Check valve main body forming die

By designing buffering and shock absorption, convenient film removal and rapid cooling mechanisms in check valve forming molds, the existing molds have been solved, and the problems of poor buffering and shock absorption effect, inconvenient film removal and low cooling efficiency are achieved when used, and a more efficient and practical molding process is achieved.

CN223043617UActive Publication Date: 2025-07-01XIAMEN XINHONGSHUO TECHNOLOGY CO LTD
View PDF 0 Cites 0 Cited by

Patent Information

Application Number
CN202421866098.4
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-08-02
Publication Date
2025-07-01
Estimated Expiration
2034-08-02

AI Technical Summary

Technical Problem

The existing check valve molds are not well buffered and shock-absorbing when used, and are inconvenient to remove films and low cooling efficiency, resulting in the mold being undustrous, poor film removal and reduced die-casting effect.

Method used

A check valve body forming mold including a buffering and shock absorbing mechanism, a convenient membrane decompression mechanism and a rapid cooling mechanism are designed. The buffering and shock absorbing mechanism reduces the impact force between the upper mold frame and the lower mold frame through the cooperation of the buffer spring and the buffer plate; it facilitates the membrane defiling mechanism to achieve automatic membrane defiling through the cooperation of the gear plate, the special-shaped membrane defiling plate and the membrane defiling assembly; the rapid cooling mechanism quickly cools through the cooperation of the water inlet pipe, the sealing plate and the telescopic column.

Benefits of technology

This mold can effectively buffer and absorb shock during die-casting, improve the durability of the mold; realize automatic film removal, improve film removal efficiency and effect; quickly reduce cooling, and improve the quality and efficiency of die-casting molding.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN223043617U_ABST
    Figure CN223043617U_ABST
Patent Text Reader

Abstract

The utility model relates to the technical field of check valve main bodies, in particular to a check valve main body forming die which comprises a lower die frame, convenient demoulding mechanisms are arranged in the lower die frame and on the surface of a die plate, buffering and damping mechanisms are arranged on the inner wall of the lower die frame and the inner wall of an upper die frame, and a rapid cooling mechanism is arranged in the upper die frame. According to the forming die, when the forming die is used for performing die-casting forming on the check valve, buffering and damping treatment can be performed between the lower die frame and the upper die frame, so that the forming die is more durable, automatic demolding treatment can be performed on the cast and formed check valve when the forming die is used, the production efficiency is improved, and the production cost is reduced. According to the forming die for the check valve, the forming die is more practical in use, the demolding effect on the check valve is better, the interior of the upper die frame can be rapidly cooled when the forming die is used, and the die-casting effect on the check valve is better when the forming die is used.
Need to check novelty before this filing date? Find Prior Art

Description

Technical Field

[0001] The utility model relates to the technical field of check valve bodies, in particular to a forming die for a check valve body. Background Technique

[0002] A check valve refers to a valve whose closing member is a circular valve flap and which blocks the reverse flow of the medium by its own weight and the action of the medium pressure. The special mold for a transparent spherical check valve is a mold used for manufacturing and producing check valves. A mold is various molds and tools used in industrial production to obtain the required products by methods such as injection molding, blow molding, extrusion, die casting, or forging, smelting, stamping, etc.

[0003] When a check valve is being prepared, due to excessive injection of the forming die-casting material, it may cause the material to bond between the die bodies, making it difficult to open during demolding and making it difficult to demold simply, efficiently, and stably. In addition, the existing forming molds also have some disadvantages to a certain extent. When the existing forming mold is in use, there will be impact vibrations between the lower mold base and the upper mold base, and the buffer and shock absorption effect of the existing forming mold during use is not good enough. This makes it impossible to buffer and shock-absorb between the lower mold base and the upper mold base when the forming mold is in use, making the forming mold less durable; when the forming mold is in use, demolding is required, and the existing forming mold is not convenient enough during demolding. This makes it impossible to automatically demold the check valve after casting and forming when the forming mold is in use, making the forming mold less practical during use and reducing the demolding effect on the check valve; when the forming mold is in use, the temperature on the surface of the upper mold base will continuously rise, and the cooling efficiency of the existing forming mold during use is relatively low. This makes it impossible to quickly cool the inside of the upper mold base when the forming mold is in use, making the die-casting effect of the forming mold on the check valve decrease. Content of the Utility Model

[0004] The purpose of the utility model is to provide a forming die for a check valve body to solve the problems of insufficient buffer and shock absorption effect, inconvenience during demolding, and low cooling efficiency when the forming die is in use as mentioned in the above background technique.

