Pneumatic triple mixing valve and its working method

Abstract

This invention belongs to the field of engineering components technology, specifically relating to valves, and more particularly to a pneumatic triple-combination mixing valve and its operating method. One type of pneumatic triple-combination mixing valve includes a valve body with a first inlet, a second inlet, and a third inlet on its side wall; an outlet located on one side of the valve body; a mixing channel communicating with the outlet within the valve body; three independent valve chambers communicating with the mixing channel via a first flow channel, a second flow channel, and a third flow channel, respectively; a linkage valve assembly located on the inner wall of the third flow channel near the mixing channel, the linkage valve assembly being linked with and synchronously opening and closing with the third valve core corresponding to the third inlet; and a check valve assembly located inside the third inlet near the third valve core. When the third valve core closes, it drives the linkage valve assembly to close synchronously to seal the third flow channel. The check valve assembly is normally closed, blocking the third inlet, and only opens when the pressure at the third inlet exceeds a set threshold.

Description

Technical Field

[0001] This invention belongs to the field of engineering components technology, specifically relating to valves, and more particularly to a pneumatic triple mixing valve and its working method. Background Technology

[0002] In conductor manufacturing processes, steps such as cleaning and etching often require mixing various process liquids in specific proportions before supplying them to the processing equipment. Existing liquid supply systems typically employ multiple independent valves to control different liquid pipelines, with external pipelines connecting the outlets of each valve to achieve mixing. This approach has significant technical drawbacks: A multi-valve discrete layout requires a large number of external pipelines and connectors, resulting in large installation space, low system integration, and is not conducive to the compact design of semiconductor equipment. The liquids only undergo simple convection after merging, resulting in a short mixing path and insufficient disturbance. This can easily lead to problems such as uneven mixing and large concentration gradients, which directly affect process uniformity and product yield.

[0003] In existing technologies, multi-port combination valves are often used to solve the above-mentioned defects. However, when the corresponding inlet valve (such as the third inlet) is closed, the high-pressure liquid in other channels will backflow and scour the valve port and valve core, causing damage to the valve core sealing surface and affecting the sealing effect. When the corresponding inlet valve (such as the third inlet) is open, due to the high water pressure inside the combination valve, the liquid inside the combination valve is prone to backflow from the corresponding valve (such as the third inlet), resulting in liquid waste and reduced process stability.

[0004] Therefore, how to solve the problem of water flowing out in reverse due to the opening of the corresponding inlet valve (such as the third inlet) is a technical problem that urgently needs to be solved in this field.

[0005] It should be noted that the information disclosed in this background section is only for understanding the background technology of this application concept, and therefore, the above description is not considered to constitute information related to the technology. Summary of the Invention

[0006] This disclosure provides at least one pneumatic triple-combination valve and its operating method.

[0007] In a first aspect, embodiments of this disclosure provide a pneumatic triple mixing valve, comprising: The valve body contains three independent valve chambers and a first liquid inlet, a second liquid inlet and a third liquid inlet corresponding to the three independent valve chambers respectively. Each independent valve chamber is equipped with a valve core. The outlet is located on one side of the valve body, and a mixing channel communicating with the outlet is provided inside the valve body. The three independent valve chambers are connected to the mixing channel through the first flow channel, the second flow channel, and the third flow channel, respectively; The third flow channel is provided with a linkage valve assembly on the inner wall near the mixing channel. The linkage valve assembly is linked with the third valve core corresponding to the third inlet and opens and closes synchronously with it. A check valve assembly is located inside the third inlet near the third valve core. When the third valve core closes, it drives the linkage valve assembly to close synchronously to seal the third flow channel; The check valve assembly is normally closed to block the third inlet, and opens only when the pressure at the third inlet exceeds the set threshold of the check valve assembly.

[0008] In one alternative embodiment, the liquid outlet directions of the first flow channel and the third flow channel are arranged opposite to each other, so that the liquids output from the first flow channel and the third flow channel are mixed in a countercurrent manner within the mixing channel.

[0009] In one optional embodiment, the linkage valve assembly includes: A retaining ring is fixed to the inner wall of the third flow channel; A sealing disc, which is hinged to the side wall of the retaining ring, the side wall abutting against the retaining ring to seal the third flow channel; A connecting sleeve is fitted onto the fixing rod on the outer wall of the third valve core; The linkage rod has its two ends hinged to the connecting sleeve and the sealing plate, respectively; When the third valve core moves upward, it pulls the linkage rod to move upward in sync, and the linkage rod pulls the sealing disc to flip upward to open the third flow channel.

[0010] In one optional embodiment, the linkage rod is an elastic element, and its length is greater than the distance between the connecting sleeve and the sealing disc; wherein, when the third valve core moves downward, it pushes the linkage rod to move downward synchronously, and the linkage rod pushes the sealing disc to flip downward to seal the third flow channel; After the third valve core and the sealing disc seal synchronously, the linkage rod elastically deforms into an arc shape.

[0011] In one optional embodiment, a check valve chamber is provided near the third liquid inlet of the valve body, and the check valve assembly is disposed in the check valve chamber; The check valve assembly includes: The system includes a check spring, a check washer, and a check valve plate, wherein the check valve plate is fixed to the side wall of the check washer, and the check spring abuts against the check washer. The check spring is adapted to push the check valve plate toward the third inlet to seal the third inlet.

[0012] In one optional embodiment, the check valve plate is a circular flexible sealing plate, and the check gasket is a rigid support plate, and the two are coaxially fixedly connected.

[0013] In one optional embodiment, the upper end of the valve body is provided with a pneumatic control unit corresponding to the three valve chambers, and the pneumatic control unit includes: a piston, a return spring, an air inlet and an air outlet; The lower end of the piston is connected to the valve core, and the upper end abuts against the return spring. Under the action of the return spring, the valve core is normally closed and pressed against the bottom of the valve cavity. When air is introduced into the air inlet, the piston drives the valve core to open upward.

[0014] In one optional embodiment, the piston divides the pneumatic control unit into an upper air chamber and a lower air chamber, with the air inlet connected to the lower air chamber and the air outlet connected to the upper air chamber. When the ventilation is turned on, the gas in the upper air chamber is discharged through the air outlet.

[0015] In one optional embodiment, the first liquid inlet, the second liquid inlet, and the third liquid inlet are located on the same side or opposite side of the valve body, and the liquid inlet direction is perpendicular to the axis of the mixing channel.

[0016] In one alternative embodiment, a sealing ring is provided on the bottom wall of each valve core, the inner diameter of which is larger than the diameter of the corresponding flow channel.

[0017] Secondly, this disclosure also provides a method for operating a pneumatic triple mixing valve, comprising the following steps: In the closed state, the third valve core corresponding to the third inlet is closed, the linkage valve assembly descends with the third valve core to seal the port of the third flow channel near the mixing channel, and the check valve assembly blocks the third inlet. When the liquid inlet is opened, air is supplied to the pneumatic control unit. The piston drives the third valve core to rise. The linkage valve assembly opens the third flow channel as the valve core rises. The liquid inlet pressure pushes open the check valve assembly. The liquid enters the mixing channel through the third liquid inlet and the third flow channel. The liquid is mixed and discharged. Liquid is introduced into the first inlet and the third inlet at the same time. The liquids output from the first flow channel and the third flow channel are mixed by flushing in the mixing channel. After mixing, the liquid is output from the outlet. When the valve is closed and reset, the air supply stops. The third valve core descends and closes under the action of the spring. The linkage valve assembly descends synchronously to seal the third flow channel. The check valve assembly resets and blocks the third liquid inlet to prevent backflow and impact.

[0018] The beneficial effects of this invention are that it provides a pneumatic triple-flow mixing valve and its operating method. By incorporating a linkage valve assembly and a check valve assembly within the triple-flow mixing valve body, it achieves sealing at the third flow channel end and blocking at the third inlet, respectively. This collaboratively solves the dual technical challenges of backflow impact in the closed state and liquid backflow in the open state, significantly improving the valve's service life and operational reliability. Furthermore, by setting the liquid storage directions of the first and third flow channels opposite each other, and enabling the two liquids to form opposing flows within the mixing channel, it not only extends the mixing path but also improves the mixing effect, achieving thorough and uniform mixing within a short stroke.

[0019] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 A perspective view of the pneumatic triple mixing valve provided in an embodiment of this disclosure; Figure 2 This is a front view of the pneumatic triple mixing valve provided in an embodiment of this disclosure; Figure 3 Provided for the embodiments of this disclosure Figure 2 Sectional perspective of AA; Figure 4 Provided for the embodiments of this disclosure Figure 2 Sectional front view of BB; Figure 5 A sectional perspective view of the valve body and linkage valve assembly provided in the embodiments of this disclosure; Figure 6 This is a perspective view of the linkage valve assembly provided in an embodiment of this disclosure.

[0023] In the picture: 1. Valve body; 10. Check valve chamber; 2. First inlet; 20. First flow channel; 3. Second liquid inlet; 30. Second flow channel; 4. Third liquid inlet; 40. Third valve core; 41. Third flow channel; 5. Liquid outlet; 50. Mixing channel; 6. Linkage valve assembly; 61. Retaining ring; 62. Sealing disc; 63. Connecting sleeve; 64. Linkage rod; 7. Check valve assembly; 71. Check spring; 72. Check gasket; 73. Check valve plate; 8. Pneumatic control unit; 81. Piston; 82. Return spring; 83. Air inlet; 84. Air outlet. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] In this document, when it is mentioned that a first component is located on a second component, this can mean that the first component can be directly formed on the second component, or that a third component can be inserted between the first and second components. Furthermore, in the accompanying drawings, the thickness of the components may be exaggerated or reduced for the purpose of effectively describing the technical content.

[0026] The terminology used herein is for the purpose of describing specific exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “one,” and “the” may also be intended to include plural forms unless this is clearly stated otherwise. The terms “including,” “comprising,” and “having” are inclusive. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

[0027] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0028] like Figures 1 to 6 As shown, at least one embodiment provides a pneumatic triple mixing valve, comprising: a valve body 1, with three independent valve chambers inside the valve body 1, each valve chamber corresponding to a liquid inlet; a pneumatic control unit 8 corresponding to the three valve chambers is provided at the upper end of the valve body 1, the pneumatic control unit 8 being used to control the independent opening and closing of the corresponding liquid inlets. A first liquid inlet 2, a second liquid inlet 3, and a third liquid inlet 4 are correspondingly provided on the side wall of the valve body 1, the three liquid inlets may be located on the same side or both sides of the valve body 1. In this embodiment, the second liquid inlet 3 and the third liquid inlet 4 are located on one side of the valve body 1, and the first liquid inlet 2 is located on the other side of the valve body 1. The directions of the three liquid inlets are perpendicular to the axis of the mixing channel 50.

[0029] A liquid outlet 5 is located on one side of the valve body 1 near the third liquid inlet 4. A mixing channel 50 extending along the length of the valve body 1 is formed inside the liquid outlet 5, and the mixing channel 50 is directly connected to the liquid outlet 5. Three independent valve chambers are connected to the mixing channel 50 via a first flow channel 20, a second flow channel 30, and a third flow channel 41, respectively. The liquid outlet directions of the first flow channel 20 and the third flow channel 41 are opposite, allowing the two liquids to mix against each other within the mixing channel 50. This not only extends the mixing path but also improves the mixing effect, achieving thorough and uniform mixing within a short stroke, thus improving mixing efficiency.

[0030] like Figure 3 The third flow channel 41 is provided with a linkage valve assembly 6 near the inner wall of the mixing channel 50. The linkage valve assembly 6 is linked with the third valve core 40 corresponding to the third liquid inlet 4 and opens and closes synchronously.

[0031] Reference Appendix Figure 6 Specifically, the linkage valve assembly 6 includes: a fixing ring 61, which is fixed to the inner wall of the third flow channel 41, forming a sealing support base and also used to limit the sealing disc 62. The sealing disc 62 is hinged to the side wall of the fixing ring 61. After being flipped into place, the side wall tightly abuts against the fixing ring 61, achieving a complete seal of the third flow channel 41. At the same time, the flipping opening direction of the sealing disc 62 is opposite to the direction of the flow from the third flow channel 41 to the mixing channel 50. A connecting sleeve 63 is fixedly sleeved on the fixing rod on the outer wall of the third valve core 40. The fixing rod extends radially along the third valve core 40. Specifically, the upper end of the connecting sleeve 63 has an opening, and the inside has a circular groove that matches the outer diameter of the fixing rod. During assembly, the fixing rod is aligned with the fixing rod through the opening, and the connecting sleeve 63 is pushed towards the fixing rod, so that the fixing rod is inserted into the circular groove, thereby fixing the connecting sleeve 63 to the fixing rod. The linkage rod 64 is an elastic rod with its two ends hinged to the connecting sleeve 63 and the sealing plate 62 respectively, and its length is greater than the distance between the connecting sleeve 63 and the sealing plate 62.

[0032] like Figure 5 and Figure 6 The working principle of the linkage valve assembly 6 is as follows: When the third valve core 40 opens upwards, the connecting sleeve 63 pulls the linkage rod 64 upwards, and the linkage rod 64 pulls the sealing disc 62 upwards to open the third flow channel 41. When the third valve core 40 closes downwards, the connecting sleeve 63 pushes the linkage rod 64 downwards, and the linkage rod 64 pushes the sealing disc 62 downwards to seal the third flow channel 41. After the third flow channel 41 is completely sealed by the sealing disc 62, the elastic linkage rod 64 undergoes arc-shaped elastic deformation, providing continuous pre-tightening force to ensure reliable sealing. The linkage valve assembly 6 not only prevents water flow in the mixing channel 50 from impacting the third valve core 40, but also prevents residual liquid in the third flow channel 41 from flowing into the mixing channel 50 when the third inlet 4 is closed, further improving the stability and mixing accuracy of the mixture.

[0033] like Figure 4 A check valve chamber 10 is machined near the third inlet port 4 in the valve body 1. A check valve assembly 7 is installed inside the check valve chamber 10 to normally close and block the third inlet port 4, preventing fluid in the valve body 1 from flowing out through the third inlet port 4. Specifically, the check valve assembly 7 includes: a check spring 71, one end of which abuts against the inner wall of the check valve chamber 10, and the other end is fixed to the side wall of the check gasket 72. The check spring 71 provides the normally closed preload force for the check valve plate 73; the check gasket 72 is a rigid support plate used to support and position the check valve plate 73, and is coaxially arranged with the check valve plate 73; the check valve plate 73 is a circular flexible sealing plate, coaxially fixedly connected with the check gasket 72, and used to block the third inlet port 4. When the water pressure in the third inlet 4 is less than a set threshold, the check spring 71 pushes the check gasket 72 and the check valve plate 73, causing the check valve plate 73 to fit tightly against the inside of the third inlet 4, forming a normally closed seal. However, when the inlet pressure of the third inlet 4 exceeds the set threshold of the check spring 71, the liquid pressure opens the check valve plate 73, allowing the liquid in the third inlet 4 to enter the mixing channel 50 within the valve body 1. The check valve assembly 7 achieves unilateral sealing at the third inlet, solving the technical problem of liquid backflow when the third valve core 40 is open. Continue to refer to the appendix Figure 4 The upper end of valve body 1 corresponds to three valve chambers, each equipped with a pneumatic control unit 8. The three pneumatic control units 8 have identical structures. Each pneumatic control unit 8 includes a piston 81, which is vertically mounted within its corresponding chamber, dividing the chamber into an upper chamber and a lower chamber. The upper chamber corresponds to an outlet 84, and the lower chamber corresponds to an inlet 83. A return spring 82 is installed in the upper chamber, its upper end abutting against the top wall of the chamber and its lower end abutting against the piston 81, used to push the piston 81 downwards. The inlet 83 connects to the lower chamber for receiving control air pressure; the outlet 84 connects to the upper chamber for exhaust. In the normally closed state, the return spring 82 presses down on the piston 81, causing the piston 81 to move the corresponding valve core (such as the third valve core 40) downwards against the bottom of the valve chamber, achieving shut-off. In the open state, compressed air enters through the inlet 83, increasing the pressure in the lower chamber, pushing the piston 81 upwards against the return spring 82, causing the valve core to rise synchronously, opening the valve chamber; gas from the upper chamber is discharged through the outlet 84.

[0034] The bottom walls of the first valve core, the second valve core, and the third valve core 40 are all equipped with sealing rings. The inner diameter of the sealing ring is larger than the diameter of the corresponding flow channel. When the valve core is closed, the sealing ring fits tightly with the valve seat at the bottom of the valve cavity to form a surface seal, which improves the shut-off sealing performance and prevents internal leakage.

[0035] At least one embodiment provides a method for operating a pneumatic triple mixing valve, comprising the following steps: In the closed state, the third valve core 40 corresponding to the third inlet 4 is closed, the linkage valve assembly 6 descends with the third valve core 40 to seal the port of the third flow channel 41 near the mixing channel 50, and the check valve assembly 7 blocks the third inlet 4. When the liquid inlet is opened, air is supplied to the pneumatic control unit 8. The piston 81 drives the third valve core 40 to rise. The linkage valve assembly 6 opens the third flow channel 41 as the valve core rises. The liquid inlet pressure pushes open the check valve assembly 7. The liquid enters the mixing channel 50 through the third liquid inlet 4 and the third flow channel 41. The liquid is mixed and discharged. Liquid is introduced into the first inlet 2 and the third inlet 4 at the same time. The liquid output from the first flow channel 20 and the third flow channel 41 is mixed and flushed in the mixing channel 50. After mixing, the liquid is discharged from the outlet 5. When the valve is closed and reset, the air supply stops. The third valve core 40 descends and closes under the action of the spring. The linkage valve assembly 6 descends synchronously to seal the third flow channel 41. The check valve assembly 7 resets and blocks the third liquid inlet 4 to prevent backflow and impact.

[0036] In the description of the embodiments of the present invention, unless otherwise expressly specified and limited, the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0037] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence unless expressly indicated herein. Based on the above-described preferred embodiments of the invention, and through the above description, those skilled in the art can make various changes and modifications without departing from the technical spirit of the invention. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A pneumatic triple mixing valve, characterized in that, include: The valve body (1) has three independent valve chambers and a first liquid inlet (2), a second liquid inlet (3) and a third liquid inlet (4) corresponding to the three independent valve chambers respectively. Each independent valve chamber is provided with a valve core. The outlet (5) is located on one side of the valve body (1), and a mixing channel (50) communicating with the outlet (5) is provided inside the valve body (1). The three independent valve chambers are connected to the mixing channel (50) through the first flow channel (20), the second flow channel (30) and the third flow channel (41), respectively; The third flow channel (41) is provided with a linkage valve assembly (6) near the inner wall of the mixing channel (50). The linkage valve assembly (6) is linked with the third valve core (40) corresponding to the third inlet (4) and opens and closes synchronously with it. Check valve assembly (7) is located inside the third inlet (4) near the third valve core (40); When the third valve core (40) is closed, it drives the linkage valve assembly (6) to close synchronously to seal the third flow channel (41). The check valve assembly (7) is normally closed to block the third inlet (4), and is only opened when the pressure at the third inlet (4) is greater than the set threshold of the check valve assembly (7); The liquid outlet directions of the first flow channel (20) and the third flow channel (41) are set opposite to each other so that the liquids output from the first flow channel (20) and the third flow channel (41) are mixed in the mixing channel (50). The linkage valve assembly (6) includes: A fixing ring (61) is fixed to the inner wall of the third flow channel (41); A sealing disc (62) is hinged to the side wall of a retaining ring (61), and the side wall of the sealing disc (62) abuts against the retaining ring (61) to seal the third flow channel (41). The connecting sleeve (63) is fitted onto the fixing rod on the outer wall of the third valve core (40); The linkage rod (64) is hinged at both ends to the connecting sleeve (63) and the sealing plate (62) respectively; When the third valve core (40) moves upward, it pulls the linkage rod (64) to move upward in sync. The linkage rod (64) pulls the sealing disc (62) to flip upward to open the third flow channel (41). The linkage rod (64) is an elastic element, and its length is greater than the distance between the connecting sleeve (63) and the sealing disc (62); wherein, when the third valve core (40) moves downward, it pushes the linkage rod (64) to move downward synchronously, and the linkage rod (64) pushes the sealing disc (62) to flip downward to seal the third flow channel (41). After the third valve core (40) and the sealing disc (62) are sealed synchronously, the linkage rod (64) elastically deforms into an arc shape.

2. The pneumatic triple mixing valve as described in claim 1, characterized in that, The valve body (1) has a check valve chamber (10) near the third liquid inlet (4), and the check valve assembly (7) is disposed in the check valve chamber (10); The check valve assembly (7) includes: Check spring (71), check washer (72) and check valve plate (73), wherein the check valve plate (73) is fixed to the side wall of the check washer (72) and the check spring (71) abuts against the check washer (72); The check spring (71) is adapted to push the check valve plate (73) toward the third inlet (4) to seal the third inlet (4).

3. The pneumatic triple mixing valve as described in claim 2, characterized in that, The check valve plate (73) is a circular flexible sealing plate, and the check gasket (72) is a rigid support plate. The two are coaxially fixedly connected.

4. The pneumatic triple mixing valve as described in claim 1, characterized in that, The upper end of the valve body (1) is provided with a pneumatic control unit (8) corresponding to the three valve chambers. The pneumatic control unit (8) includes: a piston (81), a return spring (82), an air inlet (83), and an air outlet (84). The lower end of the piston (81) is connected to the valve core, and the upper end is in contact with the return spring (82). Under the action of the return spring (82), the valve core is normally closed and pressed against the bottom of the valve cavity. When the air inlet (83) is ventilated, the piston (81) drives the valve core to open upward.

5. The pneumatic triple mixing valve as described in claim 4, characterized in that, The piston (81) divides the interior of the pneumatic control unit (8) into an upper air chamber and a lower air chamber. The air inlet (83) is connected to the lower air chamber, and the air outlet (84) is connected to the upper air chamber. When the ventilation is turned on, the gas in the upper air chamber is discharged through the air outlet (84).

6. The pneumatic triple mixing valve as described in claim 1, characterized in that, The first liquid inlet (2), the second liquid inlet (3), and the third liquid inlet (4) are located on the same side or opposite side of the valve body (1), and the liquid inlet direction is perpendicular to the axis of the mixing channel (50).

7. The pneumatic triple mixing valve as described in claim 1, characterized in that, Each valve core has a sealing ring on its bottom wall, and the inner diameter of the sealing ring is larger than the diameter of the corresponding flow channel.

8. A method for operating a pneumatic triple mixing valve, comprising the pneumatic triple mixing valve as described in any one of claims 1-7, characterized in that, Includes the following steps: In the closed state, the third valve core (40) corresponding to the third inlet (4) is closed, the linkage valve assembly (6) descends with the third valve core (40) to seal the port of the third flow channel (41) near the mixing channel (50), and the check valve assembly (7) blocks the third inlet (4). When the liquid inlet is opened, air is supplied to the pneumatic control unit (8). The piston (81) drives the third valve core (40) to rise. The linkage valve assembly (6) opens the third flow channel (41) as the valve core rises. The liquid inlet pressure pushes open the check valve assembly (7). The liquid enters the mixing channel (50) through the third liquid inlet (4) and the third flow channel (41). The liquid is mixed and discharged. The first inlet (2) and the third inlet (4) are filled with liquid at the same time. The liquid output from the first flow channel (20) and the third flow channel (41) are mixed in the mixing channel (50). After mixing, the liquid is discharged from the outlet (5). When the valve is closed and reset, the air supply is stopped. The third valve core (40) descends and closes under the action of the spring. The linkage valve assembly (6) descends synchronously to seal the third flow channel (41). The check valve assembly (7) resets and blocks the third liquid inlet (4) to prevent backflow and impact.

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