CN120551568B - Welding device and welding method for rocket engine spray pipe - Google Patents
Welding device and welding method for rocket engine spray pipeInfo
- Publication number
- CN120551568B CN120551568B CN202511054392.4A CN202511054392A CN120551568B CN 120551568 B CN120551568 B CN 120551568B CN 202511054392 A CN202511054392 A CN 202511054392A CN 120551568 B CN120551568 B CN 120551568B
- Authority
- CN
- China
- Prior art keywords
- inner support
- welding
- protection
- support member
- gas
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Arc Welding In General (AREA)
Abstract
The invention discloses a welding device and a welding method for a rocket engine spray pipe, and belongs to the technical field of welding of space engines. The welding device of the rocket engine spray pipe comprises a first tool for clamping a melon petal to be welded of the engine spray pipe, a second tool for clamping a barrel to be welded, and a gas protection bracket cover for protecting the front surface of a welding line of the engine spray pipe from inert gas. The first tool comprises a first inner supporting piece, a pressing plate is sleeved outside the first inner supporting piece, a first pressing structure for pressing the edges of melon petals is arranged on the pressing plate, the second tool comprises a second inner supporting piece and a third inner supporting piece for supporting the barrel, and a pressing mechanism for pressing the splicing position of the adjacent barrel is arranged outside the second inner supporting piece or the third inner supporting piece. The welding device and the welding method for the rocket engine spray pipe can solve the problems that the existing engine spray pipe is easy to oxidize and generate defects in the welding process in the atmosphere, and the welding cost is high.
Description
Technical Field
The invention relates to the technical field of welding of space engines, in particular to a welding device and a welding method for a rocket engine spray pipe.
Background
With the rapid development of aerospace technology, the performance requirements on key parts such as liquid rocket engines are becoming severe, and particularly, the large-scale and light-weight are becoming important trends. Niobium (Nb) and its alloys are ideal materials for manufacturing high-temperature structural members such as large-size nozzle extensions of liquid rocket engines due to their excellent high-temperature strength and good corrosion resistance. However, niobium alloys are high temperature reactive metals that face significant challenges in welding, especially when manufacturing large-scale thin-walled components.
The primary challenge is that the niobium alloy has high chemical activity, is easy to react with oxygen violently in high-temperature welding, and causes severe oxidation of a welding line and a heat affected zone, so that the hardness of the niobium alloy is increased, and the plasticity and the toughness of the niobium alloy are greatly reduced. The interface between the oxide layer and the substrate is easy to become a source of stress concentration, and fatal defects such as welding cracks are induced. In addition, for large-size, thin-walled nozzle structures, heat input control and deformation control during welding are critical, and uneven heating and cooling can easily result in unacceptable deformation or residual stresses in the component.
The traditional welding method has certain limitations that the vacuum electron beam welding can provide high-quality welding lines, but equipment is expensive, the process is complex, and the manufacturing efficiency and the cost of the large-scale spray pipe are severely limited by the size of a vacuum chamber. Conventional atmospheric environment laser welding has high efficiency and good flexibility, but the standard protection modes such as side blowing, coaxial blowing and the like are difficult to provide sufficient and effective protection for niobium alloy, and the defects of extremely easy oxidation, air holes and the like of welding seams cannot meet the high reliability requirement of aerospace products. In recent years, vacuum laser welding technology (for example, vacuum swing laser welding disclosed in chinese patent CN114985933 a) combines the advantages of laser welding and solves the oxidation problem by utilizing a vacuum environment, but the fundamental constraint of the technology, that is, the technology relies on large-scale vacuum equipment, which results in high cost and long production period, and is difficult to realize low-cost, high-efficiency and large-scale manufacturing of large-size niobium alloy spray pipes.
Disclosure of Invention
The invention aims to provide a welding device and a welding method for rocket engine spray pipes, which solve the problems that the existing engine spray pipes are easy to oxidize and generate defects in the welding process in the atmosphere and the welding cost is high.
In order to achieve the above object, the present invention provides a welding device for a rocket engine nozzle, comprising:
The first tool is used for clamping melon petals to be welded of the engine spray pipe and assembling the melon petals into a cylinder, and comprises a first inner support piece, wherein a pressing plate is sleeved outside the first inner support piece, the melon petals are positioned between the first inner support piece and the pressing plate, and a first pressing structure for pressing the edges of the melon petals is arranged on the pressing plate;
The second tool is used for clamping the cylinder to be welded and assembling the cylinder into the engine spray pipe, and comprises a second inner support piece and a third inner support piece which support the cylinder, wherein a pressing mechanism for pressing the splicing part of the adjacent cylinders is arranged outside the second inner support piece or the third inner support piece;
The gas protection support cover is arranged on the welding head and used for protecting the front face of the welding line of the engine spray pipe by inert gas, and the first tool and the second tool are provided with back gas protection structures used for protecting the back face of the welding line by inert gas.
Preferably, the outer surface of the first inner support piece is a profiling surface attached to the melon petals, the first protection structure of the back gas protection structure is arranged on the first inner support piece, the first inner support piece is arranged on the rotary table, the first protection structure comprises a first protection air passage, the first protection air passage is arranged on the outer side surface of the first inner support piece, the first protection air passage is located at the joint of two adjacent melon petals, an air inlet hole is formed in one end of the first protection air passage, and the air inlet hole is connected with an inert gas bottle through a connecting pipe.
Preferably, a plurality of adjusting members for adjusting the distance between the pressing plate and the first inner supporting member are arranged between the pressing plate and the first inner supporting member, one end of each adjusting member is provided with a strip-shaped adjusting hole for adjusting the installation position of the adjusting member on the pressing plate, the adjusting member is fixed at the top end of the pressing plate through bolts penetrating through the adjusting holes, and the other end of each adjusting member is connected with the first inner supporting member through jackscrews.
