JP2002079940A - Vibration damper for rolling stock - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a rolling stock, having improved control performance and replacing a conventional oil damper. SOLUTION: The control device 5 for the rolling stock comprises a pair of expansion members as actuators 20 having induction power generating ability, to be arranged at a vibration transmitting portion between a rolling stock body and a truck, one having a coil 23 wound thereon and the other having a permanent magnet 24 held thereon, and control means 33, 34 for detecting the generation of induced electromotive force in the coil 23 to control the connection of a load resistance. A current is carried in the coil 23 by consuming the induced electromotive force, generated by receiving vibration with the load resistance of a predetermined resistance value connected to the coil 23, and force generated in a magnetic field of the permanent magnet 24 is used as expansion reaction of the actuators 20 to damp vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping device for a railway vehicle which suppresses vertical and horizontal vibrations of a vehicle body that occur when the railway vehicle travels.

[0002]

2. Description of the Related Art In a railway vehicle, an air spring provided between a bogie and a vehicle body generally reduces vibration from the bogie, but does not have a capability of rapidly damping the vibration of the bogie itself. The throttle of the air chamber is appropriately narrowed by an electromagnetic valve so as to serve as a damper. However, even in this case, since the response of the air spring is extremely large due to the compressibility of the air, the effect of suppressing the vibration due to the rapid reduction of the throttle area is small. There is a problem that kickback occurs and vibration is conversely expanded.

[0003] For this reason, oil dampers have recently been used together with railway vehicles, and so-called semi-active dampers or the like, in which the degree of vibration suppression can be varied depending on the degree of vibration, have been used. As the semi-active damper, for example, one disclosed in JP-A-9-301164 can be mentioned.

[0004]

However, such conventional oil dampers have been practically used because of their low compressibility of the working fluid oil. However, the compressibility of the working fluid and the response delay of the valve are completely reduced. However, there was a delay in the switching reaction when switching the damping force, and there was a limit in the controllability of high-frequency vibration. Also, even in the unload state where the reaction force is ideally zero, unnecessary reaction force is generated due to the pipeline resistance of the hydraulic oil and the sliding resistance of the oil seal attached to prevent oil leakage. As a result, the damping ability was limited. In railway vehicles, the cushioning effect is also performed by the axle box support device that engages the wheelset and bogie frame,
When the ride comfort is secured to some extent, it is very difficult to further reduce the vibration with an oil damper that does not actively generate a damping force like an active. In addition, the oil damper needs to be periodically inspected and replaced with a working fluid and a worn portion of the seal, but the work load is large, and there is a problem other than the function.

[0005] Therefore, an object of the present invention is to replace such a conventional oil damper, and an object of the present invention is to provide a control device for a railway vehicle with improved control performance.

[0006]

SUMMARY OF THE INVENTION Accordingly, a control apparatus for a railway vehicle according to the present invention is a pair of expandable and contractable members arranged at a vibration transmitting portion between a vehicle body and a bogie, and one of the members is provided with a coil. The other has an actuator having an induction power generation capacity holding a permanent magnet and a control means for detecting the generation of an induced electromotive force in the coil and controlling the connection of a load resistor. The generated induced electromotive force is consumed by a load resistance having a predetermined resistance value connected to the coil, thereby causing a current to flow through the coil, and using the force generated in the magnetic field of the permanent magnet as the expansion / contraction reaction force of the actuator to vibrate. Is attenuated.

Further, in the control device for a railway vehicle according to the present invention, the control means includes an acceleration sensor for detecting an absolute acceleration in the vibration of the vehicle body, and an expansion / contraction judgment for judging the expansion / contraction state of the actuator from the direction of the induced electromotive force. Unit, a resistance control unit that can arbitrarily switch the resistance value of the load resistance,
A switch switching unit for connecting and disconnecting the load resistance and the coil, and a controller for operating the resistance control unit and the switch switching unit based on signals from the acceleration sensor and the expansion / contraction determination unit, I do.

