Actuator, fluid quantity monitoring device, and power generation device

Abstract

[Problem] To provide an actuator capable of reciprocating a piston without requiring switching of a fluid to be supplied to a cylinder. [Solution] The present invention includes: a piston structure 112 reciprocally accommodated in a cylinder 111 in which a fluid flows in one direction from an inflow port 110a toward an outflow port 110b, so as to tightly partition a first space SP1 on the inflow port 110a side and a second space SP2 on the outflow port 110b side; a piston urging member 114 that urges the piston structure 112 in the cylinder 111 toward the inflow port 110a side; a state switching mechanism (112a (120), 115, 116) that, when the piston structure 112 moves to the outflow port 110b side, switches the first space SP1 and the second space SP2 in a non-communicating state to a communicating state, and when the piston structure 112 moves to the inflow port 110a side, switches the first space SP1 and the second space SP2 in a communicating state to a non-communicating state.

Description

Actuator, Fluid Quantitative Monitoring Device, and Power Generation Device

[0001] The present invention relates to an actuator that reciprocates a piston structure in a cylinder, a fluid quantitative monitoring device using the actuator, and a power generation device using the actuator.

[0002] An actuator having a structure in which a piston reciprocates in a cylinder is known (see, for example, Patent Document 1). In this actuator, a first oil chamber and a second oil chamber are formed on both sides of the piston in the cylinder. Oil (fluid) can enter and exit each of the first oil chamber and the second oil chamber through ports. Then, by supplying oil (fluid) at a predetermined pressure to the first oil chamber, the piston moves in the cylinder toward the second oil chamber side. On the other hand, by supplying predetermined oil (fluid) to the second oil chamber side, the piston moves in the cylinder toward the first oil chamber side. Thus, by alternately switching the supply destination of the oil (fluid) at a predetermined pressure between the first oil chamber and the second oil chamber, the piston reciprocates in the cylinder.

[0003] Japanese Patent Application Laid-Open No. 2016-194354

[0004] In the conventional actuator as described above, an operation for switching the fluid supplied into the cylinder is required, and the mechanism (such as a switching mechanism) for driving the actuator becomes complicated.

[0005] The present invention has been made in view of such circumstances, and provides an actuator capable of reciprocating a piston without requiring switching of the fluid supplied to the cylinder.

[0006] Further, the present invention provides a fluid quantitative monitoring device using the actuator.

[0007] Furthermore, the present invention provides a power generation device using the actuator.

[0008] The actuator according to the present invention comprises a cylinder through which fluid flows in one direction from an inlet to an outlet; a piston structure housed within the cylinder so as to be reciprocable, tightly partitioning the space of the cylinder into a first space on the inlet side and a second space on the outlet side; a piston biasing member that biases the piston structure within the cylinder toward the inlet side; and a state switching mechanism that switches the non-communicating first space and the second space toward a communicating state when the piston structure moves toward the outlet side, and switches the communicating first space and the second space toward a non-communicating state when the piston structure moves toward the inlet side, wherein fluid with a pressure such that the piston structure moves toward the outlet side against the biasing of the piston structure toward the inlet side by the piston biasing member is introduced from the inlet into the first space of the cylinder.

[0009] In this configuration, the fluid flowing into the first space from the cylinder inlet, under pressure, moves the piston structure within the cylinder towards the outlet side, resisting the biasing force toward the inlet side by the piston biasing member, and the fluid in the second space is pushed out from the outlet. When the piston structure is moving towards the outlet side in this way, the state switching mechanism switches the non-communicating first space and the second space to a communicating state. As a result, the pressure difference between the first space and the second space sandwiching the piston structure disappears, and the piston structure moving towards the outlet side begins to move towards the inlet side due to the biasing force toward the inlet side by the piston biasing member. Then, while the piston structure is moving towards the inlet side, the fluid flowing into the first space from the inlet flows further into the second space from the first space, and the state switching mechanism switches the communicating first space and the second space to a non-communicating state.

[0010] Then, due to the pressure of the fluid flowing into the first space from the inlet, the piston structure begins to move toward the outlet side against the biasing force of the piston biasing member, and the fluid in the second space is pushed out of the outlet by the piston structure. Thereafter, in a situation where the fluid is flowing in one direction from the inlet to the outlet, the piston structure repeatedly moves back and forth between the outlet side and the inlet side as described above.

[0011] In the actuator according to the present invention, the state switching mechanism may be configured to include: a structure in which the cylinder has a small inner diameter portion on the inlet side and a large inner diameter portion on the outlet side; a structural portion of the piston structure that tightly partitions the small inner diameter portion of the cylinder into the first space and the second space; and a structure that connects the first space and the second space when the tightly partitioning structural portion of the piston structure has entered the large inner diameter portion.

[0012] With this configuration, when the piston structure is moving toward the outlet side, if there is a structural part in the small inner diameter portion of the cylinder that tightly separates the first space and the second space of the piston structure, the first space and the second space are not in communication. The fluid flowing in from the cylinder inlet into the first space under pressure causes the piston structure to move toward the outlet side within the cylinder against the biasing force toward the inlet side by the piston biasing member, and the fluid in the second space is pushed out from the outlet. When the structural part in the small inner diameter portion that tightly separates the first space and the second space of the piston structure (not in communication state) enters the large inner diameter portion as the piston structure moves toward the outlet side, the structure that connects the first space and the second space of the piston structure causes them to become in communication state (communication state) (switching from non-communication state to communication state). As a result, the pressure difference between the first and second spaces surrounding the piston structure disappears, and the piston structure, having lost its own inertial force, begins to move towards the inlet due to the biasing force of the piston biasing member toward the inlet. Then, as the piston structure moves toward the inlet, the fluid flowing from the inlet into the first space flows further into the second space, and as the structural part that tightly separates the first and second spaces of the piston structure enters the small inner diameter section, the first and second spaces become disconnected (switching from a connected state to a disconnected state). Even after the first space and the second space switch to a disconnected state, the piston structure continues to move toward the inlet while compressing the fluid in the first space due to its inertial force toward the inlet and the biasing force of the piston biasing member.

[0013] As a result, the inertial force of the piston structure is lost due to the pressure of the fluid flowing into the first space from the inlet, and against the biasing force of the piston biasing member, the piston structure begins to move toward the outlet, and the fluid in the second space is pushed out of the outlet by the piston structure. Thereafter, in a situation where the fluid is flowing in one direction from the inlet to the outlet, the piston structure repeatedly moves back and forth within the cylinder having a small inner diameter portion and a large inner diameter portion, moving toward the outlet (movement from the small inner diameter portion to the large inner diameter portion) and moving toward the inlet (movement from the large inner diameter portion to the small inner diameter portion), as described above.

[0014] In the actuator according to the present invention, the piston structure is reciprocable between the bottom dead center position on the inlet side and the top dead center position on the outlet side within the cylinder, and has a communication passage formed to connect the first space and the second space, and the state switching mechanism may include a communication passage opening / closing mechanism that switches from the non-communication state in which the communication passage is closed to the communication state in which the communication passage is open when the piston structure moves from the bottom dead center position to the top dead center position, and switches from the communication state in which the communication passage is open to the non-communication state in which the communication passage is closed when the piston structure moves from the top dead center position to the bottom dead center position.

[0015] With this configuration, as the piston structure moves from the bottom dead center position to the top dead center position, the communication channel opening / closing mechanism switches the communication channel of the piston structure from a closed, non-communicating state to an open, communicating state. As a result, the pressure difference between the first space and the second space surrounding the piston structure disappears, the piston structure reaches the top dead center position, and begins to move toward the bottom dead center position due to the biasing force of the piston biasing member toward the inlet side. As the piston structure moves toward the bottom dead center position, the fluid flowing from the inlet into the first space flows through the communication channel of the piston structure and further from the first space into the second space.

[0016] The communication channel opening / closing mechanism switches the open and communicating channel of the piston structure to a closed and non-communicating state while the piston structure is moving from the top dead center position to the bottom dead center position. As a result, the piston structure, which is moving towards the inlet side, reaches the bottom dead center position and, due to the pressure of the fluid flowing into the first space from the inlet, begins to move towards the top dead center position against the biasing force of the piston biasing member, and the fluid in the second space is pushed out from the outlet. Thereafter, with the fluid flowing in one direction from the inlet to the outlet, the piston structure repeatedly moves back and forth between the top dead center position (outlet side) and the bottom dead center position (inlet side) as described above.

[0017] In the actuator according to the present invention, the piston structure may be configured to include a movable member that is movable relative to the communication passage and is biased in a direction that opens the communication passage when the piston structure moves from the bottom dead center position to the top dead center position, switching from a non-communication state in which the communication passage is closed to a communication state in which the communication passage is open, and a member holding part that holds the movable member so that it can reciprocate.

[0018] In this configuration, when the piston structure moves from the bottom dead center position (inlet side) to the top dead center position (outlet side), the movable member, which is reciprocally held in the member holding part of the piston structure, closes the opening on the first space side of the communication passage of the piston structure, so that the first space and the second space are not in communication. In this state, as the piston structure moves further toward the top dead center position, the movable member is biased and moves in the direction that opens the communication passage of the piston structure, and the communication passage of the piston structure is opened, so that the first space and the second space are in communication. Then the pressure difference between the first space and the second space that sandwich the piston structure disappears, the piston structure reaches the top dead center position, and due to the biasing of the piston biasing member toward the inlet side (bottom dead center position side), it starts moving toward the bottom dead center position.

[0019] When the piston structure is moving toward the bottom dead center position (inlet side) with the opening on the first space side of the communication passage of the piston structure open, the movable member, which is reciprocally held in the member holding part of the piston structure, is biased in the piston structure to move in a direction that closes the communication passage, the communication passage of the piston structure is closed, and the first space and the second space become disconnected. Then, the piston structure reaches the bottom dead center position and, due to the pressure of the fluid flowing from the inlet into the first space, begins to move toward the top dead center position against the biasing force of the piston biasing member, and the fluid in the second space is pushed out from the outlet. Thereafter, with the fluid flowing in one direction from the inlet to the outlet, the piston structure repeatedly reciprocates between the top dead center position (outlet side) and the bottom dead center position (inlet side) as described above.

[0020] In the actuator according to the present invention, the piston structure is arranged on the inlet side of the communication passage and has a movable member that is movable relative to the communication passage, and the communication passage opening / closing mechanism may be configured to include a first movement restricting member that restricts the movement of the movable member, which moves toward the outlet side together with the movement of the piston structure when the opening on the first space side of the communication passage is closed, at a first predetermined position in the cylinder, and a second movement restricting member that restricts the movement of the movable member, which moves toward the inlet side together with the piston structure when the opening on the first space side of the communication passage is open, at a second predetermined position in the cylinder.

[0021] In this configuration, when the piston structure (including the movable member) is moving from the bottom dead center position (inlet side) to the top dead center position (outlet side), the movable member closes the opening on the first space side of the communication passage of the piston structure, and the first space and the second space are not in communication. In this state, as the piston structure moves further toward the top dead center position together with the movable member, when the movement of the movable member is restricted at the first predetermined position by the first movement restricting member (communication passage opening / closing mechanism), the continuous movement toward the top dead center position (outlet side) accompanied by the inertial force of the piston body of the piston structure causes the restricted movable member to move relatively away from the opening on the first space side of the communication passage of the piston structure, the communication passage of the piston structure is opened, and the first space and the second space become in communication. As a result, the pressure difference between the first and second spaces surrounding the piston structure disappears, the piston structure reaches the top dead center position, and after its own inertial force is eliminated, it begins to move toward the bottom dead center position due to the biasing force of the piston biasing member toward the inlet side (bottom dead center position side).

[0022] When the piston structure is moving toward the bottom dead center position (inlet side) with the moving member opening the opening on the first space side of the communication passage of the piston structure, if the movement of the moving member is restricted at a second predetermined position by the second movement restricting member (communication passage opening / closing mechanism) in the piston structure, the restricted moving member moves in a direction that relatively closes the opening on the first space side of the communication passage of the piston structure. As a result, the moving member closes the opening on the first space side of the piston structure, and the first space and the second space become disconnected. Then, the piston structure (piston body and moving member) reaches the bottom dead center position and, due to the pressure of the fluid flowing from the inlet into the first space, begins to move toward the top dead center position against the biasing force of the piston biasing member, and the fluid in the second space is pushed out from the outlet. Thereafter, with the fluid flowing in one direction from the inlet to the outlet, the piston structure repeatedly moves back and forth between the top dead center position (outlet side) and the bottom dead center position (inlet side) as described above.

[0023] In the actuator according to the present invention, the communication passage is formed in the axial direction of the cylinder, and the first movement restricting member may be configured to include a rod-shaped member that passes through the communication passage of the piston structure from the outlet side.

[0024] In this configuration, in a piston structure that moves toward the top dead center position, the moving member abuts against the tip of a rod-shaped member, which is positioned to pass through the communication channel of the piston structure from the outlet side, at a first predetermined position, thereby restricting further movement of the moving member.

[0025] The rod-shaped member may be fixed to the cylinder or may be movable together with the piston structure. In the latter case, the actuator according to the present invention has a rod holding portion that holds the rod-shaped member so that it is movable together with the piston structure and is positioned within the piston structure in a state in which it is movable relative to the piston structure, and a rod movement restricting portion that restricts the movement of the rod-shaped member that moves together with the piston structure when the piston structure moves toward the outlet side, and the rod-shaped member is restricted by the rod movement restricting portion that the rod-shaped member protrudes from the communication passage of the piston structure that is moving toward the outlet side, thereby restricting the movement of the moving member toward the outlet side.

[0026] In this configuration, when the piston structure (including the movable member) moves toward the outlet side, the rod-shaped member positioned within the piston structure moves together with the piston structure. When the movement of the rod-shaped member moving together with the piston structure is restricted by the rod movement restricting unit, the continuous movement of the piston structure toward the top dead center position (outlet side) causes the tip of the rod-shaped member positioned within the piston structure to pass through the communication channel and protrude from the opening on the first space side, thereby restricting the movement of the movable member that is moving toward the top dead center position (outlet side) together with the piston structure.

[0027] In the actuator according to the present invention, the rod-shaped member may include a hollow pipe.

[0028] With this configuration, as the piston structure moves toward the bottom dead center position, the first space and the second space can be connected through the hollow portion of the hollow pipe.

[0029] In the actuator according to the present invention, when the movable member moves toward the inlet side together with the piston structure, the actuator may be configured to include a biasing member that biases the movable member toward the inlet side.

[0030] With this configuration, when the piston structure moves toward the top dead center position (outlet side), the moving member whose movement is restricted by the first movement restricting member can be moved more smoothly toward the inlet side (bottom dead center position) by a biasing force toward the inlet side (bottom dead center position). As a result, the moving member that was blocking the opening on the first space side of the communication passage of the piston structure can be smoothly separated from that opening, and the first space and the second space, separated by the piston structure, can be reliably connected through the communication passage. This allows the fluid in the first space, including the fluid flowing in from the inlet, to flow more smoothly into the second space through the communication passage when the piston structure, having reached the top dead center position, moves toward the bottom dead center position.

[0031] In the actuator according to the present invention, the piston structure may be configured to include a member holding portion that holds the movable member so that it can reciprocate on the inlet side of the communication passage, and a biasing member provided at the inlet-side end of the member holding portion that biases the movable member, which is movably held by the member holding portion, toward the inlet.

[0032] With this configuration, the movable member is restricted from moving toward the outlet side (top dead center position side) by the first movement restricting member, and then, as it moves relatively away from the opening on the first space side of the communication passage of the piston structure within the member holding part, it is biased toward the inlet side (bottom dead center position side) by the biasing member. As a result, the movable member can move away from the opening more smoothly.

[0033] In the actuator according to the present invention, the biasing member may be configured to have a structure that provides a magnetic biasing force to the moving member.

[0034] With this configuration, the biasing member can apply a biasing force to the moving member by utilizing suction or repulsion forces.

[0035] In this case, the biasing member may be a source of magnetic force (e.g., a magnet) and the moving member may be a magnetic material (e.g., iron), or the moving member may be a source of magnetic force (e.g., a magnet) and the biasing member may be a magnetic material (e.g., iron), or both the biasing member and the moving member may be sources of magnetic force (e.g., magnets).

[0036] The actuator according to the present invention may be configured to have an elastic member provided on the moving member so as to face the opening on the inlet side of the communication passage of the piston structure.

[0037] With this configuration, the opening on the first space side of the communication channel of the piston structure can be reliably closed by the moving member.

[0038] In the actuator according to the present invention, the piston structure may be configured to have a cylindrical movable member that is movable in the axial direction of the cylinder, and a communication passage that can be opened and closed on the side surface of the movable member.

[0039] With this configuration, as the piston structure moves from the bottom dead center position to the top dead center position, the communication channel opening / closing mechanism switches from a non-communicated state, where the communication channel of the piston structure is closed by the side surface of the cylindrical moving member, to a communicated state, where it is open. As a result, the pressure difference between the first space and the second space surrounding the piston structure disappears, the piston structure reaches the top dead center position, and begins to move toward the bottom dead center position due to the biasing force of the piston biasing member toward the inlet side. As the piston structure moves toward the bottom dead center position, the fluid flowing from the inlet into the first space flows through the communication channel of the piston structure and further from the first space into the second space.

