JPH0210724B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a vehicle height adjustment device, and more particularly to an improvement in a vehicle height adjustment device that can obtain a desired vehicle height by driving a pneumatic actuator in response to changes in load capacity. The height of a vehicle is closely related to ride comfort and handling stability, and is preferably set at an optimal height. However, in general vehicles,
Since the optimal vehicle height is set according to a predetermined load capacity determined at the time of design, the vehicle height deviates from the optimal value every time the load capacity changes depending on the number of passengers or the amount of luggage, which may affect ride comfort or This was a major cause of deterioration in steering stability. Conventionally, there has been a known device in which a pneumatic actuator is provided between the vehicle body side and the wheel side, and when the vehicle height changes, the supply or discharge of pressurized air to the actuator is controlled to adjust the optimum vehicle height according to the load capacity. According to this device, ride comfort and handling stability are improved,
Furthermore, it is also possible to arbitrarily select the vehicle height by taking into account vehicle speed and other information. In the conventional device described above, a compressor is used to supply pressurized air to the actuator, but this device has the problem that it takes a relatively long time to supply pressurized air. In a vehicle height adjustment device, a reservoir is provided between a compressor and an actuator, and by constantly filling the reservoir with pressurized air by the compressor, pressurized air is rapidly supplied from the reservoir to the actuator. In fact, it had the advantage of being able to supply the liquid almost instantaneously, whereas the conventional device without a reservoir required more than ten seconds. However, with this improved conventional device,
Since the compressor's pressurized air is always temporarily stored in the reservoir, it takes a lot of time to fill the reservoir with the required amount of pressurized air, and as a result, it is difficult for passengers to get on and off or to load and unload cargo. If this is done multiple times in a short period of time, the air in the reservoir will become insufficient and effective vehicle height adjustment will not be possible until the reservoir, which has a relatively large capacity, is filled with the required amount using the compressor. There was a drawback. In such a case, the time required to adjust the vehicle height is extended to more than ten minutes, resulting in the disadvantage that suitable vehicle height adjustment is impossible. The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to provide an improvement that allows desired adjustment to be made in a relatively short time even when vehicle height adjustments are made frequently. The purpose of the present invention is to provide a vehicle height adjustment device that provides improved vehicle height adjustment. In order to achieve the above object, the present invention provides at least one pneumatic actuator that is provided between the vehicle body side and the wheel side and adjusts the vehicle height by changing the supplied air pressure; A compressor that forms a supply source of pressurized air, a reservoir that accumulates pressurized air from the compressor and supplies it to the pneumatic actuator, and a reservoir that detects the height of the vehicle body and controls the compressor and supplies the air to the pneumatic actuator. A control circuit for controlling the supply and discharge of pressurized air, and a vehicle height adjustment device in which the compressor and the reservoir are connected in parallel to the pneumatic actuator so that the compressor and the reservoir can each separately supply pressurized air directly to the pneumatic actuator. In addition, a check valve and an air supply valve are switchably connected to the reservoir, and when the air pressure in the reservoir drops below a predetermined value, the reservoir is disconnected from the pneumatic actuator and compressor by the check valve, and the compressor is disconnected from the air pressure actuator. The vehicle height adjustment function of the pneumatic actuator is performed only by pressurized air from the vehicle. Hereinafter, preferred embodiments of the present invention will be described based on the drawings. FIG. 1 shows the system configuration of the vehicle height adjustment device according to the present invention. In the embodiment, pneumatic actuators are provided in all four wheels, and actuators 10a and 10b on the front wheel side are provided in the shock absorber on the front wheel side. It consists of a pneumatic piston,
Similarly, the actuators 10c and 10d on the rear wheel side
It is also located inside the shock absorber on the rear wheel side. A compressor 12 is provided to provide a source of pressurized air to each actuator 10, and is driven by a motor 14. The pressurized air from the compressor 12 is then transferred to a dryer 16.
and is supplied to each actuator 10 via the residual pressure valve 18. The front wheel side of the pneumatic actuator 10 is commonly connected to the pressurized air supply system from the compressor 12 via the front wheel air supply valve 20, and similarly, the rear wheel side actuators 10c and 10d are connected to the rear wheel air supply system. A valve 22 connects it to a pressurized air supply system. Further, a discharge valve 24 is provided between the compressor 12 and the dryer 16, and pressurized air from the actuator 10 is discharged into the atmosphere from the discharge valve 24 when lowering the vehicle height. In the present invention, a reservoir 26 is provided to store the pressurized air of the compressor 12,
The reservoir 26 is connected to each of the air supply valves 20 and 22 via a reservoir opening/closing valve 28 and a reservoir valve 30.
It is connected to the. Therefore, in the present invention,
Pressurized air supply system by pressurizer 12 and reservoir 26
It is understood that a pressurized air supply system according to the present invention is connected in parallel to the actuator 10.
As a result, in the actuator 10, the reservoir 26
Pressurized air can be supplied from at least one or both of the pressurizer 12 and the pressurizer 12,
It becomes possible to always obtain a quick and good adjustment effect in various vehicle height adjustment states. Further, in the present invention, the reservoir on-off valve 2
8 includes both a check valve 32 and an air supply valve 34, and the check valve 32 and the air supply valve 34 can be switched arbitrarily. When the check valve 32 is selected, a supply state is obtained in which pressurized air from the reservoir 26 is supplied to the actuator 10, and when the air supply valve 34 is selected, pressurized air from the compressor 12 is supplied to the actuator 10. is reservoir 2
6 is obtained. The air supply valves 20, 22, the discharge valve 24, the reservoir opening/closing valve 28, and the reservoir valve 30 each have an electromagnetically driven valve structure, and are opened, closed, or switched by a control circuit depending on the vehicle height and other conditions. FIG. 2 shows an embodiment of the control circuit suitable for FIG. The control circuit 36 includes a vehicle height adjustment circuit 38, receives vehicle height and vehicle speed signals from a front vehicle height sensor 40, a rear vehicle height sensor 42, and a vehicle speed sensor 44 provided on the vehicle body, and adjusts the vehicle height and vehicle speed signals based on these various input information. A predetermined vehicle height adjustment signal is output, thereby electromagnetically driving each of the valves. That is, the solenoids 20a, 22a, 24a, 30 that drive the respective valves
a respectively drive transistors 46-1 to 46;
-4, an excitation current based on a vehicle height adjustment signal is supplied, and the actuator 10 is controlled according to each mode to be described later. The control circuit 36 further includes a pressure switch 48 that detects the internal pressure of the reservoir 26 and a pressure switch 48 that detects the internal pressure of the reservoir 26.
6 is supplied, and when the internal pressure drops below a predetermined value, the pressure switch 48 is turned on, and as a result, the transistor 50 of the control circuit 36 is switched from the on state to the off state, and the An exciting current is supplied to the solenoid 28a of the reservoir opening/closing valve 28. Other inputs of the Noah gate 52 include the front wheel and rear wheel intake valves 2.
0 and 22 are supplied, and as will be described later, the reservoir opening/closing valve 28 is opened only when the pressurized air supply path to each actuator 10 is closed. The pressure switch 48 has a hysteresis characteristic to prevent hunting effect due to fluctuations in internal pressure. _FIG . It is understood that the off-operation occurs when the internal pressure increases above _P1 . The embodiment of the present invention has the above configuration, and its operation will be explained below based on the table below.

[Table] - Optional Modes 1 to 4 are states in which the internal pressure of the reservoir 26 is sufficiently high, and at this time the control circuit 36 outputs a predetermined vehicle height adjustment signal selected by the vehicle height adjustment circuit 38. Therefore, the front side or rear side of the vehicle body can be arbitrarily controlled to be high or low, and the aerodynamic characteristics and other properties during driving can be set to optimal values. Mode 1 is a mode in which the front side is raised, and the exhaust valve 24 and the rear wheel intake valve 22 are closed, and the front wheel intake valve 20 and the reservoir valve 30 are opened. At this time, the check valve 32 is selected as the reservoir on-off valve 28, and from the above-mentioned valve states, the pressurized air filled in the reservoir 26 is transferred to the check valve 32 of the reservoir on-off valve 28, the reservoir, and the valve. 32 and is supplied to the actuators 10a, 10b through the front wheel intake valve 20, and as a result, the front side of the vehicle body can be raised. At this time, the compressor 12 is also rotated by the energization of the motor 14, and the pressurized air is dried by the dryer 16, and then passes through the residual pressure valve 18 and the front wheel air supply valve 20 to the front actuator 10a, 10
b, and the actuators 10a and 10b receive pressurized air from the reservoir 26 and compressor 12 in parallel. However, in normal cases, the actuators 10a, 10b are instantaneously supplied with air mostly by the pressurized air stored in the reservoir 26, and the supply from the compressor 12 remains in a small amount. When the front side is lowered in mode 2, only the front wheel air intake valve 20 and the exhaust valve 24 are opened, and air is exhausted from the actuators 10a and 10b until the front side of the vehicle body reaches a predetermined height. Similarly, modes 3 and 4 indicate the rear side raising and lowering states, respectively, and are completely the same as the aforementioned modes, except that the control of the front wheel and rear wheel intake valves 20, 22 is reversed. It is. Next, the internal pressure of the reservoir 26 decreases below a predetermined value, and, for example, the passenger gets on and off the vehicle multiple times in a short period of time, and as a result, pressurized air is frequently supplied to and discharged from the actuator 10, and the reservoir 26 is The case where the pressurized air filled in the air conditioner 26 has been consumed will be explained using modes 5 and 6. In this case, the front wheel and rear wheel intake valves 20, 22, the exhaust valve 24, the reservoir valve 30, and the compressor 1
Condition 2 is the same as when there is internal pressure in the reservoir 26, but in the present invention, the raising operation is performed when the internal pressure in the reservoir 26 is insufficient, that is, when pressurized air is supplied to the actuator 10. The conditions of the reservoir and valve 30 are different. That is, in the table, in mode 5 and mode 7,
The reservoir valve 30 is characterized in that it is in a non-energized state, that is, it is closed, unlike when there is pressure. That is, when the internal pressure of the reservoir 26 is insufficient, the reservoir 26 is separated from the actuator 10 by the reservoir valve 30, and pressurized air is supplied to the actuator 10 only from the compressor 12. shall be. In the present invention, the compressor 12 is connected to the actuator 10 in parallel with the reservoir 26, so even if the reservoir 26 is separated from the actuator 10, the compressor 12 can directly supply pressurized air to the desired amount. can be supplied to the actuator 10,
A predetermined vehicle height adjustment effect can be achieved. When the actuator 10 is operated only by the compressor 12 in this way, it is not necessary to fill the reservoir 26, so that the desired action can be performed in a relatively short time. Next, if the internal pressure of the reservoir 26 has fallen below a predetermined value, the compressor 12 fills the reservoir 26 with pressurized air while the vehicle height is not being adjusted, and this state is set in the mode. 9. In the present invention, since the reservoir 26 is provided with the reservoir opening/closing valve 28 including the check valve 32 and the air supply valve 34, when filling pressurized air in mode 9, the reservoir opening/closing valve 30 is opened and the reservoir opening/closing valve is simultaneously opened. 28
By switching the air supply valve to the air supply valve 34 side and driving the compressor 12, the compressor 12 supplies the desired pressurized air to the reservoir 26, and the relatively large capacity reservoir 26 is used to adjust the vehicle height. This makes it possible to reliably fill the container while it is still in use. As described above, according to the embodiment of the present invention shown in the system diagram of FIG. 1, it is possible to perform an optimal adjustment action suitable for each vehicle height adjustment state, and to perform quick and reliable vehicle height adjustment. It has the advantage of being able to Although the reservoir opening/closing valve 28 according to the present invention described above can be formed by combining the separate check valve 32 and the air supply valve 34, FIG.
The structure of a reservoir opening/closing valve 28 suitable for the present invention is shown in which these are integrally combined. A solenoid case 58 is hermetically fixed to the valve board 56 which is airtightly connected to the pressurized air flow pipe of the reservoir 26 by brazing or the like. is fixedly supported. A solenoid 28a is fixed to the outside of the sleeve 62, and a core 64 is fixed to the inside thereof. The solenoid 28a is connected to the solenoid case 5.
The excitation signal from the control circuit 36 is supplied to the solenoid 28a through a lead wire 66 drawn out from the solenoid case 58. A plunger 68 is further slidably inserted in the sleeve 62 in the axial direction, and a valve 70 fixed to one end of the plunger 68 is attached to the valve base plate 5.
It faces a valve seat 72 fixed to 6 and controls opening and closing of a flow orifice 74. A spring 76 is inserted between the plunger 68 and the core 64, and the urging force of the spring 76 presses the valve 70 against the valve seat 72, and in this state the flow orifice 74 is closed. In the embodiment, the biasing force of the spring 76 is set to a predetermined value,
As a result, when the pressure on the flow orifice 74 side increases, the valve 70 can move away from the valve seat 72 against the biasing force of the spring 76. The flow orifice 74 is the reservoir 2 of FIG.
6 side, and an opening 78 provided in the valve board 56 is connected to the reservoir and valve 30 side. The reservoir opening/closing valve 28 of this embodiment has the above configuration, and when the solenoid 28a is not energized, the valve 70 is operated by the spring 7.
6 against the valve seat 72, and as a result,
The flow from the reservoir or valve valve 30 side to the reservoir 26 is closed, and the flow from the reservoir 26 to the reservoir or valve valve 30 side is due to the pressure of the reservoir 26 or the pressure on the valve valve 30 side and the spring. This becomes possible only when the biasing force becomes larger than the biasing force of 76. From the above, it is understood that the reservoir opening/closing valve 28 works as the check valve 32 when the solenoid 28a is not energized. On the other hand, when the solenoid 28a is energized, the plunger 68 moves upward in FIG. It is understood that the valve 30 is in communication with the reservoir opening/closing valve 28 and serves as the air supply valve 34. As described above, according to the embodiment shown in FIG. 4, the reservoir opening/closing valve can be formed as a small and simple valve, which is extremely effective for the present invention. As explained above, according to the present invention, the vehicle height can be arbitrarily adjusted based on various driving conditions, and in normal cases, the vehicle body can be adjusted very quickly using pressurized air stored in the reservoir. It can be adjusted and if the pressurized air in the reservoir is insufficient,
By separating the reservoir from the actuator and sending pressurized air directly from the compressor to the actuator, it is possible to obtain an extremely reliable vehicle height adjustment device that eliminates the delay in operation caused by the filling time of the reservoir.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing a preferred embodiment of the vehicle height adjustment device according to the present invention, FIG. 2 is a circuit diagram showing a control circuit suitable for the embodiment of FIG. 1, and FIG. FIG. 4, which is a characteristic diagram of the pressure sensor, is a sectional view of a main part showing an embodiment of a reservoir opening/closing valve suitable for the present invention. 10a, 10b, 10c, 10d...Pneumatic actuator, 12...Compressor, 26...Reservoir, 28...Reservoir opening/closing valve, 28a...Solenoid, 32...Check valve, 34...Air supply valve, 36 …
...Control circuit, 68...Plunger, 70...Valve,
72... Valve seat, 74... Flow orifice, 76...
…spring.

Claims (1)

[Scope of Claims] 1. At least one pneumatic actuator that is provided between the vehicle body side and the wheel side and adjusts the vehicle height by changing the supplied air pressure, and a supply of pressurized air that is supplied to the pneumatic actuator. a compressor that forms a power supply, a reservoir that accumulates pressurized air from the compressor and supplies it to the pneumatic actuator, and a reservoir that detects the height of the vehicle body to control the compressor and supply pressurized air to the pneumatic actuator. and a control circuit for controlling emissions, wherein the compressor and the reservoir are each connected in parallel to the pneumatic actuator so as to separately supply pressurized air directly to the pneumatic actuator, and the reservoir is A check valve and an air supply valve are switchably connected, and when the air pressure in the reservoir drops below a predetermined value, the reservoir is disconnected from the pneumatic actuator and compressor by the check valve, and pressurized air from the compressor is disconnected. A vehicle height adjustment device characterized in that the vehicle height adjustment action of a pneumatic actuator is performed only by. 2. In the device according to claim 1, the check valve and the air supply valve include a valve that closes the flow orifice at a predetermined pressure by the biasing force of a spring, and a solenoid that opens the valve against the biasing force of the spring. A vehicle height adjustment device comprising an integrated on-off valve comprising: