A method of brazing a combustion chamber head adapter segment assembly and assembly

Abstract

A brazing method for a combustion chamber head transition section assembly is disclosed. The combustion chamber head transition section assembly includes a combustion chamber head transition section and multiple splash guards. The combustion chamber head transition section includes multiple central holes and conical impact surfaces surrounding the central holes. The splash guards include cylindrical and conical surfaces. During the welding process, the impact height between the end face of the central hole and the end face of the cylindrical surface is controlled to maintain the design requirements. This invention is simple to operate and highly precise. This invention also provides a combustion chamber head transition section assembly.

Description

Technical Field

[0001] This invention belongs to the field of aero-engines, and specifically relates to a brazing method and assembly for a combustion chamber head transition section. Background Technology

[0002] The combustion chamber head transition section assembly of an aero-engine is mounted on the engine's flame tube, forming the combustion zone of the combustion chamber together with the inner and outer rings of the flame tube. Modern engine combustion chamber temperatures are increasingly high, approaching or even exceeding the long-term service temperature limits of most high-temperature alloys. Therefore, the combustion chamber head transition section assembly is equipped with a splash guard to isolate the high-temperature flame within the combustion chamber, preventing damage to the component structure. The splash guard itself also requires impact cooling using cooling gas ejected from the impact holes of the combustion chamber head transition section to protect its structure from high-temperature damage. The distance between the impact hole and the splash guard, i.e., the impact height, is a key factor affecting the impact cooling effect, requiring high precision. Typically, the combustion chamber head transition section and the splash guard are connected using vacuum brazing to form the combustion chamber head transition section assembly. However, existing welding methods struggle to accurately control the impact height, resulting in insufficient precision and affecting the quality of the welded product. Summary of the Invention

[0003] The purpose of this invention is to provide a brazing method for a combustion chamber head transition section assembly, which can accurately control the impact height between the combustion chamber head and the splash plate, thereby improving the welding precision of the parts. This invention also provides a combustion chamber head transition section assembly.

[0004] According to one aspect of the present invention, a brazing method for a combustion chamber head transition section assembly is provided. The combustion chamber head transition section assembly includes a combustion chamber head transition section and a plurality of splash deflectors. The combustion chamber head transition section includes a plurality of central holes and a conical impact surface surrounding the central holes. The splash deflectors include a cylindrical portion and a conical portion. The cylindrical portion of the splash deflector is welded to the wall surface of the central holes using vacuum brazing. The method includes the following steps:

[0005] a) Apply solder to the outer side of the cylindrical portion of the splash deflector and insert the cylindrical portion of the splash deflector axially into the center hole of the combustion chamber head transition section;

[0006] b) Adjust the relative position of the combustion chamber head transition section and the splash deflector so that the axial drop between the end face of the central hole and the end face of the cylindrical section is equal to H2, thereby making the impact height between the impact surface of the combustion chamber head transition section and the conical surface of the splash deflector equal to H1.

[0007] c) The combustion chamber head transition section and the splash guard are sent into a vacuum furnace to complete the brazing.

[0008] The combustion chamber head transition section assembly includes an overall annular combustion chamber head transition section. Multiple central holes for connecting to the fuel injection pipe are evenly distributed on the combustion chamber head transition section. Each central hole location requires a brazed splash guard to protect the combustion chamber head transition section from damage caused by the high temperatures inside the combustion chamber. Around each central hole of the combustion chamber head transition section is a conical impact surface with impact holes for cooling the splash guard. The distance between the impact surface and the conical surface of the splash guard, i.e., the impact height H1, is a crucial parameter affecting the impact cooling effect. However, due to the complex structure, this gap cannot be directly measured and positioned during welding, leading to dimensional deviations and poor welding quality. By indirectly adjusting H1 by controlling the relative height difference H2 between the surface of the central hole and the end of the cylindrical surface of the splash guard, welding accuracy can be effectively improved, thus enhancing the finished quality of the combustion chamber head transition section assembly.

[0009] Further, in step c), the method for adjusting the position of the part is to provide a plug, the plug including a cylindrical boss with a height equal to H2, and insert the plug into one side of the surface of the central hole so that the end face of the cylindrical part abuts against the cylindrical boss of the plug. Using the plug allows for rapid adjustment of the splash guard position, improving production efficiency.

[0010] Furthermore, in step b), when inserting the cylindrical portion into the central hole, the method further includes inserting a positioning strip between the conical portions of adjacent splash guards. Inserting positioning strips between adjacent splash guards prevents the splash guards from skewing or interfering, ensures that the cylindrical portion is coaxially mounted with the central hole, and guarantees that the gap between adjacent splash guards meets design requirements.

[0011] According to another aspect of the present invention, a combustion chamber head transition section assembly is provided, including a combustion chamber head transition section and a splash deflector. The combustion chamber head includes a central bore and a conical impact surface, and the splash deflector includes a cylindrical portion and a conical portion. The height difference between the end face of the central bore and the end face of the cylindrical portion is determined according to H2 = H1 / sinA + L2 - L3, where H1 is the designed impact height between the impact surface and the conical portion, A is the angle between the impact surface and the conical portion relative to the axial direction of the central bore, L2 is the circumferential depth of the central bore, and L3 is the axial length of the cylindrical portion. This height difference between the end face of the central bore and the end face of the cylindrical portion ensures that the impact height of the combustion chamber head transition section assembly meets design requirements and effectively provides cooling protection for the splash deflector during engine operation.

[0012] Furthermore, a brazing filler groove is provided on the outer side of the cylindrical section for storing brazing filler metal. Due to the high precision requirements of the engine, the gap between the cylindrical section and the center hole is small, and the amount of brazing filler metal that can be accommodated during welding is limited. When the brazing filler metal is insufficient, the brazing filler metal in the brazing filler groove can flow into the welding surface to ensure that the part is fully welded.

[0013] Furthermore, the inner wall of the central hole has a groove at a position corresponding to the brazing filler groove. The groove on the inner wall of the central hole can accommodate more brazing filler metal, ensuring full penetration during the welding process of the parts. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the engine combustion chamber structure in one embodiment;

[0015] Figure 2 This is a partial structural schematic diagram of the engine combustion chamber head transition section assembly in one embodiment;

[0016] Figure 3 This is an enlarged schematic diagram of a portion of the structure of the engine combustion chamber head transition section assembly in one embodiment;

[0017] Figure 4 This is a schematic diagram of the assembly of the engine combustion chamber head transition section assembly in one embodiment.

[0018] The purpose of the above-described drawings is to provide a detailed description of the technical solution of the present invention so that those skilled in the art can understand the technical concept of the present invention, and not to limit the implementation of the present invention. It should be understood that, for the sake of brevity, the above-described drawings do not depict the parts in their entirety and all details strictly according to actual scale, but only schematically illustrate the structures related to the technical features of the present invention. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0020] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment herein. The phrase appearing in various places in the specification does not necessarily refer to the same embodiment, nor is it limited to mutually exclusive, independent, or alternative embodiments. Those skilled in the art will understand that the embodiments herein can be combined with other embodiments without causing structural conflicts.

[0021] In this description, unless otherwise explicitly specified and limited, the technical terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to the connection of mechanical structures or the relationship of signal connection; they can refer to the fixing and assembly of physical structures or the installation and data writing of program software. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0022] In this description, terms such as “surface,” “end,” “axial,” “circumferential,” and “length,” which indicate orientation or positional relationship, are intended to accurately describe the embodiments and simplify the description, and are not intended to limit the parts or structures involved to have a specific orientation, or to be installed or operated in a specific orientation, and should not be construed as limiting the embodiments described herein.

[0023] According to one embodiment of the present invention, a brazing method for a combustion chamber head transition section assembly is provided. A typical aero-engine combustion chamber structure is as follows: Figure 1 As shown, it is formed by a combustion chamber head transition section assembly including a combustion chamber head transition section 1 and a splash plate 2, and an outer ring 5 and an inner ring 6 of the flame tube. Among them, combined with... Figure 4 The combustion chamber head transition section 1 is generally annular, with multiple central holes 11 evenly arranged circumferentially for connecting fuel injectors 3. The main swirl generator 4 is installed at each central hole 11 at the front end of the combustion chamber 7, along with the fuel injectors 3. A splash plate 2 is welded to the inner side of each central hole 11. During engine operation, fuel and air burn intensely in the combustion chamber 7 to provide power to the engine. The splash plate 2 serves to block the high-temperature combustion gases and protect the combustion chamber head transition section 1. Depending on the engine size and structural design, the combustion chamber head transition section 1 typically has 16-21 central holes, corresponding to the same number of fuel injectors 3, main swirl generators 4, and splash plates 2.

[0024] Because the temperature inside the engine combustion chamber 7 is very high, the splash guard 2 needs to be cooled to maintain its service life. Figure 2 As shown, at each central hole 11, the combustion chamber head transition section 1 includes a cylindrical central hole wall 12 and a conical impact surface 13, with impact holes 14 provided on the impact surface 13. The splash plate 2 includes a cylindrical portion 21 connected to the central hole 12 and a conical portion 22 at the same angle as the impact surface 13. Cooling gas is ejected from the impact holes 14 and impacts the surface of the conical portion 22, thus cooling the splash plate 2. The distance between the impact surface 13 of the combustion chamber head transition section 1 and the conical portion 22 of the splash plate 2, i.e., the impact height H1, is a key parameter determining the impact cooling effect, typically set to 1.5mm-2mm with an accuracy requirement of ±0.2mm. However, the assembly of the combustion chamber head transition section assembly is as follows... Figure 4 As shown, all splash guards 2 need to be densely and precisely installed on the combustion chamber head transition section 1. It is impossible to measure and control the distance between the impact surface 13 and the conical surface 22 from the outside, which may lead to unstable quality of the welded product.

[0025] In an embodiment of the present invention, the welding process of the combustion chamber head transition section is as follows:

[0026] Optionally, based on the structural design, a design value H1 for the impact height between the impact surface 13 and the conical surface 22 is provided, and the relative drop H2 between the end face of the central hole 11 and the end of the cylindrical surface 21 is calculated or obtained through simulation measurement. The end face of the central hole 11 and the end of the cylindrical surface 21 both refer to the side furthest from the combustion chamber 7.

[0027] Before welding, brazing filler metal is applied to the outer surface of the cylindrical section 21 and inserted axially along the central hole 11. In some embodiments, a brazing filler metal groove 23 is provided on the outer side of the cylindrical section 21 of the splash plate 2, and in other embodiments, a groove 15 is also provided at the corresponding position on the inner surface of the wall 12 of the central hole 11. Due to the high installation precision of the combustion chamber head transition section assembly, the gap between the wall 12 and the cylindrical section 21 is very small, and the amount of brazing filler metal that can be accommodated is limited. If the brazing filler metal is not applied evenly or if it is tilted or pushed during installation, insufficient brazing filler metal in some areas may cause incomplete welding. However, the brazing filler metal groove 23 and the groove 15 can store additional brazing filler metal during the brazing process. This brazing filler metal can melt and flow between the wall 12 and the cylindrical section 21 during brazing, ensuring sufficient wetting of the brazing filler metal, allowing the joint surface to be fully penetrated, and improving the welding quality.

[0028] Adjust the relative position of the splash deflector 2 and the transition section of the combustion chamber head so that the distance between the end face of the central hole 11 and the end of the cylindrical section 21 is equal to H2, to meet the structural requirements for welding. In some embodiments, such as Figure 3 As shown, this process is achieved by inserting a plug 8 into one side of the central hole end face. The surface of the plug 8 is provided with a cylindrical boss 81, the protrusion height of which is equal to H2, and its diameter is not less than the cylindrical part 21. After insertion, it can abut against the end face of the cylindrical part 21 so that the installation position of the splash plate 2 meets the design requirements.

[0029] like Figure 4 As shown, repeat the above steps until all splash guards 2 are installed. In some embodiments, when inserting splash guards 2 at adjacent positions, a positioning strip 9 can also be inserted between the conical surfaces 22 of adjacent splash guards 2 to ensure that the insertion direction of the splash guard 2 is consistent with the axial direction of the central hole 11 and to avoid interference caused by the rotation of the splash guard 2 around the central hole 11. The design gap between adjacent splash guards 2 is usually 1.5mm-2.0mm±0.2mm, and the size of the positioning strip 9 should be consistent with this design gap value to meet assembly requirements while ensuring that the gap between the splash guards 2 meets the design requirements.

[0030] The above method can be used to easily and accurately weld the combustion chamber head transition section assembly, ensuring that the impact height meets the design requirements and avoiding quality problems such as deformation and interference during the welding process.