Therefore, according to such a railway vehicle control device, it is possible to arbitrarily switch the resistance value of the load resistance connected to the coil and obtain an appropriate expansion / contraction reaction force corresponding to the damping force of the actuator. Moreover, since the control is performed by electrical control, the response to vibration is high, and the controllability to high-frequency vibration is excellent. Further, when the load resistance R is eliminated, no current flows through the coil and no expansion / contraction reaction force is generated, so that the unloaded state in the skyhook control can be achieved. Furthermore, because of the electric control, there is no difficulty in handling the working fluid in the oil damper, and the work load for maintenance is significantly reduced.

The vibration damping device for a railway vehicle according to the present invention is a pair of expandable and contractable members arranged at a vibration transmitting portion between the vehicle body and the bogie, and a coil is wound around one of the members and the other is wound around the other. Is an actuator having an inductive power generation capability holding a permanent magnet, and an induced electromotive force generated by vibration is consumed by a load resistance having a predetermined resistance value connected to the coil, so that a current flows through the coil and the permanent magnet is driven. A semi-active control circuit that attenuates vibration by using a force generated in a magnetic field as an expansion / contraction reaction force of the actuator, and a power supply connected to the coil to supply a current having a predetermined current value, and to actively attenuate the vibration. And a control means having a switch switching unit for switching between the semi-active control circuit and the active control circuit. The features.

In the control apparatus for a railway vehicle according to the present invention, the control means includes a semi-active control circuit, a resistance control unit capable of arbitrarily switching a resistance value of the load resistance, and an active control circuit. A sign reversing unit connected to the power supply for reversing the direction of current flow, and a current control unit for obtaining a current having an arbitrary current value from the power supply, and an acceleration for detecting an absolute acceleration in the vibration of the vehicle body. A sensor, an expansion / contraction sensor for detecting the expansion / contraction state of the actuator from a stroke, and arbitrarily operating the resistance control unit, the sign inversion unit, the current control unit, and the switch switching unit based on signals from the acceleration sensor and the expansion / contraction sensor. And a control controller.

Therefore, according to the railway vehicle control device, a semi-active damper capable of obtaining an expansion / contraction reaction force by arbitrarily switching the resistance value of the load resistance connected to the coil, and connecting the coil to a power supply. The actuator can function as an active damper that can obtain an active expansion and contraction reaction force, and has high responsiveness to vibration and excellent controllability to high frequency vibration.
Energy saving can be realized in that active control is not performed in full time. In addition, because of the electrical control, there is no difficulty in handling the working fluid in the oil damper, and the work load for maintenance is significantly reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a railcar damping device according to the present invention will be described with reference to the drawings.
The railcar damping device described in the present embodiment (hereinafter, simply referred to as a "damping device") constitutes a semi-active type damping mechanism for vertical vibration control. If the mounting direction is changed, it is of course possible to perform left-right vibration suppression control.

First, FIG. 1 is a conceptual diagram showing a state in which a vibration damping device is mounted on a railway vehicle. In a railway vehicle, a wheelset is attached to a bogie frame via a shaft spring device and a bearing, and the vehicle body is supported by an air spring on the bogie frame. Wheelset 1,1
Are arranged in front and rear with respect to a bogie frame (not shown) as shown in the figure, and between them, cross beams 2a,
2b is fixed at both ends. On the other hand, a center pin 3 is suspended from the vehicle body 10, and a rear cross beam 2a (right side in the drawing) and the center pin 3 are connected by one link 4 as shown in the figure, and the propulsive force acting on this bogie is one link. 4 is transmitted to the vehicle body 10 via the center pin 3. Therefore, the center pin 3 bears a part of the load, and at the same time, serves as the center of rotation of the bogie frame, and transmits the propulsive force in the front-rear direction to pull the vehicle body.

