JP4898326B2 - Roll control device - Google Patents

Description

  The present invention relates to a roll control device that suppresses a roll of a vehicle body in a vehicle.

  Conventionally, as this type of roll control device, for example, a hydraulically variable roll control device previously proposed by the patent applicant has been known.

  That is, in this proposed roll control device, one end of a stabilizer connecting the suspension arms of the left and right wheels in the front and rear wheels is on the rod side of the hydraulic cylinder that applies a moment to each stabilizer, and the suspension arm is on the cylinder tube side. It is connected.

  The rod-side chamber and the piston-side chamber of both hydraulic cylinders on the front and rear wheel sides are each connected to a hydraulic pump via a diverter valve, and the fluid supplied from the hydraulic pump is distributed by the diverter valve, respectively. A directional switching valve is provided between both hydraulic cylinders and the diversion valve, and a rod side chamber of each hydraulic cylinder is operated by switching operation of the directional switching valve. And one of the piston side chambers is selected, and the fluid after the diversion is supplied to one of the selected rod side chamber and piston side chamber.

  Further, a pressure control valve is provided downstream of the above-described diversion valve and upstream of the direction switching valve, and the pressure of the fluid supplied to one of the rod side chamber and the piston side chamber by this pressure control valve is provided. The other of the rod side chamber and the piston side chamber is connected to the tank by the direction switching valve.

Therefore, in this roll control device, when lateral acceleration is applied to the vehicle body while the vehicle is running and a roll is generated in the vehicle, the direction of one of the corresponding rod side chamber and piston side chamber is switched in order to suppress this roll. Each hydraulic cylinder is selected by a valve, and further, the pressure of one of the selected rod side chamber and piston side chamber is appropriately controlled by a pressure control valve, and the other pressure of the rod side chamber and piston side chamber is induced to the tank pressure. The thrust of each hydraulic cylinder is applied to the stabilizers for the front and rear wheels and the roll moment acting on the vehicle body is applied to the vehicle body by the centrifugal force, and the roll moment in the opposite direction is applied to the vehicle body to cause the roll motion generated in the vehicle body. It is effectively suppressed (see, for example, Patent Document 1).
Japanese Patent Application Laid-Open No. 2004-136814 (Invention Column, FIG. 2)

  In the conventional vehicle roll control device, the control for suppressing the roll is performed based on whether or not the roll moment is applied to the vehicle body, and particularly, the control in consideration of the rough road traveling is not performed.

  Here, when the vehicle travels on a rough road where the road surface is significantly undulated, if the function of the stabilizer is exhibited, the ground contact force of the wheel against the road surface will be worsened. In such a case, the stabilizer It is desirable to diminish the function, but when driving on rough roads, the roll moment will act on the vehicle body, so in conventional roll control devices, roll suppression control may be performed, so There is a fear that it will be pointed out that the running performance of the vehicle on a rough road will be impaired.

  In addition, as described above, when the roll suppression control is performed when traveling on a rough road, the wheel connected to the suspension that moves in synchronization with the stabilizer may not come into contact with the road surface, and thus the wheel side There is a concern that the trunk lot from will not be sufficiently transmitted to the road surface.

  Accordingly, the present invention has been developed to improve the above-described problems, and an object of the present invention is to provide a roll control device capable of improving the running performance of a vehicle when traveling on a rough road. That is.

The roll control device in the problem solving means of the present invention includes a fluid pressure source, a tank, a one-rod fluid pressure cylinder connected to one end of a vehicle stabilizer and having a rod side chamber and a piston side chamber, and a fluid pressure cylinder. A direction switching valve that selects either the rod-side chamber or the piston-side chamber and connects to the fluid pressure source, a pressure control valve that controls the pressure of the fluid supplied to the fluid pressure cylinder, and a direction that drives and controls the pressure control valve in roll control device and a control device for switching control of the switching valve, the vehicle is provided with a rough road determining means for determining whether undulations of the road surface is traveling significant rough road ,, the rough road judgment If means determines that the vehicle is running on a rough road, to connect the piston side chamber to the fluid pressure source while controlling the pressure control valve so that the pressure of the fluid supplied to the fluid pressure cylinder is minimized Together control the direction switching valve to be connected to the rod-side chamber to the tank, a push-up thrust rods commensurate with the minimum pressure of the piston side chamber, characterized in that greater than depressing the thrust rod by the pressure of the rod side chamber.

Further, the roll control device in another means for solving the problems of the present invention includes a fluid pressure source, a tank, a rod side chamber and a piston side chamber respectively connected to one end of each stabilizer of the vehicle front and rear wheels , and a front wheel side and a rear wheel. Side rod-type fluid pressure cylinder, a flow dividing valve for distributing the fluid supplied from the fluid pressure source to the front wheel side fluid pressure cylinder and the rear wheel side fluid pressure cylinder, the flow dividing valve and each fluid pressure Directional valves on the front and rear wheels that select either the rod-side chamber or piston-side chamber of each fluid pressure cylinder and are connected to the fluid pressure source, and are supplied to each fluid pressure cylinder. In a roll control device comprising a front wheel side pressure control valve and a rear wheel side pressure control valve for controlling the pressure of fluid to be driven, and a control device for driving and controlling each pressure control valve and switching and controlling each direction switching valve, If both are provided rough road determining means for determining whether undulations of the road surface is traveling significant rough road ,, the rough road determining means determines that the vehicle rough road running, the fluid pressure cylinder While controlling the pressure control valve so as to minimize the pressure of the fluid to be supplied, each piston side chamber is connected to the fluid pressure source, and each directional switch valve is controlled to connect each rod side chamber to the tank. The push-up thrust of the rod corresponding to the minimum pressure is made larger than the push-down thrust of the rod due to the pressure in each rod side chamber .

According to the present invention, during traveling on a rough road, the piston side chamber of the fluid pressure cylinder is connected to the fluid pressure source via the direction switching valve, the other rod side chamber is connected to the tank side, and the hydraulic oil is pressurized. When passing through the control valve, a slight pressure loss occurs, and the minimum pressure corresponding to this pressure loss is supplied to the piston side chamber. Therefore, the pressure in the piston side chamber becomes larger than the pressure in the rod side chamber by the pressure loss.
Therefore, the thrust pushing up the rod in the piston side chamber is larger than the thrust pushing down the rod in the rod side chamber, and the thrust generated by the fluid pressure cylinder is smaller than when the function of the stabilizer is reduced during normal control. The stabilizer function will not be completely diminished.
As described above , according to the roll control device of the present invention, the stabilizer function is not completely reduced even when traveling on a rough road. It can be further improved, and it is possible to improve traveling performance on rough roads, and the hydraulic cylinder generates only a thrust corresponding to the differential pressure due to the pressure loss of the pressure control valve, and its expansion and contraction is also free. Therefore, the function of the stabilizer is not exerted excessively, the wheel stroke is not hindered, and the rough road surface of the rough road can be flexibly dealt with.

  Therefore, in the roll control device of the present invention, it is possible to follow the road surface with the wheel to improve the running performance when traveling on a rough road.

  FIG. 1 is a diagram showing a roll control device according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional view of the hydraulic cylinder. FIG. 3 is a diagram showing a map of pressure command values created using the lateral acceleration as a parameter. FIG. 4 is a diagram showing a map of pressure command values created using the required pressure as a parameter.

  The roll control device of the present invention will be described below based on the embodiment shown in the drawings. In the roll control device according to one embodiment, as shown in FIG. 1, rods 3 of hydraulic cylinders 2f and 2r driven by one-rod hydraulic pressure are provided at one ends of stabilizers 1f and 1r provided on the front and rear wheels of the vehicle. The cylinder tube 4 side of the hydraulic cylinders 2f and 2r is connected to a suspension arm (not shown). Therefore, in the present embodiment, the fluid pressure is hydraulic. In connecting the hydraulic cylinders 2f, 2r and the stabilizers 1f, 1r, the cylinder tube 4 side may be connected to one end of the stabilizers 1f, 1r.

  As shown in FIG. 2, the front wheel side hydraulic cylinder 2f and the rear wheel side hydraulic cylinder 2r include a cylinder tube 4, a piston 5 slidably inserted into the cylinder tube 4, and one end thereof being a piston. The rod 3 is connected to the other end of the stabilizers 1f and 1r, and the rod side chamber 6 and the piston side chamber 7 defined by the piston 5 in the cylinder tube 4 are provided. 4, a port 10 that opens to the rod side chamber 6 and a port 11 that opens to the piston side chamber 7 are formed.

  Thereby, each hydraulic cylinder 2f, 2r applies a thrust force that pushes the rod 3 downward in FIG. 2 against the cylinder tube 4 by applying a hydraulic pressure as fluid pressure to the rod side chamber 6 through the port 10. Pressure that is generated according to the pressure, and conversely, exerts a thrust force that pushes the rod 3 upward in FIG. 2 with respect to the cylinder tube 4 by applying hydraulic pressure as fluid pressure to the piston side chamber 7 through the port 11. The torsional moment can be given to the stabilizers 1f and 1r by these thrusts.

  In this way, the hydraulic cylinder 2f on the front wheel side acts as an actuator that applies a moment to the front wheel stabilizer 1f, and the hydraulic cylinder 2r on the rear wheel side serves as an actuator that applies a moment to the rear wheel stabilizer 1r. It is supposed to work.

  Returning to FIG. 1, the front wheel side hydraulic cylinder 2 f switches the direction of the push-pull type front wheel side via supply / discharge passages 25 f and 26 f connected to the ports 10 and 11 in the rod side chamber 6 and the piston side chamber 7, respectively. The hydraulic cylinder 2r on the rear wheel side is connected to the valve 12f, and the push-pull type rear cylinder 25r and 26r are connected to the ports 10 and 11 in the rod side chamber 6 and the piston side chamber 7 respectively. It is connected to the direction switching valve 12r on the wheel side.

  Each of the directional switching valves 12f and 12r described above is configured as a four-port three-position switching valve having a supply port P, a discharge port T, and two control ports A and B. The supply port P is connected to the supply flow paths 30f and 30r, respectively. The discharge port T is connected to the tank 19 via the discharge passages 29f and 29r, respectively, while the control ports A and B are respectively connected to the hydraulic cylinder 2f on the front wheel side. The ports 10 and 11 are connected to the ports 10 and 11 of the hydraulic cylinder 2f on the rear wheel side. That is, the control ports A and B in the front wheel direction switching valve 12f are connected to the supply / discharge passages 25f and 26f, and the control ports A and B in the rear wheel direction switching valve 12r are connected to the supply and discharge passages 25r and 26r. , Each connected. The hydraulic pump 20 uses a vehicle drive engine (not shown) as a drive source in the same manner as the conventional roll control device, and the fluid pressure source includes various known types of pumps such as a gear pump, for example. Can be adopted.

  The directional control valves 12f and 12r have a communication position where the supply port P communicates with the control port A and a discharge port T communicates with the control port B, and a blocking position where the ports P, T, A and B are blocked. And three communication positions, the supply port P communicating with the control port B and the discharge port T communicating with the control port A. Both ends are energized by springs (not shown), and current is supplied to the solenoids 27f and 27r. Is applied to push the valve bodies (not shown) in the direction switching valves 12f and 12r, the supply port P communicates with the control port A, the discharge port T and the control port B, and the current flows through the solenoids 27f and 27r. Is applied to suck the valve bodies (not shown) in the direction switching valves 12f and 12r, the supply port P, the control port B, the discharge port T, and the control port A In a state where no current is applied, the valve body (not shown) is maintained in a neutral position by a spring force so as to block each port P, T, A, B. It is set to take one of the communication positions described above in the applied state.

  That is, one of the rod side chamber 6 and the piston side chamber 7 of each hydraulic cylinder 2f, 2r is selected by switching the direction switching valves 12f, 12r, and a hydraulic pump is connected to the selected rod side chamber 6 or piston side chamber 7. The hydraulic oil discharged from the engine 20 can be supplied, and the direction of the moment acting on the stabilizers 1f and 1r can be determined by the switching operation of the direction switching valves 12f and 12r.

  The supply port P in the front wheel side direction switching valve 12f leads to one outlet port D of the diversion valve 35 through the supply flow path 30f, and the supply port P in the rear wheel side direction switching valve 12r supplies The flow path 30r leads to the other outlet port E of the diversion valve 35, and the diversion valve 35 has its inlet port C connected to the discharge port of the hydraulic pump 20 as a fluid pressure source via the flow path 28. The hydraulic oil discharged from the hydraulic pump 20 is divided at a constant flow rate ratio, and the divided hydraulic oil is distributed to the hydraulic cylinders 2f and 2r through the directional switching valves 12f and 12r.

  Further, a relief valve 13 is provided between the flow path 28 and the tank 19, and specifically, the relief valve 13 is provided in the middle of a passage 32 connecting the flow path 28 and the discharge flow path 29f. Is provided. The relief valve 13 has a communication position for communicating the passage 32 and a blocking position for blocking the passage valve 32. When the internal pressure of the flow path 28 is abnormally increased, the relief valve 13 is opened by the pilot pressure and allows hydraulic oil to escape to the tank 19. ing. The passage 32 may be provided so as to connect the tank 19 or the discharge flow path 29r and the flow path 28, instead of being provided so as to connect the flow path 28 and the discharge flow path 29f.

  Further, a pressure control valve 14 and a check valve 16 are provided in parallel between the front wheel side supply flow path 30f and the discharge flow path 29f, and the rear wheel side supply flow path 30r and the discharge flow path 29r. The pressure control valve 15 and the check valve 17 are provided in parallel.

  That is, the supply port P in the directional switching valve 12f leads to the check valve 16 that sequentially blocks the flow of hydraulic oil from the supply flow path 30f when the supply flow path 30f is traced upstream, and further passes through the supply flow path 30f. Going upstream, the upstream side of the pressure control valve 14 and one outlet port D of the flow dividing valve 35 are sequentially communicated, and further, the relief valve 13 is connected via a flow path 28 connected to the inlet port C of the flow dividing valve 35. It communicates with the hydraulic pump 20 as an upstream side and a fluid pressure source.

  Further, the discharge port T of the direction switching valve 12f leads to the check valve 16, the downstream side of the pressure control valve 14, and the downstream side of the relief valve 13 in order when going down the discharge flow path 29f. It leads to the tank 19.

  On the other hand, the supply port P in the direction switching valve 12r leads to a check valve 17 that blocks the flow of hydraulic oil from the supply flow path 30r through the supply flow path 30r, and further goes back upstream in the supply flow path 30r. The upstream side of the relief valve 13 and the fluid pressure are connected to the upstream side of the pressure control valve 15 and the other outlet port E of the diversion valve 35, and further through a flow path 28 connected to the inlet port C of the diversion valve 35. It communicates with the hydraulic pump 20 as the source.

  Further, the discharge port T of the direction switching valve 12r communicates with the check valve 17 through the discharge flow path 29r, and further on the downstream side of the pressure control valve 15 and the downstream of the relief valve 13 in descending order further down the discharge flow path 29r. To the side, and finally to the tank 19.

  The tank 19 and the hydraulic pump 20 are communicated with each other through a suction pipe 33, and the hydraulic oil supplied from the hydraulic pump 20 is finally guided to the tank 19 and the flow path 28, each supply flow path 30f, 30r, each discharge flow path 29f, 29r and the supply / discharge flow paths 25f, 25r, 26f, 26r are recirculated.

  In turn, the pressure control valve 14 opens the passage 31 that connects the supply flow path 30f and the discharge flow path 29f, and blocks the passage 31 from the communication position that connects the supply flow path 30f and the discharge flow path 29f. It has a shut-off position, a spring (not shown) is provided at one end, and a solenoid 14a facing the spring is provided at the other end. When the solenoid 14a is excited, it can be switched to the shut-off position. Yes, the valve opening area can be proportionally controlled in proportion to the current applied to the solenoid 14a.

  Therefore, in the state where no current is applied to the solenoid 14a, the valve opening area is maximized due to the spring force, and the valve opening area is normally set so that the cutoff position is taken when the solenoid 14a is applied.

  In the state where the valve opening area is maximized, the pressure control valve 14 guides the pressure in the supply flow path 30f to the tank pressure to minimize it, and on the other hand, by reducing the valve opening area, the pressure supply valve 30f The internal pressure is increased.

  On the other hand, the pressure control valve 15 has the same configuration as the pressure control valve 14 described above, and opens the passage 34 connecting the supply flow path 30r and the discharge flow path 29r, thereby supplying the supply flow path 30r and the discharge flow path 29r. And a blocking position for blocking the passage 34. One end is provided with a spring (not shown), and the other end is provided with a solenoid 15a facing the spring. The solenoid 15a is excited. Then, the valve can be switched to the cutoff position, and the valve opening area can be proportionally controlled in proportion to the current applied to the solenoid 15a.

  Therefore, when no current is applied to the solenoid 15a, the valve opening area is maximized due to the spring force and the valve opening area is normally set.

  As with the pressure control valve 14, the pressure control valve 15 also minimizes the valve opening area by guiding the pressure in the supply flow path 30r to the tank pressure when the valve opening area is maximized. Thus, the pressure in the supply flow path 30r is increased.

  As the check valves 16 and 17, those which have been widely used in various hydraulic devices from the past can be applied as they are, and since their configurations are well known, detailed description is given here. Description is omitted.

  Further, a pressure detector 41 for detecting the pressure acting on the rod side chamber 6 or the piston side chamber 7 receiving the supply of hydraulic oil from the hydraulic pump 20 among the rod side chamber 6 and the piston side chamber 7 of the hydraulic cylinder 2f is supplied. It is provided in the middle of the passage 30f and detects the pressure in the supply passage 30f. If the pressure detector 41 is provided at such a position, the pressure in the rod side chamber 6 or the piston side chamber 7 receiving the hydraulic pressure from the hydraulic cylinder 2f in the state in which the direction switching valve 12f takes the communication position in the pressure detector 41 is used. It is possible to detect.

  In addition, a pressure detector 42 for detecting the pressure acting on the rod side chamber 6 or the piston side chamber 7 receiving the supply of hydraulic oil from the hydraulic pump 20 of the hydraulic cylinder 2r is provided in the middle of the supply flow path 30r, and the rear The pressure in the wheel-side supply flow path 30r is detected. If the pressure detector 42 is provided at such a position, the pressure in the rod side chamber 6 or the piston side chamber 7 receiving the hydraulic pressure from the hydraulic cylinder 2r is detected in a state where the rear-wheel direction switching valve 12r is in the communication position. Is possible.

  In addition to the above, in addition to the above, the pressure control valves 14 and 15 are driven by the lateral acceleration acting on the vehicle body and the pressure signal output by the pressure detectors 41 and 42 to control the pressure control valves 14 and 15. A controller 43 is provided as a control device for adjusting the opening area and controlling the moment that the hydraulic cylinders 2f, 2r give to the stabilizers 1f, 1r while switching the direction switching valves 12f, 12r.

  The controller 43 includes a lateral acceleration detector (not shown, for example, a lateral acceleration sensor provided at a corresponding part of the vehicle body) that detects the direction and magnitude of the lateral acceleration acting on the vehicle body as a lateral acceleration signal, and the pressure described above. Connected to the detectors 41 and 42, these lateral acceleration signals and pressure signals are processed, currents are applied to the solenoids 14a, 15a, 27f and 27r, and the direction switching valves 12f and 12r and the pressure control valves 14 and 15 are applied. Drive.

  That is, the controller 43 includes four output terminals (not shown). These output terminals are connected to the solenoids 27f and 27r of the direction switching valves 12f and 12r and the pressure control valve 14 and the signal lines 44, 45, 46 and 47, respectively. The controller 43 controls the direction switching valves 12f and 12r and the pressure control valves 14 and 15 in connection with the 15 solenoids 14a and 15a.

  Furthermore, the roll control device according to the present embodiment includes a rough road traveling determination unit 50 that determines whether or not the vehicle is traveling on a rough road. When the rough road traveling determination means 50 determines that the vehicle is traveling on a rough road, it outputs a rough road traveling signal to the controller 43, while the controller 43 outputs a rough road traveling signal. When received, the control for running on a rough road different from the normal roll control is performed.

  The rough road traveling determination means 50 is connected to a switch 51 that can be manually operated by the vehicle occupant. For example, when the vehicle receives an on signal from the switch by an on operation of the switch, the vehicle occupies the rough road. It is determined that the vehicle is traveling on a rough road until the switch 51 is turned off and an off signal is received.

  The switch 51 may detect a shift range of a transmission installed in a four-wheel drive vehicle or the like. For example, when the switch 51 is switched to a range used when driving on a rough road, May be output to the rough road traveling determination means 50, and an off signal may be output to the rough road traveling determination means 50 when the range is switched to another range.

Further, instead of the above, the rough road traveling determination means 50 may determine that the vehicle is traveling on a rough road, for example, by analyzing the vertical acceleration, lateral acceleration, and vehicle speed of the vehicle body. Good. Specifically, for example, when the vehicle speed is low and the vertical acceleration of the vehicle body changes significantly, it is determined that the vehicle is traveling on a rough road, or the frequency at which the lateral acceleration is relatively high. It may be determined that the vehicle is traveling on a rough road when it changes in vibration.

  Next, the operation of the roll control device will be described. First, a case where the rough road traveling determination unit 50 determines that the vehicle is not traveling on a rough road will be described. In such a case, the roll control device performs normal roll control.

  For example, when the vehicle is traveling straight on a flat road, that is, when there is no lateral acceleration detection signal from the lateral acceleration detector, the vehicle body does not roll, so if the torsional rigidity of the stabilizers 1f and 1r is increased, I feel uncomfortable. In such a state, the controller 43 maximizes the valve opening area without supplying current to the solenoids 14a, 15a of the pressure control valves 14, 15 in order to reduce the function of the stabilizer. , 30r is induced to the tank pressure. As a result, the hydraulic oil from the hydraulic pump 20 returns to the tank 19 via the discharge passage 29f through the communication position of the pressure control valve 14 and according to the valve opening area. Furthermore, current is supplied to the solenoids 27f and 27r of the direction switching valves 12f and 12r, and the valve bodies in the direction switching valves 12f and 12r are pushed to communicate the supply port P with the control port A, the discharge port T, and the control port B. Try to take a communication position.

  That is, when the lateral acceleration is in the vicinity of 0, the direction switching valves 12f and 12r are maintained so as to take the communication position, so that the rod side chamber 6 in each hydraulic cylinder 2f and 2r is connected to the hydraulic pump 20 side. The other piston side chamber 7 is connected to the tank 19 side.

  Here, although the opening area of the pressure control valves 14 and 15 is maintained at the maximum opening area, a slight pressure loss occurs when the hydraulic oil passes through these pressure control valves 14 and 15, and the rod side chamber 6 A difference corresponding to the pressure loss occurs in the pressure in the piston side chamber 7. Since the direction switching valves 12f and 12r take the communication position, the pressure in the rod side chamber 6 becomes larger than the pressure in the piston side chamber 7 by a pressure loss.

  Therefore, a thrust force that pushes down the rod 3 obtained by multiplying the pressure receiving area of the rod side chamber 6 (the area obtained by subtracting the cross sectional area of the rod 3 from the cross sectional area of the piston 5) downward in FIG. The thrust generated by the rod 3 obtained by multiplying the pressure receiving area (the cross-sectional area of the piston 5) by the pressure of the piston side chamber 7 upwards in FIG. 2 is opposed to the thrust generated by the hydraulic cylinders 2f and 2r. When the pressure receiving area of the rod side chamber 6 is d1, the pressure receiving area of the piston side chamber 7 is d2, and the pressures of the rod side chamber 6 and the piston side chamber 7 when the pressure control valves 14 and 15 are not energized are p1 and p2, respectively. If d1 · p1 = d2 · p2 is established, the hydraulic cylinders 2f and 2r can be prevented from generating any thrust.

  As can be understood from the above description, in the roll control device according to the present embodiment, when no roll moment is applied to the vehicle body, the hydraulic cylinders 2f and 2r are maintained in a state in which little thrust is generated. Therefore, the functions of the stabilizers 1f and 1r are surely diminished, and there is no problem that the functions of the stabilizers 1f and 1r appear in the conventional roll control device. Riding comfort in the vehicle can be improved.

  Further, in the conventional roll control device, since the direction switching valve is set to be switched at the same time as the pressure control valve is driven, it acts on the vehicle after the control for suppressing the roll is performed. When the lateral acceleration is eliminated, the directional control valve maintains the position when the control for suppressing the roll is performed, and the hydraulic pump side and the tank side are connected to the piston side chamber during straight running after the roll suppression control. Which of the rod side chambers is connected depends on the roll direction of the immediately preceding vehicle body, and the effectiveness of the stabilizer during straight traveling after roll restraint control differs depending on the roll direction of the immediately preceding vehicle body, which is In some cases, the user may feel uncomfortable. However, as described above, the roll control device according to the present embodiment also solves such a problem.

  At this time, when the hydraulic cylinders 2f and 2r are moved by the unevenness of the road surface and the pressure in the supply flow paths 30f and 30r becomes lower than the pressure in the discharge flow paths 29f and 29r, the check valves 16, Since 17 opens, the rod side chamber 6 and the piston side chamber 7 of each hydraulic cylinder 2f, 2r do not become negative pressure, and the situation where the expansion and contraction of the hydraulic cylinders 2f, 2r is hindered is avoided.

  On the other hand, when the vehicle enters a turning state and a lateral acceleration is generated in the vehicle body, such as during cornering or when the vehicle speed is high and the steering angle is large, the controller 43 detects the lateral acceleration detected by the lateral acceleration detector. A signal is input.

