High-airtightness modular vent valve

Abstract

The high-airtightness modular vent valve comprises a power supply end, an SMA actuator module and an air channel, the SMA actuator module comprises an SMA actuator cavity and an SMA conductive part, and a plunger, a spring and a valve deck are sequentially arranged in the SMA actuator cavity in the direction away from the power supply end; the spring is connected with the plunger and the valve cover, the valve cover is provided with a first channel for the SMA conductive part to penetrate through, one end of the SMA conductive part is embedded in the plunger, the other end of the SMA conductive part is arranged in the first channel and extends to a power supply end, and the power supply end is used for electrifying the SMA conductive part; the plunger plugs the air inlet channel when the SMA conductive part is in a non-power-on state, and the plunger is stressed to move in the direction away from the air inlet channel when the SMA conductive part is in a power-on state, so that the air inlet channel communicates with the SMA actuator cavity and further communicates with the air outlet channel; the air inlet channel and the air outlet channel are connected with an external air channel. The vent valve can be modularly mounted on different air paths, and is wide in application range and high in air tightness.

Description

Technical Field

[0001] The present invention relates to the technical field of valves, and particularly to a high-airtightness modular ventilation valve. Background Art

[0002] A ventilation valve is a common industrial device, and its main function is to control the flow and pressure of gas. The working principle of the ventilation valve is to control the flow rate and pressure of gas by adjusting the opening degree of the valve, so as to achieve the control and regulation of gas.

[0003] The application range of the ventilation valve is very wide, and it can be used in various gas control systems. In a compressed air system, the ventilation valve can be used to control the pressure and flow rate of compressed air to ensure the stable operation of the system. In a gas transmission system, the ventilation valve can be used to control the flow rate and pressure of gas to ensure the safe transmission of gas. In a gas separation system, the ventilation valve can be used to control the flow rate and pressure of gas to achieve the separation and purification of gas.

[0004] Due to the wide application of the ventilation valve, ventilation valves with different structures need to be designed separately in different systems, which increases the use cost. Therefore, a modular-designed ventilation valve is needed.

[0005] The valve is the core component of the ventilation valve, and its opening degree determines the flow rate and pressure of gas. A ventilation valve using a shape memory alloy material as the valve has the effect of automatically controlling the gas flow rate and pressure.

[0006] The existing shape memory alloy ventilation valves have advantages in the effect of automatically and precisely controlling the gas flow rate and pressure. However, at the same time, they also have the disadvantage of poor airtightness. During the movement of the shape memory alloy valve, the gas outside the ventilation valve easily enters the inside of the ventilation valve through the air passage and contacts the circuit board. The water vapor carried in the outside air easily accelerates the aging of the electronic components on the circuit board after long-term contact, and even causes a short circuit. The principle of the shape memory alloy valve is to generate heat through conduction and then deform to play the role of a valve. If the circuit board that supplies power to the shape memory alloy conductive part fails, the ventilation valve loses its function of controlling the gas flow rate and pressure.

[0007] Moreover, the existing ventilation valve has a complex structure and lacks modular design, making it inconvenient to repair and replace the corresponding valve actuator fixed in the housing during production in the application scenarios where a ventilation valve is needed. Especially in the application scenarios with multiple gas paths, the ventilation valve lacking modular design needs to specifically mold and manufacture the corresponding number of housings according to the number of different gas paths, which increases the mold design cost.

[0008] Therefore, a ventilation valve with good airtightness and modularity is needed to effectively isolate the outside air and is also more convenient to meet the application scenarios of different gas paths. Summary of the Invention

[0009] To solve the above problems, the present invention provides a highly airtight modular ventilation valve with excellent airtightness, which can effectively isolate the external air from contacting the electronic components at the power supply end. Moreover, the overall structure is modular, enabling it to be more conveniently applied to different gas paths, and can be installed more quickly for complex gas paths and simplifies the design of gas path pipelines.

[0010] The solution provided by the present invention is: a highly airtight modular ventilation valve, including a power supply end, an SMA actuator module, and an air passage. The SMA actuator module includes an SMA actuator cavity and an SMA conductive member. Inside the SMA actuator cavity, a plunger, a return spring, and a valve cover are sequentially arranged in the direction away from the power supply end;

[0011] The return spring connects the plunger and the valve cover. The valve cover is provided with a first passage for the SMA conductive member to pass through. One end of the SMA conductive member is embedded in the plunger, and the other end of the SMA conductive member is placed in the first passage and extends to the power supply end. The power supply end is used for energizing the SMA conductive member;

[0012] The air passage includes an intake air passage and an exhaust air passage. The plunger blocks the intake air passage when the SMA conductive member is not energized. When the SMA conductive member is energized, the plunger moves in a direction away from the intake air passage under force, so that the intake air passage communicates with the SMA actuator cavity, and then communicates with the exhaust air passage;

[0013] The valve cover includes an inner part and an outer part that are integrally connected. The outer contour of the inner part fits the inner wall of the SMA actuator cavity. The outer part is located outside the SMA actuator cavity. The end face of the outer part extends radially so that the end face of the outer part completely covers the diameter end of the SMA actuator cavity close to the power supply end;

[0014] The intake air passage and the exhaust air passage are connected to an external gas path.

[0015] Preferably, the SMA conductive member is an integrally formed U-shaped conductive wire. The bent ends of the U-shaped conductive wire are embedded in the plunger, and the straight ends of the U-shaped conductive wire are placed in the first passage of the valve cover and extend to the power supply end.

