JP3156519B2 - Alignment control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alignment control device for a vehicle suspension system, and more particularly to an input device for inputting an excessive road surface.
This is to prevent the internal pressure of the drive system of the actuator for changing the caster angle of the wheel from becoming abnormally high.

[0002]

2. Description of the Related Art Conventionally, there has been known a vehicle suspension device including an actuator for changing an arm length of a specific suspension arm, a vehicle body mounting position, and the like, and a controller for controlling the actuator. When the controller drives the actuator, the positional relationship between the arms and struts of the suspension device changes, and therefore, the alignment of the suspension device, that is, the caster angle and trail of the suspension device, the toe angle and camber angle of the wheel, and the like. Changes. The controller positively operates the alignment according to the running state of the vehicle to improve the straight running stability and the turning stability of the vehicle.

[0003] The caster angle is extremely important in terms of steering performance and running stability. When the caster angle is increased, the restoring moment for returning to the straight running position when the wheels deviate from the straight running position during running increases. The running stability during running is improved. In view of the above, various alignment control devices for varying the caster angle by driving an actuator have been conventionally proposed (for example, Japanese Patent Publication No. Sho 62-316).
No. 41). In a conventional alignment control device, a main body of a hydraulically operated actuator is supported on a vehicle body via a bush, and an end of an operating rod of the actuator is connected to a wheel side. Then, the actuation rod reciprocates by driving the actuator to change the caster angle,
For example, by making the caster angle variable according to the vehicle speed, steering easiness during middle-to-low speed running and steering response during high-speed running are obtained, and steering performance and high-speed running stability are improved. .

[0004]

In the conventional alignment control device, the caster angle is changed by driving the actuator, the pressure oil is fixed in the system while the pressure oil is filled in the actuator, and the caster angle is maintained. ing. For this reason, even if external force acts, it is not necessary to apply pressure oil to maintain the caster angle, and energy saving is achieved. However, if there is excessive input from the wheel side, such as when riding on a curb while traveling, the pressure in the hydraulic path of the actuator becomes abnormally high, causing a large impact and possibly damaging the actuator and piping. was there.

The present invention has been made in view of the above circumstances, and provides an alignment control device that prevents an internal pressure of a drive system of an actuator for changing a caster angle of a wheel from being abnormally high when an excessive road surface is input. With the goal.

[0006]

[MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
According to the present invention, an actuator that changes the caster angle of the wheel, a driving unit that operates the actuator, and a target caster angle calculated based on the running state of the vehicle and the actual caster angle is set to the target caster angle Control means for operating the actuator so as to be provided, and a valve member provided between the actuator and the driving means and allowing only the flow of a driving source from the actuator to the driving means side. Features.

That is, according to the present invention, the cylinder body divided into the first hydraulic chamber and the second hydraulic chamber by the piston is provided, and the operating rod connected to the wheel side is connected to the piston to reduce the caster angle of the wheel. An actuator to be changed, a driving means including a hydraulic pump and a hydraulic tank, and supplying pressure oil to the actuator to operate the actuator, and a caster angle calculated based on a running state of the vehicle to calculate a target caster angle. Control means for operating the actuator so that the angle becomes the target caster angle; and a control means interposed between the hydraulic chamber and the hydraulic tank of the cylinder body and from the hydraulic chamber side to the hydraulic tank side. A valve member that allows only the flow of pressure oil to the first hydraulic chamber and the actuator that communicates the first hydraulic chamber with the second hydraulic chamber. A disc valve is formed in the piston, and a disc valve that allows the flow of the pressure oil through the orifice from only one of the first hydraulic chamber and the second hydraulic chamber is provided on the second side on the side where the pressure oil flows. A second hydraulic chamber or the first hydraulic chamber provided in the second hydraulic chamber or the first hydraulic chamber, and the second hydraulic chamber or the first hydraulic chamber on the side where the disc valve is provided is communicated with the valve member.

