JP2758012B2 - Vehicle suspension device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a suspension device for a vehicle that controls the supply and discharge of a fluid to a fluid cylinder to vary suspension characteristics, and particularly when a passenger gets on and off when the vehicle stops. Etc. relates to the improvement of the control in such cases.

(Prior Art) Conventionally, as a vehicle suspension device, for example, as disclosed in Japanese Patent Application Laid-Open No. 63-130418, a fluid cylinder is disposed between a vehicle body and each wheel, and the fluid cylinder is connected to each fluid cylinder. Control the supply and discharge of each wheel independently to make the suspension characteristics of the vehicle variable according to the driving conditions.
A so-called active control suspension device (ACS device) is known.

(Problems to be Solved by the Invention) In the ACS apparatus as described above, a stroke sensor for detecting a cylinder stroke amount of each fluid cylinder is provided in order to ensure a good posture and ride comfort of the vehicle. A vertical acceleration sensor for detecting the vertical acceleration of the vehicle is provided, and the vertical vibration of the vehicle is appropriately suppressed based on the sensor output to improve the riding comfort. desired.

However, when the vehicle is stopped, the occupants may get on and off or load / unload luggage.In this case, the vehicle vibrates up and down, and the up and down vibration of the vehicle is detected by the up / down acceleration sensor and each fluid cylinder is detected. Supply and discharge control of fluid to
As a result, the vibration of the vehicle is generated due to the supply / discharge control of the fluid, and the occupant may feel strange.

The present invention has been made in view of such a point, and its object is to provide a stroke sensor and a vertical acceleration sensor as described above to control the supply and discharge of fluid, when the vehicle stops, to get on and off the occupant, etc. An object of the present invention is to effectively prevent vehicle vibration caused by fluid supply / discharge control even if the accompanying vehicle vibration occurs.

(Means for Solving the Problems) In order to achieve the above object, in the present invention, when the vehicle stops, the supply / discharge control of the fluid to / from each fluid cylinder is gently performed or stopped.

Specifically, according to the first aspect of the present invention, a fluid cylinder is provided between a vehicle body and each wheel, and a suspension characteristic of the vehicle is variably controlled by controlling a flow rate to each fluid cylinder. A suspension detecting device for detecting a cylinder stroke amount of the fluid cylinder, a vertical acceleration detecting device for detecting a vertical acceleration of the vehicle, and a controller for each of the fluid cylinders based on outputs of the two detecting devices. Control means for controlling the supply and discharge of fluid, wherein the control means changes the ratio of the control gain based on the output of the vertical acceleration detecting means to the control gain based on the output of the stroke detecting means when the vehicle stops. Control gain changing unit that performs the control.

According to a second aspect of the present invention, there is provided a vehicle in which a fluid cylinder is disposed between a vehicle body and each wheel, and a suspension characteristic of the vehicle is made variable by controlling a flow rate to each fluid cylinder. In the suspension device, a stroke detecting means for detecting a cylinder stroke amount of the fluid cylinder, a vertical acceleration detecting means for detecting a vertical acceleration of the vehicle, and a flow of the fluid to each of the fluid cylinders based on outputs of the both detecting means. Control means for controlling supply / discharge, wherein the control means reduces the control gain based on the output of the vertical acceleration detecting means when the vehicle stops and does not change the control gain based on the output of the stroke detecting means. It has a gain changing unit.

Here, in the invention of claim 3, the control means according to claim 1 or 2 calculates an independent control amount for each of three components of bounce, pitch and roll based on the output of the vertical acceleration detection means. The control gain changing unit changes the control gains of all the components to be small. Further, in the invention of claim 4, according to claim 1 described above.
Alternatively, the control gain changing unit in 2 changes the control gain based on the output of the vertical acceleration detecting means to a small value when the vehicle speed is equal to or less than the predetermined vehicle speed value.

(Operation) With the above configuration, in the inventions of claims 1 to 4, when the vehicle is stopped such as when the vehicle speed is equal to or lower than a predetermined vehicle speed value, the control gain of the control based on the output of the vertical acceleration detection means is smaller than the normal value. Therefore, even if the vehicle vibrates due to the occupant getting on / off or loading / unloading the load, the supply / discharge of fluid to / from each fluid cylinder is performed gently. Vibration is prevented.

(Effects of the Invention) As described above, according to the vehicle suspension device of the inventions of claims 1 to 4, the respective wheels of each wheel are output based on the output of the means for detecting the stroke of the fluid cylinder and the means for detecting the vertical acceleration of the vehicle. When the suspension characteristics are variable by controlling the supply and discharge of fluid to and from the fluid cylinder, when the vehicle is stopped, the control gain of the control based on the vertical acceleration signal of the vehicle is made smaller than the normal value, so Even if the vehicle vibrates up and down as the cargo is loaded and unloaded, the vehicle can be prevented from vibrating due to the fluid supply / discharge control caused by the up / down vibration, and the discomfort given to the occupant can be eliminated.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

In FIG. 1, 1 is a vehicle body, 2F is a front wheel, 2R is a rear wheel, and fluid cylinders 3 are arranged between the vehicle body 1 and the front wheel 2F and between the vehicle body 1 and the rear wheel 2R. I have. Each of the fluid cylinders 3 is a piston fitted in a cylinder body 3a.
It has a fluid chamber 3c defined by 3b. The upper end of the rod 3d connected to the piston 3b is connected to the vehicle body 1, and the cylinder body 3a is connected to the wheels 2F, 2R, respectively.

Gas springs 5 are connected to the fluid chambers 3c of the respective fluid cylinders 3 via communication passages 4, respectively. Each gas spring 5 is partitioned by a diaphragm 5e into a gas chamber 5f and a fluid chamber 5g, and the fluid chamber 5g communicates with the fluid chamber 3c of the fluid cylinder 3.

Reference numeral 8 denotes a hydraulic pump, and reference numerals 9 and 9 denote flow control valves provided in a high-pressure line 10 that communicates the hydraulic pump 8 with each of the fluid cylinders 3.
It has a function of adjusting the flow rate by supplying / discharging fluid (oil) to / from the apparatus.

Further, reference numeral 12 denotes a main pressure sensor for detecting an oil discharge pressure of the hydraulic pump 8 (specifically, a pressure of oil storage in accumulators 22a and 22b described later), and reference numeral 13 denotes a fluid chamber of each fluid cylinder 3.
A cylinder pressure sensor 14 for detecting the fluid pressure 3c, and a vehicle height sensor 14 as a stroke detecting means for detecting a vehicle height (a cylinder stroke amount of the fluid cylinder 3) of the corresponding wheel 2F, 2R. Reference numeral 15 denotes a vertical acceleration sensor as vertical acceleration detecting means for detecting the vertical acceleration of the vehicle (the sprung acceleration of the wheels 2F and 2R), 16 a lateral acceleration sensor for detecting the lateral acceleration of the vehicle, and 17 a front wheel serving as a steering wheel. A steering angle sensor for detecting the steering angle of 2F, and a vehicle speed sensor 18 for detecting the vehicle speed. The detection signals of the above sensors are input to a controller 19 having a CPU and the like therein, and the controller 19 outputs the fluid to each fluid cylinder 3 based on the outputs of the vehicle height sensor 14, the vertical acceleration sensor 15, and the like. And control means for variably controlling suspension characteristics by controlling supply / discharge of the vehicle.

Next, a hydraulic circuit for controlling the supply and discharge of fluid to and from the fluid cylinder 3 is shown in FIG. In the figure, a hydraulic pump 8 is composed of a variable displacement type swash plate piston pump, and is connected to a hydraulic pump 21 for a power steering device driven by a drive source 20 in a duplex manner. Three accumulators 22a, 22a, 22a are connected to the high pressure line 10 connected to the hydraulic pump 8 at the same location, and the high pressure line 10 is connected to the front wheel side passage 10F and the rear wheel side passage 10R at the connection point. And it is forked. Further, the front wheel side passage 10F is the left front wheel side passage 1
0FL and the right front wheel side passage 10FR.
FR is the corresponding wheel fluid cylinder 3FL, 3FR fluid chamber 3c
Is communicated. On the other hand, one accumulator 22b is communicatively connected to the rear wheel side passage 10R, and is branched downstream into a left rear wheel side passage 10RL and a right rear wheel side passage 10RR. The fluid chambers 3c of the fluid cylinders 3RL, 3RR of the corresponding wheels communicate with each other.

Each of the gas springs 5FL, 5FR, 5RL, and 5RR connected to each of the fluid cylinders 3FL, 3FR, 3RL, and 3RR is specifically provided with a plurality (four in the figure) of these gas springs 5a and 5b. , 5c, 5
“d” is connected in parallel with the fluid chamber 3c of the corresponding fluid cylinder 3 via the communication path 4. Each of the gas springs 5a to 5d has an orifice 25 interposed at a branch portion of the communication path 4, and has a damping action at each of the orifices 25 and a buffer action for the gas sealed in the gas chamber 5f. And to demonstrate both. The first gas spring 5a and the second gas spring 5a
A damping force switching valve 26 for adjusting the passage area of the communication passage 4 is interposed in the communication passage 4 between the gas spring 5b and the gas spring 5b. It has two positions, a throttle position where the passage area is significantly reduced.

An unload valve 27 and a flow control valve 28 are connected to the high-pressure line 10 on the upstream side of the accumulator 22a. The unload valve 27 is configured to introduce a pressure oil discharged from the hydraulic pump 8 to the swash plate operating cylinder 8a of the hydraulic pump 8 to reduce an oil discharge amount of the hydraulic pump 8, A discharge position for discharging pressurized oil, and the oil discharge pressure of the hydraulic pump 8 is set to a predetermined upper limit oil discharge pressure (160 ± 10 k
gf / cm ² ) or more, it switches from the discharge position to the introduction position, and changes this state to the predetermined lower limit discharge pressure (120 ± 10 kg).
f / cm ² ) or less, and keeps the oil discharge pressure of the hydraulic pump 8 within a predetermined range (120 to 160).
kg f / cm ² ). The flow control valve 28 is configured to introduce the pressure oil from the hydraulic pump 8 to the swash plate operating cylinder 8a of the hydraulic pump 8 via the unload valve 27, and to unload the pressure oil in the cylinder 8a. A discharge position for discharging from the valve 27 to the reserve tank 29, and restricting the high pressure line 10 when the oil discharge pressure of the hydraulic pump 8 is maintained within a predetermined range by the unload valve 27.
It has a function of maintaining a constant differential pressure between the upper and lower portions of the 30 disposition portion and maintaining a constant oil discharge amount of the hydraulic pump 8.
Thus, the supply of oil to each fluid cylinder 3 is performed by oil storage in the accumulators 22a and 22b (this oil pressure is referred to as main pressure).

On the other hand, four flow control valves 9, 9,... Corresponding to the four wheels of the vehicle are provided downstream of the accumulator 22a of the high-pressure line 10. Hereinafter, since the configuration of the portion corresponding to each wheel is the same, only the left front wheel side will be described, and the description of the other will be omitted. That is, the flow control valve 9 includes the inflow valve 35 and the discharge valve 37. The inflow valve 35 has two positions, a closed position and a fluid supply position (open position) with a variable opening degree, and is provided in the left front wheel side passage 10FL of the high-pressure line 10 to be in the fluid supply position. The fluid stored in the accumulator 22a is supplied to the fluid cylinder 3FL from the left front wheel side passage 10FL. The discharge valve 37 has two positions, a closed position and a fluid discharge position (open position) with a variable opening, and a low pressure line connecting the left front wheel side passage 10FL to the reserve tank 29.
The fluid supplied to the fluid cylinder 3FL at the fluid discharge position is discharged to the reserve tank 29 via the low-pressure line 36. Each of the inflow valve 35 and the discharge valve 37 has a built-in differential pressure valve that maintains the pressure of the fluid at a predetermined value at the open position.

A pilot pressure responsive check valve 38 is provided in the left front wheel side passage 10FL between the inflow valve 35 and the fluid cylinder 3FL. The check valve 38 is connected to the pilot line
The hydraulic pressure in the high-pressure line 10 upstream of the inflow valve 35 (that is, the main pressure) is introduced as pilot pressure by 39,
It is provided to close when the pilot pressure is 40 kgf / cm ² or less. That is, only when the main pressure is 40 kgf / cm ² or more, the supply of the pressure oil to the fluid cylinder 3 and the discharge of the oil in the fluid cylinder 3 can be performed.

In FIG. 2, reference numeral 41 denotes an accumulator 22 of the high-pressure line 10.
a A fail-safe valve interposed in a communication passage 42 that communicates the downstream side with the low-pressure line 36, and is switched to an open position in the event of a failure to return the oil stored in the accumulators 22a and 22b to the reserve tank 29, and Has the function of canceling. Also,
Reference numeral 43 denotes a throttle provided in the pilot line 39, which has a function of delaying the closing of the check valve 38 when the fail-safe valve 41 is opened. Reference numeral 44 denotes a relief valve which opens when the hydraulic pressure of the fluid chamber 3c of each of the fluid cylinders 3FL and 3FR on the front wheel side rises abnormally and returns the oil to the low pressure line 36. Reference numeral 45 denotes a return accumulator connected to the low-pressure line 36, which performs a pressure accumulation operation when oil is discharged from each of the fluid cylinders 3.

Next, the flow rate control of each fluid cylinder 3 by the controller 19 will be described with reference to FIG.

In the figure, basically, a control system A for controlling the attitude of the vehicle based on the detection signals of the vehicle height sensors 14 of the respective wheels, and a vertical vibration of the vehicle based on the detection signals of the three vertical acceleration sensors 15 are shown. A control system B that ensures a good ride comfort by reducing
A control system C for equalizing the supporting load between the left and right wheels on the front wheel side and the rear wheel side based on the detection signal of the cylinder pressure sensor 13 of each wheel.

And Thus, in the control system A, 40 is out of the vehicle height sensor 14, the output X FR of the left and right front wheels 2 _F side, the output X RR of right and left rear wheels 2 _R side with summing X FL, the X RL It is a bounce component calculation unit that calculates the bounce component of the vehicle in total. Further, 41 is an output X FR of the left and right front wheels 2 _F side, the sum of X FL, outputs X RR of right and left rear wheels 2 _R side, by subtracting the sum of X RL, calculating a pitch component of the vehicle Pitch component calculator, 42
Will calculate the difference X FR-X FL of the output of the left and right front wheels 2 _F side, of the right and left rear wheels 2 _R side outputs the difference X RR-X RL, roll component arithmetic for calculating the roll component of the vehicle Department.

Reference numeral 43 denotes a bounce component of the vehicle calculated by the bounce component calculation unit 40, and the following PD control (proportional-differential control) formula K _B1 + {T _B2 · S / (1 + T _B2 · S)} · K _B2 K _B1 , K _B2 ; a bounce control unit that calculates a control amount for the flow control valve 9 of each wheel in the bounce control based on the proportionality constant S; Also,
Reference numeral 44 denotes a pitch control unit which inputs the vehicle pitch component calculated by the pitch component calculation unit 41 and calculates the control amount of each flow control valve 9 in the pitch control based on the same proportional-differential control formula as above. And 45, the vehicle roll component calculated by the roll component calculation unit 42 and the target roll angle T ROLL (described later) of the vehicle are input and only the target roll angle T ROLL is calculated based on the same proportional-differential control equation as described above. This is a roll control unit that calculates a control amount of each flow control valve 9 in roll control so as to make a tilted posture.

In order to control the vehicle to the target posture,
After inverting each control amount calculated in 43 to 45 for each wheel (inverting in the opposite direction to the positive and negative directions of the signal input of the vehicle height sensor 14), the bounce, pitch, and roll control amounts for each wheel are calculated. The control quantities Q FR, Q FL,
Q RR and QRL.

In the control system B, reference numeral 50 denotes a bounce component calculation unit for calculating the bounce component of the vehicle by summing the outputs G FR, G FL, and GR of the three vertical acceleration sensors 15, and 51 denotes a three vertical acceleration sensor 15. of the output FG FR of the right and left front wheels 2 _F side, by subtracting the output GR of the rear wheel 2 _R side from the sum of each half value of G FL,
Pitch component arithmetic unit which calculates a pitch component of the vehicle, 52 from the output G FR of the right front wheel 2 _F side, by subtracting the output G FL of the left front wheel 2 _F side, the roll component calculating section for calculating a roll component of the vehicle It is.

In addition, 53 receives the bounce component of the vehicle calculated by the bounce component calculation unit 50 and inputs the following IPD control (integral-proportional-differential control) formula {T _B3 / (1 + T _B3 · S)} · K _B3 + K _B4 + {T _B5 · S / (1 + T _B5 · S)} · K _B5 K _B3 , K _B4 , K _B5 ; Proportional constant S; Control amount for each wheel flow control valve 9 in bounce control based on operator Is a bounce control unit that calculates Also,
Reference numeral 54 denotes a pitch control unit that inputs the vehicle pitch component calculated by the pitch component calculation unit 51 and calculates the control amount of each flow control valve 9 in the pitch control based on the same integral-proportional-differential control equation as described above. Similarly, 55 is input with the roll component of the vehicle calculated by the roll component calculation unit 52, and the same integration-proportional-
This is a roll control unit that calculates a control amount of each flow control valve 9 in roll control based on a differential control formula.

Then, in order to suppress the vertical vibration of the vehicle for each of the bounce component, the pitch component, and the roll component, the control amounts calculated by the control units 53 to 55 are inverted for each wheel in the same manner as in the case of the control system A. After that, the control amounts of bounce, pitch, and roll for each wheel are added to obtain the corresponding control amounts QFR, QFL, QRR, and QRL of the fluid cylinder 3. Note that the control amount for each wheel calculated by each of the control units 53 to 55 is determined by dividing the control amount for the front wheels by a weighting coefficient
(K = 1.08) is corrected to a large value.

Thus, in the control system B, the bounce control unit 53,
The pitch control unit 54 and the roll control unit 55 each have a vehicle speed sensor
As shown in the table below, when the vehicle speed V is extremely low speed V _O (for example, 5 km / h), and when V ≧ V _O , the respective proportional constants K _{B of the} formula for controlling the control amount are obtained. i, K _P i, K _R i (i = 3 ~
5) is set to a normal value, and when the vehicle stops at V <V _O , each proportional constant is changed to be smaller than the normal value, so that when the vehicle stops at V <V _O , the control integration based on the output of the vertical acceleration sensor 15. It functions as a control gain changing unit that changes only each control gain of the term, the proportional term and the derivative term to be smaller than the normal value.

Further, in the control system C, 60 receives the cylinder pressure PFR, PFL signals of the two cylinder pressure sensors 13 on the front wheel side, and receives a cylinder pressure difference (PFR-P This is a warp control unit including a front-wheel-side cylinder-pressure-ratio calculator 60a for calculating the ratio FL) and a rear-wheel-side cylinder-pressure-ratio calculator 60b for calculating a similar cylinder pressure ratio on the rear wheel. Therefore, the cylinder pressure ratio on the rear wheel side is
In after a predetermined factor, which is subtracted from the front wheel cylinder pressure ratio, as a result weighted by the front wheel with a predetermined magnification by a factor W _A, after which the inverted in order to uniform between the left and right wheels a control amount for each wheel And the control amount Q of the corresponding flow control valve 9
FR, Q FL, Q RR, Q RL.

In addition, in the figure, various switching controls are performed by the control system D in order to increase the responsiveness of the flow rate control of each fluid cylinder 3 when the vehicle turns.

That is, in the control system D, the steering angular velocity _M
Is multiplied by the vehicle speed V, and as a result, a value S ₁ obtained by subtracting the reference value G ₁ from _MV is input to the turning determination unit 65. Also inputs the value S ₂ to the reference value G ₂ is subtracted from the current lateral acceleration G _S of the vehicle in the turning decision unit 65. Then, in the turning determination unit 65, the input S ₁
Alternatively, when S ₂ ≧ 0, it is determined that the vehicle is turning, and a hardening signal Sa of suspension characteristics is output, and a damping force switching valve is provided to improve the followability of the flow control to each fluid cylinder 3. 26 is switched to the aperture position, the proportional constants K ij (i = _B , _P , _R , j = 1 to 5) of the control systems A and B are set to the value K Hard during turning, and the target roll angle T A map G map (Gs) for storing ROLL in advance (a map having a large value as the lateral acceleration Gs increases, T ROLL = 0 at a predetermined value Gs1, a negative value below Gs1, and a positive value over an area exceeding Gs1) Is set to a value corresponding to the lateral acceleration Gs at that time.

On the other hand, when the inputs S ₁ and S ₂ <0 in the turning determination unit 65,
Judging that the vehicle is going straight ahead, softening signal of suspension characteristics
Sb is output to switch the damping force switching valve 26 to the open position, each proportional constant Kij is set to the normal value KSoft, and the target roll angle TROLL = 0.

Therefore, in the above embodiment, the vehicle speed V is V ≧ 5k
When the vehicle travels at m / h, each proportional constant K _{B in} the control system B of FIG. 3 based on the vertical acceleration signal of the vehicle from the vertical acceleration sensors 15.
i, K _P i, K _R i (i = 3 to 5) are set to normal values, and the respective control gains of the integral, proportional and differential controls become normal values. The evacuation speed becomes appropriate. As a result, the vehicle is brought into a stable posture by the posture control of the control system A shown in the figure based on the vehicle height signal of the vehicle height sensor 14... Ride comfort is ensured.

Also, when the vehicle is stopped at a vehicle speed V of V <5 km / h, the occupant may get on and off or load / unload luggage. In this case, the vehicle moves up and down. In this case, the vertical fluctuation of the vehicle is detected by the vertical acceleration sensors 15.
The control by the control system B based on the vertical acceleration signal is performed. However, this time, the respective proportionality constant K _B i of control in the control system _{B, K P i, K R} i (i = 3~5) is changed less than normal value, the integral, proportional And only each control gain of the differential control becomes smaller than the normal value, so that the supply / discharge speed of the fluid to each fluid cylinder 3 is reduced by that amount, and the vertical vibration of the vehicle is suppressed moderately. Since the vehicle is effectively prevented from vibrating up and down by the control of the control system B caused by loading and unloading of luggage, the occupant does not feel uncomfortable.

In the above embodiment, the proportionality constant K _B i in the control system B based on the vertical acceleration signal, K _P i, K _R i and (i = 3~5) V <5km
Although the value is changed to be smaller than the normal value when the vehicle stops at / h, the width of the change may be appropriately set, and the present invention includes a case where the control gain is changed to a zero value, for example.

Further, in the above embodiment, the present invention is applied to the suspension device provided with the gas spring 5, but the present invention is similarly applied to a suspension device provided with only the fluid cylinder 3 without the gas spring and having variable suspension characteristics. Of course, it can be applied.

[Brief description of the drawings]

1 is an overall schematic configuration diagram, FIG. 2 is a hydraulic circuit diagram, and FIG. 3 is a control block diagram showing variable control of suspension characteristics by a controller. 3 FF ~ 3 RR …… Fluid cylinder, 9 …… Flow control valve, 14…
... Vehicle height sensor (stroke detecting means), 15 ... vertical acceleration sensor (vertical acceleration detecting means), 18 ... vehicle speed sensor,
19 Controller (control means).

Continuation of front page (56) References JP-A-63-130418 (JP, A) JP-A-61-37509 (JP, A) JP-A-63-11408 (JP, A) JP-A-2-231213 (JP) , A) Japanese Utility Model Showa 62-60404 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B60G 17/015

Claims (4)

(57) [Claims] 1. A suspension apparatus for a vehicle, wherein a fluid cylinder is disposed between a vehicle body and each wheel and a suspension characteristic of the vehicle is made variable by controlling a flow rate to each of the fluid cylinders. Stroke detecting means for detecting the cylinder stroke of the cylinder, vertical acceleration detecting means for detecting the vertical acceleration of the vehicle, and control means for controlling the supply and discharge of the fluid to and from each of the fluid cylinders based on the outputs of the two detecting means Wherein the control means has a control gain changing unit that changes a ratio of a control gain based on an output of the vertical acceleration detecting means to a control gain based on an output of the stroke detecting means when the vehicle stops. A suspension device for a vehicle. 2. A vehicle suspension apparatus according to claim 1, wherein a fluid cylinder is disposed between the vehicle body and each wheel, and a flow rate of the fluid to each fluid cylinder is controlled to vary a suspension characteristic of the vehicle. Stroke detecting means for detecting the cylinder stroke of the cylinder, vertical acceleration detecting means for detecting the vertical acceleration of the vehicle, and control means for controlling the supply and discharge of the fluid to and from each of the fluid cylinders based on the outputs of the two detecting means The control means has a control gain changing unit that changes the control gain based on the output of the vertical acceleration detection means to a small value when the vehicle stops and does not change the control gain based on the output of the stroke detection means. A suspension device for a vehicle. 3. The control means calculates an independent control amount for each of three components of bounce, pitch, and roll based on the output of the vertical acceleration detection means,
3. The vehicle suspension device according to claim 1, wherein the control gain changing unit changes the control gain of all components to a small value. 4. The control gain changing unit according to claim 1, wherein the control gain changing unit changes the control gain based on the output of the vertical acceleration detecting means when the vehicle speed is equal to or lower than a predetermined vehicle speed value. A vehicle suspension device according to claim 1.