JP2023119628A - Cylinder device - Google Patents

Abstract

To provide a cylinder device capable of improving a damping coefficient when the cylinder device functions as a damper while exhibiting a function as an actuator without increasing the weight and size.SOLUTION: A cylinder device C includes a telescopic unit 1, a tank 7, and an actuator circuit A and a damper circuit D provided between a cylinder 2 and the tank 7 in the telescopic unit 1. The actuator circuit A has a thrust adjustment unit FT provided in a control passage 40 communicating a rod side chamber 5 with the tank 7. The damper circuit D includes a pressure side relief valve 27 on a pressure side damping passage 26 for connecting a piston side chamber 6 to the thrust adjustment unit FT.SELECTED DRAWING: Figure 1

Description

The present invention relates to a cylinder device.

Conventionally, a cylinder device exerts a thrust force, drives an object to which the thrust force is applied, assists the displacement of the object, and suppresses the vibration of the object. For example, when the vehicle body of a railway vehicle is targeted, the cylinder device is interposed horizontally between the vehicle body and the bogie of the railway vehicle, and is used for the purpose of suppressing vibration in the lateral direction with respect to the traveling direction of the vehicle body. be done. For example, the cylinder device can be used as an actuator that actively applies thrust to the vehicle body to suppress vibration of the vehicle body, or as a damper that generates a damping force when expanding and contracting due to the vibration of the vehicle body and suppresses vibration of the vehicle body. can also work.

Such a cylinder device includes, for example, a cylinder, a rod movably inserted into the cylinder, a rod movably inserted into the cylinder and connected to the rod, and the inside of the cylinder filled with hydraulic oil. A piston that separates a side chamber and a piston side chamber, a tank that stores hydraulic oil, a first on-off valve provided in a first passage that communicates the rod side chamber and the piston side chamber, and a first opening and closing valve that communicates the piston side chamber and the tank. A second on-off valve provided in two passages, a pump for supplying liquid to the rod-side chamber, a motor for driving the pump, a discharge passage communicating between the rod-side chamber and the tank, and a valve opening pressure provided in the discharge passage. , a rectifying 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 (for example, See Patent Document 1).

When the pump is stopped and the first on-off valve and the second on-off valve are closed, the cylinder device configured in this manner enters a damper mode. It functions as a uniflow damper that reaches the tank through the side chambers in order. The cylinder device generates a damping force that hinders the expansion and contraction by applying resistance to the flow of hydraulic oil discharged from the cylinder to the tank through the discharge passage by the variable relief valve during the expansion and contraction.

JP 2016-060438 A

As mentioned above, the conventional cylinder device can function as both an actuator and a damper as required, but in the damper mode it functions as a uniflow type damper. In the damper mode cylinder device, hydraulic fluid is discharged from the rod-side chamber, which contracts during extension, to the tank through the variable relief valve, and hydraulic fluid is supplied from the tank to the piston-side chamber, which expands, through the suction passage. Therefore, when the damper mode cylinder device is extended, the pressure in the rod-side chamber, which rises by the variable relief valve, acts on the pressure-receiving surface facing the rod-side chamber of the piston, and the tank pressure is applied to the pressure-receiving surface of the piston facing the piston-side chamber. works. Assuming that the tank pressure is 0, the cylinder device in the damper mode during the extension operation generates a damping force of a value obtained by multiplying the pressure in the rod side chamber by the pressure receiving area on the rod side chamber side of the piston.

On the other hand, when the damper mode cylinder device contracts, hydraulic fluid moves from the contracted piston-side chamber to the rod-side chamber through the rectifying passage, and the volume of hydraulic fluid that the rod enters into the cylinder is variable. It is discharged to the tank through the relief valve. Therefore, when the damper mode cylinder device is contracted, the pressure in the cylinder, which is increased by the variable relief valve, acts equally on the pressure receiving surface on the rod side chamber side and the pressure receiving surface on the piston side chamber side of the piston. Since the difference between the pressure-receiving area on the rod-side chamber side and the pressure-receiving area on the piston-side chamber side of the piston is equal to the cross-sectional area of the rod, the cylinder device in damper mode during contraction operation multiplies the pressure in the cylinder by the cross-sectional area of the rod. Generates a damping force of the specified value.

Since the cylinder device suppresses lateral vibration of the vehicle body with respect to the bogie, if there is an imbalance between the damping force during the extension operation and the damping force during the contraction operation, the vehicle body will move with respect to the bogie while repeating expansion and contraction. is biased toward the direction of operation where the damping force is smaller, which is undesirable. Therefore, in the cylinder device that functions as a uniflow type damper, the cross-sectional area of the rod is set to 1/2 of the cross-sectional area of the piston, so that the stroke amount in the cylinder is the same regardless of whether it is extended or retracted. If there is, the same flow rate of hydraulic oil is allowed to pass through the variable relief valve, and the same damping force can be generated during the extension operation and during the contraction operation. Thus, in the conventional cylinder device, there are design restrictions on the rod diameter and the piston diameter.

Here, hydraulic oil, which is the working medium of the cylinder device, has viscoelasticity, and in order to increase the damping coefficient of the cylinder device and generate a large damping force, it is necessary to increase the rigidity of the oil column. In order to increase the rigidity of the oil column, it is necessary to increase the pressure-receiving area of the piston, so the diameter of the cylinder should be increased. Therefore, it is difficult to increase the cylinder diameter.

On the other hand, the relief valve on the extension side provides resistance to the flow of hydraulic fluid moving from the rod-side chamber to the piston-side chamber during extension to generate an extension-side damping force, and during contraction, the flow of hydraulic fluid moving from the piston-side chamber to the tank is compressed. In a bi-flow damper that generates a compression damping force by applying resistance with a relief valve, the rebound damping force and the compression damping force can be set arbitrarily by the relief valve on the rebound side and the relief valve on the compression side, respectively. The damping coefficient can be increased without increasing the size of the However, in the bi-flow type damper, when hydraulic fluid is supplied to the piston-side chamber, the hydraulic fluid escapes from the pressure-side relief valve to the tank, making it difficult to use the damper as an actuator.

As described above, in the conventional cylinder device, if the damping coefficient is increased, there is a problem that the size of the cylinder device is increased or the use as an actuator becomes problematic. It should be noted that such problems are not limited to cylinder devices used for railroad vehicles, and the same applies to vehicles other than railroad vehicles, structures, machines, etc. to which the cylinder devices apply thrust force. Therefore, if an attempt is made to increase the damping coefficient, the size of the cylinder device will be increased, or problems will arise in its use as an actuator.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a cylinder device that can increase the damping coefficient when functioning as a damper while exhibiting the function as an actuator without causing an increase in size.

The cylinder device of the present invention comprises a cylinder, a rod movably inserted into the cylinder, and a piston movably 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 telescopic unit, a tank, a pump capable of supplying liquid from the tank to the cylinder, an adjustment passage communicating between the rod side chamber and the tank and provided with a variable relief valve in the middle, and communicating between the rod side chamber and the tank. An actuator circuit that has a bypass passage in which a relief valve and a bypass passage opening/closing valve are provided in series in the middle thereof to drive the expansion unit to expand and contract; , an extension-side relief valve provided in the extension-side damping passage to provide resistance to the flow of liquid from the rod-side chamber to the piston-side chamber, and a compression-side damping connecting the piston-side chamber between the relief valve of the bypass passage and the bypass passage opening/closing valve a pressure-side relief valve provided in the compression-side damping passage to provide resistance to the flow of liquid from the piston-side chamber to the tank; a suction passage communicating between the tank and the piston-side chamber; and a suction passage provided in the suction passage from the tank to the piston-side chamber. and a damper circuit including a suction check valve that allows the flow of liquid toward the The valve opening pressure can be adjusted when energized, and the bypass passage opening/closing valve closes when the solenoid is energized, opens when the solenoid is not energized, and closes the bypass passage opening/closing valve in the actuator mode for driving the pump. In the damper mode for stopping the pump, the bypass passage opening/closing valve is opened to open the bypass passage.

The cylinder device of the present embodiment configured in this way can function both as an actuator and as a damper, and when functioning as a damper, the damping force characteristics during the extension operation and the damping force characteristics during the contraction operation are The same characteristics can be set by setting the expansion side relief valve and the compression side relief valve regardless of the setting of the diameter of the rod and the diameter of the cylinder.

Further, the cylinder device configured in this way can function as an actuator by supplying liquid from the pump to the cylinder by the actuator circuit, blocking the pressure-side damping passage with the bypass passage opening/closing valve, and stopping the pump to open and close the bypass passage. It can function as a damper by opening the compression side damping passage with a valve and utilizing the damper circuit. Further, when the cylinder device configured in this manner functions as a damper, when the telescopic unit is extended, the damping force is generated by the extension side relief valve, and when the telescopic unit is retracted, the compression side relief valve can generate a damping force.

Another cylinder device of the present invention includes a cylinder, a rod movably inserted into the cylinder, a rod-side chamber and a piston-side chamber movably inserted into the cylinder and connected to the rod. , a tank, a pump capable of supplying liquid from the tank to the cylinder, a control passage that communicates the rod-side chamber and the tank, and a thrust adjustment section provided in the control passage. an actuator circuit capable of telescopically driving the telescopic unit; a rebound-side damping passage communicating between the rod-side chamber and the piston-side chamber; a compression-side damping passage that connects the piston-side chamber to the thrust force adjusting portion; a compression-side relief valve that is provided in the compression-side damping passage and provides resistance to the flow of liquid from the piston-side chamber to the tank; the tank and the piston-side chamber; and a damper circuit including a suction check valve provided in the suction passage and allowing liquid to flow from the tank to the piston-side chamber. a relief valve that opens when the pressure on the rod side chamber side reaches a valve opening pressure; and a variable relief valve that can adjust the valve opening pressure by energization; The relief valve and the variable relief valve are arranged in series in order from the side, and the compression side damping passage connects the piston side chamber between the relief valve and the variable relief valve of the adjustment passage.

The other cylinder device of the present invention configured in this way can function both as an actuator and as a damper, and when functioning as a damper, the damping force characteristics during the extension operation and the damping force characteristics during the contraction operation are The same characteristics can be set by setting the expansion side relief valve and the compression side relief valve regardless of the setting of the diameter of the rod and the diameter of the cylinder.

In the cylinder device configured in this way, even if the thrust force adjustment unit does not have an on-off valve for blocking the compression-side damping passage in the actuator mode, the compression-side damping force can be generated in the damper mode using the compression-side relief valve. , the structure of the thrust force adjusting unit is simplified and an on-off valve is not required, so that the manufacturing cost can be reduced.

Furthermore, the cylinder device has a variable relief valve whose actuator circuit can adjust the valve opening pressure and adjusts the pressure of the liquid supplied from the pump into the cylinder by adjusting the valve opening pressure. The valve opening pressure may be set to be higher than the maximum valve opening pressure that the variable relief valve can take in the actuator mode. According to the cylinder device configured in this way, when functioning as an actuator, the liquid supplied from the pump into the cylinder does not escape from the rod-side chamber to the piston-side chamber. reduced.

According to the cylinder device of the present invention, it is possible to improve the damping coefficient when functioning as a damper while exhibiting the function as an actuator without causing an increase in size.

1 is a circuit diagram of a cylinder device according to a first embodiment; FIG. FIG. 4 is a diagram showing a state in which the cylinder device is interposed between the vehicle body and bogie of the railroad vehicle; It is a circuit diagram of a cylinder device in a second embodiment.

The present invention will be described below based on each embodiment shown in the drawings. In the cylinder device of each embodiment, the members and parts with common reference numerals have the same configuration. Therefore, in order to avoid duplication of explanation, the detailed explanation of the configuration explained in the explanation of the cylinder device of one embodiment will be omitted in the explanation of the cylinder device of the other embodiment. In describing the cylinder device of the present invention, in each embodiment, a cylinder device applied to a railroad vehicle has been described as an example, but the cylinder device of the present invention is applicable to vehicles other than railroad vehicles and structures. It can also be used for driving or suppressing vibration of objects such as buildings, machines, and the like.

<First embodiment>
BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on each embodiment shown in the drawings. The cylinder device C according to the first embodiment includes an expansion unit 1, a tank 7, an actuator circuit A, and a damper circuit D, as shown in FIG. In this embodiment, as shown in FIG. 2, two cylinder devices C are used in parallel and interposed between the vehicle body S and the bogie B of the railway vehicle T. A single cylinder device C may be interposed between the vehicle body S and the bogie B to suppress vibration in the horizontal direction.

Each part of the cylinder device C will be described below. The telescopic unit 1 includes a cylinder 2, a rod 3 movably inserted into the cylinder 2, and a rod side chamber 5 and a piston side chamber 5 movably inserted into the cylinder 2 and connected to the rod 3. 6 and a piston 4 .

The rod-side chamber 5 and the piston-side chamber 6 are filled with working oil as a liquid, and the tank 7 is filled with gas in addition to the working oil. The liquid can also be water or an aqueous solution in addition to hydraulic oil. The inside of the tank 7 does not have to be pressurized by compressing and filling the gas, but it may be pressurized.

The cylinder 2 has a cylindrical shape, the right end of which is closed by a lid 19 in FIG. 1, and an annular rod guide 20 is attached to the left end of FIG. A rod 3 that is movably inserted into the cylinder 2 is movably inserted in the inner circumference of the rod guide 20 . The rod 3 has one end connected to a piston 4 movably inserted in the cylinder 2 and the other end protruding outside the cylinder 2 so as to be axially movable with respect to the cylinder 2 . ing.

The cylinder device C also includes an outer cylinder 21 that covers the outer circumference of the cylinder 2 . The left end and right end of the outer cylinder 21 in FIG. 1 are closed with a lid 19 and a rod guide 20, similarly to the cylinder 2, and the annular gap between the outer cylinder 21 and the cylinder 2 forms a tank 7. there is A lid 19 that closes the left end of the rod 3 in FIG. 1 and the right end of the cylinder 2 is provided with a mounting portion (not shown). can.

The actuator circuit A is a circuit that is provided between the cylinder 2 and the tank 7, has a pump 14 capable of supplying hydraulic oil from the tank 7 to the cylinder 2, and drives the telescopic unit 1 to extend and retract. The actuator circuit A supplies hydraulic oil into the cylinder 2 by driving the pump 14, selects one of the extension direction and the contraction direction of the telescopic unit 1, and causes the telescopic unit 1 to generate thrust in the selected direction. Along with this, the thrust can be adjusted.

Specifically, the actuator circuit A is provided between the cylinder 2 and the tank 7, as shown in FIG. 15, a control passage 40 communicating between the rod-side chamber 5 and the tank 7, a thrust adjustment portion FT provided in the control passage 40, a first passage 10 communicating between the rod-side chamber 5 and the piston-side chamber 6, a first A first on-off valve 11 provided in the passage 10 , a second passage 12 communicating between the piston-side chamber 6 and the tank 7 , and a second on-off valve 13 provided in the second passage 12 .

The pump 14 is driven by a motor 15, and in the cylinder device C of the present embodiment, hydraulic oil is discharged only in one direction. A discharge port of the pump 14 communicates with the rod-side chamber 5 through a supply passage 22 that communicates the rod-side chamber 5 and the tank 7 , and a suction port communicates with the tank 7 through the supply passage 22 . Therefore, when the pump 14 is driven by the motor 15 , the hydraulic oil is sucked from the tank 7 and supplied to the rod-side chamber 5 .

As described above, the pump 14 only discharges hydraulic oil in one direction and does not switch the rotation direction, so there is no problem that the discharge amount changes when switching the rotation, and an inexpensive gear pump or the like can be used. . Furthermore, since the direction of rotation of the pump 14 is always the same, the motor 15, which is the driving source for driving the pump 14, does not require high responsiveness to rotation switching, and the motor 15 is accordingly inexpensive. can be used. The supply passage 22 is provided with a check valve 23 that prevents backflow of hydraulic oil from the rod-side chamber 5 to the pump 14 .

Further, in the actuator circuit A of the present embodiment, the first opening/closing valve 11 is provided in the first passage 10 communicating between the rod side chamber 5 and the piston side chamber 6, and the first opening/closing valve 11 communicating between the piston side chamber 6 and the tank 7 is provided. A second on-off valve 13 is provided in the second passage 12 .

In the case of this embodiment, the first on-off valve 11 is an electromagnetic on-off valve. A valve body 11a having a blocking position 11c for blocking communication with the piston-side chamber 6, a spring 11d for biasing the valve body 11a to take the blocking position 11c, and a spring 11d for pushing the valve body 11a against the spring 11d when energized. and a solenoid 11e for switching to the communicating position 11b.

In the case of this embodiment, the second on-off valve 13 is an electromagnetic on-off valve. 7, a spring 13d that biases the valve body 13a so as to adopt the blocking position 13c, and the valve body 13a communicates against the spring 13d when energized. and a solenoid 13e for switching to the position 13b.

Thrust adjustment unit FT includes an adjustment passage P1 and a bypass passage P2 connected in parallel in the middle of control passage 40 communicating rod side chamber 5 and tank 7, a variable relief valve 41 provided in adjustment passage P1, a bypass A relief valve 43 and a bypass passage opening/closing valve 44 are provided in series in this order from the rod side chamber 5 side in the passage P2.

Thus, in the cylinder device C of the first embodiment, the rod-side chamber 5 and the tank 7 are connected through the control passage 40 and the adjustment passage P1 and the bypass passage P2 provided in the middle of the control passage 40. there is As described above, the adjustment passage P1 is provided with the variable relief valve 41 capable of changing the valve opening pressure, and the bypass passage P2 is provided with the relief valve 43 and the bypass passage opening/closing valve 44 in series.

The relief valve 43 includes a valve body 43a provided in the bypass passage P2, a spring 43b that biases the valve body 43a so as to shut off the bypass passage P2, and a pressure on the rod side chamber side upstream of the valve body 43a. and a pilot passage 43c for biasing the valve element 43a in the valve opening direction against the spring 43b. The valve opening pressure of the relief valve 43 is set in advance to a predetermined valve opening pressure by the force of the spring 43b that biases the valve body 43a.

When the bypass passage opening/closing valve 44 provided downstream of the relief valve 43 is open, the pressure in the rod-side chamber 5 upstream of the bypass passage P2 acting on the valve element 43a is the relief pressure of the relief valve 43 (open pressure). valve pressure), the force that pushes the valve body 43a overcomes the force of the spring 43b that biases the valve body 43a, causing the valve body 43a to retreat and the relief valve 43 to open the bypass passage P2. Open.

The bypass passage opening/closing valve 44 includes a valve body 44a that can be opened and closed, provided on the tank side downstream of the relief valve 43 in the bypass passage P2, and a spring 44b that biases the valve body 44a so as to open the bypass passage P2. and a solenoid Sol for switching the valve body 44a to a position for blocking the bypass passage P2 by generating thrust against the spring 44b when energized. In this manner, the bypass passage open/close valve 44 is an electromagnetic valve that cuts off the bypass passage P2 when a current of a predetermined value or more is applied to the solenoid Sol and the solenoid Sol generates a thrust exceeding the biasing force of the spring 44b.

Further, the bypass passage opening/closing valve 44 assumes a position in which the valve body 44a is urged by the spring 44b to open the bypass passage P2 when the solenoid Sol is not energized. That is, when the solenoid Sol is not energized, the bypass passage opening/closing valve 44 is opened to open the bypass passage P2.

The variable relief valve 41 includes a valve body 41a provided in the adjustment passage P1, a spring 41b that biases the valve body 41a so as to block the adjustment passage P1, and a rod side chamber side upstream of the valve body 41a. It comprises a pilot passage 41c for applying pressure to the valve body 41a so as to urge the valve body 41a in the valve opening direction against the spring 41b, and a solenoid Sol for generating a thrust against the spring 41b when energized. there is The variable relief valve 41 is an electromagnetic valve that can adjust the valve opening pressure by adjusting the amount of current flowing through the solenoid Sol. The thrust of the solenoid Sol is transmitted to the valve body 41a of the variable relief valve 41 through the valve body 44a. More specifically, when a current of a predetermined value or higher is supplied to the solenoid Sol, the valve body 44a of the bypass passage opening/closing valve 44 blocks the bypass passage P2 and contacts the valve body 41a of the variable relief valve 41 to reduce the thrust of the solenoid Sol. It is transmitted to the valve body 41a.

When the pressure in the rod side chamber 5 upstream of the control passage 40 acting on the valve body 41a exceeds the relief pressure (valve opening pressure) of the variable relief valve 41, this pressure and the solenoid Sol push the valve body 41a. is overcome by the resultant force of the biasing force of the spring 41b biasing the valve body 41a and the biasing force of the spring 44b biasing the valve body 44a, the valve body 41a retreats, and the variable relief valve 41 is closed in the adjustment passage. Release P1.

Further, in the variable relief valve 41, the thrust generated by the solenoid Sol can be increased by increasing the amount of current supplied to the solenoid Sol. Therefore, when the amount of current supplied to the solenoid Sol is maximized, the opening pressure of the variable relief valve 41 is minimized, and conversely, when no current is supplied to the solenoid Sol, the valve opening pressure of the variable relief valve 41 is maximized. When the amount of current supplied to the solenoid Sol is changed to a predetermined value or more, the valve opening pressure of the variable relief valve 41 can be changed while the bypass passage opening/closing valve 44 is closed. In this way, the variable relief valve 41 and the bypass passage opening/closing valve 44 share one solenoid Sol, and are electromagnetic valves driven by the same solenoid Sol. Therefore, the thrust force of the solenoid Sol can be applied to the valve bodies 41a and 44a of the variable relief valve 41 and the bypass passage opening/closing valve 44, respectively.

When the solenoid Sol is energized, not only can the valve opening pressure of the variable relief valve 41 be adjusted according to the amount of current supplied to the solenoid Sol, but also the bypass passage opening/closing valve 44 can be closed. On the contrary, when the current is not supplied to the solenoid Sol, the bypass passage opening/closing valve 44 can be opened while maximizing the opening pressure of the variable relief valve 41 .

In addition, regardless of the opening/closing state of the first opening/closing valve 11 and the second opening/closing valve 13, the pressure in the rod side chamber 5 exceeds the valve opening pressure due to excessive input in the expansion/contraction direction of the telescopic unit 1. Then, the adjustment passage P1 is opened to connect the rod-side chamber 5 to the tank 7. Thus, the variable relief valve 41 discharges the pressure in the rod-side chamber 5 to the tank 7 to protect the entire system of the cylinder device C against excessive input to the telescopic unit 1 .

Next, the damper circuit D includes a rebound-side damping passage 24 that communicates the rod-side chamber 5 and the piston-side chamber 6, and a damper circuit D that is provided in the rebound-side damping passage 24 to resist the flow of hydraulic oil from the rod-side chamber 5 to the piston-side chamber 6. a compression-side damping passage 26 that connects the piston-side chamber 6 to the thrust force adjusting portion FT; A first pressure-side relief valve 27 as a pressure-side relief valve, a suction passage 28 communicating between the tank 7 and the piston-side chamber 6, and a suction passage 28 provided in the suction passage 28 to allow hydraulic oil to flow from the tank 7 toward the piston-side chamber 6. A suction check valve 29, an extension side suction passage 30 that communicates with the tank 7 and the rod side chamber 5, and an extension side that is provided in the extension side suction passage 30 and allows only the flow of hydraulic oil from the tank 7 toward the rod side chamber 5. A check valve 31, a pressure-side passage 32 communicating between the piston-side chamber 6 and the rod-side chamber 5, and a second pressure-side relief valve provided in the pressure-side passage 32 to provide resistance to the flow of hydraulic oil from the piston-side chamber 6 to the rod-side chamber 5. 33.

The extension side damping passage 24 is provided in the piston 4 and communicates the rod side chamber 5 and the piston side chamber 6 . Further, the extension side relief valve 25 is provided in the piston 4, the pressure in the rod side chamber 5 exceeds the pressure in the piston side chamber 6, and the difference between the pressure in the rod side chamber 5 and the pressure in the piston side chamber 6 is When the valve opening pressure is reached, the valve is opened to give resistance to the flow of hydraulic oil from the rod side chamber 5 to the piston side chamber 6. - 特許庁The extension side relief valve 25 closes the extension side damping passage 24 against the flow of hydraulic oil from the piston side chamber 6 toward the rod side chamber 5 to block the extension side damping passage 24 . Therefore, the extension-side damping passage 24 is set as a one-way passage that allows hydraulic oil to flow only from the rod-side chamber 5 to the piston-side chamber 6 by the extension-side relief valve 25 .

The opening pressure of the extension-side relief valve 25 is set to be equal to or greater than the difference between the pressure in the rod-side chamber 5 and the pressure in the piston-side chamber 6 when the telescopic unit 1 generates maximum thrust to the contraction side by the actuator circuit A. there is Therefore, even if the pump 14 in the actuator circuit A is driven to generate the maximum thrust force in the contraction direction of the telescopic unit 1, the extension side relief valve 25 is not opened and the extension side damping passage 24 is kept closed. .

The compression-side damping passage 26 connects the piston-side chamber 6 to the thrust force adjustment portion FT. Specifically, the pressure-side damping passage 26 connects the piston-side chamber 6 between the relief valve 43 and the bypass passage opening/closing valve 44 of the bypass passage P2. Therefore, when the bypass passage opening/closing valve 44 is in the open state, the piston side chamber 6 moves toward the tank 7 through the pressure side damping passage 26, the bypass passage opening/closing valve 44, the bypass passage P2, and the control passage 40 downstream of the thrust force adjusting portion FT. is communicated with. When the bypass passage opening/closing valve 44 is closed, communication between the piston side chamber 6 and the tank 7 via the compression side damping passage 26 is cut off. Since the compression side damping passage 26 is connected between the relief valve 43 of the bypass passage P2 and the bypass passage opening/closing valve 44, opening and closing the bypass passage opening/closing valve 44 disposed downstream of the compression side damping passage 26 causes the compression side damping passage to open. 26 can be switched between disconnection and communication.

Further, in the first pressure-side relief valve 27 as a pressure-side relief valve, when the bypass passage opening/closing valve 44 is opened, the pressure in the piston-side chamber 6 exceeds the pressure in the tank 7, and the pressure in the piston-side chamber 6 and the pressure in the tank 7 reaches the valve opening pressure, the valve opens to give resistance to the flow of hydraulic oil from the piston side chamber 6 to the tank 7. - 特許庁The first pressure side relief valve 27 closes the pressure side damping passage 26 against the flow of hydraulic oil from the tank 7 toward the piston side chamber 6 to block the pressure side damping passage 26 . Therefore, the compression-side damping passage 26 is set as a one-way passage that allows the hydraulic oil to flow only from the piston-side chamber 6 toward the tank 7 by means of the first compression-side relief valve 27 . When the bypass passage opening/closing valve 44 is closed, the first compression side relief valve 27 is not opened because communication between the piston side chamber 6 and the tank 7 is cut off via the compression side damping passage 26 .

The suction passage 28 communicates the tank 7 and the piston side chamber 6 . In addition, the suction check valve 29 opens when the pressure in the tank 7 exceeds the pressure in the piston side chamber 6 to allow passage of hydraulic oil from the tank 7 toward the piston side chamber 6 without giving much resistance. . The suction check valve 29 closes the suction passage 28 against the flow of hydraulic oil from the piston-side chamber 6 toward the tank 7 to cut off the suction passage 28 . Therefore, the suction passage 28 is set as a one-way passage that allows only the flow of hydraulic oil from the tank 7 toward the piston side chamber 6 by the suction check valve 29 .

Furthermore, the extension side suction passage 30 communicates the tank 7 and the rod side chamber 5 . In addition, the extension side check valve 31 opens when the pressure in the tank 7 exceeds the pressure in the rod side chamber 5, allowing hydraulic oil to pass from the tank 7 toward the rod side chamber 5 without giving much resistance. do. The expansion side check valve 31 closes the expansion side suction passage 30 against the flow of hydraulic oil from the rod side chamber 5 toward the tank 7 to block the expansion side suction passage 30 . Therefore, the extension-side suction passage 30 is set as a one-way passage that allows only the flow of hydraulic oil from the tank 7 toward the rod-side chamber 5 by the extension-side check valve 31 .

The pressure-side passage 32 is provided in the piston 4 and communicates the piston-side chamber 6 and the rod-side chamber 5 . The second pressure side relief valve 33 is provided in the piston 4, the pressure in the piston side chamber 6 exceeds the pressure in the rod side chamber 5, and the difference between the pressure in the piston side chamber 6 and the pressure in the rod side chamber 5 is reaches the valve opening pressure, the valve opens to resist the flow of hydraulic oil from the piston-side chamber 6 to the rod-side chamber 5 . The second pressure-side relief valve 33 closes the pressure-side passage 32 against the flow of hydraulic oil from the rod-side chamber 5 to the piston-side chamber 6 to block the pressure-side passage 32 . Therefore, the pressure-side passage 32 is set as a one-way passage through which the second pressure-side relief valve 33 allows hydraulic oil to flow only from the piston-side chamber 6 toward the rod-side chamber 5 .

The cylinder device C is constructed as described above, and the operation of the cylinder device C will be described below. First, an actuator mode in which the actuator circuit A is used to cause the cylinder device C to function as an actuator will be described. When the cylinder device C is to generate thrust in the extension direction, the first on-off valve 11 is set to the communication position 11b and the second on-off valve 13 is set to the shutoff position 13c, and the pump 14 is driven by the motor 15 to move the thrust from the tank 7 into the cylinder 2. Supply hydraulic oil. Further, a current of a predetermined value or more is applied to the solenoid Sol to close the bypass passage open/close valve 44 to block the bypass passage P2, and the valve opening pressure of the variable relief valve 41 is adjusted to the thrust to be exerted by the cylinder device C. Adjust accordingly.

With this arrangement, the rod-side chamber 5 and the piston-side chamber 6 are brought into communication with each other through the first passage 10 by opening the first on-off valve 11, and hydraulic oil is supplied from the pump 14 to the rod-side chamber 5 and the piston-side chamber 6. be done. Further, since the bypass passage open/close valve 44 is closed, the compression side damping passage 26 is blocked, so the hydraulic oil supplied into the cylinder 2 cannot move from the piston side chamber 6 to the tank 7 . In the actuator mode in which the cylinder device C functions as an actuator in this manner, the compression side damping passage 26 is blocked by the bypass passage opening/closing valve 44 .

Therefore, when the pump 14 is driven by the motor 15 with the first on-off valve 11 at the communication position 11b and the second on-off valve 13 at the shut-off position 13c, the hydraulic fluid supplied from the pump 14 into the cylinder 2 moves against the cylinder 2. 4 is pushed in the leftward direction in FIG. 1, the cylinder device C generates thrust in the extension direction.

When the pressures in the rod-side chamber 5 and the piston-side chamber 6 exceed the valve opening pressure of the variable relief valve 41, the variable relief valve 41 opens and hydraulic oil is discharged to the tank 7 through the adjustment passage P1. The pressures in the rod side chamber 5 and the piston side chamber 6 are equal to the valve opening pressure of the variable relief valve 41 . In this manner, the variable relief valve 41 adjusts the pressure of hydraulic oil supplied from the pump 14 into the cylinder 2 by adjusting the valve opening pressure. Therefore, the cylinder device C generates a thrust in the extension direction obtained by multiplying the pressure receiving area difference between the piston-side chamber side and the rod-side chamber side of the piston 4 by the valve opening pressure of the variable relief valve 41 . Thrust can be adjusted by adjustment. In this state, even if the telescopic unit 1 is forcibly contracted by an external force, the pressures in the rod side chamber 5 and the piston side chamber 6 are controlled to be equal to the opening pressure of the variable relief valve 41. , generates a thrust in the extensional direction that suppresses contraction.

When the telescopic unit 1 is contracted at high speed by an external force while the cylinder device C is generating thrust in the extension direction and the pressure inside the piston side chamber 6 becomes abnormally high, the second compression side relief valve 33 is opened. Since the hydraulic fluid in the piston side chamber 6 is moved to the rod side chamber 5, the cylinder device C is protected.

On the other hand, when the cylinder device C is caused to generate thrust in the contraction direction, the first on-off valve 11 is set to the blocking position 11c and the second on-off valve 13 is set to the communication position 13b, and the pump 14 is driven by the motor 15 to Hydraulic oil is supplied from 7 to the rod-side chamber 5 . Further, a current of a predetermined value or more is applied to the solenoid Sol to close the bypass passage open/close valve 44 to block the bypass passage P2, and the valve opening pressure of the variable relief valve 41 is adjusted to the thrust to be exerted by the cylinder device C. Adjust accordingly.

By doing so, the piston-side chamber 6 and the tank 7 are communicated through the second passage 12 by opening the second on-off valve 13, and the first on-off valve 11 is closed to open the rod-side chamber 5 and the piston. Since communication with the side chamber 6 is cut off, hydraulic fluid discharged from the pump 14 is supplied only to the rod side chamber 5 . Also, since the bypass passage opening/closing valve 44 is closed, the compression side damping passage 26 is blocked, but the piston side chamber 6 and the tank 7 are communicated with each other through the second passage 12 .

Therefore, when the pump 14 is driven by the motor 15 with the first on-off valve 11 at the blocking position 11c and the second on-off valve 13 at the communicating position 13b, the hydraulic oil supplied from the pump 14 to the rod-side chamber 5 moves against the cylinder 2. 4 is pushed to the right in FIG. 1, the cylinder device C generates thrust in the contraction direction. Then, the cylinder device C obtains a value obtained by multiplying a value obtained by multiplying the pressure receiving area on the rod side chamber side of the piston 4 by the valve opening pressure of the variable relief valve 41 by the pressure receiving area on the piston side chamber side of the piston 4 and the pressure in the tank 7. A thrust in the contraction direction equal to the subtracted value is generated, and the thrust can be adjusted by adjusting the opening pressure of the variable relief valve 41 . In this state, even if the telescopic unit 1 is forcibly extended by an external force, the pressure in the rod side chamber 5 is controlled to be equal to the valve opening pressure of the variable relief valve 41, so the extension is suppressed in the contraction direction. produces a thrust of

When the cylinder device C of the present embodiment is caused to generate a thrust force in the contraction direction, it is necessary to supply hydraulic oil to the rod side chamber 5 while the communication between the rod side chamber 5 and the piston side chamber 6 is cut off, as described above. There is Here, the extension side damping passage 24 in the damper circuit D allows hydraulic oil to flow from the rod side chamber 5 to the piston side chamber 6 when the extension side relief valve 25 is opened. Therefore, when the cylinder device C of the present embodiment is caused to generate a thrust force in the contraction direction, if the extension side relief valve 25 is opened, the working oil escapes from the rod side chamber 5 to the piston side chamber 6, resulting in poor efficiency. , the valve opening pressure of the extension side relief valve 25 is set to be equal to or greater than the difference between the pressure in the rod side chamber 5 and the pressure in the piston side chamber 6 when the telescopic unit 1 generates the maximum thrust force to the contraction side by the actuator circuit A. ing. The maximum thrust in the contraction direction of the cylinder device C in the actuator mode is generated when the variable relief valve 41 maximizes the opening pressure. Therefore, the extension side relief valve 25 does not open even if the valve opening pressure of the variable relief valve 41 is maximized when the cylinder device C of the present embodiment functions as an actuator that generates thrust in the contraction direction. Hydraulic oil is prevented from moving from the rod side chamber 5 to the piston side chamber 6 through the side damping passage 24. - 特許庁In this way, the opening pressure of the extension side relief valve 25 is greater than the difference between the pressure in the rod side chamber 5 and the pressure in the piston side chamber 6 when the telescopic unit 1 generates the maximum thrust force to the contraction side by the actuator circuit A. When set, the cylinder device C can efficiently generate thrust in the contraction direction as an actuator, and energy consumption is reduced. As described above, in the cylinder device C of the present embodiment, the extension side relief valve 25 does not need to open even if the variable relief valve 41 that controls the pressure in the rod side chamber 5 maximizes the valve opening pressure. The valve opening pressure of the expansion side relief valve 25 should just be higher than the maximum valve opening pressure of the variable relief valve 41 . In this case, the opening pressure of the extension side relief valve 25 is not the maximum valve opening pressure on the hardware of the variable relief valve 41, but rather than the maximum valve opening pressure that the variable relief valve 41 can take on control in the actuator mode. It can be higher.

As described above, from the viewpoint of efficiency, the valve opening pressure of the extension side relief valve 25 is set to the pressure in the rod side chamber 5 and the pressure in the piston side chamber 6 when the telescopic unit 1 generates the maximum thrust to the contraction side by the actuator circuit A. However, even if the valve opening pressure is set to be less than the difference, the cylinder device C can generate thrust in the contraction direction as an actuator.

When the telescopic unit 1 is extended at high speed by an external force while the cylinder device C is generating a thrust in the contraction direction, and the inside of the rod-side chamber 5 becomes abnormally high pressure, the extension-side relief valve 25 opens and the rod Since the hydraulic fluid in the side chamber 5 is moved to the piston side chamber 6, the cylinder device C is protected.

In this manner, the cylinder device C opens and closes the first on-off valve 11 and the second on-off valve 13 and adjusts the valve opening pressure of the variable relief valve 41, thereby opening the variable relief valve 41 in both the extending direction and the retracting direction. Thrust can be generated within the valve opening pressure adjustment range. Therefore, in the actuator mode, the cylinder device C functions as an actuator by controlling the first on-off valve 11, the second on-off valve 13 and the variable relief valve 41 while driving the pump 14. Vibration can be suppressed.

Next, a damper mode in which the damper circuit D is used to cause the cylinder device C to function as a damper will be described. When the cylinder device C is set to the damper mode, the first on-off valve 11 is set to the shutoff position 11c, the second on-off valve 13 is set to the shutoff position 13c, and the motor 15 is not driven and the pump 14 is stopped. In addition, the solenoid Sol is de-energized, and the bypass passage opening/closing valve 44 is opened to open the bypass passage P2.

In this state, communication between the rod side chamber 5 and the piston side chamber 6 through the first passage 10 is cut off, and communication between the piston side chamber 6 and the tank 7 through the second passage 12 is cut off. When the solenoid Sol is de-energized, the bypass passage opening/closing valve 44 is opened, so that the piston-side chamber 6 and the tank 7 are communicated with each other through the compression-side damping passage 26 . In the damper mode in which the cylinder device C functions as a damper in this manner, the compression side damping passage 26 is opened by opening the bypass passage opening/closing valve 44 .

When the telescopic unit 1 is extended by an external force while the cylinder device C is in the damper mode, the piston 4 moves leftward in FIG. Let The contracted hydraulic fluid in the rod side chamber 5 passes through one or both of the relief valve 43 of the bypass passage P2 and the extension side relief valve 25 of the extension side damping passage 24, and flows through the relief valve 43 and the extension side relief valve 25. moves to the tank 7 or the expanding piston side chamber 6 while being resisted by one or both of When the telescopic unit 1 is extended, the rod 3 withdraws from the cylinder 2, causing a shortage of hydraulic oil in the cylinder 2. However, the suction check valve 29 is opened and the shortage of hydraulic oil is discharged through the suction passage 28 to the tank. 7 to the piston-side chamber 6 . In this way, when the cylinder device C is in the damper mode and the telescopic unit 1 is extended, the pressure in the rod side chamber 5 is increased by the relief valve 43 and the extension side relief valve 25, and the pressure in the piston side chamber 6 is reduced to tank pressure. equal to pressure. Therefore, the cylinder device C has a value obtained by subtracting a value obtained by multiplying the pressure in the piston-side chamber side of the piston 4 by the pressure in the tank 7 from a value obtained by multiplying the pressure in the rod-side chamber 5 by the pressure-receiving area on the rod-side chamber side of the piston 4. A damping force equal to is generated in a direction that prevents the extension of the telescopic unit 1 .

Furthermore, when the telescopic unit 1 is contracted by an external force while the cylinder device C is in the damper mode, the piston 4 moves to the right in FIG. Let The hydraulic fluid in the contracted piston-side chamber 6 passes through the second pressure-side relief valve 33 in the pressure-side passage 32 and moves to the expanded rod-side chamber 5 . When the telescopic unit 1 is retracted, the rod 3 enters the cylinder 2, causing an excess of hydraulic oil in the cylinder 2. of hydraulic oil is discharged from the piston-side chamber 6 to the tank 7 . In this way, when the cylinder device C enters the damper mode and the telescopic unit 1 contracts, the pressure in the piston-side chamber 6 rises by the first pressure-side relief valve 27 and the second pressure-side relief valve 33, and the pressure in the rod-side chamber 5 The pressure is reduced, and the pressure in the piston side chamber 6 becomes higher than the pressure in the rod side chamber 5 . Therefore, in the cylinder device C, a value obtained by multiplying the pressure in the rod side chamber 5 by the pressure in the rod side chamber 5 is subtracted from the value obtained by multiplying the pressure in the piston side chamber 6 by the pressure receiving area on the piston side chamber side of the piston 4. A damping force equal to the value is generated in a direction that prevents the telescopic unit 1 from contracting. In addition, in the cylinder device C of the present embodiment, since the damper circuit D includes the expansion side suction passage 30 and the expansion side check valve 31, when the telescopic unit 1 in the cylinder device C in the damper mode contracts, When the pressure in the rod side chamber 5 becomes lower than the tank pressure, the extension side check valve 31 opens and hydraulic oil is supplied from the tank 7 to the rod side chamber 5 . Therefore, when the cylinder device C of the present embodiment contracts in the damper mode, the inside of the rod-side chamber 5 does not become negative pressure, and the occurrence of aeration and the change of the telescopic unit 1 from contraction to extension are damped. It does not cause a situation where the generation of force is delayed.

In this manner, the cylinder device C generates a damping force that hinders the extension or contraction of the telescopic unit 1 when the telescopic unit 1 is extended or contracted by an external force in the state of the damper mode. The cylinder device C in the damper mode generates a damping force by one or both of the relief valve 43 and the extension side relief valve 25 when the telescopic unit 1 is extended, and the first compression side relief valve when the telescopic unit 1 is retracted. 27 and the second compression side relief valve 33 generate a damping force. Therefore, the damping force characteristic of the damping force generated with respect to the piston speed during the extension operation of the cylinder device C in the damper mode is set by the relief valve 43 and the extension side relief valve 25, and the contraction of the cylinder device C in the damper mode The damping force characteristics of the damping force generated with respect to the piston speed during operation are set by the first compression side relief valve 27 and the second compression side relief valve 33. Can be set independently.

That is, the damping force characteristics during the extension operation and the contraction operation of the cylinder device C of the present embodiment in the damper mode are relief regardless of the setting of the pressure receiving area on the rod side chamber side and the pressure receiving area on the piston side chamber side of the piston 4. It can be independently adjusted by setting the valve 43 , the expansion side relief valve 25 , the first compression side relief valve 27 and the second compression side relief valve 33 . In other words, when making the two damping force characteristics of the extension operation and the contraction operation of the cylinder device C of the present embodiment in the damper mode the same, the cross-sectional area of the rod 3 is set to the cross-sectional area of the piston 4. It is not necessary to halve the diameter of the rod 3 and the diameter of the piston 4 (the diameter of the cylinder 2). By setting the compression side relief valve 27 and the second compression side relief valve 33, the above two damping force characteristics may be adjusted to be the same characteristics.

The damper circuit D of the present embodiment includes the expansion side suction passage 30 and the expansion side check valve 31, and expands from the tank 7 when the telescopic unit 1 in the cylinder device C in the damper mode is contracted. Since the hydraulic fluid is permitted to flow toward the rod-side chamber 5, the pressure-side passage 32 and the second pressure-side relief valve 33 may be omitted. In this case, by setting the relief valve 43, the expansion side relief valve 25, and the first compression side relief valve 27, two damping force characteristics during the extension operation and the contraction operation of the cylinder device C of the present embodiment in the damper mode are obtained. should be adjusted so that they are the same.

However, when the pressure-side passage 32 and the second pressure-side relief valve 33 are provided, when the pressure in the piston-side chamber 6 becomes abnormally high when the telescopic unit 1 in the cylinder device C in the damper mode is contracted, the second There is an advantage that the 2-pressure side relief valve 33 is opened and the working oil in the piston side chamber 6 is moved to the rod side chamber 5 to protect the cylinder device C.

Further, since the damper circuit D of the present embodiment includes the compression-side passage 32 and the second compression-side relief valve 33, when the telescopic unit 1 in the cylinder device C in the damper mode is contracted, the pressure-side passage 32 is used to compress the piston-side chamber. If there is no concern that the rod side chamber 5 will become negative pressure due to hydraulic fluid supplied from 6 to the rod side chamber 5, the extension side suction passage 30 and the extension side check valve 31 can be omitted.

In addition, instead of the second compression side relief valve 33, the compression side passage 32 is provided with a check valve that does not give much resistance to the hydraulic oil passing therethrough. Alternatively, the damping force may be generated only by the resistance of the first compression side relief valve 27 . In this case, the damping force characteristic of the damping force generated with respect to the piston speed during the extension operation of the cylinder device C in the damper mode can be set by the extension side relief valve 25, and the piston speed during the contraction operation of the cylinder device C in the damper mode can be set by the first compression side relief valve 27. Therefore, regardless of the setting of the pressure receiving area on the rod side chamber side and the pressure receiving area on the piston side chamber side of the piston 4, the damping force characteristics during the extension operation and the contraction operation of the cylinder device C in the damper mode can be set to the same characteristics.

As described above, the cylinder device C of the present embodiment includes the cylinder 2, the rod 3 movably inserted into the cylinder 2, and the rod 3 movably inserted into the cylinder 2 and connected to the rod 3. into a rod-side chamber 5 and a piston-side chamber 6; a tank 7; a pump 14 capable of supplying hydraulic oil (liquid) from the tank 7 to the cylinder 2; 7 and an actuator circuit A having a thrust adjusting section FT provided in the control passage 40 and capable of driving the telescopic unit 1 to extend and retract, and the rod side chamber 5 and the piston side chamber 6 are communicated with each other. an extension side damping passage 24, an extension side relief valve 25 provided in the extension side damping passage 24 to provide resistance to the flow of hydraulic oil (liquid) from the rod side chamber 5 to the piston side chamber 6, and thrust adjustment of the piston side chamber 6. a pressure-side damping passage 26 connected to portion FT; and a first pressure-side relief valve (pressure-side relief valve) 27 provided in the pressure-side damping passage 26 to provide resistance to the flow of hydraulic oil (liquid) from the piston-side chamber 6 toward the tank 7. , a suction passage 28 communicating between the tank 7 and the piston side chamber 6, and a suction check valve 29 provided in the suction passage 28 for allowing hydraulic oil (liquid) to flow from the tank 7 to the piston side chamber 6. D.

The cylinder device C of the present embodiment configured as described above can function as an actuator by supplying hydraulic oil (liquid) from the pump 14 to the cylinder 2 by the actuator circuit A, and stops the pump 14 to cause the damper circuit D to operate. can be used as a damper.

When the cylinder device C of the present embodiment functions as a damper, when the telescopic unit 1 is extended, the extension side relief valve 25 is used to generate a damping force, and the telescopic unit 1 is retracted. In this case, the damping force can be generated by using the first pressure side relief valve (pressure side relief valve) 27 . Therefore, when the cylinder device C of the present embodiment functions as a damper, the damping force characteristics during the extension operation and the damping force characteristics during the contraction operation are combined with the diameter of the rod 3 and the diameter of the piston 4 (the diameter of the cylinder 2 The same characteristics can be set by setting the expansion side relief valve 25 and the first pressure side relief valve (pressure side relief valve) 27 regardless of the setting of the diameter).

That is, in the cylinder device C of the present embodiment, even if the diameter of the rod 3 is reduced to the extent that the strength permits, instead of increasing the diameter of the cylinder 2, the damping force during the extension operation when functioning as a damper The characteristic and the damping force characteristic at the time of contraction can be set to be the same. Instead of increasing the diameter of the cylinder 2, if the diameter of the rod 3 is reduced to the extent that the strength permits, the pressure receiving area of the piston 4 can be increased, and the rigidity of the hydraulic oil (liquid) in the telescopic unit 1 ( Since the rigidity of the liquid column can be increased, the cylinder device C of the present embodiment can generate a high damping force with good response when functioning as a damper by increasing the damping coefficient. Therefore, according to the cylinder device C of the present embodiment, it is possible to improve the damping coefficient when functioning as a damper while exhibiting the function as an actuator without causing an increase in size.

Further, in the cylinder device C of the first embodiment, the thrust force adjustment unit FT includes an adjustment passage P1 and a bypass passage P2 provided in parallel in the middle of the control passage 40, and a variable relief valve provided in the adjustment passage P1. 41, and a relief valve 43 and a bypass passage opening/closing valve 44 which are provided in series from the rod side chamber 5 side in the bypass passage P2. The variable relief valve 41 and the bypass passage opening/closing valve 44 are electromagnetic valves connected between the bypass passage opening/closing valve 44 and driven by the same solenoid Sol. The variable relief valve 41 is opened when the solenoid Sol is energized. The valve pressure can be adjusted, and the bypass passage opening/closing valve 44 closes when the solenoid Sol is energized and opens when the solenoid Sol is not energized. The bypass passage P2 is blocked by closing the valve, and the bypass passage P2 is opened by opening the bypass passage opening/closing valve 44 in the damper mode in which the pump 14 is stopped.

In the cylinder device C of the present embodiment configured as described above, the hydraulic oil (liquid) is supplied from the pump 14 to the cylinder 2 by the actuator circuit A, and the bypass passage opening/closing valve 44 shuts off the compression side damping passage 26 to operate the actuator. In addition, by stopping the pump 14 and opening the compression side damping passage 26 with the bypass passage opening/closing valve 44, the damper circuit D can be used to function as a damper.

When the cylinder device C of the present embodiment functions as a damper, the extension side relief valve 25 generates a damping force when the telescopic unit 1 is extended, and when the telescopic unit 1 is retracted, the damping force is generated. A damping force can be generated by the first pressure side relief valve (pressure side relief valve) 27 . Therefore, when the cylinder device C of the present embodiment functions as a damper, the damping force characteristics during the extension operation and the damping force characteristics during the contraction operation are combined with the diameter of the rod 3 and the diameter of the piston 4 (the diameter of the cylinder 2 The same characteristics can be set by setting the expansion side relief valve 25 and the first pressure side relief valve (pressure side relief valve) 27 regardless of the setting of the diameter).

That is, in the cylinder device C of the present embodiment, even if the diameter of the rod 3 is reduced to the extent that the strength permits, instead of increasing the diameter of the cylinder 2, the damping force during the extension operation when functioning as a damper The characteristic and the damping force characteristic at the time of contraction can be set to be the same. Instead of increasing the diameter of the cylinder 2, if the diameter of the rod 3 is reduced to the extent that the strength permits, the pressure receiving area of the piston 4 can be increased, and the rigidity of the hydraulic oil (liquid) in the telescopic unit 1 ( Since the rigidity of the liquid column can be increased, the cylinder device C of the present embodiment can generate a high damping force with good response when functioning as a damper by increasing the damping coefficient. Therefore, according to the cylinder device C of the present embodiment, it is possible to improve the damping coefficient when functioning as a damper while exhibiting the function as an actuator without causing an increase in size. Even if the cross-sectional area of the rod 3 is set to 1/2 of the cross-sectional area of the piston 4 as in the uniflow damper, if the pressure-side passage 32 and the second pressure-side relief valve 33 are provided, the contraction of the cylinder device C Since the pressure in the piston-side chamber 6 can be made higher than the pressure in the rod-side chamber 5, the damping coefficient during the contraction operation can be made higher than in the conventional cylinder device. Therefore, if the pressure side passage 32 and the second pressure side relief valve 33 are provided, the degree of freedom in setting the cross-sectional area of the rod 3 and the cross-sectional area of the piston 4 is improved.

Further, in the cylinder device C of the present embodiment, when the motor 15 of the cylinder device C and the valves 11, 13, 41, and 44, which are solenoid valves, cannot be energized, the bypass passage opening/closing valve is automatically opened. 44 communicates the compression side damping passage 26 and the cylinder device C is switched to the damper mode. Therefore, according to the cylinder device C of the present embodiment, the damper circuit D is automatically enabled and switched to the damper mode in the event of a failure, so that vibration of the vehicle body S of the railway vehicle T can be suppressed even in the event of failure.

Further, in the cylinder device C of the present embodiment, the damper circuit D is provided in the extension side suction passage 30 that communicates the tank 7 and the rod side chamber 5 and in the extension side suction passage 30 to direct the damper circuit D from the tank 7 to the rod side chamber 5 . It includes an extension side check valve 31 that allows only the flow of hydraulic oil (liquid). According to the cylinder device C configured in this way, when the telescopic unit 1 is contracted, the inside of the rod side chamber 5 does not become negative pressure, so that aeration is generated and the telescopic unit 1 is prevented from contracting and extending. It is possible to avoid delaying the generation of the damping force at the time of switching.

Further, in the cylinder device C of the present embodiment, the actuator circuit A can adjust the valve opening pressure, and the pressure of the hydraulic oil (liquid) supplied from the pump 14 into the cylinder 2 is adjusted by adjusting the valve opening pressure. It has a variable relief valve 41 for adjustment, and the valve opening pressure of the extension side relief valve 25 is higher than the maximum valve opening pressure that the variable relief valve 41 can take in the actuator mode. In the cylinder device C configured in this way, when functioning as an actuator, the hydraulic oil (liquid) supplied from the pump 14 into the cylinder 2 does not escape from the rod-side chamber 5 to the piston-side chamber 6, so that the thrust on the contraction side is efficiently generated. can be generated and energy consumption is also reduced.

<Second Embodiment>
As shown in FIG. 3, the cylinder device C1 according to the second embodiment includes an expansion unit 1, a tank 7, an actuator circuit A1, and a damper circuit D1. In the present embodiment, two cylinder devices C1 are interposed in parallel between the vehicle body S and the bogie B of the railroad vehicle T in the same manner as the cylinder device C, and the vibration of the vehicle body S in the horizontal direction is suppressed. However, only one cylinder device C1 may be interposed between the vehicle body S and the bogie B and used.

Each part of the cylinder device C1 will be described below. The telescopic unit 1 in the cylinder device C1 has the same configuration as the telescopic unit 1 in the cylinder device C. As shown in FIG.

The actuator circuit A1 is a circuit that is provided between the cylinder 2 and the tank 7, has a pump 14 capable of supplying hydraulic oil from the tank 7 to the cylinder 2, and drives the telescopic unit 1 to extend and retract. By driving the pump 14, the actuator circuit A supplies hydraulic oil into the cylinder 2, selects one of the extension direction and the contraction direction, and causes the telescopic unit 1 to generate a thrust in the selected direction, and the thrust can be adjusted.

Specifically, the actuator circuit A is provided between the cylinder 2 and the tank 7, as shown in FIG. 15, a control passage 40 communicating between the rod side chamber 5 and the tank 7, a thrust adjustment portion FT1 provided in the control passage 40, a first passage 10 communicating between the rod side chamber 5 and the piston side chamber 6, a first A first on-off valve 11 provided in the passage 10 , a second passage 12 communicating between the piston-side chamber 6 and the tank 7 , and a second on-off valve 13 provided in the second passage 12 .

The actuator circuit A1 in the cylinder device C1 of the second embodiment differs from the actuator circuit A in the cylinder device C of the first embodiment only in the configuration of the thrust force adjustment section FT1, and the other configurations are the same. It has

In the cylinder device C1 of the second embodiment, the rod-side chamber 5 and the tank 7 are connected through the control passage 40, and the thrust adjustment section FT1 is provided in the middle of the control passage 40. The thrust force adjustment unit FT1 includes an adjustment passage P3 provided in the middle of the control passage 40, a relief valve 46 that opens when the pressure on the rod side chamber 5 side reaches the valve opening pressure, and the valve opening pressure can be adjusted by energization. The relief valve 46 and the variable relief valve 47 are provided in series in order from the rod side chamber 5 side in the adjustment passage P3.

The relief valve 46 includes a valve body 46a provided in the adjustment passage P3, a spring 46b that biases the valve body 46a so as to shut off the adjustment passage P3, and a spring 46b on the rod side chamber 5 side upstream of the valve body 46a. and a pilot passage 46c for applying pressure to the valve body 46a against the spring 46b in the valve opening direction. The valve opening pressure of the relief valve 46 is set in advance to a predetermined valve opening pressure by the force of the spring 46b that biases the valve body 46a.

The variable relief valve 47 includes a valve body 47a provided in the adjustment passage P3, a spring 47b that biases the valve body 47a so as to block the adjustment passage P3, and a rod-side chamber 5 side upstream of the valve body 47a. and a solenoid 47d for generating a thrust force against the spring 47b when energized. ing. The variable relief valve 41 is an electromagnetic valve that can adjust the valve opening pressure by adjusting the amount of current flowing through the solenoid 47d.

When the pressure upstream of the variable relief valve 47 in the adjustment passage P3 acting on the valve body 47a and downstream of the relief valve 46 exceeds the relief pressure (valve opening pressure) of the variable relief valve 47, this pressure and the solenoid The force of 47d pushing the valve body 47a overcomes the biasing force of the spring 47b that biases the valve body 47a, the valve body 47a retreats, and the variable relief valve 47 opens the adjustment passage P3.

Further, in the variable relief valve 47, the thrust generated by the solenoid 47d can be increased by increasing the amount of current supplied to the solenoid 47d. Therefore, when the amount of current supplied to the solenoid 47d is maximized, the valve opening pressure of the variable relief valve 47 is minimized. Conversely, when no current is supplied to the solenoid 47d, the valve opening pressure of the variable relief valve 47 is maximized.

Subsequently, the damper circuit D1 includes a rebound-side damping passage 24 that communicates the rod-side chamber 5 and the piston-side chamber 6, and a damper circuit D1 provided in the rebound-side damping passage 24 to resist the flow of hydraulic oil from the rod-side chamber 5 to the piston-side chamber 6. a compression-side damping passage 26 connected to the piston-side chamber 6 and the thrust force adjusting portion FT1; A first pressure-side relief valve 27 as a pressure-side relief valve, a suction passage 28 communicating between the tank 7 and the piston-side chamber 6, and a suction passage 28 provided in the suction passage 28 to allow hydraulic oil to flow from the tank 7 toward the piston-side chamber 6. A suction check valve 29, an extension side suction passage 30 that communicates with the tank 7 and the rod side chamber 5, and an extension side that is provided in the extension side suction passage 30 and allows only the flow of hydraulic oil from the tank 7 toward the rod side chamber 5. A check valve 31, a pressure-side passage 32 communicating between the piston-side chamber 6 and the rod-side chamber 5, and a second pressure-side relief valve provided in the pressure-side passage 32 to provide resistance to the flow of hydraulic oil from the piston-side chamber 6 to the rod-side chamber 5. 33.

In the damper circuit D1 in the cylinder device C1 of the second embodiment and the damper circuit D in the cylinder device C of the first embodiment, the compression side damping passage 26 is the relief valve 46 of the adjustment passage P3 in the thrust force adjustment portion FT1. It is different in that it is connected to the variable relief valve 47, and otherwise has the same configuration.

As described above, the compression-side damping passage 26 is connected to the thrust force adjusting portion FT1, but unlike the cylinder device C of the first embodiment, the adjusting passage P3 of the thrust force adjusting portion FT1 has an open/close valve. is not provided, communication between the compression side damping passage 26 and the tank 7 is not interrupted.

The cylinder device C1 is configured as described above, and the operation of the cylinder device C1 will be described below. First, an actuator mode in which the actuator circuit A1 is used to cause the cylinder device C1 to function as an actuator will be described. When the thrust in the extension direction is generated in the cylinder device C1, the first on-off valve 11 is set to the communication position 11b and the second on-off valve 13 is set to the shutoff position 13c, and the pump 14 is driven by the motor 15 to move the thrust from the tank 7 into the cylinder 2. Supply hydraulic oil. Further, the valve opening pressure of the variable relief valve 47 is adjusted according to the thrust to be exerted by the cylinder device C1 by adjusting the amount of current supplied to the solenoid 47d.

With this arrangement, the rod-side chamber 5 and the piston-side chamber 6 are brought into communication with each other through the first passage 10 by opening the first on-off valve 11, and hydraulic oil is supplied from the pump 14 to the rod-side chamber 5 and the piston-side chamber 6. be done.

Therefore, when the pump 14 is driven by the motor 15 with the first on-off valve 11 at the communication position 11b and the second on-off valve 13 at the shut-off position 13c, the hydraulic fluid supplied from the pump 14 into the cylinder 2 moves against the cylinder 2. 4 is pushed in the leftward direction in FIG. 1, the cylinder device C1 generates thrust in the extension direction.

In the cylinder device C1 of the second embodiment, the compression side damping passage 26 is not blocked by the on-off valve. Therefore, the hydraulic oil supplied into the cylinder 2 can move from the rod-side chamber 5 to the tank 7 via the control passage 40 and the thrust force adjusting portion FT1, and also from the piston-side chamber 6 to the compression-side damping passage 26 and the first compression-side relief. It can be moved to the tank 7 via the valve 27 and the thrust force adjusting section FT1.

Both the pressure in the rod-side chamber 5 and the pressure in the piston-side chamber 6 communicating with the rod-side chamber 5 through the first passage 10 exceed the opening pressures of the relief valve 46 and the first pressure-side relief valve 27, and When the variable relief valve 47 opens, the hydraulic fluid in the rod side chamber 5 moves to the tank 7 via the control passage 40 and the adjustment passage P3, and the hydraulic fluid in the piston side chamber 6 flows through the compression side damping passage 26 and the adjustment passage P3. to tank 7 via

That is, when the first on-off valve 11 is in the communication position 11b and the second on-off valve 13 is in the shutoff position 13c, the relief valve 46 and the first pressure side relief valve 27 are arranged in parallel between the cylinder 2 and the tank 7. In addition, the circuit configuration is such that the variable relief valve 47 is arranged downstream of the relief valve 46 and the first pressure side relief valve 27 .

When the first on-off valve 11 is in the communicating position 11b and the second on-off valve 13 is in the blocking position 13c, if hydraulic oil is supplied from the pump 14 into the cylinder 2 and the hydraulic oil becomes excessive in the cylinder 2, After passing through one or both of the relief valve 46 and the first pressure side relief valve 27, the hydraulic oil pushed out from the variable relief valve 47 always passes through the variable relief valve 47 and moves to the tank 7. The pressure in the cylinder 2 can be adjusted by adjusting the valve opening pressure. Thus, in the cylinder device C1 of the second embodiment, when the first on-off valve 11 is in the communication position 11b and the second on-off valve 13 is in the shutoff position 13c, the relief valve 46, the first pressure-side relief valve 27 and The variable relief valve 47 acts as a resistance to increase the pressure in the cylinder 2, and the cylinder device C1 generates thrust in the extension direction.

As described above, in the cylinder device C1 of the second embodiment, when the first on-off valve 11 is in the communicating position 11b and the second on-off valve 13 is in the blocking position 13c, the piston-side chamber of the piston 4 is The pressure in the rod side chamber 5 is multiplied by the pressure receiving area difference between the side and rod side chambers to generate a thrust in the extension direction. In this state, even if the telescopic unit 1 is forcibly contracted by an external force, the pressure in the rod-side chamber 5 and the piston-side chamber 6 is controlled by the variable relief valve 47, and the thrust in the extension direction suppressing the contraction is generated. Occur.

When the telescopic unit 1 contracts at high speed due to an external force while the cylinder device C1 is generating thrust in the extension direction, and the pressure in the piston side chamber 6 becomes abnormally high, the second pressure side relief valve 33 opens. As a result, the hydraulic fluid in the piston side chamber 6 is moved to the rod side chamber 5, so the cylinder device C1 is protected.

On the other hand, when a thrust force is generated in the contraction direction of the cylinder device C1, the first on-off valve 11 is set to the blocking position 11c and the second on-off valve 13 is set to the communicating position 13b, and the pump 14 is driven by the motor 15 to Hydraulic oil is supplied from 7 to the rod-side chamber 5 . Further, the valve opening pressure of the variable relief valve 47 is adjusted according to the thrust to be exerted by the cylinder device C1 by adjusting the amount of current supplied to the solenoid 47d.

By doing so, the piston-side chamber 6 and the tank 7 are communicated through the second passage 12 by opening the second on-off valve 13, and the first on-off valve 11 is closed to open the rod-side chamber 5 and the piston. Since communication with the side chamber 6 is cut off, hydraulic fluid discharged from the pump 14 is supplied only to the rod side chamber 5 . In addition, in the cylinder device C1, the compression side damping passage 26 is not blocked by the on-off valve. It moves from the piston side chamber 6 to the tank 7 by passing through only.

Therefore, when the pump 14 is driven by the motor 15 with the first on-off valve 11 at the blocking position 11c and the second on-off valve 13 at the communicating position 13b, the hydraulic oil supplied from the pump 14 to the rod-side chamber 5 moves against the cylinder 2. 4 is pushed rightward in FIG. 1, the cylinder device C1 generates thrust in the contraction direction.

In the cylinder device C1 of the second embodiment, when the first on-off valve 11 is set to the blocking position 11c and the second on-off valve 13 is set to the communicating position 13b, and the pump 14 is driven by the motor 15, hydraulic oil is supplied only to the rod side chamber 5. supplied. When the hydraulic oil in the rod side chamber 5 becomes excessive, the hydraulic oil pushed out from the rod side chamber 5 passes through the relief valve 46 and the variable relief valve 47 and moves to the tank 7, so the variable relief valve 47 is opened. By adjusting the pressure, it is possible to adjust the pressure in the cylinder 2 . Therefore, in the cylinder device C1 of the second embodiment, when the first on-off valve 11 is in the blocking position 11c and the second on-off valve 13 is in the communicating position 13b, the relief valve 46 and the variable relief valve 47 act as resistance. The pressure in the cylinder 2 rises and the cylinder device C1 generates thrust in the contraction direction.

As described above, in the cylinder device C1 of the second embodiment, when the first on-off valve 11 is in the communicating position 11b and the second on-off valve 13 is in the blocking position 13c, the rod-side chamber of the piston 4 is A thrust in the contraction direction equal to the value obtained by subtracting the value obtained by multiplying the pressure-receiving area on the side and the pressure-receiving area on the piston side by the pressure in the tank 7 is generated, and the thrust is adjusted by adjusting the opening pressure of the variable relief valve 47. obtain. In this state, even if the telescopic unit 1 is forcibly extended by an external force, the pressure in the rod-side chamber 5 is controlled by the variable relief valve 47, so a thrust in the retraction direction is generated to suppress the extension.

When the cylinder device C1 of the present embodiment is caused to generate a thrust force in the contraction direction, it is necessary to supply the hydraulic oil to the rod side chamber 5 while the communication between the rod side chamber 5 and the piston side chamber 6 is cut off, as described above. There is Here, the extension side damping passage 24 in the damper circuit D1 allows hydraulic oil to flow from the rod side chamber 5 toward the piston side chamber 6 when the extension side relief valve 25 is opened.

Therefore, when the thrust in the contraction direction is generated in the cylinder device C1 of the present embodiment, if the extension-side relief valve 25 is opened, the working oil escapes from the rod-side chamber 5 to the piston-side chamber 6, resulting in poor efficiency. , the opening pressure of the extension side relief valve 25 is set to be equal to or greater than the difference between the pressure in the rod side chamber 5 and the pressure in the piston side chamber 6 when the telescopic unit 1 generates the maximum thrust force to the contraction side by the actuator circuit A1. ing. The maximum thrust in the contraction direction of the cylinder device C1 in the actuator mode is generated when the variable relief valve 47 maximizes the opening pressure. Therefore, the extension side relief valve 25 does not open even if the valve opening pressure of the variable relief valve 47 is maximized when the cylinder device C1 of the present embodiment functions as an actuator that generates thrust in the contraction direction. Hydraulic oil is prevented from moving from the rod side chamber 5 to the piston side chamber 6 through the side damping passage 24. - 特許庁In this way, the valve opening pressure of the extension side relief valve 25 is greater than the difference between the pressure in the rod side chamber 5 and the pressure in the piston side chamber 6 when the telescopic unit 1 generates the maximum thrust to the contraction side by the actuator circuit A1. When set, the cylinder device C1 can efficiently generate thrust in the contraction direction as an actuator, and energy consumption is reduced. As described above, in the cylinder device C1 of the present embodiment, the extension side relief valve 25 does not need to open even if the variable relief valve 47 that controls the pressure in the rod side chamber 5 has the maximum valve opening pressure. The opening pressure of the extension-side relief valve 25 is higher than the pressure loss caused by the relief valve 46 and the variable relief valve 47 when the variable relief valve 47 is set to the maximum valve opening pressure, that is, the pressure loss caused by the thrust adjustment unit FT1. Just do it. In this case, the opening pressure of the extension-side relief valve 25 is not the maximum pressure loss on the hardware of the thrust force adjustment unit FT1, but is higher than the maximum pressure loss that the thrust force adjustment unit FT1 can take on control in the actuator mode. may be

As described above, from the viewpoint of efficiency, the valve opening pressure of the extension side relief valve 25 is set to the pressure in the rod side chamber 5 and the pressure in the piston side chamber 6 when the telescopic unit 1 generates the maximum thrust to the contraction side by the actuator circuit A1. However, even if the valve opening pressure is set to be less than the difference, the cylinder device C1 can generate thrust in the contraction direction as an actuator.

When the telescopic unit 1 is extended at high speed by an external force while the cylinder device C1 is generating thrust in the contraction direction, and the inside of the rod side chamber 5 becomes abnormally high pressure, the extension side relief valve 25 opens and the rod Since the hydraulic fluid in the side chamber 5 is moved to the piston side chamber 6, the cylinder device C1 is protected.

In this manner, the cylinder device C1 is adjustable in both the extension direction and the contraction direction by opening and closing the first on-off valve 11 and the second on-off valve 13 and adjusting the valve opening pressure of the variable relief valve 47. can generate thrust. Therefore, in the actuator mode, the cylinder device C1 functions as an actuator by controlling the first opening/closing valve 11, the second opening/closing valve 13, and the variable relief valve 41 while driving the pump 14. Vibration can be suppressed.

Next, a damper mode in which the damper circuit D1 is used to cause the cylinder device C to function as a damper will be described. When the cylinder device C1 is set to the damper mode, the first opening/closing valve 11 is set to the blocking position 11c, the second opening/closing valve 13 is set to the blocking position 13c, and the motor 15 is not driven and the pump 14 is stopped. Also, the solenoid 47d may be energized or de-energized.

In this state, communication between the rod side chamber 5 and the piston side chamber 6 through the first passage 10 is cut off, and communication between the piston side chamber 6 and the tank 7 through the second passage 12 is cut off. Even in the damper mode in which the cylinder device C1 functions as a damper as described above, the compression side damping passage 26 is communicated with the tank 7 via the variable relief valve 47 in the thrust force adjustment section FT1.

When the telescopic unit 1 is extended by an external force while the cylinder device C1 is in the damper mode, the piston 4 moves leftward in FIG. Let The contracted hydraulic oil in the rod side chamber 5 passes through one or both of the thrust adjustment portion FT1 and the extension side relief valve 25 of the extension side damping passage 24, and flows through one of the thrust adjustment portion FT1 and the extension side relief valve 25. Alternatively, it moves to the tank 7 or the expanding piston-side chamber 6 while being resisted by both. When the telescopic unit 1 is extended, the rod 3 withdraws from the cylinder 2, causing a shortage of hydraulic oil in the cylinder 2. However, the suction check valve 29 is opened and the shortage of hydraulic oil is discharged through the suction passage 28 to the tank. 7 to the piston-side chamber 6 . In this way, when the cylinder device C1 is in the damper mode and the telescopic unit 1 is extended, the pressure in the rod side chamber 5 is increased by the thrust force adjusting portion FT1 and the extension side relief valve 25, and the pressure in the piston side chamber 6 is increased. Equal to tank pressure. Therefore, the cylinder device C1 has a value obtained by subtracting a value obtained by multiplying the pressure in the piston-side chamber side of the piston 4 by the pressure in the tank 7 from a value obtained by multiplying the pressure in the rod-side chamber 5 by the pressure-receiving area on the rod-side chamber side of the piston 4. A damping force equal to is generated in a direction that prevents the extension of the telescopic unit 1 .

Furthermore, when the telescopic unit 1 is contracted by an external force while the cylinder device C1 is in the damper mode, the piston 4 moves to the right in FIG. Let The hydraulic fluid in the contracted piston-side chamber 6 passes through the second pressure-side relief valve 33 in the pressure-side passage 32 and moves to the expanded rod-side chamber 5 . When the telescopic unit 1 is contracted, the rod 3 enters the cylinder 2, so the hydraulic oil becomes excessive in the cylinder 2. Excess hydraulic oil is discharged from the piston-side chamber 6 to the tank 7 through the passage 26, the adjustment passage P3 and the control passage 40. In this way, when the cylinder device C1 enters the damper mode and the telescopic unit 1 contracts, the pressure in the piston-side chamber 6 is increased by the first pressure-side relief valve 27, the variable relief valve 47, and the second pressure-side relief valve 33. The pressure in the rod side chamber 5 is reduced, and the pressure in the piston side chamber 6 becomes higher than the pressure in the rod side chamber 5 . Therefore, the cylinder device C1 subtracts a value obtained by multiplying the pressure in the rod side chamber 5 by the pressure in the rod side chamber 5 from the value obtained by multiplying the pressure in the piston side chamber 6 by the pressure receiving area on the piston side chamber side of the piston 4. A damping force equal to the value is generated in a direction that prevents the telescopic unit 1 from contracting. In addition, in the cylinder device C1 of the present embodiment, the damper circuit D1 includes the expansion side suction passage 30 and the expansion side check valve 31. Therefore, when the telescopic unit 1 in the cylinder device C1 in the damper mode contracts, When the pressure in the rod side chamber 5 becomes lower than the tank pressure, the extension side check valve 31 opens and hydraulic oil is supplied from the tank 7 to the rod side chamber 5 . Therefore, when the cylinder device C1 of the present embodiment contracts in the damper mode, the inside of the rod-side chamber 5 does not become negative pressure, and the occurrence of aeration and the change of the telescopic unit 1 from contraction to extension are damped. It does not cause a situation where the generation of force is delayed.

In this manner, the cylinder device C1 generates a damping force that hinders the extension or contraction of the telescopic unit 1 when the telescopic unit 1 is extended or contracted by an external force in the state of the damper mode. The cylinder device C1 in the damper mode generates a damping force by one or both of the thrust adjustment part FT1 and the extension side relief valve 25 when the telescopic unit 1 is extended, and the first compression side relief when the telescopic unit 1 is retracted. A damping force is generated by the valve 27 , the variable relief valve 47 and the second pressure side relief valve 33 . Therefore, the damping force characteristic of the damping force generated with respect to the piston speed during the extension operation of the cylinder device C1 in the damper mode is determined by the relief valve 46 and the variable relief valve 47 in the thrust adjustment unit FT1 and the extension side relief valve 25. The damping force characteristic of the damping force generated with respect to the piston speed during the contraction operation of the cylinder device C1 in the damper mode is determined by the first pressure side relief valve 27, the variable relief valve 47, and the second pressure side relief valve 33. Since the damping force characteristics are set, the damping force characteristics during the extension operation and during the contraction operation can be set independently.

That is, the damping force characteristics during the extension operation and the contraction operation of the cylinder device C of the present embodiment in the damper mode are relief regardless of the setting of the pressure receiving area on the rod side chamber side and the pressure receiving area on the piston side chamber side of the piston 4. It can be independently adjusted by setting the valve 46 , the variable relief valve 47 , the expansion side relief valve 25 , the first compression side relief valve 27 and the second compression side relief valve 33 . In other words, when making the two damping force characteristics of the cylinder device C1 of the present embodiment in the damper mode the same during one extension operation and during the contraction operation, the cross-sectional area of the rod 3 is set to the cross-sectional area of the piston 4. It is not necessary to halve the diameter of the rod 3 and the diameter of the piston 4 (the diameter of the cylinder 2), after arbitrarily determining the diameter of the rod 3 and the diameter of the cylinder 2 within the range permitted by the strength, the relief valve 46, the variable relief valve 47, the extension side By setting the relief valve 25, the first compression side relief valve 27, and the second compression side relief valve 33, the two damping force characteristics may be adjusted to be the same characteristics.

In addition, the damper circuit D1 of the present embodiment includes the expansion side suction passage 30 and the expansion side check valve 31, and expands from the tank 7 when the telescopic unit 1 in the cylinder device C1 in the damper mode is contracted. Since the hydraulic fluid is permitted to flow toward the rod-side chamber 5, the pressure-side passage 32 and the second pressure-side relief valve 33 may be omitted. In this case, depending on the setting of the relief valve 46, the variable relief valve 47, the expansion side relief valve 25, and the first compression side relief valve 27, the cylinder device C1 of the present embodiment in the damper mode can be set to extend or contract. It is only necessary to adjust the two damping force characteristics to be the same.

However, when the pressure-side passage 32 and the second pressure-side relief valve 33 are provided, when the pressure in the piston-side chamber 6 becomes abnormally high when the telescopic unit 1 in the cylinder device C1 in the damper mode is contracted, the second There is an advantage that the 2-pressure side relief valve 33 is opened and the hydraulic oil in the piston side chamber 6 is moved to the rod side chamber 5 to protect the cylinder device C1.

In addition, since the damper circuit D1 of the present embodiment includes the pressure-side passage 32 and the second pressure-side relief valve 33, when the telescopic unit 1 in the cylinder device C1 in the damper mode is contracted, the pressure-side passage 32 is used to compress the piston-side chamber. If there is no concern that the rod side chamber 5 will become negative pressure due to hydraulic fluid supplied from 6 to the rod side chamber 5, the extension side suction passage 30 and the extension side check valve 31 can be omitted.

In addition, instead of the second pressure-side relief valve 33, the pressure-side passage 32 is provided with a check valve that does not give much resistance to the hydraulic oil passing therethrough. In addition, the resistance of the first compression side relief valve 27 and the variable relief valve 47 may generate a damping force. In this case, the damping force characteristic of the damping force generated with respect to the piston speed during the extension operation of the cylinder device C1 in the damper mode can be set by the extension side relief valve 25, and the piston speed during the contraction operation of the cylinder device C in the damper mode can be set by the first compression side relief valve 27 and the variable relief valve 47 . Therefore, regardless of the setting of the pressure-receiving area on the rod-side chamber side and the pressure-receiving area on the piston-side chamber side of the piston 4, the damping force characteristics during the extension operation and the contraction operation of the cylinder device C1 in the damper mode can be set to the same characteristics.

As described above, the cylinder device C1 of the present embodiment includes the cylinder 2, the rod 3 movably inserted into the cylinder 2, and the rod 3 movably inserted into the cylinder 2 and connected to the rod 3. into a rod-side chamber 5 and a piston-side chamber 6; a tank 7; a pump 14 capable of supplying hydraulic oil (liquid) from the tank 7 to the cylinder 2; 7 and an actuator circuit A1, which has a thrust force adjusting section FT1 provided in the control passage 40, and which can drive the telescopic unit 1 to extend and retract, and the rod side chamber 5 and the piston side chamber 6 are communicated with each other. an extension side damping passage 24, an extension side relief valve 25 provided in the extension side damping passage 24 to provide resistance to the flow of hydraulic oil (liquid) from the rod side chamber 5 to the piston side chamber 6, and thrust adjustment of the piston side chamber 6. a compression-side damping passage 26 connected to the portion FT1; , a suction passage 28 communicating between the tank 7 and the piston side chamber 6, and a suction check valve 29 provided in the suction passage 28 for allowing hydraulic oil (liquid) to flow from the tank 7 to the piston side chamber 6. D1.

The cylinder device C1 of the present embodiment configured as described above can function as an actuator by supplying hydraulic oil (liquid) from the pump 14 to the cylinder 2 by means of the actuator circuit A1, and stops the pump 14 to operate the damper circuit D1. can be used as a damper.

When the cylinder device C1 of the present embodiment functions as a damper, when the telescopic unit 1 is extended, the extension side relief valve 25 is used to generate a damping force, and the telescopic unit 1 is retracted. In this case, the damping force can be generated by using the first pressure side relief valve (pressure side relief valve) 27 . Therefore, when the cylinder device C1 of the present embodiment functions as a damper, the damping force characteristics during the extension operation and the damping force characteristics during the contraction operation are set to the diameter of the rod 3 and the diameter of the piston 4 (the diameter of the cylinder 2 The same characteristics can be set by setting the expansion side relief valve 25 and the first pressure side relief valve (pressure side relief valve) 27 regardless of the setting of the diameter).

That is, in the cylinder device C1 of the present embodiment, even if the diameter of the rod 3 is reduced to the extent that the strength permits, instead of increasing the diameter of the cylinder 2, the damping force at the time of extension operation when functioning as a damper The characteristic and the damping force characteristic at the time of contraction can be set to be the same. Instead of increasing the diameter of the cylinder 2, if the diameter of the rod 3 is reduced to the extent that the strength permits, the pressure receiving area of the piston 4 can be increased, and the rigidity of the hydraulic oil (liquid) in the telescopic unit 1 ( Since the rigidity of the liquid column can be increased, the cylinder device C1 of the present embodiment can generate a high damping force with good response when functioning as a damper by increasing the damping coefficient. Therefore, according to the cylinder device C1 of the present embodiment, it is possible to improve the damping coefficient when functioning as a damper while exhibiting the function as an actuator without causing an increase in size.

In the cylinder device C of the first embodiment, the pressure side damping passage 26 provided with the first pressure side relief valve 27 is replaced with the relief valve 43 of the bypass passage P2 provided with the bypass passage opening/closing valve 44 in the thrust adjustment section FT. In the actuator mode, the bypass passage opening/closing valve 44 is connected to the passage opening/closing valve 44 to block the compression side damping passage 26. However, in the cylinder device C1 of the second embodiment, in the actuator mode, Also, the compression side damping passage 26 is connected to the upstream of the variable relief valve 47 of the thrust adjustment unit FT1 without blocking the compression side damping passage 26 by the opening and closing valve, and the first compression side relief valve 27 is used to generate the thrust of the cylinder device C1 in the actuator mode. . On the other hand, the cylinder device C of the first embodiment and the cylinder device C1 of the second embodiment always use the first compression side relief valve 27 to generate damping force in the damper mode. As described above, the thrust force adjusting units FT and FT1 may be configured to generate a damping force by using the first compression side relief valve 27 in the damper mode, and in the actuator mode, the cylinder device C of the first embodiment. Alternatively, the compression damping passage 26 provided with the first compression relief valve 27 may be completely blocked, or the compression damping passage 26 may be communicated without being blocked as in the cylinder device C1 of the second embodiment. state.

That is, when only one adjustment passage P3 having a variable relief valve 47 capable of adjusting the thrust is provided as in the thrust force adjustment unit FT1 of the second embodiment, the compression side damping passage 26 is variable. It may be connected upstream of the relief valve 47 . Further, like the thrust force adjustment unit FT of the first embodiment, the adjustment passage P1 provided with the variable relief valve 41 capable of adjusting the thrust, and the bypass passage P2 provided with the bypass passage opening/closing valve 44 that opens in the damper mode. , the pressure-side damping passage 26 may be connected upstream of the bypass passage opening/closing valve 44 of the bypass passage P2 that is enabled in the damper mode. Further, the thrust force adjusting units FT and FT1 may have three or more parallel passages, and the compression side damping passage 26 is the upstream of the variable relief valve or the opening/closing valve of the passage provided with the variable relief valve or the opening/closing valve. should be connected to As described above, the thrust adjusting units FT, FT1 can adjust the thrust of the cylinder devices C, C1 by controlling the pressure in the upstream cylinder 2 in the actuator mode. The compression-side damping passage 26 may be connected upstream of the variable relief valve or on-off valve of the passage that is in communication during the damper mode.

Further, in the cylinder device C1 of the second embodiment, the thrust force adjustment part FT1 opens when the pressure on the side of the adjustment passage P3 provided in the control passage 40 and the rod side chamber 5 reaches the valve opening pressure. Equipped with a relief valve 46 and a variable relief valve 46 capable of adjusting the valve opening pressure by energization. The passage 26 connects the piston side chamber 6 between the relief valve 46 and the variable relief valve 47 of the adjustment passage P3.

In the cylinder device C1 of the present embodiment configured as described above, even if the thrust force adjustment unit FT1 does not have an on-off valve that shuts off the compression-side damping passage 26 in the actuator mode, the first compression-side relief valve 27 is used in the damper mode. Compression-side damping force can be generated by using this, and the configuration of the thrust force adjustment unit FT1 is simplified, and an on-off valve is not required, so the manufacturing cost of the cylinder device C1 can be reduced.

When the cylinder device C1 of the present embodiment functions as a damper, the extension side relief valve 25 generates a damping force when the telescopic unit 1 is extended, and when the telescopic unit 1 is retracted, the damping force is generated. A damping force can be generated by the first pressure side relief valve (pressure side relief valve) 27 . Therefore, when the cylinder device C1 of the present embodiment functions as a damper, the damping force characteristics during the extension operation and the damping force characteristics during the contraction operation are set to the diameter of the rod 3 and the diameter of the piston 4 (the diameter of the cylinder 2 The same characteristics can be set by setting the expansion side relief valve 25 and the first pressure side relief valve (pressure side relief valve) 27 regardless of the setting of the diameter).

That is, in the cylinder device C1 of the present embodiment, even if the diameter of the rod 3 is reduced to the extent that the strength permits, instead of increasing the diameter of the cylinder 2, the damping force at the time of extension operation when functioning as a damper The characteristic and the damping force characteristic at the time of contraction can be set to be the same. Instead of increasing the diameter of the cylinder 2, if the diameter of the rod 3 is reduced to the extent that the strength permits, the pressure receiving area of the piston 4 can be increased, and the rigidity of the hydraulic oil (liquid) in the telescopic unit 1 ( Since the rigidity of the liquid column can be increased, the cylinder device C of the present embodiment can generate a high damping force with good response when functioning as a damper by increasing the damping coefficient. Therefore, according to the cylinder device C1 of the present embodiment, it is possible to improve the damping coefficient when functioning as a damper while exhibiting the function as an actuator without causing an increase in size. Even if the cross-sectional area of the rod 3 is set to 1/2 of the cross-sectional area of the piston 4 as in the uniflow damper, if the pressure-side passage 32 and the second pressure-side relief valve 33 are provided, the contraction of the cylinder device C1 can be achieved. Since the pressure in the piston-side chamber 6 can be made higher than the pressure in the rod-side chamber 5, the damping coefficient during the contraction operation can be made higher than in the conventional cylinder device. Therefore, if the pressure side passage 32 and the second pressure side relief valve 33 are provided, the degree of freedom in setting the cross-sectional area of the rod 3 and the cross-sectional area of the piston 4 is improved.

Further, in the cylinder device C of the present embodiment, when the motor 15 of the cylinder device C and the valves 11, 13, and 47, which are electromagnetic valves, cannot be energized, the cylinder device C1 automatically enters the damper mode. switch to Therefore, according to the cylinder device C1 of the present embodiment, the damper circuit D1 is automatically activated and switched to the damper mode in the event of failure, so that vibration of the vehicle body S of the railway vehicle T can be suppressed even in the event of failure.

In the cylinder device C1 of the present embodiment, the damper circuit D1 is provided in the extension side suction passage 30 that communicates the tank 7 and the rod side chamber 5, and in the extension side suction passage 30 so that the damper circuit D1 extends from the tank 7 to the rod side chamber 5. It includes an extension side check valve 31 that allows only the flow of hydraulic oil (liquid). According to the cylinder device C1 configured as described above, when the telescopic unit 1 is contracted, the inside of the rod-side chamber 5 does not become negative pressure. It is possible to avoid delaying the generation of the damping force at the time of switching.

Furthermore, in the cylinder device C1 of the present embodiment, the actuator circuit A1 can adjust the valve opening pressure, and has a variable relief valve 47 that adjusts the pressure in the cylinder 2 by adjusting the valve opening pressure. The valve opening pressure of the relief valve 25 is higher than the maximum pressure loss that the thrust force adjustment unit FT1 can take in the actuator mode. In the cylinder device C1 configured in this way, when functioning as an actuator, the hydraulic oil (liquid) supplied from the pump 14 into the cylinder 2 does not escape from the rod-side chamber 5 to the piston-side chamber 6, so the thrust on the contraction side is efficiently generated. can be generated and energy consumption is also reduced.

This concludes the description of the embodiments of the invention, but the scope of the invention is of course not limited to the exact details shown or described.

DESCRIPTION OF SYMBOLS 1... Telescopic unit, 2... Cylinder, 3... Rod, 4... Piston, 5... Rod side chamber, 6... Piston side chamber, 7... Tank, 14... Pump , 24... Expansion side attenuation passage 25... Expansion side relief valve 26... Compression side attenuation passage 27... First compression side relief valve (compression side relief valve) 28... Suction passage 29 Suction check valve 30 Expansion side suction passage 31 Expansion side check valve 40 Control passage 41, 47 Variable relief valve 42 Bypass passage 43 , 46... Relief valve, 44... Bypass passage opening/closing valve, A, A1... Actuator circuit, C, C1... Cylinder device, D, D1... Damper circuit, FT, FT1... Thrust adjustment unit, P1, P3...Adjustment passage, P2...Bypass path, Sol...Solenoid

Claims (3)

a cylinder, a rod movably inserted into the cylinder, and a piston movably inserted into the cylinder and connected to the rod to partition the inside of the cylinder into a rod-side chamber and a piston-side chamber. a telescopic unit;
a tank;
a pump capable of supplying liquid from the tank to the cylinder; an adjustment passage that communicates between the rod-side chamber and the tank and is provided with a variable relief valve along the way; an actuator circuit having a bypass passage in which a relief valve and a bypass passage opening/closing valve are provided in series, and capable of driving the telescopic unit to expand and contract;
an extension-side damping passage communicating between the rod-side chamber and the piston-side chamber; an extension-side relief valve provided in the extension-side damping passage to provide resistance to the flow of liquid from the rod-side chamber to the piston-side chamber; and the piston. A pressure side damping passage connecting a side chamber between the relief valve of the bypass passage and the bypass passage opening/closing valve, and a pressure side provided in the pressure side damping passage to provide resistance to the flow of liquid from the piston side chamber to the tank. a damper circuit including a relief valve, a suction passage communicating between the tank and the piston-side chamber, and a suction check valve provided in the suction passage and allowing liquid to flow from the tank toward the piston-side chamber. ,
The variable relief valve and the bypass passage open/close valve are electromagnetic valves driven by the same solenoid,
The variable relief valve is capable of adjusting valve opening pressure when the solenoid is energized,
the bypass passage opening/closing valve closes when the solenoid is energized and opens when the solenoid is not energized;
Closing the bypass passage opening/closing valve to block the bypass passage in an actuator mode for driving the pump, and opening the bypass passage opening/closing valve to open the bypass passage in a damper mode for stopping the pump. A cylinder device characterized by: a cylinder, a rod movably inserted into the cylinder, and a piston movably inserted into the cylinder and connected to the rod to partition the inside of the cylinder into a rod-side chamber and a piston-side chamber. a telescopic unit;
a tank;
a pump that can supply liquid from the tank to the cylinder; a control passage that communicates the rod-side chamber and the tank; and a thrust adjustment section that is provided in the control passage. an actuator circuit that allows
an extension-side damping passage communicating between the rod-side chamber and the piston-side chamber; an extension-side relief valve provided in the extension-side damping passage to provide resistance to the flow of liquid from the rod-side chamber to the piston-side chamber; and the piston. a compression side damping passage connecting a side chamber to the thrust force adjusting section; a compression side relief valve provided in the compression side damping passage to provide resistance to the flow of liquid from the piston side chamber toward the tank; and separating the tank and the piston side chamber. a damper circuit including a communicating suction passage and a suction check valve provided in the suction passage and allowing liquid to flow from the tank to the piston-side chamber;
The thrust adjustment unit includes an adjustment passage provided in the middle of the control passage, a relief valve that opens when the pressure on the rod side chamber side reaches a valve opening pressure, and a variable valve that can adjust the valve opening pressure by energization. a relief valve, wherein the relief valve and the variable relief valve are arranged in series in the adjustment passage in order from the rod-side chamber side,
A cylinder device, wherein the compression-side damping passage connects the piston-side chamber between the relief valve and the variable relief valve of the adjustment passage. The cylinder device according to claim 1 or 2, wherein a valve opening pressure of said extension side relief valve is higher than a maximum valve opening pressure that said variable relief valve can take in said actuator mode.