JPS6341210Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention makes the spring constant of the fluid spring substantially zero during normal running, and prevents the occurrence of rolls, dives, squats, etc. when the load is transferred. Regarding electronically controlled suspension that improves comfort and handling stability.

An automobile equipped with a suspension having a fluid spring can adjust the vehicle height by adjusting the internal pressure of the fluid spring.

However, if fluid is supplied to the fluid springs to raise the vehicle height when a large number of passengers are on board and the vehicle height is lowered, the internal pressure of the fluid springs will increase, making the suspension harder and harder to ride. The downside was that it made me feel uncomfortable. Furthermore, in automobiles equipped with such electronically controlled suspensions, it is desired to further improve riding comfort and steering stability by preventing rolls, dives, and squats caused by load movement.

This idea was made in view of the above points,
The purpose of this is to make the spring constant of the fluid spring virtually zero during normal driving, and to change the internal pressure of the fluid spring when a load is transferred to prevent rolls, dives, squats, etc. The objective is to provide an electronically controlled suspension that improves ride comfort and handling stability.

Hereinafter, an electronically controlled suspension according to an embodiment of the invention will be described with reference to the drawings. In the figure, 11 is a suspension device. This suspension device 11 incorporates a strut-type damping force switching type shock absorber, and the suspension function is achieved by a coil spring 12, an air spring 13, and a shock absorber 17. The shock absorber 17 is switched between hardware and software by an absorber switching actuator (not shown). Further, the compressed air chamber of the air spring chamber 16 of the air spring 13 is adjusted via an air passage 15 formed within the piston rod 14. Furthermore, cylinder 1 of this device 11
The lower part of 71 is attached to the wheel 18,
The upper part of the device 11 is attached to the vehicle body via a mount rubber 19. Here, 20 is a vehicle height sensor attached to the vehicle body side, 21 is a load sensor composed of, for example, a piezoelectric element and detects the load on each wheel, and 22 is a pressure sensor that detects the internal pressure in the air spring chamber 16. .

By the way, 31 has three levels of vehicle height (``HIGH'',
This is a vehicle height selection switch that selects between ``MIDDLE'' and ``LOW.'' The operation signal of this vehicle height selection switch 31 is input to a target vehicle height setting circuit 32, and a vehicle height signal indicating a vehicle height corresponding to each stage is set. The vehicle height signal output from the target vehicle height setting circuit 32 and the vehicle height signal output from the vehicle height sensor 20 are each input to a vehicle height signal comparison circuit 33, and the respective vehicle height signals are compared. Based on the comparison signal from the vehicle height signal comparison circuit 33, the internal pressure correction signal generation circuit 34 outputs an internal pressure correction signal corresponding to the difference between the respective vehicle height signals to one input terminal of the adder 35.

Reference numeral 36 denotes a reference internal pressure value storage unit that stores the reference internal pressure value of the air spring chamber 16 when the vehicle is empty.The reference internal pressure value stored in this reference internal pressure value storage unit 36 is sent to the internal pressure setting signal generation circuit 37. The signal is input and converted into a reference internal pressure signal corresponding to the reference internal pressure value. Then, this reference internal pressure signal is sent to the adder 35.
is input to the other input terminal of. In this adder 35, the internal pressure correction signal and the reference internal pressure signal are added to calculate a target internal pressure signal.

Further, the load on each wheel sensed by the load sensor 21 is extracted as a load signal by a load detector 38. The load signal output from the load detector 38 is sent to a memory 39 that stores the latest load W ₀ for each wheel, and a load increase calculating section 40 that calculates the increase in load. Furthermore, the internal pressure within the air spring chamber 16 sensed by the pressure sensor 22 is extracted as an internal pressure signal by the internal pressure detector 41. The internal pressure signal output from the internal pressure detector 41 is stored in the memory 39 that stores the latest internal pressure P ₀ . The load increase calculation section 40
The value ΔP (=W−W ₀ /A) obtained by converting the load increase calculated in step 1 into internal pressure is input to the adder 42 .

By the way, 43 is a reserve tank in which compressed air is stored. In other words, the air sent from the air cleaner (not shown) is sent to the compressor 4.
It is compressed in 4, dried in a dryer 45, and stored in this reserve tank 43. Here, 43a is a pressure switch, and 46 is an engine. Furthermore, an electropneumatic proportional valve 47 and a solenoid valve 48 for preventing leakage of compressed air when the power is turned off are interposed between the reserve tank 43 and the air passage 15 communicating with the air spring chamber 16. The electro-pneumatic proportional valve 47 receives the output of the adder 35 or the adder 42 sorted by a selector 49 and input as a control signal. This electro-pneumatic proportional valve 47 is a control valve that adjusts the opening degree of the valve and the direction in which compressed air flows in accordance with an input signal, and controls the pressure on the air spring chamber 16 side to a pressure that corresponds to the input signal. Here, 50 is a muffler.

Reference numeral 51 denotes a power supply ON/OFF detection circuit that detects whether the ignition is on or off, and the output of this power supply ON/OFF detection circuit 51 is input to a solenoid valve drive circuit 52 which controls the opening/closing of the solenoid valve 48. Ru. Turn on the above power/
When the OFF detection circuit 51 detects that the power is turned off, the solenoid valve 48 closes.

By the way, 53 is a steering wheel angle sensor that detects the rotation angle of a steering wheel (not shown), and the output of this steering wheel angle sensor 53 is a threshold value discrimination circuit that outputs an H level signal when the rotation angle of the steering wheel exceeds a certain angle. 54. Furthermore, 55 is an acceleration sensor as a vehicle body attitude sensor that detects changes in the attitude of the vehicle body. This acceleration sensor 55 is designed to detect changes in pitch, roll, and yaw of the vehicle body posture on the automobile springs using a weight or the like. 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. The output of the acceleration sensor 55 is input to a threshold value determination circuit 56 which outputs an H level signal when the acceleration state of the vehicle body (front/rear, up/down, left/right) exceeds a certain value. Furthermore, 57 is an accelerator opening sensor that detects the opening of the accelerator, and the output of this accelerator opening sensor 57 is input to a threshold value determination circuit 58 that outputs an H level signal when the accelerator opening exceeds a certain value. Ru. Furthermore, 59 is a brake pressure sensor that detects the degree of depression of the brake, and the output of this brake pressure sensor 59 is input to a threshold value determination circuit 60 that outputs an H level signal when the degree of depression of the brake exceeds a certain value. . Also, 61
is a speed sensor that detects the vehicle speed, and the output of this speed sensor 61 is input to a threshold value determination circuit 62 that outputs an H level signal when the vehicle speed exceeds a certain speed. The threshold value determination circuits 54, 56, 58,
The outputs of 60 are input to OR circuits 63, respectively. The output of the OR circuit 63 is the selector 4.
9 and a vehicle height adjustment stop force control circuit 64 that stops the vehicle height adjustment or forcibly switches the vehicle height to a lower vehicle height. The selector 49 closes to the adder 42 side when the H level signal is input from the OR circuit 63. Further, the output signal of the threshold value determination circuit 62 is also input to the vehicle height adjustment/stop force control circuit 64 .

Next, the operation of this device configured as described above will be explained. First, when an ignition switch (not shown) is turned on, the process shown in the flowchart of FIG. 2 is started. First, the engine is started in step _S1 . At the same time, in step _S2 , the reference internal pressure value stored in the reference internal pressure value storage section 36 is sent to the internal pressure setting signal generation circuit 37 and converted into a reference internal pressure signal corresponding to the reference internal pressure value. This reference internal pressure signal is input as a control signal to the electropneumatic proportional valve 47 via the selector 49. Next, proceeding to step _S3 , the solenoid valve 48 that has sealed off the air spring chamber 16 is opened.
Then, in accordance with this control signal input to the electropneumatic proportional valve 47, compressed air is supplied by the voltage proportional valve 47 so that the reference internal pressure Pp is generated in the air spring chamber 16.
Exhaust is controlled. The process then proceeds to step _S4 , where the load W and reference internal pressure of each wheel detected by the load sensor 21 and pressure sensor 22 are detected and stored in the memory 39 as Wo and Pp. Next, proceeding to step _S5 , the vehicle height detected by the vehicle height sensor 20 is compared in the vehicle height signal comparison circuit 33 to see if it is equal to the target vehicle height output from the target vehicle height setting circuit 32. If it is determined ``YES'' in this step <sub>S5</sub> , the process proceeds to step <sub>S6</sub> , and the load sensor 21 and pressure sensor 22 detect the load W of each wheel in the air spring chamber 1.
The internal pressure P of 6 is detected, and then the process returns to step <sub>S5</sub> . Furthermore, the load W detected in step <sub>S6</sub> above
The internal pressure P is averaged, for example, 20 times and stored in the memory 39. On the other hand, if the determination in step <sub>S5</sub> is "NO", the process proceeds to step <sub>S7</sub> , where it is detected whether the conditions for adjusting the vehicle height are satisfied. For example, when the vehicle speed is 3 km/h or less, the vehicle height adjustment is performed immediately, and when the vehicle speed is 3 km/h or more, the vehicle height adjustment is performed when this state continues for 10 seconds. For example, when the vehicle height selection switch 31 is set to the "HIGH" position, which raises the vehicle height, the vehicle height signal comparison circuit 33 determines that the target vehicle height is greater than the output of the vehicle height sensor 20. and,
The vehicle height is adjusted in step <sub>S8</sub> . In this example, since the target vehicle height is larger, the internal pressure correction signal generation circuit 34 outputs a positive internal pressure correction signal. As a result, the positive internal pressure correction signal is added to the reference internal pressure signal supplied to the electropneumatic proportional valve 47. Therefore, the compressed air stored in the reserve tank 43 is sent into the air spring chamber 16 via the electropneumatic proportional valve 47 in an amount corresponding to the positive internal pressure correction signal. As a result, the vehicle height becomes higher. After this vehicle height adjustment, even if the internal pressure of the air spring chamber 16 changes, the electropneumatic proportional valve 47 is controlled to keep the internal pressure constant. Also, during vehicle height adjustment, the load W and internal pressure P are continuously detected by the load sensor 21 and the pressure sensor 22, and the memory 3
9 is stored. After the process of step <sub>S8</sub> is completed, the process returns to the process of step <sub>S5</sub> . This step S <sub>5</sub>
In the process, if the determination is ``YES'', the processes from step _S6 onwards are performed. Note that when the vehicle height selection switch 31 is set to the "LOW" position, a negative internal pressure correction signal output from the internal pressure correction signal generation circuit 34 is input to the electropneumatic proportional valve 47. Therefore, the compressed air stored in the air spring chamber 16 is discharged to the muffler 50 via the solenoid valve 48 and the electropneumatic proportional valve 47 in an amount corresponding to the negative internal pressure correction signal. As a result, the vehicle height decreases. As described above, the vehicle height is adjusted by the operation of the flowchart shown in FIG.

Next, vehicle body attitude control will be explained using the flowchart shown in FIG. Threshold value determination circuits 54 and 5 are based on the handle angle sensor 53, acceleration sensor 55, accelerator opening sensor 57, and brake pressure sensor 59.
When an H level signal is output from 6, 58, and ₆₀ , a determination of ``YES'' is made in step S1, and the vehicle body posture control is performed in step _S2 and thereafter. Also,
An H level signal is output from the OR circuit 63 to the vehicle height adjustment stop force control circuit 64, and the vehicle height adjustment is stopped under the control of the vehicle height adjustment stop force control circuit 64. Further, the output of the OR circuit 63 is output to the selector 49.
Since the output of the adder 42 is inputted to the electropneumatic proportional valve 47 via the selector 49 as a control signal. Next, the process proceeds to step _S2 , and the load W detected by the load sensor 21 is outputted to the load increase calculating section 40 via the load detector 38. Then, in this load increase calculating section 40, "ΔP=
W−Wo/A” is calculated. The load increase calculation unit 40 calculates the amount of change ΔP in the internal pressure within the air spring chamber 16 by dividing the change in the load applied to each wheel (W-Wo) by the pressure receiving area A. The amount of change ΔP in the internal pressure is added to the reference internal pressure signal in an adder 42. Then, the sum of the reference internal pressure signal and the internal pressure change amount ΔP is input to the electropneumatic proportional valve 47 as a control signal. For example, when the load W detected by the load sensor 21 increases, ΔP becomes positive, and the compressed air stored in the reserve tank 43 is sent to the air spring chamber 16 via the electropneumatic proportional valve 47. This raises the vehicle height.
In other words, the rear of the car lowers when the load is applied at the start, but by raising the vehicle height, the body maintains a horizontal posture and improves riding comfort. On the other hand, when the load W detected by the load sensor 21 decreases, ΔP becomes negative, and the compressed air in the air spring chamber 16 is discharged to the muffler 50 via the electropneumatic proportional valve 47. Therefore, the vehicle height is lowered. for example,
By lowering the vehicle height, the rear of the car lifts up, which occurs when the brakes are applied suddenly, keeping the vehicle level and providing a comfortable ride. When the above processing is completed, the process returns to step _S1 , and when it is determined that vehicle body posture control is not necessary, the process returns to step _S5 of the flowchart of FIG.

