Welding fixture and welding method for head assembly of flame tube of aero-engine

Abstract

The invention discloses an aero-engine flame tube head assembly welding clamp and welding method.The aero-engine flame tube head assembly welding clamp comprises a supporting assembly, an outer pressing assembly, a positioning assembly, an inner pressing assembly and an adjusting piece, the outer pressing assembly is arranged on the supporting assembly, and the positioning assembly comprises a positioning bottom plate and a positioning cone; the positioning bottom plate is in inserted fit with the supporting assembly in the vertical direction and forms a datum plane arranged in the horizontal direction, the outer wall face of the positioning cone is used for profiling an inner cone of the head of the flame tube so as to support a flow guide plate and further cooperate with the head of the flame tube to position the flow guide plate, and the inner pressing assembly is used for pressing and fixing the flow guide plate. The adjusting piece is used for adjusting a gap between two adjacent guide plates; compared with the prior art, one-time clamping and welding of a plurality of flow guide plates are achieved, the consistency of the flame tube head assembly is good, the welding efficiency is high, it can be ensured that the key size of the flame tube head assembly is qualified when the flame tube head assembly is welded and assembled, and the welding difficulty is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of welding equipment, and in particular, to a welding fixture for a flame tube head assembly of an aircraft engine. In addition, the present invention also relates to a welding method for a flame tube head assembly of an aircraft engine using the welding fixture for the flame tube head assembly of the aircraft engine. Background Art

[0002] The flame tube head assembly is an important hot end component of the combustion chamber of an aircraft engine. The main body of the part is an annular structure. It is necessary to use argon arc welding to weld multiple guide plates at uniform intervals along the circumference. Each guide plate is spot welded in four sections along the circumference of the welding part. During the welding process, the key dimensions A and L must be qualified. Dimension A is the distance between the guide plate and the inner cone of the flame tube head, and dimension L is the circumferential gap between two adjacent guide plates.

[0003] Since the guide plate welding point is located on the outer circle of the cone of the flame tube head, but there are two reversed flange edges on the cone part, the welding space is narrow and the welding is difficult; in addition, multiple guide plates are evenly distributed on the inner cone surface of the flame tube head, and the gaps between them need to be uniform. If the assembly and welding method is adopted, although the fixture structure is relatively simple, the welding efficiency is low, and the welding cannot be coordinated with each other. After welding one by one, it is easy to have a large cumulative error, unqualified dimension L, and the risk of scrapping parts. In addition, after the guide plate and the flame head are assembled, the two form a double-layer closed cavity structure, and dimension A is located in the cavity. Therefore, if dimension A cannot be qualified when the parts are welded, it is difficult to confirm that dimension A is qualified by measurement after welding is completed. Summary of the invention

[0004] The invention provides a welding fixture and a welding method for an aircraft engine flame tube head assembly, so as to solve the technical problems that it is difficult to ensure the key dimensions of the existing flame tube head assembly are qualified during welding and assembly, and the welding is difficult.

[0005] According to one aspect of the present invention, a welding fixture for an aircraft engine flame tube head assembly is provided, comprising a supporting assembly, an external clamping assembly, a positioning assembly, an internal clamping assembly and an adjusting member, wherein the supporting assembly is used to support the flame tube head from the bottom, the external clamping assembly is arranged on the supporting assembly and is used to cooperate with the supporting assembly to clamp and fix the flame tube head, the positioning assembly comprises a positioning base plate and a positioning cone, the positioning base plate is plugged and matched with the supporting assembly in the vertical direction and forms a reference surface arranged in the horizontal direction, the outer wall surface of the positioning cone is used to contour the inner cone of the flame tube head to support the guide plate, and then cooperate with the flame tube head to position the guide plate, the internal clamping assembly is used to penetrate the positioning cone, the guide plate and the flame tube head to apply a clamping force close to the flame tube head to the positioning cone, and then clamp and fix the guide plate, and the adjusting member is used to plug and match with the positioning cone and be inserted between two adjacent guide plates to adjust the gap between the two adjacent guide plates.

[0006] As a further improvement of the above technical solution:

[0007] Furthermore, the support assembly includes a support base plate and a plurality of support members, an external clamping assembly is arranged on the support base plate, the positioning base plate and the support base plate are plug-fitted together, a plurality of support members are arranged on the support base plate at intervals along the circumference of the support base plate and are staggered in the circumferential direction with the internal clamping assembly, and the plurality of support members are used to support the flame tube head from the bottom.

[0008] Furthermore, the fitting tolerance of the plug-in fit between the positioning base plate and the supporting base plate is H7 / g6.

[0009] Furthermore, a mounting portion extending radially outward is provided on the outer ring wall of the support base plate, and a support hole is opened on the mounting portion. The support member includes a support column vertically arranged on the support hole and a connecting screw passing through the support hole and threadedly connected to the support hole for mounting the support column on the mounting portion. There are multiple mounting portions, and the mounting portions and support members are arranged one by one.

[0010] Furthermore, the external clamping assembly includes an annular pressure plate and a plurality of clamping members, the annular pressure plate is used to press the flame tube head vertically downward, the plurality of clamping members are evenly arranged at circumferential intervals along the supporting base plate, and the clamping members include a clamping bolt vertically penetrated through the mounting portion and the pressing portion, and a clamping nut threadedly connected to the free end of the clamping bolt.

[0011] Furthermore, the positioning base plate, the positioning cone, the supporting base plate and the annular pressure plate are all made of aluminum material.

[0012] Furthermore, a connecting hole is opened on the supporting base plate, a threaded bushing is arranged in the connecting hole, and the positioning assembly also includes a fixing screw that passes through the positioning base plate and is connected to the threaded bushing and is used to fix the positioning base plate to the supporting base plate.

[0013] Furthermore, a plurality of U-shaped grooves are provided on the positioning cone, and the plurality of U-shaped grooves are evenly arranged along the circumferential direction and correspondingly arranged along the horizontal direction. The adjustment member is arranged in a U shape and is used to simultaneously engage with two U-shaped grooves in the vertical direction.

[0014] Furthermore, the internal clamping assembly includes a pressing portion arranged in a cross shape for pressing the flame tube head, a connecting portion arranged on the pressing portion, and a butterfly nut, the free end of the connecting portion is used to pass through the flame tube head, the guide plate and the positioning cone in sequence, and the butterfly nut is threadedly connected to the free end of the connecting portion.

[0015] According to another aspect of the present invention, a method for welding an aircraft engine flame tube head assembly is also provided, which includes the above-mentioned aircraft engine flame tube head assembly welding fixture, including the following steps: S1, pressing and fixing the flame tube head to the support assembly through an external clamping assembly, and using the flame tube head to center the circular holes of multiple guide plates; S2, plugging the positioning base plate in the positioning assembly into the support assembly, and making the outer wall of the positioning cone face the guide plate to support the guide plate, and then cooperating with the flame tube head to position the guide plate; S3, passing the positioning cone, the guide plate and the flame tube head through an internal clamping assembly to preliminarily clamp the guide plate, and then adjusting the gap between two adjacent guide plates in turn through an adjusting member, and after the gap is adjusted to the right position, the guide plate is fully clamped by the internal clamping assembly; S4, turning over the welding fixture to weld and fix the guide plate to the flame tube head, and after the welding is completed, the external clamping assembly, the internal clamping assembly and the positioning assembly are disassembled in turn, and then the welding of the next flame tube head assembly can be carried out.

[0016] The present invention has the following beneficial effects:

[0017] The welding fixture of the aircraft engine flame tube head assembly of the present invention presses and fixes the flame tube head through the cooperation of the supporting assembly and the external clamping assembly, the positioning assembly is plugged and matched with the supporting base plate in the vertical direction through the positioning base plate to form a reference surface arranged in the horizontal direction, and then the outer wall surface of the positioning cone is contoured to the inner cone of the flame tube head to support multiple guide plates, and the flame tube head is used to center the circular holes of the guide plates to achieve reliable positioning of the multiple guide plates, and the internal clamping assembly is penetrated through the positioning cone, the guide plate and the flame tube head to apply a clamping force close to the flame tube head to the positioning cone, and then the guide plate is preliminarily pressed and fixed, at this time, the adjustment member is plugged and matched with the positioning cone and clamped between the two adjacent guide plates to adjust the gap between the two adjacent guide plates, thereby ensuring that the circumferential gap between the two adjacent guide plates is full. If the requirements are met, the guide plate is fully clamped and fixed by the internal clamping assembly; after the guide plate is reliably positioned and fixed, since the reference surface is arranged horizontally, the vertical distance between the installation edge of the flame tube head and the reference surface, as well as the vertical distance between the center of the upper end surface of the guide plate and the reference surface can be easily and accurately measured, and then the distance between the inner cone of the flame tube head and the guide plate can be obtained by simple conversion to confirm whether the size is qualified; after the key dimensions are confirmed to be qualified, the welding fixture is turned over to quickly complete the welding and fixing of multiple guide plates; compared with the prior art, this scheme realizes the one-time clamping and welding of multiple guide plates, the flame tube head assembly has good consistency and high welding efficiency, which can ensure that the key dimensions of the flame tube head assembly are qualified during welding and assembly, and greatly reduce the difficulty of welding, with strong practicality and suitable for wide promotion and application.

[0018] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0020] Figure 1 It is a structural schematic diagram of a welding fixture for an aircraft engine flame tube head assembly according to a preferred embodiment of the present invention;

[0021] Figure 2 It is a structural schematic diagram of a welding fixture for an aircraft engine flame tube head assembly according to a preferred embodiment of the present invention;

[0022] Figure 3 It is a cross-sectional schematic diagram of a welding fixture for an aircraft engine flame tube head assembly according to a preferred embodiment of the present invention;

[0023] Figure 4It is a partial structural schematic diagram of a welding fixture for an aircraft engine flame tube head assembly according to a preferred embodiment of the present invention;

[0024] Figure 5 It is a partial structural schematic diagram of a welding fixture for an aircraft engine flame tube head assembly according to a preferred embodiment of the present invention;

[0025] Figure 6 It is a simplified schematic diagram of the dimensions of a welding fixture for an aircraft engine flame tube head assembly according to a preferred embodiment of the present invention.

[0026] Legend:

[0027] 100, support assembly; 110, support base plate; 120, support column; 130, connecting screw; 140, threaded bushing; 200, external clamping assembly; 210, annular pressure plate; 220, clamping bolt; 230, clamping nut; 300, positioning assembly; 310, positioning base plate; 320, positioning cone; 330, fixing screw; 400, internal clamping assembly; 410, pressing part; 420, connecting part; 430, butterfly nut; 500, adjusting part. DETAILED DESCRIPTION

[0028] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0029] like Figure 1-Figure 4 As shown, the welding fixture of the aircraft engine flame tube head assembly of this embodiment includes a support assembly 100, an external clamping assembly 200, a positioning assembly 300, an internal clamping assembly 400 and an adjusting member 500. The support assembly 100 is used to support the flame tube head from the bottom, the external clamping assembly 200 is arranged on the support assembly 100 and is used to cooperate with the support assembly 100 to clamp and fix the flame tube head, the positioning assembly 300 includes a positioning base plate 310 and a positioning cone 320, and the positioning base plate 310 is plugged and matched with the support assembly 100 in the vertical direction to form a The outer wall of the positioning cone 320 is used to imitate the inner cone of the flame tube head to support the guide plate, and then cooperate with the flame tube head to position the guide plate. The inner clamping assembly 400 is used to pass through the positioning cone 320, the guide plate and the flame tube head to apply a clamping force close to the flame tube head to the positioning cone 320, and then clamp and fix the guide plate. The adjusting member 500 is used to be plugged into and matched with the positioning cone 320 and inserted between two adjacent guide plates to adjust the gap between the two adjacent guide plates.

[0030] like Figure 1-Figure 4 As shown, optionally, the positioning base plate 310 and the positioning cone 320 are integrally formed into a unitary structure.

[0031] like Figure 1-Figure 4 As shown, specifically, the welding fixture of the aircraft engine flame tube head assembly of the present invention is used to press and fix the flame tube head through the support assembly 100 and the external clamping assembly 200. The positioning assembly 300 is plugged and matched with the support base plate 110 in the vertical direction through the positioning base plate 310 to form a reference surface arranged in the horizontal direction. The outer wall surface of the positioning cone 320 is shaped like the inner cone of the flame tube head to support the guide plate, and the flame tube head is used to center the circular hole of the guide plate to achieve reliable positioning of the guide plate. The internal clamping assembly 400 is penetrated through the positioning cone 320, the guide plate and the flame tube head to apply a clamping force close to the flame tube head to the positioning cone 320, thereby preliminarily clamping and fixing the guide plate. At this time, the adjustment member 500 is plugged and matched with the positioning cone 320 and clamped between two adjacent guide plates to adjust the gap between the two adjacent guide plates. Thereby ensuring that the circumferential gap between two adjacent guide plates meets the requirements, and then the guide plates are fully clamped and fixed by the internal clamping assembly 400; after the guide plates are reliably positioned and fixed, since the reference plane is arranged horizontally, the vertical spacing between the installation edge of the flame tube head and the reference plane, as well as the vertical spacing between the center of the upper end surface of the guide plate and the reference plane can be easily and accurately measured, and then the distance between the inner cone of the flame tube head and the guide plate can be obtained by simple conversion to confirm whether the size is qualified; after the key dimensions are confirmed to be qualified, the welding fixture is flipped over to quickly complete the welding and fixing of the guide plates; compared with the prior art, this scheme realizes the one-time clamping and welding of multiple guide plates, the flame tube head assembly has good consistency and high welding efficiency, which can ensure that the key dimensions of the flame tube head assembly are qualified during welding and assembly, and greatly reduce the welding difficulty, with strong practicality and suitable for wide promotion and application.

[0032] like Figure 5 and Figure 6 As shown, in this embodiment, the conversion formula for the distance between the inner cone of the flame tube head and the guide plate is:

[0033] A=[(A1-A2) / sinα]-t, A1=Hh;

[0034] Among them, A is the distance between the inner cone of the flame tube head and the guide plate, A1 is the vertical spacing between the mounting edge of the flame tube head and the center of the upper end surface of the guide plate, A2 is the vertical spacing between the mounting edge of the flame tube head and the center of the outer wall of the inner cone of the flame tube head, H is the vertical spacing between the mounting edge of the flame tube head and the reference plane, h is the vertical spacing between the center of the upper end surface of the guide plate and the reference plane, t is the thickness of the guide plate, and α is the taper of the inner cone of the flame tube head.

[0035] like Figure 5 and Figure 6As shown, it should be understood that, among the above parameters, A2, t and α are fixed values ​​during welding assembly, and A1 is obtained by converting H and h. Therefore, during assembly, H and h are accurately controlled by welding fixtures to ensure that A meets the requirements, and plug-in matching is used to ensure that the matching accuracy meets the requirements, and then a horizontally arranged reference plane is formed to facilitate the measurement of H and h.

[0036] It should be understood that the above calculation formula realizes the conversion of the size of the closed cavity inside the part, solving the problem that the size of the closed cavity inside the part cannot be measured and guaranteed.

[0037] like Figure 1 and Figure 2 As shown, in this embodiment, the support assembly 100 includes a support base plate 110 and a plurality of support members, the outer clamping assembly 200 is arranged on the support base plate 110, the positioning base plate 310 and the support base plate 110 are plugged and matched, and the plurality of support members are arranged on the support base plate 110 at intervals along the circumference of the support base plate 110 and are arranged in a staggered manner with the inner clamping assembly 400 in the circumferential direction, and the plurality of support members are used to support the flame tube head from the bottom. Specifically, the support assembly 100 installs the outer clamping assembly 200, the positioning assembly 300 and the plurality of support members through the support base plate 110, and then uniformly supports the flame tube head from the bottom through the plurality of support members, and the support members and the inner clamping assembly 400 are arranged in a staggered manner in the circumferential direction, so as to provide sufficient welding space for welding the guide plate, thereby reducing the welding difficulty and improving the welding efficiency.

[0038] In this embodiment, the fitting tolerance of the plug-in fit between the positioning base plate 310 and the supporting base plate 110 is H7 / g6. Specifically, H7 / g6 is a high-precision clearance fit, which ensures that the positioning base plate 310 and the supporting base plate 110 have a high-precision clearance fit, thereby facilitating disassembly and assembly while improving assembly accuracy, thereby achieving precise control of H and h.

[0039] like Figure 1-Figure 3 As shown, in this embodiment, a mounting portion extending radially outward is provided on the outer ring wall of the support base plate 110, and a support hole is opened on the mounting portion. The support member includes a support column 120 vertically arranged on the support hole and a connecting screw 130 passing through the support hole and threadedly connected to the support hole for mounting the support column 120 on the mounting portion. There are multiple mounting portions, and the mounting portions and the support members are arranged one by one.

[0040] like Figure 1-Figure 3As shown, in this embodiment, the external clamping assembly 200 includes an annular clamping plate 210 and a plurality of clamping members, the annular clamping plate 210 is used to press the flame tube head vertically downward, the plurality of clamping members are evenly arranged at intervals along the circumference of the support base plate 110, and the clamping members include a clamping bolt 220 vertically penetrated through the mounting portion and the pressing portion 410, and a clamping nut 230 threadedly connected to the free end of the clamping bolt 220. Specifically, when the annular clamping plate 210 presses the flame tube head vertically downward, the clamping bolt 220 vertically penetrates through the mounting portion and the pressing portion 410, and then is threadedly connected to the free end of the clamping bolt 220 through the clamping nut 230, so as to clamp and fix the flame tube head on the support base plate 110.

[0041] In this embodiment, the positioning base plate 310, the positioning cone 320, the supporting base plate 110 and the annular pressure plate 210 are all made of aluminum material, so as to greatly reduce the weight of the welding fixture and facilitate the flipping operation.

[0042] like Figure 1-Figure 3 As shown, in this embodiment, a connection hole is provided on the support base plate 110, and a threaded bushing 140 is arranged in the connection hole. The positioning assembly 300 also includes a fixing screw 330 that is penetrated through the positioning base plate 310 and connected to the threaded bushing 140 for fixing the positioning base plate 310 on the support base plate 110. Specifically, the fixing screw 330 is penetrated through the positioning base plate 310 to be connected with the threaded bushing 140, thereby fixing the positioning base plate 310 on the support base plate 110. Since the support base plate 110 is made of aluminum material, if the thread is directly opened on the support base plate 110, the thread strength is relatively low, and frequent tightening and loosening may easily lead to its failure and damage. Therefore, the thread strength is improved by the threaded bushing 140 to ensure reliable assembly. Optionally, a plurality of connection holes are provided, and the plurality of connection holes are evenly arranged at intervals along the circumference of the support base plate 110, and the fixing screws 330, the threaded bushing 140 and the connection holes are arranged one by one.

[0043] like Figure 1-Figure 3 As shown, in this embodiment, a plurality of U-shaped grooves are provided on the positioning cone 320, and the plurality of U-shaped grooves are evenly arranged at intervals along the circumferential direction and correspondingly arranged in the horizontal direction, and the adjustment member 500 is arranged in a U-shape and is used to be plugged and matched with two U-shaped grooves in the vertical direction at the same time. Specifically, by being arranged in a U-shape and plugged and matched with two U-shaped grooves in the vertical direction at the same time, when it is inserted between two adjacent guide plates, the gap between the two adjacent guide plates can be evenly adjusted to ensure that the gap between the two adjacent guide plates meets the requirements; and the number of U-shaped grooves arranged at intervals along the circumferential direction is the same as the number of guide plates, so as to adjust the gap between the two adjacent guide plates in sequence.

[0044] like Figure 3-Figure 4As shown, in this embodiment, the internal pressing assembly 400 includes a pressing portion 410 arranged in a cross shape for pressing the flame tube head, a connecting portion 420 arranged on the pressing portion 410, and a butterfly nut 430, the free end of the connecting portion 420 is used to be sequentially penetrated through the flame tube head, the guide plate and the positioning cone 320, and the butterfly nut 430 is threadedly connected to the free end of the connecting portion 420. Specifically, the free end of the connecting portion 420 is sequentially penetrated through the flame tube head, the guide plate and the positioning cone 320, so that the pressing portion 410 is in contact with the flame tube head, and then the butterfly nut 430 is threadedly connected to the free end of the connecting portion 420, so that the initial and full compression of the guide plate can be achieved by rotating the butterfly nut 430; and the cross-shaped pressing portion 410 facilitates the welding and fixing of the guide plate.

[0045] like Figure 1-Figure 3 As shown, the welding method of the aircraft engine flame tube head assembly of this embodiment adopts the above-mentioned aircraft engine flame tube head assembly welding fixture, and includes the following steps: S1, pressing and fixing the flame tube head on the support assembly 100 through the external clamping assembly 200, and using the flame tube head to center the circular holes of multiple guide plates; S2, plugging the positioning base plate 310 in the positioning assembly 300 onto the support assembly 100, and making the outer wall of the positioning cone 320 face the guide plate to support it, and then cooperating with the flame tube head to position the guide plate; S3, The inner clamping assembly 400 is passed through the positioning cone 320, the guide plate and the flame tube head to preliminarily clamp the guide plate, and then the gap between the two adjacent guide plates is adjusted in sequence through the adjusting member 500. After the gap is adjusted in place, the guide plate is fully clamped by the inner clamping assembly 400; S4, the welding fixture is turned over to weld the guide plate to the flame tube head. After the welding is completed, the outer clamping assembly 200, the inner clamping assembly 400 and the positioning assembly 300 are disassembled in sequence, and then the welding of the next flame tube head assembly can be carried out. Specifically, by adopting the above-mentioned aircraft engine flame tube head assembly welding fixture, the assembly welding of the flame tube head assembly is completed, and the key dimensions are guaranteed to be qualified during the assembly process, sufficient welding space is provided for welding, the welding efficiency is high, the quality is good, the practicability is strong, and it is suitable for wide promotion and application.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A welding fixture for an aircraft engine flame tube head assembly, characterized in that: The invention comprises a support assembly (100), an external clamping assembly (200), a positioning assembly (300), an internal clamping assembly (400) and an adjusting member (500), wherein the support assembly (100) is used to support the flame tube head from the bottom, the external clamping assembly (200) is arranged on the support assembly (100) and is used to cooperate with the support assembly (100) to clamp and fix the flame tube head, and the positioning assembly (300) comprises a positioning base plate (310) and a positioning cone (320), and the positioning base plate (310) is plug-fitted with the support assembly (100) in the vertical direction and forms a positioning cone in the horizontal direction. The outer wall of the positioning cone (320) is used to imitate the inner cone of the flame tube head to support the guide plate, and then cooperate with the flame tube head to position the guide plate. The inner clamping component (400) is used to pass through the positioning cone (320), the guide plate and the flame tube head to apply a clamping force close to the flame tube head to the positioning cone (320), and then clamp the guide plate to fix it. The adjustment member (500) is used to be plugged into the positioning cone (320) and inserted between two adjacent guide plates to adjust the gap between the two adjacent guide plates.

2. The welding fixture for the aviation engine flame tube head assembly according to claim 1, characterized in that: The support assembly (100) comprises a support base plate (110) and a plurality of support members, an external clamping assembly (200) is arranged on the support base plate (110), a positioning base plate (310) and the support base plate (110) are plug-fitted together, a plurality of support members are arranged on the support base plate (110) at intervals along the circumference of the support base plate (110) and are staggered in the circumferential direction with the internal clamping assembly (400), and the plurality of support members are used to support the flame tube head from the bottom.

3. The welding fixture for the aviation engine flame tube head assembly according to claim 2, characterized in that: The fitting tolerance of the plug-in fitting between the positioning base plate (310) and the supporting base plate (110) is H7 / g6.

4. The welding fixture for the aviation engine flame tube head assembly according to claim 2, characterized in that: An outer ring wall of the support base plate (110) is provided with a mounting portion extending radially outward, and a support hole is opened on the mounting portion. The support member includes a support column (120) arranged vertically on the support hole and a connecting screw (130) passing through the support hole and threadedly connected to the support hole for mounting the support column (120) on the mounting portion. There are multiple mounting portions, and the mounting portions and the support members are arranged one by one.

5. The welding fixture for the aviation engine flame tube head assembly according to claim 4, characterized in that: The external clamping assembly (200) includes an annular pressure plate (210) and a plurality of clamping members, wherein the annular pressure plate (210) is used to press the flame tube head downward vertically, and the plurality of clamping members are evenly arranged at intervals along the circumference of the supporting base plate (110), and the clamping members include a clamping bolt (220) vertically penetrated through the mounting portion and the pressing portion (410), and a clamping nut (230) threadedly connected to the free end of the clamping bolt (220).

6. The welding fixture for the aviation engine flame tube head assembly according to claim 5, characterized in that: The positioning base plate (310), the positioning cone (320), the supporting base plate (110) and the annular pressure plate (210) are all made of aluminum material.

7. The welding fixture for the aviation engine flame tube head assembly according to claim 6, characterized in that: A connecting hole is provided on the supporting base plate (110), and a threaded bushing (140) is arranged in the connecting hole. The positioning assembly (300) further comprises a fixing screw (330) which is passed through the positioning base plate (310) and connected to the threaded bushing (140) and is used to fix the positioning base plate (310) to the supporting base plate (110).

8. The welding fixture for the aviation engine flame tube head assembly according to any one of claims 1 to 7, characterized in that: The positioning cone (320) is provided with a plurality of U-shaped grooves, which are evenly spaced in the circumferential direction and correspondingly arranged in the horizontal direction. The adjustment member (500) is arranged in a U shape and is used to be plugged into and matched with two U-shaped grooves in the vertical direction at the same time.

9. The welding fixture for the aviation engine flame tube head assembly according to any one of claims 1 to 7, characterized in that: The inner pressing assembly (400) comprises a pressing portion (410) arranged in a cross shape for pressing against the flame tube head, a connecting portion (420) arranged on the pressing portion (410), and a butterfly nut (430), wherein the free end of the connecting portion (420) is used to be sequentially passed through the flame tube head, the guide plate and the positioning cone (320), and the butterfly nut (430) is threadedly connected to the free end of the connecting portion (420).

10. A welding method for an aircraft engine flame tube head assembly, characterized in that: The welding fixture for the aviation engine flame tube head assembly according to any one of claims 1 to 9 comprises the following steps: S1, pressing and fixing the flame tube head onto the support assembly (100) by means of an external pressing assembly (200), and centering the circular holes of the plurality of guide plates by means of the flame tube head; S2, inserting the positioning base plate (310) in the positioning assembly (300) onto the supporting assembly (100), and making the outer wall of the positioning cone (320) lean against the guide plate, thereby cooperating with the flame tube head to position the guide plate; S3, the guide plate is initially pressed by passing an internal pressing component (400) through the positioning cone (320), the guide plate and the flame tube head, and the gap between two adjacent guide plates is adjusted in sequence by the adjusting member (500). After the gap is adjusted to the right position, the guide plate is fully pressed by the internal pressing component (400); S4, flip the welding fixture to weld and fix the guide plate to the flame tube head. After the welding is completed, the outer clamping assembly (200), the inner clamping assembly (400) and the positioning assembly (300) are disassembled in sequence, and then the welding of the next flame tube head assembly can be carried out.

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