JPH039231Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a control circuit for a vehicle height adjustment device.

In recent years, vehicle height adjustment devices that use shock absorbers that expand and contract by supplying and discharging fluid have been put into practical use, but in the case of such devices, the control circuit is an important component that affects cost and reliability. It is one of the elements.

In recent years, with advances in semiconductor devices, control circuits have generally tended to be constructed from logic circuits using semiconductors. On the contrary, using semiconductors is disadvantageous.

In other words, since the conditions in which control circuits are installed in vehicles are extremely poor, such as changes in power supply voltage, temperature changes, and vibrations, in order to prevent malfunctions caused by these factors, it is necessary to install a constant voltage circuit, carefully select circuit elements, etc. The drawback was that it required a lot of time and production costs were high.

The present invention was developed in view of the above-mentioned drawbacks, and it is possible to automatically control the vehicle height to a predetermined level by simply operating the operation switch with a single touch, and has a simple structure and low cost without using semiconductor logic elements. The purpose of this invention is to provide a control circuit for a vehicle height adjustment device that can be used in a vehicle height adjustment system.

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 front solenoid valve 4 is installed between the compressor 3 and the front shock absorber 1.
A rear solenoid valve 5 is provided between the rear shock absorber 2 and the rear shock absorber 2.

A pressure switch 6 on the high pressure side and a pressure switch 7 on the low pressure side, which serve as pressure sensors, are provided between the front solenoid valve 4 and the front shock absorber 1.
A pressure switch 8 on the high pressure side and a pressure switch 9 on the low pressure side, which also serve as pressure sensors, are provided between the shock absorber 2 and the rear shock absorber 2. Note that a piezoelectric element, a resistance wire strain gauge, or the like may be used as the pressure sensor.

Reference numeral 10 denotes sub-tanks provided in the front and rear air pipes P, respectively, for reducing the spring constant of the shock absorbers 1 and 2 due to the air pressure.

11 is a dryer for air drying provided between the solenoid valves 4, 5 and the compressor 3, and 12 is a solenoid valve for air discharge.

13 inputs the detection signals of the pressure switches 6 to 9 and operates the compressor 3 and the solenoid valves 4, 5,
12 is a control circuit that controls the control circuit 13; 15 is the same control circuit 13;
This is an indicator lamp that displays the control status of the

Reference numeral 14 denotes an operation switch for controlling the control circuit 13, and in this example, as shown in FIG.
a, and a bidirectional type residual contact 14b that operates in conjunction with this.

Next, the control circuit 13 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 14 to the high side.The automatic reset contact 14a causes the terminals c and b to be turned on only during this operation. Closed and residual contact 1 as shown by the dashed line
4b keeps the terminal ba closed. (Terminals c and b of the automatic return contact 14a are connected to the operating switch 14.
Turns on only when operated by hand, remaining contact 1
Terminal ab of terminal 4b remains on even if the operating switch 14 is moved. ) During this operation, if the internal pressure of the shock absorbers 1 and 2 is lower than the set pressure (high) of the pressure switches 6 and 8 on the high pressure side, the pressure switches 6 and 8 are turned on as shown in Fig. 3, so the diode A current flows through D1 and D2, and relay RL1 for the first self-holding circuit is activated.
As a result, when the normally open contact RL1a turns on, the contact RL1a, the diode D3, and the residual type contact 14
terminals a, b of b and pressure switches 6, 8 on the high pressure side
The first self-holding circuit consisting of the same relay RL
1 is self-retained. (At this time, the second self-holding circuit, which will be described later, is prohibited because the terminals d and e of the residual contact 14b are turned off.) At the same time, the relay RL2 is turned on by the normally open contact RL1a. is activated and its normally open contact RL2
a is turned on and the compressor motor 3 starts operating. On the other hand, the front solenoid valve 4 is connected to the pressure switch 6, and the rear solenoid valve 5 is connected to the pressure switch 8, so that they operate simultaneously to open the flow path. Note that if only one of the pressure switches 6 and 8 is turned on, only the solenoid valve on the side of the pressure switch that is turned on operates.

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 switches 6 and 8 on the high pressure side are turned off and the operation of the compressor 3 is stopped. However, in this example, the operating pressure of pressure switches 6 and 8 on the high pressure side is
It is set to 5K and 5.5K respectively. Therefore, when the pressure reaches 5K, the pressure switch 6 is activated (turned off) and the solenoid valve 4 is closed. As a result, the internal pressure of the front shock absorber 1 is 5K.
However, since the pressure switch 8 is not yet activated at this point, air is sent to the rear shock absorber 2 by the compressor 3. And this rear shock absorber 2
When the internal pressure reaches 5.5K, the pressure switch 8 is activated (turned off) and the solenoid valve 5 is closed. Then, when both pressure switches 6 and 8 are turned off, relay RL1
The first self-holding circuit including the first self-holding circuit and the relay RL2 are deactivated, and the compressor 3 is stopped. In this way, the height of the vehicle is adjusted to the higher side.