The actuator is provided for each of the left and right front wheels, while the valve member has two input ports and one output port, and the second hydraulic chamber or the second hydraulic chamber of one of the actuators is provided. One hydraulic chamber is connected to one input port of the valve member, and the second hydraulic chamber or the first hydraulic chamber of the other actuator is connected to the other input port of the valve member. An output port communicates with the hydraulic tank side.

[0009]

According to the above construction , the driving means is driven by the control means in accordance with the running state of the vehicle, and the actuator is operated to change the caster angle to the target caster angle.
If there is an excessive road surface input from the wheel side, the valve member allows only the flow of the drive source from the actuator to the drive means side, returns the drive source to the drive means side, and absorbs the excessive road surface input.

That is, according to the present invention, when there is an excessive road surface input from the wheel side, the internal pressure of the first hydraulic chamber or the second hydraulic chamber increases, and the pressure is applied from the orifice to the hydraulic chamber on the side where the disk valve is provided. Oil flows into the hydraulic chamber through the valve member from the hydraulic chamber on the side where the disk valve is provided, and is guided to the hydraulic tank, and the valve member connected to one of the first hydraulic chamber and the second hydraulic chamber causes an excessive road surface. The input is absorbed in the system of pressure oil. Further, when there is an excessive road surface input from the wheel side, the pressure oil flows into the respective input ports of the one valve member from the hydraulic chamber on the side where the disk valves of the actuators corresponding to the left and right front wheels are provided, and flows in. The pressure oil is guided from the output port to the hydraulic tank, and the road surface input is absorbed in the pressure oil system by one valve member.

[0011]

1 is a schematic configuration of an alignment control apparatus according to an embodiment of the present invention. FIG. 2 is a hydraulic circuit of an actuator. FIG.
FIG. 4 shows details of the damping valve, FIG. 5 shows the flow state of the pressure oil of the variable damping valve constituting the damping valve, FIG. 6 shows the performance of the variable damping valve, and FIGS. The description of the operation of the variable valve is shown. The suspension device 1 shown in FIG. 1 is, for example, a multi-link type suspension device in which left and right front wheels are respectively connected to a vehicle body (not shown). FIG. 1 shows a suspension device 1 for connecting, for example, a left front wheel (hereinafter referred to as a wheel) 2 to a vehicle body side.

As shown in FIG. 1, a suspension device 1
A knuckle 3 for rotatably supporting the wheel 2 and an upper arm 4 for connecting the extension 3a of the knuckle 3 to the vehicle body side.
And lower arms 5, 6 for connecting the lower end of the knuckle 3 to the vehicle body side. An actuator 7 is interposed between the lower arm 5 and the vehicle body, and the caster angle θ of the wheel 2 is set to a desired angle by the operation of the actuator 7. The hydraulic pressure is supplied to the actuator 7 from a hydraulic pressure source 9 by switching a flow control valve (electromagnetic valve) 8, and the electromagnetic valve 8 performs a switching operation based on a control voltage commanded by an ECU 10 as control means. That is, the driving means is constituted by the solenoid valve 8 and the hydraulic pressure source 9. The ECU 10 includes a vehicle speed sensor 11, a steering wheel angle sensor 12, a lateral acceleration sensor (lateral G sensor) 13, and a longitudinal acceleration sensor (longitudinal G sensor).
The information from the sensor 14 is input. The ECU 10 reads the steering wheel angle, the steering wheel angular velocity, the front / rear G, and the left / right G based on the information obtained from the sensors 11 to 14, and calculates and reads the lateral acceleration (calculated lateral g). The ECU 10 calculates and reads a road surface friction coefficient (road surface μ) based on the hydraulic pressure of a power steering device (not shown). Further, information from a stroke sensor 15 that detects the operation stroke of the actuator 7 is input to the ECU 10. ECU10
Then, handle angle, handle angular velocity, front and rear G, left and right G,
A target caster angle as a target is calculated based on the calculated lateral g and the road surface μ, and a control command is output from the ECU 10 to the electromagnetic valve 8 so as to operate the actuator 7 so that the caster angle θ becomes the target caster angle. Then, feedback control is performed based on information on the operation stroke of the actuator 7.

