JP6283969B2 - Cylinder device - Google Patents

Description

  The present invention relates to a cylinder device.

  Conventionally, in this type of cylinder device, for example, a railway vehicle is used that is interposed between a vehicle body and a carriage to suppress left-right vibration with respect to the traveling direction of the vehicle body. It has been.

  Such a cylinder device includes, for example, a cylinder, a piston that is slidably inserted into the cylinder, a rod that is inserted into the cylinder and connected to the piston, and a rod-side chamber that is partitioned in the cylinder by the piston. And a piston side chamber, a tank, and an electromagnetic relief valve provided in the middle of an attenuation passage that communicates the rod side chamber and the tank (see, for example, Patent Document 1).

  The cylinder device can control the pressure in the cylinder with an electromagnetic relief valve to adjust the generated force level, and exerts the optimal control force to suppress the vibration of the vehicle body of the railway vehicle, and the vehicle body vibration is effective. Can be suppressed.

  By the way, if a strong earthquake occurs while the railway vehicle is running, the car body may shake greatly and derail.Therefore, in such a case, we want to prevent the derailment by making the cylinder device exhibit a high damping force. . In addition, when an earthquake occurs, it may not be possible to receive power supply. Therefore, a shock absorber is required to exhibit a high damping force under a situation corresponding to a control failure.

  Therefore, in the conventional cylinder device, the normal passage and the emergency passage parallel to the normal passage form a damping passage, and the normal passage is arranged in series with the variable relief valve and the variable relief valve. In addition to providing a normally closed type on-off valve that closes when energized, a passive valve and a normally open type on-off valve that is arranged in series with the passive valve and opens when not energized are provided in the middle of the emergency passage.

  In this way, the emergency passage is enabled in the event of a control failure, and a high damping force is reliably exerted by the passive valve, so that the vibration of the vehicle body can be suppressed, so even if an earthquake occurs while the railway vehicle is running The vehicle body vibration is rapidly reduced, and derailment can be effectively suppressed.

JP 2014-189216 A

  In this way, in the conventional cylinder device, even if it is not possible to receive power supply in the event of an earthquake, it can exhibit a high damping force and suppress the vibration of the vehicle body, but for that purpose, in addition to providing an emergency passage, It is necessary to provide two normally open type on-off valves and passive valves.

  Therefore, the number of parts of the cylinder device is increased, and two electromagnetic on-off valves are required, which increases the cost and the cost of the cylinder device, and increases the size of the entire device.

  Therefore, the present invention was devised to improve the above-mentioned problems, and an object of the present invention is to provide an inexpensive and compact cylinder device that can effectively prevent derailment during an earthquake.

  In order to achieve the above-described object, the cylinder device of the present invention includes a relief valve in a rod-side chamber partitioned by a piston in a cylinder, a relief passage that communicates with a tank, and a normally open type that reduces a flow area when the flow rate increases. And a damping valve. In this way, the cylinder device is equipped with a damping valve that reduces the flow path area by increasing the flow rate, so that the piston speed exhibits a higher damping force in the high speed range than when only the relief valve exhibits the damping force. In addition, even if an earthquake occurs while the railway vehicle is running, the vehicle body vibration can be quickly reduced and derailment can be effectively suppressed. Moreover, in the cylinder device of the present invention, it is not necessary to provide an emergency passage, two normally closed and normally open type on-off valves, and a passive valve unlike the conventional cylinder device.

In the cylinder device according to claim 2, the damping valve energizes the housing having a valve hole communicating with both the rod side chamber and the tank, the valve body accommodated in the valve hole so as to be movable in the axial direction, and the valve body. A spring, and a first damping valve passage and a second damping valve passage provided in the valve body,
When the valve body retreats against the housing against the biasing force of the spring, the flow passage area of the first damping valve passage is reduced. If the cylinder device is configured in this way, the second damping valve passage is not closed by the movement of the valve body, so that the tuning force characteristic of the cylinder device can be easily tuned and the minimum flow path can be obtained even if the compression length of the spring is changed. You can enjoy the advantage that does not affect the area.

  Furthermore, in the cylinder device according to the third aspect, the damping valve is configured to have a stopper for restricting the backward movement of the valve body before the spring is fully compressed. In the cylinder device configured as described above, even if the valve body is retracted to the maximum, the spring wire does not come into close contact with each other, so that an excessive load in the axial direction does not act on the spring, and the spring can be protected.

In the cylinder device according to the fourth aspect, the damping valve is attached to and detached from the valve seat provided in the housing, and the spring contacts the counter valve seat side end, and opens from the side portion of the flange portion in the radial direction. A radial hole extending and communicating with the first damping valve passage and the second damping valve passage is provided. In the cylinder device configured as described above, the radial hole is provided at a position where it does not interfere with the spring, so that the liquid that has passed through the radial hole does not need to pass between the spring wires. Therefore, in this cylinder device, even if the distance between the wire rods of the spring is narrowed due to the retraction of the valve body, the operation of the valve body is damped and the movement becomes slow, or the damping force characteristic is difficult to tune as intended. There will be no disadvantage.

  The cylinder device according to claim 5 further includes a first on-off valve provided in the middle of the first passage communicating the rod side chamber and the piston side chamber, and a second passage communicating the piston side chamber and the tank. The second on-off valve, a rectifying passage that allows only the flow from the piston side chamber to the rod side chamber, and a suction passage that allows only the flow from the tank to the piston side chamber. In the cylinder device configured as described above, semi-active control based on Karnop's Skyhook theory can be easily realized, and the cylinder device can function as a Skyhook semi-active damper.

