JP7037354B2 - Improvement of liquid leakage detection mechanism - Google Patents

Description

The present disclosure relates to an improvement of a liquid leakage detection mechanism. More specifically, the present disclosure relates to an improvement of a liquid leakage detection mechanism for detecting a liquid leakage in a cylinder mechanism.

In a general cylinder mechanism, a sealing member is provided between the cylinder and a piston rod that slides with respect to the cylinder, and the working fluid is sealed in the cylinder by this sealing member. Such a cylinder mechanism is applied to a fluid pressure type actuator or a fluid pump.

Since such a sealing member is usually composed of an elastic member made of rubber or the like, it wears with use. Japanese Unexamined Patent Publication No. 2016-45068 discloses a liquid leakage detection mechanism configured to detect fluid leakage from a worn seal member.

Japanese Unexamined Patent Publication No. 2016-045068

Since the conventional liquid leakage detection mechanism detects liquid leakage from the sealed member whose wear has progressed, the fluid leaked from the seal member may contaminate the external environment. It is desired that the degree of wear of the seal member can be detected before the seal member deteriorates so that the fluid leaks to the external space.

It is an object of the present disclosure to provide a novel liquid leakage detection mechanism. One of the specific objects of the present disclosure is to provide a liquid leakage detection mechanism capable of detecting the degree of wear of the sealing member before the fluid leaks to the external space. Other purposes of this disclosure will become apparent with reference to the entire specification.

The liquid leakage detection mechanism according to the embodiment of the present invention is provided in the cylinder having a cylinder chamber and having a communication hole for connecting the cylinder chamber and the external space, and the cylinder so as to penetrate the communication hole. It is equipped with a cylinder rod. In the cylinder, a flow path having one end connected to the first position of the communication hole is formed. The liquid leakage detection mechanism further includes a seal member provided at a second position closer to the cylinder chamber than the first position of the communication hole, and a tank connected to the other end of the flow path. ..

In the above embodiment, a part of the fluid in the cylinder chamber seeps out toward the external space in the communication hole due to the pressure difference between the cylinder chamber and the external space. The fluid seeping out from the cylinder chamber enters the flow path formed in the cylinder from the first position of the communication hole, and flows into the tank via this flow path. Therefore, the degree of wear of the seal member can be determined based on the amount of fluid stored in this tank. In the above embodiment, the fluid that seeps out from the cylinder chamber through the seal member before wear can be stored in the tank due to the pressure difference between the cylinder chamber and the external space. Therefore, it is possible to monitor the degree of wear of the seal member even before the seal member is worn to the extent that the fluid leaks to the external space. This makes it possible to replace the sealing member before the fluid leaks to the external space.

In one embodiment of the invention, the tank is at least partially transparent or translucent.

According to the above embodiment, since the tank is transparent or translucent, the fluid in the tank can be visually recognized from the outside.

In one embodiment of the invention, the tank has a scale for measuring the amount of the fluid that has flowed in through the flow path.

According to the above embodiment, the amount of fluid in the tank can be measured by reading the scale.

In one embodiment of the invention, the tank is formed in a spiral shape.

According to the above embodiment, the size of the tank can be reduced.

In one embodiment of the invention, the tank is formed along the outer surface of the cylinder body.

According to the above embodiment, by arranging the tank near the cylinder body, it is possible to suppress a collision between the tank and another object.

The liquid leakage detection mechanism according to the embodiment of the present invention further includes a check valve provided in the flow path and configured to prevent backflow from the tank to the communication hole.

According to the above embodiment, the backflow of the fluid from the tank can be prevented.

The liquid leakage detection mechanism according to the embodiment of the present invention further includes a level meter for detecting the amount of fluid stored in the tank.

According to the above embodiment, the level meter can detect the amount of fluid stored in the tank.

The liquid leakage detection mechanism according to the embodiment of the present invention further includes a scraper provided at a third position on the external space side of the communication hole at the first position.

According to the above embodiment, the scraper seals the fluid that has exuded from the sealing member to the external space side in the communication hole so as not to leak into the external space.

An embodiment of the present invention provides a novel liquid leakage detection mechanism. An embodiment of the present invention provides a liquid leakage detection mechanism capable of detecting the degree of wear of a sealing member before a fluid leaks into an external space.

It is a figure which shows typically the actuator to which the liquid leakage detection mechanism by one Embodiment of this invention is applied. It is a figure which shows the part of the actuator of FIG. 1 enlarged and schematically. It is a figure which shows typically the actuator which the tank was removed. It is a figure schematically explaining a part of the actuator to which the liquid leakage detection mechanism by another embodiment of this invention is applied. It is a figure schematically explaining a part of the actuator to which the liquid leakage detection mechanism by another embodiment of this invention is applied. It is a figure schematically explaining a part of the actuator to which the liquid leakage detection mechanism by another embodiment of this invention is applied. It is a figure schematically explaining a part of the actuator to which the liquid leakage detection mechanism by another embodiment of this invention is applied.

Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings as appropriate. The same reference numerals are given to the components common to each drawing. It should be noted that each drawing is not always drawn to the correct scale for convenience of explanation.

The liquid leakage detection mechanism according to one aspect of the present invention can be applied to a cylinder mechanism having a cylinder having a cylinder chamber and a piston unit slidably provided in the cylinder. The cylinder is formed with a communication hole connecting the cylinder chamber and the external space. The piston unit may have a piston that partitions the cylinder into two cylinder chambers and a piston rod that extends from the piston. The cylinder unit may be provided in the cylinder so that the piston rod can slide in the communication hole along the extending direction thereof. The liquid leakage detection mechanism according to one aspect of the present invention is configured to detect liquid leakage in the path from the cylinder chamber through the communication hole. Cylinder mechanisms to which the leak detection mechanisms disclosed herein apply may include fluid pressure actuators, fluid pumps, and other cylinder mechanisms that operate at various fluid pressures.

First, with reference to FIG. 1, an actuator to which the liquid leakage detection mechanism according to one aspect of the present invention is applied will be described. FIG. 1 is a diagram schematically showing an actuator 10 to which a liquid leakage detection mechanism according to an embodiment of the present invention is applied. The actuator 10 can be used to drive a movable member in transportation equipment such as an aircraft, various industrial machines, and various machines other than these. The actuator 10 is an example of a cylinder mechanism to which the liquid leakage detection mechanism disclosed in the present specification is applied.

FIG. 1 shows a fluid pressure actuator. As shown in the figure, the actuator 10 has a cylinder 11, a piston unit 12, and a position sensor 20 that detects the position of the piston unit 12 with respect to the cylinder 11.

The cylinder 11 has a cylindrical member 11a and a gland member 11b. One of the tubular members 11a in the longitudinal direction (direction along the central axis A) is open, and the other is closed. That is, the tubular member 11a is formed in a bottomed tubular shape. The tubular member 11a is formed with a first port 18a and a second port 18b that communicate with the fluid pressure circuit 17. The fluid pressure circuit 17 can include a working fluid source that supplies the working fluid to the actuator 10, a reservoir that stores the working fluid discharged from the actuator 10, and various valves.

The gland member 11b is formed in a cylindrical shape with both ends open in the longitudinal direction, and is screwed inside the tubular member 11a in the vicinity of the opening of the tubular member 11a. The gland member 11b may be fitted inside the tubular member 11a. Since the gland member 11b is formed in a cylindrical shape with both ends open, the communication hole 11d connecting the cylinder chamber in the cylinder 11 and the external space 100 is defined by the inner peripheral surface of the gland member 11b. That is, the cylinder 11 is formed with a communication hole 11d that connects the cylinder chamber and the external space 100. The external space 100 means a space outside the cylinder 11. The fluid pressure circuit 17 for supplying / discharging the working fluid to / from the cylinder 11 is not included in the external space 100.

A ring-shaped groove extending in the circumferential direction of the central axis A is formed on the outer peripheral surface of the gland member 11b, and the seal member 11c is provided in this groove. The seal member 11c is, for example, an O-ring made of an elastic member.

The tubular member 11a and the gland member 11b described herein are examples of constituent members of the cylinder 11. The shapes, arrangements, and joining embodiments of the tubular member 11a and the gland member 11b are not limited to the embodiments explicitly described herein. The cylinder 11 may include members other than the tubular member 11a and the gland member 11b.

The piston unit 12 has a piston 13, a piston rod 14 connected to the piston 13, and a clevis 15 attached to the piston rod 14. The piston 13 and the piston rod 14 are arranged inside the cylinder 11. A part of the piston rod 14 projects to the outside of the cylinder 11 (that is, the external space 100).

The piston 13 is formed in a cylindrical shape. The piston 13 is arranged inside the cylindrical member 11a so that its outer peripheral surface abuts on the inner peripheral surface of the tubular member 11a. The outer peripheral surface of the piston 13 and the inner peripheral surface of the tubular member 11a are sealed by the sealing member 11e. As a result, the piston 13 divides the internal space of the cylinder 11 into the first cylinder chamber 19a and the second cylinder chamber 19b. The supply of the working fluid to the first cylinder chamber 19a and the discharge of the working fluid from the first cylinder chamber 19a are performed via the first port 18a. Similarly, the supply of the working fluid to the second cylinder chamber 19b and the discharge of the working fluid from the second cylinder chamber 19b are performed via the second port 18b.

The piston rod 14 includes a first cylindrical member 14a extending from the piston 13 toward the open end of the cylinder 11 and a second tubular member 14b extending from the piston 13 toward the side opposite to the first tubular member 14a. , Have.

The piston rod 14 is provided in the cylinder 11 so as to penetrate the communication hole 11d of the cylinder 11. Specifically, the piston rod 14 is provided so as to come into contact with the inner peripheral surface of the ground member 11b on the outer peripheral surface of the first tubular member 14a.

The clevis 15 has a mounting portion 15a that is rotatably attached to a movable member to be driven, and a shaft portion 15b that protrudes from the mounting portion 15a. A male screw is formed on the outer surface of the shaft portion 15b, and this male screw is screwed with a female screw formed on the inner peripheral surface of the first tubular member 14a.

The piston unit 12 is provided so as to be movable with respect to the cylinder 11 along the central axis A thereof. When the piston unit 12 moves in the first moving direction W1 along the central axis A, the actuator 10 expands, and when the piston unit 12 moves in the second moving direction W2 along the central axis A, the actuator 10 contracts. The actuator 10 operates by supplying and discharging the working fluid to and from the first cylinder chamber 19a and the second cylinder chamber 19b. The piston unit 12 described herein is exemplary, and the shapes, arrangements, and joining embodiments of the components of the piston unit 12 are not limited to those expressly described herein. For example, in the piston unit 12, the piston rod 14 and the clevis 15 may be formed as one member.

Inside the second cylindrical member 14b of the piston rod 14, a position sensor 20 for detecting the position of the piston unit 12 is provided. The position sensor 20 is, for example, a linear variable differential transformer (LVDT).

Next, the operation of the actuator 10 described above will be described. When the actuator 10 is contracted, the control valve provided in the fluid pressure circuit 17 is switched based on a command from a controller (not shown), whereby the working fluid is supplied to the first cylinder chamber 19a and the second cylinder chamber 19b. The working fluid is discharged from. As a result, the piston unit 12 moves from the neutral position to the second moving direction W2. On the other hand, when the actuator 10 is extended, the control valve is switched based on a command from a controller (not shown), whereby the working fluid is supplied to the second cylinder chamber 19b and the working fluid is discharged from the first cylinder chamber 19a. Will be done. As a result, the piston unit 12 moves in the first moving direction W1.

Next, with reference to FIGS. 2 and 3, the actuator 10 and the liquid leakage detection mechanism applied to the actuator 10 will be described. FIG. 2 is an enlarged diagram schematically showing a part of the actuator 10. Specifically, FIG. 2 schematically shows a cross section of the actuator 10 in the vicinity of the opening of the cylinder 11. FIG. 3 is a diagram schematically showing an actuator 10 from which the tank 41 has been removed.

As shown in the figure, a first groove 31a, a second groove 32a, and a third groove 33a are formed on the inner peripheral surface of the gland member 11b, respectively. The first groove 31a is formed on the inner peripheral surface of the ground member 11b at the first position in the direction of the central axis A. The second groove 32a is formed on the inner peripheral surface of the ground member 11b at the second position in the direction of the central axis A. The third groove 33a is formed on the inner peripheral surface of the ground member 11b at the third position in the direction of the central axis A. In the direction of the central axis A, the second position is arranged on the inner side of the cylinder 11 (the side closer to the first cylinder chamber 19a) than the first position, and the third position is the outer space 100 than the first position. It is arranged on the side (the side far from the first cylinder chamber 19a). The first groove 31a, the second groove 32a, and the third groove 33a are all formed in a ring shape extending in the circumferential direction of the central axis A. The third groove 33a is open to the external space 100.

The second groove 32a is provided with a seal member 32. The seal member 32 is, for example, an O-ring made of an elastic member. The seal member 32 has a gap between the outer peripheral surface of the first tubular member 14a of the piston rod 14 and the inner peripheral surface of the gland member 11b so that the fluid in the first cylinder chamber 19a does not leak to the external space. Seal. That is, the seal member 32 is a member for sealing the fluid in the first cylinder chamber 19a. As the sealing member 32, various sealing members capable of sealing the fluid in the first cylinder chamber 19a can be used in addition to the O-ring.

A scraper 33 is provided in the third groove 33a. The scraper 33 is a member made of a resin material such as rubber, and has a ring shape extending along the circumferential direction of the central axis A. The scraper 33 is provided so as to abut on the outer peripheral surface of the first cylindrical member 14a of the piston rod 14. The scraper 33 is configured to scrape off foreign matter adhering to the outer peripheral surface of the piston rod 14 when the piston rod 14 moves in the second moving direction W2.

The gland member 11b is formed with a flow path 34 connecting the communication hole 11 and the external space 100. The flow path 34 is connected to the first groove 31a at one end thereof. As shown in FIG. 3, the flow path 34 is formed so that when the tank 41 described later is removed from the gland member 11b, the other end thereof opens from the gland member 11b toward the external space 100. To. The flow path 34 connects the first groove 31a and the internal space of the tank 41.

The specific shape and arrangement of the flow path 34 explicitly described herein is exemplary. The shape and arrangement of the flow path 34 may be appropriately changed as long as it does not contradict the gist of the present invention. For example, the flow path 34 can be formed so as to have a curved shape by manufacturing the cylinder 11 by a laminated molding method (also referred to as “Additive Manufacturing” or simply “AM”). The flow path 34 may be formed in a cylinder component other than the gland member 11b.

The scraper 33 provides a gap between the inner peripheral surface of the gland member 11b and the outer peripheral surface of the first tubular member 14a so that the fluid of the first groove 31a does not leak to the external space 100 through the communication hole 11d. It is configured to be sealed. As described above, the scraper 33 has a function of preventing foreign matter from entering the inside of the cylinder 11 and a function of sealing the fluid from the first groove 31a through the communication hole 11d. There is.

A tank 41 is attached to the gland member 11b. The tank 41 is attached to the outer surface of the gland member 11b facing the external space 100. In the illustrated embodiment, the tank 41 is on the opposite side of the base 41a, the tubular tank body 41b extending outward from the base 41a along the central axis A to the ground member 11b, and the base 41a of the tank body 41b. A terminal portion 41c provided at the end is provided.

The base portion 41a is formed in a cylindrical shape, and a male screw is formed on the outer peripheral surface thereof. The tank 41 is attached to the gland member 11b by screwing the base portion 41a with the female screw formed on the gland member 11b. The base 41a is fastened to the gland member 11b by the fixing ring 44. A through hole 41e is formed inside the base portion 41a. One end of the through hole 41e is connected to the flow path 34, and the other end is connected to the tank body 41b.

The tank body 41b is formed in a hollow tubular shape, and is configured so that the fluid flowing from the first groove 31a through the flow path 34 and the through hole 41e can be stored in the internal space thereof. The internal space of the tank body 41b is defined by the inner peripheral surface 41d of the tank body 41b. In the illustrated embodiment, the tank body 41b is formed in a tubular shape extending along the central axis A.

The float 43 is housed in the internal space of the tank body 41b. The float 43 is provided so as to move in the internal space of the tank body 41b according to the amount of the fluid flowing into the tank body 41b. For example, the float 43 is arranged at a reference position when the tank body 41b is empty, and moves from the reference position in the extending direction of the tank body 41b according to the amount of fluid flowing into the tank body 41. Configured and arranged.

The tank body 41b may be transparent or translucent so that the fluid and the float 43 stored therein can be visually recognized from the outside. The float 43 may be colored in order to improve visibility from the outside.

The tank body 41b may be provided with a scale 42. By reading the numerical value of the scale 42 at the position where the float 43 has reached, the amount of fluid stored in the tank body 41b can be measured.

A terminal portion 41c is formed at the tip of the tank body 41b. The terminal portion 41c is stretched in a direction substantially orthogonal to the stretching direction of the tank body 41b. The end portion 41c prevents the float 43 from falling off. Further, the terminal portion 41c can prevent the fluid leaking from between the inner peripheral surface 41d of the tank body 41b and the float 43 from leaking out from the tank 41.

A check valve 50 is provided in the flow path 34. The check valve 50 is configured to open when a pressure larger than a predetermined valve opening pressure is applied from the first groove 31a side to the tank 41 side. The check valve 50 can prevent the fluid stored in the tank 41 from flowing back into the first groove 31a and the communication hole 11d. In addition, the liquid level of the liquid stored in the tank 41 can be stabilized. The valve opening pressure of the check valve 50 is determined to be opened by the fluid pressure of the fluid accumulated in the first groove 31a. The valve opening pressure of the check valve 50 is such that when the fluid pressure of the fluid accumulated in the first groove 31a acts on the check valve 50 and the scraper 33, the check valve 50 does not leak the fluid from the scraper 33 to the external space 100. Is set to a pressure that opens the valve. As a result, the fluid accumulated in the first groove 31a does not pass through the scraper 33 and leak to the external space 100, but passes through the flow path 34 and is stored in the tank 41.

The tank 41 is an example of a tank applicable to the liquid leakage detection mechanism of the present invention, and the specific shape, arrangement, and function of the tank applicable to the present invention are not limited to the tank 41. Subsequently, a modified example of the tank 41 will be described with reference to FIGS. 4 and 5 in sequence.

In the embodiment shown in FIG. 4, the tank 141 is provided in place of the tank 41 shown in FIGS. 1 to 3. The tank 141 of FIG. 4 has a base portion 141a screwed to the gland member 11b, a tank main body 141b extending from the base portion 141, and a fixing ring 144 for tightening the base portion 141a to the gland member 141. The tank body 141b is formed in a spiral shape. The spiral-shaped tank body 141b can be manufactured by a laminated molding method.

Since the tank body 141b has a spiral shape, the size of the tank 141 can be reduced as compared with the case where the tank body extends in one direction.

In the embodiment shown in FIG. 5, the tank 241 is provided in place of the tank 41 shown in FIGS. 1 to 3. The tank 241 of FIG. 5 has a base portion 241a fitted into the gland member 11b, and a tank body 241b extending from the base portion 241 along the outer surface of the gland member 11b. The tank body 241b may have a miranda shape that is bent a plurality of times along the outer surface of the gland member 11b, for example, as shown in the figure. The tank body 241b having a plurality of bent shapes can be manufactured by a laminated molding method.

By extending the tank body 241b along the outer surface of the gland member 11b, the tank 241 can be arranged inside the gland member 11b and in the vicinity of the outer surface thereof. As a result, the collision between the tank 241 and other members can be suppressed.

In the actuator 10 described above, the fluid in the first cylinder chamber 19a seeps out toward the external space 100 through the communication hole 11d due to the pressure difference between the first cylinder chamber 19a and the external space 100. The fluid seeping out from the first cylinder chamber 19a enters the flow path 34 from the first groove 31a of the communication hole 11d, and flows into the tanks 41, 141, and 24 via the flow path 34. Therefore, the degree of wear of the seal member 32 can be determined based on the amount of fluid stored in these tanks. In each of the above embodiments, a fluid that seeps out from the cylinder chamber 19a1 through the seal member 32 before the seal member 32 is worn or deteriorated due to a pressure difference between the cylinder chamber 19a1 and the external space 100 is a tank. It can be stored in 41, 141,241. The amount of fluid stored in the tanks 41, 141,241 can be visually confirmed every predetermined period, every predetermined operation cycle, or at any timing other than these. In this way, even before the seal member 32 is worn to the extent that the fluid leaks to the external space 100, the seal member 32 is worn based on the amount of the fluid stored in the tanks 41, 141,241. The degree of can be monitored. This makes it possible to replace the seal member 32 before the fluid leaks into the external space 100.

Next, still another embodiment of the present invention will be described with reference to FIG. FIG. 6 is a diagram schematically illustrating a part of an actuator to which the liquid leakage detection mechanism according to another embodiment of the present invention is applied. In the embodiment shown in FIG. 6, a tank 341 is provided in place of the tank 41 shown in FIGS. 1 to 3, and the fluid stored in the tank 341 has reached a predetermined amount. Is detected by the detection switch 343.

In the illustrated embodiment, the tank 341 has a tubular tank body 341a that is open at both ends and extends in the longitudinal direction, and a plunger 341b provided inside the tank body 341a. The tank body 341a is embedded in a recess formed in the gland member 11b at its base end. The internal space of the tank body 341a is connected to the flow path 34 via an opening on the base end side of the tank body 341a. As described above, the tank 341 is configured and arranged so that the fluid accumulated in the first groove 31a flows into the tank main body 341a via the flow path 34.

The plunger 341b is slidably provided inside the tank body 341a along the longitudinal direction of the tank body 341a. The plunger 341b is configured to move away from the flow path 34 in the longitudinal direction of the tank body 341a according to the amount of fluid flowing into the tank body 341a.

A detection switch 343 is provided on the orbit of the plunger 341b. The detection switch 343 is provided on, for example, a support base 344 attached to the ground member 11b. The detection switch 343 is configured to detect that the plunger 341b has been pushed out of the tank body 341a to a predetermined position. For example, the detection switch 343 is configured to be turned on by the tip 341c of the plunger 341b that has moved to the position corresponding to the upper limit value when the fluid is stored in the tank body 341a up to the upper limit value. A controller 345 may be connected to the detection switch 343. The detection switch 343 may be configured to output a detection signal to the controller 345 when turned on.

The controller 345 may include a CPU that performs various arithmetic processes, a memory that stores various programs and various data, and a device interface that is connected to the detection switch 343 and other devices. The controller 345 can determine, for example, based on the detection signal from the detection switch 343, that the fluid stored in the tank body 341a exceeds the upper limit set for the tank body 341a. The controller 345 may be configured to light an alarm lamp (not shown) according to the determination result.

The controller 345 may be configured to transmit a signal indicating that the amount of fluid stored in the tank body 341a has reached the upper limit to an external device (not shown) according to the determination result. As a result, by operating the external device, it is possible to confirm that the fluid storage amount in the tank body 341a has reached the upper limit even from a remote location.

According to the above embodiment, it is possible to detect that the fluid stored in the tank main body 341a has reached the upper limit amount by the detection switch 343. Based on the detection result of the detection switch 343, the degree of wear of the seal member 32 is determined. The detection switch 343 may be a level switch that detects that the amount of fluid stored in the tank body 341a has reached a predetermined amount. The level switch may be configured to output a detection signal to the controller 345 when the plunger 341b moves to a predetermined checkpoint. A plurality of checkpoints may be set in the level switch. By setting a plurality of checkpoints, the amount of fluid stored in the tank body 341a can be detected with high accuracy.

Next, still another embodiment of the present invention will be described with reference to FIG. 7. FIG. 7 is a diagram schematically illustrating a part of an actuator to which the liquid leakage detection mechanism according to another embodiment of the present invention is applied. In the embodiment shown in FIG. 7, the tank 441 is provided in place of the tank 41 shown in FIGS. 1 to 3.

In the illustrated embodiment, the tank 441 has a base 441a fitted into the gland member 11b and a tank body 441b connected to the base 441.

The base portion 441a is formed in a cylindrical shape with both ends open, and is embedded in the gland member 11b so that one end of the internal space thereof is connected to the flow path 34. The other end of the internal space of the base 441a is connected to the internal space of the tank body 441b so that the fluid that has entered the base 441a from the flow path 34 flows into the tank body 441b.

The tank body 441b is configured to be able to store the fluid flowing from the flow path 34 via the base 441a into the internal space thereof. The tank body 441b is formed with a through hole 441c that connects the internal space and the external space 100. A first check valve 444 is provided in the through hole 441c. The first check valve 444 is configured to open when the air pressure in the internal space of the tank body 441b becomes larger than the air pressure in the external space 100 by the first valve opening pressure. The first check valve 444 is configured and arranged so as to close the through hole 441c when the valve is closed and to communicate the internal space of the tank body 441b with the external space 100 when the valve is opened.

A second check valve 445 is provided at the connection position between the tank main body 441b and the base portion 441a. The second check valve 445 is configured to open when the air pressure in the internal space of the tank body 441b becomes larger than the air pressure in the internal space of the base 441a by the second valve opening pressure. The air pressure in the internal space of the base 441a is equal to the air pressure in the flow path 34. The second check valve 445 is configured and arranged so as to block the communication between the flow path 34 and the internal space of the tank body 441b when the valve is closed, and to communicate the flow path 34 and the internal space of the tank body 441b when the valve is opened. To.

The tank body 441b is provided with a level meter 442. The level meter 442 is configured to detect the stored amount of the fluid 110 stored in the tank main body 441b and output a detection signal indicating the detected stored amount to the controller 443. The amount of the fluid 110 stored in the tank body 441b may be determined by detecting the position of the liquid level 110a of the fluid 110.

The controller 443 may include a CPU that performs various arithmetic processes, a memory that stores various programs and various data, and a device interface that is connected to a level meter 442 and other devices. The controller 443 can determine, for example, based on the detection signal from the level meter 442, that the fluid stored in the tank body 441a exceeds the upper limit set for the tank body 441a. Similar to the controller 345, the controller 443 may be configured to light an alarm lamp (not shown) according to the determination result, and the fluid storage amount in the tank body 441a has reached the upper limit in the external device. It may be configured to transmit a signal indicating.

The operation of the tank 441 described above will be described. The first check valve 444 and the second check valve 445 provided in the tank 441 operate, for example, in an environment where the air pressure in the external space 100 changes significantly. Such a large change in air pressure in the external space 100 can occur when the actuator 10 is mounted on an aircraft, for example. When the actuator 10 is mounted on an aircraft, the atmospheric pressure in the external space 100 becomes the atmospheric pressure on the ground surface when the aircraft is parked, and the atmospheric pressure in the external space becomes the atmospheric pressure in the sky when the aircraft is flying. The air pressure in the external space 100 is greatly reduced as compared with the above.

The tank body 441b is emptied at the start of operation. When both the pressure in the external space 100 and the pressure in the internal space of the tank body 441b are large, such as when the aircraft is parked, the pressure difference between the external space 100 and the internal space of the tank body 441b is the first valve opening. Since the pressure is smaller than the pressure and the pressure in the internal space of the tank body 441b is larger than the fluid pressure of the flow path 34 to be higher than the second valve opening pressure, the first check valve 444 is closed and the second check valve 445 is opened. I'm talking.

Next, when the aircraft reaches a certain altitude after taking off, the air pressure in the external space 100 drops, and the air pressure in the internal space of the tank body 441b becomes larger than the air pressure in the external space 100 by more than the first valve opening pressure. As a result, the first check valve 444 is opened. When the first check valve 444 is opened, the internal space of the tank body 441b also has the same low pressure as the external space 100. Due to the decrease in air pressure in the internal space of the tank body 441b, the difference between the air pressure in the internal space of the tank body 441b and the fluid pressure in the flow path 34 becomes smaller than the second valve opening pressure. Therefore, the second check valve 445 is closed. Further, in the sky, the air pressure in the external space 100 becomes low, so that the fluid is sucked up from the first cylinder chamber 19a to the first groove 31a. The fluid in the first groove 31a is sucked up into the flow path 34 by the capillary phenomenon. In the sky, since the second check valve 445 is closed, the fluid stays in the internal space of the flow path 34 and the base 441a and does not flow into the tank body 441b.

Next, when the aircraft descends to a predetermined altitude for landing, the air pressure in the external space 100 rises, so that the first check valve 444 is closed again and the through hole 441c is closed. At this time, the air pressure in the internal space of the tank body 441b is about the same as the air pressure in the external space 100 at the altitude when the first check valve 444 is closed. At the altitude when the first check valve 444 is closed, or in the process of lowering the altitude to the ground after that, the air pressure in the internal space of the tank body 441b becomes the second valve opening pressure rather than the fluid pressure of the flow path 34. The second check valve 444 opens again as it becomes larger than the above.

Since the pressure in the internal space of the tank body 441b is lower than the atmospheric pressure when the second check valve 444 is opened, the fluid in the internal space of the flow path 34 and the base 441a flows into the tank body 441b. .. By measuring the amount of fluid flowing into the tank body 441b using, for example, a level meter 442, the flow rate of the fluid passing through the seal member 32 in one flight from takeoff to landing is detected. Based on the amount of the detected fluid, the degree of wear of the seal member 32 can be determined. For example, when the amount of the detected fluid is larger than a predetermined upper limit value, it is determined that the seal member 32 is in the replacement time.

As described above, according to the above embodiment, the amount of fluid stored in the tank body 441a can be detected, and the degree of wear of the seal member 32 can be determined based on the detected value.

The dimensions, materials, and arrangement of each component described herein are not limited to those expressly described in the embodiments, and each component may be included in the scope of the present invention. Can be modified to have the dimensions, materials, and arrangement of. In addition, components not explicitly described in the present specification may be added to the described embodiments, or some of the components described in each embodiment may be omitted.

Specific shapes and arrangements of the constituent members of the actuator 10 specified in the present specification are exemplified. Unless contrary to the gist of the present invention, the shape, arrangement, and function of each component of the actuator 10 may be changed as appropriate. A part of the modification of the actuator 10 will be described below. The modification described below is merely an example, and it is possible to add a modification not explicitly described in the present specification to the constituent members of the actuator 10.

The controls and operations performed by the controllers 345 and 443 may be distributed and executed by a plurality of controllers. Further, some or all of the controls and operations performed by the controllers 345 and 443 may be executed by a controller different from the controllers 345 and 443.

The gland member 11b may be provided with a sealing member other than those described in the present specification. For example, a groove extending in the circumferential direction of the central axis A may be formed between the first groove 31a and the third groove 33a of the gland member 11b, and an additional sealing member may be provided in this groove.

10 Actuator 11 Cylinder 11a Cylindrical member 11b Gland member 11c Seal member 11d Communication hole 12 Piston unit 13 Piston 14 Piston rod 19a 1st cylinder chamber 19b 2nd cylinder chamber 20 Position sensor 31a 1st groove 32 Seal member 32a 2nd groove 33 Scraper 33a 3rd groove 34 Flow path 41, 141,241,341,441 Tank 42 Memory 43 Float 50 Check valve 100 External space 343 Switch 345, 443 Controller 442 Level meter

Claims (8)

It has a cylinder chamber, a communication hole that connects the cylinder chamber and the external space, and one end of the communication hole that connects the communication hole and the external space and is connected to the first position of the communication hole. A cylinder with a flow path with an open end ,
A piston rod provided in the cylinder so as to penetrate the communication hole,
A seal member provided at a second position on the cylinder chamber side of the communication hole at the first position, and a seal member.
With the tank connected to the other end of the flow path,
A liquid leak detection mechanism equipped with. The tank is at least partially transparent or translucent.
The liquid leakage detection mechanism according to claim 1. The tank has a scale for measuring the amount of fluid flowing in from the cylinder chamber through the communication hole and the flow path.
The liquid leakage detection mechanism according to claim 1 or 2. The tank is formed in a spiral shape.
The liquid leakage detection mechanism according to any one of claims 1 to 3. The tank is a separate member from the cylinder body.
The tank is attached to the outer surface of the cylinder body,
The liquid leakage detection mechanism according to any one of claims 1 to 4. A check valve provided in the flow path and configured to prevent backflow from the tank to the communication hole is further provided.
The liquid leakage detection mechanism according to any one of claims 1 to 5. Further equipped with a level meter for detecting the amount of fluid stored in the tank.
The liquid leakage detection mechanism according to any one of claims 1 to 6. Further, a scraper provided at a third position on the external space side of the first position of the communication hole is further provided.
The liquid leakage detection mechanism according to any one of claims 1 to 7.

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