CN110198877B

CN110198877B - Damping device for railway vehicle

Info

Publication number: CN110198877B
Application number: CN201880008215.4A
Authority: CN
Inventors: 作田敦; 小川贵之; 青木淳
Original assignee: KYB Corp
Current assignee: KYB Corp
Priority date: 2017-01-30
Filing date: 2018-01-15
Publication date: 2020-11-03
Anticipated expiration: 2038-01-15
Also published as: CN110198877A; JP2018122625A; JP6374999B2; WO2018139226A1

Abstract

A railway vehicle damping device (V) according to the present invention comprises: an actuator (A) which can be unloaded while the pump (12) is driven by the motor (15), an acceleration sensor (40) which is provided on the vehicle body (B) and detects the acceleration in the left-right direction of the vehicle body (B), and a controller (C) which controls the actuator (A) on the basis of the acceleration, wherein the offset value which eliminates the drift component contained in the output value of the acceleration sensor (40) is measured while the motor (15) is driven and the actuator (A) is unloaded.

Description

Damping device for railway vehicle

Technical Field

The present invention relates to an improvement of a railway vehicle damping device.

Background

Railway vehicles are sometimes provided with a railway vehicle vibration damping device which includes a double-acting actuator mounted between a vehicle body and front and rear bogies, an acceleration sensor for detecting acceleration in the front and rear directions of the vehicle body, and a controller for controlling the actuator, and suppresses vibration in the left and right directions with respect to the traveling direction of the vehicle body.

In such a railway vehicle damping device, as disclosed in JP2013-1304A, for example, a controller obtains a control force to be generated by an actuator from an acceleration detected by an acceleration sensor, and causes the actuator to generate a thrust force for suppressing vibration of a vehicle body, thereby suppressing vibration of the vehicle body.

Disclosure of Invention

The actuator in the railway vehicle damping device is an electric hydraulic cylinder, and performs an expansion and contraction operation by pressure oil supplied to a cylinder from a pump driven by an electric motor.

An inverter for driving a motor is mounted on such an actuator, and noise is superimposed on the output of the acceleration sensor under the influence of electromagnetic waves or the like generated by a current flowing through the inverter when the motor is driven, thereby generating drift.

Since the drift component caused by noise superimposed on the output of the acceleration sensor is low frequency, a method of removing the drift component by performing high-pass filtering processing on the output of the acceleration sensor is generally used.

However, in the case of performing the high-pass filtering process, the acceleration detected by the acceleration sensor is advanced in phase from the actual acceleration, and it takes time until the drift component is completely removed and the output is stabilized. Therefore, when the vibration damping control is executed at the time of starting the motor, the controller obtains the control force from the drift component and drives the actuator, even though the acceleration is not actually applied to the vehicle body, and there is a problem that the vibration damping effect is deteriorated.

In contrast, since the drift amount of the acceleration sensor at the time of starting the motor can be measured in advance, it is also tried to set it as an offset value and to eliminate the drift component included in the output of the acceleration sensor by using the offset value at the time of starting the motor.

However, the drift amount may change due to aging of the acceleration sensor, and even if the output of the acceleration sensor is corrected using the offset value fixed in advance, there is still a problem that the drift amount deviates from the actual acceleration and the damping effect is deteriorated.

Accordingly, an object of the present invention is to provide a railway vehicle damping device capable of removing a drift component from an output of an acceleration sensor without impairing the damping effect.

The railway vehicle damping device of the present invention comprises: the vehicle body control device includes an actuator for unloading while a pump is driven by a motor, an acceleration sensor provided in a vehicle body and detecting an acceleration in a left-right direction of the vehicle body, and a controller for controlling the actuator based on the acceleration.

Drawings

Fig. 1 is a cross section of a railway vehicle on which a railway vehicle damping device according to one embodiment is mounted.

Fig. 2 is a detailed view of an example of the actuator.

Fig. 3 is a control block diagram of a controller in the railway vehicle damping device according to the embodiment.

Fig. 4 is a flow chart showing the steps of measuring and determining an offset value.

Detailed Description

The present invention will be described below with reference to embodiments shown in the drawings. A railway vehicle vibration damping device V according to one embodiment is used as a vibration damping device for a vehicle body B of a railway vehicle, and includes, as shown in fig. 1: the vehicle includes an actuator a attached in pair between a vehicle body B and a bogie T, an acceleration sensor 40 provided on the vehicle body B and detecting an acceleration α in the left-right direction of the vehicle body B, and a controller C controlling the actuator a. Specifically, in the case of a railway vehicle, the actuator a is connected to a plug P hanging downward from the vehicle body B, and is mounted in a pair between the vehicle body B and the bogie T.

The bogie T rotatably holds the wheels W, and a suspension spring S called a bolster spring is mounted between the vehicle body B and the bogie T to elastically support the vehicle body B, thereby allowing the vehicle body B to move laterally with respect to the bogie T.

Further, these actuators a basically suppress vibrations of the vehicle body B in the horizontal lateral direction with respect to the vehicle forward direction by active control by the controller C.

The controller C obtains a control force F to be generated by the actuator a from the acceleration α of the vehicle body B in the horizontal lateral direction with respect to the vehicle forward direction detected by the acceleration sensor 40, and issues a command to generate a thrust force corresponding to the control force F to each actuator a. In this way, the railway vehicle damping device V suppresses the lateral vibration of the vehicle body B by causing the actuator a to generate the control force F.

Next, a specific structure of the actuator a will be described. In the illustrated example, two actuators a are provided for each carriage T, but only one actuator a may be provided. One controller C may be provided for each actuator a.

In this example, as shown in fig. 2, the actuator a includes: a cylinder 2 connected to one of a body B and a bogie T of the railway vehicle; a piston 3 slidably inserted into the cylinder 2; a rod 4 inserted into the cylinder 2 and connected to the piston 3 and the other of the vehicle body B and the bogie T; a tank 7 for storing the working fluid; a pump 12 capable of sucking the working fluid from the tank 7 and supplying the working fluid to the rod side chamber 5; a motor 15 that drives the pump 12; and a hydraulic circuit HC for controlling switching of expansion and contraction of the actuator a and thrust, and is configured as a single rod type actuator.

In this example, the rod side chamber 5 and the piston side chamber 6 are filled with working oil as a working liquid, and the tank 7 is filled with gas in addition to the working oil. In addition, the inside of the case 7 does not need to be pressurized particularly by filling the compressed gas. The working fluid may be other than the working oil.

The hydraulic circuit HC includes: a first on-off valve 9 provided in a first passage 8 that communicates the rod-side chamber 5 and the piston-side chamber 6; a second on-off valve 11 provided in a second passage 10 that communicates the piston-side chamber 6 with the tank 7; and a variable relief valve 22 that is provided in the discharge passage 21 of the rod side chamber 5 and the tank 7 and has a variable valve opening pressure.

Basically, when the first passage 8 is brought into a communicating state by the first on-off valve 9, the second on-off valve 11 is closed, and the pump 12 is driven, the actuator a extends, and when the second passage 10 is brought into a communicating state by the second on-off valve 11, the first on-off valve 9 is closed, and the pump 12 is driven, the actuator a contracts.

Hereinafter, each part of the actuator a will be described in detail. The cylinder 2 has a cylindrical shape, and the right end of the cylinder is closed by a cap 13 in fig. 2, and the left end of the cylinder is attached with an annular rod guide 14 in fig. 2. Further, the rod 4 inserted into the cylinder 2 so as to be movable is inserted into the rod guide 14 so as to be slidable. One end of the rod 4 protrudes outside the cylinder 2, and the other end inside the cylinder 2 is connected to a piston 3 slidably inserted into the cylinder 2.

Further, the outer periphery of the rod 14 and the cylinder 2 are sealed by a sealing member, not shown, so that the inside of the cylinder 2 is maintained in a sealed state. The rod side chamber 5 and the piston side chamber 6 defined by the piston 3 in the cylinder 2 are filled with the working oil as described above.

In the case of the actuator a, the pressure receiving area of the piston 3 on the rod side chamber 5 side is made half the pressure receiving area of the piston 3 on the piston side chamber 6 side by setting the sectional area of the rod 4 to be half the sectional area of the piston 3. Therefore, if the pressures in the rod side chamber 5 are made the same during the expansion operation and the contraction operation, the thrust forces generated during the expansion and contraction operations are the same, and the amount of hydraulic oil with respect to the displacement amount of the actuator a is the same on both the expansion and contraction sides.

Specifically, when the actuator a is caused to perform an expansion operation, the rod side chamber 5 and the piston side chamber 6 are brought into communication with each other. Then, the pressures in the rod side chamber 5 and the piston side chamber 6 become equal, and the actuator a generates thrust obtained by multiplying the pressure by the pressure receiving area difference between the rod side chamber 5 side and the piston side chamber 6 side of the piston 3. On the other hand, when the actuator a is caused to perform the contraction operation, the communication between the rod side chamber 5 and the piston side chamber 6 is blocked, and the piston side chamber 6 and the case 7 are brought into a state of communication. Then, the actuator a generates a thrust force obtained by multiplying the pressure in the rod side chamber 5 by the pressure receiving area on the rod side chamber 5 side of the piston 3.

In summary, the thrust generated by the actuator a is a value obtained by multiplying one-half of the cross-sectional area of the piston 3 by the pressure of the rod-side chamber 5 in both expansion and contraction. Therefore, when controlling the thrust of the actuator a, the pressure of the rod side chamber 5 may be controlled in both the expansion operation and the contraction operation. In the actuator a of this example, since the pressure receiving area on the rod side chamber 5 side of the piston 3 is set to be half the pressure receiving area on the piston side chamber 6 side, the pressure in the rod side chamber 5 is the same on the expansion side and the contraction side when the same thrust is generated on both the expansion and contraction sides, and therefore the control is simple. Further, since the amount of hydraulic oil with respect to the displacement amount is also the same, there is an advantage that the responsiveness is the same on both the expansion and contraction sides. Even when the pressure receiving area of the piston 3 on the rod side chamber 5 side is not set to be one-half of the pressure receiving area of the piston side chamber 6 side, the thrust on both expansion and contraction sides of the actuator a can be controlled by the pressure in the rod side chamber 5.

Returning to the above, the cover 13 for closing the left end of the rod 4 in fig. 2 and the right end of the cylinder 2 is provided with a mounting portion, not shown, and the actuator a can be mounted between the body B and the bogie T of the railway vehicle.

The rod side chamber 5 and the piston side chamber 6 are communicated with each other through a first passage 8, and a first on-off valve 9 is provided in the middle of the first passage 8. The first passage 8 communicates the rod side chamber 5 and the piston side chamber 6 outside the cylinder 2, but may be provided in the piston 3.

The first on-off valve 9 is an electromagnetic on-off valve and includes a communication position at which the first passage 8 is opened to communicate the rod side chamber 5 with the piston side chamber 6, and a blocking position at which the first passage 8 is blocked to block communication between the rod side chamber 5 and the piston side chamber 6. The first on-off valve 9 is located at the on position when energized, and at the off position when not energized.

Next, the piston side chamber 6 and the tank 7 are communicated through the second passage 10, and a second on-off valve 11 is provided in the middle of the second passage 10. The second on-off valve 11 is an electromagnetic on-off valve and includes a communication position at which the second passage 10 is opened to communicate the piston side chamber 6 with the tank 7 and a blocking position at which the second passage 10 is blocked to block communication between the piston side chamber 6 and the tank 7. The second on-off valve 11 is located at the on position when energized, and at the off position when not energized.

The pump 12 is driven by the motor 15 that rotates at a predetermined rotation speed under the control of the controller C, and discharges the hydraulic oil in only one direction. The discharge port of the pump 12 communicates with the rod side chamber 5 through the supply passage 16, and the suction port communicates with the casing 7, so that when the motor 15 is driven, the pump 12 sucks the working oil from the casing 7 and supplies the working oil to the rod side chamber 5.

As described above, since the pump 12 discharges the hydraulic oil only in one direction and the switching operation of the rotation direction is not performed, the problem of the discharge amount changing at the time of the rotation switching does not occur, and an inexpensive gear pump or the like can be used. Further, since the rotation direction of the pump 12 is always the same direction, the motor 15 as the drive source for driving the pump 12 is not required to have high responsiveness to rotation switching, and accordingly, an inexpensive motor can be used as the motor 15. Further, a check valve 17 that prevents the working oil from flowing backward from the rod side chamber 5 toward the pump 12 is provided in the middle of the supply passage 16. The motor 15 is driven by receiving power supply from an inverter circuit, not shown, controlled by the controller C.

Further, as described above, the hydraulic circuit HC of this example includes the discharge passage 21 that connects the rod side chamber 5 and the tank 7, and the variable relief valve 22 that is provided in the middle of the discharge passage 21 and whose valve opening pressure is variable.

In this example, the variable relief valve 22 is a proportional electromagnetic relief valve, and the valve opening pressure is adjusted in accordance with the amount of current supplied, and is set to the minimum when the amount of current is maximum, and to the maximum when no current is supplied.

In the case where the discharge passage 21 and the variable relief valve 22 are provided in this manner, when the actuator a is caused to perform the expansion and contraction operation, the pressure in the rod side chamber 5 can be adjusted to the valve opening pressure of the variable relief valve 22, and the thrust of the actuator a can be controlled in accordance with the amount of current supplied to the variable relief valve 22. In the case where the discharge passage 21 and the variable relief valve 22 are provided, a sensor or the like required to adjust the thrust force of the actuator a is not required, and the motor 15 does not need to be highly controlled in order to adjust the discharge flow rate of the pump 12. Therefore, the railway vehicle damping device V is inexpensive, and a robust system can be constructed both in terms of hardware and software.

When the first on-off valve 9 is opened and the second on-off valve 11 is closed, or when the first on-off valve 9 is closed and the second on-off valve 11 is opened, the damping force can be exerted by the actuator a only in either expansion or contraction with respect to the vibration input from the external force regardless of the driving state of the pump 12. Therefore, for example, when the direction in which the damping force is exerted is a direction in which the vehicle body B vibrates due to the vibration of the bogie T of the railway vehicle, the actuator a can be caused to function as a damper that acts in one direction so as not to output the damping force in that direction. Therefore, the actuator a can easily realize semi-active control based on the skyhook theory of Karnopp, and thus can also function as a semi-active damper.

When a proportional electromagnetic relief valve capable of changing the valve opening pressure in proportion to the amount of current applied is used as the variable relief valve 22, the control of the valve opening pressure is simple, but the variable relief valve is not limited to the proportional electromagnetic relief valve as long as the valve opening pressure can be adjusted.

Regardless of the open/close states of the first on-off valve 9 and the second on-off valve 11, the variable relief valve 22 opens the discharge passage 21 when there is an excessive input in the actuator a in the expansion/contraction direction and the pressure in the rod side chamber 5 exceeds the valve opening pressure. In this way, the variable relief valve 22 discharges the pressure in the rod side chamber 5 toward the tank 7 when the pressure in the rod side chamber 5 becomes equal to or higher than the valve opening pressure, and therefore the pressure in the cylinder 2 can be prevented from becoming excessively high, and the entire system of the actuator a can be protected. Therefore, even when the discharge passage 21 and the variable relief valve 22 are provided, the system can be protected.

In addition to the above configuration, the hydraulic circuit HC in the actuator a of the present example further includes: a rectifying passage 18 that allows only the working oil to flow from the piston-side chamber 6 toward the rod-side chamber 5, and an intake passage 19 that allows only the working oil to flow from the tank 7 toward the piston-side chamber 6. Therefore, when the actuator a is expanded and contracted with the first and second on-off valves 9 and 11 closed, the hydraulic oil is pushed out from the cylinder 2. Further, since the variable relief valve 22 applies resistance to the flow of the hydraulic oil discharged from the cylinder 2, the actuator a of the present example functions as a one-way flow type damper in a state where the first open/close valve 9 and the second open/close valve 11 are closed.

More specifically, the rectifying passage 18 is a one-way passage that communicates between the piston-side chamber 6 and the rod-side chamber 5 and allows the working oil to flow only from the piston-side chamber 6 to the rod-side chamber 5 by providing a check valve 18a in the middle. The suction passage 19 communicates the tank 7 with the piston-side chamber 6, and is provided with a check valve 19a in the middle, and is set as a one-way passage that allows only the flow of the hydraulic oil from the tank 7 to the piston-side chamber 6. The rectifying duct 18 may be combined with the first duct 8 when the blocking position of the first switching valve 9 is set to a check valve, and the suction duct 19 may be combined with the second duct 10 when the blocking position of the second switching valve 11 is set to a check valve.

In the actuator a thus configured, even if the first on-off valve 9 and the second on-off valve 11 are both in the shutoff position, the rod side chamber 5, the piston side chamber 6, and the tank 7 are communicated in series through the rectifying passage 18, the suction passage 19, and the discharge passage 21. The rectifying passage 18, the suction passage 19, and the discharge passage 21 are set to be unidirectional passages. Therefore, when the actuator a expands and contracts by an external force, the working oil is inevitably discharged from the cylinder 2 and returned to the tank 7 via the discharge passage 21, and the working oil that is lacking in the cylinder 2 is supplied from the tank 7 into the cylinder 2 via the suction passage 19. The variable relief valve 22 serves as a resistance against the flow of the hydraulic oil, and adjusts the pressure in the cylinder 2 to the valve opening pressure, so that the actuator a functions as a passive one-way flow type damper.

In the event of a failure such that power cannot be supplied to each device of the actuator a, the first on-off valve 9 and the second on-off valve 11 are located at the blocking positions, and the variable relief valve 22 functions as a pressure control valve whose valve opening pressure is fixed to the maximum. Therefore, in such a failure, the actuator a automatically functions as a passive damper.

Next, when the actuator a is caused to generate a desired thrust in the extension direction, the controller C basically rotates the electric motor 15 to supply the hydraulic oil from the pump 12 into the cylinder 2, and causes the first switching valve 9 to be positioned at the communication position and the second switching valve 11 to be positioned at the blocking position. As a result, the rod side chamber 5 and the piston side chamber 6 are in a state of communication, and the hydraulic oil is supplied from the pump 12 to both chambers, whereby the piston 3 is pushed leftward in fig. 2, and the actuator a generates thrust in the expansion direction. When the pressures in the rod side chamber 5 and the piston side chamber 6 exceed the valve opening pressure of the variable relief valve 22, the variable relief valve 22 opens, and the hydraulic oil is discharged to the tank 7 through the discharge passage 21. Therefore, the pressures in the rod side chamber 5 and the piston side chamber 6 are controlled to the valve opening pressures of the variable relief valve 22 determined according to the amount of current applied to the variable relief valve 22. The actuator a generates an extension-direction thrust that is a value obtained by multiplying a pressure receiving area difference between the piston-side chamber 6 side and the rod-side chamber 5 side of the piston 3 by the pressure in the rod-side chamber 5 and the piston-side chamber 6 controlled by the variable relief valve 22.

On the other hand, when the actuator a is caused to generate a desired thrust in the contraction direction, the controller C rotates the electric motor 15 to supply the working oil from the pump 12 into the rod side chamber 5, and causes the first switching valve 9 to be positioned at the blocking position and the second switching valve 11 to be positioned at the communication position. As a result, the piston side chamber 6 and the tank 7 are brought into a state of communication, and the working oil is supplied from the pump 12 to the rod side chamber 5, so that the piston 3 is pushed to the right in fig. 2, and the actuator a is caused to generate thrust in the contraction direction. Then, as described above, when the current amount of the variable relief valve 22 is adjusted, the actuator a generates a thrust in the contraction direction obtained by multiplying the pressure receiving area of the piston 3 on the rod side chamber 5 side by the pressure in the rod side chamber 5 controlled by the variable relief valve 22.

Here, when the actuator a automatically expands and contracts, not due to an external force, the upper limit of the pressure of the rod-side chamber 5 is limited to the discharge pressure of the pump 12 driven by the motor 15. That is, when the actuator a automatically expands and contracts, not due to an external force, the upper limit of the pressure of the rod-side chamber 5 is limited to the maximum torque that the motor 15 can output.

The actuator a may function not only as an actuator but also as a damper by opening and closing only the first and second opening/closing valves 9 and 11 regardless of the driving state of the motor 15. Further, when the actuator a is switched from the actuator to the damper, it is not necessary to perform complicated and drastic switching operation of the first and second switching valves 9 and 11, and thus a system with high responsiveness and reliability can be provided.

Further, when the first on-off valve 9 and the second on-off valve 11 are positioned at the communication position, the rod side chamber 5 and the piston side chamber 6 are communicated with the case 7 through the first passage 8 and the second passage 10. In this state, the actuator a is in the unloaded state, and even if the pump 12 is driven by the motor 15, the pressure in the rod side chamber 5 and the piston side chamber 6 is always the tank pressure, so that the actuator a does not expand or contract and does not generate thrust. In the unloaded state, the actuator a expands and contracts with almost no resistance when forcibly expanding and contracting by an external force regardless of driving and non-driving of the pump 12.

Further, since the actuator a of this example is of a single-rod type, it is easier to secure a stroke length, and the overall length of the actuator is shortened as compared with a double-rod type actuator, thereby improving mountability to a railway vehicle.

The hydraulic oil supplied from the pump 12 in the actuator a of this example and the flow of the hydraulic oil by the expansion and contraction operation pass through the rod side chamber 5 and the piston side chamber 6 in this order, and finally return to the tank 7. Therefore, even if gas is mixed in the rod side chamber 5 or the piston side chamber 6, the gas is automatically discharged to the case 7 by the expansion and contraction operation of the actuator a, and thus, the responsiveness of generating thrust can be prevented from being deteriorated. Therefore, in manufacturing the actuator a, complicated assembly in oil or assembly in a vacuum environment is not forced, and high degassing of the working oil is not required, so that productivity can be improved and manufacturing cost can be reduced. Further, even if gas is mixed in the rod side chamber 5 or the piston side chamber 6, the gas is automatically discharged to the case 7 by the expansion and contraction operation of the actuator a, so that frequent maintenance for recovering performance is not required, and the labor and cost burden in maintenance can be reduced.

Next, as shown in fig. 3, the controller C of the present example includes: a correction unit 41 that corrects the output value output from the acceleration sensor 40 to obtain an acceleration α acting on the vehicle body B in a horizontal lateral direction with respect to the vehicle advancing direction of the vehicle body B; a control calculation unit 42 that obtains a control force F to be output by the actuator a from the acceleration α; and a driving unit 43 for driving the motor 15, the first switching valve 9, the second switching valve 11, and the variable relief valve 22 in accordance with the control force F.

The acceleration sensor 40 is provided on the vehicle body B, and detects a horizontal lateral acceleration with respect to the vehicle advancing direction of the vehicle body B and outputs the detected acceleration to the controller C. Further, the acceleration sensor 40 detects the acceleration as a positive value when facing in the direction to the right in fig. 1, and conversely, as a negative value when facing in the direction to the left in fig. 1.

When the motor 15 is driven, the correction unit 41 subtracts the offset value from the output value output from the acceleration sensor 40 to obtain the acceleration α acting on the vehicle body B in the horizontal lateral direction with respect to the vehicle advancing direction of the vehicle body B. On the other hand, the correction unit 41 does not perform correction based on the offset value when the motor 15 is not driven, and outputs the output value output from the acceleration sensor 40 as it is as the acceleration α.

As shown in fig. 4, the offset value is determined by measurement. The measurement of the offset value is performed by arranging the railway vehicle on a flat track. The controller C drives the pump 12 by the motor 15 to set the first and second switching valves 9 and 11 to the communication positions, thereby setting the actuator a to the unloading state (step ST 1). When the actuator a is in the unloaded state, the actuator a does not exert a thrust force, and the vehicle body B is not vibrated, and therefore, the vehicle body B should not be subjected to acceleration in a horizontal lateral direction with respect to the vehicle forward direction. However, when the acceleration of the vehicle body B is detected by the acceleration sensor 40 in this state, a drift component due to electromagnetic noise or the like generated in the inverter circuit that drives the motor 15 is superimposed on the output value of the acceleration sensor 40. That is, in this state, the output value of the acceleration sensor 40 does not indicate that the acceleration acting on the vehicle body B is 0, but detects an acceleration of a value pushing the vehicle body B in either of the left and right directions, which is a drift component due to the electromagnetic noise or the like. Therefore, the controller C drives the pump 12 by the motor 15, positions the first and second switching valves 9 and 11 at the communication positions, sets the actuator a to the unloading state, acquires the output value of the acceleration sensor 40 (step ST2), determines the output value of the acceleration sensor 40 as a new offset value (step ST3), and updates the offset value to the newly determined offset value (step ST 4).

The offset value may be determined by sampling the output value once, but the output value of the acceleration sensor 40 may contain other noise components, and therefore, in this example, the offset value is determined as follows. The controller C samples the output values of the acceleration sensor 40 a predetermined number of times at a predetermined sampling period, and sets an average value of the output values obtained by dividing the sum of the obtained output values by the predetermined number of times as an offset value. In addition, when the output values are sequentially added every time the output values are sampled and divided by the predetermined number of times after the predetermined number of times of sampling is completed, the total value of the sampled output values is always maintained, and the memory resources, not shown, in the controller C are not compressed. That is, when the sum of the output values is calculated after all the sampled output values are stored, the output values need to be stored in the memory a predetermined number of times, but when the output values are added each time, the sum of one sampled output value only needs to be stored in the memory. Since the average value of the output values is set as the offset value in this way, the offset value from which only the drift component due to noise or the like when the motor 15 is driven can be removed can be obtained with high accuracy.

In addition, when determining the offset value, a moving average of the output value of the acceleration sensor 40 may be obtained, and the offset value may be used. The offset value thus obtained is stored in a memory in the controller C, and is updated each time the offset value is measured and determined.

Then, the correction unit 41 obtains the acceleration α by correcting the output value of the acceleration sensor 40 when the motor 15 is driven, using the latest offset value at all times. Since the offset value is a value obtained by removing the drift component when the motor 15 is driven, the offset value is not superimposed on the output value of the acceleration sensor 40 when the motor 15 is not driven. Therefore, the correction unit 41 does not perform correction based on the offset value when the motor 15 is not driven, and outputs the output value output from the acceleration sensor 40 as it is as the acceleration α. Since the value of the superimposed drift component in the output value of the acceleration sensor 40 when the motor 15 is driven changes slowly with time due to aging of the acceleration sensor 40 or the like, the measurement and update of the offset value may be performed by regular inspection such as regular inspection, but the measurement and update of the offset value may be performed at the time of each routine inspection or pre-operation inspection.

The control calculation unit 42 performs processing using a band-pass filter that removes a steady acceleration, a drift component, or noise during traveling on a curve included in the acceleration α obtained by the correction unit 41, and thereby obtains the control force F to be exerted by the actuator a. In this example, the control arithmetic unit 42 is an H ∞ controller and obtains a control force F indicating a thrust force to be output by the actuator a in order to suppress vibration of the vehicle body B, from the acceleration α. The control force F is given a positive or negative sign depending on the direction, and the sign indicates the direction of the thrust to be output by the actuator a. After obtaining the control force F, the control arithmetic unit 42 outputs a control command corresponding to the control force F to the drive unit 43 so that the actuator a outputs the control force F.

After receiving the control command, the driving unit 43 supplies or stops supplying current to the first and second switching valves 9 and 11 according to the sign of the control force F indicated by the control command, thereby driving the first and second switching valves 9 and 11 to open or close. More specifically, when the extension direction of the actuator a is positive and the contraction direction is negative, the driving unit 43 operates as follows. When the control force F is positive in sign, the thrust direction of the actuator a is the expansion direction, and therefore the driving unit 43 positions the first open/close valve 9 at the communication position and the second open/close valve 11 at the shutoff position. Then, the hydraulic oil is supplied from the pump 12 to both the rod side chamber 5 and the piston side chamber 6, and the actuator a is caused to generate thrust in the expansion direction. On the other hand, when the control force F has a negative sign, the thrust direction of the actuator a is the contraction direction, and therefore the driving unit 43 positions the first on-off valve 9 at the blocking position and the second on-off valve 11 at the communication position. Then, the hydraulic oil is supplied from the pump 12 only to the rod side chamber 5, and the rod side chamber 5 and the tank 7 communicate with each other, so that the actuator a generates thrust in the contraction direction.

In this example, the control arithmetic unit 42 obtains the control force F from only the acceleration α. In contrast, the acceleration sensors 40 may be provided in the front and rear of the vehicle body B, the yaw acceleration (sway acceleration) and the yaw acceleration (yaw acceleration) of the vehicle body B may be obtained from the acceleration α in the front and rear of the vehicle body B, and the control force for suppressing the yaw may be obtained from the yaw acceleration and the yaw acceleration. In the case of such a configuration, the control force F may be obtained by adding the control force for suppressing the rolling and the control force for suppressing the yawing, and the control forces F may be output from the actuators a provided between the vehicle body B and the carriages T disposed in front of and behind the vehicle body B.

Although not shown, the controller C may specifically include, as hardware resources, the following configurations, for example: an a/D converter for acquiring a signal output from the acceleration sensor 40; a storage device such as a ROM (Read Only Memory) that stores a program used for processing to acquire an output value of the acceleration sensor 40 and control the actuator a; an arithmetic device such as a CPU (Central Processing Unit) that executes Processing based on the program; and a storage device such as a RAM (Random access Memory) for providing a storage area to the CPU, and the CPU executes the program to realize each section in the control arithmetic unit 42 of the controller C.

In this way, the railway vehicle damping device V includes: the present invention relates to a vehicle drive system including an actuator a which can expand and contract by supplying a working fluid from a pump 12 driven by a motor 15 and can unload the working fluid while the pump 12 is driven by the motor 15, an acceleration sensor 40 which is provided on a vehicle body B and detects an acceleration in the left-right direction of the vehicle body B, and a controller C which controls the actuator a based on the acceleration, and a drift component offset value which is included in an output value of the acceleration sensor 40 is measured while the motor 15 is driven and the actuator a is unloaded. Therefore, the railway vehicle damping device V can unload the actuator a even when the motor 15 is driven, and can measure the drift component superimposed on the output value of the acceleration sensor 40 in a safe state in which the motor 15 is driven and the vehicle body B is not vibrated. Therefore, the railway vehicle damping device V can update the offset value by the measurement without performing the high-pass filtering process on the output of the acceleration sensor 40. Thus, according to the railway vehicle damping device V, the offset value can be maintained at the optimum value, and it is not necessary to perform the high-pass filtering process for removing the drift component included in the output value of the acceleration sensor 40 due to the influence of the driving of the motor 15, and it is not necessary to wait for the phase offset and the stability of the detected acceleration, and therefore, the damping effect can be maintained well. Therefore, according to the railway vehicle damping device V of the present invention, the drift component can be removed from the output of the acceleration sensor without impairing the damping effect.

In the railway vehicle vibration damping device V of the present example, the output value is corrected based on the offset value only when the electric motor 15 is driven. In this way, when the motor 15 is switched from non-driving to driving and from driving to non-driving, a situation in which the value of the acceleration α used for control changes greatly does not occur. Therefore, in the railway vehicle vibration damping device V of the present example, a good vibration damping effect can be obtained even when the electric motor 15 is switched from non-drive to drive and when the electric motor 15 is switched from drive to non-drive. The superimposed drift component in the output value of the acceleration sensor 40 when the motor 15 is driven is added or subtracted to or from the output value in steps by switching on/off (driving/non-driving) of the motor 15. Therefore, when the validity and invalidity of the subtraction of the offset value are switched by the switching of the on/off of the motor 15, the value of the acceleration α output from the correction portion 41 continues and does not change according to the on/off of the motor 15. Therefore, even if the activation/deactivation of the electric motor 15 is performed, the shock absorbing performance does not deteriorate, so that the electric motor 15 can be deactivated in a situation where it is not necessary to drive the electric motor 15 during the running of the railway vehicle, whereby the energy consumption of the railway vehicle shock absorbing device V can be suppressed.

Further, in the railway vehicle damping device V of the present example, the output values of the acceleration sensor 40 when the motor 15 is driven are measured a predetermined number of times, and the average value obtained by dividing the value obtained by sequentially adding the obtained output values by the predetermined number of times is used as the offset value. Thus, the memory resources of the controller C are not compressed, and the processing can be performed by the memory having a small capacity, so that the railway vehicle damping device V is inexpensive.

Further, the railway vehicle damping device V of the present example includes: a cylinder body 2; a piston 3; a rod 4; a box body 7; a pump 12 for supplying working oil to the rod side chamber 5; motor 15 driving pump 12: a first on-off valve 9 provided in a first passage 8 that communicates the rod-side chamber 5 with the piston-side chamber 6; a second on-off valve 11 provided in a second passage 10 that communicates the piston-side chamber 6 with the tank 7; a variable relief valve 22 that is provided in the discharge passage 21 of the rod side chamber 5 and the tank 7 and has a variable valve opening pressure; a flow straightening passage 18 that allows only the working oil to flow from the piston-side chamber 6 to the rod-side chamber 5; and an intake passage 19 that allows only the working oil to flow from the case 7 to the piston-side chamber 6. In the railway vehicle vibration damping device V configured as described above, the actuator a functions as a skyhook semi-active damper even when the pump 12 is stopped, and therefore the vibration damping effect is not lost even while the pump 12 is stopped.

The actuator a is not limited to the above-described specific configuration as long as it can be expanded and contracted by supplying the working fluid from the pump driven by the motor and can be unloaded while the pump is driven by the motor.

While the preferred embodiments of the present invention have been illustrated and described in detail, modifications, variations and changes may be made without departing from the scope of the claims.

The present application claims priority to a special application 2017-014308, which was filed in the patent office on 30/1/2017, and the entire contents of which are incorporated herein by reference.

Claims

1. A railway vehicle damping device is characterized by comprising:

an actuator that is installed between a vehicle body and a bogie of a railway vehicle, can expand and contract by supplying a working fluid from a pump driven by a motor, and can be unloaded during driving of the pump by the motor;

an acceleration sensor that is provided on the vehicle body and detects an acceleration in a left-right direction of the vehicle body; and

a controller that controls the actuator according to the acceleration;

during the period in which the pump is driven by the motor and the actuator is unloaded, the controller controls to measure an offset value for eliminating a drift component included in an output value of the acceleration sensor.

2. A vibration damper for railway vehicles according to claim 1,

the controller corrects the output value with the offset value only when the motor is driven.

3. A vibration damper for railway vehicles according to claim 1,

the offset value is obtained by measuring the output value of the acceleration sensor at the time of the motor drive a predetermined number of times while the pump is driven by the motor and the actuator is unloaded, and dividing the value obtained by sequentially adding the output values by the predetermined number of times.

4. A vibration damper for railway vehicles according to claim 1,

the actuator is provided with:

a cylinder body;

a piston slidably inserted into the cylinder;

a rod inserted into the cylinder and connected with the piston;

a rod-side chamber and a piston-side chamber partitioned by the piston within the cylinder;

a box body;

the pump which can suck out the working fluid from the tank and supply the working fluid to the rod side chamber;

the motor that drives the pump;

a first on-off valve provided in a first passage that communicates the rod-side chamber with the piston-side chamber;

a second on-off valve provided in a second passage that communicates the piston-side chamber with the tank;

a variable relief valve provided in a discharge passage connecting the rod side chamber and the tank;

a flow straightening passage that allows only the working oil to flow from the piston-side chamber to the rod-side chamber; and

a suction passage that allows only the working oil to flow from the tank to the piston-side chamber.