Actuator, valve and thermo switch

Abstract

To provide an actuator, a valve and a thermo switch that enable downsizing while suppressing heat leak.SOLUTION: An actuator 10 comprises: an expansion / contraction part 20 that is formed in to such a bag-shaped that it expands when heated and contracts when cooled, and has a first side part 21 fixed to another member 2, and a second side part 22 arranged opposite the first side part 21; and a pressure transmission unit 30 that is provided on the second side part 22, and transmits pressure caused by the expansion of the expansion / contraction part 20 to the outside.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an actuator, a valve, and a thermoswitch. [Background technology]

[0002] Patent Document 1 discloses an overheating prevention device that uses a bimetal element. This overheating prevention device is a type of so-called thermoswitch, and includes a thermal reversal bimetal that changes state when the temperature of a heater rises above a predetermined temperature, a movable pin supported by the thermal reversal bimetal, and a movable contact provided opposite the movable pin. When the thermal reversal of the thermal reversal bimetal occurs, the movable contact is pushed up by the movable pin, thereby cutting off the flow of electricity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-260506 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the technology described in Patent Document 1, which uses a bimetal element as an actuator whose state changes with heat, the contact area between the bimetal element and the heater is large, which makes it prone to heat leakage from the bimetal element and also makes the device large.

[0005] In consideration of the above, an object of the present invention is to provide an actuator, a valve, and a thermoswitch that can be miniaturized while suppressing heat leakage. [Means for solving the problem]

[0006] The actuator described in claim 1 is a bag-shaped expansion / contraction unit that expands when heated and contracts when cooled, and has a first side portion fixed to another member and a second side portion provided opposite the first side portion, and a pressure transmission unit provided on the second side portion that transmits pressure caused by expansion of the expansion / contraction unit to the outside.

[0007] In the actuator described in claim 1, for example, when the bag-shaped expansion / contraction portion expands due to heat transferred from another member to the first side portion, pressure is transferred to the outside via the pressure transfer portion provided on the second side portion. In other words, the expansion and contraction of the bag-shaped expansion / contraction portion displaces the pressure transfer portion, thereby transferring the pressure due to the expansion to the outside. By using the bag-shaped expansion / contraction portion, the pressure transfer portion can be displaced not by the first side portion fixed to the other member, but by displacing the second side portion facing the first side portion. This allows the contact surface with the other member to be smaller than with a bimetal element that is in full contact with the other member and changes state due to a temperature rise. As a result, the actuator can be miniaturized while suppressing heat leak.

[0008] The actuator described in claim 2 has the configuration described in claim 1, and an adsorbent is provided inside the expansion / contraction section that can adsorb and desorb gas contained inside depending on at least one of temperature and pressure.

[0009] In the actuator described in claim 2, the number density of gas within the expansion / contraction section changes due to adsorption and desorption of gas by the adsorbent housed therein during the expansion or contraction process. Therefore, for example, when gas desorbs from the adsorbent due to an increase in temperature or pressure, the number density of gas within the expansion / contraction section increases, accelerating the increase in pressure. In other words, desorption of gas from the adsorbent can increase the rate of volume change within the expansion / contraction section relative to the rate of change in temperature compared to when gas is adsorbed. As a result, the sensitivity of the actuator can be increased, allowing for efficient miniaturization.

[0010] The actuator according to a third aspect of the present invention has the configuration according to the second aspect, wherein the adsorbent contains a metal organic framework as an adsorbent for the gas.

[0011] In the actuator according to claim 3, the adsorbent that utilizes the gas adsorption performance of the metal organic framework can adsorb and desorb gas within the expansion / contraction portion.

[0012] The actuator according to a fourth aspect of the present invention has the configuration according to the second aspect, wherein the adsorbent contains silica zeolite as an adsorbent for the gas.

[0013] In the actuator according to claim 4, the adsorbent that utilizes the gas adsorption performance of silica zeolite can adsorb and desorb gas within the expansion / contraction portion.

[0014] The actuator described in claim 5 has the configuration described in any one of claims 1 to 4, wherein the expansion / contraction section is in the shape of a bag having spring properties along the direction of displacement due to expansion or contraction.

