Air tightness tester for alumina ceramic sealing element

Abstract

The utility model relates to the technical field of sealing element detection, in particular to an air tightness inspection tester for an aluminum oxide ceramic sealing element, which comprises an outer cylinder and a sealing element body, and further comprises an inner cylinder which is rotatably mounted in the outer cylinder, the bottom of the inner cylinder is communicated with a connecting pipe, and the connecting pipe is rotatably connected with the inner cylinder and fixedly penetrates through the outer cylinder. The curing material is preheated to 60 DEG C to enable the curing material to be in a semi-flow state, the plasticity of the material is utilized, automatic deformation filling can be achieved along with the edge contour of the sealing piece, no matter how the plane size, the shape and the edge radian of the sealing piece are changed, a completely-attached sealing interface can be formed through pressing, and the sealing piece is not prone to deformation. And then curing is carried out through irradiation of an ultraviolet lamp, so that a sealed environment is formed in the inner cylinder, air tightness detection is realized through inflation pressure maintaining and air pressure detection, and the problem that a traditional rigid tool is difficult to adapt to a special-shaped sealing element is solved.

Description

Technical Field

[0001] This utility model relates to the field of sealing component testing technology, and in particular to an airtightness testing instrument for alumina ceramic sealing components. Background Technology

[0002] In aerospace, semiconductor, and high-end equipment industries, alumina ceramic seals are widely used due to their excellent high-temperature resistance and corrosion resistance. Their airtightness is a key indicator determining the reliability of equipment. Currently, the traditional method for airtightness testing of planar alumina ceramic seals mainly relies on rigid tooling positioning—using a pre-set, fixed-size sealing groove or clamp to forcibly fix the seal to the sealing interface of the testing equipment, and then detecting the leakage through inflation and pressure holding.

[0003] However, the planar dimensions, geometry, and edge curvature of seals vary. Traditional rigid tooling needs to be designed and processed separately for each specification. For multi-variety, small-batch production scenarios, there are problems of time-consuming and costly changeovers. Rigid contact is difficult to completely fit the micro-contour of the seal edge, which can easily form tiny gaps. This can cause gas to leak from the contact surface between the tooling and the seal during testing, resulting in deviations in the test results. Utility Model Content

[0004] The purpose of this invention is to provide an airtightness testing instrument for alumina ceramic seals, which solves the problem that traditional testing instruments cannot be properly adapted to planar seals of different shapes and sizes.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An airtightness tester for alumina ceramic seals includes an outer cylinder and a seal body, and further includes:

[0007] An inner cylinder is rotatably installed inside an outer cylinder. A connecting pipe is connected to the bottom of the inner cylinder. The connecting pipe is rotatably connected to the inner cylinder and is fixedly inserted through the outer cylinder.

[0008] A curing material, which is fused with the sealing body and placed on top of the inner cylinder;

[0009] End cap, which is disposed on the top of the outer cylinder for pressing and fixing the material and sealing the outer cylinder;

[0010] The ultraviolet lamp includes a first ultraviolet irradiation lamp and a second ultraviolet irradiation lamp in a ring structure. The first ultraviolet irradiation lamp is fixedly installed on the inner wall of the inner cylinder, and the second ultraviolet irradiation lamp is fixedly installed on the bottom of the end cap. The driving component is disposed inside the outer cylinder and is used to drive the inner cylinder to rotate.

[0011] A pressure sensor is fixedly installed on the bottom wall of the inner cylinder to detect changes in internal air pressure.

[0012] Preferably, a bracket is fixedly installed on the side wall of the outer cylinder. The bracket has an "L" shaped structure, and an electric push rod is fixedly installed on the top of the bracket. The free end of the electric push rod is fixedly connected to the end cap.

[0013] Preferably, heating elements are uniformly fixedly installed on the inner wall of the outer cylinder.