Next, when the operation switch 14 is operated to the low side, terminals c and d are closed by the automatic return contact 14a as shown by the broken line only during this operation, and the terminal de is closed by the residual contact 14b. It is maintained.
(Terminals c and d of the automatic return contact 14a are turned on only when the operation switch 14 is manually operated to the low side, and terminals d and e of the residual contact 14b remain on even when the operation switch 14 is released. )The internal pressures of the shock absorbers 1 and 2 are 5K and 5.5K when they are operated to the high pressure side, so the pressure switches 7 and 9 on the low pressure side are
Since it is closed and on as shown in the figure, solenoid valves 4 and 5 and relay RL3 operate. Therefore, the normally open contact RL3a of relay RL3 is turned on, and the contact RL3a, diode D12, toggle contact d,
e and a second pressure switch consisting of pressure switches 7 and 9 on the low pressure side.
The solenoid valve 12 is operated while being self-held by the self-holding circuit. (Note that the first self-holding circuit is disabled because the terminal de on the residual contact 14b side is turned off.) Therefore, the flow paths of the solenoid valves 4, 5, and 12 are opened by the above operation. , air is discharged to the outside from the solenoid valve 12, and the internal pressure of the shock absorbers 1 and 2 decreases. In this example, the pressure switch 7 is set to operate at a pressure of 2K and the pressure switch 9 is set to operate at a pressure of 2.3K, so when the internal pressure of the rear shock absorber 2 is reduced to 2.3K, the pressure shown in FIG. Pressure switch 9 is first actuated to open its contacts as shown. Therefore, the solenoid valve 5 is deactivated and its flow path is closed, so that the internal pressure of the rear shock absorber 2 is maintained at 2.3K. At this point, as shown in FIG. 3, the pressure switch 7 is on, so the flow path between the solenoid valves 4 and 12 is open, and the internal pressure of the front shock absorber 1 continues to decrease.
And the internal pressure of this shock absorber 1 is 2K
When the pressure is reduced to 2K, the pressure switch 7 operates and opens its contacts, and the solenoid valve 4 is deactivated to maintain the internal pressure of the shock absorber 1 at 2K.
Further, the operation of the solenoid valve 12 is also canceled.

Next, the display lamp 15 will be explained.
The lamp 15a 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 15a is connected to the switch 14.
When is not operated to the high side, diode D4,
The base is held at a low level via pressure switches 6, 8, diodes D7, D9, and solenoid valves 4, 5 (or diodes D1, D2 and relay RL1). Next, when the switch 14 is operated to the high side, the contact b of the switch 14 becomes high level, so that the transistor is connected by the resistor R1.
The base of Tr1 is pulled up to high level and the first lamp 15a is lit. Also, the second lamp 1
5b lights up while adjusting the switch 14 to the low side and when the adjustment is completed. The third lamp 15c is lit during pressure increasing operation (when the compressor is operating), and the fourth lamp 15d is lit during pressure reducing operation (when the solenoid valve 12 is operating).

In this way, in this example, the vehicle height is automatically controlled to a predetermined low or high vehicle height by simply operating the operating switch 14 with a single touch. Moreover, the prohibition circuit that prevents both the first and second self-holding circuits from operating at the same time when the operating switch 14 is accidentally operated to the low side while adjusting the vehicle height to a high vehicle height is the residual contact 14b.
The circuit is simplified by the amount of this remaining contact 14b.

Note that although this example describes the case where air is used as the fluid, other fluids such as oil can also be used.

In other words, the present invention provides the first method of adjusting the vehicle height to the higher side.
A control circuit for a vehicle height adjustment device including a self-holding circuit, a second self-holding circuit that adjusts the vehicle height to a lower side, and an operation switch that sends an activation signal and a prohibition signal to the first and second self-holding circuits. By configuring this, the vehicle height can be automatically controlled to a predetermined height by just one-touch operation of the operating switch, and the cost can be reduced due to the simple configuration without using semiconductor logic elements. It has an excellent feature of being able to provide a control circuit.

[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, 6, 8... High pressure side pressure switch (pressure sensor), 7, 9... Low pressure side pressure switch (pressure sensor), 12... Solenoid valve, 13... ...control circuit.

Claims (1)

[Scope of utility model registration request] A first self-holding circuit made up of relays for operating a compressor motor that compresses fluid; and a second self-holding circuit made of relays for operating a solenoid valve that discharges fluid. ,
A bidirectional type automatic return contact that generates a starting signal to activate the first and second self-holding circuits, and a bidirectional type automatic return contact that generates a starting signal to activate the first and second self-holding circuits, and both relays to prohibit the activation of the other self-holding circuit when one self-holding circuit is activated. 1. A control circuit for a vehicle height adjustment device, comprising an operating switch comprising a self-holding contact and a bidirectional residual contact connected in series and operating in conjunction with the automatic return contact.