Air tightness detection tool of welded bellows assembly for mechanical sealing
By combining the segmented ring-type fixed-distance adjustment component and the manual pressure application component, the problems of poor compatibility and damage during the testing of welded bellows components for airtightness testing are solved, achieving efficient and accurate testing results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- DANDONG KAIMING FLUID MACHINERY MFG
- Filing Date
- 2026-03-09
- Publication Date
- 2026-04-14
AI Technical Summary
Traditional welding bellows assembly airtightness testing fixtures have poor adaptability, requiring frequent fixture changes, resulting in low production efficiency. Furthermore, the testing process can easily damage the components, affecting the accuracy of the test results.
The device employs a split-ring fixed-distance adjustment assembly and a manual pressure application assembly. The split-ring fixed-distance adjustment assembly allows for flexible adaptation of components of different specifications, while the buffer plate and buffer spring buffer pressure to avoid rigid impact. Combined with the smooth pressing and sealing structure of the manual pressure application assembly, the device ensures the quality of testing.
It enables flexible adaptation of welded bellows assemblies of different specifications, reduces tooling change costs, improves testing efficiency, protects the integrity of the assemblies, and ensures the accuracy of test results.
Smart Images
Figure CN224122124U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of airtightness testing technology for welded bellows, specifically to an airtightness testing fixture for a welded bellows assembly for mechanical seals. Background Technology
[0002] Welded bellows are commonly used elastic sealing elements in mechanical seals, vacuum equipment, fluid control and other fields. They are made of multiple thin metal annular diaphragms that are precisely welded together to form a corrugated tubular elastic component. Some are paired with end caps, flanges and other connecting parts. They can generate elastic deformation in the axial and radial directions and have functions such as sealing, compensation, vibration reduction and force transmission. They are also one of the core dynamic sealing components in mechanical seals.
[0003] In the production and processing of welded bellows assemblies for mechanical seals, airtightness testing is a crucial process to ensure product quality and performance. Traditional testing fixtures are mostly designed with fixed spacing, which cannot flexibly adjust the height to suit bellows assemblies of different lengths. Multiple sets of special fixtures are required for different product specifications, which not only significantly increases the cost of production fixtures but also leads to low testing efficiency due to frequent fixture changes, making it difficult to meet the testing needs of mass production. Furthermore, the fixtures lack effective buffer protection and precise limiting structures. During manual pressure testing, rigid impacts can easily cause damage such as cracking of the weld joints of the bellows assembly and plastic deformation of the bellows body. Excessive compression can also directly affect the subsequent performance of the assembly, further reducing the accuracy of the airtightness test results. To address these issues, the inventors have proposed an airtightness testing fixture for welded bellows assemblies for mechanical seals. Utility Model Content
[0004] To address the issues of poor compatibility during testing and to prevent damage caused by excessive pressure during testing, this invention aims to provide a tooling for testing the airtightness of welded bellows assemblies for mechanical seals.
[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a tooling for testing the air tightness of a welded bellows assembly for a mechanical seal, comprising a base plate, two symmetrically distributed tie rods fixedly installed at the top of the base plate, an upper plate fixedly installed at the top of the two tie rods by external hexagonal screws, a manual pressure application component in the middle of the upper plate, a SiC pad in the middle of the top of the base plate, a split ring type fixed distance adjustment component on the top of the SiC pad, an O-ring fixedly installed at the bottom of the SiC pad and embedded in the top of the base plate, an air inlet in the middle of the base plate and the air inlet being connected to an external air storage tank through a conduit.
