Vibration control device for railroad vehicle

1. A vibration control device for railroad vehicles for suppressing the vibration of a vehicle body of a railroad vehicle, comprising an actuator including:

a cylinder coupled to one of a truck and the vehicle body of the railroad vehicle, a piston slidably inserted in the cylinder, a rod inserted in the cylinder and coupled to the piston and the other of the truck and the vehicle body, a rod-side chamber and a piston-side chamber partitioned in the cylinder by the piston, a tank, a first on-off valve disposed at an intermediate position of a first passage communicating between the rod-side chamber and the piston-side chamber, a second on-off valve disposed at an intermediate position of a second passage communicating between the piston-side chamber and the tank, and a pump for supplying fluid to the rod-side chamber,

wherein a warm-up operation of the actuator is performed by opening the first and second on-off valves and driving the pump after the vibration control device is started and before a transition is made to a normal control mode for suppressing the vibration of the vehicle body.

2. The vibration control device according to claim 1 , wherein:

the actuator includes a discharge passage connecting the rod-side chamber to the tank, and a variable relief valve disposed at an intermediate position of the discharge passage and capable of changing a valve opening pressure; and

the valve opening pressure of the variable relief valve is set to be minimum during the warm-up operation.

3. The vibration control device according to claim 1 , wherein:

two or more actuators are provided;

the two or more actuators include a damper circuit for causing the two or more actuators to function as a damper in a state where the first and second on-off valves are closed; and

at least one of the two or more actuators is caused to function as a damper during the warm-up operation.

4. The vibration control device according to claim 3 , wherein:

the damper circuit includes a suction passage which permits only a flow of the fluid from the tank toward the piston-side chamber and a rectifying passage which permits only a flow of the fluid from the piston-side chamber toward the rod-side chamber.

5. The vibration control device according to claim 1 , wherein:

the actuator includes two or more actuators that include a damper circuit for causing the actuators to function as a damper in a state where the first and second on-off valves are closed; and

at least one of the actuators is caused to function as a damper during the warm-up operation.

6. The vibration control device according to claim 5 , wherein:

the damper circuit includes a suction passage which permits only a flow of the fluid from the tank toward the piston-side chamber and a rectifying passage which permits only a flow of the fluid from the piston-side chamber toward the rod-side chamber.

7. A vibration control device for suppressing a vibration of a vehicle body of a railroad vehicle disposed upon a truck, the vibration control device comprising an actuator including:

a cylinder coupled to one of the truck and the vehicle body of the railroad vehicle;

a rod inserted in the cylinder and being coupled to the other of the truck and the vehicle body;

a piston slidably inserted in the cylinder with the rod being coupled to the piston, the piston partitioning the cylinder into a rod-side chamber and a piston-side chamber;

a tank;

a first on-off valve disposed at an intermediate position of a first passage communicating between the rod-side chamber and the piston-side chamber;

a second on-off valve disposed at an intermediate position of a second passage communicating between the piston-side chamber and the tank; and

a pump for supplying fluid to the rod-side chamber,

wherein a warm-up operation of the actuator is performed by opening the first and second on-off valves and driving the pump after the vibration control device is first started from a stopped state where the railroad vehicle is not in service, and before any transition is made to a normal control mode for suppressing the vibration of the vehicle body after the vibration control device is first started.

8. A method of vibration control for suppressing a vibration of a vehicle body of a railroad vehicle disposed upon a truck, the method comprising:

providing a vibration control device having an actuator including:

a cylinder coupled to one of the truck and the vehicle body of the railroad vehicle;

a rod inserted in the cylinder and being coupled to the other of the truck and the vehicle body;

a piston slidably inserted in the cylinder with the rod being coupled to the piston, the piston partitioning the cylinder into a rod-side chamber and a piston-side chamber;

a tank;

a first on-off valve disposed at an intermediate position of a first passage communicating between the rod-side chamber and the piston-side chamber;

a second on-off valve disposed at an intermediate position of a second passage communicating between the piston-side chamber and the tank; and

a pump for supplying fluid to the rod-side chamber;

controlling a warm-up operation of the actuator by opening the first and second on-off valves and driving the pump after the vibration control device is first started from a stopped state where the railroad vehicle is not in service, and before any transition is made to a normal control mode for suppressing the vibration of the vehicle body after the vibration control device is first started.