Press-fitting apparatus for large-size nozzle of liquid-propellant rocket engine

Abstract

A press-fitting apparatus for a large-size nozzle of a liquid-propellant rocket engine, comprising a base (1), a sleeve (2), a main shaft (3), a gland (4), a tire body (5), a hydraulic system (12), a pressing plate (6), a double-end stud (7), a limiting block (8), a handle (9), backing rings (10), and a final assembly tire body (11), wherein the sleeve (2) is mounted on the base (1); the main shaft (3) is mounted inside the sleeve (2); the hydraulic system (12) is connected to the main shaft (3) and is used for driving the main shaft (3) to move downwards; the tire body (5) is mounted on the base (1); the handle (9) is mounted on the limiting block (8); the limiting block (8) is mounted on the upper portion of the main shaft (3); the handle (9) and the limiting block (8) are placed on the gland (4); the gland (4) is arranged above the tire body (5); the final assembly tire body (11) is used for supporting the upper section, the middle section and the lower section of a nozzle subjected to press-fitting and brazing. The press-fitting apparatus can implement press-fitting of the inner and outer walls of the upper portion, the middle portion and the lower portion of a product, turning of abutment surfaces, and turning of the whole product subjected to brazing, so that the assembling and press-fitting requirements are satisfied, and it is ensured that the abutment size of the three sections of the product is consistent, thereby improving the brazing quality, and achieving good manufacturability and practicability.

Description

A large-size nozzle pressing device for a liquid rocket engine

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application with application number 202311539050.2, filed with the Chinese Patent Office on November 17, 2023, entitled "A Large-Size Nozzle Pressing Device for a Liquid Rocket Engine," the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The invention relates to a pressing device, in particular to a large-size nozzle pressing device for a liquid rocket engine, and belongs to the field of mechanical manufacturing and processing. Background Art

[0004] The nozzle is a core component of a liquid rocket engine. The reliability of its working state directly affects whether the liquid rocket engine can work normally, and the welding quality of the nozzle is a key indicator of its reliable operation. If there is no pressing device in the welding process of the nozzle, one of the disadvantages is that the product is not of ideal size when it is formed, there is a certain amount of processing deformation, the roundness is poor, and the inner and outer walls cannot be completely fitted, so the inner and outer walls cannot be directly fitted. The second disadvantage is that due to the crystal structure of the product, the plasticity is poor at room temperature and cold deformation is difficult. If the inner and outer walls are forced to fit together by external force such as knocking, it will cause local cracks in the product. At the same time, the fitting effect is not ideal, affecting the strength of the brazing seam. The third disadvantage is that the product needs to provide effective support during the turning process. Without a positioning jig, the product will deform, and there is no benchmark for processing, making it impossible to complete the processing process. Summary of the Invention

[0005] The technical problem addressed by this invention is to overcome the shortcomings of existing technologies by providing a press-fitting device that is easy to install, features controllable press-fitting force, and provides support during lathe machining. This device is specifically designed for nozzle lathe machining and butt-jointing press-fitting. This device solves issues such as loose fit between the nozzle's inner and outer walls, inconsistent joint dimensions between sections, and lack of support during lathe assembly, effectively improving nozzle welding quality.

[0006] The technical solution of the present invention is:

[0007] A large-size nozzle pressing device for a liquid rocket engine, comprising a base, a sleeve, a main shaft, a gland, a carcass, a hydraulic system, a pressing plate, a stud, a limit block, a handle, a gasket, and an assembly carcass;

[0008] The sleeve is mounted on the base through a threaded structure, and the spindle is mounted in the sleeve through a clearance fit; the hydraulic system is connected to the spindle to drive the spindle downward; the carcass is mounted on the base through a threaded structure; the handle is mounted on the limit block through a threaded structure, the limit block is mounted on the upper part of the spindle, and the handle and limit block are placed on the gland; the gland is placed above the carcass;

[0009] The assembly carcass is used to support the upper, middle and lower sections of the nozzle after press-fit brazing. Pads are welded on the assembly carcass to ensure that the assembly carcass fits tightly against the large and small ends of each section of the nozzle. The assembly carcass is used to realize the lathing of each section of the nozzle and the welding between the sections.

[0010] Preferably, it also includes a pressing plate and studs;

[0011] When the nozzle sections are turned on the assembly carcass, a pressure plate is installed on the product to be processed, and studs connect the pressure plate and the base, so that the product always fits the assembly carcass during the turning process.

[0012] Preferably, the carcass is a casting, the interior of which is a hollow structure and is designed with reinforcing ribs to reduce the weight of the carcass while ensuring the strength of its structure.

[0013] Preferably, by replacing the carcass and the gland, the press-fit brazing of different sections of the liquid rocket nozzle can be achieved.

[0014] Preferably, the profile of the carcass is consistent with the profile of the nozzle section to be processed, ensuring that it is completely fitted with the nozzle section to be processed.

[0015] Preferably, the inner diameter of the gland is the same as the outer diameter of the upper end surface of the small end of the nozzle section to be processed.

[0016] Preferably, the hydraulic system can be started and stopped at any time, and its pressure is adjustable.

[0017] A method for applying a large-size nozzle pressing device for a liquid rocket engine comprises the following steps:

[0018] Step 1: Select the carcass and gland corresponding to the upper section of the nozzle, and execute S1-S5 to process the upper section of the nozzle;

[0019] S1. Install the sleeve on the base, install the main shaft in the sleeve through clearance fit, connect the hydraulic system and the main shaft, and install the carcass on the base through the threaded structure;

[0020] S2. Fit the inner wall of the product onto the carcass, and fit the outer wall of the product onto the inner wall;

[0021] S3. The gland is placed on top of the carcass; the handle is mounted on the limit block through a threaded structure, the limit block is mounted on the upper part of the main shaft, and the handle and the limit block are placed on the gland;

[0022] S4. Start the hydraulic system, which drives the main shaft to move downward. The limit block moves downward with the main shaft, thereby driving the gland to move downward, so that the gland applies force to the outer wall of the product. After the outer wall and the inner wall of the product are tightly fitted, the inner and outer walls are sealed and welded. Then, the gland is removed and the inner and outer walls that are sealed and welded together are brazed.

[0023] S5. Install the final assembly carcass on the base, set the brazed product on the final assembly carcass, install a pressure plate on the large end of the product, and connect the pressure plate and the base with studs to ensure that the product always fits the final assembly carcass during the lathing process. After lathing the inner and outer wall sealing parts, process the large and small ends of the product to meet the joint dimensions. After processing, remove the product and final assembly carcass.

[0024] Step 2: Replace the carcass and gland with the carcass and gland corresponding to the middle section of the nozzle, and repeat S1-S5 to process the middle section of the nozzle;

[0025] Step 3: Replace the carcass and gland with the carcass and gland corresponding to the lower section of the nozzle, and repeat S1-S5 to process the lower section of the nozzle;

[0026] Step 4: Install the assembly carcass on the base, and sequentially fit the lower section and middle section of the nozzle onto the assembly carcass, and weld the connection between the lower section and the middle section; then fit the upper section of the nozzle onto the assembly carcass, and weld the connection between the upper section and the middle section.

[0027] The advantages of the present invention compared with the prior art are:

[0028] (1) The carcass and assembly carcass used in the present invention can correct the processing deformation of the product, round it, and achieve smooth fitting of the inner and outer walls of the product, effectively fitting them, and improving the strength of the brazing seam;

[0029] (2) Since the total wall thickness of the product at the docking position is about 14 mm, the structure is very rigid, and additional stress still exists after brazing. In order to expand and correct the shape of this section of the product, a large load needs to be applied. The hydraulic force application system adopted by the present invention can effectively solve the problem of difficulty in applying force;

[0030] (3) The hydraulic force application system adopted by the present invention replaces external force knocking and other methods to avoid local cracks in the product;

[0031] (4) The gasket ring used in the present invention can achieve the tightening of each section of the product after brazing, and realize the size of the vehicle docking interface when the product is in the expanded state, thereby ensuring that the docking state meets the requirements;

[0032] (5) The present invention is specially used for the process of nozzle machining and butt-jointing and pressing, which solves the problems of loose fitting of the inner and outer walls of the nozzle, inconsistent butt-jointing dimensions of each section, and lack of support during the lathe assembly process, thereby effectively improving the welding quality of the nozzle. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a structural diagram of a pressing device;

[0034] Figure 2 is a diagram of the final assembly carcass structure;

[0035] Figure 3 is a diagram of the carcass structure;

[0036] Figure 4 is a structural diagram of the gland;

[0037] Figure 5 is a structural diagram of the pressing plate;

[0038] Figure 6 is a structural diagram of the pressing plate (top view);

[0039] Figure 7 is a structural diagram of a stud bolt. DETAILED DESCRIPTION

[0040] The present invention will be described below with reference to the accompanying drawings.

[0041] As shown in Figures 1 and 2, it is a schematic diagram of a large-size nozzle pressing device for a liquid rocket engine, which includes a base 1, a sleeve 2, a main shaft 3, a gland 4, a carcass 5, a hydraulic system 12, a pressure plate 6, a stud 7, a limit block 8, a handle 9, a gasket 10, and an assembly carcass 11.

[0042] Sleeve 2 is mounted on base 1 via a threaded structure, and spindle 3 is installed in sleeve 2 with a clearance fit. Hydraulic system 12 is connected to spindle 3 to drive spindle 3 downward. Carcass 5 is mounted on base 1 via a threaded structure. Handle 9 is mounted on limit block 8 via a threaded structure. Limit block 8 is installed on the upper part of spindle 3, and handle 9 and limit block 8 are placed on gland 4. Gland 4 is placed on top of carcass 5. The above structure forms the nozzle press-fit structure. By replacing the carcass and gland, different sections of the liquid rocket nozzle can be press-fit brazed.

[0043] The assembly carcass 11 is used to support the upper, middle, and lower sections of the nozzle after press-fitting and brazing. A gasket 10 is welded to the assembly carcass 11, ensuring a tight fit between the large and small ends of each section of the nozzle. The assembly carcass 11 is used for lathing each section of the nozzle and for welding each section together. When the assembly carcass 11 is lathing each section of the nozzle, a pressure plate 6 is installed on the product to be machined. Studs 7 connect the pressure plate 6 to the base, ensuring that the product remains in contact with the assembly carcass 11 during lathing. The carcass 5 is a casting with a hollow interior and internally designed reinforcing ribs to reduce the carcass' weight while ensuring structural strength. The profile of the carcass 5 is consistent with that of the section of the nozzle to be machined, ensuring a complete fit. The inner diameter of the pressure cap is the same as the outer diameter of the upper end face of the small end of the nozzle section to be machined.

[0044] In this invention, the spindle 3 and hydraulic system 12 are universal, allowing the inner and outer walls of the upper, middle, and lower parts of the product to be pressed together by replacing the carcass and gland. After brazing, the product expands, creating a gap between it and the carcass 5. A backing ring 10 is welded to the large carcass 11, tightly fitting the large and small ends of the product. After the inner and outer walls of the product are pressed together, the pressure plate 6 is connected to the carcass 5 via studs 7, ensuring that the product remains in contact with the carcass 5 during the turning process. The hydraulic system 12 can be started and stopped at any time, and its pressure is adjustable.

[0045] Figure 3 is a diagram of the carcass structure, Figure 4 is a diagram of the gland structure, Figure 5 is a diagram of the pressure plate structure, and Figure 6 is a top view of the pressure plate structure; Figure 7 is a diagram of the stud structure.

[0046] An application method of a large-size nozzle pressing device for a liquid rocket engine is as follows:

[0047] The inner wall of the product is fitted onto the carcass 5. After machining the inner wall end face, the outer wall of the product is fitted onto the inner wall. The hydraulic system 12 is started. The hydraulic system drives the main shaft 3 downward and applies force to the limit block 8, thereby driving the pressure cover 4 downward so that the pressure cover 4 applies force to the outer wall of the product. After the inner wall of the product is tightly fitted, the inner and outer walls of the product are sealed and welded, and then the inner and outer walls are sent into the furnace as a whole for brazing. After brazing is completed, the product is fitted onto the final assembly carcass 11. Since brazing causes the product to deform and a gap is created between the product and the prototype surface of the carcass, a gasket 10 is welded onto the final assembly carcass 11 to support the large and small ends of the product and to round it by applying external force. Subsequently, the pressure plate 6 is installed at the large end of the product. After the pressure plate 6 is connected to the base 1 by the stud 7, the pressure is relieved and the processing of the docking dimensions of the large and small ends of the product is carried out. The product consists of three parts: upper, middle and lower. Each section of the product will have the same process as mentioned above, and only the corresponding carcass and pressure cover need to be replaced. After each section of the product has been processed through the above steps and is ready for assembly, the lower section and middle section of the product are sequentially mounted on the assembly carcass 11 and their connection positions are welded; thereafter, the upper section of the product is mounted on the assembly carcass 11 and the connection positions of the upper section and the middle section are welded.

[0048] This invention achieves the lamination of the inner and outer walls of the upper, middle, and lower sections, lathe machining of the butt joints, and lathe machining of the entire product after brazing. This meets assembly and lamination requirements, ensuring consistent dimensions among the three sections and improving weld quality. This convenient assembly is specifically designed for laminating and lathing individual sections and the entire nozzle, offering excellent processability and practicality.

[0049] Parts of the present invention that are not described in detail belong to the common knowledge of those skilled in the art.

Claims

1. A large-size nozzle pressing device for a liquid rocket engine, characterized in that: It comprises a base (1), a sleeve (2), a main shaft (3), a gland (4), a carcass (5), a hydraulic system (12), a pressure plate (6), a stud (7), a limit block (8), a handle (9), a gasket (10), and an assembly carcass (11); The sleeve (2) is mounted on the base (1) through a threaded structure, and the main shaft (3) is mounted in the sleeve (2) through a clearance fit; the hydraulic system (12) is connected to the main shaft (3) and is used to drive the main shaft (3) to move downward; the carcass (5) is mounted on the base (1) through a threaded structure; the handle (9) is mounted on the limit block (8) through a threaded structure, the limit block (8) is mounted on the upper part of the main shaft (3), and the handle (9) and the limit block (8) are placed on the gland (4); the gland (4) is placed above the carcass (5); The assembly carcass (11) is used to support the upper section, middle section and lower section of the nozzle after press-fit brazing. A cushion ring (10) is welded on the assembly carcass (11) so that the assembly carcass is tightly fitted with the large and small ends of each section of the nozzle. The assembly carcass (11) is used to realize the lathing of each section of the nozzle and the welding between each section.

2. A large-size nozzle pressing device for a liquid rocket engine according to claim 1, characterized in that: It also includes a pressing plate (6) and a stud bolt (7); When the assembly carcass (11) is lathe-machined to realize each section of the nozzle, a pressing plate (6) is installed on the product to be machined, and a stud (7) connects the pressing plate (6) and the base, so that the product is always in contact with the assembly carcass (11) during the lathe-machine process.

3. A large-size nozzle pressing device for a liquid rocket engine according to claim 1, characterized in that: The carcass (5) is a casting, the interior of which is a hollow structure and is provided with reinforcing ribs, so as to reduce the weight of the carcass while ensuring the strength of the structure.

4. A large-size nozzle pressing device for a liquid rocket engine according to claim 1, characterized in that: By replacing the carcass and the gland, the different sections of the liquid rocket nozzle can be pressed and brazed.

5. A large-size nozzle pressing device for a liquid rocket engine according to claim 4, characterized in that: The profile of the carcass (5) is consistent with the profile of the nozzle section to be processed, ensuring that it is completely fitted with the nozzle section to be processed.

6. A large-size nozzle pressing device for a liquid rocket engine according to claim 1, characterized in that: The inner diameter of the gland is the same as the outer diameter of the upper end surface of the small end of the nozzle section to be processed.

7. A large-size nozzle pressing device for a liquid rocket engine according to claim 1, characterized in that: The hydraulic system (12) can be started and stopped at any time, and its pressure is adjustable.

8. An application method of a large-size nozzle pressing device for a liquid rocket engine, characterized in that: The steps include: Step 1: Select the carcass and gland corresponding to the upper section of the nozzle, and execute S1-S5 to process the upper section of the nozzle; S1, installing the sleeve (2) on the base (1), installing the main shaft (3) in the sleeve (2) through clearance fit, connecting the hydraulic system (12) and the main shaft (3), and installing the carcass (5) on the base (1) through a threaded structure; S2, fitting the inner wall of the product onto the carcass (5), and fitting the outer wall of the product onto the inner wall; S3, the gland (4) is placed above the carcass (5); the handle (9) is installed on the limit block (8) through a threaded structure, the limit block (8) is installed on the upper part of the main shaft (3), and the handle (9) and the limit block (8) are placed on the gland (4); S4, starting the hydraulic system (12), the hydraulic system (12) drives the main shaft (3) to move downward, the limit block (8) follows the main shaft (3) to move downward, thereby driving the gland (4) to move downward, so that the gland (4) applies force to the outer wall of the product, and after the outer wall and the inner wall of the product are tightly fitted, the inner and outer walls are sealed and welded, and then the gland is removed, and the inner and outer walls that are sealed and welded as a whole are brazed; S5, installing the final assembly carcass on the base (1), putting the brazed product on the final assembly carcass, installing a pressure plate (6) on the large end of the product, connecting the pressure plate (6) and the base with a stud (7), so that the product always fits with the final assembly carcass (11) during the lathing process, and after lathing the sealing welding parts of the inner and outer walls, the product is processed to the butt joint size of the large and small ends; after the processing is completed, the product and the final assembly carcass are removed; Step 2: Replace the carcass and gland with the carcass and gland corresponding to the middle section of the nozzle, repeat S1-S5, and process the middle section of the nozzle; Step 3: Replace the carcass and gland with the carcass and gland of the corresponding lower section of the nozzle, repeat S1-S5, and process the lower section of the nozzle; Step 4: Install the assembly carcass on the base (1), sequentially fit the lower section and middle section of the nozzle onto the assembly carcass, and weld the connection between the lower section and the middle section; then fit the upper section of the nozzle onto the assembly carcass, and weld the connection between the upper section and the middle section.

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