Sealing terminal board air tightness detection device

Abstract

The utility model relates to the field, and especially relates to a sealing terminal board air tightness detection device comprising an upper sealing structure, a lower sealing structure, an upper air injection pipeline and a lower air injection pipeline; the upper sealing structure comprises an upper outer sleeve and a plurality of upper inner sleeves arranged in the upper outer sleeve; the lower sealing structure comprises a lower outer sleeve and a plurality of lower inner sleeves arranged in the lower outer sleeve; a to-be-tested sealing terminal plate is horizontally placed in the lower internal sleeve in a suspended manner, and the lower internal sleeve and the upper internal sleeve are matched to press the to-be-tested sealing terminal plate; one end of the lower gas injection pipeline is communicated with an external steam source, and the other end of the lower gas injection pipeline is communicated with the lower sealing external cavity and the lower internal sleeves. According to the utility model, the upper and lower sealing structures form a double-sealing cavity through the outer sleeve and the inner sleeve, and the upper and lower gas injection pipelines are combined for independent gas supply, so that uniform pressurization of the whole area (including the edge area) of the terminal board can be realized, and the comprehensiveness and accuracy of leakage detection are remarkably improved.

Description

Technical Field

[0001] This utility model relates to the field of electrical component testing technology, specifically a device for testing the airtightness of a sealed terminal block. Background Technology

[0002] Sealed terminal blocks are crucial components of current transformers and voltage transformers in the high-voltage switchgear industry. In power systems, they are essential parts of switchgear, serving both as terminals and providing a seal. Quality issues with sealed terminal blocks during the assembly of current and voltage transformers include: scratches and dents on the epoxy resin parts, deformation of studs due to impacts, stud breakage, incorrect stud numbering, and cracks in the injection molding areas. Cracks in the injection molding areas and internal pores can lead to axial and end-face air leakage in the sealed terminal block.

[0003] The factory testing of sealed terminal blocks requires each unit to undergo airtightness testing. There are three existing airtightness testing methods: SF6 wrapping method, negative pressure helium leak detection, and positive pressure helium leak detection. The SF6 wrapping method uses a partial wrapping approach. The process involves placing the component under test into a leak detection fixture, evacuating it, injecting SF6 gas, wrapping it with plastic film at flange joints, and allowing it to stand for 4 hours before testing. If the SF6 gas concentration at all wrapped areas is less than 1 ppm, the component is considered to have passed airtightness testing. However, this method requires manual assembly and wrapping of the component, and the SF6 gas injection requires a 4-hour standing period before testing, resulting in high workload and low efficiency. Negative pressure helium leak detection (such as...) Figure 1 (As shown) This method connects the workpiece to a vacuum pump to create a negative pressure environment. Helium gas is then injected onto the surface of the object. If a leak occurs in the workpiece, the leaking gas will enter the negative pressure environment, and a helium leak detector will detect it. However, due to the difference between the detection conditions and the working conditions of the sealing terminal block, there is a certain false positive rate in the detection results. Furthermore, the actual working condition of the workpiece is positive pressure (rated pressure), but leak detection uses negative pressure, leading to a certain false positive rate and making it difficult to guarantee the reliability of the detection. Positive pressure helium leak detection (such as...) Figure 2(As shown) The internal sealed chamber of the product under inspection needs to be filled with helium gas at a pressure higher than one atmosphere. When there is a leak on the surface of the product, helium gas will enter the surrounding atmosphere through the leak. Then, a suction gun is used to detect the increase in helium concentration in the atmosphere around the product, thereby achieving leakage measurement. According to the different methods of collecting helium gas, the positive pressure method can be divided into the positive pressure suction gun method and the positive pressure accumulation method. The positive pressure suction gun method uses a leak detector suction gun to scan and explore the outer surface of the product under inspection, which can achieve precise location of leaks. The positive pressure accumulation method uses a leak detection device with a certain sealing function to seal the workpiece under inspection, and uses a leak detector suction gun to measure the change in helium concentration in the helium chamber before and after a certain period of time, thereby achieving precise measurement of the total leakage rate of the product under inspection. However, the workpiece under inspection is manually assembled or sealed with hinges, but the reliability of hinge-sealed sealing is difficult to guarantee.

