering are not separately required, the structure can be simplified and the device can be downsized. .

Also, since the second control valve 23 'is provided between the first control valve 23 and the tank 41, the hydraulic control system for automatic steering is arranged downstream of the hydraulic control system for normal steering. When the automatic steering mode is changed to the normal steering mode, the flow of the pressure oil can be smoothly changed, and it is possible to prevent the driver from being shocked.

Further, the auxiliary hydraulic actuator 50 for the automatic steering mode can be made compact in the steering force transmission system.

Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. Note that the same parts as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted, and differences will be described.

A rack and pinion type steering device 1 "shown in FIG. 9 has an input shaft 2" formed of a single member connected to a steering wheel (not shown), and the input shaft 2 "is connected to the input shaft 2" via a torsion bar 3 ". An output shaft 4 "is coaxially connected. The torsion bar 3" is connected to the input shaft 2 "via the pin 5 and connected to the output shaft 4" via the serration 6. Thereby, the input shaft 2 "and the output shaft 4" are relatively rotatable elastically according to the steering force of the driver.

In a normal steering mode in which the vehicle is steered based on the driver's steering force and the steering assist force generated by the hydraulic cylinder 18, the input shaft 2 "is rotated by the steering torque based on the driver's steering force. The rotation of the input shaft 2 "is transmitted to the pinion 7 via the torsion bar 3".

The second valve member 25 of the first control valve 23, which is the same as that of the first embodiment, is integrally formed on the outer periphery of the input shaft 2 ", and rotates together with the input shaft 2".
The torsion bar 3 "is twisted by the steering torque based on the steering force of the driver, and the first and second valve members 24 and 25 rotate relative to each other because the shafts 2 and 4 elastically rotate relative to each other. The relative rotation amount of the members 24 and 25 is set as the operation amount of the first control valve 23.

Each pressure oil discharge recess 30 of the first control valve 23,
It communicates with the first discharge space 150 "below the first valve member 24 via the extension recess 30". The first discharge space 15
0 ″ communicates with a second discharge space 152 ″ below the cylinder 151 ″ surrounding the first valve member 24. The first control valve 23 is connected to an oil passage formed in the cylinder 151 ″. To the oil chambers 21 and 22 of the pump 37 and the hydraulic cylinder 18. The second discharge space 151 "communicates with a third discharge space 153" formed between the valve housing 10a "and the output shaft 4". The third discharge space 153 "communicates with the tank 41 via the second control valve 23 '. In the present embodiment, the valve housing 10a" is formed by connecting two members.

As shown in FIGS. 9 to 11 and 14, an auxiliary hydraulic actuator 50 "is provided. The auxiliary hydraulic actuator 50" is provided with a movable member 53 "displaceably provided on the output shaft 4". This moving member 53 ″
A right steering oil chamber 51 "and a left steering oil chamber 52", and a connecting member 54 for connecting a moving member 53 "thereof to the first valve member 24. In the present embodiment, one end of the output shaft 4" is provided. A pair of recesses 4 a ″ and 4 b ″ are formed on the outer periphery on the side (the upper end side in FIG. 1).
a ", 4b" are fitted with blocks 60a, 60b ", and one end of the output shaft 4" and both blocks 60a, 60b ".
a and 60b "constitute a cylindrical portion. An annular member 55" is fitted around the outer periphery of the cylindrical portion. At one end of the output shaft 4 ", a through-hole 56" connecting the two recesses 4a "and 4b" is formed, and a guide cylinder 140 "is formed in the through-hole 56".
The moving member 53 "is inserted into the guide tube 140" so as to be movable in the axial direction. The guide cylinder 1
Inside the 40 ", a portion between one end of the moving member 53" and one block 60a "constitutes the right steering oil chamber 51", and the other end of the moving member 53 "and the other block 60b".
Constitutes the left steering oil chamber 52 ″.

