JPH0230383Y2 - - Google Patents

Description

[Detailed Description of the Invention] A conventional power steering device for a vehicle transmits the operating rod of a hydraulic cylinder provided in the vehicle body to a nut lever via a relay rod.

However, in order to install the hydraulic cylinder and relay rod, space had to be provided on the underside of the vehicle body, which reduced the freedom in designing the vehicle body.

The present invention solves the above problems, and includes a nut that rotatably supports the wheel, a king pin that fixes the nut and is rotatably attached to the suspension system of the vehicle, and a king pin that is installed on the suspension system and drives the king pin in rotation. A power steering device for a vehicle including an actuator, the actuator comprising a rotor rotatably disposed in a casing to which the suspension device is fixed and fixed to the king pin, and a stator provided in the casing. and first and second chambers formed between the rotor and the stator and forming a pair with each other, and a neutral holding wedge formed in the casing so as to be insertable into and removed from the recess of the rotor. The concave portion of the rotor and the wedge are formed in a tapered shape, further comprising: a hydraulic pressure supply means for selectively supplying and controlling hydraulic pressure to the first or second chamber; a drive means for driving and controlling the wedge; and a handle. The power steering device for a vehicle is characterized in that it is equipped with a control means for controlling the operation of the hydraulic pressure supply means and the drive means according to an operation, and since the actuator is provided in the suspension device around the king pin, the space on the underside of the vehicle body is saved. can be used effectively.

In particular, according to the present application, a neutral holding wedge formed in the casing so as to be inserted into and removed from the recess of the rotor is provided in the casing, and since the recess and the wedge of the rotor are formed in a tapered shape, the control means can drive the wedge. By controlling the operation of the means to control the state of insertion and removal of the wedge into the recess of the rotor, the wheels can be reliably kept in the neutral state when steering is not required, and the wheels can be returned to the neutral state from the steered state. can also be done reliably.

Examples of the present invention will be described in detail below. In the first embodiment shown in FIGS. 1 to 6,
As shown in FIG. 1, the rear suspension 1 of a front-wheel drive vehicle includes left and right trailing arms 2, a beam axle 3 attached to the vehicle body (not shown) via the trailing arms 2 and a coil spring (not shown), and the same axle 3. A rear wheel 6 is rotatably mounted on the rear wheel 5, and the rear wheel 6 is rotatably mounted on the rear wheel 6. The rotary actuator 7 is attached to both left and right ends of the axle 3, and drives the king pin 4.

That is, the rotary actuator is shown in FIGS. 2 and 3 (note that the rotary actuator is formed symmetrically on the left and right sides in FIGS. (It is drawn to indicate the state.) As shown in
A case 71 fixed to an end of the axle 3, a rotor 72 rotatably disposed in a central cylindrical portion 712 of the case 71, and a rotor 72 disposed within the central cylindrical portion 712 and inserted into a notch of the rotor 72. Same rotor 7
2, a stator 73 and a rotor 7 have surfaces facing each other.
2 and the stator 73.
and a second chamber 75. The wedge 76 is disposed in a space 77 provided on the left and right sides of the case 71 so as to be movable in the left and right directions in FIGS. 763, large tapered part 7
64, and can be inserted and fitted into a recess 78 formed in the rotor 72. Recess 78 is wedge 7
6 is inserted, the first side 781 that comes into contact with the straight part 761, the second side 782 that comes into contact with the small tapered part 763, and the curved part 783 that is continuous with the first side 781 and is located on the outer periphery of the rotor 72. have. The springs 79 and 80 are interposed between the case 71 and the wedge 76, and push the wedge 76 into the recess 78.
is pushing towards. The king pin 4 has a serration 41 formed on the outer periphery of the intermediate portion, and is inserted into a hole formed on the rotational axis of the rotor 72, and is connected to the serration formed on the wall of the hole and the serration 41.
The king pin 4 is fixed to the rotor 72 so as to rotate integrally therewith. The oil passage 42 communicates with the recess 78 of the rotor 72 through the king pin 4, and a nipple 43 is provided at the entrance of the oil passage 42. The king pin 4 has a ball bearing 81 at the top and a tapered roller bearing 82 at the bottom.
The knuckle 5 is supported by the case 71 and fixed by lock pins 44 at both upper and lower ends. 8
3, 84, 85, 86, and 87 are oil seals. A position sensor 9 is provided in the cavity 77 and detects the position of the wedge 76.

As shown in FIG. 4, the control circuit includes a four-way switching valve 10 as a hydraulic pressure supply means, a three-way switching valve 11 as a driving means, and a controller 12 as a control means.
The four-way switching valve 10 has four ports communicating with an oil pump 13 driven by the engine, a reservoir 14, and a first chamber 74 and a second chamber 75 of the rotary actuator 7, respectively. In addition, the three-way switching valve 11 includes an oil pump 13, a reservoir 14,
and nipple 43 of rotary actuator 7
Each of the three ports communicates with the oil passage 42 via the three ports. The controller includes a vehicle speed sensor 15,
Steering wheel angle sensor 1 via A/D converter 16
7. Connect position sensor 9 to the input side, and connect 4 to the output side.
first and second solenoids 18, 19 of the direction switching valve 10;
The solenoid 20 of the three-way switching valve 11 is connected.