Note that when the vehicle speed detected by the speed sensor 61 is equal to or higher than the speed set by the threshold value determination circuit 62, an H level signal is sent from the threshold value determination circuit 62 to the vehicle height adjustment stop force control circuit 64. Output. Therefore, a low vehicle height is forcibly selected under the control of the vehicle height adjustment/stop forced control circuit 64. Thereby, running stability during high-speed operation can be improved.

Next, an electronically controlled suspension according to another embodiment of this invention will be described with reference to FIG. In the figure, 11 is a suspension device. This suspension device 11 incorporates a strut type damping force switching type shock absorber, and includes a coil spring 12 and an air spring 13.
The suspension function is achieved by the shock absorber 17 and the shock absorber 17. The shock absorber 17 is switched between hardware and software by an absorber switching actuator (not shown). Further, the amount of compressed air in the air spring chamber 16 of the air spring 13 is adjusted via an air passage 15 formed within the piston rod 14. Furthermore, the lower part of the cylinder 171 of the device 11 is attached to the wheel 18, and the upper part of the device 11 is attached to the vehicle body via a mount rubber 19. Here, 20 is a vehicle height sensor attached to the vehicle body side, 21 is a load sensor composed of, for example, a piezoelectric element and detects the load on each wheel, and 22 is a pressure sensor that detects the internal pressure in the air spring chamber 16. be.

By the way, 31 has three levels of vehicle height (``HIGH'',
This is a vehicle height selection switch that selects between ``MIDDLE'' and ``LOW.'' The operation signal of this vehicle height selection switch 31 is input to a target vehicle height setting circuit 32, and a vehicle height signal indicating a vehicle height corresponding to each stage is set. The vehicle height signal output from the target vehicle height setting circuit 32 and the vehicle height signal output from the vehicle height sensor 20 are each input to a vehicle height signal comparison circuit 33, and the respective vehicle height signals are compared. Based on the comparison signal from the vehicle height signal comparison circuit 33, the internal pressure correction signal generation circuit 34 outputs an internal pressure correction signal corresponding to the difference between the respective vehicle height signals to one input terminal of the adder 35.

Reference numeral 36 denotes a reference internal pressure value storage unit that stores the reference internal pressure value of the air spring chamber 16 when the vehicle is empty.The reference internal pressure value stored in this reference internal pressure value storage unit 36 is sent to the internal pressure setting signal generation circuit 37. The signal is input and converted into a reference internal pressure signal corresponding to the reference internal pressure value. Then, this reference internal pressure signal is sent to the adder 35.
is input to the other input terminal of. In this adder 35, the internal pressure correction signal and the reference internal pressure signal are added to calculate a target internal pressure signal.

Further, the load on each wheel sensed by the load sensor 21 is extracted as a load signal by a load detector 38. The load signal outputted from the load detector 38 is sent to a memory 39 that stores the latest load Wo for each wheel and a load increase calculation section 40 that calculates the increase in load. A value ΔP (=W-Wo/A) obtained by converting the load increase calculated by the load increase calculating section 40 into an internal pressure is inputted to one input terminal of the adder 42 via the selector 141. The output signal of the adder 35 is input to the other input terminal of the adder 42 .

Incidentally, the internal pressure of the air spring chamber 16 detected by the pressure sensor 22 is converted into an internal pressure signal by the internal pressure detector 143. And the adder 4
A difference signal between the target internal pressure signal output from the servo valve drive amplifier 144 and the internal pressure signal is input to the servo valve drive amplifier 144. The output of this servo valve drive amplifier 144 is output to a servo valve 145 that can change the flow direction of compressed air and control its flow rate. In other words,
The servo valve drive amplifier 144 controls the servo valve 145 so that the fed back internal pressure signal becomes equal to the target internal pressure signal.

By the way, 146 is a reserve tank in which compressed air is stored. That is, atmospheric air sent from an air cleaner (not shown) is compressed in a compressor 147, dried in a dryer 148, and stored in this reserve tank 146. Here, 146a is a pressure switch, 15
9 is an engine. This reserve tank 146 is connected to the air passage 15 communicating with the air spring chamber 16 via the servo valve 145.
Here, 50 is a muffler.

Further, 51 is a power supply ON/OFF detection circuit that detects the ON/OFF state of the power supply, that is, the ignition. The output signal of this power ON/OFF detection circuit 51 is input to the servo valve neutral position fixing signal generation circuit 152. When the power ON/OFF detection circuit 51 detects that the power is turned off, the servo valve neutral position fixing signal generation circuit 152 outputs a signal to the servo valve drive amplifier 144 to return the servo valve 145 to the neutral position. do.

By the way, 53 is a steering wheel angle sensor that detects the rotation angle of a steering wheel (not shown), and the output of this steering wheel angle sensor 53 is a threshold value discrimination circuit that outputs an H level signal when the rotation angle of the steering wheel exceeds a certain angle. 54. Furthermore, 55 is an acceleration sensor as a vehicle body attitude sensor that detects changes in the attitude of the vehicle body. This acceleration sensor 55 is designed to detect changes in pitch, roll, and yaw of the vehicle body posture on the automobile springs using a weight or the like. 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. The output of the acceleration sensor 55 is input to a threshold value determination circuit 56 which outputs an H level signal when the acceleration state of the vehicle body (front/rear, up/down, left/right) exceeds a certain value. Furthermore, 57 is an accelerator opening sensor that detects the opening of the accelerator, and the output of this accelerator opening sensor 57 is input to a threshold value determination circuit 58 that outputs an H level signal when the accelerator opening exceeds a certain value. Ru. Furthermore, 59 is a brake pressure sensor that detects the degree of depression of the brake, and the output of this brake pressure sensor 59 is input to a threshold value determination circuit 60 that outputs an H level signal when the degree of depression of the brake exceeds a certain value. . Also, 61
is a speed sensor that detects the vehicle speed, and the output of this speed sensor 61 is input to a threshold value determination circuit 62 that outputs an H level signal when the vehicle speed exceeds a certain speed. The threshold value determination circuits 54, 56, 58,
The outputs of 60 are input to OR circuits 63, respectively. Then, the output of the OR circuit 63 is the selector 1
41 and a vehicle height adjustment stop force control circuit 64 that stops the vehicle height adjustment or forcibly switches the vehicle height to a lower vehicle height. The selector 141 is the OR circuit 63
When an H level signal is input from the gate, it becomes closed. Further, the output signal of the threshold value determination circuit 62 is also input to the vehicle height adjustment/stop force control circuit 64 .

Next, the operation of another embodiment of the invention configured as described above will be explained. First, the case of adjusting the vehicle height will be explained. For example, if you want to raise the vehicle height, set the vehicle height selection switch 31 to the "HIGH" position. As a result,
A target vehicle height setting circuit 32 sets a vehicle height signal indicating a high vehicle height. The vehicle height signal output from the target vehicle height setting circuit 32 and the vehicle height sensor 20
The vehicle height signals outputted from the vehicle height signals are respectively input to a vehicle height signal comparison circuit 33, and the respective vehicle height signals are compared. Based on the comparison signal from the vehicle height signal comparison circuit 33, the internal pressure correction signal generation circuit 34
An internal pressure correction signal is output according to the difference in vehicle height signals. In other words, an internal pressure correction signal that increases the internal pressure of the air spring chamber 16 is output. Then, in the adder 35, the reference internal pressure signal outputted from the internal pressure setting signal generation circuit 37 and the internal pressure correction signal are added to calculate a target internal pressure signal. Then, the internal pressure detector 143 is detected by the servo valve drive amplifier 144.
The internal pressure signal fed back from the adder 35
The servo valve 145 is controlled so that the output becomes equal to the target internal pressure signal. In this case, since the target internal pressure signal is larger, the servo valve 145 is driven and the compressed air stored in the reserve tank 146 is supplied to the air spring chamber 16. As a result, the vehicle height becomes higher, and when the internal pressure signal fed back by the internal pressure detector 143 becomes equal to the target internal pressure signal, the servo valve drive amplifier 144
The servo valve 145 is returned to the neutral position,
Compressed air supply is stopped. Below, air spring chamber 1
The internal pressure of No. 6 is fed back as an internal pressure signal output from the internal pressure detector 143, and is always maintained at the internal pressure determined by the target internal pressure signal. Therefore, after adjusting the vehicle height, even if the internal pressure of the air spring chamber 16 changes due to some vibrations of the vehicle, the servo valve 145 maintains it at the target internal pressure determined by the target internal pressure signal.
is driven, the spring constant of the air spring 13 becomes zero, the suspension becomes soft, and the riding comfort is good.

In addition, when lowering the vehicle height, the vehicle height selection switch 31 is set to the "LOW" position, but in this case, the target internal pressure signal will be smaller than the internal pressure signal from the internal pressure detector 143.
By driving the servo valve drive amplifier 144, the servo valve 145 is switched to a position where the compressed air in the air spring chamber 16 is discharged to the muffler 50. This lowers the vehicle height.