The outer periphery of the moving member 53 "has a flat surface facing each other and a portion along a cylindrical surface between the two flat surfaces. One end of the connecting member 54 moves so as to be orthogonal to the flat surface. It is fixed to the member 53 ″. The moving member 53 ″
, The first valve member 24 is elastically connected to the output shaft 4 ″ so as to be relatively rotatable.
Compression coil springs 58 "and 59" are disposed between 1 "and 52" so as to be sandwiched between the moving member 53 "and the blocks 60a" and 60b ". The other end of the connecting member 54 is the first embodiment. In the same manner as described above, the first valve member 24 is inserted into a notch 24a formed at the lower end of the first valve member 24. The moving direction of the moving member 53 "is within a plane orthogonal to the axis of the output shaft 4". In addition, as shown in Fig. 11, a notch 4p is formed at one end of the output shaft 4 to allow the connection member 54 to move, as shown in Fig. 11. When the torsion bar 3 ″ is twisted according to the steering torque based on the force, the friction between the first valve member 24 and the second valve member 25, and the friction between the first valve member 24 and the valve housing 10a ″. Depending on the friction, the first valve member 24
Is rotated by the spring 5.
Blocked by 8 ", 59" preload. As a result, the two valve members 24 and 25 are relatively rotated according to the steering force of the driver, and the moving member 53 ″ is prevented from accidentally moving in the normal steering mode. In the automatic steering mode, The movement of the moving member 53 ″ causes the first valve member 24 to rotate relative to the output shaft 4 ″, and the movement of the moving member 53 ″ in one direction causes the spring 58 ″ of the right steering oil chamber 51 ″ to be elastic. The spring 59 "of the left steering oil chamber 52 is elastically deformed by the movement in the other direction. That is, by the movement of the moving member 53", the two valve members 24 and 25 are relatively elastically rotated. it can. Note that the first valve member 24 and the output shaft 4 "can be relatively rotated elastically via, for example, a spring joined to the first valve member 24 and the output shaft 4" without passing through the moving member 53 ". May be connected.

The right steering oil chamber 51 ″ and the left steering oil chamber 5
2 ″ is connected to a second control valve 23 ′ similar to the first embodiment.

The first circumferential groove 62a of the second control valve 23 '
Are the auxiliary valve housing 61 "and the valve housing 1
0a ", an oil passage 70", 71 "formed in the outer periphery of the annular member 55", a peripheral groove 55a "formed in the outer periphery of the annular member 55", and an oil passage 72 "formed in one block 60b". Left steering oil chamber 52 "of the auxiliary hydraulic actuator 50"
Lead to. The second circumferential groove 62b of the second control valve 23 '
Auxiliary valve housing 61 "and valve housing 10
a "formed in oil passages 73" and 74 ", an annular groove 55b" formed in the outer periphery of the annular member 55 ", and an oil passage 77" formed in the other block 60a ". The auxiliary hydraulic actuator 50 "communicates with the right steering oil chamber 51". The third and fifth circumferential grooves 66 of the second control valve 23 '.
a and 66c communicate with the third discharge space 153 "via oil passages 76" and 77 "formed in the auxiliary valve housing 61" and the valve housing 10a ", and from the third discharge space 153" to the first discharge space 153 ". It communicates with the pump 37 via the control valve 23. The fourth circumferential groove 66b of the second control valve 23 'is connected to an oil passage 78 "formed in the valve housing 10a" via an oil passage 79 "formed in the auxiliary valve housing 61".
And the oil passage 78 "is connected to the valve housing 10a".
The oil chambers 51 "and 52" of the auxiliary hydraulic actuator 50 "are connected to the pump 37 via the second control valve 23 '. The hydraulic circuit shown in FIG. 6 is configured.

As in the first embodiment, in the automatic steering mode, the control device 81 outputs a control signal for the motor 80 based on an external signal input via the receiver 85, and
By operating the control valve 23 ′, the opening degrees of the first to fourth throttle portions A ′, B ′, C ′, D ′ of the second control valve 23 ′ change, and the pressure oil supplied from the pump 37 is changed. Is the second control valve 23 '
Is controlled by Thus, the hydraulic pressure is applied to the right steering oil chamber 51 "and the left steering oil chamber 52" of the auxiliary hydraulic actuator 50 ", and the force for operating the first control valve 23 is increased by the auxiliary hydraulic actuator 50". Generated by That is, the first control valve 23 is operated based on the force generated by the auxiliary hydraulic actuator 50 ″, and the hydraulic pressure of the pressure oil supplied from the pump 37 is controlled by the first control valve 23. Pressure oil is supplied from the pump 37 to the first oil chamber 21 of the hydraulic cylinder 18, and during left steering, pressure oil is supplied from the pump 37 to the first oil chamber 22 of the hydraulic cylinder 18, so that a steering force acts on the rack 8. .