[0005] To achieve the above object, the present utility model provides the following technical solutions: A forming die for a check valve body, including a lower die carrier, on the surface of which an upper die carrier is provided, on the surface of the upper die carrier a feed inlet is installed, on the surface of the lower die carrier lifting columns are all installed, the top ends of the lifting columns are fixed to the inner wall of the upper die carrier, inside the lower die carrier a support frame is installed, on the surface of the lower die carrier a die plate is installed, on the surfaces of the die plates rod bodies are all installed, one end of the rod bodies extends above the die plate, inside the lower die carrier and on the surface of the die plate a convenient demolding mechanism is provided, the convenient demolding mechanism internally includes a gear disc, a special-shaped demolding plate and a convenient demolding part, on the inner walls of the lower die carrier and the upper die carrier a buffer and shock-absorbing mechanism is provided, the buffer and shock-absorbing mechanism internally includes a buffer column, a buffer frame and a buffer and shock-absorbing part, inside the upper die carrier a rapid cooling mechanism is provided, the rapid cooling mechanism internally includes a fixed cavity, a water inlet pipe, a plugging plate, a fixed cylinder and a telescopic column.

[0006] Preferably, the convenient demolding part is provided inside the lower die carrier and on the surface of the die plate, the convenient demolding part is composed of a demolding component and an ejector plate, inside the lower die carrier an ejector plate is installed, and on the surface of the ejector plate a demolding component is installed.

[0007] Preferably, gear discs are provided on the surfaces of the support frames, on the surface at the central position of the gear discs a special-shaped demolding plate is installed, one end of the special-shaped demolding plate penetrates through the lower die carrier and the die plate and extends into the die plate, and on the surface at the bottom position of the special-shaped demolding plate it is fixed to the surface of the demolding component.

[0008] Preferably, the buffer and shock-absorbing part is provided on the inner wall of the upper die carrier, the buffer and shock-absorbing part is composed of a buffer spring and a buffer plate, buffer frames are installed on the inner walls of the upper die carrier, a buffer plate is provided inside the buffer frames, one end of the buffer plate extends outside the buffer frame, and the buffer plate and the inner wall of the buffer frame are in sliding fit with each other.

[0009] Preferably, equally spaced buffer springs are installed inside the buffer frames, one end of the buffer springs is fixed to the surface of the buffer plate, buffer columns are installed on the inner walls of the lower die carrier, and the buffer columns cooperate with the buffer plate.

[0010] Preferably, a fixed cavity is opened inside the upper die carrier, a water inlet pipe is installed on the surface of the lower die carrier, and one end of the water inlet pipe penetrates through the upper die carrier and extends into the fixed cavity.

[0011] Preferably, above the water inlet pipe a plugging plate for plugging the surface of the water inlet pipe is provided, fixed cylinders are installed on the surfaces of the upper die carrier, and fixed cylinders are installed on the surfaces of the upper die carrier.

[0012] Preferably, a telescopic column is installed inside the fixed cylinder. The output end of the telescopic column is fixed to the surface at the bottom of the plugging plate, and the inner wall of the plugging plate is in contact with the surface of the water inlet pipe.

[0013] Compared with the prior art, the beneficial effects of the present utility model are as follows: This check valve body forming die not only enables the forming die to buffer and shock-absorb between the lower die holder and the upper die holder when the forming die is used for die-casting the check valve, making the forming die more durable, but also enables the forming die to automatically demold the check valve after casting and molding when in use, making the forming die more practical when in use and having a better demolding effect on the check valve. Moreover, it enables the forming die to quickly cool the inside of the upper die holder when in use, making the die-casting effect of the forming die on the check valve better.

