A threaded quick connect tool for air tightness testing

Abstract

The application relates to the technical field of air tightness detection, in particular to a threaded quick connection jig for air tightness detection. The jig comprises an executing mechanism, the executing mechanism comprises a threaded block arranged in an axial direction, a push shaft and a shaft sleeve, the threaded block is divided into a plurality of arc petals in the axial direction, and the axial gap between adjacent petals enables the threaded block to have radial elastic deformation capacity. The conical head of the push shaft can expand or contract the arc petals to adjust the interference fit between the outer diameter and the product thread. When working, the handle is pressed, the roller extrudes the top rod transmission, and the push rod and the shaft sleeve move cooperatively to push the threaded block to the front end of the jig; after the handle is released, the spring drives the push shaft to reset, the conical head reopens the arc petals to realize coupling. The axial component force generated by the thread taper automatically compresses the O-shaped ring to complete end face sealing. The application changes the rotary threaded connection into an axial push-pull type connection, and the assembly and disassembly can be completed by pressing with one hand, without the need of raw material belts, the disassembly and assembly time is greatly shortened, and the sealing is reliable.

Description

Technical Field

[0001] This invention belongs to the technical field of airtightness testing auxiliary devices, specifically a threaded quick-connect fixture for airtightness testing. Background Technology

[0002] In the manufacturing and quality control processes of pumps and volumetric sealing products, airtightness testing is a crucial step in ensuring product reliability. Airtightness testing typically requires connecting the product's inlet and outlet threaded interfaces to allow gas to be introduced and its sealing performance monitored. Currently, the industry commonly uses threaded connections for airtightness testing. Specifically, a threaded plug with a connecting gas tube is screwed into the threaded interface of the product under test, and PTFE tape is wrapped around the plug's threads to achieve a seal. This traditional connection method has revealed increasingly prominent problems in long-term industrial practice.

[0003] Because of the purely threaded connection method, workers must use wrenches and other tools to tighten the plug properly during airtightness testing. The entire disassembly and assembly process is time-consuming, severely impacting the overall efficiency of the testing process. With increasing factory capacity requirements and rising labor costs, this inefficient connection method has become a bottleneck restricting further improvements in production efficiency. Workers need to invest a significant amount of physical labor in repeated tightening operations, which not only increases labor intensity but also easily leads to unstable sealing performance due to human factors. Furthermore, as a disposable material, the procurement and replacement of PTFE tape constitute a considerable production cost.

[0004] In view of the above-mentioned technical problems, there is an urgent need to develop a special fixture that can quickly disassemble and assemble threaded interfaces to replace the traditional screw-in connection method. This would effectively improve the efficiency of airtightness testing, reduce the labor intensity of workers, and eliminate the dependence on consumable materials such as PTFE tape. This is of great practical significance for improving the manufacturing level and quality testing capabilities of pump products.

[0005] In view of this, this application proposes a threaded quick-connect fixture for airtightness testing. Summary of the Invention

[0006] This invention addresses the shortcomings of existing threaded connection methods in airtightness testing, such as long assembly and disassembly times, low efficiency, high labor intensity, the need for PTFE tape as a sealing material, and high production costs. It provides a threaded quick connection fixture for airtightness testing.

[0007] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a threaded quick-connect fixture for airtightness testing, comprising a handle assembly, a transmission mechanism, and an actuator. The handle assembly is located outside the tailstock and includes a handle body and a roller component located inside the handle body.

[0008] The actuator includes a threaded block, a push shaft, and a bushing arranged along the axial direction of the fixture. The threaded block is located at the foremost position of the fixture. The push shaft passes through the main structure of the fixture and its front end extends into the internal cavity of the threaded block. The bushing is sleeved on the outside of the push shaft and is located between the push rod and the threaded block for transmitting axial movement.

[0009] The threaded block comprises multiple arc-shaped segments formed by equal division along the axial direction. An axial gap extending into the inner cavity of the threaded block is formed between adjacent arc-shaped segments, creating a tensioning structure with radial elastic deformation capability. When the push shaft moves forward axially, its head applies an inward radial compressive force to the inner walls of the multiple arc-shaped segments of the threaded block, reducing the outer diameter of the threaded block to a size smaller than the inner diameter of the internal thread of the product being tested. When the push shaft moves backward axially, its head applies an outward radial spreading force to the inner walls of the multiple arc-shaped segments of the threaded block, increasing the outer diameter of the threaded block and forming an interference fit with the internal thread of the product being tested.

[0010] The transmission mechanism includes a push rod and a push rod. The push rod is positioned below the handle assembly and forms a rolling engagement structure with the roller assembly. The tail of the push rod has an arcuate surface for the roller assembly to roll. When the handle body is pressed, the roller assembly rolls along the arcuate surface, pressing the push rod to move axially. The push rod is drively connected to the push rod. When the push rod moves to contact the positioning surface of the push rod, the push rod follows the push rod to continue axial movement, thereby transmitting the axial movement of the push rod to the push shaft and the bushing.