Preferably, the first pressing structure comprises a first pressing claw, an avoidance hole penetrating through the pressing plate is formed in the pressing plate, the avoidance hole is formed in the joint of adjacent melon petals, the first pressing claws are arranged at the avoidance hole in a linear array mode, the first pressing claws on two sides of the avoidance hole are respectively pressed and fixed on the edges of the two adjacent melon petals, and a mounting hole for mounting the first pressing claws is formed in the pressing plate.
Preferably, the side surfaces of the second inner supporting piece and the third inner supporting piece are profiling surfaces attached to the inner side surfaces of the cylinders, the second inner supporting piece and the third inner supporting piece are arranged on the upright posts, the outer surfaces of the upright posts are provided with external threads, the second inner supporting piece and the third inner supporting piece are connected with the upright posts through locking nuts, the second protection structure of the back gas protection structure is arranged in the middle of the outer surfaces of the second inner supporting piece and the third inner supporting piece, the second protection structure comprises a second protection air channel, the second protection air channel is located at the joint of two adjacent cylinders, and the second protection air channel is connected with the inert gas bottle through a connecting pipe.
Preferably, the pressing structure comprises a second pressing structure and a third pressing structure, the third pressing structure is located above the second pressing structure, the second pressing structure is used for pressing and fastening the top end of the lower cylinder body on the second inner support piece or the third inner support piece, the third pressing structure is used for pressing and fixing the bottom end of the upper cylinder body on the second inner support piece or the third inner support piece, the third pressing structure comprises a top plate, the top plate is arranged on the upright post, a second pressing ring is arranged below the top plate, the second pressing ring is connected with the top plate through a plurality of second connecting rods, a plurality of third pressing claws are arranged on the second pressing ring and used for pressing the bottom end of the upper cylinder body on the side wall of the second inner support piece or the side wall of the third inner support piece, and the third pressing claws are connected with the second pressing ring through bolts.
Preferably, the second pressing structure comprises a bottom plate, the bottom plate is arranged on the rotary table, the upright posts are arranged on the bottom plate, a first pressing ring is arranged above the bottom plate and connected with the bottom plate through a plurality of first connecting rods, a plurality of second pressing claws which press the top end of the lower cylinder body on the side wall of the second inner supporting piece or the side wall of the third inner supporting piece are arranged on the first pressing ring, and the second pressing claws are connected with the first pressing ring through bolts.
Preferably, the gas protection bracket comprises a shell, wherein one end of the shell is provided with a clamping column, the shell is connected with the welding head through the clamping column and the universal gauge stand, an air chamber is arranged in the shell, an air inlet communicated with the air chamber is arranged on the shell, and the air inlet is connected with the inert gas bottle through a connecting pipe;
The middle part of the air chamber is provided with a main protection channel which is used for protecting the welding area with inert gas; the front end of the air chamber is provided with a front protection air passage inclining forwards, and the front protection air passage is used for performing pre-welding protection on a part to be welded;
The main protection air passage comprises a first diffusion cavity and a second diffusion cavity, wherein the first diffusion cavity is communicated with the air chamber through a communication hole, the first diffusion cavity is communicated with the second diffusion cavity through a plurality of flow equalizing holes, a plurality of air outlet holes are formed in the second diffusion cavity, and an oxygen content detection sensor is arranged in the second diffusion cavity.
The welding method of the welding device based on the rocket engine spray pipe comprises the following steps of:
s1, connecting a gas protection support cover with a welding head through a universal gauge stand, and adjusting the angle and the distance between the gas protection support cover and a melon petal or a barrel through the universal gauge stand, wherein the center of the gas protection support cover is centered with the center of a welding line track;
s2, assembling melon petals by adopting a first tool, fixing a first inner support piece on a rotary table, placing the melon petals on a profiling surface of the outer surface of the first inner support piece, adjusting the distance between the first inner support piece and a pressing plate according to the thickness of the melon petals by an adjusting piece, locking the first inner support piece and the pressing plate by jackscrews, and fastening and fixing a melon petal clamp between the first inner support piece and the pressing plate;
S3, using a spanner with a force sensor to install a first pressing claw on the pressing plate, and uniformly pressing the edge pressure of the melon petals to be welded on a first inner supporting piece by the first pressing claw;
S4, introducing inert gas in an inert gas bottle into the gas protection support cover and the first protection air passage through the connecting pipe, pre-purging the melon segments to be welded, starting the laser welder after the oxygen content detection sensor is stable, and welding a longitudinal connecting seam between adjacent melon segments through the laser welding head to weld the melon segments into a cylinder;
S5, assembling the cylinder bodies by adopting a second tool, adjusting the distance between the second inner supporting piece and the third inner supporting piece through a locking nut according to the height of the cylinder bodies to be welded, respectively placing the two cylinder bodies to be welded outside the second inner supporting piece and the third inner supporting piece and attaching the two cylinder bodies to the profiling surfaces of the second inner supporting piece and the third inner supporting piece, and positioning a second protection air passage at the joint of the two adjacent cylinder bodies;
S6, installing a first compression ring outside the third inner support piece, wherein the first compression ring is connected with the bottom plate through a first connecting rod, installing a top plate on the upright post, installing a second compression ring outside the third inner support piece, and connecting the second compression ring with the top plate through a second connecting rod;
S7, introducing inert gas in an inert gas bottle into the gas protection bracket and the second protection air passage through the connecting pipe, pre-purging the cylinder to be welded, starting the laser welder after the oxygen content detection sensor is stable, welding the transverse connecting joints between the adjacent cylinders through the laser welding head, and welding the cylinder into an engine spray pipe in a symmetrical welding mode, wherein the welding angle of each welding is 10-15 degrees.
Preferably, the method comprises the steps of,
In the S4 and the S7, the total flow of the inert gas in the gas protection bracket cover is 15L/min-25L/min, and the total flow of the inert gas in the first protection air passage and the second protection air passage is 10L/min-15L/min;
In the S4 and the S7, the laser power is 2200W, the welding speed is 2m/min, the defocusing amount is +2mm, the swing amplitude is 0.8mm, the swing frequency is 130Hz, and a circular swing mode is adopted.
The welding device and the welding method of the rocket engine spray pipe have the advantages that:
1. The gas shield of the invention avoids the dependence on expensive and huge vacuum systems, obviously reduces the equipment investment and operation cost, and improves the production flexibility and efficiency.
2. The gas shield provided by the invention has the advantages that the oxidation and the nitridation in the welding process are greatly reduced, the swing welding is combined in the welding process, so that the air holes are reduced, the weld joint forming is improved, the crack sensitivity is reduced, and the welding defect is effectively restrained.
3. The sectional type independent pressure-adjustable structure of the first tool and the second tool ensures the assembly precision of the large thin-wall component and the structural stability in the welding process, and effectively controls the welding deformation.
4. The preparation method has adjustable parameters and wide range, is suitable for welding niobium alloy spray pipes with different wall thicknesses and structures, has stable and reliable process and ensures that the quality of welding seams meets the requirement of spaceflight.
The technical scheme of the invention is further described in detail through the drawings and the embodiments.
Drawings
FIG. 1 is a schematic diagram of an embodiment of the present invention;
fig. 2 is a schematic perspective view of a first tool according to an embodiment of the present invention;
FIG. 3 is a schematic perspective view of a platen according to an embodiment of the present invention;
FIG. 4 is a schematic perspective view of a first inner support according to an embodiment of the present invention;
FIG. 5 is an enlarged view of A in FIG. 4;
Fig. 6 is a schematic diagram of a second tool perspective structure according to an embodiment of the present invention;
FIG. 7 is a schematic diagram of a front view of a second tool according to an embodiment of the present invention;
FIG. 8 is a schematic cross-sectional view of a second tooling according to an embodiment of the present invention;
FIG. 9 is a schematic perspective view of a third pressing structure according to an embodiment of the present invention;
FIG. 10 is an enlarged view of B in FIG. 8;
FIG. 11 is a schematic perspective view of a gas shield according to an embodiment of the present invention;
FIG. 12 is a schematic cross-sectional view of a gas shield according to an embodiment of the present invention;
FIG. 13 is a schematic perspective view of an engine nozzle according to an embodiment of the present invention;
FIG. 14 is a macroscopic topography of an engine nozzle weld of an embodiment of the present invention, (a) the front of the weld and (b) the back of the weld;
FIG. 15 is a macro-topography of an engine nozzle weld when welding without a gas shield;
FIG. 16 is a graph of macroscopic topography after tensile testing of an engine nozzle weld joint according to an embodiment of the present invention;
fig. 17 is a schematic view of a circular oscillation mode of a laser welding head in an engine nozzle welding process according to an embodiment of the present invention.
Reference numerals
1. A first tool; 11, a first inner supporting piece, 12, a pressing plate, 13, an adjusting piece, 14, a first pressing claw, 15, an avoidance hole, 16, a mounting hole, 17, a first protection air passage, 18 and an air inlet hole;
2. The second tool, 21, the upright post, 22, a second inner support, 23, a third inner support, 24, a bottom plate, 25, a first connecting rod, 26, a second pressing claw, 27, a top plate, 28, a second connecting rod, 29, a third pressing claw, 210, a first pressing ring, 211, a second pressing ring, 212, a second protection air passage, 213 and a locking nut;
3. A gas shield; 31, a shell, 32, an air inlet, 33, a clamping column, 34, an oxygen content detection sensor, 35, an air chamber, 36, a communication hole, 37, a first diffusion cavity, 38, a flow equalizing hole, 39, a second diffusion cavity, 310, an air outlet, 311, a front protection air passage, 312 and a rear protection air passage;
4. The engine jet pipe comprises an engine jet pipe, a first cylinder, a second cylinder, a third cylinder, a melon petal, a reinforcing rib and a third cylinder, wherein the engine jet pipe comprises a first cylinder, a second cylinder, a third cylinder, a melon petal and a reinforcing rib;
5. and (5) a welding head.
Detailed Description
In the description of the present invention, it should be noted that, the azimuth or positional relationship indicated by the terms "upper", "lower", "inner", "outer", etc., are based on the azimuth or positional relationship shown in the drawings, or the azimuth or positional relationship in which the inventive product is conventionally put in use, are merely for convenience of describing the present invention and simplifying the description, and are not indicative or implying that the apparatus or element to be referred to must have a specific azimuth, be configured and operated in a specific azimuth, and therefore should not be construed as limiting the present invention. In the description of the present invention, it should also be noted that, unless explicitly specified and limited otherwise, the terms "configured," "mounted," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, integrally connected, mechanically connected, electrically connected, directly connected, indirectly connected through an intermediate medium, or in communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
In the present application, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. If there is a discrepancy, the meaning described in the present specification or the meaning obtained from the content described in the present specification is used. In addition, the terminology used herein is for the purpose of describing embodiments of the application only and is not intended to be limiting of the application.
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
As shown in fig. 13, the engine nozzle 4 includes a first cylinder 41, a second cylinder 42, and a third cylinder 43 that are sequentially connected, the first cylinder 41, the second cylinder 42, and the third cylinder 43 respectively form a small end and a large end at both ends in the axial direction, and the first cylinder 41, the second cylinder 42, and the third cylinder 43 form the engine nozzle 4 by transverse circumferential weld seam welding. Each section of the cylinder is formed by welding a plurality of melon petals 44 by longitudinal welding.
As shown in fig. 1. A welding apparatus for a rocket engine nozzle, comprising:
The first tooling is used for clamping the melon segments to be welded of the engine spray pipe, assembling the melon segments into the first tooling 1, clamping the melon segments 44 to be welded of the engine spray pipe 4, and assembling the melon segments 44 into a cylinder. And the second tool 2 is used for clamping the cylinder to be welded and assembling the cylinder into the engine spray pipe 4. The gas protection bracket cover 3 is arranged on the welding head 5, and inert gas protection is carried out on the front surface of the welding seam of the engine spray pipe 4. And the first tool 1 and the second tool 2 are provided with a back gas protection structure for protecting the back of the welding line by inert gas.
As shown in fig. 2,3 and 4. The first tooling 1 comprises a first inner support piece 11, and the outer surface of the first inner support piece 11 is a profiling surface attached to a melon petal 44. The outer part of the first inner support 11 is sleeved with a pressing plate 12, the melon petals 44 are located between the first inner support 11 and the pressing plate 12, and the pressing plate 12 presses the melon petals 44 on the outer surface of the first inner support 11. The first inner support 11 is provided on the rotary table.
A plurality of adjusting members 13 for adjusting the distance between the pressing plate 12 and the first inner supporting member 11 are provided between the pressing plate 12 and the first inner supporting member 11. One end of the adjusting member 13 is provided with an elongated adjusting hole for adjusting the mounting position of the adjusting member 13 on the pressing plate 12, and a bolt passes through the adjusting hole to fix the adjusting member 13 on the top end of the pressing plate 12. The length of the adjusting member 13 extending out of the pressing plate 12 can be adjusted through the elongated adjusting hole, so that the distance between the pressing plate 12 and the first inner supporting member 11 can be adjusted as required. The other end of the adjusting piece 13 is connected with the first inner supporting piece 11 through a jackscrew, so that locking and fixing between the pressing plate 12 and the first inner supporting piece 11 are realized.
The platen 12 is provided with a first hold-down structure that holds down the edges of the melon petals 44. The first pressing structure comprises a first pressing claw 14, an avoidance hole 15 penetrating through the pressing plate 12 is formed in the pressing plate 12, and the avoidance hole 15 is located at the joint of adjacent melon petals 44. The first pressing claws 14 are arranged at the avoidance holes 15 in a linear array, and the first pressing claws 14 are uniformly arranged at intervals along the longitudinal direction. The first pressing claws 14 at the two sides of the avoiding hole 15 respectively press and fix the edges of the two adjacent melon petals 44. The platen 12 is provided with a mounting hole 16 for mounting the first presser foot 14, and the first presser foot 14 is fixed to the platen 12 by a bolt.
The first inner support 11, the platen 12 are of different sizes depending on the size of the melon petals 44. The first inner support 11 of this embodiment is mounted in use on a turntable, the inner surface of the melon petals 44 being in full engagement with the melon petals 44 profiled surface of the outer surface of the first inner support 11. After the melon petals 44 are in place, the platen 12 is installed. An adjusting member 13 is mounted on the platen 12 to fine tune the gap between the platen 12 and the first inner support member 11 to ensure that the edges of the petals 44 are pressed against the first inner support member 11.
The rocket engine nozzle 4 of the present embodiment employs independently adjustable first presser fingers 14 arranged in segments along both sides of the weld during longitudinal welding of the nozzle. The complex contour of the spray pipe can be precisely attached through the cooperation with the first inner supporting piece 11, and even and controllable clamping force application is realized through independently adjusting the pressure of each first pressing claw 14, so that the weld joint gap and the offset are effectively ensured, the thermal deformation in the welding process is obviously restrained, and the geometric accuracy of the component is maintained. The first pressing claw 14 of the present embodiment is located on both sides of the longitudinal seam to be welded of the two melon petals 44, and when the melon petals 44 are pressed by the first pressing claw 14, the first pressing claw 14 is mounted by using a wrench with a pressure sensor. The bolts driving the first pressing claws 14 are gradually and alternately screwed when the first pressing claws 14 are installed, a spanner with a pressure sensor controls the pressure of each first pressing claw 14 to be uniformly distributed in the screwing process, the size is moderate, the edges of the melon petals 44 are secondarily ensured to be pressed on the first inner supporting piece 11, and the gaps and the misplaced variables of all the melon petals 44 are less than 10% of the wall thickness.
As shown in fig. 6, 7 and 8. The second tooling 2 comprises a second inner support piece 22 and a third inner support piece 23 which support the cylinder, and the side surfaces of the second inner support piece 22 and the third inner support piece 23 are profiling surfaces attached to the inner side surface of the cylinder. The second inner support piece 22 and the third inner support piece 23 are arranged on the upright post 21, external threads are arranged on the outer surface of the upright post 21, and the second inner support piece 22 and the third inner support piece 23 are connected with the upright post 21 through locking nuts 213. The distance between the second inner support 22 and the third inner support 23 is adjusted by rotating the lock nut 213 on the upright 21.
The second inner support member 22 or the third inner support member 23 is provided with a pressing mechanism outside thereof for pressing the splice of the adjacent cylinders. The compressing structure comprises a second compressing structure and a third compressing structure, and the third compressing structure is located above the second compressing structure. The second pressing structure is used for pressing and fixing the top end of the lower cylinder on the second inner support piece 22 or the third inner support piece 23, and the third pressing structure is used for pressing and fixing the bottom end of the upper cylinder on the second inner support piece 22 or the third inner support piece 23.
As shown in fig. 9 and 10. The third pressing structure includes a top plate 27, and the top plate 27 is disposed on the upright 21 by a lock nut 213. A second pressing ring 211 is arranged below the top plate 27, and the second pressing ring 211 is fixedly connected with the top plate 27 through a plurality of second connecting rods 28. The second press ring 211 is provided with a plurality of third press claws 29 for pressing the bottom end of the upper cylinder body on the side wall of the second inner support piece 22 or the third inner support piece 23, and the third press claws 29 are connected with the second press ring 211 through bolts.
The second pressing structure includes a bottom plate 24, and the bottom plate 24 is disposed on the rotary table. The upright post 21 is connected with the bottom plate 24 through a locking nut 213, a first pressing ring 210 is arranged above the bottom plate 24, and the first pressing ring 210 is fixedly connected with the bottom plate 24 through a plurality of first connecting rods 25. The first press ring 210 is provided with a plurality of second press claws 26 for pressing the top end of the lower cylinder onto the side wall of the second inner support 22 or the third inner support 23, and the second press claws 26 are connected with the first press ring 210 through bolts. The coaxiality of the two cylinders to be welded is ensured by adjusting the pressure and the position of the corresponding second pressing claw 26 and third pressing claw 29 through bolts, so that the butt end faces of the cylinders are parallel and tightly attached, and the gap and the error quantity of the adjacent cylinders are adjusted to be smaller than 10% of the wall thickness.
The second pressing structure and the third pressing structure press the first cylinder 41 and the second cylinder 42 against the outside of the third inner support 23 while the welding connection of the first cylinder 41 and the second cylinder 42 is performed. When the first cylinder 41 is connected with the second cylinder 42 and then is connected with the third cylinder 43, the height of the second inner support member 22 is adjusted, and the second pressing structure and the third pressing structure press the bottom end of the second cylinder 42 and the top end of the third cylinder 43 outside the second inner support member 22. The second compression structure and the third compression structure need to be replaced, and the compression needs of the first cylinder 41, the second cylinder 42 and the third cylinder 43 are satisfied.
As shown in fig. 11 and 12, the gas shield 3 includes a housing 31, a clamping column 33 is provided at one end of the housing 31, and the housing 31 is connected to the welding head 5 through the clamping column 33 and the universal gauge stand. The welding head 5 is an existing laser welding head 5, the universal gauge stand is an existing structure, the multi-degree-of-freedom adjusting capability can be realized through the universal gauge stand, and the positions and angles of the gas shield 3 in the X direction, the Y direction and the Z direction can be accurately adjusted. The inside of casing 31 is provided with air chamber 35, is provided with the air inlet 32 of intercommunication air chamber 35 on the casing 31, and air inlet 32 passes through the connecting pipe and is connected with the inert gas bottle.
The middle part of the air chamber 35 is provided with a main protection channel for inert gas protection of the welding area. The front end of the air chamber 35 is provided with a front protection passage 311 inclined forward, and the front protection passage 311 is used for performing pre-welding protection on a part to be welded. The rear end of the air chamber 35 is provided with a rear protection air passage 312 inclined rearward, and the rear protection air passage 312 is used for purging the welded weld. The front protection channel and the rear protection channel are narrow long gaps respectively positioned at the front end and the rear end edge of the bottom of the shell 31, and gas entering from the front protection channel and the rear protection channel is sprayed obliquely, so that the effects of better pre-welding protection and post-welding cooling purging can be achieved.
Different protection requirements for different areas can be achieved by designing the front protection channel, the rear protection channel and the main protection airflow channel in different sizes. Such as increasing the size of the front guard channel, the rear guard channel, or the size of the main guard airflow channel.
The main protection air passage includes a first diffusion chamber 37 and a second diffusion chamber 39, the first diffusion chamber 37 being in communication with the air chamber 35 through the communication hole 36. The first diffusion cavity 37 is communicated with the second diffusion cavity 39 through a plurality of flow equalizing holes 38, and a plurality of air outlet holes 310 are formed in the second diffusion cavity 39.
The inert shielding gas enters the interior through a gas inlet 32 provided at the top of the housing 31 during use. The gas first enters the plenum 35, which plenum 35 serves as the initial plenum and distribution chamber. The gas protection bracket cover 3 is used for realizing accurate protection of welding at different stages, downward from the top air chamber 35, dividing the inside into three areas with independent functions through a partition plate structure, and respectively arranging a front protection channel and a rear protection channel at two sides for guiding part of gas to the front end and the rear end of the shell 31 so as to realize purging before welding and tailing cooling protection after welding. The middle area is the main protection air flow channel, the air enters the first diffusion cavity 37, the flow equalizing hole 38 and the second diffusion cavity 39 from the air chamber 35, the inert gas flowing out from the air outlet hole 310 forms a stable inert atmosphere layer in the welding area, and the air is effectively isolated to inhibit oxidation in the welding process.
Because the quality of the main protection air flow is critical to the welding effect, the main protection air flow channel of the embodiment is provided with a two-stage diffusion structure. The gas entering from the air chamber 35 firstly passes through the uniform flow hole 38 downwards from the first diffusion cavity 37 to realize primary diffusion, then enters into the independent shallow wide second diffusion cavity 39 positioned right below the uniform flow hole 38, and the gas is secondarily mixed, decelerated and pressure stabilized in the second diffusion cavity 39 to form a high-uniformity low-turbulence airflow, so that the air is effectively isolated, and oxidation is restrained to obtain a high-quality welding joint.
An oxygen content detection sensor 34 is provided in the second diffusion chamber 39. A minute passage is provided at the second diffusion chamber 39 of the present embodiment, and the oxygen content detection sensor 34 is provided at the minute passage. The design can realize real-time monitoring of the actual oxygen content of the main shielding gas to be sprayed. The monitoring signal can be used for process recording and exceeding alarm, and the quality of the protective gas is ensured to be in a controlled state all the time.
As shown in fig. 5, the backside gas shield structure includes a first shield structure and a second shield structure. The first protection structure is arranged on the first inner support 11, the first protection structure comprises a first protection air passage 17, and the first protection air passage 17 is arranged on the outer side surface of the first inner support 11. The first protected airway 17 is located at the splice of two adjacent melon petals 44. One end of the first protection air passage 17 is provided with an air inlet hole 18, and the air inlet hole 18 is connected with an inert gas bottle through a connecting pipe.