[0004] CN219416601U discloses a sealing terminal leakage test fixture, comprising: a base with a first cavity, a first adapter on the base communicating with the first cavity; a cover plate with a second cavity, a second adapter on the cover plate communicating with the second cavity, wherein when the cover plate closes the base, the second cavity and the first cavity form a sealed chamber for accommodating the sealing terminal, and a first sealing component is provided at the contact point between the sealing terminal and the second cavity; and fasteners respectively provided on the base and the cover plate for fastening the base and the cover plate. However, because the base and the cover plate are hinged to ensure sealing, the hinge has relatively limited bearing capacity and is not suitable for bearing large loads. The clamping force required for the sealing terminal plate to press and seal is about 90kN, which is not suitable for using a hinge for clamping and sealing; moreover, the hinge will loosen and fatigue after long-term use, resulting in a decrease in locking performance. In addition, the loading and unloading of the sealing terminal plate and the assembly of the cover plate are all done manually, which is labor-intensive and has low testing efficiency. Utility Model Content

[0005] To address the problem that hinged joints in existing technologies cannot meet the requirements for compression sealing, this utility model provides a device for detecting the airtightness of a sealing terminal block.

[0006] This utility model is achieved through the following technical solution:

[0007] A sealing terminal block airtightness testing device includes an upper sealing structure, a lower sealing structure, an upper air injection pipeline, and a lower air injection pipeline;

[0008] The upper sealing structure includes an upper outer sleeve and multiple upper inner sleeves arranged in the upper outer sleeve, forming an upper sealing outer cavity between the upper outer sleeve and the upper inner sleeves; one end of the upper air injection pipeline is connected to an external air source, and the other end is connected to the upper sealing outer cavity and the multiple upper inner sleeves.

[0009] The lower sealing structure includes a lower outer sleeve and multiple lower inner sleeves arranged in the lower outer sleeve. The lower outer sleeve and the lower inner sleeve form a lower sealing outer cavity. The lower inner sleeves correspond one-to-one with the upper inner sleeves. The sealing terminal plate to be tested is suspended and placed horizontally in the lower inner sleeve. The lower inner sleeve and the upper inner sleeve cooperate to press the sealing terminal plate to be tested. One end of the lower gas injection pipeline is connected to an external gas source, and the other end is connected to the lower sealing outer cavity and the multiple lower inner sleeves.

[0010] Preferably, the cross-sectional area of ​​the lower inner sleeve is larger than that of the upper inner sleeve.

[0011] Preferably, the outer diameter of the upper inner sleeve is equal to the inner diameter of the lower inner sleeve.

[0012] Preferably, the top of the top plate is provided with a pressure structure, which includes a pressure plate and multiple pressure shafts. The top of the pressure plate is connected to the pressure device, one end of the pressure shaft is fixedly connected to the bottom of the pressure plate, and the other end is fixedly connected to the top plate. The pressure shafts correspond one-to-one with the upper inner sleeves, and the pressure shafts and the upper inner sleeves are coaxially arranged.

[0013] Preferably, a pressure sensor is also provided on the pressure shaft.

[0014] Preferably, the pressure shaft is a telescopic shaft structure.

[0015] Preferably, both the upper and lower gas injection lines are equipped with corresponding solenoid valves.

[0016] Preferably, the upper outer sleeve and the lower outer sleeve are fitted together by a groove and protrusion structure.

[0017] Preferably, an annular terminal plate support is provided on the side wall of the lower inner sleeve, and the sealing terminal plate to be tested is placed on the sealing buffer ring.

[0018] Preferably, a sealing buffer ring is provided between the terminal block support and the sealed terminal block to be tested.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] This utility model discloses a sealing terminal board airtightness testing device that uses a rapid compression sealing method, avoiding the cumbersome manual bolt assembly and the unreliability of hinge locking. A single compression action can seal the inner and outer sealing cavities simultaneously, that is, simultaneously achieving the sealing between the lower sealing cavity and the sealing terminal board, and the sealing between the upper sealing cavity and the lower sealing cavity. Multiple sealing terminal boards to be tested can be tested simultaneously, resulting in high testing efficiency and accurate and reliable test results.

[0021] Furthermore, the outer cavity of the upper sealing cavity and the outer cavity of the upper sealing cavity are connected to the upper gas injection pipeline and the lower gas injection pipeline respectively through solenoid valves and gas pipes. In the event of helium leakage in the inner cavity, helium can be recovered from the outer cavity to avoid helium waste and achieve recycling. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of negative pressure helium leak detection in existing technology;

[0023] Figure 2 This is a schematic diagram of positive pressure helium leak detection in existing technology;

[0024] Figure 3 This is a schematic diagram of the structure of a sealing terminal block airtightness testing device according to the present invention;

[0025] Figure 4 This is a schematic diagram of the upper sealing cavity in the airtightness testing device for a sealed terminal block according to the present invention.

[0026] Figure 5 This is a top view of the upper sealing cavity in the airtightness testing device for a sealed terminal block according to this utility model;

[0027] Figure 6 This is a schematic diagram of the lower sealing cavity in the airtightness testing device for a sealing terminal block according to the present invention;

[0028] Figure 7 This is a top view of the lower sealing cavity in the airtightness testing device for a sealing terminal block according to this utility model.

[0029] In the diagram, 1. Pressure plate; 2. Pressure adjustment structure; 3. Pressure sensor; 4. Pressure shaft; 5. Inner cavity of upper sealing chamber; 6. Outer cavity of upper sealing chamber; 7. Test sealing terminal plate; 8. Inner cavity of lower sealing chamber; 9. Outer cavity of lower sealing chamber; 10. Second solenoid valve; 11. Lower air injection line; 12. Lower external sleeve; 13. Terminal plate support; 14. Upper air injection line; 15. First solenoid valve; 16. Upper external air injection branch pipe; 17. Lower external air injection branch pipe. Detailed Implementation

[0030] The present invention will be further described in detail below with reference to specific embodiments. The description is for explanation and not limitation of the present invention.

[0031] This utility model discloses a device for detecting the airtightness of a sealed terminal block, referring to... Figure 3 It includes an upper sealing structure, a lower sealing structure, an upper gas injection line 14, and a lower gas injection line 11.

[0032] Reference Figure 4 , 5The upper sealing structure includes an upper outer sleeve and multiple upper inner sleeves arranged within the upper outer sleeve. An inner cavity 5 of the upper sealing cavity is formed inside the upper inner sleeve, and an outer sealing cavity is formed between the upper outer sleeve and the upper inner sleeves. In one embodiment, the upper sealing structure includes a top plate, an upper outer sleeve, and multiple upper inner sleeves. The tops of both the upper outer sleeve and the upper inner sleeves are fixedly connected to the top plate, and the multiple upper inner sleeves are evenly arranged within the upper outer sleeve.

[0033] In one embodiment, a pressure structure is provided on the top of the top plate. The pressure structure includes a pressure plate 1 and multiple pressure shafts 4. The top of the pressure plate 1 is connected to a pressure device, and one end of each pressure shaft 4 is fixedly connected to the bottom of the pressure plate 1, while the other end is fixedly connected to the top plate. Each pressure shaft 4 corresponds to an upper inner sleeve, and the pressure shafts 4 and the upper inner sleeves are coaxially arranged. The pressure plate 1 and the pressure shafts 4 apply pressure through the top plate. The coaxiality of the pressure shafts 4 and the upper inner sleeves ensures uniform pressure distribution. Each pressure shaft 4 corresponds to one inner sleeve, ensuring uniform force distribution across all parts of the terminal block and avoiding excessive or insufficient local pressure that could affect the test results.

[0034] In one embodiment, a pressure sensor 3 is also provided on the pressure shaft 4. The pressure on the sealing terminal plate under test can be monitored by the pressure sensor 3 and adjusted by the pressure adjustment device.

[0035] In one embodiment, a pressure adjustment structure 2 is provided on the pressure shaft 4. In this embodiment, the pressure shaft 4 adopts a telescopic structure, such as a threaded telescopic structure or a through hole, telescopic protrusion structure, etc., which can realize length adjustment.

[0036] One end of the upper air injection line 14 is connected to an external air source, and the other end is connected to the upper sealed external cavity and multiple upper internal sleeves. In one embodiment, the upper air injection line 14 includes a connected upper air injection main pipe, an upper external air injection branch pipe 16, and multiple upper internal air injection branch pipes. The upper air injection main pipe is connected to an external air source, and the upper internal air injection branch pipes pass through the top plate and are connected to the interior of the upper internal sleeves; the upper external air injection branch pipes 16 are connected to the upper sealed external cavity.

[0037] Reference Figure 6 , 7 The lower sealing structure includes a lower outer sleeve 12 and a plurality of lower inner sleeves arranged within the lower outer sleeve 12. The lower inner sleeves form a lower sealing cavity inner cavity 8, and the lower outer sleeve 12 and the lower inner sleeve 12 form a lower sealing outer cavity. Each lower inner sleeve corresponds one-to-one with an upper inner sleeve. In one embodiment, the lower sealing structure includes a base plate, a lower outer sleeve 12, and a plurality of lower inner sleeves. The bottoms of both the lower inner sleeves and the lower outer sleeve 12 are connected to the base plate. The lower inner sleeves are evenly arranged within the lower outer sleeve 12, and each lower inner sleeve corresponds one-to-one with an upper inner sleeve.

[0038] In one embodiment, the upper outer sleeve and the lower outer sleeve 12 are fitted together by a groove and protrusion structure.

[0039] One end of the gas injection line 11 is connected to an external gas source, and the other end is connected to the lower sealing external cavity and multiple lower internal sleeves. Specifically, one end of the gas injection line 11 is connected to an external gas source, and the other end is connected to the lower sealing external cavity and multiple lower internal sleeves. In one embodiment, the gas injection line 11 includes a connected gas injection main pipe, a lower external gas injection branch pipe, and multiple lower internal gas injection branch pipes. The gas injection main pipe is connected to an external gas source, the lower internal gas injection branch pipes pass through the bottom plate and are connected to the lower internal sleeves, and the lower external gas injection branch pipes are connected to the lower sealing external cavity.

[0040] Both the upper gas injection line 14 and the lower gas injection line 11 are equipped with corresponding solenoid valves. In one embodiment, the upper external gas injection branch 16 and multiple upper internal gas injection branch lines are each equipped with a first solenoid valve 15; the lower external gas injection branch line and multiple lower internal gas injection branch lines are each equipped with a second solenoid valve 10.

[0041] The sealing terminal plate 7 to be tested is placed horizontally and suspended in the lower inner sleeve. The lower inner sleeve and the upper inner sleeve cooperate to press the sealing terminal plate 7 under test. In one embodiment, the cross-sectional area of ​​the lower inner sleeve is larger than that of the upper inner sleeve. When the upper and lower inner sleeves cooperate to press the terminal plate, the larger lower inner sleeve may provide better support, prevent the terminal plate from deforming, and ensure sealing, avoiding misjudgment due to local stress concentration.

[0042] In one embodiment, the outer diameter of the upper inner sleeve is equal to the inner diameter of the lower inner sleeve, thereby ensuring a tight fit between the upper and lower sleeves and preventing air leakage. When the two sleeves are pressed against the sealing terminal plate, the contact surface is more compact, improving the sealing effect and ensuring the accuracy of airtightness testing.

[0043] In one embodiment, an annular terminal plate support 13 is provided on the side wall of the lower inner sleeve, and the sealing terminal plate 7 to be tested is placed on the sealing buffer ring. The annular terminal plate support 13 can evenly distribute the pressure and prevent the terminal plate from deforming.

[0044] In one embodiment, a sealing buffer ring is provided between the terminal plate support 13 and the sealing terminal plate 7 to be tested. The sealing buffer ring can play a good role in buffering and sealing, so as to prevent the sealing terminal plate from being cracked during the sealing process and to maintain a good sealing state.

[0045] The specific testing process of the airtightness testing device for a sealed terminal block according to this utility model is as follows:

[0046] The upper sealing structure rises to its highest limit, the side of the sealing terminal plate 7 with the sealing groove facing upwards is placed in the sealing groove, and then the sealing ring is placed on the terminal plate support 13. A sealing buffer ring of a certain thickness (such as EPDM rubber) is bonded to the upper surface of the terminal plate support 13.

[0047] The upper sealing structure descends and simultaneously presses the test sealing terminal plate 7 and the lower outer sleeve 12. The pressure on each test sealing terminal plate can be monitored by the pressure sensor 3. If uneven pressure occurs, it can be adjusted by the pressure adjustment structure. After reaching the set sealing pressure, the pressure is maintained so that the sealing terminal plate is in a press-sealed state.

[0048] Each sealed terminal block 7 under test is filled with N2 or compressed air at a certain pressure for large leak detection. If the pressure drop of the air pressure gauge in the lower sealed cavity 8 is within the specified range, it indicates that the large leak detection is qualified, and the next step of leak detection is carried out.

[0049] The inner cavity 8 of the lower sealing cavity and the inner cavity 5 of the upper sealing cavity are simultaneously evacuated. After reaching the set vacuum level, helium is introduced into the inner cavity 8 of the lower sealing cavity in a stepped pressure manner until the rated sealing pressure is reached. At each step pressure, the detection device in the upper sealing cavity will detect the leakage rate. If the leakage rate exceeds the standard at a certain step pressure, the sealing terminal block under test will be deemed unqualified and helium will no longer be introduced into the inner cavity 8 of the lower sealing cavity. If the leakage rate is qualified at a certain step pressure, helium will continue to be introduced into the inner cavity 8 of the lower sealing cavity to the next step pressure, and so on until the rated leak detection pressure is reached.

[0050] After the test is completed, the second solenoid valve 10 connected to the inner cavity 8 of the lower sealing cavity is opened, helium gas is recovered through the pipeline, the inner cavity 5 of the upper sealing cavity is vented and rises to its original position, the sealing terminal plate is removed, and the test is completed.

[0051] This utility model discloses a sealing terminal block airtightness testing device. The upper and lower sealing structures form a double-sealed cavity through an outer sleeve and an inner sleeve. Combined with independent air supply from the upper and lower air injection pipes 11, uniform pressurization can be achieved over the entire terminal block (including edge areas), significantly improving the comprehensiveness and accuracy of leak detection. Simultaneously, by ensuring that the outer diameter of the upper inner sleeve is equal to the inner diameter of the lower inner sleeve, a seamless connection is achieved when the upper and lower sleeves are fitted together. This, along with the groove and protrusion positioning structure, effectively eliminates assembly gaps, minimizing the risk of system leakage. The combination of the annular terminal block support 13 and the sealing buffer ring provides uniform support to prevent deformation and absorbs local pressure through the buffer material, effectively protecting the precision terminal block from physical damage during testing. This significantly improves testing efficiency, equipment versatility, and the safety of the tested component while enhancing testing accuracy.

[0052] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the technical solution of the present utility model in any way. Those skilled in the art should understand that, without departing from the spirit and principles of the present utility model, the technical solution can be modified and replaced in several simple ways, and these modifications and replacements are all within the scope of protection covered by the claims.

Claims

1. A sealed terminal block air tightness detection device, characterized by, The upper sealing structure, the lower sealing structure, the upper gas injection pipeline (14) and the lower gas injection pipeline (11); The upper sealing structure comprises an upper outer sleeve and a plurality of upper inner sleeves arranged in the upper outer sleeve, and an upper sealing outer cavity is formed between the upper outer sleeve and the upper inner sleeves; one end of the upper gas injection pipeline (14) is in communication with an external gas source, and the other end is in communication with the upper sealing outer cavity and the plurality of upper inner sleeves; The lower sealing structure comprises a lower outer sleeve (12) and a plurality of lower inner sleeves arranged in the lower outer sleeve (12), and a lower sealing outer cavity is formed between the lower outer sleeve (12) and the lower outer sleeve (12), and the lower inner sleeves correspond to the upper inner sleeves one by one; the to-be-tested sealed terminal plate (7) is horizontally placed in the lower inner sleeves in a suspended manner, and the lower inner sleeves and the upper inner sleeves press the to-be-tested sealed terminal plate (7) tightly; one end of the lower gas injection pipeline (11) is in communication with an external gas source, and the other end is in communication with the lower sealing outer cavity and the plurality of lower inner sleeves.

2. The sealed terminal plate air tightness detection apparatus according to claim 1, characterized by The cross-sectional area of the lower inner sleeve is greater than that of the upper inner sleeve.

3. The sealed terminal plate air tightness detection apparatus according to claim 2, characterized by The outer diameter of the upper inner sleeve is equal to the inner diameter of the lower inner sleeve.

4. The sealed terminal plate air tightness detection apparatus according to claim 1, characterized by The top of the top plate is provided with a pressure structure, and the pressure structure comprises a pressure disc (1) and a plurality of pressure shafts (4); the top of the pressure disc (1) is connected with a pressure device, one end of the pressure shaft (4) is fixedly connected with the bottom of the pressure disc (1), and the other end is fixedly connected with the top plate; the pressure shaft (4) corresponds to the upper inner sleeve one by one, and the pressure shaft (4) is coaxially arranged with the upper inner sleeve.

5. The sealed terminal plate air tightness detection apparatus according to claim 4, characterized by The pressure shaft (4) is further provided with a pressure sensor (3).

6. The sealed terminal plate air tightness detection apparatus according to claim 4, characterized by The pressure shaft (4) is a telescopic shaft structure.

7. The sealed terminal plate air tightness detection apparatus according to claim 2, characterized by The upper gas injection pipeline (14) and the lower gas injection pipeline (11) are both provided with corresponding electromagnetic valves.

8. The sealed terminal plate air tightness detection apparatus according to claim 1, characterized by The upper outer sleeve and the lower outer sleeve (12) are matched through a groove-bump structure.

9. The sealed terminal plate air tightness detection apparatus according to claim 1, characterized by The side wall of the lower inner sleeve is provided with an annular terminal plate support (13), and the to-be-tested sealed terminal plate (7) is placed on the sealing buffer ring.

10. The sealed terminal plate air tightness detection apparatus according to claim 9, characterized by A sealing buffer ring is arranged between the terminal plate support (13) and the to-be-tested sealed terminal plate (7).

Images