Steady flow valve

Abstract

The present invention discloses a flow stabilizer valve, which has a water inlet, a water outlet, a valve body and a valve core. The valve body includes a body and a receiving cavity, and the receiving cavity is arranged inside the body. An inlet channel is provided on one side surface of the body facing the receiving cavity, and the inlet channel is recessed from the side surface of the body facing the receiving cavity towards the side away from the receiving cavity; the valve core is arranged in the receiving cavity, and the valve core is a corrugated spring. The valve core has a first convex portion protruding towards the water inlet side, and is configured to be able to move towards the water outlet side under the action of water pressure; the first convex portion and the inlet channel are in the same radial direction of the flow stabilizer valve, and the inlet channel extends towards the water outlet in the axial direction of the flow stabilizer valve to exceed the end surface of the valve core facing the water outlet. The flow stabilizer valve in the present invention has a simple structure. By designing the valve core as a corrugated spring and utilizing the spring characteristics to realize the deformation and reset of the valve core, and then controlling the size of the flow channel between the valve core and the inlet channel, so as to play a role in stabilizing the flow, and the cost is low.

Description

Technical Field

[0001] The present invention relates to the field of valve bodies, and particularly to a flow stabilizing valve. Background Art

[0002] In the water circuit system of a gas water heater, a water flow stabilizing device is provided to improve problems such as the fluctuation of the hot water outlet temperature caused by the fluctuation of the water flow, thereby improving the user experience of using the gas water heater. And there are also relevant requirements in 5.2.2.4.6 of GB6932-2015 "Household Gas Instantaneous Water Heater": The water circuit system should be provided with a flow stabilizing or flow regulating device.

[0003] In life, with the continuous increase of high-rise buildings, the water pressure situation in users' homes is becoming more and more complex. In some communities, the water pressure in the water circuit system is high and the water pressure fluctuates greatly, which brings certain troubles to the use of existing gas water heaters. The existing water flow stabilizing devices have complex structures, involve many components, and are costly. It is necessary to develop a low-cost water flow stabilizing device to effectively solve the problem of large fluctuations in the hot water outlet temperature when using a gas water heater in high water pressure areas. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a flow stabilizing valve to overcome the defects of complex structure and high cost of the existing water flow stabilizing devices.

[0005] The present invention solves the above technical problem through the following technical solutions:

[0006] A flow stabilizing valve has a water inlet and a water outlet, and the flow stabilizing valve includes:

[0007] A valve body, including a body and a receiving cavity. The receiving cavity is provided in the body. The two ends of the receiving cavity in the axial direction of the flow stabilizing valve are through. On one side surface of the body facing the receiving cavity in the radial direction of the flow stabilizing valve, a water inlet channel is provided. The water inlet channel is recessed from the side surface of the body facing the receiving cavity towards the side away from the receiving cavity.

[0008] A valve core is provided in the receiving cavity. The valve core is a corrugated spring. The valve core has a first protruding portion protruding towards the water inlet side. The first protruding portion is configured to be able to move towards the water outlet side under the action of water pressure.

[0009] Wherein, the first protruding portion and the water inlet channel are in the same radial direction of the flow stabilizing valve. The water inlet channel extends in the axial direction of the flow stabilizing valve towards the water outlet to exceed the end surface of the valve core facing the water outlet.

[0010] In this solution, a flow passage for water flow is formed between one end of the valve core facing the water outlet and the water inlet passage to supply water flow to the water outlet. When the valve core is subjected to the water pressure from the water inlet, the first convex part moves towards the water outlet, and the flow passage between the valve core and the water inlet passage becomes smaller, thereby playing a role in stabilizing the flow. The flow stabilizer valve in this solution has a simple structure. By designing the valve core as a corrugated spring and utilizing the spring characteristics to realize the deformation and reset of the valve core, and then controlling the size of the flow passage between the valve core and the water inlet passage to play a role in stabilizing the flow, the cost is low.

[0011] Preferably, the body includes a first valve body part and a second valve body part connected to each other. The first valve body part is sleeved on the outer periphery of the second valve body part. The first valve body part and the second valve body part form the accommodation cavity in the radial direction of the flow stabilizer valve. The water inlet passage is arranged on one side surface of the first valve body part facing the accommodation cavity.

[0012] In this solution, the area of one side surface of the first valve body part facing the accommodation cavity is larger than the area of one side surface of the second valve body part facing the accommodation cavity. By arranging the water inlet passage on the first valve body part, the size of the water inlet passage can be increased, providing a larger flow space for the water flow.

[0013] Preferably, the valve body further includes a connecting part. The connecting part is arranged in the accommodation cavity. The connecting part is located on the side of the valve core facing the water outlet. The two ends of the connecting part in the radial direction of the flow stabilizer valve are respectively connected to the first valve body part and the second valve body part. An outlet passage is arranged on the connecting part, and the two ends of the outlet passage in the axial direction of the flow stabilizer valve are through.

[0014] Preferably, the outlet passage and the first convex part are in the same radial direction of the flow stabilizer valve.

[0015] In this solution, the above setting facilitates the outflow of water flow.

[0016] Preferably, the number of the first convex parts is multiple, and the multiple first convex parts are arranged at intervals in the circumferential direction of the flow stabilizer valve.

[0017] In this solution, the above setting enables the water flow to be dispersed more evenly, further enhancing the flow stabilizing effect of the flow stabilizer valve.

[0018] Preferably, the number of the water inlet passages is multiple, and the number of the water inlet passages is the same as the number of the first convex parts. The first convex parts and the water inlet passages are arranged in one-to-one correspondence;

[0019] And / or, when the flow stabilizer valve has a water outlet channel, the number of the water outlet channels is multiple, and the number of the water outlet channels is the same as that of the first protrusions, and the first protrusions and the water outlet channels are arranged in one-to-one correspondence.

[0020] In this solution, the above setting enables the water flow to be more evenly dispersed, further enhancing the flow stabilizing effect of the flow stabilizer valve.

[0021] Preferably, one end of the water inlet channel facing the water inlet penetrates through the body.

[0022] In this solution, the above setting enables the water flow to directly flow into the water inlet channel from the water inlet of the valve body.

[0023] Preferably, the end of the water inlet channel away from the water inlet is an arc end, and the side surface of the arc end facing the water inlet is an arc surface recessed in a direction away from the water inlet.

[0024] Preferably, a positioning portion is provided inside the body. Along the radial direction of the flow stabilizer valve, the positioning portion extends from the side surface of the body facing the accommodating cavity towards the accommodating cavity, and the side surface of the valve core facing the water outlet abuts against the positioning portion.

[0025] In this solution, the positioning portion facilitates the quick installation of the valve core and the valve body on the one hand, improving the assembly efficiency, and on the other hand, the positioning portion can also support the valve core to prevent the valve core from moving as a whole under the action of water pressure.

[0026] Preferably, the flow stabilizer valve further includes a fixing assembly, and the fixing assembly includes a second protrusion and a second recess. One of the second protrusion and the second recess is provided on the body, and the other of the second protrusion and the second recess is provided on the valve core, and the second protrusion is received in the second recess.

[0027] In this solution, the above setting is used to realize the connection between the valve core and the valve body, prevent the valve core from easily moving in the accommodating cavity, so that the first protrusion of the valve core can always be aligned with the water inlet channel, and ensure the flow stabilizing effect of the flow stabilizer valve.

[0028] Preferably, the valve core further has a first recess recessed in a direction away from the water inlet, and the second protrusion or the second recess is provided on the first recess.

[0029] In this solution, the above setting avoids the movement of the second protrusion or the second recess caused by the movement of the first protrusion of the valve core, and ensures the stability of the connection between the valve core and the valve body.

[0030] Preferably, the material of the valve core is shape memory alloy.

[0031] In this solution, according to the characteristics of the shape memory alloy, when the water temperature is high in summer, the protruding amplitude of the first protruding part of the valve core increases, thereby increasing the flow passage and the flow rate. When the water temperature is low in winter, the protruding amplitude of the first protruding part of the valve core decreases, thereby reducing the flow passage and the flow rate.

[0032] The positive and progressive effects of the present invention are as follows: A flow passage for water flow is formed between the end of the valve core facing the water outlet and the water inlet passage to supply the water flow to flow towards the water outlet. When the valve core is subjected to the water pressure from the water inlet, the first protruding part moves towards the water outlet, and the flow passage between the valve core and the water inlet passage becomes smaller, thereby playing a role in stabilizing the flow. The flow stabilizer valve in the present invention has a simple structure. By designing the valve core as a corrugated spring and utilizing the spring characteristics to realize the deformation and reset of the valve core, and further controlling the size of the flow passage between the valve core and the water inlet passage to play a role in stabilizing the flow, the cost is low. Description of the Drawings

[0033] Figure 1 It is a three-dimensional structural schematic diagram of the flow stabilizer valve in the initial state of an embodiment of the present invention.

[0034] Figure 2 It is another three-dimensional structural schematic diagram of the flow stabilizer valve in the initial state of an embodiment of the present invention.

[0035] Figure 3 It is an internal structural schematic diagram of the flow stabilizer valve in the initial state of an embodiment of the present invention.

[0036] Figure 4 It is another internal structural schematic diagram of the flow stabilizer valve in the initial state of an embodiment of the present invention.

[0037] Figure 5 It is a three-dimensional structural schematic diagram of the valve body of an embodiment of the present invention.

[0038] Figure 6 It is a three-dimensional structural schematic diagram of the valve core of an embodiment of the present invention.

[0039] Figure 7 It is a three-dimensional structural schematic diagram of the flow stabilizer valve in the flow stabilization state of an embodiment of the present invention.

[0040] Figure 8 It is an internal structural schematic diagram of the flow stabilizer valve in the flow stabilization state of an embodiment of the present invention.

[0041] Figure 9 It is an internal structural schematic diagram of the flow stabilizer valve of an embodiment of the present invention.

[0042] Description of the Reference Numerals:

[0043] Water inlet 11

[0044] Water outlet 12

[0045] Valve body 2

[0046] Main body 21

[0047] First valve body part 211

[0048] Second valve body part 212

[0049] Connecting part 213

[0050] Water outlet channel 2131

[0051] Positioning part 214

[0052] Accommodating cavity 22

[0053] Water inlet channel 23

[0054] Arc end 231

[0055] Valve core 3

[0056] First protruding part 31

[0057] First recessed part 32

[0058] Flow-through channel 4

[0059] Second protruding part 51

[0060] Second recessed part 52 Specific embodiments

[0061] The present invention will be further described below by way of examples, but the present invention is not limited to the scope of the described examples.

[0062] As Figure 1 and Figure 2 shown, the present embodiment provides a flow-stabilizing valve, which can be used in a water circuit system such as a water heater to ensure the stable flow of water in the water circuit system.

[0063] As Figures 1-4 shown, the flow-stabilizing valve in the present embodiment has a cylindrical structure. The two ports of the flow-stabilizing valve in its axial direction are respectively a water inlet 11 and a water outlet 12. Water flows into the flow-stabilizing valve from the water inlet 11 and is discharged from the water outlet 12. In other alternative embodiments, the flow-stabilizing valve can also have other shapes, such as rectangular.

[0064] As Figures 1-6 shown, the flow-stabilizing valve includes a valve body 2 and a valve core 3. The valve core 3 can move relative to the valve body 2 to achieve the flow-stabilizing function of the flow-stabilizing valve.

[0065] As Figures 1-5As shown, the valve body 2 includes a main body 21 and a receiving cavity 22. The receiving cavity 22 is provided inside the main body 21 and is used to accommodate the valve core 3. The two ends of the receiving cavity 22 in the axial direction of the flow stabilizing valve are through, so as to facilitate the water flow to flow from the water inlet 11 of the flow stabilizing valve to the water outlet 12. On one side surface of the main body 21 facing the receiving cavity 22 in the radial direction of the flow stabilizing valve, a water inlet passage 23 is provided. The water inlet passage 23 is recessed from the side surface of the main body 21 facing the receiving cavity 22 towards the side away from the receiving cavity 22, and the water inlet passage 23 is used for the water flow to flow.

[0066] Specifically, as Figure 3 and Figure 5 shown, the main body 21 includes a first valve body part 211, a second valve body part 212 and a connecting part 213. The first valve body part 211 is sleeved on the outer periphery of the second valve body part 212. The first valve body part 211 and the second valve body part 212 form the receiving cavity 22 in the radial direction of the flow stabilizing valve. The connecting part 213 is provided inside the receiving cavity 22. The connecting part 213 is located on the side of the valve core 3 facing the water outlet 12. The two ends of the connecting part 213 in the radial direction of the flow stabilizing valve are respectively connected to the first valve body part 211 and the second valve body part 212. An outlet passage 2131 is provided on the connecting part 213, and the two ends of the outlet passage 2131 in the axial direction of the flow stabilizing valve are through.

[0067] Among them, the water inlet passage 23 in this embodiment is provided on the side surface of the first valve body part 211 facing the receiving cavity 22. Since the area of the side surface of the first valve body part 211 facing the receiving cavity 22 is larger than the area of the side surface of the second valve body part 212 facing the receiving cavity 22, setting the water inlet passage 23 on the first valve body part 211 can increase the size of the water inlet passage 23 and provide a larger flow space for the water flow. In other alternative embodiments, the water inlet passage 23 can also be provided on the side surface of the second valve body part 212 facing the receiving cavity 22.

[0068] Furthermore, as Figure 1 shown, one end of the water inlet passage 23 facing the water inlet 11 penetrates through the main body 21, so that the water flow can directly flow into the water inlet passage 23 from the water inlet 11 of the valve body 2, without the water flow needing to pass through the receiving cavity 22 and then enter the water inlet passage 23.

[0069] Furthermore, as Figure 4 shown, one end of the water inlet passage 23 away from the water inlet 11 is an arc end 231. The side surface of the arc end 231 facing the water inlet 11 is an arc surface recessed towards the direction away from the water inlet 11, so as to facilitate the water flow.

[0070] As Figure 1 , Figure 3 , Figure 4 and Figure 6As shown, the valve core 3 is placed in the accommodating cavity 22. There are minute gaps between the two side walls of the valve core 3 in the radial direction of the flow-stabilizing valve and the corresponding first valve body part 211 and second valve body part 212 on the corresponding sides, to facilitate the movement of the valve core 3 relative to the valve body 2. The valve core 3 in this embodiment is a corrugated spring, having a first convex part 31 protruding towards the water inlet 11 side, and a first concave part 32 recessed towards the direction away from the water inlet 11. The first convex part 31 is arranged to be able to move towards the water outlet 12 side under the action of water pressure, and can be reset according to the elastic characteristics of the spring itself when the water pressure decreases, so as to realize the movement and reset of the valve core 3 relative to the valve body 2.

[0071] Preferably, the material of the valve core 3 in this embodiment is shape memory alloy, and the shape memory alloy material is automatically adjusted according to the water temperature, which is convenient and stable. Specifically, according to the characteristics of shape memory alloy, in summer when the water temperature is high, the protruding amplitude of the first convex part of the valve core 3 increases, thereby increasing the flow passage 4 and increasing the flow rate, which can prevent the water temperature of the water heater from overheating. In winter when the water temperature is low, the protruding amplitude of the first convex part of the valve core 3 decreases, thereby reducing the flow passage 4 and reducing the flow rate, which can prevent the water temperature of the water heater from not reaching the target temperature.

[0072] In other alternative embodiments, the valve core 3 can also be made of other common spring materials.

[0073] As Figure 3 and Figure 4 shown, the first convex part 31 and the water inlet passage 23 are in the same radial direction of the flow-stabilizing valve. The water inlet passage 23 extends in the direction of the water outlet 12 in the axial direction of the flow-stabilizing valve to exceed the end face of the valve core 3 facing the water outlet 12, so that a flow passage 4 for water flow is formed between the end of the valve core 3 facing the water outlet 12 and the water inlet passage 23, for the water flow to flow towards the water outlet 12.

[0074] Specifically, Figure 3 the arrow direction in

[0075] The steady flow valve in this embodiment has a simple structure. By designing the valve core 3 as a corrugated spring, the deformation and reset of the valve core 3 are realized by using the spring characteristics, and then the size of the flow passage 4 between the valve core 3 and the water inlet passage 23 is controlled to play a role in steady flow, with strong reliability and low cost.

[0076] The following briefly describes the working process of the steady flow valve according to the specific structure of the steady flow valve described above:

[0077] As Figure 1 shown, in the initial state of the steady flow valve, the corrugated spring does not deform. As Figure 7 and Figure 8 shown, when water flows in, as the water pressure increases, the water flow rate through the entire steady flow valve increases. When the water pressure reaches the operating pressure of the corrugated spring, the steady flow valve switches to the steady flow state. As the water pressure continues to increase, the corrugated spring will be compressed and deformed, causing the first protrusion 31 to move towards the water outlet 12 side. The flow cross-section of the water inlet passage 23 on the side of the first protrusion 31 facing the water outlet 12 becomes smaller, resulting in the reduction of the flow passage 4 between the valve core 3 and the water inlet passage 23, so that the water flow rate through the entire steady flow valve remains unchanged, playing a role in stabilizing the water flow rate.

[0078] As Figure 1 shown, the number of the first protrusions 31 is multiple, and the multiple first protrusions 31 are arranged at intervals along the circumferential direction of the steady flow valve, enabling the water flow to be more evenly dispersed and further enhancing the steady flow effect of the steady flow valve.

[0079] As Figure 1 shown, the number of the water inlet passages 23 is multiple, and the number of the water inlet passages 23 is the same as that of the first protrusions 31. The first protrusions 31 and the water inlet passages 23 are arranged in one-to-one correspondence, further enabling the water flow to be more evenly dispersed and further enhancing the steady flow effect of the steady flow valve.

[0080] As Figure 3 and Figure 4 shown, the water outlet passage 2131 and the first protrusion 31 are in the same radial direction of the steady flow valve to facilitate the outflow of water. Further, the number of the water outlet passages 2131 is multiple, and the number of the water outlet passages 2131 is the same as that of the first protrusions 31. The first protrusions 31 and the water outlet passages 2131 are arranged in one-to-one correspondence, further enabling the water flow to be more evenly dispersed and further enhancing the steady flow effect of the steady flow valve.

[0081] In other alternative embodiments, the number of the water inlet passages 23 and / or the water outlet passages 2131 can also be only one, and one water inlet passage 23 and / or one water outlet passage 2131 corresponds to multiple first protrusions 31.

[0082] In other alternative embodiments, the water outlet channel 2131 may also be staggered from the first protrusion 31.

[0083] As Figures 3-5 shown, a positioning portion 214 is provided inside the body 21. The positioning portion 214 in this embodiment is a stepped structure. Specifically, along the radial direction of the flow stabilizer valve, the positioning portion 214 extends from the side of the body 21 facing the accommodating cavity 22 towards the accommodating cavity 22, and the side surface of the valve core 3 facing the water outlet 12 abuts against the positioning portion 214. On the one hand, the positioning portion 214 facilitates the quick installation of the valve core 3 and the valve body 2, improving the assembly efficiency. On the other hand, the positioning portion 214 can also support the valve core 3, preventing the valve core 3 from moving as a whole under the action of water pressure.

[0084] As Figure 6 and Figure 9 shown, the flow stabilizer valve further includes a fixing assembly. The fixing assembly includes a second protrusion 51 and a second recess 52. In this embodiment, the second protrusion 51 is provided on the outer peripheral side of the valve core 3, and the second recess 52 is provided on the side of the first valve body portion 211 facing the accommodating groove. The second protrusion 51 is received in the second recess 52 to realize the connection between the valve core 3 and the valve body 2, prevent the valve core 3 from moving easily in the accommodating cavity 22, so that the first protrusion of the valve core 3 can always be aligned with the water inlet channel 23, ensuring the flow stabilizing effect of the flow stabilizer valve.

[0085] Furthermore, as Figure 9 shown, the second protrusion 51 is provided on the first recess 32 to avoid the movement of the second protrusion 51 or the second recess 52 caused by the movement of the first protrusion of the valve core 3, ensuring the stability of the connection between the valve core 3 and the valve body 2.

[0086] In other alternative embodiments, it may also be that the second protrusion 51 is provided on the inner peripheral side of the valve core 3, and the second recess 52 is provided on the side of the second valve body portion 212 facing the accommodating groove. Or, it may also be that the second protrusion 51 is provided on the body 21, and the second recess 52 is provided on the valve core 3.

[0087] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are all based on the orientation or positional relationship shown in the drawings of the device or component, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0088] Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that this is only an example, and the protection scope of the present invention is defined by the appended claims. Without departing from the principle and essence of the present invention, those skilled in the art can make various changes or modifications to these embodiments, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A steady flow valve, having a water inlet and a water outlet, is characterized in that, The flow stabilizer valve includes: A valve body, including a main body and a receiving cavity. The receiving cavity is provided inside the main body. Both ends of the receiving cavity in the axial direction of the flow stabilizer valve are through. On one side surface of the main body facing the receiving cavity in the radial direction of the flow stabilizer valve, a water inlet channel is provided. The water inlet channel is formed by being recessed from the side surface of the main body facing the receiving cavity towards the side away from the receiving cavity. A valve core, provided in the receiving cavity. The valve core is a corrugated spring. The valve core has a first protruding portion protruding towards the water inlet side. The first protruding portion is configured to be able to move towards the water outlet side under the action of water pressure. Wherein, the first protruding portion and the water inlet channel are in the same radial direction of the flow stabilizer valve. The water inlet channel extends towards the water outlet in the axial direction of the flow stabilizer valve to extend beyond the end face of the valve core facing the water outlet.

2. The steady flow valve according to claim 1, wherein, The main body includes a first valve body portion and a second valve body portion connected to each other. The first valve body portion is sleeved on the outer periphery of the second valve body portion. The first valve body portion and the second valve body portion form the receiving cavity in the radial direction of the flow stabilizer valve. The water inlet channel is provided on one side surface of the first valve body portion facing the receiving cavity.

3. The steady flow valve according to claim 2, characterized in that, The valve body further includes a connecting portion, provided in the receiving cavity. The connecting portion is located on the side of the valve core facing the water outlet. Both ends of the connecting portion in the radial direction of the flow stabilizer valve are respectively connected to the first valve body portion and the second valve body portion. A water outlet channel is provided on the connecting portion. Both ends of the water outlet channel in the axial direction of the flow stabilizer valve are through.

4. The steady flow valve according to claim 3, wherein The water outlet channel and the first protruding portion are in the same radial direction of the flow stabilizer valve.

5. The steady flow valve according to any one of claims 1-4, characterized in that, The number of the first protruding portions is multiple, and the multiple first protruding portions are arranged at intervals along the circumferential direction of the flow stabilizer valve.

6. The steady flow valve according to claim 5, characterized in that, The number of the water inlet channels is multiple, and the number of the water inlet channels is the same as the number of the first protruding portions. The first protruding portions and the water inlet channels are arranged in one-to-one correspondence. And / or, when the flow stabilizer valve has a water outlet channel, the number of the water outlet channels is multiple, and the number of the water outlet channels is the same as the number of the first protruding portions. The first protruding portions and the water outlet channels are arranged in one-to-one correspondence.

7. The steady flow valve according to claim 1, characterized in that, One end of the water inlet channel facing the water inlet penetrates through the main body.

8. The steady flow valve according to claim 1, characterized in that, One end of the water inlet channel away from the water inlet is an arc end. The side surface of the arc end facing the water inlet is an arc surface recessed towards the direction away from the water inlet.

9. The steady flow valve according to claim 1, characterized in that, A positioning portion is provided inside the main body. Along the radial direction of the flow stabilizer valve, the positioning portion extends from the side surface of the main body facing the receiving cavity towards the direction close to the receiving cavity. The side surface of the valve core facing the water outlet abuts against the positioning portion.

10. The steady flow valve according to claim 9, wherein, The flow stabilizer valve further includes a fixing assembly. The fixing assembly includes a second protruding portion and a second recessed portion. One of the second protruding portion and the second recessed portion is provided on the main body, and the other of the second protruding portion and the second recessed portion is provided on the valve core. The second protruding portion is received in the second recessed portion.

11. The steady flow valve according to claim 10, characterized in that, The spool further has a first recessed portion recessed in a direction away from the water inlet, and the second protrusion or the second recessed portion is provided on the first recessed portion.

12. The steady flow valve according to claim 1, wherein, The material of the spool is a shape memory alloy.

Images