The second protection structure is provided in the middle of the outer surfaces of the second and third inner supports 22 and 23. The second protection structure comprises a second protection air passage 212, the second protection air passage 212 is positioned at the joint of two adjacent cylinders, and the second protection air passage 212 is connected with an inert gas bottle through a connecting pipe.
The inert gas is high-purity argon with the purity of 99.999 percent.
In this embodiment, the material of the engine nozzle 4 is a niobium alloy, such as a niobium-hafnium alloy, a niobium-tungsten alloy, and a niobium-zirconium alloy, and the niobium alloy not only has high-temperature strength and oxidation resistance, but also has good workability . Of course in other embodiments the material of the lance may also be a tungsten alloy. The engine nozzle 4 has a first cylinder 41, a second cylinder 42, and a third cylinder 43 in this order from a small end portion to a large end portion. The thickness of each of the first cylinder 41, the second cylinder 42 and the third cylinder 43 was 1mm. The number m of melon pieces 44 divided by the first cylinder 41, the second cylinder 42 and the third cylinder 43 is 6, 8 and 10.
In this embodiment, sheet metal forming is performed according to the number and characteristics of the divided melon petals 44, in this embodiment, the curvature of each section of the spray pipe is different, each section of melon petals 44 has the characteristics of each section in shape, and illustratively, the melon petals 44 of the first cylinder 41, the second cylinder 42 and the melon petals 44 of the third cylinder 43 are profiled, and after the melon petals 44 are formed, milling is performed on the melon petals 44 to ensure that enough allowance is provided for tight butt joint of longitudinal seams and circumferential seams. And (3) polishing the surfaces to be welded by using sand paper with different mesh numbers, removing surface oxides and improving the flatness of the welded surfaces. And then wiping the welding surface by using ethanol with the concentration of 75 percent to remove granular impurities attached to the surface.
The welding method of the welding device based on the rocket engine spray pipe 4 comprises the following steps:
S1, connecting the gas shield 3 with the laser welding head 5.
The gas protection support cover 3 is connected with the welding head 5 through a universal gauge stand, the angle and the distance between the gas protection support cover 3 and the melon petals 44 or the barrel are adjusted through the universal gauge stand, the bottom of the shell 31 is ensured to be parallel to the surface of a workpiece, the optimal action distance of 5mm to 10mm is maintained, and the center of the gas protection support cover 3 is centered with the center of a welding line track.
S2, assembling melon petals 44 by adopting the first tool 1. The method comprises the following steps:
The first inner support 11 is fixed to the turntable and the melon petals 44 are placed on the contoured surface of the outer surface of the first inner support 11.
The distance between the first inner support 11 and the pressing plate 12 is adjusted according to the thickness of the melon petals 44 through the adjusting piece 13, the first inner support 11 and the pressing plate 12 are locked through jackscrews, and the melon petals 44 are clamped and fixed between the first inner support 11 and the pressing plate 12, so that the upper ends and the lower ends of two adjacent melon petals 44 are aligned.
S3, using a spanner with a force sensor to install a first pressing claw 14 on the pressing plate 12, and uniformly pressing the edge pressure to be welded of the melon petals 44 on the first inner support piece 11 by the first pressing claw 14.
The bolts driving the first pressing claws 14 are screwed down step by step and alternately during the installation, a spanner with a pressure sensor controls the pressure distribution of each first pressing claw 14 to be uniform and moderate in size, and the edges of the melon petals 44 are secondarily ensured to be pressed on the first inner support 11, and the gaps and the misplaced quantities of all the melon petals 44 are less than 10% of the wall thickness.
S4, welding the melon petals 44 to form a cylinder.
And introducing inert gas in an inert gas bottle into the gas protection bracket cover 3 and the first protection air passage 17 through connecting pipes, pre-purging the melon petals 44 to be welded, starting a laser welder after the oxygen content detection sensor 34 is stable, and welding a longitudinal connecting seam between the adjacent melon petals 44 through the laser welding head 5 to weld the melon petals 44 into a cylinder.
After welding the two adjacent melon petals 44, the rotary table rotates for a certain angle, and S4 is repeated to finish the welding of all longitudinal welding seams on the first cylinder 41. And repeating S2, S3 and S4 to finish the welding of the second cylinder 42 and the third cylinder 43.
S5, assembling the cylinder body by adopting the second tool 2. Specific:
The distance between the second inner support 22 and the third inner support 23 is adjusted by the lock nut 213 according to the height of the second cylinder 42 to be welded.
The first cylinder 41 and the second cylinder 42 to be welded are placed outside the third inner support 23 and the second inner support 22, respectively, and are attached to the contoured surfaces of the second inner support 22 and the third inner support 23. The second cylinder 42 and the first cylinder 41 are positioned by the inclined sides of the second and third inner supports 22 and 23, respectively. The second protection air passage 212 on the third inner support 23 is located at the junction of the first cylinder 41 and the second cylinder 42.
And S6, installing a first compression ring 210 outside the third inner support 23, wherein the first compression ring 210 is connected with the bottom plate 24 through a first connecting rod 25. The top plate 27 is mounted on the upright 21 by a lock nut 213, and a second press ring 211 is mounted on the outside of the third inner support 23, and the second press ring 211 is connected to the top plate 27 by a second connecting rod 28. The second pressing claw 26 and the third pressing claw 29 are respectively arranged outside the first pressing ring 210 and the second pressing ring 211 through bolts, and the pressure of the second pressing claw 26 and the third pressing claw 29 is adjusted through a spanner with a pressure sensor, so that the pressure of the second pressing claw 26 and the third pressing claw 29 is uniformly pressed on the bottom end of the first cylinder 41 and the top end of the second cylinder 42. When the first pressure ring 210 and the second pressure ring 211 are installed, levelness of the first pressure ring 210 and the second pressure ring 211 is guaranteed, inclination is prevented, and adjustment accuracy of the cylinder body is improved.
The second pressing claw 26 and the third pressing claw 29 press-fasten the second cylinder 42 and the first cylinder 41 on the profiling surface of the third inner support 23, respectively, and the gap and the error amount between the first cylinder 41 and the second cylinder 42 are less than 10% of the wall thickness.
And S7, introducing inert gas in the inert gas bottle into the gas protection bracket cover 3 and the second protection air passage 212 through the connecting pipe, and pre-purging the cylinder to be welded. After the oxygen content detection sensor 34 is stabilized, the laser welder is started, and the transverse connecting seam between the adjacent cylinders is welded through the laser welding head 5.
Before starting the laser, full pre-purging is performed, ventilation is continued for 10 seconds to 30 seconds or more until the sensor reading is stable and reaches the standard, the air in the protection area is ensured to be completely replaced, and a reliable inert atmosphere environment is established.
The welding angle of each welding is 10-15 degrees, and after each section of welding is finished, the welding is returned to the position of the welding starting point and then rotated 180 degrees for symmetrical welding. Before laser automatic welding, manual spot welding is adopted, and spot welding is performed once every 20mm-30mm, so that the pre-welding of the first cylinder 41 and the second cylinder 42 is realized.
After the circumferential weld between the first cylinder 41 and the second cylinder 42 is completed, the welding is performed with the third cylinder 43. First, the height of the second inner support 22 is adjusted according to the height of the third cylinder 43, the bottom end of the third cylinder 43 is sleeved on the outer side surface of the bottom plate 24, and the outer side surface of the bottom plate 24 is a profiling surface of the inner surface of the third cylinder 43. The second cylinder 42 is sleeved outside the second inner support 22. The first press ring 210, the second press ring 211, the first connecting rod 25 and the second connecting rod 28 are replaced so that the second press jaw 26 and the third press jaw 29 are pressed against the outer surface of the second inner support 22. The welding of the second cylinder 42 and the third cylinder 43 is performed in the same manner as the welding of the first cylinder 41 and the second cylinder 42. Inert gas is shielded from the backside of the weld by a second shielded gas passage 212 on the second inner support 22.
After the annular welding seams of the first cylinder 41, the second cylinder 42 and the third cylinder 43 are welded, the engine spray pipe 4 is obtained, the middle part and the bottom of the engine spray pipe 4 are respectively welded with reinforcing ribs 45, and the reinforcing ribs 45 are of annular structures formed by splicing the ribs in a one-section mode.
In the steps S4 and S7, the total flow of the inert gas in the gas shield 3 is 15L/min-25L/min, and the total flow of the inert gas in the first protection air passage 17 and the second protection air passage 212 is 10L/min-15L/min.
In the S4 and the S7, the laser power is 2200W, the welding speed is 2m/min, the defocusing amount is +2mm, the swing amplitude is 0.8mm, the swing frequency is 130Hz, and a circular swing mode is adopted. After the welding procedure is started, the laser welding head 5 and the gas shield 3 synchronously move along the welding line track, and the laser beam performs swing welding. The steady gas shielding is maintained throughout and process parameters and oxygen content detection sensor 34 readings are monitored. And (5) maintaining the protective gas for 20s after welding, closing the gas after the gas is sufficiently cooled, and loosening the tool to take off the workpiece.
According to the embodiment, the laser power, the welding speed and the defocusing amount are reasonably set, and the proper laser beam swinging mode, swinging amplitude and frequency are selected, so that the effective stirring effect on a molten pool can be realized while the enough penetration and the welding efficiency are ensured. The stirring is helpful for promoting the micro bubbles possibly generated in the molten pool to float upwards and escape, reducing the air hole defect, and meanwhile, the swing expands the effective action range of the laser, is helpful for forming the weld morphology with smooth transition and more uniform stress distribution, and can refine the weld structure to a certain extent.
After the longitudinal seams between the melon petals 44 and the circumferential seams between the cylinders are welded, the welding seams on the inner wall of the spray pipe are polished, and then a heat treatment process is needed to eliminate welding stress, and meanwhile, the roundness of the outlet of the spray pipe is also needed to be corrected. The welding seam polishing mode adopts the equipment such as a precise angle grinder, a rotary file, a straight grinder and the like to carry out manual polishing, ensures that the height of the welding seam and the base material are basically at the same height, and the polishing surface requires smooth transition.
Compared with non-swing welding, the optimized swing welding is adopted under the atmosphere protection and tool support provided by the gas protection bracket cover 3 in the embodiment welding process, so that the stability of a molten pool can be remarkably improved, the escape of bubbles can be promoted, the welding line forming can be optimized, the defect sensitivity can be reduced, and a more reliable and higher-quality welding joint can be obtained. Fig. 17 is a schematic diagram of a circular swing mode of a laser welding head in a welding process of a rocket engine nozzle 4 according to an embodiment of the present invention. In the process of longitudinally splicing and welding the melon petals 44 to obtain the cylinder and annularly splicing and welding adjacent cylinders to obtain the spray pipe, a circular swing mode of the laser welding head is adopted.
FIG. 14 is a macro-topography of the weld of the engine nozzle 4 of an embodiment of the present invention. As shown in fig. 14, in the process of longitudinally welding the melon petals 44 to obtain the barrel and circumferentially welding the adjacent barrel to obtain the spray pipe, a gas shield is used, so that the weld joint is well formed, the surface is bright and clean, and the defects of no oxidative discoloration, no splashing undercut and the like are overcome. When the mechanical property tensile test is carried out, the tensile strength reaches 480MPa.
