JPH02106421A - Vehicle attitude control device - Google Patents

Abstract

PURPOSE:To perform stabilized, smooth attitude control at any time without using sensors or the like by using an oil flow control valve interlocked to the vertical movements of a lower arm to control the flow rate of oil to a hydraulic actuator disposed in series together with a suspension spring. CONSTITUTION:When the left wheel axle load increases at the time of for example a right turn of a vehicle, a suspension spring 18 is compressed and the vehicle height on the left side decreases. Namely a lower arm 14 centered on a pivot 15 moves upward, a bell crank 23 rotates clockwise about a pivot 24, and a spool 32 of an oil flow rate control valve 30 moves to the left. The pressure oil from a hydraulic pump 36 is supplied via pipes 37, 28, etc. to an upper end chamber 2 of a hydraulic actuator A while the oil in the lower end chamber 3 is returned via pipes 29, 34 to an oil tank 35. As a result, a piston 5 projects downward and the lower arm 14 is pushed back. As a result, the sinking of the vehicle body on the left side is eliminated.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a vehicle body attitude control device.

[Prior Art] A conventional vehicle body posture control device electrically detects the vehicle height of each wheel using a vehicle height sensor, drives an electromagnetic actuator or motor based on the detection result of the vehicle height sensor, and uses hydraulic or pneumatic Controls the actuator's fluid circuit. In this device, one end of the vehicle height sensor is connected under the spring, so it has the disadvantage that it is susceptible to damage due to vibration and error movement due to the influence of electromagnetic waves.

As disclosed in Japanese Unexamined Patent Publication No. 51-43159, there is also a system that mechanically detects changes in vehicle height and directly drives a hydraulic valve, but in this technology, a hydraulic actuator controls the vehicle height. The problem is that the response to changes in vehicle height is poor because it only works to raise the vehicle height, and the operation to lower the vehicle height is dependent on the vehicle weight.

[Problems to be Solved by the Invention] The purpose of the present invention is to provide a system in which an oil flow control valve is mechanically driven in response to changes in vehicle height, is not affected by vibrations or electromagnetic waves, and has excellent ability to follow changes in road surface. An object of the present invention is to provide an all device for controlling the posture of a vehicle body.

[Means for Solving the Problem] In order to achieve the above object, the structure of the present invention is to reduce the amount of oil that operates in conjunction with the vertical movement of the lower arm that is pivotably supported on the vehicle body and supports the knuckle of the wheel at the tip. With the control valve,
This adjusts the amount of oil in both end chambers of a hydraulic actuator that is arranged in series with a suspension spring between the vehicle body and the lower arm.

[Function] For example, when the wheel 40 is lifted up due to a change in the road surface, the
The arm 14 rotates upward around the support shaft 15, the bell crank 23 accordingly rotates around the support shaft 24, and the spool 32 of the oil amount control valve 30 moves to the left.
Pressure oil is supplied from the hydraulic pump 36 to the upper end chamber 2 of the hydraulic actuator A via the oil 1 control valve 30. Therefore, the rod 6 is pushed down together with the piston 5, and the lower arm 14 is pushed down via the suspension spring 18. In this way, when the lower arm 14 is returned to its original inclination, the oil extraction control well 30 becomes the neutral position, and the lower arm 1 is placed at that position.
4 is maintained, the change in vehicle height due to the vertical movement of the wheels 40 is eventually canceled out, and the vehicle height is always maintained at a substantially constant height.

On the other hand, if the wheel 40 falls into a groove or the like, the oil amount control valve 30 moves in the opposite direction, and the oil is supplied to the upper end chamber 2 of the hydraulic pressure 7 actuator A, thereby canceling out the reduction in vehicle height.

[Embodiments of the Invention] FIG. 1 shows a single wheel suspension system equipped with a vehicle body attitude control device according to the present invention. A support shaft 15 in the longitudinal direction is attached to the vehicle body 1.
The lower arm 14 is tiltably supported, and a knuckle 10 is connected to the tip of the lower arm 14 via a ball joint 12. A wheel 40 is rotatably supported on the knuckle 10. A shock absorber 8 is connected between the lower arm 14 and the bottom of the vehicle body 1, and a suspension spring 18 and a hydraulic actuator A are arranged in series. The hydraulic actuator A has a piston 5 fitted inside a cylinder 4 connected to the bottom of the vehicle body 1, and end chambers 2 and 3 are defined. A rod 6 connected to the piston 5 projects downward, and a suspension spring 18 is interposed between a spring seat 7 connected to the rod 6 and a spring seat of the lower arm 14.

An upper arm 19 is tiltably supported by a support shaft 21 on the side wall of the vehicle body 1, and the tip of the upper arm 19 is connected to a ball joint 9.
is connected to the upper end of the knuckle 10, thereby forming a known double wishbone suspension mechanism. However, the present invention is not limited to this suspension mechanism, but can also be applied to a strut type suspension mechanism.

The oil amount control valve 30 that controls the hydraulic circuit of the hydraulic actuator A is attached to a spool 32 in a housing 31 connected to the vehicle body.
A rod protruding from the spool 32 is connected to the link 26 by a pin 27. The other end of the link 26 is connected to the bell crank 23 by a pin 25.
is connected to one arm of. The bell crank 23 is rotatably supported on the vehicle body by a support shaft 24, and the other arm is attached to a pin 20.
It is connected to link 17 by. The lower end of the link 17 is connected to the intermediate portion of the lower arm 14 by a ball joint 16.

