An ultra-thin driver for micro-space driving

Abstract

This utility model relates to the field of shape memory alloy actuator technology, and in particular to an ultra-thin actuator for driving in micro-spaces using shape memory alloy drive wires, with an ultra-thin actuator size ≤2mm. It is suitable for miniature locks or valves, and lightweight flow valves. It includes panel A, panel B, an actuator assembly, and a shape memory alloy drive wire assembly. Panels A and B are provided with fixing latch holes. The fixing latch hole of panel A is connected to the fixing latch hole of panel B via a connecting copper pin, forming a hollow sandwich structure. The actuator assembly is located within the hollow cavity of the hollow sandwich structure and is connected to the shape memory alloy drive wire assembly. The shape memory alloy drive wire assembly is electrically connected to a power source. The power source powers the shape memory alloy drive wire assembly, causing deformation that drives the actuator assembly to slide. Through multiple shape memory alloy drive wires and multi-stage actuator plates, the contraction and tension are progressively superimposed, improving the driving performance in micro-spaces and ultra-thin environments.

Description

Technical Field

[0001] This utility model relates to the field of shape memory alloy actuator technology, and in particular to an ultra-thin actuator for driving in minute spaces using a shape memory alloy drive wire, with a size ≤2mm. It is suitable for miniature locks or valves, and lightweight flow valves. Background Technology

[0002] Shape memory alloys (SMAs) are metallic materials with unique thermoelastic martensitic phase transformation properties. They can recover their initial preset shape after undergoing low-temperature plastic deformation through thermal excitation; this property is known as the shape memory effect (SME). Taking the nickel-titanium-based shape memory alloy drive wire involved in this patent as an example, it exhibits significant bidirectional shape memory characteristics: when the temperature exceeds the austenitic phase transformation critical point, the drive wire can generate a 3%-4% linear shrinkage strain; when the temperature drops below the martensitic phase transformation temperature, it recovers its initial length. This reversible strain characteristic makes it an ideal micro-drive element.

[0003] Shape memory alloy (SMA) actuators, built upon the aforementioned characteristics, typically consist of three parts: a drive wire, a mechanical transmission mechanism, and a control circuit. Based on the output form, they can be divided into two categories: linear drive and rotary drive. Compared to traditional electromagnetic drive devices, they have the following core advantages: 1. Ultra-low power consumption: The operating current is only 200-500mA, which is comparable to that of a micro electromagnetic motor, but the energy conversion efficiency can reach 2-5 times that of a DC motor of the same specification, making it particularly suitable for portable devices and battery-powered scenarios; 2. Ultra-high energy density: The power density per unit mass reaches over 100W / kg, which is 4000 times that of traditional electromagnetic actuators and 1000 times that of biological muscle tissue, enabling miniaturized high-power output; 3. Extreme miniaturization capability: Through optimized structural design, the power-to-weight ratio increases exponentially with the reduction of device size, maintaining high-efficiency output even at the millimeter scale; 4. Silent driving characteristics: No electromagnetic interference or mechanical vibration noise, and the motion pattern is similar to biological muscle tissue, meeting the requirements of quiet environments such as medical and precision instruments; 5. Integrated cost advantage: The linear drive output characteristic eliminates the need for additional components such as reduction gears, reducing system complexity by more than 60%, and the overall cost is only 30%-40% of that of a rotary motor with the same performance; 6. Digital control compatibility: It can be directly connected to a microprocessor interface to achieve precise displacement control through PWM pulse width modulation, with a response time of <100ms.

[0004] Based on the above-mentioned technological advantages, shape memory alloy actuators have been widely used in cutting-edge fields such as aerospace precision actuators, micro-bionic robots, minimally invasive surgical instruments, and intelligent prostheses.

[0005] Defects and shortcomings of existing technology: 1. Insufficient structural compactness: Existing drivers mostly use multi-stage lever or gear transmission mechanisms, which cannot avoid the disadvantage of large size and are difficult to meet the integration requirements of microelectromechanical systems (MEMS); 2. High mass: Although the mass of the shape memory alloy drive wire is very small, the existing driver structure is complex and the supporting auxiliary actuator is heavy, resulting in a large overall mass. 3. Dynamic response hysteresis: The thermally driven method has a thermal conduction hysteresis of 3-5 seconds, and the action cycle interval is relatively long, making it difficult to achieve high-frequency response. Utility Model Content

[0006] This invention addresses the shortcomings of existing technologies by providing an ultra-thin actuator that is fast-acting, ultra-thin in size, and easy to install and remove, suitable for driving in small spaces.

[0007] The present invention solves the existing technical problems by adopting the following technical solution: An ultra-thin actuator for driving in a small space includes a panel A, a panel B, an actuator assembly, and a memory alloy drive wire assembly; the panel A and the panel B are provided with fixing latch holes, and the fixing latch hole of the panel A is connected to the fixing latch hole of the panel B by connecting copper pins to form a hollow sandwich structure. The actuator assembly is located within the hollow cavity of the hollow sandwich structure. It is connected to a shape memory alloy (MMA) drive wire assembly, which is electrically connected to a power source. The power source powers the MMA drive wire assembly, causing it to deform and drive the actuator assembly to slide. The actuator assembly consists of a three-stage actuator, a two-stage actuator plate, and a first-stage actuator plate. The MMA drive wire assembly consists of a first MMA drive wire and a second MMA drive wire. The three-stage actuator, the two-stage actuator plate, and the first-stage actuator plate are connected end-to-end via the first and second MMA drive wires. The multiple MMA drive wires and multi-stage actuator plates allow for progressively stacked contraction and tension, improving the driving performance in micro-spaces and ultra-thin environments.

[0008] The three-level execution plates, the two-level execution plates, and the one-level execution plates of the execution plate group are arranged sequentially along the height direction, with gaps between them. The first memory alloy drive wire and the second memory alloy drive wire are located within the gaps between the three-level execution plates, the two-level execution plates, and the one-level execution plates. The third-level actuator plate, the second-level actuator plate, and the first-level actuator plate are provided with sliding holes. Connecting copper pins pass through the sliding holes, and the third-level actuator plate, the second-level actuator plate, and the first-level actuator plate slide along the connecting copper pins through the sliding holes. Each actuator plate operates independently and has a sliding limit, and the movement stroke of each actuator plate is accumulated.

[0009] The first and second shape memory alloy driving wires have copper terminals at their ends. Panels A and B have sliding holes. One end of the first or second shape memory alloy driving wire has a copper terminal located in the sliding hole on panel A, and the other end has a copper terminal located in the sliding hole on panel B. The first and second shape memory alloy driving wires are arranged alternately. This ensures balanced force distribution, and the hollow clamping action of panels A and B further enhances positioning and limits the movement, ensuring precise execution of each actuator action.

[0010] It also includes a return spring. The third-stage actuator is provided with a sliding reset groove, and a limiting pin is provided in the sliding reset groove. One end of the return spring is hooked to the third-stage actuator via the limiting pin, and the other end of the third-stage actuator is hooked to panel A and panel B via a connecting copper pin. The return spring resets the actuator when no power is applied, ensuring smooth operation of the next memory alloy wire retraction drive.

[0011] The actuator assembly includes a third-level actuator plate, a second-level actuator plate, and a first-level actuator plate, each equipped with two sets of sliding holes arranged in parallel. These three sets of sliding holes form a three-level linear sliding pair, which slides along connecting copper pins via sliding holes. This multi-level linear sliding pair combination allows for drive transmission, and the drive stroke requirements can be met by adding or removing linear sliding pairs to effectively control the size of the drive actuator unit.

[0012] It also includes a valve body and a valve core. The valve core consists of a sliding rod, a sliding block, a sealing head, and a return spring. The sliding block has sliding rods at both ends; one sliding rod is fitted with a return spring, and the other sliding rod has a sealing head. The valve body has a liquid guiding chamber and a sliding groove. The liquid guiding chamber is connected to the sliding groove through a connecting hole, and is connected to the inlet and outlet. A valve body sealing plate is provided on the side of the liquid guiding chamber to form a fluid cavity. The valve core is inserted into the sliding groove and slides along the sliding groove. The sliding groove has a sliding insertion hole, through which the sliding rod of the valve core passes. The valve core has a sliding insertion hole; the other end of the sliding rod passes through the connecting hole into the liquid guiding chamber. The sliding rod is threadedly connected to the sealing head. The return spring applies force to press the sliding block tightly, and presses the sealing head of the sliding block tightly against the liquid inlet. The three-stage actuator is equipped with a sliding latch, which is connected to the sliding block latch. When energized, the first and second memory alloy drive wires contract, and the three-stage linear sliding pair drives the sliding block step by step, pushing the sliding latch to move. The sliding latch drives the sliding block and the sealing head to move away from the liquid inlet and connect to the pipeline. The above-described structure allows for liquid inlet and outlet control in a micro-environment. The three-stage linear sliding pair drives the sealing head to control the opening and closing of the liquid inlet, further realizing liquid inlet and outlet control in a micro-space.

[0013] The sealing head is frustum-shaped, with tower-shaped connectors on the inlet and outlet, which connect to the pipeline. The frustum-shaped design facilitates force application to seal the inlet, and the tower-shaped connectors on the inlet and outlet allow for quick connection to the pipeline.

[0014] Panel A has a positive terminal V+ and a negative terminal V-. Both panels A and B have printed circuit boards (PCBs). The third-level actuator, second-level actuator board, and first-level actuator board are made of high-nickel white copper sheet metal. The high-nickel white copper sheet metal has a PCB installed on it. The positive terminal V+ of panel A is connected to a locking hole in panel A via the PCB. The locking hole in panel A is connected to the locking hole in panel B via a connecting copper pin. The locking hole in panel B is connected to a sliding hole in panel B to form the positive terminal. The negative terminal V- of panel A is connected to... The circuit board is connected to another fixing latch hole of panel A. The other fixing latch hole of panel A is connected to another fixing latch hole of panel B through a connecting copper pin. The other fixing latch hole of panel B is connected to another sliding hole of panel B to form the negative electrode. The positive and negative electrodes are electrically connected through the three-stage linear sliding joint, the three-stage actuator plate, the two-stage actuator board, the one-stage actuator board, the first memory alloy drive wire, and the second memory alloy drive wire to form the positive and negative electrode circuit. The copper terminals on the ends of the first memory alloy drive wire and the second memory alloy drive wire are electrically connected to the sliding hole.

[0015] The sliding hole is equipped with an electrode spring, model FDX0033C2, which is in close contact with the copper terminals of the first and second shape memory alloy driving wires. The first and second shape memory alloy driving wires have a diameter of 0.15mm-0.3mm and a length of 40-50mm, and can generate a linear contraction strain of 3%-4% after being energized; the 0.15mm diameter driving wire provides a 3N output force with a response time of 0.5s; the 0.3mm diameter driving wire provides a 12N output force with a response time of 0.9s.

[0016] The thickness of the hollow sandwich structure formed by panels A and B is ≤2mm. Thermal grease is applied to panels A and B, with the grease located within the hollow sandwich structure. Thermal grease is also applied between panel A and the valve body. The thermal conductivity of the thermal grease is ≥3W / (m·K), and its thickness is 0.1-0.3mm. Applying the thermal grease creates additional heat dissipation channels and shortens the actuation cycle interval by 3-4 seconds. The overall dimensions of the actuator are 55mm × 12.5mm × 2mm, with a weight ≤3g and an actuation stroke of 4±0.5mm. These dimensions are for valve body application only and can be customized according to requirements.

[0017] The beneficial effects of this utility model are as follows: 1. This utility model is a linear actuator that utilizes the characteristic of a shape memory alloy drive wire to shrink when heated by electricity and return to its original length when cooled by power-off, thereby driving the actuator plate to move. This enables the locking pin of a lock to move and unlock, and the locking pin of a load release mechanism to open. It can be installed in miniature valve bodies, miniature bionic robot power actuators, etc. This design adopts a unique structure, using two PCB boards with printed circuits sandwiching a thin copper plate actuator plate, integrating the circuitry onto the actuator body. This simplifies the structure, essentially fusing the circuitry with the casing, avoiding messy wires, and effectively utilizing space, resulting in an overall thickness of only 2mm.

