JPS6067211A - Suspension device for vehicle - Google Patents

Abstract

PURPOSE:To allow change in spring constant and damping force for better travelling comfort and stability by interconnecting gas chambers of main and auxiliary actuators through a gas passage and providing in the gas passage a switch valve whose opening and closing can be controlled. CONSTITUTION:A main actuator 1 includes a cylinder 3 having inside thereof an oil chamber 5 and at the lowermost end thereof a fixture 4 for attaching the actuator to an axle. An auxiliary actuator 2 is divided by a free piston 30 into an oil chamber 31 and a gas chamber 32. The gas chamber 32 and the gas chamber 12 of the main actuator 1 are interconnected through a gas passage 33 and, a switch valve 34 is provided in the gas passage. At normal straight driving on a smooth road, the valve 34 is open, allowing communication between the gas chambers 12, 13 to lower the spring constant, and an orifice 19 for adjusting damping force is open to reduce the damping force for improved travelling comfort. At turning or others, the valve 34 is closed to raise the spring constant, and the orifice 19 is closed to increase the damping force for better stability of the vehicle body posture.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle suspension system that can improve ride comfort and handling stability.

Suspension systems using hydraulic and pneumatic actuators are known as an alternative to conventional metal springs such as coil springs or leaf springs. This type of suspension device can provide a buffering function using compressed gas and a damping force using an orifice.

However, since the repulsion constant of a hydraulic wall pressure actuator is determined by the pressure of the enclosed gas and the volume of the gas chamber, it is not always possible to obtain the optimum erection depending on the driving conditions of the vehicle.

Therefore, the applicant previously proposed the patent application No. 58-4288.
In No. 9, a sub actuator is provided in addition to the main actuator, the gas chambers of both actuators are communicated with each other, and the effective gas chamber volume is completely changed by switching the on-off valve, thereby making it possible to change the spring constant. There is.

The present invention was proposed to further improve this, and its purpose is to not only change the spring constant, but also change the damping force, and to An object of the present invention is to provide a complete suspension system for a vehicle that can provide good ride comfort and handling stability by appropriately changing the spring constant and the reducing force depending on the vehicle and road surface conditions.

That is, the gist of the present invention is to provide a cylinder having an oil chamber inside, a hollow rod telescopically inserted into the cylinder and having an oil chamber and a gas chamber inside, and the above-mentioned cylinder provided in the rod. A piston part with an orifice that communicates the oil chamber of the cylinder and the oil chamber of the rod, and a metal fitting 48 L
, equipped with a main actuator. It is now defunct and has a secondary actuator with an internal gas chamber. And these Lord e
The gas chambers of the sub-actuators are connected to each other by a gas passage, and an on-off valve that can be opened and closed is provided in the middle of this gas passage. The vehicle suspension system further comprises an orifice control mechanism for controlling the opening amount or flow resistance of the orifice of the piston portion from outside the hollow rod.

According to the present invention having the above structure, if the on-off valve is fully opened and the flow path of the orifice is widened by the orifice control mechanism, the effective gas chamber volume will not increase when the plurality of gas chambers are integrated through the on-off valve. As the constant decreases, the flow resistance of the orifice decreases and the damping force decreases. Therefore, good riding comfort can be obtained, for example, when the vehicle travels straight on a good road. On the other hand, if the on-off valve is closed and the orifice flow path is narrowed by the orifice control mechanism, the effective gas volume becomes smaller, the spring constant increases, and the damping force becomes smaller. Therefore, the steering stability is improved when turning or when driving on a rough road.

The above-mentioned on-off valve and orifice control mechanism may be configured to control the vehicle speed, for example.
The turning state, road surface condition, etc. may be detected by various sensors and the control may be automatically controlled based on the signals, or the switching may be performed manually as appropriate. Further, depending on the case, it may be used to deal with road surface conditions or driving conditions by changing only one of the spring constant and damping force.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 indicates a main actuator, and 2 indicates a sub actuator. The main actuator 1 is constructed as described below. That is, 3 is a cylinder, and a mounting 84 is provided at the lower end of the cylinder 3 in the drawing for mounting to a member on the axle side. Further, an oil chamber 5 is provided inside the cylinder 3 and contains oil. Further, an oil seal 6 and a rift mount stop horn 4 rubber 7 are attached to the upper end side of the cylinder 3 in the drawing.

A hollow rod 8 is extendably inserted into the cylinder 3. The outside of this rod 8 is covered with a protective cover 9. 10 indicates a non-no-no-ya rubber. The inside of the hollow rod 8 is partitioned into upper and lower parts by a free piston 1, and the upper part contains a gas chamber 12 containing high pressure gas such as nitrogen.
However, an oil chamber 3 is also formed on the lower side. The oil chamber 13 communicates with the oil chamber 5 of the cylinder via an orifice 15 provided in the piston portion 14. As shown in FIGS. 2 and 3, the orifice 15 is a combination of a first orifice 17 formed in the valve dea 16 and a loop plate 18, which can be opened and closed. That is, the second orifice 19 for adjusting the damping force.
It consists of...

The second orifices 19 are opened and closed by rotating an operating shaft 21 inserted through the cylindrical body 20, depending on the rotational position of the operating shaft 21.

The operating shaft 2 passes through the hollow rod 8 and the free piston 11 in the vertical direction and projects outward from the upper end of the rod 8, and this projecting portion is connected to the drive shafts of the rotary solenoids 2, 2.

Further, the operating shaft 21 is configured to rotate within a 23 on the outer peripheral surface side of the operating shaft 2 for maintaining liquid tightness. Therefore, in the case of this embodiment, the operating shaft 2, the rotary solenoid 22, etc. constitute an orifice control mechanism 24.

Further, in FIG. 3, 25 and 26 indicate seal washers. These seal washers 2s and 26 are arranged in a dense layer on the lower surface of the free piston 1 to seal the gas when the free piston 1 descends to the lower limit position and the gas chamber 2 reaches its maximum volume.

Also, between the material (for example, polymethylpentene L" 11-1: hollowed out and floated on oil, free piston 1) below the northeast of the 7 Lee piston 1 lft oil and the inner surface of the hollow rod 8, and the free piston 1 No and Bahia”
23, the sliding resistance of the free piston 1 can be significantly reduced.

On the other hand, the sub actuator 2 has a free piston 3 inside.
o into an oil chamber 3 and a gas chamber 32.

This gas chamber 32 is filled with high pressure gas such as M element.

This gas chamber 32 and the gas chamber 12 of the main actuator are connected to each other by a gas passage 33. Further, an on-off valve 34 using a solenoid valve or the like is provided in the middle of this gas passage 33.

Further, a hydraulic unit 35 is connected to the oil chamber 3, and
1 allows oil to be put in and taken out. 36 is a hydraulic power source, 37 is a switching valve for oil supply, 38 is a switching valve for draining oil, 3
9 is a tank.

The on-off valve 34, the switching valve 37.3g, and the rotary solenoid 22 are controlled by a tljlJ controller 4o such as a micro-noise sensor. This 1t
The tlJ controller 4o includes, for example, a vehicle height detector 41, a speed sensor 42, a head/dollar sensor 43, and a brake sensor 4o.
44, accelerator sensor 45, handbrake 7/su 46
It is designed so that signals from etc. can be input.

The embodiment device configured as described above opens the gas passage opening/closing valve 34 when traveling straight on a normal road, and both gas chambers 12 are opened.
．． 32 are connected to lower the spring constant, and the orifice (second orifice) 19 for adjusting the damping force is an egg.
Reduce damping force. This makes the rice taste better.

On the other hand, when operating the steering wheel such as when turning or changing lanes, the steering angle applied to the steering wheel sensor 43 or the angular velocity and the traveling speed output from the speed sensor 42 may exceed the set value. When
The on-off valve 34 is closed to reduce the number of springs in the gas chamber 12, and the rotary solenoid 22ff is driven so that the orifice 19 is closed to fully increase the damping force. This makes it possible to stabilize the attitude of the single unit and improve maneuverability.

In this case, either the on-off valve 34 or the orifice 2 19 may be closed.

According to the same principle, if sudden acceleration or deceleration is detected by the brake sensor 44 or the accelerator sensor 45, for example, the on-off valve 34 is closed to release the entire spring constant, and the orifice 19 is closed to apply damping force. Make the music louder.

By doing so, the longitudinal inclination of the vehicle body during sudden acceleration and deceleration is suppressed. Incidentally, the detection of the brake pedal mouse may be performed by detecting a plurality of brake pedals or continuously.

Further, either the on-off valve 34 or the orifice 19 may be closed.

Further, according to the apparatus of the above embodiment, eastern adjustment can also be performed. For example, if the controller 40 is operated with a switch that does not have a curvature, and the controller 40 is issued a tortoise Ql setting command, the changeover valve 37 is set so that the difference between the actual vehicle height detected by the vehicle height detector 41 and the set tortoise height is eliminated. .38 is automatically controlled, and by supplying or discharging oil to oil chamber 3, the gas chamber 32°12
The gas compression force applied to tL is adjusted. The rod 8 stops when it reaches the set position. However, when the on-off valve 34 is in the closed state, the vehicle height is not adjusted.

Furthermore, when a command to set the maximum vehicle height position is issued when changing a tire, etc., the switching valve 37 opens only when the handbrake sensor 46 detects that the handbrake has been applied, and the oil enters the oil chamber 3. It can be sent to the maximum vehicle height position.

Furthermore, if the 1lll vehicle 40 is programmed to lower the m height when the speed sensor 42 detects a vehicle speed higher than a set speed, stability during high-speed driving can be further improved.

Furthermore, a predetermined time delay may be added to the torsion height setting operation based on the signal from the vehicle height detector 4, so that the vehicle does not respond to temporary changes in the cylinder due to, for example, bumps on the road surface.

Alternatively, if vehicle height changes are input continuously in a short period of time, it is determined that the vehicle is traveling on a love road, and the controller 40 can be programmed to increase the damping force or to automatically increase the east height. good.

As a starting point, vehicle height adjustment, switching of spring foot suspension, and damping force adjustment can be performed automatically, semi-automatically, or manually depending on road conditions, vehicle body conditions, and driving conditions, improving ride comfort and handling stability. Akane not only improves sexual performance, but also has a variety of functions.

In the present invention, the vehicle height adjustment function, that is, the hydraulic unit 35 is not necessarily necessary, and the intended purpose of the present invention can be achieved even if a sub actuator having only a gas chamber is employed. Furthermore, in carrying out the present invention, the cylinder, rod, piston portion, orifice, on-off valve, orifice control mechanism, etc. may be modified to all types without departing from the spirit of the present invention. It goes without saying.

As described above, according to the present invention, great effects can be obtained in improving riding comfort and steering stability.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic configuration diagram showing a main actuator and a sub actuator in cross section, FIG. 2 is a cross-sectional view taken along line 1-■ in FIG. 1, and FIG. The figure is a longitudinal sectional view taken along the line ill-ill in FIG. 2. DESCRIPTION OF SYMBOLS 1...Main actuator, 2...Sub actuator, 3...Cylinder, 5...Oil chamber, 8...Hollow J rod, No.2...Gas chamber, 13...Oil chamber, 4... Piston part, 15... Orifice, 19... Orifice (for damping force adjustment), 2... Operation shaft, 22...
Rotating solenoid, 2+...orifice control mechanism.

Claims (1)

[Scope of Claims] A cylinder having an oil chamber inside, a hollow rod telescopically inserted into this cylinder and having an oil chamber and a gas chamber inside, and a hollow rod provided in this rod and having an oil chamber in the cylinder. A piston portion having an orifice that communicates the chamber with the oil chamber of the rod;
A sub-actuator having a gas chamber inside is provided, the gas chamber of the main actuator and the gas chamber of the sub-actuator are connected to each other by a gas passage, and an on-off valve that can be opened and closed is provided in the middle of the gas passage; A heavy-duty suspension system, comprising: an orifice control mechanism for controlling the opening amount or flow resistance force of the orifice of the piston portion from the outside of the hollow rod.