An anti-freezing valve and a gas water heater using the anti-freezing valve

Abstract

The present invention relates to an anti-freezing valve and a gas water heater applying the anti-freezing valve. The anti-freezing valve includes a valve body having an accommodation cavity therein. An inlet, an outlet and a drain port, all communicating with the accommodation cavity, are formed in the valve body; a valve ball rotatably disposed in the accommodation cavity and capable of rotating to a first position or a second position. The valve ball has a through water passage. In a state where the valve ball is in the first position, two ends of the water passage respectively correspond to fluid communication with the inlet and the outlet. In a state where the valve ball is in the second position, two ends of the water passage respectively correspond to fluid communication with the outlet and the drain port; a valve rod, one end of the valve rod passes through the valve body and is connected to the valve ball, and the other end is located outside the valve body as a driving end. The arrangement of the valve rod enables the anti-freezing valve of the present invention to have a low dependence on electrical components and can be manually operated.

Description

Technical Field

[0001] The present invention belongs to the technical field of water heaters, and particularly relates to an anti-freezing valve and a gas water heater applying the anti-freezing valve. Background Art

[0002] The gas water heater is communicated with the outdoor environment through an exhaust pipe. In cold winter, when the outdoor temperature is below zero degree Celsius, cold air is likely to enter the interior of the water heater along the exhaust pipe, causing the weak parts of the waterway pipeline of the water heater to freeze and crack. Therefore, most gas water heaters are equipped with an electric heating anti-freezing device, which plays a certain anti-freezing function. The electric heating anti-freezing device must be in the powered-on state of the water heater to start working normally. Some users have the habit of unplugging the power plug after using the water heater, or there is a power outage at home, or the newly decorated house is not used for a long time and the power is cut off. All the above situations may cause the electric heating device to fail to start, resulting in the freezing and cracking of the water heater pipeline. The waterway of the water heater is usually a normally open valve at the water inlet end and a normally closed valve at the water outlet end. If the user fails to close the water inlet valve in time, the whole machine will leak water, causing property losses and safety problems such as the floor being flooded and electrical leakage.

[0003] To solve the above problems, the "valve ball and anti-freezing valve having the same" disclosed in the Chinese utility model patent with the patent number CN201220167240.7 (publication number CN202708175U) is provided. The valve ball includes a body, a first channel, and a second channel. The first channel is arranged on the body, the second channel is arranged on the body, and the first channel and the second channel are not communicated with each other. The anti-freezing valve includes a valve body, the aforementioned valve ball, and a valve rod for driving the valve ball to rotate. The valve ball is arranged in the valve body. The valve body is provided with a water inlet, a water outlet, and a drain port. The first channel is correspondingly arranged with the water outlet and the water inlet, and the second channel is correspondingly arranged with the drain port and the water outlet. In the water inlet state, the first channel makes the water inlet and the water outlet communicate with each other, and the drain port is in a closed state. In the drainage state, the second channel makes the drain port and the water outlet communicate with each other, so that the accumulated water retained in the water tank of the gas water heater connected to the anti-freezing valve can be completely discharged.

[0004] The anti-freezing valve has the following defects: 1. There is no limit structure for limiting the rotation angle of the valve rod. In this way, if the valve rod rotates excessively or fails to rotate in place, it is easy to cause the first channel not to communicate with the water inlet and the water outlet, or the second channel not to correspond to the drain port and the water outlet; 2. The valve rod is used less frequently and is only used when drainage is required. When the valve rod is not used for a long time, the internal lubricating oil will condense, making it difficult for the valve rod to rotate; 3. Two non-communicating first channels and second channels need to be opened on the valve ball. That is, two flow channels are required to realize the switching from the communication between the water inlet and the water outlet to the communication between the drain port and the water outlet. One flow channel communicates with the water inlet and the water outlet, and the other flow channel communicates with the drain port and the water outlet. This is relatively complex and not easy to process.

[0005] For another example, the "Antifreeze Valve for Solar Water Heater Pipeline" disclosed in the Chinese utility model patent with the patent number CN200720023750.6 (publication number CN201093097Y) is composed of an electronic actuator, a valve core, and a valve body. The valve core is a ball valve, which is a two-position three-way valve. There is a right-angle channel in the valve core, and the on-off of the water path is controlled by the electronic actuator. There is only one channel provided in the valve core of this antifreeze valve, which is relatively simple. However, the rotation of the valve core is controlled by the electronic actuator. In the case of power failure, the valve core cannot be rotated, and the water in the pipeline cannot be drained, ultimately resulting in the pipeline being cracked. Summary of the Invention

[0006] The first technical problem to be solved by the present invention is to provide an antifreeze valve in view of the current situation of the prior art, in which the rotation of the valve ball does not depend on an electronic control element.

[0007] The second technical problem to be solved by the present invention is to provide an antifreeze valve in view of the current situation of the prior art, which can prevent the valve stem that drives the rotation of the valve ball from being difficult to rotate after long-term non-use.

[0008] The third technical problem to be solved by the present invention is to provide a water heater applying the above-mentioned antifreeze valve in view of the current situation of the prior art, in which the rotation of the valve ball does not depend on an electronic control element.

[0009] The technical solution adopted by the present invention to solve the above first technical problem is as follows: An antifreeze valve includes

[0010] a valve body having an accommodation cavity therein, and an inlet, an outlet, and a drain port are provided on the valve body and are all in communication with the accommodation cavity;

[0011] a valve ball rotatably disposed in the above-mentioned accommodation cavity and capable of rotating to a first position or a second position. The valve ball has a through water channel. In the state where the valve ball is in the first position, the two ends of the water channel respectively correspond to fluid communication with the inlet and the outlet. In the state where the valve ball is in the second position, the two ends of the water channel respectively correspond to fluid communication with the outlet and the drain port;

[0012] characterized in that it further includes

[0013] a valve stem, one end of the valve stem passes through the valve body and is connected to the valve ball, and the other end is located outside the valve body as a driving end.

[0014] To facilitate the waterway switching, the water passage includes a first passage and a second passage that both pass through the center of the valve ball and are perpendicular to each other. One end of each of the first passage and the second passage penetrates the valve ball. The centerlines of the water inlet ends of the water outlet and the drain outlet are perpendicular to each other, and the centerline of the water inlet end of the water outlet and the centerline of the water outlet end of the water inlet are perpendicular to each other. This structural form of the valve body and the valve ball enables the user to achieve waterway switching by simply rotating 90 degrees clockwise or counterclockwise, avoiding the situation where the internal waterway of the valve ball is complex and the user is prone to not rotating it in place.

[0015] To facilitate the user to rotate the valve stem, a knob for facilitating the rotation of the valve stem is provided at the driving end of the valve stem, and a limiting structure for restricting the rotation angle of the valve stem is provided between the knob and the valve body. The setting of the limiting structure further prevents the situation where the user fails to rotate the valve ball in place and the waterway switching fails.

[0016] The limiting structure can have various structural forms. Preferably, the valve body has a valve stem seat at the position corresponding to the valve stem for the valve stem to pass through and rotate relatively. Axially extending first limiting ribs and second limiting ribs are circumferentially spaced on the peripheral wall of the valve stem seat. A resisting block that can alternatively abut against the two is provided on the knob at the position corresponding to the space between the first limiting rib and the second limiting rib. The first limiting rib, the second limiting rib, and the resisting block together constitute the limiting structure.

[0017] To further facilitate the user to rotate the valve stem in place to achieve effective waterway switching, an identification plate for indicating the rotation position of the knob is provided between the knob and the valve body. The identification plate is connected to the valve body and has through holes for the valve stem seat, the first limiting rib, and the second limiting rib to pass through. An identification structure for indicating the rotation position of the knob is provided on the identification plate. In this way, the user can rotate the knob to the position corresponding to the identification structure according to the identification structure on the identification plate.

[0018] To ensure the sealing between the valve ball and the valve body, a first sealing ring that is adjacent to the water outlet end of the water inlet and is in sealing contact with the valve ball and a second sealing ring that is adjacent to the water inlet end of the drain outlet and is in sealing contact with the valve ball are provided in the accommodating cavity of the valve body. The first sealing ring can prevent water from leaking into the accommodating cavity from the water inlet and then flowing out from the water outlet when the water outlet and the drain outlet are in fluid communication; the second sealing ring ensures that water does not leak out from the drain outlet when the water outlet and the water inlet are in fluid communication.

[0019] The technical solution adopted by the present invention to solve the above second technical problem is: the anti-freezing valve further includes a driving assembly that can push the valve stem to rotate a small angle. A perforation for the valve stem to pass through is provided on the valve body, and a accommodating groove communicated with the perforation is provided outside the perforation. The driving assembly is arranged in the accommodating groove and can at least partially extend out of the accommodating groove to push the valve stem to rotate.

[0020] The driving component can have various structural forms. Preferably, the driving component is a temperature-sensing driving device, including a heating coil, paraffin wax, and a push rod. The paraffin wax and the push rod are arranged in sequence along the direction close to the valve stem. The heating coil is arranged on the outer peripheral wall of the paraffin wax. A convex block is protruded on the outer wall of the valve stem, and the convex block is located on the moving path of the push rod towards the valve stem. When the user uses the water heater, the heating coil works, and the paraffin wax undergoes a phase change and expands, thereby pushing the push rod towards the valve stem. During the movement of the push rod, it will push the convex block on the valve stem, so that the valve stem can achieve a micro-angle rotation, and then the valve stem can be easily rotated. When the user does not use the water heater, when the water heater is in the standby state or the shutdown state, the heating coil does not work, the paraffin wax returns to the solid state, and the reverse rotation of the valve stem can make the convex block push the push rod back to the initial position.

[0021] In order to keep the paraffin wax and the push rod in contact all the time, the driving component further includes a spring arranged in the accommodating groove. The two ends of the spring respectively abut against the inner wall of the accommodating groove and the paraffin wax. The spring makes the paraffin wax and the push rod always keep in contact. This not only facilitates the paraffin wax to push the push rod towards the convex block, but also can prevent the hard interference between the convex block and the paraffin wax. Because if the spring is not set, when the paraffin wax returns to the solid state, there will be a gap between the paraffin wax and the push rod. At this time, when the convex block pushes the push rod to reset, the convex block will hit the paraffin wax and cause component damage, while setting the spring can solve this problem.

[0022] The technical solution adopted by the present invention to solve the above-mentioned third technical problem is: a gas water heater applying the above-mentioned anti-freezing valve, which is characterized in that: it further includes a water heater body, and the water outlet of the valve body is in fluid communication with the water inlet end of the water heater body.

[0023] In the present invention, the so-called "fluid communication" refers to the spatial position relationship between two components or parts (hereinafter uniformly referred to as the first part and the second part respectively), that is, the fluid (gas, liquid or a mixture of both) can flow from the first part along the flow path and / or be transported to the second part. It can be that the first part and the second part are directly connected, or the first part and the second part are indirectly connected through at least one third party. The third party can be a fluid channel such as a pipe, a channel, a conduit, a flow guide, a hole, a groove, etc., or a chamber allowing the fluid to flow through or a combination of the above.

[0024] Advantages of the present invention compared with the prior art: 1. The present invention is provided with a valve stem, which drives the valve ball to rotate, thus avoiding the situation that when there is no power, the valve ball cannot rotate to switch the water path and cause water drainage failure. If the anti-freezing valve cannot drain water, it will cause the water in the pipeline to freeze and crack the pipeline, resulting in water leakage. The setting of the valve stem makes the anti-freezing valve of the present invention less dependent on electrical components and can be manually operated; 2. The through water passage is arranged inside the ball valve of the present invention, and the internal water path structure is simple. On the one hand, it is convenient for processing, and on the other hand, it is also convenient for water path switching. Otherwise, if the internal water path is complex, it will increase the difficulty for users to switch the water path, and it is also easy to cause the situation that the valve ball does not rotate in place and the water path switching fails; 3. The present invention is provided with a driving component. When the valve stem has not been used for a long time, the driving component can partially extend out of the accommodating groove to push the valve stem to rotate a small angle, thus relieving the dilemma that the valve stem is difficult to rotate and facilitating the user to rotate the valve stem to switch the water path. Brief Description of the Drawings

[0025] Figure 1 Structural schematic diagram of the anti-freezing valve according to Embodiment 1 of the present invention;

[0026] Figure 2 is Figure 1 structural schematic diagram in another direction;

[0027] Figure 3 is Figure 1 cross-sectional view of (the valve ball is in the first position);

[0028] Figure 4 is Figure 1 cross-sectional view of (the valve ball is in the second position);

[0029] Figure 5 is Figure 1 another cross-sectional view in another direction;

[0030] Figure 6 is Figure 1 exploded schematic diagram;

[0031] Figure 7 is Figure 1 structural schematic diagram of the valve ball in;

[0032] Figure 8 is Figure 1 structural schematic diagram of the knob in;

[0033] Figure 9 is Figure 1 structural schematic diagram of the anti-freezing valve applied to a gas water heater in;

[0034] Figure 10 Cross-sectional view of the anti-freezing valve according to Embodiment 2 of the present invention;

[0035] Figure 11For Figure 10 A cross-sectional view of the drive assembly in Specific embodiments

[0036] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

[0037] Embodiment 1

[0038] As Figures 1 - 9 shown, the gas water heater of the present preferred embodiment includes a water heater body 8 and an antifreeze valve A, wherein the antifreeze valve A includes a valve body 1, a valve ball 2, a valve stem 3 and a knob 4.

[0039] The valve body 1 has a receiving cavity 11 therein, and the valve body 1 is provided with a water inlet 12, a water outlet 13 and a drain port 14 that are all in communication with the receiving cavity 11. The water outlet 13 of the valve body 1 is in fluid communication with the water inlet end of the water heater body 8.

[0040] The valve ball 2 is rotatably disposed in the above-mentioned receiving cavity 11 and can be rotated to a first position or a second position. A through water passage 21 is provided in the valve ball 2, that is, both ends of the water passage 21 penetrate the outer wall of the valve ball 2. As Figure 3 shown, in the state where the valve ball 2 is in the first position, both ends of the water passage 21 respectively correspond to and are in fluid communication with the water inlet 12 and the water outlet 13. As Figure 4 shown, in the state where the valve ball 2 is in the second position, both ends of the water passage 21 respectively correspond to and are in fluid communication with the water outlet 13 and the drain port 14.

[0041] As Figure 3 , 7 shown, in this embodiment, the water passage 21 includes a first passage 211 and a second passage 212 that both pass through the center of the valve ball 2 and are perpendicular to each other. One end of both the first passage 211 and the second passage 212 penetrates the valve ball 2. The end of the first passage 211 that penetrates the valve ball 2 and the end of the second passage 212 that penetrates the valve ball 2 are the two ends of the water passage 21. The center line of the water inlet end of the water outlet 13 and the center line of the water inlet end of the drain port 14 are perpendicular to each other, and the center line of the water inlet end of the water outlet 13 and the center line of the water outlet end of the water inlet 12 are perpendicular to each other. In this way, the valve ball 2 can be rotated 90 degrees clockwise or counterclockwise to achieve the switching between the first position and the second position, so as to achieve the switching of the water path.

[0042] As can be seen from the above, only one water passage 21 (formed by the first passage 211 and the second passage 212 together) is provided in the valve ball 2 of this embodiment, which is convenient for processing and manufacturing, and the water path is simple, which is convenient for users to switch the water path.

[0043] One end of the valve stem 3 passes through the valve body 1 and is connected to the valve ball 2. A through hole 17 for the valve stem 3 to pass through is provided on the valve body 1, and a first slot 22 for one end of the valve stem 3 to be inserted therein is provided on the valve ball 2. The other end of the valve stem 3 is located outside the valve body 1 as a driving end, and a knob 4 for facilitating the rotation of the valve stem 3 is provided on the driving end of the valve stem 3. A second slot 42 for the driving end of the valve stem 3 to be inserted therein is provided on the knob 4. The cross-section of the driving end of the valve stem 3 is D-shaped, and the cross-section of the second slot 42 is D-shaped and adapted to the driving end of the valve stem 3, so as to prevent the valve stem 3 from rotating relative to the knob 4.

[0044] As Figure 6 , 8 shown, a limiting structure for limiting the rotation angle of the valve stem 3 is provided between the knob 4 and the valve body 1. The setting of the limiting structure can prevent the situation that the user fails to rotate in place and the water path switching fails. In this embodiment, the valve body 1 has a valve stem seat 19 for the valve stem 3 to pass through at a position corresponding to the valve stem 3, and the valve stem 3 can rotate relative to the valve stem seat 19. The through hole 17 is partially opened on the valve stem seat 19. Axially extending first limiting ribs 15 and second limiting ribs 16 are provided on the peripheral wall of the valve stem seat 19 at circumferential intervals. On the knob 4, a blocking block 41 that can selectively abut against the two (the two refer to the first limiting rib 15 and the second limiting rib 16) is provided at a position corresponding to the position between the first limiting rib 15 and the second limiting rib 16. The first limiting rib 15, the second limiting rib 16 and the blocking block 41 together constitute the aforementioned limiting structure.

[0045] The rotation range of the blocking block 41 is limited between the first limiting rib 15 and the second limiting rib 16. When the blocking block 41 abuts against the first limiting rib 15, the valve ball 2 is in the first position; when the blocking block 41 abuts against the second limiting rib 16, the valve ball 2 is in the second position.

[0046] Of course, the limiting structure can also be provided between the valve stem 3 and the valve body 1. In this case, the blocking block 41 needs to be provided on the valve stem 3, and the first limiting rib 15 and the second limiting rib 16 are still provided on the valve body 1.

[0047] As Figure 2 , 6 shown, a marking plate 5 for prompting the rotation position of the knob 4 is provided between the knob 4 and the valve body 1. The marking plate 5 is connected to the valve body 1, and a special-shaped through hole 51 for the valve stem seat 19, the first limiting rib 15 and the second limiting rib 16 to pass through is provided on the marking plate 5. A marking structure 52 for indicating the rotation position of the knob 4 is provided on the marking plate 5. In this way, the user can rotate the knob 4 to the corresponding position on the marking plate 5 according to the marking structure 52 on the marking plate 5. In this embodiment, as Figure 2 shown, the marking structure 52 is the words "Power on and work" and "Anti-freezing drainage". Of course, it can also be other structures, such as scales, etc.

[0048] As shown in Figure 3 and 4 As shown, in the accommodation cavity 11 of the valve body 1, there are a first sealing ring 61 in sealing contact with the valve ball 2 adjacent to the water outlet end of the water inlet 12 and a second sealing ring 62 in sealing contact with the valve ball 2 adjacent to the water inlet end of the drain port 14.

[0049] The first sealing ring 61 is annular, and the wall surface thereof facing the valve ball 2 is in arc transition connection with the inner hole of the first sealing ring 61. In this way, the first sealing ring 61 can be well matched with the valve ball 2, and it can prevent water from leaking into the accommodation cavity 11 and flowing out from the water outlet 13 to cause water leakage when the water outlet 13 and the drain port 14 are in fluid communication.

[0050] The second sealing ring 62 is provided with a stepped hole with a gradually increasing aperture in the direction towards the valve ball 2, and each hole of the stepped hole is in arc transition connection with the corresponding wall surface of the second sealing ring 62 facing the valve ball 2. In this way, the second sealing ring 62 can be well matched with the valve ball 2, so that when the water outlet 13 and the water inlet 12 are in fluid communication, water will not leak out from the drain port 14.

[0051] As shown in Figure 1 and 2 In this embodiment, the valve body 1 includes a hollow pipe body 1a and a valve cover 1b threadedly connected to the pipe body. The water inlet 12 and the water outlet 13 are provided on the pipe body 1a, and the drain port 14 is provided on the valve cover 1b, which facilitates the disassembly of the valve cover 1b and the subsequent installation of a drain pipe at the drain port 14.

[0052] Embodiment 2

[0053] The difference between Embodiment 2 and Embodiment 1 is that: a driving assembly 7 is further provided.

[0054] As shown in Figure 10 and 11 As shown, a receiving groove 18 communicating with the through hole 17 is provided radially outside the through hole 17. In this embodiment, the receiving groove 18 is provided on the first limiting rib 15, and the driving assembly 7 is disposed in the receiving groove 18 and can at least partially extend out of the receiving groove 18 to push the valve stem 3 to rotate. The driving assembly 7 is a temperature-sensitive driving device, including a spring 74, a heating coil 71, paraffin wax 72 and a push rod 73. The paraffin wax 72 and the push rod 73 are arranged in sequence along the direction close to the valve stem 3. The heating coil 71 is arranged on the outer peripheral wall of the paraffin wax 72. The paraffin wax 72 can be accommodated in a bladder. A convex block 31 is protruded on the outer wall of the valve stem 3, and the convex block 31 is located on the moving path of the push rod 73 towards the valve stem 3. The two ends of the spring 74 respectively abut against the inner wall of the receiving groove 18 and the paraffin wax 72.

[0055] The heating coil 71 is electrically connected to the controller of the water heater (a PLC controller can be used). When the user uses the water heater, the controller receives a signal and controls the heating coil 71 to work. The paraffin 72 undergoes a phase change and expands, thereby pushing the ejector rod 73 to move towards the valve rod 3. During the movement of the ejector rod 73, it will push the convex block 31 on the valve rod 3, so that the valve rod 3 realizes a micro-angle rotation, and then the valve rod 3 can be easily rotated; when the user does not use the water heater and the water heater is in the standby state or the shutdown state, the controller receives a signal and controls the heating coil 71 not to work. The paraffin 72 returns to the solid state, and the reverse rotation of the valve rod 3 can make the convex block 31 push the ejector rod 73 back to the initial position. Of course, the heating coil 71 can also be controlled to work or not by other means.

[0056] In order to facilitate the convex block 31 to push the ejector rod 73, the edge corner of the end of the ejector rod 73 facing the convex block 31 can be set as an arc surface.

[0057] Of course, the driving component 7 can also be an electric push rod.

Claims

1. An anti-freezing valve, comprising a valve body (1) having an accommodation cavity (11) therein, and an inlet (12), an outlet (13) and a drain port (14) are formed on the valve body (1) and are all in communication with the accommodation cavity (11); a valve ball (2) rotatably disposed in the accommodation cavity (11) and capable of rotating to a first position or a second position. The valve ball (2) has a through water passage (21). When the valve ball (2) is in the first position, both ends of the water passage (21) respectively correspond to fluid communication with the inlet (12) and the outlet (13). When the valve ball (2) is in the second position, both ends of the water passage (21) respectively correspond to fluid communication with the outlet (13) and the drain port (14); characterized in that It further includes a valve stem (3), one end of the valve stem (3) passes through the valve body (1) and is connected to the valve ball (2), and the other end is located outside the valve body (1) as a driving end; a first sealing ring (61) is arranged in the accommodating cavity (11) of the valve body (1) at the water outlet end adjacent to the water inlet (12) and in sealing contact with the valve ball (2). The first sealing ring (61) is annular, and the wall surface facing the valve ball (2) is in arc transition connection with the inner hole of the first sealing ring (61); The antifreeze valve further includes a driving assembly (7) capable of pushing the valve stem (3) to rotate by a small angle. A through hole (17) for the valve stem (3) to pass through is formed in the valve body (1), and a accommodating groove (18) communicated with the through hole (17) is arranged outside the through hole (17). The driving assembly (7) is arranged in the accommodating groove (18) and can at least partially extend out of the accommodating groove (18) to push the valve stem (3) to rotate.

2. The anti-freezing valve according to claim 1, characterized in that: The water passage (21) includes a first passage (211) and a second passage (212) that both pass through the center of the valve ball (2) and are perpendicular to each other. One end of each of the first passage (211) and the second passage (212) penetrates the valve ball (2). The center lines of the water inlet ends of the water outlet (13) and the drain outlet (14) are perpendicular to each other, and the center line of the water inlet end of the water outlet (13) and the center line of the water outlet end of the water inlet (12) are perpendicular to each other.

3. The anti-freezing valve according to claim 1, characterized in that: A knob (4) for facilitating the rotation of the valve stem (3) is arranged on the driving end of the valve stem (3), and a limiting structure for restricting the rotation angle of the valve stem (3) is arranged between the knob (4) and the valve body (1).

4. The anti-freezing valve according to claim 3, characterized in that: The valve body (1) has a valve stem seat (19) at the position corresponding to the valve stem (3) for the valve stem (3) to pass through and rotate relatively therein. Axially extending first limiting ribs (15) and second limiting ribs (16) are arranged on the circumferential wall of the valve stem seat (19) at intervals in the circumferential direction. A resisting block (41) that can alternatively abut against the two is arranged on the knob (4) at the position corresponding to the space between the first limiting rib (15) and the second limiting rib (16). The first limiting rib (15), the second limiting rib (16) and the resisting block (41) together constitute the limiting structure.

5. The anti-freezing valve according to claim 4, characterized in that: A marking plate (5) for indicating the rotation position of the knob (4) is arranged between the knob (4) and the valve body (1). The marking plate (5) is connected to the valve body (1), and through holes (51) for the valve stem seat (19), the first limiting rib (15) and the second limiting rib (16) to pass through are formed on the marking plate (5). A marking structure (52) for indicating the rotation position of the knob (4) is arranged on the marking plate (5).

6. The anti-freezing valve according to claim 1, characterized in that: A second sealing ring (62) is arranged in the accommodating cavity (11) of the valve body (1) at the water inlet end adjacent to the drain outlet (14) and in sealing contact with the valve ball (2).

7. The anti-freezing valve according to claim 1, characterized in that: The driving component (7) is a temperature-sensitive driving device, including a heating coil (71), paraffin wax (72) and a push rod (73). The paraffin wax (72) and the push rod (73) are arranged in sequence along the direction close to the valve rod (3). The heating coil (71) is arranged on the outer peripheral wall of the paraffin wax (72). A convex block (31) is protruded on the outer wall of the valve rod (3), and the convex block (31) is located on the moving path of the push rod (73) towards the valve rod (3).

8. The anti-freezing valve according to claim 7, characterized in that: The driving component (7) further includes a spring (74) arranged in the accommodation groove (18). Two ends of the spring (74) respectively abut against the inner wall of the accommodation groove (18) and the paraffin wax (72).

9. A gas water heater applying the anti-freezing valve according to any one of claims 1 to 8, characterized in that: It further includes a water heater body (8). The water outlet (13) of the valve body (1) is in fluid communication with the water inlet end of the water heater body (8).

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