Return valve and water supply system

Abstract

The present invention discloses a return water valve and a water supply system. The return water valve includes a valve body, a check valve, and a first elastic member. The valve body has a water flow channel, and the water flow channel includes a first flow channel and a second flow channel arranged at intervals, and a third flow channel connecting the first flow channel and the second flow channel. The check valve is used to unidirectionally introduce water in the first flow channel into the second flow channel. The check valve is movably installed in the water flow channel, and the check valve blocks the third flow channel in the initial position. The first elastic member is used to make the check valve have a tendency to reset to the initial position. The check valve is used to leave the initial position when the water pressure difference between the first flow channel and the second flow channel increases to a preset pressure difference, so as to open the third flow channel. Thus, the return water valve is installed in the water path of the water supply system, and a return water path can be formed, so that the water supply system has a zero cold water function.

Description

Technical Field

[0001] The present invention relates to the technical field of zero - cold water supply, and particularly to a return water valve and a water supply system. Background Art

[0002] A water supply system, such as a water heater water supply system or a wall - hung boiler water supply system, etc., is used to provide water for users. It generally includes a gas heating device (such as a gas water heater or a wall - hung boiler, etc.), a cold water pipe, a hot water pipe, a mixing device and a water outlet end. The water outlet end is connected to the gas heating device through the cold water pipe, the hot water pipe and the mixing device.

[0003] In the related art, in order to enable the water supply system to have the zero - cold water function, a return water valve with a one - way valve is usually added in the water supply system. The return water valve is connected in the cold water pipe and the hot water pipe to form a return water waterway in the water supply system. Summary of the Invention

[0004] The main object of the present invention is to propose a new return water valve for forming a return water waterway in a water supply system.

[0005] To achieve the above object, the present invention proposes a return water valve, which includes:

[0006] A valve body having a water flow channel, the water flow channel including a first flow channel and a second flow channel arranged at intervals, and a third flow channel connecting the first flow channel and the second flow channel;

[0007] A one - way valve for unidirectionally introducing water in the first flow channel into the second flow channel; the one - way valve is movably installed in the water flow channel, and the one - way valve blocks the third flow channel in the initial position; and

[0008] A first elastic member provided in the water flow channel, the first elastic member being used to make the one - way valve have a tendency to reset to the initial position;

[0009] Wherein, the one - way valve is used to leave the initial position when the water pressure difference between the first flow channel and the second flow channel increases to a preset pressure difference to open the third flow channel.

[0010] Optionally, the one - way valve is movably installed in the third flow channel, and the first elastic member is provided in the third flow channel;

[0011] The return water valve further includes a temperature control assembly, the temperature control assembly including a temperature control driving assembly and a regulating valve core. The regulating valve core is located on the water outlet side of the one - way valve, and the regulating valve core is movably arranged in the water flow channel in a direction away from or close to the one - way valve;

[0012] Wherein, the one-way valve is configured to move towards the direction close to the regulating valve core when the water pressure difference between the first flow channel and the second flow channel increases to a preset pressure difference, so as to open the third flow channel;

[0013] The temperature control driving assembly is installed in the water flow channel. The temperature control driving assembly is configured to drive the regulating valve core to move towards the direction close to the one-way valve when the water temperature in the water flow channel rises to a preset temperature, so as to drive the one-way valve that has left the initial position to reset.

[0014] Optionally, when the one-way valve is in the initial position, there is an initial distance between the one-way valve and the regulating valve core. The initial distance is less than the sum of the maximum movable distance of the regulating valve core and the maximum movable distance of the one-way valve, and is greater than or equal to the maximum movable distance of the regulating valve core.

[0015] Optionally, the temperature control assembly further includes a valve core sleeve. The valve core sleeve is disposed in the third flow channel, and the regulating valve core is movably disposed in the valve core sleeve;

[0016] The first elastic member is a first spring. The first spring is sleeved outside the one-way valve, and two ends of the first spring are respectively disposed on the one-way valve and the valve core sleeve, so that the one-way valve has a tendency to reset to the initial position.

[0017] Optionally, the valve core sleeve is provided with a first water passing structure, and / or the regulating valve core is provided with a second water passing structure, and / or a water passing gap is formed between the outer peripheral surface of the regulating valve core and the inner wall surface of the valve core sleeve.

[0018] Optionally, the inner wall surface of the valve core sleeve is provided with an inner support. The inner support has a mounting through hole, and one end of the regulating valve core is slidably mounted in the mounting through hole, and the first end of the first spring is disposed on the inner support.

[0019] Optionally, the temperature control driving assembly includes a push rod, a temperature sensing shell and a temperature sensing medium that expands when heated. The temperature sensing shell is located on the water outlet side of the one-way valve. The push rod is slidably mounted in the temperature sensing shell, and the regulating valve core is mounted on the outer end of the push rod; the temperature sensing medium is disposed in the temperature sensing shell. The temperature sensing medium is configured to expand when the water temperature in the water flow channel rises to a preset temperature, so as to cause the push rod to extend, and drive the regulating valve core to move towards the direction close to the one-way valve; the temperature sensing medium is further configured to contract when cooled.

[0020] Optionally, the temperature control assembly further includes a third elastic member, and the third elastic member is configured to make the regulating valve core have a tendency to reset.

[0021] Optionally, the third elastic member is a third spring, the third spring is sleeved outside the regulating valve core, and two ends of the third spring are respectively arranged on the inner support and the regulating valve core, so that the regulating valve core has a tendency to reset.

[0022] Optionally, the regulating valve core includes a valve core main body and a limiting convex portion protruding from the circumferential surface of the valve core main body. An installation groove is formed on the end surface of one end of the valve core main body, and the outer end of the ejector rod is installed in the installation groove; two ends of the third spring are respectively arranged on the inner support and the limiting convex portion, so that the regulating valve core has a tendency to reset; a water passing through hole communicating with the installation groove is arranged on the valve core main body.

[0023] Optionally, the one-way valve includes a second elastic member, a valve housing, and a one-way valve core movably installed in the valve housing. Two ends of the second elastic member are respectively arranged on the valve housing and the one-way valve core, so that the one-way valve core has a tendency to reset to the closed position for closing the one-way valve; the first spring is sleeved outside the valve housing, and two ends of the first spring are respectively arranged on the valve housing and the valve core sleeve, so that the one-way valve has a tendency to reset to the initial position.

[0024] Optionally, a gear position convex portion protrudes from the outer circumferential surface of the valve housing, and the second end of the first spring is arranged on the gear position convex portion.

[0025] Optionally, a sealing ring convex is formed on the inner wall surface of the third flow channel. When the one-way valve is in the initial position, the gear position convex portion abuts against the sealing ring convex.

[0026] Optionally, the one-way valve further includes a sealing ring, the sealing ring is installed on the side of the gear position convex portion away from the regulating valve core, and when the one-way valve is in the initial position, the sealing ring is clamped between the sealing ring convex and the gear position convex portion to block the third flow channel.