[0016] Preferably, the SMA conductive member is detachably connected to the plunger. When the SMA conductive member is detachably connected to the plunger, a first groove for inserting the SMA conductive member is formed on the radial side surface of the plunger, and a second groove is provided on the inner wall of the first groove close to the central axis of the plunger.

[0017] Preferably, a supporting member is further provided between the valve cover and the power supply end, the supporting member is sleeved on the outside of the straight section of the U-shaped conductive wire, and the supporting member is fitted with the end face of the external part of the valve cover, and sealant is applied to the periphery of the fitting part between the supporting member and the external part.

[0018] Preferably, the valve cover further comprises a supporting member integrally connected to the external portion, and the supporting member is sleeved outside the straight section of the U-shaped conductive wire.

[0019] Preferably, the radial surface of the built-in part of the valve cover is provided with at least one circle of sealing grooves, the sealing grooves are used to embed a sealing ring, and after the sealing ring is embedded in the sealing grooves, it has an interference fit with the inner wall of the SMA actuator cavity, and the gap between the sealing grooves and the SMA actuator cavity is sealed by a sealant.

[0020] Preferably, the plunger is provided with a countersunk hole whose inner diameter matches the outer diameter of the return spring, and one end of the return spring is placed in the countersunk hole and connected to the bottom surface of the countersunk hole.

[0021] Preferably, the SMA conductive member is any one of a nickel-titanium shape memory alloy conductive member, a copper-aluminum-zinc shape memory alloy conductive member, and a titanium-nickel-niobium shape memory alloy conductive member.

[0022] Preferably, the air inlet duct is connected to the external air circuit through an air inlet, and the air outlet duct is connected to the external air circuit through an air outlet, and the external air circuit includes a multi-air-port valve housing provided with at least two SMA actuator module mounting positions, and the multi-air-port valve housing is provided with air outlets and integrated air inlets having the same number as the SMA actuator module mounting positions, one end of the integrated air inlet is connected to an air storage chamber, and the other end is connected to an air discharge end, and the air storage chamber is used to supply air to the air inlet; when the SMA actuator module is placed in the SMA actuator module mounting position, the air inlet duct in a single SMA actuator module is connected to the integrated air inlet, and the air outlet duct in a single SMA actuator module is connected to the corresponding unique air outlet on the multi-air-port valve housing, and the control of the gas flow and direction in the external air circuit is achieved by installing different numbers of SMA actuator modules and installing SMA actuator modules on different SMA actuator module mounting positions.

[0023] Preferably, the external air circuit is a sphygmomanometer air circuit, which includes an air storage pipe, a slow air release pipe, a fast air release pipe, an air inlet pipe, and an air outlet pipe, wherein the air inlet pipe is connected to the air storage pipe and the air inlet pipe is integrally connected to the air inlet duct; one end of the slow air release pipe is connected to the air storage pipe, and the other end is directly connected to the outside; one end of the fast air release pipe is integrally connected to the air outlet duct, and the other end is directly connected to the outside; one end of the air outlet pipe is connected to the air storage pipe, and the other end is connected to the cuff; the diameter of the slow air release pipe is smaller than the diameter of the fast air release pipe.

[0024] Beneficial effects:

[0025] 1. In the ventilation valve of the present invention, the SMA conductive member, the plunger, the return spring, and the valve cover are all placed in the same SMA actuator cavity. The SMA actuator cavity can preferably be designed as a regular cuboid structure, which further facilitates the modular application of the ventilation valve and enables convenient and rapid installation at the positions where the ventilation valve needs to be applied in complex gas circuit structures.

[0026] 2. A return spring is connected between the plunger and the valve cover in the present invention. In the power-off state of the SMA conductive member, the SMA conductive member is in a martensite state, and the pulling force of the SMA conductive member is less than the force of the return spring. The return spring pushes the movable plunger to the right. Affected by the return spring, the SMA conductive member extends, driving the movable plunger to move towards the intake air passage. The movable plunger with a sealing rubber blocks the intake air passage, preventing the gas in the intake port and the gas storage cavity from entering the SMA actuator cavity and hindering gas exchange. In the power-on state of the SMA conductive member, the SMA conductive member undergoes a phase change to an austenite state, and the pulling force of the SMA conductive member is greater than the force of the return spring. The SMA conductive member pulls the plunger to move leftward, opening the intake air passage. The gas in the intake port and the gas storage cavity flows into the outlet air passage through the intake air passage to complete gas exchange. At the same time, the return spring is compressed. After stopping the power supply of the SMA conductive member, the SMA conductive member naturally cools to a martensite state, and the force of the SMA conductive member is less than the force of the return spring, blocking the intake air passage again to complete an action cycle. The entire process of controlling gas flow has a high degree of automation and a good blocking effect when blocking the intake air passage.

[0027] 3. The valve cover of the present invention includes an inner part and an outer part integrally connected. The outer contour of the inner part fits the inner wall of the SMA actuator cavity. The outer part is located outside the SMA actuator cavity. The end face of the outer part extends radially so that the end face of the outer part completely covers the diameter end of the SMA actuator cavity near the power supply end. This not only improves the airtightness of the valve cover relative to the SMA actuator cavity, preventing external gas from entering the SMA actuator cavity from one end of the valve cover and affecting gas flow changes, but also improves the airtightness of the valve cover relative to the PCB board. When the intake air passage intakes air, the gas cannot pass through the contact between the valve cover and the PCB board, enabling the PCB board to work in a dry environment for a long time, increasing the service life of the PCB board, and preventing the SMA conductive member from malfunctioning due to moisture-induced short circuits.

[0028] 4. The plunger of the present invention is designed with a counterbore to accommodate the return spring, improving the stability of the connection of the return spring and increasing the telescopic range of the return spring without increasing the length of the SMA actuator cavity, thereby improving the practicability of the ventilation valve.

[0029] 5. A clamping member is further provided between the valve cover and the power supply end of the present invention. The clamping member is sleeved outside the straight section of the U-shaped conductive wire, and the clamping member is in contact with the end face of the external part of the valve cover. A sealing glue is applied around the joint of the clamping member and the external part; or the valve cover further includes a clamping member integrally connected to the external part, and the clamping member is sleeved outside the straight section of the U-shaped conductive wire. Through the guiding action of the clamping member or the clamping member, the position and length of the SMA conductive member are limited during installation, so that it can better contact the electronic components on the PCB board precisely, and play a protective role for the SMA conductive member extending outside the valve cover.

[0030] 6. The intake air passage and the exhaust air passage in the present invention are arranged on the same side of the SMA actuator cavity, which is convenient for quick connection with the external air circuit, reduces the number of pipelines of the external air circuit, and can be directly used for air circuits that require multiple ventilation valves such as the air circuit of an automotive seat, and can also be used for air circuit structures that require high precision of gas flow such as the air circuit of a sphygmomanometer. For different air circuit structures, there is no need to redesign the structure of the ventilation valve. Compared with the traditional ventilation valve that can only be used in specific occasions, it has greater generality and lower overall manufacturing cost.

[0031] 7. The SMA conductive member of the present invention is detachably connected to the plunger. When the SMA conductive member is detachably connected to the plunger, a first groove for passing the SMA conductive member is formed on the radial side surface of the plunger, and a second groove is provided on the inner wall of the first groove close to the central axis of the plunger. The SMA conductive member first passes through the first groove for shaping and then is embedded into the second groove. Since the second groove is provided on the inner wall of the first groove, when the SMA conductive member is embedded into the second groove, the inner wall of the first groove is naturally higher than the bottom surface of the second groove. When the SMA conductive member is embedded into the second groove, the inner wall of the first groove forms a limit for the SMA conductive member. By providing different numbers of second grooves, different numbers of SMA conductive members can be installed on the same plunger, so as to change the value of the sum of the pulling forces of the SMA conductive members, and it is convenient to adapt to the requirements of different ventilation volumes under different air circuit structures.

[0032] It should be understood that all combinations of the foregoing concepts and additional concepts described in more detail below can be regarded as part of the inventive subject matter of the present disclosure as long as such concepts do not conflict with each other.

[0033] The foregoing and other aspects, embodiments, and features of the teachings of the present invention can be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the present invention, such as the features and / or beneficial effects of the exemplary embodiments, will be apparent in the following description, or will be learned through the practice of the specific embodiments according to the teachings of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are not drawn to the scale of actual reference objects. In the accompanying drawings, each identical or approximately identical component shown in each figure may be denoted by the same reference numeral. For the sake of clarity, not every component is labeled in each figure. Now, embodiments of various aspects of the present invention will be described by way of example and with reference to the accompanying drawings, wherein:

[0035] Figure 1 It is a sectional view of the structure of a high-airtightness modular ventilation valve according to an embodiment of the present invention.

[0036] Figure 2 It is an exploded view of the overall structure of a high-airtightness modular ventilation valve according to an embodiment of the present invention.

[0037] Figure 3 It is a schematic diagram of the structure of a plunger according to an embodiment of the present invention.

[0038] Figure 4 It is a sectional view of the structure of a valve cover according to an embodiment of the present invention.

[0039] Figure 5 It is a schematic diagram of the application of the first gas path structure of the high-airtightness modular ventilation valve of the present invention.

[0040] Figure 6 It is a schematic diagram of the application of the second gas path structure of the high-airtightness modular ventilation valve of the present invention.

[0041] Figure 7 It is a sectional schematic diagram of the application of the second gas path structure of the high-airtightness modular ventilation valve of the present invention.

[0042] Explanation of reference numerals in the accompanying drawings:

[0043] 101 - SMA actuator cavity; 102 - return spring; 103 - SMA conductive part; 104 - valve cover; 105 - plunger; 2 - intake air passage; 3 - sealing rubber gasket; 4 - air storage cavity; 5 - air outlet; 6 - outlet air passage; 7 - bottom cover; 8 - PCB board; 9 - clamping part; 201 - intake section; 200 - insertion section; 202 - exhaust port; 1051 - counterbore; 1052 - first groove; 1053 - second groove; 1041 - built-in part; 1042 - external part; 1043 - sealing ring; 41 - air leakage end; 42 - integrated intake port; 300 - air valve housing; 400 - intake pipe; 401 - outlet pipe; 402 - slow air leakage pipe; 403 - air storage pipe; 404 - fast air leakage pipe; 405 - sensing outlet pipe. Detailed implementation manners

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings understood by those of ordinary skill in the art to which the present invention pertains.