The single link 4 is a stepped rod member,
It is arranged at the center position of the bogie frame, and one straight portion thereof is pivotally supported by the cross beam 2a and the center pin 3 as shown in the figure. An actuator 20 that constitutes the vibration damping device 5 is provided at the other end of the other straight portion that is bent downward. The vibration damping device 5 is an electromagnetic semi-active damper. An upper frame and a lower frame (which will be described in detail later) constituting the actuator 20 are supported by the cross beam 2b and the tip of the single link 4, respectively, and are vertically moved. Are located in That is, one of the actuators 20 is connected to the vehicle body 10 and the other is connected to the bogie.

FIG. 2 is a block diagram showing the vibration damping device 5. The vibration damping device 5 includes the actuator 2 having the upper frame 21 and the lower frame 22 fitted as described above.
It has 0. Specifically, the upper frame 21 and the lower frame 22 are each formed of a bottomed cylindrical body in which cylindrical portions having different diameters are concentrically arranged in three layers, and the upper frame 21 having a large diameter is located outside. It is fitted up and down so that it becomes.
The upper frame 21 of the actuator 20 is wound with a coil 23 in a cylindrical shape, and the lower frame 22 is fitted with a permanent magnet 24. In particular, the coil 23 of the upper frame 21 is divided into four upper and lower stages by alternately winding the normal winding coil 23a and the reverse winding coil 23b, and the permanent magnets 24 of the lower frame 22 are N poles corresponding to the winding direction of the coil. NS magnets 24a and SN magnets 24b are alternately arranged such that the S pole and the S pole are reversed inside and outside.

The cylindrical portion of the upper frame 21 is formed with a large diameter so as to be located outside the cylindrical portion of the lower frame 22, so that iron powder or the like does not enter between the outermost cylindrical portions. A dust seal 25 is provided circumferentially. The upper frame 21 and the lower frame 22 which are fitted up and down are provided with a slide rod 26 suspended from the axis of the upper frame 21, and the slide rod 26 is attached to the lower frame 22.
Linear bearing guide 27 inserted and fixed in the inner peripheral cylinder of
The upper frame 21 and the lower frame 22 are configured to move up and down while maintaining a certain gap. Incidentally, in the case of the example shown in FIG. 1, the actuator 20 is connected to the vehicle body 10 via the single link 4 and to the bogie side via the cross beam 2b. However, in FIG. 2, for simplicity, it is expressed as being connected to the vehicle body from above and being connected to the bogie from below.

Subsequently, a control unit is connected to the coil 24 wound around the upper frame 21 in this manner. The control unit includes an acceleration sensor 31 that detects the vertical acceleration of the vehicle body, an expansion / contraction determination unit 32 that detects the relative expansion and contraction of the upper frame 21 and the lower frame 22 based on the direction of the induced electromotive force generated in the coil 24. And each is connected to the controller 33. Further, a resistance control unit 34 and a switch switching unit 35 are connected to the coil 23 via an expansion / contraction determination unit 32, and these are controlled by a controller 33. The resistance control unit 34 is variable so as to arbitrarily set the resistance value of the load resistance R. The controller 33 that performs switching of the load resistance R and the switch S has a preset setting for performing switching control according to the vibration direction signal obtained from the acceleration sensor 31 and the expansion / contraction signal obtained from the expansion / contraction determination unit 32. The stored program is stored.

Therefore, in the vibration damping device 5 of the present embodiment, the vibration of the vehicle body is executed in the following manner by such a configuration. In the vibration damping device 5, as described above, the actuator 20 including the upper frame 21 and the lower frame 22 having the coil 23 and the permanent magnet 24 constitutes an induction generator having an induction power generation capability, and the induction power generation generated by a disturbance input. The electric power generated by the fluctuation of the body stroke is consumed by the load resistance R to obtain the expansion / contraction reaction force which is the damping force.

Therefore, first, the coil 23 (conductor) crosses between the magnetic fluxes of the permanent magnets 24 provided on the lower frame 22 to generate an induced electromotive force in the coil 23. The induced electromotive force e is expressed by e = v · B · L (1) according to Fleming's right hand rule. In this case, e is the induced voltage, v is the coil 23
Is the speed at which B moves in the direction perpendicular to the magnetic flux, B is the magnetic flux density, and L is the length of the coil 23 in the magnetic flux.

Then, a current flows through the coil 23 by the induced electromotive force generated in this manner. According to Ohm's law, the current i is given by: i = e / R = v · B · L / R (2) R is a load resistance. On the other hand, the expansion / contraction reaction force F generated in the coil 23 due to this circuit current is obtained according to Fleming's left-hand rule, and F = BiL = vB ² L ² / R (3)

Accordingly, the expansion / contraction reaction force F generated in the coil 23 is directly proportional to the moving speed of the coil 23, that is, the moving speed of the vehicle body connected to the upper frame 21, and acts in a direction opposite to the moving direction. Therefore, since the value of the expansion / contraction reaction force F changes depending on the load resistance R, if this value is changed, the upper frame 2
The combination of 1 and the lower frame 22 can function as if it were a damping mechanism (damper). And coil 2
When the loop 3 is completely cut to eliminate the load resistance R,
The circuit can be brought into the unload state in the skyhook control without causing the current to flow in the circuit and generating the expansion / contraction reaction force F.

Next, FIG. 2 constructed based on such a principle will be described.
In the vibration damping device 5, the damping control is specifically performed as follows. When a vertical vibration is generated in the vehicle body, the acceleration of the vehicle body moving up and down is detected by the acceleration sensor 31, and the acceleration signal is sent to the controller 33. The expansion / contraction judging section 32 detects the vibration direction based on the direction of the induced electromotive force according to the moving direction, and sends an expansion / contraction signal indicating the moving direction to the controller 33. That is, when the coil 23 moves up and down relative to the permanent magnet 24, the induced electromotive force is generated by crossing the magnetic flux in the horizontal direction by the permanent magnet 24. The expansion / contraction direction of the actuator 20 is confirmed by the expansion / contraction determining unit 32 based on the direction of the induced electromotive force, and the timing of unloading / onloading is determined.

In the controller 33, the speed obtained by integrating the acceleration signal from the acceleration sensor 31 is used as a command value by multiplying the speed obtained by removing unnecessary frequency components by a gain of -K. Then, the sign of this command value and the expansion / contraction determination unit 3
The presence / absence of the load resistor R is determined from the sign bit of the electromotive force output from 2 and XOR (exclusive OR) or XNOR (the inverse bit of the XOR output) of the logical operation. From this result, the presence or absence of the connection of the load resistor R, that is, the switching between the two-stage skyhook control of on-load and unload is performed.

The two-stage skyhook control is performed by switching of a switch S using an element such as a relay or a MOS-FET in a switch switching unit 35. When a current flows through a circuit to which a load resistor R is connected, an induced induction is generated. Consumes electromotive force. When the vehicle body is in the swinging direction, the flowing current causes an expansion / contraction reaction force F to act between the coil 23 and the permanent magnet 24 in a direction to support the swinging. In the resistance control unit 35,
In order to adjust the expansion / contraction reaction force F, the load resistance R is controlled so as to have a predetermined resistance value. Specifically, it is conceivable to switch the connection of a plurality of load resistors having different resistance values, or to change the resistance value using an element.

The load resistance R at this time is determined in accordance with the above equation (3) based on a command value corresponding to the expansion / contraction speed of the actuator 20, and a resistance value that is inversely proportional to the command value is determined. The control of the resistance control unit 34 having a predetermined resistance value is performed. The induced electromotive force generated is consumed by the load resistance R, whereby a current flows to the coil 23, and an expansion / contraction reaction force F optimal for attenuating vibration is obtained by the resistance value of the load resistance R based on the command value.

