JPH036485Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a vehicle height adjustment device that can prevent hunting during vehicle height adjustment.

A suspension unit having a fluid chamber interposed between the wheel side member and the vehicle body side member is provided for each wheel, and the supply and exhaust to this fluid chamber is controlled to adjust the vehicle height and when turning. There is an electronically controlled suspension device that can perform posture control. In such a device, if only a normal vehicle height adjustment system is used, the diameter of the air piping and valve orifice will be approximately φ1 to 1.5, but if an attitude control system is added, a large amount of air can be pumped in a short time. Since it is necessary to send the air to the suspension unit, the diameter of the air piping and the orifice of the valve must also be large, and approximately φ5 is required. If such an attitude control system is used to adjust the vehicle height, there is a concern that the air supply and exhaust speeds will be too high and the vehicle height adjustment will cause hunting.

This idea was made in view of the above points,
The purpose is to provide a vehicle height adjustment device that can prevent hunting during vehicle height adjustment.

An embodiment of this invention will be described below with reference to the drawings. In Fig. 1, the air suspension units FS1, FS2, RS1, and RS2 each have almost the same structure. The unit is coded S.
The explanation will be made using the following figure, and only the parts necessary for vehicle height control will be illustrated and explained.

That is, the air suspension unit S incorporates a strut-type shock absorber 1, and this shock absorber 1 is fitted into a cylinder attached to the front wheel or rear wheel side, and is slidably inserted into the cylinder. The cylinder is equipped with a piston, and the cylinder moves up and down relative to the piston rod 2 in response to the up and down movement of the wheels, thereby making it possible to effectively absorb shock.

By the way, a main air spring chamber 3 which also serves as a vehicle height adjustment fluid chamber is disposed in the upper part of the shock absorber 1 coaxially with the piston rod 2. A part of this main air spring chamber 3 is provided with a bellows 4. As a result, the piston rod 2 can be moved up and down by supplying and discharging air to the main air spring chamber 3 through the passage 2a provided in the piston rod 2.

Further, the outer wall of the shock absorber 1 is provided with a spring receiver 5a facing upward, and the outer wall of the main air spring chamber 3 is provided with a spring receiver 5b facing downward. A coil spring 6 is loaded between the coil springs 5b and 5b.

Thus, the vehicle height adjustment of the automobile is carried out as follows. In other words, compressed air for vehicle height adjustment is
As shown in FIG. 1, air is stored in a reserve tank 14 via a dryer 12 and a check valve 13 from a compressor 11 as a compressed air generator. In other words, the compressor 11 compresses the atmospheric air sent from the air cleaner 15 to the dryer 1.
The compressed air dried with silica gel or the like from the dryer 12 is stored in the reserve tank 14. The progress in which compressed air is supplied from the reserve tank 14 to the suspension unit S is shown by solid arrows. That is, compressed air from the reserve tank 14 is sent to the suspension units FS1, FS2 via the air supply solenoid valve 16, check valve 17, and three-way valves 181, 182. Further, compressed air from the reserve tank 14 is sent to the suspension units RS1, RS2 via the air supply solenoid valve 16, check valve 19, and three-way valves 183, 184. Note that the three-way valves 181 to 184 and the three-way valve 185 described below
The two states will be explained using FIG.

On the other hand, the progress of exhaust gas from the suspension unit S is indicated by broken line arrows. In other words, the compressed air from the suspension units FS1 and FS2 is supplied to the three-way valves 181, 182, the three-way valve 185, the narrow pipe A or the large diameter pipe B, the dryer 12, the exhaust solenoid valve 20, the check valve 21, and the air cleaner 15. released to the atmosphere via. Also,
Compressed air from suspension units RS1 and RS2 is supplied through three-way valves 183, 184 and three-way valve 18.
5. The air is released to the atmosphere through the small diameter pipe A or the large diameter pipe B, the dryer 12, the exhaust solenoid valve 20, the check valve 21, and the air cleaner 15.

In addition, 22 is a vehicle height sensor, and this vehicle height sensor 2
2 is a front vehicle height sensor 22F that is attached to the lower arm 23 of the front right suspension of the automobile to detect the front vehicle height of the automobile, and a front vehicle height sensor 22F that is attached to the lateral rod 24 of the rear left suspension of the automobile to detect the rear vehicle height of the automobile. A front vehicle height detection signal and a rear vehicle height detection signal are supplied from these vehicle height sensors 22F and 22R to a control unit 25 serving as a vehicle height adjustment control section. be done.

Each sensor 22F, 22 in the vehicle height sensor 22
R is the Hall IC element and one of the magnets connected to the wheel FA.
and the other side is attached to the vehicle body B side to detect the distance from the normal vehicle height level and the low vehicle height or high vehicle height level, respectively. Note that the vehicle height sensor may be of any other type, for example, one using a phototransistor.

Furthermore, the speedometer 26 has a built-in vehicle speed sensor 27, which detects the vehicle speed and sends a detection signal to the control unit 2.
Mechanical speedometers use a reed switch type vehicle speed sensor, and electronic speedometers use a transistor-based open collector output type sensor.

Further, an acceleration sensor 28 is provided as a vehicle body posture sensor that detects changes in the posture of the vehicle body.
This acceleration sensor 28 is designed to detect changes in pitch, roll, and yaw of the vehicle body posture on the automobile spring. For example, when there is no acceleration, the weight is in a hanging state, and the light from the light emitting diode is directed toward the shielding plate. The structure is such that the absence of acceleration can be detected by blocking the light from reaching the photodiode.

When acceleration acts in the front and back, left and right, or up and down directions, the weight tilts or moves, and the acceleration state of the vehicle body is detected.

Also, 29 is an indicator that displays the oil pressure.
The display of this indicator 29 is controlled by the control unit 25. A steering sensor 30 detects the rotational speed of the steering wheel 31, that is, the steering speed, and its detection signal is sent to the control unit 25. moreover,
Reference numeral 32 denotes an accelerator opening sensor (not shown) for detecting the depression angle of an accelerator pedal of the engine, and its detection signal is sent to the control unit 25. Further, 33 is a compressor relay for driving the compressor 11, and this compressor relay 33 is controlled by a control signal from the control unit 25. Furthermore, 34 is a pressure switch that is turned on when the pressure in the reserve tank 14 falls below a predetermined value, and its output signal is output to the control unit 25. In other words,
When the pressure in the reserve tank 14 falls below the set value, the pressure switch 34 is turned on, and the compressor relay 33 is activated under the control of the control unit 25.
is activated. As a result, the compressor 11 is driven to feed compressed air into the reserve tank 14, and the pressure inside the reserve tank 14 is made to exceed the set value.

The opening and closing of the air supply solenoid valve 16, the exhaust solenoid valve 20, and the three-way valves 181 to 185 are controlled by control signals from the control unit 25.

Next, FIG. 2 shows the three-way valves 181 to 18 in FIG.
Two states of valve No. 5 are shown below. FIG. 2A shows a state in which the three-way valves 181 to 185 are driven, and in this state compressed air moves along the path indicated by arrow A.

On the other hand, FIG. 2B shows a state in which the three-way valves 181 to 185 are not driven, and in this state compressed air moves along the path indicated by arrow B.

Next, we will explain the operation of one embodiment of this invention configured as described above.For example, when the brake is stepped on, the vehicle height on the front wheel side decreases and the vehicle height on the rear wheel side increases. If the front wheel suspension unit FS is
1. Air is supplied to FS2 and exhausted from rear wheel suspension units RS1 and RS2. In this manner, in the case of attitude control, the three-way valves 183 and 184 are turned on, the three-way valve 185 is turned off, and the exhaust solenoid valve 20 is turned on by a control signal from the control unit 25. Therefore, the air discharged from the suspension units RS1 and RS2 is transferred to the three-way valves 183, 184, the three-way valve 185, and the three-way valve 185.
It is released to the atmosphere through the thick pipe B, the dryer 12, the exhaust solenoid valve 20, the check valve 21, and the air cleaner 15. Since exhaust is performed through the thick pipe B in this manner, attitude control is quickly performed.

On the other hand, when it is determined that the vehicle height is high based on the vehicle height detection signals output from the vehicle height sensors 22F and 22R, the three-way valves 181 to 184 and 185 and the exhaust solenoid valve 20 are turned on by a control signal from the control unit 25. be done. For this reason, suspension units FS1, FS2, RS1. R.S.
The air discharged from 2 is the three-way valve 181-18.
4, three-way valve 185, thin pipe A, dryer 12,
Exhaust solenoid valve 20, check valve 2
1. It is released to the atmosphere via the air cleaner 15. Since the exhaust is carried out through the thin pipe A in this manner, the exhaust speed is sufficiently slowed down and the vehicle height is gradually lowered. Therefore, hunting during vehicle height adjustment can be prevented.

In the above embodiment, a thick pipe B was provided in the exhaust path to bypass the thin pipe A, but similar piping was provided between the air supply path, for example, the air supply solenoid valve 16 and the check valve 17 to control the attitude. Air may be supplied to each suspension unit quickly when adjusting the vehicle height, and slowly when adjusting the vehicle height.

As described in detail above, according to this invention, it is possible to provide a vehicle height adjustment device that can prevent hunting during vehicle height adjustment.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of the vehicle height adjusting device according to this invention, and FIGS. 2A and 2B are diagrams showing the on/off states of the three-way valve. 16...Air supply solenoid valve, 181-18
5...Three-way valve, 20...Exhaust solenoid valve, 25...Control unit.

Claims (1)

[Scope of utility model registration request] A fluid pressure suspension unit provided for each wheel, which is interposed between a wheel side member and a vehicle body side member and has a fluid chamber, and at least one of the supply and exhaust paths for the fluid chamber of this suspension unit. A small diameter pipe is installed in the path of A vehicle height adjustment device comprising means for adjusting the vehicle height.