An air tight test fixture
By designing an airtightness test fixture, using inlet and outlet connectors to seal with a thin-walled cylinder, and a support cylinder to provide stable support, the problem of poor reliability in airtightness testing of thin-walled welded parts is solved, achieving high reliability and versatility, while also expanding the testing functions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- 新乡平原航空液压设备有限公司
- Filing Date
- 2023-05-06
- Publication Date
- 2026-05-12
AI Technical Summary
In existing technologies, thin-walled welded components of aerospace filters are prone to deformation or scratching of seals during airtightness testing, resulting in poor reliability.
An airtightness test fixture was designed, which uses an inlet connector and an outlet connector to seal with a thin-walled cylinder and provides stable support through a support cylinder to avoid contact between the sealing ring and the sharp end of the thin-walled cylinder. Tapered pipe threads are used to improve versatility, and the outside of the support cylinder is provided with a notch and an elastic collar to enhance connection stability.
It improves the reliability and versatility of airtightness testing, avoids thin-walled cylinder deformation and seal failure, and expands the testing function to flow detection.
Smart Images
Figure CN116464847B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of sealing test devices, and in particular relates to an airtightness test fixture. Background Technology
[0002] The outer cylinder of aerospace filter products is a thin-walled welded component. After welding, the airtightness of the weld needs to be tested. The traditional testing method is to connect the flange to both ends of the filter with bolts to form an end seal between the filter and the flange. Then, air is circulated into the filter through the vent of the flange, and it is observed whether there is any gas leakage.
[0003] Because the filter wall is thin (≤1mm) and its ends are relatively sharp, it is easy to cause the filter to deform or scratch the seals at the flange ends when disassembling and assembling the flange and bolts, resulting in sealing failure and poor reliability. Summary of the Invention
[0004] The purpose of this invention is to provide an airtightness test fixture to solve the technical problem of insufficient reliability in airtightness testing of thin-walled cylindrical parts in the prior art.
[0005] To achieve the above objectives, the technical solution for the airtightness testing fixture provided by this invention is as follows:
[0006] An airtightness test fixture includes an inlet connector and an outlet connector. The inlet connector has a mounting hole for mounting the inlet end of the thin-walled cylinder under test, and the outlet connector has a mounting hole for mounting the outlet end of the thin-walled cylinder under test. The mounting holes of both the inlet connector and the outlet connector are provided with sealing rings for circumferential sealing with the thin-walled cylinder under test. The inlet connector has a sealing connection structure for sealing connection with the test bench and an air passage.
[0007] The beneficial effects are as follows: This invention improves upon existing airtightness testing fixtures. During testing, the inlet connector is sealed to the test bench, allowing the test bench gas to directly enter the thin-walled cylinder under test through the inlet connector. Both the inlet and outlet connectors in this invention are sealed to the outer circumference of the thin-walled cylinder under test, eliminating the need for repeated disassembly and reassembly of bolts and flanges. Furthermore, the sealing ring does not contact the sharp ends of the thin-walled cylinder. Compared to bolt-flange type sealing fixtures, this significantly improves the reliability of both the fixture and the test.
[0008] As a further improvement, the sealing connection structure includes a tapered pipe thread located on the outer periphery of the inlet connector.
[0009] The beneficial effect is that the tapered pipe thread is a standardized sealing structure, and the test fixture can be directly installed on the test bench with the same standard tapered pipe thread vent, thus improving the versatility of the test fixture.
[0010] As a further improvement, the test fixture also includes a support cylinder, which is used to be fitted onto the outside of the thin-walled cylinder under test, with one end used to support the sealing ring and the other end used to stop and engage with the stepped large-diameter section of the thin-walled cylinder under test; or the support cylinder is an elastic support cylinder that can be tightly fitted onto the outside of the thin-walled cylinder under test, with one end used to support the sealing ring.
[0011] The beneficial effect is that the support cylinder can provide stable support for the sealing ring, preventing excessive gas pressure from blowing the sealing ring away and causing sealing failure.
[0012] As a further improvement, the elastic support cylinder is provided with a slit that can expand to form an installation channel for mounting the thin-walled cylinder of the test subject.
[0013] The beneficial effect is that it makes it easier for the elastic support sleeve to be fitted onto the outside of the thin-walled sleeve.
[0014] As a further improvement, the cut is an obliquely arranged bevel.
[0015] The beneficial effect is that it can form a coating on the elastic support cylinder, improving the connection stability between the elastic support cylinder and the thin-walled cylinder.
[0016] As a further improvement, the elastic support cylinder is also provided with an elastic collar on its outer side.
[0017] The beneficial effect is that it improves the stability of the connection between the elastic support cylinder and the thin-walled cylinder.
[0018] As a further improvement, the outlet connector is provided with a sealing connection structure for sealing connection with the test bench and an air passage.
[0019] The beneficial effect is that both ends of the thin-walled cylinder can be connected to the test bench, so the test fixture can also be used for flow detection, thus expanding the function of the test fixture.
[0020] As a further improvement, the inlet and outlet connectors are detachably connected and together form a test cavity for mounting the thin-walled tube under test.
[0021] The beneficial effect is that the inlet and outlet joints form a clamping and covering effect on the tested thin-walled cylinder, making the thin-walled cylinder structure more stable and less prone to deformation, thus further improving the reliability of the test.
[0022] As a further improvement, the outlet connector is also provided with an observation window.
[0023] The beneficial effect is that it makes it easier to observe whether the thin-walled cylinder is leaking air. Attached Figure Description
[0024] Figure 1 This is a cross-sectional view of the structure of Embodiment 1 of the airtightness test fixture in this invention;
[0025] Figure 2 for Figure 1 A magnified view of a section at point I;
[0026] Figure 3 for Figure 1 A schematic diagram of the structure of the central support cylinder.
[0027] Explanation of reference numerals in the attached figures:
[0028] 1. Inlet connector; 2. Sealing ring; 3. Collar ring; 4. Support cylinder; 5. Test thin-walled cylinder; 6. Observation window; 7. Outlet connector; 41. Angled opening. Detailed Implementation
[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0030] Therefore, the following detailed description of the embodiments of the 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 invention without inventive effort are within the scope of protection of the invention.
[0031] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any actual relationship or order between these entities or operations. Furthermore, terms such as "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the process or method that includes said element.
[0032] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the term "provided with" should be interpreted broadly. For example, the object "provided with" can be a part of the main body, or it can be separately arranged from the main body and connected to the main body. This connection can be a detachable connection or a non-detachable connection. Those skilled in the art can understand the specific meaning of the above terms in this invention through specific circumstances.
[0034] The present invention will be further described in detail below with reference to the embodiments.
[0035] Specific embodiment 1 of the airtightness test fixture provided by the present invention:
[0036] The airtightness testing fixture provided in this embodiment is as follows: Figure 1 As shown, it includes an inlet connector 1 and an outlet connector 7, which are connected by threads. Both inlet connector 1 and outlet connector 7 have mounting holes for circumferential sealing with the inlet and outlet ends of the thin-walled cylinder 5 under test. The left end of inlet connector 1 has a sealing connection structure for sealing the test bench, and also has a test gas inlet (gas passage). Figure 1 and Figure 2 As shown, sealing rings 2 are provided in the mounting holes of the inlet connector 1 and the outlet connector 7. The sealing rings 2 are fitted around the outer circumference of the thin-walled cylinder 5 under test, sealing the gap between the inlet connector 1 / outlet connector 7 and the outer circumference of the thin-walled cylinder 5 under test. Specifically, the inlet connector 1 / outlet connector 7 may or may not have sealing ring grooves, as long as a sealing fit between the inlet connector 1 and the thin-walled cylinder 5 under test is achieved. During testing, the left end of the inlet connector 1 is directly and sealed to the test bench, and the test gas can enter the thin-walled cylinder 5 under test from the inlet connector 1.
[0037] In this embodiment, the sealing connection structure provided at the left end of the inlet connector 1 is a tapered pipe thread structure. As a standardized sealing fit structure, the tapered pipe thread can improve the versatility of the test fixture, as long as the test bench has a tapered pipe thread hole of the same specification.
[0038] This embodiment also includes a support cylinder 4, such as Figure 1 and Figure 2As shown, the support cylinder 4 can be fitted around the outer periphery of the thin-walled cylinder 5 under test, with one end directly abutting against the sealing ring 2 to support the sealing ring 2 and prevent the gas from blowing away the sealing ring 2 and causing sealing failure when the inlet pressure is too high. In this embodiment, the support cylinder 4 is an elastic cylinder that can deform outward and open when subjected to radial force, increasing the inner diameter of the cylinder, and is fitted into the end of the thin-walled cylinder 5 under test. In addition, the other end of the support cylinder 4 abuts against the stepped large-diameter section of the thin-walled cylinder 5 under test, and the thin-walled cylinder 5 under test provides stable support for the support cylinder 4.
[0039] It should be noted that the tested thin-walled cylinder 5 in this embodiment is an aerospace filter, such as... Figure 1 and Figure 2 As shown, the diameter at both ends and the middle is relatively large, so the support cylinder 4 is set as an elastic cylinder, which can be easily fitted onto the thin-walled cylinder 5 under test, and the thin-walled cylinder 5 under test can provide stable support for the support cylinder 4. In fact, the support cylinder 4 can also be a rigid cylinder, as long as it can pass through both ends of the thin-walled cylinder 5 under test. In addition, when the thin-walled cylinder 5 under test is a straight cylinder, the support cylinder 4 can still be set as an elastic cylinder. After being fitted onto the thin-walled cylinder 5 under test, it can fit tightly against the outer circumference of the thin-walled cylinder 5 under the action of elasticity, providing stable support for the sealing ring 2. Specifically, the material of the elastic cylinder can be tetrafluoroethylene.
[0040] In this embodiment, a collar 3 is also fitted on the outside of the support cylinder 4. The collar 3 is also an elastic ring, and its elasticity can improve the connection reliability between the support cylinder 4 and the thin-walled cylinder 5 under test.
[0041] In this embodiment, the support cylinder 4 is also provided with a slit. When subjected to an outward elastic force, the slit opens, allowing the test thin-walled cylinder 5 to be fitted through the slit; that is, the slit forms an installation channel for the test thin-walled cylinder 5. Specifically, as shown... Figure 3 As shown, the cut in this embodiment is a beveled cut 41. At this time, the beveled cut 41 can form a covering effect on the thin-walled cylinder 5 under test, thereby improving the connection stability.
[0042] In this embodiment, the right end of the outlet connector 7 has the same structure as the left end of the inlet connector 1, that is, it also has a sealing connection structure for connecting to the test bench and an air passage. In this case, the test fixture can be used not only for airtightness testing but also for flow rate and velocity detection. The test gas can enter from one end of the test fixture and flow out from the other end. This expands the functionality of the test fixture.
[0043] During the airtightness test, the thin-walled cylinder 5 under test is first installed inside the outlet connector 7, then the inlet connector 1 is screwed into the outlet connector 7, and finally the whole assembly is connected to the test bench. During the airtightness test, the entire assembly can be immersed in alcohol to observe for air bubbles. For easier observation, the outlet connector 7 is also equipped with an observation window 6.
[0044] In this embodiment, the airtightness test fixture is circumferentially sealed to the thin-walled cylinder under test, eliminating the need for repeated disassembly and reassembly of bolts and flanges. The sealing ring also does not come into contact with the sharp ends of the thin-walled cylinder. Compared with bolt and flange type sealing fixtures, this greatly improves the reliability of the fixture and the test.
[0045] The specific embodiment 2 of the airtightness test fixture provided by the present invention differs from embodiment 1 mainly in that: in embodiment 1, the sealing connection structure for connecting the inlet connector 1 to the test bench is a tapered pipe thread. In this embodiment, the end of the inlet connector 1 is provided with a sealing ring, and the sealing connection with the test bench is achieved through the sealing ring.
[0046] The specific embodiment 3 of the airtightness test fixture provided by the present invention differs from embodiment 1 mainly in that: in embodiment 1, a collar 3 is fitted on the outside of the support cylinder 4. In this embodiment, the collar 3 may not be provided.
[0047] The specific embodiment 4 of the airtightness test fixture provided by the present invention differs from embodiment 1 mainly in that: in embodiment 1, the inlet connector 1 and the outlet connector 7 are detachably connected by threads, and the outlet connector 7 and the inlet connector 1 together form a test cavity for mounting the thin-walled cylinder under test, which can improve the stability of the thin-walled cylinder under test during the test. In this embodiment, the inlet connector 1 and the outlet connector 7 may not be connected.
[0048] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still make modifications to the technical solutions described in the foregoing embodiments without creative effort, or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. An airtightness test fixture, comprising an inlet connector and an outlet connector, wherein the inlet connector has a mounting hole for mounting the inlet end of a thin-walled cylinder under test, and the outlet connector has a mounting hole for mounting the outlet end of the thin-walled cylinder under test, characterized in that, Both the inlet and outlet connectors have mounting holes equipped with sealing rings for circumferential sealing with the thin-walled cylinder under test. The inlet connector has a sealing connection structure for sealing connection with the test bench and an air passage. The test fixture also includes a support cylinder, which is used to fit around the outside of the thin-walled cylinder under test. One end face of the support cylinder is used to support the sealing ring, and the other end face is used to stop the stepped large-diameter section of the thin-walled cylinder under test. Alternatively, the support cylinder is an elastic support cylinder that can be tightly fitted around the outside of the thin-walled cylinder under test, with one end face used to support the sealing ring.
2. The airtightness test fixture according to claim 1, characterized in that, The sealing connection structure includes a tapered pipe thread located on the outer periphery of the inlet connector.
3. The airtightness test fixture according to claim 1, characterized in that, The elastic support cylinder has a slit that can expand to form an installation channel for mounting the thin-walled cylinder of the test subject.
4. The airtightness test fixture according to claim 3, characterized in that, The cut is an obliquely arranged cut.
5. The airtightness test fixture according to claim 1, characterized in that, The elastic support cylinder is also provided with an elastic collar on its outer side.
6. The airtightness test fixture according to claim 1 or 2, characterized in that, The outlet connector is equipped with a sealing connection structure for sealing connection with the test bench and an air passage.
7. The airtightness test fixture according to claim 1 or 2, characterized in that, The inlet and outlet connectors are detachably connected and together form a test cavity for installing the thin-walled tube under test.
8. The airtightness test fixture according to claim 7, characterized in that, The outlet connector is also equipped with an observation window.