[0045] The terms "first", "second", and similar terms used in the description and claims of this patent application for invention do not denote any order, quantity, or importance, but are merely used to distinguish different components. Similarly, unless the context clearly indicates otherwise, singular forms such as "a", "an", or "the" do not denote a limitation of quantity, but rather indicate the presence of at least one. Terms such as "comprising" or "including" are intended to mean that the elements or items appearing before "comprising" or "including" cover the features, wholes, steps, operations, elements, and / or components listed after "comprising" or "including", and do not exclude the existence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations. Terms such as "up", "down", "left", "right", etc. are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0046] As Figure 1 and Figure 2 shown, the present invention provides a highly airtight modular ventilation valve, including a power supply end, an SMA actuator module, and an air passage. The SMA actuator module includes an SMA actuator cavity 101 and an SMA conductive member 103. Inside the SMA actuator cavity 101, a plunger 105, a return spring 102, and a valve cover 104 are sequentially arranged in a direction away from the power supply end.

[0047] The return spring connects the plunger 105 and the valve cover 104. The valve cover 104 is provided with a first passage for the SMA conductive member 103 to pass through. One end of the SMA conductive member 103 is embedded in the plunger 105, and the other end of the SMA conductive member 103 is placed in the first passage and extends to the power supply end. The power supply end is used for energizing the SMA conductive member 103.

[0048] The SMA conductive part 103, the plunger 105, the return spring 102, and the valve cover 104 in the ventilation valve are all placed in the same SMA actuator cavity. The SMA actuator cavity 101 can preferably be designed as a regular cuboid structure, which is further beneficial to the modular application of the ventilation valve and enables convenient and rapid installation at the positions where the ventilation valve needs to be applied in complex gas circuit structures.

[0049] The air passage includes an intake air passage 2 and an exhaust air passage 6. The plunger 105 blocks the intake air passage 2 when the SMA conductive part 103 is in a non-energized state. When the SMA conductive part 103 is energized, the plunger 105 moves in a direction away from the intake air passage 2 under force, so that the intake air passage 2 communicates with the SMA actuator cavity 101 and then with the exhaust air passage 6. The intake air passage 2 and the exhaust air passage 6 are arranged on the same side of the SMA actuator cavity 101, which is convenient for quick connection to the external gas circuit and reduces the number of pipes in the external gas circuit.

[0050] The valve cover 104 includes an inner part 1041 and an outer part 1042 that are integrally connected. The outer contour of the inner part 1041 fits the inner wall of the SMA actuator cavity 101, and the outer part 1042 is located outside the SMA actuator cavity 101. The end face of the outer part 1042 extends radially so that the end face of the outer part 1042 completely covers the diameter end of the SMA actuator cavity 101 on the side close to the power supply end. In this way, not only the airtightness of the valve cover 104 relative to the SMA actuator cavity 101 is improved, and external gas cannot enter the SMA actuator cavity 101 from one end of the valve cover 104 to affect the gas flow change, but also the airtightness of the valve cover 104 relative to the PCB board 8 is improved. When the intake air passage 2 intakes air, the gas cannot contact the PCB board 8 through the valve cover 104, enabling the PCB board 8 to work in a dry environment for a long time, increasing the service life of the PCB board 8, and preventing the SMA conductive part 103 from malfunctioning due to damp short-circuit.

[0051] The intake air passage 2 and the exhaust air passage 6 are connected to the external gas circuit. Please refer to Figure 2As shown in the figure, on the housing of the SMA actuator cavity 101, a ventilation valve multi-module combination is realized by connecting a pipeline containing an exhaust port 202, an intake section 201, and a plug-in section 200. The plug-in section 200 is in communication with the intake section 201, and the exhaust port 202 is not in communication with either the intake section 201 or the plug-in section 200. The exhaust port 202 is in communication with the outlet airway 6 and the outlet 5 inside the housing where the SMA actuator cavity 101 is located, and the intake section 201 is in communication with the intake airway 2 and the air storage cavity 4 inside the housing where the SMA actuator cavity 101 is located. In this way, the simplest air path of a single module of the ventilation valve is formed. The external contour of the plug-in section 200 adapts to the internal contour of the intake section 201 and is used to be plugged into the intake section 201 connected to another ventilation valve. According to the needs of different numbers of ventilation valves, the multi-module combination of the ventilation valve can be completed only through the assembly and cooperation of the plug-in section 200 and the intake section 201. The operation is very convenient, and at the same time, the pipeline design is simple.

[0052] In some embodiments of the present invention, the SMA conductive member 103 is an integrally formed U-shaped conductive wire. The bent ends of the U-shaped conductive wire are embedded in the plunger 105, and the straight ends of the U-shaped conductive wire are placed in the first channel of the valve cover 104 and extend to the power supply terminal.

[0053] In some embodiments of the present invention, the power supply terminal is a PCB board 8 connected to an external power supply or an internal power supply. When the power supply terminal adopts the PCB board 8, the PCB board 8 is installed on the bottom cover 7, and the bottom cover 7 is connected to the housing where the SMA actuator cavity is located to form a sealed housing.

[0054] In some embodiments of the present invention, a clamping member 9 is further provided between the valve cover 104 and the power supply terminal. The clamping member 9 is sleeved outside the straight section of the U-shaped conductive wire, and the clamping member 9 is in contact with the end face of the external part 1042 of the valve cover 104. A sealing glue is applied around the contact area between the clamping member 9 and the external part 1042.

[0055] In some embodiments of the present invention, the valve cover 104 further includes a clamping member 9 integrally connected to the external part 1042, and the clamping member 9 is sleeved outside the straight section of the U-shaped conductive wire.

