JPH0825939A - Vehicle height adjusting device - Google Patents

Abstract

PURPOSE:To accumulate the vibrational energy of a body as fluid pressure and use this fluid pressure for vehicle height adjustment. CONSTITUTION:Front and rear wheel axles 10, 20 are individually supported to a body by fluid pressure type actuators A, B and springs 9, 19 connected mutually in parallel. In the respective actuators A, B, rods 4, 14 protruding from pistons 7, 17 fittingly mounted to cylinders 5, 15 are connected to either a body 2 or the axles 10, 20. A changeover type check valve 43 is insert- connected to a passage connecting the upper end chamber of the front wheel actuator A and the lower end chamber of the rear wheel actuator B to each other, and a changeover type check valve 44 allowing flow in the reverse direction to the changeover type check valve 43 is insert-connected to a passage connecting the lower end chamber of the front wheel actuator A and the upper end chamber of the rear wheel actuator B to each other. A pressure accumulator 34a is connected to a passage connecting at least one of the changeover type check valves 43, 44 to the rear wheel actuator B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle height adjusting device for a vehicle which accumulates vibration energy of a vehicle body in a four-wheel vehicle as a fluid pressure and uses it for vehicle height adjustment.

[0002]

2. Description of the Related Art A hydraulic suspension system for a vehicle disclosed in Japanese Unexamined Patent Publication No. Sho 58-56985 discloses a large-sized vehicle connected by a common rod when a piston of a hydraulic shock absorber of, for example, a front wheel of a motorcycle is vertically displaced. The hydraulic actuator of the diameter is driven to suppress the vertical displacement of the front wheels. However, since the hydraulic suspensions for the front and rear wheels work independently, the vehicle height cannot be adjusted.

In an ordinary hydraulic suspension system for a four-wheeled vehicle, in order to keep the vehicle body substantially parallel to the road surface against changes in the road surface, hydraulic oil is supplied from a hydraulic pump to an actuator for suspending front wheels or rear wheels, and other The actuator oil is returned to the oil tank. Therefore, it is possible to freely adjust the vehicle height by adjusting the oil amount of each front and rear actuator depending on the driving condition, but it is not necessary to install a hydraulic pump just for adjusting the vehicle height. This is not preferable because it reduces fuel consumption and increases vehicle weight.

[0004]

In view of the above problems, the object of the present invention is to accumulate the vibration energy of the vehicle body as fluid pressure and utilize the fluid pressure for vehicle height adjustment. To provide.

[0005]

In order to achieve the above object, the structure of the present invention supports the axles of the front and rear wheels with respect to the vehicle body separately by means of fluid pressure type actuators and springs connected in series to each other. The actuator is a rod that protrudes from a piston fitted in a cylinder and is connected to one of the vehicle body and the axle.The first switching check valve is installed in the passage that connects the upper end chamber of the front wheel actuator and the lower end chamber of the rear wheel actuator. The first switching check valve and the second switching check valve that allows reverse flow are inserted and connected in the passage connecting the lower chamber of the front wheel actuator and the upper chamber of the rear wheel actuator. However, a pressure accumulator is connected to a passage connecting at least one of the first and second switching check valves and at least one actuator of the front and rear wheels.

[0006]

When the vehicle height is increased, the switching check valve is switched to the vehicle height raising position. When the front wheel actuator extends while the front wheel passes through the concave or convex portion of the road surface, the working fluid in the upper chamber of the front wheel actuator flows to the lower chamber of the rear wheel actuator via the switching check valve, and the rear wheel The working fluid in the upper end chamber of the actuator of (1) flows to the lower end chamber of the front wheel actuator, and the vehicle height gradually increases.

When lowering the vehicle height, the switching type check valve is switched to the vehicle height lowering position. If the front wheel actuator shrinks while the front wheel passes through a convex or concave portion of the road surface, the working fluid in the lower end chamber of the front wheel actuator flows through the switching check valve to the upper end chamber of the rear wheel actuator, and the rear wheel The working fluid in the lower end chamber of the actuator of (1) flows to the upper end chamber of the front wheel actuator, and the vehicle height gradually decreases.

The pressure accumulator accumulates excess energy of the actuator due to the vibration of the vehicle body as fluid pressure and supplies it to the insufficient actuator. That is, the difference in the amount of working fluid due to the different cross-sectional areas of the upper and lower chambers of the actuator is balanced.

[0009]

1 is a hydraulic circuit diagram of a vehicle height adjusting device for a vehicle when hydraulic pressure is used as a working fluid of an actuator according to the present invention. The axle 10 of the front wheel 11 is supported on the vehicle body 2 by a spring 9 and an actuator A which are connected in series with each other. In the actuator A, a piston 7 is fitted in a cylinder 5 to define an end chamber 6 and an end chamber 8, and an upper end of a rod 4 connected to the piston 7 is connected to a vehicle body 2 by a bush or a pin 3. The spring 9 is interposed between the cylinder 5 and the axle 10.

Similarly to the axle 10 of the front wheel 11, the axle 20 of the rear wheel is also supported by the vehicle body 2 by a spring 19 and an actuator B which are connected in series. In the actuator B, the piston 17 is fitted in the cylinder 15 so that the end chamber 16 and the end chamber 1 are
8 is divided and the upper end of the rod 14 connected to the piston 17 is connected to the vehicle body 2 by a bush or a pin 13. The spring 19 is interposed between the cylinder 15 and the axle 20. In the vehicle height adjusting device described above, the actuator A,
The vertical arrangement of B and the springs 9 and 19 may be reversed.

The upper end chamber 6 of the actuator A has a passage 41,
It is possible to communicate with the pressure accumulator 34a via the switching check valve 44 and the passage 48, and further to communicate with the lower end chamber 18 of the actuator B for the rear wheel via the passage 48, the switching check valve 46 and the passage 50. The upper end chamber 16 of the actuator B is communicated with the pressure accumulator 34 via a passage 49, a switching check valve 45 and a passage 47, and further to the lower end chamber 8 of the actuator A via a passage 47, a switching check valve 43 and a passage 42. Communication is possible. The switchable check valves 43 to 46 are configured to allow the reverse flow of oil when the vehicle height rising position shown in the drawing is switched to the vehicle height lowering position. For this reason, it is preferable to use the switching type check valves 43, 44 and the switching type check valves 45, 46 of the double type in which the check valves are arranged side by side.

Next, the operation of the vehicle height adjusting device according to the present invention will be described. When the switching check valves 43 to 46 are set to the vehicle height increasing position shown in the drawing, when the front wheel 11 passes through the recessed portion of the road surface, the spring 9 and the actuator A extend and the oil in the upper end chamber 6 of the actuator A passes through the passage 41, Switchable check valve 4
4, through the passage 48 to the pressure accumulator 34a, and then the passage 4
8, through the switching check valve 46 and the passage 50 to flow into the lower end chamber 18 of the actuator B. At the same time, the oil in the upper end chamber 16 of the actuator B passes through the passage 49, the switching check valve 45, and the passage 4
7 to the pressure accumulator 34, and further to the end chamber 8 via the passage 47, the switching check valve 43, and the passage 42. Accumulator 3
Numerals 4 and 34a work to eliminate excess and deficiency between the amount of oil discharged from the upper chambers 6 and 16 and the amount of oil supplied to the lower chambers 18 and 8. In this way, actuators A and B expand,
The vehicle height increases.

On the contrary, when the switching check valves 43 to 46 are switched to the vehicle height lowering position, the spring 9 and the actuator A are contracted when the front wheel 11 passes through the convex portion of the road surface, and the lower end chamber 8 of the actuator A. Oil flows to the pressure accumulator 34 via the passage 42, the switching check valve 43 and the passage 47, and further flows to the upper end chamber 16 of the actuator B via the passage 47, the switching check valve 45 and the passage 49. At the same time, the lower end chamber 1 of actuator B
8 flows through the passage 50, the switching check valve 46 and the passage 48 to the pressure accumulator 34a, and further the passage 48 and the switching check valve 4
4, through the passage 41 to the upper end chamber 6 of the actuator A. The pressure accumulators 34 and 34a work to eliminate excess and deficiency between the amount of oil discharged from the lower end chambers 8 and 18 and the amount of oil supplied to the upper end chambers 6 and 16. In this way, actuator A,
B becomes smaller and the vehicle height becomes lower. Therefore, the driver manually switches the switching check valves 43 to 46 in accordance with the road conditions, so that the high vehicle height in which the pistons of the actuators A and B come into contact with the upper end wall of the cylinder and the actuator A. , B can be switched to a low vehicle height in which each piston abuts on the lower end wall of the cylinder.

In the above-mentioned embodiment, the vehicle height is adjusted to two levels, high and low. However, if the switching check valves 43 to 46 of the type in which the oil passage is blocked at the neutral position are used, the vehicle height can be increased. Can be adjusted steplessly.

In the above-described vehicle height adjusting device, pneumatic pressure may be used instead of hydraulic pressure, and the switching check valve 4 on one side may be used.
3, 44 and one pressure accumulator 34a (see FIG. 2), only one switching check valve 43 and one pressure accumulator 34a are provided in the same passage or different passages (see FIG. 3) However, it has almost the same effect. Also,
The switching check valve 43 is separated from the switching check valve 44, and, for example, the working fluid pressure that pushes the switching check valve 44 open is applied to the switching check valve 43 as pilot fluid pressure, and the switching check valve 43 is operated. 43 may be switched to the position shown in FIG. Further, the switching check valves 43 and 44 can be operated by utilizing the vertical inertial force of the vehicle body.

In the modified embodiment shown in FIG. 2, front and rear wheel axles 10 and 20 are separately supported with respect to the vehicle body 2 by fluid pressure type actuators A and B and springs 9 and 19 which are connected in series. Actuators A and B are cylinders 5 and 15
Rods 4,1 protruding from pistons 7,17 fitted in
4 is connected to the vehicle body 2 and one of the axles 10 and 20, and a switching check valve 44 is provided in passages 41 and 48 connecting the upper end chamber 6 of the front wheel actuator A and the lower end chamber 18 of the rear wheel actuator B. A pressure accumulator 34a is inserted and connected in series, and a switching check valve 43 is inserted and connected to passages 42 and 47 connecting the lower end chamber 8 of the front wheel actuator A and the upper end chamber 16 of the rear wheel actuator B.

In the modified embodiment shown in FIG. 3, front and rear wheel axles 10 and 20 are separately supported on a vehicle body 2 by fluid pressure type actuators A and B and springs 9 and 19 which are connected in series. Actuators A and B are cylinders 5 and 15
Rods 4,1 protruding from pistons 7,17 fitted in
4 is connected to the vehicle body 2 and one of the axles 10 and 20, and the pressure accumulator 34a is provided in the passages 41 and 48 that connect the upper end chamber 6 of the front wheel actuator A and the lower end chamber 18 of the rear wheel actuator B.
To connect the lower end chamber 8 of the front wheel actuator A and the upper end chamber 16 of the rear wheel actuator B to the passages 42, 4
7, a switching check valve 43 is inserted and connected.

[0018]

As described above, according to the present invention, the axles of the front and rear wheels are separately supported with respect to the vehicle body by the fluid pressure type actuator and the spring which are connected in series with each other, and each actuator is formed by a piston fitted in the cylinder. The protruding rod is connected to one of the vehicle body and the axle, and the first switching check valve is inserted and connected to the passage connecting the upper end chamber of the front wheel actuator and the lower end chamber of the rear wheel actuator. The first switching type check valve and the second switching type check valve that allows the flow in the reverse direction are inserted and connected in the passage connecting the lower end chamber and the upper end chamber of the actuator for the rear wheel, and the first and second switching are performed. A pressure accumulator is connected to the passage that connects at least one of the check valves and the actuators of at least one of the front and rear wheels, and the upper end of the actuators for the front and rear wheels can be set by manually switching the check valves. And the working fluid exchanged between the lower chamber of the rear wheel of the actuator, the actuator of the front and rear wheels are flex equally, freely adjust the vehicle height.

Since the vehicle height adjusting device according to the present invention does not require a hydraulic pump, the structure is simple, the manufacturing cost is low, and the vehicle height adjusting device can be applied to a small vehicle having a small engine output. Can be improved.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram of a vehicle height adjusting device for a vehicle according to the present invention.

FIG. 2 is a hydraulic circuit diagram of a vehicle height adjusting device for a vehicle according to a partially modified embodiment of the present invention.

FIG. 3 is a hydraulic circuit diagram of a vehicle height adjusting device for a vehicle according to a partially modified embodiment of the present invention.

[Explanation of symbols]

A, B: Actuator 2: Vehicle body 4,14: Rod 5,15: Cylinder 6,16: End chamber 7,17: Piston 8,18: End chamber 9,19: Spring 10,20: Axle 43,44: No. First and second switching check valves

Claims (3)

[Claims] Claims: 1. The front and rear wheel axles of the vehicle body are separately supported by fluid pressure type actuators and springs connected in series to each other, and each actuator has rods protruding from a piston fitted in a cylinder of the vehicle body and axles. The first switching check valve is inserted into and connected to the passage connecting the upper end chamber of the front wheel actuator and the lower end chamber of the rear wheel actuator, and the lower end chamber of the front wheel actuator and the rear wheel actuator are connected. A first switching check valve and a second switching check valve that allows flow in the opposite direction are inserted and connected in a passage connecting the upper chambers,
A vehicle height adjusting device for a vehicle, characterized in that a pressure accumulator is connected to a passage connecting at least one of the first and second switching check valves and at least one actuator of the front and rear wheels. 2. The first and second switching check valves, wherein the working fluid in the upper chamber of the front wheel actuator flows to the lower chamber of the rear wheel actuator, and the working fluid in the upper chamber of the rear wheel actuator is The vehicle height rising position that flows to the lower end chamber of the front wheel actuator, the working fluid of the lower end chamber of the front wheel actuator flows to the upper end chamber of the rear wheel actuator, and the working fluid of the rear wheel actuator lower end chamber flows to the front wheel actuator. The vehicle height adjusting device for a vehicle according to claim 1, wherein the vehicle height adjusting device is switched to a vehicle height lowering position where it flows to the upper end chamber. 3. The front and rear wheel axles of the vehicle body are separately supported by fluid pressure type actuators and springs connected in series to each other, and each actuator has a rod projecting from a piston fitted in a cylinder of the vehicle body and axle. It is connected to one of the first passage that connects the upper end chamber of the front wheel actuator and the lower end chamber of the rear wheel actuator, and the second passage that connects the lower end chamber of the front wheel actuator and the upper end chamber of the rear wheel actuator. A vehicle height adjusting device for a vehicle, wherein a switching check valve is inserted and connected to one side, and a pressure accumulator is connected to the other of the first and second passages.