JPH03114907A - Suspension device of automobile - Google Patents

Abstract

PURPOSE:To improve responsibility of reverse roll control in an active suspension device composed of hydraulic shock absorber and spring, when the reverse roll is controlled by a turning state detection signal, by lowering signal sensitivity of a vertical acceleration detecting means to a riding feeling control means. CONSTITUTION:Based on a detection signal of a turning state detecting means 1, an aimed value of reverse roll is set by an aimed value setting means 2, and the reverse roll is controlled by a reverse roll control means 3. Riding feeling control is performed by a riding feeling control means 6, based on the detection signal of a vertical acceleration detecting means 4, while a sensitivity lowering means 5 is provided between the vertical acceleration detecting means 4 and the riding feeling control means 6, and a signal of the reverse roll control is input from the reverse roll control means 3. By the signal, signal sensitivity of the vertical acceleration detecting means 4 is lowered, and the starting of riding feeling control is suppressed during the reverse roll control. In this structure, responsiveness of the reverse roll is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a suspension device for a vehicle.

(Prior art and its problems) A vehicle suspension, generally called a passive suspension, has a damper unit consisting of a hydraulic damper and a spring (generally a coil spring), and has preset characteristics of the damper unit. Suspension characteristics are uniformly set. Of course, it is also possible to make the damping force of the hydraulic damper variable, but this does not change the suspension characteristics.

On the other hand, recently, so-called active suspensions have been proposed in which the suspension characteristics can be changed arbitrarily.In this active suspension, basically, the unsprung weight and the unsprung weight are A cylinder device is installed between them, and the suspension characteristics are controlled by controlling the supply and discharge of hydraulic fluid to the cylinder device (see Japanese Patent Publication No. 14365/1983).

In other words, in this active suspension,
In response to the signal from the vertical acceleration detection means, ride comfort control suppresses vertical vibration of the vehicle body, or when the vehicle is in a turning state, the suspension characteristics are increased for roll control, torsion suppression control, etc. according to the turning state. subject to change.

By the way, as a roll control in an active suspension, reverse roll, that is, control in which the vehicle height on the inner wheel side of a turn is lower than that on the outer wheel side of a turn, is known.

This reverse roll control and the ride comfort control are contradictory controls. To explain this point in detail, when hydraulic fluid is supplied to and discharged from the cylinder device in order to reverse roll the vehicle body, the higher the responsiveness of this reverse roll control, the more vertical acceleration will occur due to the reverse roll. This means that ride comfort control is started with the start of reverse roll control. That is, with the start of reverse roll control, first ride comfort control is activated, and control to suppress this reverse roll is started, resulting in a problem that reverse roll is performed slowly.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a suspension device for a vehicle that improves the responsiveness of reverse roll control when it has reverse roll control and ride comfort control.

(Means and operations for solving the problem) To achieve the above object, the present invention has the following configuration. That is, a cylinder is provided between the unsprung weight and the unsprung weight. A turning state detection means for detecting a turning state of a vehicle, assuming a suspension system for a vehicle in which a device is installed and the supply and discharge of hydraulic fluid to the cylinder device are controlled based on preset conditions. , target value setting for receiving a signal from the turning state detection means and setting a target roll angle for a reverse roll in which the vehicle height on the inner wheel side of the turn is smaller than the vehicle height of the outer wheel side of the turn, depending on the turning state of the vehicle; means, reverse roll control means for receiving a signal from the target value setting means and supplying and discharging the working fluid of the cylinder device so as to achieve the target roll angle, and vertical acceleration detection means for detecting the vertical acceleration of the vehicle body. and ride comfort control means that receives a signal from the vertical acceleration detection means and supplies and discharges working fluid from the cylinder device so as to suppress vertical vibration of the vehicle body.

The vehicle body is configured to include a sensitivity reducing means for reducing the signal sensitivity of the vertical acceleration detection means when the vehicle body is reversely rolled by the reverse roll control means.

(Function, Effect) With the above configuration, when performing reverse roll control, even if this reverse roll control is started, ride comfort control will not be started immediately in response to the occurrence of vertical acceleration accompanying the start of reverse roll control. . Therefore, there are no factors that inhibit the responsiveness of the reverse roll control, so it is possible to improve the responsiveness of the reverse roll control.

