Water heater drainage pipeline control valve

Abstract

The invention relates to the technical field of water heater pipeline control, in particular to a water heater drainage pipeline control valve which comprises a valve body, and a water inlet channel, a first water outlet channel and a second water outlet channel are formed in the valve body; the first valve element is rotationally arranged in the valve body; the second valve element is arranged on the inner side of the first valve element, the second valve element and the first valve element are coaxially arranged, and the second valve element is located between the water inlet channel and the first water outlet channel and between the water inlet channel and the second water outlet channel; the manual driving mechanism is connected to the first valve element; the temperature control driving mechanism is connected to the second valve element; the first valve element and the second valve element are of a coaxial nested structure. The water temperature of the water inlet channel is responded in real time through the built-in temperature control driving mechanism, and when cold water exists in the water inlet channel, the cold water is automatically guided to the second water outlet channel and can be pumped back to the water heater to be heated again; and hot water is switched to the first water outlet channel for supply, so that water and energy are remarkably saved.

Description

Technical Field

[0001] This invention relates to the field of water heater pipe control technology, specifically to a water heater drain pipe control valve. Background Technology

[0002] In residential and commercial hot water supply systems, especially gas water heaters, instant electric water heaters, or storage water heater systems with circulating pumps, there is a common problem of water and energy waste: because there is a section of cold water pipe between the hot water outlet and the water heater, users must first drain this section of cold water before hot water can flow out. This not only directly wastes precious water resources but also results in a poor user experience, requiring a long wait.

[0003] In existing technologies, some solutions to this problem employ the installation of a water recirculation system, using a pump to return cold water from the pipes to the water heater for reheating. However, the core control components of such systems typically rely on an electronic control circuit consisting of a temperature sensor, electronic controller, and solenoid valve. This type of solution has the following inherent drawbacks:

[0004] Complex structure and high cost: It requires a separate controller, power supply and wiring, which makes installation and maintenance inconvenient and the overall system cost high.

[0005] Relying on external power sources, reliability is affected by the environment: In humid environments such as bathrooms and kitchens, electronic components are at risk of short circuits and failures, resulting in insufficient long-term stability.

[0006] Rigid control logic: The system typically requires manual triggering by the user or relies on timers, failing to achieve truly precise, fully automatic control based on real-time water temperature. Especially in pure temperature control mode, the system is prone to frequent false starts when no one is using the water, causing the water heater to repeatedly heat up and heat to continuously dissipate from the pipes, resulting in inefficient consumption of electricity and gas. This not only increases users' daily energy expenses but also contradicts the current national policy of vigorously promoting energy conservation and emission reduction.

[0007] Therefore, the market urgently needs a fully automatic, fast-responding, power-free, and absolutely safe mechanical valve to intelligently identify and switch between hot water output and cold water return, fundamentally solving the problem of water waste when discharging cold water. Summary of the Invention

[0008] The purpose of this invention is to provide a control valve for the drain pipe of a water heater to solve the problems mentioned in the background art.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a control valve for a water heater drain pipe, comprising:

[0010] A valve body having an inlet channel and a first outlet channel and a second outlet channel respectively connected to the inlet channel;

[0011] The first valve core is rotatably disposed in the valve body and located at the flow path position of the first water outlet channel and the second water outlet channel, and is used to control the overall opening or closing of the first water outlet channel and the second water outlet channel.

[0012] The second valve core is disposed inside the first valve core and arranged coaxially with the first valve core. The second valve core is located between the water inlet channel and the first water outlet channel and the second water outlet channel.

[0013] A manual drive mechanism is connected to the first valve core;

[0014] A temperature control drive mechanism is connected to the second valve core;

[0015] in,

[0016] The first valve core and the second valve core have a coaxial nested structure.

[0017] The rotation of the first valve core does not cause the second valve core to rotate synchronously.

[0018] There is no transmission connection between the temperature control drive mechanism and the first valve core.

[0019] Optionally, the valve body has a T-shaped three-way structure, the water inlet channel is located at the bottom of the valve body, and the first water outlet channel and the second water outlet channel are horizontally opposite to each other on the left and right sides of the valve body; a through hole is provided through the top of the valve body, and the manual drive mechanism includes a vertically arranged connecting sleeve and an operating handle arranged at the upper end of the connecting sleeve. The connecting sleeve is fixedly connected to the first valve core, and the connecting sleeve is rotatably arranged with respect to the through hole.

