JPH03239615A - Vehicle floor height adjusting device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is an air suspension system for a vehicle, and when overload is detected, the compressor is stopped to prevent overpressure and the vehicle height is adjusted. The present invention relates to a vehicle height adjustment device for a vehicle that is controlled to stop the vehicle.

(Prior Art) Conventionally, compressed air is supplied to an air suspension installed between the vehicle body and each wheel, and the vehicle height is adjusted by controlling the supply and discharge of this compressed air. Many high adjustment devices are used, for example,
Various proposals have been made, such as the one disclosed in Publication No. 137.

These vehicle height adjustment devices generally include an air suspension installed between the vehicle body and each wheel to adjust the vehicle height of each wheel, a vehicle height sensor that detects the vehicle height of each wheel, and an air chamber in each air suspension. A vehicle height adjustment valve device that controls supply and discharge of compressed air to the vehicle, a pressure switch to prevent overpressure in the pneumatic circuit, and a control unit that controls each operation based on signals from each vehicle height sensor. , this control 1 uni 1
At the vehicle height sensor, the detection signal value of the vehicle height sensor of each wheel is compared with the target vehicle height value, and the supply and discharge of compressed air is controlled through the operation control of the vehicle height adjustment valve device to adjust the vehicle height. It is.

<Problem to be solved by the invention;> However, in the conventional vehicle height adjustment device described above, in order to prevent overpressure in the overloaded pneumatic circuit, when the pressure from the compressor exceeds a predetermined value, the compressor This is suitable for W4, which requires a pressure valve to be installed in the pneumatic circuit to stop the compressor operation when the contacts of the relay are separated.

Since the pressure switch is placed in the middle of the piping, it is necessary to set up the body and fittings for the pressure switch.
However, there were problems such as the need for a harness to input the pressure switch signal to the control unit, making the system complex and costly.

The present invention has been made in view of the above-mentioned problems, and the relief pressure of the exhaust valve installed in the compressor is set higher than the practical i & high pressure, and when the relief pressure reaches the above-mentioned level, the discharge from the compressor/saucer is stopped. Vehicle height adjustment that suppresses the pressure and stops the vehicle height from rising, and also prevents compressor overload by stopping the compressor if the vehicle height does not rise even after the compressor operates for a predetermined period of time. The purpose is to provide a device.

・〈Means for solving the problem;〉 In order to achieve this object distantly, the present invention provides an air suspension installed between the vehicle body and each axle to adjust the vehicle height of each wheel, and an air suspension for each wheel. A vehicle height sensor that detects the vehicle height, a vehicle height adjustment valve device that controls the supply and discharge of compressed air to and from the air chamber of the air suspension of each wheel, and a vehicle height adjustment valve that receives the signal from the vehicle height sensor. In a vehicle height adjustment device equipped with a control unit that controls the operation of the device, when the pressure on the discharge side of the compressor exceeds a preset relief pressure, the pressure in the pneumatic circuit of the air suspension is reduced from the exhaust valve. In addition to providing relief, if the vehicle height does not rise to a specified level within a predetermined time when the vehicle height rises based on the visual vehicle high signal from the control unit, it is determined that the vehicle is overloaded and is controlled to stop the operation of the compressor. It is characterized by this.

(Function) Based on such a configuration, the present invention allows the vehicle height increase request signal to be controlled by the vehicle height sensor signal or the select switch in the vehicle interior! input to activate the compressor. At this time, if the vehicle is overloaded, the pressure in the pneumatic circuit system increases L and the exhaust valve relief mechanism operates to release compressed air to the atmosphere, so the compressor discharge pressure is set in advance. The pressure will not rise above the relief pressure of the exhaust valve.

Therefore, overloading the compressor is prevented, and even if the compressor operates for a predetermined period of time, if it is determined that the vehicle height will not rise based on the signal from the vehicle height sensor, the compressor will stop operating. Overpressurization of the pneumatic circuit system is prevented.

- [Example] Hereinafter, the configuration of a vehicle height adjustment device according to the present invention will be described in detail based on the drawings.

FIG. 1 is a schematic circuit diagram showing a vehicle height adjustment device according to the present invention. In the figure, reference numeral 1 is a compressor that serves as a pressure source for this vehicle height adjustment device, 2 is a motor that drives this compressor 1, and 3 is a compressor connected to the discharge side and suction side of the compressor V1, which is connected to the air suspension's pneumatic pressure. This is an exhaust valve that releases the pressure in the circuit to the atmosphere. When the pressure on the discharge side of the compressor 1 exceeds a preset relief pressure, the exhaust valve relieves and releases the compressed air to the atmosphere. There is.