(The following is a blank space) (Example) An example of the present invention will be described below based on the attached drawings. In addition, the code rFJ used with numbers in the following explanation is for the front wheel, rRJ is for the rear wheel, rFRJ is for the right front wheel, rFLJ is for the left front wheel, rRRJ is for the right rear wheel, rRl,
" means for the left rear wheel, and therefore, when there is no need to specifically distinguish between these, these identification codes will not be used in the explanation.

1 (IFR1IFI4, IRR, IR
L) is a cylinder device provided for each front, rear, left, and right wheel, and these include a cylinder 2 connected to the unsprung weight, and a piston rod 3 extending from inside the cylinder 2 and connected to the unsprung weight. and has. Inside the cylinder 2, a liquid chamber 5 is defined above by a piston 4 integrated with a piston rod 3, and this liquid chamber 5 and a lower chamber are in communication. As a result, when the hydraulic fluid is supplied to the liquid chamber 5, the piston rod 3 extends and the vehicle height increases, and when the hydraulic fluid is discharged from the liquid chamber 5, the vehicle height decreases.

For the liquid chamber 5 of each cylinder device l, a gas spring 6 (
6FR16F11.6RR16RL) is connected. Each of the gas springs 6 is composed of four cylindrical springs 7 having a small diameter, and the cylindrical springs 7 are connected to the liquid chamber 5 through an orifice 8 in parallel to each other. Of these four cylindrical springs 7, except for one, the remaining three are connected to the liquid chamber 5 via a switching valve 9. As a result, when the switching valve 9 is in the switching position as shown, the four cylindrical springs 7 are communicated only through the orifice 8, and the damping force at this time is small. Furthermore, when the switching valve 9 is switched from the illustrated position, the three cylindrical springs 7 are also communicated with the liquid chamber 5 via the orifice IO built into the switching valve 9, resulting in a large damping force. Become something. Of course, by changing the switching position of the switching valve 9, the spring characteristics of the gas spring 6 are also changed. The suspension characteristics can also be changed by changing the amount of hydraulic fluid supplied to the fluid chamber 5 of the cylinder device 1.

In the figure, reference numeral 11 denotes a pump driven by an engine, and high-pressure hydraulic fluid pumped up by the pump 11 from a reservoir tank 12 is discharged into a common passage 13.

The common passage 13 is branched into a front passage 14F and a rear passage 14R, and the front passage 14F is further divided into a right front passage 14F.
R and a left front passage 14FL. The front right passage 14FR is connected to the liquid chamber 5 of the front right wheel cylinder device IFH, and the front left passage 14FL is connected to the liquid chamber 5 of the front left wheel cylinder device IFH. A pilot valve 16FR serving as a supply flow rate control valve 15FR1 and a delay valve is connected to this front right passage 14FH from its upstream side. Similarly, a supply flow rate control valve 15FI and a pilot valve 16FI are connected to the left front passage 14FL from the flow side thereof.

A first relief passage 17FR for the right front passage is connected to the front right passage 14FH from between the single valves 15FR and 16FR, and this first relief passage 17FR finally passes through the front wheel relief passage 18F to the reservoir tank 12. It is connected to A discharge flow rate control valve 19FR is connected to the first relief passage 17FH. Moreover, the passage 14FR downstream of the pilot valve 16FR is connected to the first relief passage 17FH via the second relief passage 20FR, and the relief valve 21FR is connected to this. Furthermore, a filter 29FR is interposed in the passage 14FH closest to the cylinder device IFR. This filter 29FR
is the cylinder device IFR and the valve 1 located closest to it.
Located between 6FR121FR and the cylinder device IFR
Abrasion powder generated from the valve 16 due to sliding etc.
Prevents it from flowing to the FR121FR side.

Note that the passage configuration for the left front wheel is also configured in the same manner as the passage configuration for the right front wheel, so a redundant explanation thereof will be omitted.

A main accumulator 22 is connected to the common passage 13, and an accumulator 23F is also connected to the front wheel relief passage 18F. This main accumulator 22 serves as a pressure accumulation source for hydraulic fluid together with a sub-accumulator 24 to be described later, and is intended to prevent the amount of hydraulic fluid supplied to the cylinder device 1 from becoming insufficient. Further, the accumulator 23F is provided to prevent the high-pressure hydraulic fluid in the front wheel cylinder device 1 from being suddenly discharged to the low-pressure reservoir tank 12, that is, to prevent the water hammer phenomenon.

The hydraulic fluid supply/discharge passage for the rear wheel cylinder device IRR% IRL is also configured in the same manner as for the front wheels, so a redundant explanation thereof will be omitted. However, it should be noted that there is no equivalent to the pilot valve 21FR121FL in the rear wheel passage, and the length of the passage from the main accumulator 22 in the rear wheel passage 14R is longer than that for the front wheels. A sub accumulator 24 is provided.

The common passage 13, that is, each passage 14F for the front and rear wheels,
14R via the relief passage 25.

It is connected to the front wheel relief passage 18F, and the relief passage 25 is connected to a control valve 26 which is an electromagnetic on-off valve.

In FIG. 1, 27 is a filter, and 28 is a pressure regulating valve as pressure accumulation control means for adjusting the discharge pressure from the pump 11, that is, the pressure accumulated in the accumulator 22, to be within a predetermined range. In the embodiment, the pump 11 is configured as a variable displacement swash plate piston type and is integrated into the pump 11 (discharge pressure 120 to 160 kg/cm2).

The pilot valve 16 controls the pressure of the front and rear passages 14F or 14R1 and therefore the common passage 13 and the cylinder equipment f.
It opens and closes depending on the pressure difference between the pressure on the IT side and the pressure on the IT side. For this reason,
For front wheel pilot valves 16FR and 16FL,
A common pilot passage 31F branched from the passage 14F is led out, and of the two branched pilot passages branched from the common pilot passage 31F, one passage 31FR is connected to the pilot valve 16FR, and the other passage 3IF is connected to the pilot valve 16FR.
L is connected to the pilot valve 16F1.

An orifice 32F is provided in the common pilot passage 31F. Note that the pilot passage for the rear wheels is similarly configured.

Each of the pilot valves 16 is configured as shown in FIG. 2, for example, and the one shown is for the right front wheel. This pilot valve 16 has one inside its casing 33.
A main channel 34 forming a part of the passage 14FR is formed,
A passage 14FR is connected to the main passage 34. A valve seat 35 is formed in the middle of the main flow path 34, and the opening/closing piston 36, which is slidably inserted into the casing 33, is seated on the valve seat 35, so that the pilot valve 1
6FR is opened and closed.

The opening/closing piston 36 is integrated with a control piston 38 via a valve shaft 37. This control piston 38 is
It is slidably inserted into the casing 33 to define a liquid chamber 39 within the casing 33, and the liquid chamber 39 is connected to the branch pilot passage 31FR via a control flow path 40. .

The control piston 36 is then operated by a return spring 41.
, the direction in which the opening/closing piston 36 is seated on the valve seat 35,
That is, the pilot valve 16FR is biased in the closing direction. Furthermore, the pressure of the main flow path 34 is applied to the control piston 38 via the communication port 42 on the side opposite to the liquid chamber 39 . As a result, inside the liquid chamber 39 (common passage 1
3 side) becomes 1/4 or less of the pressure in the main flow path 34 (cylinder device IFR side), the opening/closing piston 36 seats on the valve seat 35 and the pilot valve 16FR is closed.

Here, from the state where the pilot valve 16FR is open,
When the pressure in the 13 common passages decreases significantly, this pressure decrease is delayed by the action of the orifice 32F, and the pressure decreases in the liquid chamber 39.
Therefore, the pilot valve 16FR is closed after a delay from the pressure drop (in the embodiment, this delay time is set to about 1 second).

Next, the effect of the above-mentioned answer will be explained.

■Switching valve 9 In the embodiment, the switching valve 9 is operated to increase the damping force only during turning.

■Relief valve 21 The relief valve 21 is normally closed and the cylinder device 1
The side pressure is a predetermined amount J: (160 to 200 in the example)
kg/cm2), it is opened.

In other words, it serves as a safety valve that prevents the pressure on the cylinder device l side from rising abnormally.

Of course, the relief valve 21 is a cylinder device IRR for the rear wheels.
Although it can also be provided for 1 IRL, in the example, it is assumed that the vehicle has a weight distribution set to be considerably larger on the front side than on the rear side, so that the pressure on the rear wheel side is equal to the pressure on the front wheel side. The relief valve 21 is not provided on the rear wheel side in consideration of the fact that it does not become larger than the above.

(2) Flow rate control valves 15.19 Both the supply and discharge flow rate control valves 15.19 are electromagnetic spool valves that can be switched between an open state and a closed state as appropriate. However, when it is open, it has a differential pressure adjustment function that keeps the differential pressure between the upstream and downstream sides almost constant (due to flow rate control, this differential pressure must be kept constant). ). More specifically, the displacement position or opening degree of the spool of the flow control valve 15.19 is changed in proportion to the supplied current, and this supplied current is determined based on a flow rate-current correspondence map created and stored in advance. Determined based on That is, the supplied current corresponds to the required flow rate at that time.

By controlling the flow rate control valves 15 and 19, the supply and discharge of hydraulic fluid to the cylinder device 1 are controlled, thereby controlling the suspension characteristics.

In addition to this, when the ignition is OFF, this O
For a predetermined period of time (2 minutes in the embodiment) from the time of FF, only the control in the direction of lowering the vehicle height is performed. In other words, it takes into account changes in the payload caused by getting off the vehicle, etc., and prevents the vehicle height from becoming partially high (maintaining the standard vehicle height).
.

■Control Valve 26 The control valve 26 is normally closed by being energized, and is opened in the event of a failure. This failure can occur, for example, when part of the flow control valve 15 or 19 becomes stuck, when the sensors described below fail, when the hydraulic pressure of the hydraulic fluid fails, or when the pump 11 fails. There are cases etc.

In addition, in the embodiment, the control valve 26 is opened after a predetermined period of time (for example, 2 minutes) has elapsed since the ignition was turned off.

Note that when this control valve 26 opens, the pilot valve 1
6 is closed later as described above.

■Pilot valve 16 As already mentioned, the pilot valve 16 is opened with a delay after the pressure in the common passage 13 decreases due to the action of the orifices 32F and 32H. For example, in the event of a failure in which a part of the current control valve 15 remains open, the passage 14FR-14R may be caused by a drop in pilot pressure caused by the opening operation of the control valve 26.
L is closed to confine the hydraulic fluid in the cylinder devices IFR to IRL, and the vehicle height is maintained. Of course, at this time,
The suspension characteristics are fixed to so-called passive characteristics.

Figure 3 shows the control system of the hydraulic fluid circuit shown in Figure 1. In this Fig. 3, WFR is the right front wheel, WF
L is the left front wheel, WRR is the right rear wheel, WRL is the left rear wheel,
U is a control unit configured using a microcomputer. This control unit U includes each sensor or switch 5IFR to 51RL, 52FR to 52RL,
Signals from 53FR153FL, 53R and 61-65 are manually input. In addition, from the control unit U, the switching valve 9
, the flow rate control valve 15 (15FR-15RL), 19
(19FR-19RL) is output to the control valve 26.

The sensors 51FR to 51RL are connected to each cylinder device IF.
It is installed in the R-IRL to detect the amount of extension, that is, the vehicle height at each wheel position. Sensor 52FR~5
2RL detects the pressure in the liquid chamber 5 of each cylinder device IFR-IRL (see also FIG. 1). sensor 5
3FR153FL and 53R are G sensors that detect acceleration in the vertical direction. However, on the front side of vehicle B, there are two G sensors 53FR and
53FL, but at the rear of the vehicle B, only one G sensor 53R is provided at the middle position between the left and right sides on the rear axle. In this way, one virtual plane representing the vehicle body B is defined by the three G sensors, and this virtual plane is set to be a substantially horizontal plane.

The sensor 61 detects vehicle speed. Above sensor 6
Reference numeral 2 detects the operation of the steering wheel, that is, the steering angle.

The control unit U basically performs active control conceptually shown in FIG. 4, that is, in the embodiment, vehicle attitude control (vehicle height signal control), ride comfort control (vertical acceleration signal control), and vehicle control. torsion control (pressure signal control).

The results of these multiple controls are finally expressed as the flow rate of the hydraulic fluid flowing through the flow rate control valves 15 and 19 as flow rate adjusting means.

79f2LaL Now, an example of how to control the suspension characteristics based on the outputs of each sensor will be explained with reference to FIGS. 4 and 5.

The contents of this control can be roughly divided into the following: posture control of the vehicle body B based on the output of the vehicle height sensor, ride comfort control based on the output of the G sensor, and torsion suppression control of the vehicle body B based on the output of the pressure sensor. It is divided into the following.

■Attitude control (vehicle height sensor signal control) This control consists of three attitude controls that suppress bounce, pitch, and roll.
Feedback control is performed using PD sub-control (proportional-derivative control).