[0040] The communication channel opening / closing mechanism switches the open and communicating channel of the piston structure to a non-communicating state, closed by the side of the cylindrical moving member, while the piston structure is moving from the top dead center position to the bottom dead center position. As a result, the piston structure, which is moving towards the inlet side, reaches the bottom dead center position and, due to the pressure of the fluid flowing into the first space from the inlet, begins to move towards the top dead center position against the biasing force of the piston biasing member, and the fluid in the second space is pushed out from the outlet. Thereafter, with the fluid flowing in one direction from the inlet to the outlet, the piston structure repeatedly moves back and forth between the top dead center position (outlet side) and the bottom dead center position (inlet side) as described above.

[0041] The fluid quantitative monitoring device according to the present invention is a fluid quantitative monitoring device connected in series to a fluid flow path and monitoring whether a certain amount of fluid is flowing through the flow path, and comprises one of the actuators described above, and a piston motion detection unit that detects the movement of the piston structure within the cylinder of the actuator and outputs a detection signal corresponding to that movement.

[0042] In this configuration, when fluid flows in one direction from the inlet to the outlet within the cylinder of the actuator, the piston structure repeatedly reciprocates, moving towards the outlet and then back towards the inlet. During this process, each time the piston structure moves towards the outlet, an amount of fluid corresponding to the size of the second space is discharged into the flow path. The piston motion detection unit outputs a detection signal corresponding to the movement (reciprocating motion) of the piston structure within the cylinder. As the movement of the piston member (amplitude, velocity, etc.) changes in accordance with fluctuations in the condition of the fluid flowing through the flow path, the detection signal also changes accordingly. Therefore, based on the state of the detection signal from the piston detection unit, it is possible to determine whether the fluid is flowing through the flow path at a certain quantity (normally).

[0043] The power generation device according to the present invention has a configuration comprising one of the aforementioned actuators and a converter that converts the movement of the piston structure within the cylinder of the actuator into electrical energy.

[0044] With such a configuration, in a situation where fluid flows unidirectionally from the inlet to the outlet inside the cylinder of the actuator, the piston structure repeats reciprocating movements of moving toward the outlet side and moving toward the inlet side. In the process, the transducer converts the movement (reciprocating movement) of the piston structure inside the cylinder into electrical energy. Effect

[0045] According to the actuator of the present invention, it becomes possible to reciprocate the piston without the need to switch the fluid supplied to the cylinder.

[0046] Further, according to the fluid quantitative monitoring device of the present invention, using the above actuator, it is possible to monitor that the fluid is flowing through the flow path quantitatively.

[0047] Furthermore, according to the power generation device of the present invention, using the above actuator, electrical energy can be generated.

[0048] Figure 1 is a cross-sectional view showing the structure of an actuator according to the first embodiment of the present invention. Figure 2 is a cross-sectional view showing the operating state (1) of the actuator. Figure 3 is a cross-sectional view showing the operating state (2) of the actuator. Figure 4 is a cross-sectional view showing the operating state (3) of the actuator. Figure 5 is a cross-sectional view showing the operating state (4) of the actuator. Figure 6 is a cross-sectional view showing the operating state (5) of the actuator. Figure 7 is a cross-sectional view showing a first modified example of the actuator. Figure 8 is a cross-sectional view showing a second modified example of the actuator. Figure 9 is a cross-sectional view showing a third modified example of the actuator. Figure 10 is a cross-sectional view showing a fourth modified example of the actuator. Figure 11 is a cross-sectional view showing the structure of an actuator according to the second embodiment of the present invention and a fluid quantitative monitoring device using the same. Figure 12 is a cross-sectional view showing the operating state (1) of the actuator. Figure 13A is a cross-sectional view showing a partially enlarged view of the operating state (2) of the actuator. Figure 13B is a cross-sectional view showing a partially enlarged view of the operating state (3) of the actuator. Figure 14A is a cross-sectional view showing a partially enlarged view of the operating state (4) of the actuator. Figure 14B is a cross-sectional view showing a partially enlarged view of the actuator's operating state (5). Figure 15 is a cross-sectional view showing the actuator's operating state (6). Figure 16 is a cross-sectional view showing the structure of an actuator according to a third embodiment of the present invention and a power generation device using the same. Figure 17 is a cross-sectional view showing the actuator's operating state (1). Figure 18 is a cross-sectional view showing the actuator's operating state (2). Figure 19 is a cross-sectional view showing the actuator's operating state (3). Figure 20 is a cross-sectional view showing the actuator's operating state (4). Figure 21 is a cross-sectional view showing the actuator's operating state (5). Figure 22 is a cross-sectional view showing the actuator's operating state (6). Figure 23 is a cross-sectional view showing the actuator's operating state (7). Figure 24 is a cross-sectional view showing a modified example of the actuator and the structure of a power generation device using the same. Figure 25 is a cross-sectional view showing the structure of an actuator according to a fourth embodiment of the present invention.Figure 26 is a cross-sectional view showing the operating state of the actuator. Figure 27 is a cross-sectional view showing the structure of an actuator according to the fifth embodiment of the present invention. Figure 28 is a cross-sectional view showing the structure of an actuator according to the sixth embodiment of the present invention and a power generation device using the same. Figure 29 is a cross-sectional view showing the operating state (1) of the actuator. Figure 30 is a cross-sectional view showing the operating state (2) of the actuator. Figure 31 is a cross-sectional view showing the operating state (3) of the actuator. Figure 32 is a cross-sectional view showing the operating state (4) of the actuator. Figure 33 is a cross-sectional view showing the operating state (5) of the actuator. Figure 34 is a cross-sectional view showing a modified example of the actuator and the structure of a power generation device using the same. Figure 35 is a cross-sectional view showing the structure of an actuator according to the seventh embodiment of the present invention and a power generation device using the same. Figure 36 is a cross-sectional view showing the operating state of the actuator.

[0049] Embodiments of the present invention will be described below with reference to the drawings.

[0050] The actuator according to the first embodiment of the present invention is configured as shown in Figure 1.

[0051] In the actuator 100 shown in Figure 1, a piston structure 112 is reciprocally housed within a cylinder 111. The cylinder 111 consists of a cylinder body portion 111a with an internal space 122 and a fluid introduction cylinder portion 111b with an internal space 121, which are connected in series such that their internal spaces 121 and 122 are in communication, and airtightness is maintained by an O-ring 125. The open end of the fluid introduction cylinder portion 111b, which is one end of the cylinder 111, is formed as an inlet 110a, and the open end of the cylinder body portion 111a, which is the other end of the cylinder 111, is formed as an outlet 110b. A fluid (which may be a gas, liquid, or viscous fluid) at a predetermined pressure introduced from the inlet 110a flows through the cylinder 111 (fluid introduction cylinder portion 111b, cylinder body portion 111a) in one direction toward the outlet 110b.

[0052] The piston structure 112 is reciprocally mounted within the internal space 122 of the cylinder body 111a. The piston structure 112 includes the piston body 112a, an O-ring 126, and a movable member 113. The piston body 112a has a member holding portion 112b extending toward the inlet 110a side, and the member holding portion 112b is cylindrical with a plurality of notches formed in the axial direction of the cylinder 111. In addition, the side surface of the end on the inlet 110a side is in slidable contact with the inner diameter portion of the cylinder body 111a, preventing the piston structure 112 from tilting. The movable member 113 is housed and held within the member holding portion 112b in a state that allows it to reciprocate with a certain contact resistance. An O-ring 126 provided on the outer circumference of the piston body 112a maintains airtightness between the first space SP1 on the inlet 110a side and the second space SP2 on the outlet 110b side, with the piston structure 112 (specifically the position of the O-ring 126) as the boundary. Furthermore, a communication channel 120 is formed in the piston body 112a so that the first space SP1 and the second space SP2 are connected (linked). Note that the piston body 112a and the member holding part 112b are not a single unit as described above, but may be a mated structure.

[0053] The internal space 122 of the cylinder body 111a is composed of a main space 122a through which the piston structure 112 reciprocates, and an outlet space 122b that extends from the main space 122a and is narrower than the main space 122a, leading to the outlet 110b. At the stepped boundary between the main space 122a and the narrower outlet space 122b, the base of a rod-shaped member 115 of a predetermined length, which serves as a rod-shaped first movement restricting member extending toward the inlet 110a, is fixed between a return spring 114 and the bottom surface of the cylinder body 111a. A communication hole 124 is formed at the base of the rod-shaped member 115, connecting the main space 122a and the outlet space 122b. The rod-shaped member 115 and the communication passage 120 formed in the piston body portion 112a of the piston structure 112 are in a positional relationship such that when the piston structure 112 moves toward the outlet 110b, the rod-shaped member 115 passes through the communication passage 120 in the piston body portion 112a with a certain gap. When the moving member 113 of the piston structure 112 moves toward the outlet 110b while blocking the opening on the first space SP1 side of the communication passage 120, it abuts against the tip of the rod-shaped member 115, and the rod-shaped member 115 restricts the further movement of the moving member 113 at a first predetermined position inside the cylinder 111 (cylinder body portion 111a) (functioning as a first movement restricting member).

[0054] A convex body 116, acting as a second movement restricting member, is fixed or integrally formed at the end of the fluid introduction cylinder section 111b on the cylinder body section 111a side, so as to protrude into the internal space 122 (main space 122a) of the cylinder body section 111a. The convex body 116 and the member holding portion 112b of the piston structure 112 are in a positional relationship such that when the piston structure 112 moves toward the inlet 110a side, the convex body 116 enters the member holding portion 112b. With the opening on the first space SP1 side of the communication flow path 120 open, the moving member 113 of the piston structure 112 moving toward the inlet 110a side abuts against the tip of the convex body 116, and the convex body 116 restricts further movement of the moving member 113 at a second predetermined position within the cylinder 111 (cylinder body section 111a) (functioning as a second movement restricting member).

[0055] Furthermore, a return spring 114 is provided in the internal space 122 (main space 122a) of the cylinder body 111a. This return spring 114 functions as a piston biasing member, biasing the piston structure 112 toward the inlet 110a due to its repulsive force.

[0056] The piston structure 112 reciprocates within the internal space 122 (main space 122a) of the cylinder 111 (cylinder body portion 111a) between the bottom dead center position (see Figure 1), which is the position closest to the inlet 110a, and the top dead center position (see Figure 4), which is the position closest to the outlet 110b, as follows (see Figures 2 to 6 in addition to Figure 1).

[0057] The piston structure 112, including the piston body portion 112a, which is in a state where the opening on the first space SP1 side of the communication passage 120 is blocked by the moving member 113 (non-communication state), begins to move from the bottom dead center position (see Figure 1) against the repulsive force (biasing) of the return spring 114 due to the fluid of a predetermined pressure flowing into the first space SP1 from the inlet 110a of the cylinder 111 (fluid introduction cylinder portion 111b). As shown in Figure 2, the piston structure 112 moves toward the outlet 110b (towards the top dead center position), and the rod-shaped member 115 moves through the communication passage 120 formed in the piston body portion 112a of the piston structure 112 to a position (first predetermined position) where the tip of the rod-shaped member 115 abuts against the moving member 113, as shown in Figure 3. This restricts the movement of the moving member 113 toward the top dead center position (outlet 110b side). While the piston structure 112 is moving in this manner, fluid flows into the first space SP1, and the fluid in the second space SP2 is pushed out from the outlet 110b by the piston structure 112.

[0058] From the moment the tip of the rod-shaped member 115 abuts the movable member 113 (the start of the restriction of the movement of the movable member 113), the piston structure 112 continues to move toward the top dead center position (outlet 110b side) accompanied by further inertial force, causing the restricted movable member 113 to move relatively away from the opening on the first space SP1 side of the communication passage 120, as shown in Figure 4. In this state, a gap G is created between the opening on the first space SP1 side of the communication passage 120 and the movable member 113 (the communication passage 120 of the piston body 112a is open), at which point the inertial force of the piston structure 112 disappears, and the piston structure 112 reaches the top dead center position.

[0059] In this way, a gap G is created between the opening of the communication channel 120 on the first space SP1 side and the moving member 113, and when the communication channel 120 of the piston body 112a is opened, the first space SP1 and the second space SP2 that sandwich the piston structure 112 become connected through the gap between the communication channel 120 (inner wall) and the rod-shaped member 115 (outer wall) (non-communication state → communication state). In this state, the pressure difference between the first space SP1 and the second space SP2 that sandwich the piston structure 112 disappears, and the biasing force on the piston structure 112 acting on the outlet 110b side due to the fluid pressure in the first space SP1 also disappears. After the piston structure 112 reaches the top dead center position, it begins to move toward the inlet 110a side (towards the bottom dead center position) due to the repulsive force (biasing) of the return spring 114 toward the inlet 110a side (bottom dead center position side). As the piston structure 112 moves toward the bottom dead center position, the fluid flowing into the first space SP1 from the inlet 110a passes through the notch in the member holding portion 112b and flows from the first space SP1 to the second space SP2 through the gap G and the communication passage 120 of the piston body portion 112a.

[0060] Furthermore, as shown in Figure 5, the piston structure 112 moves toward the bottom dead center position (inlet 110a side) with the movable member 113 maintaining a gap G between itself and the piston body 112a due to the contact resistance between the movable member 113 and the member holding portion 112b, that is, with the opening on the first space SP1 side of the communication flow path 120 open. Then, the convex body 116 of the piston structure 112 enters the member holding portion 112b and moves to a position (second predetermined position) where the tip of the convex body 116 abuts against the movable member 113, as shown in Figure 6. This restricts the movement of the movable member 113 toward the bottom dead center position (inlet 110a side). From the moment the tip of the convex body 116 abuts against the movable member 113 (the start of the restriction of movement of the movable member 113), the piston structure 112 continues to move toward the bottom dead center position (towards the inlet 110a) due to the biasing force of the return spring 114. As a result, the restricted movement of the movable member 113 comes into contact with the opening on the first space SP1 side of the communication passage 120, closing the communication passage 120 (communication state → non-communication state), and the piston structure 112 reaches the bottom dead center position. Then, due to the pressure of the fluid flowing from the inlet 110a into the first space SP1, it starts moving toward the top dead center position (towards the outlet 110b) again, resisting the repulsive force (biasing force) of the return spring 114, and the fluid in the second space SP2 is pushed out from the outlet 110b. Thereafter, with the fluid flowing in one direction from the inlet 110a to the outlet 110b, the piston structure 112 repeatedly reciprocates between the top dead center position (outlet side) and the bottom dead center position (inlet side) as described above (see Figures 1 to 6).

[0061] Furthermore, in the actuator 100 described above, a rod-shaped member 115 (first movement restricting member) that restricts the movement of the movable member 113 of the piston structure 112 that moves toward the outlet 110b side at a first predetermined position inside the cylinder 111 (cylinder body portion 111a), and a convex body 116 (second movement restricting member) that restricts the movement of the movable member 113 of the piston structure 112 that moves toward the inlet 110a side at a second predetermined position inside the cylinder 111 (cylinder body portion 112a) correspond to a communication passage opening / closing mechanism (state switching mechanism) that switches the closed communication passage 120 to an open state (switching from a non-communicating state to a communicating state) when the piston structure 112 moves from the bottom dead center position to the top dead center position, and switches the open communication passage 120 to a closed state (switching from a communicating state to a non-communicating state) when the piston structure 112 moves from the top dead center position to the bottom dead center position.

[0062] According to the actuator 100 described above, when the fluid is flowing in one direction within the cylinder 111 from the inlet 110a to the outlet 110b, the piston structure 112 repeatedly reciprocates between the top dead center position (outlet 110b side) and the bottom dead center position (inlet 110a side). Therefore, the piston member 112 can be reciprocated within the cylinder 111 without the need to switch the fluid supplied to the cylinder 111.

[0063] The return spring 114 (piston biasing member) is not particularly limited as long as it biases the piston structure 112 toward the inlet 110a side, and may, for example, utilize the repulsive force of a magnet, the attractive force of a magnet, or a combination thereof. The shape of the movable member 113 is not particularly limited as long as it is a shape that can be reciprocated and housed within the member holding part 11b, and can be, for example, cylindrical, spherical, etc. The convex body 116 may be rod-shaped, or it may be constructed using an elastic spring.

[0064] Next, a first modified example of the actuator according to the first embodiment of the present invention will be described with reference to Figure 7.

[0065] The actuator 100 shown in Figure 7 is characterized in that, instead of the rod-shaped member 115 (see Figure 1) fixed to the cylinder 111 as the first movement restricting member, a rod-shaped member 117 is provided reciprocally within the piston structure 112, and a ring-shaped magnet 118 is provided in the member holding portion 112b of the piston structure 112, along with the movable member 113, as a biasing member that biases the movable member 113 toward the inlet 110a. Note that in Figure 7, the same (or corresponding) parts are assigned to the actuator 100 described above (see Figures 1 to 6).

[0066] In the actuator 100 shown in Figure 7, the piston structure 112 includes the aforementioned piston body 112a, piston inner 112e, O-ring 126, rod-shaped member 117, ring-shaped magnet 118, movable member 113, and member holder 112b that holds the movable member 113, as well as a rod holder 112c positioned on the outlet 110b side from the piston body 112a. The piston inner 112e can be made of a different material from the piston body 112a, and a communication passage 120 is formed in its center in the axial direction of the cylinder, with its outer circumference press-fitted and fixed to the inner diameter of the piston body 112a. The rod holder 112c holds the rod-shaped member 117 in a state where it can move (reciprocate) relative to the piston structure 112, and so that it passes through the communication passage 120 of the piston inner 112e from the outlet 110b side with a certain gap. A hole is formed on the side surface of the rod holder 112c that connects the inside and outside. The rod holder portion 112c is held by the piston structure 112 by a return spring 114. The end of the rod-shaped member 117 on the outlet 110b side is thicker than the inner diameter of the outlet space 122b leading to the outlet 110b, and an outward-facing flange is formed on this thicker portion, with a groove formed at its end connecting the main space 122a and the outlet space 122b. The rod holder portion 112c is cylindrical with multiple gaps extending in the direction in which the piston structure 112 moves, and an inward-facing flange is formed on its end on the outlet 110b side. The outward-facing flange of the rod-shaped member 117 catches on the inward-facing flange of the rod holder portion 112c, preventing the rod-shaped member 117 from falling out of the rod holder portion 112c. In addition, the portion of the rod-shaped member 117 closer to the tip than the flange protrudes from the end of the rod holder portion 112c on the outlet 110b side.

[0067] Furthermore, a ring-shaped magnet 118 is provided at the end of the member holding portion 112b on the inlet 110a side. The convex body 116 that protrudes from the fluid introduction cylinder portion 111b into the cylinder body portion 111b is in a positional relationship in which the convex body 116 penetrates the ring-shaped magnet 118. In this case, the movable member 113 held by the member holding portion 112b may be a magnetic material that receives an attractive force (biasing toward the inlet 110a side) from the magnet 118 (biasing member), such as iron or a magnet.

[0068] Alternatively, instead of the magnet 118, a simple magnetic material (for example, iron) may be used, and the movable member 113 may be formed from the magnet. In this case, the magnetic material (for example, iron) can be said to provide a biasing force toward the inlet 110a side to the movable member 113 formed from the magnet.

[0069] The actuator 100 with the structure described above operates as follows.

[0070] The moving member 113 blocks the communication passage 120 of the piston inner 112e. The piston structure 112 moves from the bottom dead center position (position shown in Figure 7) towards the top dead center position (outlet 110b side) together with the moving member 113, which is held by the member holding part 112b, which has a magnet 118 at its end, and the rod-shaped member 117, which is held by the rod holding part 112c, against the repulsive force (biasing) towards the inlet 110a side caused by the return spring 114 due to the fluid of a predetermined pressure flowing into the first space SP1 from the inlet 110a of the cylinder 111. At this time, the moving member 113 is subjected to a biasing force toward the inlet 110a side by the magnet 118, but the biasing force toward the outlet 110b side due to the pressure difference between the first space SP1 and the second space SP2 is stronger, so the state in which the communication passage 120 is blocked is maintained. Then, the thicker end of the rod-shaped member 117, which moves along with the piston structure 112, abuts against the stepped portion (rod movement restricting portion) at the boundary between the main space 122a and the outlet space 122b in the cylinder body 111a, thereby restricting the movement of the rod-shaped member 117. Furthermore, the moving member 113 abuts against the tip end (first predetermined position) of the rod-shaped member 117 on the inlet 110a side as it passes through the communication passage 120 of the piston inner 112e, thereby restricting the movement of the moving member 113 toward the top dead center position.

[0071] When the movement of the movable member 113 toward the top dead center position is restricted in this way, the continuous movement toward the top dead center position of the piston structure 112, accompanied by inertial force, causes the restricted movable member 113 to move relatively away from the piston inner 112e, and the communication passage 120 of the piston inner 112e becomes open. As a result, the first space SP1 and the second space SP2, separated by the piston structure 112, become connected through the gap between the open communication passage 120 (inner wall) and the rod-shaped member 117 (outer wall), and the pressure difference between the first space and the second space that sandwich the piston structure 112 disappears. Furthermore, the pressure on the movable member 113 from the fluid on the first space SP1 side toward the outlet 110b side also disappears, and the movable member 113 in the member holding part 112b moves until it is attracted to the magnet 118 and comes into contact with the magnet 118.

[0072] In this way, by forcibly separating (moving away from) the moving member 113 from the opening on the inlet 110a side of the communication passage 120 of the piston inner 112e by the magnetic force of the magnet 118, the flow path of the fluid flowing into the communication passage 120 from the opening on the inlet 110a side is reliably secured. As a result, the fluid flows more smoothly from the first space SP1 to the second space SP2, making the return of the piston structure 112 to the bottom dead center position by the repulsive force (biasing) of the return spring 114 after reaching the top dead center position more reliable, and the travel time is also shortened.

[0073] Then, when the piston structure 112 moves toward the bottom dead center position after reaching the top dead center position, the moving member 113 is attracted to the magnet 118 within the member holding portion 112b, so the open state of the communication passage 120 can be maintained even without contact resistance between the member holding portion 112b and the moving member 113. The moving member 113 is then restricted from moving any further toward the bottom dead center position by the tip of the convex shape 116 that enters the member holding portion 112b. As a result, from the moment the tip of the convex shape 116 abuts against the moving member 113, the return spring 114 causes the piston structure 112 to continue moving toward the bottom dead center position, and the restricted movement of the moving member 113 is pulled away from the magnet 118, causing it to come into contact with the piston inner 112e and close the communication passage 120. Then, similar to the actuator 100 described above (see Figures 1 to 6), the piston structure 112, which has moved toward the inlet 110a, reaches the bottom dead center position. Then, due to the pressure of the fluid flowing from the inlet 110a into the first space SP1, it again resists the repulsive force (biasing) from the return spring 114 and begins to move toward the top dead center position (towards the outlet 110b), pushing the fluid in the second space SP2 out of the outlet 110b. Thereafter, with the fluid flowing in one direction from the inlet 110a to the outlet 110b, the piston structure repeatedly reciprocates between the top dead center position (outlet side) and the bottom dead center position (inlet side) as described above.

[0074] Next, a second modified example of the actuator according to the first embodiment of the present invention is configured as shown in Figure 8.

[0075] The actuator 100 shown in Figure 8 is characterized by the use of a hollow pipe assembly 119 instead of the rod-shaped member 117 in the actuator 100 shown in Figure 7. In Figure 8, the same (or corresponding) parts as those in the aforementioned actuator 100 (see Figure 7) are assigned the same reference numerals.

[0076] In the actuator 100 shown in Figure 8, instead of the rod-shaped member 117 shown in Figure 7, a hollow pipe assembly 119 is held within the rod-holding portion 112c of the piston structure 112 so as to be able to move (reciprocate) relative to the piston structure 112, and so as to pass through the through hole 112f of the piston inner 112e from the outlet 110b side while maintaining airtightness. The outer circumference of the piston inner 112e is press-fitted and fixed to the inner diameter portion of the piston body portion 112a. The hollow pipe assembly 119 has a hollow pipe 119a, a cap portion 119b fitted and fixed to the outlet 110b end of the hollow pipe 119a, and an anti-entry portion 119c that is adhesively fixed. A notch is formed at the outlet 110b end of the hollow pipe assembly 119, and the inside and outside of the pipe are in communication at the outlet 110b end. The outer diameter of the cap portion 119b is larger than the inner diameter of the outlet space 122b leading to the outlet 110b, and an outward-facing flange is formed on the cap portion 119b. The flange of the cap portion 119b catches on the inward-facing flange of the rod holder portion 112c, preventing the hollow pipe assembly 119 from falling out of the rod holder portion 112c. The portion of the cap portion 119b on the tip side of the flange in the hollow pipe assembly 119 protrudes from the end of the rod holder portion 112c on the outlet 110b side.

[0077] In the actuator 100 with the structure described above, the difference between the hollow pipe assembly 119 and the rod-shaped member 117 in the actuator 100 shown in Figure 7 will be explained. When the piston structure 112 moves toward the top dead center position (outlet 110b side), the moving member 113 abuts against the tip (first predetermined position) on the inlet 110a side of the hollow pipe 119a (hollow pipe assembly 119) passing through the through hole 112f of the piston inner 112e, and even after the movement of the moving member 113 toward the top dead center position is restricted, the communication passage 120 connecting the first space SP1 and the second space SP2 is not connected. Therefore, the piston structure 112 continues to move relative to the moving member 113, and the distance between the inlet side end of the moving member 113 and the outlet side end of the magnet 118 decreases. Then, the force of the magnet 118 attracting the moving member 113 toward the inlet side is stronger than the biasing force due to the pressure difference between the first space SP1 and the second space SP2 that biases the moving member 113 toward the outlet 110b side, and the moving member moves toward the inlet side. At this time, the pipe assembly 119 also moves together, but its movement is restricted by the intrusion prevention part 119c, so the tip of the hollow pipe 119a (hollow pipe assembly 119) toward the inlet 110a side and the moving member 113 are separated, and the first space SP1 and the second space, separated by the piston structure 112, become connected through the communication channel 120 in the hollow portion of the hollow pipe 119a, and the hollow pipe assembly 119 moves toward the outlet 110b side due to the fluid flowing from the first space SP1 to the second space SP2. As a result, the fluid flows more smoothly from the first space SP1 to the second space SP2, making the return of the piston structure 112 to the bottom dead center position by the repulsive force (biasing) of the return spring 114 after reaching the top dead center position more reliable, and shortening the travel time.

[0078] The inner diameter of the through hole 112f and the outer diameter of the hollow pipe 119a may be sealed with an O-ring or the like. The hollow pipe assembly 119 does not necessarily have to be hollow all the way through; it is sufficient if a similar flow path is formed. In addition, the inlet end of the hollow pipe assembly 119, whose movement is restricted by the intrusion prevention part 119c, and the outlet end of the movable member 113, which is attracted to and in close contact with the magnet 118, are configured to have a gap.

[0079] Next, a third modified example of the actuator according to the first embodiment of the present invention will be described with reference to Figure 9.

[0080] The actuator 100 shown in Figure 9 is characterized by having a structure that draws the reciprocating motion of the piston structure 112 out of the cylinder 111. In Figure 9, the same (or corresponding) parts as the actuator 100 described above (see Figure 7) are given the same reference numerals.

[0081] In the actuator 100 shown in Figure 9, the piston structure 112 includes a piston body portion 112a, a movable member 113, and a member holding portion 112b that holds the movable member 113, as well as two operating bars 112d that extend from the piston body portion 112a toward the outlet 110b and protrude to the outside from the tip of the cylinder body 111a. These two operating bars 112d protrude to the outside through a through hole 127 formed at the tip of the cylinder 111 (cylinder body 111a).

[0082] In such an actuator 100, as described above (see Figures 1 to 6), when the fluid flows in one direction from the inlet 110a to the outlet 110b, the piston structure 112 repeatedly reciprocates between the top dead center position (outlet side) and the bottom dead center position (inlet side). Due to the reciprocating motion of the piston structure 112 with a stroke corresponding to the distance between the top dead center position and the bottom dead center position, the operating bar 112d included in the piston structure 112 also reciprocates with a stroke corresponding to the distance between the top dead center position and the bottom dead center position. This allows the reciprocating motion of the piston structure 112 to be drawn outside the cylinder 111. For example, by attaching a magnet to the operating bar 112d and causing it to reciprocate inside a coil, a generator can be constructed. In addition, it is possible to attach an elastic body to the operating bar 112d to apply vibration, connect a link mechanism to convert it into rotational motion, or monitor the movement of the bar to monitor the movement of the piston structure 112. In other words, various forms of actuators can be constructed depending on what is to be attached to the operating bar 112d.

[0083] Furthermore, the piston biasing member (return spring 114) that biases the piston structure 112 toward the inlet 110a can be provided outside the cylinder 111 to bias the operating bar 112d, rather than inside the cylinder 111. This increases the design flexibility.

[0084] Next, a fourth modified example of the actuator according to the first embodiment of the present invention will be described with reference to Figure 10.

[0085] The actuator 100 shown in Figure 10 is a modified example of the actuator shown in Figure 1, characterized in that a flow path leading to a communication flow path 120 is formed between the outer circumference of the moving member and the member holding portion 112b. The description will be simplified and redundant. In Figure 10, the same (or corresponding) parts as those of the actuator 100 described above are given the same reference numerals.

[0086] In Figure 10, the piston structure 112, which is reciprocally housed within the cylinder 111, has a piston body portion 112a and a movable member 113 that is reciprocally housed in a member holding portion 112b formed inside the piston body. A communication channel 120 is formed in the piston body 112a to connect a first space SP1 and a second space SP2, and the movable member 113 is positioned to face the opening on the inlet 110a side and is slidably held within the member holding portion 112b that protrudes on the outlet 110b side. The end face of the member holding portion 112b on the inlet 110a side is provided with a stepped portion to prevent the movable member 113 from falling out. The movable member 113 has multiple (two) flow channels 113a extending along its peripheral wall. When the movable member 113 is blocking the opening of the communication flow channel 120, the flow channels 120a and the communication flow channel 120 are not in communication. When the movable member 113 moves away from the opening of the communication flow channel 120, the flow channels 120a and the communication flow channel 120 become in communication. The flow channels 120a may also be formed in the inner diameter portion of the member holding portion 112b of the piston body portion 112a at the corresponding location. An O-ring 126 is provided on the outer circumference of the piston body 112a, and the O-ring 126 maintains airtightness between the first space SP1 on the inlet 110a side and the second space SP2 on the outlet 110b side, with the piston structure 112 (piston body portion 112a) as the boundary.

[0087] Inside the cylinder 111, a rod-shaped member 115 (first movement restricting member) extending from the outlet 110b side is provided in a position that allows it to pass through the communication passage 120 of the piston body 112a, similar to the example described above (see Figure 1). Also, similar to the example described above (see Figure 1), a convex body 116 (second movement restricting member) protruding into the cylinder body 111a is provided in a position that allows it to enter the member holding portion 112b of the piston body 112a from the opening on the inlet 110a side.

[0088] In the actuator 100 of the structure described above (modification 4), when the piston structure 112 (piston body portion 112a) moves from the inlet 110a side (bottom dead center position side) to the outlet 110b side (top dead center position side), the moving member 113 closes the opening on the inlet 110a side of the communication passage 120 of the piston body portion 112a, so that the first space SP1 and the second space SP2 are not in communication. In this state, as the piston structure 112 moves further toward the outlet 110b side (top dead center position side), when the movement of the moving member 113 is restricted at the first predetermined position by the rod-shaped member 115 (first movement restricting member: communication flow path opening / closing mechanism), the continuous movement toward the outlet 110b side (top dead center position side) accompanied by the inertial force of the piston body 112a causes the restricted moving member 113 to move relatively away from the opening on the inlet 110a side of the communication flow path 120, and the first space SP1 and the second space SP2 become in communication through the flow path 113a of the moving member 113. As a result, the pressure difference between the first space SP1 and the second space SP2 that sandwich the piston structure 112 (piston body portion 112a) disappears, and after the piston structure 112 (piston body portion 112a) reaches the top dead center position, it begins to move toward the bottom dead center position due to the biasing force of the return spring 114 (piston biasing member) toward the inlet 110a side (bottom dead center position side).

[0089] When the piston structure 112 moves toward the inlet 110a side (bottom dead center position side) with the movable member 113 opening the communication passage 120 of the piston body 112a, if the movable member 113 is restricted from moving at a second predetermined position by the convex body 116 (second movement restricting member: communication passage opening / closing mechanism) on the piston body 112a, the continuous movement of the piston structure 112 (piston body 112a) toward the inlet 110a side (bottom dead center position side) by the return spring 114 causes the restricted movable member 113 to move relatively toward the opening on the inlet 110a side of the communication passage 120 of the piston body 112a, and the end face of the movable member 113 closes the communication passage 120, resulting in a state of non-communication between the first space SP1 and the second space SP2. Then, after reaching the bottom dead center position, the piston structure 112 begins to move toward the top dead center position against the biasing force of the return spring 114 (piston biasing member) due to the pressure of the fluid flowing into the first space SP1 from the inlet 110a, and the fluid in the second space SP2 is pushed out from the outlet 110b. Thereafter, with the fluid flowing in one direction from the inlet 110a to the outlet 110b, the piston structure 112 repeatedly moves back and forth between the top dead center position (outlet side) and the bottom dead center position (inlet side) as described above.

[0090] Next, an actuator according to a second embodiment of the present invention and a fluid quantitative monitoring device equipped with the actuator will be described.

[0091] A fluid quantity monitoring device is, for example, a device that monitors whether a certain amount of oil, grease, or other fluid is being supplied to the moving parts of a machine to reduce friction. This fluid quantity monitoring device is equipped with an actuator in which a piston structure repeatedly reciprocates between the top dead center position (outlet side) and the bottom dead center position (inlet side) when the fluid (oil or grease) is flowing in one direction from the inlet to the outlet inside the cylinder.

[0092] A fluid quantitative monitoring device equipped with an actuator according to a second embodiment of the present invention is configured as shown in Figure 11.

[0093] In Figure 11, this fluid quantitative monitoring device includes the actuator 200 shown in Figure 11 and a sensor unit 250 as a piston movement detection unit. The actuator 200 shown in Figure 11 is characterized in that a magnet is installed on the outlet 210b side of the piston inner 212e, thereby biasing the moving member 213 toward the outlet 110b side as well. The previously mentioned description has been omitted and simplified, and the differences will be explained. Also, in Figure 11, the same (or corresponding) parts as the actuator 100 (see Figures 1 to 8) are assigned the same reference numbers.

[0094] As shown in enlarged view in Figures 13A to 14B, the piston inner 212e has a through hole 228 that penetrates from the inlet 210a side to the outlet 210b side with a step, and its outer circumference is fixed to the inner diameter of the piston body 212a by press-fitting. In addition, a seal tube 235 is provided in a predetermined portion of the through hole 228 so as to be in close contact with its inner wall, as shown in enlarged view in Figures 13A to 14B. The seal tube 235 seals the hollow pipe 215a in a slidable state.

[0095] A hollow pipe assembly 215 is housed within the rod holder 212c so as to be able to reciprocate, and has a through hole 242 on its side that connects its internal space to the main space 222a, and is held by the piston structure 112 by a return spring 214.

[0096] As described above, the hollow pipe 215a of the hollow pipe assembly 215 held by the rod holder portion 212c passes through the through hole 228 (see Figures 13A to 14B) in which the seal tube 235 of the piston inner 212e is fitted. The hollow pipe 215a constitutes a communication channel 220 formed in the piston body portion 212a (piston structure 212), including the piston inner 212e, to connect the first space SP1 and the second space SP2. A ring-shaped magnet 219 is provided on the outlet 210b side of the piston inner 212e through which the hollow pipe 215a passes, and a pipe biasing spring 223 is provided inside the rod holder portion 212c to bias the hollow pipe assembly 215 toward the outlet 210b side. Furthermore, small holes 241 are formed in predetermined parts of the peripheral wall of the hollow pipe 215a, penetrating the peripheral wall, as shown in enlarged view in Figures 13A to 14B.

[0097] A ring-shaped magnet 218 (biasing member) is provided and fixed to the inlet 210a side end of the member holding portion 212b, which holds the movable member 213 so that it can reciprocate. The movable member 213 is also made of a magnet. A magnetic attractive force acts between the movable member 213 (magnet) and the magnet 218. A magnetic attractive force also acts between the movable member 213 (magnet) and the magnet 219, which is passed through a piston inner 212e made of, for example, iron. An elastic member 233 (for example, a synthetic rubber sheet) is attached to the end face of the movable member 213 on the outlet 210b side, which faces the opening on the inlet 210a side of the through hole 228 (see Figures 13A to 14B) of the piston inner 212e. An inlet-side spacer 234 made of an elastic material is attached to the end face of the movable member 213 on the outlet 210a side.

[0098] A return spring 214 is provided in the internal space 222 (main space 222a) of the cylinder body 211a. This return spring 214 functions as a piston biasing member, biasing the piston structure 212 toward the inlet 210a due to its repulsive force.

[0099] A check ball 230 is provided in the internal space 221 of the fluid introduction cylinder section 211b, which has an inlet 210a formed at one end, sandwiched between a stopper 231 and a compression spring 232. The compression spring 232 prevents backflow of the fluid by pressing the check ball 230 against the stopper 231 with a certain biasing force. A convex body 216 (second movement restricting member) is fixed or integrally formed at the end of the fluid introduction cylinder section 211b on the cylinder body section 211a side, so as to protrude into the internal space 222 (main space 222a) of the cylinder body section 211a. A ring-shaped magnet 217 is also provided so as to fit into the convex body 216. The fluid introduction cylinder section 211b communicates with the main space 222 through the central flow path as well as through the notches on both sides.

[0100] The sensor unit 250 (piston motion detection unit) is provided on a predetermined location on the outer circumferential surface of the cylinder 211 of the actuator 200, and non-contactively detects the movement (reciprocating motion) of the piston structure 212 within the cylinder 211, and outputs a detection signal corresponding to that movement. Specifically, the sensor unit 250 has a magnetic detection unit that outputs a detection signal corresponding to the change in the influence of the magnetic force generated from each magnet that reciprocates as the piston structure 212 within the cylinder 211.

[0101] The operation of the actuator 200 with the structure described above and the operation of the fluid quantity monitoring device corresponding to its operation will be explained.

[0102] In the actuator 200, when a fluid at a predetermined pressure (such as oil or grease to be supplied to the moving parts of the machine) flows in from the inlet 210a of the cylinder 211, the fluid pushes aside the check ball 230, which is pressed by the compression spring 232, and flows to the outlet 210b side. The piston structure 212 inside the cylinder 211 (cylinder body portion 211a) has its opening on the first space SP1 side of the piston inner 212e, which leads to the communication passage 220 of the hollow pipe assembly 215, blocked by the moving member 213, so that the first space SP1 and the second space SP2, separated by this piston structure 212 (O-ring 226), are not in communication. Here, the movable member 213 (magnet) is attracted to the piston inner 212e, which is made of iron (a magnetic material), and the magnet 219, and closes the opening on the inlet 210a side of the through hole 228 of the piston inner 212e via the outlet-side elastic member 233, so that the first space SP1 and the second space SP2 are reliably kept out of communication.

[0103] In this state, as described above, the piston structure 212, pushed by the fluid of a predetermined pressure that flows in displacing the check ball 230, moves from the bottom dead center position (inlet 210a side) to the top dead center position (outlet 210b side) against the repulsive force (biasing) toward the inlet 210a side by the return spring 214 and the attractive force between the magnets 218 and 217. During this process, the movement of the piston structure 212 toward the top dead center position causes the fluid (oil or grease, etc.) in the second space SP2 to flow out from the outlet 210b and be supplied to the movable parts of the machine.

[0104] Then, the end of the hollow pipe assembly 215, which is held by the rod holding portion 212c that moves along with the piston structure 212, and which is provided with the cap portion 215b, abuts against the stepped portion (rod movement restricting portion: first movement restricting member) at the boundary between the main space 222a and the outlet space 222b in the cylinder body portion 211a, thereby restricting the movement of the hollow pipe assembly 215 toward the outlet 210b. As a result, the moving member 213 abuts against the tip portion (first predetermined position) of the hollow pipe assembly 215 (hollow pipe 215a) that penetrates the piston inner 212e via the outlet-side elastic member 233, and the movement of the moving member 213 toward the top dead center position is also restricted.

[0105] Even after the movement of the movable member 213 toward the top dead center position is restricted in this manner, the communication passage 220 connecting the first space SP1 and the second space SP2 is not connected. Therefore, the movement of the piston structure 212 toward the top dead center position continues, and the hollow pipe assembly 215 moves toward the inlet 210a side within the rod holding portion 212c (piston structure 212) against the biasing force of the pipe biasing spring 223. At this time, the outlet side 210b end of the hollow pipe assembly 215 abuts against the stepped portion (rod movement restricting portion) at the boundary between the main space 222a and the outlet space 222b in the cylinder body portion 211a. To prevent the internal cylinder space 222a and the outlet 210b from being closed and hindering the movement of the piston structure 212, a through hole 142 is provided in the hollow pipe 215a. The fluid in the internal space 222a of the cylinder passes through the gap between the cap portion 215b and the rod holding portion 212c, through the through-hole in the hollow pipe 215a, and out to the outlet 210b. As the tip of the hollow pipe assembly 215, which moves relative to the piston structure 212, protrudes from the opening on the inlet 210a side of the piston inner 212e, and is pushed by the hollow pipe assembly 215 (hollow pipe 215a) via the outlet-side elastic member 233 while maintaining airtightness, the moving member 213 moves away from the piston inner 212e. As the attractive force of the magnet 219 (outlet 210b side) passing through the piston inner 212e on the moving member 213 decreases, the attractive force of the magnet 218 (inlet 210a side) on the moving member 213 increases, and finally, the moving member 213, having moved away from the piston inner 212e, moves until it abuts against the magnet 218 located at the inlet 210a side end of the member holding portion 212b, as shown in Figure 12. At this time, if the hollow pipe assembly 215 moves together with the movable member 213, the communication passage 220 of the hollow pipe 215a cannot be opened. Therefore, the pipe biasing spring 223 prevents excessive entry into the first space SP1.

[0106] In this manner, as the moving member 213 moves in the member holding portion 212b until it abuts against the magnet 218 at its end as shown in Figure 12, the hollow pipe 215a (hollow pipe assembly 215) and the moving member 213 may take on the states shown in Figures 13A and 13B, or the states shown in Figures 14A and 14B, depending on the flow velocity (fluid pressure) and viscosity (resistance) of the supplied fluid (oil or grease).

[0107] In the case shown in Figures 13A and 13B, as shown in Figure 13A, the movable member 213 is pushed by the hollow pipe 215a and is slightly separated from the piston inner 212e. Due to the flow velocity and viscosity of the fluid (oil or grease, etc.), before the small hole 241 in the hollow pipe 215a is exposed from the seal tube 235, the movable member 213 moves due to the attractive force of the magnet 218 until it abuts against the magnet 218, as shown in Figure 13B. Then, the first space SP1 and the second space SP2, separated by the piston structure 212 (O-ring 226), become connected through the communication passage 220 of the hollow pipe 215a that penetrates the piston inner 212e.

[0108] On the other hand, in the case shown in Figures 14A and 14B, due to the relationship between the velocity and viscosity of the fluid (oil or grease, etc.), as shown in Figure 14A, at the moment the small hole 241 of the hollow pipe 215a that pushes the moving member 213 is exposed from the seal tube 235, the moving member 213 is not attracted to the magnet 218, and the first space SP1 and the second space SP2, separated by the piston structure 212, become connected through the small hole 241 of the hollow pipe 215a. As a result, the pressure difference between the first space SP1 and the second space SP2 disappears, and the biasing force acting on the movable member 213 toward the outlet 210b due to the fluid pressure difference between the first space SP1 and the second space SP2 is eliminated. Therefore, the force of the magnet 218 attracting the movable member 213 toward the inlet 210a side becomes stronger than the biasing force that is biasing the movable member 213 toward the outlet 210b side, and as shown in Figure 14B, the movable member 213 moves toward the inlet 210a side and becomes connected.

[0109] As described above, in both the cases shown in Figures 13A and 13B and Figures 14A and 14B, when the moving member 213 moves within the member holding portion 212b until it abuts against the magnet 218, and the first space SP1 and the second space SP2 are in communication through the hollow pipe 215a (communication channel 220) (see Figures 13B and 14B), the pressure difference between the first space SP1 and the second space SP2 disappears, and the piston structure 212, after reaching the top dead center position, begins to move toward the inlet 210a due to the repulsive force (biasing) of the return spring 214 toward the inlet 210a side (bottom dead center position side), as shown in Figure 15. The hollow pipe assembly 215 moves toward the outlet 210b due to the resistance of the fluid flowing from the first space SP1 to the second space SP2 and the pipe biasing spring 223, widening the communication channel connecting the first space SP1 and the second space SP2. As the piston structure 212 moves toward the bottom dead center position, the fluid flowing from the inlet 210a into the first space SP1 flows further from the first space SP1 to the second space SP2 through the communication channel 220 of the hollow pipe 215a that penetrates the piston inner 212e.

[0110] Furthermore, the biasing force from the return spring 214 and the attractive force from the magnets 218 and 217 combine to ensure that the piston structure 212 moves reliably toward the bottom dead center position (towards the inlet 210a side). The piston structure 212 then moves to a position (second predetermined position) where the convex body 216 enters the member holding portion 212b and the tip of the convex body 216 abuts against the movable member 213 via the inlet-side spacer 234. This restricts the movement of the movable member 213 toward the bottom dead center position (towards the inlet 210a side). From the moment the tip of the convex body 216 abuts the movable member 213 via the inlet-side spacer 234 (the start of the restriction of movement of the movable member 213), further movement of the piston structure 212 toward the bottom dead center position (inlet 210a side) causes the restricted-movement movable member 213 to abut against the piston inner 212e, closing the communication passage 220, including the through hole 228 in the piston inner 212e.

[0111] Then, the piston structure 212, which has been moving toward the inlet 210a, reaches the bottom dead center position. After reaching the bottom dead center position, the piston structure 212 begins to move toward the top dead center position (towards the outlet 210b) against the repulsive force (bias) of the return spring 214 and the attractive force between the magnets 218 and 217, due to the pressure of the fluid flowing from the inlet 210a into the first space SP1, and the fluid in the second space SP2 is pushed out from the outlet 210b. Thereafter, with the fluid flowing in one direction from the inlet 210a to the outlet 210b, the piston structure 212 repeatedly moves back and forth between the top dead center position (outlet side) and the bottom dead center position (inlet side) as described above.

[0112] When the piston structure 212 (including the movable member 213 made of magnets) within the cylinder 211 of the actuator 200 described above reciprocates between the top dead center position and the bottom dead center position as described above, the sensor unit 250 outputs a detection signal (voltage value) in response to changes in the influence of the magnetic force generated from each magnet (movable member 213, etc.) inside the sensor unit 250 on the sensor unit 250. Based on the waveform of this detection signal, it is possible to determine whether fluid (oil or grease, etc.) is flowing out properly from the actuator 200, that is, whether the correct amount (quantitative) of fluid (oil or grease, etc.) is being supplied to the moving parts of the machine.

[0113] With the actuator 200 described above, when fluid is flowing in one direction within the cylinder 211 from the inlet 210a to the outlet 210b, the piston structure 212 repeatedly reciprocates between the top dead center position (outlet 210b side) and the bottom dead center position (inlet 210a side), allowing the piston member 212 to reciprocate within the cylinder 211 without requiring a switch in the fluid supplied to the cylinder 211. Furthermore, a fluid quantitative monitoring device using such an actuator 200 can determine whether a fixed amount of fluid, such as oil or grease, is being supplied to the moving parts of a machine.

[0114] Furthermore, even if fluid exceeding the reciprocating range of the piston structure 212 flows into the hollow pipe 215a, the small hole 241 allows the first space SP1 and the outlet 210b to communicate through the small hole 241, thus preventing damage to the piping due to an abnormal increase in pressure and maintaining the fluid supply. The magnet 217 exerts a stronger biasing force toward the inlet 210a side of the piston structure 212 near the bottom dead center position where the biasing force of the return spring 214 weakens, enabling reliable operation without increasing the overall operating pressure.

[0115] Furthermore, the inlet-side spacer 234 prevents the movable member 213 and the magnet 218 from coming into close contact, ensuring a certain distance between them. This allows the force separating the movable member 213 and the magnet 218 after the movement restriction of the movable member 213 by the tip of the convex body 216 begins to be suppressed, without changing the magnitude of the magnetic force of the magnet 218. By using an elastic material, the impact with the tip of the convex body 116 when the movement of the movable member 213 is restricted, and the collision between the restricted-movement movable member and the piston inner 212e when the piston structure 212 reaches its bottom dead center after the movement restriction are mitigated, thereby suppressing vibration and noise. This embodiment is not limited to this one, as long as the arrangement has a similar effect.

[0116] The material of the seal tube 235 is preferably an elastic material, but is not limited to that. Also, in this embodiment, the material of the piston inner 212e is iron (magnetic material), but is not limited to that material. The piston inner 212e may be a non-magnetic material including an elastic material, or it may be a magnet. Furthermore, the presence or absence of the magnet 219 is not limited. This is because, as a result, when the movable member 213 is closing the communication flow path, a biasing force acts on the movable member 213 toward the outlet 210b side, and when the movable member 213 is separated from the end face of the piston inner 212e, a force acts to bias the movable member 213 toward the inlet 210a side, and this is just one example of such a configuration. In addition, the outlet-side elastic member 233 (elastic member) may be formed into a ring shape and installed on the inlet 210a side end face of the piston inner 212e, or it may be provided on the inlet 210a side tip of the hollow pipe 215a. Furthermore, the inlet-side spacer 234 is preferably made of a non-magnetic elastic material.

[0117] Furthermore, the fluid is not limited to oil or grease, but may also be a gas. Additionally, by using a transparent cylinder 211 and an optical detection unit, it becomes possible to optically detect the movement of the piston structure 212, and this configuration is also acceptable.

[0118] Next, an actuator according to a third embodiment and a power generation device equipped with that actuator will be described.

[0119] A power generation device equipped with an actuator according to the third embodiment of the present invention is configured as shown in Figure 16.

[0120] In Figure 16, the power generation device comprises an actuator 300 and three electromotive coil units 350a, 350b, and 350c (converters) that convert the reciprocating motion of a piston structure 312 within a cylinder 311 of the actuator 300 into electrical energy.

[0121] The actuator 300 includes a cylinder 311 and a piston structure 312 that reciprocates within the cylinder 311. An introduction block 301, having a through hole connecting an introduction channel 322a formed at one end of the cylinder 311 to the main space 322, is fitted and fixed in place by an O-ring 303, maintaining airtightness. An outlet block 302, having an outlet channel 322b formed at the other end of the cylinder 311, is fitted and fixed in place by an O-ring 304, maintaining airtightness. Through holes 302a and 302b are provided on the side and end faces of the outlet block 302, respectively, connecting the main space 322 to the outlet channel 322b. The through hole 302a is provided in a position that is not closed by the end of the hollow pipe 315. Either the through hole 302a or the through hole 315c may be present. Furthermore, a main space 322 is formed in the cylinder 311 between the introduction block 301 and the outlet block 302, communicating with the respective introduction passage 322a and outlet passage 322b. The outward-facing end of the introduction block 301 (introduction passage 322a) opens as an inlet 310a through which fluid (for example, a gas such as air) flows in, and the outward-facing end of the outlet block 302 (outlet passage 322b) opens as an outlet 310b through which the fluid passing through the cylinder 311 flows out. The piston structure 312 reciprocates within the main space 322 of the cylinder 311.

[0122] The piston body portion 312a of the piston structure 312 has a ring-shaped magnet 319 fitted and fixed to the outermost diameter portion on the inlet 310a side, and a ring-shaped magnet 334 is fitted and fixed to the inlet 310a end of the member holder 312b that extends toward the inlet 310a side. The piston body portion 312a has a through hole 312d that penetrates from the inlet 310a side to the outlet 310b side, and the movable member 313 is held within the member holder portion 312b so as to be able to reciprocate between the end face of the opening on the inlet side 310a of the through hole 312d and the magnet 334. The member holder portion 312b is provided with an axially extending notch, forming a flow path that connects to the opening on the inlet 310a side of the through hole 312d. The through-hole 312d of the piston body 312a expands in two stages from the inlet 310a side towards the outlet 310b side. A ring-shaped small magnet 333 is fitted and fixed in the stepped portion, and a ring-shaped small magnet 332 is adhesively bonded to it so as to join it to the outlet 310b side. The inner and outer diameters of the ring-shaped small magnet 332 are larger than the corresponding inner and outer diameters of the ring-shaped small magnet 333. Furthermore, a ring-shaped magnet 331 is provided so as to slide against the inner wall of the cylinder 311 so as to join it to the outlet 310b side of the ring-shaped small magnet 332. The inner diameter of this ring-shaped magnet 331 is smaller than the inner diameter of the small magnet 332 to which it joins, and it is positioned in a direction that repels magnet 319. Magnets 331, 332, and 333 are arranged in a straight line, with their north and south poles alternately arranged so as to attract each other. The magnet 333 adjusts the biasing force of the movable member 313 toward the inlet 310b side depending on its arrangement and the magnitude of its magnetic force. The movable member 313, which is held reciprocally by the aforementioned magnet 319, piston body 312a, member holding part 312b, and small magnets 333 and 334, along with the ring-shaped small magnets 332 and 331, the hollow pipe 315, and the V-ring 326, all form a single piston structure 312 that reciprocates within the main space 322 of the cylinder 311.

[0123] A hollow pipe 315 is provided so as to be reciprocable that it passes through the through hole 312d of the piston body 312a and through the ring-shaped small magnets 333, 332, and magnet 331, which are arranged in series. The hollow portion of the hollow pipe 315 functions as a communication passage 320 that connects the first space SP1 and the second space SP2, which are separated by the piston structure 312 within the cylinder 311. Multiple small through holes 315c are formed in the outer circumferential wall of the hollow pipe 315, which connect its own internal space to the main space 322. As shown in Figures 13 and 14 above, a small hole 315d is formed in a predetermined part of the circumferential wall near the inlet 310a side, penetrating the circumferential wall. In addition, a flange 315a that protrudes outward is formed in a predetermined part of the outer circumferential wall of the hollow pipe 315. The flange 315a is positioned within the inner space of the ring-shaped small magnet 332 so that its movement is restricted by the magnet 331 and the small magnet 333. This restricts the movement of the hollow pipe 315 toward the inlet side 310a and toward the outlet side 310b. Furthermore, the hollow pipe 315 is in a state where it can slide tightly against the through hole 312d of the piston body 312a, ensuring airtightness of the sliding part.

[0124] Furthermore, in the piston structure 312, a V-ring 326 is provided on the outer circumference of the small magnet 332 that reciprocates within the cylinder 311. This V-ring 326 maintains airtightness between the first space SP1 on the inlet 310a side and the space SP2 on the outlet 310b side, with the piston structure 312 as the boundary. The V-ring 326 may also be installed in the opposite direction to that shown in the figure. This reduces resistance when the piston structure moves to the bottom dead center position, allowing for smoother movement.

[0125] Within the cylinder 311 (main space 322), a return spring 314 is provided between the outlet block 302 and the piston structure 312, which is capable of reciprocating within the cylinder 311. This return spring 314 functions as a piston biasing member, biasing the piston structure 312 toward the inlet 310a due to its repulsive force.

[0126] The movable member 313 (magnet), formed from a magnet, can receive a force in the direction of attraction from the small magnets 333, 332, and 331, which are located beyond the piston body portion 312a of the magnetic material. The movable member 313 (magnet) can also receive a force in the direction of attraction from the small magnet 334 provided at the end of the member holding portion 312b on the inlet 310a side. Furthermore, the movable member 313 (magnet), which is reciprocating within the member holding portion 312b, can receive attractive or repulsive forces from the magnet 319 depending on its position within the member holding portion 312b. Specifically, when the movable member 313 is in contact with the opening of the through hole 312d of the piston body portion 312a, it can receive a force in the direction of attraction from the magnet 319, while when the movable member 313 is at a position away from the opening of the through hole 312d of the piston body portion 312a, it can receive a force in the direction of repulsion from the magnet 319.

[0127] A convex body 316 is provided so as to protrude from the introduction block 301 toward the main space 322 of the cylinder 311. A magnet 318 is fixed to the tip of the convex body 316. In addition, a ring-shaped magnet 317 is joined to the introduction block 301 so as to surround the convex body 316 with the magnet 318 at its tip. The magnet 317 can exert an attractive force on the magnet 319 of the piston structure 312, while exerting a repulsive force on the moving member 313 (magnet). The magnet 318 provided at the tip of the convex body 316 can also exert a repulsive force on the moving member 313. The convex body 316 is positioned so as to penetrate a small ring-shaped magnet 334 provided at the end of the member holding portion 312b of the piston body portion 312a on the inlet 310a side.

[0128] As in the example described above (see Figures 11 to 15), an outlet-side elastic member is attached to the surface of the piston body portion 312a of the movable member 313 facing the opening of the through hole 312d, and an inlet-side spacer (elastic member) is attached to the opposite surface. In addition, an elastic sheet is attached to the tip surface of the portion of the cylinder 311 of the outlet block 302 that protrudes toward the main space 322.

[0129] The three electromotive coil units 350a, 350b, and 350c are arranged to enclose and closely surround the cylinder 311 of the actuator 300, and their winding directions are opposite. These three electromotive coils 350a, 350b, and 350c (converters) generate electric current (electrical energy) in response to the movement of the piston structure 312 within the cylinder 311 of the actuator 300.

[0130] The operation of the actuator 300 with the structure described above and the operation of the power generation device in accordance with that operation will be explained.

[0131] Initially, as shown in Figure 16, the piston structure 312 in the bottom dead center position within the cylinder 311 has its opening on the first space SP1 side of the through hole 312d of the piston body portion 312a blocked by the moving member 313 via the outlet-side elastic member, resulting in a state of non-communication between the first space SP1 and the second space SP2, separated by the piston structure 312 (V-ring 326). Here, the moving member 313 (magnet) is attracted to the magnet 319, is also attracted by the small magnets 333, 332, and 331, receives a repulsive force from the magnet 318 provided at the tip of the convex body 316, and further receives a repulsive force from the magnet 317, and tightly blocks the opening of the through hole 312d of the piston body portion 312a via the outlet-side elastic member, thus ensuring that the first space SP1 and the second space SP2 remain in a state of non-communication.

[0132] In this state, when a fluid (for example, a gas such as air) at a predetermined pressure flows into the cylinder 311 through the inlet 310a (formed in the introduction block 301), the pressure of the fluid causes the piston structure 312 to move from the bottom dead center position to the top dead center position, as shown in Figure 17, against the repulsive force (biasing) toward the inlet 310a side by the return spring 314 and the attractive force (biasing) between the magnets 319 and 317. During this process, the fluid (for example, air) in the second space PS2 flows out from the outlet 310b.

[0133] Then, as shown in Figure 18, the tip of the hollow pipe 315 that passes through the piston body portion 312a, which moves along with the movement of the piston structure 312, abuts against the elastic sheet (rod movement restricting portion) on the tip surface of the protruding portion of the outlet block 302, thereby restricting the movement of the hollow pipe 315 toward the outlet 310b. Consequently, the movement of the moving member 313 toward the top dead center position, which abuts against the tip portion (first predetermined position) of the hollow pipe 315 that passes through the piston body portion 312a via the outlet-side elastic member, is also restricted (function of the first movement restricting member).

[0134] Even after the movement of the movable member 313 toward the top dead center position is restricted in this manner, the communication channel 320 connecting the first space SP1 and the second space SP2 is not connected, so the movement of the piston structure 312 toward the top dead center position continues. Due to the continuous movement of the piston structure 312 toward the top dead center position, the tip surface of the hollow pipe 315 moves toward the inlet 310a side while sealing the communication channel 320 by contact with the outlet side elastic member, as shown in Figure 19, the tip of the hollow pipe 315 protrudes from the opening on the inlet 310a side of the through hole 312d, and the movable member 313 moves away from that opening. As a result, the attractive force from the small magnets 333, 332, and 331 weakens on the movable member 313 (magnet) due to its positional relationship, and the attractive force from magnet 319 changes from an attractive force to a repulsive force, while the attractive force from small magnet 334 strengthens. Then, as shown in Figure 20, the movable member 313 moves until it abuts against the small magnet 334 located at the end of the member holding portion 312b on the inlet 310a side. At this time, since the hollow pipe 315 is restricted from entering the inlet 310a side by the flange 315a, a gap is created between its tip and the magnet 334.

[0135] In this way, when the movable member 313 is in close contact with the small magnet 334, the communication channel 320 of the hollow pipe 315 is opened, and the first space SP1 and the second space SP2 are connected through the communication channel 320 of the hollow pipe 315. As a result, the pressure difference between the first space SP1 and the second space disappears, the piston structure 312 reaches the top dead center position, and due to the repulsive force (biasing) of the return spring 314, it begins to move toward the inlet 310a (bottom dead center position side), as shown in Figure 21. When the piston structure 312 moves toward the bottom dead center position, the fluid flowing from the inlet 310a into the first space SP1 passes through the notch of the member holding part 312b and flows from the first space SP1 to the second space SP2 through the communication channel 320 of the hollow pipe 315 that penetrates the piston body part 312a.

[0136] Furthermore, the biasing force from the return spring 314 and the attractive force between the magnets 319 and 317, which increases as it approaches the bottom dead center position, work together to ensure that the piston structure 312 moves toward the bottom dead center position (towards the inlet 310a side). Then, the convex body 316 of the piston structure 312 enters the member holding portion 312b and moves to a position (second predetermined position) where the tip of the convex body 316 (magnet 318: second movement restricting member) abuts against the moving member 313, as shown in Figure 22. This restricts the movement of the moving member 313 toward the bottom dead center position (towards the inlet 310a side). From the moment the tip of the convex body 316 (magnet 318) strikes the movable member 313 (start of movement restriction of the movable member 313), the further continuous movement of the piston structure 312 toward the bottom dead center position (inlet 310a side) causes the movable member 313 to move relatively toward the outlet 310b side within the member holding portion 312b, as shown in Figure 23, and finally, as shown in Figure 16, strikes the opening end of the through hole 312d of the piston body portion 312a, which connects the first space SP1 and the second space SP2, and closes the opening.

[0137] Then, the piston structure 312, which has moved toward the inlet 310a, reaches the bottom dead center position (see Figure 16), and due to the pressure of the fluid flowing in from the inlet 310a, it begins to move toward the top dead center position (towards the outlet 310b) against the repulsive force (bias) of the return spring 314 and the attractive force (bias) of the magnets 319 and 317, and the fluid in the second space SP2 flows out from the outlet 310b. Thereafter, with the fluid flowing in one direction from the inlet 310a to the outlet 310b, the piston structure 312 repeatedly moves back and forth between the top dead center position (outlet 310b side) and the bottom dead center position (inlet 310a side) as described above.

[0138] As the piston structure 312 reciprocates within the cylinder 311 of the actuator 300 described above, the influence of the magnetic flux generated from magnets 331, 332, 333, and 319 on each of the three electromotive coil units 350a, 350b, and 350c changes. In response to this change in magnetic flux influence, an electric current (electrical energy) is generated in the three electromotive coil units 350a, 350b, and 350c. The current, which includes an AC component, generated in the three electromotive coil units 350a, 350b, and 350c is rectified into a DC current by a rectifier, stored in a capacitor, and can then supply stable electricity.

[0139] With the actuator 300 described above, when a fluid (for example, a gas such as air) flows in one direction within the cylinder 311 from the inlet 310a to the outlet 310b, the piston structure 312 reciprocates between the top dead center position (outlet 310b side) and the bottom dead center position (inlet 310a side), allowing the piston structure 312 to reciprocate within the cylinder 311 without requiring a switch in the fluid supplied to the cylinder 311. Furthermore, a power generation device using such an actuator 300 can generate electrical energy corresponding to the reciprocating motion of the piston structure 312 (including magnets 331, 332, 333, and 319) within the cylinder 311 without requiring a complex configuration.

[0140] Furthermore, in the actuator 300 described above, an elastic sheet is attached to the tip surface of the protruding portion of the outlet block 302, and an outlet-side elastic member and an inlet-side spacer are attached to two surfaces of the movable member 313. Therefore, as in the case of the actuator 200 described above (see Figures 11 to 15), the vibration and operating noise of the actuator 300 can be reduced.

[0141] Furthermore, the magnet 317 does not necessarily have to be inside the cylinder 311, and may be outside the cylinder 311. Its shape is also not limited to a ring shape. The number and winding direction of the coils are not limited to those described above. The polarity and presence or absence of the magnet are also not limited to those described above. This is because, as a result, it is sufficient that, from among the components, when the movable member 313 is closing the communication flow path, a biasing force acts on the movable member 313 toward the outlet 310b, and when the movable member 313 is separated from the end face of the piston body 312a, a force acts on the movable member 313 toward the inlet 310a.

[0142] Magnets of the same polarity may be molded as a single unit, or they may be divided into multiple magnets and stacked together. Furthermore, flow control valves can be provided at both the inlet 310a and the outlet 310b. By appropriately adjusting the flow rate on the inlet 310a and outlet 310b sides, vibration and operating noise can be reduced. In addition, the amount of power generated per unit flow rate can be improved, enabling more efficient power generation.

[0143] Furthermore, the piston structure 312 may be provided with a portion that slidably contacts the inner diameter portion of the cylinder 311, thereby preventing tilting. The V-ring 326 may be positioned with its opening facing the outlet 310b side. The magnet 318 at the tip of the convex body 316 is installed in a direction that repels the movable member 313 (magnet), so that the movable member 313 can switch from a non-communicating state to a communicative state without contact due to its repulsive force, and the piston structure 312 can move towards the top dead center side without colliding when it reaches the bottom dead center due to the pressure of the incoming fluid.

[0144] In this embodiment, a magnet 318 is used, but instead, a spring may be used to restrict the movement of the moving member 313. Furthermore, a spring may be placed between magnets 319 and 317, which will mitigate the collision when the piston structure 312 reaches its bottom dead center. Note that, as in other embodiments, the reciprocating motion of the piston structure 312 is possible even without using magnets 318 or a spring to replace them.

[0145] The protrusion 316, which serves as the second restricting portion, enters into the member holding portion 312b and restricts the movement of the movable member 313 toward the inlet 310a. However, the protrusion 316, which serves as the second restricting portion, may be flat, and its shape is not limited, as long as a part of the movable member protrudes toward the inlet 310a from the end face of the member holding portion 312b. Similarly, a spring member, which replaces the magnet 318 described above, may be slidably installed at the inlet end of the movable member 313 so as to protrude toward the inlet 310a from the member holding portion 312b.

[0146] Furthermore, the notch provided in the sliding portion of the movable member 313 of the member holding portion 312b serves as a passage connecting the first space SP1 and the second space SP2 when the communication passage 320 is in communication. In other words, it does not have to be a notch; it could be a groove, or a passage could be formed in the movable member.

[0147] Next, a modified example of the actuator according to the third embodiment of the present invention described above will be explained with reference to Figure 24.

[0148] The actuator 300 shown in Figure 24 is a simplified version of the actuator 300 described above (see Figures 16 to 23). In Figure 24, the same (or corresponding) parts as those of the actuator 300 described above are given the same reference numerals.

[0149] In the actuator 300 shown in Figure 24, the magnets 331, 332, 333, 317, 334, and 318 (located at the tip of the convex body 316) that were present in the actuators 300 shown in Figures 16 to 23 are omitted. In addition, in the piston structure 312, a rod holding portion 312c is provided at the outlet 310b end of the member holding portion 312b to support and hold the hollow pipe 315 in a loosely fitted state, and is held by the biasing force of the return spring 314. Instead of a V-ring 326, an O-ring 327 is used to maintain airtightness between the first space SP1 and the second space SP2 separated by the piston structure 312. In addition, two flanges 315a and 315b that protrude outward are formed on the hollow pipe 315. One flange 315a catches on the rod holder 312c, restricting further movement of the hollow pipe 315 toward the outlet 310b. Additionally, the other flange 315b and the outlet 310b end face of the piston body 312b restrict the movement of the hollow pipe 315 toward the inlet 310a. This configuration allows for a gap to be created between the inlet 310a end face of the hollow pipe 315 and the outlet 310b end face of the moving member 313 when the hollow pipe 315 and the moving member 313 are moved to their maximum extent toward the inlet 310a. The fixing member 334b ​​is installed to prevent the movable member 313 from falling towards the inlet 310a side. In this embodiment, it is made of a non-magnetic material, but the basic operation is that the communication passage 320 switches from a non-communicating state to a communicating state at the top dead center and from a communicating state to a non-communicating state at the bottom dead center. Depending on the design requirements, it may be made of a magnetic material or even a magnet. The piston body 312a is molded from a non-magnetic material.

[0150] The principle of switching the communication flow path between the ring magnet 319 and the movable member 313 (magnet) will be explained. As shown in Figure 24, when the two magnets 319 and 313 are arranged so that their like poles face each other, when the end face of the movable member 313 (magnet) on the outlet side is in contact with the end face of the through hole 312d of the piston body 312a on the inlet side 310a, a magnetic force is generated in the movable member 313 (magnet) toward the center of the ring magnet 319, thus biasing it toward the outlet side 310b. On the other hand, when the end face of the movable member 313 (magnet) on the outlet side 310b is separated from the end face of the through hole 312d of the piston body 312a on the inlet side 310a, a repulsive magnetic force acts because the two magnets 319 and 313 have like poles facing each other. Therefore, the movable member 313 (magnet) is biased toward the inlet side.

[0151] In addition, a single electromotive coil unit 350 is provided instead of the three electromotive coil units 350a, 350b, and 350c that were provided in the power generation device equipped with the actuator 300 shown in Figures 16 to 23 above. The power generation device generates electrical energy based on the current induced in this single electromotive coil unit 350.

[0152] In the actuator 300 shown in Figure 24, similar to the actuators 300 shown in Figures 16 to 23, when a fluid (for example, a gas such as air) flows in one direction from the inlet 310a to the outlet 310b of the cylinder 311, the actuator 300 provides the following functions: pressing force on the piston structure 312 toward the outlet 310b due to the fluid, biasing force on the piston structure 312 toward the inlet 310a due to the return spring 314, and magnetic attraction between the magnet 319 and the moving member 313 (magnet). Due to the repulsive action, the restriction of the hollow pipe 315's movement toward the outlet 310b by the protruding portion of the lead-out block 302, and the restriction of the moving member 313's movement toward the inlet 310a by the convex body 316, the opening of the through hole 312d in the piston body portion 312a on the inlet 310a side and the communication flow path 320 of the hollow pipe 315 are repeatedly opened and closed by the moving member 313, and the first space SP1 and the second space separated by the piston structure 312 are repeatedly switched between a non-communication state and a communication state. Accordingly, the piston structure 312 repeatedly reciprocates within the cylinder 311. Then, the reciprocating motion of the magnet 319 accompanying the reciprocating motion of the piston structure 312 changes the effect of the magnetic flux generated from the magnet 319 on the electromotive coil unit 350, and accordingly the electromotive coil unit 350 (converter) generates an electric current.

[0153] According to the actuator 300 described above (see Figure 24), even with a relatively simple configuration, the piston structure 312 can be reciprocated within the cylinder 311 when a fluid (for example, a gas such as air) is flowing in one direction from the inlet 310a to the outlet 310b. Furthermore, a power generation device using such an actuator 300 can generate electrical energy corresponding to the reciprocating motion of the piston structure 312 within the cylinder 311.

[0154] Next, an actuator according to a fourth embodiment of the present invention will be described.

[0155] An actuator according to a fourth embodiment of the present invention is configured as shown in Figure 25.

[0156] In the actuator 400 shown in Figure 25, the internal space of the cylinder 411, which has an inlet 410a at one end and an outlet 410b at the other end, is divided into spaces 421, 422, 423, and 424, whose inner diameters gradually decrease from the inlet 410a side to the outlet 410b side. An introduction block 401 is fitted into space 421, which extends from the inlet 410a of the cylinder 411, by screws on its outer circumference, and is sealed at the contact portion (tapered portion) with the cylinder 411. Multiple communication holes are formed in the introduction block 401, extending from space 421 to the adjacent space 422, and a movement restricting portion 401a is formed in the flow path that protrudes toward space 422.

[0157] The boundary portion of the cylinder 411 between space 422 and the adjacent space 423 is narrowed in diameter, forming a stepped portion 422a that continues into space 423. A spherical movable member 413 is housed in space 422 so as to be able to reciprocate between a movement restricting portion 401a protruding from space 421 and the stepped portion 422a. In space 423 adjacent to space 422 where the movable member 413 is provided, a piston body portion 412a is housed so as to be able to reciprocate. The flange portion of the piston body portion 412a, which is formed to protrude outward at its end on the outlet 410b side, is in close sliding contact with the inner wall of space 423, and airtightness is maintained between the first space SP1 on the inlet 410a side and the second space SP2 on the outlet 410b side, separated by this portion. Furthermore, a communication channel 420 is formed in the piston body 412a, connecting the first space SP1 on the inlet 410a side and the second space SP2 on the outlet 410b side. An opening spring 417 is provided between the piston body 412a and the movable member 413, applying a force (repulsive force) that separates the piston body 412a and the movable member 413.

[0158] A return spring 414 is provided between the stepped portion formed at the boundary between the space 424 following the outlet 410b and the adjacent space 423, and the piston body 412a. The return spring 414 biases the piston body 412a toward the inlet 410a.

[0159] In the actuator 400 with the structure described above, a piston structure 412 is housed reciprocally within a cylinder 411 and comprises a piston body 412a with a communication channel 420 formed therein, a movable member 413 positioned on the inlet 410a side of the piston body 412a and movable relative to the piston body 412a, and a release spring 417 that applies a force to separate the piston body 412a from the movable member 413. The movable member 413 moves along a member holding portion 412b formed within the cylinder 411. A groove parallel to the central axis of the cylinder 411 is formed in the member holding portion 412b, allowing fluid to move. This groove is formed so that the stepped portion 422a extends beyond the outlet 410b side.

[0160] In such an actuator 400, the state at the bottom dead center shown in Figure 25 is such that the movement of the movable member 413 toward the inlet 410a is restricted by the movement restricting part 401a, the release spring 417 is compressed by the biasing force of the return spring 414 toward the inlet 410a, and the movable member 413 comes into contact with the opening of the piston body 412a toward the inlet 410a, blocking the communication passage 420. When fluid flows in from the inlet 410a of the cylinder 411 at a certain pressure, a pressure difference is created between the first space SP1 and the second space SP2, and a biasing force acts in the direction of compressing the release spring 417 between the movable member 413 and the piston body 412a. As more fluid flows in and the pressure in the first space SP1 increases, the piston structure 412 moves from the bottom dead center position (position shown in Figure 25) to the top dead center position (position shown in Figure 26), resisting the biasing towards the inlet 410a side by the return spring 414 (piston biasing member). As the piston structure moves toward the top dead center position, the fluid in the second space SP2 (spaces 424, 423) is pushed out from the outlet 410b. During this process, the moving member 413 compresses the release spring 417 and closes the opening on the inlet 410a side of the communication passage 420 of the piston structure 412, so that the first space SP1 and the second space are not in communication with each other, separated by the piston structure 412.

[0161] In this state, as the piston structure 412 moves further toward the top dead center position (outlet 410b side), as shown in Figure 26, when the movement of the moving member 413 is restricted by the stepped portion 422a (first movement restricting member, first predetermined position) of the space 422, the continuous movement toward the top dead center position (outlet 410b side), including the inertial force of the piston body portion 412a of the piston structure 412, causes the restricted moving member 413 to move relatively away from the piston body portion 412a, opening the communication passage 420 of the piston body portion 412a, and the first space SP1 and the second space SP2 become in communication through the communication passage 420.

[0162] As a result, the pressure difference between the first space SP1 and the second space SP2, which sandwich the piston structure 412 (piston body portion 412a), disappears, and the piston structure 412 reaches the top dead center position. The piston body portion 412a and the moving member 413 (piston structure 412), which are separated by the biasing force toward the inlet 410a side by the return spring 414 and the repulsive force by the release spring 417, begin to move toward the bottom dead center position (inlet 410a side) while maintaining that state. As the piston structure 412 moves toward the bottom dead center position, the fluid flowing from the inlet 410a into the first space SP1 passes through the flow path formed in the member holding portion 412b and flows from the first space SP1 to the second space SP2 through the communication flow path 420 of the piston body portion 412a.

[0163] When the piston structure 412 moves toward the bottom dead center position (inlet 410a side) with the movable member 413 opening the opening on the first space SP1 side of the communication passage 420 in the piston body 412a, the movable member 413 abuts against the tip (second predetermined position) of the movement restricting portion 401a (second movement restricting member) of the introduction block 401, thereby restricting the movement of the movable member 413. As a result, the restricted movable member 413 moves relative to the piston body 412a against the repulsive force of the release spring 417 and abuts against the piston body 412a. This causes the movable member 413 to close the opening on the first space SP1 side of the communication passage 420 in the piston body 412a, resulting in a state of non-communication between the first space SP1 and the second space SP2. In this state, the piston structure 412 reaches the bottom dead center position (see Figure 25), and due to the pressure of the fluid flowing in from the inlet 410a, it begins to move toward the top dead center position (see Figure 26) against the biasing force of the return spring 414, and the fluid in the second space SP2 (spaces 424, 423) is pushed out from the outlet 410b. Thereafter, as the fluid flows in one direction from the inlet 410a to the outlet 410b, the piston structure 412 repeatedly reciprocates between the top dead center position (outlet side 410b) and the bottom dead center position (inlet 410a side), as described above.

[0164] With this actuator 400, similar to the actuators described above, when the fluid is flowing in one direction within the cylinder 411 from the inlet 410a to the outlet 410b, the piston structure 412 (piston body portion 412a) repeatedly reciprocates between the top dead center position (outlet 410b side) and the bottom dead center position (inlet 410a side). Therefore, the piston structure 412 (piston body portion 412a) can be reciprocated within the cylinder 411 without the need to switch the fluid supplied to the cylinder 411.

[0165] Furthermore, the movement restricting portion 401a is not limited to a convex shape, as long as it can restrict the movement of the moving member 413. It may be flat or concave, and its shape is not limited as long as it can restrict the movement of the moving member 413 toward the inlet 410a.

[0166] In this embodiment, a stepped portion 422a is used as the first restricting portion, but a rod-shaped member or the like used in other embodiments (Figure 1) may also be used. Furthermore, as shown in Figures 7 and 8, the rod-shaped member may be made to move integrally with the piston structure 412. It goes without saying that the moving member 413 is not limited to a sphere and can be combined with other embodiments.

[0167] Next, an actuator according to a fifth embodiment of the present invention will be described.

[0168] An actuator according to a fifth embodiment of the present invention is configured as shown in Figure 27. The actuator 500 shown in Figure 27 has a structure that integrates the structure of the actuator 200 shown in Figures 11 to 15 and the structure of the actuator 400 shown in Figures 25 to 26. The actuator 500 shown in Figure 27 is a modified example of Figure 11, and is characterized in that an open spring 517 is provided on the biasing member that biases the movable member 513 toward the outlet 510a, and the biasing spring 517 is biased in a direction that compresses due to the magnetic attraction between the magnet 519 and the movable member 513. The above description has been omitted and simplified, and the differences will be explained.

[0169] In the actuator 500 with the structure shown in Figure 27, the piston structure 512, which is reciprocally housed within the cylinder 511 (cylinder body 511a), includes a piston inner 512e which has a through hole and is sleeve-shaped, a movable member 513 (sphere), a member holding part 512b which holds the piston body 512a and the movable member 513 (sphere) so as to be reciprocally movable on the inlet 510a side of the piston body 512a, and a rod holding part 512c. The through hole in the piston inner 512e and the hollow pipe 515a are slidably airtight. The piston inner 512e and the piston 512a are integrally joined by press-fitting. The member holding part 512b is provided with an axially extending notch, forming a flow path connected to the through hole in the piston inner 512e. A stopper ring 524 made of a non-magnetic material is provided at the open end of the member holding portion 512b on the inlet 510a side to prevent the movable member 513 from falling out of the member holding portion 512b. The movable member 513 is formed in the shape of a sphere, and an elastic member layer 513a, such as a synthetic rubber layer, is formed on its outer circumferential surface. An opening spring 517 is provided between the piston inner 512e and the movable member 513 to bias them in a direction that separates them, and this opening spring 517 is also included in the piston structure 512 which is reciprocally housed within the cylinder 511. An O-ring 526 provided on the outer circumferential surface of the piston body portion 512a maintains airtightness between the first space SP1 on the inlet 510a side and the second space SP2 on the outlet 510b side, with the piston structure 512 (piston body portion 512a) as the boundary. A hollow pipe assembly 515, having a hollow pipe 515a and a cap portion 515b fitted and fixed to the end of the hollow pipe 515a, is reciprocally housed within the rod holder portion 512c. A ring-shaped magnet 519 is provided in the rod holder portion 512c, through which the hollow pipe 515a passes so as to abut against the piston inner portion 512e, and a pipe biasing spring 523 is provided to bias the hollow pipe assembly 515 toward the outlet 510b. The pipe biasing spring 523 is made of a conical spring that is resistant to buckling and has a short contact length, and is shaped so that its outer diameter decreases toward the outlet 510b.

[0170] Similar to the actuator 200 according to the second embodiment (see Figures 11 to 15), a check ball 531 is provided in the internal space 521 of the fluid introduction cylinder section 511b, which has an inlet 510a formed at one end, sandwiched between a stopper 531 and a compression spring 532. The fluid introduction cylinder section 511b communicates with the main space 522 through a central flow path as well as through notches on both sides thereof.

[0171] The piston inner 512e is made of iron (a magnetic material), and a ring-shaped magnet 519 is fixed to the end face on the outlet side 510b by its magnetic force. The material of the piston inner 512e and the stopper ring 524 may be magnet, magnetic material, or non-magnetic material. The material of the moving member 513 may be magnet or magnetic material. This is because, as a result, when the moving member 513 is closed to the opening on the inlet 510a side of the piston inner 512e connected to the communication flow path 120 by the spring biasing force and magnetic biasing force of the main components (ring-shaped magnet 119, piston inner 512e, moving member 513, stopper ring 524, and release spring 517), a biasing force acts on the moving member 513 toward the outlet 510b side, and when the moving member 513 moves away from the opening on the inlet 510a side of the piston inner 512e, a force acts on the moving member 513 toward the inlet 510a side. If the piston inner 512e and the piston body 512a are made of the same material, they may be molded as a single unit as shown in Figure 1. In this embodiment, the histone body is molded from a non-magnetic material.

[0172] Furthermore, in combinations of materials that generate an attractive magnetic force between the piston inner 512e and the moving member 513, the ring-shaped magnet 519 can be omitted.

[0173] The actuator 500 in Figure 27, which has a structure in which a piston structure 512 is provided to reciprocate freely inside the cylinder 511 (cylinder body 511a) as described above, operates as follows.

[0174] When fluid at a predetermined pressure flows in from the inlet 510a of the cylinder 511, the fluid pushes aside the check ball 530, which is pressed by the compression spring 532, and flows to the outlet 510b side. The piston structure 512 inside the cylinder 511 (cylinder body 511a) has its opening on the first space SP1 side of the piston inner 512e, which leads to the communication passage 520 of the hollow pipe 515a (hollow pipe assembly 515), blocked by the movable member 513, so that the first space SP1 and the second space SP2, separated by the piston structure 512 (O-ring 526), ​​are not in communication. Here, the movable member 513 is attracted to the magnet 519 and also blocks the opening of the piston inner 512e via the elastic member layer 513a on its surface, so that the first space SP1 and the second space SP2 are reliably kept out of communication.

[0175] In this state, as described above, the piston structure 512, pushed by the fluid of a predetermined pressure that flows in displacing the check ball 530, moves from the bottom dead center position (inlet 510a side) to the top dead center position (outlet 510b side) against the repulsive force (biasing) toward the inlet 510a side by the return spring 514. During this process, the fluid in the second space SP2 flows out from the outlet 510b as the piston structure 512 moves toward the top dead center position.

[0176] Then, the end of the hollow pipe assembly 515, which is held by the rod holding portion 512c that moves along with the piston structure 512, and which is provided with the cap portion 515b, abuts against the stepped portion (rod movement restricting portion: first movement restricting member) at the boundary between the main space 522a and the outlet space 522b in the cylinder body portion 511a, thereby restricting the movement of the hollow pipe assembly 515 toward the outlet 510b. As a result, the moving member 513 abuts against the tip portion (first predetermined position) of the hollow pipe assembly 515 (hollow pipe 515a) that penetrates the piston inner 512e via the elastic member layer 513a, and the movement of the moving member 513 toward the top dead center position is also restricted.

[0177] Even after the movement of the movable member 513 toward the top dead center position is restricted in this manner, the communication passage 520 connecting the first space SP1 and the second space SP2 is not connected, so the movement of the piston structure 512 toward the top dead center position continues, and the hollow pipe assembly 515 moves toward the inlet 510a side within the rod holding part 512c (piston structure 512) against the biasing force of the pipe biasing spring 523. In this way, the tip of the hollow pipe assembly 515, which is moving relative to the piston structure 512, protrudes from the opening on the inlet 510a side of the piston inner 512e, and is pushed by the hollow pipe assembly 515 (hollow pipe 515a) while maintaining airtightness via the elastic member layer 513a, causing the movable member 513 to separate from the piston inner 512e. As the movable member 513 moves away from the piston inner 512e, the effect of the magnet 519's attractive force on the movable member 513 through the piston inner 512e decreases. Finally, the movable member 513, having moved away from the piston inner 512e, moves due to the repulsive force of the release spring 517 until it abuts against the stopper ring 524 located at the inlet 510a end of the member holding portion 512b. At this time, if the hollow pipe assembly 515 moves together with the movable member 513, the communication passage 520 cannot be opened. Therefore, the pipe biasing spring 523 prevents excessive intrusion into the first space SP1. Note that the attractive force of the magnet is inversely proportional to the square of the distance, so as it moves away from the piston inner 512e, the force attracting the movable member 513 weakens rapidly.

[0178] As the movable member 513 moves in the member holding portion 512b until it abuts against the stopper ring 524 at its end, and the first space SP1 and the second space SP2 are connected through the hollow pipe 515a (communication channel 520), the pressure difference between the first space SP1 and the second space SP2 disappears, the piston structure 512 reaches the top dead center position, and begins to move toward the inlet 510a due to the repulsive force (biasing) of the return spring 514 toward the inlet 510a side (bottom dead center position side). The hollow pipe assembly 515 moves toward the outlet 510b side due to the resistance of the fluid flowing from the first space SP1 to the second space SP2 and the pipe biasing spring 523, and the communication channel connecting the first space SP1 and the second space SP2 widens. As the piston structure 512 moves toward the bottom dead center position, the fluid flowing into the first space SP1 from the inlet 510a flows further from the first space SP1 to the second space SP2 through the communication channel 520 of the hollow pipe 515a that penetrates the piston inner 512e.

[0179] As the piston structure 512 moves toward the bottom dead center position (inlet 510a side) in this manner, the movement restricting portion 518 (second movement restricting member) enters the member holding portion 512b, and the tip of the movement restricting portion 518 abuts against the moving member 513 (second predetermined position). This restricts the movement of the moving member 513 toward the bottom dead center position (inlet 510a side). From the moment the tip of the movement restricting portion 518 abuts against the moving member 513 (start of movement restriction of the moving member), further continuous movement of the piston structure 512 toward the bottom dead center position (inlet 510a side) causes the restricted moving member 513 to abut against the piston inner 512e, closing the communication passage 120, including the through hole in the piston inner 512e.

[0180] Then, the piston structure 512, which has moved toward the inlet 510a, reaches the bottom dead center position, and the fluid flowing from the inlet 510a into the first space SP1 pushes aside the check ball 530, which is being pressed by the compression spring 532, and flows toward the outlet 510b side. Due to the pressure of this fluid, the piston structure 512 begins to move toward the top dead center position (towards the outlet 510b) again, resisting the repulsive force (bias) from the return spring 514, and the fluid in the second space SP2 is pushed out from the outlet 510b. Thereafter, with the fluid flowing in one direction from the inlet 510a to the outlet 510b, the piston structure 512 repeatedly moves back and forth between the top dead center position (outlet side) and the bottom dead center position (inlet side) as described above.

[0181] With the actuator 500 described above, similar to the actuators described above, when the fluid is flowing in one direction within the cylinder 511 from the inlet 510a to the outlet 510b, the piston structure 512 reciprocates between the top dead center position (outlet 510b side) and the bottom dead center position (inlet 510a side), allowing the piston structure 512 to reciprocate within the cylinder 511 without requiring a switch in the fluid supplied to the cylinder 511.

[0182] Next, an actuator according to a sixth embodiment of the present invention and a power generation device using the same will be described.

[0183] A power generation device using an actuator according to the sixth embodiment of the present invention is configured as shown in Figure 28. The actuator 600 used in this embodiment is characterized in that a movable member is positioned on the outlet 610b side of the communication channel 620, and the movable member 613 is moved by magnetic attraction at the top dead center position and the bottom dead center position to open and close the communication channel 620.

[0184] In Figure 28, the power generation device comprises an actuator 600 and an electromotive coil unit 650 (converter) that converts the reciprocating motion of a piston structure 612 within a cylinder 611 of the actuator 600 into electrical energy.

[0185] The actuator 600 has a cylinder 611 and a piston structure 612 that reciprocates within the cylinder 611. An introduction block 601 with an introduction channel 622a is fitted and fixed to one end of the cylinder 611 while maintaining airtightness. An outlet block 602 with an outlet channel 622b is fitted and fixed to the other end of the cylinder 611 while maintaining airtightness. A main space 622 is formed inside the cylinder 611 between the introduction block 601 and the outlet block 602, communicating with the respective introduction channel 622a and outlet channel 622b, and the piston structure 612 is housed in this main space 622 so as to be able to reciprocate. The outward-facing end of the introduction block 601 (introduction channel 622a) opens as an inlet 610a through which fluid flows in, and the outward-facing end of the outlet block 602 (outlet channel 622b) opens as an outlet 610b through which the fluid passing inside the cylinder 611 flows out. Furthermore, the introduction block 601 has a piston-facing portion 601a having a surface of a certain width that faces the piston structure 612, and the output block 602 also has a piston-facing portion 602a having a surface of a certain width that faces the piston structure 612. The piston-facing portion 602a protrudes toward the main space 622 and is formed so that the distance to the moving member 613 decreases when the piston structure 612 reaches its top dead center, thereby making the magnetic movement of the moving member 613 more reliable. The flow path from the introduction channel 622a of the introduction block 601 to its main space 622 is formed so that the flow path does not close even when the piston structure 612 reaches its bottom dead center on the inlet 610a side. Similarly, the flow path from the output channel 622b of the output block 602 to its main space 622 is formed so that the flow path does not close even when the piston structure 612 reaches its top dead center on the outlet 610b side. Each of the introduction block 601 and the output block 602 is formed of a magnetic material (for example, iron or a magnet).

[0186] The piston structure 612 has a piston body 612a, the end on the inlet side 610a is closed with a lid and the end on the outlet side 610b is open, and a movable member 613 is housed inside the piston body 612a so as to be in close sliding contact with the inner wall (member holding part) of the piston body 612a. A flange 616 (stopper part) that protrudes inward is formed on the open end of the piston body 612a, and a protrusion 615a (see Figures 31 to 33) is formed on the inner wall of the closed end (lid) on the inlet side 610a of the piston body 612a. The movable member 613 is reciprocating between the closed end on the inlet side 610a where the protrusion 615a is formed and the flange 616 formed on the open end on the outlet side 610b. An O-ring 626 is provided on the outer circumference of the piston body 612a, and this O-ring 626 maintains airtightness between the first space SP1 on the inlet 610a side and SP2 on the outlet 610b side, with the piston structure 612 (specifically, the position of the O-ring provided on the piston body 612a) as the boundary.

[0187] One or more communication passages 620 (small holes) are formed in a predetermined location near the closed end of the piston body 612a (a position that can be opened and closed by the reciprocating motion of the movable member 613) so as to be opposite to the sliding surface of the movable member 613 with the piston body 612a. The movable member 613 also has through holes 613a that penetrate the movable member 613 and open at its inlet 610a end and its outlet 610b end. Here, the communication passages 620 (small holes) of the piston body 612a and the through holes 613a of the movable member 613 form a passage that connects the first space SP1 and the second space SP2. The through holes 613a may be grooves as long as they do not overlap with the communication passages 620.

[0188] The movable member 613, which is housed so as to be reciprocable within the member holding portion of the piston body 612a, is made of a magnet. As a result, an attractive force acts on the movable member 613 toward the piston opposing portion 601a (for example, iron or a magnet) of the introduction block 601 in the cylinder 611, in proportion to its distance, and an attractive force acts toward the piston opposing portion 602a (for example, iron or a magnet) of the outlet block 602, in proportion to its distance. In addition, a return spring 614 is provided between the outlet block 602 and the piston body 612a of the piston structure 612, so that the piston structure 612 (piston body 612a) is biased toward the inlet 610a side.

[0189] An electromotive coil unit 650 (converter) is provided on the outer circumference of the cylinder 611. The electromotive coil unit 650 generates an electric current (electrical energy) in accordance with the movement of the moving member 613 (magnet) accompanying the reciprocating motion of the piston structure 612 inside the cylinder 611.

[0190] The operation of the actuator 600 with the structure described above and the operation of the power generation device corresponding to its operation will be explained.

[0191] Initially, in the piston structure 612 located at the bottom dead center position within the cylinder 611, the attractive force acting between the piston-facing portion 601a (magnetic material) of the introduction block 601 and the moving member 613 (magnet) holds the moving member 613 in contact with the inner wall where the convex portion 615a of the closed end (lid) of the piston body portion 612a is formed. At this time, the communication passage 620 (small hole) of the piston body portion 612a is closed by the outer circumferential surface of the moving member 613, and the first space SP1 and the second space SP2, separated by the piston structure 612 (piston body portion 612a: O-ring 626), are not in communication.

[0192] In this state, when fluid at a predetermined pressure flows into the cylinder 611 (main space 622) through the introduction channel 622a of the introduction block 601 from the inlet 610a, the pressure of the fluid causes the piston structure 612 to move from the bottom dead center position to the top dead center position, as shown in Figure 29, against the repulsive force (biasing) toward the inlet 610a side by the return spring 614 and the suction force between it and the piston-facing portion 601a of the introduction block 601. During this process, the fluid in the second space SP2 flows out from the outlet 610b through the outlet channel 622b of the outlet block 602. At this time, because the pressure on the first space SP1 side acts only on the side of the moving member 613 due to the communication channel 620 (small hole), no biasing force is generated to move the moving member 613 toward the inlet 610a side and the outlet 610b side. Therefore, the state in which the communication channel 620 (small hole) is closed can be maintained.

[0193] Furthermore, as shown in Figure 30, in this state (where the first space SP1 and the second space are not in communication), the piston structure 612 moves toward the outlet 610b side, and the moving member 613 approaches the piston-facing portion 602a of the outlet block 602. Then, at the first predetermined position, the influence of the attractive force of the moving member 613 (magnet) on the piston-facing portion 602a of the outlet block 602 becomes greater than the influence of the attractive force on the piston-facing portion 601a of the introduction block 601, and as shown in Figure 31, the moving member 613 moves until it is restricted by the flange 616 (stopper portion) at the outlet 610b side end of the piston body portion 612a (to the open end of the piston body portion 612a). Note that once the moving member 613 starts to move, the attractive force toward the outlet 610b side becomes stronger, while the attractive force toward the inlet 610a side becomes weaker, thus promoting its movement. As a result, the communication channel 620 (small hole) formed in the piston body 612a is opened, and the first space SP1 and the second space SP2, separated by the piston structure 612 (piston body 612a), are in communication through the through hole 613a of the movable member 613. Furthermore, due to the protrusion 615a (see Figure 31) formed on the inner wall of the closed end (lid) of the piston body 612a on the inlet 610a side, the end face of the movable member 613 on the inlet 610a side is not in close contact with the inner wall of the closed end (lid) of the piston body 612a because a space corresponding to the height of the protrusion 615a is formed. This allows the movable member 613 to move smoothly toward the outlet 610b side, and as a result, the reciprocating motion of the movable member 613 is also smooth.

[0194] As a result, the pressure difference between the first space SP1 and the second space disappears, and the piston structure 612 reaches the top dead center position. Against the repulsive force (biasing) of the return spring 614 and the suction force between the piston-facing portion 602a of the introduction block 602, it begins to move toward the inlet 610a (bottom dead center position side). As the piston structure 612 moves sequentially toward the bottom dead center position, as shown in Figures 32 and 33, the fluid flowing from the inlet 610a into the first space SP1 flows from the first space SP1 to the second space SP2 through the communication channel 620 (small hole) of the piston body portion 612a and the through hole 613a of the moving member 613.

[0195] Furthermore, as the piston structure 612 approaches the introduction block 601 (bottom dead center position), the attractive force of the moving member 613 (magnet) on the piston opposing portion 601a (magnetic material) increases, and as the piston structure 612 approaches the inlet 610a, the moving member 613 moves within the piston body portion 612a until it contacts the protrusion 615a formed on the closed end (lid) of the piston body portion 612a at the second predetermined position (see Figure 28). As a result, the communication passage 620 (small hole) of the piston body portion 612a is closed by the outer circumferential surface of the moving member 613. At this time, the end face of the piston body portion 612a on the inlet 610a side and the piston opposing portion 601a of the introduction block 601 may or may not be in contact. Note that the magnet of the moving member 613 may be integrally molded in a direction that repels magnets of the same poles.

[0196] Then, the piston structure 612, which has moved toward the inlet 610a, reaches the bottom dead center position (see Figure 28), and due to the pressure of the fluid flowing in from the inlet 610a, the piston structure 612 begins to move toward the top dead center position (outlet 610b side), resisting the repulsive force (biasing) from the return spring 614 and the suction force between it and the piston-facing portion 601a of the introduction block 601, and the fluid in the second space SP2 is pushed out from the outlet 610b. Thereafter, with the fluid flowing in one direction from the inlet 610a to the outlet 610b, the piston structure 612 repeatedly moves back and forth between the top dead center position (outlet side) and the bottom dead center position (inlet side) as described above (see Figures 28 to 33).

[0197] As the moving member 613 (magnet) of the piston structure 612 reciprocates within the cylinder 611 of the actuator 600 described above, the influence of the magnetic flux generated from the moving member 613 (magnet) on the electromotive coil unit 650 changes. In response to this change in the influence of the magnetic flux, an electric current (electrical energy) is generated in the electromotive coil unit 650 (converter).

[0198] With the actuator 600 described above, similar to the actuators described above, when the fluid is flowing in one direction within the cylinder 611 from the inlet 610a to the outlet 610b, the piston structure 612 reciprocates between the top dead center position (outlet 610b side) and the bottom dead center position (inlet 610a side), allowing the piston structure 612 to reciprocate within the cylinder 611 without requiring a switch in the fluid supplied to the cylinder 611. Furthermore, a power generation device using such an actuator 600 can generate electrical energy corresponding to the reciprocating motion of the piston structure 612 (including the moving member 613 (magnet)) within the cylinder 611.

[0199] Furthermore, in the piston structure 612 of the actuator 600 described above, an elastic member such as a urethane sheet may be attached to the closed end (lid) of the piston body portion 612a or to the piston opposing portion 601a. ​​This can reduce the noise when the piston body portion 612a strikes the piston opposing portion 601a, and as a result, the operating noise of the actuator 600 can be reduced.

[0200] Furthermore, from the viewpoint of realizing the reciprocating motion of the piston structure 612, the introduction block 601, the outlet block 602, and the moving member 613 may each be made of a magnetic material or a magnet, and the combination thereof is such that when the piston structure 612 is near the bottom dead center, the moving member 613 moves toward the inlet 610a side due to the magnetic attraction between the introduction block 601 and the moving member 613, closing the communication channel 620 (small hole), and when the piston structure 612 is near the top dead center, the moving member 613 moves toward the outlet 610b side due to the magnetic attraction between the outlet block 602 and the moving member 613, opening the communication channel 620 (small hole).

[0201] As mentioned above, even if reciprocating motion is possible, the moving member must be a magnet in order to generate electricity with the electromotive coil unit 650 installed on the outer circumference of the cylinder 111. Alternatively, a separate magnet for power generation must be installed on the piston structure 612, or the reciprocating motion of the piston structure 612 must be output to the outside and converted into electrical energy.

[0202] Next, a modified example of the actuator 600 described above will be explained with reference to Figure 34.

[0203] The actuator 600 shown in Figure 34 is characterized by using a piston body 612a in the opposite direction to the piston body 612a described above (see Figures 28 to 33), with the end on the inlet side 610a open and the end on the outlet side 610b closed with a lid. Furthermore, the introduction block 601 and the output block 602 are not merely magnetic materials, but are composed of magnets with polarity that exert a repulsive force against the moving member 613 (magnet). Note that in Figure 34, the same (or corresponding) parts as those of the actuator 600 described above (see Figure 28) are assigned the same reference numbers.

[0204] In such an actuator 600, when the piston structure 612 (piston body 612a, moving member 613) moves from the inlet 610a side (bottom dead center position side) to the outlet 610b side (top dead center position side), the moving member 613 moves toward the outlet 610b side along with the movement of the piston structure 612 (first space SP1 and second space SP2 are not in communication state) with the communication passage 620 (small hole) on the closed end side of the piston body 612a blocked, and at the first predetermined position, the movement toward the outlet 610b side is restricted by the repulsive action with the block opposing part 602a (first movement restricting member) of the lead block 602, and the piston structure 612 (piston body 612a) continues to move toward the outlet 610b side until the communication passage 620 is opened, and even after the communication passage 620 is opened, it continues to move toward the outlet 610b side until the inertial force is eliminated. Then, the communication channel 620 (small hole) is opened, and the first space SP1 and the second space SP2, which were previously not in communication, become connected through the communication channel 620 of the piston structure 612. As a result, the pressure difference between the first space SP1 and the second space SP2, which are sandwiching the piston structure 612, disappears, and the piston structure 612 reaches the top dead center position and begins to move toward the bottom dead center position due to the biasing force of the return spring 614 toward the inlet 610a side. As the piston structure 612 moves toward the bottom dead center position, the fluid flowing from the inlet 610a into the first space SP1 flows further from the first space SP1 to the second space SP2 through the communication channels of the piston structure 612 (communication channel 620 (small hole) in the piston body 612a, and the through hole 613a in the moving member 613).