A dryer 4 is connected to the discharge side of the compressor 1, and the compressed air discharged from the compressor 1 is dehumidified by the dryer 4 and sent to the air suspension of each wheel.

A supply valve 6a for supplying and discharging compressed air to the suspension system of each wheel is connected to a conduit through which compressed air is sent to the air suspension of each wheel via the dryer 4.
, 6b, 6c, these supply valves 6a! : Front right wheel, 6b is front left wheel, 6
c is for each air suspension for the rear right and left wheels.

6d is a through valve that opens and closes the flow path between the rear right and left suspension systems. Each supply valve 6a
, 6b, 6c, and the through valve 6d are connected to sub-tanks 7a, 7b, 7c, and 7d for changing spring constants, and minimum pressure guarantee valves 8a, 8b, and 8c, which are all check valves, are provided along the way. , 8d and check valves 9a, 9b
9c and 9d are interposed in parallel. Furthermore, cut valves 10a, 10b, 10C, and 10d for opening and closing each flow path are provided in the air flow path from the sub-tanks 7a, 7b, 7c, and 7d to each air suspension.

The air suspension for each wheel is either for the front right and left wheels or struts 11a and Ilb with integrated air springs.
, shock absorbers 12a and 12b for the rear right and left wheels are integrated with air springs. Each wheel has a front variable resistance vehicle height sensor 13a.
, 13b and a rear variable resistance vehicle height sensor 14. 15 is a control unit that controls the air suspension of each wheel. This control unit 15 includes each vehicle height sensor 13a.

Signals from 13b and 14 are input, and signals calculated by the comparison means, control means, etc. are output to the exhaust valve 3, each supply valve 6a, 6b, 6c, through valve 6d, cut valve 10a, 10b, 10c10d, and motor 2. It is designed to perform vehicle height adjustment control.

Here, what is indicated by a broken line in the figure is each vehicle height sensor 13a.
, 13b, 14 are sent to the control unit 15.
The line indicated by the two-dot chain line is a control signal line that transmits the control signal output from the control unit 15 to each device. Note that, for convenience of explanation, the control signal line (two-dot chain line) is shown only for the air suspension of the front right wheel, but it is similarly provided for the air suspension of the other wheels.

On the other hand, the exhaust valve 3 connected to the discharge side and suction side of the compressor 1 has a base 37 as shown in Fig. 1M2.
A casing 34 installed with bolts or the like with a seal 371 airtightly interposed between the casing 34, three lids closing the upper opening of the casing 34, and a chamber formed by the lid 39 and the casing 34. The bobbin 35 housed in the bobbin 34a and the bobbin 3
The solenoid 3 is installed in the housing 34 surrounding the solenoid 5.
0, and an exhaust pulp valve 32 slidably housed within the bobbin 35.

The exhaust valve 32 includes a valve body 321 that slides within the bobbin 35, and a valve body 323 made of an elastic material and fitted into a center hole 322 of the valve body 321.

A spring 31 is compressed between this valve body 321 and a stopper 36 fixed in the bobbin 35, and the exhaust valve 32 is always urged downward to keep the bottom 323a of the valve body 323
This blocks communication between the compressed air inlet 38 of the compressor I formed in the base 37 and the atmosphere opening port 33 .

Further, the upper part of the valve body 323 slightly protrudes from the valve body 321 to perform an llfr action with the stopper 36.

When the control unit 15 determines that overloading occurs when the vehicle height does not rise to a specified level within a predetermined period of time when the vehicle height is raised based on the target vehicle height signal, the exhaust valve 3 energizes the solenoid 30 based on the signal. The valve body 321 and the valve body 323 are slid upward in the figure against the spring 31, and the valve body 323 communicates the inlet 38 with the atmosphere release port 33, and the compressed air is released from the atmosphere release port 33 to the atmosphere. Provides a relief effect.

Also, when the pressure on the discharge side of the compressor 1 communicating with the pneumatic circuit exceeds the relief pressure set in advance by the spring pressure of the spring 31, the valve body 3 of the exhaust valve 3
21 is slid upward in the figure against the spring 31, and at the same time, the valve body 323 connects the inlet 038 and the atmosphere release port 33, and the compressed air is released from the atmosphere release port 33 to the atmosphere. Do this.

