JPH054507A - Suspension device of vehicle - Google Patents

Abstract

PURPOSE:To prevent lowering of running stability just after making the power by discriminating whether a time until the accuracy in an aging-stabilized type detecting means for detecting the behavior of a car is stabilized has elapsed or not, and regulating control of a flow control valve until the time elapses. CONSTITUTION:Fluid cylinders 3 are disposed between a vehicle body 1 and front wheels 2F and between the vehicle body and rear wheels 2R. An oil pressure circuit 10 having a flow control valve 9 is connected to an oil pressure pump 8. In this arrangement, a pressure sensor 13 and a ground clearance sensor 14, for example, are disposed as an immediate response detecting means for detecting the behavior of the car body 1 and a vertical acceleration sensor 15 and a lateral acceleration sensor 18, for example, are installed as an aging- stabilized type detecting means. According to detection signals from the respective sensors, the flow control valve 9 is controlled by a controller 19. At this time, the controller 19 regulates the control for the flow control valve 9 until the lapse of accuracy stabilization time in the aging-stabilized type detecting means 15, 18 is discriminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention controls a fluid cylinder disposed between a vehicle body side member and each wheel side member, and the supply and discharge of a working fluid to and from a hydraulic chamber of the fluid cylinder. The present invention relates to a vehicle suspension device including a flow control valve that changes suspension characteristics.

[0002]

2. Description of the Related Art Conventionally, for example, JP-A-63-130418.
As disclosed in the publication, the fluid in the fluid cylinder is controlled by controlling the supply and discharge of the working fluid to and from the fluid cylinders provided between the vehicle body side member and each wheel side member according to the operating state of the vehicle. Active suspension devices are known that are configured to vary the amount to alter suspension characteristics.

The above active suspension device includes a flow control valve for controlling the supply and discharge of the working fluid to and from the hydraulic chamber of the fluid cylinder, a vertical acceleration detecting means for detecting the vertical acceleration of the vehicle body, and a lateral acceleration of the vehicle body. Lateral acceleration detecting means for detecting acceleration, longitudinal acceleration detecting means for detecting longitudinal acceleration of the vehicle body, integrating means for integrating detection signals of the vertical acceleration detecting means, and output signals of the detecting means and integrating means. And a control means for determining the control amount of the flow control valve based on The roll displacement of the vehicle body is controlled by PID controlling the supply / discharge amount of the working fluid to / from the cylinder.

[0004]

The detection means used to control the active suspension device is a gyroscope and a tuning fork vibrating type in which a stable detection signal cannot be obtained until a certain period of time elapses after the power is turned on. Stable detection means such as an acceleration sensor and the like, and an instant response type detection means such as a vehicle height sensor such as a potentiometer and an optical sensor capable of obtaining a stable detection signal in a short time after the power is turned on. There is. Then, the control amount of the flow control valve is obtained based on the detection signal output from the above-mentioned time-stable detection means, and a control signal corresponding to this control amount is output to execute variable control of suspension characteristics. In this case, there is a problem in that it is difficult to execute appropriate control until the detection accuracy of the time-stable detection means becomes stable.

The present invention has been made in order to solve the above-mentioned problems, and in a vehicle suspension device using a time-stable detection means, an inaccurate detection signal is output immediately after the power is turned on. The purpose is to prevent the deterioration of running stability due to.

[0006]

The invention according to claim 1 is
A fluid cylinder provided between the vehicle body side member and each wheel side member, and a flow rate control valve for changing suspension characteristics by controlling supply / discharge of a working fluid to / from a hydraulic chamber of the fluid cylinder. In a suspension device for a vehicle, a time-stable detection means for detecting the behavior of the vehicle body and an immediate response detection means, and a control for obtaining the control amount of the flow control valve based on the detection signal output from each detection means Means for determining whether or not a precision stabilization time corresponding to the time from the power-on of the vehicle until the detection accuracy of the time-stable detection means is stabilized has been passed to the control means. A regulating means for regulating the control of the flow rate control valve is provided until the determination means confirms that the accuracy stabilization time has elapsed.

