Reusable large-diameter double-channel redundant sealing structure of carrier rocket

Abstract

A reusable large-diameter double-channel redundant sealing structure of a carrier rocket comprises a convex flange, a concave flange, a movable lantern ring, a clamping block, a metal disc-shaped ring and a metal O-shaped ring. The convex flange and the concave flange are respectively welded and fixed at two ends of two pipelines to be connected; the lower end surface of the convex flange is matched with the upper end surface of the concave flange; the movable lantern ring is arranged on one side of the concave flange, is provided with bolt holes along the circumferential direction and is matched with the bolt holes of the convex flange; the clamping block is mounted between the convex flange and the movable lantern ring, so that the edges of the convex flange and the movable lantern ring are prevented from buckling deformation after being stressed, and reliable sealing is ensured; the metal disc-shaped ring is arranged between the convex flange and the concave flange and is used for preventing a medium from leaking from a sealing part; and the metal O-shaped ring is arranged between the convex flange and the concave flange and is used for preventing a medium from leaking from a sealing part. The problem that an existing sealing technology cannot meet the requirement for high-reliability repeated use of the carrier rocket is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of launch vehicle sealing, and in particular relates to a reusable double-channel redundant sealing structure. Background Art

[0002] With the development of my country's aerospace technology, the demand for launch vehicles to be reused has been put forward, which has brought more challenges to the design of sealing structures. The difficulties in designing reusable sealing structures mainly include high leakage rate requirements, strong temperature adaptability, high reliability, and repeated disassembly and assembly. For large-diameter sealing structures, due to the large diameter of the flange, the flange is prone to warping and deformation after being pressurized, resulting in a larger gap between the sealing surfaces and affecting the sealing effect. If the compensation capacity of the sealing structure is insufficient, it will cause leakage of the medium, adding more difficulty to the sealing design.

[0003] At present, the commonly used sealing structures for large-diameter parts such as the propellant delivery pipes and tank manhole covers of launch vehicles are: rubber O-ring seals, metal O-ring seals and indium wire seals. The rubber material of the rubber O-ring hardens under low temperature conditions and is not suitable for low-temperature propellant environments; the PFA coating of the metal O-ring has limited compression rebound and insufficient compensation for flange deformation; the indium wire is difficult to disassemble and clean after installation and is not suitable for repeated use conditions. Therefore, the currently commonly used large-diameter sealing structures are difficult to meet the high and low temperature cycle conditions and high reliability repeated use requirements of launch vehicles. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the above-mentioned deficiencies of the prior art and to provide a large-caliber dual-channel redundant sealing structure with reliable sealing and strong compensation capability, so as to solve the problem that the existing sealing technology cannot meet the high-reliability reuse of launch vehicles.

[0005] The technical solution of the present invention is: a reusable large-caliber double-channel redundant sealing structure for a launch vehicle, comprising: a convex flange, a concave flange, a slip ring, a clamping block, a metal disc ring and a metal O-ring; the convex flange and the concave flange are respectively welded and fixed at the two ends of two pipelines to be connected; the lower end surface of the convex flange is matched with the upper end surface of the concave flange for installation; the slip ring is installed on one side of the concave flange, and bolt holes are provided along the circumferential direction, and are matched with the bolt holes of the convex flange for installation; the clamping block is installed between the convex flange and the slip ring to prevent the edges of the convex flange and the slip ring from warping and deformation after being stressed, thereby ensuring reliable sealing; the metal disc ring is installed between the convex flange and the concave flange to prevent the medium from leaking from the sealing part; the metal O-ring is installed between the convex flange and the concave flange to prevent the medium from leaking from the sealing part.

[0006] The lower end surface of the convex flange is designed with a convex part, and the upper end surface of the concave flange is provided with a concave part. The convex part of the lower end surface of the convex flange and the concave part of the concave flange are matched with tongue and groove to form an annular sealing groove gap for installing a metal disc ring.