[0056] Through the guiding action of the clamping member 9 or the clamping member 9, the present invention limits the position and length of the SMA conductive member 103 during installation, enables better precise contact with the electronic components on the PCB board 8, and protects the SMA conductive member 103 extending outside the valve cover 104.

[0057] Please refer to Figure 4As shown, in some embodiments of the present invention, at least one sealing groove is provided on the radial surface of the built-in part 1041 of the valve cover 104. The sealing groove is used to embed the sealing ring 1043. After the sealing ring 1043 is embedded in the sealing groove, it is in interference fit with the inner wall of the SMA actuator cavity 101. The gap between the sealing groove and the SMA actuator cavity 101 is sealed with sealant.

[0058] In the present invention, the end face of the external part 1042 is radially extended to completely cover the diameter end of the SMA actuator cavity 101 near the power supply end, which plays a role in blocking the gas and the PCB board 8. The present invention also sets a sealing groove on the radial surface of the built-in part of the valve cover 104 to embed the sealing ring 1043, adding an air flow blocking obstacle in the necessary flow direction of the contact between the gas and the PCB board. The gap between the sealing groove and the SMA actuator cavity 101 is sealed with sealant, further blocking the contact between the gas and the PCB board.

[0059] In some embodiments of the present invention, a sealing rubber gasket 3 is fixed on the axial surface of the plunger 105 near the intake air passage 2 and the exhaust air passage 6. When the SMA conductive part 103 is in a non-energized state, the sealing rubber gasket 3 directly blocks the intake air passage 2. Since the restoring force of the return spring 102 is greater than the pulling force of the SMA conductive part 103 when the SMA conductive part 103 is in a non-energized state, the plunger 105 is pushed by the return spring 102 towards the intake air passage 2. The sealing rubber gasket 3 follows the plunger 105 and closely abuts against the intake port of the intake air passage 2. The sealing rubber gasket 3 has a certain elasticity, and the intake port of the intake air passage 2 tightly presses on the surface of the sealing rubber gasket 3, which has a better sealing effect compared to the intake port of the intake air passage 2 directly contacting the surface of the plunger 105 and will not cause wear to the surface of the plunger 105. By setting the sealing rubber gasket 3, the residual gas in the intake air passage is directly prevented from contacting the PCB board at the gas source.

[0060] By taking sealing measures at the gas source end, the path position, and the end close to the PCB board, the present invention can completely eliminate the adverse effects of water vapor in the air on the electronic components on the PCB board, greatly improving the service life and stability of the PCB board during use.

[0061] In some embodiments of the present invention, a counterbore 1051 with an inner diameter adapted to the outer diameter of the spring is provided on the plunger 105. One end of the spring is placed in the counterbore 1051 and connected to the bottom surface of the counterbore 1051. By designing the counterbore 1051 to accommodate the spring, the stability of the spring connection is improved. While increasing the telescopic range of the spring, it is not necessary to extend the length of the SMA actuator cavity 101, making the overall structure simple and improving the practicability of the air vent valve.

[0062] Please refer to Figure 3 As shown, in some embodiments of the present invention, the SMA conductive member 103 is detachably connected to the plunger 105. When the SMA conductive member 103 is detachably connected to the plunger 105, a first groove 1052 for inserting the SMA conductive member 103 is formed on the radial side surface of the plunger 105. A second groove 1053 is provided on the inner wall of the first groove 1052 close to the central axis of the plunger 105. The SMA conductive member 103 first passes through the first groove 1052 for shaping and then is embedded in the second groove 1053. Since the second groove 1053 is provided on the inner wall of the first groove 1052, when the SMA conductive member 103 is embedded in the second groove 1053, the inner wall of the first groove 1052 is naturally higher than the bottom surface of the second groove 1053. When the SMA conductive member 103 is embedded in the second groove 1053, the inner wall of the first groove 1052 forms a limit for the SMA conductive member 103. By providing different numbers of second grooves 1053, different numbers of SMA conductive members 103 can be installed on the same plunger 105, thereby changing the value of the sum of the pulling forces of the SMA conductive members 103 to facilitate adapting to the requirements of different ventilation volumes under different gas path structures.

[0063] Under the traditional combination method in which the SMA conductive member 103 and the plunger 105 cannot be separated, the displacement that the plunger 105 can generate is limited, and it cannot adapt to different spring elastic forces and is difficult to meet the needs of different ventilation volumes. Therefore, it is also not conducive to the modular application of the ventilation valve under different gas path structures. Since the ventilation volume requirements corresponding to different gas path structures vary greatly, different types of ventilation valves are required. Detachably installing the SMA conductive member 103 and the plunger 105 can achieve meeting the control requirements of different ventilation volumes on the same ventilation valve without changing other structures.

[0064] The traditional combination method in which the SMA conductive member 103 and the plunger 105 cannot be separated will also cause the SMA conductive element to be easily detached. Moreover, when the SMA conductive element is detached or damaged, since the SMA conductive element is fixed inside the plunger 105, the plunger 105 is also scrapped, resulting in high scrapping costs and increased time and economic costs for subsequent replacement.

[0065] In some embodiments of the present invention, a limiting member is provided on the second groove 1053 for embedding the SMA conductive member 103. The limiting member can further limit the SMA conductive member 103 to prevent displacement of the SMA conductive member 103 in the second groove 1053. The limiting member is a convex post or a retaining piece provided on the second groove 1053. When the limiting member is a convex post, when the SMA conductive member 103 is embedded into the second groove 1053 and passes through the convex post, a certain number of turns are wound around the convex post, thereby playing a further limiting role. When the limiting member is a retaining piece, a set of retaining piece units is defined to include 2 retaining pieces symmetrically arranged with the center line of the second groove 1053 as the center line. One end of each retaining piece in each retaining piece unit is fixed on the second groove 1053, and the other end is a free end. The two free ends in a set of retaining piece units are in contact in the natural state. When the SMA conductive member 103 is embedded into the second groove 1053 and passes through the retaining piece unit, it passes through between the free ends of the two retaining pieces, and the free ends of the two retaining pieces are in close contact with the surface of the SMA conductive member 103 to play a limiting role.

[0066] In some embodiments of the present invention, the SMA conductive member 103 is any one of a nickel-titanium shape memory alloy conductive member, a copper-aluminum-zinc shape memory alloy conductive member, and a titanium-nickel-niobium shape memory alloy conductive member.

[0067] Please refer to Figure 5 As shown, in some embodiments of the present invention, the intake air passage 2 is connected to an external air circuit through an air inlet, and the outlet passage is connected to an external air circuit through an air outlet 5. The external air circuit includes a multi-air-port valve housing 300 provided with at least two SMA actuator module mounting positions. The multi-air-port valve housing 300 is provided with the same number of air outlets 5 as the number of SMA actuator module mounting positions and an integrated air inlet 42. One end of the integrated air inlet 42 is connected to an air storage chamber 4, and the other end is connected to a pressure relief end 41. The air storage chamber 4 is used to supply air to the air inlet; when the SMA actuator module is placed in the SMA actuator module mounting position, the intake air passage in a single SMA actuator module communicates with the integrated air inlet 42, and the outlet air passage in a single SMA actuator module communicates with the corresponding unique air outlet 5 on the multi-air-port valve housing 300. By installing different numbers of SMA actuator modules and installing SMA actuator modules at different SMA actuator module mounting positions, the gas flow rate and direction in the external air circuit are controlled.

[0068] Please refer to Figure 6 and Figure 7As shown, in some embodiments of the present invention, the external air circuit is a sphygmomanometer air circuit. The sphygmomanometer air circuit includes a gas storage pipe 403, a slow air release pipe 402, a fast air release pipe 404, an air inlet pipe 400, and an air outlet pipe 401. The air inlet pipe 400 is connected to the gas storage pipe 403 and is integrally connected to the intake air passage 2; one end of the slow air release pipe 402 is connected to the gas storage pipe 403, and the other end leads directly to the outside; one end of the fast air release pipe 404 is integrally connected to the outlet air passage 6, and the other end leads directly to the outside; one end of the air outlet pipe 401 is connected to the gas storage pipe 403, and the other end is connected to the cuff; the diameter of the slow air release pipe 402 is smaller than the diameter of the fast air release pipe 404. A sensing air outlet pipe 405 is connected to the radial side of the air outlet pipe 401. The sensing air outlet pipe 405 is used to connect to a pressure sensor.

[0069] When the external air circuit is a sphygmomanometer air circuit, the working principle of the ventilation valve and the air circuit is as follows: Turn on the air pump, inject gas into the air inlet pipe 400 through the air pump. After the gas passes through the gas storage pipe 403 and enters the air outlet pipe 401, it then enters the cuff. Due to the diameter limitation of the slow air release pipe 402, when the exhaust speed of the slow air release pipe 402 is less than 3 millimeters of mercury per second, the gas discharged from the slow air release pipe 402 does not affect the gas pressure in the cuff.

[0070] As the air pressure in the cuff increases, the artery is compressed and blood flow is blocked. Then, the pressure sensor records the air pressure to measure the systolic blood pressure. After measuring the systolic blood pressure, turn off the air pump. The electronic sphygmomanometer slowly releases the air pressure in the cuff through the first air outlet. When the air pressure decreases, the artery reopens and blood flow resumes normal. The pressure sensor records the air pressure to measure the diastolic blood pressure. After measuring the diastolic blood pressure, the PCB board 8 supplies power or the power supply directly supplies power. The SMA conductive member 103 undergoes a phase change, changing from the martensite state to the austenite state. The SMA conductive member 103 generates a pulling force, and the pulling force of the SMA conductive member 103 is greater than the elastic force of the return spring 102. The SMA conductive member 103 pulls the plunger 105 to move in the direction away from the intake air passage 2. The intake air passage 2 is connected to the SMA actuator cavity 101, and the fast air release pipe 404 is connected to the SMA actuator cavity 101. The gas passes through the intake air passage 2 and then is quickly discharged through the fast air release pipe 404, and the gas in the electronic sphygmomanometer is discharged. After the gas discharge is completed, stop supplying power to the SMA conductive member 103. The SMA conductive member 103 naturally cools to the martensite state, and the pulling force of the SMA conductive member 103 is less than the elastic force of the return spring 102, and the air outlet of the intake air passage 2 and the air inlet of the fast air release pipe 404 are blocked again. The sensing air outlet pipe 405 is used to connect to a pressure sensor. During the measurement process, the electronic sphygmomanometer will display the measurement data on the display screen of the electronic sphygmomanometer.

[0071] By using the ventilation valve of the present invention on a sphygmomanometer, the functions of the solenoid valve and the air release valve can be integrated, reducing the occupied volume of the solenoid valve and the air release valve in the electronic sphygmomanometer, shrinking the volume of the electronic sphygmomanometer, enabling the electronic sphygmomanometer to be designed into a more portable structure, and improving the practicality of a ventilation valve for an electronic sphygmomanometer. Through the design of the connection relationships of the various air passages in the air valve, the air circuit of the electronic sphygmomanometer is simplified, the failure rate is reduced, and the use stability of a ventilation valve for an electronic sphygmomanometer is improved.

[0072] The working principle of the SMA conductive member functioning as a valve switch in each embodiment of the present invention is as follows: A spring is connected between the plunger 105 and the valve cover 104. In the power-off state of the SMA conductive member 103, the SMA conductive member 103 is in a martensite state, the pulling force of the SMA conductive member 103 is less than the force of the return spring 102, the return spring 102 pushes the movable plunger 105 to the right, and the SMA conductive member 103 extends under the influence of the return spring 102, driving the plunger 105 to move in the direction close to the intake air passage 2. The movable plunger 105 with a sealing rubber blocks the intake air passage 2, hindering the gas in the air inlet and the air storage cavity 4 from entering the SMA actuator cavity and hindering gas exchange. In the power-on state of the SMA conductive member 103, the SMA conductive member 103 undergoes a phase transformation into an austenite state, the pulling force of the SMA conductive member 103 is greater than the force of the return spring 102, the SMA conductive member 103 pulls the plunger 105 to move leftward, opening the intake air passage 2, and the gas in the air inlet and the air storage cavity 4 flows into the outlet air passage 6 through the intake air passage 2 to complete gas exchange. At the same time, the return spring 102 is compressed. After stopping the power supply to the SMA conductive member 103, the SMA conductive member 103 naturally cools to a martensite state, the force of the SMA conductive member 103 is less than the force of the return spring 102, and the intake air passage 2 is blocked again, completing one action cycle. The entire process of controlling gas flow has a high degree of automation and a good blocking effect when blocking the intake air passage 2.

[0073] The intake air passage 2 and the outlet air passage 6 in the present invention are arranged on the same side of the SMA actuator cavity 101, facilitating quick connection to the external air circuit, reducing the number of pipes in the external air circuit, and can be directly used on air circuits that require multiple ventilation valves such as the air circuit of an automotive seat, and can also be used on air circuit structures that require high precision of gas flow rate such as the air circuit of a sphygmomanometer. For different air circuit structures, there is no need to redesign the structure of the ventilation valve. Compared with traditional ventilation valves that can only be used in specific occasions, it has greater generality and lower overall manufacturing cost.

[0074] In the process of modularizing the ventilation valve, it is necessary to conduct an overall design of the shape memory alloy as the valve structure and the design of the gas path. For valves generally using shape memory alloy, only the selection of the shape memory alloy material is considered, and the cooperation between the structure of the shape memory alloy during use and other components is not taken into account. In the modular design, the shape memory alloy not only serves as a material but also participates in the overall structure of the ventilation valve as a specific structural component. In the present invention, specifically, the SMA conductive member 103 is a U-shaped conductive wire formed integrally. The bent ends of the U-shaped conductive wire are embedded in the plunger 105, and the straight ends of the U-shaped conductive wire are placed in the first channel of the valve cover 104 and extend to the power supply end. By being embedded in the plunger 105, the bent ends of the SMA conductive member 103 can fully drive the plunger 105 to move within the SMA actuator cavity. The straight segment of the SMA conductive member 103 passes through the first channel of the valve cover 104 and extends to the power supply end, which not only plays a role in conducting current but also integrates the valve cover 104 and the SMA conductive member 103. The valve cover 104 not only serves as a seal but also becomes the installation component of the SMA conductive member 103. The reasonable design of the valve cover 104, the plunger 105, and the SMA conductive member 103 forms an integral whole that can be placed in the SMA actuator cavity simultaneously and serves as a valve, with a compact fit, saving the volume of the SMA actuator cavity.

[0075] Moreover, in the modular design of the present invention, the shape memory alloy serves as a conductive member. By adjusting the magnitude of the current flowing through the shape memory alloy, the deformation amount of the shape memory alloy can be changed, thereby enabling the design of multiple ventilation ports, making the modular design of the present invention capable of meeting the requirements for use in different application scenarios, rather than simply being a compact design in terms of structure. Compared with general valves where the shape memory alloy can only be used as a simple switch, it has greater superiority.

[0076] The modular design of the present invention is also reflected in the modular design of the gas pipeline, and the modular design of the gas pipeline can be realized based on the modular design of the ventilation valve of the present invention. Generally speaking, the modular design of the gas pipeline is only designed separately, and the valves used in the pipelines that require valves are still complex in structure. One of the gas path embodiments provided by the present invention realizes that only by placing the SMA actuator module in the installation position of the SMA actuator module, the air inlet channel in a single SMA actuator module communicates with the integrated air inlet 42, and the air outlet channel in a single SMA actuator module communicates with the corresponding unique air outlet 5 on the multi-air port valve housing 300. By installing different numbers of SMA actuator modules and installing SMA actuator modules at different installation positions of the SMA actuator modules, the control of the gas flow rate and direction in the external gas path is realized. The gas path of the sphygmomanometer provided by the present invention also reduces the number of pipelines and shrinks the volume of the electronic sphygmomanometer due to the modular design of the ventilation valve, enabling the electronic sphygmomanometer to be designed into a more portable structure, and improving the practicability of a ventilation valve for an electronic sphygmomanometer. The organic combination of the modular ventilation valve and the modular gas path design enables multi-gas path products using the ventilation valve to be further simplified, which is difficult to achieve with the modularization of a single structure.

[0077] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Those with ordinary knowledge in the technical field to which the present invention pertains can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to what is defined by the claims.

Claims

1. A highly airtight modular ventilation valve, characterized in that, it includes a power supply end, an SMA actuator module and an air passage. The SMA actuator module includes an SMA actuator cavity and an SMA conductive member. Inside the SMA actuator cavity, a plunger, a return spring and a valve cover are sequentially arranged in a direction away from the power supply end; the return spring connects the plunger and the valve cover. The valve cover is provided with a first passage for the SMA conductive member to pass through. One end of the SMA conductive member is embedded in the plunger, and the other end of the SMA conductive member is placed in the first passage and extends to the power supply end. The power supply end is used for energizing the SMA conductive member; the air passage includes an intake air passage and an exhaust air passage. The plunger blocks the intake air passage in a state where the SMA conductive member is not energized. The plunger moves in a direction away from the intake air passage under the action of force in a state where the SMA conductive member is energized, so that the intake air passage communicates with the SMA actuator cavity and then with the exhaust air passage; the valve cover includes an inner part and an outer part connected integrally. The outer contour of the inner part fits the inner wall of the SMA actuator cavity. The outer part is located outside the SMA actuator cavity. The end face of the outer part extends radially so that the end face of the outer part completely covers the diameter end of the SMA actuator cavity close to the power supply end; the intake air passage and the exhaust air passage are connected to an external air circuit.

2. The highly airtight modular ventilation valve according to claim 1, characterized in that, the SMA conductive member is an integrally formed U-shaped conductive wire. The bent end of the U-shaped conductive wire is embedded in the plunger, and the straight end of the U-shaped conductive wire is placed in the first passage of the valve cover and extends to the power supply end.

3. The highly airtight modular ventilation valve according to claim 1, characterized in that, the SMA conductive member is detachably connected to the plunger. When the SMA conductive member is detachably connected to the plunger, a first groove for the SMA conductive member to penetrate is provided on the radial side surface of the plunger, and a second groove is provided on the inner wall of the first groove close to the central axis of the plunger.

4. The highly airtight modular ventilation valve according to claim 2, characterized in that, a clamping member is further provided between the valve cover and the power supply end. The clamping member is sleeved outside the straight section of the U-shaped conductive wire, and the clamping member is attached to the end face of the outer part of the valve cover. A sealing glue is applied to the periphery of the joint of the clamping member and the outer part.

5. The highly airtight modular ventilation valve according to claim 2, characterized in that, the valve cover further includes a clamping member integrally connected to the outer part. The clamping member is sleeved outside the straight section of the U-shaped conductive wire.

6. The highly airtight modular ventilation valve according to claim 1, characterized in that, The radial surface of the built-in part of the valve cover is provided with at least one circle of sealing grooves for embedding sealing rings. After the sealing rings are embedded in the sealing grooves, they are in interference fit with the inner wall of the SMA actuator cavity, and the gap between the sealing grooves and the SMA actuator cavity is sealed with sealant.

7. The highly airtight modular ventilation valve according to claim 1, characterized in that a counterbore with an inner diameter adapted to the outer diameter of the return spring is provided on the plunger, and one end of the return spring is placed in the counterbore and connected to the bottom surface of the counterbore.

8. The highly airtight modular ventilation valve according to claim 1 or 2, characterized in that the SMA conductive part is any one of a nickel-titanium shape memory alloy conductive part, a copper-aluminum-zinc shape memory alloy conductive part, and a titanium-nickel-niobium shape memory alloy conductive part.

9. The highly airtight modular ventilation valve according to claim 1, characterized in that the intake air passage is connected to an external air path through an air inlet, and the exhaust air passage is connected to an external air path through an air outlet. The external air path includes a multi-air-port valve housing provided with at least two SMA actuator module mounting positions. The multi-air-port valve housing is provided with the same number of air outlets as the SMA actuator module mounting positions and an integrated air inlet. One end of the integrated air inlet is connected to a storage cavity, and the other end is connected to a deflation end. The storage cavity is used to supply air to the air inlet; when the SMA actuator module is placed in the SMA actuator module mounting position, the intake air passage in a single SMA actuator module communicates with the integrated air inlet, and the exhaust air passage in a single SMA actuator module communicates with the corresponding unique air outlet on the multi-air-port valve housing. By installing different numbers of SMA actuator modules and installing SMA actuator modules at different SMA actuator module mounting positions, the control of the gas flow rate and direction in the external air path is achieved.

10. The highly airtight modular ventilation valve according to claim 1, characterized in that the external air path is a sphygmomanometer air path, and the sphygmomanometer air path includes a gas storage pipe, a slow deflation pipe, a fast deflation pipe, an inlet pipe, and an outlet pipe. The inlet pipe communicates with the gas storage pipe and is integrally connected to the intake air passage; one end of the slow deflation pipe communicates with the gas storage pipe, and the other end leads directly to the outside; one end of the fast deflation pipe is integrally connected to the exhaust air passage, and the other end leads directly to the outside; one end of the outlet pipe communicates with the gas storage pipe, and the other end communicates with a cuff; the diameter of the slow deflation pipe is smaller than the diameter of the fast deflation pipe.

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