According to a second aspect of the invention, in the suspension device for a vehicle according to the first aspect, in which a gas spring communicating with the hydraulic chamber of the fluid cylinder is provided, it is determined that the accuracy stabilization time has elapsed from the time when the power was turned on. The supply / discharge of the working fluid to / from the hydraulic chamber of the fluid cylinder is stopped until the confirmation by the means.

According to a third aspect of the present invention, in the vehicle body suspension device according to the first aspect, the time-dependent stable detecting means operates until the determining means confirms that the accuracy stable time has elapsed from the time when the power was turned on. The control gain corresponding to the output detection signal is set to 0, and the control gain corresponding to the detection signal output from the immediate response type detection means is reduced as compared with the normal time.

According to a fourth aspect of the present invention, in the vehicle body suspension device according to the first aspect, from the time when the power is turned on until the determination means confirms that the accuracy stabilization time has elapsed, the time-dependent stable detection means is used. The control gain corresponding to the output detection signal is set to 0, and the control gain corresponding to the detection signal output from the immediate response type detection means is reduced as compared with the normal time, and the immediate response type detection means is also provided. The control gain corresponding to the differential value of the detection signal output from is increased.

According to a fifth aspect of the present invention, a fluid cylinder is provided between the vehicle body side member and each wheel side member.
In a vehicle suspension device including a flow control valve that changes suspension characteristics by controlling supply and discharge of a working fluid to and from a hydraulic chamber of a fluid cylinder,
A time-stable detection means and an immediate response detection means for detecting the behavior of the vehicle body, and a control means for obtaining the control amount of the flow control valve based on the detection signal output from each detection means are provided. The means is provided with restriction means for restricting the control of the flow control valve by the control means when the power of the vehicle is turned on, and for gradually releasing the restriction state as time passes.

[0011]

According to the invention described in claim 1, the control state of the flow control valve is maintained until it is confirmed in the discriminating means that the accuracy stabilization time for stabilizing the detection accuracy of the time-stable detection means has elapsed. Is regulated, and when it is confirmed that the accuracy stabilization time has elapsed, a transition is made to a normal control state in which the flow control valve is controlled based on the control amount obtained according to the detection signal of each detection means. Will be done.

According to the second aspect of the present invention, the operation of the flow control valve is continued until it is confirmed by the discriminating means that the accuracy stabilization time for stabilizing the detection accuracy of the time-stable detection means has elapsed. The restraint stops the supply and discharge of the working fluid to and from the fluid chamber of the fluid cylinder, and the gas spring sets the suspension characteristic to a fixed state.

According to the third aspect of the present invention, the time-stable detection means is provided until it is confirmed in the discriminating means that the accuracy stabilization time for stabilizing the detection accuracy of the time-stable detection means has elapsed. The control of the flow rate control valve according to the detection signal is stopped, and the control according to the detection signal of the immediate response type detection means is executed while being regulated.

According to the invention described in claim 4, the immediate response type detecting means is provided until it is confirmed in the discriminating means that the accuracy stabilization time for stabilizing the detection accuracy of the time stable detecting means has elapsed. The control of the flow rate control valve according to the detection signal is executed in the regulated state, and the control according to the differential value of the detection signal is actively executed.

According to the fifth aspect of the present invention, when the power of the vehicle is turned on, the control state of the flow control valve is regulated by the regulation means, and this regulation state is gradually released with the lapse of time, thereby stabilizing the accuracy. When the time has passed, the normal control state is entered.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic structure of a vehicle suspension system according to the present invention, in which a vehicle body 1 and front wheels 2 of the vehicle are shown.
Fluid cylinders 3 are respectively provided between the F and the rear wheels 2R. The fluid cylinder 3 includes a cylinder body 3a whose lower end is connected to a wheel-side member, and a piston 3b which is fitted in the cylinder body 3a and forms a hydraulic chamber 3c inside the cylinder body 3a. There is. On the upper surface of the piston 3b, a piston rod 3d having an upper end supported by the vehicle body 1 is provided in a protruding manner.

A communication passage 4 communicating with a gas spring 5 is connected to the hydraulic chamber 3c of the fluid cylinder 3. The gas spring 5 is connected to the gas chamber 5f by the diaphragm 5e.
And a hydraulic chamber 5g, which communicates with the hydraulic chamber 3c of the fluid cylinder 3 via the communication passage 4 and a passage provided in the piston 3b of the fluid cylinder 3. .

