JPS6158327B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle height adjustment device.

2. Description of the Related Art Conventionally, vehicle height adjustment devices that automatically adjust the height of a vehicle by operating a switch or the like usually perform closed-loop control using a vehicle height sensor to maintain a constant vehicle height. However, in the case of such a vehicle height adjustment device, the vehicle height sensor itself is expensive, and the sensing part of this device is constantly moving due to vibrations around the suspension, so there are concerns about durability. The control circuit also had the disadvantage of being complex and expensive.

Therefore, in order to solve this problem, it is possible to use a pressure sensor to detect and control the internal pressure of the shock absorber. However, in this method, in order to protect the shock absorber, air There was a problem in that it was necessary to take measures to prevent the vehicle height from significantly lowering even if a leak occurred.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a vehicle height adjustment device that automatically increases the internal pressure of a shock absorber when it falls below the minimum allowable pressure. be.

To achieve this objective, the present invention includes a pressure sensor provided in a flow path communicating with the shock absorber.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

First, in FIG. 1 showing the overall configuration of the vehicle height adjustment device, 1 is a front shock absorber that can adjust the vehicle height using air pressure, 2 is a rear shock absorber, and these are connected to a pipe P.
It is connected to a compressor 3 for compressing air. A solenoid valve 4 is provided between the front shock absorber 1 and the rear shock absorber 2, and a high pressure side valve serving as a pressure sensor is provided between the solenoid valve 4 and the front shock absorber 1. A pressure switch 5 and a low pressure side pressure switch 6 are provided, and a solenoid valve 4 is provided.
Pressure switches 7 and 8, which serve as pressure sensors for setting the minimum allowable pressure, are provided between the solenoid valve 4 and the shock absorber 1 on the front side and between the solenoid valve 4 and the shock absorber 2 on the rear side, respectively. . In addition, piezoelectric elements,
A resistance wire strain meter or the like may also be used.

9 is a dryer for drying air provided between the compressor 3 and the pipe P, and 10 is a solenoid valve for discharging air.

11 is a control circuit that inputs detection signals from the pressure switches 5, 6, 7, and 8 to control the compressor 3 and the electromagnetic valves 4 and 10; 12 is an operation switch for operating the control circuit 11; 13 is a control circuit; This is an indicator lamp that displays the status.

Next, the control circuit 11 of the vehicle height adjusting device configured as described above will be explained based on FIG. 2.

First, turn on the main switch SW1 (this may be linked to a key switch (not shown)) and then operate the operation switch 12 to the high side. Momentary contacts c and b close only during this operation as shown by the broken line. In addition, toggle contacts b and a are kept closed. (Momentary contacts c and b are switch 12
The toggle contacts a and b are turned on only when the switch 12 is operated by hand, and the toggle contacts a and b remain on even when the switch 12 is released. ) During this operation, if the internal pressure of the shock absorber 1 is lower than the set pressure (high) of the pressure switch 5 on the high pressure side, the pressure switch 5 is on, so the relay RL1 is activated. As a result, when the normally open contact RL1a turns on, the same contact RL1a,
The relay is activated by a circuit consisting of a diode D1, toggle contacts a and b, and a pressure switch 5 on the high pressure side.
RL1 is self-held while the pressure switch 5 on the high pressure side is on, and when the normally open contact RL1a is turned on, the relay RL2 is also activated, and the compressor motor 3 is operated by the normally open contact RL2a. is started. On the other hand, the normally open contact RL1
When a is turned on, a current flows through the diode D4, and the solenoid valve 4 is activated to open the flow path.

Next, when the internal pressure of the shock absorbers 1 and 2 increases due to the operation of the compressor 3 and reaches the set pressure (high), the pressure switch 5 on the high pressure side is turned off and the self-holding of the relay RL1 is released. will be stopped. However, in this example, the pressure switch 5 on the high pressure side is 5 as shown in FIG.
The contact is set to turn off when the pressure exceeds Kg/cm ² . Therefore, the internal pressure of the front and rear shock absorbers 1 and 2 is controlled by the switch 11.
When it is operated to the high side, it becomes 5Kg/cm ² .

Furthermore, when the compressor 3 stops operating, the electromagnetic valve 4 is also released and the flow path of the pipe P is closed. Therefore, the shock absorber 1 on the front side and the shock absorber 2 on the rear side do not influence each other due to pressure fluctuations. (For example, the front and rear vehicle heights can be kept almost constant on slopes, etc.) Similarly, when the switch 12 is operated to the low side, the internal pressure of the shock absorbers 1 and 2 is 5K, so the pressure on the low pressure side Since switch 6 is closed and on as shown in Figure 3, relay RL3
is activated. Therefore, the normally open contact RL3a of this
is turned on, and the same contact RL3a, diode D2, toggle contacts d and e, and the pressure switch 6 on the low pressure side are turned on.
The solenoid valve 4 and the solenoid valve 10 for air discharge are operated.
Therefore, the flow paths of the electromagnetic valves 4 and 10 are opened, air is released from the electromagnetic valve 10 to the outside, and the internal pressure of the shock absorbers 1 and 2 is reduced. And this internal pressure
When the pressure decreases to 3K, the pressure switch 6 is turned off as shown in FIG. Therefore, the solenoid valves 4 and 10 are deactivated and their flow paths are closed, and the internal pressures of the front shock absorber 1 and the rear shock absorber 2 are maintained at 3K.

By lowering the internal pressure of the shock absorbers 1 and 2 in this way, the height of the vehicle can be lowered. Further, if the switch 12 is operated to the high side from this state, the internal pressure of the shock absorbers 1 and 2 will increase through the same process as described above, and the vehicle height will become higher.

In this example, the internal pressures of the front and rear shock absorbers 1 and 2 are adjusted to the same pressure, but if you want to create a difference in the front and rear vehicle heights, adjust the shock absorber springs, etc. Just read it and adjust.

Next, a case will be described in which the internal pressure of the front or rear shock absorber decreases due to air leakage after the vehicle height has been adjusted in this manner.

For example, when the vehicle height is set to the low side (when the switch 12 is set to the low side), air leakage may cause damage to the front shock absorber 1.
If the internal pressure (which may be on the rear side) drops below the minimum allowable pressure of 2K, the pressure switch 7 (or 8 in the case of the rear side) is turned on as shown in Figure 3. becomes. For this reason,
Normally open contact RL1a of relay RL1 is turned on, and compressor 3 and solenoid valve 4 are operated. Therefore,
The internal pressures of the shock absorbers 1 and 2 are both increased, but as shown in Fig. 3, the pressure switch 6 is off (therefore, the relay RL3 is not activated). When the pressure increases by the amount indicated by h in FIG. 3, the pressure switches 7 and 8 are turned off and the operation of the compressor 3 and solenoid valve 4 is stopped. That is, the internal pressures of the shock absorbers 1 and 2 are now increased by the minimum allowable pressure plus the hysteresis.

Furthermore, if the internal pressure of the shock absorber 1 or 2 decreases and one of the pressure switches 7 and 8 is turned on while the switch 12 is operated to the high side, the pressure switch 5 for setting the high pressure side is turned on. As shown in Figure 3, it is on, so relay RL1
is self-held, and the control circuit 11 performs the same circuit operation as when the switch 12 is turned to the high side. Therefore, in this case, the internal pressure of the shock absorbers 1 and 2 is increased to 5K. In this way, in this example, a decrease in vehicle height due to a decrease in the internal pressure of the shock absorbers 1 and 2 is prevented.

Next, the display lamp 13 will be explained.
The lamp 13a lights up during adjustment to the high side and when the adjustment is completed. That is, the transistor Tr1, whose collector is connected to the first lamp 13a, is connected to the switch 12.
When not operated to the high side, the base is held at the low level by the resistor R1. Next, when the switch 12 is operated to the high side, the switch 12
Since the contact a of the transistor Tr1 becomes high level, the base of the transistor Tr1 is pulled up to a high level by the resistor R2, and the first lamp 13a is turned on. Similarly, the second lamp 13b is connected to the switch 12.
Lights up while adjusting to the low side and when adjustment is completed. Third
The lamp 13c is lit only during pressure increasing or decreasing operation (when the solenoid valve 4 is activated). Furthermore, the fourth
The lamp 13d lights up when the internal pressure of the shock absorbers 1, 2 decreases below the minimum allowable pressure set by the pressure switches 7, 8 and at least one of the switches 7, 8 is turned on. The light goes out when the internal pressure of the switch 2 is increased by the compressor 3 and both switches 7 and 8 are turned off.

It goes without saying that the above-described sequence circuit may be constructed from a logic circuit using ordinary semiconductor elements. Further, in this example, a case has been described in which air is used as the fluid, but it goes without saying that other fluids such as oil can also be used.

In other words, the present invention provides a pressure sensor in the flow path communicating with the shock absorber to set the minimum allowable melting pressure of the shock absorber, thereby preventing damage to the lower part of the body or damage to the shock absorber due to a drop in vehicle height. A major feature of this system is that it can prevent problems from occurring.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is an explanatory diagram showing the overall structure of the vehicle height adjustment device, and FIG.
The figure is a circuit diagram of the control circuit, and FIG. 3 is a characteristic diagram showing the operating state of the pressure switch. 1...Front side shock absorber, 2...
...Rear side shock absorber, 3... Compressor, 7, 8... Pressure switch for setting the minimum allowable pressure, 11... Control circuit.

Claims (1)

[Scope of Claims] 1. A fluid actuator for adjusting the vehicle height of a vehicle, a fluid supply/discharge means for supplying and discharging fluid to and from the actuator, a pressure detection means for detecting the pressure of the fluid, and a fluid actuator for adjusting the vehicle height to a set value. A vehicle height adjustment device comprising a pressure adjustment means for controlling a fluid supply/discharge means to adjust the vehicle height by adjusting the vehicle height, wherein the pressure detected by the pressure detection means is a minimum value smaller than the set value. A vehicle height adjustment device characterized in that a warning device is activated when the pressure is lower than an allowable pressure.