[0205] As the piston structure 612 moves from the top dead center position to the bottom dead center position, at a second predetermined position, the moving member 613, which moves toward the inlet 610a side along with the movement of the piston body 612a with the communication passage 620 (small hole) open, is restricted from moving toward the inlet 610a side by the repulsive force from the block opposing portion 601a (second movement restricting member) of the introduction block 601. As the piston structure 612 (piston body 612a) continues to move toward the inlet 610a side (bottom dead center position side) by the return spring 614, the restricted moving member 613 moves relatively toward the protrusion 615a of the closed end (lid) of the piston body 612a, and the communication passage 620 (small hole) is closed by the moving member 613, and the first space SP1 and the second space SP2, which were in communication, become disconnected. Then, the piston structure 612 reaches the bottom dead center position and, due to the pressure of the fluid flowing from the inlet 610a into the first space SP1, begins to move toward the top dead center position against the biasing force of the return spring 614, pushing the fluid in the second space SP2 out from the outlet 610b. Thereafter, with the fluid flowing in one direction from the inlet 610a to the outlet 610b, the piston structure 612 repeatedly reciprocates between the top dead center position (outlet 610b side) and the bottom dead center position (inlet 610a side) as described above. Based on the reciprocating motion of the moving member 613 (magnet) within the cylinder 611 described above, an electric current (electrical energy) is generated in the electromotive coil unit 650.

[0206] Furthermore, even if the pressure on the first space SP1 side rises while the movable member 613 is blocking the communication channel 620 (small hole), a space is formed between the movable member 613 and the protrusion 615a provided on the closed end (lid) of the piston body 612a. Therefore, the same pressure acts on the two end faces of the movable member 613 through the through hole 613a, and no force is generated to move the movable member 613. In addition, the magnets of the movable member 613 may be integrally molded in a direction that repels magnets of the same poles, and there may be one or multiple electromotive coil units 650.

[0207] Next, an actuator according to a seventh embodiment of the present invention and a power generation device using the same will be described.

[0208] A power generation device using an actuator according to the seventh embodiment of the present invention is configured as shown in Figure 35.

[0209] In Figure 35, the power generation device includes an actuator 700 and two electromotive coil units 750a and 750b (converters) that convert the reciprocating motion of a piston structure 712 within a cylinder 711 of the actuator 700 into electrical energy.

[0210] The actuator 700 includes a cylinder 711 and a piston structure 712 that reciprocates within the cylinder 711. The cylinder 711 has a small inner diameter portion 711a having a predetermined inner diameter and a large inner diameter portion 711b having an inner diameter larger than the inner diameter of the small inner diameter portion 711a, and is structured to gradually widen in a tapered manner from the small inner diameter portion 711a to connect to the large inner diameter portion 711b. An introduction block 701 with an introduction channel 722c formed therein is fitted and fixed to the end of the small inner diameter portion 711a opposite to the large inner diameter portion 711b (one end of the cylinder 711), with airtightness maintained by an O-ring 703. Similarly, an outlet block 702 with an outlet channel 722d formed therein is fitted and fixed to the end of the large inner diameter portion 711b opposite to the small inner diameter portion 711a (the other end of the cylinder 711), with airtightness maintained by an O-ring 704. A space 722a is formed in the small inner diameter portion 711a of the cylinder 711, which communicates with the introduction passage 722c of the introduction block 701, and a space 722b is formed in the large inner diameter portion 711b of the cylinder 711, which communicates with the outlet passage 722d of the outlet block 702. The outward-facing end of the introduction block 701 (introduction passage 722c) opens as an inlet 710a through which fluid (for example, a gas such as air) flows in. The outward-facing end of the outlet block 702 (outlet passage 722d) opens as an outlet 710b through which fluid passing through the cylinder 711 (spaces 722a and 722b) flows out. The piston structure 712 reciprocates within spaces 722a and 722b of the cylinder 711.

[0211] The piston structure 712 includes a ring-shaped magnet 719, a piston body portion 712a fitted and fixed to the ring-shaped magnet 719, and ring-shaped small magnets 732 and 733 provided within the piston body portion 712a. The end of the piston body portion 712a on the outlet 710b side is open, while the end on the inlet 710a side is closed. At the outlet 710b side end of the piston body portion 712a, a ring-shaped magnet 731 is provided so as to abut against the small magnet 732 and so as to slide against the inner wall of the small inner diameter portion 711a (space 722a) of the cylinder 711. Together with the aforementioned magnet 719, piston body portion 712a, and the small magnets 732 and 733 provided within the piston body portion 712a, the ring-shaped magnet 731 and the V-ring 726 reciprocate as a single unit within the spaces 722a and 722b of the cylinder 711.

[0212] A V-ring 726 is provided on the outer circumference of the piston body 712a, with its opening facing the outlet 710b side. This V-ring 726 maintains airtightness between the space SP1 on the inlet 710a side and the space SP2 on the outlet 710b side, separated by the piston structure 712, in the small inner diameter portion 711a of the cylinder 711. Inside the cylinder 711, a return spring 714 is provided between the outlet block 702 and the magnet 731 in the piston structure 712. This return spring 714 biases the entire piston structure 712 toward the inlet 710a side with its repulsive force. In addition, a ring-shaped magnet 717 is fixed to the outlet 710b side end face of the space 722a of the introduction block 701.

[0213] The two electromotive coil units 750a and 750b are densely arranged to enclose the cylinder 711 of the actuator 700 (small inner diameter portion 711a, large inner diameter portion 711b). These two electromotive coil units 750a and 750b (converters) generate electric current (electrical energy) in response to the movement of the piston structure 712 within the cylinder 711 of the actuator 700.

[0214] The operation of the actuator 700 with the structure described above and the operation of the power generation device in accordance with that operation will be explained.

[0215] Initially, the piston structure 712, located at the bottom dead center position within the small inner diameter portion 711a of the cylinder 711, has its magnet 719 joined to the magnet 717 that is in contact with the introduction block 701, as shown in Figure 36. In this state, the first space SP1 and the second space SP2, separated by the piston structure 712 (piston body portion 712a (V-ring 726)), are not in communication. When a fluid at a predetermined pressure (for example, a gas such as air) flows in from the inlet 710a (formed therein), the piston structure 712 moves from the bottom dead center position towards the top dead center position (outlet 710b side) against the repulsive force (bias) towards the inlet 710a side by the return spring 714 and the attractive force (bias) between the magnets 719 and 717, due to the pressure of the fluid. During this process, the fluid (for example, air) in the second space SP2 flows out from the outlet 710b.

[0216] Then, as shown in Figure 37, the portion of the V-ring 726 provided on the outer circumferential surface of the piston body portion 712a of the piston structure 712 that is moving toward the top dead center position enters the large inner diameter portion 711b from the small inner diameter portion 711a. At this point, the airtight seal between the first space SP1 and the second space SP2 is released, and the first space SP1, which includes the space 722a of the small inner diameter portion 711a, and the second space SP2, which includes the space 722b of the large inner diameter portion 711b, become connected through the gap between the outer circumferential surfaces of the piston body portion 712a and the magnet 719 and the inner circumferential surface of the small inner diameter portion 711a of the cylinder 711 (a structure that connects the first space SP1 and the second space SP2). At this time, the piston structure 712 continues to move due to its own inertial force. As a result, the pressure difference between the first space SP1 and the second space SP2, which sandwich the piston structure 712, disappears, and after the piston structure 712 reaches the top dead center position (after its own inertial force is eliminated), it begins to move toward the inlet 710a (bottom dead center position side) due to the repulsive force (biasing) of the return spring 714. As the piston structure 712 moves toward the bottom dead center position, the fluid flowing from the inlet 710a into the first space SP1 flows further from the first space SP1 to the second space SP2 through the gap between the outer surfaces of the piston body 712a and the magnet 719 and the inner surface of the small inner diameter portion 711a of the cylinder 711.

[0217] Furthermore, the biasing force provided by the return spring 714, combined with the increasing attractive force between magnets 719 and 717 as it approaches the bottom dead center position, causes the piston structure 712 to begin moving toward the bottom dead center position (inlet 710a side). When the O-ring 726 provided on the outer circumferential surface of the piston body 712a enters the small inner diameter portion 711a from the large inner diameter portion 711b, airtightness is ensured between the spaces SP1 and SP2 separated by the piston structure 712 (V-ring 726), and the first space SP1 and the second space become disconnected.

[0218] Then, with a predetermined pressure applied to the outlet 710b side by the fluid (for example, a compressible fluid such as air) flowing in from the inlet 710a, the piston structure 712 compresses the fluid in the first space SP1, including space 722a, due to the inertial force based on the movement on the inlet 710a side up to that point, the biasing force of the return spring 714 toward the inlet 710a side, and the attractive force of magnets 719 and 717, and continues to move toward the inlet 710a side. As a result, the biasing force that biases the piston structure 712 toward the outlet 710b side increases due to the fluid of the predetermined pressure flowing into the first space SP1. The piston structure 712 reaches its bottom dead center during operation when the inertial force of the piston structure 712 toward the inlet 710a, the biasing force of the return spring 714 toward the inlet 710a, and the biasing force on the piston structure 712 toward the outlet 710b due to the attractive force between magnets 719 and 717 and the pressure in the first space SP1 are balanced. At this time, magnets 719 and 717 may or may not be in contact.

[0219] After the piston structure 712 reaches the bottom dead center position, the pressure of the fluid flowing in from the inlet 710a causes the piston structure 712 to begin moving towards the top dead center position (towards the outlet 710b) against the repulsive force (bias) of the return spring 714 and the attractive force (bias) of the magnets 719 and 717, and the fluid in the second space SP2 flows out from the outlet 710b. Thereafter, with the fluid flowing in one direction from the inlet 710a to the outlet 710b, the piston structure 712 repeatedly moves back and forth between the top dead center position (outlet 710b side) and the bottom dead center position (inlet 710a side) as described above.

[0220] As the piston structure 712 reciprocates within the cylinder 711 of the actuator 700 described above, the influence of the magnetic flux generated by the magnets 731, 732, 733, and 719 on the two electromotive coil units 750a and 750b, respectively, changes. In response to this change in the influence of the magnetic flux, an electric current (electrical energy) is generated in the two electromotive coil units 750a and 750b (converters).

[0221] With the actuator 700 described above, similar to the actuators described above, when a fluid (for example, a gas such as air) flows in one direction within the cylinder 711 from the inlet 710a to the outlet 710b, the piston structure 712 reciprocates between the top dead center position (outlet 710b side) and the bottom dead center position (inlet 710a side), allowing the piston structure 712 to reciprocate within the cylinder 711 without requiring a switch in the fluid supplied to the cylinder 711. Furthermore, a power generation device using such an actuator 700 can generate electrical energy (power) corresponding to the reciprocating motion of the piston structure 712 (including magnets 731, 732, 733, and 719) within the cylinder 711.

[0222] Furthermore, the actuators used in the aforementioned fluid quantity monitoring device are not limited to the actuator 200 with the structure described above (Figures 11 to 15). For example, actuators 100 shown in Figures 1 to 8, actuator 100 shown in Figure 10, actuator 300 shown in Figures 16 to 24, actuator 400 shown in Figures 25 to 26, actuator 500 shown in Figure 27, actuator 600 shown in Figures 28 to 34, and actuator 700 shown in Figures 35 to 36, as well as actuators with other structures, can be used. Similarly, in the aforementioned power generation device, actuators 100, 200, 500, and actuators with other structures, other than actuators 300, 600, and 700, can be used.

[0223] Furthermore, the magnet on the outlet side of the piston body 712a may be molded as a single piece, or multiple magnets may be stacked. Moreover, its shape is not limited to a ring, but may be a cylinder, for example. In order to weaken the attractive force due to the close contact between magnets 719 and 717, a spacer made of a non-magnetic material may be placed between the two magnets.

[0224] Although embodiments of the present invention have been described above, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments described above can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments are included in the scope and spirit of the invention, as well as in the invention described in the claims.

[0225] The fluid actuator according to the present invention has the effect of enabling the piston to reciprocate without requiring switching of the fluid supplied to the cylinder, and is useful as a fluid actuator that reciprocates a piston member by a fluid flowing in one direction within the cylinder.

[0226] 100, 200, 300, 400, 500, 600, 700 Actuators 111, 211, 311, 411, 511, 611, 711 Cylinders 112, 212, 312, 512, 612, 712 Piston structures 250 Sensor units 350, 650, 750 Converters 110a, 210a, 310a, 410a, 510a, 610a, 710a Inlets 110b, 210b, 310b, 410b, 510b, 610b, 710b Outlets 111a Cylinder body 111b Fluid introduction cylinder 112a Piston body 112b Member holder 112c Rod holder 112d Operating bar 113 Moving member 114 Return spring 115, 117 Rod-shaped member 116 Convex body 118 Magnet 119 Hollow pipe assembly 119a Hollow pipe 119b Cap section 120, 220, 320, 520 Communication channel 420, 620 Through hole (communication channel) 121, 122 Internal space 124 Communication hole 125, 126 O-ring

Claims

A cylinder through which fluid flows in one direction from the inlet to the outlet, A piston structure is housed within the cylinder so as to be reciprocable, and such that it tightly partitions the space of the cylinder into a first space on the inlet side and a second space on the outlet side. A piston biasing member that biases the piston structure within the cylinder toward the inlet side, The piston structure has a state switching mechanism that switches the first space and the second space from a non-communicating state to a communicating state while the piston structure is moving toward the outlet side, and switches the first space and the second space from a communicating state to a non-communicating state while the piston structure is moving toward the inlet side. An actuator that allows fluid at a pressure such that the piston structure moves toward the outlet side against the biasing of the piston structure toward the inlet side by the piston biasing member to flow from the inlet into the first space of the cylinder. 　 The state switching mechanism is, The cylinder has a structure having a small inner diameter portion on the inlet side and a large inner diameter portion on the outlet side, The piston structure has a structural portion that tightly partitions the first space and the second space in the small inner diameter portion of the cylinder, The actuator according to claim 1, further comprising a structure that connects the first space and the second space while the tightly partitioned structural portion of the piston structure is engaged with the large inner diameter portion. 　 The piston structure is reciprocable between the bottom dead center position on the inlet side and the top dead center position on the outlet side within the cylinder, and has a communication passage formed to connect the first space and the second space. The state switching mechanism is, The actuator according to claim 1, comprising a communication channel opening / closing mechanism that, while the piston structure is moving from the bottom dead center position to the top dead center position, switches from a non-communicating state in which the communication channel is closed to a communicating state in which the communication channel is open, and while the piston structure is moving from the top dead center position to the bottom dead center position, switches from a communicating state in which the communication channel is open to a non-communicating state in which the communication channel is closed. 　 The piston structure is A movable member that is movable relative to the communication passage and, during the movement of the piston structure from the bottom dead center position to the top dead center position, is biased in the direction that the communication passage is opened when switching from the non-communication state in which the communication passage is closed to the communication state in which the communication passage is open, A member holding portion that holds the aforementioned movable member so that it can reciprocate, The actuator according to claim 3, having the following features. 　 The piston structure is The communication channel is positioned on the inlet side and has a movable member that is movable relative to the communication channel, The aforementioned communication channel opening and closing mechanism is A first movement restricting member restricts the movement of the moving member, which moves toward the outlet side along with the movement of the piston structure, at a first predetermined position within the cylinder, while blocking the opening on the first space side of the communication passage, The actuator according to claim 3, further comprising: a second movement restricting member that restricts the movement of the moving member, which moves toward the inlet side together with the piston structure while the opening on the first space side of the communication passage is open, at a second predetermined position within the cylinder. 　 The actuator according to claim 5, wherein the communication passage is formed in the axial direction of the cylinder, and the first movement restricting member includes a rod-shaped member arranged to pass through the communication passage of the piston structure from the outlet side. 　 The actuator according to claim 6, wherein the rod-shaped member is fixed to the cylinder. 　 A rod holding portion holds the rod-shaped member so that it is movable together with the piston structure and can move relative to the piston structure, and is positioned within the piston structure. The piston structure has a rod movement restricting section that restricts the movement of the rod-shaped member that moves together with the piston structure while the piston structure is moving toward the outlet side, The actuator according to claim 6, wherein the rod-shaped member is restricted by the rod movement restricting part, causing the rod-shaped member to protrude from the communication channel of the piston structure moving toward the outlet side, thereby restricting the movement of the moving member toward the outlet side. 　 The actuator according to any one of claims 6 to 8, wherein the rod-shaped member includes a hollow pipe. The actuator according to claim 5, further comprising a biasing member that biases the moving member toward the inlet when the moving member moves toward the inlet together with the piston structure. 　 The piston structure is A member holding portion that holds the movable member so that it can reciprocate at the inlet side of the communication channel, The actuator according to claim 5, further comprising a biasing member provided at the inlet-side end of the member holding portion for biasing the movable member, which is movably held by the member holding portion, toward the inlet side. 　 The actuator according to claim 10, wherein the biasing member has a structure that provides a magnetic biasing force to the moving member. 　 The actuator according to claim 5, further comprising an elastic member provided on the moving member so as to face the opening on the inlet side of the communication passage of the piston structure. 　 The actuator according to claim 3, wherein the piston structure has a cylindrical movable member that is movable in the axial direction of the cylinder and a communication passage that can be opened and closed on the side surface of the movable member. 　 A fluid quantitative monitoring device connected in series to a fluid flow path, which monitors whether a certain amount of fluid is flowing through the flow path, comprising an actuator according to any one of claims 1 to 8 and 10 to 14, A fluid quantitative monitoring device comprising: a piston motion detection unit that detects the movement of the piston structure within the cylinder of the actuator and outputs a detection signal corresponding to that movement. 　 An actuator according to any one of claims 1 to 8 and claims 10 to 14, A power generation device comprising a converter that converts the movement of the piston structure within the cylinder of the actuator into electrical energy.

Images