The hydraulic circuit of the actuator 7 will be described with reference to FIG. Actuators 7 are provided on both the left and right wheels. For the front left wheel, L is added to the code, and for the front right wheel, the code is R.
The description will be made with reference to FIG. The hydraulic source 9 is provided with tandem-type oil pumps 21 and 22, and the oil in the hydraulic tank 23 is pumped by driving the oil pumps 21 and 22. One oil pump 21 is connected to a P / S valve 24 for power steering.
The power cylinder 25 is operated via the P / S valve 24. The other oil pump 22 is connected to the solenoid valve 8 by an oil passage 28 through a check valve 26 and an accumulator 27.
L, 8R are connected to the pressure side ports of the solenoid valves 8L, 8R.
The return port is connected to an oil passage 29, and the return port is connected to the hydraulic tank 23 by the oil passage 29.
The first output port is connected to each of the two output ports of the solenoid valves 8L and 8R.
The oil passage 30 and the second oil passage 31 are connected to each other,
The oil passage 30 and the second oil passage 31 are connected to the actuators 7L and 7R.
It is connected to the. In the illustrated example, a P / P for power steering is
The oil was pumped to the S valve 24 and the solenoid valves 8L and 8R. However, one oil pump was
It is also possible to connect the P / S valve 24 and the solenoid valves 8L and 8R.

The structure of the actuator 7 will be described with reference to FIGS. The actuator 7 includes a mount rubber 19 having a body 32 in which a large-diameter arm support portion 33 and a small-diameter cylinder body 34 are connected, and mounted between a pair of flanges formed on the outer peripheral surface of the arm support portion 33. And is fixed to the vehicle body side through. The cylinder body 34 is
The space between 5 and the end cap 36 is partitioned into a first hydraulic chamber 38 and a second hydraulic chamber 39 by a piston 37, and a base end of an operating rod 40 is fixed to the piston 37. The distal end of the operating rod 40 slidably penetrates the partition wall 35 and protrudes into the arm support 33, and the distal end of the operating rod 40 is connected to the lower arm 5 (see FIG. 1) of the wheel. A first port 41 of the first hydraulic chamber 38 has a first oil passage 30
The second oil passage 31 is connected to the second port 42 of the second hydraulic chamber 39. When the solenoid portions 8a of the solenoid valves 8L and 8R are excited, the pressure side port and the return side port are switched so as to be selectively communicated with the first oil passage 30 and the second oil passage 31.

That is, when the oil passage 28 connected to the pressure side port communicates with the first oil passage 30 by switching of the solenoid valves 8L and 8R, and the oil passage 29 connected to the return side port communicates with the second oil passage 31. Pressure oil is supplied to the first hydraulic chamber 38 and oil is supplied from the second hydraulic chamber 39 to the hydraulic tank 23.
The operating rod 40 moves in the direction of arrow A in FIG. 3, for example, toward the rear side of the vehicle via the piston 37, so that the caster angle is reduced. Also, the solenoid valve 8L,
If the path is connected in reverse by switching 8R, the second
Pressure oil is supplied into the hydraulic chamber 39 and the first hydraulic chamber 38
Oil is discharged from the inside to the hydraulic tank 23, and the operating rod 40 moves in the direction of arrow B in FIG. 3 (the front side of the vehicle) via the piston 37, so that the caster angle increases. The oil passage 2 is switched by switching the solenoid valves 8L and 8R.
In a case where the second and third hydraulic passages 8 and 29 do not communicate with either the first hydraulic passage 30 or the second hydraulic passage 31, the hydraulic oil in the first hydraulic chamber 38 and the second hydraulic chamber 39 is locked, and the operating rod 40 is fixed. In this state, the caster angle is fixed.