[0015] In the actuator according to claim 5, the expansion / contraction section has spring properties, so that the movement direction of the expansion / contraction section when it is in operation can be easily adjusted.

[0016] The valve described in claim 6 is a valve that includes the actuator described in claim 1 and is capable of opening and closing a fluid flow path, and includes a valve housing as the other component that forms part of the flow path, a movable valve unit that is provided inside the valve housing and is movable between a closed position and an open position along the flow path direction, thereby allowing the flow path within the valve housing to be opened and closed, an expansion and contraction unit that is provided inside the valve housing and expands or contracts along the flow path direction due to heat exchange with the fluid, and a pressure transmission unit that transmits pressure due to expansion of the expansion and contraction unit to the movable valve unit.

[0017] The valve described in claim 6 includes a valve housing that forms part of a fluid flow path and a movable valve portion that moves within the valve housing along the flow path. Here, the actuator has an expansion / contraction portion provided within the valve housing, and performs heat exchange with the fluid with the first side portion fixed to the valve housing. This causes the expansion / contraction portion to expand or contract along the flow path, and the pressure transmission portion transmits pressure to the movable valve portion in response to input from the second side portion during expansion. This allows the movable valve portion to move between a closed position and an open position along the fluid flow path, opening and closing the flow path within the valve housing. Such a valve can be applied, for example, to a thermostat that opens and closes the refrigerant flow path in a vehicle, and can achieve miniaturization while suppressing heat leaks from the thermostat.

[0018] The thermoswitch described in claim 7 is a thermoswitch that includes the actuator described in claim 1 and that allows the heater unit to be switched on / off by opening and closing electrical contacts, and includes a pair of conductive parts that face each other along the displacement direction of the expansion / contraction unit due to expansion or contraction and have the contacts between them, a heat transfer part that is the other member that is aligned with the pair of conductive parts along the displacement direction and transfers heat from the heater unit to the first side part, and the pressure transfer part that transfers the displacement due to expansion or contraction of the expansion / contraction unit to one of the pair of conductive parts so as to close the contacts in a contracted state and open the contacts in an expanded state.

[0019] In the thermoswitch described in claim 7, the heater unit can be switched on / off by opening and closing the contacts of a pair of conductive parts. In the thermoswitch, a pair of conductive parts and a heat-conducting part are aligned along the displacement direction of the expansion / contraction part of the actuator. A first side part is fixed to this heat-conducting part, which transmits heat from the heater unit to the expansion / contraction part and transmits displacement accompanying expansion or contraction to one of the pair of conductive parts via the pressure-transmitting part. Specifically, the pressure-transmitting part displaces one of the conductive parts so that the contacts close when the expansion / contraction part is contracted and open when the expansion / contraction part is expanded. This allows the heater unit to be switched on / off. Such a thermoswitch can be applied, for example, to a thermoswitch that prevents overheating of a heater unit installed in an electrical appliance, and can be made smaller while suppressing heat leakage from the thermoswitch. [Effects of the Invention]

[0020] As described above, the actuator, valve, and thermoswitch according to the present invention can provide an actuator that can be made smaller while suppressing heat leakage. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a cross-sectional view schematically illustrating an actuator according to an embodiment. [Figure 2] 1 is a cross-sectional view schematically illustrating an example of a valve to which an actuator according to an embodiment is applied, showing a contracted state of an expansion / contraction section. [Figure 3] 1 is a schematic diagram showing an example of a first thermoswitch to which an actuator according to an embodiment is applied, showing a state in which the contacts are closed. DETAILED DESCRIPTION OF THE INVENTION

[0022] An embodiment of an actuator according to the present invention, and a valve and a thermoswitch configured using the actuator will be described below with reference to Figures 1 to 4. The actuator according to the present invention has a bag-shaped expansion / contraction section whose one side is fixed to another member, and transmits pressure due to expansion of the expansion / contraction section to the outside via a pressure transmission section.