[0027] Optionally, a plurality of gear position convex portions are circumferentially spaced apart on the valve housing to open the third flow channel when the one-way valve leaves the initial position; or, the gear position convex portion is an annular convex portion, and a water passing hole is formed on the gear position convex portion to open the third flow channel when the one-way valve leaves the initial position; and / or,

[0028] A water passing gap is arranged between the end surface of the gear position convex portion and the inner wall surface of the third flow channel to open the third flow channel when the one-way valve leaves the initial position.

[0029] The present invention further provides a water supply system, including:

[0030] A gas heating device;

[0031] The water outlet end, and the water outlet end is connected to the gas heating device through a cold water pipe, a hot water pipe and a water mixing device; and

[0032] The return water valve as described above, wherein the first flow channel of the return water valve is connected to the hot water pipe, and the second flow channel of the return water valve is connected to the cold water pipe.

[0033] Optionally, the gas heating device is a gas water heater or a gas wall-mounted boiler.

[0034] The present invention also provides a water supply system, comprising:

[0035] A gas heating device;

[0036] A water outlet end, and the water outlet end is connected to the gas heating device through a cold water pipe, a hot water pipe and a water mixing device;

[0037] The return water valve as described above, wherein the second flow channel of the return water valve is connected to the cold water pipe or the water inlet pipe of the gas heating device; and

[0038] A return water pipe, one end of the return water pipe is connected to the hot water pipe, and the other end is connected to the first flow channel of the return water valve.

[0039] In the present invention, the return water valve is installed in the water circuit of the water supply system, and a return water circuit can be formed, so that the water supply system has the zero cold water function; and it can also solve the problem that the hot water in the hot water pipe or the return water pipe of the water supply system easily flows into the cold water pipe through the return water valve when boosting and delivering hot water. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0041] Figure 1 It is a schematic structural diagram of an embodiment of the water supply system of the present invention;

[0042] Figure 2 It is a schematic structural diagram of another embodiment of the water supply system of the present invention;

[0043] Figure 3 It is a schematic structural diagram of an embodiment of the return water valve of the present invention;

[0044] Figure 4 For Figure 3 It is a schematic structural diagram of the return water valve in the cold state circulation state in

[0045] Figure 5 is Figure 3 a schematic structural view of the return water valve in a hot state circulation state in

[0046] Figure 6 is Figure 3 a schematic structural view of the return water valve in a hot state pressurization state in

[0047] Figure 7 is Figure 3 an explosion schematic view of the return water valve in

[0048] Figure 8 is Figure 7 a schematic structural view of the check valve in

[0049] Figure 9 is Figure 7 a schematic structural view of the regulating valve core in

[0050] Explanation of the reference numerals in the attached drawings:

[0051]

[0052]

[0053] The realization, functional features and advantages of the object of the present invention will be further described with reference to the embodiments and the accompanying drawings. Specific embodiments

[0054] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0055] It should be noted that if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features.

[0056] In addition, the meaning of "and / or" appearing throughout the text is that it includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, or solution B, or a solution that satisfies both A and B at the same time.

[0057] The present invention provides a return water valve and a water supply system.

[0058] Among them, as Figure 1 and 2As shown, the return water valve 100 is used in the water supply system 1000, that is, the water supply system 1000 includes the return water valve 100, so that the water supply system 1000 has the zero-cold water function to achieve the timed cruising and heat preservation functions. The return water valve 100 will be introduced in detail below in combination with the structure of the water supply system 1000. Optionally, the water supply system 1000 is a water heater water supply system 1000 (including but not limited to a gas water heater system) or a wall-mounted boiler water supply system 1000, etc. The gas water heater system will be taken as an example for illustration below.

[0059] In an embodiment of the present invention, as Figure 1 and 2 shown, the water supply system 1000 further includes a gas heating device 200, a cold water pipe 300, a hot water pipe 400, a mixing device 600, a water outlet end 700, a return water valve 100, etc. The water outlet end 700 is connected to the gas heating device 200 through the cold water pipe 300, the hot water pipe 400, and the mixing device 600; the return water valve 100 is installed in the water circuit of the water supply system 1000 to form a return water circuit, so as to enable the water supply system 1000 to have the zero-cold water function.

[0060] Specifically, as Figure 1 and 2 shown, the gas heating device 200 has a cold water inlet 201 and a hot water outlet 202, and the mixing device 600 has a hot water connection port, a cold water connection port, and a mixed water outlet.

[0061] Among them, one end of the cold water pipe 300 and the cold water inlet 201 are both connected (i.e., communicated) with a water supply pipe (such as a tap water pipe, etc.), and the other end of the cold water pipe 300 is communicated with the cold water connection port; one end of the hot water pipe 400 is communicated with the hot water outlet 202, and the other end is communicated with the hot water connection port, and the mixed water outlet is communicated with the water outlet end 700. In this way, by adjusting the mixing device 600, the water outlet end 700 can send out cold water alone or send out mixed hot water at a suitable temperature.

[0062] Optionally, a cold water joint is provided at the cold water inlet 201; and / or, a hot water joint is provided at the hot water outlet 202.

[0063] Optionally, the water supply system 1000 includes a water inlet pipe 210, the cold water inlet 201 is communicated with the water supply pipe through the water inlet pipe 210, and the cold water pipe 300 is communicated with the water inlet pipe 210.

[0064] Optionally, the water outlet end 700 can be a shower head or a faucet, etc.

[0065] Optionally, there can be multiple water outlet ends 700.

[0066] Optionally, the mixing device 600 is a mixing valve or other mixing device 600 with a similar function to the mixing valve.

[0067] Optionally, the gas heating device 200 is a gas water heater, a gas wall-mounted boiler, etc. Hereinafter, a gas water heater will be taken as an example for illustration.

[0068] In an embodiment of the present invention, as Figures 3 - 9 shown, the return water valve 100 includes a valve body 10, a check valve 20, and a first elastic member 50.

[0069] Wherein, the valve body 10 has a water flow channel, and the water flow channel includes a first flow channel 11 and a second flow channel 12 arranged at intervals, and a third flow channel 13 connecting the first flow channel 11 and the second flow channel 12.

[0070] Wherein, the check valve 20 is used to unidirectionally introduce the water in the first flow channel 11 into the second flow channel 12; the check valve 20 is movably installed in the water flow channel, and the check valve 20 blocks the third flow channel 13 in the initial position.

[0071] Specifically, the check valve 20 is movably installed in the third flow channel 13 to facilitate the design and control of the movement of the check valve 20. Of course, in other embodiments, the check valve 20 may also be at least partially disposed in the third flow channel 13, that is, partially disposed in the third flow channel 13 and partially disposed in the first flow channel 11 or the second flow channel 12.

