JPS58112817A - Method of controlling height of automobile with air suspension - Google Patents

Abstract

PURPOSE:To improve the posture-retaining performance of an automobile, by providing automobile height sensors for the air suspension units of all wheels and controlling the wheels independently of one another and by effecting air feed before air discharge when air feed/discharge signals are produced for plural wheels. CONSTITUTION:The ascent or descent signals of automobile height sensors for air suspension units A-D, which last longer than a time set by a timer T1, are entered into a controller 5. When the ascent signals are entered into the controller 5, the solenoid valve L1 of a reserve tank 3 is opened and the ascent signals are transmitted through OR circuits OR3-OR6 to open suspension air feed/discharge solenoid valves L3-L6. When the descent signals are entered into the controller 5, a solenoid valve L2 is opened. When the ascent and the descent signals are simultaneously generated, the ascent signal is applied prior to the descent signal by AND circuits AND7-AND10 to cause downward displacement after upward displacement. A proper posture is thus always maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle height control method for an air suspension for an automobile.

In an automobile wheel suspension system that uses an air suspension that utilizes the volumetric elasticity of air sealed inside, air is supplied from the outside to the air sealed part of the air suspension. The vehicle height can be lowered by discharging the air that is being held outside to the outside.In the air suspension described above, the present invention is capable of accurately and automatically controlling the vehicle height of all four wheels, front, rear, left and right, independently of each other. However, it is an object of the present invention to provide a vehicle height control method that makes it possible to maintain a correct vehicle posture at all times.

Figure 1 shows the air suspensions A, B, for the front, rear, left and right wheels.
This is a diagram showing the supply and exhaust systems of C and D. In the diagram t41, 1 is a compressor, 2 is a dryer, and 3 is a reserve tank. When the compressor 1 is driven, air is transferred to the reserve tank 3 via the dryer 2 and the solenoid valve Ij. Based on the signal from the vehicle height sensor (not shown) installed in each air subpension A, B, C, and DK, the air stored under pressure in the reservoir/reservoir 3 is transferred to each air suspension. Man.

Supply B, C, and DK respectively to raise the vehicle height,
Or exhaust pulp L! Open each air suspension A,
K is designed so that the air in B, C, and D can be discharged to the outside to lower the vehicle height.

Lh # L4 e Ll # Lb it When it comes to controlling the supply and exhaust of each air suspension A, kl, C, and D, the compressor 1 drive control solenoid L7 is activated to drive the compressor 1, and the reserve Air is supplied to the tank 3 to maintain the air pressure inside the reserve tank 3 at a predetermined value.

Reference numeral 5 denotes a control device, and the control device 5 controls each solenoid pulp L adapted to the signals based on inputs such as a signal from the vehicle height sensor and a signal from the pressure sensor 4.
6, the compressor drive control solenoid L1, etc. are controlled to be energized. 6 indicates a power source.

A specific circuit example of the control device 5 is shown in FIG.

That is, the control device 5 includes each air suspension A,
The up signal and down signal of each vehicle height sensor B, C, and D are inputted, respectively, and a timer T1 is provided in the input circuit for each of these signals, and the timer T1 is set. Short-term signals shorter than the set time are cut off here, and the signal is input only when the signal continues for the set time.This allows the vehicle to be controlled by temporary changes in vehicle height due to bounces, rebounds, etc. This prevents malfunctions in which the device 5 operates.

When the up signal among the above signals is input, an output signal to open the solenoid valve L1 of the reserve tank 3s is issued via the OR circuits ORt and ORt, and an up signal is issued via the OR circuits ORi to OR4. Air suspension air supply/exhaust solenoid pulp Lm
An output signal is issued to open L6 to L6, and air is supplied from the reserve tank 3 to the air suspension to raise the vehicle height.

When the down signal is input, the exhaust solenoid pulp L! is output via the OR circuit OR7. It emits an output signal to open the air suspension solenoid valves Ll to LA that have issued the down signal via OR circuits ORi to OR&, and also outputs an output signal to open the air suspension solenoid valves Ll to LA that have issued the down signal. It is designed to exhaust air from the suspension to the outside and lower the vehicle height.

When the pressure signal P of the pressure sensor 4 is input, an output signal is generated to open the solenoid valve L1 of the reserve tank 3s via the OR circuit ORz, and an output signal is output to operate the drive control solenoid L7 of the compressor t1. A signal is issued, the compressor 1 is driven, and air is supplied into the reserve tank 3, so that the air pressure in the reserve tank 3 is always maintained at a predetermined value.