[0006] Preferably, the segmented ring-type fixed-distance adjustment component includes four segmented outer frames arranged in a ring array. The four segmented outer frames are closed to form a circular frame. A sliding inner frame is vertically slidably installed on the inner wall of the segmented outer frame. A push plate is fixedly installed at the bottom end of the sliding inner frame. A limit frame is fixedly installed in the middle of the outer wall of the segmented outer frame. A limit bolt is inserted through the limit frame. Vertically equidistant limit grooves are opened on the outer side of the sliding inner frame, and the limit bolts are inserted into the corresponding limit grooves. A plug is fixedly installed on one side of the outer wall of the segmented outer frame, and a plug that cooperates with the plug is opened on the other side. The groove has a partition fixedly sleeved on the outer wall of the limiting bolt, and the partition slides on the inner wall of the limiting frame. A return spring is sleeved on the outer wall of the limiting bolt, and the two ends of the return spring are fixedly connected to the outer wall of the partition and the inner wall of the limiting frame, respectively. An inner plate is fixedly installed on both sides of the inner wall of the sliding inner frame. A guide rod is vertically slidably inserted in the middle of the inner plate. A buffer plate is fixedly installed at the top of the guide rod. A baffle is fixedly sleeved on the outer wall of the guide rod, and the top of the baffle is in contact with the top of the inner wall of the sliding inner frame. A buffer spring is sleeved on the outer wall of the guide rod, and the two ends of the buffer spring are fixedly connected to the bottom of the baffle and the top of the inner plate, respectively.
[0007] Preferably, the manual pressure application component includes a threaded copper sleeve and a plate. The threaded copper sleeve is fixedly installed at the top center of the upper plate, and the plate is located directly below the upper plate. A lead screw is threadedly connected to the inner wall of the threaded copper sleeve. A pressure plate is fixedly installed at the top center of the plate. A rubber wedge ring is fixedly installed at the bottom center of the plate. A handle is fixedly installed at the top of the lead screw, and a ball is fixedly installed at the bottom of the lead screw. The top of the pressure plate is arc-shaped.
[0008] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0009] 1. This utility model, by setting a segmented ring-type fixed distance adjustment component, allows the vertical height of the segmented outer frame and the sliding inner frame to be adjusted, and is quickly locked by limit bolts and limit grooves. It can be adapted to welded corrugated pipe components of different specifications without changing tooling. At the same time, the buffer plate first bears the downward pressure and the buffer spring elastically relieves the force, effectively avoiding rigid impact during the testing process. This not only greatly reduces the tooling adaptation cost and improves the efficiency of testing operations, but also protects the components and ensures the quality of testing.
[0010] 2. This utility model, by setting a manual pressure component, enables the screw and the threaded copper sleeve to achieve smooth downward pressure. Combined with the automatic leveling structure of the ball and the arc-shaped pressure plate, it ensures uniform pressure on the plate and makes the rubber wedge ring tightly fit the tail end of the bellows assembly, providing a reliable top seal for the formation of the detection chamber. The handle-type operation is convenient and labor-saving, and it is suitable for the manual inspection operation needs of the production site. Attached Figure Description
[0011] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0012] Figure 1 This is a schematic diagram of the front structure of this utility model;
[0013] Figure 2 This is a schematic diagram of the overall side profile of this utility model;
[0014] Figure 3 This is a schematic diagram of the manual pressure application component in this utility model;
[0015] Figure 4 This is a schematic diagram of the closed structure of the segmented ring-type fixed-distance adjustment component in this utility model;
[0016] Figure 5 This is a schematic diagram of the side profile of the segmented ring-type distance adjustment component in this utility model;
[0017] Figure 6 This is a schematic diagram of the segmented outer frame structure in this utility model;
[0018] Figure 7 This is a schematic diagram of the sliding inner frame structure in this utility model;
[0019] Figure 8 This is a schematic diagram of the side profile of the sliding inner frame in this utility model;
[0020] Figure 9 for Figure 2 Enlarged schematic diagram of the structure at point A in the middle.