[0072] Wherein, the first elastic member 50 is used to make the check valve 20 have a tendency to reset to the initial position, so that the check valve 20 can be normally in the initial position. Specifically, the first elastic member 50 is disposed in the water flow channel.

[0073] Wherein, the check valve 20 is used to leave the initial position when the water pressure difference between the first flow channel 11 and the second flow channel 12 increases to a preset pressure difference to open the third flow channel 13.

[0074] Specifically, the check valve 20 is a normally closed switch. When the check valve 20 is closed, the water in the first flow channel 11 cannot flow through the check valve 20 to the second flow channel 12; after the check valve 20 is opened, the water in the first flow channel 11 can pass through the check valve 20 so that the water in the first flow channel 11 can flow to the second flow channel 12.

[0075] It can be understood that when the one-way valve 20 is in the initial position and the one-way valve 20 is closed, the one-way valve 20 can block the third flow channel 13 to prevent the water in the first flow channel 11 from flowing to the second flow channel 12. However, when the one-way valve 20 leaves the initial position and / or the one-way valve 20 is opened, the third flow channel 13 will be opened, and the water in the first flow channel 11 can flow to the second flow channel 12 through the third flow channel 13.

[0076] Specifically, the preset pressure difference may be greater than the opening threshold of the one-way valve 20 (i.e., the critical pressure value / pressure difference value for switching the one-way valve 20 from the closed state to the open state, in other words, when the water pressure difference in the first flow channel 11 and the second flow channel 12 increases to the opening threshold, the one-way valve 20 opens), or may be less than the opening threshold of the one-way valve 20, or may be equal to the opening threshold of the one-way valve 20. For example, the preset pressure difference may be equal to the opening threshold of the one-way valve 20, that is, the preset pressure difference may be slightly greater than, equal to, or slightly less than the opening threshold of the one-way valve 20. In this way, when the one-way valve 20 leaves the initial position, the one-way valve 20 may also be opened at the same time.

[0077] The function of the return valve 100 is described in detail below in combination with the structures of different water supply systems 1000.

[0078] In one embodiment of the water supply system 1000, the water supply system 1000 is not provided with a return pipe 500; Figure 1 As shown, the first flow channel 11 is connected to the heat exchange tube, and the second flow channel 12 is connected to the cold water pipe 300. When there are multiple water outlets 700, the return valve 100 can be optionally arranged at the farthest water outlet 700.

[0079] Specifically, one end of the first flow channel 11 (such as the B end in the figure) is connected to the hot water inlet through the hot water pipe 400, and the other end of the first flow channel 11 (such as the A end in the figure) is connected to the hot water outlet 202 through the hot water pipe 400; one end of the second flow channel 12 (such as the C end in the figure) is connected to the cold water inlet through the cold water pipe 300, and the other end of the second flow channel 12 (such as the D end in the figure) is connected to the water inlet pipe 210 through the cold water pipe 300. In this way, a return water path can be formed between the hot water pipe 400, the first flow channel 11, the third flow channel 13 and / or the fourth flow channel, the second flow channel 12, the cold water pipe 300, the water inlet pipe 210 and the gas heating device 200, and the return water valve 100 is arranged in the return water path.

[0080] Of course, the above water return valve 100 can also be used in a water supply system 1000 having a water return pipe 500. For example, in another embodiment of the water supply system 1000 of the present invention, Figure 2As shown, the water supply system 1000 includes a return water pipe 500. One end of the return water pipe 500 is connected to the hot water pipe 400, and the other end is connected to one end of the first flow channel 11 (end A in the figure). The other end of the first flow channel 11 (end B in the figure) is blocked (such as blocked by an end cap).

[0081] And in this embodiment, the second flow channel 12 is connected to the water inlet pipe 210 or the cold water pipe 300.

[0082] Optionally, as Figure 2 shown, the second flow channel 12 is connected to the water inlet pipe 210; specifically, one end of the second flow channel 12 (end C in the figure) is communicated with the cold water inlet 201 through the water inlet pipe 210, and the other end of the second flow channel 12 (end D in the figure) is communicated with the cold water pipe 300 through the water inlet pipe 210.

[0083] Optionally, the return water valve 100 is arranged close to the gas heating device 200.

[0084] And in this embodiment, when there are multiple water outlet ends 700, the return water pipe 500 is connected to the most distal water outlet end 700.

[0085] In this way, a return water water path can be formed among the hot water pipe 400, the return water pipe 500, the first flow channel 11, the third flow channel 13 and / or the fourth flow channel, the second flow channel 12, the water inlet pipe 210, and the heat exchanger of the gas heating device 200, etc.; the return water valve 100 is arranged in this return water water path.

[0086] Specifically, for the above two embodiments, as Figure 1 and 2 shown, the gas heating device 200 further includes a circulating water pump 800. The circulating water pump 800 is arranged in the return water water path, and the circulating water pump 800 is used to drive water to flow in the return water water path. Optionally, the circulating water pump 800 is arranged between the heat exchanger of the gas heating device 200 and the cold water inlet 201, so that the circulating water pump 800 can also be used to suck cold water and / or boost water supply, etc.

[0087] Specifically, when the water supply system 1000 in the above two embodiments uses the zero - cold - water function for circulating pre - heating, the circulation pump 800 will push the water in the return water waterway to flow, increasing the water pressure in the first flow channel 11, so that the difference in water pressure between the first flow channel 11 and the second flow channel 12 increases; when the water pressure difference between the first flow channel 11 and the second flow channel 12 increases to a preset pressure difference (here, it is illustrated by taking the preset pressure difference to be equivalent to the opening threshold of the check valve 20), the check valve 20 leaves the initial position and the check valve 20 opens, so that the water in the first flow channel 11 can flow into the second flow channel 12 through the third flow channel 13, enabling the water to circulate in the return water waterway, so as to realize the circulating pre - heating of the water in the hot water pipe 400, etc.

[0088] It can be understood that when the circulating pre - heating ends, the circulation pump 800 is turned off, so that the water pressure in the hot water pipe 400 and the water pressure in the cold water pipe 300 gradually tend to be balanced, the check valve 20 closes, and under the action of the first elastic member 50, it resets to the initial position.

[0089] When hot water is turned on and pressurized at the water outlet end 700 (i.e., when pressurized hot water is supplied), the circulation pump 800 is used for pressurization to increase the water output and the water outlet speed. Due to the characteristic curve of the pump, when the pump is just started, the water pressure in the first flow channel 11 will increase rapidly, so that the check valve 20 leaves the initial position and the check valve 20 opens, causing water mixing; when some time after starting, that is, when the water supply flow rate at the water outlet end 700 is relatively large, the pressure difference between the inlet and outlet of the circulation pump 800 will decrease. Therefore, by adjusting the values of the preset pressure difference and the opening threshold of the check valve 20, such as making the water pressure difference between the first flow channel 11 and the second flow channel 12 not reach the preset pressure difference and the opening threshold of the check valve 20 at this time, the check valve 20 closes and resets to the initial position to block the third flow channel 13, so as to prevent the hot water in the first flow channel 11 from flowing into the second flow channel 12, that is, to achieve the effect of preventing water mixing when pressurized hot water is supplied, so as to avoid mis - starting the gas heating device 200 for pre - heating circulation, etc.

[0090] It should be noted that the preset pressure difference can be adjusted by adjusting the elastic parameters of the first elastic member 50 itself or the initial elastic force value of the first elastic member 50 when the check valve 20 is in the initial position.

[0091] It should be noted that when the preset pressure difference is less than the opening threshold of the check valve 20, when using the zero - cold - water function for circulating pre - heating, there may also be a situation where "the check valve 20 leaves the initial position to open the third flow channel 13, but the check valve 20 does not open".

[0092] It can be understood that, by movably arranging the one-way valve 20 in the valve body 10 and blocking the third flow channel 13 at the initial position of the one-way valve 20, the first elastic member 50 causes the one-way valve 20 to have a tendency to reset to the initial position, and when the water pressure difference between the first flow channel 11 and the second flow channel 12 increases to a preset pressure difference, it leaves the initial position to open the third flow channel 13; a one-way normally closed switch structure can be formed between the one-way valve 20 and the third flow channel 13, so that the return water valve 100 has two normally closed switch structures in parallel for controlling the on / off of the third flow channel 13, so that when the zero cold water function is used for circulating preheating, at least one of the two normally closed switch structures can be opened to ensure / increase the flow rate in the circulating water path and increase / ensure the preheating speed.

[0093] In the present invention, the return water valve 100 is installed in the water path of the water supply system 1000, and a return water path can be formed to enable the water supply system 1000 to have the zero cold water function; it can also solve the problem that the hot water in the hot water pipe 400 or the return water pipe 500 of the water supply system 1000 easily flows into the cold water pipe 300 through the return water valve 100 when boosting and sending hot water.

[0094] In a further improvement of the present invention, a temperature control component 30 can also be added to cooperate with the above two normally closed switch structures to improve the performance of the return water valve 100. The following will be described in detail.

[0095] Further, as Figures 3 - 9 shown, the one-way valve 20 is movably installed in the third flow channel 13, and the first elastic member 50 is arranged in the third flow channel 13 to facilitate the design of the first elastic member 50.

[0096] Further, as Figures 3 - 9 shown, the return water valve 100 further includes a temperature control component 30, the temperature control component 30 includes an adjusting valve core 31, the adjusting valve core 31 is located on the water outlet side of the one-way valve 20, the adjusting valve core 31 is movably arranged in the water flow channel in a direction away from or close to the one-way valve 20, and the adjusting valve core 31 is used to move in a direction close to the one-way valve 20 when the water temperature in the valve body 10 rises to a preset temperature.

[0097] Further, as Figures 3 - 9 shown, the one-way valve 20 is used to move in a direction close to the adjusting valve core 31 when the water pressure difference between the first flow channel 11 and the second flow channel 12 increases to a preset pressure difference to open the third flow channel 13.

[0098] Further, as Figures 3 - 9 shown, the adjusting valve core 31 is used to move in a direction close to the one-way valve 20 when the water temperature in the valve body 10 rises to a preset temperature to drive the one-way valve 20 that has left the initial position to reset.

[0099] Specifically, as Figures 3 - 9 shown, the temperature control assembly 30 further includes a temperature control driving assembly 32. The temperature control driving assembly 32 is installed in the water flow channel, and is configured to drive the regulating valve core 31 to move towards the check valve 20 when the water temperature in the water flow channel rises to a preset temperature.

[0100] Specifically, when the check valve 20 is in the initial position, there is an initial distance between the check valve 20 and the regulating valve core 31. The initial distance is less than the sum of the maximum movable distance of the regulating valve core 31 and the maximum movable distance of the check valve 20, and is greater than or equal to the maximum movable distance of the regulating valve core 31.

[0101] Specifically, when the check valve 20 moves towards the regulating valve core 31, it can move onto the moving track of the regulating valve core 31. By making the initial distance less than the sum of the maximum movable distance of the regulating valve core 31 and the maximum movable distance of the check valve 20, and greater than or equal to the maximum movable distance of the regulating valve core 31, when the regulating valve core 31 moves towards the check valve 20, the check valve 20 that has moved onto the moving track of the regulating valve core 31 can be driven to move in the direction of resetting to the initial position.

[0102] Optionally, the initial distance is equal to the maximum movable distance of the regulating valve core 31, so that when the regulating valve core 31 moves towards the check valve 20, the check valve 20 is driven to reset to the initial position.

[0103] Specifically, as Figure 4 shown, when the water supply system 1000 in the above two embodiments uses the zero - cold - water function for circulating pre - heating, the circulation pump 800 will push the water in the return water waterway to flow, increasing the water pressure in the first flow channel 11, thereby increasing the difference in water pressure between the first flow channel 11 and the second flow channel 12; when the water pressure difference between the first flow channel 11 and the second flow channel 12 increases to a preset pressure difference (here, it is described by taking the preset pressure difference as less than the opening threshold of the check valve 20 as an example), the check valve 20 moves towards the regulating valve core 31 and leaves the initial position to open the third flow channel 13, but the check valve 20 is not fully opened, so that the water in the first flow channel 11 can flow into the second flow channel 12 through the third flow channel 13, enabling the water to circulate in the return water waterway to realize circulating pre - heating of the water in the hot water pipe 400, etc. At this time, as Figure 4 shown, the return water valve 100 is in the cold - state circulation state, and the check valve 20 is located on the moving track of the regulating valve core 31.

[0104] Please refer to Figure 5, when the water temperature in the hot water pipe 400 or the return water pipe 500 rises to a certain temperature but does not reach the expected preheating temperature (such as 100 etc.), and when the water temperature in the water flow channel (specifically at the temperature control component 30) rises to the preset temperature, the regulating valve core 31 moves towards the direction close to the one-way valve 20. Since the initial distance is made less than the sum of the maximum movable distance of the regulating valve core 31 and the maximum movable distance of the one-way valve 20, and is greater than or equal to the maximum movable distance of the regulating valve core 31, and the one-way valve 20 is located on the moving track of the regulating valve core 31, so during the movement of the regulating valve core 31, it will abut against the one-way valve 20 and drive the one-way valve 20 on the moving track of the regulating valve core 31 to move towards the direction of resetting to the initial position.

[0105] It can be understood that if the initial distance is equal to the maximum movable distance of the regulating valve core 31, the regulating valve core 31 can drive the one-way valve 20 to reset to the initial position to block the third flow channel 13; but since the expected preheating temperature is not reached and the circulating preheating is not over, the circulating water pump 800 still pushes the water in the return water circuit to flow, so the water pressure difference between the first flow channel 11 and the second flow channel 12 will continue to increase until the one-way valve 20 is opened to open the third flow channel 13 so that the water can continue to circulate in the return water circuit to continue the circulating preheating until the expected preheating temperature is reached. At this time, as Figure 5 shown, the return water valve 100 is in the hot state circulation state.