In this case, when the air pressure in the reserve tank 3 drops and the pressure sensor 4 issues a signal, each air suspension A,
When any one of B, C, and D is discharging air, the compressor 1 is driven and Ll opens, and the air supplied by the compressor 1 and the air in the reserve tank 3 are discharged to the outside. It will be done. Therefore, an AND circuit AND1 is inserted in the input circuit of the signal P of the pressure sensor 4, and this solenoid pulp L! By inverting the output signal that activates the exhaust solenoid valve L with the inverter 11 and taking the AND of the output signal, the exhaust solenoid valve L
2 is open, the signal P of the pressure sensor 4 is canceled, and the exhaust solenoid valve L! After is closed, L
1 is opened, the compressor 1 is driven, and air is replenished into the reserve tank 3.

For example, when the vehicle height changes due to acceleration, such as when the vehicle turns or accelerates or decelerates, the G sensor 08 detects the acceleration, generates an acceleration signal K, and inverts the acceleration signal K at will by the inverter. Based on the signals and the operation of each of the air valves L2 to L4, when an acceleration of a predetermined value or more is applied, the air suspension is not supplied or exhausted at all.

Incidentally, the supply and #P operation cut by the signal KK of the G sensor GS may be provided on the input circuit side of the vehicle height sensor signal to cut off the human power of the vehicle height sensor signal.

K and each air suspension A as above.

In systems that automatically control air supply and exhaust for B, C, and D separately, the up and down signals are emitted in duplicate, such as one suspension emitting an up signal and another air suspension emitting a down signal at the same time. Sometimes. In this case, if air supply and exhaust operate simultaneously, the air in the air suspension that should be supplied will also be exhausted to the outside, lowering the vehicle height and possibly causing a serious accident such as the vehicle touching the ground.

Therefore, in the present invention, as shown in FIG. 2, AND circuits ANDy to AND+ are used as the down signal input circuit.

are interposed respectively, and the AND circuits AND7 to AND@
By inverting the up signal with an inverter Is and adding a circuit to AND the two, when the up signal is input, the input of the down signal is stopped, and after the up operation is completed, the down signal is input. A signal is input to perform the down operation.

In this way, when the up signal and down signal are issued twice, priority is given to the up operation, and the down operation is performed after the up operation is completed, thereby completely preventing accidents such as the vehicle body touching down as described above. It is something that can be prevented.

In FIG. 2, T is a timer, which is used to keep the control device 5 plowing for a predetermined time set after the ignition switch Ig is turned off and the engine is stopped.

That is, when the engine is stopped and the occupant exits the vehicle, the vehicle height changes as the occupant exits the vehicle. Therefore, the timer T2 is set to 5 to allow the control device 5 to operate for a predetermined period of time even after the engine is stopped. From 1 and K, the control device 5 corrects the change in vehicle height after the passenger exits the vehicle, and maintains the correct vehicle posture. After that, the control device 5 is automatically activated by the timer TzK.
This function allows the vehicle to maintain the correct posture during parking.

The setting time of the timer T2 is approximately 1 minute to several minutes, which is enough to achieve the desired purpose.

As described above, according to the present invention, it is possible to independently and automatically control the vehicle height of the air suspension of all the front, rear, left and right wheels, and it is possible to maintain the correct vehicle posture at all times.
When the air supply signal and exhaust signal are duplicated from two or more suspensions, the air supply signal is given priority and the exhaust operation is performed after the air supply operation is completed. This can completely prevent the danger of air being discharged in the opposite direction, and can bring about a great practical effect.

[Brief explanation of the drawing]

Figure 1 shows an example of an air suspension air supply/exhaust system, and Figure 2 shows an example of the circuit of the control device shown in Figure 1. 1... Compressor, 3... Reserve tank, 4...
...Pressure t>y, s...Control device, 6...
tilt, A, B, C, D...air suspension,
L1~G...Solenoid pulp, OR1~7...OR circuit, AND1~1o...AND circuit, 11~M...
・Inverter, T+, Tz...timer. Same as above Takuo Adachi rfI chief)i

Claims (1)

[Claims] In an air suspension that makes it possible to adjust the vehicle height by filling air inside and supplying air to the sealed part and discharging the air inside the sealed part to the outside, air suspension for all wheels on the front, rear, left and right sides. A vehicle height sensor is installed in each of the air suspensions, and air supply and exhaust are performed independently for each air suspension based on the air supply signal and exhaust signal from the vehicle height sensor, and air supply and exhaust signals are transmitted from two or more air suspensions. A vehicle height control method for an air suspension for an automobile in which when multiple signals are issued, priority is given to the air supply signal, and the exhaust operation is performed when the air supply operation is completed*.