The operation of the vehicle height side M device according to the present invention configured as described above will be explained based on the flowchart of FIG.

First, use the stay 7 S 1゜1 to check the vehicle height sensor 13 for each wheel.
The detection signal of the vehicle height value is read into the control unit 15 from a, 13b, and 14, and in step 1o2, when there is a request to raise the vehicle height, the compressor 1 is operated in the steering wheel 103, and the control unit 15 compares in step S104. The means determines whether the vehicle height signal reaches the target vehicle height within a predetermined time (A seconds). Then, in the control unit 1, the vehicle height value signal calculates the control 31i of each wheel with respect to the target vehicle height value, and based on the output of the control means, the vehicle height adjustment valve device of each air suspension,
That is, supply valves 6a, 6b, 6c through valves 6d, cut valves 10a, 10b, 10c10d,
A control signal is output to any of the exhaust valves 3 to control the sub tanks 7a, 7b, 7c, and 7d of each air suspension, the struts 11a, 11b, and the shock absorber 12a.
, 12b, compress...! If the vehicle height signal reaches the target vehicle height within a predetermined time (A seconds), the process proceeds to S105 and the target vehicle height is reached. Stop the operation from compressor 1.

In addition, if the vehicle height value signal of vehicle height set/body 4 does not reach the target vehicle height value within a predetermined time (A seconds) in step 3104, the process proceeds to 6, stay 7" A second) It is determined whether or not the vehicle height has risen by a predetermined value (B am ) or more during the elapsed land period. If the vehicle height has risen by a predetermined value (B rm ) or more, the process proceeds to step S1.7 and the timer starts. It is re-centered, and the operation of step S L04 is repeated again.

On the other hand, if the vehicle height does not rise by more than a predetermined value (B rm ) after a predetermined period of time (A seconds) has elapsed in step +r7S+o6, the process proceeds to step 5IOi1, where compressor 1 is activated to prevent overpressure in the pneumatic circuit. A signal to stop the motor is output from the control unit 15 to the motor 2, and
In step S1°, the vehicle interior monitor (for example, a display lamp) is arranged to display an overload indication to the occupants.

<Effects of the Invention:> As explained above, the vehicle height adjustment device according to the present invention exhausts the pressure in the pneumatic circuit of the air suspension when the pressure on the discharge side of the compressor exceeds a preset relief pressure. In addition to providing relief from the valve, if the vehicle height does not rise to the specified level within a predetermined time when the vehicle height rises based on the target vehicle height signal from the control unit, it is determined that the vehicle is overloaded and controls the compressor/sower to stop operating. It's Tenarushino. Therefore, there is no need to provide a pressure switch in the pneumatic circuit as in the conventional example, making it possible to simplify the system and reduce costs.Furthermore, when overloaded, the compressor can be stopped by stopping its operation. Overload on the saucer can be prevented, and when the pressure in the pneumatic circuit reaches the relief pressure or higher, the exhaust valve opens to release the air to the atmosphere, so it is possible to prevent excessive pressure rise in the pneumatic circuit.

[Brief explanation of drawings]

FIG. 1 is a schematic circuit diagram showing a vehicle height adjustment device according to the present invention, FIG. 2 is an enlarged sectional view showing the configuration of an exhaust valve, and FIG. 3 is a flowchart explaining the operation of the control unit. 1... Compressor, 3... Exhaust valve, 6a, 6b, 6c,... Supply valve, 6d...
Through valve, 10a, 10b, 10c, 10d...Cut valve, 11a, llb...Strut, 12a, 12b...Shock absorber 13a 1
3b, 14---vehicle height sensor, 15...control unit.

Claims (1)

[Claims] An air suspension installed between the vehicle body and each axle that adjusts the vehicle height of each wheel, a vehicle height sensor that detects the vehicle height of each wheel, and compressed air from a compressor to the air chamber of the air suspension of each wheel. In a vehicle height adjustment device that includes a vehicle height adjustment valve device that controls air supply and exhaust, and a control unit that controls the operation of the vehicle height adjustment valve device based on a signal from the vehicle height sensor, the pressure on the discharge side of the compressor is When the relief pressure exceeds a preset relief pressure, the pressure in the pneumatic circuit of the air suspension is relieved from the exhaust valve, and the vehicle height is raised to the specified height within a predetermined time based on the target vehicle height value signal from the control unit. A vehicle height adjustment device for a vehicle, characterized in that if there is no rise, it is determined that the vehicle is overloaded and controls the compressor to stop operating.