[0106] The following continues to take the example where the initial distance is equal to the maximum movable distance of the regulating valve core 31 for illustration.

[0107] As Figure 6 shown, when the water outlet end 700 opens hot water and pressurizes (that is, pressurizes and delivers hot water), the circulating water pump 800 will be used to pressurize to increase the water output and the water outlet speed. Due to the characteristic curve of the water pump, when the water pump is just started, the water pressure in the first flow channel 11 will increase rapidly, so that the one-way valve 20 leaves the initial position or the one-way valve 20 is opened, resulting in water cross-flow.

[0108] It can be understood that when the water outlet end 700 opens hot water and pressurizes (that is, pressurizes and delivers hot water), there are two situations at this time. One is that the hot water pipe 400 contains hot water, and the other is that the hot water pipe 400 contains cold water.

[0109] For the case where the water in the hot water pipe 400 is cold water, when the water pump is just started, the water pressure in the first flow channel 11 will increase rapidly, causing the check valve 20 to leave its initial position and resulting in water cross-flow; after a period of time when it is started, when the hot water reaches the return water valve 100, the regulating valve core 31 moves towards the direction close to the check valve 20 to drive the check valve 20 that has moved to the movement track of the regulating valve core 31 to reset to its initial position; at this time, since the water supply flow rate at the water outlet end 700 is relatively large, the pressure difference between the inlet and outlet of the circulating water pump 800 will decrease, which is not sufficient to open the check valve 20, so the third flow channel 13 is blocked, thereby preventing the hot water in the first flow channel 11 from flowing into the second flow channel 12, that is, achieving the effect of preventing water cross-flow during pressurized hot water supply, so as to avoid mis-starting the gas heating device 200 for preheating circulation, etc. At this time, as Figure 6 shown, the return water valve 100 is in a hot state pressurization state.

[0110] For the case where the water in the hot water pipe 400 is hot water, the water in the return water valve 100 communicated with the hot water pipe 400 is also hot water, that is, the regulating valve core 31 is in a state of abutting against the check valve 20 to fix it in its initial position. In this case, when the water pump is just started, the water pressure in the first flow channel 11 will increase rapidly, causing the check valve 20 to be opened and resulting in water cross-flow; after a period of time when it is started, since the water supply flow rate at the water outlet end 700 is relatively large, the pressure difference between the inlet and outlet of the circulating water pump 800 will decrease, and the check valve 20 closes, and the third flow channel 13 is blocked, thereby preventing the hot water in the first flow channel 11 from flowing into the second flow channel 12, that is, achieving the effect of preventing water cross-flow during pressurized hot water supply.

[0111] That is to say, in the design, the effect of preventing water cross-flow during pressurized hot water supply can be achieved by increasing the opening threshold of the check valve 20.

[0112] Furthermore, as Figures 3 - 9 shown, the check valve 20 includes a second elastic member 23, a valve housing 22, and a check valve core 21. The check valve core 21 is movably installed in the valve housing 22 to open or close the check valve 20.

[0113] Specifically, the check valve core 21 has a closed position for closing the check valve 20. The two ends of the second elastic member 23 are respectively disposed on the valve housing 22 and the check valve core 21, so that the check valve core 21 has a tendency to reset to the closed position for closing the check valve 20. Among them, the first elastic member 50 acts on the valve housing 22, so that the check valve core 21 has a tendency to reset to the closed position for closing the check valve 20.

[0114] It can be understood that the opening threshold can be adjusted by adjusting the self-elastic parameters of the second elastic member 23 or the initial elastic force value of the second elastic member 23 when the check valve core 21 is in the closed position.

[0115] Further, as Figures 3 - 9 shown, the temperature control component 30 further includes a valve core sleeve 36. The valve core sleeve 36 is disposed in the third flow channel 13, and the regulating valve core 31 is movably disposed in the valve core sleeve 36.

[0116] Specifically, the valve core sleeve 36 is fixedly installed in the third flow channel 13, and the regulating valve core 31 is slidably disposed in the valve core sleeve 36.

[0117] Further, as Figures 3 - 9 shown, two ends of the first elastic member 50 are respectively disposed on the one-way valve 20 and the valve core sleeve 36, so that the one-way valve 20 has a tendency to reset to the initial position.

[0118] Specifically, as Figures 3 - 9 shown, the first elastic member 50 is a first spring. The first spring is sleeved outside the one-way valve 20, and two ends of the first spring are respectively disposed on the one-way valve 20 and the valve core sleeve 36, so that the one-way valve 20 has a tendency to reset to the initial position. In this way, the structure can be simplified, and the performance of the spring is relatively stable, thereby improving the reliability.

[0119] Of course, in other embodiments, the first elastic member 50 can also be an elastic pressing sheet, or a rubber band, or other elastic members such as a rib.

[0120] In a specific embodiment, in order to prevent the valve core sleeve 36 and the regulating valve core 31 from blocking the third flow channel 13, the valve core sleeve 36 may be provided with a first water passing structure, and / or the regulating valve core 31 may be provided with a second water passing structure, and / or a water passing gap is formed between the outer peripheral surface of the regulating valve core 31 and the inner wall surface of the valve core sleeve 36, and / or a flow through gap is provided between the valve core sleeve 36 and the inner wall surface of the third flow channel 13, and so on. Hereinafter, the case where the regulating valve core 31 is provided with a second water passing structure will be taken as an example for description.

[0121] Further, an inner support 361 is provided on the inner wall surface of the valve core sleeve 36. The inner support 361 has an installation through hole 3611, and one end of the regulating valve core 31 is slidably installed in the installation through hole 3611, and the first end of the first spring is disposed on the inner support 361.

[0122] Specifically, the first end of the first spring abuts against the inner support 361.

[0123] In this way, on the one hand, the stability of the movement of the regulating valve core 31 can be improved, and on the other hand, it is also convenient to arrange the first spring.

[0124] It can be understood that the inner support 361 has a water passing through hole.

[0125] Further, asFigures 3 - 9 As shown, the one-way valve 20 abuts against one end of the regulating valve core 31 or the inner support 361 at the maximum moving position. In this way, the movement of the one-way valve 20 in the direction close to the regulating valve core 31 can be limited.

[0126] Further, as Figures 3 - 9 shown, the first spring is sleeved outside the valve housing 22, and both ends of the first spring are respectively arranged on the valve housing 22 and the valve core sleeve 36, so that the one-way valve 20 has a tendency to reset to the initial position.