For each of these three attitude controls, how to handle the output from each vehicle height sensor is indicated by the "+" and "-" signs shown on the left side of the figure for each control section for bounce, pitch, and roll. This is shown by Furthermore, the "+" and "-" signs shown on the right side of each control section in the figure indicate that each control section controls posture changes. A code opposite to that shown on the left side of the center is given.

In other words, in bounce control, PD sub-control is performed in a direction in which the added value of each vehicle height on the left and right front sides and the added value of each vehicle height on the left and right rear sides match the reference vehicle height value, and the control formula used at this time is This is shown in the following equation (1).

KBl+ (TB2・S/(1+TB2・S)) ・
KH2... (1) KBI, KH2, TB2: Control gain (constant) S: Operator In addition, in pitch control, the added value of the vehicle height on the left and right rear sides is added to the added value of each vehicle height on the left and right front sides. PD sub-control is performed in the direction in which the subtracted value becomes zero. Furthermore, regarding roll control, PD sub-control is performed to achieve the target roll angle, which will be explained in detail later.

Each of the control values obtained from the three PD sub-controls described above is obtained for each of the four cylinder devices 1, and is added to each other for each control value for each cylinder device 1. Finally, the control values for the four attitude control is determined as the flow rate signal QXFR-QXRL.

Of course, for both the pitch control and roll control, the control equations for the PD sub-control are in the form of equation (1) above (however, the control gains are set for pitch control and roll control). .

(2) Riding comfort control (G sensor signal control) This riding comfort control is intended to prevent the deterioration of riding comfort caused by the attitude control in (2) above. Therefore, in response to the three attitude controls mentioned in (2) above, feedback control is performed using IPD control (integral-proportional integrated control) for each of bounce, pitch, and roll to suppress the vertical acceleration. The control equation for this IPD control is shown in the following equation (2).

(TB3/ (1+ Ta2・S)) ・K B3+
K B4+ (T B3・S/(1+TB3・S)) ・
KH2・ ・ ・ (2) KH2, KH2, Ta2: Control gain (constant) S: Operator However, in the above equation (2), each control gain is
Dedicated ones are used for bounce control, pitch control, and roll control.

Since there are only three G-sensors for ride comfort control, the arithmetic mean of the front left and right vertical accelerations is used as the front vertical acceleration for pitch control. In addition, during roll control, only the left and right vertical accelerations on the front side are used, and the vertical accelerations on the rear side are not used.

In this ride comfort control as well, each control value obtained by the three IPD controls described above is obtained for each of the four cylinder devices 1, and is added to each other for each control value for each cylinder 1, and finally Four flow signals Q for ride comfort control
GFR-QGRL.

■Warb control (pressure signal control) Warb control is a control that suppresses torsion of the vehicle body B. That is, since the pressure acting on each cylinder device 1 corresponds to the load on each wheel, control is performed so that the torsion of the vehicle body B due to this load does not become large.

Specifically, feedback control is performed in a direction such that the ratio of the difference and the sum of left and right pressures is 1 for each of the front side and rear side of the vehicle body. The weighting is such that the amount of torsion on the front side and the rear side of the vehicle body is weighted by a coefficient ωF, and the weighting is applied to each of the above-mentioned controls (1) and (2) by a coefficient ωA. Of course, in this torsion suppression control as well, the control value is finally determined as the flow rate signal QPFR-QPRL (%) for each of the four cylinder devices l. Furthermore, the weighting is such that the difference between the left and right steering characteristics can be changed by changing one or both of the coefficients ωR1ωL.

The flow rate signals for attitude control, ride comfort control, and torsion suppression control determined for each of the four cylinder devices 1 as described above are finally added to form a final flow rate signal QF.
It is determined as R-QRL.

■The control gain of the control formula used in the explanation of FIG. There is. Here, when the vehicle is in a turning state, the damping force switching valve 10 is switched to the throttle position in order to harden the suspension characteristics, and the above-mentioned proportional The constants K i (i = B + ~B4) are each set to a large set K Hardl, and the target roll angle T RO
From the map that stores LL in advance, the lateral acceleration Gs at that time
(hereinafter referred to as tank Gs). An example of this map is shown in FIG. Incidentally, in the case of a passive suspension vehicle, as shown in Figure 7, as the lateral acceleration (lateral G) increases, the roll angle (positive roll) increases.