As shown in FIG. 3, an orifice 43 communicating with a first hydraulic chamber 38 and a second hydraulic chamber 39 is formed in the piston 37, and an orifice 43 is formed in the first hydraulic chamber 38.
Is provided only from the first hydraulic chamber 38 side. When the pressure in the first hydraulic chamber 38 increases, the orifice 43 is closed by the disc valve 44, and the pressure oil flows from the first port 41 to the first oil passage 30. When the pressure in the second hydraulic chamber 39 increases, the pressure oil from the orifice 43 presses the disk valve 44, and the disk valve 44 moves to the left in the drawing, and the second hydraulic chamber 39
The internal pressure oil flows into the first hydraulic chamber 38, and the pressure oil flows from the first port 41 to the first oil passage 30 as described above. That is,
The disc valve 44 provided in the first hydraulic chamber 38 on the side where the pressure oil flows in allows the flow of the pressure oil through the orifice 43 only from the second hydraulic chamber 39 side. As shown in FIG. 2, the first of each of the actuators 7L and 7R
Each first oil passage 30 connected to the hydraulic chamber 38 is connected to a branch oil passage 51, and each branch oil passage 51 is connected to the input side of one damping valve 52. An oil passage 53 is connected to the output side of the damping valve 52, and the oil passage 53 is connected to the hydraulic tank 2.
3 is connected to an oil passage 29.

The damping valve 52 will be described with reference to FIGS. As shown in FIG. 4, the damping valve 52 is configured such that a check valve 54 as a valve member and a damping force variable valve 55 are arranged in series.

Referring to FIG. 4, the check valve 54 as the valve member of the present invention will be described. Two input passages 56 are formed in the check valve 54, and each of the input passages 56 is connected to the branch oil passage 51. Each input passage 56
The valve body 57 communicates with one valve chamber 57, and a pair of valve bodies 59 for closing the respective communication ports 58 are provided in the valve chamber 57. The pair of valve bodies 59 are respectively connected to the communication ports 5 by compression springs 60.
The communication port 58 is normally closed by a valve body 59 by the urging force of the compression spring 60. The size of the valve chamber 57 is changed by adjusting the screw portion 61, and the urging force of the compression spring 60, that is, the valve body 59
Can adjust the force to close the communication port 58. on the other hand,
Each input passage 56 is connected to the inlet 62 of the variable damping force valve 55, and the valve chamber 57 is connected to the hydraulic tank 23 (see FIG. 2) through the return chamber 64 of the flow path 63 of the variable damping force valve 55. It is connected to road 53. That is, when the pressure oil in the branch oil passage 51 becomes high pressure in a state where the inlet portion 62 of the damping force variable valve 55 is closed, the valve body 59 is pressed against the high pressure oil against the urging force of the compression spring 60. The communication port 58
Is opened, and the high-pressure oil flows from the valve chamber 57 to the damping force variable valve 5.
5 is returned to the hydraulic tank 23 through the return chamber 64 and the oil passage 53, and the check valve 54 allows the flow of the pressure oil to the hydraulic tank 23 side.

The variable damping force valve 55 will be described with reference to FIGS. The flow path 63 of the damping force variable valve 55 has two inlet portions 62 as input ports and an output port 65.
The output port 65 is provided with a hydraulic tank 23.
The oil passage 53 connected to the side is connected. A spool 66 is slidably provided in the flow path 63.
6 is a spring 68 when the solenoid 67 is excited.
Is moved against the urging force. The spool 64 is provided with a large-diameter portion 69 that closes the two inlet portions 62 and a small-diameter portion 70 that forms a return chamber 64 for connecting the valve chamber 57 of the check valve 54 to the oil passage 53. A passage 71 is formed in the axis of the spool 66, and the passage 71 is provided with an opening 72 communicating with the return chamber 64. Also, the passage 71
Is provided with an opening 73 which communicates with the inlet 62 when the spool 66 is moved and the closing of the inlet 62 by the large diameter portion 69 is opened. As shown in FIG. 5, when the inlet 62 is open, the pressure oil from the input passage 56 of the check valve 54 is supplied to the inlet 6 as indicated by an arrow in the drawing.
2 to the passage 71 through the opening 73 and the opening 7
2 through the return chamber 64 to the hydraulic tank 23 (see FIG. 2).
Is returned to.