In the automatic steering mode, a relief oil passage 111 "connecting the pump 37 and the tank 41 is provided in the second control valve 23 'so that the normal steering mode can be switched by applying the driver's steering force. A normally closed on-off valve 112 "is provided in the relief oil passage 111" so as to be opened by the driver's steering force.

That is, as shown in FIG. 10, the open / close valve 112 "is connected to the output shaft 4" and the two blocks 60.
a ", 60b" is inserted into a through-hole 201 "through a guide cylinder 202" so as to be displaceably inserted through an open / close spool 2
The guide tube 202 "has a set screw 20".
9 "to the output shaft 4". The displacement direction of the opening / closing spool 203 ″ is the input / output shaft 2 ″,
The first peripheral groove 202a "and the second peripheral groove 2 are formed on the inner periphery of the guide cylinder 202".
02b "is formed.
A plurality of through holes 203e "communicating with the first circumferential groove 202a" and a plurality of through holes 203f "communicating with the second circumferential groove 202b" are formed in the peripheral wall of the 3 ". The first circumferential groove 20 at one end and the other end of the
The recess 203a "communicates with the hole 2a" through the through hole 203e ".
And a concave portion 203b "communicating with the second circumferential groove 202b" through a through hole 203f ". As shown in (1), (2), and (3) of FIG.
02 ", the first circumferential groove 202a" and the second circumferential groove 2
An opening 202h "is formed between the opening 202h" and the opening 202h ". A circumferential groove 203h "communicating with the opening 202h" is formed on the outer periphery of the opening / closing spool 203 ".

As shown in FIG. 11, an arm 211 "extending in the radial direction is integrated with the input shaft 2". The arm 211 ″ is inserted into the recess 4 c ″ at one end of the output shaft 4 ″ such that movement around the axis of the input shaft 2 ″ is allowed. A roller 213 "is attached to the arm 211" via a support shaft. The roller 213 "is connected to the opening 202 of the guide cylinder 202".
h "through the torsion bar 3" of the two shafts 2 "and 4" according to the steering force of the driver. The open / close spool 203 ″ and both shafts 2 ″ and 4 ″ are linked so that the open / close spool 203 ″ moves in the axial direction.

The circumferential groove 203 of the opening / closing spool 203 ″
The opening 202h "of the guide cylinder 202" communicating with the output shaft 4 "is connected to the recess 4c" of the output shaft 4 "and the second discharge space 15".
2 ", the third discharge space 153", and the second control valve 23 '
Through the pump 37. The opening / closing spool 20
Through hole 20 communicating with each of the 3 ″ recesses 203a ″ and 203b ″
1 "communicates with an oil passage 47 between the input shaft 2" and the inner and outer peripheries of the torsion bar 3 "via oil passages 60e" and 60f "formed in each of the blocks 60a" and 60b ". Is an oil passage 239 "formed in the input shaft 2".
From the tank 41 via the discharge port 160 ". Thereby, the second discharge space 152", the third discharge space 153 ", the concave portion 4c" of the output shaft 4 ", the opening 202h" of the guide cylinder 202 ", and the like. The circumferential groove 203h "of the opening / closing spool 203" and the first and second circumferential grooves 2 of the guide cylinder 202 "
02a ″, 202b ″, opening / closing spool 203 ″ through hole 2
03e ″, 203f ″, recesses 203a ″, 203b ″,
Oil passage 6 of through hole 201 ″ and each block 60 a ″, 60 b ″
0e ″, 60f ″, oil path 47 between input shaft 2 ″ and inner and outer circumferences of torsion bar 3 ″, oil path 2 of input shaft 2 ″
39 "and the discharge port 160" constitute a relief oil passage 111 "connecting the pump 37 and the tank 41.

