Two-phase flow driving structure

Abstract

The invention discloses a two-phase flow driving structure and aims to utilize a corrugated pipe as a pump body and drive liquid to flow through deformation of the corrugated pipe, the corrugated pipe is of an all-metal structure, can bear larger pressure and is good in sealing effect, and according to the technical scheme, the two-phase flow driving structure comprises the pump body, a driving assembly and two channels, the channels are used for allowing liquid to flow, the pump body is connected with the two channels and comprises a telescopic corrugated pipe, and the driving assembly drives the corrugated pipe to stretch out and draw back so that the liquid in the channels can flow.

Description

Technical Field

[0001] The present invention belongs to the technical field of thermal management, and more specifically, relates to a two-phase flow driving structure. Background Art

[0002] Two-phase flow is a common system in thermal management, which has the ability to transfer high-power heat with a small temperature difference. Compared with traditional liquid cooling, the two-phase flow system is lighter in weight, smaller in volume, and can cool a higher heat flux density.

[0003] In two-phase flow heat transfer, the liquid usually returns by capillary structure or gravity. However, the capillary force is very small and cannot overcome gravity to transfer heat from top to bottom in large sizes. In the case of high-power heat transfer, liquid supply shortage is also likely to occur. If a pump is used to drive the liquid flow, ordinary pumps mostly use elastic parts such as rubber for sealing. In a two-phase flow system, the temperature change is large and the pressure fluctuation is also large, and the elastic parts cannot maintain good sealing performance. Therefore, ordinary pumps cannot achieve complete airtightness and cannot be directly applied. Summary of the Invention

[0004] The main object of the present invention is to provide a two-phase flow driving structure, aiming to use a bellows as a pump body and rely on the deformation of the bellows to drive the liquid flow. The bellows is a full-metal structure that can withstand greater pressure and has a good sealing effect.

[0005] According to a first aspect of the present invention, a two-phase flow driving structure is provided, including a pump body, a driving component, and two channels for the liquid to flow through. The pump body is connected to the two channels. The pump body includes a telescopic bellows, and the driving component drives the bellows to expand and contract to make the liquid in the channels flow.

[0006] In the above two-phase flow driving structure, there are two fixed plate bodies arranged at intervals. An active block is provided between the two fixed plate bodies. There are two bellows located between the two fixed plate bodies, and the bellows and the active block are arranged alternately. The bellows is connected to the fixed plate body and the active block.

[0007] A pipe body is connected to the fixed plate body, and the channel is located in the pipe body. A first through hole is provided on the fixed plate body, and the first through hole connects the bellows adjacent to the fixed plate body and the channel.

[0008] The driving component drives the active block to act, so that the active block drives the bellows to expand and contract.

[0009] In the above two-phase flow driving structure, the two channels are connected. A first elastic pressing piece is provided on the side of the first through hole facing away from the bellows to make the liquid flow unidirectionally from the bellows to the channel.

[0010] In the above two-phase flow driving structure, a chamber is provided in the movable block. The chamber communicates with the channel. The chamber communicates with the two bellows through two second through holes respectively. A second elastic pressing piece is provided on the side of the second through hole facing away from the chamber to allow liquid to flow unidirectionally from the chamber to the bellows.

[0011] In the above two-phase flow driving structure, a protective cover is provided on the side of the fixed plate body facing away from the bellows. The protective cover covers the first through hole, and the pipe body communicates with the protective cover.

[0012] In the above two-phase flow driving structure, the two fixed plate bodies are connected by guide posts, and the movable block is slidably matched with the guide posts.

[0013] In the above two-phase flow driving structure, the channel is divided into a first channel and a second channel;

[0014] A first elastic pressing piece is provided on the side of the first through hole connected to the first channel facing away from the first channel. A second through hole communicating the two bellows is provided on the movable block. A second elastic pressing piece is provided on the side of the second through hole away from the first channel. A third elastic pressing piece is provided on the side of the first through hole connected to the second channel close to the second channel to allow liquid to flow unidirectionally from the first channel to the second channel.

[0015] In the above two-phase flow driving structure, a heat pipe is included, and the channels are all arranged in the heat pipe.

[0016] In the above two-phase flow driving structure, two movable plates are included. The heat pipe is located between the two movable plates. The two movable plates are connected by guide posts. The guide posts are slidably matched with the heat pipe. The bellows includes a first bellows and a second bellows. The first bellows is located between one of the movable plates and the heat pipe. The second bellows is located between the other movable plate and the heat pipe;

[0017] The channel is divided into a first channel and a second channel. The heat pipe is provided with a first liquid passing hole, a second liquid passing hole, a third liquid passing hole and a fourth liquid passing hole. The first liquid passing hole communicates the first channel and the first bellows. The second liquid passing hole communicates the first channel and the second bellows. The third liquid passing hole communicates the second channel and the first bellows. The fourth liquid passing hole communicates the second channel and the second bellows;

[0018] The driving assembly drives the movable plate to approach or move away from the heat pipe to expand and contract the bellows.

[0019] In the above two-phase flow driving structure, a first elastic pressing piece is provided on one side of the first liquid passing hole close to the first corrugated pipe, so that liquid can flow unidirectionally from the first channel to the first corrugated pipe;

[0020] A second elastic pressing piece is provided on one side of the second liquid passing hole close to the second corrugated pipe, so that liquid can flow unidirectionally from the first channel to the second corrugated pipe;

[0021] A third elastic pressing piece is provided on one side of the third liquid passing hole far from the first corrugated pipe, so that liquid can flow unidirectionally from the first corrugated pipe to the second channel;

[0022] A fourth elastic pressing piece is provided on one side of the fourth liquid passing hole far from the second corrugated pipe, so that liquid can flow unidirectionally from the second corrugated pipe to the second channel.

[0023] One of the technical solutions in the above technical solutions of the present invention has at least the following advantages or beneficial effects:

[0024] In the present invention, a corrugated pipe is used to construct a pump body, and the deformation of the corrugated pipe is used to drive the liquid to flow, avoiding the problem of insufficient liquid supply in the two-phase flow system; the method of driving the liquid to flow through the elastic deformation of the metal does not need to solve the problem of the sealing friction surface, and the sealing is better and more reliable;

[0025] At the same time, by using the structure of fixing two corrugated pipes between two plates with relatively fixed positions, the problem of large range fluctuations in the pressure at both ends of the corrugated pipe caused by large changes in liquid temperature can be adapted, the driving structure can be simplified, and the service life of the driving structure can be extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described below with reference to the drawings and embodiments;

[0027] Figure 1 is a schematic structural diagram of Embodiment 1 of the present invention;

[0028] Figure 2 is a structural sectional view of Embodiment 1 of the present invention;

[0029] Figure 3 is a schematic structural diagram of Embodiment 2 of the present invention;

[0030] Figure 4 is a structural sectional view of Embodiment 2 of the present invention;

[0031] Figure 5 is a schematic structural diagram of Embodiment 3 of the present invention;

[0032] Figure 6 is a structural sectional view of Embodiment 3 of the present invention.

[0033] Among them, the reference signs of each figure are as follows:

[0034] 1. Pump body; 11. Bellows; 111. First bellows; 112. Second bellows; 2. Channel; 21. First channel; 22. Second channel; 3. Fixed plate body; 31. First through hole; 4. Movable block; 41. Second through hole; 42. Chamber; 5. Pipe body; 6. Guide post; 7. Protective cover; 8. Isothermal plate body; 81. First liquid passing hole; 82. Second liquid passing hole; 83. Third liquid passing hole; 84. Fourth liquid passing hole; 9. Movable plate; 101. First elastic pressing piece; 102. Second elastic pressing piece; 103. Third elastic pressing piece; 104. Fourth elastic pressing piece. Specific embodiments

[0035] The following details the embodiments of the present invention. The examples of the embodiments are shown in the drawings, where the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0036] The following disclosure provides many different embodiments or examples for implementing different solutions of the present invention.

[0037] Embodiment 1

[0038] Referring to Figures 1 to 2 As shown, a two-phase flow driving structure includes a pump body 1, a driving assembly (not shown in the figure), and two channels 2. The channels 2 are for liquid flow. The pump body 1 is connected to the two channels 2. The pump body 1 includes a telescopic bellows 11. The driving assembly drives the bellows 11 to expand and contract to make the liquid in the channels 2 flow;

[0039] The bellows 11 is used to construct the pump body 1, and the deformation of the bellows 11 drives the liquid to flow, avoiding the problem of insufficient liquid supply in the two-phase flow system; generally, the bellows 11 is made of metal material and can withstand a large pressure. The method of driving the liquid flow through the elastic deformation of the metal does not need to solve the problem of the sealing friction surface, and the sealing is better and more reliable.

[0040] In this embodiment, it includes two fixed plate bodies 3 arranged at intervals. There is a movable block 4 between the two fixed plate bodies 3. There are two bellows 11 located between the two fixed plate bodies 3. The bellows 11 and the movable block 4 are arranged alternately. The bellows 11 is connected to the fixed plate body 3 and the movable block 4;

[0041] A pipe body 5 is connected to the fixed plate body 3. The channel 2 is located in the pipe body 5. The fixed plate body 3 is provided with a first through hole 31. The first through hole 31 connects the bellows 11 adjacent to the fixed plate body 3 and the channel 2;

[0042] Channel 2 is divided into a first channel 21 and a second channel 22; the first channel 21 is connected to the cooling device of the two-phase flow system, and the second channel 22 is connected to the heating device of the two-phase flow system. The fluid driven by the pump body 1 absorbs heat and evaporates in the heating device to generate steam. The steam releases heat in the cooling device and condenses into a liquid, and then flows into the pump body 1 through the first channel 21 for recycling;

[0043] On the side of the first through hole 31 connected to the first channel 21 facing away from the first channel 21, there is a first elastic pressing piece 101. On the movable block 4, there is a second through hole 41 connecting the two bellows 11. On the side of the second through hole 41 away from the first channel 21, there is a second elastic pressing piece 102. On the side of the first through hole 31 connected to the second channel 22 close to the second channel 22, there is a third elastic pressing piece 103;

[0044] The driving component drives the movable block 4 to act, so that the movable block 4 drives the bellows 11 to expand and contract, and the expansion and contraction of the bellows 11 drives the liquid to flow;

[0045] When the movable block 4 moves from a position close to the first channel 21 to a position close to the second channel 22, the second elastic pressing piece 102 on the movable block 4 is resisted by the liquid between the movable plate and the second channel 22, and the second elastic pressing piece 102 will seal the second through hole 41. And the third elastic pressing piece 103 will open the first through hole 31 under the impact of the liquid in the bellows 11 close to the second channel 22. Therefore, the movable block 4 will push the liquid in the bellows 11 close to the second channel 22 into the second channel 22, and the first elastic pressing piece 101 will also open the first through hole 31 under the impact of the liquid in the first channel 21, and the liquid in the first channel 21 will enter the bellows 11 close to the first channel 21, and the liquid starts to flow; when the movable block 4 moves from a position close to the second channel 22 to a position close to the first channel 21, the third elastic pressing piece 103 will be pressured by the liquid in the second channel 22, and the third elastic pressing piece 103 will seal the first through hole 31, and the liquid in the second channel 22 will not enter the bellows 11 close to the second channel 22. The second elastic pressing piece 102 will open under the impact of the liquid in the bellows 11 close to the first channel 21, thus opening the second channel 22, and the liquid can be transferred from the bellows 11 close to the first channel 21 to the bellows 11 close to the second channel 22. The first elastic pressing piece 101 is pressured by the liquid in the bellows 11 close to the first channel 21, and the first elastic pressing piece 101 will also seal the first through hole 31, and the liquid will not flow from the bellows 11 close to the first channel 21 to the first channel 21. In this way, the liquid in the driving structure will only unidirectionally transfer from the first channel 21 to the second channel 22; the liquid in the second channel 22 flows through the heating device, absorbs heat and evaporates, then flows through the cooling device to release heat and condense, and finally flows back to the first channel 21 for recycling.

[0046] A structure in which two bellows 11 are fixed between two plates with relatively fixed positions is used to cancel out the pressures at both ends of the two bellows, so as to adapt to the problem of large range fluctuations in the pressures at both ends of the bellows caused by large changes in liquid temperature; the elastic deformation of the bellows 11 is used to drive the liquid flow to ensure the sealing performance of the pump body 1.

[0047] In this embodiment, the first elastic pressing piece 101, the second elastic pressing piece 102 and the third elastic pressing piece 103 have similar structures. They are all a sheet body connected to a metal elastic strip. Relying on the elasticity of the metal elastic strip, the sheet body can cover the through hole. Without external force, the sheet body is in a state of covering the through hole. When the sheet body is pushed by external force, the sheet body will move.

[0048] In this embodiment, the two fixed plate bodies 3 are connected by guide posts 6, and the movable block 4 is slidably matched with the guide posts 6, so that the movable block 4 moves more smoothly. At the same time, the moving direction of the movable block 4 can be restricted to ensure that the movable block 4 drives the bellows 11 to expand and contract, and to prevent the movable block 4 from tearing the bellows 11.

[0049] Embodiment 2

[0050] Refer to Figures 3 to 4 As shown, a two-phase flow driving structure includes a pump body 1, a driving component and two channels 2. The channels 2 are for liquid to flow. The pump body 1 is connected to the two channels 2. The pump body 1 includes a telescopic bellows 11;

[0051] It also includes two fixed plate bodies 3 arranged at intervals. There is a movable block 4 between the two fixed plate bodies 3. There are two bellows 11 located between the two fixed plate bodies 3. The bellows 11 and the movable block 4 are arranged alternately. The bellows 11 are connected to the fixed plate bodies 3 and the movable block 4;

[0052] A pipe body 5 is connected to the fixed plate body 3. The channel 2 is located in the pipe body 5. A first through hole 31 is provided on the fixed plate body 3. The first through hole 31 connects the bellows 11 adjacent to the fixed plate body 3 and the channel 2;

[0053] A first elastic pressing piece 101 is provided on the side of the first through hole 31 facing away from the bellows 11;

[0054] The movable block 4 has a chamber 42. The chamber 42 is communicated with the two bellows 11 through two second through holes 41 respectively. Second elastic pressing pieces 102 are provided on the sides of the second through holes 41 facing away from the chamber 42; the two pipe bodies 5 can be connected together to communicate the two channels 2. At the same time, a pipe is connected to the pipe body 5. The pipe is communicated with the chamber 42 outside the pump body 1 to communicate the channel 2 with the chamber 42 so that the liquid can circulate;

[0055] The driving component drives the movable block 4 to act to drive the bellows 11 to expand and contract by the movable block 4;

[0056] The channel 2 is divided into channel A and channel B. When the movable plate moves from a position close to channel A to a position close to channel B, the second elastic pressing piece 102 close to channel B seals the second through hole 41 under the pressure of the liquid in the corrugated pipe 11. The first elastic pressing piece 101 close to channel B will open the first through hole 31 under the impact of the liquid in the corrugated pipe 11. Therefore, the movable plate can push the liquid from the corrugated pipe 11 into channel B. The second elastic pressing piece 102 close to channel A opens the second through hole 41 under the impact of the liquid in the chamber 42, and the liquid can enter the corrugated pipe 11 close to channel A from the chamber 42. The first elastic pressing piece 101 close to channel A seals the first through hole 31 under the pressure of the liquid in channel A, and the liquid in channel A will not enter the corrugated pipe 11. When the movable plate moves from a position close to channel B to a position close to channel A, the second elastic pressing piece 102 close to channel A seals the second through hole 41 under the pressure of the liquid in the corrugated pipe 11. The first elastic pressing piece 101 close to channel A will open the first through hole 31 under the impact of the liquid in the corrugated pipe 11. Therefore, the movable plate can push the liquid from the corrugated pipe 11 into channel A. The second elastic pressing piece 102 close to channel B opens the second through hole 41 under the impact of the liquid in the chamber 42, and the liquid can enter the corrugated pipe 11 close to channel B from the chamber 42. The first elastic pressing piece 101 close to channel B seals the first through hole 31 under the pressure of the liquid in channel B, and the liquid in channel B will not enter the corrugated pipe 11.

[0057] With this structure, the two corrugated pipes 11 work alternately to increase the flow rate of the pump.

[0058] In this embodiment, a protective cover 7 is provided on the side of the fixed plate body 3 facing away from the corrugated pipe 11. The protective cover 7 covers the first through hole 31, and the pipe body 5 is communicated with the protective cover 7, which is convenient for installing the pipe body 5.

[0059] In this embodiment, the two fixed plate bodies 3 are connected by a guide post 6. The movable block 4 is slidably matched with the guide post 6, so that the movable block 4 moves more smoothly. At the same time, the moving direction of the movable block 4 can be restricted to ensure that the movable block 4 drives the corrugated pipe 11 to expand and contract, and avoid the movable block 4 from tearing the corrugated pipe 11.

[0060] Embodiment 3

[0061] Refer to Figures 5 to 6 As shown, a two-phase flow driving structure includes a pump body 1, a driving component (not shown in the figure), and two channels 2 for liquid to flow. The pump body 1 is connected to the two channels 2. The pump body 1 includes a telescopic corrugated pipe 11, and the driving component drives the corrugated pipe 11 to expand and contract to make the liquid in the channel 2 flow.

[0062] Specifically, it further includes a heat pipe body 8, and the channels 2 are all arranged in the heat pipe body 8;

[0063] It further includes two movable plates 9. The heat pipe body 8 is located between the two movable plates 9. The two movable plates 9 are connected by guide posts 6. The guide posts 6 are in sliding fit with the heat pipe body 8. The corrugated pipe 11 includes a first corrugated pipe 111 and a second corrugated pipe 112. The first corrugated pipe 111 is located between one of the movable plates 9 and the heat pipe body 8, and the second corrugated pipe 112 is located between the other movable plate 9 and the heat pipe body 8;

[0064] The channel 2 is divided into a first channel 21 and a second channel 22. The heat pipe body 8 is provided with a first liquid passing hole 81, a second liquid passing hole 82, a third liquid passing hole 83 and a fourth liquid passing hole 84. The first liquid passing hole 81 communicates with the first channel 21 and the first corrugated pipe 111, the second liquid passing hole 82 communicates with the first channel 21 and the second corrugated pipe 112, the third liquid passing hole 83 communicates with the second channel 22 and the first corrugated pipe 111, and the fourth liquid passing hole 84 communicates with the second channel 22 and the second corrugated pipe 112;

[0065] The driving assembly drives the movable plate 9 to approach or move away from the heat pipe body 8, so as to make the corrugated pipe 11 expand and contract, thereby driving the liquid to flow in the heat pipe body 8 and improving the heat conduction capacity of the heat pipe body 8.

[0066] In this embodiment, a first elastic pressing piece 101 is provided on one side of the first liquid passing hole 81 close to the first corrugated pipe 111; a second elastic pressing piece 102 is provided on one side of the second liquid passing hole 82 close to the second corrugated pipe 112; a third elastic pressing piece 103 is provided on one side of the third liquid passing hole 83 far from the first corrugated pipe 111; a fourth elastic pressing piece 104 is provided on one side of the fourth liquid passing hole 84 far from the second corrugated pipe 112;

[0067] When the first corrugated pipe 111 is compressed, the first elastic pressing piece 101 will seal the first liquid passing hole 81 under the pressure of the liquid in the first corrugated pipe 111, and the liquid in the first corrugated pipe 111 will not enter the first channel 21. The third elastic pressing piece 103 will open the third liquid passing hole 83 under the impact of the liquid in the first corrugated pipe 111, and the liquid in the first corrugated pipe 111 will enter the second channel 22. The second elastic pressing piece 102 will open the second liquid passing hole 82 under the impact of the liquid in the first channel 21, and the liquid in the first channel 21 will enter the second corrugated pipe 112. The fourth elastic pressing piece 104 will seal the fourth liquid passing hole 84 under the pressure of the liquid in the second channel 22, and the liquid in the second channel 22 will not enter the second corrugated pipe 112;

[0068] When the second corrugated pipe 112 is compressed, under the pressure of the liquid in the second corrugated pipe 112, the second elastic pressing piece 102 will seal the second liquid passing hole 82, and the liquid in the second corrugated pipe 112 will not enter the first channel 21. Under the impact of the liquid in the second corrugated pipe 112, the fourth elastic pressing piece 104 will open the fourth liquid passing hole 84, and the liquid in the second corrugated pipe 112 will enter the second channel 22. Under the impact of the liquid in the first channel 21, the first elastic pressing piece 101 will open the first liquid passing hole 81, and the liquid in the first channel 21 will enter the first corrugated pipe 111. Under the pressure of the liquid in the second channel 22, the third elastic pressing piece 103 will seal the third liquid passing hole 83, and the liquid in the second channel 22 will not enter the first corrugated pipe 111;

[0069] Therefore, during the operation of the driving structure, the first channel 21 is always discharging liquid, and the second channel 22 is always receiving liquid, and they operate in this cycle. The liquid in the second channel 22 flows outside the pump body 1, passes through the heated area to evaporate and absorb heat, then passes through the cooling area to condense and release heat, and then flows back to the first channel 21 for another cycle.

[0070] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A two-phase flow driving structure, characterized in that: It comprises a pump body, a driving assembly and two channels, wherein the channels are used for liquid flow, the pump body connects the two channels, the pump body comprises a telescopic bellows, and the driving assembly drives the bellows to telescope so as to allow the liquid in the channels to flow.

2. The two-phase flow driving structure according to claim 1, characterized in that: It comprises two fixed plates arranged at intervals, a movable block is arranged between the two fixed plates, there are two bellows located between the two fixed plates, the bellows and the movable block are arranged alternately, and the bellows connects the fixed plates and the movable block; The fixed plate body is connected to a tube body, the channel is located in the tube body, the fixed plate body is provided with a first through hole, the first through hole connects the corrugated tube adjacent to the fixed plate body and the channel; The driving assembly drives the movable block to move, so that the movable block drives the bellows to expand and contract.

3. The two-phase flow driving structure according to claim 2, characterized in that: The two channels are connected, and a first elastic pressing sheet is provided on a side of the first through hole facing away from the bellows to allow liquid to flow from the bellows to the channel in one direction.

4. The two-phase flow driving structure according to claim 3, characterized in that: The movable block has a chamber in it, the chamber is connected to the channel, and the chamber is connected to the two bellows through two second through holes respectively. A second elastic pressing sheet is provided on the side of the second through hole facing away from the chamber to allow liquid to flow unidirectionally from the chamber to the bellows.

5. The two-phase flow driving structure according to claim 2, characterized in that: A protective cover is provided on the side of the fixed plate body facing away from the corrugated tube. The protective cover is provided on the first through hole, and the tube body is communicated with the protective cover.

6. The two-phase flow driving structure according to claim 2, characterized in that: The two fixed plates are connected via guide posts, and the movable block is slidably matched with the guide posts.

7. The two-phase flow driving structure according to claim 6, characterized in that: The channel is divided into a first channel and a second channel; A first elastic pressing sheet is provided on the side of the first through hole connected to the first channel facing away from the first channel, a second through hole connecting the two bellows is provided on the movable block, a second elastic pressing sheet is provided on the side of the second through hole away from the first channel, and a third elastic pressing sheet is provided on the side of the first through hole connected to the second channel close to the second channel, so as to allow liquid to flow unidirectionally from the first channel to the second channel.

8. The two-phase flow driving structure according to claim 1, characterized in that: It comprises a temperature equalizing plate body, and the channels are all arranged in the temperature equalizing plate body.

9. The two-phase flow driving structure according to claim 8, characterized in that: It includes two movable plates, the temperature balancing plate body is located between the two movable plates, the two movable plates are connected by a guide column, the guide column and the temperature balancing plate body are slidably matched, the bellows includes a first bellows and a second bellows, the first bellows is located between one of the movable plates and the temperature balancing plate body, and the second bellows is located between the other movable plate and the temperature balancing plate body; The channel is divided into a first channel and a second channel, and a first liquid hole, a second liquid hole, a third liquid hole and a fourth liquid hole are provided on the temperature uniformity plate body, the first liquid hole connects the first channel and the first bellows, the second liquid hole connects the first channel and the second bellows, the third liquid hole connects the second channel and the first bellows, and the fourth liquid hole connects the second channel and the second bellows; The driving assembly drives the movable plate to move closer to or farther from the temperature-averaging plate body, so as to allow the bellows to expand and contract.

10. The two-phase flow driving structure according to claim 9, characterized in that: A first elastic pressing sheet is provided on one side of the first liquid passage hole close to the first bellows to allow liquid to flow from the first channel to the first bellows in one direction; A second elastic pressing sheet is provided on one side of the second liquid passage hole close to the second bellows to allow liquid to flow from the first channel to the second bellows in one direction; A third elastic pressing sheet is provided on a side of the third liquid passage hole away from the first bellows to allow liquid to flow from the first bellows to the second channel in one direction; A fourth elastic pressing sheet is provided on a side of the fourth liquid passage hole away from the second bellows to allow liquid to flow from the second bellows to the second channel in one direction.

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