[0023] The actuator 10, valve 40, and first thermoswitch 60 according to the embodiment will be described in detail below. Note that unless otherwise specified in the specification, each element is not limited to one, and may be present in multiple numbers. Furthermore, in the drawings, substantially identical elements are denoted by the same reference numerals, and redundant explanations in the specification will be omitted.

[0024] <Actuator> 1 is a cross-sectional view that schematically shows an actuator 10. As shown in FIG. 1, the actuator 10 is configured to include an expansion / contraction section 20 and a pressure transmission section 30.

[0025] (Expansion / contraction section) The expansion / contraction unit 20 is formed in a bag shape from a material such as resin or metal, and its internal space expands when heated and contracts when cooled. Figure 1 shows gas 6 (gas molecules) sealed inside the expansion / contraction unit 20. Note that, as an example, the gas 6 is hydrogen (H) gas.

[0026] The expansion / contraction portion 20 has a first side surface portion 21 fixed to the other member 2, a second side surface portion 22 provided opposite the first side surface portion 21, and a third side surface portion 23 connecting the outer edge of the first side surface portion 21 with the outer edge of the second side surface portion 22. The first side surface portion 21 and the second side surface portion 22 face each other along the displacement direction H of the expansion / contraction portion 20 due to expansion or contraction.

[0027] Here, the third side surface portion 23 has an accordion-folded shape in the vertical cross section shown in Fig. 1 due to alternating mountain folds and valley folds along the displacement direction H. In this way, the third side surface portion 23 has at least one inflection point 23A caused by folding back in the vertical cross section. This gives the expansion / contraction portion 20 a springy configuration along the displacement direction H.

[0028] (adsorbent) Here, inside the expansion / contraction section 20, an adsorbent 26 is provided that is capable of adsorbing and desorbing the gas 6 accommodated inside in accordance with at least one of the temperature and the pressure.

[0029] Here, the adsorbent 26 is configured to be applied to the first side surface portion 21 of the expansion / contraction section 20 so as to form a thin film layer, but it may also be configured so that granular material is contained inside. Also, the adsorbent 26 may be formed in layer form on a side surface different from the first side surface portion 21. In terms of increasing the efficiency of heat conduction from the other member 2, it is preferable that the adsorbent 26 be formed on the first side surface portion 21.

[0030] The adsorbent 26 may be configured to include a porous material as an adsorbent for the gas 6.

[0031] An example of the porous material is a metal organic framework (MOF).

[0032] Metal-organic frameworks are materials formed by metal ions and organic ligands and have a highly regular lattice structure. Metal-organic frameworks can occlude (adsorb) gas molecules such as water molecules and hydrogen molecules within their lattice structure and release them under specific conditions. Metal ions that can be used include those extracted from inorganic metal compounds such as metal oxides and metal salts of zinc (Zn), copper (Cu), cobalt (Co), zirconium (Zr), etc. Organic ligands that can be used include those having functional groups capable of coordinating with metal atoms, such as carboxyl groups, imidazole groups, and amide groups.

[0033] When the adsorbent contains a metal organic framework, for example, the powdered metal organic framework can be mixed with a resin binder to form the adsorbent 26. From the viewpoint of enhancing the adsorption ability of the gas 6, a metal organic framework having open metal sites is preferable. Note that the open metal sites are metal ion sites to which guest molecules (for example, the gas 6 in this embodiment) can be coordinated.

[0034] An example of the porous material is silica zeolite.

[0035] Silica zeolite is a zeolite whose main component is silica (SiO2) and has a porous skeletal structure. Silica zeolite can adsorb gas molecules such as water molecules and hydrogen molecules inside its skeletal structure and release them under certain conditions.

[0036] When silica zeolite is included as the adsorbent, for example, powdered silica zeolite can be mixed with a resin binder to form the adsorbent 26. From the viewpoint of enhancing the adsorption ability of the gas 6, the silica zeolite is preferably a low-silica zeolite, and more preferably has an aluminum (Al) / silicon (Si) molar ratio of 0.3 or more.