[0007] The radial clearance of the tongue and groove is not less than 1.6 mm, and an oblique cone guide surface is provided on the raised part of the lower end surface of the convex flange to ensure that the metal disc ring can smoothly fall into the sealing position during assembly; after installation, the metal disc ring is pressurized to form the first seal with the convex flange and the concave flange sealing surface, which is a radial seal.

[0008] The angle of the inclined cone guide surface is designed to be 10° to 15°.

[0009] A rectangular sealing groove is provided on the upper end surface of the concave flange for installing a metal O-ring; after the metal O-ring is installed, it is pressurized to form a second seal with the sealing surfaces of the convex flange and the concave flange, namely, an axial seal.

[0010] The invention also includes fasteners in the form of bolts and nuts, which are used to fix and connect the convex flange, the concave flange, the loose ring and the clamping block.

[0011] The clamping block is installed in cooperation with each fastener, and the thickness of the clamping block is 0.5mm smaller than the thickness of the concave flange. A through hole is provided in the middle of the clamping block. When installing, the clamping block is first placed at the bolt hole position between the convex flange and the slip ring, and the fastener is fixedly installed through the bolt hole. The inner side of the clamping block has an arc surface that cooperates with the outer circumference of the concave flange to prevent the clamping block from rotating after assembly.

[0012] A leak detection hole is designed on the outer surface of the convex flange, and the leak detection channel corresponding to the leak detection hole is located between the axial seal and the radial seal; after the sealing structure is installed, the cavity of the sealed part in the pipe is pressurized, and the leak detection hole detects the sealing performance of the metal disc ring; the leak detection hole is pressurized to detect the sealing performance of the metal O-ring.

[0013] The leak detection hole interface is designed to be threaded, so that the leak detection hole can be easily blocked with a plugging cover after installation.

[0014] The advantages of the present invention compared with the prior art are:

[0015] 1. The design of the present invention adopts the form of "metal O-ring + metal disc ring". During assembly, the flange first contacts and compresses the metal disc ring, and then compresses the metal O-ring, which minimizes the coupling between the two redundant seals; the metal disc ring is placed on the inner side that directly senses the pressure, and is radially tightened by the pressure, serving as the first seal to improve the sealing performance.

[0016] 2. In order to solve the problem of assembly dimension interference caused by welding deformation that is prone to occur in large-diameter flanges, the present invention is designed to increase the fitting clearance between the mortise and tenon of the concave and convex flanges and provide an inclined cone guide surface to enhance the installation compensation capability of the dual-channel redundant sealing structure.

[0017] 3. To solve the problem of warping of large-diameter flanges after being compressed, the present invention provides a clamping block between the convex flange and the slip-on ring to limit the deformation of the flange; the inner side of the clamping block cooperates with the slip-on flange through an arc surface to prevent the clamping block from rotating around the bolt.

[0018] 4. The leak detection hole provided between the two seals of the present invention can be used to detect the sealing effect of the metal O-ring and the metal disc ring respectively, so as to judge the effectiveness of the reusable sealing structure; the leak detection hole interface is in the form of a threaded connection, which is convenient for sealing the inner and outer seals after installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the sealing structure assembly of the present invention;

[0020] Figure 2 It is an enlarged schematic diagram of the assembly of the sealing structure of the present invention;

[0021] Figure 3 It is a schematic cross-sectional view of the assembly of the clamp block and the fastener of the present invention;

[0022] Figure 4 It is a schematic cross-sectional view of the leak detection hole of the sealing structure of the present invention. DETAILED DESCRIPTION

[0023] like Figure 1 , which is a reusable large-caliber double-channel redundant sealing structure for a launch vehicle of the present invention, and is composed of a convex flange 1, a concave flange 2, a loose ring 3, a clamping block 4, a metal disc ring 5, a metal O-ring 6, and a fastener 7. The convex flange 1 and the concave flange 2 are respectively welded and fixed at the two ends of the two pipelines to be connected, and the lower end surface of the convex flange 1 matches the upper end surface of the concave flange 2; the clamping block 4 is installed between the convex flange 1 and the loose ring 3; the fastener 7 connects and fixes the convex flange 1, the concave flange 2, the loose ring 3, and the clamping block 4; the metal disc ring 5 and the metal O-ring 6 are installed between the convex flange 1 and the concave flange 2.