As shown in FIG. 5, a variable orifice part 74 is formed in the large diameter part 69 of the spool 66,
The opening area of No. 2 changes according to the moving position of the spool 66. The amount of movement of the spool 66 is regulated by the control current i (A) for the solenoid 67. FIG. 6 shows a relationship between an equivalent orifice area, which is an opening area of the inlet 62 corresponding to the moving position of the spool 66, and a control current i (A) for the solenoid 67. As shown in the figure, when the control current i is 0 (A), the equivalent orifice area is 0 (A).
(The inlet section 62 is closed by the large diameter section 69)
The spool 66 moves to the position shown in FIG. When the control current i is 1.0 (A), the spool 66 moves against the biasing force of the spring 68 in a state where the equivalent orifice area is maximized (a state in which the inlet 62 is opened by the variable orifice 74) ( The state shown in FIG. 8). When the control current i is 0.5 (A), the spool 66 resists the urging force of the spring 68 in a state where the equivalent orifice area is about 20% of the maximum (a state in which the inlet 62 is slightly opened by the variable orifice 74). And move (the state shown in FIG. 7). Excitation of the solenoid 67 of the variable damping force valve 55 is controlled by the ECU 10 by operating the select switch 80 (see FIG. 2).
That is, the select switch 80 always sets the control current i to 0.
(A), the position (HARD), the position (SOFT) where the control current i is always 1.0 (A), and the position (AUTO) where the control current i is variable according to the running state of the vehicle. Can be selected.

When the caster angle is fixed, that is, when the hydraulic fluid in the first hydraulic chamber 38 and the second hydraulic chamber 39 shown in FIG. The operation when the section 62 is opened by the variable orifice section 74 will be described. In this state, for example, when there is an input from the wheel side while traveling forward on an uneven road, the operating rod 40 moves in the direction of the arrow A in FIG. 3 (the second hydraulic chamber 39 side). When the operating rod 40 moves to the second hydraulic chamber 39 side, the high-pressure hydraulic oil passes through the orifice 43 and presses the disc valve 44, and the hydraulic oil in the second hydraulic chamber 39 enters the first hydraulic chamber 38. Inflow. The pressure oil that has flowed into the first hydraulic chamber 38 is sent to the inlet 62 of the variable damping force valve 55 through the branch oil passage 51 and the check valve 54. Then, the pressure oil sent to the inlet 62 is guided to the passage 71 through the opening 73, returned to the hydraulic tank 23 from the return chamber 64 through the opening 72, and the input from the wheel side is transmitted to the vehicle body. Absorbed without.

When the vehicle travels backward on an uneven road and receives an input from the wheel side, the operating rod 40 is moved in the direction of arrow B in FIG.
(To the hydraulic chamber 38 side). When the operating rod 40 moves to the first hydraulic chamber 38 side, the orifice 43 is closed by the disc valve 44, and the high-pressure hydraulic oil passes through the branch oil passage 51 and the check valve 54 and enters the inlet of the damping force variable valve 55. 62, and is returned from the damping force variable valve 55 to the hydraulic tank 23 as described above, and the input from the wheel side is absorbed without being transmitted to the vehicle body. As described above, the pressure oil from the actuator 7 side due to the road surface input can be released to the hydraulic tank 23 by one damping force variable valve 55 regardless of whether the vehicle is traveling forward or backward.

When the caster angle is fixed,
The operation when the inlet 62 is closed by the large diameter portion 69 will be described. In this state, even if there is an input from the wheel side as described above, since the inlet portion 62 of the damping force variable valve 55 is closed, the pressure oil in the first hydraulic chamber 38 or the second hydraulic chamber 39 The input from the wheel side is not returned to the tank 23 and is absorbed in the pressure oil system of the actuators 7L and 7R. Accordingly, by changing the equivalent orifice area of the inlet portion 62 by the variable orifice portion 74 by changing the control current i for exciting the solenoid 67, the actuators 7L and 7R can be changed from a state in which the input from the wheel side is completely absorbed.
Thus, the state of absorbing the input from the wheel side can be arbitrarily changed to a state in which the pressure oil is absorbed in the system.

