JPS626817A - Suspension device for automobile - Google Patents

Abstract

PURPOSE:To regulate the extent of ground load in each wheel properly and simply, when wheels come into a state of being stacked, by feeding the wheel in this stack state and another wheel situated on a diagonal line with this, with a pressure fluid via a pressure detecting switch in a reserve tank. CONSTITUTION:When a wheel gets into a stacking state during car running in a state that a car level is low, by way of example, if the wheel losing its traction is, for example, a front wheel at the right, an R button of a switch 34 is pressed. If so, both first and second selector valves 12 and 13 and a tank on-off valve 15 are all opened whereby a compressor is operated. And, simultaneously with this, warning sound emission by a buzzer 32 and flickering by an R lamp by an indicator 33 are started. With this constitution, both second and third fluid actuators 22 and 23 are extended longer, while internal pressure in a passage L2 and a reserve tank 10 also goes up, and both first and second pressure detecting switches 5 and 6 are turned on. Then, at that point that a fourth pressure detecting switch 8 is turned on, it judges that the extent of ground load of each wheel sufficiently grows large.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an automobile suspension device having a vehicle height adjustment function.

(Prior Art) Although it is desirable for the vehicle height of an automobile to be low in terms of running stability, if the vehicle height is too low, there is a risk that the lower surface of the vehicle body may come into contact with the ground when driving on a bumpy road. For this reason, as disclosed in Japanese Patent Application Laid-Open No. 58-30809, various driving conditions are detected by sensors,
A vehicle height control method has been proposed that prevents damage to the vehicle body by controlling the suspension to lower the vehicle body on good roads and raise the vehicle body on bad roads.

Further, when a car is traveling on an uneven road surface and one wheel falls into a depression on the road surface, for example, if the left front wheel a falls into the fourth part, as shown in FIG. The right rear wheel d, which is located diagonally to the left front wheel a with respect to the axis X-x connecting the front wheel and the left rear wheel C, lifts up or the ground load becomes extremely small. Therefore, if this wheel d is a driving wheel, the wheel d will idle,
There is no driving force or traction force sufficient to push the front wheel a out of the recess on the road surface, making it impossible to escape from the recess.

Further, when a four-wheel drive vehicle is traveling on snow or sand, one of the drive wheels may dig into the snow or sand on the road surface due to a difference in frictional resistance from the road surface. now,
Assuming that the left front wheel a shown in FIG. The vehicle lifts up or the ground load decreases, causing it to spin idly, and as a result, the left front wheel a is unable to escape from the recess it has dug itself.

In view of this, the present applicant has filed patent application No. 58-1922.
In No. 46, a condition in which one of the four wheels becomes stuck due to falling into a recess or digging into snow or sand (hereinafter, this condition is referred to as a stuck condition)
If this happens, the vehicle height of only the suspension that supports the stuck wheel and the wheels located diagonally to this wheel is increased, and the stuck wheel and the wheels located diagonally to this We are proposing a suspension device that increases the ground contact load of the wheels that cause the vehicle to get stuck. Hereinafter, such vehicle height control will be referred to as diagonal control.

When the suspension device proposed above is used, when a wheel becomes stuck, the vehicle height of the support part of the stuck wheel and the wheels located on the diagonal thereof is raised by the operation of the passenger, and these wheels are raised. This is to ensure that the wheels receive the necessary and sufficient ground load to escape the stuck condition, but even if the vehicle height is raised by operation, the ground contact load may not be sufficient, or conversely, the ground contact load may become too large. There is a problem in that it is difficult to control the air pressure supply during diagonal control, such as the possibility that the ground contact load of the opposite wheel may decrease.

(Object of the Invention) In view of such problems, the present invention provides a system for escaping the stuck condition when the wheels are stuck and the wheels located diagonally therefrom. It is an object of the present invention to provide a suspension device for an automobile that can perform vehicle height adjustment control that provides an appropriate ground load in a simple manner.

(Structure of the Invention) The suspension device of the present invention includes a fluid actuator that is expandable and retractable by supplying and discharging pressurized fluid to a variable volume fluid chamber.
Disposed between a support member that supports the wheels and the vehicle body, pressurized fluid pressurized by a compressor is stored in a reservoir tank, and this pressurized fluid can be supplied and discharged to the fluid chamber via a switching valve, A pressure switch is placed in the reservoir tank to detect the fluid pressure in the tank, and when this fluid pressure decreases, a compressor is driven to maintain this fluid pressure at a predetermined pressure, and the reservoir tank and fluid actuator are connected. An on-off valve is disposed in the passage, and the compressor, switching valve, and on-off valve are configured to be operated by an operating signal from a control signal output means. The control signal output means has a function of outputting a vehicle height adjustment signal and a function of outputting a stack escape signal. This is a function that outputs a control signal to raise the vehicle height by supplying pressurized fluid to the fluid chamber, or to lower the vehicle height by discharging pressurized fluid from this fluid chamber.The stuck escape signal output function is used when one of the wheels is stuck. , pressurized fluid is supplied to the fluid chamber of the fluid actuator disposed between this wheel and the vehicle body and the wheel located diagonally to this wheel, and the fluid pressure in the reserve tank is set to a predetermined value or higher using a pressure switch. It is characterized in that it is a function that outputs a control signal so as to supply the signal until it is detected.

(Embodiments) Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a pneumatic circuit diagram of a suspension device according to an embodiment of the present invention. A compressor 2 driven by a motor 1 pressurizes air and sends it out to a passage L1, and this pressurized air is sent to a passage L2 via a dryer 3 and a check valve 4.

The first to third pressure switches 5.6.7 are connected to the passage L2, and the first to fourth switching valves 11 to 14 and the tank opening/closing valve 15 are connected to the passage L2.

The first to fourth switching valves 11 to 14 are opened and closed by the operation of solenoids 11a to 14a, respectively, thereby communicating and blocking passages L2 and each of the passages L4 to L7. The passages L4 to L7 communicate with the variable volume fluid chambers of the first to fourth actuators 21 to 24, which are disposed between the vehicle body and the support member that supports each wheel, and are connected to the variable volume fluid chambers of the first to fourth actuators 21 to 24, respectively, and are connected to the variable volume fluid chambers of the first to fourth actuators 21 to 24, respectively. Fourth switching valve 11
Pressurized air is supplied to and discharged from the fluid chamber in accordance with the opening/closing operations of the fluid actuators 21 to 14, and the fluid actuators 21 to 24 expand and contract. The tank opening/closing valve 15 is opened and closed by the operation of the solenoid 15a, and by opening it, the pressurized air sent to the passage 2 is stored in the reserve tank via the passage L3, and the 4 switching valves 21-24
When opened, the stored pressurized air is sent out to the fluid chambers of the fluid actuators 21-24. A relief valve 9 is provided in the passage L3 to prevent the air pressure in the reserve tank 10 from exceeding the maximum allowable pressure. Further, a fourth pressure detection switch 8 is connected to the reserve tank 10 to detect the pressure inside the reserve tank. Note that an exhaust opening/closing valve 16 operated by a solenoid 16a communicates with the passage L1 communicating with the outlet side of the compressor 2, and by opening this valve 16, the air in the fluid chambers of the fluid actuators 21 to 24 is released. It is now possible to discharge and retract the fluid actuators 21-24.

FIG. 2 is a control circuit diagram for controlling the operation of the pneumatic circuit diagram shown in FIG. 1. This control is performed by controller 2.
0 to the first to fourth switching valves 11 to 14 via lines 21 to 24, lines 25 and 2.
6 to the tank opening/closing valve 15 and the exhaust opening/closing valve 16, these valves 11
- 16 are operated, supplying and discharging pressurized air to the fluid chambers of the first to fourth fluid actuators 21 to 24 arranged between each wheel a to d and the vehicle body, and pressurizing the reserve tank 10. Air is supplied and discharged, and the passage L2 is communicated with and cut off from the atmosphere. Furthermore, the operation of the compressor 2 is controlled by the III signal sent from the controller 20 to the compressor 2 via a line 27. The controller 20 is supplied with detection signals from the first to fourth pressure detection switches 5 to 8 via lines 5a to 8a, detection signals from an engine operation detection sensor 31 via a line 31a, and a manual signal via a line 34a. An input signal from the switch 34 is input, and this manual switch 34
When an input signal is inputted, the operation of each valve and compressor 2 is controlled based on each detection signal, and at the same time, a warning sound is generated by a buzzer 32 and a display is displayed by an indicator 33 as necessary.

Next, the operation of this device will be explained using FIG. 1 and FIG. 2 together. According to this device, manual switch 3
The vehicle height can be adjusted by pressing the "H" button in 4, "R" or "
Diagonal control is possible with the LIT button, but vehicle height adjustment is only possible when the vehicle is stopped.
Only two-stage switching of HIG)-1 and LOW is possible. Further, this device can only operate when the engine operation detection sensor 31 detects that the engine is operating.

To raise the vehicle height, press manual switch 34 IN H.
Press the I+ button to turn it on. As a result, the first to fourth switching valves 11 to 14 open, the compressor 2 is driven by the motor 1, and at the same time, the tank opening/closing valve 1
5 opens. At this time, the "H" lamp of the indicator 33 flashes and the buzzer 32 emits a warning sound. Thereby, the pressurized air in the reserve tank 10 and the compressed air from the compressor 2 are supplied to the fluid actuators 21 to 2.
4 is extended and the vehicle height is raised. The tank opening/closing valve 15 closes 10 seconds after opening, and the internal pressure of the passage L2 (this is equal to the fluid internal pressure of the fluid actuator) is 6.8 kg7'c.
When Ii, the first pressure detection switch 5 is turned on,
This closes the third and fourth switching valves 13.14. Next, when the internal pressure of the passage L2 reaches 7.8 to 9/cd, the second pressure detection switch 6 is turned on, and the vehicle height tJ
P is determined to be completed and the first and second switching valves 11.1
2 is closed, the operation of the compressor 2 and the warning of the buzzer 32 are stopped, and the indicator 33 lights up "F (TI clamp). Even if the pressure detection switch 1 and the second pressure detection switch 5.6 are turned OFF, the system is not activated. Does not work again.

To lower the vehicle height, press the manual switch 34 “HII”.
Press the button to turn it off. This allows the first
~Fourth switching valves 11 to 14 and exhaust opening/closing valve 1
6 opens, and the air in the fluid chambers of the fluid actuators 21 to 24 is discharged.

ii When the Hu button is turned OFF, the "H" lamp of the indicator 33 starts lighting up, and the buzzer 32 emits a warning sound. After 45 seconds have passed after pressing the "H" button F, it is determined that the vehicle height has been lowered. Then, all the above-mentioned valves are closed, the indicator 33 is turned off, and the buzzer 32 is deactivated.

In addition, since it is necessary to always store a predetermined amount of pressurized air in the reserve tank 10, the fourth pressure detection switch 8 is turned OFF and the tank internal pressure is below the standard (9.0K in this example).
t/ci), the tank opening/closing valve 15 is opened and the compressor 2 is operated to feed pressurized air into the tank to maintain the tank internal pressure above the standard.

Next, diagonal control will be explained.

First, a description will be given of a case where the vehicle gets stuck while driving with the vehicle height at LOW. At this time, check which of the left and right front wheels is losing traction, and if it is the right front wheel, for example, use the manual switch 3
Press the “R” button.

As a result, the second and third switching valves 12,13 and the tank opening/closing valve 15 are opened, and the compressor 2 is operated. At this time, the buzzer 32 starts generating a warning sound and the indicator 33 starts blinking the "R, 11 lamp. As a result, pressurized air is supplied to the fluid chambers of the second and third fluid actuators 22 and 23. The actuators 22 and 23 extend. This also increases the internal pressure in the passage L2 and the reserve tank 10.
The first and second pressure detection switches 5 and 6 are 6, respectively.
, 8 Kg l cd , 7 , 8 K9/cti
The fourth pressure detection switch 8 is turned on.
turns ON at a pressure of 9/l:i at 9.0. This pressure increases in proportion to the ground load of the wheels, and the fourth
When the pressure reaches the pressure that turns on the pressure detection switch 8, it is determined that the ground load of the wheels to which the actuators 22 and 23 are attached is sufficiently large, and that diagonal control is complete, and each valve is closed and the indicator 3 is turned on.
The "R" lamp of 3 is lit, while the warning sound of the buzzer 32 continues. When you get out of the stuck state using this diagonal control, use the manual switch 3.
By pressing the "RII" button in step 4, the same operation as lowering the vehicle height described above is performed and the vehicle returns to its original state.The warning sound from the buzzer 32 indicates that the diagonal control has been completed and the vehicle height has been lowered to its original state. It will stop only when

Next, a description will be given of a case where the vehicle gets stuck while driving with the vehicle height at HIGH. At this time as well, check which front wheel is losing traction, and if it is the right front wheel, press the "R" button on the manual switch 34.
．． 14 and the exhaust valve 16 are opened, the buzzer 32 begins to sound, and the ° "R" lamp of the indicator 33 begins to blink. This causes the pressurized air in the fluid chambers of the first and fourth fluid actuators 21.24 to be exhausted, causing these actuators 21.24 to retract.

