JPS58110315A - Car height adjusting device - Google Patents

Abstract

PURPOSE:To maintain front and rear car heights constant even on a slant road with a simple structure and high reliability by providing a solenoid valve in a passage communicating between front and rear shock absorbers and by cutting it off to close the passage except during the car height adjusting time. CONSTITUTION:When the internal pressure of shock absorbers 1, 2 is increased to reach a preset pressure by the operation of a compressor 3, a pressure switch 5 on the high pressure side is made off, releasing the self-hold of a relay RL1, and the operation of the compressor 3 is stopped, then the operation of a solenoid valve 4 is also released, closing the passage of a pipe P. Accordingly, the shock absorber 1 on the front side and the shock absorber 2 on the rear side are not affected to each other on pressure changes. Next, when a switch 11 is operated to the low side, a relay RL3 is operated, and the solenoid valve 4 and the solenoid valve 9 for discharging air are also operated, thus opening the passages of the solenoid valves 4, 9.

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 control 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.

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 having a simple structure and high reliability.

In order to achieve the above object, the present invention has a pressure '3'j'4〒≠ for detecting the pressure of the fluid, and an electromagnetic valve interposed in a flow path communicating with each shaker 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 the front side seat 8 that can adjust the vehicle height using air pressure.
The shock absorber 2 is a shock absorber 2 of the same rear @j, and these are connected by a pipe P 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 pressure sensor is provided between the solenoid valve 4 and the front shock absorber 1. A pressure switch 5 on the high pressure side and a pressure switch 6 on the low pressure side are provided. Note that a piezoelectric element, a resistance wire strain gauge, or the like may be used as the pressure sensor.

Reference numeral 7 denotes sub-tanks provided in the front and rear air pipes P, respectively, for reducing the spring constant due to the air pressure of the lock absorber 1.2.

8 is a dryer for static drying provided between the ml compressor 3 and the pipe P, and 9 is a solenoid valve for air discharge.

10 is the pressure switch 5. A control circuit inputs the detection signal B and controls the compressor 6 and the electromagnetic valves 4 and 9, 11 is an operation switch for operating the control circuit 10, and 12 is an indicator lamp for displaying the control status.

Next, the control circuit 1 of the vehicle height adjustment device configured as described above will be described.
0 will be explained based on FIG.

First, turn on the main switch SW1 (this may be linked to a key switch (not shown)) and then operate the operation switch 11 to the high side. Momentary contacts c and b close only during this operation, as shown by the broken line. , and toggle contacts S and A are kept closed. (The momentary contacts c and b are turned on only when the switch 11 is operated by hand, and the toggle contacts a and b remain on even if the switch 11 is released.) 1
If the internal pressure is below the pressure switch 50 set pressure (high) on the high pressure side, the pressure switch 5 is on, so relay RL is activated.
1 is activated. As a result, when the normally open contact RL1a turns on, the contact point RL1a, the diode D1, and the toggle contact a
, b and the pressure switch 5 on the high pressure side, the relay RL1 is self-held while the pressure switch 5 on the high pressure side is turned on, and when the normally open contact RL1a is turned on, the relay RL2 is activated and this is stopped. Normally open contact RL
2a starts the operation of the compressor motor 6. On the other hand, when the normally open contact RL1a is turned on, a current flows through the diode D4 to operate the solenoid valve 4 and open its flow path.

Then, the pressure switch 5 on the high pressure side turns off and relay RL1
Since the self-holding of the compressor 3 is released, the operation of the compressor 3 is stopped. However, in this example, the pressure switch 5 on the high pressure side is set so that its contact is turned off at a pressure of 5 kQ/d or more, as shown in FIG.

For this reason, the front side and rear side shield absorber 1
, 2 becomes 5 when the switch 11 is operated to the high side.
kg/d. Further, when the compressor 6 stops operating, the electromagnetic valve 4 is also released and the flow path of the pipe P is closed. Therefore, the front shock absorber 1 and the rear shock absorber 2 do not influence each other due to pressure fluctuations. (For example, the front and rear vehicle heights can be kept almost constant even on slopes, etc.) Similarly, if the switch 11 is operated to the low side this time, the internal pressure of the shock absorber 1.2 is 5, so the low pressure Since the side pressure switch 6 is closed and on as shown in FIG. 3, the relay RL3 is activated. Therefore, the normally open contact RL3a of this is turned on, and the contact point RL3a, the diode D2. It is self-maintained by a circuit consisting of toggle contacts d and e and the pressure switch 6 on the low pressure side, and the solenoid valve 4 and the solenoid valve 9 for air discharge are operated. Therefore,
The flow paths of the electromagnetic valves 4 and 9 are opened, and air is discharged from the electromagnetic valve 9 to the outside, thereby reducing the internal pressure of the shock absorbers 1 and 2. When this internal pressure is reduced to 3K, the pressure switch 6 is activated to turn off its contact as shown in FIG. Therefore, the solenoid valve 4.9 is deactivated and its flow path is closed, and the internal pressures of the front lock absorber 1 and the rear lock absorber 2 are maintained at 6.

By lowering the internal pressure of the lock absorbers 1 and 2 in this manner, the height of the vehicle can be lowered. Also,
If the switch 11 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 increase.

Note that 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. You can adjust it by.

Next, to explain the display lamp 12, the first lamp 1
2a lights up during adjustment to the high side and when adjustment is completed. That is, the base of the transistor Tr1, whose collector is connected to the first lamp 12a, is held at a low level by the resistor R1 unless the switch 11 is operated to the high side. Next, when the switch 11 is operated to &II, the contact a of the switch 11 becomes high level, so the resistance R
2, the pace of the transistor Tr1 is pulled up to a high level, and the first lamp 12a is turned on.

Similarly, the second lamp 12b lights up while the switch 11 is being adjusted to the low side and when the adjustment is completed. The third horn 12c lights up only during pressure increasing or decreasing operation (when the solenoid valve 4 is activated).

Note that the above-described sequence circuit may of course be constructed by a logic circuit using a normal semiconductor element. Further, in this example, the case where air is used as the fluid has been described, but it goes without saying that other fluids such as oil can also be used.

That is, the present invention provides a vehicle height adjustment device that sets the vehicle height using a pressure sensor, in which a solenoid valve is interposed between flow paths communicating with each shock absorber, so that the solenoid valve is not operated at times other than when adjusting the vehicle height. Due to the structure in which the flow path is closed, it is possible to provide a vehicle height adjustment device with an extremely simple structure and high reliability. Moreover, even though the fluid pressure of each shock absorber can be adjusted in common, the flow path connecting each shock absorber is closed by the solenoid valve except during this adjustment. It has a desirable feature that the front and rear vehicle heights can be kept almost constant even when there is a large difference in the loads applied to the side shock absorbers.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; Fig. 1 is an explanatory diagram showing the overall configuration of the vehicle height adjustment device, Fig. 2 is a circuit diagram of the control circuit, and Fig. 6 shows the operating state of the pressure switch. FIG. 1... Shock absorber on the front side 2... Shock absorber on the rear side 3... Compressor 4... Solenoid valve 5... Pressure switch on the high pressure side 6... Pressure switch on the low pressure side? - Solenoid valve 10 for air exhaust - Control circuit Applicant: Toyota Motor Corporation Representative Patent attorney: Hidehiko Okada

Claims (1)

[Claims] A vehicle height adjustment device that adjusts the height of a vehicle by supplying and discharging fluid to a plurality of shake absorbers, and sets the vehicle height using a pressure sensor that detects the pressure of the fluid. A solenoid valve is interposed in the flow path that communicates between each shock absorber, and when adjusting the vehicle height, the solenoid valve is opened to commonly adjust the fluid pressure of each shock absorber. A vehicle height adjusting device characterized in that the electromagnetic valve is otherwise shut off to close the flow path.