  The controller 43 is energized so as to increase the current supplied from the output terminal to the solenoids 14a and 15a of the pressure control valves 14 and 15 through the signal lines 44 and 45 based on the detection signal, and the pressure control valve 14 , 15 is adjusted to reduce the valve opening area.

  The hydraulic oil supplied from the hydraulic pump 20 is sent to the supply ports P of the direction switching valves 12f and 12r, and the discharge ports T of these direction switching valves 12f and 12r are communicated with the tank 19.

  On the other hand, based on the detection signal from the lateral acceleration detector, the controller 43 sends the hydraulic cylinders 2f, 2r to the stabilizers 1f, 1r corresponding to the magnitude and direction of the roll moment due to the centrifugal force acting on the vehicle body at that time. The moment that should be applied and its direction are calculated, and a control signal according to this is output as a current from each output terminal.

  The control signal currents individually output from the respective output terminals of the controller 43 are sent through the respective signal lines 44, 45, 46, 47 through the solenoids 14a, 15a of the corresponding pressure control valves 14, 15, and the direction switching valves 12f, 12r. The solenoids 27f and 27r are energized to control the pressure control valves 14 and 15 and the direction switching valves 12f and 12r.

  Along with this, the direction switching valves 12f and 12r correspond to the direction of the roll moment acting on the vehicle body so that the stabilizers 1f and 1r can be applied with a moment in the direction opposite to the roll moment. The hydraulic pump 20 is switched so that the supply port P communicates with the control port A, the discharge port T, and the control port B, or the supply port P communicates with the control port B, the discharge port T, and the control port A. Is supplied to either of the ports 10 and 11 of the hydraulic cylinders 2f and 2r.

  Thus, in the hydraulic cylinders 2f and 2r, the pressure in the rod side chamber 6 or the piston side chamber 7 on the hydraulic oil inflow side is increased by the hydraulic oil flowing into either of the ports 10 and 11, for example, in FIG. When the hydraulic oil is supplied to the rod side chamber 6 of the cylinders 2f and 2r, the rod 3 moves downward in FIG. 2, and when the hydraulic oil is supplied to the other piston side chamber 7, the rod 3 moves upward in FIG. As a result, thrust in the extending direction or contracting direction is generated in the hydraulic cylinders 2f and 2r, and these thrusts are applied to the stabilizers 1f and 1r for the front and rear wheels so that the direction and magnitude of the roll moment acting on the vehicle body are increased. It becomes possible to generate the opposing moments in the stabilizers 1f and 1r, and consequently to suppress the roll of the vehicle body. That is, when a roll is generated on the vehicle body, the front and rear wheel stabilizers 1f and 1r are twisted in a direction to tilt the vehicle body to the opposite side in accordance with the magnitude of the lateral acceleration. As a result, the stabilizers 1f and 1r increase the torsional rigidity in that direction and suppress the roll motion that is about to occur in the vehicle body. It should be noted that control suitable for the characteristics of the vehicle on which this roll control device is mounted can be performed, so that the magnitude of the moment applied to the stabilizers 1f and 1r with respect to the roll moment is adapted to the characteristics of the vehicle. The controller 43 may calculate so that

  Moreover, the specific process of the controller 43 at the time of the above-mentioned body roll is as follows. First, on the basis of the lateral acceleration, the controller 43 recognizes that the vehicle body is rolling, and as described above, detection is performed so that a moment countering the roll moment acting on the vehicle body is applied to the stabilizers 1f and 1r. Based on the lateral acceleration, two pressure command values on the front wheel side and the rear wheel side, which are pressures required for either the rod side chamber 6 or the piston side chamber 7 of the hydraulic cylinders 2f and 2r, are calculated.

  Specifically, when calculating each pressure command value, the controller 43 refers to the pressure command value map created using the lateral acceleration indicated by the solid line in FIG. 3 as a parameter, and based on the lateral acceleration, the hydraulic cylinders 2f, 2r The map calculates the pressure to be supplied to the cylinder, determines which of the rod side chamber 6 and the piston side chamber 7 of the hydraulic cylinders 2f and 2r should be supplied with pressure, controls the direction switching valves 12f and 12r, and controls the pressure. The control valves 14 and 15 are driven and controlled. The sign of the lateral acceleration is, for example, positive in the direction acting to roll the vehicle body in the right direction with respect to the traveling direction of the vehicle body, and negative in the direction acting to roll the vehicle body in the left direction.

  Further, the controller 43 drives the pressure control valves 14 and 15 so that the pressure control valves 14 and 15 are not driven until the lateral acceleration becomes a predetermined magnitude as shown by the solid line in the map of FIG. A dead zone region is set in the command value, and this dead zone region is set including a point where the lateral acceleration is zero-crossed. When the detected lateral acceleration is in the dead zone, the pressure command value is set to 0, the controller 43 does not drive the pressure control valves 14 and 15, and the passages 31 and 34 are in an open state. Will be maintained.

  In the above description, the pressure command value is calculated using the map. However, it is also possible to calculate the pressure command value without using the map. Further, since the pressure command value is also used for determining the switching of the direction switching valves 12f and 12r, the pressure command value is set to take a negative value when the lateral acceleration takes a negative value. 14 and 15 do not actually set the pressure supplied to the hydraulic cylinders 2f and 2r to a negative value, so that the absolute value of the pressure command value is input to a feedback loop for obtaining a current command value described later. Will be.

  On the other hand, when switching the direction switching valves 12f, 12r, the controller 43 does not switch from one communication position to the other communication position until the lateral acceleration reaches the first threshold, as shown by the broken line in FIG. In addition, a dead zone region in the range from the first threshold value to the second threshold value is set for the lateral acceleration so as not to switch from the other communication position to the one communication position until the lateral acceleration reaches the second threshold value. . The dead zone regions of the direction switching valves 12f and 12r are set so as not to include a point where the lateral acceleration is zero-crossed, and are set so as to be within the dead zone of the pressure control valves 14 and 15.

  Therefore, for example, when the dead zone region in the direction switching valves 12f and 12r is set to the negative region of the lateral acceleration, a lateral acceleration having a positive value acts on the vehicle body and a moment opposite to this is generated in the roll control device. When the pressure is supplied to the rod side chamber 6 for this purpose, the direction switching valves 12f and 12r are set to the communication position for supplying the pressure to the rod side chamber 6, but the lateral acceleration is reduced and eliminated. Until the first threshold value at which the lateral acceleration takes a predetermined negative value is taken, the communication position for supplying pressure to the rod side chamber 6 is maintained for the direction switching valves 12f and 12r, and then the lateral acceleration becomes a predetermined negative value. When the negative threshold value is further increased beyond the first threshold value, the direction switching valves 12f and 12r are now turned on in order to cause the roll control device to generate a moment in the opposite direction. So that switching to the communication position to supply pressure to the ton side chamber 7.

  On the contrary, when the lateral acceleration changes from a negative value to a positive value, when the lateral acceleration increases in the positive direction, the directional control valves 12f and 12r are moved to the piston when the second threshold value is exceeded. The communication position for supplying pressure to the side chamber 7 is switched to the communication position for supplying pressure to the rod side chamber 6. In any case, when the lateral acceleration is in the vicinity of 0, the direction switching valves 12f and 12r are connected to the rod side chamber. A communication position for connecting 6 to the hydraulic pump 20 side is adopted. Note that this is the same even if the first threshold value and the second threshold value are set to positive values, so that the dead zone regions of the direction switching valves 12f and 12r are set to the positive region of the lateral acceleration. It doesn't matter.

  Thus, by setting the switching drive of the direction switching valves 12f and 12r, when the lateral acceleration is in the vicinity of 0 and the function of the stabilizers 1f and 1r needs to be reduced, the rod is surely connected. It is possible to connect the side chamber 6 to the hydraulic pump 20 side so that little thrust is generated in the hydraulic cylinders 2f and 2r, thereby reliably improving the riding comfort of the vehicle in a state where no roll moment is generated in the vehicle body. can do.

  In addition, if the direction switching valves 12f and 12r are switched while avoiding the zero crossing point of the lateral acceleration and the rod side chamber 6 is connected to the hydraulic pump 20 side at the zero crossing point, the dead zone region is set. However, in the present embodiment, in the switching operation of the direction switching valves 12f and 12r, since a dead zone is set and hysteresis is provided, detection of lateral acceleration or detection signal of the lateral acceleration detector is provided. It is possible to prevent vibrational switching due to noise or the like contained in the.

  Since the dead zone areas of the direction switching valves 12f and 12r are set to be narrower than the dead zone areas of the pressure control valves 14 and 15, this is limited to when the absolute value of the lateral acceleration increases from zero. Of course, whenever the sign of the lateral acceleration changes, the direction switching valves 12f and 12r are controlled to be switched prior to the pressure increasing operation by the pressure control valves 14 and 15. If the sign does not change even if the lateral acceleration changes, the roll direction of the vehicle body does not change, and the direction switching valves 12f and 12r have the rod side chambers of the hydraulic cylinders 2f and 2r so as to suppress the roll. 6 or a communication position where pressure is supplied to the piston side chamber 7 is maintained.

  That is, when the lateral acceleration acts on the vehicle body, the controller 43 selects one of the communication positions so as to supply the required pressure to either the rod side chamber 6 or the piston side chamber 7 of the hydraulic cylinders 2f, 2r. Then, the current is supplied to the pressure control valves 14 and 15 after switching the direction switching valves 12f and 12r to supply the current so that the ports P, T, A and B communicate with each other. In the control of the pressure control valves 14, 15, the pressure values on the front and rear wheels detected by the pressure detectors 41, 42 are compared with the above-described pressure command values. The current supplied to the solenoids 14a and 15a of the pressure control valves 14 and 15 is controlled so as to decrease, so that the pressure command value and the detected pressure value are the same.

  By controlling in this way, the hydraulic fluid supplied from the hydraulic pump 20 is boosted according to the pressure command value by the pressure control valves 14 and 15, and this boosted hydraulic fluid is the direction switching valve of the hydraulic cylinders 2f and 2r. The pressure is directed to the rod side chamber 6 or the piston side chamber 7 selected by 12f and 12r, and the pressure according to the pressure command value calculated by the controller 43 is supplied to the selected rod side chamber 6 or piston side chamber 7 of the hydraulic cylinders 2f and 2r. Will be.

  More specifically, the controller 43 calculates the deviation between the pressure command value on the front wheel side and the pressure detected by the pressure detector 41, and the deviation between the pressure command value on the rear wheel side and the pressure detected by the pressure detector 42, respectively. The current command value to be supplied to the solenoids 14a and 15a is calculated by proportional integral control or proportional integral differential control feedback control based on each deviation, and currents are supplied to the solenoids 14a and 15a in accordance with the calculated current command values. To supply.

  In the above-described roll suppression control when the vehicle is traveling straight and turning, it goes without saying that map calculation may be used to improve calculation speed when converting pressure to current to be supplied to the solenoids 14a and 15a. is there.

  From the above description, in this roll control device, the pressure control valves 14 and 15 are not driven and pressured prior to the direction switching valves 12f and 12r, and the rod-side chamber 6 of the hydraulic cylinders 2f and 2r. Alternatively, it is possible to prevent a sudden increase in fluid pressure from acting on the piston side chamber, and to improve the riding comfort in the vehicle without generating abnormal noise or vibrating the vehicle body.

  Furthermore, even if the responsiveness of the direction switching valves 12f and 12r and the pressure control valves 14 and 15 varies, the direction switching valves 12f and 12r can be reliably switched ahead of the pressure control valves 14 and 15. Therefore, not only stable roll control is always possible, but also the trouble of performing tuning for control in product units can be omitted, and the cost of the roll control device is reduced.

  The range of the dead zone for the lateral acceleration of the pressure control valves 14 and 15 can be set so as to be symmetric in the negative direction and the positive direction around the zero cross point of the lateral acceleration. It is also possible to set asymmetric as appropriate according to the distribution.

  Further, in the above description, dead zones are provided in the control of the pressure control valves 14 and 15 and the direction switching valves 12f and 12r with reference to the lateral acceleration. However, as described above, the stabilizers 1f and 1r are provided with the vehicle body. The required pressure to be supplied to the pressure chambers of the actuators 2f and 2r required to generate a moment that opposes the roll moment is obtained from the lateral acceleration, and the pressure command value is calculated based on this required pressure. Thus, a dead zone region may be provided for the control of the pressure control valves 14 and 15 and the direction switching valves 12f and 12r with respect to the required pressure, that is, a dead zone region of the pressure command value may be set with respect to the required pressure. .

  That is, as shown by the solid line in FIG. 4, when the required pressure is in the dead zone region of the pressure command value, the pressure control valves 14 and 15 are not driven without being supplied with current, as shown by the broken line in FIG. The direction switching valves 12f and 12r may be set so as to be performed in the dead zone region with respect to the required pressure.

  Further, in the present embodiment, the hydraulic cylinders 2f and 2r on the front wheel side and the rear wheel side are driven by the hydraulic pump 20 as one fluid pressure source. However, when two fluid pressure sources are provided, It is also possible to supply pressure independently to the front wheel side hydraulic cylinder 2f and the rear wheel side hydraulic cylinder 2r.

  Further, although a lateral acceleration detector is provided to obtain the lateral acceleration, the lateral acceleration is estimated from the vehicle steering angle and the vehicle speed, and the switching of the direction switching valves 12f and 12r is a positive region of the lateral acceleration or negative. You may set to complete in the area.

  Next, the operation of the roll control device when the rough road traveling determination means 50 determines that the vehicle is traveling on a rough road will be described.

  When the vehicle is traveling on a rough road, control different from the normal roll control described above is performed, and the control logic of the pressure control valves 14 and 15 and the direction switching valves 12f and 12r described above is not applied.

  Specifically, when the controller 43 receives a rough road traveling signal from the rough road traveling determination means 50, the controller 43 does not supply current to the solenoids 14a and 15a of the pressure control valves 14 and 15 in order to reduce the function of the stabilizer. The opening area is maximized, and the pressure in the supply flow paths 30f and 30r is guided to the tank pressure. As a result, the hydraulic oil from the hydraulic pump 20 returns to the tank 19 via the discharge passage 29f through the communication position of the pressure control valve 14 and according to the valve opening area. Further, current is supplied to the solenoids 27f and 27r of the direction switching valves 12f and 12r, current is applied to the solenoids 27f and 27r, and the valve bodies in the direction switching valves 12f and 12r are sucked, and the supply port P and the control port B In addition, a communication position for connecting the discharge port T and the control port A is adopted.

  That is, during traveling on rough roads, the direction switching valves 12f and 12r are maintained so as to take the above communication position, so that the piston side chamber 7 in each hydraulic cylinder 2f and 2r is connected to the hydraulic pump 20 side and the other rod The side chamber 6 is connected to the tank 19 side.

  Here, although the opening area of the pressure control valves 14 and 15 is maintained at the maximum opening area, a slight pressure loss occurs when the hydraulic oil passes through these pressure control valves 14 and 15, and the rod side chamber 6 A difference corresponding to the pressure loss occurs in the pressure in the piston side chamber 7. Since the direction switching valves 12f and 12r take the communication position, the pressure in the piston side chamber 7 becomes larger than the pressure in the rod side chamber 6 by a pressure loss.

  Therefore, the thrust for pushing the rod 3 obtained by multiplying the pressure receiving area of the piston side chamber 7 (the cross sectional area of the piston 5) by the pressure of the piston side chamber 7 upward in FIG. 2 is the pressure receiving area of the rod side chamber 6 (from the cross sectional area of the piston 5 to the rod). 2), the thrust generated by the hydraulic cylinders 2f and 2r is increased during the normal control. , 1r is larger than the case of reducing the function.

  As can be understood from the above description, in the roll control device according to the present embodiment, when the vehicle is traveling on a rough road, the hydraulic cylinders 2f and 2r correspond to the differential pressure due to the pressure loss. The state in which thrust is generated is maintained, and the functions of the stabilizers 1f and 1r are not completely diminished.

  Since the functions of the stabilizers 1f and 1r are not completely diminished as described above, the ground contact load of the wheels can be further increased even when traveling on a rough road, and the running performance when traveling on a rough road can be improved. In addition, the hydraulic cylinders 2f and 2r generate only a thrust commensurate with the differential pressure due to the pressure loss of the pressure control valves 14 and 15, and the expansion and contraction of the hydraulic cylinders 2f and 2r is free. Without being disturbed, the stroke of the wheel is not hindered, and it is possible to flexibly cope with uneven road surfaces on rough roads.

  Therefore, in the roll control device according to the present embodiment, it is possible to improve the running performance when traveling on rough roads by causing the wheels to follow the road surface.

  Further, during traveling on rough roads, the piston side chamber 7 of each hydraulic cylinder 2f, 2r is always connected to the hydraulic pump 20 side, and the other rod side chamber 6 is connected to the tank 19 side. , 1r does not vary depending on the roll direction of the vehicle body immediately before, and the feeling of operation of the vehicle is not changed, particularly when traveling on a rough road that causes the vehicle occupant to feel uneasy.

  Finally, the operation at the time of a failure will be described. When an abnormality occurs in the roll control device or a vehicle equipped with the roll control device and the control becomes impossible, the direction switching valves 12f and 12r, the pressure control valve 14, When an abnormality occurs in the control system such as disconnection of the respective signal lines 44, 45, 46, 47 with respect to 15, the controller 43 detects this and stops the operation of the direction switching valves 12f, 12r and the pressure control valves 14, 15 To do.

  Then, the pressure control valves 14 and 15 maximize the valve opening area by the spring force, and the direction switching valves 12f and 12r shift to the blocking positions where the ports P, T, A, and B are blocked by the spring force.

  Since the hydraulic cylinders 2f and 2r are locked in a state in which hydraulic oil is prevented from entering and exiting by the direction switching valves 12f and 12r and cannot rotate, the stabilizers 1f and 1r are provided with hydraulic cylinders 2f for suppressing rolls. , 2r simply stops functioning and functions as a normal stabilizer, that is, a stabilizer to which the hydraulic cylinders 2f, 2r are not connected, and does not hinder the running performance of the vehicle.

  In other words, even if a roll moment that twists them acts on the stabilizers 1f and 1r, the stabilizers 1f and 1r are hydraulically stiffened by blocking the flow of hydraulic oil with the direction switching valves 12f and 12r. The roll of the vehicle body is suppressed while maintaining a state closer to normal steering characteristics while maintaining at least a function as a normal stabilizer through the cylinders 2f and 2r.

  In this way, when a control system abnormality occurs during roll control of the vehicle body at cornering, the torsional rigidity of the front and rear wheel stabilizers 1f, 1r is controlled while the hydraulic cylinders 2f, 2r are kept in a block state. maintain.

  Thus, even if the fail-safe operation is performed, the vehicle body roll rigidity and the steering characteristics before and after the change are not changed, and the fail-safe operation is surely performed without causing a great change in the steering characteristics of the vehicle.

  Even if the pressure control valve 14 is closed due to contamination or the like in the event of an abnormality, the hydraulic oil supplied from the hydraulic pump 20 increases the pressure in the flow path 28, so that the relief valve 13 Since it is opened and flows into the tank 19, the roll control device is prevented from being damaged.

  In each embodiment, the pressure detectors 41 and 42 detect the pressure in the rod side chamber 6 or the piston side chamber 7 to which the hydraulic pressure of the hydraulic cylinders 2f and 2r is supplied. However, the pressure detectors 41 and 42 are used. Without knowing, if the capacity of the hydraulic pump 20 is determined in advance, it is possible to grasp how much pressure is acting on the rod side chamber 6 or the piston side chamber 7 by the valve opening area of the pressure control valves 14, 15. In this case, the controller 43 may recognize the pressure value depending on how much power is supplied to the pressure control valves 14 and 15.

  This is the end of the description of the present invention, but it goes without saying that the scope of the present invention is not limited to the details shown or described.

It is the figure which showed the roll control apparatus in one embodiment of this invention. It is a longitudinal cross-sectional view of a hydraulic cylinder. It is a figure which shows the map of the pressure command value produced using lateral acceleration as a parameter. It is a figure which shows the map of the pressure command value produced using the request pressure as a parameter.

Explanation of symbols

1f, 1r Stabilizers 2f, 2r Hydraulic cylinder 3 Rod 4 Cylinder tube 5 Piston 6 Rod side chamber 7 Piston side chamber 10, 11 Hydraulic cylinder port 12f, 12r Directional switching valve 13 Relief valve 14, 15 Pressure control valves 14a, 15a, 27f, 27r Solenoid 16, 17 Check valve 19 Tank 20 Hydraulic pump 25f, 25r, 26f, 26r as fluid pressure source Supply / discharge flow path 29f, 29r Discharge flow path 30f, 30r Supply flow path 31, 32, 34 Passage 33 Suction pipe 35 Flow dividing valve 41, 42 Pressure detector 43 Controller 44, 45, 46, 47 Signal line 50 Rough road travel judging means 51 Switch

Claims (8)

One of a fluid pressure source, a tank, a single rod type fluid pressure cylinder connected to one end of a vehicle stabilizer and having a rod side chamber and a piston side chamber, and a rod side chamber and a piston side chamber of the fluid pressure cylinder are selected. A direction switching valve connected to the fluid pressure source, a pressure control valve for controlling the pressure of the fluid supplied to the fluid pressure cylinder, and a control device for driving and controlling the pressure control valve and for switching the direction switching valve. In the roll control device, when providing a rough road traveling determination means for determining whether or not the vehicle is traveling on a rough road with significantly uneven road surface, the rough road traveling determination means determines that the vehicle is traveling on a rough road, directional control to be connected to the piston-side chamber while controlling the pressure control valve so that the pressure of the fluid supplied to the fluid pressure cylinder is minimized tank rod side chamber causes connected to a fluid pressure source To control the valve, roll control device, characterized in that the push-up thrust rods commensurate with the minimum pressure of the piston side chamber larger than depressed thrust of the rod by the pressure of the rod side chamber. Supplied from a fluid pressure source, a fluid pressure source, a tank, a front wheel side and a rear wheel side single rod type fluid pressure cylinder having a rod side chamber and a piston side chamber respectively connected to one end of each stabilizer of the vehicle front and rear wheels Distributing fluid to be supplied to the fluid pressure cylinder on the front wheel side and the fluid pressure cylinder on the rear wheel side, and a rod side chamber of each fluid pressure cylinder interposed between the flow dividing valve and each fluid pressure cylinder. A front-wheel-side and rear-wheel-side directional control valve that selects either the piston-side chamber and connects to a fluid pressure source, or front-wheel-side and rear-wheel-side pressure control that controls the pressure of fluid supplied to each fluid pressure cylinder in roll control device including a valve, and a control unit for switching control of the directional control valve to control driving each pressure control valve, it is determined whether the vehicle is undulating road surface is traveling significant rough road If ,, the rough road determining means provided road traveling judging means judges that the vehicle is running on a rough road, the piston side chamber while controlling the pressure control valve so that the pressure of the fluid supplied to the fluid pressure cylinder is minimized Is connected to the fluid pressure source and the directional control valve is controlled so that each rod side chamber is connected to the tank, and the rod push-up thrust corresponding to the minimum pressure in each piston-side chamber is the rod push-down thrust due to the pressure in each rod-side chamber. A roll control device characterized by being made larger . A supply passage for connecting the fluid pressure source and the direction switching valve; and a discharge passage for connecting the direction switching valve and the tank. The pressure control valve is provided in the middle of the passage connecting the supply passage and the discharge passage. When it is determined that the vehicle is traveling on a rough road, the opening area of the pressure control valve is maximized, and the direction switching valve connects the piston side chamber to the fluid pressure source and connects the rod side chamber to the tank. The roll control device according to claim 1, wherein the roll control device is controlled as follows. The roll according to any one of claims 1 to 3, wherein the rough road traveling determination means includes a manually operable switch, and determines that the vehicle is traveling on a rough road by turning on the switch. Control device. When it is determined that the vehicle is not traveling on a rough road and the roll moment does not act on the vehicle body, the pressure control valve is controlled so that the pressure of the fluid supplied to the fluid pressure cylinder is minimized, and the rod side chamber is connected to the fluid pressure source. The roll control device according to any one of claims 1 to 4, wherein the directional control valve is controlled in such a manner. When it is determined that the vehicle is not traveling on a rough road, the pressure control valve is driven based on the lateral acceleration acting on the vehicle body to control the pressure, and the direction of the roll is determined by determining the direction of the roll based on the lateral acceleration. In the dead zone region including the point where the lateral acceleration is zero-crossed with respect to the lateral acceleration, the pressure control valve is not driven to increase the pressure, and the direction switching valve is switched within the dead zone region. 6. The directional control valve is controlled so as to connect the fluid pressure source to the rod side chamber at a point where the lateral acceleration is zero-crossed while avoiding a point where the lateral acceleration is zero-crossed. The roll control apparatus described. When it is determined that the vehicle is not traveling on a rough road, the pressure is controlled by driving the pressure control valve based on the pressure command value obtained from the lateral acceleration acting on the vehicle body, and the roll direction is determined based on the pressure command value. The direction switching valve is controlled by switching the direction switching valve. In the dead zone set including the point where the pressure command value is zero-crossed with respect to the pressure command value, the pressure control valve is not driven to increase the pressure. The direction switching valve is controlled so as to connect the fluid pressure source to the rod side chamber at the point where the pressure command value is zero-crossed within the dead zone region and avoiding the point where the pressure command value is zero-crossed. The roll control device according to any one of claims 1 to 5. The roll control device according to any one of claims 1 to 7, wherein the fluid pressure cylinder is connected to one end of the stabilizer so that the suspension of the vehicle also extends when extended.

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