When there is no driver's steering force and the input shaft 2 "and the output shaft 4" are not rotating relative to each other, as shown in FIGS. Circumferential groove 203h ″ and guide cylinder 202 ″
The space between each of the inner circumferential grooves 202a ″ and 202b ″ is closed. That is, the escape oil passage 111 "is closed. When the input shaft 2" and the output shaft 4 "rotate relative to each other due to the driver's leftward steering force, the opening / closing spool 203" is displaced in one axial direction. This allows
As shown in FIG. 13, the peripheral groove 203h "on the outer periphery of the opening / closing spool 203" and the second peripheral groove 20 on the inner periphery of the guide cylinder 202 ".
2b ". The relief oil passage 111 is thereby opened.
Is opened. As the input shaft 2 "and the output shaft 4" rotate relative to each other due to the driver's rightward steering force, the open / close spool 203 "is displaced in the other axial direction.
Thereby, the peripheral groove 203 on the outer periphery of the opening / closing spool 203 ″
h "and the second circumferential groove 202b" on the inner circumference of the guide cylinder 202 "are opened. Thereby, the relief oil passage 111 is opened.

The other configuration of the second embodiment is the same as that of the first embodiment. According to the second embodiment, the same functions and effects as those of the first embodiment can be obtained. Further, since the opening / closing valve 112 "can be provided on one of the input / output shafts 2" and 4 ", the axial dimension of the steering device can be reduced.

The present invention is not limited to the above embodiment. For example, the present invention can be applied to a ball screw type steering device.

[0077]

According to the present invention, in a steering device capable of selecting an automatic steering mode or a normal steering mode, safety is improved, the device is reduced in size, the structure is simplified, and the manufacturing cost is reduced. The automatic steering mode can be reliably and smoothly changed from the normal steering mode to the normal steering mode, and the shock acting on the driver at the time of the change can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a steering device according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG. 1;

FIG. 4 is a view taken in the direction of the arrow IV in FIG. 3;

FIG. 5 is a view taken in the direction of the arrow V in FIG. 3;

FIG. 6 is a hydraulic circuit diagram of the steering device according to the embodiment of the present invention.

FIG. 7 is a sectional view of a main part of the steering device according to the first embodiment of the present invention;

FIG. 8 is a cross-sectional view of the on-off valve according to the first embodiment of the present invention in a state where the escape oil passage is closed, and FIG. 8 is a cross-sectional view in a state where the escape oil passage is opened.

FIG. 9 is a sectional view of a steering device according to a second embodiment of the present invention.

FIG. 10 is a sectional view taken along line XX of FIG. 9;

FIG. 11 is a sectional view taken along the line XI-XI in FIG. 9;

FIG. 12 shows an opening / closing valve (1) according to a second embodiment of the present invention.
Is a partially broken plan view, (2) is a partially broken side view, and (3) is a cross sectional view.

FIG. 13 is a partially broken plan view of the on-off valve according to the second embodiment of the present invention with a relief oil passage opened.

FIG. 14 is a sectional view of a main part of a steering device according to a second embodiment of the present invention.

[Explanation of symbols]

 2, 2 "input shaft 2a first shaft portion 2b first shaft portion 4, 4" output shaft 18 hydraulic cylinder 23 first control valve 23 'second control valve 24 first valve member 25 second valve member 37 pump 41 tank Reference Signs List 50 auxiliary hydraulic actuator 51, 51 ″ right steering oil chamber 52, 52 ″ left steering oil chamber 53, 53 ″ moving member 54 connecting member 61 control device 62 receiver 111, 111 ″ relief oil passage 112, 112 ″ opening / closing valve 113 First rotating member 114 Second rotating member 203 ″ Opening / closing spools A, B, C, D Throttle section

Claims (5)

[Claims] The vehicle is steered based on a normal steering mode in which the vehicle is steered based on a driver's steering force and a steering assist force generated by a hydraulic actuator, and a steering force generated by the hydraulic actuator in response to an external signal. A steering device capable of selecting between an automatic steering mode and a hydraulic oil supply pump, an auxiliary hydraulic actuator, an operation of a driver's steering force, and an operation of a force generated by the auxiliary hydraulic actuator. And a second control valve that is operated based on the external signal. In a normal steering mode, the hydraulic pressure of the pressure oil supplied from the pump is based on the steering force of the driver. Controlled by the first control valve that is actuated, a steering assist force corresponding to the amount of actuation is generated by the hydraulic actuator, and automatic steering is performed. In the mode, the hydraulic pressure of the hydraulic oil supplied from the pump is controlled by the second control valve, so that a force for operating the first control valve is generated by the auxiliary hydraulic actuator, and supplied from the pump. The hydraulic pressure of the pressurized oil is controlled by the first control valve that is operated based on the force generated by the auxiliary hydraulic actuator, so that a steering force corresponding to the operation amount is generated by the hydraulic actuator, and in the automatic steering mode, A relief oil passage connecting the pump and the tank is provided with a second oil passage so that the normal steering mode can be switched by applying the steering force of the driver.
A steering device provided in parallel with a control valve, and a normally closed opening / closing valve provided in a relief oil passage so as to be opened by a driver's steering force. 2. An input shaft for a driver's steering force and an output shaft, the input shaft having a first shaft portion on the steering wheel side and a second shaft portion on the output shaft side, and both shaft portions are A second shaft portion of the input shaft and an output shaft are connected to be elastically relatively rotatable according to the steering force of the driver, The first control valve has a first valve member and a second valve member, and one of the two valve members is elastically relatively rotatable on an output shaft in accordance with a force generated by the auxiliary hydraulic actuator. The other of the two valve members is connected to and rotatable with the second shaft portion of the input shaft, and the relative rotation amount of the two valve members is set as the operation amount of the first control valve. The hydraulic pressure acting on the hydraulic actuator can be controlled in accordance with the relative rotation amount of the material, and the auxiliary hydraulic actuator can be displaced on one of the two shafts to which one of the two valve members is elastically connected to be relatively rotatable. , A left and right steering oil chamber partitioned by the moving member, and a connecting member for connecting the moving member to one of the two valve members, and a right steering oil chamber by the second control valve. And the left steering oil chamber can be actuated alternatively, and the displacement of the moving member due to the pressure difference between the right steering oil chamber oil pressure and the left steering oil chamber oil pressure changes the connecting member. Transmitted to one of the two valve members via the second valve member, the two valve members can be relatively rotated. The open / close valve has a first rotating member and a second rotating member, and one of the two rotating members is provided. Is the input shaft The relief oil passage is opened by the relative rotation of the two rotating members by the driver's steering force, wherein the other of the two rotating members is rotatable along with the other of the two shaft portions. Item 2. The steering device according to item 1. 3. An apparatus according to claim 1, further comprising an input shaft and an output shaft for a driver's steering force, wherein both shafts are connected to be elastically rotatable in accordance with the driver's steering force. It has a valve member and a second valve member, one of the two valve members is attached to one of the two shafts,
The auxiliary hydraulic actuator is elastically connected to be relatively rotatable according to the force generated by the auxiliary hydraulic actuator.
The two shafts are rotatable together with the other, the relative rotation amount of both valve members is the operation amount of the first control valve, and the hydraulic pressure acting on the hydraulic actuator can be controlled according to the relative rotation amount of both valve members. The auxiliary hydraulic actuator includes a movable member that is displaceably provided on one of the shafts to which one of the two valve members is elastically connected to be relatively rotatable, and a left and right steering oil chamber partitioned by the movable member. A connecting member for connecting the moving member to one of the two valve members, and the second control valve can selectively actuate hydraulic pressure to the right steering oil chamber and the left steering oil chamber. The displacement of the moving member due to the pressure difference between the oil pressure of the right steering oil chamber and the oil pressure of the left steering oil chamber is transmitted to one of the two valve members via the connecting member, so that the two valve members are relatively moved. Rotate The open / close valve has an open / close spool that can be displaced so as to open and close the relief oil passage on one of both shafts, and the relative rotation of the two shafts according to the driver's steering force causes the open / close valve to rotate. The steering device according to claim 1, wherein the open / close spool and both shafts are linked so that the relief oil passage is opened. 4. The input shaft and the output shaft are coaxially connected, the first valve member is cylindrical, and the second valve member is coaxially inserted into the first valve member so as to be relatively rotatable. An axially extending recess is formed in the inner periphery of the first valve member and the outer periphery of the second valve member at intervals in the circumferential direction. A portion between the valve member side concave portion and the edge along the axial direction is a throttle portion provided in an oil passage between the hydraulic actuator and the pump, and the opening degree of the throttle portion is changed by the relative rotation of both valve members. The steering device according to claim 2, wherein the hydraulic pressure of the pressure oil supplied to the hydraulic actuator is controlled accordingly. 5. The steering apparatus according to claim 1, wherein a second control valve is provided between the first control valve and the tank.