JP2019043296A - Cylinder device and vibration damping device for railway vehicle - Google Patents

Abstract

To provide a cylinder device which can effectively prevent derailment at the time of an earthquake, and a vibration damping device for a railway vehicle.SOLUTION: A cylinder device C1 comprises: a cylinder 2; a rod 4 inserted in the cylinder 2; a piston 3 which is slidably inserted in the cylinder 2 and is connected to the rod 4, and partitions the interior of the cylinder 2 into a rod side chamber 5 and a piston side chamber 6; a tank 8; a discharge passage 21 which causes the rod side chamber 5 to communicate with the tank 8; a relief valve 22 provided in the discharge passage 21; and an attenuation part 23 which generates a pressure loss greater than that of the relief valve 22 when a relative speed of the piston 3 to the cylinder 2 becomes a prescribed speed or higher.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a cylinder device and a damping device for a railway vehicle.

  Heretofore, this type of cylinder device is used, for example, as a railway vehicle damping device that suppresses vibrations in the lateral direction with respect to the traveling direction of the vehicle body in the railway vehicle. The railway vehicle vibration damping device is composed of a plurality of cylinder devices interposed between the vehicle body and the bogie, and suppresses the vibration of the vehicle body by the thrust or damping force exerted by the cylinder device.

  The cylinder device used for such a railway vehicle damping device includes, for example, a cylinder, a piston slidably inserted in the cylinder, and a rod inserted in the cylinder and coupled to the piston The cylinder comprises a rod side chamber and a piston side chamber partitioned by pistons, a tank, and an electromagnetic relief valve provided in the middle of a discharge passage communicating the rod side chamber and the tank (see, for example, Patent Document 1).

  And the damping device for rail vehicles controls the pressure in a cylinder with an electromagnetic relief valve, heightens and lowers the thrust or damping force which a cylinder apparatus generates, and suppresses the vibration of the body of a rail vehicle.

Unexamined-Japanese-Patent No. 2010-65797

  By the way, if a strong earthquake occurs while the railway vehicle is traveling, the vehicle body may shake significantly and derail the wheel, and in such a case, the damping device for railway vehicles has a high damping force to the cylinder device. I want to make it work and prevent derailment in advance. Further, when an earthquake occurs, power supply may not be received, and therefore, it is required for the cylinder device to exert high damping force under a condition corresponding to control failure.

  Then, this invention aims at provision of the cylinder apparatus which can prevent the wheel removal at the time of an earthquake effectively, and the damping device for rail vehicles.

  The cylinder device according to the present invention comprises a cylinder, a rod inserted into the cylinder, and a piston slidably inserted into the cylinder and connected to the rod to divide the inside of the cylinder into a rod side chamber and a piston side chamber A tank, a discharge passage communicating the rod side chamber with the tank, a relief valve provided in the discharge passage, and a damping portion which causes a larger pressure loss than the relief valve when the relative velocity of the piston with respect to the cylinder becomes a predetermined velocity or more. Have. In the cylinder device thus configured, even if the vehicle body exhibits significant vibration due to an earthquake, high damping force can be exerted to reduce the vibration of the vehicle body, and even if an earthquake occurs while the railway vehicle is traveling, Vibrations are reduced quickly and derailment can be effectively suppressed.

  The cylinder device may also include a straightening passage that allows only the flow of liquid from the piston side chamber to the rod side chamber, and a suction passage that allows only the flow of liquid from the tank to the piston side chamber. The cylinder device thus configured can function as a passive damper.

  Furthermore, the cylinder device includes a first on-off valve provided in a first passage communicating the rod side chamber with the piston side chamber, and a second on-off valve provided in a second passage communicating the piston side chamber with the tank. It is also good. In the cylinder device configured as described above, when the straightening passage and the suction passage are provided, semi-active control based on Kalnop's skyhook theory can be easily realized and can function as a skyhook semi-active damper.

  Furthermore, the cylinder device may include a supply passage communicating the tank and the rod side chamber, and a pump provided in the supply passage and capable of supplying liquid from the tank to the rod side chamber. The cylinder device configured in this way can function as an actuator. In addition, when the cylinder device configured in this way includes the straightening passage and the suction passage, switching of the state of the actuator and the skyhook semi-active damper can be performed by switching the pump stop and drive, or bothersome and steep It can be performed without the switching operation of the first on-off valve and the second on-off valve.

  The cylinder device includes a damping valve having a damping portion provided downstream of the relief valve, a bypass path branching off upstream of the damping valve in the discharge passage and bypassing the damping valve and communicating with the tank, the damping valve and the bypass valve It may be configured to include a switching valve that selects one of the paths. The cylinder device configured in this way is not affected by the damping valve because the switching valve selects the detour path and bypasses the damping valve in normal times other than the earthquake, and the damping valve is effective during earthquake and has high damping force Can be effectively prevented.

  Further, the vibration control device for a railway vehicle includes a plurality of cylinder devices interposed between a car body and a carriage in the railway vehicle, and each cylinder device generates a sum of damping forces generated by the damping unit per earthquake It is configured to be equal to the required damping force required. According to the vibration control device for a railway vehicle configured as described above, even if the vehicle body exhibits significant vibration due to an earthquake, high damping force can be exerted to reduce the vibration of the vehicle body, and the earthquake occurs while the railway vehicle is traveling. Even if it occurs, the vibration of the vehicle body can be reduced quickly and derailment can be effectively suppressed. Moreover, according to the damping device for railway vehicles configured in this way, it is possible to prevent an increase in the outer diameter of each cylinder device and an increase in size of the brackets on the railway vehicle side. It becomes.

  Furthermore, the damping device for railway vehicles may make the damping force generated by each cylinder device equal to a value obtained by dividing the necessary damping force by the number of cylinder devices installed on one truck. In the railway vehicle damping device configured as described above, machining, assembly, and maintenance of each cylinder device are also extremely easy.

  According to the cylinder device and the damping device for a railway vehicle of the present invention, it is possible to effectively prevent wheel removal at the time of an earthquake.

It is a figure which shows the cylinder apparatus in the state mounted in the rail vehicle. It is a hydraulic circuit diagram of the cylinder apparatus in a first embodiment. It is the figure which showed the damping force characteristic which is the characteristic of the damping force with respect to the expansion-contraction speed of the cylinder apparatus in 1st embodiment. It is a hydraulic circuit diagram of the cylinder apparatus in 2nd embodiment.

  Hereinafter, the present invention will be described based on the embodiments shown in the drawings. The same reference numerals are given to configurations common to the cylinder device and the railway vehicle damping device according to each embodiment described below, and in order to avoid duplication of description, description in the description of one embodiment is given. The detailed description of the above configuration is omitted in the description of the other embodiments.

First Embodiment
Vibration damping device S1 for railway vehicles in the first embodiment is used for damping vehicle body B of a railway vehicle. As shown in FIGS. 1 and 2, the damping device S1 for a railway vehicle according to this embodiment includes a plurality of cylinder devices C1 interposed between a vehicle body B and a bogie T.

  In the case of a rail car, the cylinder device C1 is connected to a pin P hanging down below the vehicle body B, and is interposed in parallel between the vehicle body B and the truck T in a pair. The carriage T rotatably holds the wheel W, and a suspension spring CS is interposed between the vehicle body B and the carriage T, and the vehicle body B is elastically supported from the lower side. Lateral movement of B is permitted.

  The cylinder device C1 is, as shown in FIG. 2, a cylinder 2 connected to a car body B of a railway vehicle, and slidably inserted into the cylinder 2 to divide the inside of the cylinder 2 into a rod side chamber 5 and a piston side chamber 6 And a rod 4 inserted into the cylinder 2 and connected to the piston 3 and the carriage T, and a tank 8 provided between the cylinder 2 and the outer cylinder 7 covering the outer periphery of the cylinder 2. The cylinder device C1 further includes a discharge passage 21 communicating the rod side chamber 5 with the tank 8, a variable relief valve 22 as a relief valve provided in the discharge passage 21, and a damping unit 23.

  Hereinafter, each part of the cylinder device C1 will be described in detail. As shown in FIG. 2, both the cylinder 2 and the outer cylinder 7 are cylindrical, and the opening on the left end side in FIG. 2 is annular and closed by a rod guide 9 fitted to both. The opening on the right end side of the outer cylinder 7 in FIG. 2 is closed by a bottom cap 10 fitted to both. Further, a rod 4 movably inserted into the cylinder 2 is slidably inserted into the rod guide 9, and axial movement of the rod 4 is guided by the rod guide 9. Further, one end of the rod 4 protrudes out of the cylinder 2 through the rod guide 9, and the other end in the cylinder 2 is connected to the piston 3 slidably inserted in the cylinder 2.

  The outer periphery of the rod 4, between the rod guide 9 and the cylinder 2, between the rod guide 9 and the outer cylinder 7, between the cylinder 2 and the bottom cap 10, and between the outer cylinder 7 and the bottom cap 10, Each is sealed by a sealing member (not shown). Thus, the inside of the cylinder 2 and the tank 8 are maintained in a sealed state.

  In addition, in the present embodiment, the rod side chamber 5 and the piston side chamber 6 partitioned by the piston 3 in the cylinder 2 are filled with the hydraulic oil as the hydraulic fluid, and the tank 8 stores the hydraulic oil. It is filled with gas. The inside of the tank 8 is not particularly required to be compressed and filled with gas to be pressurized. Also, as the working fluid, other fluids may be used besides the working oil.

  In the cylinder device C1, although not shown, the rod 4 is connected to one of the bogie and the car body of the railway vehicle, and the cylinder 2 is connected to the other of the bogie and the car body, and interposed between the bogie and the car body. Since the cylinder device C1 is set to a single rod type, it is easy to secure a stroke length compared to a double rod type cylinder device, the entire length of the cylinder device C1 is shortened, and the mountability to a railway vehicle is improved Do.

  Further, in the case of this cylinder device C1, the cross-sectional area of the rod 4 is half of the cross-sectional area of the piston 3, and the pressure receiving area on the rod side chamber 5 side of the piston 3 is half the pressure receiving area on the piston side chamber 6 side. It is supposed to be. Therefore, the flow rate discharged from the inside of the cylinder 2 to the tank 8 through the discharge passage 21 becomes equal at the time of expansion and contraction of the cylinder device C1.

  Returning back, the bottom cap 10 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 this cylinder device C1 is mounted between the car body B and the truck T in the railway vehicle. Are able to intervene.

  And, in the cylinder device C1 of this example, the rod side chamber 5 and the piston side chamber 6 are communicated by the first passage 11, and the first on-off valve 12 is provided in the first passage 11 . The first passage 11 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 12 is an electromagnetic on-off valve, and has a communication position for connecting the rod side chamber 5 and the piston side chamber 6 and a blocking position for disconnecting the rod side chamber 5 and the piston side chamber 6 from each other. Sometimes, the first passage 11 is opened to connect the rod side chamber 5 and the piston side chamber 6 with each other.

  Further, in the cylinder device C1 of this example, the piston side chamber 6 and the tank 8 are communicated by the second passage 13, and in the middle of the second passage 13, a second on-off valve 14 is provided. There is. The second on-off valve 14 is an electromagnetic on-off valve, and has a communication position for communicating the piston side chamber 6 with the tank 8 and a blocking position for breaking the communication between the piston side chamber 6 and the tank 8 The second passage 13 is opened to communicate the piston side chamber 6 with the tank 8.

  The discharge passage 21 connects the rod side chamber 5 and the tank 8, and in the middle thereof, a variable relief valve 22 capable of changing the valve opening pressure is provided. The variable relief valve 22 in this example is a proportional electromagnetic relief valve, which can adjust the valve opening pressure in accordance with the amount of supplied current, and when the amount of current is maximized, the valve opening pressure is minimized. If there is no supply, the valve opening pressure is maximized.

  In this example, the damping unit 23 branches from the damping valve V provided downstream of the variable relief valve 22 in the discharge passage 21 and the upstream of the damping valve V in the discharge passage 21 and bypasses the damping valve V to the tank 8. A bypass path BP to be communicated and a switching valve 24 provided between the variable relief valve 22 of the discharge passage 21 and the damping valve V are provided.

  In the present example, the damping valve V is an orifice. The pressure loss when the hydraulic fluid at a flow rate discharged from inside the cylinder 2 to the tank 8 through the discharge passage 21 when the cylinder device C1 expands and contracts at a predetermined speed or more passes through the damping valve V The pressure loss is set to be larger than that when passing through the variable relief valve 22 at the time of energization. Specifically, the predetermined speed is set to the expansion / contraction speed of the cylinder device C1 that will reach when an earthquake occurs, and is set to 0.2 m / sec in this example. The flow rate of the hydraulic oil passing through the discharge passage 21 is a value obtained by subtracting the cross-sectional area of the rod 4 from the cross-sectional area of the piston 3 and the movement amount of the piston 3. Therefore, when the predetermined speed is set, the flow rate discharged to the tank 8 from the inside of the cylinder 2 through the discharge passage 21 when expanding and contracting at the predetermined speed is uniquely determined, and this flow rate is set as the set flow rate.

  The switching valve 24 is provided in the discharge passage 21 at a first position 24b communicating the downstream of the variable relief valve 22 to the bypass path BP, and a second position 24c connecting the downstream of the variable relief valve 22 to the damping valve V A spring 24d biasing the valve body 24a to take the first position 24b, and a pressure upstream of the switching valve 24 downstream of the variable relief valve 22 relative to the valve body 24a. And a pilot passage 24e acting to take the second position 24c. The switching valve 24 is adapted to cause a pressure loss with respect to the passage of hydraulic fluid when the first position 24 b is taken. When the flow rate of the hydraulic oil reaches the set flow rate, the force pushing the valve body 24a by the pressure introduced in the pilot passage 24e overcomes the biasing force of the spring 24d, and the valve body 24a moves from the first position 24b to the second position. Switch to 24c. Therefore, when the flow rate of the hydraulic fluid flowing through the discharge passage 21 does not reach the set flow rate, the switching valve 24 selects the bypass path BP and causes the hydraulic fluid to flow to the tank 8 without passing through the damping valve V. On the other hand, the switching valve 24 selects the damping valve V when the flow rate of the hydraulic oil flowing through the discharge passage 21 is equal to or higher than the set flow rate, and the hydraulic oil passing through the variable relief valve 22 via the damping valve V flows to the tank 8 . That is, the switching valve 24 selects the bypass path BP when the cylinder device C1 expands and contracts below a predetermined speed, and selects the damping valve V when the cylinder device C1 expands and contracts at a predetermined speed or higher. Since the bypass path BP passes the hydraulic oil with little resistance, the pressure loss generated at the first position 24 b and the bypass path BP is set to be very small compared to the pressure loss generated at the variable relief valve 22. ing.

  Therefore, the damping unit 23 causes only a small pressure loss compared to the variable relief valve 22 when the relative speed of the piston 3 with respect to the cylinder 2 is less than the predetermined speed, and the damping valve V changes the pressure when the relative speed is equal to or higher than the predetermined speed. A pressure loss larger than that of the relief valve 22 is generated.

  Further, as shown in FIG. 2, the cylinder device C1 of the present example is provided with a straightening passage 18 that allows only the flow from the piston side chamber 6 to the rod side chamber 5. The straightening passage 18 may be provided other than the piston 3. Furthermore, the cylinder device C1 of the present example is provided with a suction passage 19 that allows only the flow from the tank 8 toward the piston side chamber 6.

  Therefore, in the cylinder device C1 of this example, when the first on-off valve 12 and the second on-off valve 14 take the blocking position, they operate from the rod side chamber 5, which is compressed when it receives an external force and expands. Oil is pushed into the tank 8 through the discharge passage 21. Then, hydraulic oil is supplied from the tank 8 through the suction passage 19 to the piston side chamber 6 to be expanded. When the extension speed of the cylinder device C1 is less than a predetermined speed at the time of the extension operation, the cylinder device C1 exerts a resistance to the flow of the hydraulic oil by the variable relief valve 22 to exert a damping force which suppresses the extension. In addition, when the extension speed of the cylinder device C1 becomes equal to or higher than the predetermined speed during the extension operation, the cylinder device C1 applies resistance to the flow of hydraulic oil by the damping valve V in the variable relief valve 22 and the damping unit 23 to suppress extension. Demonstrate damping force.

  On the contrary, when the first on-off valve 12 and the second on-off valve 14 take the blocking position, the piston side chamber 6 is compressed from the piston side chamber 6 through the straightening passage 18 when the cylinder device C1 contracts due to external force. The hydraulic oil moves to 5 Further, at the time of contraction of the cylinder device C 1, the rod 4 intrudes into the cylinder 2, so the volume of hydraulic oil which the rod 4 intrudes into the cylinder 2 becomes excessive in the cylinder 2 to the tank 8 through the discharge passage 21. Exhausted. When the contraction speed of the cylinder device C1 is less than a predetermined speed at the time of the contraction operation, the cylinder device C1 exerts resistance to the flow of hydraulic oil by the variable relief valve 22 to exert a damping force that suppresses the contraction. In addition, when the contraction speed of the cylinder device C1 becomes equal to or higher than the predetermined speed at the time of contraction operation, the cylinder device C1 applies resistance to the flow of hydraulic oil by the damping valve V in the variable relief valve 22 and the damping unit 23 to suppress contraction. Demonstrate damping force.

  In this case, the flow rate of the hydraulic oil passing through the discharge passage 21 is an amount obtained by multiplying the cross-sectional area of the rod 4 by the amount of movement of the piston 3. Here, since the cross-sectional area of the rod 4 is set to a half of the cross-sectional area of the piston 3, if the amount of movement of the piston 3 is the same even if the cylinder device C1 expands or contracts, discharge The flow rates of the hydraulic oil passing through the passage 21 become equal. Therefore, the cylinder device C1 can exert equal damping force if the moving speed of the piston 3 is the same on both sides of expansion and contraction.

  In addition, the first on-off valve 12 and the second on-off valve 14 both take off positions when deenergized, and in the event of power supply failure, the cylinder device C1 of this example always has a damping force against expansion and contraction as described above. Since it exerts, it functions as a passive damper.

  Further, in the cylinder device C1 of this example, when the first on-off valve 12 is in the communication position and the second on-off valve 14 is in the blocking position, the rod side chamber 5 and the piston side chamber 6 communicate via the first passage 11 However, the communication between the piston side chamber 6 and the tank 8 is cut off. In this state, when the cylinder device C1 receives an external force and contracts, hydraulic oil of a volume that the rod 4 intrudes into the cylinder 2 is discharged from the cylinder 2 to the discharge passage 21 and exerts a damping force against the contraction as described above. Do. On the other hand, in this state, when the cylinder device C1 extends, the working oil moves from the reducing rod side chamber 5 to the expanding piston side chamber 6 via the first passage 11 and the operation for the volume of the rod 4 withdraws from the cylinder 2 Oil is supplied from the tank 8 into the cylinder 2 via the suction passage 19. Therefore, in this case, since the hydraulic oil does not flow to the discharge passage 21, the cylinder device C1 does not exert a damping force.

  Furthermore, in the cylinder device C1 of the present example, when the first on-off valve 12 is in the blocking position and the second on-off valve 14 is in the communicating position, the rod side chamber 5 and the piston side chamber 6 are disconnected. The tank 6 and the tank 8 are in communication via the second passage 13. In this state, when the cylinder device C1 receives an external force and expands, the hydraulic oil is discharged from the rod side chamber 5 to the discharge passage 21 as the rod side chamber 5 is contracted, and the damping force opposing the expansion is exerted as described above. On the other hand, in this state, when the cylinder device C1 contracts, the working oil moves from the shrinking piston side chamber 6 to the expanding rod side chamber 5 through the straightening passage 18 and the volume of the rod 4 enters the cylinder 2 Oil is discharged from the piston side chamber 6 into the tank 8 through the second passage 13. Therefore, in this case, since the hydraulic oil does not flow to the discharge passage 21, the cylinder device C1 does not exert a damping force. As described above, in this cylinder device C1, it is possible to function as a one-way damper that selects either the extension or the contraction to exhibit the damping force.

  The damping force characteristic at the time of non-energization in cylinder apparatus C1 comprised in this way becomes as showing in FIG. When the power is not supplied, power is not supplied to the first opening / closing valve 12, the second opening / closing valve 14 and the variable relief valve 22, the cylinder device C1 functions as a passive damper, and the valve opening pressure of the variable relief valve 22 is maximized. There is. The damping force characteristic of the cylinder device C1 at the time of non-energization is the relative speed of the piston 3 with respect to the cylinder 2, that is, the expansion and contraction speed of the cylinder device C1 is a variable relief valve if it is less than a predetermined speed (0.2 m / sec in this example). Since the damping force is exhibited at 22, the damping force characteristic exhibits the characteristic of the variable relief valve 22 as shown in FIG. When the relative velocity of the piston 3 with respect to the cylinder 2 becomes high and reaches a predetermined velocity or more, the switching valve 24 switches to the second position 24 c and the hydraulic oil passes through the damping valve V. In this case, hydraulic oil having a flow rate equal to or higher than the set flow rate flows through the damping valve V, and in this state, the pressure loss in the damping valve V is larger than the pressure loss in the variable relief valve 22. Therefore, when the expansion / contraction speed of the cylinder device C1 is 0.2 m / sec or more which is a predetermined speed, the damping force characteristic of the cylinder device C1 exhibits the characteristic of the damping valve V. Specifically, as shown in FIG. 3, the square characteristic of the orifice appears, and the cylinder device C1 exerts a high damping force. In addition, when the valve opening pressure of the variable relief valve 22 is adjusted, the range below the characteristic line in FIG. 3 is within the range where the expansion and contraction speed of the cylinder device C1 where only the characteristics of the variable relief valve 22 appear is less than 0.2 m / sec. The damping force of the cylinder device C1 can be adjusted in height.

  And damping device S1 for rail vehicles of this example is provided with two cylinder devices C1 per bogie T. The damping force required per one truck T is empirically known in order to suppress the vibration of the vehicle body B and prevent the wheels W from derailing from the rails at the time of an earthquake occurrence. Therefore, the damping device S1 for railway vehicles according to the present invention may be provided with a damping force that is equal to or greater than the damping force (necessary damping force) necessary for preventing the wheels from derailing with the two cylinder devices C1. In order to exert the required damping force. Specifically, damping device S1 for a railway vehicle according to the present embodiment is provided with two cylinder devices C1 in one bogie T, so the necessary damping force is required when each cylinder device C1 expands and contracts at a reference speed. It is designed to output one half of the total, and exert the necessary damping force as a whole.

  When damping device S1 for railway vehicles exerts necessary damping force at the time of earthquake, in order to prevent derailing at the time of earthquake, it is desirable to exert necessary damping force at the reference speed where the expansion and contraction speed of cylinder device C1 becomes a standard Be done. And, since each cylinder device C1 exerts a half of the necessary damping force, each cylinder device C1 exerts a half of the necessary damping force at the reference speed since the damping device S1 for railway vehicles of this example It should be possible. The reference speed is set to a speed higher than the predetermined speed and at which a derailment may occur in the rail vehicle, and is set to 0.6 m / sec in this example. Also, the required damping force is set to 80 kN. Therefore, as shown in FIG. 3, each cylinder device C1 is set so that the expansion / contraction speed of the cylinder device C1 exhibits a damping force of 40 kN at 0.6 m / sec. For the expansion / contraction speed exceeding the reference speed, the sum of the damping forces of the respective cylinder devices C1 only needs to be equal to or more than the necessary damping force. In this example, since two cylinder devices C1 are provided for one carriage T, each cylinder device C1 outputs half the necessary damping force at the reference speed, but the necessary damping is necessary. The share of power can be changed. Further, if the number of installations per one carriage T of the cylinder device C1 is three or more, the sum of the damping forces output by each cylinder device C1 at the reference speed may be set to be equal to or more than the necessary damping force. The necessary damping force may be set to a value suitable for a railway vehicle.

  Returning to the above, when the first on-off valve 12 and the second on-off valve 14 are in the blocking position, the cylinder device C1 functions as a passive damper, and variable if the expansion and contraction speed of the cylinder device C1 is less than a predetermined speed. By adjusting the valve opening pressure by adjusting the amount of current supplied to the relief valve 22, the damping force can be adjusted. In addition, when the first on-off valve 12 and the second on-off valve 14 are in the blocking position, the cylinder device C1 functions as a passive damper, and the damping generated by the damping valve V when the expansion and contraction speed of the cylinder device C1 becomes equal to or more than a predetermined speed The power is high.

  Further, as described above, when the first on-off valve 12 is in the communication position and the second on-off valve 14 is in the blocking position, and when the first on-off valve 12 is in the blocking position and the second on-off valve 14 is in the communication position. The cylinder device C1 is in a mode in which the cylinder device C1 exerts a damping force only to either extension or contraction. Therefore, for example, if this mode is selected, if the direction in which the damping force is exerted is the direction in which the vehicle body is excited by the vibration of the bogie of the railway vehicle, the damping force is not output in such a direction. The cylinder device C1 can be used as a one-effect damper. Therefore, in this cylinder device C1, since semi-active control based on Kalnop's skyhook theory can be easily realized, the cylinder device C1 can function as a skyhook semi-active damper. When the first on-off valve 12 and the second on-off valve 14 are opened and closed in this manner, the damping force is exerted by the variable relief valve 22 when the expansion and contraction speed of the cylinder device C1 is less than the predetermined speed. Adjustment of is possible. Further, even when the first on-off valve 12 and the second on-off valve 14 are opened and closed, the cylinder device C1 has a high damping force due to the damping valve V when the expansion and contraction speed of the cylinder device C1 is equal to or higher than a predetermined speed. Demonstrate.

  Subsequently, at the time of control failure where the power supply is cut off due to occurrence of a large earthquake or the like while the railway vehicle is traveling, the first on-off valve 12 and the second on-off valve 14 take the shutoff position. The device C1 functions as a passive damper. In this state, whenever the cylinder device C1 expands and contracts, the hydraulic fluid is discharged from the cylinder 2 and the discharged hydraulic fluid flows into the tank 8 through the discharge passage 21. Therefore, although the cylinder device C1 exhibits damping force even at the time of this control failure, when the truck vibrates sharply due to a large earthquake and the relative speed with the vehicle body is high, the expansion and contraction speed of the cylinder device C1 becomes equal to or more than a predetermined speed Since the cylinder device C1 exerts a damping force by the damping valve V, the cylinder device C1 exerts a damping force higher than that of the normal mode in which the damping force is exerted only by the variable relief valve 22.

  From the above, according to the cylinder device C1 of the present invention, even if the vehicle body B exhibits significant vibration due to an earthquake, high damping force can be exerted to reduce the vibration of the vehicle body B, and an earthquake occurs while the railway vehicle is traveling. Even in this case, the vibration of the vehicle body B can be rapidly reduced and the derailing can be effectively suppressed.

  Further, according to the vibration control device S1 for railway vehicles of the present invention, even if the vehicle body B exhibits significant vibration due to an earthquake, high damping force can be exerted to reduce the vibration of the vehicle body B, and the railway vehicle is traveling Even if an earthquake occurs, the vibration of the vehicle body B is promptly reduced, and the wheel removal can be effectively suppressed. And, because the damping device S1 for railway vehicles of this example includes a plurality of cylinder devices C1 installed for one bogie T, the necessary damping force for preventing each cylinder device C1 from derailing Share and demonstrate. Therefore, in the damping device S1 for a railway vehicle according to the present embodiment, the upper limit of the damping force to be exerted by each cylinder device C1 can be lowered compared to the case where the necessary damping force is exerted by only one cylinder device C1. The diameter of the rod 4 of each cylinder device C1 becomes smaller and the outer diameters of the cylinder 2 and the outer cylinder 7 also become smaller. In addition, when the necessary damping force is exhibited by one cylinder device, it is inevitable to increase the size of the bracket for mounting the cylinder device on the side of the railway vehicle due to the problem of strength, but in the damping device S1 for railway vehicles of this example, Since each cylinder device C1 shares the necessary damping force, enlargement of the bracket can be avoided. Therefore, while the damping device S1 for rail vehicles can prevent the removal of the wheels, it is possible to prevent the diameter increase of the outer diameter of each cylinder device C1 and the enlargement of the bracket on the rail vehicle side. The mountability to a rail car becomes good.

  Furthermore, in the damping device S1 for a railway vehicle according to this embodiment, the damping force exerted when expanding and contracting at the reference speed in each cylinder device C1 is set to a value obtained by dividing the necessary damping force by the number of installations. Therefore, the respective parts such as the cylinder 2, the piston 3 and the rod 4 constituting each cylinder device C1 can be constituted by the common parts, which can further contribute to the miniaturization, and the bracket on the railway vehicle side also becomes the common part. Therefore, machining, assembly, and maintenance of each cylinder device C1 in the railcar damping device S1 become very easy.

  Further, in the present example, the damping unit 23 branches from the damping valve V provided downstream of the variable relief valve 22 in the discharge passage 21 and the upstream of the damping valve V in the discharge passage 21 and bypasses the damping valve V A bypass path BP communicated with the valve 8 and a switching valve 24 provided between the variable relief valve 22 of the discharge passage 21 and the damping valve V are provided. The predetermined speed at which the damping unit 23 starts to exert a high damping force is set to the relative speed of the vehicle body B with respect to the carriage T which will reach at the time of earthquake in this example. In the cylinder device C1 in which the damping unit 23 is configured as described above, the switching valve 24 selects the bypass path BP and bypasses the damping valve V under normal conditions other than earthquakes, so that the earthquake is not affected by the damping valve V. Sometimes, the damping valve V is effective to exert a high damping force to effectively prevent derailing. In addition, although the damping valve V may be inexpensive because it is an orifice in this example, a valve other than the orifice may be employed. Furthermore, in the present example, the predetermined speed is set to 0.2 m / sec, but may be set to another numerical value.

  In addition, the attenuation part 23 is not limited to the said structure. The damping unit 23 may be any one as long as it generates a pressure loss larger than that of the relief valve (variable relief valve 22) when the relative velocity of the piston 3 with respect to the cylinder 2 is equal to or more than a predetermined velocity. In this way, the damping unit 23 causes a small pressure loss by the relief valve (variable relief valve 22) below a predetermined speed, so the damping force exerted by the relief valve (variable relief valve 22) in normal times is There is little influence of and can prevent derailment at the time of earthquake.

  Further, in the cylinder device C1 of the present example, the first on-off valve 12 provided in the middle of the first passage 11 for communicating the rod side chamber 5 and the piston side chamber 6 and the piston side chamber 6 and the tank 8 are communicated. A second on-off valve 14 provided in the middle of the second passage 13, a straightening passage 18 allowing only the flow from the piston side chamber 6 to the rod side chamber 5, and a suction passage allowing only the flow from the tank 8 to the piston side chamber 6 It has 19 and. Therefore, in the cylinder device C1 of this example, semi-active control based on Kalnop's skyhook theory can be easily realized, and the cylinder device C1 can function as a skyhook semi-active damper. The straightening passage 18 may be integrated into the shutoff position of the first on-off valve 12 and the suction passage 19 may be integrated into the shutoff position of the second on-off valve 14. When the first passage 11, the first on-off valve 12, the second passage 13 and the second on-off valve 14 are eliminated from the configuration of the cylinder device C1, the cylinder device C1 functions as a passive damper. Therefore, it is not necessary to make the cylinder device C1 function as a skyhook semi-active damper, and when making it function only as a passive damper, the first passage 11, the first on-off valve 12, the second passage 13 and the second on-off valve 14 May be abolished.

  In the cylinder device C1 of this example, the relief valve is the variable relief valve 22, but when the damping force is not variable, the relief valve may be a relief valve having a constant valve opening pressure. As described above, even if the cylinder device C1 is configured, at the time of an earthquake, the damping valve V can reduce the flow passage area to increase the damping force, thereby preventing wheel removal.

Second Embodiment
The cylinder device C2 according to the second embodiment is, as shown in FIG. 4, provided with a pump 15 capable of supplying hydraulic oil to the rod side chamber 5 in the configuration of the cylinder device C1 according to the first embodiment. is there. Further, although not shown, damping device S2 for a railway vehicle is provided with two cylinder devices C2 for one bogie T as in the damping device S1 for a railway vehicle according to the first embodiment. .

  Specifically, the cylinder device C2 includes a supply passage 16 communicating the tank 8 with the rod side chamber 5, and a pump 15 provided in the supply passage 16 for sucking the hydraulic oil from the tank 8 and discharging it to the rod side chamber 5. A check valve 17 is provided on the discharge side of the pump 15 of the supply passage 16 to block the flow of hydraulic fluid from the rod side chamber 5 toward the tank 8.

  The pump 15 is driven by a motor 20 controlled by a controller (not shown), and is a pump that discharges hydraulic oil only in one direction. The pump 15 is installed with a suction port in the supply passage 16 and a discharge port facing the rod side chamber 5 on the tank 8 side. When driven by the motor 20, the pump 15 sucks hydraulic oil from the tank 8 and Supply hydraulic oil to

  As described above, the pump 15 only discharges the hydraulic oil in one direction and there is no switching operation of the rotation direction, so there is no problem that the discharge amount changes at the time of rotation switching, and an inexpensive gear pump can be used .

  Furthermore, since the direction of rotation of the pump 15 is always the same, high responsiveness to rotational switching is not required even in the motor 20 which is a drive source for driving the pump 15, and the motor 20 is also inexpensive accordingly Can be used. The check valve 17 is provided to prevent the backflow of hydraulic oil to the pump 15 side when the cylinder device C2 is forced to expand and contract by an external force.

  Subsequently, to cause the cylinder device C2 configured as described above to exert a desired thrust in the extension direction, the motor 20 is rotated to supply the hydraulic oil from the pump 15 into the cylinder 2 while the first on-off valve 12 is The communication position is set, and the second on-off valve 14 is set to the blocking position. Then, the rod side chamber 5 and the piston side chamber 6 are in communication and hydraulic fluid is supplied from the pump 15 to both of them, and the piston 3 is pushed leftward in FIG. 4 and the cylinder device C2 exerts a thrust in the extension direction . When the pressure in the rod side chamber 5 and the pressure in the piston side chamber 6 exceeds the valve opening pressure of the variable relief valve 22, the variable relief valve 22 is opened and the hydraulic oil is discharged to the tank 8 via 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 pressure of the variable relief valve 22 determined by the amount of current supplied to the variable relief valve 22. Then, the cylinder device C2 extends the direction in which the pressure receiving area difference between the piston side chamber 6 side and the rod side chamber 5 side in the piston 3 is multiplied by the pressure in the rod side chamber 5 and the pressure in the piston side chamber 6 controlled by the variable relief valve 22 Demonstrate the thrust of

  On the other hand, in order to cause the cylinder device C2 to exert a desired thrust in the contraction direction, the motor 20 is rotated to supply the hydraulic oil from the pump 15 into the rod side chamber 5, and the first on-off valve 12 is set to the blocking position. The second on-off valve 14 is in the communication position. Then, the piston side chamber 6 and the tank 8 are in communication with each other and hydraulic fluid is supplied from the pump 15 to the rod side chamber 5, so that the piston 3 is pushed to the right in FIG. Do. Then, in the same manner as described above, by adjusting the amount of current supplied to the variable relief valve 22, the cylinder device C2 controls the pressure receiving area on the rod side chamber 5 side of the piston 3 and the pressure in the rod side chamber 5 controlled by the variable relief valve 22. It exerts the thrust in the contraction direction multiplied. Thus, the cylinder device C2 in the second embodiment can function as an actuator.

  When the rod 4 moves to the left in FIG. 4 by an external force in a state where the first on-off valve 12 is opened and the second on-off valve 14 is closed, the cylinder device C2 is a rod regardless of whether the pump 15 is driven or not. It does not exert force in the direction that impedes the movement of 4, that is, in the contraction direction. In this case, while the pump 15 is in operation, the discharge flow rate of the pump 15 can not catch up with the volume change in the cylinder 2 which decreases when the rod 4 exits from the cylinder 2. Hydraulic oil is supplied. Further, in this case, when the pump 15 is not driven, the working oil is supplied from the tank 8 into the cylinder 2 through the suction passage 19 by the volume corresponding to the rod 4 exiting from the cylinder 2. In any case, since the pressure in the cylinder 2 is the tank pressure in this case, the cylinder device C2 does not exert a damping force in the direction that hinders the movement of the rod 4, that is, the contraction direction.

  When the rod 4 is moved to the right in FIG. 4 by an external force in a state where the first on-off valve 12 is opened and the second on-off valve 14 is closed, regardless of whether the pump 15 is driven, The hydraulic oil pushed out of the cylinder 2 by the entry of the rod 4 is returned to the tank 8 through the discharge passage 21. In this case, since the pressure in the cylinder 2 is controlled by the variable relief valve 22 to a desired pressure, the cylinder device C2 can exert a force in the direction that impedes the movement of the rod 4, that is, the extension direction.

  On the other hand, in a state where the first on-off valve 12 is closed and the second on-off valve 14 is opened, when the rod 4 is moved to the right in FIG. It does not exert the force in the direction that impedes the movement of 4, that is, the extension direction. In this case, while the pump 15 is in operation, the discharge flow rate of the pump 15 can not catch up with the volume change in the rod side chamber 5 that increases when the rod 4 enters the cylinder 2. The hydraulic oil is supplied into 5. Further, although the volume of working oil in the cylinder 2 intruding of the rod 4 becomes excessive in the cylinder 2 in order for the rod 4 to enter the cylinder 2, the piston side chamber 6 on the compression side passes through the second passage 13, The excess hydraulic oil is discharged to the tank 8. Further, in this case, even when the pump 15 is not driven, the hydraulic oil corresponding to the volume in the rod side chamber 5 which increases when the rod 4 enters the cylinder 2 is transmitted through the flow straightening passage 18 as in driving. It is supplied from the piston side chamber 6. Then, the hydraulic oil of a volume corresponding to the cylinder 2 invading the rod 4 is discharged from the piston side chamber 6 to be compressed to the tank 8 through the second passage 13. In any case, since the pressure in the cylinder 2 is the tank pressure in this case, the cylinder device C2 does not exert a damping force in the direction that hinders the movement of the rod 4, that is, in the extension direction.

  When the rod 4 is moved to the left in FIG. 4 by an external force in a state in which the first on-off valve 12 is closed and the second on-off valve 14 is open, the rod side chamber 5 is The extruded hydraulic oil is returned to the tank 8 through the discharge passage 21. In this case, since the pressure in the rod side chamber 5 is controlled to a desired pressure by the variable relief valve 22, the cylinder device C2 can exert a force in the direction to prevent the movement of the rod 4, that is, the contraction direction.

  That is, when the first on-off valve 12 is opened and the second on-off valve 14 is closed, or the first on-off valve 12 is closed and the second on-off valve 14 is opened, the cylinder device C2 is In this state, a damping force is exerted only on either the extension or the contraction with respect to the vibration input from the external force.

  Therefore, for example, when the direction in which the force is exerted is a direction in which the vehicle body B is excited by the vibration of the bogie T of the rail vehicle, the cylinder device C2 of this example does not exert force in such a direction. The device C2 can function as a one-effect damper. Therefore, since this cylinder device C2 can easily realize semi-active control based on Kalnop's skyhook theory, it can also function as a semi-active damper.

  And even in this cylinder device C2, as can be understood from the description of the cylinder device C1 of the first embodiment, it can also function as a damper only by opening and closing the first on-off valve 12 and the second on-off valve 14. That is, even when the pump 20 is driven by the motor 20, when the cylinder device C2 is forcibly extended or contracted by an external force, it can also function as a skyhook semi-active damper as a passive damper, and the variable relief valve The damping force can also be adjusted by adjusting the 22 valve opening pressure. Thus, the cylinder device C2 not only functions as an actuator, but can also function as a damper only by opening and closing the first on-off valve 12 and the second on-off valve 14 regardless of the driving condition of the motor 20. The direction in which the cylinder device C2 is to exert thrust or damping force is controlled only by opening and closing the first on-off valve 12 and the second on-off valve 14, and the direction to exert thrust and damping force is the same. The opening and closing states of the first on-off valve 12 and the second on-off valve 14 coincide with each other. Therefore, in the cylinder device C2, switching of the state of the actuator and the skyhook semi-active damper involves switching between stopping and driving of the pump 15 and switching operation of the complicated and steep first on-off valve 12 and second on-off valve 14 It can be done without. Therefore, the cylinder device C2 is a system with high responsiveness and reliability.

  Since the cylinder device C2 configured in this manner includes the damping portion 23, when the cylinder device C2 is expanded or contracted by an external force, the damping valve V is increased as the cylinder device C1 is expanded or contracted, as in the cylinder device C1. Demonstrate high damping force by Therefore, even with the cylinder device C2 of the present invention, even if the vehicle body B exhibits significant vibration, high damping force can be exerted to reduce the vibration of the vehicle body B, and an earthquake occurs while the railway vehicle is traveling Also, the vibration of the vehicle body B can be rapidly reduced, and the derailing can be effectively suppressed.

  Further, according to the vibration control device S2 for railway vehicles of the present invention, even if the vehicle body B exhibits significant vibration due to an earthquake, high damping force can be exerted to reduce the vibration of the vehicle body B, and the railway vehicle is traveling Even if an earthquake occurs, the vibration of the vehicle body B is promptly reduced, and the wheel removal can be effectively suppressed. And, because the damping device S2 for railway vehicles of this example is provided with a plurality of cylinder devices C2 installed for one bogie T, the necessary damping force for preventing each cylinder device C2 from derailing Share and demonstrate. Therefore, in the damping device S2 for railway vehicles of the present embodiment, the upper limit of the damping force to be exerted by each cylinder device C2 can be lowered compared to the case where the necessary damping force is exhibited by only one cylinder device C2. The diameter of the rod 4 of each cylinder device C2 becomes smaller and the outer diameters of the cylinder 2 and the outer cylinder 7 also become smaller. In addition, when the necessary damping force is exhibited by one cylinder device, it is inevitable to increase the size of the bracket for mounting the cylinder device on the side of the railway vehicle due to the problem of strength, but in the damping device for railway vehicle S2 of this example, Since each cylinder device C2 shares the necessary damping force, the enlargement of the bracket can be avoided. Therefore, while the damping device S2 for rail vehicles can prevent the removal of the wheels, it is possible to prevent the diameter increase of the outer diameter of each cylinder device C2 and the enlargement of the bracket on the rail vehicle side. The mountability to a rail car becomes good.

  Furthermore, in damping apparatus S2 for rail vehicles of this example, the damping force exerted when expanding and contracting at the reference speed is set to a value obtained by dividing the necessary damping force by the number of installations, so that each cylinder device C2 The respective parts such as the cylinder 2, the piston 3 and the rod 4 constituting the cylinder device C2 can be constituted by common parts, which can further contribute to the downsizing, and the bracket on the rail vehicle side is also a common part. Therefore, machining, assembly, and maintenance of each cylinder device C2 in the railway vehicle damping device S2 are also extremely easy.

<Variation of vibration damping device for railway vehicles>
In addition, although the damping device for railway vehicles may be configured by a plurality of cylinder devices C1 (C2) having exactly the same configuration, from the viewpoint of preventing wheel removal when an earthquake occurs, cylinder device C1 and cylinder devices It may be configured with C2, that is, configured with a plurality of cylinder devices having different configurations. Therefore, the damping device for rail vehicles has only the passive damper function which eliminated the first passage 11, the first on-off valve 12, the second passage 13 and the second on-off valve 14 from the cylinder device C1 and the configuration of the cylinder device C1. You may be comprised with the cylinder apparatus which has. Therefore, the damping device for railway vehicles is a cylinder device having only a passive damper function in which the first passage 11, the first on-off valve 12, the second passage 13 and the second on-off valve 14 are eliminated from the configuration of the cylinder device C1, cylinder A plurality of arbitrary cylinder devices may be appropriately selected and combined from the device C1 and the cylinder device C2. Even in this case, the damping device for a railway vehicle can exert high damping force even if the vehicle body B exhibits significant vibration due to an earthquake and can reduce the vibration of the vehicle body B, and an earthquake occurs while the railway vehicle is traveling. Even if it occurs, the vibration of the vehicle body B is rapidly reduced, and the derailing can be effectively suppressed. Moreover, since the damping device for rail vehicles is provided with a plurality of cylinder devices installed for one bogie T, each cylinder device shares and exerts the necessary damping force for preventing derailment. , Will be good for mounting on railway cars.

  While the preferred embodiments of the present invention have been described above in detail, modifications, variations and changes are possible without departing from the scope of the claims.

Reference Signs List 2 cylinder 3 piston 4 rod 5 rod side chamber 6 piston side chamber 8 tank 11 first passage 12 12 First on-off valve, 13 ... second passage, 14 ... second on-off valve, 15 ... pump, 16 ... supply passage, 18 ... straightening passage, 19 ... suction passage, 21 ... discharge passage, 22 ... relief valve, 23 ... damping unit, 24 ... change-over valve, B ... body, BP ... detour, C1, C2, ... cylinder device, S1 , S2: vibration damping device for railway vehicles, T: bogie, V: damping valve

Claims (7)

A cylinder filled with liquid,
A rod inserted into the cylinder;
A piston slidably inserted into the cylinder and coupled to the rod to divide the inside of the cylinder into a rod side chamber and a piston side chamber;
A tank for storing the liquid;
A discharge passage communicating the rod side chamber and the tank;
A relief valve provided in the discharge passage;
A cylinder unit comprising: a damping portion that causes a pressure loss larger than that of the relief valve when the relative velocity of the piston with respect to the cylinder becomes equal to or higher than a predetermined velocity. A flow straightening passage which allows only the liquid flow of the liquid from the piston side chamber to the rod side chamber;
The cylinder device according to claim 1, further comprising: a suction passage that allows only the flow of the liquid from the tank to the piston side chamber. A first on-off valve provided in a first passage communicating the rod side chamber and the piston side chamber;
The cylinder device according to claim 1 or 2, further comprising: a second on-off valve provided in a second passage communicating the piston side chamber and the tank. A supply passage connecting the tank and the rod side chamber;
The cylinder device according to claim 3, further comprising: a pump provided in the supply passage and capable of supplying the liquid from the tank to the rod side chamber. The attenuation unit is
A damping valve provided downstream of the relief valve;
A bypass path branched from the upstream of the damping valve of the discharge passage and bypassing the damping valve to be communicated with the tank;
The cylinder device according to any one of claims 1 to 4, further comprising a switching valve that selects one of the damping valve and the bypass path. A cylinder filled with liquid, a rod inserted into the cylinder, and a piston slidably inserted into the cylinder and connected to the rod to divide the inside of the cylinder into a rod side chamber and a piston side chamber A tank for storing the liquid, a straightening passage for permitting only the flow of the liquid from the piston side chamber to the rod side chamber, and a suction passage for permitting only the flow of the liquid from the tank to the piston side chamber A damping passage causing a pressure loss larger than that of the relief valve when the relative velocity of the piston with respect to the cylinder is higher than a predetermined velocity, a discharge passage communicating the rod side chamber and the tank, a relief valve provided in the discharge passage, A cylinder device having a part;
A cylinder filled with liquid, a rod inserted into the cylinder, and a piston slidably inserted into the cylinder and connected to the rod to divide the inside of the cylinder into a rod side chamber and a piston side chamber A tank for storing the liquid, a straightening passage for permitting only the flow of the liquid from the piston side chamber to the rod side chamber, and a suction passage for permitting only the flow of the liquid from the tank to the piston side chamber A first on-off valve provided in a first passage communicating the rod side chamber with the piston side chamber, a second on-off valve provided in a second passage communicating the piston side chamber with the tank, and the rod side chamber A discharge passage communicating with the tank, a relief valve provided in the discharge passage, and a predetermined velocity of the piston relative to the cylinder Cylinder device having an upper and a damping unit that causes a large pressure loss than the relief valve,
And a cylinder filled with liquid, a rod inserted into the cylinder, and slidably inserted into the cylinder and connected to the rod to divide the inside of the cylinder into a rod side chamber and a piston side chamber Piston, a tank for storing the liquid, a first on-off valve provided in a first passage communicating the rod side chamber and the piston side chamber, and a second passage communicating the piston side chamber and the tank A second on-off valve, a supply passage communicating the tank and the rod side chamber, a pump provided in the supply passage and capable of supplying the liquid from the tank to the rod side chamber, the rod side chamber and the tank When the relative velocity of the piston with respect to the cylinder becomes equal to or greater than a predetermined velocity, the discharge passage communicating the two, the relief valve provided in the discharge passage, Of the cylinder device having a damping portion that causes a large pressure loss than off valve,
Equipped with multiple cylinder units arbitrarily selected,
Each of the cylinder devices is interposed between a car body and a truck in a railway vehicle,
Each of the cylinder devices exerts a damping force by the damping unit when the relative velocity of the piston with respect to the cylinder is equal to or greater than a predetermined velocity.
A damping device for a railway vehicle, wherein a sum of damping forces generated by the damping units when the respective cylinder devices expand and contract at a reference speed is equal to a required damping force required per truck at the time of an earthquake. The damping force generated by the damping unit when each cylinder device expands and contracts at a reference speed is equal to a value obtained by dividing the necessary damping force by the number of cylinder devices installed in one carriage. The damping device for railway vehicles according to claim 6, characterized in that

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