Output ports of the oil quantity control valve 30 are communicated via pipes 28, 29 to the end chambers 2, 3 of the hydraulic actuator A, respectively. Further, the annular grooves on both end sides of the oil amount control valve 30 are communicated with the discharge port of the hydraulic pump 36 via a pipe 37. A hydraulic pressure/flow control valve 38 and a pressure accumulator 39 are connected in the middle of the pipe 37 .

A central annular groove of the oil amount control valve 30 is communicated with an oil tank 35 via a pipe 34.

As shown in Fig. 2, hydraulic actuators AI are installed for each wheel in order to adjust the posture of the entire vehicle body.

A2 , A3 , and A4 are provided, each of which sends pressure oil from the hydraulic pump 36 to one end chamber of the hydraulic actuators A1 to A4 via the oil amount control valve 30, and sends the oil in the other end chamber to the oil tank 35. Configured to return to.

As shown in FIG. 3, the oil amount control valve 30 is
An annular groove 31b is provided at the center of the inner circumferential surface of the
a, 31C are provided, and the annular Fl! 31b and annular groove 31
An output port 28a that communicates with the tube 28 and an output port 29a that communicates with the tube 29 are provided between the tubes 1 and 2. Annular groove 31a
and the annular groove 31c are communicated with the pipe 37, while the annular groove 31
b is communicated with the tube 34. The spool 32 is in the neutral position shown, biased by a spring 33, and the boats 28a, 29a
Annular grooves 32a and 32b are formed which communicate with each other.

Next, the operation of the vehicle body attitude control device according to the present invention will be explained. While the vehicle is traveling straight on a flat road, the lower arm 4 is held at the neutral position shown, the oil amount control valve 30 is also at the neutral position, and the piston 5 of the hydraulic actuator A is held at the neutral position shown. For example, when the vehicle turns right, if the axle load on the left wheel increases due to centrifugal force, the suspension spring 18 is compressed, and the vehicle height on the left side is lowered. That is, the lower arm 14 moves upward around the support shaft 15, the bell crank 23 rotates clockwise in FIG. 1 around the support shaft 24, and the spool 32 of the oil amount control valve 30 moves to the left. do. By moving the spool 32 leftward, the annular groove 32a communicates with the annular groove 31a, and the annular groove 32b communicates with the annular groove 31b. Therefore, pressure oil from the hydraulic pump 36 is supplied to the upper end chamber 2 of the hydraulic actuator A via the pipe 37, the annular grooves 318, 32a, the boat 28a, and the pipe 28,
The oil in the lower end chamber 3 flows through the pipe 29, boat 29a, and annular groove 32.
b31b and is returned to the oil tank 35 via the pipe 34. In this way, the piston 5 protrudes downward and the lower arm 14 is pushed back to the illustrated position, so that the sinking of the left side of the vehicle body is eliminated.

When the lower arm 14 is pushed back to the illustrated position by the hydraulic actuator A, the spool 32 is returned to the illustrated neutral position by the operation of the bell crank 23, the operation of the hydraulic actuator A is stopped at that position, and the vehicle height is reduced to that height. Keep it. When the inclination of the lower arm 14 changes due to changes in the road surface or movement of the axle load, the oil amount control valve 30 operates continuously to cancel this change, and the hydraulic actuator A moves the lower arm 14 from its reference position. It operates to cancel out the change in the slope of .

Conversely, when the lower arm 14 tilts downward due to a decrease in the axle load or the wheel 40 falls into a depression, the spool 32 is pushed to the right by the bell crank 23, and the pressure fluid from the hydraulic pump 36 is pumped to the lower side of the hydraulic actuator A. sent to end room 3,
The piston 5 moves upward, thereby canceling out the change in vehicle height.

Even when the wheel 40 hits a protrusion on the road and is thrown up,
Similarly, the lower arm 14 is pushed back to the illustrated position by the hydraulic actuator A, thereby suppressing changes in vehicle height.

[Effects of the Invention] As described above, the present invention has an oil flow control valve that operates in conjunction with the vertical movement of the lower arm, which is pivotably supported on the vehicle body and supports the knuckles of the wheels at its tip, to control the flow between the vehicle body and the lower arm. The oil volume control valve adjusts the amount of oil in both end chambers of the hydraulic actuator, which is installed in series with the suspension spring. operates, a hydraulic circuit for the hydraulic actuator is formed, and the lower arm is pushed back to the neutral position, thereby suppressing changes in the vehicle height of each wheel and maintaining the vehicle body approximately horizontal.

According to the present invention, the cuff control valve is operated directly in conjunction with the inclination of the lower arm, so compared to the conventional vehicle height sensor that detects changes in vehicle height electrically, the vehicle height sensor is Malfunctions due to damage or electromagnetic waves are avoided,
Smooth and stable posture control is always achieved.

[Brief explanation of drawings]

FIG. 1 is a front sectional view of a vehicle body attitude control device according to the present invention, FIG. 2 is a hydraulic circuit diagram of the vehicle body attitude control device as a whole, and FIG.
The figure is a side sectional view of the oil amount control valve. A: Hydraulic actuator 1: Vehicle body 2.3: End chamber 4
Niji cylinder 5: Piston 14: Lower arm 15:
Support shaft 18: Suspension spring 23: Bell crank 24: Support shaft 30: Oil flow control valve 32 Nisbourg 36: Hydraulic pump 40: Wheel patent applicant Isuzu Motors Co., Ltd.

Claims (1)

[Claims] A hydraulic actuator is installed in series with a suspension spring between the vehicle body and the lower arm using an oil flow control valve that operates in conjunction with the vertical movement of the lower arm, which is pivotably supported on the vehicle body and supports the wheel knuckles at its tip. A vehicle body attitude control device characterized by adjusting the amount of oil in both end chambers.