An automatic thermostatic water mixing valve based on shape memory alloy and bimetallic strip

Abstract

The present invention discloses an automatic thermostatic water mixing valve based on shape memory alloy and bimetallic strip, and belongs to the technical field of thermostatic water mixing valve. The valve body shell is provided with a hot water access end, a cold water access end and a water outlet end in sequence from top to bottom, and a valve cover and an end cover are provided at the upper and lower ends of the valve body shell, respectively. The valve cover is provided with an upper adjusting rod with adjustable position, the upper adjusting rod is connected to the lower adjusting rod, and a movable positioning sleeve is provided at the bottom of the lower adjusting rod. The top of the valve core positioning rod is connected to the positioning sleeve, and the valve core positioning rod is fixed to the middle of the sliding valve core. The sliding valve core is movably arranged in the water inlet cavity of the valve body, and the top and bottom of the water inlet cavity are respectively provided with a hot water inlet and a cold water inlet. The beneficial effect of the present invention is: shape memory alloy and bimetallic strip are applied to the water mixing valve, so that the water mixing valve can adjust the mixing ratio of hot and cold water according to the change of water temperature, thereby effectively achieving the purpose of constant temperature water supply.

Description

Technical Field

[0001] The invention relates to an automatic thermostatic water mixing valve based on a shape memory alloy and a bimetallic strip, belonging to the technical field of thermostatic water mixing valves. Background Art

[0002] The thermostatic mixing valve is a supporting product specially developed for hot water systems, mainly used in electric water heaters, solar water heaters and geothermal heating water systems. The mechanical mixing valve mostly relies on manually adjusting the different opening degrees of the valve to adjust the water temperature. The process of adjusting the water temperature often requires repeated adjustments to obtain a suitable temperature. The adjustment process not only wastes water resources, but also affects the user experience. Especially in places where the water supply pressure is unstable, the mixing valve switch needs to be constantly adjusted due to the frequent fluctuations in water pressure, which leads to poor user experience and the risk of scalding. There are currently two main automatic temperature adjustment methods for thermostatic faucets, which use different thermostatic valve cores, namely wax thermostatic element (Wax Element) valve core and shape memory alloy (Shape Memory Alloys, abbreviated as SMA) spring valve core. The wax thermostatic element valve core has a slow reaction speed, and the shape memory alloy temperature control spring valve core can only move in one direction, quickly closing the hot water outlet. Although it can ensure that there is no scalding, external force is still required to open the hot water outlet. The other method is to use electronic components for control. Two stepper motors are used to control the opening of the hot and cold water valve cores respectively to achieve control of the mixing ratio of hot and cold water and the valve outlet flow rate, thereby achieving regulation and control of the valve outlet water temperature and flow rate. However, this system is relatively large in size and noisy, and is only suitable for large places, such as the swimming pool temperature control system of a hot spring resort, but not for home use. Summary of the invention

[0003] In order to solve the defects of the prior art, the purpose of the present invention is to provide an automatic constant temperature mixing valve based on shape memory alloy and bimetallic strip, which automatically changes the opening according to the change of water temperature, so as to achieve the purpose of constant temperature water supply.

[0004] The technical solution of the present invention is: an automatic thermostatic water mixing valve based on shape memory alloy and bimetallic strip, the valve body shell is provided with a hot water inlet end, a cold water inlet end and a water outlet end in sequence from top to bottom, the upper and lower ends of the valve body shell are provided with a valve cover and an end cover respectively, the valve cover is provided with an upper adjusting rod with adjustable position, the upper adjusting rod is connected to the lower adjusting rod, a movable positioning sleeve is provided at the bottom of the lower adjusting rod, the top of the valve core positioning rod is connected to the positioning sleeve, the valve core positioning rod is fixed to the middle of the sliding valve core, the sliding valve core is movably arranged in the water inlet cavity of the valve body, and the top and bottom of the water inlet cavity are respectively provided with Hot water inlet and cold water inlet, the moving path of the sliding valve core passes through the hot water inlet and the cold water inlet, the bottom of the sliding valve core is connected to the spring positioning rod in the mixing water chamber through a connecting block, the temperature control spring is located on the outer periphery of the spring positioning rod, the top of the temperature control spring is connected to the spring positioning rod, the bottom of the temperature control spring is fixed to the bottom of the mixing water chamber, a bimetallic strip is provided at the bottom outlet of the mixing water chamber, the middle part of the bimetallic strip is fixed to the bottom of the spring positioning rod, the outer edge of the bimetallic strip is located at the bottom of the shoulder at the water outlet, the transition chamber is located at the bottom of the bimetallic strip, and the water outlet end is located at the bottom of the transition chamber side.

[0005] The top of the positioning sleeve is connected to the adjusting spring, and the top of the adjusting spring is connected to a cushion block fixed on the top of the lower adjusting rod.

[0006] The bimetallic strip is fixed to the bottom of the spring positioning rod by means of a set screw, and washers are arranged on the upper and lower sides of the bimetallic strip.

[0007] The upper adjusting rod is threadedly connected to the valve cover.

[0008] The top of the lower regulating rod is a hexagonal structure, and the valve cover is provided with a hexagonal inner cavity matching the hexagonal structure.

[0009] The upper regulating rod and the valve cover are sealed by a sealing ring a, a sealing ring b is provided between the valve body and the valve body shell, and a sealing ring c is provided between the outer periphery of the water outlet and the valve body shell.

[0010] The temperature control spring is a shape memory alloy temperature control spring.

[0011] The beneficial effects of the present invention are: shape memory alloys and bimetallic strips are applied to a water mixing valve, so that the water mixing valve can adaptively adjust the mixing ratio of cold and hot water according to changes in water temperature, thereby effectively achieving the purpose of constant temperature water supply; the shape memory alloy can instantly close the hot water outlet when the water temperature reaches above a preset temperature, thereby preventing users from being scalded. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the structure of the present invention;

[0013] Figure 2 for Figure 1 A partial enlarged view of .

[0014] The reference numerals in the figure are as follows: 1. valve body shell, 2. hot water access end, 3. cold water access end, 4. water outlet end, 5. valve cover, 6. end cover, 7. upper adjusting rod, 8. valve body, 9. lower adjusting rod, 10. positioning sleeve, 11. adjusting spring, 12. cushion block, 13. valve core positioning rod, 14. sliding valve core, 15. hot water inlet, 16. connecting block, 17. spring positioning rod, 18. temperature control spring, 19. bimetallic strip, 20. set screw, 21. gasket, 22. shoulder, 23. cold water inlet, 24. sealing ring a, 25. sealing ring b, 26. sealing ring c, 27. water outlet. DETAILED DESCRIPTION

[0015] The following is combined with Figure 1-2 The present invention is further described:

[0016] An automatic thermostatic water mixing valve based on shape memory alloy and bimetallic strip, wherein a valve body shell 1 is provided with a hot water access end 2, a cold water access end 3 and a water outlet end 4 from top to bottom, a valve cover 5 and an end cover 6 are provided at the upper and lower ends of the valve body shell 1, respectively, an upper adjusting rod 7 which is positionally adjustable by threaded connection is provided on the valve cover 5, the upper adjusting rod 7 is connected to a lower adjusting rod 9, the top of the lower adjusting rod 9 is a hexagonal structure, and a hexagonal inner cavity which cooperates with the hexagonal structure is opened on the valve cover 5, thereby limiting the axial rotation of the lower adjusting rod 9, A movable positioning sleeve 10 is provided at the bottom of the lower adjusting rod 9, the top of the positioning sleeve 10 is connected to the adjusting spring 11, the top of the adjusting spring 11 is connected to the cushion block 12 fixed at the top of the lower adjusting rod 9, the top of the valve core positioning rod 13 is connected to the positioning sleeve 10, the valve core positioning rod 13 is fixed to the middle of the sliding valve core 14, so that the sliding valve core 14 can only move up and down on the straight line where the valve core positioning rod 13 is located, and the sliding valve core 14 is movably arranged in the water inlet cavity of the valve body 8, and the top and bottom of the water inlet cavity are respectively provided with a hot water inlet 15 and a cold water inlet 23, the moving path of the sliding valve core 14 passes through the hot water inlet 15 and the cold water inlet 23, and the size of the hot water inlet 15 and the cold water inlet 23 is changed by moving the sliding valve core 14 up and down, thereby changing the water inlet speed of the hot and cold water. By changing the water inlet speed of the hot and cold water, the water inlet amount of the hot and cold water per unit time is changed, so that the temperature of the hot and cold water after mixing tends to be constant. The bottom of the sliding valve core 14 is connected to the spring positioning rod 17 in the water mixing chamber through the connecting block 16, and the temperature control spring 18 is located on the outer periphery of the spring positioning rod 17. The spring 18 is a shape memory alloy temperature control spring. The top of the temperature control spring 18 is connected to the spring positioning rod 17. The bottom of the temperature control spring 18 is fixed to the bottom of the mixing chamber. A bimetallic strip 19 is provided at the bottom outlet of the mixing chamber. The middle of the bimetallic strip 19 is fixed to the bottom of the spring positioning rod 17 by a set screw 20. Washers 21 are provided on the upper and lower sides of the bimetallic strip 19. The outer edge of the bimetallic strip 19 is located at the bottom of the shoulder 22 at the water outlet 27. The transition chamber is located at the bottom of the bimetallic strip 19, and the water outlet end 4 is located at the bottom of the transition chamber side.

[0017] When the mixing ratio of cold water and hot water is unknown in the initial state, if the water temperature is higher than the deformation temperature of the shape memory alloy temperature control spring at the beginning, the shape memory alloy temperature control spring will deform rapidly, pushing the sliding valve core 14 to close the hot water inlet 15. The reaction time of the bimetallic strip is much longer than that of the memory alloy. Therefore, at the moment when the shape memory alloy temperature control spring pushes the sliding valve core 14, the bimetallic strip 19 has not had time to deform due to heat. After the hot water inlet 15 is closed, a large amount of cold water enters the mixing water chamber. However, since the water pressure in the cold water chamber is greater than the water pressure in the hot water chamber at this time, The hot water outlet will not open automatically. The bimetallic strip 19 is deformed due to the cold. The outer edge of the bimetallic strip 19 rests on the shoulder at the water outlet 27. The middle part of the bimetallic strip 19 moves downward, thereby pulling the spring positioning rod 17 and the sliding valve core 14 to move slowly downward. The sliding valve core 14 pulls the hot water inlet 15 to slowly open again, allowing hot water to enter again. The water temperature in the mixing water chamber gradually increases, and the tension of the bimetallic strip 19 and the tension of the shape memory alloy temperature control spring gradually reach a balance, thereby ensuring that the user will not be scalded when the water is discharged and ensuring the constant temperature characteristics of the mixed water.

[0018] The upper regulating rod 7 and the valve cover 5 are sealed by a sealing ring a24, a sealing ring b25 is provided between the valve body 8 and the valve body shell 1, and a sealing ring c26 is provided between the outer periphery of the water outlet 27 and the valve body shell 1 to prevent water leakage.

[0019] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An automatic thermostatic water mixing valve based on shape memory alloy and bimetallic strip, characterized in that: The valve body shell (1) is provided with a hot water inlet end (2), a cold water inlet end (3) and a water outlet end (4) in sequence from top to bottom. The upper and lower ends of the valve body shell (1) are provided with a valve cover (5) and an end cover (6) respectively. The valve cover (5) is provided with an upper adjustment rod (7) whose position can be adjusted. The upper adjustment rod (7) is connected to the valve cover (5) and to a lower adjustment rod (9) through a thread. The top of the lower adjustment rod (9) is a hexagonal structure. The valve cover (5) is provided with a hexagonal inner cavity matching the hexagonal structure. The bottom of the lower adjustment rod (9) is provided with a movable positioning sleeve (10). The top of the positioning sleeve (10) is connected to the regulating spring (11), the top of the regulating spring (11) is connected to a cushion block (12) fixed at the top of the lower regulating rod (9), the top of the valve core positioning rod (13) is connected to the positioning sleeve (10), the valve core positioning rod (13) is fixed to the middle of the sliding valve core (14), the sliding valve core (14) is movably arranged in the water inlet cavity of the valve body (8), the top and bottom of the water inlet cavity are respectively provided with a hot water inlet (15) and a cold water inlet (23), and the moving path of the sliding valve core (14) passes through the hot water inlet (15) and the cold water inlet (23). 23), the bottom of the sliding valve core (14) is connected to the spring positioning rod (17) in the water mixing chamber through a connecting block (16), the temperature control spring (18) is a shape memory alloy temperature control spring, and is located on the outer periphery of the spring positioning rod (17), the top of the temperature control spring (18) is connected to the spring positioning rod (17), the bottom of the temperature control spring (18) is fixed to the bottom of the water mixing chamber, and a bimetallic strip (19) is provided at the bottom outlet of the water mixing chamber, the middle of the bimetallic strip (19) is fixed to the bottom of the spring positioning rod (17) by a set screw (20), and the bimetallic strip (19) is fixed to the bottom of the spring positioning rod (17) by a set screw (20). 9) are provided with gaskets (21) on the upper and lower sides, the outer edge of the bimetallic strip (19) is located at the bottom of the shaft shoulder (22) at the water outlet (27), gaskets (21) are provided on the upper and lower sides of the metal strip (19), the transition cavity is located at the bottom of the bimetallic strip (19), and the water outlet end (4) is located at the bottom of the transition cavity side. In addition, the upper regulating rod (7) and the valve cover (5) are sealed by a sealing ring a (24), a sealing ring b (25) is provided between the valve body (8) and the valve body shell (1), and a sealing ring c (26) is provided between the outer periphery of the water outlet (27) and the valve body shell (1).

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