Therefore, according to the above equation (2), the load resistance R
Current flows through the coil 23, for example, when a downward sway due to vibration occurs, the vibration is suppressed by the expansion / contraction reaction force F upward, and the actuator 20 exhibits a function as a damper for attenuating the vibration of the vehicle body. . On the other hand, the passive damper cannot generate the expansion / contraction reaction force F in the same direction as the moving direction of the vehicle body. Therefore, when the vehicle body moves in the returning direction, the switch S is turned off as described above. The loop of the coil 23 is cut off to bring the coil 23 into an unloaded state in which the expansion / contraction reaction force F is not generated.

Therefore, the damping device 5 according to the present embodiment is used.
According to the above, as described above, the coil 23 which is an induction power generator
Is proportional to the vibration speed, and the load resistance R
, The actuator 20 of the upper frame 21 having the coil 23 and the lower frame 22 having the permanent magnet can function as if it were a damping damper. By switching,
It is possible to efficiently dissipate the mechanical energy.
The damping device 5 is a damping damper that performs electrical control, and thus has good responsiveness, and is excellent in damping high-frequency vibration by high-speed switching.

In the unloaded state, an ideal state in which the reaction force becomes zero can be realized. Therefore, the performance of the skyhook control based on the Carnop theory can be improved to improve the vibration damping performance. Furthermore, because of the electric control, there is no difficulty in handling the working fluid in the oil damper, and the work load for maintenance is significantly reduced.

On the other hand, the vibration damping device 5 according to the present embodiment is provided to suppress vibration in the vertical direction, and as shown in FIG. ing. By attaching to the single link 4 in this manner, the single link 4 can be arranged in a well-balanced manner at the center of the vehicle body, and since the single link 4 itself is easily removed, the handling of the vibration damping device 5 and the like can be easily performed. Also, one link 4 of the present embodiment.
Is a special shape having a stepped shape, but operates like a lever with the connection portion with the center pin 3 as a fulcrum, so that the vibration is amplified in the vibration damping device 5. Therefore, by performing vibration suppression for the vibration speed amplified by the leverage ratio, the vibration originally generated in the vehicle body can be suppressed at a higher level.

Next, a second embodiment of the vibration damping device according to the present invention will be described. This vibration damping device is of a so-called hybrid control type in which switching to active control for actively damping is enabled in addition to the first embodiment having a semi-active control structure. FIG.
1 is a block diagram showing a vibration damping device according to the present embodiment.
In the vibration damping device 6, the actuator 20 including the upper frame 21 and the lower frame 22 is configured in the same manner as in the above-described embodiment (the same reference numerals are given and detailed description is omitted). There is a difference in the control unit from the first embodiment.

The control unit has an acceleration sensor 41 for detecting the vertical acceleration of the vehicle body. A stroke sensor 42 is attached to the tip of the slide rod 26 provided on the upper frame 21 to determine the expansion and contraction of the actuator 20. And
Each is connected to the controller 43. On the other hand, the coil 23 is connected to a switch switching unit 44 that switches between active and semi-active. The switch switching section 44 switches between two circuits, and one of the switches is a load resistor R for performing semi-active control.
Is connected to a resistance control unit 45 capable of switching the resistance value of the current control unit 56.
And a power supply 48 via a sign inverting unit 47. The controller 34 is connected to the switch switching unit 44, the resistance control unit 45, the current control unit 56, and the sign reversing unit 47, and stores a preset program for controlling them.

Therefore, in the vibration damping device 6, in order to attenuate the vertical vibration of the vehicle body similarly to the vibration damping device 5 of the above-described embodiment, when the vehicle body is in the swinging direction, first expand and contract in the opposite direction to support it. A reaction force F is generated. That is, the induced electromotive force generated by the movement of the coil 23 is
Is consumed by the load resistance R, and an electric current flows through the coil 23, so that an expansion / contraction reaction force F opposing the vibration is generated between the coil 23 and the permanent magnet 24, and the vibration is damped. In the resistance control unit 45, the load resistance R is varied according to a command value from the controller 43, and an optimal expansion / contraction reaction force F for attenuating the vibration is generated. Such semi-active control is the same as in the first embodiment.

On the other hand, when the vehicle body moves in the returning direction, the resistance control unit 45 is disconnected by the switching operation of the switch switching unit 44, the semi-active circuit is unloaded, and the coil 23 is connected to the active circuit. Is done. Therefore, the power supply 48 is connected, and the direction of the current flowing through the coil 23 is switched by the control of the sign inverting unit 47 based on the expansion / contraction signal. Then, in the current control unit 46, the load resistance R is varied according to a command value from the control controller 43, and an appropriate power supply current is passed through the coil 23.
Therefore, an appropriate expansion / contraction reaction force F for attenuating the vibration is actively generated in the actuator 20, whereby active control is performed.

Therefore, in the vibration damping device 6 of the present embodiment, the vibration is always attenuated by switching between semi-active and active, so that higher vibration damping performance can be obtained. In addition to this type of active control, passive control during semi-active control is used to suppress vibration, so that power consumption can be reduced by half compared to control that is always performed using active control, and energy savings can be achieved. The intended vibration control system was achieved. Further, similarly to the first embodiment, the dynamic energy can be efficiently dissipated by switching to an appropriate damping coefficient for a vibration state or a disturbance. Since it is an electrically controllable damping damper, the damping device 6 has good responsiveness in switching the damping force, and has excellent damping performance of high-frequency vibration by high-speed switching. Furthermore, because of the electrical control, there is no difficulty in handling the working fluid in the oil damper, and the work load for maintenance is significantly reduced.

Each of the vibration damping devices 5 and 6 shown in FIGS. 2 and 3 is used as an auxiliary device for an air spring or a shaft spring. A type that is integrated with a spring is proposed. FIG. 4 is a cross-sectional view showing a vibration damping device integrated with an air spring. In this vibration damping device 50, a core member 51 formed of a ferrite-based magnetic material including a disk portion and a cylindrical portion having a diaphragm 51a formed in the center is provided, and a coil 52 is provided around the cylindrical portion. Are wound, and a permanent magnet 54 is fixed to the upper surface plate 53 with respect to the core member 51. Therefore, according to such a vibration damping device 50, the core member 51 is magnetized by a magnetic field generated when a current in a predetermined direction is applied to the coil, and is attracted or repelled by the permanent magnet. Assists the damping action of Therefore, problems such as a response delay due to the compressibility of the air of the air spring can be solved.

The railway vehicle control device according to the present invention has been described with reference to the first and second embodiments.
The present invention is not limited to this, and various changes can be made without departing from the gist of the present invention. For example, as described above, it is possible to use not only the vertical vibration suppression described in the embodiment but also the horizontal vibration suppression. Further, the actuator attached between the vehicle body and the bogie is not limited to the configuration shown in the embodiment.

[0037]

According to the present invention, there is provided a pair of expandable and contractable members arranged at a vibration transmitting portion between a vehicle body and a bogie, wherein one of the members is wound with a coil and the other holds a permanent magnet. An actuator having an ability, and control means for detecting the generation of induced electromotive force in the coil and controlling connection of a load resistor, wherein the induced electromotive force generated by vibration is connected to a predetermined resistance connected to the coil. The current is passed through the coil by consuming the load resistance of the value, and the force generated in the magnetic field of the permanent magnet is set to the expansion / contraction reaction force of the actuator to attenuate the vibration. It has become possible to provide a railway vehicle control device with improved control performance.

Further, the present invention provides a pair of expandable and contractable members arranged at a vibration transmitting portion between a vehicle body and a bogie,
An actuator having an inductive power generation capability in which a coil is wound on one side and a permanent magnet is held on the other side, and an induced electromotive force generated by vibration is consumed by a load resistance having a predetermined resistance value connected to the coil. A semi-active control circuit that applies a current to the coil and attenuates vibration by using a force generated in the magnetic field of the permanent magnet as an expansion / contraction reaction force of the actuator, and connects a power supply to the coil to generate a current having a predetermined current value. Since it has a configuration having an active control circuit for generating an active expansion / contraction reaction force in the direction of flowing and attenuating vibration, and control means including a switch switching unit for switching between the semi-active control circuit and the active control circuit. Thus, it has become possible to provide a railway vehicle control device with improved control performance replacing the conventional oil damper.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a state in which a railway vehicle control device according to the present invention is mounted on a railway vehicle.

FIG. 2 is a block diagram showing a first embodiment of a railway vehicle control device according to the present invention.

FIG. 3 is a block diagram showing a second embodiment of the railway vehicle control device according to the present invention.

FIG. 4 is a cross-sectional view showing a vibration damping device integrated with an air spring.

[Explanation of symbols]

 5, 6 Railway vehicle control device 20 Actuator 21 Upper frame 22 Lower frame 23 Coil 24 Permanent magnet 31 Acceleration sensor 32 Expansion / contraction judging unit 33 Control controller 34 Resistance control unit 35 Switch switching unit

Claims (4)

[Claims] 1. A pair of expandable and contractable members disposed at a vibration transmitting portion between a vehicle body and a bogie, wherein one of the members has a coil wound around the other and a permanent magnet held on the other, and has an induction power generation capability. And a control means for detecting the generation of an induced electromotive force in the coil and controlling the connection of a load resistor, wherein the induced electromotive force generated by the vibration is connected to the coil with a predetermined resistance value. A control device for a railway vehicle, wherein current is passed through the coil when consumed by resistance, and a force generated in a magnetic field of the permanent magnet is made a reaction force of expansion and contraction of the actuator to attenuate vibration. . 2. The control device for a railway vehicle according to claim 1, wherein the control unit determines an expansion / contraction state of the actuator based on a direction of the induced electromotive force. Expansion and contraction determination unit, a resistance control unit that can arbitrarily switch the resistance value of the load resistance, a switch switching unit that connects and disconnects the load resistance from the coil, and signals from the acceleration sensor and the expansion and contraction determination unit. A control device for a railway vehicle, comprising: a control controller that operates the resistance control unit and the switch switching unit based on the control. 3. A pair of expandable and contractable members arranged at a vibration transmitting portion between a vehicle body and a bogie, wherein one of the members has a coil wound around the other and a permanent magnet holding an induction power generating capability. And an induced electromotive force generated by the vibration is consumed by a load resistance having a predetermined resistance value connected to the coil, so that a current flows through the coil, and a force generated in a magnetic field of the permanent magnet is generated by the actuator. A semi-active control circuit that attenuates vibration by an expansion / contraction reaction force, and an active control circuit that connects a power supply to the coil to flow a current of a predetermined current value, and generates an active expansion / contraction reaction force in a direction to attenuate the vibration. And a control means having a switch switching unit for switching between the semi-active control circuit and the active control circuit. 4. The control device for a railway vehicle according to claim 3, wherein the control means includes: a resistance control unit capable of arbitrarily switching a resistance value of the load resistance in the semi-active control circuit; The circuit is provided with a sign reversing unit connected to the power supply for reversing the direction of current flow, and a current control unit for obtaining a current of an arbitrary current value from the power supply, and an absolute acceleration in vibration of the vehicle body is provided. An acceleration sensor for detecting, an expansion / contraction sensor for detecting the expansion / contraction state of the actuator from a stroke, and the resistance control unit, the sign inversion unit, the current control unit, and the switch switching unit based on signals from the acceleration sensor and the expansion / contraction sensor. A railway vehicle vibration damping device, comprising: