JP4816894B2 - Suspension device - Google Patents

Description

  The present invention relates to a suspension device provided in a vehicle such as an automobile.

As an example of a conventional suspension device, there is an active suspension system disclosed in Patent Document 1. This active suspension system is interposed between the vehicle body and each wheel and has front and rear left and right cylinders that adjust the vehicle height by supplying and discharging pressure fluid, and supplying and discharging pressure fluid to and from the front and rear left and right cylinders. This is done by operating one pump driven by the engine. The active suspension system also includes a tank that stores pressurized pressure fluid.
JP-A-2-246816

By the way, in the above-described conventional technology, a tank for storing a large amount of fluid is provided so that pressure fluid can be supplied to the left and right cylinders of the front and rear portions, and this causes an increase in the size of the device. . Further, the pump is driven by an engine, and the pump installation location is restricted.
The present invention has been made in view of the above circumstances, and provides a suspension device that can ensure good riding comfort and steering stability with a simple structure and can increase design flexibility. With the goal.

First aspect of the present invention, the suspension device having a suspension unit before after lateral consisting fluid pressure cylinder which expands and contracts depending interposed in the supply and discharge of fluid between the vehicle body and vehicle wheels before after left The two bidirectional transfer means capable of selectively carrying out the bidirectional transfer of fluid and the left and right cylinders are connected to each other independently through the bidirectional transfer means, respectively. The left and right connection pipes of the system, the diagonal connection pipes that connect the diagonal cylinders independently through the bidirectional transfer means, the left and right connection pipes, and the diagonal connection pipes, respectively. It is characterized by comprising a flow path switching means for selectively communicating one and blocking the other, and a controller for controlling the bidirectional transfer means and the flow path switching means.

According to a second aspect of the invention, the suspension device having a suspension unit before after lateral consisting fluid pressure cylinder which expands and contracts depending interposed in the supply and discharge of fluid between the vehicle body and vehicle wheels before after left The two bidirectional transfer means capable of selectively carrying out the bidirectional transfer of fluid and the front and rear cylinders are connected to each other via the bidirectional transfer means independently of each other. A system front-rear connection pipe, two diagonal connection pipes that independently connect the diagonal cylinders to each other via the bidirectional transfer means, the front-rear connection pipe, and the diagonal connection pipe ; selectively communicating one with and the passage switching device for blocking the other, and a controller for controlling the bidirectional transfer means and said channel switching means, comprising the.

According to a third aspect of the invention, the suspension device having a suspension unit before after lateral consisting fluid pressure cylinder which expands and contracts depending interposed in the supply and discharge of fluid between the vehicle body and vehicle wheels before after left The two bidirectional transfer means capable of selectively carrying out the bidirectional transfer of fluid and the left and right cylinders are connected to each other independently through the bidirectional transfer means, respectively. selection and left connection pipe of the system, the front and rear cylinder to the left and right independently, and before and after the connection pipe 2 system connected to each other respectively via the two-way transfer means, and said longitudinal connecting pipe to the right and left connecting pipe to communicate one to the channel switching means for interrupting the other, and a controller for controlling the bidirectional transfer means and said channel switching means, comprising the.

According to the first to third aspects of the present invention, the controller controls the bidirectional transfer means and the flow path switching means, so that the fluid is transferred and supplied from the cylinder on the extension side to the cylinder on the contraction side. Can be performed. Thereby, a roll motion, a pitching motion, etc. are suppressed, and a good riding comfort and steering stability can be ensured accordingly. The posture can be controlled well without using a large tank or the like for accumulating the pressurized fluid required for the conventional active suspension, and the device can be simplified.

A suspension device according to a first embodiment of the present invention will be described below with reference to FIGS.
1A and 1B, a suspension device 1 includes a fluid pressure cylinder (a hydraulic cylinder) interposed between a vehicle body 3 of a vehicle 2, such as an automobile, and front and rear wheels 4FL, 4FR, 4RL, 4RR. Hereinafter, the cylinders are referred to as cylinders.) 5FL, 5FR, 5RL, 5RR and front and rear suspension units 7FL, 7FR, 7RL comprising gas springs 6FL, 6FR, 6RL, 6RR connected to the cylinders 5FL, 5FR, 5RL, 5RR, respectively. , 7RR.

  The suspension units 7FL, 7FR, 7RL, and 7RR on the left and right of the front and rear portions have the same configuration and are collectively referred to as the suspension unit 7 as appropriate. Note that the front and rear left and right suspension units of the cylinders 5FL, 5FR, 5RL, 5RR, gas springs 6FL, 6FR, 6RL, 6RR and cylinder / gas spring connecting pipes 8FL, 8FR, 8RL, 8RR, which will be described later, are also provided. The same as in the case of 7.

  The cylinder 5 defines a cylindrical cylinder body 12 having a bottom 10 and a lid 11 and the inside of the cylinder body 12 as first and second chambers (hereinafter referred to as cylinder first and second chambers 13 and 14). A piston 15 that is slidably housed in a liquid-tight state in the cylinder body 12, and a piston rod 16 that has one end connected to the piston 15 and the other end extending outside the cylinder 5 through the lid 11. , Is roughly composed of. The cylinder body 12 is fixed to the wheel 4 side, the piston rod 16 is fixed to the upper mount 17 on the vehicle body 3 side, and the cylinder 5 is interposed between the vehicle body 3 and the front and rear wheels 4 as described above. It is disguised. A coil spring 20 is interposed between the upper mount 17 and the spring receiver 12 </ b> A attached to the cylinder body 12 (as a result, the wheel 4 side) while being externally attached to the piston rod 16.

A piston side passage 21 is formed in the piston 15 and the piston rod 16. One end of the piston-side passage 21 opens into the cylinder first chamber 13, and the other end opens outside the piston rod 16.
The piston 15 is formed with an orifice (not shown). When a fluid such as an oil liquid is supplied to the cylinder first chamber 13, the piston rod 16 having a volume corresponding to the supply amount of the fluid projects out of the cylinder body 12, and the cylinder 5 extends and operates. When the fluid is discharged from the cylinder first chamber 13, the piston rod 16 corresponding to the volume of the fluid discharged is stored in the cylinder body 12, and the cylinder 5 is contracted and operated.

The gas spring 6 includes a hollow gas spring body 23 and a flexible member that defines the gas spring body 23 in first and second chambers (hereinafter referred to as gas spring first and second chambers 24 and 25). 26. Each gas spring first chamber 24 is connected to each piston-side passage 21 via a cylinder / gas spring connecting pipe 8FL, 8FR, 8RL, 8RR, and thus connected to each cylinder first chamber 13. Gas is sealed in the gas spring second chamber 25. When the fluid pressure acting on the cylinder first chamber 13 and thus the cylinder 5 changes, the gas spring 6 receives the change of the fluid pressure by the gas spring second chamber 25 and changes its volume.
It is desirable to provide a damping force generating means for generating a damping force between each gas spring first chamber 24 and each cylinder / gas spring connecting pipe 8.

The front left cylinder / gas spring connection pipe 8FL and the front right cylinder / gas spring connection pipe 8FR, and the rear left cylinder / gas spring connection pipe 8RL and the rear right cylinder / gas spring connection pipe 8RR, They are connected via connecting pipes (hereinafter referred to as front left / right connecting pipe 27F and rear left / right connecting pipe 27R as appropriate) as two systems of left and right connecting pipes of the invention.
In the middle of the front left and right connecting pipe 27F, a first flow path switching valve 60F and a front bidirectional pump 28F in a 3 port 2 position (hereinafter referred to as the first and second operating positions) having a solenoid 68 are connected in series. Is provided. The three ports of the first flow path switching valve 60F are hereinafter referred to as first, second, and third ports 61, 62, and 63. In the front left and right connection pipe 27F, the front bidirectional pump 28F is a cylinder 5FR side portion (hereinafter referred to as the front connection pipe right side portion 27Fa, which is the front right side of the first flow path switching valve 60F, and the opposite side portion is in front. Part connection pipe left side portion 27Fb).

In the middle of the rear left and right connecting pipes 27R, there are three ports (hereinafter referred to as first, second, and third ports 61, 62, 63) having solenoid 68 and two positions (hereinafter referred to as first and second operating positions). ) Of the second flow path switching valve 60R (referred to collectively as the flow path switching valve together with the first flow path switching valve 60F) and the rear bidirectional pump 28R (hereinafter referred to as the front bidirectional pump 28F). As appropriate, it is collectively referred to as a bidirectional pump 28). The three ports of the second flow path switching valve 60R are also referred to as first, second, and third ports 61, 62, and 63 in the same manner as the first flow path switching valve 60F.
In the rear left and right connection pipe 27R, the rear bidirectional pump 28R is a cylinder 5RR side portion (hereinafter referred to as a rear connection pipe right side portion 27Ra, the rear portion of the rear connection pipe left side portion). 27Rb). The bidirectional pump 28 constitutes one of the bidirectional transfer means of the present invention, and the flow path switching valve 60 constitutes a flow path switching means.
The bidirectional pump 28 has an impeller (not shown) that can rotate forward and reverse, and by changing the rotation direction of the impeller, the transfer direction of fluid such as oil is changed from one direction to the other direction opposite to this one direction. Be able to.

For example, in the front bidirectional pump 28F provided in the middle of the front left and right connecting pipe 27F, the fluid is transferred from the front right cylinder 5FR to the front left cylinder 5FL by rotating the impeller in one direction (forward rotation). On the other hand, by rotating the impeller in the other direction opposite to the one direction (reverse rotation), the fluid can be transferred from the front left cylinder 5FL to the front right cylinder 5FR.
The impeller of the bidirectional pump 28 is connected to a rotor (not shown) of a motor 30 that can rotate forward and backward. The direction of fluid transfer by the bidirectional pump 28 can be switched by switching the rotation direction of the motor 30.

  The motor 30 is driven by a motor driver 32 controlled by a controller 31. The controller 31 includes a lateral acceleration sensor 33, a steering angle sensor 34, a vehicle speed sensor 35, a longitudinal acceleration sensor 36, a brake switch 37, an accelerator opening sensor 38, a cylinder pressure sensor 81, and a vertical acceleration sensor (hereinafter, a vertical G sensor as appropriate). 82) is connected. The controller 31 includes lateral acceleration, steering angle, vehicle speed, longitudinal acceleration, accelerator opening, cylinder pressure, vertical acceleration, and brake operation from the sensors (33 to 36, 38, 81, 82) and the switch (37). The motion state of the vehicle 2 (including vibration state, roll motion, pitching motion, etc.) is calculated on the basis of the above information, and based on the result obtained by this calculation, the motor driver 32 (and thus the motor 30 and the bidirectional motion). The pump 28) and the first and second flow path switching valves 60F and 60R are controlled to adjust the direction and amount of fluid flow by the bidirectional pump 28 and the first and second flow path switching valves 60F and 60R. . In roll control to be described later, detection information of the lateral acceleration sensor 33, the steering angle sensor 34, and the vehicle speed sensor 35 is mainly used.

In the first flow path switching valve 60F, the first port 61 is connected to the front connecting pipe left side portion 27Fb, and the second port 62 is connected to the front connecting pipe right side portion 27Fa. The third port 63 of the first flow path switching valve 60F and the middle part of the rear connection pipe left side portion 27Rb are connected via a first flow path switching valve / rear left cylinder connection pipe 66.
In the second flow path switching valve 60R, the first port 61 is connected to the rear connecting pipe left side portion 27Rb, and the second port 62 is connected to the rear connecting pipe right side portion 27Ra. The third port 63 of the second flow path switching valve 60R and the middle portion of the front connection pipe left side portion 27Fb are connected via a second flow path switching valve / front left cylinder connection pipe 67.
In the present invention, the front right cylinder 5FR and the rear left cylinder 5RL are connected by the front connecting pipe right side portion 27Fa, the first flow path switching valve / rear left cylinder connecting pipe 66, and the rear connecting pipe left side portion 27Rb. Of the front connection pipe left side portion 27Fb, the second flow path switching valve and the front left cylinder connection pipe 67, the rear connection pipe right side portion 27Ra, and the front left cylinder 5FL Another of the diagonal connection pipes of the present invention for connecting the rear right cylinder 5RR is formed.

When the solenoid 68 is not excited, the first flow path switching valve 60F is in the first operating position (the state shown in FIG. 1), and the first port 61 and the second port 62 are in communication. In this communication state, the front left and right cylinders 5FL and 5FR communicate with each other. When the solenoid 68 is energized, the second operating position (state shown in FIG. 2) is established, and the second port 62 and the third port 63 are communicated.
The second flow path switching valve 60R is in the first operating position (the state shown in FIG. 1) when the solenoid 68 is not excited, and the first port 61 and the second port 62 are in communication. In this communication state, the left and right cylinders 5RL and 5RR communicate with each other. When the solenoid 68 is energized, the second operating position (state shown in FIG. 2) is established, and the second port 62 and the third port 63 are communicated.
Although the first and second flow path switching valves 60F and 60R are controlled by the controller 31, excitation and release of the solenoids 68 are performed simultaneously.

When the vehicle 2 turns (right turn, left turn) and turns accelerated / brake [right turn acceleration / brake, left turn acceleration / brake], the operation of the suspension device 1 configured as described above An example will be described below.
When the vehicle 2 turns, the direction opposite to the turning direction of the vehicle 2 [for example, if the turning direction is the left direction (counterclockwise), the opposite direction is the right direction (clockwise). ], The roll (the movement of the vehicle body 3 around the longitudinal axis of the vehicle body 3 due to the centrifugal force and the lateral force of the wheel 4) is generated, and the ground load applied to the wheel 4 is opposite to the turning direction. Move to.
At this time, based on information from the lateral acceleration sensor 33, the steering angle sensor 34, the vehicle speed sensor 35, and the like, the controller 31 calculates the motion state (roll motion) of the vehicle 2 and controls the content corresponding to the roll motion. Generate a signal. The controller 31 outputs the control signal to the motor driver 32 to drive the motor 30 and controls the first and second flow path switching valves 60F and 60R.

  When the motion state (roll motion) of the vehicle 2 is calculated, the controller 31 does not excite the solenoids 68 of the first and second flow path switching valves 60F and 60R, and moves to the first operating position as shown in FIG. Change to the set status (roll control status). Further, the rotation direction of the impeller of the bidirectional pump 28 is set to be different depending on the turning direction as described later.

  That is, in the turning of the vehicle 2 described above, when the vehicle 2 turns to the right, the front left that is the contraction side (sinking side), the front right that is the expansion side with respect to the cylinders 5FL and 5RL on the rear left, The impellers of the front and rear bidirectional pumps 28F and 28R are rotated in one direction (forward rotation) so that the fluid is transferred from the rear right cylinders 5FR and 5RR.

  By forwardly rotating the impellers of the front and rear bidirectional pumps 28F and 28R, fluid flows in the direction from the front right and rear right cylinders 5FR and 5RR to the front left and rear left cylinders 5FL and 5RL. Force acts. The fluid receives the force in the same direction, passes through the first flow path switching valve 60F and the front connection pipe left side portion 27Fb, passes through the second flow path switching valve 60R and the rear connection pipe left side portion 27Rb, and moves forward. The cylinders are transferred to the left and rear left cylinders 5FL and 5RL and supplied to the cylinder first chambers 13 respectively. By supplying fluid to the cylinder first chambers 13 of the front left and rear left cylinders 5FL and 5RL, the pistons of the front left and rear left cylinders 5FL and 5RL are stroked upward in FIG. This force acts on the vehicle body 3 via each piston rod 16 to suppress the roll motion.

  When the vehicle 2 makes a left turn, the behavior of the vehicle 2 performs a roll motion that is inclined in the opposite direction compared to the case of the right turn. At this time, the impellers of the bidirectional pumps 28F and 28R at the front and rear portions are rotated (reversely rotated) in the opposite direction to the rotation (forward rotation) in the case of the right turn. The fluid receives a force corresponding to the rotation direction of the impeller, is transferred to the front right and rear right cylinders 5FR and 5RR, and is supplied to each cylinder first chamber 13. By supplying fluid to the cylinder first chambers 13 of the front right and rear right cylinders 5FR and 5RR, the pistons 15 of the front right and rear right cylinders 5FR and 5RR are stroked upward in FIG. This force acts on the vehicle body 3 via the piston rod 16 and suppresses the roll motion that occurs as the vehicle 2 turns counterclockwise.

  In this way, the fluid can be transferred to both the left and right cylinders 5 by the action of the bidirectional pump 28, and the roll angle (using the differential pressure due to the fluid transfer is used regardless of whether the vehicle 2 rolls to the left or right). Roll motion) can be reduced, and good ride comfort and steering stability can be ensured as much as the roll angle is reduced. Furthermore, the impact of unsprung input can be reduced.

Further, when the vehicle 2 accelerates and brakes for turning, the front part of the vehicle 2 rises and the rear part of the vehicle 2 falls during turning acceleration due to the centrifugal force and the lateral force of the wheels 4 and the acceleration and inertial force in the longitudinal direction. Further, at the time of turning braking, the front portion of the vehicle 2 is lowered and the rear portion of the vehicle 2 is raised (pitching motion is performed), and a roll motion in which the vehicle 2 is tilted in the opposite direction to the turning direction is simultaneously generated.
At this time, lateral acceleration, steering angle, vehicle speed, longitudinal acceleration, brake operation, accelerator opening, cylinder from the sensors (33 to 36, 38, 81, 82) and the switch (37) attached to the vehicle 2 A motion state (roll motion and pitching motion) of the vehicle 2 is calculated based on each information of pressure and vertical acceleration, and a control signal having contents corresponding to the roll motion is generated. The controller 31 outputs the control signal to the motor driver 32 to drive the motor 30, and controls the first and second flow path switching valves 60F and 60R in accordance with this.

  When the controller 31 calculates the motion state (roll motion and pitching motion) of the vehicle 2, the controller 31 excites the solenoid 68 of the flow path switching valve and, as shown in FIG. Pitch composite control state). In this state, the front connection pipe right side portion 27Fa and the first flow path switching valve / rear left cylinder connection pipe 66 are communicated with each other via the first flow path switching valve 60F, whereby the front right cylinder 5FR. And the rear left cylinder 5RL is communicated. Similarly, the rear connection pipe right side portion 27Ra and the second flow path switching valve / front left cylinder connection pipe 67 communicate with each other via the second flow path switching valve 60R, whereby the front left cylinder 5FL and the rear right cylinder 5RR are communicated.

  In the case of right turn acceleration / brake among the turning acceleration and turning braking of the vehicle 2, fluid is transferred from the rear right cylinder 5RR on the expansion side to the front left cylinder 5FL on the contraction side. As shown, the impeller of the front bidirectional pump 28F is rotated. Further, the impeller of the rear bidirectional pump 28R is rotated so that the fluid is transferred from the front right cylinder 5FR on the expansion side to the rear left cylinder 5RL on the contraction side.

  Due to the rotation of the impeller of the front bidirectional pump 28F, a force in the direction from the front right cylinder 5FR to the rear left cylinder 5RL (the left direction in FIG. 2) acts on the fluid. Further, due to the rotation of the impeller of the rear bidirectional pump 28R, a force in the direction from the rear right cylinder 5RR to the front left cylinder 5FL (the left direction in FIG. 2) acts on the fluid.

  Then, the fluid receives the force in the same direction, is transferred to the rear left cylinder 5RL through the first flow path switching valve 60F and the first flow path switching valve / rear left cylinder connecting pipe 66, and the second It is transferred to the front left cylinder 5FL through the flow path switching valve 60R and the second flow path switching valve / front left cylinder connection pipe 67 and supplied to each cylinder first chamber 13. By supplying fluid to the cylinder first chambers 13 of the front left cylinder 5FL and the rear left cylinder 5RL, the piston 15 of the front left cylinder 5FL and the rear left cylinder 5RL is moved upward in FIG. Stroke force acts on the vehicle body 3 via the piston rod 16, and the pitching motion and roll motion are suppressed.

  Further, at the time of left turn acceleration / brake which is opposite to the right turn acceleration / brake, the impeller of the front bidirectional pump 28F rotates in the opposite direction to that at the right turn acceleration / brake, so The force in the direction from the rear left cylinder 5RL to the front right cylinder 5FR (right direction in FIG. 2) acts. Further, the impeller of the rear bidirectional pump 28R rotates in the opposite direction to that in the right turn acceleration / braking, so that the fluid flows from the front left cylinder 5FL to the rear right cylinder 5RR (see FIG. (2 right direction) force acts.

  Then, the operation of the front bidirectional pump 28F causes the fluid from the rear left cylinder 5RL to flow through the first flow path switching valve / rear left cylinder connecting pipe 66 and the first flow path switching valve 60F to the front right cylinder. The fluid from the front left cylinder 5FL is transferred to the second flow path switching valve / front left cylinder connecting pipe 67 and the second flow path switching valve 60R by the operation of the rear bidirectional pump 28R. Then, it is transferred to the rear right cylinder 5 RR and supplied to each cylinder first chamber 13.

By supplying fluid to the cylinder first chambers 13 of the front right cylinder 5FR and the rear right cylinder 5RR, the pistons 15 of the front right cylinder 5FR and the rear right cylinder 5RR are moved upward in FIG. Stroke force acts on the vehicle body 3 via the piston rod 16, and the pitching motion and roll motion are suppressed.
As described above, the fluid can be transferred to either of the diagonally connected cylinders 5 by the action of the bidirectional pump, and the differential pressure due to the fluid transfer is utilized regardless of the direction of the vehicle 2 in the roll motion or the pitching motion. Thus, the roll angle (roll motion) and the pitch amount (pitching motion) can be reduced, and good riding comfort and steering stability can be ensured as much as the pitching motion and roll motion are reduced.

Moreover, in this 1st Embodiment, there exists an effect | action and effect shown to following (1)-(5). Note that the second to third embodiments described later also have the following operations (1) to (5) as in the first embodiment.
(1) Compared with the prior art in which a tank for storing a large amount of fluid supplied to the left and right cylinders in the front and rear portions is provided, roll control can be performed without installing a tank. And weight reduction can be achieved.
(2) Since the pump is not driven by the engine as compared with the above-described conventional technique in which the pump is driven by the engine and the pump installation location is restricted, the degree of freedom of the pump installation location increases.

(3) Since the motor 30 only needs to be driven during control, the capacity of the motor 30 can be reduced and energy can be reduced.
(4) Since the pressure required for the bidirectional pump only needs to be large enough to support the fluctuating load accompanying the vehicle motion, the capacity of the motor required for driving the bidirectional pump may be small. .
(5) When the vehicle 2 rides on a convex part or falls into the concave part while traveling straight ahead, for example, when the unsprung vertical movement occurs, the cylinder 5 expands and contracts, and the fluid pressure in the cylinder first chamber 13 However, in response to the change in the fluid pressure in the cylinder first chamber 13, the gas spring second chamber 25 of the gas spring 6 connected to the cylinder first chamber 13 performs a spring action, and the fluid pressure is reduced. Absorb changes and maintain a good ride.

  In the above embodiment, the front left and right cylinders 5FL and 5FR are connected via the bidirectional pump 28F, and the rear left and right cylinders 5RL and 5RR are connected via the bidirectional pump 28R, The cylinders 5FL and 5RR arranged at the corners are connected via the bidirectional pump 28R, and the cylinders 5FR and 5RL are connected via the bidirectional pump 28F. Although what is switched by controlling the flow path switching valve 60R is shown, the present invention is not limited to this, and as shown in FIG. 3, the right and left cylinders 5FR and 5RR are connected via a bidirectional pump 88R. The left and right front and rear cylinders 5FL, 5RL are connected via a bidirectional pump 88L, and the cylinders 5FL, 5RR arranged diagonally are connected to the bidirectional pump 88. Further, the state in which the cylinders 5FR and 5RL are connected via the bidirectional pump 88L is switched by controlling the first flow path switching valve 89R and the second flow path switching valve 89L. May be. (Second embodiment).

  In this case, the configuration is exactly the same as when the left side of the vehicle 2 in the first embodiment (FIGS. 1 and 2) is the front front and the right side is the rear rear, and therefore the detailed description is omitted. Is omitted. 3, 27TR and 27TL are the right front and rear connection pipes and the left front and rear connection pipes corresponding to the front left and right connection pipes 27F and the rear left and right connection pipes 27R in FIG. Correspondingly, in FIG. 3, 27TRa and 27TRb indicate the rear side portion of the right front and rear connection pipe and the front side portion of the right front and rear connection pipe, respectively. 27TLa and 27TLb indicate the rear side portion of the left front and rear connection pipe and the front side of the left front and rear connection pipe, respectively. Each part is shown.

  The operation of the second embodiment is substantially the same as that of the example of the first embodiment. However, in the present embodiment, as shown in FIG. Pitching motion can be suppressed with the two-channel switching valve 89L set to the first operating position. Further, the pitching motion and the roll motion can be suppressed in a state where the first flow path switching valve 89R and the second flow path switching valve 89L are set to the second operating position. For this reason, according to the second embodiment, it is possible to ensure good riding comfort and steering stability because the pitching motion and the roll motion are reduced.

Next, a suspension device according to a third embodiment of the present invention will be described with reference to FIGS. 4 and 5, the same parts as those in FIGS. 1 to 3 are denoted by the same reference numerals, and the description thereof is omitted as appropriate.
In the present embodiment, the front left and right cylinders 5FL, 5FR are connected via a bidirectional pump 28F, and the rear left and right cylinders 5RL, 5RR are connected via a bidirectional pump 28R, and the right side The front and rear cylinders 5FR and 5RR are connected via a bidirectional pump 28R, and the left and right front and rear cylinders 5FL and 5RL are connected via a bidirectional pump 28F with one flow path switching valve 60A. It performs control to communicate and block.
This suspension device includes a flow path switching valve 60A having a solenoid 68 in four ports (referred to as first to fourth ports 61 to 64) and two positions (referred to as first and second operation positions). By using the path switching valve 60A, the front connection pipe left side portion 27Fb, the front connection pipe right side portion 27Fa, the rear connection pipe left side portion 27Rb, the rear connection pipe right side portion 27Ra are communicated and blocked, and the front and rear cylinders 5FL, 5FR , 5RL, 5RR are connected and disconnected.

The flow path switching valve 60A is set to the first operating position (the state shown in FIG. 4) with the solenoid 68 in the non-excited state, and the second operating position (the state shown in FIG. 5) when the solenoid 68 is excited. Set to When the flow path switching valve 60A is set to the first operating position, the first and second ports 61 and 62 are communicated, and the third and fourth ports 63 and 64 are communicated. When the second operating position is set, the first and third ports 61 and 63 are communicated, and the second and fourth ports 62 and 64 are communicated.
The first port 61 is connected to the front connection pipe left side portion 27Fb. The second port 62 is connected to the front connection pipe right side portion 27Fa. The third port 63 is connected to the rear connecting pipe left side portion 27Rb. Further, the rear connection pipe right side portion 27Ra is connected to the fourth port.
A front bidirectional pump 28F is provided in the middle of the front connection pipe left side portion 27Fb. A rear bidirectional pump 28R is provided in the middle of the rear connection pipe right side portion 27Ra.

In the third embodiment, when the flow path switching valve 60A is set to the first operating position (FIG. 4), the front left cylinder 5FL and the front right cylinder 5FR are provided on the left side of the front connecting pipe. 27Fb, the flow path switching valve 60A and the front connection pipe right side part 27Fa, and the rear left cylinder 5RL and the rear right cylinder 5RR are connected to the rear connection pipe left side part 27Rb, the flow path switching valve 60A and the rear part. The connection pipe is connected via the right portion 27Ra.
Further, when the flow path switching valve 60A is set to the second operating position (FIG. 5), the front left cylinder 5FL and the rear left cylinder 5RL include the front connection pipe left side portion 27Fb, the flow path switching valve 60A. And the front right cylinder 5FR and the rear right cylinder 5RR are connected to the front connection pipe right side part 27Fa, the flow path switching valve 60A and the rear connection pipe right side part 27Ra. Connected through.
The front connection pipe right side portion 27Fa and the rear connection pipe right side portion 27Ra constitute one of the front and rear connection pipes of the present invention, and the rear connection pipe left side portion 27Rb and the front connection pipe left side portion 27Fb of the front and rear connection pipes of the present invention. Configure the other.

In the third embodiment, when the controller 31 calculates that the vehicle is rolling based on information from each sensor or the like, as shown in FIG. 4, the controller 31 sets the flow path switching valve 60A to the first operating position. In this state, the roll control is performed as in the example of FIG.
In this roll control, as in the example of FIG. 1, the fluid can be transferred to either the left or right cylinder 5 by the action of the bidirectional pump 28, and the fluid is transferred regardless of whether the vehicle 2 rolls to the left or right. The roll angle (roll motion) can be reduced by utilizing the pressure difference due to, and as the roll angle is reduced, good riding comfort and steering stability can be ensured. Furthermore, the impact of unsprung input can be reduced.

Further, when the vehicle 2 performs, for example, acceleration or braking to perform a pitching motion, and the controller 31 calculates that the vehicle is performing a pitching motion based on information from each sensor or the like, the controller 31 is illustrated in FIG. As described above, the solenoid 68 of the flow path switching valve 60A is excited, and the flow path switching valve 60A is set to the second operating position (pitch control state).
That is, the front left cylinder 5FL and the rear left cylinder 5RL are communicated via the flow path switching valve 60A, and the front right cylinder 5FR and the rear right cylinder 5RR are communicated via the flow path switching valve 60A. .

  And, the behavior in which the front part of the vehicle 2 descends and the rear part rises with braking (hereinafter referred to as vehicle body forward tilting motion), and the behavior in the opposite direction to the vehicle body forward tilting motion with acceleration (the front part of the vehicle 2 rises). Then, the motor 30 is controlled to change the rotational direction of the front and rear bidirectional pumps 28F and 28R in accordance with the behavior of the rear part being lowered.

  That is, the controller 31 calculates the forward leaning motion of the vehicle body, with the flow path switching valve 60A set to the second operating position as shown in FIG. The cylinders (rear left and right cylinders 5RL, 5RR) are rotated in a direction in which fluid can be transferred to the front cylinders (front left and right cylinders 5FL, 5FR). Fluid is supplied to the chamber 13. By supplying this fluid, a force that strokes upward in FIG. 1B acts on each piston 15 of the front left and right cylinders 5FL and 5FR, and this force acts on the vehicle body 3 via the piston rod 16 to cause pitching. Movement (vehicle body tilting movement) is suppressed.

Further, when the vehicle body rearward tilting motion is calculated, the front side cylinders (front side) of the front and rear bidirectional pumps 28F and 28R are set with the flow path switching valve 60A set to the second operating position as shown in FIG. The left and right cylinders 5FL, 5FR) are rotated in a direction in which the fluid can be transferred from the rear cylinders (rear left and right cylinders 5RL, 5RR) to the cylinder first chambers 13 of the rear left and right cylinders 5RL, 5RR. Supply. By supplying this fluid, a force that strokes upward in FIG. 1B acts on each piston 15 of the rear left and right cylinders 5RL, 5RR, and this force acts on the vehicle body 3 via the piston rod 16 to cause pitching motion. (Vehicle leaning motion) is suppressed.
For this reason, according to the third embodiment, good ride comfort and steering stability can be ensured as much as the pitching motion is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS The suspension apparatus which concerns on 1st Embodiment of this invention is shown, (A) is a piping system figure which shows the state at the time of the roll control, (B) is sectional drawing which shows the member arrange | positioned in the cylinder and its vicinity. . FIG. 2 is a piping system diagram showing a state of the suspension device of FIG. 1 at the time of combined roll and pitch control. It is a piping system diagram showing typically a suspension device concerning a 2nd embodiment of the present invention. It is a piping system diagram which shows the state at the time of roll control about the suspension apparatus which concerns on 3rd Embodiment of this invention. FIG. 5 is a piping system diagram showing a state during pitch control of the suspension device of FIG. 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Suspension apparatus, 2 ... Vehicle, 5FL, 5FR, 5RL, 5RR ... Front and rear left and right cylinders, 6FL, 6FR, 6RL, 6RR ... Front and rear left and right gas springs, 8FL ... Front left cylinder and gas spring connection pipe 8FR: Front right cylinder / gas spring connection pipe, 8RL ... Rear left cylinder / gas spring connection pipe, 8RR ... Rear right cylinder / gas spring connection pipe, 27F, 27R ... Front, rear connection pipe, 28F , 28R ... front, rear bidirectional pump, 31 ... controller, 60F, 60R ... first and second flow path switching valves, 66 ... first flow path switching valve and rear left cylinder connection piping, 67 ... second flow Road switching valve, front left cylinder connection piping.

Claims (3)

A suspension apparatus having a left and right suspension units before and after consisting fluid pressure cylinder which expands and contracts depending interposed in the supply and discharge of fluid between the vehicle body and vehicle wheels before after left,
Two bidirectional transfer means capable of selectively performing bidirectional transfer of fluid;
Two left and right connecting pipes that connect the left and right cylinders independently from each other through the bidirectional transfer means;
Two diagonal connection pipes that connect the cylinders on the diagonal line independently to each other via the bidirectional transfer means;
Channel switching means for selectively communicating one of the left and right connection pipes and the diagonal connection pipe and blocking the other ;
And a controller for controlling the bidirectional transfer means and the flow path switching means. A suspension apparatus having a left and right suspension units before and after consisting fluid pressure cylinder which expands and contracts depending interposed in the supply and discharge of fluid between the vehicle body and vehicle wheels before after left,
Two bidirectional transfer means capable of selectively performing bidirectional transfer of fluid;
Two front and rear connection pipes that connect the front and rear cylinders independently to each other via the bidirectional transfer means;
Two diagonal connection pipes that independently connect the cylinders on the diagonal line to each other via the bidirectional transfer means;
A flow path switching means for selectively communicating one of the front and rear connection pipes and the diagonal connection pipe, and blocking the other ;
And a controller for controlling the bidirectional transfer means and the flow path switching means. A suspension apparatus having a left and right suspension units before and after consisting fluid pressure cylinder which expands and contracts depending interposed in the supply and discharge of fluid between the vehicle body and vehicle wheels before after left,
Two bidirectional transfer means capable of selectively performing bidirectional transfer of fluid;
Two left and right connecting pipes that connect the left and right cylinders independently from each other through the bidirectional transfer means;
Two front and rear connection pipes that connect the front and rear cylinders independently to each other via the bidirectional transfer means;
A channel switching means for selectively communicating one of the left and right connection pipes and the front and rear connection pipes, and blocking the other ;
And a controller for controlling the bidirectional transfer means and the flow path switching means.

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