JPH0569724B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of controlling a pneumatic vehicle height adjustment device.

[Prior art]

Conventionally, pneumatic vehicle height control systems only made adjustments when the ignition switch (hereinafter referred to as Ig, Sw) was turned on and the engine was running, but it is now possible to adjust the height of the vehicle when the ignition switch (hereinafter referred to as Ig or Sw) is turned on and the engine is running. and Ig, Sw are OFF
Since it is convenient to continue the adjustment operation for a certain period of time even after the adjustment, a vehicle height adjustment device with a self-destruct function and a built-in delay circuit has been proposed, for example, in Japanese Patent Laid-Open No. 56-99808.

[Problem to be solved by the invention]

However, the self-destruction function described above can only be adjusted to lower the vehicle height, and adjustment to raise the vehicle height during the self-destruction operation is prohibited in consideration of battery discharge. In other words, pneumatic vehicle height adjustment is normally performed by intake and exhaust air into an air spring, but compressed air must be sent in during intake, and a compressor (motor) must be driven, so when the engine is stopped, ,
Since the motor drive (approximately 10A) puts a heavy burden on the battery, we had no choice but to prohibit intake operation.

An object of the present invention is to provide a pneumatic vehicle height adjustment device that eliminates the drawbacks of the prior art vehicle height adjustment device described above and is capable of controlling the vehicle height up and down even after the ignition switch is turned off. It is in.

[Means to solve the problem]

The above objects include: an air spring that adjusts the vehicle height of a vehicle; and an intake/exhaust valve means that is driven in response to a vehicle height adjustment signal and discharges air from the air spring to the outside or supplies air to the air spring. , a high-pressure reserve tank that stores high-pressure air to be supplied to the air spring; a pressure sensor that detects the pressure of the high-pressure reserve tank; and a pressure sensor that is activated when the output of the pressure sensor falls below a predetermined value to supply air to the high-pressure reserve tank. In the control method for a pneumatic vehicle height adjustment device having a compressor that supplies a After the engine switch is opened, stopping of the engine is postponed for a predetermined period of time, and the compressor is driven to increase the pressure in the high-pressure reserve tank to a pressure sufficient to adjust the vehicle height upward, and then the engine is stopped. This is achieved by

[Effect]

With the present invention configured in this way, even if the pressure in the reserve tank drops below the pressure required to raise the vehicle height when the ignition switch is turned off to stop the engine, Before the engine stops, the pressure in the reserve tank can be increased above the pressure required to raise and adjust the vehicle height.

As a result, even after the ignition switch is turned off, it is not only possible to perform a self-destructive action that lowers the vehicle height, but also to raise and adjust the vehicle height. ,
If the vehicle is equipped with a height adjustment device, it will be possible to automatically return it to an initial position higher than the current position, resulting in an extremely user-friendly vehicle height adjustment device.

〔Example〕

A pneumatic vehicle height adjustment device generally includes a high-pressure air reserve tank means, a pressure drop detection means in the tank, and a self-destruct circuit means. A basic configuration block diagram of the pneumatic vehicle height adjustment device according to FIG. 2 is shown. Basically, vehicle height adjustment is to adjust the height of the air spring 8 to be constant.

First, when lowering the vehicle height, by opening the exhaust valve 5, air from the air spring 8 passes through the dryer 4 and is exhausted to the outside air, the pressure inside the air spring 8 decreases, and the vehicle height decreases.

On the other hand, when raising the vehicle height, the exhaust valve 5 is closed, the reserve tank valve 3 is opened, and compressed air is sent from the high-pressure air reserve tank 1 to the air spring 8 to raise the vehicle height. However, since the reserve tank 1 is not inexhaustible, the pressure drop detection means 2 monitors the pressure in the reserve tank 1, and if the pressure drops below a certain value, the compressor 7 is rotated via the motor 6, and the dryer 4, High pressure air is stored via reserve tank valve 3.
Now, if we consider the case when Ig and Sw are turned OFF and the engine stops, the exhaust operation only requires opening and closing of the exhaust valve 5, but the intake operation depends on the pressure in the reserve tank 1 at that time. That is, when the pressure is high, it is sufficient to open and close the reserve tank valve 3, but when this air pressure is low and the low pressure detection means 2 is ON, it is necessary to operate the compressor 7 of the motor 6 at the same time. Yes, this increases the burden on the battery.

From the above, by controlling the high-pressure air reserve tank 1 so that it is always at high pressure when the engine is stopped, the intake operation after the engine is stopped is performed only by the reserve tank valve 3, and a drop in battery can be prevented. I can do it.

Next, an embodiment of the present invention will be described below with reference to FIG. In this embodiment, the heights of the front and rear wheels are independently detected by a front (FRONT) vehicle height sensor 23 and a rear (REAR) vehicle height sensor 24, and the front air spring 11 and rear air spring are detected by the front valve 12 and rear valve 19. 21 independently.
The vehicle height control operations on the front and rear sides are the same, so the operations on the rear and front sides will be explained at the same time.

First, when Ig and Sw are turned ON, vehicle height adjustment means 2
2 starts adjustment. Input signals include a rear vehicle height sensor 24 (front vehicle height sensor 23) and a tank low pressure detection switch 20, and the input signals are processed and output to four valves in the air system, namely exhaust valve 1.
8. Reserve tank valve 13, rear valve 1
9. Drive (front side valve 12). When receiving a "high" signal from the rear vehicle height sensor 24, the vehicle height adjusting means 22 outputs a drive signal to the exhaust valve 18 and the rear valve 19, and exhausts air from the rear air spring 21. On the other hand, when receiving a signal indicating "low" from the rear vehicle height sensor, the vehicle height adjusting means 22 drives the reserve tank valve 13 and the rear valve 19, and the high pressure air reserve tank 14 causes the rear air spring 21 to Inhale. Normally, the above adjustments are performed in a closed loop.