[0014] 1. By providing a buffer and shock-absorbing mechanism, when the upper die holder moves downward, the upper die holder drives the buffer frame to move downward. Under the elastic force of the buffer spring inside the buffer frame, the buffer plate is driven to move, causing the buffer plate to slide inside the buffer frame. When the upper die holder die-casts the check valve, the buffer column moves to contact the surface of the buffer plate. At this time, the buffer plate is extruded and moves inside the buffer frame, and the impact force generated when the upper die holder descends for die-casting is greatly reduced under the action of the buffer spring, realizing the function of buffering and shock-absorbing between the lower die holder and the upper die holder of the forming die. Thus, the forming die can buffer and shock-absorb between the lower die holder and the upper die holder when in use, making the forming die more durable.

[0015] 2. By providing a convenient demolding mechanism, when it is necessary to demold the die-cast check valve, the demolding component on the surface of the ejector plate drives the special-shaped demolding plate to move, causing the special-shaped demolding plate to move upward into the inside of the die plate. Under the action of the demolding component, the special-shaped demolding plate pushes the check valve formed on the surface of the die plate, making the formed check valve away from the surface of the die plate and demolding the check valve, realizing the function of automatic demolding of the forming die. Thus, the forming die can automatically demold the check valve after casting and molding when in use, making the forming die more practical when in use and having a better demolding effect on the check valve.

[0016] 3. By providing a rapid cooling mechanism, on the surface of the plugging plate away from the water inlet pipe under normal conditions, the user introduces a refrigerant into the interior of the fixed cavity through the water inlet pipe. After the refrigerant enters the interior of the fixed cavity, it rapidly cools the interior of the upper mold base. At this time, under the action of the telescopic column inside the fixed cylinder, the plugging plate is driven to move downward, so that the plugging plate moves to contact the surface of the water inlet pipe, blocking the cold air inside the fixed cavity, making the cooling effect better when the refrigerant cools the upper mold base, greatly improving the cooling efficiency, realizing the function of rapidly cooling the surface of the upper mold base by the forming mold, so that the forming mold can rapidly cool the interior of the upper mold base during use, and making the die-casting effect of the check valve better when the forming mold is in use. Description of the Drawings

[0017] Figure 1 is a three-dimensional structure schematic diagram of the present utility model;

[0018] Figure 2 is a three-dimensional sectional structure schematic diagram of the present utility model;

[0019] Figure 3 is a front sectional structure schematic diagram of the present utility model;

[0020] Figure 4 is a side sectional structure schematic diagram of the present utility model;

[0021] Figure 5 is a top sectional structure schematic diagram of the present utility model;

[0022] Figure 6 of the present utility model Figure 3 structural schematic diagram of the buffer and shock absorption mechanism;

[0023] Figure 7 is a structural schematic diagram of the rapid cooling mechanism of the present utility model.

[0024] In the figure: 1. Lower mold base; 101. Upper mold base; 102. Feed inlet; 103. Lifting column; 104. Mold plate; 105. Support frame; 106. Rod body; 2. Demolding facilitating mechanism; 201. Tooth disc; 202. Special-shaped demolding plate; 203. Demolding facilitating part; 2031. Demolding assembly; 2032. Ejector plate; 3. Buffer and shock absorption mechanism; 301. Buffer column; 302. Buffer frame; 303. Buffer and shock absorption part; 3031. Buffer spring; 3032. Buffer plate; 4. Rapid cooling mechanism; 401. Fixed cavity; 402. Water inlet pipe; 403. Plugging plate; 404. Fixed cylinder; 405. Telescopic column. Detailed Embodiment

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. In addition, terms such as "first", "second", "third", "upper, lower, left, right" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. At the same time, in the description of the present utility model, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present utility model.

[0026] The structure of a check valve body forming die provided by the present utility model is as Figure 1 and Figure 2 shown, including a lower die holder 1. An upper die holder 101 is arranged on the surface of the lower die holder 1. A feed inlet 102 is installed on the surface of the upper die holder 101. Lifting columns 103 are installed on the surface of the lower die holder 1. The top ends of the lifting columns 103 are fixed to the inner wall of the upper die holder 101. A support frame 105 is installed inside the lower die holder 1. A die plate 104 is installed on the surface of the lower die holder 1. Rod bodies 106 are installed on the surface of the die plate 104. One end of the rod body 106 extends above the die plate 104.

[0027] Furthermore, as Figure 3 and Figure 4 shown, convenient demolding mechanisms 2 are arranged inside the lower die holder 1 and on the surface of the die plate 104. The inside of the convenient demolding mechanism 2 includes a gear disk 201, a special-shaped demolding plate 202, and a convenient demolding part 203. The convenient demolding part 203 is arranged inside the lower die holder 1 and on the surface of the die plate 104. The convenient demolding part 203 is composed of a demolding assembly 2031 and an ejector plate 2032. An ejector plate 2032 is installed inside the lower die holder 1. A demolding assembly 2031 is installed on the surface of the ejector plate 2032. Gear disks 201 are arranged on the surface of the support frame 105. A special-shaped demolding plate 202 is installed on the surface at the central position of the gear disk 201. One end of the special-shaped demolding plate 202 penetrates through the lower die holder 1 and the die plate 104 and extends into the die plate 104. The surface at the bottom position of the special-shaped demolding plate 202 is fixed to the surface of the demolding assembly 2031.

[0028] During implementation, when demolding the check valve formed by die casting is required, the demolding assembly 2031 on the surface of the ejector plate 2032 drives the special-shaped demolding plate 202 to move, causing the special-shaped demolding plate 202 to move upward into the interior of the mold plate 104. Under the action of the demolding assembly 2031, the special-shaped demolding plate 202 pushes the check valve formed on the surface of the mold plate 104, causing the formed check valve to move away from the surface of the mold plate 104, and demolding the check valve to achieve the function of automatic demolding of the forming mold.

[0029] Further, as Figure 3 and Figure 6 shown, buffer and shock-absorbing mechanisms 3 are provided on the inner walls of the lower mold base 1 and the upper mold base 101. The buffer and shock-absorbing mechanism 3 includes a buffer column 301, a buffer frame 302, and a buffer and shock-absorbing part 303. The buffer and shock-absorbing part 303 is arranged on the inner wall of the upper mold base 101 and is composed of a buffer spring 3031 and a buffer plate 3032. Buffer frames 302 are installed on the inner walls of the upper mold base 101. A buffer plate 3032 is arranged inside the buffer frame 302. One end of the buffer plate 3032 extends to the outside of the buffer frame 302, and the buffer plate 3032 is slidably engaged with the inner wall of the buffer frame 302. Equally spaced buffer springs 3031 are installed inside the buffer frame 302. One end of the buffer spring 3031 is fixed to the surface of the buffer plate 3032. Buffer columns 301 are installed on the inner walls of the lower mold base 1, and the buffer columns 301 cooperate with the buffer plate 3032.

[0030] During implementation, when the upper mold base 101 moves downward, the upper mold base 101 drives the buffer frame 302 to move downward. Under the elastic force of the buffer spring 3031 inside the buffer frame 302, the buffer plate 3032 is driven to move, causing the buffer plate 3032 to slide inside the buffer frame 302. When the upper mold base 101 performs die casting on the check valve, the buffer column 301 moves to contact the surface of the buffer plate 3032. At this time, the buffer plate 3032 is pushed inward into the buffer frame 302, and under the action of the buffer spring 3031, the impact force generated when the upper mold base 101 descends for die casting is greatly reduced, so as to achieve the function of buffering and shock absorption between the lower mold base 1 and the upper mold base 101 of the forming mold.

[0031] Further, as Figure 3 and Figure 7As shown in the figure, a rapid cooling mechanism 4 is provided inside the upper die holder 101. The inside of the rapid cooling mechanism 4 includes a fixed cavity 401, a water inlet pipe 402, a sealing plate 403, a fixed cylinder 404, and a telescopic column 405. A fixed cavity 401 is formed inside the upper die holder 101. A water inlet pipe 402 is installed on the surface of the lower die holder 1. One end of the water inlet pipe 402 penetrates through the upper die holder 101 and extends into the fixed cavity 401. Above the water inlet pipe 402, there is a sealing plate 403 for sealing the surface of the water inlet pipe 402. Fixed cylinders 404 are installed on the surface of the upper die holder 101. Telescopic columns 405 are installed inside the fixed cylinders 404. The output end of the telescopic column 405 is fixed to the surface at the bottom position of the sealing plate 403. The inner wall of the sealing plate 403 is in contact with the surface of the water inlet pipe 402.

[0032] During implementation, in the normal state, the sealing plate 403 is away from the surface of the water inlet pipe 402. The user introduces a refrigerant into the fixed cavity 401 through the water inlet pipe 402. After the refrigerant enters the fixed cavity 401, it rapidly cools the inside of the upper die holder 101. At this time, under the action of the telescopic column 405 inside the fixed cylinder 404, the sealing plate 403 is driven to move downward, so that the sealing plate 403 moves to contact the surface of the water inlet pipe 402, blocking the cold air inside the fixed cavity 401, making the cooling effect better when the refrigerant cools the upper die holder 101, and greatly improving the cooling efficiency, so as to realize the function of rapidly cooling the surface of the upper die holder 101 by the forming die.

[0033] Working principle: When in use, first, the lower die holder 1 is placed at a designated position. Under the action of the lifting column 103, the upper die holder 101 is driven to move downward to die-cast the check valve. When the upper die holder 101 moves downward, the upper die holder 101 drives the buffer frame 302 to move downward. Under the elastic force of the buffer spring 3031 inside the buffer frame 302, the buffer plate 3032 is driven to move, so that the buffer plate 3032 slides inside the buffer frame 302. When the upper die holder 101 die-casts the check valve, the buffer column 301 moves to contact the surface of the buffer plate 3032. At this time, the buffer plate 3032 is squeezed and moves into the buffer frame 302. Under the action of the buffer spring 3031, the impact force generated when the upper die holder 101 descends for die-casting is greatly reduced, so as to realize the function of buffering and shock absorption between the lower die holder 1 and the upper die holder 101 by the forming die, so that the forming die can perform buffering and shock absorption treatment between the lower die holder 1 and the upper die holder 101 when in use, making the forming die more durable.

[0034] Subsequently, when it is necessary to demold the check valve formed by die casting, the demolding assembly 2031 on the surface of the ejector plate 2032 drives the special-shaped demolding plate 202 to move, so that the special-shaped demolding plate 202 moves upward into the interior of the mold plate 104. Under the action of the demolding assembly 2031, the special-shaped demolding plate 202 pushes the check valve formed on the surface of the mold plate 104, so that the formed check valve moves away from the surface of the mold plate 104, and the demolding treatment of the check valve is carried out to realize the function of automatic demolding of the forming mold. Thus, when the forming mold is used, it can automatically demold the check valve after casting and forming, making the forming mold more practical in use and having a better demolding effect on the check valve.

[0035] Subsequently, in the normal state, the plugging plate 403 is away from the surface of the water inlet pipe 402. The user introduces the refrigerant into the interior of the fixed cavity 401 through the water inlet pipe 402. After the refrigerant enters the interior of the fixed cavity 401, it quickly cools the interior of the upper mold base 101. At this time, under the action of the telescopic column 405 in the fixed cylinder 404, the plugging plate 403 is driven to move downward, so that the plugging plate 403 moves to contact the surface of the water inlet pipe 402, blocking the cold air in the fixed cavity 401, making the cooling effect better when the refrigerant cools the upper mold base 101 and greatly improving the cooling efficiency, so as to realize the function of quickly cooling the surface of the upper mold base 101 by the forming mold. Thus, when the forming mold is used, it can quickly cool the interior of the upper mold base 101, making the die casting effect of the check valve better when the forming mold is used, and finally completing the use work of the forming mold.

[0036] For those skilled in the art, it is obvious that the present utility model is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present utility model. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present utility model is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present utility model. Any reference signs in the claims should not be regarded as limiting the claimed rights.