[0021] In the diagram: 1. Base plate; 2. Pull rod; 3. Top plate; 4. Manual pressure application assembly; 41. Threaded copper sleeve; 42. Flat plate; 43. Lead screw; 44. Pressure plate; 45. Rubber wedge ring; 46. Handle; 5. Split ring type distance adjustment assembly; 51. Split outer frame; 52. Sliding inner frame; 53. Push plate; 54. Limit frame; 55. Limit bolt; 56. Limit groove; 57. Partition plate; 58. Return spring; 59. Insertion block; 510. Insertion groove; 511. Internal plate; 512. Guide rod; 513. Buffer plate; 514. Baffle; 515. Buffer spring; 6. SiC pad; 7. O-ring; 8. Air inlet. Detailed Implementation
[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0023] like Figure 1-9 As shown, this utility model provides a tooling for testing the air tightness of a welded bellows assembly for mechanical seals, including a base plate 1, two symmetrically distributed tie rods 2 fixedly installed at the top of the base plate 1, an upper plate 3 fixedly installed at the top of the two tie rods 2 by external hexagonal screws, a manual pressure application component 4 provided in the middle of the upper plate 3, a SiC pad 6 provided in the middle of the top of the base plate 1, and a split ring type fixed distance adjustment component 5 provided on the top of the SiC pad 6.
[0024] The segmented ring-type fixed-distance adjustment component 5 includes four segmented outer frames 51 arranged in a ring array. The four segmented outer frames 51 are closed to form a circular frame. A sliding inner frame 52 is vertically slidably installed on the inner wall of the segmented outer frame 51. A push plate 53 is fixedly installed at the bottom end of the sliding inner frame 52. A limit frame 54 is fixedly installed in the middle of the outer wall of the segmented outer frame 51. A limit bolt 55 is inserted through the limit frame 54. A vertically equidistant limit groove 56 is opened on the outer side of the sliding inner frame 52, and the limit bolt 55 is inserted into the corresponding limit groove 56. A plug-in block 59 is fixedly installed on one side of the outer wall of the segmented outer frame 51, and a plug-in groove 510 that cooperates with the plug-in block 59 is opened on the other side.
[0025] By adopting the above technical solution, the split ring-type fixed distance adjustment component 5 can be quickly disassembled and assembled. At the same time, the fixed distance height can be flexibly adjusted by the cooperation of the sliding inner frame 52 and the limit bolt 55, which can be adapted to welded corrugated pipe components of different specifications.
[0026] The manual pressure application component 4 includes a threaded copper sleeve 41 and a plate 42. The threaded copper sleeve 41 is fixedly installed at the top center of the upper plate 3, and the plate 42 is located directly below the upper plate 3. The inner wall of the threaded copper sleeve 41 is threaded with a lead screw 43. A pressure plate 44 is fixedly installed at the top center of the plate 42, and a rubber wedge ring 45 is fixedly installed at the bottom center of the plate 42.
[0027] By adopting the above technical solution, manually rotating the lead screw 43 can drive the plate 42 to press down stably, so that the rubber wedge ring 45 can fit tightly against the bellows assembly, providing a sealing basis for airtightness testing.
[0028] An inner plate 511 is fixedly installed on both sides of the inner wall of the sliding inner frame 52. A guide rod 512 is vertically slidably inserted in the middle of the inner plate 511, and a buffer plate 513 is fixedly installed at the top of the guide rod 512.
[0029] By adopting the above technical solution, the buffer plate 513 is vertically inserted into the top of the sliding inner frame 52 via the guide rod 512.
[0030] The outer wall of the limiting bolt 55 is fixedly fitted with a partition 57, and the partition 57 slides on the inner wall of the limiting frame 54. The outer wall of the limiting bolt 55 is fitted with a return spring 58, and the two ends of the return spring 58 are fixedly connected to the outer wall of the partition 57 and the inner wall of the limiting frame 54, respectively.
[0031] By adopting the above technical solution, the reset spring 58 can drive the limit bolt 55 to automatically reset and insert into the corresponding limit groove 56.
[0032] A baffle 514 is fixedly sleeved on the outer wall of the guide rod 512, and the top of the baffle 514 is in contact with the top of the inner wall of the sliding inner frame 52. A buffer spring 515 is sleeved on the outer wall of the guide rod 512, and the two ends of the buffer spring 515 are fixedly connected to the bottom end of the baffle 514 and the top end of the inner plate 511, respectively.
[0033] By adopting the above technical solution, the downward pressure of the plate 42 can be buffered by the buffer spring 515.
[0034] An O-ring 7 is fixedly installed at the bottom of the SIC pad 6, and the O-ring 7 is embedded in the top of the base plate 1.
[0035] By adopting the above technical solution, the SIC pad 6 and the O-ring 7 cooperate to seal the bottom of the bellows assembly, and together with the rubber wedge ring 45 at the top, form a closed detection cavity.
[0036] A handle 46 is fixedly installed at the top of the lead screw 43, and a ball is fixedly installed at the bottom of the lead screw 43. The top of the pressure plate 44 is arc-shaped.
[0037] By adopting the above technical solution, the handle 46 facilitates manual operation of the lead screw 43, and the cooperation between the ball and the arc-shaped pressing plate 44 can achieve automatic leveling, ensuring the uniformity of force when the plate 42 is pressed down.
[0038] An air inlet 8 is provided in the middle of the base plate 1, and the air inlet 8 is connected to an external air storage tank through a conduit.
[0039] By adopting the above technical solution, detection gas can be introduced into the sealed detection chamber through the air inlet 8 to realize the air tightness detection of the welded bellows assembly.
[0040] Working principle: In the actual testing process, firstly, according to the specifications of the corrugated pipe assembly, manually pull the limiting bolt 55 outward to make it disengage from the corresponding limiting groove 56. Then, push the sliding inner frame 52 vertically through the push plate 53 to adjust the fixed distance height. After the adjustment is completed, release the limiting bolt 55. Under the action of the reset spring 58, push the limiting bolt 55 into the corresponding limiting groove 56 through the partition plate 57 to complete the fixed distance height locking. After the fixed distance height of the four segmented outer frames 51 is adjusted, the four segmented outer frames 51 are wrapped around the outside of the welded corrugated pipe assembly to be tested. The plug block 59 is vertically plugged into the plug groove 510 to form a circular frame.
[0041] Embed the O-ring 7 at the bottom of the SiC pad 6 into the corresponding position at the top of the base plate 1. Place the bellows assembly with the friction pair end of the segmented ring-type distance adjustment component 5 facing down on top of the SiC pad 6. Place the rubber wedge ring 45 at the tail end of the bellows assembly, ensuring that the rubber wedge ring 45 is in contact with the tail end of the assembly. Then, manually turn the handle 46. The handle 46 drives the lead screw 43 to rotate and descend with the cooperation of the threaded copper sleeve 41, so that the ball at the bottom of the lead screw 43 contacts the arc-shaped surface of the pressure plate 44. Then, continue to turn the handle 46, and the lead screw 43 drives the plate 42 to apply downward pressure through the pressure plate 44. When the plate 42 drives the rubber wedge ring 45 to contact the bellows assembly, the buffer plate 513 first bears the pressure and compresses the buffer spring 515 to avoid rigid impact. Continue to rotate the handle 46 to make the bottom end of the buffer plate 513 fit with the top end of the sliding inner frame 52. At this time, the bellows assembly is pressed from the free state to the detection height. The split ring fixed distance adjustment component 5 begins to suppress the re-compression. At the same time, the vertical reaction force of the split ring fixed distance adjustment component 5 applies pressure to the SIC pad 6 and O-ring 7 to enhance the sealing effect. Finally, a complete inspection sealing cavity is formed in the inner diameter space of the bellows assembly.
[0042] Subsequently, the test gas is controlled to enter the inspection sealing chamber through an external gas storage tank, a conduit, and then through the air inlet 8 on the base plate 1. Once the pressure gauge on the gas storage tank reaches 0.17 MPa, the test gas supply is cut off. After observing for 5 minutes, the pressure gauge reading is recorded. A reading ≥ 0.156 MPa indicates that the bellows assembly has passed inspection. Alternatively, the above-mentioned testing fixture can be submerged in a water tank for verification. Observe for any bubbles. If no bubbles are generated, the bellows assembly has passed inspection. If bubbles are present, it indicates that there are welding leaks in the bellows assembly. Observe carefully, mark the leaks after water comes out, and re-weld them. Repeat the above steps until the inspection is passed.
[0043] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.
Claims
1. A tooling for testing the airtightness of a welded bellows assembly for a mechanical seal, comprising a base plate (1), characterized in that: The bottom plate (1) has two symmetrically distributed tie rods (2) fixedly installed at the top. The top of the two tie rods (2) is fixedly installed with an upper plate (3) by external hexagonal screws. The upper plate (3) has a manual pressure component (4) in the middle. The bottom plate (1) has a SIC pad (6) in the middle. The top of the SIC pad (6) has a split ring fixed distance adjustment component (5). The segmented ring-type fixed distance adjustment component (5) includes four segmented outer frames (51) arranged in a ring array. The four segmented outer frames (51) are closed to form a circular frame. A sliding inner frame (52) is vertically slidably installed on the inner wall of the segmented outer frame (51). A push plate (53) is fixedly installed at the bottom end of the sliding inner frame (52). A limit frame (54) is fixedly installed in the middle of the outer wall of the segmented outer frame (51). A limit bolt (55) is inserted through the limit frame (54). A vertically equidistant limit groove (56) is opened on the outer side of the sliding inner frame (52), and the limit bolt (55) is inserted into the corresponding limit groove (56). A plug-in block (59) is fixedly installed on one side of the outer wall of the segmented outer frame (51), and a plug-in groove (510) is opened on the other side to cooperate with the plug-in block (59).
2. The airtightness testing fixture for a welded bellows assembly for a mechanical seal as described in claim 1, characterized in that, The manual pressure application component (4) includes a threaded copper sleeve (41) and a plate (42). The threaded copper sleeve (41) is fixedly installed at the top center of the upper plate (3), and the plate (42) is located directly below the upper plate (3). The inner wall of the threaded copper sleeve (41) is threaded with a lead screw (43). A pressure plate (44) is fixedly installed at the top center of the plate (42), and a rubber wedge ring (45) is fixedly installed at the bottom center of the plate (42).
3. The airtightness testing fixture for a welded bellows assembly for a mechanical seal as described in claim 1, characterized in that, The sliding inner frame (52) has an inner plate (511) fixedly installed on both sides of the inner wall. A guide rod (512) is vertically slidably inserted in the middle of the inner plate (511), and a buffer plate (513) is fixedly installed at the top of the guide rod (512).
4. The airtightness testing fixture for a welded bellows assembly for a mechanical seal as described in claim 1, characterized in that, The outer wall of the limiting bolt (55) is fixedly fitted with a partition (57), and the partition (57) slides on the inner wall of the limiting frame (54). The outer wall of the limiting bolt (55) is fitted with a reset spring (58), and the two ends of the reset spring (58) are fixedly connected to the outer wall of the partition (57) and the inner wall of the limiting frame (54) respectively.
5. The airtightness testing fixture for a welded bellows assembly for a mechanical seal as described in claim 3, characterized in that, The guide rod (512) is fixedly fitted with a baffle (514) on its outer wall, and the top of the baffle (514) is in contact with the top of the inner wall of the sliding inner frame (52). The guide rod (512) is fitted with a buffer spring (515) on its outer wall, and the two ends of the buffer spring (515) are fixedly connected to the bottom end of the baffle (514) and the top end of the inner plate (511) respectively.
6. The airtightness testing fixture for a welded bellows assembly for a mechanical seal as described in claim 1, characterized in that, An O-ring (7) is fixedly installed at the bottom of the SIC pad (6), and the O-ring (7) is embedded in the top of the base plate (1).
7. The airtightness testing fixture for a welded bellows assembly for a mechanical seal as described in claim 2, characterized in that, A handle (46) is fixedly installed at the top of the lead screw (43), a ball is fixedly installed at the bottom of the lead screw (43), and the top of the pressure plate (44) is arc-shaped.
8. The airtightness testing fixture for a welded bellows assembly for a mechanical seal as described in claim 1, characterized in that, An air inlet (8) is provided in the middle of the base plate (1), and the air inlet (8) is connected to an external air storage tank through a conduit.