  In addition to the configuration of the fifth aspect, the cylinder device of the sixth aspect includes a pump that supplies liquid to the rod side chamber, and the relief valve is configured as a variable relief valve. The cylinder device configured as described above can function not only as an actuator but also as a skyhook semi-active damper. Further, in the cylinder device according to the sixth aspect of the present invention, the switching of the actuator and the skyhook semi-active damper is not accompanied by the stoppage and switching of the pump or the troublesome and steep switching operation of the first on-off valve and the second on-off valve. It can be done. Therefore, the cylinder device according to claim 6 is a system with high responsiveness and reliability.

  As described above, according to the cylinder device of the present invention, it is possible to effectively prevent derailment during an earthquake, and to reduce the cost and size.

It is a circuit diagram of a buffer in a first embodiment. It is sectional drawing of a damping valve. It is a figure which shows the damping characteristic of the buffer in 1st embodiment. It is sectional drawing of one modification of a damping valve. It is sectional drawing of the other modification of a damping valve. It is a circuit diagram of a shock absorber in a second embodiment.

  The present invention will be described below based on the embodiments shown in the drawings. In the cylinder device C1 of the first embodiment and the cylinder device C2 of the second embodiment, the members and parts to which common reference numerals are attached have the same configuration. Therefore, in order to avoid duplication of description, it will be described in detail in the description of the cylinder device C1 of the first embodiment, and detailed description will be omitted in the description of the cylinder device C2 of the second embodiment.

<First embodiment>
As shown in FIG. 1, the cylinder device C1 in the first embodiment basically includes a cylinder 2, a piston 3 that is slidably inserted into the cylinder 2, and a cylinder 2 that is inserted into the cylinder 2. A rod 4 connected to the piston 3, a rod side chamber 5 and a piston side chamber 6 partitioned by the piston 3 in the cylinder 2, a tank 7, a damping passage 8 communicating the rod side chamber 5 and the tank 7, and a damping passage 8 Is provided with a relief valve RV and a damping valve V provided in the middle, and is configured as a so-called single rod type cylinder device.

  The rod side chamber 5 and the piston side chamber 6 are filled with a liquid such as hydraulic oil, and the tank 7 is filled with a gas in addition to the liquid. In addition, it is not necessary to compress and fill the inside of the tank 7 with a gas in particular.

  Hereinafter, each part of the cylinder device C1 will be described in detail. The cylinder 2 has a cylindrical shape, and the right end in FIG. 1 is closed by a lid 13, and an annular rod guide 14 is attached to the left end in FIG. A rod 4 that is movably inserted into the cylinder 2 is slidably inserted into the rod guide 14. One end of the rod 4 protrudes outside the cylinder 2, and the other end in the cylinder 2 is connected to a piston 3 that is slidably inserted into the cylinder 2.

  Although not shown, the cylinder device C1 is interposed between the carriage and the vehicle body by connecting the rod 4 to one of the carriage and the vehicle body and the cylinder 2 to the other of the carriage and the vehicle body. Since the cylinder device C1 is set to a single rod type, it is easier to secure a stroke length than the double rod type cylinder device, the overall length of the cylinder device C1 is shortened, and the mounting property to the railway vehicle is improved. To do.

  Note that the outer periphery of the rod guide 14 and the cylinder 2 are sealed by a seal member (not shown), whereby the inside of the cylinder 2 is maintained in a sealed state. The rod side chamber 5 and the piston side chamber 6 partitioned by the piston 3 in the cylinder 2 are filled with hydraulic oil as a liquid as described above.

  Further, in the case of this cylinder device C1, the cross-sectional area of the rod 4 is halved 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 of the pressure receiving area on the piston side chamber 6 side. It is supposed to be. Therefore, the flow rate discharged from the cylinder 2 to the tank 7 through the damping passage 8 becomes equal when the cylinder device C1 is extended and contracted.

  Returning, the lid 4 that closes the left end of the rod 4 in FIG. 1 and the right end of the cylinder 2 is provided with a mounting portion (not shown), and the cylinder device C1 is interposed between the vehicle body and the carriage in the railway vehicle. it can.

  In the cylinder device C1 of this example, the rod side chamber 5 and the piston side chamber 6 are communicated with each other by a first passage 9, and a first opening / closing valve 10 is provided in the middle of the first passage 9. ing. The first passage 9 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 10 is an electromagnetic on-off valve, and has a communication position for communicating the rod side chamber 5 and the piston side chamber 6 and a blocking position for disconnecting the communication between the rod side chamber 5 and the piston side chamber 6. Sometimes the first passage 9 is opened to allow the rod side chamber 5 and the piston side chamber 6 to communicate with each other.

  Further, in the cylinder device C1 of this example, the piston side chamber 6 and the tank 7 are communicated with each other by the second passage 11, and a second opening / closing valve 12 is provided in the middle of the second passage 11. Yes. The second on-off valve 12 is an electromagnetic on-off valve, and has a communication position for communicating the piston side chamber 6 and the tank 7 and a shut-off position for disconnecting communication between the piston side chamber 6 and the tank 7. The second passage 11 is opened to allow the piston side chamber 6 and the tank 7 to communicate with each other.

