JPH09257084A - Active suspension device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve suspension performance with a simple device by transducing acceleration of a vehicle body to displacement of a rod by means of a weight, first and second coil springs and a damper when vertical speed is increased on a vehicle body, and thereby displacing a guide valve for supplying hydraulic pressure to a cylinder. SOLUTION: When acceleration upward, for instance, is generated on a vehicle body 13, a weight 1 is displaced downward in respect to a sleeve 8, and at the same time a guide valve 4 is displaced downward. Hydraulic pressure is applied to an upper surface of a piston 4 for lifting a cylinder 15, and relative displacement between a tire 16 and the vehicle body 13 is decreased. As a result, downward acceleration is generated on the vehicle body 13, and the initial upward acceleration is canceled. In the case that relative displacement between the vehicle body 13 and the tire 16 is shifted from a neutral position by rolling or the like, a second coil spring 9 is moved by means of a link rod 10. The guide valve 4 is moved, and the piston 14 is moved for returning the relative displacement to the neutral position. The rolling of the vehicle is decreased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active suspension device applied to a vehicle suspension.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional active suspension device. The vehicle body 13 and the wheels (tires) 16 are connected via a piston 14 and a cylinder 15. The cylinder 15 is connected to the hydraulic pump 5 via an electrohydraulic valve 19.

A position detector 23 for detecting the position with respect to the vehicle body 13 is provided on the wheel side of the piston 14 and the cylinder 15, and the output thereof is sent to a calculator 18. Also the car body 13
An accelerometer (acceleration detector) 20 is attached to the and the output is sent to the calculator 18. The output of the calculator 18 is sent to the electrohydraulic valve 19.

In the above, the vehicle body 13 is supported by the wheels via the piston 14 and the cylinder 15. Calculator 18
Calculates and amplifies the acceleration signal of the vehicle body 13 detected by the accelerometer 20 and the position signal of the relative displacement of the vehicle body 13 and the piston 14 detected by the position detector 23, and outputs a command signal for canceling the acceleration by the electrohydraulic pressure. Send to valve 19. Upon receiving this command signal, the electrohydraulic valve 19 switches the hydraulic pressure from the hydraulic pump 5 to move the piston 14 so as to reduce the acceleration of the vehicle body 13.

[0005]

The above-mentioned conventional device requires an accelerometer for detecting the acceleration of the vehicle body and an arithmetic unit, and these parts are expensive. Further, the structure of the device is complicated, and there is a problem in reliability and durability.

[0006]

The present invention employs the following means to solve the above-mentioned problems.

That is, as an active suspension device, a piston and a cylinder for connecting between a vehicle body and wheels, a rod fixed to the vehicle body side and having a hole substantially parallel to the cylinder, and having a guide valve and a damper in the hole are passed through. At the same time, a hydraulic pressure distribution means in which a port connected to the cylinder and a port connected to a hydraulic pressure source communicate with the hole, a weight attached to the upper end of the rod through a first coil spring, and a weight of the rod. A link support arm that is arranged in the direction opposite to the cylinder and has one end fixed to the hydraulic pressure distribution means, a link rod that is pin-connected between the link support arm and the wheel side of the piston and the cylinder, the lower end of the rod, and the A second coil spring provided between the link rods is provided.

In the above, for example, when an upward acceleration is generated in the vehicle body 1, the weight, the first and second coil springs and the damper change the acceleration of the vehicle body into the displacement of the rod.
Therefore, the guide valve is displaced, and the hydraulic pressure from the hydraulic pressure source is sent to the cylinder to contract the piston and the cylinder. As a result, the wheel is displaced toward the vehicle body side, a downward acceleration is generated in the vehicle body, and the upward acceleration of the vehicle body is canceled.

Further, when the piston and the cylinder contract from the neutral state due to the rolling motion of the vehicle body, the guide valve is displaced upward from the neutral position via the link rod and the second coil spring. Due to this displacement, the oil pressure from the oil pressure source is sent to the cylinder, and the piston and the oil pressure are extended and returned to the neutral state.

As described above, the vertical acceleration and the roll motion are attenuated by the simple device, and the suspension having good performance can be obtained.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

 (1) A first embodiment of the present invention will be described with reference to FIG.

A piston 14 and a cylinder 15 connect between the vehicle body 13 and the wheels (tires) 16. Here, the piston 14 side is fixed to the vehicle body 13.

On the front or rear side of the vehicle body 13, an upper portion of a sleeve 8 having a hole a whose axis is substantially parallel to the axis of the cylinder 15 is attached to the vehicle body 13. A rod 11 is passed coaxially with the hole a, a damper 3 is provided in the upper portion, and two guide valves 4 are provided in the center with a gap. The weight 1 is attached to the end of the rod 11 above the sleeve 8 via the first coil spring 2. One end of the link support arm 7 that is bent downward is fixed to the lower side of the sleeve 8 on the side opposite to the wheels 16. The other end of the link support arm 7 and the wheel side of the cylinder 15 are pin-connected by the link rod 10. The lower end of the rod 11 and the link rod 10 are connected by a second coil spring.

A port connected to a hydraulic source, that is, a port for the hydraulic pump 5, is provided between the guide valves 4 of the sleeve 8 and above and below the guide valve 4 and communicates with the hole a, and is connected to the pump 5.
A port connected to the cylinder, that is, a cylinder port communicates with the position of the guide valve 4.
It is connected to 5 with a hose 12. At this time, the upper port of the sleeve 8 is connected to the lower port of the cylinder 15.

Here, the sleeve 8, the rod 11, the damper 3, and the guide valve 4 are hydraulic distribution means.

In the above, the weight 1, the first and second coil springs 2, 9 and the damper 3 have their vibration characteristics adjusted so that the acceleration of the vehicle body 13 is converted into the displacement of the rod 11 and can be detected as the displacement of the guide valve 4. There is.

For example, when an upward acceleration is generated in the vehicle body 13, the weight 1 is displaced downward with respect to the sleeve 8,
At the same time, the guide valve 4 is also displaced downward. Then, the hydraulic pressure acts on the upper surface of the piston 14 to lift the cylinder 15 with respect to the piston, so that the relative displacement between the tire 16 and the vehicle body 13 decreases. As a result, downward acceleration is generated in the vehicle body 13, and the initial upward acceleration is canceled.

As described above, since the vertical acceleration of the vehicle body 13 is always kept at a low level, the ride comfort is very good.

Further, since the weight 1 does not react to the lateral acceleration when the vehicle body 13 turns a curve, the relative displacement between the vehicle body 13 and the tire 16 remains constant, but the vehicle body 1
When the relative displacement of the vehicle body 13 and the tire 16 is moved from the neutral position due to the roll movement of the No. 3, the link rod 10 supported by the link support arm 7 moves the second coil spring 9, and the guide valve 4 moves (relative displacement). ) Then, the piston 14 moves by the hydraulic pressure so as to return its relative displacement to the neutral position, so that the roll movement of the vehicle body 13 becomes very small.

In this way, it is possible to achieve a high level of riding comfort without using an accelerometer using an expensive strain gauge and a calculator as in the prior art. Moreover, since the structure is simple, the cost is low and it is hard to break.

(2) A second embodiment of the present invention will be described with reference to FIG.

The vehicle body 13 and the wheels 16 are connected by a piston 14 and a cylinder 15. Here, the cylinder 17 side is fixed to the vehicle body 13.

The cylinder 1 is provided in front of or behind the vehicle body 13.
A hole a having an axis substantially parallel to the axis of 7 is provided adjacent to the cylinder 17. The hole a forms the sleeve 8. Hole a
A rod 11 is passed coaxially with, a damper 3 is provided in the upper part, and a guide valve 4 is provided in the center. The weight 1 is attached to the end of the rod 11 above the sleeve 8 via the first coil spring 2. One end of the link support arm 7 that is bent downward is fixed to the lower side of the sleeve 8 on the side opposite to the wheels 16. The other end of the link support arm 7 and the wheel side of the cylinder 15 are pin-connected by the link rod 10. The lower end of the rod 11 and the link rod 10 are connected by a second coil spring.

Ports for the hydraulic pump 5 are communicated with the hole a above and below the guide valve 4 of the sleeve 8 and are connected to the pump 5. A cylinder port is connected to the hole a at the position of the guide valve 4 and its lower part, and is connected to the cylinder 17. At this time, the upper port of the sleeve 8 is connected to the upper port of the cylinder 17.

Here, the sleeve 8, the rod 11, the damper 3, and the guide valve 4 are hydraulic distribution means.

In the above, when an upward acceleration is generated in the vehicle body 13, the weight 1 is displaced downward with respect to the cylinder 17, and at the same time, the guide valve 4 is also displaced downward. Then, the hydraulic pressure acts on the lower surface of the piston 14 to contract the piston 14 and the cylinder 17, so that the tire 16 and the vehicle body 13
The relative displacement of is reduced. As a result, downward acceleration is generated in the vehicle body 13, and the initial upward acceleration is canceled.

As described above, since the vertical acceleration of the vehicle body 13 is always kept at a low level, the riding comfort is very good.

Since the weight 1 does not react to the lateral acceleration when the vehicle body 13 bends a curve, the relative displacement between the vehicle body 13 and the tire 16 remains constant, but the vehicle body 13 moves due to the rolling motion of the vehicle body 13 or the like. When the relative displacement between the tire 16 and the tire 16 moves from the neutral position, the link rod 10 supported by the link fulcrum 11 moves the coil spring 9, and the guide valve 4
Moves and the hydraulic pressure operates so as to return the relative displacement of the vehicle body 13 and the tire 16 to the neutral position, so that the rolling motion of the vehicle body becomes very small.

In this way, a high level of riding comfort can be achieved without using an expensive accelerometer or calculator. or,
The structure is simple, the cost is low, and it is hard to break.

[0030]

According to the present invention as described above,
An expensive accelerometer and an arithmetic unit unlike the conventional device are not required, and an inexpensive and robust active suspension device can be obtained.

[Brief description of drawings]

FIG. 1 is a partial sectional view of a configuration according to a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of components of a second embodiment of the present invention.

FIG. 3 is a partial cross-sectional view of a configuration of a conventional example.

[Explanation of symbols]

 1 Weight 2 First Coil Spring 3 Damper 4 Guide Valve 5 Hydraulic Pump 7 Link Support Arm 8 Sleeve 9 Second Coil Spring 10 Link Rod 11 Rod 12 Hose 13 Body 14 Piston 15, 17 Cylinder 16 Wheel 18 Computer 19 Electro-hydraulic Valve 20 Accelerometer 23 Position detector

Claims (1)

[Claims] Claim: What is claimed is: 1. A piston and a cylinder for connecting a vehicle body and a wheel, a hole fixed to the vehicle body and substantially parallel to the cylinder, and a rod having a guide valve and a damper in the hole. Includes a hydraulic pressure distribution means in which a port connected to the cylinder and a port connected to a hydraulic pressure source communicate with each other, a weight attached to the upper end of the rod via a first coil spring, and a rod opposite to the cylinder in the cylinder direction. A link support arm that is arranged and fixed at one end to the hydraulic distribution means, a link rod that is pin-connected between the link support arm and the wheel side of the piston and the cylinder, and provided between the lower end of the rod and the link rod. An active suspension device comprising: a second coil spring that is provided.