A spatial engine thrust line deflection correction device and method

Abstract

The application provides a space engine thrust line deflection correction device and method, which comprises the following steps: firstly, a welding assembly device is used to weld a short body of a nozzle and an extension section, so as to reduce the thrust line deflection caused by welding; secondly, a space engine mounting reference surface is determined, the inner surface of the engine nozzle under a global coordinate system is sampled, the initial value of the thrust line angle and the thrust line deflection vector of the inner surface and the mounting surface are fitted according to the sampling result, and the space engine which does not meet the mounting requirements is adjusted by adding adjusting shims in the mounting hole position. The inner surface of the engine nozzle under the global coordinate system is sampled again for the space engine after adjustment, and the thrust line angle and the thrust line deflection vector of the inner surface and the mounting surface are fitted again according to the sampling result. The application reduces the action line deflection of the space engine.

Description

Technical Field

[0001] This invention belongs to the field of liquid rocket engine manufacturing technology, specifically relating to a device and method for correcting the skewness of the thrust line of a space engine. Background Technology

[0002] As the heart of a liquid rocket engine, the engine embodies the essence of rocket propulsion: the acceleration and ejection of matter, with the reaction force generating thrust. For a bicomponent liquid rocket engine, the process of converting propellant energy into thrust can be described as follows: liquid propellant, in an appropriate mixture ratio, is injected into the combustion chamber and atomized into droplets. These droplets then evaporate through heat transfer from the surrounding combustion gases. The size and velocity of the droplets continuously change within the combustion flow. The evaporated propellant rapidly mixes, is further heated, and reacts quickly. As the combustion products flow towards and through the throat, their velocity accelerates to the speed of sound, then to supersonic speeds in the nozzle expansion section, and finally is ejected outwards. Therefore, the engine body, as a crucial structural component, plays a vital role in engine performance.

[0003] Existing engine manufacturing processes only require high-thrust vertical launch, thus the thrust line skew requirements are not high; the thrust line angle of existing engines is required to be less than 2°, and the thrust line offset is not specified. However, space engines, which require precise orbit insertion and control in space, have very high requirements for thrust line skew, demanding a thrust line angle of less than 0.167° and a thrust line offset of less than 1mm. Engines manufactured using conventional processes do not meet these requirements.

[0004] Content of the invention

[0005] The technical problem solved by the present invention is to overcome the shortcomings of the prior art and provide a space engine thrust line deviation correction device and method to reduce the deviation of the space engine thrust line.

[0006] The technical solution of the present invention is: a space engine thrust line deviation correction device, which includes a first nut, a left top block, a right top block, a shaft, a pad, a pin, and a second nut;

[0007] The first nut is located at one end of the shaft. The left top block, right top block and pad block are all provided with central through holes and are passed through the shaft in sequence along the length of the shaft. The second nut is located at the other end of the shaft.

[0008] The left top block is a T-shaped column structure, with its large end next to the first nut and its small end's circumferential outer surface matching the inner wall surface of the inlet end of the short section of the space engine nozzle. It is embedded inside the inlet end of the short section of the nozzle to position the short section of the nozzle. The pad block is fixed by a pin connection to the shaft. One end of the pad block's circumferential outer surface matches the inner wall surface of the throat of the short section of the nozzle and is embedded inside the throat of the short section of the nozzle. The other end's circumferential outer surface matches the inner wall surface of the small end of the nozzle extension and is located inside the small end of the nozzle extension. The right top block's circumferential outer surface matches the inner wall surface of the large end of the nozzle extension and is embedded inside the large end of the nozzle extension.

[0009] The first nut and the second nut push the left top block and the right top block from both ends of the shaft toward the middle, so that the inlet end of the short part of the nozzle abuts against the large end limit of the left top block, and the right top block presses against the inner wall of the nozzle extension, pushing the nozzle extension toward the short part of the nozzle.

[0010] The coaxiality of the central through holes and outer surfaces of the left top block, right top block and pad block all meet the preset requirements. The inner wall surfaces of the short body and extension section of the nozzle are clamped to ensure the coaxiality of the welding between the short body and the extension section.

[0011] The pad has a groove around its circumference, which is located at the junction of the short part of the nozzle and the extension of the thrust chamber, to facilitate the butt welding of the short part of the nozzle and the extension.

[0012] Preferably, the groove depth in the circumferential direction of the pad is 1-2 mm.

[0013] Another technical solution of the present invention is: a method for correcting the skewness of the thrust line of a space engine, the method comprising the following steps:

[0014] S1. Weld the simulated parts at the joint between the short section and the extension section of the nozzle to obtain the optimal welding parameters;

[0015] S2. Fix the short section and extension section of the space engine nozzle to be processed on the above device, and weld the short section and extension section of the nozzle to be processed according to the optimal welding parameters obtained in step S1 to obtain the space engine nozzle.

[0016] S3. Weld the space engine nozzle to one end of the engine head, and connect the other end of the engine head to the fixed transition flange through the mounting flange; both the transition flange and the mounting flange are provided with three mounting holes for bolt connection, and the two are connected by bolts. The mounting flange adjusts its attitude by placing gaskets in the three mounting holes; the center of the three mounting holes forms an equilateral triangle, and the center of the equilateral triangle coincides with the center of the transition flange.

[0017] S4. Use the fixed end face of the transition flange as the space engine mounting reference surface, take the center of the space engine mounting reference surface as the origin, the space engine mounting reference surface as the XOY plane, and the straight line perpendicular to the space engine mounting reference surface as the Z axis to establish a global coordinate system.

[0018] S5. Collect the coordinates of the measuring points on the inner surface of the nozzle in the global coordinate system;

[0019] S6. In the simulation software, establish a space engine installation model to simulate the installation scenario of the space engine. Based on the coordinates of the measuring points on the inner surface of the space engine nozzle in the global coordinate system, calculate the theoretical values ​​of the gaskets at the three mounting holes that meet the requirements for both the thrust line angle and the nozzle thrust line offset.

[0020] The thrust line angle of the nozzle is the angle between the central axis of the nozzle and the Z-axis of the global coordinate system; the thrust line offset vector is the vector from the origin of the global coordinate system to the intersection of the thrust line and the XOY plane.

[0021] S7. Based on the calculation results of step S6, process the adjustment shims, and then place the processed adjustment shims at the three mounting holes according to the theoretical calculation values ​​for trial installation.

[0022] S8. Repeat steps S5 to S7 until the thrust line angle and nozzle thrust line offset both meet the requirements.

[0023] Preferably, the specific method of step S1 is as follows:

[0024] The joint between the short section and the extension section of the solid rocket motor nozzle is fitted and acid-washed. Then, the aforementioned device is used to fix and assemble the short section and extension section of the solid rocket motor nozzle. After clamping and alignment, it is placed in a vacuum equipment. Formal welding and surface finishing welding are carried out successively. After unpacking, weld leaks are ground and X-ray flaw detection is performed. After passing the inspection, it is delivered.

[0025] Preferably, the specific steps of step S6 are as follows:

[0026] S6.1 Based on the coordinates of the measuring points on the inner wall of the nozzle in the global coordinate system, the nozzle centerline is fitted and generated, and the initial values ​​of the nozzle thrust line angle and thrust line offset vector are calculated.

[0027] S6.2. Based on the thrust line angle and the initial value of the thrust line offset vector, determine the height adjustment direction at the three mounting holes of the mounting flange. While adjusting the position of the three mounting holes of the mounting flange, calculate in real time the theoretical calculated value of the gasket at the three mounting holes when the sum of the squares of the distances between the M points between the mounting flange and the transition flange is the minimum. M is greater than or equal to 3, and the M points are not on the same straight line.

[0028] Preferably, in step S2, the adapter flange faces upward and the engine nozzle faces downward.

[0029] Preferably, the simulated part of the joint between the short section and the extension section of the nozzle is a bar stock of the same grade as the engine nozzle substrate, and the size of the simulated part is consistent with the diameter and thickness of the joint weld of the product.

[0030] Preferably, step S1 requires that the front and back surfaces of the simulated part after welding meet the Class I standard requirements of GJB1718A-2005 "Electron Beam Welding".

[0031] Preferably, the thrust line angle is no greater than 0.167°.

[0032] Preferably, the thrust line offset and the thrust line spacing are no more than 1 mm.

[0033] Compared with the prior art, the present invention has the following advantages:

[0034] (1) This invention first precisely controls the most important welding factors affecting thrust line deviation at the source to reduce welding deformation. Secondly, the installation of adjustment shims is added later to readjust and eliminate minor deformations. This can greatly reduce the scrap of engine production and obtain highly reliable and accurate thrust line angle and thrust line deviation vector.

[0035] (2) The left top block, right top block, pad block and shaft of the present invention are used together to clamp the inner wall of the short body and the extension section of the thrust chamber to ensure the coaxiality of the welding of the short body and the extension section, and to assist the butt welding of the short body and the extension section.

[0036] (3) The present invention is based on the optimization of the current process flow and makes modifications within the smallest range, thus the cost is lower and it is easier to implement. Attached Figure Description

[0037] Figure 1 This is an embodiment of the welding and assembly device for the short body and the extension section of the present invention;

[0038] Figure 2 This is a flowchart of the welding process according to an embodiment of the present invention;

[0039] Figure 3(a) is a schematic diagram of the Z-axis of the reference plane coordinate system of the space engine in an embodiment of the present invention;

[0040] Figure 3(b) is a schematic diagram of the XOY coordinate system of the space engine reference plane in an embodiment of the present invention;

[0041] Figure 4(a) is a top view of the adjusting shim according to an embodiment of the present invention;

[0042] Figure 4(b) is a cross-sectional view of the adjusting shim according to an embodiment of the present invention;

[0043] Figure 5 This is a flowchart of the space engine thrust line deviation correction method according to an embodiment of the present invention. Detailed Implementation

[0044] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0045] Example 1:

[0046] like Figure 1 As shown, the present invention provides a space engine thrust line deviation correction device, which includes a first nut 1, a left top block 2, a right top block 3, a shaft 4, a pad 5, a pin 6, and a second nut 7; in this embodiment, the first nut and the second nut are M20 hexagonal nuts.

[0047] The first nut is located at one end of the shaft. The left top block, right top block and pad block are all provided with central through holes and are passed through the shaft in sequence along the length of the shaft. The second nut is located at the other end of the shaft.

[0048] The left top block is a T-shaped column structure, with its large end next to the first nut and its small end's circumferential outer surface matching the inner wall surface of the inlet end of the short section of the space engine nozzle. It is embedded inside the inlet end of the short section of the nozzle to position the short section of the nozzle. The pad block is fixed by a pin connection to the shaft. One end of the pad block's circumferential outer surface matches the inner wall surface of the throat of the short section of the nozzle and is embedded inside the throat of the short section of the nozzle. The other end's circumferential outer surface matches the inner wall surface of the small end of the nozzle extension and is located inside the small end of the nozzle extension. The right top block's circumferential outer surface matches the inner wall surface of the large end of the nozzle extension and is embedded inside the large end of the nozzle extension.

[0049] The first nut and the second nut push the left top block and the right top block from both ends of the shaft toward the middle, so that the inlet end of the short part of the nozzle abuts against the large end limit of the left top block, and the right top block presses against the inner wall of the nozzle extension, pushing the nozzle extension toward the short part of the nozzle.

[0050] The coaxiality of the central through holes and outer surfaces of the left top block, right top block and pad block all meet the preset requirements. The inner wall surfaces of the short body and extension section of the nozzle are clamped to ensure the coaxiality of the welding between the short body and the extension section.

[0051] The pad has a groove around its circumference, which is located at the junction of the short part of the nozzle and the extension of the thrust chamber, to facilitate the butt welding of the short part of the nozzle and the extension.

[0052] Preferably, the groove depth in the circumferential direction of the pad is 1-2 mm.

[0053] Example 2:

[0054] like Figure 5 As shown, based on the aforementioned device, the present invention provides a method for correcting the skewness of the thrust line of a space engine, the method comprising the following steps:

[0055] S1. Weld the simulated parts at the joint between the short section and the extension section of the nozzle to obtain the optimal welding parameters;

[0056] The simulated part for the joint between the short section and the extension section of the nozzle is a bar stock of the same grade as the engine nozzle substrate. The dimensions of the simulated part are consistent with the diameter and thickness of the weld joint of the product. Before the formal welding of each batch of products, the simulated part must be welded to confirm and re-inspect the welding parameters. It is required that the front and back sides of the simulated part have good shape after welding and uniform penetration. The shape of the front and back sides of the simulated part after welding must meet the Class I standard requirements of GJB1718A-2005 "Electron Beam Welding".

[0057] S2. Fix the short section and extension section of the space engine nozzle to be processed onto the above-mentioned device, and weld the short section and extension section of the nozzle to be processed according to the optimal welding parameters obtained in step S1 to obtain the space engine nozzle; Figure 2 As shown, the specific welding process flow in this embodiment is as follows:

[0058] The joint between the short section and the extension section of the solid rocket motor nozzle is fitted and acid-washed. Then, using the aforementioned equipment, the short section and extension section of the solid rocket motor nozzle are fixedly assembled and clamped for alignment (coaxiality less than Φ0.1mm). Afterward, it is placed in a vacuum chamber, and formal welding and surface finishing welding are performed sequentially. After unpacking, weld leaks are ground off, and X-ray flaw detection is conducted. Once qualified, it is delivered. The adapter flange faces upward, and the engine nozzle faces downward.

[0059] When using the above-mentioned device to fix and assemble the short body and extension section of the solid rocket motor nozzle, first use a cylindrical pin to fix the pad block to the shaft, install the right top block in place, install the short body and extension section in place after passing through the shaft, then install the left top block, and use M8 and M20 hexagonal nuts to clamp and align the installation state. After alignment, the runout of the left end face is less than 0.1mm.

[0060] The short section of the solid rocket motor nozzle and the extension section to be welded are matched. After matching, the mating gap is required to be no more than 0.10mm, the cumulative gap length is no more than 10mm, and the misalignment is no more than 0.10mm. After matching, acid pickling is performed to remove surface oil stains.

[0061] S3. Weld the space engine nozzle to one end of the engine head, and connect the other end of the engine head to the fixed transition flange through the mounting flange, as shown in Figure 3(a); both the transition flange and the mounting flange are provided with three mounting holes for bolt connection, and the two are connected by bolts. The mounting flange adjusts its posture by placing gaskets at the three mounting holes; the center of the three mounting holes forms an equilateral triangle, and the center of the equilateral triangle coincides with the center of the transition flange; as shown in Figure 3(b), the three mounting holes of the present invention are numbered 9, 10, and 11 respectively.

[0062] S4. Take the fixed end face 8 of the transition flange as the space engine installation reference surface, take the center of the space engine installation reference surface as the origin, the space engine installation reference surface as the XOY plane, and the straight line perpendicular to the space engine installation reference surface as the Z axis to establish a global coordinate system.

[0063] S5. Collect the coordinates of the measuring points on the inner surface of the nozzle in the global coordinate system;

[0064] S6. In the simulation software, establish a space engine installation model to simulate the installation scenario of the space engine. Based on the coordinates of the measuring points on the inner surface of the space engine nozzle in the global coordinate system, calculate the theoretical values ​​of the gaskets at the three mounting holes that meet the requirements for both the thrust line angle and the nozzle thrust line offset.

[0065] The thrust line angle of the nozzle is the angle between the central axis of the nozzle and the Z-axis of the global coordinate system; the thrust line offset vector is the vector from the origin of the global coordinate system to the intersection of the thrust line and the XOY plane.

[0066] The specific steps are as follows:

[0067] S6.1 Based on the coordinates of the measuring points on the inner wall of the nozzle in the global coordinate system, the nozzle centerline is fitted and generated, and the initial values ​​of the nozzle thrust line angle and thrust line offset vector are calculated.

[0068] S6.2. Based on the thrust line angle and the initial value of the thrust line offset vector, determine the height adjustment direction at the three mounting holes of the mounting flange. While adjusting the position of the three mounting holes of the mounting flange, calculate in real time the theoretical calculated value of the gasket at the three mounting holes when the sum of the squares of the distances between the M points between the mounting flange and the transition flange is the minimum. M is greater than or equal to 3, and the M points are not on the same straight line.

[0069] S7. Based on the calculation results of step S6, process the adjustment shims, and then place the processed adjustment shims at the three mounting holes according to the theoretical calculation values ​​for trial installation; the shims are shown in Figure 4(a) and Figure 4(b).

[0070] S8. Repeat steps S5 to S7 until the thrust line angle and nozzle thrust line offset both meet the requirements.

[0071] In this embodiment of the invention, the thrust line angle is no greater than 0.167°. The thrust line offset distance is no greater than 1 mm.

[0072] The data from this embodiment, implemented according to the invention, are shown in the table below. The first pass rate was 14.3%, and the adjusted pass rate was 100%.

[0073]

[0074] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A method for correcting the skewness of the thrust line of action of a space engine, characterized in that... Includes the following steps: S1. Weld the simulated parts at the joint between the short section and the extension section of the nozzle to obtain the optimal welding parameters; S2. Fix the short section and extension section of the space engine nozzle to be processed on the space engine thrust line deviation correction device, and weld the short section and extension section of the nozzle to be processed according to the optimal welding parameters obtained in step S1 to obtain the space engine nozzle. The space engine thrust line deviation correction device includes a first nut, a left top block, a right top block, a shaft, a pad, a pin, and a second nut; The first nut is located at one end of the shaft. The left top block, right top block and pad block are all provided with central through holes and are passed through the shaft in sequence along the length of the shaft. The second nut is located at the other end of the shaft. The left top block is a T-shaped column structure, with its large end next to the first nut and its small end's circumferential outer surface matching the inner wall surface of the inlet end of the short section of the space engine nozzle. It is embedded inside the inlet end of the short section of the nozzle to position the short section of the nozzle. The pad block is fixed by a pin and shaft connection. One end of the pad block's circumferential outer surface matches the inner wall surface of the throat of the short section of the nozzle and is embedded inside the throat of the short section of the nozzle. The other end's circumferential outer surface matches the inner wall surface of the small end of the nozzle extension section and is located inside the small end of the nozzle extension section. The right top block's circumferential outer surface matches the inner wall surface of the large end of the nozzle extension section and is embedded inside the large end of the nozzle extension section. The first nut and the second nut push the left top block and the right top block from both ends of the shaft toward the middle, so that the inlet end of the short part of the nozzle abuts against the large end of the left top block, and the right top block presses against the inner wall of the nozzle extension section, pushing the nozzle extension section toward the short part of the nozzle. The coaxiality of the central through holes and outer surfaces of the left top block, right top block and pad block all meet the preset requirements. The inner wall surfaces of the short body and extension section of the nozzle are clamped to ensure the coaxiality of the welding between the short body and the extension section. The pad has a groove around its circumference, which is located at the junction of the short body and the extension section of the nozzle, to facilitate the butt welding of the short body and the extension section of the nozzle. S3. Weld the space engine nozzle to one end of the engine head, and connect the other end of the engine head to the fixed transition flange through the mounting flange; both the transition flange and the mounting flange are provided with three mounting holes for bolt connection, and the two are connected by bolts. The mounting flange adjusts its attitude by placing adjusting shims at the three mounting holes; the center of the three mounting holes forms an equilateral triangle, and the center of the equilateral triangle coincides with the center of the transition flange. S4. Use the fixed end face of the transition flange as the space engine mounting reference surface, take the center of the space engine mounting reference surface as the origin, the space engine mounting reference surface as the XOY plane, and the straight line perpendicular to the space engine mounting reference surface as the Z axis to establish a global coordinate system. S5. Collect the coordinates of the measuring points on the inner surface of the nozzle in the global coordinate system; S6. In the simulation software, establish a space engine installation model to simulate the installation scenario of the space engine. Based on the coordinates of the measuring points on the inner surface of the space engine nozzle in the global coordinate system, calculate the theoretical values ​​of the gaskets at the three mounting holes that meet the requirements for both the thrust line angle and the nozzle thrust line offset. The thrust line angle of the nozzle is the angle between the central axis of the nozzle and the Z-axis of the global coordinate system; the thrust line offset vector is the vector from the origin of the global coordinate system to the intersection of the thrust line and the XOY plane. S7. Based on the calculation results of step S6, process the adjustment shims, and then place the processed adjustment shims at the three mounting holes according to the theoretical calculation values ​​for trial installation. S8. Repeat steps S5 to S7 until the thrust line angle and nozzle thrust line offset both meet the requirements.

2. The method for correcting the skewness of the thrust line of a space engine according to claim 1, characterized in that... The specific method for step S1 is as follows: The short section of the space engine nozzle and the extension section are fitted and acid-washed at the joint. Then, the short section of the space engine nozzle and the extension section are fixedly assembled and clamped and aligned using the device described in claim 1. They are then placed in a vacuum equipment, where formal welding and surface finishing welding are performed. After unpacking, weld leaks are ground off, X-ray flaw detection is performed, and the parts are delivered after passing the inspection.

3. The method for correcting the skewness of the thrust line of a space engine according to claim 1, characterized in that... The specific steps of step S6 are as follows: S6.

1. Based on the coordinates of the measuring points on the inner wall of the nozzle in the global coordinate system, fit and generate the nozzle centerline, and calculate the initial values ​​of the nozzle thrust line angle and thrust line offset vector; S6.

2. Based on the thrust line angle and the initial value of the thrust line offset vector, determine the height adjustment direction at the three mounting holes of the mounting flange. While adjusting the position of the three mounting holes of the mounting flange, calculate in real time the theoretical calculated value of the gasket at the three mounting holes when the sum of the squares of the distances between the M points between the mounting flange and the transition flange is the minimum. M is greater than or equal to 3, and the M points are not on the same straight line.

4. The method for correcting the skewness of the thrust line of a space engine according to claim 1, characterized in that... In step S3, the adapter flange faces upward and the engine nozzle faces downward.

5. The method for correcting the skewness of the thrust line of a space engine according to claim 1, characterized in that... The simulated part for the joint between the short section and the extension section of the nozzle is a bar stock of the same grade as the base material of the engine nozzle, and the size of the simulated part is consistent with the diameter and thickness of the joint weld of the product.

6. The method for correcting the skewness of the thrust line of a space engine according to claim 1, characterized in that... Step S1 requires that the front and back of the simulated part meet the Class I standard requirements of GJB1718A-2005 "Electron Beam Welding" after welding.

7. The method for correcting the skewness of the thrust line of a space engine according to claim 1, characterized in that... The thrust line angle is no greater than 0.167°.

8. The method for correcting the skewness of the thrust line of a space engine according to claim 1, characterized in that... The thrust line offset and thrust line spacing shall not exceed 1 mm.

9. A method for correcting the skewness of the thrust line of a space engine according to claim 1, characterized in that... The groove depth in the circumferential direction of the pad is 1~2mm.

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