With the above structure, the front wheels are positioned in a straight-ahead state in a neutral state where the steering wheel is not turned. Furthermore, since the steering wheel angle sensor 17 detects the neutral position of the steering wheel, the controller 12 does not operate the first and second solenoids 18 and 19 and the solenoid 20, and operates the four-way switching valve 10 and the three-way switching valve 11 at the fourth and second solenoids. It is maintained in the state shown in the figure. Therefore, since no oil pressure is generated in the oil passage 42, the wedge 76 is connected to the springs 79 and 8.
The rotor 72 is inserted into the recess 78 with an urging force of 0 as shown in the right half of FIGS. 2 and 3, and the rotor 72 is fixed to the case 71. Therefore, the rear wheels 6 are maintained in a neutral state, that is, in a straight-ahead state, as shown in FIG.

Next, when the vehicle speed is below a predetermined value, the steering wheel is rotated to the right to steer the front wheels to the right. When the steering angle exceeds a certain value, the controller 12 receives a signal from the steering wheel angle sensor 17 to control the three-way switching valve. The solenoid 20 of 11 is turned on, and the hydraulic pressure of the oil pump 13 is guided between the wedge 76 and the recess 78 via the oil passage 42. Then, due to this hydraulic pressure, the wedge 76 moves away from the king pin 4 against the urging force of the springs 79 and 80, moves to the position shown in the left half of FIGS. 2 and 3, stops, and comes out of the recess 78. Next, when the position sensor 9 detects that the wedge 76 has stopped, the controller 12 turns on the first solenoid 18 to communicate the oil pump 13 and the first chamber 74, and the oil pressure in the first chamber 74 causes the rotor 72 to move. rotates counterclockwise in Figures 1, 3, and 4, and this rotation is transmitted through the king pin 4 to the nut
The rear wheels 6 are steered counterclockwise (to the left) in FIG. Note that the rotation of the rotor 72 is stopped by coming into contact with the stator 73. At this time, the curved portion 783 of the recess 78 is in contact with the large tapered portion 764 of the wedge 76, as shown in FIG.

Next, when the steering wheel is rotated to the left to steer the front wheels in the neutral (straight ahead) direction and the steering angle becomes below a certain level, the controller 12 activates the solenoid 20.
OFF, the three-way switching valve 11 communicates the oil passage 42 with the reservoir 14, and releases the hydraulic pressure applied to the wedge 76. Then, after a certain period of time has elapsed after the solenoid 20 is turned off, the controller 12 turns off the first solenoid 18 and the first and second chambers 74, 75
is communicated to the reservoir 14. Then, wedge 76
is urged toward the king pin 4 by the springs 79 and 80, and the large taper portion 764 is in contact with the curved portion 783 of the recess 78, so that the urging force of the wedge 76 is applied to the rotor 72 in the direction of the arrow in FIG. The rotor 72 moves clockwise (rightward) in Figures 3 and 4.
Rotate to. Furthermore, the wedge 76 enters into the recess 78 due to the biasing force of the springs 79 and 80, and the large tapered portion 764 moves from the curved portion 783 to the first and second sides 7.
81,782 while touching it. Further, the wedge 76 is formed by the force of the springs 79 and 80.
When the small taper section 76 moves as shown in FIG.
3 comes into contact with the second side 782 and a force in the direction of the arrow in FIG. By contacting the side 782, the movement of the wedge 76 toward the king pin 4 is stopped, and the rear wheel 6 returns to neutral. The position sensor 9 confirms this stop.

Furthermore, when the vehicle speed is below a predetermined value and the steering wheel is rotated to the left more than a certain value to steer the front wheels to the left, the same effect as described above occurs, and the controller 12 turns on the solenoid 20, and then the second solenoid 19. of
ON, the rotor 72 is rotated clockwise in FIG. 3, and the rear wheel is rotated clockwise. Then, when the steering angle of the steering wheel is below a certain level, solenoid 2
0, the second solenoid 19 turns OFF and the rotor 7
2 reverses and the rear wheels 6 return to neutral.

Next, when the vehicle speed is below a predetermined value and the steering wheel is rotated, for example, to the right by a certain amount or more and the rear wheels 6 are steered to the left (counterclockwise) in FIG. 2, the controller detects that the vehicle speed has exceeded a predetermined value. 12 makes a judgment based on the signal from the vehicle speed sensor 15, turns off the solenoid 20, and then turns off the first solenoid 18.
is turned OFF, and the rotor 72 rotates clockwise in Figure 2.
The wedge 76 fits into the recess 78 and the rotor 72 returns to neutral.

Note that even if the vehicle speed exceeds a predetermined value and the steering wheel is rotated more than a certain amount while the vehicle is running, the rear wheels 6 will not be steered.

Therefore, since the rotary actuator 7 is provided on the axle 3 around the king pin 4 and is located in the back space of the rear wheel 6, there is no need to provide a housing portion on the underside of the vehicle body. Further, since the rotary actuator 7 directly rotationally drives the king pin 4 using hydraulic pressure, no steering torque reaction force is generated on the axle 3, and no force is applied to the axle 3 in the vehicle width direction. Further, since the rotary actuator 7 returns the rotor 72 to the neutral state by the biasing force of the springs 79 and 80 of the wedge 76, the return operation is reliable. Further, when the wedge 76 is inserted into the recess 78, the small taper portion 763 is inserted into the recess 78.
Since the wedge 76 and the rotor 72 are brought into contact with the side 782, no backlash occurs between the wedge 76 and the rotor 72, and the rear wheel 6 can be reliably held in a straight-ahead state when not being steered. Further, the straight portion 761 of the wedge 76 is inclined with respect to the rotation direction of the rotor 72, and when the rotor 72 tries to rotate, the straight portion 761 is pressed by the first side 781 toward the king pin 4, so that the wedge 76 is in a straight traveling state. Even if a rotational force is applied to the rotor 72 due to an impact force from the rear wheel 6, the wedge 76
The rotor 72 reliably maintains a state in which rotation is prohibited. Furthermore, when the wedge 76 enters the recess 78, the large taper part 764 first presses the rotor 72, but since the large taper part 764 and the curved part 783 of the rotor 72 are in point contact, the wedge 76 and the rotor 72 The frictional force with the second side 782 is small, and the small tapered portion 763
When the small taper portion 763 makes contact with the axis of the wedge 76 in the moving direction, the force for rotating the rotor 72 is weak even if the contact is a line contact, so the spring that presses the wedge 76 The biasing forces 79 and 80 may be small. In addition, since the king pin 4 is fixed to the rotor 72 via the serrations 41, the king pin 4 can be inserted from the lower side of the knuckle 5 through the rotor 72 to the upper side of the knuckle 5 during assembly. 5 is of integral construction, sufficient strength can be maintained. Further, the thrusting force from the tread applied to the rear wheel 6 is applied to the king pin 4 via the knuckle 5, but this is supported by the tapered roller bearing 82, and the downward pushing force of the case 71, which is a reaction force to the thrusting force, is also applied to the kingpin 4. Since the tapered roller bearing 82 supports,
The rotary actuator 7 can support the force from the road surface without twisting the king pin 4.

The second embodiment shown in FIG. 7 is a modification of the stator 73 in the first embodiment.
It has a second piston 731, 732, and a first piston,
A first chamber 74' and a second chamber 75' are provided between the second pistons 731, 732 and the stator 73, and by forming the first and second pistons 731, 732 into substantially cylindrical shapes, the piston 731, 73
Since the oil seals provided at 2 and 2 can have a circular diameter like an O-ring, the cost is reduced.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view showing the first embodiment of the present invention, FIG. 2 is an enlarged view of FIG. A control circuit diagram of the embodiment, FIG. 5 is an enlarged sectional view of the main part of the first embodiment, FIG. 6 is an enlarged sectional view of the main part of the first embodiment, and FIG.
The figure is a sectional view of a main part showing a second embodiment of the present invention. 3... Axle, 4... King pin, 5... Nutacle, 6... Rear wheel, 7... Rotary actuator, 72... Rotor, 74... First chamber, 75...
...Second chamber, 76...Wedge, 79, 80...Spring, 42...Oil passage, 81...Ball bearing, 82...Taper roller bearing, 9...Position sensor, 10...4-way switching valve, 11... Three-way switching valve, 12... Controller, 15... Vehicle speed sensor, 17... Steering wheel angle sensor, 18, 19, 2
0...Solenoid.

Claims (1)

[Scope of utility model registration request] A power steering device for a vehicle, comprising a nut that rotatably supports a wheel, a king pin fixed to the nut and rotatably mounted on a suspension system of a vehicle, and an actuator provided on the suspension system and rotatably driving the king pin. The actuator is formed between a rotor rotatably disposed in a casing to which the suspension device is fixed and fixed to the king pin, a stator provided in the casing, and the rotor and the stator. and a neutral holding wedge provided in the casing and formed so as to be insertable into and removed from the recess of the rotor; The wedge is formed into a tapered shape, and further includes a hydraulic pressure supply means for selectively supplying and controlling the supply of hydraulic pressure to the first or second chamber, a drive means for driving and controlling the wedge, and a hydraulic supply means for controlling the drive of the wedge according to the operation of the handle. A power steering device for a vehicle, comprising a control means for controlling the operation of the drive means.