The control current i (A) for the solenoid 67 in the above-described alignment control device is fixed and set to a constant value according to the driver's intention, or is automatically set to an arbitrary value according to the running state of the vehicle and road surface conditions. Settings. In other words, when the control current i (A) is fixed to a constant value according to the driver's intention, the input from the wheel side is completely absorbed so as not to be transmitted to the vehicle body, and priority is always given to riding comfort,
The input from the wheel side is absorbed only in the system of the actuator 7, and the responsiveness of the change of the caster angle by the actuator 7 is always improved so that the motion performance of the vehicle can be prioritized. In addition, when the control current i (A) is automatically set to an arbitrary value according to the running state of the vehicle or the road surface condition, when the caster angle control is performed by the operation of the actuator 7, the pressure oil is prevented from coming off. When the caster angle control with good responsiveness is performed and the caster angle control by the operation of the actuator 7 is not performed, the equivalent orifice area of the damping force variable valve 55 is changed according to the vehicle speed, the calculated lateral g, the road surface condition, and the like. Adjustment is performed to obtain a damping force according to the running state of the vehicle, so that the responsiveness of the caster angle control and the riding comfort are compatible.

Next, the operation of the alignment control device having the check valve 54 as the valve member of the present invention will be described. Fixed caster angle and variable damping force valve 5
A description will be given of a case where a large input (for example, a case where the user rides on a curb) is input from the wheel side while the entrance portion 62 of No. 5 is closed by the large-diameter portion 69. When the vehicle travels forward and there is a large input from the wheel side due to the curb ride,
The operating rod 40 is moved in the direction of arrow A in FIG.
Side). The operating rod 40 is in the second hydraulic chamber 3
9 moves to the orifice 43.
Presses the disc valve 44 through the second hydraulic chamber 39
The internal pressure oil flows into the first hydraulic chamber 38. First hydraulic chamber 3
The pressure oil flowing into the inside 8 is sent from the branch oil passage 51 to the check valve 54, and the pressure oil pushes the valve body 59 against the urging force of the compression spring 60 to open the communication port 58. When the communication port 58 is opened, the pressure oil flows from the valve chamber 57 to the return chamber 64 of the damping force variable valve 55.
The oil is returned to the hydraulic tank 23 through the oil passage 53, so that no excessive load is generated in the hydraulic system. At this time, the damping force variable valve 5
Even if the inlet port 62 of the inlet port 5 is open, if high-pressure oil exceeding the flow rate of the inlet port 62 is generated, the pressure oil is returned from the check valve 54 to the hydraulic tank 23 via the damping force variable valve 55, and This prevents damage to the hydraulic system.

When the vehicle travels backward and gets a large input from the wheel side due to climbing on a curb, the operating rod 40 largely moves in the direction of arrow B in FIG. 3 (the first hydraulic chamber 38 side). When the operating rod 40 moves toward the first hydraulic chamber 38, the orifice 43 is closed by the disc valve 44, and the high-pressure hydraulic oil is sent from the branch oil passage 51 to the check valve 54. Then, as described above, the valve body 59 is pushed by the pressure oil to open the communication port 58, and the pressure oil is returned to the hydraulic tank 23 via the damping force variable valve 55, so that no excessive load is applied to the hydraulic system.

As described above, since the check valve 54 as the valve member of the present invention is provided, the pressure oil from the actuator 7 side due to the excessive input can be reduced to one, regardless of whether the vehicle is traveling forward or backward. Check valve 54
This allows the oil to escape to the hydraulic tank 23. Also,
Even if external force is applied to the left and right wheels at the same time, the hydraulic oil from the actuator 7 side is
3 can escape. Therefore, when the caster angle is fixed and the hydraulic pressure is in the locked state, even if there is an excessive input and the pressure oil becomes high due to excessive input, such as when riding on a curb, the pressure oil can be reliably released, and the caster angle control can be performed. The normal function can be maintained without fear of the hydraulic system being damaged.

FIG. 9 shows the state of the impact and the pressure of the pressurized oil when an excessive input is made due to a curb climbing or the like. The solid line in the drawing shows the case where the check valve 54 of the present invention is provided, and the dotted line in the drawing shows the case where the check valve 54 is not provided. As can be seen from the figure, the provision of the check valve 54 reduces the impact by about half and drastically reduces the pressure of the pressure oil.

In the above-described embodiment, the damping valve 52 is connected to the first oil passage 30 of the first hydraulic chamber 38 of the actuators 7L and 7R via the branch oil passage 51. It is also possible to connect the damping valve 52 to the two oil passages 31. In this case, the disc valve 44 needs to be provided in the second hydraulic chamber 39 so that the pressure oil flows into the second hydraulic chamber 39. Further, the damping valve 52 can be connected to each of the first hydraulic chamber 38 and the second hydraulic chamber 39. In the above-described embodiment, the check valve 54
In addition to the above description, the one provided with the variable damping force valve 55 has been described, but the variable damping force valve 55 does not necessarily have to be provided .

In the above-described alignment control device, the actuator 7 for controlling the caster angle is moved from the hydraulic tank 23 to the hydraulic tank 23.
By providing the check valve 54 that allows only the flow to the hydraulic tank 23, when a large pressure rise occurs in the hydraulic chamber of the actuator 7 due to an excessive input from the wheel side, the hydraulic oil is returned to the hydraulic tank 23. Excessive input can be absorbed. An orifice 43 is provided in the piston 37 of the actuator 7, and a disc valve 44 is provided in the first hydraulic chamber 38.
Is provided to allow the pressure oil to pass through the orifice 43 only from the second hydraulic chamber 39 to the first hydraulic chamber 38, and the first hydraulic chamber 38 communicates with the check valve 54. Regardless of which side of the cylinder 39 is compressed, the high pressure oil generated by the excessive input is guided to the check valve 54. For this reason, even if there is a large input from the wheel side irrespective of the front-rear direction, the excessive input can be absorbed by one check valve 54, and the damage to the hydraulic system can be prevented and the normal function can be maintained. . Further, since the check valve 54 is provided with two input ports, even if there is a large input from the wheel side at the right or left or right and left, an excessive input can be absorbed by one check valve 54. Further, as the damping valve 52,
Since the check valve 54 and the damping force variable valve 55 are provided in series, complicated piping is unnecessary and the cost is low.

Further, in the above-described alignment control device, the variable damping force valve 55 is provided to enable the fluid to flow from the actuator 7 for controlling the caster angle to the hydraulic tank 23. 7, when the pressure rises, the pressure oil can be returned to the hydraulic tank 23 to absorb road surface input without impairing the motility improvement by the caster angle control, thereby improving the riding comfort and the motility by the caster angle control. Can be achieved in a higher dimension.

According to the above-described alignment control device ,
A valve member that allows only the flow from the actuator that controls the caster angle to the drive means side is provided, and when there is a large pressure increase in the actuator due to excessive input from the wheel side, the drive source in the actuator is switched to the valve member. , It is possible to absorb an excessive input from the wheel side transmitted to the actuator. As a result,
Excessive road surface input transmitted through an actuator that controls the caster angle can be absorbed, and impact can be reduced to prevent damage to the actuator, piping, and the like. Further, when the caster angle is controlled by the operation of the actuator, the flow of the drive source to the drive means side by the valve member is not performed, so that the caster angle control can be performed with good responsiveness. For this reason, the improvement of the mobility by the caster angle control is not impaired. As a result, in the alignment control device of the present invention, it is possible to achieve a high degree of improvement in ride comfort and mobility through caster angle control.

[0033]

[Effect of the Invention The present onset Ming alignment controller a valve member which allows only the flow from the actuator to control the caster angle to the driving unit side is provided, an orifice provided in the piston of the actuator, the first hydraulic chamber or the (2) A disk valve is provided in the hydraulic chamber so that the pressure oil passes through the orifice only to the hydraulic chamber on the side where the disk valve is provided,
Since the hydraulic chamber is communicated with the check valve, high-pressure hydraulic oil generated by an excessive input is guided to the check valve regardless of which side of the first hydraulic chamber or the second hydraulic chamber is compressed.
As a result, even if there is a large input from the wheel side regardless of the direction of the front and rear inputs, a single check valve can absorb the excessive input, and a simple mechanism prevents the hydraulic system from being damaged, thus preventing normal functions. Can be maintained. Also, since the check valve has two input ports, even if there is a large input from the wheel side at the left or right or left and right at the same time, one check valve can absorb excessive input and complicate piping etc. It is possible to surely absorb the excessive input without performing.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an alignment control device according to an embodiment of the present invention.

FIG. 2 is a hydraulic circuit diagram of an actuator.

FIG. 3 is a detailed view of a cylinder body of the actuator.

FIG. 4 is a detailed view of a damping valve.

FIG. 5 is an explanatory diagram of a flow state of pressure oil of a damping force variable valve constituting the damping valve.

FIG. 6 is a diagram illustrating the performance of a variable damping force valve.

FIG. 7 is an explanatory view of the operation of the variable damping force valve.

FIG. 8 is an explanatory view of the operation of the variable damping force valve.

FIG. 9 is a graph showing the state of impact and pressure of pressurized oil at the time of excessive input.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Suspension device 2 Wheel 3 Knuckle 4 Upper arm 5, 6 Lower arm 7 Actuator 8 Flow control valve (solenoid valve) 9 Hydraulic power source 10 ECU 11 Vehicle speed sensor 12 Handle angle sensor 13 Left and right G sensor 14 Front and rear G sensor 15 Stroke sensor 22 Oil pump 23 Hydraulic tank 34 Cylinder main body 37 Piston 38 First hydraulic chamber 39 Second hydraulic chamber 40 Operating rod 43 Orifice 51 Branch oil path 52 Damping valve 54 Check valve 55 Damping force variable valve 56 Input passage 57 Valve chamber 58 Communication passage 59 Valve body 62 Inlet 64 Return chamber 65 Output port 66 Spool 67 Solenoid 71 Passage 74 Variable orifice

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-87813 (JP, A) JP-A-3-25015 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60G 17/015

Claims (2)

(57) [Claims] A first hydraulic chamber and a second hydraulic pressure are provided by a piston.
With a cylinder body divided into a chamber and on the wheel side
An operating rod to be connected is connected to the piston to
An actuator for changing the caster angle, a hydraulic pump and
And pressurized oil to the actuator
Driving means for operating the actuator, and running of the vehicle
Calculates the target caster angle based on the state and calculates the actual key.
So that the caster angle becomes the target caster angle.
Control means for operating an actuator, and the cylinder
Interposed between the hydraulic chamber of the main body and the hydraulic tank
Together with the flow of pressure oil from the hydraulic chamber side to the hydraulic tank side.
And a valve member that permits only the actuator,
An orifice for communicating the first hydraulic chamber and the second hydraulic chamber
Pressure oil is formed in the piston and passes through the orifice
Flow through either the first hydraulic chamber or the second hydraulic chamber
The disc valve that allows only from the side where the pressure oil flows
Provided in the second hydraulic chamber or the first hydraulic chamber, and
The second hydraulic chamber on the side where the valve is provided or the
A first hydraulic chamber communicating with the valve member;
Light control device. 2. The actuator according to claim 1, further comprising :
The valve member has two inputs.
Power port and one output port.
The second hydraulic chamber or the first hydraulic chamber of the tutor
Connected to one input port of the valve member and the other
The second hydraulic chamber or the second hydraulic chamber of the actuator
1 Connect the hydraulic chamber to the other input port of the valve member,
Connect the output port of the valve storage member to the hydraulic tank side.
2. The alignment control device according to claim 1, wherein
Place.