Meanwhile, the second wheel attached to the wheel that lost traction
and the third fluid actuator 21, 23 remain as they are, so the ground load of the wheel that has lost traction increases. When 45 seconds have elapsed since the "R" button of the manual switch 34 was pressed, the main operation is judged to have been completed, the opened valve is closed, and the indicator 33 turns "R".
The lamp lights up. However, the buzzer 32 continues to sound. After this, if you escape from the stuck state, by pressing the "R" button of the manual switch 34 again,
The operation of raising the vehicle height in the vehicle height adjustment is performed, the vehicle height returns to the original state, and at this point the operation of 74-32 is stopped.

Note that the third pressure detection switch 7 detects the specified minimum pressure (0, 6#
/ai), and when the ignition is turned on, the "H" button of the manual switch 33 is turned off.
When F, open the first to fourth switching valves 11 to 14,
Detect whether the pressure at this time is 0゜6υ/d or more, and if it is 9/ci or less at 0.6', operate compressor 2 to increase this pressure to 0.6Ky/l:i. .

(Effects of the Invention) As claimed above, according to the present invention, when a wheel is stuck in a stuck state and when performing diagonal control to try to escape from the stuck state, Pressurized fluid is sent from the reserve tank and compressor into the fluid chamber of the fluid actuator located between the wheel and the vehicle body, and this pressurized fluid is supplied until the fluid pressure in the reserve tank exceeds a predetermined value. This allows us to use the reserve tank pressure detection switch to determine whether or not there is sufficient fluid supply to the wheel that is losing traction and the actuator attached to the wheel diagonally opposite it. , fluid supply IIJ m is easy.

[Brief explanation of the drawing]

Fig. 1 is a pneumatic circuit diagram of a suspension device according to the present invention, Fig. 2 is a control circuit diagram for controlling the operation of the above pneumatic circuit diagram, and Fig. 3 is a schematic plan view of an automobile to show the conventional problems. It is a diagram. 2...Compressor 5-8...Pressure detection switch 10...Reserve tank 11...Switching valve 15...Tank opening/closing valve 1
6...Exhaust on/off valves 21-24...Controller 32...Buzzer 33...Indicator 34
...Manual switch Figure 3

Claims (1)

[Scope of Claims] A fluid actuator that has a variable volume fluid chamber, is expandable and retractable by supplying and discharging pressurized fluid to the fluid chamber, and is disposed between a support member that supports a wheel and a vehicle body; a compressor that pressurizes pressurized fluid; a switching valve that connects and disconnects the compressor and the fluid actuator to supply and discharge the pressurized fluid to and from the fluid chamber; and the pressurized fluid that is pressurized by the compressor. a reserve tank for storing fluid; a pressure switch that detects the fluid pressure in the reserve tank and drives the compressor when the fluid pressure decreases to maintain the fluid pressure in the reserve tank at a predetermined pressure; the reserve tank; an on-off valve that controls opening and closing of a passage communicating with the actuator; and the compressor;
and control signal output means for outputting a signal for operating the switching valve and the opening/closing valve, and the control signal output means outputs the pressurized fluid pressurized by the compressor and stored in the reserve tank. A control signal is supplied to the fluid chamber of the fluid actuator to raise the vehicle height, and outputs a control signal to lower the vehicle height by discharging pressurized fluid from the fluid chamber, when one of the wheels has lost traction and is stuck. At this time, pressurized fluid and the reserve tank are pumped by the compressor into the fluid chamber of the fluid actuator, which is disposed between the wheel that has lost traction and the wheel located diagonally to the wheel and the vehicle body. A control signal is output to supply pressurized fluid in the reserve tank until the pressure switch detects that the fluid pressure in the reserve tank exceeds a predetermined value. Suspension device.