JPH02162111A - Control device of car height regulation type suspension - Google Patents

Abstract

PURPOSE:To improve the responsiveness by correcting the car height control signal with the adding value of the actual car height signal and the car height variation speed signal, when the turning condition of the car is detected. CONSTITUTION:A handle operation detecting circuit 432 outputs a high H signal when the rotation angle signal from a handle angle sensor 48 exceeds a specific value. A car speed discrimination circuit 433 outputs a high H signal when the car speed signal of a car speed sensor 49 exceeds a specific value. A turning time detecting device 43 outputs these H signals to an analog switch 42 to open the switch 42 when these H signals are input. By opening the analog switch 42, the correction signal Vp + Vd from a correction value computing circuit 40, as the adding value of the car height signal Vp and the differential signal Vd of the actual car height signal from a differential circuit 403, to a correction circuit 39. The correction circuit 39 corrects the car height control signal Va with the correction signal Vp + Vd, and outputs Va-(Vd+Vp) to a driving circuit (PWM circuit) 38. In such a way, the responsiveness of the car height regulation can be improved.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a control device for a vehicle height adjustable suspension, in particular,
The present invention relates to a control device for a vehicle height adjustable suspension that is configured to control the amount of working fluid supplied to and discharged from a vehicle height adjusting actuator using a solenoid valve.

(Prior Art) A height-adjustable suspension is known that can suitably improve the handling stability and ride comfort of a vehicle.

This height-adjustable suspension has a height-adjusting actuator mounted on the sprung and unsprung parts of the vehicle body, and a hydraulic adjustment valve controls the amount of working fluid supplied to and discharged from the vehicle height-adjusting actuator to adjust the current height to the target vehicle height. It operates to adjust the vehicle height.

The hydraulic adjustment valve of this type of vehicle height adjustable suspension is switched and operated by a control means to increase or decrease the pressure value in the circuit of the working fluid applied to the vehicle height adjustment actuator, and the vehicle height adjustment actuator is adjusted according to the pressure value. Adjustments are made to increase or decrease vehicle height.

Among these vehicle height adjustable suspensions, especially the 6th one
As shown in the figure, a control means 101 is connected to a solenoid valve 100 serving as a hydraulic pressure adjustment valve, and this control means 101 operates the solenoid valve 100 on duty to apply fluid pressure that increases or decreases according to the duty ratio of the solenoid valve 100 to a vehicle height adjustment actuator. supply to,
It is known that the vehicle height TA adjustment actuator is configured to increase or decrease the vehicle height.

The control means 101 here is a vehicle height control signal calculation circuit that receives an actual vehicle height signal from the vehicle height sensor 102 and target vehicle height information from the target vehicle height setting means 103, and outputs a vehicle height control signal based on both signals. 104, and an oscillator 105 that generates a duty current with a duty ratio according to the vehicle height control signal.
A duty control circuit 106 with a built-in duty current outputs an output, and a drive circuit 107 outputs a drive current corresponding to the duty current to the solenoid valve 100.

This electromagnetic valve 100 increases or decreases the pressure value in the circuit of the working fluid applied to the vehicle height adjustment actuator, and automatically adjusts the vehicle height according to the target vehicle height information.

(Problem to be solved by the invention) By the way, the vehicle height control signal calculation circuit 10 in this control means
4 is equipped with an averaging filter circuit 108 in consideration of the fact that the current actual vehicle height signal always varies due to vertical fluctuations of the wheels, which averages the actual vehicle height data within a predetermined time and calculates the average value. The vehicle height is adjusted using this as vehicle height data.

As described above, since it is necessary to average the vehicle height data, the averaging filter circuit 108 used has a relatively large time constant. For this reason, when reducing the vehicle body roll angle that occurs immediately after the vehicle steering wheel is operated, that is, when performing zero roll tA adjustment, this actual vehicle height change is not incorporated into the target vehicle height signal with a good response, and it is a matter of bad luck.

An object of the present invention is to provide a control device for a vehicle height adjustable suspension that can adjust the vehicle height with good responsiveness.

(Means for Solving the Problems) In order to achieve the above object, a control device for a vehicle height adjustable suspension according to the present invention operates the amount of working fluid supplied to a vehicle height adjustment actuator using a solenoid valve, The solenoid valve control means detects the deviation between the designated target vehicle height signal and the actual vehicle height signal from the vehicle height sensor, and sends a vehicle height control signal to the solenoid valve to maintain the vehicle at the target vehicle height. The vehicle is equipped with turning state detection means for outputting the turning information to the control means, and the control means converts the vehicle height control signal into the actual vehicle height signal when the vehicle turns. The vehicle height change speed signal is corrected by an added value of the vehicle height change speed signal and the vehicle height change speed signal.