Next, vehicle body attitude control will be explained. When H level signals are output from the threshold value determination circuits 54, 56, 58, and 60 by the handle angle sensor 53, acceleration sensor 55, accelerator opening sensor 57, and brake pressure sensor 59, subsequent vehicle body attitude control is performed. Further, an H level signal is output from the OR circuit 63 to the vehicle height adjustment stop force control circuit 64, and the vehicle height adjustment is stopped under the control of the vehicle height adjustment stop force control circuit 64. Further, since the output of the OR circuit 63 is input to the selector 141, the output signal of the load increase calculation unit 40 is input to one input terminal of the adder 42.

Next, the load W detected by the load sensor 21
is the load increase calculation unit 40 via the load detector 38.
is output to. Then, this load increase calculation section 4
0, "ΔP=W-Wo/A" is calculated. The load increase calculation unit 40 calculates the amount of change ΔP in the internal pressure in the air spring chamber 16 by determining the change in the load applied to each wheel (W-Wo) from the pressure receiving area A. The amount of change ΔP in the internal pressure is added to the reference internal pressure signal in an adder 42. Then, the sum of the reference internal pressure signal and the internal pressure change amount ΔP is input to the servo valve drive amplifier 144 as a control signal. For example, when the load W detected by the load sensor 21 increases, ΔP becomes positive,
Compressed air stored in a reserve tank 146 is sent to the air spring chamber 16 via a servo valve 145 under the control of the servo valve drive amplifier 144. This increases the vehicle height.

In other words, the rear of the car lowers when the load is applied at the start, but by raising the vehicle height, the body maintains a horizontal posture and improves riding comfort. On the other hand, when the load W detected by the load sensor 21 decreases, ΔP becomes negative, and the compressed air in the air spring chamber 16 is discharged to the muffler 50 via the servo valve 145. Therefore, the vehicle height is lowered. For example, when the rear of the car rises when the brakes are applied suddenly, the vehicle height is lowered to keep the car level and provide a comfortable ride.

Note that when the vehicle speed detected by the speed sensor 61 is equal to or higher than the speed set by the threshold value determination circuit 62, an H level signal is sent from the threshold value determination circuit 62 to the vehicle height adjustment stop force control circuit 64. Output. Therefore, a low vehicle height is forcibly selected under the control of the vehicle height adjustment/stop forced control circuit 64. Thereby, running stability during high-speed operation can be improved.

Further, when the power is turned off, the detection signal is sent to the servo valve neutral position fixing signal generation circuit 152. For this reason, the servo valve drive amplifier 14
4, the servo valve 145 is returned to the neutral position. As a result, the air spring chamber 16 after the power is turned off
This prevents air from escaping.

As detailed above, according to this invention, the spring constant of the fluid spring is made to be substantially zero during normal running, and when a load is transferred, rolls, dives, squats, etc. are prevented from occurring. It is possible to provide an electronically controlled suspension that improves ride comfort and handling stability.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an electronically controlled suspension according to an embodiment of this invention, Figs. 2 and 3 are flowcharts showing the operation of the same embodiment, and Fig. 4 is a diagram showing another embodiment of this invention. FIG. 3 is a diagram showing such an electronically controlled suspension. 11...Suspension device, 13...Air spring, 16...Air spring chamber, 31...Vehicle height selection switch, 33...Vehicle height signal comparison circuit, 34...Internal pressure correction signal generation circuit, 38...Load Detector, 47...
...Electro-pneumatic proportional valve.

Claims (1)

[Scope of utility model registration request] In a suspension comprising a fluid spring and a supply/discharge control device that controls the supply and discharge of fluid to the fluid spring to maintain the internal pressure of the fluid spring at a set internal pressure according to a control signal, the supply/discharge control device A signal output means that outputs the control signal that determines the set internal pressure, and a vehicle height sensor that compares the vehicle height detected by the vehicle height sensor with the target vehicle height, and when it is determined that vehicle height adjustment is necessary, the vehicle height is set to the target vehicle height. a vehicle height control means for correcting the control signal of the signal output means so as to match the above, a load sensor for detecting the load applied to the wheels, a driving state detection sensor for detecting the driving state of the vehicle, and a driving state detection sensor for detecting the driving state of the vehicle. and attitude control means for correcting the control signal of the signal output means in accordance with an increase or decrease in the load detected by the load sensor when the sensor detects that the vehicle body is in a state where the attitude change occurs. Electronically controlled suspension.