[0037] The adsorbent 26 has the function of adsorbing the gas 6 in an environment below a predetermined threshold temperature and below a predetermined threshold pressure, and desorbing the gas in an environment above a predetermined threshold temperature and above a predetermined threshold pressure, for example, by being heated under conditions where the temperature and pressure are set to predetermined environmental conditions. This enables the adsorption and desorption of the gas 6 according to at least one of the temperature and pressure inside the expansion / contraction section 20 by heat transferred from the other member 2.

[0038] (Pressure transmission part) A pressure transmission part 30 is provided on the second side surface part 22 of the expansion / contraction part 20. The shape and the like of this pressure transmission part 30 can be set appropriately depending on the product to which the actuator 10 is applied. From the viewpoint of suppressing heat leakage from the expansion / contraction part 20, it is preferable that the pressure transmission part 30 is made of a material with lower thermal conductivity than the expansion / contraction part 20.

[0039] The pressure transmitting portion 30 is displaced along the displacement direction H due to the expansion and contraction of the expansion / contraction portion 20, and can transmit the pressure caused by the expansion of the expansion / contraction portion to the outside.

[0040] <Valve> Next, a valve 40 to which the actuator 10 according to the above embodiment is applied will be described in detail with reference to Fig. 2. Fig. 2 is a cross-sectional view showing a schematic view of the valve 40, illustrating the contracted state of the expansion / contraction section. Note that in Fig. 2, the reference numerals for the gas 6 and the adsorbent 26 are omitted.

[0041] As shown in FIG. 2, the valve 40 includes a valve housing 42 as the other component 2, a movable valve portion 50 provided inside the valve housing 42, and an actuator 10 interposed between the valve housing 42 and the movable valve portion 50.

[0042] (valve housing) The valve housing 42 constitutes a connection portion of a plurality of pipes that form a fluid flow path F, and constitutes part of the fluid flow path. In this embodiment, a first pipe 91, a second pipe 92, and a third pipe 93 are connected to the valve housing 42. In this embodiment, the fluid supplied from the first pipe 91 to the valve housing 42 is supplied to at least one of the second pipe 92 and the third pipe 93 by opening and closing the valve 40.

[0043] Hereinafter, the flow path F inside the first pipe 91 will be referred to as the first flow path F1, the flow path F inside the second pipe 92 will be referred to as the second flow path F2, and the flow path inside the third pipe 93 will be referred to as the third flow path F3.

[0044] The valve housing 42 is configured, for example, as a cylindrical housing, and has one end in the axial direction D connected to the second pipe 92 and the other end in the axial direction D connected to the third pipe 93. In addition, an end of the first pipe 91 extending in a direction perpendicular to the axial direction D is connected to a side surface of the valve housing 42. The fluid that has passed through the first flow path F1 of the first pipe 91 passes through a through-hole 44 provided in the side surface of the valve housing 42 and is supplied to the inside of the valve housing 42. Inside the valve housing 42, the flow paths leading to the second pipe 92 and the third pipe 93 are opened and closed by movement of the movable valve unit 50.

[0045] Furthermore, valve seats 46 are provided on one side and the other side of the valve housing 42 in the axial direction D. The valve seat 46 is configured to receive a movable valve unit 50 (described later) and close the flow path when the movable valve unit 50 is in the closed position. The valve seat 46 is also configured to open an opening 47 provided in the center of the valve seat 46 and open the flow path when the movable valve unit 50 is in the open position.

[0046] Furthermore, support seats 48 are provided in the middle of the valve housing 42 in the axial direction D, protruding inward from one side and the other side in the radial direction R of the valve housing 42. The first side surface portion 21 of the actuator 10 is fixed to this support seat 48. The support seat 48 may be configured as two parts so that a pair of support seats 48 sandwich a valve stem 54 (described later) therebetween, or may be configured as a single part formed in an annular shape to surround the valve stem.

[0047] (movable valve part) The movable valve portion 50 is provided inside the valve housing 42. This movable valve portion 50 is movable between a closed position and an open position along the flow path direction (axial direction D) of the valve housing 42, thereby enabling the opening and closing of the flow path within the valve housing 42. The valve 40 of this embodiment has two movable valve portions 50, consisting of a first movable valve portion 51 and a second movable valve portion 52.