Next, when Ig and Sw are ON, if the pressure in the high pressure air reserve tank 14 falls below the specified value, the vehicle height adjustment means 22 controls the motor 17, compressor 16, and reserve tank valve in response to a signal from the low pressure detection switch 20. 13, dryer 1
5, high pressure air is supplied to the high pressure air reserve tank 14. Although the high-pressure air reserve tank 14 is thus configured to be replenished with air, the replenishment period also varies depending on the setting value of the low-pressure detection switch 20, hysteresis, and the like.
For example, if Ig and Sw are turned OFF, the pressure inside the tank may have dropped by chance, and the low pressure detection switch 20 will be activated.
When Ig and Sw are turned ON, the self-destruction function, which makes use of vehicle height adjustment for a certain period of time after Ig and Sw is turned off, is disturbed. In other words, after Ig and Sw are OFF, motor 17,
Since the compressor 16 cannot be driven, high pressure air cannot be supplied.

Therefore, according to the present invention, as shown in the embodiment, the OFF signals of Ig and Sw and the low pressure detection switch 2
The ON signal of 0 is processed by the engine stop means 26, which is composed of a microcomputer, and has the function shown in FIG. In other words, Ig, Sw
If the low pressure detection switch 20 is ON when the low pressure detection switch 20 is turned OFF, normal replenishment operation (driving the motor 17, compressor 16, and reserve tank valve 13) is performed without stopping the engine, and after the low pressure detection switch 20 is OFF, For the first time, the engine is stopped by the engine stop means. Furthermore, the replenishment operation after Ig and Sw is turned off is linked, and the indicator 27 indicates the operation to the driver. However, as shown in the flowchart in Figure 3, the replenishment operation after Ig and Sw are turned off is limited to one time. This depends on the self-destruction operation time and the frequency of adjustment operations, but one-time replenishment is sufficient for normal adjustment.

According to this embodiment, when a replenishment operation after Ig, Sw, OFF is required, the driver is notified by an indicator, which has the effect of not giving the driver anxiety that the engine will not stop due to Ig, Sw, OFF. be.

Next, the control contents of the above-mentioned engine stop means 26 will be explained in detail with reference to a control flowchart.

First, after reading that Ig and Sw are OFF (step 100), it is determined that the pressure switch is OFF (step 110), and this pressure switch is
Make sure that the engine does not stop until it is turned off.

That is, in step 120 flag A=1
(Flag A is written as "1" when the engine is stopped and "0" when the engine is started.) This is "1".
If not, the decision will be “NO” and the step will not proceed.
At 130, the compressor is started and the air pressure in the reserve tank is increased. Thereafter, this operation is repeated several times until the low pressure detection switch is turned off in step 110, that is, until the air pressure in the reserve tank reaches a predetermined value. When the low pressure detection switch is OFF, the engine is stopped (step 140) and flag A is set to "1".
is written (step 150). Furthermore, if flag A is "1" in step 120 in the figure (that is, the judgment is "Yes"), this indicates that the engine is stopped, so in this case, starting the compressor is prohibited. (Step 160). This ensures that high-pressure air is stored in the reserve tank when the engine is stopped, allowing several intake operations to be performed.

By performing the above control, it is possible to ensure that the intake and exhaust operations are performed a certain number of times for a certain period of time after the engine is stopped.

〔Effect of the invention〕

According to the present invention, it is possible to obtain a pneumatic vehicle height adjustment device that has a function of adjusting vehicle height by intake and exhaust operations for a certain period of time even after Ig and Sw are turned off, and can adjust both raising and lowering of the vehicle height. can.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the invention;
Figure 2 is a basic block diagram of the vehicle height adjustment system.
FIG. 3 is a diagram showing a control flowchart in the present invention. 1... High pressure air reserve tank, 2... Pressure drop detection means, 3... Reserve tank valve, 4...
...Dryer, 5...Exhaust valve, 6...Motor, 7...Compressor, 8...Air spring, 11
...FRONT side air spring, 12...FRONT side valve, 13... Reserve tank valve, 14...
High pressure air reserve tank, 15... dryer,
16...Compressor, 17...Motor, 18
...Exhaust valve, 19...REAR side valve, 2
0...Low pressure detection Sw, 21...REAR side air spring,
22...Vehicle height adjustment means, 23...FRONT side vehicle height sensor, 24...REAR side vehicle height sensor, 26...
...Engine stop means, 27...Indicator means.

Claims (1)

[Scope of Claims] 1. An air spring that adjusts the vehicle height of a vehicle, and an air intake that is driven in response to a vehicle height adjustment signal and that releases air from the air spring to the outside or supplies air to the air spring. Exhaust valve means, a high-pressure reserve tank storing high-pressure air to be supplied to the air spring, a pressure sensor that detects the pressure of the high-pressure reserve tank, and the high-pressure reserve tank that is activated when the output of the pressure sensor falls below a predetermined value. In the control method for a pneumatic vehicle height adjustment device having a compressor that supplies air to a vehicle, when it is determined that the output of the pressure sensor is not sufficient pressure to adjust the vehicle height upward when the ignition switch is opened. , after the ignition switch is opened, stopping the engine is postponed for a predetermined period of time, driving the compressor to increase the pressure in the high pressure reserve tank to a pressure sufficient to adjust the vehicle height upward, and then stopping the engine. A method for controlling a pneumatic vehicle height adjustment device, characterized in that: 2. The engine according to claim 1, characterized in that after the ignition switch is opened, an indicator is used to notify the user that the engine has been postponed for a predetermined period of time after the ignition switch has been opened. A method of controlling a pneumatic vehicle height adjustment device.