[0024] like Figure 2 The convex part of the lower end face of the convex flange 1 and the concave part of the concave flange 2 are matched with a tongue and groove to form an annular sealing groove gap for installing the metal disc ring 5. In order to prevent the large-diameter flange from welding and deformation, which leads to dimensional interference during flange installation, the gap is increased for the tongue and groove of the concave and convex flanges, and a 15° inclined cone guide surface is set to ensure that the metal disc ring 5 can smoothly fall into the sealing position during assembly. After installation, the metal disc ring 5 is pressurized to form the first seal with the sealing surfaces of the convex flange 1 and the concave flange 2, which is a radial seal.

[0025] The concave flange 2 is provided with a rectangular sealing groove near the bolt side for installing a metal O-ring 6. After the metal O-ring 6 is installed, it is compressed to form a second seal with the sealing surfaces of the convex flange 1 and the concave flange 2, which is an axial seal.

[0026] The fastener 7 is in the form of a bolt (stud)-nut combination, and is used to fix the convex flange 1, the concave flange 2, the loose ring 3, and the clamping block 4.

[0027] like Figure 3 The clamping block 4 is installed in cooperation with each fastener 7 and is located between the convex flange 1 and the loose ring 3 to limit the position, thereby preventing the large-diameter flange from being warped and deformed after being compressed, so as to ensure reliable sealing.

[0028] like Figure 4 In order to determine whether the two seals are effective after installation, a leak detection hole 8 is designed on the outer surface of the convex flange 1, and the leak detection channel is located between the two seals. After the sealing structure is installed, the leak detection hole detects the sealing performance of the metal disc ring 5 by charging the pipe; the leak detection hole is charged to detect the sealing performance of the metal O-ring 6; the leak detection hole interface is designed to be threaded, which is convenient for plugging the leak detection hole with a plugging cover after installation.

[0029] The design of the present invention adopts the form of "metal O-ring + metal disc ring". The metal disc ring is a radial seal and the metal O-ring is an axial seal. During assembly, the flange first contacts and compresses the metal disc ring, and then compresses the metal O-ring, which minimizes the coupling between the two redundant seals; the metal disc ring is placed on the inner side that directly senses the pressure, and is radially tightened by the pressure, serving as the first seal to improve the sealing performance.

[0030] In order to solve the problem of assembly dimension interference caused by welding deformation that is prone to occur in large-diameter flanges, the design increases the fitting clearance between the concave and convex flange tenons and sets a 15° inclined cone guide surface to enhance the installation compensation capability of the dual-channel redundant sealing structure.

[0031] In order to solve the problem of warping and deformation of large-diameter flanges after being compressed, a clamp is set between the convex flange and the slip ring to limit the deformation of the flange. The thickness of the clamp is 0.5mm less than that of the concave flange. When installing, first place the clamp at the bolt hole between the convex flange and the slip ring, and install the fastener through it. The inner side of the clamp cooperates with the slip ring flange through the arc surface to prevent the clamp from rotating around the bolt.

[0032] The leak detection hole set between the two seals can be used to detect the sealing effect of the metal O-ring and the metal disc ring respectively, so as to determine the effectiveness of the reusable sealing structure; the leak detection hole interface is in the form of a threaded connection, which is convenient for sealing the inner and outer seals after installation; the leak detection hole can be used as a discharge hole for internal media under special circumstances.

[0033] The double-channel seal plays a role of redundant sealing, further improving the sealing performance and ensuring compensation capability and high reliability. The test shows that the sealing structure of the present invention can maintain a normal low temperature leakage rate of 10 -7 Pa.m3 / s (sniffing gun method) level, which can meet the reuse requirements of the launch vehicle under high and low temperature conditions.

