Pressure maintaining device

Abstract

The invention provides a pressure maintaining device, and relates to the technical field of liquid pressure maintaining, the pressure maintaining device comprises a cylinder body communicated with a to-be-measured pipeline, a piston arranged in the cylinder body and a force applying mechanism driving the piston to move in the cylinder body, the cylinder body and the to-be-measured pipeline form a containing cavity for containing liquid, and the piston is arranged in the containing cavity. The cylinder body and the to-be-tested pipeline are filled with liquid at the same time, after a small amount of water molecules in the liquid in the to-be-tested pipeline gradually permeate through the to-be-tested pipeline and the internal pressure of the to-be-tested pipeline is gradually reduced, the force application mechanism drives the piston to move, and the piston is driven to extrude the liquid in the cylinder body to be injected into the to-be-tested pipeline. The liquid pressure in the to-be-tested pipeline can be maintained in a specified pressure range, so that the sealing performance of the to-be-tested pipeline can be fully verified.

Description

Technical Field

[0001] The invention relates to the technical field of liquid pressure maintaining technology, and in particular to a pressure maintaining device. Background Art

[0002] When liquid with a pressure of N2 is injected into the pipe to be tested, since both ends of the pipe to be tested can be closed, the liquid pressure in the pipe to be tested can be temporarily maintained at N2. However, a small amount of water molecules in the liquid will gradually penetrate the pipe to be tested, causing the internal pressure of the pipe to be tested to gradually decrease. When the internal liquid pressure value of the pipe to be tested is lower than N1, the leakage in the pipe to be tested will not be easy to be discovered during the sealing performance test, and it is impossible to detect whether there is a leakage in the pipe to be tested. Summary of the invention

[0003] The object of the present invention is to provide a pressure maintaining device, which maintains the liquid pressure inside the pipeline to be tested within a specified pressure range, so as to fully verify the sealing performance of the pipeline to be tested.

[0004] To achieve the above purpose, the technical solution of the embodiment of the present invention is as follows:

[0005] A pressure maintaining device, comprising:

[0006] A cylinder body, wherein the cylinder body is connected to the pipeline to be tested, and the cylinder body and the pipeline to be tested form a containing chamber for containing liquid;

[0007] A piston is disposed in the cylinder body and is used to squeeze the liquid in the cylinder body and inject it into the liquid cooling pipe assembly after being driven;

[0008] The force applying mechanism is used to drive the piston to move so as to squeeze the liquid in the cylinder.

[0009] Furthermore,

[0010] The force applying mechanism includes a gravity block, and the gravity block is used to drive the piston by using its own weight.

[0011] Furthermore,

[0012] The force applying mechanism includes a pushing member and an elastic member arranged between the pushing member and the piston. The pushing member is used to push the elastic member and then compress the elastic member to drive the piston by applying the elastic force of the elastic member.

[0013] Furthermore,

[0014] The elastic member is a compression spring.

[0015] Furthermore,

[0016] The force applying mechanism also includes a screw rod connected to the cylinder body, the push piece is sleeved on the screw rod, a nut is further provided on the side of the push piece away from the cylinder body, and the nut sleeve is provided on the screw rod.

[0017] Furthermore,

[0018] There are four screw rods and four nuts. The four nuts correspond to the four screw rods one by one. The four screw rods are evenly spaced along the circumference of the cylinder body.

[0019] Furthermore,

[0020] The push member is a pressure plate having four through holes, and the four through holes of the pressure plate are penetrated by four screw rods in a one-to-one correspondence, and the nut is a butterfly nut.

[0021] Furthermore,

[0022] The piston is also connected to a rod, and the rod passes through a avoidance hole provided on the pressure plate.

[0023] Furthermore,

[0024] A baffle is also provided outside the cylinder body, and the baffle is used to prevent the piston from escaping from the cylinder body.

[0025] Furthermore,

[0026] The piston is provided with an annular groove, a sealing ring is provided in the annular groove, and the sealing ring is used to block the gap between the piston and the inner wall of the cylinder body.

[0027] Compared with the prior art, the embodiments of the present invention have at least the following technical effects:

[0028] The pressure maintaining device of the embodiment of the present invention includes a cylinder body connected to the pipeline to be tested, a piston arranged in the cylinder body, and a force-applying mechanism for driving the piston to move. The cylinder body and the pipeline to be tested form a containing chamber for containing liquid. The cylinder body and the pipeline to be tested are filled with liquid at the same time. When a small amount of water molecules in the liquid in the pipeline to be tested gradually penetrates the pipeline to be tested, causing the internal pressure of the pipeline to be tested to gradually decrease, the force-applying mechanism drives the piston to move. After the piston is driven, it squeezes the liquid in the cylinder body and injects it into the pipeline to be tested. The liquid pressure inside the pipeline to be tested can be maintained within a specified pressure range, so as to fully verify the sealing performance of the pipeline to be tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the liquid cooling pipe assembly structure;

[0030] Figure 2 It is a structural schematic diagram of an embodiment;

[0031] Figure 3 is a structural schematic diagram of another embodiment;

[0032] Figure 4 is a perspective view of another embodiment;

[0033] Figure 5 This is a design dimension drawing of the inner cavity of the cylinder in another embodiment;

[0034] Figure 6 It is a schematic diagram of the structure of the liquid injection device injecting liquid into the liquid cooling pipe assembly and the cylinder body;

[0035] Figure 7 This is a schematic diagram of a first force condition of a piston in another embodiment;

[0036] Figure 8 Schematic diagram of the second force condition of the piston in another embodiment.

[0037] Description of Figure Numbers:

[0038] 10. Cylinder body; 11. Piston; 12. Gravity block; 13. Push piece; 14. Elastic piece; 15. Screw; 16. Nut; 17. Rod; 18. Baffle; 19. Sealing ring; 20. Liquid cooling pipe assembly; 21. Liquid cooling pipe; 22. Female connector; 23. Male connector; 24. Fluorine injection nozzle; 30. Pressure gauge; 31. Ball valve; 32. Water pump; 33. Water sink. DETAILED DESCRIPTION

[0039] The technical solution of the present invention is further elaborated in detail below in conjunction with the drawings and specific embodiments of the specification. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. In the following description, the expression "some embodiments" is related to a subset of all possible embodiments, but it should be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments, and can be combined with each other without conflict.

[0040] It should also be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "inside", "outside", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0041] See also Figure 1-2In one embodiment of the present invention, the pipeline to be tested is a liquid cooling pipe assembly 20, and its liquid cooling pipe assembly structure includes a liquid cooling pipe 21, and the two ends of the liquid cooling pipe 21 (such as a nylon tube or a rubber tube) are respectively connected to a female joint 22, and the two ends of the female joint 22 are respectively connected to a male joint 23, and the two ends of the male joint are respectively connected to a fluorine injection nozzle 24. The pipeline to be tested is the liquid cooling pipe assembly 20, which is only an example for explanation, and does not limit the pipeline to be tested to only be the liquid cooling pipe assembly 20. A pressure maintaining device includes a cylinder body 10 connected to the fluorine injection nozzle 24 in the liquid cooling pipe assembly 20, a piston 11 arranged in the cylinder body 10, and a force applying mechanism for driving the piston 11 to move. The cylinder body 10 and the liquid cooling pipe assembly 20 form a accommodating chamber for accommodating coolant. The cylinder body 10 and the liquid cooling pipe assembly 20 are filled with coolant at the same time. When the coolant in the liquid cooling pipe assembly 20 After a small amount of water molecules gradually penetrate through the wall of the liquid cooling tube 21, causing the internal pressure of the liquid cooling tube assembly 20 to gradually decrease, the force-applying mechanism drives the piston 11 to move. After the piston 11 is driven, it squeezes the coolant in the cylinder 10 and injects it into the liquid cooling tube assembly 20. The coolant pressure inside the liquid cooling tube assembly 20 placed in the temperature box can be maintained within a specified pressure range to fully verify the sealing performance of the liquid cooling tube assembly 20. In this embodiment, the force-applying mechanism includes a gravity block 12, which is arranged above the piston 11. The gravity block 12 uses its own weight to drive the piston 11 to move in the cylinder 10 to squeeze the coolant in the cylinder 10 and inject it into the liquid cooling tube assembly 20. The gravity block 12 applies a stable pressure to the coolant to maintain the coolant pressure inside the liquid cooling tube assembly 20 within a specified pressure range.

[0042] See also Figure 3 and Figure 4In one embodiment of the present invention, the force-applying mechanism includes a pushing member 13 and an elastic member 14 arranged between the pushing member 13 and the piston 11. After the pushing member 13 pushes the elastic member 14, the elastic member 14 is compressed to drive the piston 11 by the elastic force of the elastic member 14. In this embodiment, the elastic member 14 is a compression spring. The force-applying mechanism also includes a screw rod 15 connected to the cylinder body 10. The pushing member 13 is sleeved on the screw rod 15. A nut 16 is also arranged on the side of the pushing member 13 away from the cylinder body 10. The nut 16 is sleeved on the screw rod 15. There are four screw rods 15 and four nuts 16. The four nuts 16 correspond to the four screw rods 15 one by one. The four screw rods 15 are evenly spaced along the circumference of the cylinder body 10. The push member 13 is a pressure plate. The pressure plate has four through holes. The four through holes of the pressure plate are penetrated by the four screw rods 15 one by one. The nuts 16 are butterfly nuts 16. The piston 11 is also connected to a benchmark rod 17, which passes through a avoidance hole provided on the pressure plate. A compression spring is installed between the pressure plate and the piston 11. The butterfly nut 16 on the adjusting screw 15 can adjust the tightness of the compression spring between the push piece 13 and the piston 11, thereby adjusting the pressure of the cavity in the cylinder body 10. The piston 11 is equipped with a benchmark rod 17, which passes through a avoidance hole provided on the pressure plate. The benchmark rod 17 is provided with a scale, so that the pressure of the cavity in the cylinder body 10 can be reflected by the use of the benchmark rod 17 in conjunction with the pressure plate.

[0043] See also Figure 3 and Figure 4 In one embodiment of the present invention, a baffle 18 is further provided outside the cylinder body 10 to prevent the piston 11 from escaping from the cylinder body 10 when the pressure in the cavity of the cylinder body 10 is too high.

[0044] See also Figure 3 and Figure 4 In one embodiment of the present invention, the piston 11 is provided with an annular groove, a sealing ring 19 is provided in the annular groove, and the sealing ring 19 blocks the gap between the piston 11 and the inner wall of the cylinder body 10.

[0045] See also Figure 6 The liquid injection device includes a pressure gauge 30, a ball valve 31, a water pump 32 and a water tank 33. The pressure gauge 30, the ball valve 31, the water pump 32 and the water tank 33 are connected through a pipeline. The cylinder body 10 of the pressure maintaining device is connected to the fluorine injection nozzle 24 at one end of the liquid cooling pipe assembly 20 structure. The pipeline in the liquid injection device is connected to the fluorine injection nozzle 24 at the other end of the liquid cooling pipe assembly 20 structure. When the ball valve 31 is turned on, the water pump 32 draws the coolant in the water tank 33 into the accommodating cavity formed by the cylinder body 10 and the liquid cooling pipe assembly 20.

[0046] The cooling liquid is injected into the liquid cooling pipe assembly 20 and the cylinder 10 of the pressure maintaining device through the liquid injection device. When the internal pressure value of the liquid cooling pipe assembly 20 is slightly less than N1 as shown on the pressure gauge 30, the ball valve 31 is closed. Figure 7 As shown, that is:

[0047] Fa1=Fs1+f

[0048] Wherein: Fa1 is the force of the coolant on the piston 11, Fs1 is the force of the compression spring on the piston 11, and f is the maximum friction between the sealing ring 19 on the piston 11 and the inner wall of the cylinder body 10.

[0049] When the value of Fa1 decreases, the value of Fs1 remains unchanged, which will cause the friction force to change direction. Only when the difference between Fs1 and Fa1 is greater than f, the piston 11 can apply pressure to the coolant under the action of the compression spring. In this case, the sensitivity of the pressure holding device is greatly affected by the friction force f.

[0050] Adjust the butterfly nut 16 on the pressure maintaining device to gradually increase the compression spring force. When the pressure value in the liquid cooling pipe assembly 20 is equal to N1, stop adjusting the butterfly nut 16. Record the reading L1 of the marker 17 on the pressure maintaining device. Continue to adjust the butterfly nut 16 on the pressure maintaining device to increase the compression spring force. When the pressure value in the liquid cooling pipe 21 is equal to N2, record the reading L2 of the marker 17 on the pressure maintaining device. At this point, close the fluorine injection nozzle 24 at one end of the liquid cooling pipe assembly 20 connected to the liquid injection device (the closing operation of the fluorine injection nozzle 24 can be completed by setting a one-way valve in the fluorine injection nozzle 24), and then detach the liquid injection device.

[0051] At this time, the force on the piston 11 in the pressure maintaining device is as follows: Figure 8 As shown, that is:

[0052] Fa2+f=Fs2

[0053] Wherein: Fa2 is the force of the coolant on the piston 11, Fs2 is the force of the compression spring on the piston 11, and f is the maximum friction between the sealing ring 19 on the piston 11 and the inner wall of the cylinder body 10.

[0054] When Fa2 decreases, the compression spring force overcomes the friction force f to apply pressure to the coolant, increasing the value of Fa2. In this way, the rate at which the coolant pressure decreases will be greatly slowed down.

[0055] When the reading on the mark rod 17 is between L1 and L2 and close to L1, the butterfly nut 16 is adjusted to make the reading close to L2, so that the pressure in the liquid cooling pipe 21 assembly 20 can be restored to N2.

[0056] In order to make the present invention more understandable, further examples are given below:

[0057] The liquid cooling pipe assembly 20 is composed of a nylon tube with an outer diameter of 28 mm and a length of 300 mm. The internal coolant pressure value of the liquid cooling pipe assembly 20 is required to be 2.7-3.0 bar, and an accelerated aging test of 85°C and 85% RH for 1000 hours is performed.

[0058] The water penetration of the liquid cooling tube assembly 20 composed of nylon tubes to be verified is about 4.95g in 1000 hours, and the specific calculated values ​​are shown in the following table 1.

[0059]

[0060] Table 1

[0061] The inner cavity design size of the cylinder body 10 is as follows: Figure 5 As shown, by F=P*S (F is pressure, P is pressure, S is force area), the pressure Fa2 of the coolant on the piston 11 can be calculated. By Fs2=Fa2+f, the elastic force value that the compression spring needs to provide can be obtained.

[0062] The Fs2 values ​​for 3.0 bar and 2.7 bar are shown in Table 2 below.

[0063]

[0064] Table 2

[0065] The main parameters of the compression spring and the length change value △x of the compression spring after being subjected to pressure are shown in the following table 3.

[0066]

[0067] Table 3

[0068] When the reading on the marker 17 changes from L2 to L1, the amount of coolant discharged by the pressure holding device is:

[0069] (15.6-14.2)x1256x1.13 / 1000=1.98g (1.13 is the density of ethylene glycol at 50% solubility).

[0070] Table 1 shows that in the 1000-hour test, the penetration of the nylon tube is about 4.95 g, and 4.95 / 1.98=2.5, 1000 / 2.5 / 24=16.7 days. It can be seen that after the liquid cooling tube assembly 20 composed of nylon tubes is placed in the temperature box, the pressure holding device needs to be adjusted once every 16.7 days so that the reading on the benchmark 17 returns to L2.

[0071] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. The protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A pressure maintaining device, characterized in that: include: A cylinder body (10), the cylinder body (10) being in communication with the pipeline to be tested, the cylinder body (10) and the pipeline to be tested forming a containing chamber for containing liquid; A piston (11) is disposed in the cylinder (10) and is used to be driven to squeeze the liquid in the cylinder (10) and inject it into the pipeline to be tested; The force applying mechanism is used to drive the piston (11) to move so as to squeeze the liquid in the cylinder (10).

2. The pressure maintaining device according to claim 1, characterized in that: The force applying mechanism comprises a gravity block (12), and the gravity block (12) is used to drive the piston (11) by using its own weight.

3. The pressure maintaining device according to claim 1, characterized in that: The force applying mechanism comprises a pushing member (13) and an elastic member (14) arranged between the pushing member (13) and the piston (11); the pushing member (13) is used to push the elastic member (14) and then compress the elastic member (14) to drive the piston (11) by the elastic force of the elastic member (14).

4. The pressure maintaining device according to claim 3, characterized in that: The elastic member (14) is a compression spring.

5. The pressure maintaining device according to claim 3, characterized in that: The force applying mechanism also includes a screw rod (15) connected to the cylinder body (10), the pushing member (13) is sleeved on the screw rod (15), and a nut (16) is further provided on the side of the pushing member (13) away from the cylinder body (10), and the nut (16) is sleeved on the screw rod (15).

6. The pressure maintaining device according to claim 5, characterized in that: There are four screw rods (15) and four nuts (16). The four nuts (16) correspond to the four screw rods (15) one by one. The four screw rods (15) are evenly spaced and arranged along the circumference of the cylinder body (10).

7. The pressure maintaining device according to claim 6, characterized in that: The push member (13) is a pressure plate having four through holes, and the four through holes of the pressure plate are penetrated by four screw rods (15) in a one-to-one correspondence, and the nut (16) is a butterfly nut.

8. The pressure maintaining device according to claim 7, characterized in that: The piston (11) is also connected to a marking rod (17), and the marking rod (17) passes through an avoidance hole provided on the pressure plate.

9. The pressure maintaining device according to claim 1, characterized in that: A baffle (18) is also provided outside the cylinder body (10), and the baffle (18) is used to prevent the piston (11) from escaping from the cylinder body (10).

10. The pressure maintaining device according to claim 1, characterized in that: The piston (11) is provided with an annular groove, a sealing ring (19) is provided in the annular groove, and the sealing ring (19) is used to seal the gap between the piston (11) and the inner wall of the cylinder body (10).

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