(Function) When the vehicle turns, the vehicle height control signal is corrected by the addition value of the actual vehicle height signal and the vehicle height change speed signal, so the vehicle height control signal is adjusted with good response based on the corrected vehicle height control signal. The pressure value in the circuit of the working fluid applied to the high adjustment actuator is increased or decreased, and the vehicle height is adjusted according to the pressure value! The JR adjustment actuator can increase or decrease the vehicle height.

(Embodiment) FIG. 1 shows the main parts of a control device for a vehicle height adjustable suspension as an embodiment of the present invention. The height-adjustable suspension control device is installed on each of the left, right, front and rear wheels of the vehicle.

As shown in Fig. 2 and Fig. 1, the vehicle height g-adjustable suspension has a vehicle height adjustment actuator (
A suspension consisting of an actuator (hereinafter referred to as an actuator) 1 and a coil spring 3 is provided, and its control device is connected to a solenoid valve 2 that supplies and discharges working fluid to and from the actuator 1 in an amount corresponding to the duty ratio. It is composed of a control means 4.

The actuator 1 consists of a hydraulic cylinder 111 whose one end is connected to the sprung member 7 and a piston 112 that slides inside the hydraulic cylinder 111 and whose one end is connected to the unsprung member 8. The structure is configured to support the vehicle body load while allowing relative displacement of the vehicle body.

The solenoid valve 2 is a proportional solenoid valve used in the vehicle height adjustment hydraulic circuit 10 shown in FIG. 2, and its overall configuration is shown in FIG. 3. That is, this solenoid valve 2 consists of a pilot 11 and a main 12. The pilot 11 receives an oil passage 10 that adjusts the oil pressure from the pump 13 to pilot pressure, a poppet valve 14 that adjusts the high pressure oil from the pump to pilot pressure, and operates the poppet valve 14 on duty in response to a driving current from the control means 4. It is composed of a solenoid 15.

The main 12 includes a spool 17 that slides within the main body 16, and a load pressure chamber 18 that applies load pressure from an actuator (hereinafter referred to as an actuator) to one end of the spool 17. a pilot chamber 19 that applies pilot pressure to the spool 17;
A port 20 on the pump 13 side and a port 22 on the tank 21 side are closed simultaneously when the spool 17 is in the neutral position. The load side port 24 is always in communication with the central chamber 23 of the spool 17.

In the case of such a solenoid valve 2, the spool 17 is held at a neutral position in a steady state where the load pressure and pilot pressure do not fluctuate, and when the load actuator moves and the load pressure decreases or increases, the spool 17 moves left and right. , supplies and discharges hydraulic oil, and operates the poppet valve 1 by the drive current from the control means 4.
4 operates on duty, and an actuator pressure as a working oil pressure corresponding to the duty current value A can be outputted from the load side port 24 based on the characteristics shown in FIG.

In FIG. 2, reference numeral 25 indicates a gas spring that acts as an interference device when the load pressure suddenly increases, 31 indicates a discharge path, 32 indicates a return path, and 33 indicates a relief valve 34 that prevents excessive increase in discharge pressure. Reference numeral 35 indicates a check valve, reference numeral 36 indicates an accumulator, and reference numeral 37 indicates a check valve.
indicates an oil cooler, and numeral 38 indicates a filter, respectively.

The control means 4 includes a drive circuit 38, a correction circuit 39 that outputs a corrected vehicle height control signal to this, a correction value calculation circuit 40 that outputs a correction value to this, and outputs a vehicle height control signal to the correction circuit 39. Target vehicle height setting circuit 41.

It is comprised of a correction circuit 39 and a turning detection means 43 that controls opening and closing of an analog switch 42 between a correction value calculation circuit 40.

The drive circuit 38 includes an oscillation section and an amplification section (not shown), and is configured to generate a rectangular wave signal with a predetermined duty ratio based on the well-known PMW method (Pulse Width Modulation method). A drive current is supplied to the amplifier section here from a power supply circuit (not shown).

The target vehicle height setting circuit 41 includes a comparator 411, one input terminal of which receives the target vehicle height signal set by the target vehicle height setting means 44 via a buffer 45, and the other input terminal of which receives the target vehicle height signal set by the target vehicle height setting means 44. The actual vehicle height signal from the sensor 46 is received via the buffer 47, and the voltage corresponding to the actual vehicle height and the neutral voltage V of the vehicle height sensor are
e (set by the neutral voltage setting circuit 47) and outputs a vehicle height change signal Va.