[0127] In this way, not only can the movement stability of the one-way valve 20 be improved, but also the space occupied in the movement direction of the one-way valve 20 can be reduced. In addition, it is also convenient for the regulating valve core 31 to drive the valve housing 22 to move.

[0128] Further, as Figures 3 - 9 shown, a gear position convex portion 221 protrudes from the outer peripheral surface of the valve housing 22, and the second end of the first spring is arranged on the gear position convex portion 221. Specifically, the second end of the first spring abuts against the gear position convex portion 221.

[0129] In this way, both elastic ends of the first spring can respectively abut against the gear position convex portion 221 and the inner support 361, so that the first spring is in a compressed state, and the one-way valve 20 has a tendency to reset to the initial position.

[0130] Further, as Figures 3 - 9 shown, a sealing ring convex portion 131 is formed on the inner wall surface of the third flow channel 13. When the one-way valve 20 is in the initial position, the gear position convex portion 221 abuts against the sealing ring convex portion 131. In this way, the one-way valve 20 can be limited to the initial position.

[0131] Further, as Figures 3 - 9 shown, the one-way valve 20 further includes a sealing ring 24. The sealing ring 24 is installed on the side of the gear position convex portion 221 away from the regulating valve core 31. When the one-way valve 20 is in the initial position, the sealing ring 24 is clamped between the sealing ring convex portion 131 and the gear position convex portion 221 to block the third flow channel 13.

[0132] Optionally, the gear position convex portion 221 is arranged at one end of the valve housing 22 away from the regulating valve core 31.

[0133] Further, as Figures 3 - 9 shown, a plurality of the gear position convex portions 221 are distributed at intervals in the circumferential direction of the valve housing 22 to open the third flow channel 13 when the one-way valve 20 leaves the initial position; or, the gear position convex portion 221 is an annular convex portion, and a water passing hole is provided on the gear position convex portion 221 to open the third flow channel 13 when the one-way valve 20 leaves the initial position; and / or,

[0134] A water passing gap is provided between the end face of the gear position convex part 221 and the inner wall surface of the third flow channel 13, so as to open the third flow channel 13 when the one-way valve 20 leaves the initial position.

[0135] In this way, it is possible to open the third flow channel 13 when the one-way valve 20 leaves the initial position.

[0136] In this embodiment, a plurality of the gear position convex parts 221 are circumferentially spaced apart on the valve housing 22, and there is a water passing interval between two adjacent gear position convex parts 221. The annular protrusion formed by the plurality of gear position convex parts 221 is slidably installed in the third flow channel 13 to improve the movement stability of the valve housing 22.

[0137] Of course, in other embodiments, a sealing convex part can be convexly provided on the circumferential surface of the valve housing 22 and on the side of the gear position convex part 221 away from the regulating valve core 31 to cooperate with the sealing ring convex 131.

[0138] Furthermore, as Figures 3 - 9 shown, the valve housing 22 includes a housing body and a valve cover. The one-way valve core 21 includes a valve core head and a valve core guide post connected to the valve core head. A limiting step is convexly provided on the inner wall surface of the housing body. When the one-way valve core 21 is in the closed position, the valve core head abuts against the limiting step; the valve cover is provided with a water passing structure and a guide hole, and the valve core guide post is slidably installed in the guide hole.

[0139] The second elastic member 23 is a second spring. The second spring is sleeved outside the valve core guide post, and its two ends respectively abut against the valve core head and the valve cover.

[0140] Specifically, the regulating valve core 31 is used to abut against the valve cover to drive the valve housing 22 and the one-way valve 20 to move.

[0141] Specifically, the initial distance is the distance between the valve cover and the regulating valve core 31 in the moving direction of the regulating valve core 31.

[0142] Furthermore, as Figures 3 - 9 shown, the temperature control driving assembly 32 includes a push rod 321, a temperature sensing housing 322 and a temperature sensing medium 323 that expands when heated. The temperature sensing housing 322 is located on the water outlet side of the one-way valve 20. The push rod 321 is slidably installed in the temperature sensing housing 322, and the regulating valve core 31 is installed at the outer end of the push rod 321; the temperature sensing medium 323 is provided in the temperature sensing housing 322. The temperature sensing medium 323 is used to expand when the water temperature in the water flow channel rises to a preset temperature, so as to make the push rod 321 extend, and drive the regulating valve core 31 to move towards the direction close to the one-way valve 20; the temperature sensing medium 323 is also used to contract when cooled.

[0143] Specifically, when the water temperature of the temperature-sensitive medium 323 at the valve housing 22 rises to a preset temperature, it will expand, thereby driving the push rod 321 to slide so that the push rod 321 extends; when the water temperature at the temperature-sensitive reaction part drops below the preset temperature, the temperature-sensitive medium 323 contracts, so that the push rod 321 can be reset along with the temperature-sensitive medium 323 or driven by other reset parts.

[0144] Among them, the temperature control driving component 32 is a temperature bulb component, that is, the temperature-sensitive housing 322 and the temperature-sensitive medium 323 inside the temperature-sensitive housing 322 form a temperature bulb, and together with the push rod 321, etc., they form a temperature bulb component.

[0145] Optionally, the temperature-sensitive medium 323 is paraffin, or methanol, or toluene, etc. It should be noted that the size of the preset temperature is related to the selection of the temperature-sensitive medium 323. For example, when the temperature-sensitive medium 323 is paraffin, the preset temperature can be 37 degrees, etc.

[0146] Furthermore, as Figures 3 - 9 shown, the temperature control driving component 32 further includes a third elastic member 324, and the third elastic member 324 is used to make the regulating valve core 31 have a tendency to reset to the initial position. In this way, when the temperature-sensitive medium 323 contracts, the third elastic member 324 will drive the regulating valve core 31 and the push rod 321 to reset together, thereby improving the reliability and other performances of the return water valve 100.

[0147] In a specific embodiment, the third elastic member 324 can be selected as a spring, a spring piece, or a rubber band, etc.

[0148] In this embodiment, as Figures 3 - 9 shown, the third elastic member 324 is a third spring. In this way, the structure can be simplified, and the performance of the spring is relatively stable, thereby improving the reliability.

[0149] Furthermore, as Figures 3 - 9 shown, the third spring is sleeved outside the regulating valve core 31, and both ends of the third spring are respectively arranged on the inner support 361 and the regulating valve core 31, so that the regulating valve core 31 has a tendency to reset. In this way, not only can the stability of the movement of the regulating valve core 31 be improved, but also the space occupied in the moving direction of the regulating valve core 31 can be reduced.

[0150] Furthermore, as Figures 3 - 9 shown, the regulating valve core 31 includes a valve core main body 311 and a limiting convex portion 313 protruding from the circumferential surface of the valve core main body 311, and both ends of the third spring are respectively arranged on the inner support 361 and the limiting convex portion 313, so that the regulating valve core 31 has a tendency to reset.