[0031] Among them, the plug 8 and the positioning strip 9 can be made of hard rubber such as nitrile rubber to ensure the smallest possible amount of compression deformation while avoiding damage to the parts, so that the assembly of the parts meets the design requirements.

[0032] According to another aspect of the invention, some embodiments provide a combustion chamber head transition section assembly, such as... Figure 2 As shown, the height difference H2 between the end face of the central hole 11 of the combustion chamber head transition section 1 and the end of the cylindrical portion 21 of the splash plate 2 is determined based on H1 / sinA+L2-L3 and in combination with the allowable error range. Here, H1 is the cooling impact height of the combustion chamber head transition section assembly, A is the angle between the impact surface 14 of the combustion chamber head transition section 1 and the conical portion 22 of the splash plate 2 relative to the axial direction of the central hole 11, L2 is the axial depth of the central hole 11, i.e., the length between the two ends of the wall 12, and L3 is the axial length of the cylindrical portion, i.e., the length from the end of the cylindrical portion 21 to the position where it connects with the conical portion 22. In some embodiments, a brazing filler groove 23 for storing brazing filler metal is provided circumferentially on the outer side of the cylindrical portion 21. In some embodiments, a groove 15 is also provided at a corresponding position on the inner surface of the wall 12 of the central hole 11, which can also be used to store brazing filler metal.

[0033] The purpose of the above embodiments is to provide a further detailed description of the present invention in conjunction with the accompanying drawings so that those skilled in the art can understand the technical concept of the present invention, and not to limit the present invention. Within the scope of the claims of the present invention, optimization or equivalent substitution of the involved part structures or method steps, as well as combination of implementation methods in different embodiments without causing structural and principle conflicts, all fall within the protection scope of the present invention.

Claims

1. A method for brazing a combustion chamber head adapter assembly, said combustion chamber head adapter assembly comprising a combustion chamber head adapter and a plurality of splash plates, wherein said combustion chamber head adapter comprises a plurality of central holes and a conical impact surface surrounding said central holes, said splash plates comprising a cylindrical portion and a conical portion, said cylindrical portion of said splash plates being brazed to the wall of said central holes by vacuum brazing, characterized in that, Includes the following steps: a) Apply solder to the outer side of the cylindrical portion of the splash deflector and insert the cylindrical portion of the splash deflector axially into the center hole of the combustion chamber head transition section; b) Adjust the relative position of the combustion chamber head transition section and the splash deflector, and provide a plug, the plug including a cylindrical boss, the height of the cylindrical boss being equal to H2. Insert the plug into one side of the surface of the central hole, so that the end face of the cylindrical part abuts against the cylindrical boss of the plug, so that the axial drop between the end face of the central hole and the end of the cylindrical part is equal to H2, thereby making the impact height between the impact surface of the combustion chamber head transition section and the conical part of the splash deflector equal to H1; where H2=H1 / sinA+L2-L3, A is the angle between the impact surface and the conical part relative to the axial direction of the central hole, L2 is the axial depth of the central hole, and L3 is the axial length of the cylindrical part. c) The combustion chamber head transition section and the splash guard are sent into a vacuum furnace to complete the brazing.

2. The combustion chamber head adapter segment assembly brazing method of claim 1, wherein, In step b), when inserting the cylindrical portion into the central hole, the step of inserting a positioning strip between the conical portions of the adjacent splash guards is also included.

3. A combustor head adapter assembly comprising a combustor head adapter and a splash plate, wherein the combustor head comprises a central bore and a conical impact surface, and wherein the splash plate comprises a cylindrical portion and a conical portion, and wherein the cylindrical portion of the splash plate is positioned within the central bore of the combustor head adapter and the conical portion of the splash plate is positioned against the conical impact surface of the combustor head adapter. The height difference between the end face of the central hole and the end face of the cylindrical part is determined according to H2=H1 / sinA+L2-L3, where H1 is the design impact height between the impact surface and the conical part, A is the angle between the impact surface and the conical part relative to the axis of the central hole, L2 is the axial depth of the central hole, and L3 is the axial length of the cylindrical part.

4. The combustion chamber head transition section assembly according to claim 3, characterized in that, A brazing groove is provided on the outer circumferential side of the cylindrical surface for storing brazing filler metal.

5. The combustion chamber head transition section assembly according to claim 4, characterized in that, The inner wall of the central hole has a groove at a position corresponding to the brazing filler groove.

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