JPS6231644B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle height adjustment device for a vehicle such as a passenger car, and more particularly to a vehicle height adjustment device that reduces the load for a certain period of time immediately after the start of supply of compressed air, etc. Regarding.

A vehicle height adjustment device is a device that changes and adjusts the vehicle height so that the vehicle height is always maintained at the standard height according to the increase or decrease of the load on the vehicle body. It is possible to maintain the height and adjust the strength of the suspension capacity of the suspension system to make the ride comfortable. FIG. 2 shows an example of the configuration of a system for raising and lowering the vehicle height of a conventional vehicle height adjustment device, for example, a system for supplying or exhausting compressed air, and an electrical system for controlling these operations. reveals the problem to be solved.

When the electric motor 100 operates to operate the compressor 101, air is sucked in and compressed through the suction/discharge port 102, and the compressed air is passed through the passage 103 and is supplied to the dryer 1.
04, the liquid is stored in the tank 106 through the check valve 105. Solenoid valves 107, 108, 1 which are normally closed when the compressor 101 is in operation
When 09 is opened, the compressed air is further transmitted to the left and right front dampers 110, 111 and the left and right rear dampers 11.
2,113, thereby raising the vehicle height. This operation is an adjustment operation when the load on the vehicle body increases, and the lowering of the vehicle height is detected by the front and rear vehicle height sensors 114, 115, and based on this detection signal, the control circuit 116 consisting of a computer etc. 100 power supply unit 117,
Each of the above operations is performed by sending an activation signal to the solenoid valves 107, 108, and 109.
The time required for activation is a certain amount of time required to raise the lowered vehicle height to the standard height.

On the other hand, if the load decreases again after raising the vehicle height that has been lowered due to an increase in load, the front and rear dampers 110, 111, 112, and 113 maintain a high pressure state, so the vehicle height increases. rises further than the standard height. Therefore, in such a case, the vehicle height sensor 114, 115 detects the state of the vehicle body rising, and based on this detection signal, the normally closed solenoid valves 108, 109 and the normally closed exhaust solenoid valve 118 are opened or closed. An operating signal for this is sent from the control circuit 116, and compressed air is discharged from the intake/discharge port 102 through the bypass passage 120 having the check valve 119 by opening the solenoid valves 108, 109, 118. In this way, the vehicle height is lowered, and when the vehicle height reaches the standard height, each of the above operations is stopped and the vehicle height is adjusted.

According to the above structure and operation, when the compressor 101 is started to supply compressed air in order to raise the vehicle height that has fallen below the standard height, generally the damper 1
A certain amount of residual pressure exists in the compressor 10 to 113 and the air passage to maintain the vehicle height, and this residual pressure is applied to the compressor 101 as a large load. Therefore, in order to start the compressor 101 against this load and feed compressed air to the dampers 110 to 113 as described above, the electric motor 100 that operates the compressor 101 must be large in size and have a large output capacity. There must be. The requirement for larger electric motors to be mounted on vehicles such as passenger cars is a major problem in terms of installation space, weight, and the like.

Regarding the above-mentioned problem of the load applied to the compressor 101 when compressed air is supplied, conventionally, measures have been taken to reduce the load by, for example, opening the intake valve of the compressor. Accordingly, the structure and function of the compressor must be changed, which is troublesome and expensive.

The present inventor has created the present invention in view of the above-mentioned problems in the vehicle height adjustment device and to effectively solve the problems.

An object of the present invention is, for example, when a compressor supplies compressed air to raise the vehicle height to a standard height, the residual pressure existing in the pneumatic circuit is removed for a certain period of time, thereby reducing the load applied to the compressor immediately after supply starts. This makes it possible to start the compressor smoothly and easily even with a small electric motor with a small output capacity, and it is possible to simply change the operation of the components of the conventional pneumatic circuit without making any changes to the compressor itself. It is an object of the present invention to provide a vehicle height adjustment device which is intended to be realized by a simple method of adding.

The present invention is characterized in that, in order to achieve the above object, a normally closed exhaust solenoid valve provided in the pneumatic circuit of a conventional vehicle height adjustment device is opened for a certain period of time when the compressor is started, thereby increasing the air pressure. The structure is such that the residual pressure in the circuit is released to the outside, reducing the load on the compressor.

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a pneumatic circuit of a vehicle height adjustment device according to the present invention and an electrical system that controls the operation of each component of this pneumatic circuit. Operated by actuation. The suction port of the compressor 1 communicates with a suction/discharge port 3 that communicates with the outside, and the discharge port of the compressor 1 communicates with the left and right front dampers 8, 9 via a dryer 4, a check valve 5, and normally closed solenoid valves 6, 7. and rear damper 10, 11
and are connected by an air passage. The dryer 4 is for removing moisture from the air, and the solenoid valves 6 and 7 are normally closed, and air is supplied in either direction when the solenoids 6a and 7a are energized. It will be open so that it can be used. The dampers 8 to 11 are provided in the front and rear suspension parts of the vehicle, respectively, to support and suspend the load of the vehicle body, and each damper 8 to 11 has a part that stores compressed air and can adjust the vehicle height. have The compressed air supplied by the compressor 1 increases, and the higher the pressure, the higher the vehicle height. Note that tanks 12, 13 and a check valve 14 for circulating air from the rear toward the front are provided between the front dampers 8, 9 and the rear dampers 10, 11.
This makes it possible to optimize the pressure in each damper.

A bypass air passage 16 having a check valve 15 facing in the opposite direction to the check valve 5 is arranged in parallel to the check valve 5 . This air passage 16 is a passage used during exhaustion.

A branch point A is provided on the discharge port side of the compressor 1, and one of the branches is provided with a drain 17 to release the air pressure when it rises too much, and the other branches are normally connected by springs in the middle. Exhaust solenoid valve 1 maintained in closed state
8 is interposed therebetween, and communicates with the suction/discharge port 3 .

On the other hand, regarding the electrical system, a control circuit 19 composed of a computer or the like is provided at the center of the electrical system, and this is installed in the suspension system at the front and rear of the vehicle, and is connected to the sprung parts of the vehicle body and the unsprung parts of the wheels. Detection signals from vehicle height sensors 20 and 21 that detect changes in vehicle height due to relative movement of parts and command signals from an operating device 22 that can issue various operation commands are input, and a control circuit 19 sends signals to the electric motor 2. power supply section 23,
Each solenoid 6 of solenoid valve 6, 7, 18
It is configured to output a signal that controls the operations of a, 7a, and 18a.

In the above configuration, the pneumatic circuit according to the present invention operates as follows. When the vehicle height becomes lower than the reference height, the control circuit 19 sends operation command signals to the power supply section 23 and the solenoids 6a and 7a of the solenoid valves 6 and 7, respectively, based on the detection signals from the vehicle height sensors 20 and 21. Make it work. When electric current is applied from the power supply section 23 and the electric motor 2 is operated, the compressor 1 is operated, and the compressed air is supplied to the dampers 8 through the open solenoid valves 6 and 7.
11, thereby raising the vehicle height. When the vehicle height reaches the standard height, the vehicle height sensor 20
Based on the signal from 21, the control circuit 19 outputs a signal to stop the operation of the solenoid valves 6, 7 and the compressor 1, respectively, and the vehicle height adjustment operation is stopped.

Next, if the vehicle speed rises above the reference height after adjusting to raise the vehicle height and it becomes necessary to lower the vehicle height, the control circuit 19 similarly sends a solenoid valve based on signals from the vehicle height sensors 20 and 21. 6,
A signal is sent to operate the solenoids 6a, 7a, 18a of 7 and 18. As a result, the solenoid valves 6, 7, and 18 are opened, and compressed air is exhausted through the passage 16 and the intake/exhaust port 3. This lowers the vehicle height, and when the vehicle height reaches the reference height, the vehicle height sensor is detected as described above. 20, 21, and the control circuit 19 closes the solenoid valves 6, 7, and 18, and the vehicle height adjustment is stopped.

In the present invention, when the compressor 1 is started to raise the vehicle height, the exhaust solenoid valve 18 is opened for a certain period of time (for example, about 1 second) under the control of the control circuit 19.
In this way, when residual pressure exists in the pneumatic circuit of the dampers 8 to 11, etc., this residual pressure can be released to the outside via the check valve 15 and the solenoid valve 18. The load applied to the compressor immediately after starting the compressor 1 can be extremely reduced, and the compressor 1 can start starting smoothly. The time period during which the exhaust solenoid valve 18 is held open is the period during which the compressor 1 continues to rotate, that is, the electric motor 2 continues to rotate until a constant high torque state is reached. After the solenoid valve 18 is closed, the compressor 1 supplies compressed air to each damper.

According to the above configuration, even if the electric motor 2 is small and its output is small, it is possible to smoothly start the compressor 1.
Figures 3A and 3B are electric motors according to the present invention (Figure 3A)
This is a conceptual comparison of the relationship between torque (horizontal axis T) and supply current (vertical axis I) for the conventional electric motor (Fig. 3B), and as is clear from this figure, for the electric motor according to the present invention. The compressor 1 can be activated by electric current with a small supply.

B in FIG. 1 represents the direction in which air flows (in the case of intake and exhaust). Further, although the present embodiment has been described with reference to a pneumatic circuit, the present invention can of course be applied to a vehicle height adjustment device using a hydraulic circuit.

As is clear from the above description, the present invention provides the following effects. When raising the vehicle height above the standard height using a vehicle height adjustment device, it is possible to smoothly start the compressor, etc. even with a small, low-output electric motor. It can be realized easily and inexpensively without making any changes. Further, since the electric motor can be small, it is convenient for use in a vehicle in terms of weight, power consumption, etc. The modification work is extremely simple since it is sufficient to simply modify the electrical control.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a circuit diagram showing a pneumatic circuit and its control circuit of a vehicle height adjustment device according to the present invention, and FIG. 2 is a circuit diagram showing a conventional problem. FIG. 3, which is similar to FIG. 1, is a graph showing the current and torque characteristics of electric motors of the present invention and a conventional motor. In the drawing, 1 is a compressor, 2 is an electric motor,
3 is the intake and exhaust port, 6, 7, 18 are solenoid valves,
8 to 11 are dampers, 19 is a control circuit, 20, 21
is the vehicle height sensor.

Claims (1)

[Scope of Claims] 1. A pump device that is driven by an electric motor and pressurizes a working fluid, a damper that is connected to the pump device via a pipe line and changes the vehicle height according to the pressure of the working fluid, and a damper provided in the pipe line. a normally-closed vehicle height adjustment valve capable of opening and closing the conduit through the vehicle height adjustment valve; and a normally closed working fluid discharge valve capable of opening the conduit between the vehicle height adjustment valve and the pump device to the outside. In a vehicle height adjustment device including a valve and a control device that controls the operation of the electric motor, the vehicle height adjustment valve, and the working fluid discharge valve, the control device is configured to: when adjusting the vehicle height to increase the vehicle height, A vehicle height adjustment device, characterized in that the vehicle height adjustment valve and the working fluid discharge valve are opened, the electric motor is driven, and the working fluid discharge valve is closed after a predetermined period of time has elapsed.