A disc mounting base welding assembly jig and welding method

Abstract

The application discloses a disc-shaped part mounting seat welding combination clamp and a welding method, and belongs to the technical field of aero-engine welding. The combination clamp comprises a positioning welding clamp for positioning welding of the mounting seat and an official welding clamp for official welding; the positioning welding clamp positions the disc-shaped part through a positioning ring, a positioning pin and a pressing plate, is threadedly connected with the mounting seat through a threaded bolt and performs positioning welding on the mounting seat from an M surface; and the official welding clamp is arranged outside the mounting seat through a top block cover, is threadedly connected with the mounting seat through a bolt and performs official welding from an N surface. During welding, the mounting seat is first fixed by positioning welding, and then is transferred to the official welding clamp; and the bolt is used to apply an outward pulling force to the mounting seat, so that the inward concave tendency caused by welding stress is inhibited. The step-by-step welding strategy is adopted, the welding torch interference is effectively avoided, the inward concave deformation of the mounting seat is inhibited through the pulling force, the structure is simple, the operation is convenient, the combination clamp is suitable for welding in a vacuum argon filling box, and the size of the part after welding meets the design requirement.

Description

Technical Field

[0001] This invention relates to the field of aero-engine welding technology, specifically to a welding assembly fixture and welding method for a disc-shaped component mounting base. Background Technology

[0002] Welding technology enables the fabrication of complex structural parts, but its inherent drawback is that welding stress can cause shrinkage and deformation. To meet the design requirements of parts, individual components of welded assemblies typically have machining allowances, which are then machined to the design dimensions after welding, as is the case with most thin-walled casings in the aerospace industry. On the other hand, for structurally complex parts, such as nozzles, inspection bosses, and throttle seats, machining is difficult or even impossible after welding. Therefore, individual components must be machined to the required dimensions without any machining allowances. This necessitates strict control of welding deformation to ensure the final dimensions of the parts.

[0003] Reference Figure 1 This is a typical disc-shaped component with a diameter of Φ290mm, made of TC4 titanium alloy. The part consists of a shell, mounting edge, and mounting base welded together. In terms of manufacturing process, the shell and mounting edge are welded together first, and then a pilot hole is milled into the shell. Because the shell's sheet metal thickness is only 1.8mm, the rigidity of the part is significantly weakened after milling the pilot hole, and the welding stress generated during welding causes the mounting base to tend to concave inwards.

[0004] To reduce welding deformation, existing technologies mainly employ two methods: one is the reverse deformation method, which involves pre-deforming the part in the opposite direction of welding deformation to offset the final welding deformation. However, the amount of pre-deformation is difficult to quantify and is overly dependent on the operator's skill level and experience, resulting in poor process stability. The other method uses rigid clamps to constrain the parts, mechanically preventing shrinkage deformation. This is a common method in welding casing-type parts. For example, Chinese patent CN114871676B discloses a method and clamp for controlling welding indentation deformation when welding mounting seats after opening holes on the surface of a typical annular thin-walled casing in the aerospace machining field. This clamp uses a radial pressing and tightening method with expansion blocks. A wedge mechanism converts the longitudinal movement of the pressure block into the lateral movement of the expansion block, and the friction between the wedge contact surfaces achieves self-locking of the expansion block after tightening, thus resisting welding deformation. This technology reduces the amount of protective gas used through point-to-point distributed air intake pipes, improving the welding quality on the back side of the weld.

[0005] However, the aforementioned rigid clamp support method has the following limitations: First, this method is applicable when the welding orientation and the deformation trend of the part are opposite. In this application, if the disc-shaped mounting base is welded from the M-side, the mounting base will interfere with the welding torch, resulting in some areas being unweldable. Therefore, welding can only be performed from the N-side of the part, where the welding orientation and deformation trend are the same. The rigid support method cannot effectively suppress the inward concavity of the mounting base. Second, the disc-shaped part is made of TC4 titanium alloy, which is prone to defects when welded under atmospheric pressure, requiring welding in a vacuum argon-filled chamber. However, rigid clamps with back-side support are typically complex and bulky, making them difficult to operate in the limited space of a vacuum argon-filled chamber, thus affecting their practicality.

[0006] Therefore, how to provide a welding fixture and method for a disc-shaped component mounting base that is suitable for situations where the welding orientation and deformation trend are the same, has a simple structure, and is easy to operate in a vacuum argon-filled chamber has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] The purpose of this invention is to provide a welding assembly fixture for a disc-shaped component mounting base. First, the mounting base is positioned by argon arc welding in a positioning welding fixture, and then the mounting base is welded using a formal welding fixture. This avoids interference during the welding of the mounting base and can effectively control the welding deformation of the mounting base, so that the welded part meets the design requirements in terms of size, thereby ensuring the subsequent assembly requirements.

[0008] The technical solution of the present invention: a welding assembly fixture for a disc-shaped component mounting base, wherein the disc-shaped component includes a housing with a mounting edge and a mounting base disposed on the upper end of the housing, and includes a positioning welding fixture for positioning welding of the mounting base and a formal welding fixture for formal welding of the mounting base; The positioning welding fixture includes: The base plate is a disc-shaped stepped structure with an upper stepped end face and a lower stepped end face. A positioning ring is set on the upper stepped end face of the base plate to position and support the disc-shaped component; The clamping mechanism is set on the lower stepped end face of the base plate, including a support vertically set on the lower stepped end face, a guide sleeve horizontally set on the upper part of the support, and a threaded pin movably set in the guide sleeve. The front end of the threaded pin is provided with an external thread for threaded connection with the mounting seat. A clamping screw is also vertically set on the upper part of the support for locking the threaded pin. The formal welding fixture includes: The top block, whose bottom surface is adapted to the outer dimensions and surface of the housing, is used to cover the outside of the mounting base; Bushing, installed on the side wall of the top block; A pin, movably inserted into the bushing, has a threaded front end for threaded connection with the mounting base.

[0009] Furthermore, the positioning welding fixture is provided with multiple pressure plates evenly arranged along the circumference for pressing the disc-shaped parts.

[0010] Furthermore, the support has a positioning hole at the bottom, a cylindrical pin is inserted into the positioning hole to position the support, and a screw passes through the support to lock and fix it to the base plate.

[0011] Furthermore, the positioning ring is provided with a positioning pin, which cooperates with the positioning hole on the mounting edge of the disc-shaped component to determine the angular position of the disc-shaped component.

[0012] A method for welding a disc-shaped part using a combination fixture includes the following steps: the housing has an outer peripheral surface M and an inner end surface N. Step 1: Use a positioning welding fixture to fix the position and angular orientation of the disc-shaped part, connect it to the mounting base with a threaded pin and lock it, and perform argon arc welding positioning on the mounting base from the M side of the housing c; Step 2: Transfer the tack welded disc to the formal welding fixture, place the top block outside the mounting base, connect the top block to the mounting base by threading it through the bushing on the top block with a pin, and place it in a vacuum argon-filled chamber. Perform argon arc welding on the mounting base from the N side of the shell.

[0013] Further, step 1 specifically includes: Step 11: Align the positioning hole on the mounting edge of the disc-shaped part with the positioning pin on the positioning ring, and align the outer circle of the mounting edge of the disc-shaped part with the inner hole of the positioning ring. Press the pressure plate to fix the position and angular orientation of the disc-shaped part. Step 12: Align the mounting base with the mounting base bottom hole on the housing, rotate and move the threaded pin so that the front external thread of the threaded pin connects with the threaded hole of the mounting base; move the threaded pin forward so that the step of the threaded pin is close to the positioning surface of the support; tighten the clamping screw to lock the threaded pin and fix the mounting base. Step 13: Position the mounting base using argon arc welding from the M-side of the housing, avoiding interference areas on the mounting base. Then loosen the clamping screws and pressure plate, and remove the disc-shaped part from the positioning welding fixture.

[0014] Furthermore, in step 12, the mating gap between the mounting base and the mounting base bottom hole on the housing is no greater than 0.18 mm.

[0015] Furthermore, in step 1, before argon arc welding positioning, the bottom hole of the mounting base needs to be polished. The polishing area extends outward from the edge of the hole by no less than 25mm, and the polishing part includes the end face of the hole and both sides. In step 2, before argon arc welding, the area to be welded should be wiped with a clean silk cloth soaked in acetone to remove surface oil.

[0016] Furthermore, the welding parameters for argon arc welding positioning in step 1 are as follows: using 1.6mm TA1 welding wire, welding current of 30A to 40A, argon flow rate of 8 to 15L / min on the front side and 5 to 8L / min on the back side, tungsten electrode diameter of 2mm, and uniformly positioning welding at 6 to 8 points.

[0017] Furthermore, in step 2, the disc-shaped component, fixture, and welding wire are placed in a vacuum argon-filled chamber, evacuated to below 1.33 Pa, and then filled with argon gas. Argon arc welding is then performed from the N side. The welding parameters are: TA1 welding wire Φ1.6mm, welding current 70A~90A, and tungsten electrode diameter Φ2mm.

[0018] The beneficial effects of this invention are: 1. This invention designs a welding assembly fixture for a disc-shaped mounting base. First, the mounting base is positioned by argon arc welding in a positioning welding fixture (fixture a), and then the mounting base is welded using a formal welding fixture (fixture b). This invention can effectively control the welding deformation of the mounting base, and the dimensions after welding meet the design requirements, thereby ensuring the subsequent assembly requirements.

[0019] 2. Unlike conventional rigid clamp supports, this invention uses tensile force to limit the deformation of the mounting base, and is suitable for welding parts with the same welding orientation and welding deformation direction.

[0020] 3. The welding fixture designed in this invention has a simple structure, small size, and is easy to operate, and can be widely applied to the welding of mounting bases for small disc-shaped parts. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a cross-sectional view of the disc-shaped component of the present invention; Figure 2 This is a top view of the disc-shaped component of the present invention; Figure 3 This is a cross-sectional view of the positioning welding fixture of the present invention; Figure 4 This is a top view of the positioning welding fixture of the present invention; Figure 5 This is a cross-sectional view of the formal welding fixture of this invention; Reference numerals: 1-base plate, 2-locating ring, 3-locating pin, 4-threaded pin, 5-guide sleeve, 6-support, 7-clamping screw, 8-screw, 9-cylindrical pin, 10-pressure plate, 11-top block, 12-guide sleeve, 13-pin, a-positioning welding fixture, b-formal welding fixture, c-housing, d-mounting base. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, it should not be construed that the scope of the subject matter of the present invention is limited to the following embodiments. All modifications, substitutions and alterations made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention are included within the scope of the present invention.

[0024] A disc-shaped component positioning and welding fixture a includes a base plate 1, a positioning ring 2, a positioning pin 3, a threaded pin 4, a guide sleeve 5, a support 6, a clamping screw 7, a screw 8, a cylindrical pin 9, and a pressure plate 10. The base plate 1 is a circular disc-shaped part. The positioning ring 2 is connected to the base 1 by 6 screws. The positioning pin 3 is interference-fitted with the positioning ring 1 and fits with the positioning hole of the disc-shaped part to determine the angular position of the part.

[0025] The support 6 is positioned by a cylindrical pin 9 and then fixed to the base plate 1 with screws 8. The support 6 is equipped with a guide sleeve 5, and a threaded pin 4 passes through the guide sleeve 5. The guide sleeve 5 guides the threaded pin 4 to move back and forth.

[0026] The threaded pin 4 has an external thread at its tip. Rotate the threaded pin 4 to connect it with the mounting base d of the disc-shaped part. Then move the threaded pin 4 so that it presses against the positioning surface of the guide sleeve 5. Tighten the clamping screw 7 to fix the mounting base d.

[0027] A formal welding fixture b for a disc-shaped part includes a top block 11, a bushing 12, and a pin 13. The bottom profile of the top block 11 is the same size as the housing c of the disc-shaped part. The bushing 12 is interference-fitted with the top block 11. The pin 13 passes through the bushing 12 and is threadedly engaged with the mounting base d. The step of the pin 13 abuts against the positioning surface of the top block.

[0028] A welding assembly fixture for a disc-shaped component mounting base and its method thereof, comprising the following steps: Step 1: The clamping and welding steps of the locating welding fixture a. Step 11: Align the positioning hole on the mounting edge of the disc-shaped part with the positioning pin 3 on the positioning ring 2, align the outer circle of the mounting edge of the disc-shaped part with the inner hole of the positioning ring, press the pressure plate 10, and determine the position and angular orientation of the disc-shaped part; Step 12: Screw the threaded pin 4 into the mounting base d; Step 13: Move the threaded pin 4 forward so that the step of the threaded pin 4 is in close contact with the positioning surface of the support 6; Step 14: Tighten the clamping screw 7 to fix the threaded pin 4, thereby fixing the mounting base d of the disc-shaped part; Step 15: Position the mounting base d using argon arc welding from surface M, avoiding any interference with the mounting base d during the positioning process; Step 16: Loosen the clamping screw 7 and remove the threaded pin 4 from the mounting base d; Step 17: Release the pressure plate 10 and remove the part from the positioning welding fixture a.

[0029] Step 2: The clamping and welding steps of the formal welding fixture b. Step 21: Cover the mounting base d with the top block 1 of the welding fixture, so that the guide sleeve 2 is basically aligned with the threaded hole of the mounting base d; Step 22: Pass the pin 3 through the guide sleeve 2 and then screw it into the mounting base d; Step 23: Argon arc weld the positioning mounting base d from the N side of the part according to the welding parameters.

[0030] Example 1: Structure of a welding assembly fixture for a disc-shaped component mounting base, this fixture is designed for... Figure 1 The disc-shaped component design shown includes a housing c, a mounting edge, and a mounting base d. The housing c has a sheet metal thickness of only 1.8 mm and is made of TC4 titanium alloy. To overcome the problems of interference between the mounting base and the welding torch during welding from the M side, resulting in some areas being unweldable, and the limited operating space within the vacuum argon-filled chamber, this embodiment designs a combined fixture consisting of a positioning welding fixture a and a formal welding fixture b.

[0031] The structure of the positioning welding fixture a is as follows: Figure 3 and Figure 4 The positioning welding fixture a is used for positioning welding of the mounting base d, and includes a base plate 1, a positioning ring 2, a positioning pin 3, a clamping mechanism, and a pressure plate 10.

[0032] The base plate 1 is a circular, stepped structure with an upper stepped end face and a lower stepped end face, serving as the base for the entire fixture.

[0033] The positioning ring 2 is a circular ring structure, fixedly connected to the upper stepped end face of the base plate 1 by six screws. The inner hole of the positioning ring 2 mates with the outer circle of the mounting edge of the disc-shaped part, used to achieve radial positioning of the disc-shaped part. The positioning ring 2 is also provided with a positioning pin 3, which is interference-fitted with the positioning ring 2. Its upwardly protruding part mates with the positioning hole on the mounting edge of the disc-shaped part, used to determine the angular position of the disc-shaped part.

[0034] The clamping mechanism is located on the lower stepped end face of the base plate 1 and includes a support 6, a guide sleeve 5, a threaded pin 4, and a clamping screw 7. Specifically, the support 6 is vertically fixed to the lower stepped end face of the base plate 1. The bottom of the support 6 is provided with a positioning hole, which is precisely positioned by inserting a cylindrical pin 9 into the positioning hole, and then the screw 8 is used to pass through the support 6 and lock it to the base plate 1.

[0035] The guide sleeve 5 is horizontally inserted through the upper part of the support 6 to guide the back-and-forth movement of the threaded pin 4 and ensure the accuracy of its movement direction. The threaded pin 4 is movably inserted in the guide sleeve 5. Its front end is provided with an external thread for screwing into the threaded hole of the mounting seat d. Its rear end is provided with a step, which is used to contact the positioning surface of the support 6 and transmit axial force.

[0036] The clamping screw 7 is vertically threaded to the upper part of the support 6, and its lower end can press against the upper surface of the threaded pin 4. After the threaded pin 4 is adjusted into place, tightening the clamping screw 7 will lock the threaded pin 4 into the guide sleeve 5.

[0037] The clamp has multiple pressure plates 10, which are evenly distributed circumferentially on the lower stepped end face of the base plate 1. They are used to press and fix the disc-shaped part after it is positioned, so as to prevent it from shifting during the welding process.

[0038] The structure of the formal welding fixture b is as follows: Figure 5 The formal welding fixture b is used for formal welding of the mounting base d, and it includes a top block 11, a bushing 12, and a pin 13. The top block 11 is a cover-shaped structure, and its bottom profile is consistent with the outer dimensions and profile of the housing c, and is used to tightly cover the outside of the mounting base d.

[0039] The bushing 12 is interference-fitted on the side wall of the top block 11, and its axis is aligned with the axis of the threaded hole of the mounting seat d, and is used to guide the movement of the pin 13.

[0040] The pin 13 is movably inserted into the bushing 12, and its front end is provided with a thread that mates with the threaded hole of the mounting seat d. The pin 13 is also provided with a step. After the pin 13 passes through the bushing 12 and is screwed into the threaded hole of the mounting seat d, further screwing in will cause the step of the pin 13 to abut against the positioning surface of the top block 11, thereby applying an outward pulling force to the mounting seat d through the pin 13 to counteract the inward shrinkage deformation during welding.

[0041] The combined fixture in this embodiment achieves the following functions through the division of labor and cooperation between the positioning welding fixture a and the formal welding fixture b: Positioning welding fixture a: The positioning ring 2, positioning pin 3 and pressure plate 10 realize the precise positioning and fixation of the disc-shaped part; the threaded pin 4 in the clamping mechanism is threadedly connected to the mounting seat d, and positioning welding is performed from the M face to the mounting seat d, laying the foundation for subsequent formal welding.

[0042] Formal welding fixture b: By fitting the top block 11 with the profile of the housing c and the threaded connection between the pin 13 and the mounting seat d, the deformation trend during welding is changed from the traditional support to tension. The tension is used to suppress the inward concavity of the mounting seat d, which is suitable for situations where the welding orientation and deformation trend are the same.

[0043] Example 2: Welding method for disc-shaped component mounting base, using the combined fixture described in Example 1 to weld the disc-shaped component mounting base, the specific steps are as follows: 1. Pre-welding preparation: Polish the mounting base bottom hole on the housing c. The polishing area extends outward from the edge of the hole by no less than 25mm. The polishing area includes the end face of the hole and both sides to ensure the surface cleanliness of the welding area, which is conducive to weld formation.

[0044] II. Tack Welding Stage: Align the locating holes on the mounting edge of the disc-shaped component with the locating pins 3 on the locating ring 2, and simultaneously align the outer circle of the mounting edge of the disc-shaped component with the inner hole of the locating ring 2, so that the disc-shaped component is accurately seated on the locating ring 2. Then, tighten the pressure plate 10 to firmly fix the disc-shaped component to the base plate 1, completing the positional and angular positioning of the disc-shaped component.

[0045] Align the mounting base d with the mounting base bottom hole on the housing c, and rotate the threaded pin 4 until its front external thread fully engages with the threaded hole of the mounting base d. Move the threaded pin 4 forward until its stepped end face is flush against the vertical positioning surface of the support 6. Check the mating clearance between the mounting base d and the bottom hole, ensuring that the clearance value is no greater than 0.18mm to guarantee welding quality. Then tighten the clamping screw 7 so that its lower end abuts against the upper surface of the threaded pin 4, locking the threaded pin 4 into the guide sleeve 5, thereby fixing the mounting base d in the predetermined position.

[0046] The mounting base d is positioned by TIG welding from the M-side (outer circumferential surface) of the housing c. During welding, avoid areas on the mounting base d that may interfere with the welding torch, and weld 6-8 positioning points evenly along the circumference. Welding parameters are: TA1 welding wire (diameter Φ1.6mm), welding current 30A-40A, argon gas flow rate on the front side 8L / min-15L / min, argon gas flow rate on the back side 5L / min-8L / min, tungsten electrode diameter Φ2mm. After welding, inspect the positioning welds to ensure there are no surface defects such as porosity, cracks, or lack of fusion.

[0047] Loosen the clamping screw 7 and rotate it in the opposite direction to remove the threaded pin 4; loosen the pressure plate 10 and remove the disc-shaped part that has been tack welded from the tack welding fixture a.

[0048] 3. Formal welding stage: Use a clean silk cloth soaked in acetone to repeatedly wipe the area to be welded and the surface of the welding wire until no visible oil residue is visible, ensuring the cleanliness of the welding area and preventing welding defects.

[0049] Place the top block 11 of the formal welding fixture b outside the mounting base d, so that the bottom surface of the top block 11 fits tightly with the outer shape of the housing c, and adjust the position so that the bushing 12 on the side wall of the top block 11 is aligned with the threaded hole of the mounting base d.

[0050] The pin 13 is passed through the bushing 12, and its front thread is screwed into the threaded hole of the mounting seat d. It is continued to be screwed in until the step on the pin 13 abuts against the positioning surface of the top block 11. At this time, the pin 13 applies an outward pulling force to the mounting seat d through the threaded connection. This pulling force is opposite to the inward deformation tendency of the mounting seat d during welding, thereby effectively suppressing welding deformation.

[0051] Place the assembled disc-shaped component of the formal welding fixture b and the TA1 welding wire into the vacuum argon-filled chamber, start the vacuum system to evacuate to an absolute pressure below 1.33 Pa, and then fill the chamber with high-purity argon gas to atmospheric pressure to provide an oxygen-free protective environment for titanium alloy welding.

[0052] Argon arc welding is performed on the mounting base d from the N-side (inner end face) of the housing c, with continuous welding along the joint between the mounting base d and the housing c. The welding parameters are: TA1 welding wire (diameter Φ1.6mm), welding current 70A~90A, tungsten electrode diameter Φ2mm. After welding, the weld surface is inspected to ensure there are no defects such as porosity, incomplete penetration, cracks, or slag inclusions.

[0053] The above method effectively controls welding deformation. Unlike traditional rigid support methods, this method uses a formal welding fixture b to apply an outward pulling force to the mounting base d during the formal welding stage, effectively suppressing the inward indentation tendency caused by welding stress. This successfully solves the technical problem of inward indentation of the mounting base when welding from the N-side. The dimensions of the welded parts meet the design requirements, ensuring the accuracy requirements of subsequent assembly.

[0054] The problem of avoiding welding interference was solved by adopting a step-by-step welding strategy using a tack welding fixture a and a formal welding fixture b. First, tack welding was performed on the M side to avoid the interference between the mounting base and the welding torch; then, the welding was transferred to the N side for formal welding. This ensured both welding accessibility and weld continuity.

[0055] The fixture of this invention has a simple structure, small size, and light weight, making it easy to operate and assemble in a vacuum argon-filled box with limited space. It solves the limitations of traditional rigid fixtures that are bulky and difficult to operate, and provides a reliable process guarantee for vacuum argon arc welding of TC4 titanium alloy.

[0056] The above provides a detailed description of the welding assembly fixture and welding method for a disc-shaped component mounting base provided by the present invention. Specific examples have been used to illustrate the structure and working principle of the invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A welding assembly fixture for a disc-shaped component mounting base, the disc-shaped component comprising a housing (c) having a mounting edge and a mounting base (d) disposed on the upper end of the housing (c), characterized in that: Includes a locating welding fixture (a) for tack welding of the mounting base (d) and a formal welding fixture (b) for the formal welding of the mounting base; The positioning welding fixture (a) includes: The base plate (1) is a disc-shaped stepped structure with an upper stepped end face and a lower stepped end face. The positioning ring (2) is set on the upper stepped end face of the base plate (1) and is used to position and support the disc-shaped component; The clamping mechanism is set on the lower stepped end face of the base plate (1), including a support (6) vertically set on the lower stepped end face, a guide sleeve (5) horizontally passing through the upper part of the support (6), and a threaded pin (4) movably passing through the guide sleeve (5). The front end of the threaded pin (4) is provided with an external thread for threaded connection with the mounting seat (d). A clamping screw (7) is also vertically set on the upper part of the support (6) for locking the threaded pin (4). The formal welding fixture (b) includes: The top block (11) has a bottom surface that is compatible with the outer dimensions and surface of the housing (c) and is used to cover the outside of the mounting base (d); Bushing (12) is provided on the side wall of top block (11); A pin (13) is movably inserted into a bushing (12) and has a thread at its front end for threaded connection with a mounting base (d).

2. The welding assembly fixture for the disc-shaped component mounting base according to claim 1, characterized in that: The positioning welding fixture (a) has multiple pressure plates (10) evenly arranged along the circumference for pressing the disc-shaped parts.

3. The welding assembly fixture for the disc-shaped component mounting base according to claim 1, characterized in that: The support (6) has a positioning hole at the bottom. A cylindrical pin (9) is inserted into the positioning hole to position the support (6). A screw (8) passes through the support (6) to lock it onto the base plate (1).

4. The welding assembly fixture for the disc-shaped component mounting base according to claim 1, characterized in that: The positioning ring (2) is provided with a positioning pin (3), which cooperates with the positioning hole on the mounting edge of the disc-shaped part to determine the angular position of the disc-shaped part.

5. A method for welding a disc-shaped part using the combined fixture according to any one of claims 1-4, characterized in that: The process includes the following steps: the housing (c) has an outer peripheral surface M and an inner end surface N. Step 1: Use a positioning welding fixture (a) to fix the position and angle of the disc-shaped part, connect it to the mounting base (d) by threaded pin (4) and lock it, and perform argon arc welding positioning from the M side of the housing (c) to the mounting base (d); Step 2: Transfer the tack welded disc to the formal welding fixture (b), cover the top block (11) outside the mounting base (d), and thread it through the bushing (12) on the top block (11) with the mounting base (d) via the pin (13), and place it in a vacuum argon-filled box. Perform argon arc welding on the mounting base (d) from the N side of the shell (c).

6. The method for welding disc-shaped parts using a combined fixture according to claim 5, characterized in that: Step 1 specifically involves: Step 11: Match the positioning hole on the mounting edge of the disc-shaped part with the positioning pin (3) on the positioning ring (2), and match the outer circle of the mounting edge of the disc-shaped part with the inner hole of the positioning ring (2) to press the pressure plate (10) to fix the position and angular orientation of the disc-shaped part; Step 12: Align the mounting base (d) with the mounting base bottom hole on the housing (c), rotate and move the threaded pin (4) so ​​that the external thread at the front end of the threaded pin (4) connects with the threaded hole of the mounting base (d); move the threaded pin (4) forward so that the step of the threaded pin (4) is close to the positioning surface of the support (6); tighten the clamping screw (7) to lock the threaded pin (4) to fix the mounting base (d); Step 13: Position the mounting base (d) by argon arc welding from the M-face of the housing (c), avoiding the interference parts of the mounting base (d) during welding, and then loosen the clamping screw (7) and the pressure plate (10) to remove the disc-shaped part from the positioning welding fixture (a).

7. The method for welding disc-shaped parts using a combined fixture according to claim 6, characterized in that: In step 12, the mating gap between the mounting base (d) and the mounting base bottom hole on the housing (c) is no greater than 0.18 mm.

8. The method for welding disc-shaped parts using a combined fixture according to claim 5, characterized in that: In step 1, before argon arc welding positioning, the bottom hole of the mounting base needs to be polished. The polishing area extends outward from the edge of the hole by no less than 25mm, and the polishing part includes the end face of the hole and both sides. In step 2, before argon arc welding, the area to be welded should be wiped with a clean silk cloth soaked in acetone to remove surface oil.

9. The method for welding disc-shaped parts using a combined fixture according to claim 5, characterized in that: The welding parameters for argon arc welding positioning in step 1 are as follows: 1.6mm TA1 welding wire, welding current 30A-40A, argon flow rate 8-15L / min on the front and 5-8L / min on the back, tungsten electrode diameter 2mm, and uniform positioning welding at 6-8 points.

10. The method for welding disc-shaped parts using a combined fixture according to claim 5, characterized in that: In step 2, the disc-shaped part, the fixture and the welding wire are placed in a vacuum argon-filled box, the vacuum is evacuated to below 1.33 Pa and then filled with argon gas. Then, argon arc welding is performed from the N side. The welding parameters are: TA1 welding wire Φ1.6mm, welding current 70A~90A, tungsten electrode diameter Φ2mm.

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