  As shown in FIG. 1, the cylinder device C <b> 1 of this example includes a rectifying passage 30 that allows only a flow from the piston side chamber 6 toward the rod side chamber 5. The rectifying passage 30 may be provided in addition to the piston 3. Further, the cylinder device C1 of the present example includes a suction passage 31 that allows only a flow from the tank 7 toward the piston side chamber 6.

  Accordingly, in the cylinder device C1 of this example, when the first on-off valve 10 and the second on-off valve 12 take the shut-off position, the cylinder device C1 operates from the rod side chamber 5 that is compressed when it is extended by receiving external force. Oil is pushed through the damping passage 8 into the tank 7. Then, hydraulic oil is supplied from the tank 7 to the expanding piston side chamber 6 through the suction passage 31. Therefore, at the time of this extension operation, the cylinder device C1 provides resistance to the flow of hydraulic oil that passes through the damping passage 8 by the relief valve RV and the damping valve V, and increases the pressure in the rod side chamber 5 to counter the extension. Demonstrates damping force. In this case, the flow rate of the hydraulic oil passing through the attenuation passage 8 is an amount obtained by multiplying the cross-sectional area of the piston 3 by the value obtained by subtracting the cross-sectional area of the rod 4 from the cross-sectional area of the piston 3.

  On the contrary, when the first on-off valve 10 and the second on-off valve 12 take the shut-off position and the cylinder device C1 contracts due to external force, the piston side chamber 6 is compressed through the rectifying passage 30 to the rod side chamber. The hydraulic oil moves to 5. Further, when the cylinder device C 1 is contracted, the rod 4 enters the cylinder 2, so that the volume of hydraulic oil into which the rod 4 enters the cylinder 2 becomes excessive in the cylinder 2 and enters the tank 7 through the damping passage 8. Discharged. During this contraction operation, the cylinder device C1 provides resistance to the flow of hydraulic oil that passes through the damping passage 8 by the relief valve RV and the damping valve V, and increases the pressure in the cylinder 2 to provide a damping force that counteracts the contraction. Demonstrate. In this case, the flow rate of the hydraulic oil passing through the attenuation passage 8 is an amount obtained by multiplying the cross-sectional area of the rod 4 by the movement amount 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 movement amount of the piston 3 is the same even if the cylinder device C1 is extended or contracted, the damping is performed. The flow rates of the hydraulic oil passing through the passage 8 are equal. Therefore, if the moving speed of the piston 3 is the same on both sides of expansion and contraction, the cylinder device C1 can exhibit an equal damping force.

  Since both the first on-off valve 10 and the second on-off valve 12 take the shut-off position when the power is not supplied, the cylinder device C1 of this example always has a damping force against expansion and contraction when power fails. It functions as a passive damper.

  Further, in the cylinder device C1 of this example, when the first on-off valve 10 is in the communication position and the second on-off valve 12 is in the shut-off position, the rod side chamber 5 and the piston side chamber 6 communicate with each other via the first passage 9. However, the communication between the piston side chamber 6 and the tank 7 is cut off. When the cylinder device C1 contracts in response to an external force in this state, the volume of hydraulic oil into which the rod 4 enters the cylinder 2 is discharged from the cylinder 2 to the damping passage 8 and exhibits a damping force that counteracts the contraction as described above. To do. On the other hand, when the cylinder device C1 extends in this state, the hydraulic oil moves from the contracting rod side chamber 5 to the expanding piston side chamber 6 through the first passage 9, and the rod 4 is operated for the volume of retreating from the cylinder 2. Oil is supplied from the tank 7 into the cylinder 2 through the suction passage 31. Therefore, in this case, since the hydraulic oil does not flow into the damping passage 8, the cylinder device C1 does not exhibit a damping force.

  Further, in the cylinder device C1 of this example, when the first on-off valve 10 is set to the shut-off position and the second on-off valve 12 is set to the communication position, the communication between the rod side chamber 5 and the piston side chamber 6 is interrupted. 6 and the tank 7 are communicated with each other through the second passage 11. In this state, when the cylinder device C1 is extended by receiving an external force, the hydraulic oil is discharged from the rod side chamber 5 to the damping passage 8 as the rod side chamber 5 is contracted, and similarly exhibits a damping force that counteracts the extension. On the other hand, when the cylinder device C1 contracts in this state, the hydraulic oil moves from the contracting piston side chamber 6 to the expanding piston side chamber 6 through the rectifying passage 30, and the rod 4 enters the cylinder 2 for operation. Oil is discharged from the piston side chamber 6 into the tank 7 through the second passage 11. Therefore, in this case, since the hydraulic oil does not flow into the damping passage 8, the cylinder device C1 does not exhibit a damping force.

  Thus, this cylinder device C1 can function as a one-handed damper that exerts a damping force by selecting either expansion or contraction.

  In the case of this cylinder device C 1, an air vent orifice 26 is provided so that air mixed in the cylinder 2 can be discharged from the rod side chamber 5 to the tank 7.

  Subsequently, the damping passage 8 communicates the rod side chamber 5 and the tank 7. The damping passage 8 is provided with a relief valve RV which is a variable relief valve capable of adjusting the valve opening pressure. The damping valve 8 is provided downstream of the relief valve RV, that is, on the tank 7 side from the relief valve RV of the damping passage 8. V is provided.

  The relief valve RV is a variable relief valve as described above. Specifically, the relief valve RV is a variable electromagnetic relief valve that can adjust the valve opening pressure by the amount of current supplied to the solenoid. In this example, the relief valve RV is such that the valve opening pressure decreases when the energization amount to the solenoid is increased, and the valve opening pressure increases when the energization amount is decreased. To do.

  The damping valve V is a normally open type damping valve that reduces the flow path area when the flow rate of the passing hydraulic oil increases. Specifically, as shown in FIG. 2, the damping valve V includes a housing 20 provided in the middle of the damping passage 8 and having a valve hole 20a communicating with both the rod side chamber 5 and the tank 7, and the valve hole 20a. A valve body 21 accommodated so as to be movable in the axial direction, a spring receiver 22 accommodated and fixed in the valve hole 20a, and interposed between the valve body 21 and the spring receiver 22 to urge the valve body 21. And a spring 23 to be configured.

  The housing 20 has a hollow portion that forms a valve hole 20a, and has an inner diameter portion 20b on the inner periphery from the right side in FIG. 2, a small diameter portion 20c that is smaller in diameter than the medium diameter portion 20b, a small diameter portion 20c, and a medium diameter portion. And a large diameter portion 20d having a diameter larger than 20b. The housing 20 includes an annular valve seat 20e formed by a step portion between the small diameter portion 20c and the large diameter portion 20d, a passage 20f that opens from the outside and communicates with the medium diameter portion 20b, and a large diameter portion. A passage 20g that opens outward from 20d. Further, the middle diameter portion 20 b side of the valve hole 20 a is communicated with the rod side chamber 5 through the passage 20 f and the attenuation passage 8, and the large diameter portion 20 d side of the valve hole 20 a is communicated with the tank 7 through the passage 20 g and the attenuation passage 8.

  The valve body 21 has a larger diameter than the outer diameter of the sliding shaft portion 21a that is slidably inserted into the small diameter portion 20c and the sliding shaft portion 21a that is connected to the sliding shaft portion 21a and that is attached to and detached from the valve seat 20e. A flange portion 21b having a smaller diameter than the inner diameter of the large diameter portion 20d and a rear shaft portion 21c connected to the rear end of the flange portion 21b are provided.

Further, the valve body 21 opens from the left side in FIG. 2 which is the rear end of the rear shaft portion 21c and extends in the axial direction, and opens from the side portion of the flange portion 21b and extends in the radial direction. A radial hole 21e that opens to the opposite side of the flange portion 21b through the axial hole 21d, and a second damping that opens along the axial direction from the tip of the sliding shaft portion 21a to the axial hole 21d. an axial orifice O1 as a valve passage, extending radially and open from the side of the sliding shaft portion 21a, and a radial orifice O2 as a plurality of first damping valve passages communicating with the axial bore 21d Yes.

  The valve body 21 is accommodated in the valve hole 20a of the housing 20 with the outer periphery of the sliding shaft portion 21a being slidably inserted into the inner periphery of the small diameter portion 20c. Movement to is allowed.

  The spring receiver 22 is screwed from the rear in the valve hole 20a and to the left of the valve body 21 in FIG. 2, and closes the left end of the valve hole 20a in FIG. A spring 23 is interposed between the spring 21 and the spring 21. The spring receiver 22 is a cylindrical spring receiver main body 22a that is screwed into the large-diameter portion 20d of the valve hole 20a provided in the housing 20, and the retracted amount of the valve body 21 extending from the spring receiver main body 22a to the valve body 21 side. And a stopper portion 22b as a stopper for restricting the movement. The spring 23 is a coil spring, and is disposed on the outer periphery of the stopper portion 22b and the rear shaft portion 21c, and is interposed between the spring receiving body 22a of the spring receiver 22 and the flange portion 21b of the valve body 21. The movement in the radial direction is restricted by the stopper portion 22b and the rear shaft portion 21c. Thereby, when the spring 23 is compressed, the torsion of the spring 23 is restricted. One end of the spring 23 is in contact with the end of the flange 21b of the valve body 21 opposite to the valve seat, and the flange 21b of the valve body 21 functions as a spring receiver.

  The valve body 21 is biased by a spring 23, and the flange portion 21b is seated on the valve seat 20e in a state where the flow rate flowing through the medium diameter portion 20b is small. In this state, the distal end side of the sliding shaft portion 21a protrudes to the right in FIG. 2 from the small diameter portion 20c and faces the medium diameter portion 20b in the radial direction, and the radial orifice O2 faces the medium diameter portion 20b and has a small diameter. The axial lengths of the sliding shaft portion 21a and the small diameter portion 20c are set so as not to be blocked by the portion 20c. That is, in a state where the flange portion 21b is seated on the valve seat 20e, the axial orifice O1 and the radial orifice O2 are not closed, so that these orifices O1 and O2 are made effective and the rod side chamber 5 and the tank 7 are Communication is allowed.

  On the other hand, the valve body 21 retreats to the left in FIG. 2 with respect to the housing 20, that is, the valve body 21 moves in a direction in which the flange portion 21 b is separated from the valve seat 20 e, and the radial orifice O 2 is the small diameter portion 20 c. When it comes to face the inner periphery, the radial orifice O2 starts to be closed. When the retraction amount of the valve body 21 increases, the area where the radial orifice O2 is blocked by the inner periphery of the small diameter portion 20c increases, the effective flow area of the radial orifice O2 decreases, and the radial orifice O2 When the entire opening completely faces the inner periphery of the small diameter portion 20c, the radial orifice O2 is closed. When the radial orifice O2 is closed, only the axial orifice O1 is effective, and the flow path area of the damping valve V is limited to the area of the axial orifice O1.

  The valve hole 20a has a medium diameter portion 20b that communicates with the rod side chamber 5 through a passage 20f, and communicates with the tank 7 through a passage 20g that opens to the large diameter portion 20d. The pressure downstream of the relief valve RV acts with the cross-sectional area of 21a as the pressure receiving area. Therefore, the valve body 21 overcomes the urging force of the spring 23 and moves backward in the housing 20 to the left in FIG. 2 when the passing flow rate increases and the pressure loss increases. The retraction amount of the valve body 21 is proportional to the magnitude of the pressure acting on the sliding shaft portion 21a. Therefore, as the pressure increases, the retraction amount increases and the radial orifice O2 is gradually closed. When the valve body 21 is retracted to some extent, the valve body 21 abuts against the stopper portion 22b of the spring receiver 22 and further retreat is restricted, so that the sliding shaft portion 21a does not come out of the small diameter portion 20c. In this way, the damping valve V is set to a normally open type, and the flow passage area is reduced when the flow rate of the working oil passing therethrough increases and the pressure loss increases. In this example, the radial orifice O2 constitutes a first damping valve passage that reduces the flow path area, and always opens to the middle diameter portion 20b regardless of the retracted state of the valve body 21, and the axial direction functions effectively. The orifice O1 forms a second damping valve passage.

  When the piston speed is in the low speed region, the damping force characteristic of the cylinder device C1 configured as described above shows the square characteristic of the orifice 26 as shown by the line a in FIG. 3, and the piston speed increases. When the relief valve RV is opened, the characteristic of the relief valve RV in which an override accompanying an increase in the flow rate is superimposed on the valve opening pressure of the relief valve RV appears, as indicated by the line b in FIG. Further, when the piston speed increases and reaches a high speed region, the flow area of the radial orifice O2 of the damping valve V decreases as the flow rate increases. As shown by the characteristic, the attenuation coefficient gradually increases. Furthermore, when the piston speed increases and the flow path area of the damping valve V reaches the flow path area of the axial orifice O1, which is the minimum flow path area, the damping force characteristic of the cylinder device C1 is in response to the subsequent increase in piston speed. Thus, as indicated by the line d in FIG. 3, the damping force increases. In addition, when the valve opening pressure of the relief valve RV is adjusted, the damping force of the cylinder device C1 can be adjusted in a range where the damping valve V does not reduce the flow path area.

  In the damping valve V of this example, when the valve body 21 comes into contact with the stopper portion 22b, the backward movement of the valve body 21 with respect to the housing 20 is restricted, and the spring 23 is compressed most in the stopper portion 22b. Previously, the valve body 21 is stopped. Therefore, even if the valve body 21 is retracted to the maximum, the wires of the spring 23 are not in close contact with each other, so that an excessive load in the axial direction does not act on the spring 23 and the spring 23 can be protected.

  When the first on-off valve 10 and the second on-off valve 12 are set to the shut-off position, the cylinder device C1 configured in this manner allows hydraulic oil to flow from within the cylinder 2 via the relief valve RV and the damping valve V when it is extended or contracted by an external force. It is discharged to the tank 7. If the valve opening pressure is adjusted by adjusting the amount of current supplied to the relief valve RV, the damping force generated by the cylinder device C1 can be adjusted.

  Further, when the first on-off valve 10 is in the communication position and the second on-off valve 12 is in the shut-off position, and when the first on-off valve 10 is in the shut-off position and the second on-off valve 12 is in the communication position, as described above. The cylinder device C1 is in a mode in which a damping force is exerted only for either expansion 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 vibrated by the vibration of the railcar of the railway vehicle, the damping force is not output in such a direction. The cylinder device C1 can be a one-effect damper. Therefore, in this cylinder device C1, semi-active control based on Karnop's Skyhook theory can be easily realized, so that the cylinder device C1 can function as a Skyhook semi-active damper.

  Subsequently, when a power failure occurs due to a large earthquake during the running of the railway vehicle, the first on-off valve 10 and the second on-off valve 12 take the shut-off position, and the cylinder as described above. The device C1 functions as a passive damper. In this state, when the cylinder device C1 expands and contracts, the hydraulic oil is always discharged from the cylinder 2, and the discharged hydraulic oil flows into the tank 7 through the relief valve RV and the damping valve V. Accordingly, even when this control failure occurs, the relief valve RV and the damping valve V provide resistance to the flow of hydraulic oil, and the cylinder device C1 exhibits a damping force. However, the bogie vibrates violently due to a large earthquake. As the relative speed increases, the piston speed as the expansion / contraction speed of the cylinder device C1 also increases. When the cylinder device C1 expands and contracts at a high speed, the flow rate of the hydraulic oil passing through the damping valve V increases, and thereby the damping valve V reduces the flow path area, so that the damping force exerted by the cylinder device C1 is compared with that in normal times. And get bigger.

  That is, since the damping valve V reduces the flow path area, the cylinder device C1 has a higher damping force as shown by the lines c and d in FIG. 3 than when the damping valve RV exhibits the damping force alone. Demonstrate. As described above, in the cylinder device C1 of the present invention, even if the vehicle body exhibits significant vibrations, the vehicle body vibration can be reduced by exhibiting a high damping force, and even if an earthquake occurs while the railway vehicle is running, the vehicle body Vibration can be quickly reduced and derailment can be effectively suppressed.

  In the cylinder device C1 of the present invention, the damping valve V is provided in the damping passage 8 without providing an emergency passage, two normally closed and normally open type on-off valves, and a passive valve as in the conventional cylinder device. It is possible to prevent derailment at the time of an earthquake. Therefore, according to the cylinder device C1 of the present invention, derailment during an earthquake can be effectively prevented, the cylinder device C1 can be inexpensive, and the cylinder device C1 can be downsized as compared with the conventional cylinder device.

  The piston speed at which the damping valve V starts to decrease the flow path area is set to 20 cm / s, for example, and consideration is given so that the damping valve V does not reduce the flow path at normal times. If it does in this way, the damping valve V will reduce a flow path in a normal use area, and the cylinder apparatus C1 will exhibit a high damping force, and it can prevent the deterioration of the riding comfort of a railway vehicle in normal times. The piston speed at which the damping valve V starts to decrease the flow path area may be set to other than the above numerical values.

  Further, in the cylinder device C1 of this example, the first on-off valve 10 provided in the middle of the first passage 9 communicating the rod side chamber 5 and the piston side chamber 6, and the piston side chamber 6 and the tank 7 are communicated. A second on-off valve 12 provided in the middle of the second passage 11, a rectifying passage 30 that allows only a flow from the piston side chamber 6 to the rod side chamber 5, and a suction passage that allows only a flow from the tank 7 to the piston side chamber 6. 31. Therefore, in the cylinder device C1 of this example, semi-active control based on Karnop's Skyhook theory can be easily realized, and the cylinder device C1 can function as a Skyhook semi-active damper. The rectifying passage 30 may be integrated with the shut-off position of the first on-off valve 10, and the suction passage 31 may be integrated with the shut-off position of the second on-off valve 12. Further, when the first passage 9, the first on-off valve 10, the second passage 11, and the second on-off valve 12 are eliminated from the configuration of the cylinder device C1, the cylinder device C1 functions as a passive damper. Therefore, when the cylinder device C1 does not need to function as a skyhook semi-active damper and functions only as a passive damper, the first passage 9, the first on-off valve 10, the second passage 11, and the second on-off valve 12 are provided. It may be abolished.

  In the cylinder device C1 of this example, the relief valve RV is a variable relief valve. However, when the damping force is not variable, the relief valve RV may be a relief valve having a constant valve opening pressure. Even if the cylinder device C1 is configured in this way, the damping valve V can reduce the flow path area and increase the damping force during an earthquake, and derailment can be prevented.

  Further, in the damping valve V of the present example, the valve body 21 opens to the side of the flange portion 21b and is connected to the radial orifice O2 (first damping valve passage) and the axial orifice O1 (second damping valve passage). A radial hole 21e communicating with the direction hole 21d is provided. When the damping valve V is configured in this way, the radial hole 21e is provided at a position where it does not interfere with the spring 23, so that the hydraulic oil that has passed through the radial hole 21e does not pass between the wires of the spring 23. You do n’t have to. If the radial hole 21e is eliminated and only the axial hole 21d is used, the hydraulic oil from the rod side chamber 5 toward the tank 7 flows into the spring 23 from the rear end side opening of the rear shaft portion 21c of the axial hole 21d. Then, it passes through the wire rods of the spring 23 and goes toward the passage 20g. In this way, when the spring 23 is compressed by the retraction of the valve body 21 and the distance between the wire rods of the spring 23 is narrowed, the spring 23 becomes a resistance when the hydraulic oil passes between the wire rods. In some cases, damping is effective for the operation of 21 and the movement becomes slow, or it is difficult to tune the damping force characteristic as intended. Therefore, when the radial orifice O2 (first damping valve passage) and the axial orifice O1 (second damping valve passage) are communicated with the passage 20g in a passage having an outlet other than the inner peripheral side of the spring 23, this is the case. Can solve any problem.

  Further, in this example, a plurality of radial orifices O2 are provided on the same circumference. However, as shown in FIG. Accordingly, the radial orifice O2 may be sequentially closed, and the flow passage area may be decreased stepwise as the valve body 21 is retracted.

Furthermore, as shown in FIG. 5, even if the valve body 21 abuts against the stopper portion 22b and the backward movement of the valve body 21 is restricted, the radial orifice O2 may not be completely closed. As described above, the axial orifice O1 may be eliminated if the minimum flow path area of the damping valve V is determined in a state where the backward movement of the valve body 21 is regulated. That is, when the stopper is provided, the axial orifice O1 can be eliminated, so that the valve element 21 can be processed easily. In this case, the radial orifice O2 functions as a first damping valve passage and a second damping valve passage. In this example, the diameter of the valve body 21 is controlled in a state where the valve body 21 is in contact with the stopper portion 22b and the backward movement of the valve body 21 is restricted. A portion of the directional orifice O2 that is not closed serves as a second damping valve passage. That is, even if the backward movement of the valve body 21 is restricted by the stopper portion 22b, the portion of the radial orifice O2 that always maintains the opening to the valve hole 20a becomes the second damping valve passage. Even when the stopper is provided, as shown in FIG. 2, if the axial orifice O1 is provided so that the radial orifice O2 is completely closed as the valve element 21 is retracted, the damping valve is provided. There is an advantage that the minimum flow path area of V can always be set to the flow path area of the axial orifice O1. That is, when only the radial orifice O2 is provided, the maximum closing degree of the radial orifice O2 is determined by setting the maximum retracted position of the valve body 21, and therefore the minimum flow path of the damping valve V is adjusted by tuning the installation position of the spring receiver 22. Since it is necessary to determine the area, tuning is required for each product. Further, if the installation position of the spring receiver 22 is changed, the compression length of the spring 23 changes, so that the characteristics of the damping valve V change, and tuning becomes difficult. Therefore, in the damping valve V provided with the radial orifice O2 (first damping valve passage) and the axial orifice O1 (second damping valve passage) that is not blocked by the movement of the valve body 21 with respect to the housing 20, the cylinder device C1 The damping force characteristic can be easily tuned, and there is an advantage that even if the compression length of the spring 23 is changed, the minimum flow path area is not affected.

  Although the stopper portion 22b is provided on the spring receiver 22, it may be attached to the housing 20 separately from the spring receiver 22, for example, a pin protruding into the C ring or the valve hole 20a on the inner periphery of the housing 20. Etc. may be provided as a stopper, and when the valve element 21 is retracted, the stopper may be brought into contact with the flange portion 21b to restrict the valve element 21 from retracting.

  Further, when the spring constant of the spring 23 for energizing the valve body 21 is reduced, when the force for retreating the valve body 21 by the pressure downstream of the relief valve RV exceeds the initial load applied to the spring 23, the valve body 21 Since the radial orifice O2 (first damping valve passage) can be closed by moving quickly, it is possible to quickly shift to a damping force characteristic capable of outputting a high damping force corresponding to an earthquake. On the contrary, if the spring constant is increased, the movement of the valve body 21 becomes gentle, so that a sudden change in the damping force characteristic can be mitigated and the riding comfort in the railway vehicle can be prevented from deteriorating.

<Second Embodiment>
As shown in FIG. 6, the cylinder device C <b> 2 in the second embodiment is provided with a pump P that supplies hydraulic oil to the rod side chamber 5 in the configuration of the cylinder device C <b> 1 of the first embodiment. . Specifically, a supply passage 16 that communicates between the tank 7 and the rod side chamber 5 is provided, and a pump P that draws hydraulic oil from the tank 7 into the supply passage 16 and discharges it to the rod side chamber 5, and a discharge side of the pump P A check valve 17 for preventing the flow of hydraulic oil from the rod side chamber 5 toward the tank 7 is provided.

  The pump P is driven by a motor 15 and is a pump that discharges liquid in only one direction. The discharge port communicates with the rod side chamber 5 through a supply passage 16, and the suction port is a tank 7. Leads to. Therefore, when the pump P is driven by the motor 15, the pump P sucks the hydraulic oil from the tank 7 and supplies the hydraulic oil to the rod side chamber 5.

  As described above, since the pump P only discharges hydraulic oil in one direction and does not switch the rotation direction, there is no problem that the discharge amount changes at the time of rotation switching, and an inexpensive gear pump or the like can be used. . Further, since the rotation direction of the pump P is always the same direction, even the motor 15 that is a drive source for driving the pump P does not require high responsiveness to rotation switching, and the motor 15 is also inexpensive. Can be used. The check valve 17 is provided to prevent the backflow of hydraulic oil to the pump P side when the cylinder device C2 is forcibly expanded and contracted by an external force.

  Subsequently, when the cylinder device C2 configured as described above exerts a desired thrust in the extending direction, the first on-off valve 10 is turned on while supplying the hydraulic oil from the pump P into the cylinder 2 by rotating the motor 15. The communication position is set, and the second on-off valve 12 is set to the shut-off position. Then, the rod side chamber 5 and the piston side chamber 6 are in communication with each other, and hydraulic oil is supplied to both of them from the pump P, the piston 3 is pushed to the left in FIG. 6, and the cylinder device C2 exhibits thrust in the extending direction. . When the pressure in the rod side chamber 5 and the piston side chamber 6 exceeds the valve opening pressure of the relief valve RV, the relief valve RV opens and the hydraulic oil escapes to the tank 7 through the damping passage 8. Therefore, the pressure in the rod side chamber 5 and the piston side chamber 6 is controlled by the valve opening pressure of the relief valve RV determined by the amount of current applied to the relief valve RV. The cylinder device C2 then expands in the direction of extension of the value obtained by multiplying the 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 relief valve RV. Demonstrate thrust.

  On the other hand, when the cylinder device C2 exerts a thrust in a desired contraction direction, the motor 15 is rotated to supply hydraulic oil from the pump P into the rod side chamber 5, and the first on-off valve 10 is set to the cutoff position. The second on-off valve 12 is set to the communication position. Then, the piston side chamber 6 and the tank 7 are brought into communication with each other, and the hydraulic oil is supplied to the rod side chamber 5 from the pump P. Therefore, the piston 3 is pushed rightward in FIG. 6 and the cylinder device C2 exhibits a contraction thrust. To do. As described above, by adjusting the amount of current applied to the relief valve RV, the cylinder device C2 multiplies 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 relief valve RV. Demonstrate thrust in the contraction direction.

  Thus, the cylinder device C2 in the second embodiment can function as an actuator. In addition, as can be understood from the description of the cylinder device C1 of the first embodiment, the cylinder device C2 can also function as a damper only by opening and closing the first on-off valve 10 and the second on-off valve 12. That is, even when the pump P is driven by the motor 15, when the cylinder device C2 is forcibly expanded and contracted by an external force, it can function as either a skyhook semi-active damper or a passive damper, and the relief valve RV The damping force can be adjusted by adjusting the valve opening pressure. Thus, the cylinder device C2 not only functions as an actuator, but can function as a damper only by opening and closing the first on-off valve 10 and the second on-off valve 12, regardless of the driving state of the motor 15. The direction in which the cylinder device C2 should exert thrust or damping force is controlled only by opening and closing the first on-off valve 10 and the second on-off valve 12, and the direction in which thrust and damping force should be exerted is the same. The open / close states of the first open / close valve 10 and the second open / close valve 12 are the same. Therefore, in the cylinder device C2, switching of the state of the actuator and the skyhook semi-active damper is accompanied by switching of the stop and driving of the pump P and the troublesome and steep switching operation of the first on-off valve 10 and the second on-off valve 12. Can be done without. Therefore, the cylinder device C2 is a system with high responsiveness and reliability.

  Further, the hydraulic oil supplied from the pump P in the cylinder device C2 and the flow of the hydraulic oil by the expansion / contraction operation pass through the rod side chamber 5 and the piston side chamber 6 in 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 cylinder device C2 is automatically discharged to the tank 7 by the expansion and contraction operation, so that it is possible to prevent deterioration in the response of thrust generation.

  Therefore, when manufacturing the cylinder device C2, it is not necessary to assemble in a troublesome oil or under a vacuum environment, and it is not necessary to perform a high degree of degassing of the hydraulic oil, thereby improving productivity and reducing the manufacturing cost. Further reduction can be achieved. Furthermore, even if gas is mixed into the rod side chamber 5 or the piston side chamber 6, the gas is automatically discharged to the tank 7 by the expansion / contraction operation of the cylinder device C2, and therefore maintenance for performance recovery must be frequently performed. The maintenance labor and cost burden can be reduced.

  Even in the cylinder device C2 configured as described above, since the damping valve V that reduces the flow path area by increasing the flow rate is provided, the piston speed is higher than when the damping force is exerted only by the relief valve RV. Exhibits high damping force at high speeds. Therefore, even in the cylinder device C2 of the present invention, even if the vehicle body exhibits significant vibrations, the vehicle body vibration can be reduced by exhibiting a high damping force, and even if an earthquake occurs while the railway vehicle is running, Is quickly reduced, and derailment can be effectively suppressed.

  Even in the cylinder device C2 of the present invention, the damping passage 8 is attenuated without providing an emergency passage, two normally closed and normally open type on-off valves, and a passive valve as in the conventional cylinder device. Derailment during an earthquake can be prevented simply by providing the valve V. Therefore, according to the cylinder device C2 of the present invention, derailment during an earthquake can be effectively prevented, the cylinder device C2 can be inexpensive, and the cylinder device C2 can be downsized as compared with the conventional cylinder device.

  The preferred embodiments of the present invention have been described above in detail, but modifications, changes and modifications can be made without departing from the scope of the claims.

2 ... Cylinder, 3 ... Piston, 4 ... Rod, 5 ... Rod side chamber, 6 ... Piston side chamber, 7 ... Tank, 8 ... Damping passage, 9 ... No. One passage, 10 ... first on-off valve, 11 ... second passage, 12 ... second on-off valve, 20 ... housing, 20a ... valve hole, 21 ... valve body, 22b ... Stopper part (stopper), 23 ... Spring, 30 ... Rectification passage, 31 ... Suction passage, C1, C2 ... Cylinder device, O1 ... Axial orifice (second damping valve) Passage), O2 ... radial orifice (first damping valve passage, second damping valve passage), P ... pump, RV ... relief valve, V ... damping valve

Claims (6)

A cylinder,
A piston slidably inserted into the cylinder;
A rod inserted into the cylinder and connected to the piston;
A rod side chamber and a piston side chamber partitioned by the piston in the cylinder;
A tank,
A damping passage communicating the rod side chamber and the tank;
A relief valve provided in the damping passage;
A cylinder device, comprising: a normally open type damping valve that is provided downstream of the relief valve in the damping passage and reduces the flow area when the flow rate increases. The damping valve is
A housing having a valve hole communicating with both the rod side chamber and the tank;
A valve body accommodated in the valve hole so as to be axially movable;
A spring for biasing the valve body;
A first damping valve passage provided in the valve body;
A second damping valve passage provided in the valve body and always opening to the valve hole;
2. The cylinder device according to claim 1, wherein when the valve body moves backward against the housing against the biasing force of the spring, the flow passage area of the first damping valve passage is reduced. The damping valve is
The disc,
A spring for biasing the valve body;
3. The cylinder device according to claim 1, wherein the valve body has a stopper that restricts the backward movement of the valve body before the spring is compressed most. The damping valve is
A flange portion that is detached from and seated on a valve seat provided in the housing, and the spring abuts against an end opposite to the valve seat;
Extending radially and open from the side of the flange portion, according to claim 2, characterized in that a radial hole which is communicated with the second damping valve passage and said first damping valve passage Cylinder device. A first on-off valve provided in the middle of a first passage communicating the rod side chamber and the piston side chamber;
A second on-off valve provided in the middle of a second passage communicating the piston side chamber and the tank;
A rectifying passage that allows only a flow from the piston side chamber to the rod side chamber;
The cylinder device according to any one of claims 1 to 4, further comprising a suction passage that allows only a flow from the tank toward the piston side chamber. A pump for supplying liquid to the rod side chamber;
The cylinder device according to claim 5, wherein the relief valve is a variable relief valve.