[0014] Preferably, the driving component includes a motor, which is fixedly installed inside the outer cylinder. A gear is fixedly installed on the output shaft of the motor, and a gear ring is fixedly installed on the surface of the inner cylinder. The gear and the gear ring mesh.

[0015] Preferably, a retaining ring is fixedly installed on the outer wall of the inner cylinder near the top to support the cured material.

[0016] Preferably, a rotating sealing assembly is provided at the connection between the connecting pipe and the inner cylinder. The rotating sealing assembly includes a bearing installed at the bottom of the inner cylinder and a sealing ring surrounding the connecting pipe. The connecting pipe is rotatably connected to the inner cylinder through the bearing, and the inner wall of the sealing ring is tightly fitted to the outer wall of the connecting pipe.

[0017] This utility model has at least the following beneficial effects:

[0018] By utilizing a curing material, which is preheated to 60°C to achieve a semi-fluid state, and taking advantage of its plasticity, the material can automatically deform and fill according to the edge contour of the seal. Regardless of the changes in the plane size, shape, or edge curvature of the seal, a completely fitting sealing interface can be formed by pressing. Then, it is cured by irradiation with ultraviolet light to create a sealed environment for the inner cylinder. Finally, air tightness is tested by inflating and maintaining pressure, thus solving the problem that traditional rigid tooling is difficult to adapt to irregularly shaped seals. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of this utility model;

[0021] Figure 2 This is a sectional view of the outer cylinder of this utility model;

[0022] Figure 3 This utility model Figure 2 Schematic diagram of the structure at point A in the middle;

[0023] Figure 4 This is a schematic diagram of the structure of the second ultraviolet irradiation lamp of this utility model.

[0024] In the diagram: 1. Outer cylinder; 2. Bracket; 3. Electric push rod; 4. End cap; 5. Pressure sensor; 6. Gear; 7. Motor; 8. Gear ring; 9. Heating element; 10. First ultraviolet irradiation lamp; 11. Sealing body; 12. Curing material; 13. Fixing ring; 14. Inner cylinder; 15. Second ultraviolet irradiation lamp; 16. Connecting pipe. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0027] Reference Figure 1-4 An airtightness tester for alumina ceramic seals is disclosed. The outer cylinder 1 is a cylindrical metal shell with four heating elements 9 evenly installed on its inner wall via bolts to regulate the ambient temperature. An "L"-shaped bracket 2 is welded to the side wall of the outer cylinder 1. An electric push rod 3 (model: DT50, stroke 100mm) is bolted to the top of the bracket 2. The lower end of the piston rod of the electric push rod 3 is connected to the end cap 4 via a flange. The inner cylinder 14 is a stainless steel cylinder, with its bottom center connected to a connecting pipe 16 via a rotating sealing assembly. The rotating sealing assembly includes a deep groove ball bearing (model: 6004) and a fluororubber O-ring. The inner ring of the bearing is interference-fitted with the connecting pipe 16, and the outer ring is fixed in the bearing seat at the bottom of the inner cylinder 14. The sealing ring is fitted into the annular groove of the connecting pipe 16 and tightly fitted to the bottom surface of the inner cylinder 14, ensuring that the connecting pipe 16 remains fixed and there is no gas leakage when the inner cylinder 14 rotates. The lower end of the connecting pipe 16 passes through the bottom of the outer cylinder 1 and is connected to an external air source (such as an air compressor) via a quick connector.

[0028] Furthermore, a sealing element body 11 and a curing material 12 are placed on top of the inner cylinder 14. The curing material 12 is a UV-curable resin (model: Norland NOA61), which is chemically bonded to the surface of the alumina ceramic sealing element body 11 by a pre-treatment agent (such as a silane coupling agent). An annular retaining ring 13 is welded to the outer wall of the inner cylinder 14 near the top to support the curing material 12 and restrict its flow range. The end cap 4 is a disc made of aluminum alloy. A second ring-shaped ultraviolet irradiation lamp 15 (wavelength 365nm, power 30W) is fixed to its bottom surface by countersunk bolts. A first ring-shaped ultraviolet irradiation lamp 10 is fixedly installed on the inner wall of the inner cylinder 14. The two sets of ultraviolet lamps together form a ring irradiation system. When the curing material 12 is relatively soft, the sealing body 11 is pressed onto the surface to form a hole that matches the sealing body 11. Then, the sealing body 11 and the curing material 12 are placed together on the top of the inner cylinder and pressed tightly by the end cap 4. Finally, the two ultraviolet lamps are used to irradiate it to harden it.

[0029] Furthermore, the driving component uses a servo motor 7 (model: Panasonic MSMD02ZP1U), which is fixed inside the outer cylinder 1 via a motor mount. The output shaft of motor 7 is keyed to gear 6 (module 2, 20 teeth). A gear ring 8 (module 2, 100 teeth) is welded to the outer surface of the middle part of the inner cylinder 14. Gear 6 and gear ring 8 form a transmission pair with a reduction ratio of 5:1. Motor 7 drives the inner cylinder 14 to rotate controllably at a speed of 0-60 rpm. A pressure sensor 5 (model: MPX5010DP, range 0-100kPa) is threadedly installed at the center of the bottom wall of the inner cylinder 14. Its detection signal is transmitted to an external controller (such as a PLC) through a signal line passing through the inside of the connecting pipe 16.

[0030] In summary, a thermoplastic UV-curable material 12 (such as epoxy resin with added temperature-sensitive softener, softening point 60℃) is selected and preheated to 60-70℃ using an external heating device to make the cured material 12 a semi-fluid gel. This ensures that the cured material 12 softens as a whole without localized carbonization.

[0031] The alumina ceramic seal body 11 (pre-coated with coupling agent) is vertically pressed into the softened curing material 12. At this time, the curing material 12 undergoes plastic deformation due to softening, tightly wrapping the edge contour of the seal body 11, forming an annular positioning hole that is perfectly matched with the outer diameter of the seal.

[0032] The pressed sealing body 11 and the cured material 12 are moved as a whole to the top of the inner cylinder 14, so that the bottom surface of the cured material 12 is completely in contact with the top surface of the inner cylinder 14. At this time, the sealing body 11 and the cured material 12 will be located at the top of the inner cylinder 14. The cured material is a thermoplastic UV-curable resin, whose viscosity changes non-linearly with temperature and has good plasticity and shape retention. Therefore, although the cured material 12 has the ability to deform, it will not fall off.

[0033] Start the electric push rod 3 (model DT50, thrust 500N) until the bottom of the end cap 4 forms pressure on the cured material 12. The electric push rod 3 has a built-in pressure sensor. When it detects that the contact pressure between the end cap 4 and the sealing ring 17 reaches 200N, it will automatically stop to avoid excessive pressure on the cured material 12. Then move the end cap 4 upward.

[0034] The first ultraviolet irradiation lamp 10 and the second ultraviolet irradiation lamp 15 are turned on simultaneously, with a total light intensity of 800mW / cm². The photoinitiator in the curing material 12 generates active free radicals under ultraviolet light irradiation, initiating a resin cross-linking reaction and gradually hardening from a semi-fluid state.

[0035] The motor 7 drives the inner cylinder 14 to rotate at low speed through the meshing transmission of the gear 6 and the gear ring 8, so that the curing material 12 is uniformly exposed to light, avoiding local curing defects, and the inner cylinder can form a closed space after curing.

[0036] Dry nitrogen gas is introduced into the inner cylinder 14 through the connecting pipe 16. The inflation pressure is increased to the target value (e.g., 80 kPa, set according to the operating conditions of the seal). The inflation time is 30 seconds. The inner cylinder 14 remains stationary during the inflation process.

[0037] The rotating sealing assembly between the connecting pipe 16 and the inner cylinder 14 plays a role at this stage: the bearing 181 allows the inner cylinder 14 to rotate freely (used when testing dynamic operating conditions), and the sealing ring prevents gas from leaking from the gap between the connecting pipe 16 and the bottom of the inner cylinder.

[0038] After inflation, maintain pressure for 2 minutes. Pressure sensor 5 (model MPX5010DP) collects pressure data in real time. If the pressure drop rate is <0.2kPa / min, it is considered qualified.

[0039] After the test is completed, turn on the heating element 9 to 80°C (20°C above the softening point of the cured material) and continue heating for 3 minutes to gradually soften the cured material 12 due to the increase in temperature (the elastic modulus drops from 1.2 GPa to 0.3 GPa).

[0040] The electric push rod 3 moves in the opposite direction, lifting the end cap 4 away from the top of the outer cylinder 1. At this time, the bonding force between the softened solidified material 12 and the sealing body 11 decreases significantly.

[0041] Manually and gently lift the sealing body 11 and the curing material 12 upwards. The curing material 12 softens and deforms, separating from the top of the inner cylinder 14 and the fixing ring 13, thus completing the demolding.

[0042] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. An airtightness tester for alumina ceramic seals, comprising an outer cylinder (1) and a seal body (11), characterized in that, Also includes: The inner cylinder (14) is rotatably installed inside the outer cylinder (1). The bottom of the inner cylinder (14) is connected to a connecting pipe (16). The connecting pipe (16) is rotatably connected to the inner cylinder (14) and is fixedly inserted through the outer cylinder (1). The curing material (12) and the sealing body (11) are fused together and placed on top of the inner cylinder (14); End cap (4), the end cap (4) is provided on the top of the outer cylinder (1) for pressing and fixing the material and sealing the outer cylinder (1); The ultraviolet lamp includes a first ultraviolet lamp (10) and a second ultraviolet lamp (15) in a ring structure. The first ultraviolet lamp (10) is fixedly installed on the inner wall of the inner cylinder (14), and the second ultraviolet lamp (15) is fixedly installed on the bottom of the end cap (4). The driving component is disposed inside the outer cylinder (1) to drive the inner cylinder (14) to rotate. A pressure sensor (5) is fixedly installed on the bottom wall of the inner cylinder (14) to detect changes in internal pressure.

2. The airtightness tester for alumina ceramic seals according to claim 1, characterized in that, A bracket (2) is fixedly installed on the side wall of the outer cylinder (1). The bracket (2) has an "L" shaped structure. An electric push rod (3) is fixedly installed on the top of the bracket (2). The free end of the electric push rod (3) is fixedly connected to the end cap (4).

3. The airtightness tester for alumina ceramic seals according to claim 1, characterized in that, Heating elements (9) are uniformly fixedly installed on the inner wall of the outer cylinder (1).

4. The airtightness tester for alumina ceramic seals according to claim 1, characterized in that, The driving component includes a motor (7), which is fixedly installed inside the outer cylinder (1). A gear (6) is fixedly installed on the output shaft of the motor (7), and a gear ring (8) is fixedly installed on the surface of the inner cylinder (14). The gear (6) and the gear ring (8) mesh.

5. The airtightness tester for alumina ceramic seals according to claim 1, characterized in that, A fixing ring (13) is fixedly installed on the outer wall of the inner cylinder (14) near the top to support the curing material (12).

6. The airtightness tester for alumina ceramic seals according to claim 1, characterized in that, A rotating sealing assembly is provided at the connection between the connecting pipe (16) and the inner cylinder (14). The rotating sealing assembly includes a bearing installed at the bottom of the inner cylinder (14) and a sealing ring surrounding the connecting pipe (16). The connecting pipe (16) is rotatably connected to the inner cylinder (14) through the bearing, and the inner wall of the sealing ring is tightly fitted to the outer wall of the connecting pipe (16).

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