Manufacturing method of an ultra-low temperature high-load bidirectional sealing device

Abstract

The application provides a manufacturing method of an ultralow-temperature high-load bidirectional sealing device, which comprises the following steps: supporting a plastic ring by using a mandrel tool, and then mounting spring sheets on the outer profile surface of the plastic ring; clamping the spring sheets by using a clamp, and then mounting a pressing sleeve on the outer profile surface of the spring sheets; pressing the spring sheets by using a pressing machine to limit the spring sheets and the pressing sleeve; bidirectionally pressing the pressing sleeve, the spring sheets and the plastic ring to form a pressing sleeve assembly; measuring the distance between the end surface of the pressing sleeve assembly and the end surface of a sealing framework after pressure relief, and the distance meets the set index requirement; clamping the bidirectional sealing device, and adopting a hob to roll the outer edge and the inner hole edge; and adopting a sealing screening tool to perform an air-tightness screening test on the bidirectional sealing device. The application effectively solves the manufacturing technical problem of a liquid rocket engine low-temperature sealing device, improves the assembly efficiency and assembly quality of the sealing device, and ensures the sealing performance of the valve.

Description

Technical Field

[0001] This invention belongs to the field of liquid rocket engine manufacturing technology, and mainly relates to the manufacturing method of liquid rocket engine sealing device. Background Technology

[0002] There are many cryogenic dynamic seals in the valves of the control supply pipeline of liquid rocket engines. Conventional sealing structures such as Pan-Sai dynamic seals, packing seals and thin-walled metal seals have insufficient cryogenic compensation, which can easily lead to leakage.

[0003] The sealing device designed according to the invention "An Ultra-Low Temperature High Load-Bearing Bidirectional Sealing Device" (CN 110925434 A) (such as...) Figure 1 As shown, the device includes a sealing skeleton 1, a spring plate 2, a plastic ring 3, and a pressure sleeve 4, providing a method for manufacturing an ultra-low temperature high load-bearing bidirectional sealing device. Summary of the Invention

[0004] The technical problem solved by this invention is: This invention provides a manufacturing method for an ultra-low temperature high load-bearing bidirectional sealing device, which solves the manufacturing technical problem of large interference non-metal-metal sealing devices, effectively avoids problems such as damage to plastic rings, irregular deformation of spring plates, and poor sealing performance after assembly during the assembly process, effectively improves the assembly quality and assembly efficiency of the sealing device, and improves the sealing performance of the sealing device.

[0005] The technical solution of this invention is: a method for manufacturing an ultra-low temperature, high load-bearing bidirectional sealing device, comprising:

[0006] After using a mandrel tool to support the plastic ring, install the spring sheet on the outer surface of the plastic ring;

[0007] After clamping the spring sheet using a clamping device, place the pressure sleeve on the outer surface of the spring sheet; use a press to press the spring sheet to limit the spring sheet and the pressure sleeve.

[0008] The pressure sleeve assembly, consisting of a bidirectional pressure sleeve, a spring plate, and a plastic ring, is measured after pressure relief. The distance between the end face of the pressure sleeve assembly and the end face of the sealing skeleton meets the set index requirements.

[0009] The bidirectional sealing device is clamped by using a roller to roll the outer edge and the inner hole edge;

[0010] An airtightness screening test was conducted on the bidirectional sealing device using a sealing screening fixture.

[0011] Furthermore, the mandrel tooling is manufactured according to the inner surface dimensions of the plastic ring. The end of the mandrel tooling is equipped with a transition guide to prevent scratching the inner surface of the plastic ring during installation. The dimensional difference between the inner surface of the plastic ring and the mating conical surface of the mandrel tooling, and the dimensional difference between the inner surface of the plastic ring and the cylindrical surface of the mandrel tooling, are 0.02 to 0.05 mm.

[0012] Furthermore, after supporting the plastic ring with a mandrel tool, mounting the spring sheet onto the outer surface of the plastic ring includes:

[0013] Gradually fit the spring sheet onto the outer surface of the plastic ring. Once the spring sheet has passed the maximum interference position, remove the mandrel fixture from the plastic ring, so that the spring sheet is completely fitted onto the outer surface of the plastic ring.

[0014] Furthermore, the diameter of the clamping can is 0.1 to 0.3 mm larger than the outer diameter of the closed end of the spring sheet.

[0015] Furthermore, the step of using a clamping device to clamp the spring sheet and then fitting the pressure sleeve onto the outer surface of the spring sheet includes:

[0016] The spring sheet is held in place by clamping one end of the fixing ring with a clamping can. After the spring sheet contracts evenly, the contraction diameter of the elastic diaphragm end of the spring sheet is 0.01 to 0.03 mm smaller than the inner diameter of the pressure sleeve. Then the pressure sleeve is placed on the outer surface of the spring sheet. After the pressure sleeve passes through the stepped hole at the orifice, the spring sheet is taken out of the clamping can and then slowly pressed into the end face groove of the pressure sleeve.

[0017] Furthermore, the step of using a press to press the spring sheet to limit its position relative to the pressure sleeve includes:

[0018] Use a press to press the end face of the spring sheet to ensure that the end face of the spring sheet is flush with the end face of the pressure sleeve; check whether the elastic diaphragm end of the spring sheet and the plastic ring are fully inserted into the groove of the end face of the pressure sleeve, and check that there are no scratches or pressure marks on the inner hole of the plastic ring.

[0019] Furthermore, before the compression sleeve assembly composed of the bidirectional pressing sleeve, spring sheet, and plastic ring, the following is included:

[0020] Based on the outer diameter of the pressure sleeve, select a pressing tool with a diameter 0.2 to 0.3 mm smaller than the outer diameter of the pressure sleeve. Use a press to press one side of the pressure sleeve assembly into the sealing skeleton, and then install the other side of the pressure sleeve assembly into the sealing skeleton.

[0021] Furthermore, the clamping of the bidirectional sealing device, employing a roller to roll the outer edge and inner hole edge, includes:

[0022] The outer surface of the sealing skeleton is rolled with a ° hob, and the outer circle of the side wall of the sealing skeleton is rolled at ° and then pressed tightly against the pressure sleeve; after the sealing skeleton is rolled at both ends, the inner hole is rolled with an R-type hob.

[0023] Furthermore, the sealing and screening fixture includes an inlet nozzle, an outlet nozzle, a sealing gasket, and a mandrel; the mandrel has grooves at both ends to allow gas flow; the mandrel is installed in the inner cavity of the bidirectional sealing device, and the bidirectional sealing device is installed in the cavity formed by the docking of the inlet nozzle and the outlet nozzle; the end faces of the inlet nozzle and the outlet nozzle clamp the annular protrusion structure of the outer wall of the sealing skeleton and are sealed with a sealing gasket.

[0024] Furthermore, the airtightness screening test of the bidirectional sealing device using a sealing screening fixture includes:

[0025] Install the bidirectional sealing device into the sealing screening fixture, and introduce compressed air at 0.9MPa and 14.5MPa through the inlet nozzle. Check the radial sealing performance between the plastic ring and the mandrel. Perform an airtightness check for 3 minutes. If the leakage rate meets the requirement of 0 bubbles / 3 minutes, the test is considered qualified.

[0026] The advantages of this invention compared to the prior art are:

[0027] The method of this invention makes full use of the structural characteristics of plastic rings and spring sheets, solving the assembly problem of weak rigid parts with large interference fits. At the same time, it utilizes the deformation and contraction characteristics of spring sheets to solve the assembly problem of spring sheets in stepped holes. Through sealing screening tests, the sealing performance of delivered products is improved. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of an ultra-low temperature, high load-bearing, bidirectional sealing device.

[0029] Figure 2 This is a schematic diagram of the mandrel tooling structure of the present invention.

[0030] Figure 3 This is a schematic diagram of the clamping mechanism of the can according to the present invention.

[0031] Figure 4 This is a schematic diagram of the bidirectional pressing structure of the present invention.

[0032] Figure 5 This is a schematic diagram of the sealing screening tooling structure of the present invention. Detailed Implementation

[0033] The present invention will be described in conjunction with the accompanying drawings.

[0034] A method for manufacturing an ultra-low temperature, high load-bearing bidirectional sealing device includes:

[0035] (1) As Figure 2As shown, the mandrel fixture 5 is designed and manufactured according to the inner surface dimensions of the plastic ring 3. The end of the mandrel fixture 5 uses a transition guide to prevent scratching the inner surface of the plastic ring 3 during installation. The dimensional difference between the inner surface of the plastic ring 3 and the mating conical and cylindrical surfaces of the mandrel fixture 5 is 0.02–0.05 mm. During assembly, the plastic ring 3 is first installed on the mandrel fixture 5. Then, utilizing the elastic deformation of the spring plate 2 and the increased rigidity of the plastic ring 3 by the mandrel fixture 5, the spring plate 2 is installed on the outer surface of the plastic ring 3. After the spring plate 2 passes the maximum interference position, the mandrel fixture 5 is removed from the plastic ring 3. Utilizing the weak rigidity of the plastic ring 3, the spring plate 2 is completely installed on the outer surface of the plastic ring 3. After assembly, the assembly status of the spring plate 2 and the plastic ring 3 is checked. The spring plate 2 shows no abnormal deformation, and there are no scratches, pressure marks, or other abnormalities at both ends and the inner hole of the plastic ring 3.

[0036] (2) Figure 3 As shown, based on the designed outer diameter of the closed end of the spring sheet 2, a clamping can 6 is selected that is 0.1–0.3 mm larger than the outer diameter of the closed end of the spring sheet. Utilizing the shrinkage and deformation characteristics of the spring sheet 2, the clamping can 6 is used to hold the closed end of the spring sheet 2 (i.e., the fixing ring end of the spring sheet), causing the spring sheet 2 to shrink uniformly. The shrinkage diameter of the open end of the spring sheet 2 (i.e., the elastic diaphragm end of the spring sheet) is then 0.01–0.03 mm smaller than the inner diameter of the pressure sleeve 4. The pressure sleeve 4 is then installed on the outer surface of the spring sheet 2. After the pressure sleeve 4 passes through the stepped hole 42 at one end of the pressure sleeve 4, the spring sheet 2 is removed from the clamping can 6. The spring sheet 2 is then slowly pressed into the end face groove 41 at the other end of the pressure sleeve 4. A press is used to press the end face of the spring sheet 2, ensuring that the end face of the spring sheet 2 is flush with the end face of the pressure sleeve 4. The open end of the spring sheet 2 and the plastic ring 3 are checked to ensure they are fully inserted into the end face groove of the pressure sleeve 4, and the inner hole of the plastic ring 3 is checked for scratches, pressure marks, or other abnormalities.

[0037] (3) Figure 4 As shown, based on the outer diameter of the pressure sleeve 4, a pressing fixture 7 with a diameter 0.2-0.3 mm smaller than the outer diameter of the pressure sleeve 4 is selected. A press is used to press one side of the pressure sleeve assembly into the sealing skeleton 1, and then the other side of the pressure sleeve assembly is installed into the sealing skeleton 1. Pressing fixtures 7 are installed at both ends of the sealing skeleton 1, and they are placed together on the press. The upper and lower pressure sleeve assemblies are pressed simultaneously with a pressing force of 7000-9000 N. After holding the pressure for 3-5 minutes, the pressure is released. A height gauge is used to measure the distance between the end face of the pressure sleeve assembly and the end face of the sealing skeleton 1. This distance should meet the design specifications. Require.

[0038] (4) Mount the bidirectional sealing device 8 on a lathe, adjust the outer diameter hobbing angle to 45°, the lathe speed to 50-80 r / min, and the feed rate to 0.03-0.05 mm / r. Roll the thin-walled outer diameter of the sealing skeleton 1 at 45° and then press it tightly against the pressure sleeve 4. Use an angle gauge to measure the angle after rolling to ensure it meets 45°±1°. Check the rolling quality after rolling, and do not allow any abnormal phenomena such as cracks or wrinkles. After rolling one end of the outer diameter, turn it around and roll the other end of the outer diameter. After rolling the outer diameter, remount the lathe, adjust the position of the inner hole R hobbing tool and determine the axial position size. The lathe speed to 50-80 r / min and the feed rate to 0.01-0.03 mm / r. Roll the inner hole R to the design size. After rolling, check the inner hole rolling quality, and do not allow any abnormal phenomena such as cracks, wrinkles, or scratches on the inner hole of the plastic ring. After rolling one end of the inner hole, turn it around and roll the other end of the inner hole.

[0039] (5) The bidirectional sealing device 8 is subjected to airtight screening using a sealing screening fixture. For example... Figure 5 As shown, the sealing and screening fixture includes an inlet nozzle 9, an outlet nozzle 10, a sealing gasket 11, a mandrel 12, and bolts and nuts. The outer diameter of the mandrel 12 is the same as the outer diameter of the valve mandrel during formal assembly. A groove is cut at both ends of the mandrel 12 to allow gas flow. During assembly, the mandrel 12 is first installed in the inner cavity of the bidirectional sealing device 8. Then, the bidirectional sealing device 8 is connected to the inlet nozzle 9 and the outlet nozzle 10. The bidirectional sealing device 8 is located in the cylindrical cavity formed by the mating of the inlet nozzle 9 and the outlet nozzle 10. After the end faces of the inlet nozzle 9 and the outlet nozzle 10 clamp the annular protrusion structure on the outer wall of the sealing frame 1, they are fixed with bolts and nuts and sealed with the sealing gasket 11, ensuring a reliable connection between the bidirectional sealing device 8 and the screening fixture and achieving end face sealing. After assembly, 0.9MPa and 14.5MPa compressed air are introduced through the inlet to check the radial sealing of the plastic ring 3 and the mandrel 12. The airtightness check lasts for 3 minutes. If the leakage meets the requirement of 0 bubbles / 3 minutes, it is acceptable for delivery and use. If the requirement is not met, the sealing device shall be scrapped.

[0040] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A method for manufacturing an ultra-low temperature, high-load-bearing bidirectional sealing device, characterized in that, include: After using the mandrel tool (5) to support the plastic ring (3), the spring plate (2) is installed on the outer surface of the plastic ring (3); After clamping the spring sheet (2) with the clamping can (6), the pressure sleeve (4) is installed on the outer surface of the spring sheet (2); the spring sheet (2) is pressed with a press to limit the spring sheet (2) and the pressure sleeve (4); The pressure sleeve assembly, consisting of a bidirectional pressure sleeve (4), a spring plate (2), and a plastic ring (3), is measured after pressure relief. The distance between the end face of the pressure sleeve assembly and the end face of the sealing skeleton (1) meets the set index requirements. The bidirectional sealing device (8) is clamped by using a roller to roll the outer edge and the inner hole edge; An airtightness screening test was conducted on the bidirectional sealing device (8) using a sealing screening fixture; After using the mandrel tool (5) to support the plastic ring (3), the spring sheet (2) is mounted on the outer surface of the plastic ring (3), including: The spring sheet (2) is gradually fitted onto the outer surface of the plastic ring (3). After the spring sheet (2) passes the maximum interference position, the mandrel fixture (5) is removed from the plastic ring (3) so that the spring sheet (2) is completely fitted onto the outer surface of the plastic ring (3). The diameter of the clamping can (6) is 0.1~0.3mm larger than the outer circle of the closed end of the spring sheet (2); After clamping the spring sheet (2) with the clamping can (6), the pressure sleeve (4) is installed on the outer surface of the spring sheet (2), including: The spring sheet (2) is clamped by a clamping can (6) to hold one end of the fixing ring. After the spring sheet (2) contracts evenly, the contraction diameter of the elastic diaphragm of the spring sheet (2) is 0.01~0.03mm smaller than the inner diameter of the pressure sleeve (4). Then the pressure sleeve (4) is installed on the outer surface of the spring sheet (2). After the pressure sleeve (4) passes through the stepped hole (42), the spring sheet (2) is taken out from the clamping can (6) and then the spring sheet (2) is slowly pressed into the end face groove (41) of the pressure sleeve (2).

2. The manufacturing method of an ultra-low temperature high load-bearing bidirectional sealing device according to claim 1, characterized in that: The mandrel tooling (5) is manufactured according to the inner surface dimensions of the plastic ring (3). The end of the mandrel tooling (5) is provided with a transition guide to prevent scratching the inner surface of the plastic ring (3) during installation. The size difference between the inner surface of the plastic ring (3) and the mating conical surface of the mandrel tooling (5) and the size difference between the inner surface of the plastic ring (3) and the cylindrical surface of the mandrel tooling (5) is 0.02~0.05mm.

3. The manufacturing method of an ultra-low temperature high load-bearing bidirectional sealing device according to claim 1, characterized in that: The method of using a press to press the spring sheet (2) to limit the spring sheet (2) and the pressure sleeve (4) includes: Use a press to press the end face of the spring sheet (2) to ensure that the end face of the spring sheet (2) is flush with the end face of the pressure sleeve (4); check whether the elastic diaphragm of the spring sheet (2) and the plastic ring (3) are fully inserted into the groove (41) on the end face of the pressure sleeve (4), and check that there are no scratches or pressure marks on the inner hole of the plastic ring (3).

4. The manufacturing method of an ultra-low temperature high load-bearing bidirectional sealing device according to claim 1, characterized in that: Before the compression sleeve assembly consisting of the bidirectional compression sleeve (4), spring plate (2), and plastic ring (3), the following are included: According to the outer diameter of the pressure sleeve (4), select a pressing tool (7) with a diameter 0.2~0.3mm smaller than the outer diameter of the pressure sleeve (4), use a press to press one side of the pressure sleeve assembly into the sealing skeleton (1), and then install the other side of the pressure sleeve assembly into the sealing skeleton (1).

5. The manufacturing method of an ultra-low temperature high load-bearing bidirectional sealing device according to claim 1, characterized in that: The clamping of the bidirectional sealing device (8) involves using a roller to roll the outer edge and inner hole edge, including: The outer surface of the sealing skeleton (1) is rolled with a 45° hob, and the outer circle of the side wall of the sealing skeleton (1) is rolled at 45° and then pressed tightly against the pressure sleeve (4); after the two ends of the sealing skeleton (1) are rolled, the inner hole is rolled with an R-type hob.

6. The manufacturing method of an ultra-low temperature high load-bearing bidirectional sealing device according to claim 1, characterized in that: The sealing and screening fixture includes an inlet nozzle (9), an outlet nozzle (10), a sealing gasket (11), and a mandrel (12). The mandrel (12) has grooves at both ends to allow gas flow. The mandrel (12) is installed in the inner cavity of the bidirectional sealing device (8). The bidirectional sealing device (8) is installed in the cavity formed by the docking of the inlet nozzle (9) and the outlet nozzle (10). The end faces of the inlet nozzle (9) and the outlet nozzle (10) clamp the annular protrusion structure of the outer wall of the sealing skeleton (1) and seal it with the sealing gasket (11).

7. The manufacturing method of an ultra-low temperature high load-bearing bidirectional sealing device according to claim 1, characterized in that: The airtightness screening test of the bidirectional sealing device (8) using the sealing screening tool includes: Install the bidirectional sealing device (8) into the sealing screening fixture, and introduce compressed air of 0.9MPa and 14.5MPa from the inlet nozzle (9) to check the radial sealing performance of the plastic ring (3) and the mandrel (12). Perform the airtightness check for 3 minutes. If the leakage meets the requirement of 0 bubbles / 3 minutes, the inspection is qualified.

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