Solenoid valve driven by shape memory alloy

Abstract

The utility model discloses an electromagnetic valve driven by shape memory alloy. The electromagnetic valve comprises a valve body, the sealing assembly can be driven by the compression assembly to seal the valve body; the compression assembly is connected with the sealing assembly, the compression assembly comprises an SMA wire and a buffer spring, and the SMA wire drives the sealing assembly through the buffer spring. According to the shape memory alloy driving valve, the buffer spring is arranged, the compression piece compresses the sealing assembly through the buffer spring, after the diaphragm and the valve body are tightly attached, the buffer spring is compressed, the situation that the shape memory alloy driving valve exerts an overlarge load on the shape memory alloy (SMA wire) during contraction is prevented, and the durability of the SMA wire is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of solenoid valves, in particular to a solenoid valve driven by a shape memory alloy. Background Art

[0002] A shape memory alloy (SMA) is an alloy material that can completely eliminate the deformation that occurs at a lower temperature and restore its original shape before deformation after heating up, that is, an alloy with a "memory" function. The working principle of the shape memory alloy is as follows: when the temperature of the shape memory alloy is lower than the phase transition temperature, its shape is changed. When the shape memory alloy is heated, the temperature of the shape memory alloy gradually rises. When it reaches its phase transition temperature, the shape memory alloy will return to its shape before deformation. Due to its special physical properties, the shape memory alloy has been widely used in aerospace, mechanical and electronic products, biological medicine, building structures and other aspects.

[0003] See the attached Figure 4 As shown, when the shape memory alloy is applied to a solenoid valve, after the SMA wire is energized, it will contract due to its own heat generation when exceeding the phase change point. When the SMA wire contracts, the movable iron core 7 moves towards the valve body 6, and the core column 71, the diaphragm pressing part 53 and the diaphragm 52 also move simultaneously. The gap between the valve body 6 (sealing part) and the diaphragm 52 is closely attached, and the solenoid valve is in a sealed state. When the SMA wire contracts, the diaphragm 52 and the valve body 6 (sealing part) are closely attached, but they cannot contract anymore after being closely attached. Therefore, the SMA wire bears too much load, thereby reducing the durability of the SMA wire. Content of the Utility Model

[0004] To overcome the above disadvantages, the purpose of the utility model is to provide a solenoid valve driven by a shape memory alloy, by setting a buffer spring, preventing the shape memory alloy-driven valve from applying too much load to the shape memory alloy (SMA) when contracting, and improving the durability of the SMA wire.

[0005] To achieve the above purpose, the technical scheme adopted by the utility model is: a solenoid valve driven by a shape memory alloy, comprising:

[0006] A valve body;

[0007] A sealing assembly, which can seal the valve body under the drive of a compression assembly;

[0008] A compression assembly, which is connected to the sealing assembly. The compression assembly includes an SMA wire and a buffer spring, and the SMA wire drives the sealing assembly through the buffer spring.

[0009] In this application, by providing a buffer spring, the compression member compresses the sealing assembly through the buffer spring. After the diaphragm and the valve body are closely attached, the buffer spring is compressed, preventing the shape memory alloy drive valve from applying excessive load to the shape memory alloy (SMA wire) during contraction and improving the durability of the SMA wire.

[0010] Furthermore, the compression assembly further includes a compression member and a push rod. The push rod is connected to the sealing assembly, the compression member is connected to the SMA wire, one end of the buffer spring abuts against the push rod, and the other end abuts against the compression member.

[0011] Furthermore, a groove is provided on the side of the compression member close to the push rod. One end of the push rod away from the sealing assembly is located in the groove. In the natural state, there is a gap between the push rod and the bottom of the groove.

[0012] Furthermore, a first protrusion extending towards the side wall of the guiding through-hole is provided at one end of the push rod close to the sealing assembly. The first protrusion abuts against the guiding through-hole, and the buffer spring is arranged between the first protrusion and the compression member.

[0013] Furthermore, it further includes a bracket. One end of the SMA wire is connected to the bracket, and the other end is connected to the compression member. And the connection point where the SMA wire is connected to the compression member is located on the side away from the compression assembly with respect to the connection point where the SMA wire is connected to the bracket.

[0014] Furthermore, a positioning pin is provided at one end of the compression member away from the push rod. Two positioning pins are symmetrically provided on the brackets on both sides of the push rod. The two ends of the SMA wire are respectively connected to the two positioning pins on the bracket, and the middle part of the SMA wire is connected to the positioning pin on the compression member.

[0015] Furthermore, a limiting portion is provided on the side of the compression member close to the first protrusion and extends towards the direction of the first protrusion. The buffer spring is located in the cavity formed by the limiting portion and the first protrusion.

[0016] Furthermore, the sealing assembly includes a diaphragm provided close to the sealing through-hole. The diaphragm is connected to the push rod through a spring receiving disc.

[0017] Furthermore, it further includes a diaphragm pressing member. The diaphragm pressing member is an annular structure that fits against the wall of the sealing groove. The diaphragm pressing member abuts against the diaphragm. By providing the diaphragm pressing member, the diaphragm pressing member and the valve body clamp the edge position of the diaphragm to position the diaphragm.

[0018] Further, a second convex portion extending towards the spring receiving disc is provided on the diaphragm pressing member, a flange approaching the diaphragm pressing member is provided on the spring receiving disc, a return spring is arranged in a cavity formed by the second convex portion and the flange, one end of the return spring is connected to the flange, and the other end is connected to the second convex portion. When the compression assembly does not apply pressure to the sealing assembly, under the action of the return spring, the spring receiving disc moves towards the compression assembly, and the solenoid valve is reset.

[0019] The beneficial effects of the present utility model are as follows:

[0020] 1) In this application, by providing a buffer spring, the compression member compresses the push rod through the buffer spring. When the diaphragm and the valve body are in close fit, the buffer spring is compressed, preventing the shape memory alloy driven valve from applying excessive load to the shape memory alloy (SMA wire) when contracting, and improving the durability of the SMA wire.

[0021] 2) Through the setting of the limiting portion, on the one hand, the contact area between the guiding through hole and the compression member is increased, enhancing the stability of the compression member in the guiding through hole; on the other hand, the position of the buffer spring is limited to prevent the position of the buffer spring from shifting. Description of the Drawings

[0022] The drawings forming a part of this application are used to provide a further understanding of the present utility model. The schematic embodiments of the present utility model and their descriptions are used to explain the present utility model and do not constitute an improper limitation to the present utility model.

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings required for use in the description of the embodiments. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 Schematic diagram of the opening and closing state of the solenoid valve according to an embodiment of the present utility model;

[0025] Figure 2 Schematic diagram of the closing process of the solenoid valve according to an embodiment of the present utility model;

[0026] Figure 3 Schematic diagram of the closed state of the solenoid valve according to an embodiment of the present utility model;

[0027] Figure 4 Schematic diagram of a traditional solenoid valve driven by a shape memory alloy.

[0028] In the figure: 1. Outer shell; 2. Bracket; 21. Guide through hole; 3. Conducting wire; 4. Compression assembly; 41. Compression piece; 411. Groove; 412. Limiting part; 42. Push rod; 421. First convex part; 43. Buffer spring; 44. Positioning pin; 45. SMA conducting wire; 5. Sealing assembly; 51. Spring receiving disc; 511. Flange; 52. Diaphragm; 53. Diaphragm pressing piece; 531. Second convex part; 54. Return spring; 6. Valve body; 61. Sealing through hole; 7. Moving iron core; 71. Core column. Detailed implementation manners

[0029] In order to make the above objects, features and advantages of the present utility model more obvious and understandable, the following detailed description of the specific implementation manners of the present utility model will be given with reference to the accompanying drawings. A lot of specific details are set forth in the following description in order to fully understand the present utility model. However, the present utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present utility model. Therefore, the present utility model is not limited by the specific embodiments disclosed below.

[0030] See the attached Figures 1 to 3 As shown, an electromagnetic valve with a buffer mechanism in this embodiment includes an outer shell 1. A compression assembly 4 is arranged in the cavity formed by the outer shell 1. A bracket 2 is connected to the outer shell 1, and the bracket 2 is used to fix the compression assembly 4 located in the outer shell 1.

[0031] The compression assembly 4 includes a push rod 42. A guide through hole 21 is arranged on the bracket 2. One end of the push rod 42 is arranged in the guide through hole 21. The guide through hole 21 supports and guides the push rod 42. The push rod 42 can approach or move away from the sealing assembly 5 along the guide through hole 21. When the push rod 42 approaches the sealing assembly 5, the sealing assembly 5 is compressed to realize the closing of the electromagnetic valve. When the push rod 42 moves in the direction away from the sealing assembly 5, the opening of the electromagnetic valve is realized.

[0032] In some embodiments, the compression assembly 4 includes a compression piece 41. One end of the compression piece 41 is arranged in the guide through hole 21, and the guide through hole 21 can support and fix the compression piece 41. A groove 411 is arranged on the side surface of the compression piece 41 close to the push rod 42. One end of the push rod 42 away from the sealing assembly 5 is located in the groove 411. In the natural state (the state where the push rod 42 does not compress the compression assembly 4), there is a gap between the push rod 42 and the bottom of the groove 411.

[0033] In some embodiments, the compression assembly 4 includes an SMA wire 45. One end of the SMA wire 45 is connected to the bracket 2, and the other end is connected to the compression member 41. The connection point between the SMA wire 45 and the compression member 41 is located on the side away from the compression assembly 4 with respect to the connection point connected to the bracket 2. After the SMA wire 45 is energized, it will contract due to self-heating when exceeding the transformation point. When the SMA wire 45 contracts, the two connection points approach each other. Since the bracket 2 is fixed, the compression member 41 slides along the guiding through-hole 21 towards the sealing assembly 5, and during the sliding process, the push rod 42 is pushed to compress the sealing assembly 5.

[0034] In some embodiments, a positioning pin 44 is provided at one end of the compression member 41 away from the push rod 42. Two positioning pins 44 are symmetrically provided on the bracket 2 on both sides of the push rod 42. The two ends of the SMA wire 45 are respectively connected to the two positioning pins 44 located on the bracket 2, and the middle part of the SMA wire 45 is connected to the positioning pin 44 located on the compression member 41. When the SMA wire 45 contracts, it drives the push rod 42 to compress the sealing assembly 5. It is also possible to provide a positioning pin 44 on the bracket 2. The positioning pin 44 located on the bracket 2 and the positioning pin 44 located on the compression member 41 are respectively connected to the two ends of the SMA wire 45. When the SMA wire 45 contracts, the compression member 41 can move towards the sealing assembly 5.

[0035] In some embodiments, a first protrusion 421 extending towards the side wall of the guiding through-hole 21 is provided at one end of the push rod 42 close to the sealing assembly 5. The first protrusion 421 abuts against the guiding through-hole 21. A buffer spring 43 is provided between the first protrusion 421 and the compression member 41. One end of the buffer spring 43 abuts against the first protrusion 421, and the other end abuts against the compression member 41. The compression member 41 compresses the first protrusion 421 through the buffer spring 43, thereby driving the push rod 42 to move towards the sealing assembly 5. The buffer spring 43 can be sleeved on the push rod 42, or a plurality of buffer springs 43 can be provided and circumferentially distributed around the push rod 42.

[0036] In the existing solenoid valve, after the SMA wire 45 is energized, it will contract due to self-heating when exceeding the transformation point. When the SMA wire 45 contracts, the diaphragm 52 and the valve body 6 (sealing part) are closely attached, but they cannot contract anymore after being closely attached. Therefore, the SMA wire 45 bears too much load, thereby reducing the durability of the SMA wire 45. In this application, by providing the buffer spring 43, the compression member 41 compresses the push rod 42 through the buffer spring 43. When the diaphragm 52 and the valve body 6 (sealing part) are closely attached, the buffer spring 43 is compressed, preventing the shape memory alloy (SMA) drive valve from applying too much load to the shape memory alloy (SMA wire 45) during contraction, and improving the durability of the SMA wire 45.

[0037] In some embodiments, a limiting portion 412 is provided on a side of the compression member 41 close to the first convex portion 421 and extends in the direction of the first convex portion 421. One side of the limiting portion 412 abuts against the side wall of the guiding through hole 21. On the one hand, the contact area between the guiding through hole 21 and the compression member 41 is increased, improving the stability of the compression member 41 in the guiding through hole 21; on the other hand, the position of the buffer spring 43 is limited to prevent the position of the buffer spring 43 from shifting.

[0038] In some embodiments, it further includes a sealing assembly 5 and a valve body 6. A sealing groove is provided on a side of the valve body 6 close to the compression assembly 4. The sealing assembly 5 is arranged in the sealing groove. The sealing groove is connected to a sealing through hole 61 provided on the valve body 6, and the sealing through hole 61 communicates with the outside of the solenoid valve.

[0039] In some embodiments, the sealing assembly 5 includes a diaphragm 52 disposed close to the sealing through hole 61. The diaphragm 52 is connected to a spring receiving disc 50 and a push rod 42. When the push rod 42 moves towards the diaphragm 52, the diaphragm 52 is squeezed, causing the diaphragm 52 to fit against the valve body 6, thereby closing the solenoid valve.

[0040] In some embodiments, it further includes a diaphragm pressing member 53. The diaphragm pressing member 53 is an annular structure arranged to fit against the wall of the sealing groove. The diaphragm pressing member 53 abuts against the diaphragm 52. Through the arrangement of the diaphragm pressing member 53, the diaphragm pressing member 53 and the valve body clamp the edge position of the diaphragm 52 to position the diaphragm 52.

[0041] In some embodiments, a second convex portion 531 extending towards the spring receiving disc 51 is provided on the diaphragm pressing member 53. A flange 511 approaching the diaphragm pressing member 53 is provided on the spring receiving disc 51. A return spring 54 is arranged in the cavity formed by the second convex portion 531 and the flange 511, that is, one end of the return spring 54 is connected to the flange 511 and the other end is connected to the second convex portion 531. When the compression assembly 4 does not apply pressure to the sealing assembly 5, under the action of the return spring 54, the spring receiving disc 51 moves towards the compression assembly 4, and the solenoid valve is reset.

[0042] Working process:

[0043] See the attached Figure 1 As shown, in the natural state, there is a gap between the diaphragm 52 and the valve body 6, and the valve body 6 is in an open and closed state.

[0044] See the attached Figure 2 As shown, after the SMA wire 45 is energized, it will contract when it exceeds the transformation point due to self-heating. When the SMA wire 45 contracts, the compression member 41 drives the push rod to compress the sealing assembly 5 by compressing the buffer spring 43, causing the diaphragm 52 to fit tightly against the valve body 6.

[0045] See the attachedFigure 3 As shown, after the diaphragm 52 and the valve body 6 are closely fitted, they cannot shrink any further. The push rod 42 can no longer be driven in the direction of the sealing assembly 5. The SMA wire 45 continues to shrink, and the buffer spring 43 is elastically deformed under extrusion, preventing the shape memory alloy drive valve from applying excessive load to the shape memory alloy (SMA wire 45) during contraction and improving the durability of the SMA wire 45.

[0046] The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it. It should not be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A shape memory alloy driven solenoid valve, characterized in that: include: Valve body (6); A sealing assembly (5), wherein the sealing assembly (5) is capable of sealing the valve body (6) under the drive of the compression assembly (4); A compression assembly (4), the compression assembly (4) being connected to the sealing assembly (5), the compression assembly (4) comprising an SMA wire (45) and a buffer spring (43), the SMA wire (45) driving the sealing assembly (5) via the buffer spring (43).

2. The shape memory alloy driven solenoid valve according to claim 1, characterized in that: The compression assembly (4) further comprises a compression member (41) and a push rod (42), wherein the push rod (42) is connected to the sealing assembly (5), the compression member (41) is connected to the SMA wire (45), and one end of the buffer spring (43) abuts against the push rod (42) and the other end abuts against the compression member (41).

3. The shape memory alloy driven solenoid valve according to claim 2, characterized in that: A groove (411) is provided on the side of the compression member (41) close to the push rod (42); an end of the push rod (42) away from the sealing assembly (5) is located in the groove (411); in a natural state, a gap is left between the push rod (42) and the bottom of the groove (411).

4. The shape memory alloy driven solenoid valve according to claim 2, characterized in that: A first protrusion (421) extending in the direction of the side wall of the guide through hole (21) is provided at one end of the push rod (42) close to the sealing assembly (5); the first protrusion (421) abuts against the guide through hole (21); and the buffer spring (43) is provided between the first protrusion (421) and the compression member (41).

5. The shape memory alloy driven solenoid valve according to claim 2, characterized in that: It also comprises a bracket (2), one end of the SMA wire (45) is connected to the bracket (2), and the other end is connected to the compression member (41), and the connection point between the SMA wire (45) and the compression member (41) is located on a side of the connection point between the SMA wire (45) and the bracket (2) away from the compression assembly (4).

6. The shape memory alloy driven solenoid valve according to claim 5, characterized in that: A positioning pin (44) is provided at one end of the compression member (41) away from the push rod (42), two positioning pins (44) are symmetrically provided on the brackets (2) on both sides of the push rod (42), two ends of the SMA wire (45) are respectively connected to the two positioning pins (44) located on the brackets (2), and the middle part of the SMA wire (45) is connected to the positioning pin (44) located on the compression member (41).

7. The shape memory alloy driven solenoid valve according to claim 4, characterized in that: A limiting portion (412) is provided on a side surface of the compression member (41) close to the first protruding portion (421) and extends in the direction of the first protruding portion (421), and the buffer spring (43) is located in a cavity formed by the limiting portion (412) and the first protruding portion (421).

8. The shape memory alloy driven solenoid valve according to claim 1, characterized in that: The sealing assembly (5) comprises a diaphragm (52) arranged near the sealing through hole (61), and the diaphragm (52) is connected to the push rod (42) via a spring receiving disk (51).

9. The shape memory alloy driven solenoid valve according to claim 8, characterized in that: It also includes a diaphragm pressing piece (53), which is an annular structure arranged to fit the groove wall of the sealing groove, and the diaphragm pressing piece (53) is in abutment with the diaphragm (52).

10. The shape memory alloy driven solenoid valve according to claim 9, characterized in that: The diaphragm pressing piece (53) is provided with a second protrusion (531) extending in the direction of the spring receiving disk (51), and the spring receiving disk (51) is provided with a flange (511) close to the diaphragm pressing piece (53). The return spring (54) is arranged in a cavity formed by the second protrusion (531) and the flange (511), and one end of the return spring (54) is connected to the flange (511), and the other end is connected to the second protrusion (531).

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