The gas shield 3 is not used in the process of longitudinally welding the melon petals 44 to obtain the barrel and circularly welding the adjacent barrel to obtain the spray pipe, and only a conventional side-blowing protection mode is adopted. Fig. 15 is a view showing the macroscopic surface morphology of the weld joint of the rocket motor nozzle 4 when welding is performed without using the gas shield 3, and as is apparent from fig. 7, the weld joint surface has oxidation and penetration crack defects, and the weld joint is poorly formed. The tensile strength of the engine spray pipe 4 which is not obtained by adopting the swing welding mode is 447MPa when the mechanical property tensile test is carried out. Fig. 16 is a macroscopic morphology diagram of a welded joint of a rocket engine nozzle 4 after a tensile test, according to an embodiment of the present invention, wherein the tensile test pieces of all the embodiments show similar fracture characteristics, and the fracture positions are located in the base material.
Therefore, the welding device and the welding method for the rocket engine nozzle can solve the problems that the existing engine nozzle is easy to oxidize and generate defects in the welding process in the atmosphere and the welding cost is high.
It should be noted that the above-mentioned embodiments are merely for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present invention may be modified or substituted by the same, and the modified or substituted technical solution may not deviate from the spirit and scope of the technical solution of the present invention.
Claims (7)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202511054392.4A CN120551568B (en) | 2025-07-30 | 2025-07-30 | Welding device and welding method for rocket engine spray pipe |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202511054392.4A CN120551568B (en) | 2025-07-30 | 2025-07-30 | Welding device and welding method for rocket engine spray pipe |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN120551568A CN120551568A (en) | 2025-08-29 |
| CN120551568B true CN120551568B (en) | 2025-09-26 |
Family
ID=96826515
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202511054392.4A Active CN120551568B (en) | 2025-07-30 | 2025-07-30 | Welding device and welding method for rocket engine spray pipe |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN120551568B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110202320A (en) * | 2019-03-15 | 2019-09-06 | 蓝箭航天技术有限公司 | Composite tooling and thrust chamber preparation process for thrust chamber preparation process |
| CN111633339A (en) * | 2020-06-03 | 2020-09-08 | 蓝箭航天空间科技股份有限公司 | Laser Welding Technology of Rocket Engine Thrust Chamber and Rocket Engine Thrust Chamber |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101144002B1 (en) * | 2009-12-29 | 2012-05-09 | 한국항공우주연구원 | Fabrication Method of Outer Jacket of Combustion Chamber Nozzle for Liquid Rocket Engine Using Sheet Metal |
| CN118768878B (en) * | 2024-09-12 | 2024-11-29 | 北京神箭空天科技有限公司 | Preparation method of variable wall thickness nozzle extension section of rocket engine |
-
2025
- 2025-07-30 CN CN202511054392.4A patent/CN120551568B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110202320A (en) * | 2019-03-15 | 2019-09-06 | 蓝箭航天技术有限公司 | Composite tooling and thrust chamber preparation process for thrust chamber preparation process |
| CN111633339A (en) * | 2020-06-03 | 2020-09-08 | 蓝箭航天空间科技股份有限公司 | Laser Welding Technology of Rocket Engine Thrust Chamber and Rocket Engine Thrust Chamber |
Also Published As
| Publication number | Publication date |
|---|---|
| CN120551568A (en) | 2025-08-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9835114B1 (en) | Freeform deposition method for coolant channel closeout | |
| CN112935686B (en) | Welding repair process for breakage of large inclined roll shaft of ring rolling mill | |
| CN114192941B (en) | Double-side double-arc welding method for titanium alloy T-shaped fillet weld annular rib | |
| JPH0513195A (en) | Plasma arc torch | |
| CN114346485B (en) | Close-packed pipe space curve laser welding track planning method under weld joint tracking | |
| CN120551568B (en) | Welding device and welding method for rocket engine spray pipe | |
| CN119159287A (en) | A fixture and method for welding a mounting seat of a combustion chamber casing | |
| CN119140950A (en) | Welding tool set and welding method for special-shaped large-diameter titanium alloy thin-wall tube assembly | |
| CN112108783A (en) | Vacuum device for double-laser-beam bilateral synchronous welding of skin-stringer T-shaped structure | |
| JPH05329687A (en) | Cutting and welding device | |
| CN104801844A (en) | Electron beam welding method for tantalum and tungsten metal thin-walled circumferential welds | |
| CN106271060B (en) | A kind of method for laser welding of thin-walled tantalum pipe and thin-walled iron-nickel alloy pipe | |
| JPH0461745B2 (en) | ||
| CN217394000U (en) | 32MPa pump head advances flowing back valve box valve opening wearing and tearing welding set | |
| CN115091044B (en) | Welding tool and welding method for aluminum alloy thin-wall box | |
| CN116000409A (en) | Welding forming process for thin-wall cylinder and welded thin-wall cylinder | |
| CN100423885C (en) | Detecting tools for combustion turbine transitory section renovation technique and renovation technique thereof | |
| CN115055793A (en) | Magnetic control titanium alloy narrow gap-tungsten argon arc welding method and application | |
| CN115625425B (en) | A method for laser welding of large-size duplex stainless steel annular workpieces | |
| CN222843405U (en) | An assembly rack for manufacturing flue gas outlet pipe panels | |
| CN113478078A (en) | Device and method for laser welding clamping and back protection of three-layer structure | |
| CN118926684B (en) | Laser welding fixture and laser welding method for inner tube assembly of air conduit of aero-engine | |
| CN116213936B (en) | A dual laser beam welding shielding gas adaptive control device for T-shaped welds | |
| CN113352061B (en) | Method for producing a gas generator | |
| CN117564517B (en) | Dynamic smoke protection device for vacuum laser welding |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant |