JP6666167B2 - Hydraulic actuator - Google Patents

Description

  The invention relates to a hydraulic actuator.

  Conventionally, among hydraulic actuators including a driving unit such as a cylinder device driven by using hydraulic pressure, there is an integrated hydraulic actuator in which a driving unit, a pump, and a reservoir are integrated (for example, , Patent Document 1).

JP 2013-36616 A

  Here, if the liquid in the driving section contains air, the rigidity of the liquid column is reduced and the responsiveness is reduced. Therefore, it is common to use a hydraulic actuator with the driving section air removed. is there. When the hydraulic actuator has a large reservoir whose liquid level is in contact with the outside air, even if air is mixed into the liquid in the drive unit when the liquid is filled into the hydraulic actuator, air can be easily removed. Because, in this case, the air in the liquid collected in the reservoir becomes bubbles, gradually rises in the liquid, and escapes from the liquid surface. Therefore, if the liquid in the reservoir and the liquid in the driving unit are circulated by the pump, the liquid containing air in the circulating driving unit can be gradually replaced with the degassed (ventilated) liquid in the reservoir.

  However, when the liquid level of the reservoir does not come into contact with the atmosphere, it is difficult for air to escape from the liquid in the reservoir. Therefore, in such a hydraulic actuator, once air is mixed into the liquid therein, it is difficult for the liquid to spontaneously escape, and the mixing of air into the liquid may be prevented in advance. In this case, it is necessary to evacuate the air inside the hydraulic actuator by evacuation or the like, and then carefully inject the degassed liquid into the hydraulic actuator, resulting in poor workability.

  Therefore, an object of the present invention is to provide a hydraulic actuator that can easily release air from a driving unit.

According to an aspect of the present invention, there is provided a pump, a driving unit, a closable hydraulic circuit connected to a reservoir, and a liquid supply / discharge unit provided in the driving unit for supplying and discharging liquid to the driving unit. Two ports, a first on-off valve that is provided in a flow path of the hydraulic circuit that communicates with the pump and enables supply of liquid to the pump from outside, and the hydraulic pressure that communicates with one of the ports A second opening / closing valve that is provided in a flow path of a circuit or the driving unit and that is opened by an opening operation to enable the discharge of the liquid from the driving unit to the outside.

  According to the above configuration, even if the liquid in the drive unit contains air, when the drive unit is operated, the liquid containing air in the drive unit is discharged from the second on-off valve to the outside of the hydraulic actuator. In addition, the degassed liquid can be supplied from outside the hydraulic actuator to the inside of the drive unit.

  The invention according to claim 2 has the configuration according to claim 1, and is provided in the flow path of the hydraulic circuit that communicates with the other port or in the drive section, and the liquid from the inside of the drive section to the outside. And a third on-off valve that enables the exhaust of the air. For this reason, air bleeding in the drive unit can be performed quickly and reliably.

  According to a third aspect of the present invention, in addition to the configuration according to the first or second aspect, among the on-off valves, on-off valves other than the first on-off valve function as throttle valves when they are opened. For this reason, air bleeding in the drive unit can be further facilitated.

According to a fourth aspect of the present invention, there is provided the configuration according to any one of the first to third aspects, wherein the first on-off valve is opened to supply liquid to the pump from outside. The reservoir is pre-pressed by closing the on-off valves other than the first on-off valve by the closing operation. Therefore, the liquid column rigidity of the liquid in the driving unit can be increased, and the responsiveness of the operation can be improved. According to a fifth aspect of the present invention, in addition to the configuration according to any one of the first to fourth aspects, the hydraulic circuit is provided with a housing. A connection port that is separably connected to an external reservoir that collects liquid discharged from the driving unit to the outside through an opening / closing valve other than the first opening / closing valve; An on-off valve other than the on-off valve is provided upstream of the connection port. For this reason, an external reservoir can be provided externally, and the hydraulic actuator does not increase in size. According to a sixth aspect of the present invention, in addition to the configuration according to any one of the first to fifth aspects, the drive unit includes a cylinder, and a drive unit that is movably inserted into the cylinder so as to be movable in the cylinder. A piston that defines one working chamber; and a rod that is inserted into the cylinder and connected to the piston. Then, one of the ports communicates with one of the working chambers, and the other port communicates with the other of the working chambers. That is, the drive unit is a direct-acting cylinder device, and the expansion and contraction of the cylinder device can be switched by switching the port that receives the supply of liquid from the pump side.

According to a seventh aspect of the present invention, in addition to the configuration of the sixth aspect , the piston is connected to a distal end portion of the rod, and one of the ports communicates with the working chamber on the rod side. ing. Therefore, even when the third on-off valve is not provided, the liquid in the rod side chamber can be discharged from the second on-off valve to the outside of the hydraulic actuator.

According to an eighth aspect of the present invention, in addition to the configuration according to any one of the first to seventh aspects, the hydraulic circuit includes a circulation passage connecting the pump and the two ports, and the circulation passage. And a reservoir passage connecting the reservoir and the reservoir. As described above, when the pump and the drive unit are connected in a closed circuit, it takes time to release air even if air can be released from the reservoir. Therefore, it is particularly effective to provide at least the first and second on-off valves when the hydraulic actuator has the above-mentioned hydraulic circuit.

  ADVANTAGE OF THE INVENTION According to the hydraulic actuator of this invention, air bleeding in a drive part can be made easy.

FIG. 2 is a circuit diagram showing a state in which the hydraulic actuator according to one embodiment of the present invention is connected to an external hydraulic pressure supply source and an external reservoir. FIG. 2 is an enlarged view specifically illustrating first, second, and third on-off valves of FIG. 1. FIG. 9 is a circuit diagram showing a state where a hydraulic actuator according to a modification of the embodiment of the present invention is connected to an external hydraulic pressure supply source and an external reservoir.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same reference numbers throughout the several figures indicate the same or corresponding parts.

Hydraulic actuator A according to an embodiment of the present invention shown in FIG. 1, for example, is utilized to control the control surface of an aircraft, a cylinder device for transmitting the thrust of the hydraulic actuator A to the drive target of the control surface such as 1, a pump 2 for driving the cylinder device 1, a reservoir 3, and a hydraulic circuit 4 connecting these components. Although not shown in detail, the cylinder device 1, the pump 2, and the reservoir 3 are integrated by a housing H, and the hydraulic circuit 4 is formed in the housing H.

  The cylinder device 1 is a driving unit that is driven by receiving a supply of hydraulic pressure from a pump 2, and includes a cylindrical cylinder 10, a piston 11 slidably inserted into the cylinder 10, and FIG. A rod 12 has a left end connected to the piston 11 and a right end extending outside the cylinder 10. The cylinder device 1 expands and contracts when the rod 12 moves in and out of the cylinder 10, and the driven object is driven as the cylinder device 1 expands and contracts.

  The inside of the cylinder 10 is axially partitioned by a piston 11, and two working chambers R <b> 1 and R <b> 2 are formed in the cylinder 10 with the piston 11 as a boundary. These working chambers R1, R2 are filled with liquid such as working oil. Hereinafter, of the two working chambers R1 and R2, the working chamber on the rod 12 side is called a rod side chamber R1, and the working chamber on the piston 11 side is called a piston side chamber R2. The cylinder 10 is formed with two ports, a rod side port 10a communicating with the rod side chamber R1 and a piston side port 10b communicating with the piston side chamber R2. Therefore, the liquid can move into and out of the cylinder device 1 through the rod-side port 10a and the piston-side port 10b.

  Note that the position where the port that allows the liquid to move in and out of the cylinder device 1 is provided is not limited to the cylinder 10. For example, the rod-side port 10a may be provided in an annular rod guide that rotatably supports the rod 12 and closes one end of the cylinder 10. The piston-side port 10b closes the other end of the cylinder 10. It may be provided on the bottom cap.

  Subsequently, the pump 2 for supplying hydraulic pressure to the cylinder device 1 is a bidirectional discharge type electric hydraulic pump driven by the electric motor 20, and has two ports 2a and 2b. When driven by the electric motor 20, the pump 2 discharges the liquid sucked from one of the two ports 2a and 2b from the other port, and changes the discharge direction by the forward / reverse rotation of the electric motor 20. Is switched. Further, the pump 2 is rotationally driven when supplied with the hydraulic pressure, and rotationally drives the electric motor 20. The motor 20 generates electric power when driven to rotate in this way, and functions not only as a motor but also as a generator.

  Further, the pump 2 is connected to the cylinder device 1 through the circulation passage 40. More specifically, the circulation passage 40 connects the one port 2a of the pump 2 to the rod-side port 10a of the cylinder device 1 and the other port 2b of the pump 2 and the piston-side port 10b of the cylinder device 1. A closed circuit is formed by continuously connecting the cylinder device 1 and the pump 2 so that the liquid can circulate.

  The reservoir 3 is connected to the circulation passage 40 via a reservoir passage 41. The reservoir passage 41 has one end connected to the passage 40a and communicating with the rod side chamber R1, and the other end connected to the passage 40b. It communicates with the piston side chamber R2. Further, a shuttle valve 5 that communicates the low pressure side of the rod side chamber R1 and the piston side chamber R2 of the cylinder device 1 with the reservoir 3 is provided in the middle of the reservoir passage 41.

  A liquid and a gas are sealed in the reservoir 3. The gas is sealed in the gas chamber while compressing the gas, so that the pressure in the reservoir 3 is increased and a pre-pressure is applied to the liquid. Further, the inside of the reservoir 3 is partitioned into a gas chamber for storing gas and a liquid chamber for storing liquid by partition walls such as a bladder, a free piston, and a bellows. When the reservoir 3 is pre-pressed in this way, the reservoir 3 is communicated with the inside of the cylinder device 1 via the hydraulic circuit 4, so that the liquid column rigidity of the liquid in the cylinder device 1 is increased to improve the responsiveness of the operation. it can.

  Further, a supply passage 42 communicating with the outside of the hydraulic actuator A is connected to a portion connecting the shuttle valve 5 and the reservoir 3 in the reservoir passage 41, and an external passage provided outside the hydraulic actuator A in the supply passage 42. External hydraulic pressure supply 6 can be connected. The supply path 42 is provided with a first on-off valve 7 for opening and closing the supply path 42.

  Discharge paths 43 and 44 communicating with the outside of the hydraulic actuator A are connected to the passages 40 a and 40 b constituting the circulation path 40, and the liquid in the cylinder device 1 is supplied from the discharge paths 43 and 44 to the hydraulic actuator A. A can be discharged to external reservoirs 8A and 8B provided outside A. A second opening / closing valve 9A that opens and closes the discharge path 43 is provided in the discharge path 43 that communicates with the rod-side port 10a, and the discharge path 44 that opens and closes the discharge path 44 that communicates with the piston-side port 10b. A third on-off valve 9B is provided.

  As described above, in the present embodiment, the pump 2, the reservoir 3, and the hydraulic circuit 4 of the hydraulic actuator A connected to the cylinder device 1 are connected to the circulation passage 40, the reservoir passage 41, and these. And a supply path 42 and discharge paths 43 and 44.

  The first opening / closing valve 7 provided in the supply path 42 is designed so as not to become a throttle at least in a fully opened state, and quickly supplies the liquid from the external hydraulic pressure supply source 6 to the inside of the hydraulic actuator A. it can. On the other hand, the second and third on-off valves 9A and 9B provided in the discharge passages 43 and 44 are set so that the discharge passages 43 and 44 can be throttled in the opened state, and the pressure inside the cylinder device 1 is reduced. Can be enhanced.

  Specifically, the first, second, and third on-off valves 7, 9A, 9B in the present embodiment are screw-in stop valves, as shown in FIG. 2, and are opened and closed by manual operation. The supply passage 42 and the discharge passages 43 and 44 each have a portion that bends at a right angle, and the valve heads V1, V2, and V3 of the first, second, and third on-off valves 7, 9A, and 9B are provided in the portion. V3 are inserted.

  When the first on-off valve 7 is rotated to retreat the valve head V1 from the valve seat S1 provided in the middle of the supply path 42, the liquid can pass through the supply path 42 without resistance. When the second and third on-off valves 9A and 9B are rotated to slightly retreat the valve heads V2 and V3 from the valve seats S2 and S3 provided in the middle of the discharge passage 43, the outer circumferences of the valve heads V2 and V3 are reduced. A small gap is formed in Then, the second and third opening / closing valves 9A and 9B give resistance to the flow of the liquid passing through the discharge passages 43 and 44, and the pressure in the cylinder device 1 is increased to the external pressure (the pressure outside the hydraulic actuator A). Can be higher. That is, the second and third on-off valves 9A and 9B can function as throttle valves in the open state. Reference numeral V2 shown in FIG. 2 indicates a valve head of the second on-off valve 9A, and reference numeral S2 indicates a valve seat on which the valve head V2 is detached and seated. Further, reference numeral V3 shown in FIG. 2 indicates a valve head of the third on-off valve 9B, and reference numeral S3 indicates a valve seat on which the valve head V3 is detached and seated.

  When the first, second, and third on-off valves 7, 9A, 9B are screwed in and the valve heads V1, V2, V3 are pressed against the valve seats S1, S2, S3, the first, second, and third valves are opened. Valves 7, 9A, 9B are closed, and the supply path 42 and the discharge paths 43, 44 are closed. Then, the hydraulic circuit 4 can be shut off from the outside by the first, second, and third on-off valves 7, 9A, 9B, and the hydraulic circuit 4 can be closed. Further, the connection ports to the supply passage 42 and the discharge passages 43 and 44 which are opened at the end of the housing H are closed by plugs such as plugs after the operation of filling the hydraulic actuator A with liquid, which will be described later. The hydraulic actuator A is completed and used.

  The first, second, and third on-off valves 7, 9A, and 9B are screw-in stop valves and have a very simple structure. Also, the hydraulic actuator A does not increase in size. However, the first, second, and third on-off valves 7, 9A, 9B may be valves other than stop valves, for example, valves that are automatically opened and closed.

  Hereinafter, a liquid filling operation to the hydraulic actuator A according to the present embodiment will be described.

  First, in the empty state where the liquid is not injected, as shown in FIG. 1, the supply path 42 of the hydraulic actuator A is connected to the external hydraulic supply source 6, and the discharge paths 43 and 44 of the hydraulic actuator A are connected. Are connected to the external reservoirs 8A and 8B. With this operation, the external hydraulic pressure supply source 6 and the external reservoirs 8A and 8B are connected to the hydraulic actuator A.

  Next, the first, second, and third on-off valves 7, 9A, 9B are opened. At this time, the first on-off valve 7 is greatly opened so that the liquid can be quickly supplied from the external hydraulic pressure supply source 6 to the inside of the hydraulic actuator A. On the other hand, the degree of opening of the second and third on-off valves 9A and 9B is such that resistance is given to the flow of the liquid flowing from the inside of the hydraulic actuator A to the external reservoirs 8A and 8B through the discharge passages 43 and 44. , Slightly opened. That is, the second and third on-off valves 9A and 9B are opened so as to function as throttle valves.

  Next, a low-pressure liquid is supplied from the external hydraulic pressure supply source 6 into the hydraulic actuator A. In the supply process, when the pressures in the rod-side chamber R1 and the piston-side chamber R2 are equal, the shuttle valve 5 allows the supply path 42 to communicate with the passages 40a and 40b, so that both the rod-side chamber R1 and the piston-side chamber R2 are connected. The liquid from the external hydraulic pressure supply 6 is supplied. When the pressure in the rod-side chamber R1 becomes higher than the pressure in the piston-side chamber R2, the valve body 5a of the shuttle valve 5 moves to the left in FIG. 1 to cut off the communication between the supply passage 42 and the passage 40a, and the passage 40b The liquid from the external hydraulic pressure supply source 6 is supplied only to the low-pressure-side piston side chamber R2 in order to allow only the communication between the fluid and the supply path 42. Conversely, when the pressure in the piston side chamber R2 becomes higher than the pressure in the rod side chamber R1, the valve element 5a of the shuttle valve 5 moves rightward in FIG. 1 to cut off the communication between the supply passage 42 and the passage 40b, and The liquid from the external hydraulic pressure supply source 6 is supplied only to the low pressure side rod-side chamber R1 to allow only the communication between the supply passage 40a and the supply path 42.

  The liquid supplied from the external hydraulic pressure supply source 6 to the hydraulic actuator A is a degassed liquid, but air exists in the hydraulic actuator A before the liquid is filled. Therefore, when the liquid is first supplied from the external hydraulic pressure supply source 6 into the hydraulic actuator A, air is mixed in the liquid within the hydraulic actuator A.

  Next, the pump 2 is driven by the electric motor 20 to extend and contract the cylinder device 1 while supplying the liquid from the external hydraulic pressure supply source 6 to the inside of the hydraulic actuator A. Then, the air in the cylinder device 1 is released by repeating the expansion and contraction operation.

  Specifically, when the cylinder device 1 is extended, the pump 2 is driven by the electric motor 20 to discharge the liquid sucked from the passage 40a to the passage 40b. Then, since the third on-off valve 9B is throttled, the pressure in the piston side chamber R2 increases, so that the shuttle valve 5 cuts off the communication between the passage 40b and the reservoir 3 and the external hydraulic pressure supply source 6, and also opens the passage 40a. And the reservoir 3 and the external hydraulic pressure source 6 are allowed to communicate with each other. Then, due to the pressure of the piston side chamber R2, the piston 11 moves rightward in FIG. 1, the rod 12 retreats from the cylinder 10, and the cylinder device 1 extends.

  When the cylinder device 1 performs the extension operation, the liquid corresponding to the rod volume withdrawn from the cylinder 10 and the liquid leaking from the third on-off valve 9B to the external reservoir 8B are supplied to the external hydraulic pressure supply source 6 (reservoir 3). When the liquid is stored in both the reservoir 3 and the external hydraulic pressure supply source 6), the liquid is supplied to the passage 40a, and supplied to the pump 2 together with the liquid flowing out of the rod side chamber R1 to the passage 40a. Further, the supply amount of the liquid from the external hydraulic pressure supply source 6 to the passage 40a is such that a part of the liquid flowing from the rod side chamber R1 to the pump 2 slightly leaks from the second on-off valve 9A to the external reservoir 8A. This prevents the liquid sucked from the pump 2 from being insufficient and sucking air from the second on-off valve 9A.

  Conversely, when the cylinder device 1 is contracted, the pump 2 is driven by the electric motor 20 to discharge the liquid sucked from the passage 40b to the passage 40a. Then, since the second opening / closing valve 9A is throttled, the pressure in the rod-side chamber R1 increases, and the shuttle valve 5 cuts off the communication between the passage 40a and the reservoir 3 and the external hydraulic pressure supply source 6, and also opens the passage 40b. And the reservoir 3 and the external hydraulic pressure source 6 are allowed to communicate with each other. Then, due to the pressure of the rod side chamber R1, the piston 11 moves to the left in FIG. 2, the rod 12 enters the cylinder 10, and the cylinder device 1 contracts.

  In addition, when the cylinder device 1 performs the contraction operation, the amount of liquid that is obtained by subtracting the amount of liquid leaking to the external reservoir 8A through the second on-off valve 9A from the liquid corresponding to the rod volume entering the cylinder 10 moves to the reservoir 3. Further, a part of the liquid flowing from the piston side chamber R2 toward the reservoir 3 slightly leaks from the third on-off valve 9B to the external reservoir 8B, thereby preventing air from being sucked from the third on-off valve 9B.

  As described above, when the cylinder device 1 is expanded and contracted while supplying the liquid from the external hydraulic pressure supply source 6 to the hydraulic actuator A, a large amount of air is mixed at a stage where the number of times of expansion and contraction of the cylinder device 1 is small. The liquid is discharged from the second and third on-off valves 9A, 9B to the external reservoirs 8A, 8B. However, when the number of repetitions of expansion and contraction of the cylinder device 1 increases, the liquid containing a large amount of air in the cylinder device 1 is gradually replaced with the degassed liquid supplied from the external hydraulic pressure supply source 6. In the expansion and contraction operation of the cylinder device 1 in the liquid filling step, the liquid discharged from the second and third opening / closing valves 9A and 9B becomes the degassed liquid, and the air release in the cylinder device 1 is completed. Is repeated until.

  In the present embodiment, the liquid is hydraulic oil, which is transparent in a degassed state, but becomes cloudy due to mixing of air. Therefore, in the stage where the number of expansions and contractions of the cylinder device 1 is small, the turbid operating oil flows out of the second and third on-off valves 9A and 9B, and the transparency increases as the number of expansions and contractions increases. For this reason, when such a liquid is used in the hydraulic actuator A, the bleeding of air from the cylinder device 1 is performed when the liquid flowing out of the second and third on-off valves 9A and 9B becomes transparent. It can be visually determined that the process is completed. The method of checking the residual air in the cylinder device 1 is appropriately changed depending on the type of liquid used, the allowable air content of the liquid, and the like.

  Next, the pump 2 is stopped while the supply of the liquid from the external hydraulic pressure source 6 to the hydraulic actuator A is continued, the second and third on-off valves 9A and 9B are closed, and the pressure in the reservoir 3 is adjusted to a predetermined value. After the pressure is raised to the pressure, the first on-off valve 7 is closed. By this operation, the reservoir 3 is pre-pressed and the hydraulic circuit 4 is disconnected from the outside.

  Finally, the external hydraulic pressure source 6 and the external reservoirs 8A, 8B are separated from the hydraulic actuator A, and the connection ports of the supply path 42 and the discharge paths 43, 44 formed at the end of the housing H are plugged. Then, the operation of filling the liquid into the hydraulic actuator A is completed.

  Hereinafter, the operation of the hydraulic actuator A that has completed the liquid filling operation will be described.

  When the cylinder device 1 is extended, the pump 2 is driven by the electric motor 20 to discharge the liquid sucked from the passage 40a to the passage 40b. Then, the valve element 5a of the shuttle valve 5 moves rightward in FIG. 1 to allow communication between the rod-side chamber R1 and the reservoir 3 and also cut off communication between the piston-side chamber R2 and the reservoir 3. For this reason, the liquid is supplied to the piston side chamber R2 and the pressure in the piston side chamber R2 rises, but the pressure in the rod side chamber R1 is maintained at the pressure of the reservoir 3 (hereinafter referred to as reservoir pressure), and the piston side chamber R2 and the rod side chamber A differential pressure occurs in R1. Then, the piston 11 moves rightward in FIG. 1 in response to the pressure difference, the rod 12 retreats from the cylinder 10, the cylinder device 1 extends, and the liquid corresponding to the rod volume retreated from the cylinder 10 is supplied to the reservoir 3. Is supplied to the passage 40a.

  Conversely, when the cylinder device 1 is contracted, the pump 2 is driven by the electric motor 20 to discharge the liquid sucked from the passage 40b to the passage 40a. Then, the valve element 5a of the shuttle valve 5 moves to the left in FIG. 1 to allow communication between the piston side chamber R2 and the reservoir 3 and also cut off communication between the rod side chamber R1 and the reservoir 3. Therefore, the liquid is supplied to the rod-side chamber R1, and the pressure in the rod-side chamber R1 increases, but the pressure in the piston-side chamber R2 is maintained at the reservoir pressure, and a pressure difference occurs between the rod-side chamber R1 and the piston-side chamber R2. Then, receiving the pressure difference, the piston 11 moves to the left in FIG. 1, the rod 12 enters the cylinder 10, the cylinder device 1 contracts, and the liquid corresponding to the rod volume entered the cylinder 10 Move from the side chamber R2 to the reservoir 3.

  That is, in the hydraulic actuator A, by controlling the number of rotations of the electric motor 20 in the forward and reverse directions, the flow rate of the liquid discharged from the pump 2 is supplied to the cylinder device 1 as it is, and the cylinder device 1 is driven by expanding and contracting operation. Can operate the target. Further, when the cylinder device 1 is extended and contracted by an external force acting on a driven object, the electric motor 20 is driven to rotate to generate electric power.

  Hereinafter, the operation and effect of the hydraulic actuator A according to the present embodiment will be described.

  In the present embodiment, the hydraulic circuit 4 includes a circulation passage 40 that connects the pump 2 with the rod-side port (port) 10a and the piston-side port (port) 10b, and a reservoir passage that connects the circulation passage 40 with the reservoir 3. 41. That is, the pump 2 and the cylinder device 1 are connected by the circulation passage 40 to form a closed circuit. Therefore, the liquid discharged from the pump 2 is directly supplied to the cylinder device 1 so that the cylinder device 1 can be expanded and contracted.

  Further, when the pump 2 and the cylinder device 1 are connected in a closed circuit, only the liquid corresponding to the rod projecting / retracting volume moves between the reservoir 3 and the cylinder device 1, so that the pump 2 and the cylinder device 1 are connected in an open circuit. Then, the liquid sucked up from the reservoir (tank) by the pump 2 is supplied to the cylinder device 1 and the capacity of the reservoir can be reduced as compared with the case where the liquid discharged from the cylinder device 1 is returned to the reservoir. However, if the reservoir volume is reduced in this way, even if the reservoir 3 is opened to the atmosphere and air is released from the liquid level of the liquid in the reservoir 3, it takes time to release the air. Therefore, like the hydraulic actuator A, the external hydraulic pressure source 6 and the external reservoirs 8A and 8B can be externally attached to the hydraulic actuator A, and the external hydraulic pressure source 6 and the cylinder device 1 are opened. If the connection can be made by using, the time required for air bleeding can be further reduced.

  In the reservoir passage 41, a low-pressure priority type shuttle valve 5 for communicating the low-pressure side chamber of the rod-side chamber R1 and the piston-side chamber R2 with the reservoir 3 is provided, and the shuttle valve 5 and the reservoir in the reservoir passage 41 are connected to each other. 3 is connected to a supply path 42 that is connected to the external hydraulic pressure supply source 6. Therefore, even if the number of the external hydraulic pressure supply sources 6 is one, the external hydraulic pressure supply source 6 and the reservoir 3 can be communicated with the chamber of the rod side chamber R1 and the piston side chamber R2 on the side sucked by the pump 2.

  The configuration of the hydraulic circuit 4 is not limited to the above, and can be changed as appropriate. For example, if an on-off valve functioning as a throttle valve is provided upstream of the reservoir, the pump 2 and the cylinder device 1 may be connected in an open circuit. The supply source 6 may be connected to the passages 40a and 40b, respectively. Further, in the hydraulic actuator A, since the pump 2 is a bidirectional discharge type electric hydraulic pump, the discharge direction of the pump 2 can be changed by changing the rotation direction of the electric motor 20, but the pump 2 is moved only in one direction. Instead of a pump that discharges, a switching valve provided in the circulation passage 40 may be configured to selectively supply hydraulic pressure to the rod-side chamber R1 and the piston-side chamber R2. In addition, since the cylinder device 1 is a single rod type having a rod 12 extending from one side of the piston 11 to the outside of the cylinder 10, the shuttle valve 5 is provided, as shown in FIG. When the cylinder device 100 is configured as a double rod type having the rods 112 extending from both sides of the piston 11 to the outside of the cylinder 10, the pair of check valves 50 and 51 are reversed in place of the shuttle valve 5. The reservoir 3 and the external hydraulic pressure source 6 may be connected between the check valves 50 and 51.

  In the present embodiment, the piston 11 of the cylinder device 1 is connected to the tip of the rod 12, and the rod-side port (one port) 10a communicates with the rod-side chamber (rod-side working chamber) R1. ing. According to this configuration, when the third on-off valve 9B is omitted as described later, the liquid in the rod side chamber R1 can be discharged to the outside of the hydraulic actuator A by the second on-off valve 9A.

  When the cylinder device 1 has a single rod type like the hydraulic actuator A, when the cylinder device 1 is expanded and contracted in the liquid filling step, a rod is opened from the third opening / closing valve 9B communicating with the piston side chamber R2. It has been confirmed that the degassed liquid is discharged before the liquid discharged from the second on-off valve 9A communicating with the side chamber R1. From this, in the single rod type cylinder device 1, it is considered that the rod side chamber R1 is less likely to release air than the piston side chamber R2. Therefore, in the case of the hydraulic actuator A having the single rod type cylinder device 1 and discharging the liquid only from one of the rod side chamber R1 and the piston side chamber R2, the rod side chamber R1 from which air is difficult to escape is connected to the external reservoir. It would be preferable to connect to 8A.

  When the cylinder device 1 is expanded and contracted in the liquid filling step, the liquid containing air is also discharged from the third on-off valve 9B in a stage where the number of times of expansion and contraction is small. For this reason, the third on-off valve 9B is abolished and the liquid is discharged from one of the rod-side chamber R1 and the piston-side chamber R2 to bleed the air, and the hydraulic actuator has a single rod type cylinder device. However, the second on-off valve 9A may be provided at a portion communicating with the piston side chamber R2, and only the piston side chamber R2 may be connected to the external reservoir 8B. Such a change is possible regardless of the configuration of the hydraulic circuit 4 and the configuration of the cylinder device 1.

  In the present embodiment, the cylinder device (drive unit) 1 includes a cylinder 10, a rod-side chamber (operating chamber) R1 and a piston-side chamber (operating chamber) which are movably inserted into the cylinder 10 and are provided in the cylinder 10. It has a piston 11 for defining R2, and a rod 12 inserted into the cylinder 10 and connected to the piston 11. The rod port (one port) 10a of the two ports for supplying and discharging the liquid into the cylinder device 1, that is, the rod port 10a and the piston port 10b, is the rod side chamber (one working chamber) R1. , The piston side port (the other port) 10b communicates with the piston side chamber (the other working chamber) R2.

  That is, in the present embodiment, the driving unit that is driven by receiving the hydraulic pressure from the pump 2 is the cylinder device 1 and supplies the liquid into the cylinder 10 from one of the rod-side port 10a and the piston-side port 10b. When the liquid is discharged to the outside of the cylinder 10 from the other side, the liquid expands or contracts, and the expansion and contraction can be switched by switching the supply and discharge ports. Note that the drive unit may not be the cylinder device 1 and may be, for example, a hydraulic motor. The change is possible regardless of the configuration of the hydraulic circuit 4.

  In the present embodiment, of the first, second, and third on-off valves 7, 9A, and 9B, on-off valves other than the first on-off valve 7, that is, the second and third on-off valves 9A, 9A, and 9B. 9B functions as a throttle valve when the valve is opened. Therefore, when the hydraulic pressure is supplied to the rod-side chamber R1 or the piston-side chamber R2 by the pump 2 at the time of filling the hydraulic actuator A with the liquid, the pressure in the rod-side chamber R1 or the piston-side chamber R2 increases, and the cylinder device 1 is caused to expand and contract. In addition, when the cylinder device 1 expands and contracts, of the rod-side chamber R1 and the piston-side chamber R2, the chamber connected to the pump 2 passes through the second or third opening / closing valves 9A and 9B to the outside of the hydraulic actuator A. And the air is discharged together with the liquid. Therefore, according to the above configuration, since the cylinder device 1 can be operated by the pump 2, the air bleeding operation in the cylinder device 1 can be further facilitated.

  In the hydraulic actuator A, the second and third on-off valves 9A and 9B are the on-off valves that enable the liquid to be discharged from the inside of the cylinder device 1 that is the driving unit to the external reservoirs 8A and 8B. These are made to function as throttle valves. However, an on-off valve that enables the liquid to be discharged from the drive unit to the outside of the hydraulic actuator may be a throttle valve, and the number of on-off valves used as the throttle valve can be appropriately changed depending on the number and configuration of the discharge paths. Further, for example, when the rod 12 is pushed or pulled manually or automatically to expand and contract the cylinder device 1 to release air from the cylinder device 1, or to throttle the downstream of the second and third on-off valves 9A and 9B. In this case, the second and third on-off valves 9A and 9B do not need to function as throttle valves. These changes can be made regardless of the configuration of the hydraulic circuit 4 and the configuration of the drive unit.

  In the present embodiment, the hydraulic actuator A includes a pump 2, a cylinder device (drive unit) 1 driven by receiving a supply of hydraulic pressure from the pump 2, a reservoir 3, and a cylinder device 1. , A pump 2, a closable hydraulic circuit 4 connected to the reservoir 3, a rod-side port (port) 10 a provided in the cylinder device 1 for supplying and discharging liquid to the inside of the cylinder device 1, and a piston side A port (port) 10 b, a first opening / closing valve 7 provided in a supply path (flow path) 42 of the hydraulic circuit 4 communicating with the pump 2 and enabling supply of liquid to the pump 2 from the outside, and a rod A second opening / closing valve 9A provided in a discharge path (flow path) 43 of the hydraulic circuit 4 communicating with the side port (one port) 10a and enabling discharge of liquid from inside the cylinder device 1 to the outside; Piston side port (other Provided in the discharge path (flow path) 44 of the hydraulic circuit 4 leading to the port) 10b, and a third on-off valve 9B to allow the discharge of liquid to the outside from the cylinder device 1. Here, the outside is outside of the hydraulic actuator A. In the hydraulic actuator A, the supply of the liquid from the external hydraulic pressure supply source 6 to the pump 2 is enabled by opening the first on-off valve 7. In addition, by opening the second and third on-off valves 9A and 9B, the liquid discharged from the inside of the cylinder device 1 to the outside can be collected in the external reservoirs 8A and 8B.

  According to the above configuration, when the first, second, and third on-off valves 7, 9A, and 9B are opened, the hydraulic circuit 4 is opened to the outside of the hydraulic actuator A, and the supply of the liquid from outside to the outside is performed. Liquid can be discharged. Therefore, when the cylinder device 1 is expanded and contracted while supplying the degassed liquid from the external hydraulic pressure supply source (external) 6 to the hydraulic actuator A at the time of filling the hydraulic actuator A with the liquid, air is contained. The liquid can be discharged from the hydraulic actuator A to the external reservoirs (external) 8A, 8B. That is, the hydraulic actuator A has the reservoir 3 to be pre-pressed, and even if it has a structure in which air does not escape from the liquid stored in the reservoir 3, it is easy to bleed air from the cylinder device 1 which is a driving unit. Can be. Therefore, there is no need to worry about mixing of air into the liquid when the liquid is filled into the hydraulic actuator A, and the liquid filling operation can be facilitated.

  Further, the hydraulic actuator A has a structure in which the reservoir 3 is pre-pressed, and gas-liquid in the reservoir 3 is partitioned by a partition. When the hydraulic actuator having such a reservoir cannot discharge the liquid mixed with air to the outside during the liquid filling process (for example, Japanese Patent Application Laid-Open No. 2013-36616), once air is mixed into the hydraulic actuator, It does not escape naturally. For this reason, in the hydraulic actuator, it is necessary to prevent air from being mixed into the liquid during the entire liquid filling process. Therefore, after evacuating the air inside the hydraulic actuator by evacuation or the like, the degassed liquid is carefully injected into the hydraulic actuator as well as once the liquid is filled into the liquid due to an operation mistake during the filling of the liquid. If air is mixed in, the workability is extremely poor because it is necessary to remove the liquid from the hydraulic actuator, deaerate, and restart the filling operation from the beginning. Therefore, it is particularly effective to provide the first, second and third on-off valves 7, 9A and 9B in the actuator A having the pre-loaded reservoir 3.

Further, according to the above configuration, when the first, second, and third on-off valves 7, 9A, 9B are closed, the hydraulic circuit 4 is closed, and the hydraulic actuator A does not receive the supply of liquid from outside. Can also work. That is, the hydraulic actuator A can be used separately from the external hydraulic pressure supply source 6 that supplies the liquid from the outside to the pump 2 and the external reservoirs 8A and 8B that collect the liquid discharged from the cylinder device 1 to the outside. Therefore, for example, even if the external reservoirs 8A, 8B are made large and the liquid stored in the external reservoirs 8A, 8B and bleed is returned from the external hydraulic pressure supply source 6 to the inside of the hydraulic actuator A, The hydraulic actuator A itself does not increase in size. Further, the liquid sucked up from the external hydraulic pressure supply source 6 does not have to be collected in the external reservoirs 8A and 8B. Further, in FIG. 1, the external reservoir 8A which recovers the liquid flowing out of the second on-off valve 9A, described by dividing the external reservoir 8B to recover the spilled liquid body from the third on-off valve 9B However, they may be connected and integrated, or may be separated and separated.

  In the present embodiment, the second and third on-off valves 9A, 9B are provided in the discharge paths 43, 44 constituting the hydraulic circuit 4 in order to discharge the liquid from inside the cylinder device 1 to the outside of the hydraulic actuator A. Are provided, but these may be provided in the cylinder device 1. Further, the hydraulic actuator A of the present embodiment includes the second and third opening / closing valves 9A and 9B and can discharge the liquid from both sides to the outside of the hydraulic actuator A. Prompt and reliable. However, the third on-off valve 9B may be omitted, and the liquid in the cylinder device 1 may be discharged to the outside of the hydraulic actuator A only from the second on-off valve 9A.

  In this manner, when the discharge on-off valve is only the second on-off valve 9A, the second on-off valve 9A is provided in the discharge passage 43 or in a portion communicating with the rod-side chamber R1 of the cylinder device 1, and the rod-side chamber R1 is provided. May be discharged to the outside of the hydraulic actuator A, and the second opening / closing valve 9A is provided in the discharge path 44 or a portion communicating with the piston side chamber R2 of the cylinder device 1, and the liquid in the piston side chamber R2 is discharged. The pressure may be discharged to the outside of the actuator A. Further, when the second and third on-off valves 9A and 9B are provided in the discharge passages 43 and 44 (the hydraulic circuit 4), the rod side port 10a and the It is preferable to connect the discharge paths 43 and 44 to positions near the piston-side port 10b, but the connection positions can be changed as appropriate.

  Further, in the present embodiment, the hydraulic actuator A is used for an aircraft, but may be used for a railway vehicle or the like, and the drive target can be appropriately changed.

  These changes can be made regardless of the configuration of the hydraulic circuit 4 and the configuration of the drive unit.

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

A: hydraulic actuator, R1: rod-side chamber (one working chamber), R2: piston-side chamber (other working chamber), 1,100: cylinder device (drive unit), 2,. Pump, 3 ... Reservoir, 4 ... Hydraulic circuit, 7 ... First on-off valve, 9A ... Second on-off valve, 9B ... Third on-off valve, 10 ...・ Cylinder, 10a ・ ・ ・ Rod side port (one port), 10b ・ ・ ・ Piston side port (other port), 11 ・ ・ ・ Piston, 12, 112 ・ ・ ・ Rod, 40 ・ ・ ・ Circulation passage, 41 ... reservoir passage, 42 ... supply path (flow path leading to the pump of the hydraulic circuit), 43 ... discharge path (flow path leading to one port of the hydraulic circuit), 44 ... discharge Road (flow path to the other port of the hydraulic circuit)

Claims (8)

Pump and
A drive unit driven by receiving the supply of the hydraulic pressure from the pump,
With a reservoir,
The drive unit, the pump, and a hydraulic circuit connected to the reservoir,
Two ports provided on the drive unit for supplying and discharging liquid to the drive unit;
A first on-off valve provided in a flow path of the hydraulic circuit that communicates with the pump, and enables supply of liquid to the pump from outside,
A second opening / closing valve provided in the flow path of the hydraulic circuit communicating with one of the ports or in the driving section, and being opened by an opening operation to enable discharge of liquid from the driving section to the outside; A hydraulic actuator comprising: A third on-off valve which is provided in a flow path of the hydraulic circuit communicating with the other port or in the drive unit and enables discharge of liquid from inside the drive unit to the outside. 2. The hydraulic actuator according to 1. The hydraulic actuator according to claim 1, wherein, among the on-off valves, on-off valves other than the first on-off valve function as throttle valves when the valve is opened. In a state where the first on-off valve is opened and liquid is supplied to the pump from the outside, the on-off valves of the on-off valves other than the first on-off valve are closed by a closing operation. Reservoir is preloaded
The hydraulic actuator according to any one of claims 1 to 3, wherein: A housing in which the hydraulic circuit is formed,
The housing has a connection port that is separably connected to an external reservoir that collects liquid discharged from the driving unit to the outside through an opening / closing valve other than the first opening / closing valve among the opening / closing valves. ,
Of the on-off valves, on-off valves other than the first on-off valve are provided upstream of the connection port.
The hydraulic actuator according to any one of claims 1 to 4, wherein: The drive unit includes a cylinder, a piston movably inserted into the cylinder and defining two working chambers in the cylinder, and a rod inserted into the cylinder and connected to the piston. ,
One of the ports communicates with one of the working chambers,
The hydraulic actuator according to any one of claims 1 to 5 , wherein the other port communicates with the other working chamber. The piston is connected to a tip of the rod,
The hydraulic actuator according to claim 6 , wherein the one port communicates with the working chamber on the rod side. The said hydraulic circuit has the circulation path which connects the said pump and two said ports, and the reservoir path which connects the said circulation path and the said reservoir.The any one of Claim 1 to 7 characterized by the above-mentioned. A hydraulic actuator as described.

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