[0020] Optionally, both the first valve core and the second valve core are spherical valve cores, with the second valve core embedded inside the first valve core;

[0021] The first valve core has a first water outlet hole and a second water outlet hole arranged horizontally opposite each other. When the first valve core is in the open position, the first water outlet hole and the second water outlet hole are aligned with the first water outlet channel and the second water outlet channel. When the first valve core is in the closed position, the first water outlet hole and the second water outlet hole are misaligned with the first water outlet channel and the second water outlet channel.

[0022] The second valve core has a water inlet connection hole. The axis of the water inlet connection hole is collinear with the axis of the first water outlet channel or the second water outlet channel. An O-ring seal that seals against the first valve core is fixedly installed at the water outlet end of the water inlet connection hole.

[0023] Optionally, a valve cover is fixedly connected to the top of the valve body via a connecting block. The bottom surface of the valve cover is provided with a ring-shaped retaining groove, and the upper end of the connecting sleeve is rotatably configured with respect to the retaining groove. An obstacle clearance is formed between the retaining groove and the valve body, allowing the operating handle to be turned at a certain angle. The connecting block is configured to block and limit the turning angle of the operating handle.

[0024] Optionally, the temperature control drive mechanism includes a vertically arranged drive sleeve and a shape memory alloy drive element disposed in the drive sleeve. The drive sleeve is fixedly connected to the second valve core, and the drive sleeve and the connecting sleeve are rotatable and sealed. One end of the shape memory alloy drive element is fixed, and the other end is connected to a push plate that moves linearly up and down. A transmission pin is provided on the side of the push plate, and a drive groove is provided inside the drive sleeve. The transmission pin is embedded in the drive groove.

[0025] Optionally, the second valve core has a through-hole temperature sensing chamber that communicates with the inner cavity of the drive sleeve. The valve body is fixedly mounted with a bracket at the water inlet channel. The lower end of the shape memory alloy drive element is connected and fixed to the bracket, and the upper end is connected to the push plate.

[0026] Optionally, the middle part of the second valve core is separated by the temperature sensing chamber wall to form a sealed temperature sensing chamber isolated from the water inlet channel. The sealed temperature sensing chamber is filled with thermally conductive silicone grease. The shape memory alloy driving element is disposed in the thermally conductive silicone grease, and its upper end is connected and fixed to the valve cover, and its lower end is connected to the push plate.

[0027] Optionally, the drive groove is a smoothly transitioned irregular groove, consisting of a first vertical groove, a second vertical groove, and a spiral guide groove connecting the two. The spiral angle of the spiral guide groove is 180°. When the drive pin moves between the first vertical groove and the second vertical groove, it drives the second valve core to rotate 180°.

[0028] Optionally, a prism-shaped guide post is fixedly connected to the bottom surface of the valve cover, and the push plate is slidably disposed on the guide post; multiple drainage holes are vertically provided through the push plate.

[0029] Optionally, the shape memory alloy driving element is an alloy element that undergoes austenitic and martensitic phase transformations within a predetermined temperature range.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. This invention utilizes a built-in temperature control drive mechanism to respond in real-time to the water temperature in the inlet channel. When the inlet channel contains cold water, it automatically directs it to the second outlet channel (circulation return port), allowing it to be pumped back to the water heater for reheating. Once hot water arrives, it immediately switches to the first outlet channel (hot water outlet) for supply. This fundamentally eliminates the waiting process of flushing out a large amount of cold water, significantly saving water and energy.

[0032] 2. The entire control process relies entirely on the physical phase change and mechanical transmission of the shape memory alloy, eliminating the need for external power supplies, temperature sensors, electronic controllers, or solenoid valves. This not only significantly simplifies the system structure but also fundamentally avoids the faults, short circuits, and reliability issues that are prone to occur in electronic systems in humid environments, achieving truly maintenance-free operation.

[0033] 3. The shape memory alloy drive element used has a rapid and predictable phase change response. This allows the valve to sense water temperature changes and switch almost in real time, minimizing the transition period between hot and cold water, ensuring rapid stabilization of the outlet water temperature, and greatly improving the immediacy and comfort of water use.

[0034] 4. The unique concentric dual-valve core design creatively integrates the function of manually switching the main water circuit (via the first valve core and connecting sleeve) and the function of automatic temperature-controlled diversion (via the second valve core and SMA drive) into a single valve body. The system can operate fully automatically and intelligently, while users can manually close the valve when maintenance is required or when leaving home for an extended period of time, making operation intuitive and convenient.

[0035] 5. The present invention can adopt either a connected temperature sensing cavity structure or a closed temperature sensing cavity filled with a heat-conducting medium, which can select different temperature sensing methods according to actual use requirements and improve the flexibility of structural design.

[0036] 6. Shape memory alloys have a long phase transformation fatigue life, and the mechanical transmission components have a robust structure. The entire system has no easily aging electronic components or easily leaking liquid working media, resulting in extremely high overall durability and a service life far exceeding that of electronic control systems and traditional mechanical temperature control valves. This achieves an extremely low failure rate and total cost of ownership throughout the product lifecycle. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0038] Figure 2 This is a schematic diagram of a half-section structure of Embodiment 1 of the present invention;

[0039] Figure 3 This is a schematic diagram of the drive slot in Embodiment 1 of the present invention;

[0040] Figure 4This is a schematic diagram of a half-section structure of Embodiment 2 of the present invention.

[0041] In the diagram: 1. Valve body; 101. First water outlet channel; 102. Second water outlet channel; 103. Water inlet channel; 104. Through hole; 105. Connecting block; 106. Valve cover; 1061. Bayonet; 107. Guide post; 2. First valve core; 201. First water outlet hole; 202. Second water outlet hole; 203. Connecting sleeve; 204. Operating handle; 205. Mechanical seal; 3. Second valve core; 301. Water inlet connecting hole; 302. Drive sleeve; 303. Drive groove; 3031. First vertical groove; 3032. Spiral guide groove; 3033. Second vertical groove; 304. Connecting temperature sensing chamber; 305. Temperature sensing chamber wall; 306. Sealed temperature sensing chamber; 4. Bracket; 401. Shape memory alloy drive element; 402. Push plate; 4021. Drain hole; 403. Transmission pin. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] This embodiment provides a control valve for the drain pipe of a water heater, such as... Figure 1-4 As shown, the device includes a valve body, which is a T-shaped three-way structure. The valve body 1 has an inlet channel 103, a first outlet channel 101, and a second outlet channel 102. Specifically: the inlet channel 103 is located at the bottom of the valve body; the first outlet channel 101 and the second outlet channel 102 are horizontally opposite each other on the left and right sides of the valve body. The inlet channel 103 is connected to the water outlet pipe of the water heater, the first outlet channel 101 is connected to the user's terminal, and the second outlet channel 102 is connected to the circulating return water pipe. In the water heater system: the first outlet channel 101 serves as the hot water outlet, connected to the user's terminal; the second outlet channel 102 serves as the circulating return water outlet, connected to the water inlet of the water heater via a circulating pump, thus forming a closed-loop circulation circuit.

[0044] A through hole 104 is provided at the top of the valve body 1. A valve cover 106 is fixedly connected to the top of the valve body 1 via a connecting block 105. A ring-shaped retaining groove 1061 is provided on the bottom surface of the valve cover 106. The first valve core 2 is rotatably disposed inside the valve body 1 and is located at the flow path position of the first water outlet channel 101 and the second water outlet channel 102. The first valve core 2 is a spherical valve core, and its outer spherical surface is sealed to the inner cavity of the valve body 1 by a mechanical seal 205. The first valve core 2 has a first water outlet hole 201 and a second water outlet hole 202 arranged horizontally opposite to each other. When the first valve core 2 is in the open position: the first water outlet hole 201 is aligned with the first water outlet channel 101; the second water outlet hole 202 is aligned with the second water outlet channel 102. When the first valve core 2 is in the closed position: the first water outlet 201 is misaligned with the first water outlet channel 101; the second water outlet 202 is misaligned with the second water outlet channel 102; at this time, the spherical solid part of the first valve core 2 blocks the first water outlet channel 101 and the second water outlet channel 102, thereby blocking the water flow.

[0045] The first valve core 2 is fixedly connected to the top of the connecting sleeve 203. The connecting sleeve 203 is vertically inserted into the through hole 104 and rotatably configured with the through hole 104. The upper end of the connecting sleeve 203 is fixedly connected to the operating handle 204. The upper end of the connecting sleeve 203 is rotatably configured with the bayonet 1061. The bayonet 1061 and the valve body 1 form a clearance zone for the operating handle 204 to rotate at a certain angle. The connecting block 105 is used to block and limit the rotation angle of the operating handle 204. The rotation of the first valve core 2 does not drive the second valve core 3 to rotate synchronously.

[0046] The second valve core 3 is a spherical valve core. The second valve core 3 is embedded inside the first valve core 2 and is arranged coaxially with it. The second valve core 3 is located between the inlet channel 103 and the first outlet channel 101 and the second outlet channel 102. The second valve core 3 has an inlet connecting hole 301. The axis of the inlet connecting hole 301 is collinear with the axis of either the first outlet channel 101 or the second outlet channel 102. When the inlet connecting hole 301 is collinear with the axis of a certain outlet channel, the inlet channel 103 forms a connecting path with that outlet channel. An O-ring seal that seals against the first valve core 2 is fixedly installed at the outlet end of the inlet connecting hole 301. When the second valve core 3 rotates to the corresponding position, the O-ring seal forms a sealing contact with the inner wall of the first valve core 2, thereby preventing crossflow.

[0047] The temperature control drive mechanism is connected to the second valve core 3, but there is no transmission connection between it and the first valve core 2.

[0048] The temperature control drive mechanism includes a vertically arranged drive sleeve 302 and a shape memory alloy drive element 401 disposed within the drive sleeve 302. The drive sleeve 302 is fixedly connected to the second valve core 3. The drive sleeve 302 and the connecting sleeve 203 are rotatably and sealingly connected. A sealing structure forms a sealed fit between the drive sleeve 302 and the connecting sleeve 203 to prevent water from entering the drive mechanism area. The connecting sleeve 203 and the bayonet 1061 form a sealed fit with a mechanical seal 205 to prevent water from entering the valve body 1.

[0049] The drive sleeve 302 has a drive groove 303 inside.

[0050] The drive groove 303 is a smoothly transitioned irregularly shaped groove, including a first vertical groove 3031, a second vertical groove 3033, and a spiral guide groove 3032 connecting the two. The spiral guide groove 3032 has a spiral angle of 180°. One end of the shape memory alloy drive element 401 is fixed, and the other end is connected to a push plate 402 that can move linearly up and down.

[0051] In Example 1, a connecting temperature sensing cavity 304 is provided through the middle of the second valve core 3. The connecting temperature sensing cavity 304 is interconnected with the inner cavity of the drive sleeve 302. The water temperature change in the water inlet channel 103 can directly act on the shape memory alloy drive element 401 in the connecting temperature sensing cavity 304. Specifically, a bracket 4 is fixedly installed on the valve body 1 at the water inlet channel 103. The lower end of the shape memory alloy drive element 401 is connected and fixed to the bracket 4, and the upper end is connected to the push plate 402. A prism-shaped guide post 107 is fixedly connected to the bottom surface of the valve cover 106. The push plate 402 is slidably disposed on the guide post 107. A transmission pin 403 is provided on the side of the push plate 402 and is embedded in the drive groove 303. When the shape memory alloy drive element 401 undergoes axial contraction or extension, the push plate 402 moves linearly along the guide post 107, and the transmission pin 403 moves along the drive groove 303. The transmission pin 403 moves sequentially between the first vertical groove 3031, the spiral guide groove 3032, and the second vertical groove 3033, thereby driving the second valve core 3 to complete a 180° rotation. Multiple drain holes 4021 are vertically provided through the push plate 402. The drain holes 4021 are used to connect the upper and lower spaces of the push plate 402 to prevent the formation of a closed volume that would cause damping.

[0052] The shape memory alloy drive element 401 is an alloy element that undergoes austenitic and martensitic phase transformations within a predetermined temperature range.

[0053] In Example 2, the second valve core 3 is separated from the water inlet channel 103 by a temperature-sensing cavity wall 305 in the middle, forming a sealed temperature-sensing cavity 306. The sealed temperature-sensing cavity 306 is filled with thermally conductive silicone grease, and the shape memory alloy driving element 401 is disposed within the thermally conductive silicone grease. Water temperature changes are conducted to the interior of the sealed temperature-sensing cavity 306 through the temperature-sensing cavity wall 305. The thermally conductive silicone grease is used to enhance heat conduction efficiency and improve temperature response stability. In this example, the upper end of the shape memory alloy driving element 401 is connected and fixed to the valve cover 106, and the lower end is connected to the push plate 402. A prism-shaped guide post 107 is fixedly connected to the bottom surface of the valve cover 106, and the push plate 402 is slidably disposed on the guide post 107. A transmission pin 403 is provided on the side of the push plate 402, the transmission pin 403 is embedded in the driving groove 303, and multiple drain holes 4021 are vertically penetrating on the push plate 402.

[0054] In the above embodiment 1, the temperature control drive mechanism is further expanded. A first microswitch (not shown in the figure) is fixedly installed on the bottom surface of the valve cover 106. The first microswitch is located on the movement path of the push plate 402. When the push plate 402 undergoes axial displacement under the action of the shape memory alloy drive element 401, it can press the first microswitch. The first microswitch is electrically connected to an external microcontroller through a waterproof sealed wire. The microcontroller is electrically connected to the circulation pump. A second microswitch (not shown in the figure) is embedded in the connecting block 105 on the side that contacts the operating handle 204. The second microswitch and the first microswitch are connected in series. The second microswitch is normally open, and the first microswitch is normally closed. The microcontroller is used to control the start and stop of the circulation pump according to the pressure state of the first and second microswitches. By setting the first microswitch on the bottom surface of the valve cover 106 and using the mechanical displacement of the push plate 402 as a trigger signal, the linkage control between the temperature drive structure, the second microswitch, and the circulation pump electrical control system is realized. When the pipe contains cold water, the first microswitch is in the ON state. When the operating handle 204 is opened and the second microswitch is triggered, the second microswitch is also in the ON state. At this time, the circulation pump starts, cold water flows back and is heated. After the hot water arrives and the water circuit is switched, the first microswitch is in the OFF state, and the circulation pump that draws back the cold water automatically stops running, avoiding the situation where the circulation pump runs continuously without water or under pressure. When the operating handle 204 is closed, the second microswitch is in the OFF state, and the circulation pump stops running. Therefore, the circulation pump only starts the return water function when the operating handle 204 is opened and the water outlet is cold water, minimizing heat loss and further reducing power consumption and the additional energy loss caused by repeated reheating of the water heater.

[0055] Work process

[0056] When the water temperature in the inlet channel 103 is lower than the predetermined temperature range, the shape memory alloy drive element 401 is in a martensitic state. The second valve core 3 is in the first position, so that the axis of the inlet connecting hole 301 is collinear with the channel axis of the second outlet channel 102. The water flow path is: inlet channel 103 → inlet connecting hole 301 → second outlet channel 102.

[0057] When hot water enters the inlet channel 103 and reaches the predetermined temperature range, the shape memory alloy drive element 401 undergoes an austenitic phase transformation and generates axial displacement. The push plate 402 drives the transmission pin 403 to move along the spiral guide groove 3032, causing the second valve core 3 to rotate 180°. At this time, the axis of the inlet connecting hole 301 is collinear with the channel axis of the first outlet channel 101. The water flow path is: inlet channel 103 → inlet connecting hole 301 → first outlet channel 101. Hot water is then supplied to the water user.

[0058] When the operating handle 204 is rotated to the closed position, the first valve core 2 causes the first water outlet 201 and the second water outlet 202 to be misaligned with the first water outlet channel 101 and the second water outlet channel 102, respectively. At this time, the entire flow path is blocked, and even if the second valve core 3 is rotated, a connecting path will not be formed.

[0059] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A control valve for a water heater drain pipe, characterized in that, include: The valve body (1) has an inlet channel (103) and a first outlet channel (101) and a second outlet channel (102) respectively connected to the inlet channel (103); The first valve core (2) is rotatably disposed inside the valve body (1) and located at the flow path position of the first water outlet channel (101) and the second water outlet channel (102), and is used to control the overall opening or closing of the first water outlet channel (101) and the second water outlet channel (102); The second valve core (3) is disposed inside the first valve core (2) and coaxially arranged with the first valve core (2). The second valve core (3) is located between the water inlet channel (103) and the first water outlet channel (101) and the second water outlet channel (102). A manual drive mechanism is connected to the first valve core (2); Temperature control drive mechanism, connected to the second valve core (3); in, The first valve core (2) and the second valve core (3) are coaxially nested. The rotation of the first valve core (2) does not cause the second valve core (3) to rotate synchronously. There is no transmission connection between the temperature control drive mechanism and the first valve core (2).

2. The water heater drain pipe control valve according to claim 1, characterized in that, The valve body (1) has a T-shaped three-way structure. The water inlet channel (103) is located at the bottom of the valve body (1). The first water outlet channel (101) and the second water outlet channel (102) are horizontally opposite to each other on the left and right sides of the valve body (1). The top of the valve body (1) is provided with a through hole (104). The manual drive mechanism includes a vertically arranged connecting sleeve (203) and an operating handle (204) arranged on the upper end of the connecting sleeve (203). The connecting sleeve (203) is fixedly connected to the first valve core (2), and the connecting sleeve (203) is rotatably arranged with the through hole (104).

3. The water heater drain pipe control valve according to claim 2, characterized in that, Both the first valve core (2) and the second valve core (3) are spherical valve cores, and the second valve core (3) is embedded inside the first valve core (2); The first valve core (2) is provided with a first water outlet (201) and a second water outlet (202) arranged horizontally opposite to each other. When the first valve core (2) is in the open position, the first water outlet (201) and the second water outlet (202) are aligned with the first water outlet channel (101) and the second water outlet channel (102). When the first valve core (2) is in the closed position, the first water outlet (201) and the second water outlet (202) are misaligned with the first water outlet channel (101) and the second water outlet channel (102). The second valve core (3) is provided with a water inlet communication hole (301) (104). The axis of the water inlet communication hole (301) (104) is collinear with the channel axis of the first water outlet channel (101) or the second water outlet channel (102). The water outlet end of the water inlet communication hole (301) (104) is fixedly installed with an O-ring seal that seals against the first valve core (2).

4. The water heater drain pipe control valve according to claim 2, characterized in that, The valve body (1) is fixedly connected to a valve cover (106) at the top via a connecting block (105). The bottom surface of the valve cover (106) is provided with a ring-shaped bayonet (1061), and the upper end of the connecting sleeve (203) is rotatably set with the bayonet (1061). A clearance zone is formed between the bayonet (1061) and the valve body (1) for the operating handle (204) to be turned at a certain angle. The connecting block (105) is configured to block and limit the turning angle of the operating handle (204).

5. The water heater drain pipe control valve according to claim 4, characterized in that, The temperature control drive mechanism includes a vertically arranged drive sleeve (302) and a shape memory alloy drive element (401) disposed in the drive sleeve (302). The drive sleeve (302) is fixedly connected to the second valve core (3), and the drive sleeve (302) and the connecting sleeve (203) are rotatably and sealed together. One end of the shape memory alloy drive element (401) is fixed, and the other end is connected to a push plate (402) that moves linearly up and down. A transmission pin (403) is provided on the side of the push plate (402). A drive groove (303) is provided inside the drive sleeve (302), and the transmission pin (403) is embedded in the drive groove (303).

6. The water heater drain pipe control valve according to claim 5, characterized in that, The second valve core (3) has a through-hole temperature sensing cavity (304) that communicates with the inner cavity of the drive sleeve (302). The valve body (1) is fixedly installed with a bracket (4) at the water inlet channel (103). The lower end of the shape memory alloy drive element (401) is connected and fixed to the bracket (4), and the upper end is connected to the push plate (402).

7. The water heater drain pipe control valve according to claim 5, characterized in that, The second valve core (3) is separated from the water inlet channel (103) by a temperature sensing chamber wall (305) in the middle. The temperature sensing chamber (306) is filled with thermally conductive silicone grease. The shape memory alloy driving element (401) is located in the thermally conductive silicone grease, and its upper end is connected and fixed to the valve cover (106), and its lower end is connected to the push plate (402).

8. The water heater drain pipe control valve according to claim 6 or 7, characterized in that, The drive groove (303) is a smoothly transitioned irregular groove, consisting of a first vertical groove (3031), a second vertical groove (3033), and a spiral guide groove (3032) connecting the two. The spiral guide groove (3032) has a spiral angle of 180°. When the drive pin (403) moves between the first vertical groove (3031) and the second vertical groove (3033), it drives the second valve core (3) to rotate 180°.

9. The water heater drain pipe control valve according to claim 6 or 7, characterized in that, The bottom surface of the valve cover (106) is fixedly connected to a prism-shaped guide post (107), and the push plate (402) is slidably disposed on the guide post (107); the push plate (402) is provided with multiple drain holes (4021) vertically penetrating through it.

10. The water heater drain pipe control valve according to claim 5, characterized in that, The shape memory alloy driving element (401) is an alloy element that undergoes austenitic and martensitic phase transformations within a predetermined temperature range.

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