[0151] Specifically, both ends of the third spring respectively abut against the limiting convex portion 313 and the inner support 361, so that the third spring is in a compressed state, giving the limiting valve core a tendency to reset.

[0152] Further, as Figures 3 - 9 shown, an installation groove 314 is formed on the end face of one end of the valve core body 311 (i.e., the end facing the second flow channel 12), and the outer end of the ejector rod 321 is installed in the installation groove 314.

[0153] Further, as Figures 3 - 9 shown, a water through hole 315 communicating with the installation groove 314 is provided on the valve core body 311.

[0154] Specifically, a plurality of the water through holes 315 are circumferentially spaced apart on the valve core body 311.

[0155] Specifically, the water through hole 315 extends to the end face of the valve core body 311 facing the second flow channel 12.

[0156] In this way, blocking of the third flow channel 13 can be prevented.

[0157] Further, as Figures 3 - 9 shown, the regulating valve core 31 further includes a sliding portion 312 provided at one end of the valve core body 311 (i.e., the end facing the one-way valve 20), and the sliding portion 312 is slidably installed in the installation through hole 3611.

[0158] Wherein, the sliding portion 312 and the valve core body 311 form a stepped structure for limiting the movement of the regulating valve core 31.

[0159] Specifically, the end of the sliding portion 312 (i.e., the end facing the one-way valve 20) is used to abut against the valve housing 22 (the valve cover).

[0160] Of course, in other embodiments, the temperature sensing drive assembly can also be set in other structural forms. For example, the temperature sensing drive assembly can further include a temperature sensing seat, a temperature sensing elastic sheet and an elastic reset member provided on the temperature sensing seat, so that the regulating valve core 31 extends when the temperature sensing elastic sheet deforms due to temperature increase and the regulating valve core 31 retracts through the elastic reset member; and so on.

[0161] Of course, in other embodiments, a convex structure can also be provided on the inner wall surface of the third flow channel 13 for installing the first spring, the regulating valve core 31, the third spring, etc.

[0162] Further, as Figures 3 - 9As shown, the return water valve 100 further includes a fourth elastic member 40. The temperature control driving assembly 32 is movably disposed in the water flow channel, and the fourth elastic member 40 is configured to make the temperature control driving assembly 32 tend to move in a direction close to the one-way valve 20. Specifically, the temperature sensing housing 322 is movably disposed in the water flow channel, and the fourth elastic member 40 is configured to make the temperature sensing housing 322 tend to move in a direction close to the one-way valve 20.

[0163] Wherein, the sliding direction of the regulating valve core 31 and the moving direction of the temperature sensing housing 322 should both be in a direction close to or away from the one-way valve 20.

[0164] It can be understood that the temperature control driving assembly 32 formed by using a temperature sensing medium 323 such as paraffin usually has the characteristic of temperature sensing delay, that is, when the temperature control driving assembly 32 drives the one-way valve 20 to move to the initial position of the one-way valve 20 through the regulating valve core 31, it still has a tendency to drive the regulating valve core 31 to move, which may damage the regulating valve core 31 and the like.

[0165] However, in the present invention, by movably disposing the temperature control driving assembly 32 in the water flow channel and providing the fourth elastic member 40 to make the temperature control driving assembly 32 tend to move in a direction close to the one-way valve 20, the adverse effects brought by the temperature sensing delay characteristic of the temperature sensing medium 323 such as paraffin can be eliminated.

[0166] Optionally, as Figures 3 - 9 shown, the fourth elastic member 40 is a fourth spring. Specifically, the fourth spring is sleeved outside the temperature sensing housing 322, and one end is connected to the inner wall surface of the water flow channel, and the other end is connected to the temperature sensing housing 322, so that the temperature sensing housing 322 has a tendency to move in a direction close to the one-way valve 20.

[0167] Optionally, the elastic coefficient of the third spring is less than the elastic coefficient of the fourth spring.

[0168] Furthermore, as Figures 3 - 9 shown, in order to improve the installation and movement stability of the temperature control driving assembly 32, the temperature control assembly 30 further includes a support frame 35. The support frame 35 is fixedly installed in the third flow channel 13, and the temperature control driving assembly 32 is installed on the support frame 35.

[0169] Specifically, the support frame 35 is provided with a support hole, and the temperature sensing housing 322 is slidably installed in the support hole, so that the temperature control driving assembly 32 is movably installed in the water flow channel. Wherein, the support frame 35 is located on a side of the valve core sleeve 36 away from the one-way valve 20.

[0170] Furthermore, as Figures 3 - 8As shown, the first flow channel 11 includes a first flow section 111. One end of the first flow section 111 is provided with a first flow port, and the other end of the first flow section 111 communicates with the third flow channel 13. Moreover, the extending direction of the first flow section 111 is the same as that of the third flow channel 13.

[0171] Optionally, a filter screen 70 is further provided at the first flow port.

[0172] Furthermore, as Figures 3 - 8 shown, the second flow channel 12 includes a second flow section 121. One end of the second flow section 121 is provided with a second flow port, and the other end of the second flow section 121 communicates with the third flow channel 13. Moreover, the extending direction of the second flow section 121 is the same as that of the third flow channel 13.

[0173] The temperature control component 30 is installed in the second flow section 121 and the third flow channel 13.

[0174] Optionally, as Figures 3 - 8 shown, the first flow section 111, the third flow channel 13 and the second flow section 121 are all straight flow channels, and the first flow section 111 and the second flow section 121 are respectively arranged at both ends of the third flow channel 13.

[0175] Furthermore, as Figures 3 - 8 shown, the first flow channel 11 further includes a third flow section 112 communicating with the first flow section 111. The connection part of the first flow section 111 and the third flow section 112 communicates with the third flow channel 13, and one end of the third flow section 112 is provided with a third flow port.

[0176] The second flow channel 12 further includes a fourth flow section 122 communicating with the second flow section 121. The connection part of the second flow section 121 and the fourth flow section 122 communicates with the third flow channel 13, and one end of the fourth flow section 122 is provided with a fourth flow port.

[0177] Of course, in other embodiments, the water flow channel can also be designed into other structural forms. For example, the first flow channel 11, the second flow channel 12 and the third flow channel 13 can form an H-shaped structure, etc.

[0178] Furthermore, as Figures 3 - 8 shown, the valve core sleeve 36 is arranged in the middle section of the third flow channel 13.

[0179] Furthermore, as Figure 3 and 7 shown, the valve body 10 includes a first valve body 10a and a second valve body 10b which are cooperatively connected. The first valve body 10a has the first flow channel 11 and a part of the third flow channel 13, and the second valve body 10b has the second flow channel 12 and a part of the third flow channel 13.

[0180] Further, as Figure 3 and 7 shown, the first valve body 10a is detachably connected to the second valve body 10b.

[0181] Specifically, the first valve body 10a is snap-connected to the second valve body 10b.

[0182] Optionally, a snap ring 60 is provided at the snap connection between the first valve body 10a and the second valve body 10b.

[0183] The above are only optional embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A return water valve, characterized in that, the return water valve comprises: a valve body having a water flow channel, the water flow channel including a first flow channel and a second flow channel arranged at intervals, and a third flow channel connecting the first flow channel and the second flow channel; a check valve for unidirectionally introducing water in the first flow channel into the second flow channel; the check valve is movably installed in the water flow channel, and the check valve blocks the third flow channel in the initial position; and a first elastic member provided in the water flow channel, the first elastic member being used to make the check valve have a tendency to reset to the initial position; wherein, the check valve is used to leave the initial position when the water pressure difference between the first flow channel and the second flow channel increases to a preset pressure difference, so as to open the third flow channel.

2. The return water valve according to claim 1, characterized in that, the check valve is movably installed in the third flow channel, and the first elastic member is provided in the third flow channel; the return water valve further comprises a temperature control assembly, the temperature control assembly includes a temperature control driving assembly and a regulating valve core, the regulating valve core is located on the water outlet side of the check valve, and the regulating valve core is movably arranged in the water flow channel in a direction away from or close to the check valve; wherein, the check valve is used to move in a direction close to the regulating valve core when the water pressure difference between the first flow channel and the second flow channel increases to a preset pressure difference, so as to open the third flow channel; the temperature control driving assembly is installed in the water flow channel, and the temperature control driving assembly is used to drive the regulating valve core to move in a direction close to the check valve when the water temperature in the water flow channel rises to a preset temperature, so as to drive the check valve that has left the initial position to reset.

3. The return water valve according to claim 2, characterized in that, when the check valve is in the initial position, there is an initial distance between the check valve and the regulating valve core, the initial distance is less than the sum of the maximum movable distance of the regulating valve core and the maximum movable distance of the check valve, and is greater than or equal to the maximum movable distance of the regulating valve core.

4. The return water valve according to claim 3, characterized in that, the temperature control assembly further comprises a valve core sleeve, the valve core sleeve is provided in the third flow channel, and the regulating valve core is movably arranged in the valve core sleeve; the first elastic member is a first spring, the first spring is sleeved outside the check valve, and two ends of the first spring are respectively arranged on the check valve and the valve core sleeve, so as to make the check valve have a tendency to reset to the initial position.

5. The return water valve according to claim 4, characterized in that, the valve core sleeve is provided with a first water passing structure, and / or, the regulating valve core is provided with a second water passing structure, and / or, a water passing gap is formed between the outer peripheral surface of the regulating valve core and the inner wall surface of the valve core sleeve.

6. The return water valve according to claim 4, characterized in that, The inner wall surface of the valve core sleeve is provided with an inner support, the inner support has an installation through hole, one end of the regulating valve core is slidably installed in the installation through hole, and the first end of the first spring is arranged on the inner support.

7. The return water valve according to claim 6, characterized in that the temperature control driving assembly includes a push rod, a temperature sensing shell and a temperature sensing medium that expands when heated. The temperature sensing shell is located on the water outlet side of the one-way valve. The push rod is slidably installed in the temperature sensing shell, and the regulating valve core is installed at the outer end of the push rod; the temperature sensing medium is arranged in the temperature sensing shell. The temperature sensing medium is used to expand when the water temperature in the water flow channel rises to a preset temperature, so that the push rod extends out to drive the regulating valve core to move towards the direction close to the one-way valve; the temperature sensing medium is also used to contract when cooled.

8. The return water valve according to claim 7, characterized in that the temperature control assembly further includes a third elastic member, and the third elastic member is used to make the regulating valve core have a tendency to reset.

9. The return water valve according to claim 8, characterized in that the third elastic member is a third spring. The third spring is sleeved outside the regulating valve core, and the two ends of the third spring are respectively arranged on the inner support and the regulating valve core, so that the regulating valve core has a tendency to reset.

10. The return water valve according to claim 9, characterized in that the regulating valve core includes a valve core main body and a limiting convex portion protruding from the peripheral surface of the valve core main body. An installation groove is formed on the end surface of one end of the valve core main body, and the outer end of the push rod is installed in the installation groove; the two ends of the third spring are respectively arranged on the inner support and the limiting convex portion, so that the regulating valve core has a tendency to reset; a water passing through hole communicating with the installation groove is arranged on the valve core main body.

11. The return water valve according to claim 4, characterized in that the one-way valve includes a second elastic member, a valve shell, and a one-way valve core movably installed in the valve shell. The two ends of the second elastic member are respectively arranged on the valve shell and the one-way valve core, so that the one-way valve core has a tendency to reset to the closed position of closing the one-way valve; the first spring is sleeved outside the valve shell, and the two ends of the first spring are respectively arranged on the valve shell and the valve core sleeve, so that the one-way valve has a tendency to reset to the initial position.

12. The return water valve according to claim 11, characterized in that a gear position convex portion protrudes from the outer peripheral surface of the valve shell, and the second end of the first spring is arranged on the gear position convex portion.

13. The return water valve according to claim 12, characterized in that a sealing ring convex is formed on the inner wall surface of the third flow channel. When the one-way valve is in the initial position, the gear position convex portion abuts against the sealing ring convex.

14. The return water valve according to claim 13, characterized in that the one-way valve further includes a sealing ring. The sealing ring is installed on the side of the gear position convex portion away from the regulating valve core. When the one-way valve is in the initial position, the sealing ring is clamped between the sealing ring convex and the gear position convex portion to block the third flow channel.

15. The return water valve according to claim 13, It is characterized in that a plurality of the gear convex parts are circumferentially and spacedly distributed on the valve housing to open the third flow channel when the one-way valve leaves the initial position; alternatively, the gear convex part is an annular convex part, and a water passing hole is provided on the gear convex part to open the third flow channel when the one-way valve leaves the initial position; and / or a water passing gap is provided between the end face of the gear convex part and the inner wall surface of the third flow channel to open the third flow channel when the one-way valve leaves the initial position.

16. A water supply system It is characterized in that comprising: a gas heating device; a water outlet end, which is connected to the gas heating device through a cold water pipe, a hot water pipe and a water mixing device; and a return water valve as described in any one of claims 1 to 15, wherein the first flow channel of the return water valve is connected to the hot water pipe, and the second flow channel of the return water valve is connected to the cold water pipe.

17. The water supply system as claimed in claim 16 It is characterized in that the gas heating device is a gas water heater or a gas wall-mounted boiler.

18. A water supply system It is characterized in that comprising: a gas heating device; a water outlet end, which is connected to the gas heating device through a cold water pipe, a hot water pipe and a water mixing device; a return water valve as described in any one of claims 1 to 15, wherein the second flow channel of the return water valve is connected to the cold water pipe or the water inlet pipe of the gas heating device; and a return water pipe, one end of which is connected to the hot water pipe and the other end is connected to the first flow channel of the return water valve.

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