The vehicle height change signal Va is provided with a smoothing circuit 412, which averages the actual vehicle height data within a predetermined period of time and outputs the vehicle height control signal Va based on the average value.

The correction value calculation circuit 40 consists of an adder 401 and a proportional circuit 402 and a differential circuit 403 connected to the re-input terminal of the adder 401. The proportional circuit 402 receives the vehicle height signal V from the vehicle height sensor 46.
The differential circuit 403 calculates the differential value of the actual vehicle height signal and outputs the differential signal Vd based on the neutral voltage Vc. Then, the adder 401 outputs a correction signal (Vp+Vd) which is the sum of these two signals.

The normally closed analog switch 42 is opened by a high H signal. The turning detection means 43 connected thereto includes an AND circuit 431, and its re-input terminal is connected to a steering wheel operation detection circuit 432 and a vehicle speed determination circuit 433.

The steering wheel operation detection circuit 432 includes a steering wheel angle sensor 48.
The steering wheel is configured to receive a turning angle signal of 1, and output a high H signal if the turning angle signal exceeds a predetermined value.

On the other hand, the vehicle speed determination circuit 433 is configured to output a high H signal when the vehicle speed signal from the vehicle speed sensor 49 exceeds a set value, here 3-/h.

The correction circuit 39 converts the addition value Va - Vc of the neutral voltage Vc and the vehicle height control signal Va in a steady state, that is, when the analog switch 42 is off, and into a correction signal (Vp + Vd) when the analog switch 42 is on. and vehicle height control signal Va
The additional value Va-(Vp+Vd) is outputted as a corrected vehicle height control signal.

When the control device of such a vehicle height adjustable suspension is activated, a road reaction force is applied to the wheels, and in response to this, the actuator 1 and the coil spring 3 perform relative displacement between the spring base and the spring base, thereby absorbing the shock. Perform the operation. At the same time, a change occurs in the actual vehicle height information, the duty current for obtaining the target vehicle height is output from the drive circuit 38 to the solenoid valve 2, and the actuator 1 receives actuator pressure due to the action of the solenoid valve 2, and the operation is performed to switch to the appropriate vehicle height. The vehicle height will be reduced to zero roll. In this case, especially as shown in Figure 4, when the steering wheel angle is cut above a predetermined value while driving, the corrected vehicle height control signal becomes Va-(Vρ+Vd), and the signal increases rapidly from immediately after the steering wheel is operated. death.

As a result, the corresponding solenoid valve 2 is operated with the opening current of the required duty ratio with good response, the actuator 1 is operated with the hydraulic pressure of the appropriate actuator pressure, and the vehicle height value is adjusted (
In FIG. 4, the vehicle can be controlled to the zero roll position with good responsiveness.

(Effects of the Invention) As described above, the control device for the vehicle height g type suspension according to the present invention immediately enters zero roll control to reduce the roll angle of the vehicle body when roll occurs, such as immediately after steering wheel operation. It can be controlled to zero roll with good responsiveness.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of the main parts of a control device for a vehicle height adjustable suspension as an embodiment of the present invention, FIG. A cross-sectional view of the electromagnetic valve, Fig. 4 is a waveform diagram explaining the temporal characteristics of the same device, Fig. 5 is a characteristic diagram of drive current and oil pressure as actuator pressure, and Fig. 6 is a circuit diagram of the control means of the conventional device. It is. DESCRIPTION OF SYMBOLS 1... Actuator, 2... Solenoid valve, 4... Control means, 38... Drive circuit, 39... Correction circuit, 4
1...Target vehicle height setting circuit, 43...Turning detection means, 46...Vehicle height sensor.

Claims (1)

[Claims] A solenoid valve controls the amount of working fluid supplied to and discharged from a vehicle height adjustment actuator, and the control means for the solenoid valve detects a deviation between a designated target vehicle height signal and an actual vehicle height signal from a vehicle height sensor; In a vehicle height adjustable suspension control device configured to output a vehicle height control signal to the solenoid valve to maintain the vehicle at a target vehicle height, the vehicle includes a turning state detection device for outputting turning information to the control means. A vehicle height adjustable suspension, wherein means is attached, and the control means corrects the vehicle height control signal with an added value of the actual vehicle height signal and the vehicle height change speed signal when the vehicle turns. control device.