[0011] Furthermore, the front end of the threaded block is provided with a guide angle structure, and the threaded block is divided into n equal parts along the axial direction. One of the equal parts is removed to form the axial gap, so that the threaded block forms n-1 arc-shaped petal structures, where n is an integer ≥6.

[0012] Specifically, when the threaded block is pushed into the threaded hole of the product being tested, the guide angle structure first contacts the hole wall and guides the threaded block smoothly into the threaded hole. The threaded block is divided into equal parts along the axial direction, and one part is removed to form the axial gap, so that the threaded block forms an arc-shaped petal structure.

[0013] Furthermore, the front end of the push shaft has a tapered structure, and the tapered head expands or contracts the multiple arc-shaped lobes of the threaded block when moving axially. When the tapered head fully enters the threaded block, the n-1 arc-shaped lobes are uniformly expanded to their maximum outer diameter; when the tapered head exits the threaded block, the n-1 arc-shaped lobes contract to their minimum outer diameter under their own elasticity.

[0014] Furthermore, the present invention also includes a spring reset mechanism disposed inside the housing assembly, the spring reset mechanism comprising a first spring, a second spring, and a third spring. When the handle body is pressed, the spring reset mechanism is compressed and stores energy; when the handle body is released, the spring reset mechanism releases its elastic force to drive the push rod to move backward to tighten the threaded block. The first spring is disposed between the threaded block and the pressure block to provide the elastic force for the axial reset of the threaded block; the second spring is disposed between the bushing and the push rod to provide the elastic force for the axial reset of the push rod; the third spring is disposed between the push rod and the top rod to provide the elastic force for the axial reset of the top rod.

[0015] Furthermore, the housing assembly includes a tailstock and a housing body, the tailstock and the housing body being connected by fasteners to form a cavity structure for accommodating the internal mechanism; Furthermore, the outer shell is provided with an air inlet, which is used to connect an external air pipe and introduce detection gas into the fixture cavity.

[0016] Furthermore, it also includes the dynamic sealing mechanism. The dynamic sealing mechanism includes a first O-ring seal disposed on the end face of the threaded block. When the threaded block is threadedly coupled with the product under test, the first O-ring seal is compressed and deformed by the axial component force generated by the thread taper, filling the end face gap between the fixture and the product under test, thereby realizing the end face sealing function between the fixture and the product under test.

[0017] Furthermore, the dynamic sealing mechanism also includes a second O-ring seal disposed between the push rod and the outer housing, a third O-ring seal disposed between the push rod and the top rod, and a fourth O-ring seal disposed between the top rod and the outer housing. This dynamic sealing ring employs an O-ring structure to prevent leakage of detection gas from the moving parts.

[0018] Furthermore, it also includes a static sealing mechanism, which includes a fifth O-ring seal disposed between the tailstock and the outer casing.

[0019] Furthermore, the handle body has an anti-slip textured structure at the tail end. The anti-slip texture is arranged in a wave shape to increase the friction when the operator presses the handle and prevent the fingers from slipping.

[0020] The working principle of this invention is as follows: When connecting the product to be tested for airtightness testing, the operator presses the handle body, and the roller component rolls along the arc surface of the tail of the push rod, squeezing the push rod to move forward axially. The push rod pushes the push shaft forward, and the conical head of the push shaft exits from the inside of the threaded block, releasing the tension on the threaded block and reducing the outer diameter of the threaded block. At the same time, the push rod moves forward axially under the push of the push rod and compresses the third spring. The push rod pushes the threaded block to slide out of the front end of the fixture axially through the bushing. The operator then pushes the front end of the fixture into the threaded interface of the product to be tested, and the guide angle structure guides the threaded block smoothly into the product's threaded hole. After the threaded block enters the product's threaded hole, the operator releases the handle body, and under the combined elastic force of the first spring, the second spring, and the third spring, the push shaft is pulled backward. The tapered head of the push shaft re-enters the threaded block, radially expanding the eight arc-shaped segments, increasing the outer diameter of the threaded block and forming a tight coupling with the internal thread of the product being tested. During coupling, the axial force generated by the thread taper pushes the threaded block backward, compressing the O-ring seal and achieving a tight seal between the fixture and the two mating end faces of the product being tested. After testing, the operator presses the handle body again, repeating the aforementioned transmission process. The push shaft moves forward to release the tension, the threaded block contracts and disengages from the product thread, and the operator can easily pull out the fixture.

[0021] The beneficial effects of this invention are as follows: It replaces the traditional rotary threaded connection with an axial push-pull connection, allowing operators to tighten and loosen the threaded block simply by pressing the handle body, eliminating the need for wrapping PTFE tape and forcefully tightening the threads, significantly shortening the time required for each assembly and disassembly. The operation requires only one hand to press the handle body to complete the connection or disassembly, eliminating the need for wrenches or other tools for strenuous tightening, greatly reducing operator fatigue. The end-face O-ring seal replaces the traditional PTFE tape seal, allowing for reusable O-rings and eliminating the need for disposable materials like PTFE tape during each test, effectively reducing material costs. The axial force generated by the thread taper automatically compresses the O-ring to achieve a stable and reliable seal, unaffected by the operator's skill level. Due to the tensioning structure coupled with the product thread, it has a high tolerance for the precision of the tested product's thread, is unaffected by product thread tolerances, and has strong versatility. The entire operation requires only two simple actions: pressing and releasing the handle body, requiring no professional training for proficient operation. Attached Figure Description

[0022] Figure 1 This is a cross-sectional view of a threaded quick-connect fixture for airtightness testing according to Embodiment 1 of the present invention.

[0023] Figure 2This is a perspective view of a threaded quick-connect fixture for airtightness testing according to Embodiment 1 of the present invention.

[0024] Figure 3 This is a perspective view of the threaded quick-connect fixture from another angle in Embodiment 1 of the present invention.

[0025] The reference numerals in the attached drawings are as follows: 1. Housing assembly; 11. Tailstock; 12. Housing body; 13. Air inlet; 2. Handle assembly; 21. Handle body; 22. Roller assembly; 23. Anti-slip texture; 3. Transmission mechanism; 31. Push rod; 311. Arc surface; 32. Push rod; 4. Actuator; 41. Threaded block; 411. Arc-shaped flap; 412. Axial clearance; 413. Guide angle; 42. Push shaft; 421. Conical head; 43. Bushing; 44. Pressure block; 5. Dynamic sealing mechanism; 51. First O-ring seal; 52. Second O-ring seal; 53. Third O-ring seal; 54. Fourth O-ring seal; 6. Spring return mechanism; 61. First spring; 62. Second spring; 63. Third spring; 7. Static sealing mechanism; 71. Fifth O-ring seal; 8. PTFE gasket; 9. Ball bearing. Detailed Implementation

[0026] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] Example 1, as Figures 1-3 As shown, an embodiment of the present invention provides a threaded quick-connect fixture for airtightness testing, comprising a housing assembly 1, a handle assembly 2, a transmission mechanism 3, an actuator 4, a dynamic sealing mechanism 5, a spring reset mechanism 6, and a dynamic sealing ring 7.

[0028] The outer shell assembly 1 serves as the main skeleton structure of the entire fixture, used to enclose and protect the internal mechanical components.

[0029] The handle assembly 2 is located on the outer side of the rear of the housing assembly 1, and is used by the operator to hold and press to control the connection and disassembly of the fixture.

[0030] The transmission mechanism 3 is located inside the housing assembly 1 and is connected to the handle assembly 2 for transmitting the operator's action of pressing the handle into the axial movement of the internal actuator. The actuator 4 is located at the front end of the housing assembly 1 and is used to quickly connect and disconnect with the threaded interface of the product under test.

[0031] The dynamic sealing mechanism 5 is located at the connection end face between the actuator 4 and the product under test, and is used to achieve the sealing function during airtightness testing.

[0032] The spring reset mechanism 6 is located inside the housing assembly 1 and is used to drive each moving part to automatically reset after each action is completed.

[0033] The outer casing assembly 1 includes two main structural components: a tailstock 11 and an outer casing 12. The tailstock 11 and the outer casing 12 are connected and fixed together by hexagon socket head cap screws, forming a closed cavity structure to accommodate internal mechanisms such as the transmission mechanism 3, the actuator 4, and the spring return mechanism 6. The tailstock 11 has a mounting hole at its tail end for mounting the handle assembly 2; the outer surface of the tailstock 11 is machined with positioning steps and screw through holes for precise alignment with the outer casing 12 and secure positioning with fasteners. The outer casing 12 is a hollow cylindrical structure with an opening at its front end forming an inner cavity to accommodate the actuator 4. The rear end of the outer casing 12 is inserted into the tailstock 11. An air inlet 13 is provided on the side wall of the outer casing 12. This air inlet 13 is connected to an external air supply pipe via a threaded connection for introducing the gas medium required for airtightness testing into the fixture. In some preferred embodiments, there are two air inlets 13, located at different heights on the outer casing 12, to meet the gas source access requirements under different testing scenarios.

[0034] The handle assembly 2 includes a handle body 21, a roller component 22, and anti-slip texture 23. The handle body 21 is approximately L-shaped, with one end fixedly connected to the tailstock 11 by an internal hex screw, and the other end extending to form a pressing operation area. A shaft hole is provided on the inner side of the handle body 21 for mounting the rotating shaft of the roller component 22, allowing the roller component 22 to rotate freely around its axis. Anti-slip texture 23 is provided on the surface of the pressing operation area of ​​the handle body 21. This anti-slip texture 23 is arranged in a wave-like pattern on the outer surface of the tail end of the handle body 21. The wave-like texture design effectively increases the friction when the operator presses the handle, preventing fingers from slipping during pressing. In some embodiments, the wave height of the anti-slip texture 23 is 0.5 mm to 1.0 mm, and the wave spacing is 2 mm to 3 mm. This size design ensures sufficient anti-slip effect without causing discomfort to the operator's touch.

[0035] The transmission mechanism 3 includes a push rod 31 and a push rod 32. The push rod 31 is located below the handle assembly 2, and its tail has an arc surface 311. A roller assembly 22 is installed above the tail of the push rod 31. When the operator presses the handle body 21, the roller assembly 22 rolls along the arc surface 311 of the tail of the push rod 31, generating a downward squeezing force on the arc surface 311. This squeezing force drives the push rod 31 to move forward along the axial direction of the fixture. The front end of the push rod 31 is fixedly connected to the push shaft 42, which runs through the entire main structure of the fixture. When the push rod 31 moves forward under the squeezing of the roller assembly 22, the push rod 31 synchronously drives the push shaft 42 to move forward by an initial displacement. The push rod 32 is positioned in front of the push rod 31. The rear end face of the push rod 32 has a positioning surface. When the push rod 31 moves forward until its end face contacts the positioning surface of the push rod 32, the push rod 31 continues to move forward, and the push rod 32, pushed by the push rod 31, also begins to move forward axially. The front end of the push rod 32 is sequentially connected to the bushing 43 and the threaded block 41, thereby transmitting the axial movement of the push rod 31 sequentially to the bushing 43 and the threaded block 41, ultimately enabling the threaded block 41 to slide axially out of the front end of the fixture. This two-stage transmission design of the transmission mechanism 3 effectively decomposes and transmits the operating force of the pressing handle. The first stage involves the roller squeezing the push rod to drive the initial displacement of the push shaft; the second stage involves the push rod pushing the push rod to compress the third spring 63, causing the bushing and threaded block to slide out. The transmission in both stages is smooth and continuous, providing a good operating feel.

[0036] The actuator 4 is the core working component of this invention, including a threaded block 41, a push shaft 42, a bushing 43, and a pressure block 44. The threaded block 41 is located at the foremost position of the fixture, and its outer surface is machined with external threads. The pitch, thread angle, and nominal diameter of the external threads are completely matched with the internal threads of the threaded interface of the product being tested, so as to achieve threaded coupling during connection.

[0037] In this embodiment, the threaded block 41 includes multiple arc-shaped petals 411 formed by dividing it into nine equal parts along the axial direction. In this embodiment, after removing one of the equal parts, eight arc-shaped petals 411 are formed. An axial gap 412 is formed between adjacent arc-shaped petals 411, extending into the inner cavity of the threaded block 41. The axial gap 412 extends through the entire axial length of the threaded block 41, making the threaded block 41 an overall tensioning structure with radial elastic deformation capability. When the push shaft 42 moves forward axially, the conical head 421 of the push shaft 42 exits from the inner cavity of the threaded block 41. The conical head 421 applies an inward radial compressive force to the inner wall of the arc-shaped petals 411, causing the arc-shaped petals 411 to retract inward under their own elasticity. The outer diameter of the threaded block 41 is reduced to less than the inner diameter of the internal thread of the product being tested. At this time, the threaded block 41 can be easily inserted into the threaded hole of the product being tested. When the push shaft 42 moves axially backward, the tapered head 421 of the push shaft 42 re-enters the inner cavity of the threaded block 41. The tapered head 421 applies an outward radial spreading force to the inner wall of the arc-shaped petals 411, spreading the eight arc-shaped petals 411 outward evenly. The outer diameter of the threaded block 41 increases and forms an interference fit with the internal thread of the product being tested, thereby achieving a firm connection between the fixture and the product being tested.

[0038] Furthermore, the front end of the threaded block 41 is provided with a guide angle structure 413. The threaded block 41 is divided into n equal parts along the axial direction, and one of the parts is removed to form the axial gap, so that the threaded block 41 forms n-1 arc-shaped petal structures, where n is an integer ≥ 6. Specifically, when the threaded block 41 is pushed into the threaded hole of the product being tested, the guide angle structure 413 first contacts the wall of the product hole and guides the threaded block 41 to smoothly enter the threaded hole. The specific division method of the threaded block 41 is to divide it into equal parts along the axial direction, and remove one of the parts to form the axial gap, so that the threaded block 41 forms an arc-shaped petal structure.

[0039] The guide angle structure 413 is a tapered transition surface with a tapered angle ranging from 20 to 60 degrees. When the threaded block 41 is pushed into the threaded hole of the product being tested, the guide angle structure 413 first contacts the hole wall. Due to the obstruction of the hole wall, the guide angle structure 413 guides the arc-shaped flap 411 to gradually converge inward, causing the outer diameter of the threaded block 41 to smoothly decrease under the action of the guide angle structure 413, thus allowing it to smoothly enter the threaded hole of the product being tested. The design of the guide angle structure 413 makes the alignment and insertion process of the threaded block 41 with the threaded hole of the product simple and reliable, achieving natural guided insertion without the need for precise alignment by the operator.

[0040] The push shaft 42 penetrates the main structure of the fixture, and its front end has a tapered structure forming a tapered head 421. The diameter of the front end of the tapered head 421 is smaller than the diameter of the rear end, and the tapered angle is 15 to 25 degrees. The push shaft 42 has a shoulder structure, which limits the axial travel range of the push shaft 42 inside the fixture. When the tapered head 421 is fully inserted into the threaded block 41, the eight arc-shaped petals 411 are evenly spread to their maximum outer diameter, at which point the push shaft 42 is in the rearmost position; when the tapered head 421 is withdrawn from the threaded block 41, the eight arc-shaped petals 411 contract to their minimum outer diameter under their own elasticity, at which point the push shaft 42 is in the frontmost position.

[0041] A bushing 43 is fitted outside the push shaft 42 and located between the push rod 32 and the threaded block 41. The inner hole of the bushing 43 and the outer surface of the push shaft 42 are in a clearance fit relationship. This clearance fit design makes the bushing 43 move with low resistance and flexible movement during axial movement. A pressure block 44 is provided outside the bushing 43 and the threaded block 41. The front end of the bushing 43 contacts the rear end of the threaded block 41. The pressure block 44 is located outside the bushing 43 and the threaded block 41, restricting the axial position of the threaded block and the bushing. Specifically, the pressure block 44 is provided with a limiting groove, and the threaded block 41 is provided with a limiting protrusion that matches the limiting groove. The rear end of the bushing 43 contacts the front end of the push rod 32. When the push rod 32 moves forward, the push rod 32 pushes the bushing 43 to move forward synchronously, and the bushing 43 pushes the threaded block 41 to slide axially out of the front end of the fixture.

[0042] The spring reset mechanism 6 is located inside the housing assembly 1 and includes three spring elements: a first spring 61, a second spring 62, and a third spring 63. When the operator presses the handle body 21, all three springs are compressed and store energy; when the operator releases the handle body 21, the three springs release their elastic force and jointly drive the moving parts to reset. The first spring 61 is located between the threaded block 41 and the pressure block 44. One end of the first spring 61 abuts against the front end face of the pressure block 44, and the other end abuts against a spring seat provided inside the housing 12. When the threaded block 41 slides forward under the push of the bushing 43, the pressure block 44 compresses the first spring 61, causing the first spring 61 to store elastic potential energy. The first spring 61 also serves to push the threaded block 41 to reset axially. When the handle body 21 is released, the first spring 61 releases its elastic force to push the bushing 43 and the threaded block 41 to move backward and reset.

[0043] The second spring 62 is disposed between the bushing 43 and the push rod 32. The second spring 62 is sleeved on the outer circumferential surface of the push shaft 42, with its front end abutting against the spring mounting step at the rear of the bushing 43 and its rear end abutting against the spring mounting step at the front of the push rod 32. The second spring 62 is used to provide the elastic force for the axial return of the push rod 32. When the push rod 32 moves forward under the push of the push rod 31, the second spring 62 is compressed; when the handle body 21 is released, the second spring 62 releases its elastic force to pull the push rod 32 backward, so that the push rod 32 moves backward to return to its original position.

[0044] A third spring 63 is disposed between the push rod 32 and the top rod 31. The third spring 63 is sleeved on the outer circular surface of the top rod 31, and its front end abuts against the spring mounting step of the outer casing 12, while its rear end abuts against the spring mounting step of the top rod 31. When the top rod 31 moves forward, the third spring 63 is compressed and stores energy; when the handle body 21 is released, the third spring 63 releases, and the push rod 32 and top rod 31 move backward to reset. The elastic parameters of the three springs are carefully matched and designed to ensure a smooth and uniform reset action, allowing all moving parts to reset to their initial state in a coordinated manner.

[0045] The dynamic sealing mechanism 5 includes a first O-ring 51 disposed on the end face of the threaded block 41. During the process of the threaded block 41 forming a tight coupling with the internal thread of the product under test, due to the taper of the external thread of the threaded block 41, the internal thread of the product under test generates an axial and radial force on the external thread of the threaded block 41. This axial and radial force pushes the threaded block 41 to move axially backward and also exerts a radial force that pushes the first O-ring 51 radially outward. The threaded block 41 abuts against the first O-ring 51 and compresses it, causing the first O-ring 51 to undergo elastic deformation and fill the end face gap between the fixture and the product under test, thereby achieving a reliable seal between the two mating end faces of the fixture and the product under test. The first O-ring 51 is made of oil-resistant and corrosion-resistant rubber material with a hardness range of Shore A 60 to 70. This hardness range ensures that the first O-ring 51 has sufficient sealing compression without being too hard, which could lead to assembly difficulties or poor sealing performance. The first O-ring 51 is installed in the sealing ring mounting groove opened in the threaded block 41. The sealing ring mounting groove is precisely designed according to the cross-sectional dimensions of the first O-ring 51 to ensure that the first O-ring 51 will neither fall off nor be over-compressed after installation.

[0046] Similarly, the dynamic sealing mechanism 5 also includes a second O-ring 52 disposed between the push rod 32 and the outer casing 12, a third O-ring 53 disposed between the top rod (31) and the push rod (32), and a fourth O-ring 54 disposed between the top rod (31) and the outer casing (12). The second O-ring 52, the third O-ring 53, and the fourth O-ring 54 adopt an O-ring structure to prevent the detection gas from leaking from the moving joint. The second O-ring 52 and the third O-ring 53 are provided with PTFE gaskets 8. The PTFE gaskets 8 are made of polytetrafluoroethylene material, which has excellent corrosion resistance and sealing performance, and can provide a reliable sealing effect at the connection.

[0047] In addition to the dynamic sealing mechanism 5, the embodiments of the present invention also include a static sealing mechanism (7), which includes a fifth O-ring (74) disposed between the tailstock (11) and the outer shell (12), and can provide a reliable sealing effect at the static connection.

[0048] Furthermore, ball bearings 9 are provided between the push rod 31 and the push rod 32. As a connecting component between the push rod 31 and the push rod 32, the ball bearings play a crucial role in transmitting power and providing linear motion. They reduce friction loss through rolling friction, thereby improving transmission efficiency and positioning accuracy.

[0049] In practical use, the threaded quick-connect fixture of this invention is used to perform airtightness testing on the inlet and outlet of a certain type of pump. First, the operator connects the air inlet 13 to the air source of the airtightness testing equipment via an air pipe. Then, the front end of the fixture is aligned with the threaded interface of the product being tested for connection. In the initial state, the tapered head 421 of the push shaft 42 is located within the inner cavity of the threaded block 41, and the arc-shaped flap 411 is in its maximum outer diameter state. At this time, the outer diameter of the threaded block 41 is slightly larger than the inner diameter of the internal thread of the product being tested, and the fixture cannot be directly inserted into the threaded hole of the product.

[0050] The operator first presses the handle body 21, which rotates downwards around its connection point with the tailstock 11. The roller component 22 inside the handle body 21 rolls downwards along the arcuate surface 311 at the tail of the push rod 31. The roller component 22 applies downward pressure to the arcuate surface 311, which is decomposed into a forward force along the axial direction of the push rod 31, driving the push rod 31 forward axially. Simultaneously, the push rod 31 moves forward, causing the push shaft 42, which is fixedly connected to it, to move forward as well. The conical head 421 of the push shaft 42 gradually exits the inner cavity of the threaded block 41. After the conical head 421 exits, the arcuate petals 411 of the threaded block 41 retract inwards under the action of their own elastic restoring force, widening the axial clearance 412 and reducing the outer diameter of the threaded block 41 to a size smaller than the inner diameter of the internal thread of the product being tested.

[0051] Pressing the handle body 21 further causes the front end face of the push rod 31 to contact the positioning surface of the push rod 32. The push rod 31 then continues to move forward, and the push rod 32, pushed by the push rod 31, also begins to move forward axially. As the push rod 32 moves forward, it compresses the third spring 63, and the push rod 32 pushes the threaded block 41 axially out of the fixture front end through the bushing 43. At this time, the first spring 61 is compressed by the pressure block 44 and stores elastic potential energy. During the axial sliding out process, the threaded block 41's front guide angle structure 413 is first exposed. At this point, the outer diameter of the threaded block 41 has decreased, allowing the operator to easily push the fixture front end into the threaded interface of the product being tested. After contacting the product's hole wall, the guide angle structure 413 smoothly enters the threaded hole under the guidance of the hole wall.

[0052] After the threaded block 41 is fully inserted into the threaded hole of the product being tested, the operator releases the handle body 21. Under the combined elastic force of the three springs in the spring reset mechanism 6, each moving part begins to reset. The second spring 62 releases its elastic force, pulling the push rod 32 backward. The conical head 421 of the push shaft 42 re-enters the inner cavity of the threaded block 41, evenly spreading the eight arc-shaped petals 411 outward, increasing the outer diameter of the threaded block 41. The increased outer diameter of the threaded block 41 causes its external thread to form an interference fit with the internal thread of the product being tested, and the external thread of the threaded block 41 gradually engages with the internal thread of the product. Simultaneously, the internal thread of the product under test generates an axial and radial force on the external thread of the threaded block 41. This axial and radial force pushes the threaded block 41 to move axially backward and exerts a radial force that pushes the first O-ring seal 51 radially outward. The threaded block 41 abuts against the first O-ring seal 51 and compresses it, causing the first O-ring seal 51 to undergo elastic deformation and fill the end face gap between the fixture and the product under test, thereby achieving a reliable seal between the two mating end faces of the fixture and the product under test. The first spring 61 releases its elastic force to push the threaded block 41 back to its original position, the second spring 62 provides the elastic force for the push rod 32 to return to its original position axially, and the third spring 63 releases its elastic force to push the top rod 31 back to its original position. All moving parts eventually return to their initial positions, and a firm and sealed connection is formed between the fixture and the product under test. At this time, the airtightness testing equipment can introduce test gas into the product under test through the air inlet 13 to complete the airtightness testing process.

[0053] When the fixture needs to be disassembled after the test, the operator presses the handle body 21 again to repeat the aforementioned transmission process. The push shaft 42 moves forward, causing the conical head 421 to exit the inner cavity of the threaded block 41, releasing the supporting effect on the arc-shaped petal 411. The outer diameter of the threaded block 41 shrinks to a size smaller than the inner diameter of the product's internal thread. Under the force of the threaded threads, the external thread of the threaded block 41 disengages from the internal thread of the product being tested, allowing the operator to easily pull the fixture out from the front end, completing the entire disassembly process. The entire connection and disassembly process requires no wrenches or other tools, and no Teflon tape is needed. The operator only needs to perform two simple actions—pressing and releasing the handle body 21 with one hand—to complete all operations.

[0054] In another preferred embodiment, the connection between the outer shell 12 and the tailstock 11 can also be a snap-fit ​​connection structure. This snap-fit ​​connection structure includes an annular groove at the end of the tailstock 11 and an elastic snap fastener on the inner wall of the outer shell 12. The elastic snap fastener engages with the annular groove, enabling quick assembly and disassembly of the outer shell 12 and the tailstock 11. This design facilitates maintenance and upkeep of the internal mechanisms of the fixture. In yet another preferred embodiment, the fixed connection between the handle body 21 and the tailstock 11 can be a quick-connect pin connection in addition to hexagonal socket screws, further simplifying the assembly and disassembly process.

[0055] In Example 3, in another preferred embodiment, the number of arc-shaped lobes 411 in the threaded block 41 is not limited to eight. It can also be designed with an even number of arc-shaped lobes, such as six, ten, or twelve, depending on the size and strength requirements of the threaded interface of the product being tested. The more arc-shaped lobes 411 there are, the better the radial deformation uniformity of the threaded block 41, but the width of each arc-shaped lobe will also decrease accordingly, requiring higher strength from the arc-shaped lobes. The design scheme using eight arc-shaped lobes in this embodiment achieves the best balance between deformation uniformity and structural strength.

[0056] In Example 4, in another preferred embodiment, the cone angle of the guide angle structure 413 can be adaptively adjusted according to the thread interface angle of the product being tested, with the cone angle ranging from 20 degrees to 60 degrees. When the internal thread taper of the product being tested is large, a smaller guide angle is used; when the internal thread taper is small, a larger guide angle is used. This adjustable guide angle design allows the fixture of this embodiment to adapt to thread interfaces with different taper specifications, improving the versatility and applicability of the fixture.

[0057] In Example 5, in another preferred embodiment, the cone angle of the tapered head 421 of the push shaft 42 can also be optimized according to the structural parameters of the threaded block 41. When the cone angle of the tapered head 421 is large, the radial displacement of the arc-shaped petal 411 changes faster, and the tightening and loosening action response is more rapid; when the cone angle of the tapered head 421 is small, the radial displacement of the arc-shaped petal 411 changes more gradually, which is beneficial to achieving more precise diameter control. In this embodiment, the cone angle of the tapered head 421 is preferably 20 degrees, achieving a good balance between response speed and control accuracy.

[0058] In Example 5, in another preferred embodiment, the material of the first O-ring 51 can be selected according to the detection medium of the product being tested. When the detection medium is air, the first O-ring 51 is made of nitrile rubber; when the detection medium is nitrogen or other inert gases, the first O-ring 51 is made of fluororubber; when the detection medium is corrosive, the first O-ring 51 is made of polytetrafluoroethylene (PTFE) coated material. The first O-ring 51 made of different materials can be quickly replaced according to actual testing needs, enabling the fixture of this embodiment to adapt to various different airtightness testing scenarios. The other second O-rings 52, third O-rings 53, fourth O-rings 54, and fifth O-rings 71 can also be adjusted as needed.

[0059] In another preferred embodiment, the outer surface of the housing 12 may be provided with scale markings to indicate the axial position of the threaded block 41 relative to the housing 12. When the threaded block 41 slides out of the front end of the housing 12 to a preset position, the scale markings align with the rear end face of the threaded block 41, indicating to the operator that the fixture can now be inserted into the threaded interface of the product being tested. This scale marking design helps the operator quickly determine whether the fixture is in an insertable state, further improving operational efficiency and accuracy.

[0060] This invention's threaded quick-connect fixture replaces the traditional rotary threaded connection with an axial push-pull connection. Operators only need to press the handle body 21 with one hand to tighten and loosen the threaded block 41, eliminating the need for wrapping PTFE tape and forcefully tightening the threads, significantly shortening the assembly / disassembly time per operation. The use of an O-ring seal on the end face replaces the traditional PTFE tape seal. The O-ring is reusable, eliminating the need for disposable materials like PTFE tape during each test, effectively reducing material costs. Due to the tightening structure coupled with the product thread, it has a high tolerance for the precision of the tested product thread, is unaffected by product thread tolerances, and has strong versatility. The entire operation requires only two simple actions: pressing and releasing the handle body 21. Operators can master this skill without professional training, significantly reducing labor costs and reliance on professional testing personnel.

[0061] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A threaded quick-connect fixture for airtightness testing, comprising a housing assembly (1), a handle assembly (2), a transmission mechanism (3), an actuator (4), and a dynamic sealing mechanism (5), characterized in that: The outer casing assembly (1) includes a tailstock (11) and an outer casing (12), wherein the tailstock (11) and the outer casing (12) are connected by fasteners to form a cavity structure for accommodating the internal mechanism; The handle assembly (2) is disposed outside the tailstock (11). The handle assembly (2) includes a handle body (21) and a roller component (22) disposed inside the handle body (21). The actuator (4) includes a threaded block (41), a push shaft (42), and a bushing (43) arranged along the axial direction of the fixture. The threaded block (41) is located at the foremost position of the fixture. The push shaft (42) penetrates the main structure of the fixture and its front end extends into the internal cavity of the threaded block (41). The bushing (43) is sleeved on the outside of the push shaft (42) and is located between the push rod (32) and the threaded block (41) for transmitting axial movement. The threaded block (41) includes a plurality of arc-shaped petals (411) formed by dividing it equally along the axial direction. An axial gap (412) is formed between adjacent arc-shaped petals (411) that extends into the inner cavity of the threaded block (41). The axial gap (412) makes the threaded block (41) a tensioning structure with radial elastic deformation capability. The front end of the push shaft (42) has a tapered structure to form a tapered head (421). When the tapered head (421) is fully inserted into the threaded block (41), the arc-shaped petal (411) is evenly spread to the maximum outer diameter state. When the tapered head (421) is withdrawn from the threaded block (41), the arc-shaped petal (411) contracts to the minimum outer diameter state under its own elastic action. The dynamic sealing mechanism (5) includes a first O-ring (51) disposed on the end face of the threaded block (41). When the threaded block (41) is threadedly coupled with the product under test, the first O-ring (51) is compressed and deformed by the axial force generated by the thread taper, filling the end face gap between the fixture and the product under test. The transmission mechanism (3) is located inside the housing assembly (1) and is connected to the handle assembly (2). The transmission mechanism (3) includes a push rod (31) and a push rod (32). The push rod (31) is located below the handle assembly (2) and forms a rolling fit structure with the roller component (22). The tail of the push rod (31) is provided with an arc surface (311) for the roller component (22) to roll. The push rod (32) is connected to the push rod (31). The front end of the push rod (31) is fixedly connected to the push shaft (42). The push rod (32) is located in front of the push rod (31). The rear end face of the push rod (32) is provided with a positioning surface. When the push rod moves to contact the positioning surface of the push rod, the push rod continues to move axially with the push rod, thereby transmitting the axial movement of the push rod to the push shaft and the bushing. A ball bearing (9) is provided between the push rod (31) and the push rod (32).

2. A threaded quick-connect fixture for airtightness testing according to claim 1, characterized in that, The front end of the threaded block (41) is provided with a guide angle structure (413). The threaded block (41) is divided into n equal parts along the axial direction. One of the equal parts is removed to form the axial gap (412), so that the threaded block (41) forms n-1 arc-shaped petal structures, where n is an integer ≥6.

3. A threaded quick-connect fixture for airtightness testing according to claim 1, characterized in that, It also includes a spring reset mechanism (6), which includes a first spring (61), a second spring (62) and a third spring (63). The first spring (61) is disposed between the threaded block (41) and the pressure block (44); The second spring (62) is disposed between the bushing (43) and the push rod (32); The third spring (63) is disposed between the push rod (32) and the top rod (31).

4. A threaded quick-connect fixture for airtightness testing according to claim 3, characterized in that, The first spring (61) is used to provide the elastic force for the axial reset of the threaded block (41); The second spring (62) is used to provide the elastic force for the axial return of the push rod (32); The third spring (63) is used to provide the elastic force for the axial reset of the push rod (31).

5. A threaded quick-connect fixture for airtightness testing according to claim 1, characterized in that, The outer shell (12) is provided with an air inlet (13), which is used to connect an external air pipe and introduce detection gas into the fixture cavity.

6. A threaded quick-connect fixture for airtightness testing according to claim 1, characterized in that, The dynamic sealing mechanism (5) further includes a second O-ring (52) disposed between the push rod (32) and the outer shell (12), a third O-ring (53) disposed between the top rod (31) and the push rod (32), and a fourth O-ring (54) disposed between the top rod (31) and the outer shell (12).

7. A threaded quick-connect fixture for airtightness testing according to claim 1, characterized in that, It also includes a static sealing mechanism (7), which includes a fifth O-ring (71) disposed between the tailstock (11) and the outer casing (12).

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