Large nozzle crimping device for liquid rocket engines

Abstract

The crimping device for large-sized nozzles for liquid rocket engines belongs to the machinery manufacturing and processing field. It includes a base, sleeve, main shaft, retaining cap, cast blank, platen, double-ended screw bolt, positioning block, handle, backup ring, final assembled cast blank, and hydraulic system. The crimping device of the present invention enables the crimping of the inner and outer walls of the upper, middle, and lower parts of the product, turning of the docking surfaces, and brazing of the entire product followed by subsequent turning. This satisfies the requirements for assembly and crimping, ensures that the docking dimensions of the three segments of the product are consistent, and improves welding quality. The crimping device of the present invention is easy to use and can be used to crimp and turn each segment and the entire nozzle, demonstrating good operability and practicality.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Chinese Patent Application No. 202311539050.2 (Title: Crimping Device for Large-Dimension Nozzle for Liquid Rocket Engine), filed on November 17, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a crimping device, and more particularly to a crimping device for large-sized nozzles for liquid rocket engines, and belongs to the field of mechanical manufacturing and processing. [Background technology]

[0003] Nozzles are the core assembly of liquid rocket engines, and their reliability directly affects the engine's normal operation. Therefore, nozzle welding quality is an important indicator of reliability. The first drawback of the nozzle welding process without a crimping device is that the product's dimensional shape is not ideal, resulting in certain processing deformation and poor roundness, which prevents the inner and outer walls from fully adhering, making direct brazing impossible. The second drawback is that the product's crystalline structure makes it difficult to achieve cold deformation, resulting in poor plasticity at room temperature. Therefore, when the inner and outer walls are joined together using methods such as tapping under external force, local cracks will occur in the product, resulting in poor adhesion and affecting the strength of the brazing. The third drawback is that the product must be effectively supported during processing; if the product is not positioned properly, it will deform, resulting in a lack of a processing standard, making the process impossible to complete. Summary of the Invention

[0004] The problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a crimping device that is easy to install, has a controllable crimping force, and can provide support during turning, and is applicable to the nozzle turning and docking and crimping processes. This device solves the problems of inconsistent contact between the inner and outer walls of the nozzle, inconsistent docking dimensions of each segment, and lack of support during turning, and effectively improves the welding quality of the nozzle. The technical means of the present invention are as follows:

[0005] A crimping device for a large-sized nozzle for a liquid rocket engine, comprising a base, a sleeve, a main shaft, a cover, a cast blank, a hydraulic system, a platen, a double-threaded bolt, a positioning block, a handle, a backup ring, and a final assembly cast blank, the sleeve is attached to the base by a thread structure, the main shaft is attached in the sleeve by a clearance fit, a hydraulic system is connected to the main shaft and is used to drive the downward movement of the main shaft, the cast blank is attached to the base by a thread structure, the handle is attached to the position limiting block by a thread structure, the position limiting block is attached to the top of the main shaft, the handle and the position limiting block are located on a holding cover, and the holding cover is located above the cast blank; A crimping device for large-dimension nozzles for liquid rocket engines, in which the final assembled cast blanks are used to support the upper, middle, and lower segments of the nozzle after crimping and brazing, and backup rings are welded to the final assembled cast blanks so that the final assembled cast blanks are tightly attached to the large and small ends of each segment of the nozzle, and the final assembled cast blanks are used to perform the turning of each segment of the nozzle and the welding between each segment.

[0006] Preferably, the device further includes a platen and a double-threaded bolt. After the turning of each nozzle segment is achieved using the final assembled cast blank, a platen is attached to the product to be machined, and the platen and base are connected by double-threaded bolts, so that the product is always in close contact with the final assembled cast blank during the turning process.

[0007] Preferably, the cast blank is a casting, has a hollow structure inside, and is provided with reinforcing ribs inside, which reduces the weight of the cast blank and ensures the strength of its structure.

[0008] Preferably, the cast blank and the hold-down cap are interchangeable to allow for crimping and brazing of different segments of the liquid rocket nozzle.

[0009] Preferably, the die surface of the cast blank matches the die surface of the machined segment of the nozzle so as to fit perfectly to the machined segment of the nozzle.

[0010] Preferably, the inside diameter of the retainer cap is the same as the outside diameter of the upper end surface of the small end of the nozzle segment being machined.

[0011] Preferably, the hydraulic system can be activated or deactivated at any time and its pressure is adjustable.

[0012] A method for using a crimping device for a large-sized nozzle for a liquid rocket engine, comprising the following steps 1 to 4: Step 1: Select the casting blank and the clamping cover corresponding to the upper segment of the nozzle, and execute steps S1-S5 below to process the upper segment of the nozzle. S1: The sleeve is attached to the base, the spindle is attached to the sleeve by clearance fit, the hydraulic system and the spindle are connected, and the cast blank is attached to the base by a screw structure. S2: The inner wall of the product is fitted onto the cast blank, and the outer wall of the product is fitted onto the inner wall; S3: Place the presser lid on top of the cast blank, attach the handle to the position control block using a screw structure, attach the position control block to the top of the main shaft, and place the handle and the position control block on the presser lid. S4: The hydraulic system is activated, causing the main shaft to move downward, and the position control block to move downward along with the main shaft, causing the clamping cover to be pressed against the outer wall of the product, and the outer and outer walls of the product are tightly attached to each other, and then the inner and outer walls are seal-welded together. Then the clamping cover is removed, and the integrally seal-welded inner and outer walls are brazed. S5: The final assembly cast blank is attached to the base, the brazed product is fitted onto the final assembly cast blank, a platen is attached to the large end of the product, and the platen and base are connected with two screw bolts so that the product is always in close contact with the final assembly cast blank during the turning process. After removing the seal welded parts of the inner and outer walls through turning, the docking dimensions of the large and small ends of the product are processed. After processing is completed, the product and the final assembly cast blank are removed. Step 2: Change the casting blank and the clamping cover to the casting blank and the clamping cover corresponding to the middle segment of the nozzle, and repeat steps S1-S5 to process the middle segment of the nozzle. Step 3: Change the casting blank and the clamping cover to the casting blank and the clamping cover corresponding to the lower segment of the nozzle, and repeat steps S1-S5 to process the lower segment of the nozzle. Step 4: Attaching the final assembled cast blank to a base, fitting the lower and middle segments of the nozzle onto the final assembled cast blank in order, welding the connection between the lower and middle segments, and then fitting the upper segment of the nozzle onto the final assembled cast blank, and welding the connection between the upper and middle segments.

[0013] The present invention has the following advantages over the prior art: (1) The cast blank and final assembly cast blank used in the present invention can correct the processing deformation of the product, push up the product into a round shape, achieve a smooth assembly of the inner and outer walls of the product, effectively seal them together, and improve the strength of the brazed seam. (2) The total wall thickness of the product at the docking position is about 14 mm, and the structure is highly rigid, which will cause additional stress after brazing. In order to modify the shape of this segment of the product to push it up into a round shape, a large load needs to be applied. The hydraulic actuation system used in the present invention can effectively solve the problem of difficult actuation. (3) The hydraulic pressure actuation system used in the present invention replaces methods such as external force knocking, thereby avoiding local cracks in the product. (4) The backup ring used in the present invention allows the tensioning of each segment of the product after brazing and allows it to be machined to the size of the docking port when fastened, thereby ensuring that the docking state meets the requirements. (5) The present invention is applied to the processes of nozzle turning and docking crimping, and solves the problems of the inner and outer walls of the nozzle not being in tight contact, the docking dimensions of each segment not matching, and the lack of support during the turning process, thereby effectively improving the welding quality of the nozzle. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. [Figure 2] FIG. 1 is a structural diagram of a final assembled cast blank. [Figure 3] FIG. 1 is a structural diagram of a cast blank. [Figure 4] FIG. [Figure 5] FIG. 2 is a structural diagram of a platen. [Figure 6] 1 is a structural diagram (top view) of the platen. [Figure 7] This is a structural diagram of a double-threaded bolt. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention will now be described with reference to the drawings.

[0016] 1 and 2 are schematic diagrams of a crimping device for a large nozzle for a liquid rocket engine. This device includes a base 1, a sleeve 2, a main shaft 3, a holding cover 4, a cast blank 5, a hydraulic system 12, a platen 6, a double-ended screw bolt 7, a positioning block 8, a handle 9, a backup ring 10, and a final assembled cast blank 11.

[0017] The sleeve 2 is attached to the base 1 by a threaded structure. The main shaft 3 is attached within the sleeve 2 by a clearance fit. A hydraulic system 12 is connected to the main shaft 3 and is used to drive the downward movement of the main shaft 3. The cast blank 5 is attached to the base 1 by a threaded structure. The handle 9 is attached to the positioning block 8 by a threaded structure. The positioning block 8 is attached to the top of the main shaft 3, and the handle 9 and the positioning block 8 are provided on the holding cap 4. The holding cap 4 is located above the cast blank 5. The above structure forms a nozzle crimping structure. By replacing the cast blank and the holding cap, crimping and brazing of different segments of the liquid rocket nozzle can be achieved.

[0018] The final assembled cast blank 11 is used to support the upper, middle, and lower nozzle segments after crimping and brazing. Backup rings 10 are welded to the final assembled cast blank 11, tightly adhering the final assembled cast blank to the large and small ends of each nozzle segment. The final assembled cast blank 11 is used to turn each nozzle segment and weld each segment together. When turning each nozzle segment using the final assembled cast blank 11, a platen 6 is attached to the product to be machined, and the platen 6 is connected to the base with two threaded bolts 7, ensuring that the product is always in close contact with the final assembled cast blank 11 during the turning process. The cast blank 5 is a casting with a hollow structure and internal reinforcing ribs. This reduces the weight of the cast blank while ensuring its structural strength. The mold surface of the cast blank 5 matches the mold surface of the nozzle segment to be machined, ensuring perfect adhesion with the nozzle segment. The inner diameter of the retainer cap is the same as the outer diameter of the upper end surface of the small end of the nozzle segment being machined.

[0019] In the present invention, the spindle 3 and hydraulic system 12 are versatile, so that simply changing the cast blank and pressure cover allows the inner and outer walls of the top, middle, and bottom sections of the product to be crimped together. After brazing, the product expands, leaving a gap between it and the cast blank 5. Backup rings 10 are welded to the large cast blank 11, tightly adhering to the large and small ends of the product. After the inner and outer walls of the product are crimped together, the platen 6 and the cast blank 5 are connected by two threaded bolts 7, ensuring that the product is always in close contact with the cast blank 5 during the turning process. The hydraulic system 12 can be started or stopped at any time, and its pressure can be adjusted.

[0020] Fig. 3 is a structural diagram of a cast blank. Fig. 4 is a structural diagram of a pressure cover. Fig. 5 is a structural diagram of a platen. Fig. 6 is a top view of the platen structure. Fig. 7 is a structural diagram of a double-threaded bolt.

[0021] The method of using the large nozzle crimping device for liquid rocket engines is as follows. The inner wall of the product is fitted onto the cast blank 5, and the end face of the inner wall is turned. Then, the outer wall of the product is fitted onto the inner wall, and the hydraulic system 12 is activated. The hydraulic system moves the main shaft 3 downward, applying pressure to the positioning block 8, which moves the retainer lid 4 downward. This presses the retainer lid 4 against the outer wall of the product, forcing the inner and outer walls into tight contact. The inner and outer walls are then seal-welded, and the entire inner and outer walls are placed in a furnace for brazing. After brazing is complete, the product is fitted onto the final assembled cast blank 11. Because brazing can cause deformation of the product and create gaps between the cast blank and the base mold surface, a backup ring 10 is welded to the final assembled cast blank 11 to support the large and small ends of the product, and external force is applied to round the product. The platen 6 is then attached to the large end of the product, and the platen 6 is connected to the base 1 with two threaded bolts 7. The pressure is then released, and the large and small ends of the product are machined to the desired fit. The product consists of three parts: top, middle, and bottom. The same processes as above are used for each segment, except for the corresponding cast blank and cover. After each segment is processed to meet the combination requirements using the above steps, the bottom and middle segments of the product are fitted onto the final assembly cast blank 11, and the joints are welded. The top segment of the product is then fitted onto the final assembly cast blank 11, and the joints between the top and middle segments are welded.

[0022] The present invention realizes the crimping of the inner and outer walls of the top, middle and bottom parts of the product, turning of the docking surfaces, and brazing of the entire product followed by turning, thereby meeting the requirements of assembly and crimping, ensuring that the docking dimensions of the three segments of the product are consistent, and improving welding quality. The crimping device of the present invention is easy to use and can be used to crimp and turn each segment and the entire nozzle, with good operability and practicality.

[0023] The parts not described in detail in the present invention are techniques well known to those skilled in the art.

Claims

1. A crimping device for a large nozzle for a liquid rocket engine, comprising a base (1), a sleeve (2), a main shaft (3), a holding cover (4), a cast blank (5), a hydraulic system (12), a platen (6), a double-ended screw bolt (7), a positioning block (8), a handle (9), a backup ring (10), and a final assembled cast blank (11), The sleeve (2) is attached to the base (1) by a thread structure, the main shaft (3) is attached in the sleeve (2) by a clearance fit, the hydraulic system (12) is connected to the main shaft (3) and is used to drive the downward movement of the main shaft (3), the cast blank (5) is attached to the base (1) by a thread structure, the handle (9) is attached to the position limiting block (8) by a thread structure, the position limiting block (8) is attached to the top of the main shaft (3), the handle (9) and the position limiting block (8) are located on the hold-down cover (4), and the hold-down cover (4) is located above the cast blank (5); A crimping device for a large-sized nozzle for a liquid rocket engine, characterized in that a final assembled cast blank (11) is used to support the nozzle upper segment, middle segment, and lower segment after crimping and brazing, a backup ring (10) is welded to the final assembled cast blank (11) so that the final assembled cast blank is tightly attached to the large end and small end of each nozzle segment, and the final assembled cast blank (11) is used to perform turning of each nozzle segment and welding between each segment.

2. It further includes a platen (6) and a double-threaded bolt (7), 2. The crimping device for a large nozzle for a liquid rocket engine according to claim 1, characterized in that after the turning of each segment of the nozzle is achieved using the final assembled cast blank (11), a platen (6) is attached to the product to be machined, and the platen (6) is connected to a base by a double-threaded bolt (7), so that the product is always in close contact with the final assembled cast blank (11) during the turning process.

3. 2. The crimping device for a large nozzle for a liquid rocket engine according to claim 1, wherein the cast blank (5) is a casting, has a hollow structure, and is provided with reinforcing ribs inside, thereby reducing the weight of the cast blank and ensuring the strength of its structure.

4. 2. The crimping device for a large nozzle for a liquid rocket engine according to claim 1, wherein by replacing the cast blank and the pressure cap, crimping and brazing of different segments of the liquid rocket nozzle can be achieved.

5. 5. The crimping device for a large nozzle for a liquid rocket engine according to claim 4, characterized in that the die surface of the cast blank (5) matches the die surface of the segment of the nozzle to be machined so as to completely adhere to the segment of the nozzle to be machined.

6. 2. The crimping device for a large nozzle for a liquid rocket engine according to claim 1, wherein the inner diameter of the pressing cover is the same as the outer diameter of the upper end surface of the small end of the nozzle segment to be machined.

7. 2. The crimping device for a large nozzle for a liquid rocket engine according to claim 1, wherein the hydraulic system (12) can be started or stopped at any time, and its pressure can be adjusted.

8. A method for using a crimping device for a large-sized nozzle for a liquid rocket engine, comprising the following steps 1 to 4: Step 1: Select a casting blank and a clamping cover corresponding to the upper segment of the nozzle, and perform the following steps S1-S5 to process the upper segment of the nozzle; S1: Mounting the sleeve (2) on the base (1), mounting the main shaft (3) in the sleeve (2) with a clearance fit, connecting the hydraulic system (12) and the main shaft (3), and mounting the cast blank (5) on the base (1) with a thread structure; S2: The inner wall of the product is fitted onto the cast blank (5), and the outer wall of the product is fitted onto the inner wall; S3: Place the pressure cover (4) above the cast blank (5), attach the handle (9) to the position control block (8) using a screw structure, attach the position control block (8) to the top of the main shaft (3), and place the handle (9) and the position control block (8) on the pressure cover (4). S4: The hydraulic system (12) is activated, and the hydraulic system (12) moves the main shaft (3) downward, and the position control block (8) moves downward together with the main shaft (3), and moves the pressure cover (4) downward, so that the pressure cover (4) is pressed against the outer wall of the product, and the outer wall and the outer wall of the product are tightly adhered together, and then the inner wall and the outer wall are seal-welded, and then the pressure cover is removed, and the inner wall and the outer wall that have been seal-welded together are brazed, S5: The final assembled cast blank is attached to the base (1), the brazed product is fitted onto the final assembled cast blank, a platen (6) is attached to the large end of the product, and the platen (6) and the base are connected with two screw bolts (7) so that the product is always in close contact with the final assembled cast blank (11) during the turning process. After removing the seal welded portions of the inner and outer walls by turning, the large and small ends of the product are machined to the desired docking dimensions. After the machining is completed, the product and the final assembled cast blank are removed. Step 2: Change the cast blank and the clamping cover to a cast blank and a clamping cover corresponding to the middle segment of the nozzle, and repeat steps S1-S5 to process the middle segment of the nozzle; Step 3: Change the casting blank and the clamping cover to those corresponding to the lower segment of the nozzle, and repeat steps S1-S5 to process the lower segment of the nozzle; Step 4: The final assembled cast blank is attached to the base (1), the lower and middle segments of the nozzle are fitted onto the final assembled cast blank in order, and the connection points between the lower and middle segments are welded, and then the upper segment of the nozzle is fitted onto the final assembled cast blank, and the connection points between the upper and middle segments are welded.

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