A hydraulic pump 8 driven by an engine (not shown) is installed at the front end of the vehicle body 1, and a hydraulic line 10 having a flow control valve 9 is connected to the hydraulic pump 8. The flow rate control valve 9 controls the supply and discharge of the working fluid to the fluid cylinder 3 to adjust the flow rate of the working fluid.

Further, on the vehicle body 1, a discharge pressure sensor 12 for detecting the discharge pressure of the hydraulic pump 8, a hydraulic pressure sensor 13 for detecting the hydraulic pressure of the hydraulic chamber 3c of each fluid cylinder 3, and each wheel 2 are provided.
Vehicle height displacement with respect to F and 2R, that is, a vehicle height sensor 14 that detects a cylinder stroke, and a vertical acceleration of the vehicle,
That is, the vertical acceleration sensor 15 that detects the sprung acceleration of the wheels 2F and 2R, the steering angle sensor 16 that detects the steering angle of the steering wheel, the vehicle speed sensor 17 that detects the traveling speed of the vehicle, and the lateral vehicle acting on the vehicle body. A lateral acceleration detecting means 18 for detecting acceleration is provided. One vertical acceleration sensor 15 is provided above the left and right front wheels 2F, and one vertical acceleration sensor 15 is provided at the center of the left and right rear wheels 2R in the vehicle width direction.

The detection signals of the sensors 12 to 18 are input to the control means including a controller 19 having a CPU and the like inside. Then, a control signal corresponding to the detection signal is output from the controller 19 to the flow rate control valve 9 so that the flow rate of the working fluid supplied to and discharged from the fluid cylinder 3 is controlled, so that the suspension characteristic is variably controlled. It has become.

FIG. 2 shows a hydraulic circuit for controlling the supply and discharge of the working fluid to and from the fluid cylinder 3. A hydraulic pump 8 driven by an engine 20 is provided in this hydraulic circuit. An accumulator 22 is provided in the discharge pipe 21 of the hydraulic pump 8, and a downstream portion thereof has a pipe 23F for the front wheel 2F and a pipe 23R for the rear wheel 2R.
It branches to and. The pipe 23F for the front wheel 2F has its downstream portion branched into left and right pipes 23FL and 23FR, and both pipes 23FL and 23FR are connected to the hydraulic chambers 3c of the corresponding fluid cylinders 3FL and 3FR, respectively.
The downstream portion of the pipe 23R for the rear wheel 2R is branched into a pipe 23RL for the left rear wheel and a pipe 23RR for the right rear wheel, and both pipes 23RL, 23RR correspond to the fluid cylinder 3RL. , 3RR are connected to the hydraulic chamber 3c.

Each of the gas springs 5FL to 5RR connected to each of the fluid cylinders 3FL to 3RR has four gas spring members 5a, 5b, 5c and 5d, and the gas spring members 5a to 5d respectively. It is connected to the communication passage 4 through the branch communication passages 4a to 4d. Further, orifices 25a to 25d are provided in the branch passages 4a to 4d of the gas spring members 5a to 5d, respectively, and the damping action of the orifices 25a to 25d and the gas spring members 5 are made.
The basic function as the suspension device is achieved by the buffering action of the gas sealed in the gas chambers 5f of a to 5d.

In the communication passage 4 located between the first gas spring member 5a and the second gas spring member 5b of each of the gas springs 5FL to 5RR, the damping force for changing the damping force by adjusting the passage area is adjusted. A switching valve 26 is provided. The damping force switching valve 26 has two positions, an open position that opens the communication passage 4 and a throttle position that narrows the passage area of the communication passage 4.

The discharge pipe 21 of the hydraulic pump 8 is provided with an unload relief valve 28 near the accumulator 22. The unload relief valve 28 is operated from the closed position shown in the drawing to the open position and supplied from the hydraulic pump 8 when the discharge pressure of the working fluid detected by the discharge pressure sensor 12 is equal to or higher than the upper limit set value. The fluid is directly returned to the reserve tank 29 so that the accumulated pressure of the working fluid in the accumulator 22 is maintained at a set value. In this way, the hydraulic oil is supplied to each fluid cylinder 3 in accordance with the accumulated pressure of the accumulator 22.

Fluid cylinder 3 provided for each wheel
Since the above hydraulic circuits have the same configuration, the configuration of the hydraulic circuit for the front left wheel will be described below. The flow control valve 9 provided in the pipe 23FL for the left front wheel connects the illustrated stop position for closing all ports, the supply position for opening the pipe 23FL to the supply side, and the pipe 23FL for communication with the return passage 32. It has three positions, a discharge position and a pair of pressure compensation valves 9a. The pressure compensating valve 9a is provided to hold the hydraulic pressure of the fluid cylinder 3 at a predetermined value when the flow control valve 9 is in the supply position or the discharge position.

On the fluid cylinder 3 side of the flow control valve 9, there is provided a pilot pressure responsive on-off valve 33 for opening and closing the pipe 23FL for the left front wheel. The on-off valve 33 is provided on the front wheel side pipe 23 that communicates with the discharge pipe 21 of the hydraulic pump 8.
When the solenoid valve 34 disposed at F is opened, the hydraulic pressure of the solenoid valve 34 is introduced as pilot pressure. When the pilot pressure is equal to or higher than a predetermined value, the valve is opened to open the pipe 23FL, and the flow control valve is opened. It is possible to control the supply and discharge of hydraulic oil to and from the fluid cylinder 3 by means of 9.

In FIG. 2, reference numeral 35 is a relief valve that opens when the hydraulic pressure chamber 3c of the fluid cylinder 3 rises abnormally and returns the working fluid in the hydraulic pressure chamber 3c to the return passage 32. Further, reference numeral 36 is an ignition key interlocking valve connected to the discharge pipe 21 of the hydraulic pump 8 in the vicinity of the accumulator 22, and when the ignition key is in the off state, the working fluid stored in the accumulator 22 is opened. Is returned to the reserve tank 29 to release the high pressure state. Further, reference numeral 37 is a pump relief valve for returning the discharged oil to the reserve tank 29 to reduce the pressure when the discharge pressure of the hydraulic pump 8 is abnormally increased, and reference numeral 38 is a return accumulator provided in the return passage 32, The pressure is accumulated when the working fluid is discharged from the fluid cylinder 3.

As shown in FIG. 3, the control means composed of the controller 19 controls the vehicle height so as to match the vehicle height with the target vehicle height based on the detection signal output from the vehicle height sensor 14. 39, a vehicle height displacement speed control unit 41 that appropriately controls the vehicle height displacement speed based on the vehicle height displacement speed signal obtained by differentiating the detection signal of the vehicle height sensor 14 in the differentiator 40, and each fluid. The torsion control unit 42 for controlling the torsion of the vehicle body based on the detection signal of the hydraulic pressure output from the hydraulic pressure sensor 13 of the cylinder 3, and the vertical acceleration detection signal output from the vertical acceleration sensor 15 Based on the vertical vibration control unit 43 that controls the vertical vibration of the vehicle based on the vertical acceleration and the lateral acceleration detection signal output from the lateral acceleration sensor 18, the roll change of the vehicle is performed. The and a roll displacement controller 44 for controlling the proper state.

Then, the total control amount of the flow control valve 9 is obtained by adding the control amounts calculated in the respective control units 39, 41 to 44, and a control signal corresponding to this total control amount is output to the flow control valve 9. The suspension characteristic is thereby variably controlled.

The hydraulic pressure sensor 13 and the vehicle height sensor 14
Is composed of an immediate response type detection means such as a potentiometer, whereas the vertical acceleration sensor 15 and the lateral acceleration sensor 18 are composed of time-stable detection means such as a tuning fork vibration type sensor. In addition, the controller 19
4, the time until the detection accuracy of the time-stable detection means including the vertical acceleration sensor 15 is stabilized after the ignition key switch 45 is operated and the vehicle is powered on. A timer 46 for setting an accuracy stabilization time corresponding to the above, a judgment means 47 for judging whether or not the accuracy stabilization time has elapsed by judging whether or not the timer 46 has timed out, and the judgment means 47 described above. Until it is confirmed that the accuracy stabilization time has elapsed, the regulating means 48 for regulating the control of the flow control valve 9 is provided.

The control operation of the suspension device having the above construction will be described with reference to the flow chart shown in FIG. When this control operation starts, it is first determined in step S1 whether or not the vehicle is powered on according to the output signal of the ignition key switch 45. When the determination result is YES, in step S2, the timer 46 is started to start measuring the accuracy stable time, and then in step S3, it is determined whether or not the timer 46 has timed out.

If the decision result in the step S3 is NO, the variable control of the suspension characteristics is stopped in the step S4. That is, by setting all the control gains corresponding to the respective control amounts calculated by the respective control units 39, 41 to 44 to 0, the supply / discharge of the working fluid to / from the hydraulic chamber 3a by the flow control valve 9 is stopped. , The suspension characteristics are set to a fixed state exclusively by the gas springs 5FL, 5FR, 5RL, 5RR.

If it is determined YES in step S3 and it is confirmed that the accuracy stabilization time has elapsed, the vertical acceleration sensor 1 is operated in step S5.
5 and the lateral acceleration sensor 18, a control amount Qg based on a detection signal output from a time-dependent stable detection means is calculated, and in step S6, an immediate response type including the hydraulic pressure sensor 13 and the vehicle height sensor 14 is used. The control amount Qh is calculated based on the detection signal output from the detection means.

That is, as shown in the following equation (1), the vertical acceleration control amount Qu obtained according to the detection signal of the vertical acceleration sensor 15 and the lateral roll control amount obtained according to the detection signal of the lateral acceleration sensor 18. The first control amount Qg is calculated by adding Qr and the vehicle height displacement control amount Qx obtained according to the detection signal of the vehicle height sensor 14 and the vehicle height sensor as shown in the following equation (2). By adding the vehicle height displacement speed control amount Qxa determined according to the vehicle height displacement velocity composed of the differential value of the detection signal of No. 14 and the pressure control amount Qp determined according to the detection signal of the hydraulic pressure sensor 13, 2 controlled variable Qh
To calculate.

Qg = Quu + Qr (1) Qh = Qx + Qxa + Qp (2) Next, in step S7, a preset transition time T, that is, the state in which the suspension characteristic variable control is stopped is gradually released to the normal control state. It is determined whether or not a predetermined time set for returning has elapsed. If the determination result is NO and it is confirmed that the transition time T has not yet elapsed, in step S8, the suspension characteristic variable control is gradually shifted from the stopped state to the normal control state. Execute control during the transition period. That is, as shown in the following equation (3), step S
First controlled variable Qg and second controlled variable Qh calculated in 5 and 6
Then, as shown in FIG. 6, the total control amount Q is calculated based on the function f (x) whose value gradually increases from 0 to 1 with the passage of time within the transition time T.

Q = f (x) · (Qg + Qh) (3) Then, when YES is determined in step S7 and it is confirmed that the transition time T has elapsed, the first control amount Qg and the second control amount Qg The total control amount Q is calculated by adding the control amount Qh, and the normal control for outputting the control signal corresponding to this total control amount Q to the flow control valve 9 is executed.

As described above, the control of the flow control valve 9 is stopped and the gas spring 5 is exclusively operated until the detection accuracy of the time-stable detection means including the vertical acceleration sensor 15 and the like is stabilized.
Since the suspension characteristic is set to the fixed state by FL, 5FR, 5RL, 5RR, the variable control of the unstable suspension characteristic is executed based on the inaccurate detection signal output from the time-stable detection means. It is possible to effectively prevent this from occurring, and to effectively prevent a decrease in running stability immediately after the vehicle is powered on. After the accuracy stabilization time has elapsed, appropriate control can be executed based on the detection signals output from both the time-stable detection means and the immediate response detection means.

Further, as shown in the above embodiment, after the accuracy stabilization time has elapsed, the transition control based on the function f (x) is executed, and the suspension state of the variable control of the suspension characteristics is gradually released to the normal state. In the case where the flow control valve 9 is configured to return to the control state, the operating state of the flow rate control valve 9 is prevented from changing rapidly, and thereby the transitional period between the start-up immediately after the power is turned on and the normal control state. It is possible to properly execute variable control of the suspension characteristics in.

In the above embodiment, each control unit 39, 4
By setting all the control gains corresponding to the respective control amounts calculated in 1 to 44 to 0, the supply and discharge of the working fluid to and from the hydraulic chamber 3a is completely stopped. Sensor 15 and lateral acceleration sensor 1
Only the control gain corresponding to the detection signal output from the time-stable detection means consisting of 8 is set to 0, and only the control of the flow control valve 9 based on this detection signal is stopped, and the hydraulic pressure sensor 13 and the vehicle You may comprise so that control based on the detection signal output from the immediate response type detection means which consists of the high sensor 14 may be continued.

That is, as shown in the following equation (4), the second controlled variable Qh obtained according to the detection signal output from the immediate response type detection means and a value smaller than 1 in advance, for example, 0. The total control amount Q is calculated based on the control gain α set to about 5.

Q = α · Qh (4) As described above, the total of the flow rate control valve 9 is set in a state in which the control gain α corresponding to the detection signal output from the immediate response type detection means is lowered as compared with the normal time. When the control amount Q is calculated and the control is performed based on the total control amount Q, the control gain corresponding to the detection signal output from the time-stable detection means is set to 0. There is an advantage that it is possible to effectively prevent the deterioration of the riding comfort and the like due to the complete stop of the variable control of the suspension characteristics while suppressing the loss of the control balance.

Further, as described above, the second control amount Qh obtained according to the detection signal output from the immediate response type detection means.
In place of the configuration in which the control gain α corresponding to is uniformly reduced as compared with the normal time, as shown in the following equation (5), it corresponds to the vehicle height displacement control amount Qx obtained according to the detection signal of the vehicle height sensor 14. By setting the control gain β to, for example, about 0.8, the control gain β is reduced as compared with the normal time, and the vehicle height displacement speed control is obtained according to the vehicle height displacement speed that is the differential value of the detection signal of the vehicle height sensor 14. The control gain γ corresponding to the amount Qxa may be set to about 1.2 so as to be increased as compared with that at the time of elimination.

Qh = β · Qx + γ · Qxa + Qp (5) According to the above configuration, the decrease in the vehicle height control responsiveness due to the decrease in the control gain β is caused by the control gain γ.
Can be suppressed by positively executing the control of the vehicle high displacement speed, and the occurrence of an oscillation phenomenon or the like due to the decrease in the responsiveness can be effectively prevented.

Further, in each of the above-described embodiments, the control gain corresponding to the detection signal output from the time-stable detection means including the vertical acceleration sensor 15 and the lateral acceleration sensor 18 is set until the accuracy stabilization time elapses. Although it is set to 0 and the control of the flow control valve 9 based on this detection signal is stopped, as shown in FIG. 7, it was confirmed in step S11 that the vehicle was powered on. At this point, the first controlled variable Qg and the second controlled variable Qh are calculated in steps S12 and S13, and
4, the function f whose value gradually increases with time
It may be configured to execute the control using (y) as the control gain.

That is, in step S14,
As shown in FIG. 8, a function f whose value gradually increases from 0 to 1 by multiplying the first controlled variable Qg and the second controlled variable Qh by the time T2 when the accuracy stabilization time has elapsed from the power-on time T1.
The total control amount Q is calculated based on (y), and a control signal corresponding to this total control amount Q is output to the flow control valve 9. As a result, the control regulation state of the flow control valve 9 by the regulation means 48 is gradually released with the passage of time.

Then, in step S15, the timer 4
6 until the time is up and it is confirmed that the preset accuracy stabilization time has elapsed, steps S12 to S1.
After repeating the flow shown in FIG. 5, when it is confirmed in step S15 that the accuracy stabilization time has elapsed,
Then, the process proceeds to step S16, and normal variable control of suspension characteristics is executed.

As described above, in the case where the control regulation state by the regulation means 48 is gradually released with the passage of time, as the detection accuracy of the time-stable detection means stabilizes, the suspension becomes stable. It is possible to gradually shift the variable control of the characteristics from the regulated state to the normal control state, with the effect of preventing the deterioration of running stability immediately after turning on the power with a simple configuration, and the detection with time-stable type in normal time. There is an advantage that the effect that variable control of the suspension characteristics based on the detection signal of the means can be appropriately executed is obtained at the same time.

In the above embodiment, an example in which the vertical acceleration sensor 15 and the lateral acceleration sensor 18 which are tuning fork vibration type sensors are used as the time-stable detection means has been described, but in addition to these, a gyroscope or the like is used. The configuration of the present invention can also be applied to a vehicle suspension device that is configured to detect the turning state of the vehicle by using the angular velocity sensor described above and control the flow control valve 9 based on this detection signal. .

[0049]

As described above, according to the present invention, the behavior of the vehicle is detected by using the time-stable detection means including a tuning fork type vibration sensor and a gyroscope, and the time-stable detection means is used. In a suspension device configured to variably control suspension characteristics based on an output detection signal, the above-described time-stable detection means is normally used while preventing deterioration of running stability of a vehicle immediately after power is turned on. The control based on the detection signal can be properly performed.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram of a vehicle suspension device according to the present invention.

FIG. 2 is a circuit diagram showing a configuration of a hydraulic circuit of the suspension device.

FIG. 3 is a block diagram showing a configuration of a control unit of the suspension device.

FIG. 4 is a block diagram showing an internal configuration of a controller.

FIG. 5 is a flowchart showing a control operation of the controller.

FIG. 6 is a time chart showing a function f (x).

FIG. 7 is a flowchart showing another embodiment of the present invention.

FIG. 8 is a time chart showing a function f (y).

[Explanation of symbols]

1 car body Two wheels 3 fluid cylinder 3c hydraulic chamber 9 Flow control valve 13 Pressure sensor (speed response type detection means) 14 Vehicle height sensor (speed response type detection means) 15 Vertical acceleration sensor (temporally stable detection means) 18 Lateral acceleration sensor (time-stable detection means) 47 discrimination means 48 Control measures

Claims (5)

[Claims] 1. A fluid cylinder disposed between a vehicle body side member and each wheel side member, and a flow rate for changing suspension characteristics by controlling supply / discharge of a working fluid to / from a hydraulic chamber of the fluid cylinder. In a vehicle suspension device including a control valve, a time-stable detection means and an immediate response detection means for detecting the behavior of the vehicle body,
A control means for determining the control amount of the flow control valve based on the detection signal output from each detection means is provided, and the detection accuracy of the time-stable detection means is stabilized in this control means from the time when the vehicle is powered on. The determination means that determines whether or not the accuracy stabilization time corresponding to the time until the determination has elapsed, and the control of the flow rate control valve is restricted until the determination that the accuracy stabilization time has elapsed is determined by this determination means. A suspension device for a vehicle, comprising: 2. In a suspension device for a vehicle, which is provided with a gas spring communicating with a hydraulic chamber of a fluid cylinder, a fluid is supplied from the time of power-on until the discriminating means confirms that the accuracy stabilization time has elapsed. 2. The suspension device for a vehicle according to claim 1, wherein the supply / discharge of the working fluid to / from the hydraulic chamber of the cylinder is stopped. 3. The control gain corresponding to the detection signal output from the time-stable detection means is set to 0 from the time when the power is turned on until the determination means confirms that the accuracy stabilization time has elapsed. 2. The vehicle suspension device according to claim 1, wherein the control gain corresponding to the detection signal output from the immediate response type detection means is configured to be lower than in a normal state. 4. A control gain corresponding to a detection signal output from the time-stable detection means is set to 0 until the determination means confirms that the accuracy stabilization time has elapsed since the power was turned on. In addition, the control gain corresponding to the detection signal output from the immediate response type detection means is decreased and the control gain corresponding to the differential value of the detection signal output from the immediate response type detection means is increased as compared with the normal time. The suspension device for a vehicle according to claim 1, wherein the suspension device is configured to operate. 5. A fluid cylinder disposed between a vehicle body side member and each wheel side member, and a flow rate for changing suspension characteristics by controlling supply / discharge of a working fluid to / from a hydraulic chamber of the fluid cylinder. In a vehicle suspension device including a control valve, a time-stable detection means and an immediate response detection means for detecting the behavior of the vehicle body,
A control means for determining the control amount of the flow control valve based on the detection signal output from each detection means is provided, and the control means controls the flow control valve by the control means when the vehicle is powered on. A suspension device for a vehicle, which is provided with a restricting means for restricting the control of the vehicle and gradually releasing the restricted state as time passes.