[0048] The first movable valve portion 51 and the second movable valve portion 52 are respectively provided at one end and the other end of a valve rod 54 extending in the axial direction D. The valve rod 54 is a member that transmits the operating force from the actuator 10 to the movable valve portion 50.

[0049] The first movable valve portion 51 is supported on one end of the valve rod 54, and is disposed so as to face the valve seat portion 46 on one side of the axial direction D of the valve housing 42 connected to the second pipe 92. On the other hand, the second movable valve portion 52 is supported on the other end of the valve rod 54, and is disposed so as to face the valve seat portion 46 on the other side of the axial direction D of the valve housing 42 connected to the third pipe 93.

[0050] (Actuator operation) As described above, the actuator 10 is provided inside the valve housing 42 and is interposed between the valve housing 42 and the movable valve portion 50. In this embodiment, a pair of actuators 10 is provided on both sides of the valve stem 54. Each actuator 10 is provided between a support seat 48, which serves as another member 2 provided in the valve housing 42, and the first movable valve portion 51. In each actuator 10, the first side surface portion 21 of the expansion / contraction portion 20 is fixed to the support seat 48. In addition, the second side surface portion 22 of the actuator 10 is fixed to a pressure transmission portion 30, which is fixed to an axial intermediate portion of the valve stem 54. This pressure transmission portion 30 protrudes radially outward from the valve stem 54 and is configured to transmit displacement in the axial direction D due to expansion or contraction of the expansion / contraction portion 20 to the valve stem 54.

[0051] The pressure transmission part 30 may be configured as two parts so that it is provided as a pair on the valve stem 54, or may be configured as one part by forming it in an annular shape and press-fitting the valve stem 54 into it to secure it.

[0052] In the actuator 10 described above, the fluid supplied to the inside of the valve housing 42 through the first flow path F1 of the first piping 91 exchanges heat by coming into contact with the expansion / contraction unit 20. The expansion / contraction unit 20 expands or contracts due to the heat exchange with the fluid, and is displaced along the axial direction D.

[0053] FIG. 2 shows the contracted state of the inflation / deflation unit 20. As shown in FIG. 2, when the inflation / deflation unit 20 is in the contracted state, the first movable valve unit 51 is placed in the open position, and the flow path leading to the second pipe 92 is in the most open state. Therefore, the amount of fluid supplied to the second pipe 92 is at its maximum. Meanwhile, the second movable valve unit 52 is placed in the closed position. Therefore, the flow path leading to the third pipe 93 is closed by the second movable valve unit 52. Therefore, in this state, the fluid that has passed through the valve housing 42 is supplied only to the second flow path F2 of the second pipe 92.

[0054] When the expansion / contraction section 20 expands due to a temperature rise in the fluid, the pressure transmission section 30 is displaced in one direction in the axial direction D by input from the second side section 22, and transmits the pressure due to the expansion to the valve rod 54. As a result, the first movable valve section 51 supported on one end of the valve rod 54 moves toward the valve seat section 46 on the second piping 92 side.

[0055] When the first movable valve element 51 moves toward the valve seat 46, on the opposite side in the axial direction D, the second movable valve element 52 gradually moves away from the valve seat 46, thereby opening a flow path leading to the third pipe 93. In this state, the fluid that has passed through the interior of the valve housing 42 is supplied to both the second flow path F2 of the second pipe 92 and the third flow path F3 of the third pipe 93. The amount of fluid supplied to these two flow paths varies depending on the expansion amount of the expansion / contraction unit 20. In this embodiment, the amount of fluid supplied to the second flow path F2 is inversely proportional to the expansion amount of the expansion / contraction unit 20, and the amount of fluid supplied to the third flow path F3 is proportional to the expansion amount of the expansion / contraction unit 20.

[0056] Furthermore, when the temperature of the fluid supplied from the first pipe 91 exceeds a predetermined threshold, the expansion / contraction unit 20 enters an expanded state, and the first movable valve unit 51 abuts against the valve seat unit 46. In this state, the first movable valve unit 51 is placed in the open position, and the flow path leading to the second pipe 92 is closed. On the other hand, the second movable valve unit 52 is placed in the open position. With the second movable valve unit 52 placed in the open position, the flow path leading to the third pipe 93 is placed in the most open state, and the amount of fluid supplied to the third pipe 93 is maximized. Therefore, in this state, the fluid that has passed through the valve housing 42 is supplied only to the third flow path F3 of the third pipe 93.

[0057] The valve 40 having the above configuration can be applied to, for example, a thermostat that opens and closes a refrigerant flow path in a vehicle. In this case, for example, in a vehicle equipped with a water-cooled engine, the valve can open and close the flow path of the refrigerant (fluid) circulating between the engine and the radiator. Or, in a vehicle equipped with a water-cooled battery, the valve can open and close the flow path of the refrigerant circulating between the battery and the radiator.

[0058] <First thermo switch> Next, a first thermostatic switch 60 to which the actuator 10 according to the above embodiment is applied will be described in detail with reference to Fig. 3. Fig. 3 is a schematic diagram of the first thermostatic switch 60, showing a state in which the contacts of a pair of conductive parts 62 are closed.

[0059] As shown in FIG. 3, the first thermoswitch 60 includes a heater portion 80 that generates heat when energized, a heat transfer portion 82 as the other member 2, a pair of conductive portions 62, and an actuator 10.

[0060] The heater unit 80 includes, for example, a thermoelectric wire that generates heat by resistance heating when electricity is passed through it, and is activated by receiving power from a power source 84. The heater unit 80 enters an energized state in which power is supplied from the power source 84 when a switch 86 connecting the heater unit 80 to the power source is turned on.

[0061] The heat transfer section 82 serving as the other member 2 transfers heat from the heater section 80 to the first side surface section of the actuator 10. The heat transfer section 82 is preferably formed from a material with high thermal conductivity, and is configured, for example, by a metal plate or the like provided in contact with the heater section 80. The first side surface section 21 of the actuator 10 is fixed to the heat transfer section 82. The pressure transfer section 30 is provided on the second side surface section 22 of the actuator 10.

[0062] The pressure transmission part 30 has a push-up part 64 on the surface facing a pair of conductive parts 62, which will be described later. The push-up part 64 is a columnar member that stands upright from the pressure transmission part 30 and extends along the displacement direction H of the expansion / contraction part 20.

[0063] The pair of conductive parts 62 are arranged to be aligned with the heat transfer part 82 and the pressure transfer part 30 along the displacement direction H, and are supported by a support member 66. The pair of conductive parts 62 are made of long, plate-shaped conductive material, and have a first conductive part 62A and a second conductive part 62B that face each other along the displacement direction H. The pair of conductive parts 62 have an electrical contact 68 between the first conductive part 62A and the second conductive part 62B that enables the heater part 80 to be switched ON / OFF.

[0064] Furthermore, of the pair of conductive parts 62, the first conductive part 62A, which is located on the upper side, has one end in the longitudinal direction protruding outward more than the second conductive part 62B and faces the push-up part 64 that stands upright from the pressure transmission part 30.

[0065] In the first thermostatic switch 60 configured as described above, the heater section 80 is switched on and off by opening and closing the contacts 68, thereby preventing overheating of the heater section 80. Specifically, when the switch 86 is turned on by a user, electricity is passed through the heater section 80, causing it to heat up. When the heater section 80 is in a low temperature state, the contacts 68 between the pair of conductive sections 62 are closed, and the expansion / contraction section 20 of the actuator 10 is in a contracted state.

[0066] When the temperature of the heater section 80 rises, the heat of the heater section 80 is transferred to the expansion / contraction section 20 via the heat transfer section 82, causing the expansion / contraction section 20 to expand. As a result, the pressure transfer section 30 rises due to the input of the second side surface section 22 of the expansion / contraction section 20.

[0067] Here, when the temperature of the heater unit 80 exceeds a predetermined threshold, the tip of the push-up portion 64 of the pressure transmission unit 30 pushes up the first conductive portion 62A, opening the contact 68. This cuts off the power to the heater unit 80, preventing overheating. Thereafter, when the temperature of the heater unit 80 drops below the threshold, the push-up portion 64 descends, closing the contact 68 again. This causes the heater unit 80 to resume heating.

[0068] (Action and effect) Next, the operation and effects of the actuator 10, the valve 40, and the first thermoswitch 60 according to the above embodiment will be described.

[0069] As shown in FIG. 1 , in the actuator 10 according to this embodiment, when the bag-shaped expansion / contraction unit 20 expands due to heat transferred from the other member 2 to the first side surface 21, pressure is transferred to the outside via the pressure transfer unit 30 provided on the second side surface 22. In other words, the expansion and contraction of the bag-shaped expansion / contraction unit 20 displaces the pressure transfer unit 30, thereby transferring the pressure due to the expansion to the outside. Furthermore, by using the bag-shaped expansion / contraction unit 20, the pressure transfer unit 30 can be displaced not by the first side surface 21, which is fixed to the other member, but by displacing the second side surface 22, which faces the first side surface 21. Therefore, the contact surface with the other member 2 can be made smaller than with a bimetal element, which is in full contact with the other member and changes state as the temperature rises. As a result, the actuator 10 can be miniaturized while suppressing heat leakage.

[0070] In this embodiment, the expansion / contraction unit 20 is provided with an adsorbent 26 inside, which is capable of adsorbing and desorbing the gas 6 accommodated therein in response to at least one of temperature and pressure. Therefore, during the process of expansion or contraction of the expansion / contraction unit 20, the number density of the gas 6 in the expansion / contraction unit 20 changes due to adsorption and desorption of the gas 6 by the adsorbent 26 accommodated therein. As a result, for example, when gas is desorbed from the adsorbent 26 due to an increase in temperature or pressure, the number density of the gas 6 in the expansion / contraction unit 20 increases, accelerating the increase in pressure. In other words, desorption of the gas 6 from the adsorbent 26 can increase the rate of volume change in the expansion / contraction unit 20 relative to the rate of change in temperature, compared to when the gas 6 is adsorbed. As a result, the sensitivity of the actuator 10 can be increased, thereby efficiently achieving miniaturization.

[0071] In addition, the adsorbent 26 may be configured to include a metal organic framework as an adsorbent for the gas 6, and the adsorption and desorption of the gas 6 in the expansion / contraction section 20 can be performed by the adsorbent 26 utilizing the gas adsorption performance of the metal organic framework.

[0072] In addition, the adsorbent 26 may be configured to contain silica zeolite as an adsorbent for the gas 6, and the adsorbent 26, which utilizes the gas adsorption performance of silica zeolite, can adsorb and desorb the gas 6 within the expansion / contraction section 20.

[0073] Furthermore, in this embodiment, the actuator 10 has at least one inflection point 23A formed on the third side surface portion 23 of the expansion / contraction portion 20, thereby providing springiness along the displacement direction H due to expansion or contraction. This makes it possible to easily adjust the direction of movement of the expansion / contraction portion 20 during operation.

[0074] A valve 40 including the actuator 10 configured as described above includes a valve housing 42 that forms part of a fluid flow path F and a movable valve unit 50 that moves within the valve housing 42 along the fluid flow direction ( FIG. 2 ). The actuator 10 includes an expansion / contraction unit 20 within the valve housing 42, which exchanges heat with the fluid while the first side surface 21 is fixed to the valve housing 42. This causes the expansion / contraction unit 20 to expand or contract along the fluid flow direction, and the pressure transmission unit 30 transmits pressure to the movable valve unit 50 in response to input from the second side surface 22 during expansion. This allows the movable valve unit 50 to move between a closed position and an open position along the fluid flow direction, thereby opening and closing the fluid flow path within the valve housing 42. This valve 40 can be applied, for example, to a thermostat that opens and closes a refrigerant flow path in a vehicle. By using the actuator 10, the thermostat can be made smaller while suppressing heat leakage.

[0075] Furthermore, in a first thermoswitch 60 equipped with the actuator 10 configured as described above, the heater section 80 can be switched ON / OFF by opening and closing contacts 68 of a pair of conductive portions 62 (FIG. 3). In these thermoswitches, the pair of conductive portions 62 and a heat transfer portion 82 serving as the other member 2 are aligned along the displacement direction H of the expansion / contraction section 20 of the actuator 10. The first side surface portion 21 of the expansion / contraction section 20 is fixed to the heat transfer portion 82, and heat from the heater section 80 is transferred via the heat transfer portion 82. Displacement accompanying expansion or contraction of the expansion / contraction section 20 is transferred to one of the pair of conductive portions 62 via the pressure transfer portion 30. Specifically, the pressure transfer portion 30 displaces one of the conductive portions 62 (the first conductive portion 62A) so as to close the contacts 68 and 74 when the expansion / contraction section 20 is in a contracted state and open the contact 68 when the expansion / contraction section 20 is in an expanded state. This allows the heater section 80 to be switched ON / OFF. Such a thermoswitch can be applied, for example, to a thermoswitch that prevents overheating of a heater unit installed in an electrical appliance, etc., and by applying actuator 10, it is possible to reduce the size of the thermoswitch while suppressing heat leakage. [supplementary explanation]

[0076] The actuator 10, valve 40, and first thermoswitch 60 according to one embodiment of the present invention have been described above, but the present invention is not limited to this. The configurations of each embodiment can be modified as appropriate without departing from the spirit and scope of the invention. [Explanation of symbols]

[0077] 2 Other parts 6 Gases 10 Actuator 20 Expansion and contraction section 21 First side part 22 Second side part 26 Adsorbent 30 Pressure transmission section 40 valves 42 Valve housing (other parts) 50 Movable valve section L flow path 60 First thermo switch 62 Conductive part 68 contact points 80 Heater section 82 Heat transfer section

Claims

1. an expansion / contraction section having a bag shape that expands when heated and contracts when cooled, the expansion / contraction section having a first side surface portion fixed to another member and a second side surface portion provided opposite the first side surface portion; a pressure transmission part provided on the second side surface part and transmitting pressure caused by the expansion of the expansion / contraction part to the outside, Actuator.

2. an adsorbent capable of adsorbing and desorbing gas stored inside in accordance with at least one of temperature and pressure is provided inside the expansion / contraction section; The actuator of claim 1 .

3. The adsorbent is configured to include a metal organic framework as an adsorbent for the gas. The actuator according to claim 2 .

4. The adsorbent is configured to contain silica zeolite as an adsorbent for the gas. The actuator according to claim 2 .

5. The expansion / contraction portion has a bag shape having spring properties along the displacement direction due to expansion or contraction. The actuator according to any one of claims 1 to 4.

6. A valve that is capable of opening and closing a fluid flow path, comprising the actuator according to claim 1, a valve housing as the other member that constitutes a part of the flow path; a movable valve portion provided inside the valve housing and movable between a closed position and an open position along a flow path direction, thereby enabling opening and closing of the flow path inside the valve housing; the expansion / contraction section provided inside the valve housing and configured to expand or contract along the flow path direction due to heat exchange between the expansion / contraction section and the fluid; a pressure transmission unit that transmits pressure caused by expansion of the expansion / contraction unit to the movable valve unit, valve.

7. A thermoswitch comprising the actuator according to claim 1, which is capable of switching a heater unit ON / OFF by opening and closing an electrical contact, a pair of conductive parts that face each other along a displacement direction of the expansion / contraction part due to expansion or contraction and have the contact point therebetween; a heat transfer portion as the other member, the heat transfer portion being aligned with the pair of conductive portions along the displacement direction and transferring heat from the heater portion to the first side surface portion; the pressure transmitting portion transmitting displacement due to expansion or contraction of the expansion / contraction portion to one of the pair of conductive portions so as to close the contact in a contracted state and open the contact in an expanded state, Thermoswitch.

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