(Hereinafter, blank) The roll control is controlled based on the map shown in FIG. 6 above so that the roll angle becomes the target roll angle. That is, when the lateral G is 0.1 or more and 0.3 or less, the vehicle is controlled to perform a reverse roll, but regarding this reverse roll control,
It is said that it can be canceled using the manual switch (mode switch) installed in the driver's seat. In this reverse roll control, the G sensor 53FR153FL
53R is provided with a dead zone (hereinafter referred to as vertical G dead zone), so that vertical accelerations of 0.05 G or less are ignored.

On the premise of the above, an example of roll control will be explained based on the flowchart shown in FIG.

First, step 5111 (hereinafter, the step number is rSJ
), it is determined that the ignition is OFF, and if YES, the process advances to S2 and the upper and lower dead zones are set to 0.
．． It is set to 05.

That is, vertical acceleration within 0.05G is ignored.

In this embodiment, this means that the ignition is turned OFF,
In other words, active suspension control continues for 60 seconds after the engine is stopped to adjust the vehicle height, which prevents a drop in hydraulic fluid pressure caused by immediate response to vibrations caused by passengers getting out of the car, doors opening and closing, etc. This is for the purpose of achieving this goal.

On the other hand, when the ignition is ON, 8
Proceed to step 2, the selection of reverse roll mode is determined, and YES
In this case, the process proceeds to S4 where the vehicle speed V is read, and the next step 85 reads the steering wheel steering angle θ8, and then, in S6, the lateral Gs is determined based on the vehicle speed ■ and the steering wheel angle. Then, in the next step 87, a region determination of the lateral Gs is performed, and if the lateral Gs is greater than or equal to 001 and less than or equal to 0.3, the process proceeds to S8, and the vertical G dead zone is set to 0.05.

As a result, the vertical vibration accompanying the start of the reverse roll control is ignored, and the ride comfort control for suppressing the reverse roll control is started with a delay from the start of the reverse roll control. In other words, the vertical acceleration immediately after the start of reverse roll control is ignored, and ride comfort control is only started by the vertical acceleration immediately before the end of reverse roll control, reducing hunting of reverse roll and immediately converging to the target roll angle. .

On the other hand, when the result in S3 is No, or the result in S7 is No, the process advances to S9, where the upper and lower G dead zones are set to zero. In other words, the area where the lateral Gs is smaller than 0°Ol (
In a region where the lateral sway due to a crosswind, etc.) or the lateral Gs is greater than 0.3, both ride comfort control and roll control are achieved, and changes in the attitude of the vehicle body are suppressed.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the present invention, and is a diagram showing a hydraulic fluid circuit. FIG. 2 is a sectional view showing an example of the pilot valve in FIG. 1. FIG. 3 is a diagram showing a control system of the circuit shown in FIG. 1. FIG. 4 is a diagram showing an example for performing active control. FIG. 5 is a flowchart showing an example of control according to the present invention. FIG. 6 is a diagram showing an example of roll characteristics in an active suspension vehicle. FIG. 7 is a diagram showing an example of roll characteristics in a passive suspension vehicle. FIG. 8 is a block diagram showing the overall configuration of the present invention. U: Control unit IFR to IRL Nijilinda device 5: Liquid chamber 11: Pump 12: Reservoir tank 15FR to 15RL: Supply control valve 19FR to 19RL: Discharge control valve

Claims (1)

[Claims] (1) In a vehicle suspension system in which a cylinder device is installed between a sprung mass and an unsprung mass, and the supply and discharge of hydraulic fluid to the cylinder device is controlled based on preset conditions. , a turning state detection means for detecting a turning state of the vehicle; and a vehicle height of an inner wheel in the turn is smaller than a vehicle height of an outer wheel in the turn according to the turning state of the vehicle in response to a signal from the turning state detection means. target value setting means for setting a target roll angle of the reverse roll; and reverse roll control means for receiving a signal from the target value setting means and supplying and discharging the working fluid of the cylinder device so as to achieve the target roll angle. a vertical acceleration detection means for detecting the vertical acceleration of the vehicle body; and a ride comfort control means for receiving a signal from the vertical acceleration detection means and supplying and discharging the working fluid of the cylinder device so as to suppress vertical vibration of the vehicle body. A suspension device for a vehicle, comprising: a sensitivity reducing means for reducing the signal sensitivity of the vertical acceleration detection means when the reverse roll control means reverse rolls the vehicle body.