Claims

1. A check valve body forming die, comprising a lower die frame (1), characterized in that: The surface of the lower mold frame (1) is provided with an upper mold frame (101), the surface of the upper mold frame (101) is provided with a feed port (102), the surface of the lower mold frame (1) is provided with a lifting column (103), the top end of the lifting column (103) is fixed to the inner wall of the upper mold frame (101), the interior of the lower mold frame (1) is provided with a support frame (105), the surface of the lower mold frame (1) is provided with a mold plate (104), the surface of the mold plate (104) is provided with a rod body (106), one end of the rod body (106) extends to the top of the mold plate (104), the interior of the lower mold frame (1) and the surface of the mold plate (104) are provided with A convenient demolding mechanism (2) is provided, wherein the interior of the convenient demolding mechanism (2) includes a toothed disc (201), a special-shaped demolding plate (202) and a convenient demolding portion (203); the inner walls of the lower mold frame (1) and the upper mold frame (101) are both provided with a buffer shock absorbing mechanism (3); the interior of the buffer shock absorbing mechanism (3) includes a buffer column (301), a buffer frame (302) and a buffer shock absorbing portion (303); the interior of the upper mold frame (101) is provided with a rapid cooling mechanism (4); the interior of the rapid cooling mechanism (4) includes a fixed cavity (401), a water inlet pipe (402), a sealing plate (403), a fixed cylinder (404) and a telescopic column (405).

2. A check valve body forming mold according to claim 1, characterized in that: The convenient demolding portion (203) is arranged inside the lower mold frame (1) and on the surface of the mold plate (104), and the convenient demolding portion (203) is composed of a demolding component (2031) and an ejector plate (2032). The ejector plate (2032) is installed inside the lower mold frame (1), and the demolding component (2031) is installed on the surface of the ejector plate (2032).

3. The check valve body forming mold according to claim 1, characterized in that: The surface of the support frame (105) is provided with a toothed disc (201), and a special-shaped demolding plate (202) is installed on the surface at the center position of the toothed disc (201). One end of the special-shaped demolding plate (202) passes through the lower mold frame (1) and the mold plate (104) and extends to the interior of the mold plate (104). The surface at the bottom position of the special-shaped demolding plate (202) is fixed to the surface of the demolding component (2031).

4. The check valve body forming mold according to claim 1, characterized in that: The buffer and shock absorbing part (303) is arranged on the inner wall of the upper mold frame (101), and the buffer and shock absorbing part (303) is composed of a buffer spring (3031) and a buffer plate (3032). The inner wall of the upper mold frame (101) is installed with a buffer frame (302), and the buffer plate (3032) is arranged inside the buffer frame (302). One end of the buffer plate (3032) extends to the outside of the buffer frame (302), and the buffer plate (3032) and the inner wall of the buffer frame (302) are slidably matched with each other.

5. The check valve body forming mold according to claim 4, characterized in that: The buffer frame (302) is internally installed with buffer springs (3031) at equal intervals, one end of the buffer spring (3031) is fixed to the surface of the buffer plate (3032), and the inner wall of the lower mold frame (1) is installed with buffer columns (301), and the buffer columns (301) and the buffer plate (3032) cooperate with each other.

6. The check valve body molding die according to claim 1, characterized in that: A fixed cavity (401) is provided inside the upper mold frame (101), and a water inlet pipe (402) is installed on the surface of the lower mold frame (1), one end of the water inlet pipe (402) passes through the upper mold frame (101) and extends to the inside of the fixed cavity (401).

7. A check valve body forming mold according to claim 6, characterized in that: A blocking plate (403) for blocking the surface of the water inlet pipe (402) is arranged above the water inlet pipe (402), and a fixing cylinder (404) is installed on the surface of the upper mold frame (101). A fixing cylinder (404) is installed on the surface of the upper mold frame (101).

8. The check valve body forming mold according to claim 7, characterized in that: A telescopic column (405) is installed inside the fixing cylinder (404), and the output end of the telescopic column (405) is fixed to the surface at the bottom position of the blocking plate (403), and the inner wall of the blocking plate (403) is in contact with the surface of the water inlet pipe (402).