[0018] 2. Furthermore, the interlayer is filled with thermally conductive silicone grease, which can quickly conduct the heat generated by the drive wire to the two PCB boards and conduct the heat away through the outer surface of the PCB boards, thereby optimizing the dynamic response hysteresis problem. The action cycle interval can be shortened by 1-2 seconds by heat dissipation through the outer surface of the PCB alone. If the driver mounting surface is a metal surface, thermally conductive silicone grease can be applied to the driver and mounting surface. At this time, the heat can be transferred to the mounting surface for better heat dissipation, which can shorten the action cycle interval by 3-4 seconds. Different diameter memory alloy drive wires can be installed, such as 0.15mm to 0.3mm, to provide greater output force. To ensure that the heating resistance of the memory alloy drive wires inside the driver is the same, the diameter of the memory alloy drive wires inside the same model driver is the same. The larger the diameter of the memory alloy drive wire, the greater the output force. For example, a memory alloy drive wire with a diameter of 0.15mm can provide an output force of 3N, and a memory alloy drive wire with a diameter of 0.3mm can provide an output force of 12N. This makes it thin, small in size, light in weight, with large driving force and fast response. When the diameter of the memory alloy drive wire is 0.15mm, the response speed is 0.5s, and when it is 0.3mm, the response speed is 0.9s. The final product size is 55mm*12.5mm*2mm, the weight is 3g, and the stroke is 4±0.5mm.

[0019] 3. This design can be applied to miniature locks, valve switches, and other similar applications. It utilizes an actuator to move the lock head or valve core, thereby unlocking or releasing the valve. Currently, most refrigerant valves and flow valves on the market use solenoid valves for flow control. However, solenoid valves are large and heavy, and cannot achieve silent operation, thus limiting their use in some scenarios. For the application of this design in valve-driven scenarios, the actuator can be installed simply by fixing it to the valve body with screws. Valve opening and closing control is achieved through the deformation of a shape-memory alloy wire under current. This design achieves silent operation, is small and lightweight, easy to install, allows for modular assembly, and facilitates maintenance and replacement, providing a solution for space-constrained, lightweight, and silent operation scenarios. Attached Figure Description

[0020] Figure 1 This is a three-dimensional exploded view of the present invention; Figure 2 This is a schematic diagram of the structure of this utility model; Figure 3 This is a side view of the present invention; Figure 4 This is a schematic diagram of the symmetrical unfolding of this utility model; Figure 5 This is an exploded three-dimensional diagram of the present invention; Figure 6 This is a schematic diagram of the three-stage linear sliding pair structure of this utility model; Figure 7 This is an exploded three-dimensional view of the valve body of this utility model; Figure 8 This is a three-dimensional structural diagram of the valve body of this utility model; Figure 9 This is a schematic diagram of the valve body structure of this utility model; Figure 10 This is a schematic diagram of the printed circuit board of panel A of this utility model; Figure 11 This is a schematic diagram of the printed circuit board of panel B of this utility model; Figure 12 This is a schematic diagram of the forces acting on a three-stage linear sliding pair. Figure 13 This is a schematic diagram of the valve body opening. Figure 14 for Figure 13 Valve body sectional view; Figure 15 This is a schematic diagram of the thermal grease distribution.

[0021] The markings in the diagram are: 1 connecting copper pin, 2 first memory alloy drive wire, 3 return spring, 4 third-stage actuator plate, 5 panel A, 6 copper terminal, 7 second-stage actuator plate, 8 second memory alloy drive wire, 9 panel B, 10 first-stage actuator plate, 11 fixed locking hole, 12 sliding hole, 13 sliding reset groove, 14 limit pin, 15 sliding buckle, 16 valve body, 17 liquid guiding chamber, 18 sliding block, 19 liquid inlet, 20 liquid outlet, 21 valve body sealing plate, 22 sliding groove, 23 sliding rod, 24 sealing head, 25 reset spring, 26 connecting hole, 27 sliding insertion hole. Detailed Implementation

[0022] An ultra-thin actuator for driving in a small space includes a panel A5, a panel B9, an actuator assembly, and a memory alloy drive wire assembly; the panel A5 and the panel B9 are provided with fixing latch holes 11, and the fixing latch holes 11 of the panel A5 are connected to the fixing latch holes 11 of the panel B9 by connecting copper pins 1, forming a hollow sandwich structure. The actuator assembly is located within the hollow cavity of the hollow sandwich structure. The actuator assembly is connected to the shape memory alloy drive wire assembly, which is electrically connected to a power source. The power source powers the shape memory alloy drive wire assembly, causing it to deform and drive the actuator assembly to slide. The actuator assembly is divided into a three-stage actuator 4, a two-stage actuator plate 7, and a one-stage actuator plate 10. The shape memory alloy drive wire assembly is divided into a first shape memory alloy drive wire 2 and a second shape memory alloy drive wire 8. The three-stage actuator 4, the two-stage actuator plate 7, and the one-stage actuator plate 10 are connected end-to-end through the first shape memory alloy drive wire 2 and the second shape memory alloy drive wire 8.

[0023] The three-stage actuator 4, the two-stage actuator 7, and the one-stage actuator 10 of the actuator assembly are arranged sequentially along the height direction, with gaps between them. The first memory alloy drive wire 2 and the second memory alloy drive wire 8 are located within the gaps between the three-stage actuator 4, the two-stage actuator 7, and the one-stage actuator 10. The third-level actuator plate 4, the second-level actuator plate 7, and the first-level actuator plate 10 are provided with sliding holes 12. The connecting copper pin 1 passes through the sliding holes 12, and the third-level actuator plate 4, the second-level actuator plate 7, and the first-level actuator plate 10 slide along the connecting copper pin 1 through the sliding holes 12.

[0024] The first memory alloy driving wire 2 and the second memory alloy driving wire 8 are provided with copper terminals 6 at their ends. Panel A5 and panel B9 are provided with sliding holes 12. One end of the first memory alloy driving wire 2 or the second memory alloy driving wire 8 is located in the sliding hole 12 of panel A5, and the other end of the first memory alloy driving wire 2 or the second memory alloy driving wire 8 is located in the sliding hole 12 of panel B9. The first memory alloy driving wire 2 and the second memory alloy driving wire 8 are arranged alternately.

[0025] It also includes a return spring 3. The third-stage actuator 4 is provided with a sliding reset groove 13, and a limiting pin 14 is provided in the sliding reset groove 13. One end of the return spring 3 is hooked to the third-stage actuator 4 through the limiting pin 14, and the other end of the third-stage actuator 4 is hooked to the panel A5 and the panel B9 through the connecting copper pin 1. There are two sets of sliding holes 12 on the panel B9. The size of the lowermost set of sliding holes 12 is the same as that of the copper terminal 6, which limits the copper terminal 6 that is connected to it. The size of the other set of sliding holes 12 on the panel B9 and the two sets of sliding holes 12 on the panel A5 are larger than the size of the lowermost set of sliding holes 12. That is, the size of the sliding holes 12 on the panel A5 and the panel B9 increases sequentially from low to high. The above design reserves movement space to transfer the cumulative deformation of the first memory alloy drive wire 2 and the second memory alloy drive wire 8 to the third-stage actuator 4, and drive the valve core to work through the sliding buckle 15 of the third-stage actuator 4.

[0026] The three-stage actuator 4, the two-stage actuator 7, and the one-stage actuator 10 of the actuator assembly are provided with two sets of sliding holes 12, which are arranged in parallel. The three-stage actuator 4, the two-stage actuator 7, and the one-stage actuator 10 form a three-stage linear sliding pair, which slides along the connecting copper pin 1 through the sliding holes 12.

[0027] It also includes a valve body 16 and a valve core. The valve core is divided into a sliding rod 23, a sliding block 18, a sealing head 24, and a return spring 25. The sliding block 18 has sliding rods 23 at both ends. One side of the sliding rod 23 is fitted with a return spring 25, and the other side of the sliding rod 23 is fitted with a sealing head 24. The valve body 16 has a liquid guiding cavity 17 and a sliding groove 22. The liquid guiding cavity 17 is connected to the sliding groove 22 through a connecting hole 26. The liquid guiding cavity 17 is connected to the inlet 19 and the outlet 20. The side of the liquid guiding cavity 17 is provided with a valve body sealing plate 21 to form a fluid cavity. The valve body sealing plate 21 is connected to the valve body 16 by adhesive or thread to ensure that the valve body sealing plate 21 seals the side of the liquid guiding cavity 17 and ensures that the liquid enters along the inlet 19 and flows out along the outlet 20. A valve core is inserted into the sliding groove 22 and slides along the sliding groove 22. The sliding groove 22 is provided with a sliding insertion hole 27, and the sliding rod 23 of the valve core passes through the sliding insertion hole 27. The other end of the valve core, the sliding rod 23, passes through the connecting hole 26 and enters the liquid guiding cavity 17. The sliding rod 23 is threadedly connected to the sealing head 24. The return spring 25 applies force to press the sliding block 18 tightly and presses the sealing head 24 of the sliding block 18 tightly against the liquid inlet 19. The three-stage actuator plate 4 is provided with a sliding buckle 15, which is snapped together with the sliding block 18. When energized, the first memory alloy drive wire 2 and the second memory alloy drive wire 8 contract, and the three-stage linear sliding pair drives the sliding buckle 15 to move step by step. The sliding buckle 15 drives the sliding block 18 and the sealing head 24 to move away from the liquid inlet 19 and connect to the pipeline.

[0028] The sealing head 24 is frustum-shaped, and the inlet 19 and outlet 20 are equipped with tower-shaped connectors, which are connected to the pipeline.

[0029] Panel A5 has a positive terminal V+ and a negative terminal V-. Both panels A5 and B9 have printed circuit boards. The third-level actuator 4, the second-level actuator 7, and the first-level actuator 10 are made of high-nickel white copper sheet metal. Printed circuit boards (PCBs) are mounted on these high-nickel white copper sheet metal parts. The positive terminal V+ of panel A5 is connected to the fixing latch hole 11 of panel A5 via the printed circuit board. The fixing latch hole 11 of panel A5 is connected to the fixing latch hole 11 of panel B9 via a connecting copper pin 1. The fixing latch hole 11 of panel B9 is connected to the sliding hole 12 of panel B9 to form the positive terminal. The negative terminal V- of panel A5 is connected via... The printed circuit board is connected to another fixing latch hole 11 of panel A5. This other fixing latch hole 11 of panel A5 is connected to another fixing latch hole 11 of panel B9 via a connecting copper pin 1. The other fixing latch hole 11 of panel B9 is connected to another sliding hole 12 of panel B9 to form the negative electrode. The positive and negative electrodes are electrically connected via the three-stage linear sliding joint's three-stage actuator plate 4, two-stage actuator plate 7, first-stage actuator plate 10, and the first memory alloy drive wire 2 and second memory alloy drive wire 8 to form a positive and negative electrode circuit. The copper terminals 6 on the ends of the first memory alloy drive wire 2 and the second memory alloy drive wire 8 are electrically connected to the sliding hole 12. PCB circuit board soldering and wiring are conventional techniques in this field. Figure 10 , 11 This is just one example of wiring. The size and layout of the driver can be adjusted according to the actual installation environment, which will not be elaborated here.

[0030] The sliding hole 12 is provided with an electrode spring, the electrode spring being model FDX0033C2, and the electrode spring is in contact with the copper terminals 6 of the first memory alloy driving wire 2 and the second memory alloy driving wire 8.

[0031] The thickness of the hollow sandwich structure formed by panels A5 and B9 is ≤2mm; thermal grease is applied to panels A5 and B9, and the thermal grease is located inside the hollow sandwich to conduct heat out of the hollow sandwich. At the same time, the metal surface on which the thermal grease is applied has a certain degree of insulation to provide electrical conductivity; thermal grease is applied between panel A5 and valve body 16 to conduct heat along the direction of valve body 16. Since there is liquid inside valve body 16, the heat dissipation efficiency can be accelerated.

[0032] The following is a further explanation using specific implementation examples: There are multiple connecting copper pins 1, which are copper pillars with a diameter of 0.8mm and a length of 2mm. They mainly serve to connect panel A5 and panel B9. Some of the connecting copper pins 1 also serve to connect the circuits of the two boards. The first shape memory alloy drive wire 2 is a shape memory alloy drive wire with a diameter of 0.15mm~0.3mm and a length of 47mm. Its two ends are tightly pressed together with copper terminals 6. The copper terminals can slide left and right in the hollowed-out slot under the pull of the shape memory alloy drive wire, thereby driving the actuator to slide. The second shape memory alloy drive wire 8 is a shape memory alloy drive wire with a diameter of 0.15mm~0.3mm and a length of 47mm. Its two ends are tightly pressed together with copper terminals 6. The copper terminals can slide left and right in the hollowed-out slot under the pull of the shape memory alloy drive wire. The shape memory alloy (MMA) drive wire forms a current loop when energized. Due to heat generation, the MMA drive wire contracts by 3.5%. This contraction is achieved through displacement superposition; that is, two MMA drive wires are connected in series. Superimposing the displacements of the two MMA drive wires increases the effective stroke. To ensure that the heating resistance of the MMA drive wires inside the driver is the same, the wire diameter is the same for drivers of the same model. A larger wire diameter results in a greater output force, while a smaller wire diameter results in a faster response speed. For example, a 0.15mm diameter MMA drive wire can provide 3... With an output force of N and a response time of 0.5s, a 0.3mm diameter shape memory alloy drive wire can provide an output force of 12N and a response time of 0.9s. Therefore, an actuator driven by a 0.15mm diameter shape memory alloy drive wire, due to its smaller output force but faster response time, can be used in refrigerant valves with low flow and pressure and fast on / off response. An actuator driven by a 0.3mm diameter shape memory alloy drive wire, due to its larger output force but slower response time, can be used in refrigerant valves with high flow and pressure and less stringent on / off response requirements. Specific selection can be designed according to the operating conditions. When the power is cut off, no current flows through the shape memory alloy drive wire, and the wire cools down and returns to its original length. Under the action of the bias spring force, the actuator returns to its initial state. In practical applications, only a 55mm*12.5mm*2mm installation space is needed. The actuator can be fixed through the mounting holes on panel A, and then the actuator is connected to the protruding mounting holes of the actuator plate to achieve the driving purpose.

Claims

1. An ultrathin actuator for driving in minute spaces, characterized in that, It includes panel A (5), panel B (9), actuator assembly and memory alloy drive wire assembly; panel A (5) and panel B (9) are provided with fixing latch holes (11), and the fixing latch hole (11) of panel A (5) is connected to the fixing latch hole (11) of panel B (9) by connecting copper pin (1) to form a hollow sandwich structure; The actuator assembly is located in the hollow cavity of the hollow sandwich structure. The actuator assembly is connected to the shape memory alloy drive wire assembly, which is electrically connected to the power supply. The power supply drives the shape memory alloy drive wire assembly to slide by deforming it. The actuator assembly is divided into a three-stage actuator assembly (4), a two-stage actuator plate (7), and a one-stage actuator plate (10). The shape memory alloy drive wire assembly is divided into a first shape memory alloy drive wire (2) and a second shape memory alloy drive wire (8). The three-stage actuator assembly (4), the two-stage actuator plate (7), and the one-stage actuator plate (10) are connected end to end through the first shape memory alloy drive wire (2) and the second shape memory alloy drive wire (8).

2. The ultrathin actuator for driving in micro-spaces according to claim 1, characterized in that, The three-stage actuator (4), the two-stage actuator (7), and the one-stage actuator (10) of the actuator group are arranged sequentially along the height direction, with gaps between them. The first memory alloy drive wire (2) and the second memory alloy drive wire (8) are located within the gaps between the three-stage actuator (4), the two-stage actuator (7), and the one-stage actuator (10). The three-stage actuator (4), the two-stage actuator (7), and the one-stage actuator (10) are provided with sliding holes (12), and the connecting copper pin (1) passes through the sliding holes (12). The three-stage actuator (4), the two-stage actuator (7), and the one-stage actuator (10) slide along the connecting copper pin (1) through the sliding holes (12).

3. The ultrathin actuator for driving in micro-spaces according to claim 2, characterized in that, The first memory alloy driving wire (2) and the second memory alloy driving wire (8) are provided with copper terminals (6) at their ends. Panel A (5) and panel B (9) are provided with sliding holes (12). The copper terminal (6) at one end of the first memory alloy driving wire (2) or the second memory alloy driving wire (8) is located in the sliding hole (12) of panel A (5), and the copper terminal (6) at the other end of the first memory alloy driving wire (2) or the second memory alloy driving wire (8) is located in the sliding hole (12) of panel B (9). The first memory alloy driving wire (2) and the second memory alloy driving wire (8) are arranged alternately.

4. The ultrathin actuator for driving in micro-spaces according to claim 3, characterized in that, It also includes a recovery spring (3), and the three-stage actuator (4) is provided with a sliding reset groove (13). The sliding reset groove (13) is provided with a limiting pin (14). One end of the recovery spring (3) is hooked to the three-stage actuator (4) through the limiting pin (14), and the other end of the three-stage actuator (4) is hooked to panel A (5) and panel B (9) through a connecting copper pin (1).

5. The ultrathin actuator for micro-space actuation according to claim 4, characterized in that, The three-stage actuator (4), the two-stage actuator (7), and the first-stage actuator (10) of the actuator assembly are provided with two sets of sliding holes (12), which are arranged in parallel. The three-stage actuator (4), the two-stage actuator (7), and the first-stage actuator (10) form a three-stage linear sliding pair, which slides along the connecting copper pin (1) through the sliding holes (12).

6. An ultrathin actuator for driving in microspaces according to claim 1 or 5, characterized in that, It also includes a valve body (16) and a valve core. The valve core is divided into a sliding rod (23), a sliding block (18), a sealing head (24), and a return spring (25). The sliding block (18) has sliding rods (23) at both ends. One side of the sliding rod (23) is fitted with a return spring (25), and the other side of the sliding rod (23) is fitted with a sealing head (24). The valve body (16) has a liquid guiding cavity (17) and a sliding groove (22). The liquid guiding cavity (17) is connected to the sliding groove (22) through a connecting hole (26). The liquid guiding cavity (17) is connected to the inlet (19) and the outlet (20). The side of the liquid guiding cavity (17) is provided with a valve body sealing plate (21) to form a fluid cavity. The valve core is inserted into the sliding groove (22). The valve core slides along the sliding groove (22). The sliding groove (22) is provided with a sliding insertion hole (27). The sliding rod (23) of the core is inserted into the sliding insertion hole (27); the other end of the sliding rod (23) of the valve core is inserted into the liquid guiding cavity (17) through the connecting hole (26). The sliding rod (23) is threadedly connected to the plug head (24). The reset spring (25) applies force to press the sliding block (18) tightly and presses the plug head (24) of the sliding block (18) tightly against the liquid inlet (19). The three-stage actuator (4) is provided with a sliding buckle (15). The sliding buckle (15) is buckled with the sliding block (18). When energized, the first memory alloy drive wire (2) and the second memory alloy drive wire (8) contract the three-stage linear sliding pair to drive the sliding and push the sliding buckle (15) to move. The sliding buckle (15) drives the sliding block (18) and the plug head (24) to move away from the liquid inlet (19) and connect to the pipeline.

7. The ultrathin actuator for micro-space actuation according to claim 6, characterized in that, The plug head (24) is frustum-shaped, and the inlet (19) and outlet (20) are provided with tower-shaped connectors. The inlet (19) and outlet (20) are connected to the pipeline through the tower-shaped connectors.

8. The ultrathin actuator for micro-space actuation according to claim 7, characterized in that... The panel A (5) is provided with a positive terminal V+ and a negative terminal V-. The panels A (5) and B (9) are provided with printed circuit boards. The material of the third-level execution piece (4), the second-level execution board (7) and the first-level execution board (10) is high-nickel white copper sheet metal. The high-nickel white copper sheet metal is provided with printed circuit boards, which are PCB circuit boards. The positive terminal V+ of panel A (5) is connected to the fixing latch hole (11) of panel A (5) through the printed circuit board. The fixing latch hole (11) of panel A (5) is connected to the fixing latch hole (11) of panel B (9) through the connecting copper pin (1). The fixing latch hole (11) of panel B (9) is connected to the sliding hole (12) of panel B (9) to form a positive terminal. The negative terminal V- of panel A (5) is connected to the printing plate through the printed circuit board. The brush circuit board is connected to another fixed latch hole (11) of panel A (5). The other fixed latch hole (11) of panel A (5) is connected to another fixed latch hole (11) of panel B (9) through connecting copper pin (1). The other fixed latch hole (11) of panel B (9) is connected to another sliding hole (12) of panel B (9) to form the negative electrode. The positive and negative electrodes are electrically connected through the three-stage linear sliding pair, the three-stage actuator plate (4), the two-stage actuator plate (7), the one-stage actuator plate (10), the first memory alloy drive wire (2), and the second memory alloy drive wire (8) to form the positive and negative electrode circuit. The copper terminals (6) on the ends of the first memory alloy drive wire (2) and the second memory alloy drive wire (8) are electrically connected to the sliding hole (12).

9. The ultrathin actuator for micro-space actuation according to claim 8, characterized in that... The sliding hole (12) is provided with an electrode spring, the electrode spring being model FDX0033C2, and the electrode spring is in contact with the copper terminals (6) of the first memory alloy driving wire (2) and the second memory alloy driving wire (8).

10. The ultrathin actuator for driving in micro-spaces according to claim 1, characterized in that, The thickness of the hollow sandwich structure formed by panel A (5) and panel B (9) is ≤2mm; thermal grease is applied to panel A (5) and panel B (9), and the thermal grease is located in the hollow sandwich; thermal grease is applied between panel A (5) and valve body (16).

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