[0034] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solution of the present invention by using the technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A reusable large-caliber double-channel redundant sealing structure for a launch vehicle, characterized in that: include: Convex flange, concave flange, slip ring, clamping block, metal disc ring and metal O-ring; the convex flange and the concave flange are respectively welded and fixed at the two ends of the two pipelines to be connected; the lower end face of the convex flange is matched with the upper end face of the concave flange for installation; the slip ring is installed on one side of the concave flange, and bolt holes are opened along the circumference, and installed in cooperation with the bolt holes of the convex flange; the clamping block is installed between the convex flange and the slip ring to prevent the edges of the convex flange and the slip ring from warping and deformation after being stressed, so as to ensure reliable sealing; the metal disc ring is installed between the convex flange and the concave flange to prevent the medium from leaking from the sealing part; the metal O-ring is installed between the convex flange and the concave flange to prevent the medium from leaking from the sealing part.

2. A reusable large-caliber dual-channel redundant sealing structure for a launch vehicle according to claim 1, characterized in that: The lower end surface of the convex flange is designed with a convex part, and the upper end surface of the concave flange is provided with a concave part. The convex part of the lower end surface of the convex flange and the concave part of the concave flange are matched with tongue and groove to form an annular sealing groove gap for installing a metal disc ring.

3. A reusable large-caliber dual-channel redundant sealing structure for a launch vehicle according to claim 2, characterized in that: The radial clearance of the tongue and groove is not less than 1.6 mm, and an oblique cone guide surface is provided on the raised part of the lower end surface of the convex flange to ensure that the metal disc ring can smoothly fall into the sealing position during assembly; after installation, the metal disc ring is pressurized to form the first seal with the convex flange and the concave flange sealing surface, which is a radial seal.

4. A reusable large-caliber dual-channel redundant sealing structure for a launch vehicle according to claim 3, characterized in that: The angle of the inclined cone guide surface is designed to be 10° to 15°.

5. A reusable large-caliber dual-channel redundant sealing structure for a launch vehicle according to claim 1, characterized in that: A rectangular sealing groove is provided on the upper end surface of the concave flange for installing a metal O-ring; after the metal O-ring is installed, it is pressurized to form a second seal with the sealing surfaces of the convex flange and the concave flange, namely, an axial seal.

6. A reusable large-caliber dual-channel redundant sealing structure for a launch vehicle according to claim 1, characterized in that: The invention also includes fasteners in the form of bolts and nuts, which are used to fix and connect the convex flange, the concave flange, the loose ring and the clamping block.

7. A reusable large-caliber dual-channel redundant sealing structure for a launch vehicle according to claim 6, characterized in that: The clamping block is installed in cooperation with each fastener, and the thickness of the clamping block is 0.5mm smaller than the thickness of the concave flange. A through hole is provided in the middle of the clamping block. When installing, the clamping block is first placed at the bolt hole position between the convex flange and the slip ring, and the fastener is fixedly installed through the bolt hole. The inner side of the clamping block has an arc surface that cooperates with the outer circumference of the concave flange to prevent the clamping block from rotating after assembly.

8. A reusable large-caliber dual-channel redundant sealing structure for a launch vehicle according to claim 1, characterized in that: A leak detection hole is designed on the outer surface of the convex flange, and the leak detection channel corresponding to the leak detection hole is located between the axial seal and the radial seal; after the sealing structure is installed, the cavity of the sealed part in the pipe is pressurized, and the leak detection hole detects the sealing performance of the metal disc ring; the leak detection hole is pressurized to detect the sealing performance of the metal O-ring.

9. A reusable large-caliber dual-channel redundant sealing structure for a launch vehicle according to claim 8, characterized in that: The leak detection hole interface is designed to be threaded, so that the leak detection hole can be easily blocked with a plugging cover after installation.

Images