Method and device for welding double bevel of curved head to nozzle

Abstract

The application discloses a welding method and device for a double-bevel of a curved head and a nozzle, and the welding method comprises the following steps: optimizing a welding opening structure of the nozzle, and setting an assembling device and a welding device which are specially used for welding the nozzle and the head, so that the tightness of the nozzle and the head and the stability of a welding process are effectively ensured; and the head is welded through the assembling device and the welding device, so that manual clamping of the head and the nozzle through experience is avoided, standardization production is promoted, and the welding seam quality is further improved.

Description

Technical Field

[0001] This invention belongs to the field of end cap welding technology, specifically a welding method and apparatus for a curved end cap with double bevels and a connector. Background Technology

[0002] In satellite systems, titanium alloy tanks play a crucial role in storing propellant or other critical liquids. Satellite systems have stringent requirements for the welds of these tanks, demanding zero defects, high strength, high reliability, low deformation, and resistance to extreme environments, and implementing the most stringent standards according to their criticality level.

[0003] When the tank head is designed as a curved elliptical arc, the opening position for assembly with the nozzle is often irregular, posing a significant challenge to the assembly and welding process between the head and the nozzle. Furthermore, improper design or fabrication of the nozzle weld joint will directly lead to substandard weld quality between the head and the nozzle, potentially even causing cracks and ultimately rendering the tank unusable. Current technology is prone to weld surface defects such as welding cracks and surface collapse. These problems mainly stem from unreasonable nozzle weld joint structures and imperfections in the assembly and welding methods between the nozzle and the head. Summary of the Invention

[0004] The purpose of this invention is to provide a welding method and apparatus for a curved end cap with double bevels and a spout, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a welding fixture for a curved end cap with double bevels and a spigot, comprising an assembly device and a welding device: The assembly device includes: a positioning flange, a pull ring, a first tensioning element, an inspection block, and a set screw; the pull ring is provided above the positioning flange, and a space for placing the end cap is formed between the positioning flange and the pull ring; a columnar protrusion is provided at the center of the positioning flange, and the protrusion is used to support the top surface of the end cap; the positioning flange and the pull ring are tightened and fixed by the first tensioning element; multiple third screw holes for passing the set screw are symmetrically provided on the inner ring of the positioning flange; an inspection block is placed at the third screw hole of the positioning flange, and the inspection block is provided with a through hole corresponding to the third screw hole; the inspection block is used to support the nozzle; the inspection block is a right-angled trapezoidal block, and the angle between the inclined surface and the right-angled surface of the inspection block is equal to the angle between the axis of the nozzle hole on the curved end cap and the central axis of the curved end cap; The welding device includes: a flange clamp, a second tensioning member, a set of pressure plates, and a welding flange; the welding flange is fixed on the flange clamp, and the upper part of the welding flange is provided with a head slot for tilting the head. After the head is tilted, both ends of the head opening are fixed by pressure plates. The pressure plates and the flange clamp are tightened and fixed by the second tensioning member. After the head is tilted, the hole axis of one of the nozzles is vertical. Below the nozzle with the vertical hole axis, there is a support threaded hole that penetrates the welding flange and the flange clamp. A support bolt is threaded into the support threaded hole, and the top surface of the support bolt is parallel to the top surface of the head nozzle. The inner side wall of the head slot is provided with a curved surface that matches the outer surface of the head. The side wall of the head slot is provided with a penetrating argon gas inlet and argon gas outlet.

[0006] Preferably, the upper surface of the protrusion is a curved surface that matches the top surface of the end cap, thereby improving the stability of the end cap fixation by adapting and fitting the curved surface to the top surface of the end cap.

[0007] Preferably, the first tensioning member includes a set of first tensioning bolts and nuts, the outer ring of the positioning flange is symmetrically provided with a set of first through holes, the pull ring is provided with a second through hole corresponding vertically to the first through hole, and the first tensioning bolts are vertically inserted into the first through hole and the second through hole and locked by the nut.

[0008] Preferably, the bottom of the welding flange is provided with a positioning groove and a positioning screw hole, the top surface of the flange clamp is provided with a positioning strip that matches the positioning groove, and the flange clamp is provided with a sixth through hole corresponding to the positioning screw hole. A positioning screw is passed through the sixth through hole and the positioning screw is threadedly connected to the positioning screw hole.

[0009] Preferably, the second tensioning member includes a set of second tensioning bolts and nuts, a set of fourth through holes are symmetrically arranged on the outer ring of the flange clamp, a fifth through hole is arranged on the pressure plate corresponding vertically to the fourth through hole, and the second tensioning bolts are vertically inserted into the fourth through hole and the fifth through hole and locked by the nut.

[0010] A welding method for welding a curved end cap with double bevels to a nozzle using a welding fixture, characterized by the following steps: S1: Optimize the nozzle weld; process the nozzle hole on the end cap into an inverted conical shape; process the nozzle weld, and by controlling the taper of the nozzle weld, when the nozzle weld is inserted into the nozzle hole, with the inner arc surface of the end cap as the reference, the inner arc surface of the nozzle is 0.2 to 0.3 mm higher than the inner arc surface of the end cap, the contact straight edge length between the nozzle weld and the nozzle hole is 0.9 to 1 mm, and process a V-shaped bevel on the nozzle weld, with a bevel angle of 30° to 42.5°; S2: Assembly of end cap and nozzle: Place the outer surface of the end cap on the top of the protruding block of the positioning flange, place the pull ring on the large end of the end cap and pre-tighten it through the first tensioner; Assemble the nozzle into the nozzle hole of the end cap, aligning the nozzle with the weld joint of the end cap, and tighten the nozzle with the set screw; place the inspection block, ensuring it fits tightly against the nozzle and the surface of the positioning flange; after fitting, perform manual argon arc welding to fix the joints. S3: Welding of end cap and nozzle: Assemble the welding device onto the welding machine, fix the end cap onto the welding flange, align the nozzle to be welded with the support bolts, tighten the pressure plate with the second tensioner to fix the end cap, and tighten the nozzle with the support bolts; start the argon arc welding machine, rotate the electrode along the perimeter of the weld, the weld runout should not exceed 0.2mm; introduce argon gas for protection; perform X-ray flaw detection after welding.

[0011] Preferably, in step S2, when determining the fit between the inspection block and the nozzle and positioning flange surface, a feeler gauge is used to visually check that the bottom edge of the nozzle weld is 0.2 to 0.3 mm lower than the bottom edge of the head weld.

[0012] Preferably, in step S2, when performing manual argon arc welding, the weld points are evenly distributed at 4 to 8 points. Compared with the prior art, the beneficial effects of the present invention are:

[0013] This invention optimizes the weld joint structure of the nozzle and, by setting up a dedicated assembly and welding device for welding the nozzle and end cap, effectively ensures the tightness of the assembly between the nozzle and the end cap and the stability of the welding process. Furthermore, by using the assembly and welding devices for welding the end cap, the manual clamping of the end cap and nozzle based on experience is avoided, which is conducive to promoting standardized production and further improving the quality of the weld. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the connection structure between the end cap and the assembly device provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the connection structure between the end cap and the welding device provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the end cap structure provided in an embodiment of the present invention; Figure 4 yes Figure 3 Enlarged view of point A in the middle; In the diagram, 1-positioning flange, 2-pull ring, 3-first tension bolt, 4-inspection block, 5-set screw, 6-end, 7-connector, 8-flange clamp, 9-second tension bolt, 10-pressure plate, 11-welding flange, 12-positioning screw, 13-support bolt, 14-electrode, 101-first through hole, 102-third screw hole, 103-protrusion block, 201-second through hole, 601-inner arc surface of end cap, 701-inner arc surface of connector, 801-fourth through hole, 802-positioning strip, 803-sixth through hole, 1001-fifth through hole, 1101-positioning groove, 1102-positioning screw hole, 1103-end slot, 1104-argon inlet, 1105-argon outlet, 1106-support threaded hole. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] Please see Figure 1 and Figure 2 This invention provides a technical solution: a welding fixture for welding a curved end cap with a double bevel and a spigot, comprising an assembly device and a welding device. The assembly device includes: a positioning flange 1, a pull ring 2, a set of first tensioning bolts 3, an inspection block 4, and a set screw 5; the outer ring of the positioning flange 1 is symmetrically provided with first through holes 101 for the first tensioning bolts 3 to pass through; the pull ring 2 is located directly above the positioning flange 1 and has a second through hole 201 vertically corresponding to the first through hole 101; the first tensioning bolts 3 are vertically passed through the first through hole 101 and the second through hole 201 and locked with nuts; the inner ring of the positioning flange 1 is symmetrically provided with multiple third screw holes 102 for the set screws to pass through; the inspection block 4 is a right-angled trapezoidal block, and the angle between the inclined surface and the right-angled surface of the inspection block 4 is equal to the angle between the axis of the nozzle hole on the end cap 6 and the central axis of the end cap 6; a columnar protrusion 103 is provided at the center of the positioning flange 1, and the upper surface of the protrusion 103 matches the top surface of the end cap 6; The welding device includes: a flange clamp 8, a set of second tension bolts 9, a set of pressure plates 10, and a welding flange 11; the outer ring of the flange clamp 8 is symmetrically provided with a set of fourth through holes 801, and the pressure plate 10 is provided with a fifth through hole 1001. The second tension bolts 9 are vertically inserted into the fourth through hole 801 and the fifth through hole 1001 and locked with nuts; the bottom of the welding flange 11 is provided with a positioning groove 1101 and a positioning screw hole 1102, the top surface of the flange clamp 8 is provided with a positioning strip 802 that matches the positioning groove 1101, and the flange clamp 8 is provided with a sixth through hole 803 that corresponds to the positioning screw hole 1102. A positioning screw 12 is inserted through the sixth through hole 803 and is threadedly connected to the positioning screw hole 1102; the upper part of the welding flange 11 is provided with a head slot 1103 for placing the head 6, and the inner side of the side wall of the head slot 1103 is provided with a curved surface that matches the outer surface of the head 6. The side wall of the head slot 1103 is provided with a through argon gas inlet 1104 and an argon gas outlet 1105; a support threaded hole 1106 is provided below the upper connector 7 of the welding flange 11, and a support bolt 13 is threadedly connected to the support threaded hole 1106, and the top surface of the support bolt 13 is parallel to the top surface of the connector 7.

[0017] Based on the above welding fixture, this embodiment provides a method for welding a curved end cap with a double bevel to a nozzle, including the following steps: S1: Optimize the nozzle weld joint, refer to... Figure 3 and Figure 4 The nozzle hole on the end cap 6 is machined into an inverted conical shape. When machining the weld joint of the nozzle 7, the taper of the conical surface of the weld joint of the nozzle 7 is controlled so that when the weld joint of the nozzle 7 is inserted into the nozzle hole, the inner arc surface 601 of the end cap is used as a reference, and the inner arc surface 701 of the nozzle is 0.2 to 0.3 mm higher than the inner arc surface 601 of the end cap. In order to ensure that the argon arc welding can penetrate, the contact straight edge length between the weld joint of the nozzle 7 and the nozzle hole is 0.9 to 1 mm, and a V-shaped bevel is machined on the weld joint of the nozzle 7, with a bevel angle β of 30° to 42.5°. S2: Assembly of end cap and nozzle: Place the outer surface of end cap 6 on the top curved surface of the protruding block 103 of positioning flange 1, place pull ring 2 on the large end of end cap 6 and pre-tighten it with the first tensioning bolt 3; assemble nozzle 7 into nozzle hole of end cap 6, align nozzle 7 with the weld joint of nozzle hole of end cap 6, and tighten nozzle with set screw 5; place inspection block 4 to ensure tight fit between inspection block 4 and nozzle 7 and positioning flange 1 surface. When checking the fit between inspection block 4 and nozzle 7 and positioning flange 1 surface, visually check with feeler gauge that the bottom edge of nozzle 7 weld is 0.2-0.3mm lower than the bottom edge of end cap 6 weld; after fitting, perform manual argon arc welding for spot fixation, with 4-8 weld points evenly distributed.

[0018] S3: Welding of end cap and nozzle: Assemble the welding device onto the welding machine, fix the end cap 6 onto the welding flange 11, align the nozzle 7 to be welded with the support bolt 13, tighten the pressure plate 10 with the second tension bolt 9 to fix the end cap 6, and tighten the nozzle 7 with the support bolt 13; start the argon arc welding machine, rotate the electrode 14 along the periphery of the weld, the weld runout should not exceed 0.2mm; introduce argon gas for protection; perform X-ray flaw detection after welding.

[0019] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A welding fixture for a curved end cap with double bevels and a spout, characterized in that: Includes assembly equipment and welding equipment: The assembly device includes: a positioning flange, a pull ring, a first tensioning element, an inspection block, and a set screw; the pull ring is provided above the positioning flange, and a space for placing the end cap is formed between the positioning flange and the pull ring; a columnar protrusion is provided at the center of the positioning flange, and the protrusion is used to support the top surface of the end cap; the positioning flange and the pull ring are tightened and fixed by the first tensioning element; multiple third screw holes for passing through the set screw are symmetrically provided on the inner ring of the positioning flange; an inspection block is placed at the third screw hole of the positioning flange, and the inspection block is provided with a through hole corresponding to the third screw hole; the inspection block is used to support the nozzle; the inspection block is a right-angled trapezoidal block, and the angle between the inclined surface and the right-angled surface of the inspection block is equal to the angle between the axis of the nozzle hole on the curved end cap and the central axis of the curved end cap; The welding device includes: a flange clamp, a second tensioning member, a set of pressure plates, and a welding flange; the welding flange is fixed on the flange clamp, and the upper part of the welding flange is provided with a head slot for tilting the head. After the head is tilted, both ends of the head opening are fixed by pressure plates. The pressure plates and the flange clamp are tightened and fixed by the second tensioning member. After the head is tilted, the hole axis of one of the nozzles is vertical. Below the nozzle with the vertical hole axis, there is a support threaded hole that penetrates the welding flange and the flange clamp. A support bolt is threaded into the support threaded hole, and the top surface of the support bolt is parallel to the top surface of the head nozzle. The inner side wall of the head slot is provided with a curved surface that matches the outer surface of the head. The side wall of the head slot is provided with a penetrating argon gas inlet and argon gas outlet.

2. The welding fixture as described in claim 1, characterized in that, The upper surface of the protrusion is a curved surface that matches the top surface of the end cap.

3. The welding fixture as described in claim 1 or 2, characterized in that, The first tensioning member includes a set of first tensioning bolts and nuts. The outer ring of the positioning flange is symmetrically provided with a set of first through holes. The pull ring is provided with a second through hole at a position vertically corresponding to the first through hole. The first tensioning bolts are vertically inserted into the first through hole and the second through hole and locked by the nuts.

4. The welding fixture as described in claim 1, characterized in that, The bottom of the welding flange is provided with a positioning groove and a positioning screw hole. The top surface of the flange clamp is provided with a positioning strip that matches the positioning groove. The flange clamp is provided with a sixth through hole corresponding to the positioning screw hole. A positioning screw passes through the sixth through hole and is threadedly connected to the positioning screw hole.

5. The welding fixture as described in claim 1 or 4, characterized in that, The second tensioning member includes a set of second tensioning bolts and nuts. A set of fourth through holes are symmetrically arranged on the outer ring of the flange clamp. A fifth through hole is arranged on the pressure plate at a position vertically corresponding to the fourth through hole. The second tensioning bolts are vertically inserted into the fourth and fifth through holes and locked by the nuts.

6. A method for welding a curved end cap with a double bevel and a nozzle based on the welding fixture described in any one of claims 1-5, characterized in that, Includes the following steps: S1: Optimize the nozzle weld; process the nozzle hole on the end cap into an inverted conical shape; process the nozzle weld, and by controlling the taper of the nozzle weld, when the nozzle weld is inserted into the nozzle hole, with the inner arc surface of the end cap as the reference, the inner arc surface of the nozzle is 0.2 to 0.3 mm higher than the inner arc surface of the end cap, the contact straight edge length between the nozzle weld and the nozzle hole is 0.9 to 1 mm, and process a V-shaped bevel on the nozzle weld, with a bevel angle of 30° to 42.5°; S2: Assembly of end cap and nozzle: Place the outer surface of the end cap on the top of the protruding block of the positioning flange, place the pull ring on the large end of the end cap and pre-tighten it through the first tensioner; Assemble the nozzle into the nozzle hole of the end cap, aligning the nozzle with the weld joint of the end cap, and tighten the nozzle with the set screw; place the inspection block, ensuring it fits tightly against the nozzle and the surface of the positioning flange; after fitting, perform manual argon arc welding to fix the joints. S3: Welding of end cap and nozzle: Assemble the welding device onto the welding machine, fix the end cap onto the welding flange and align the nozzle to be welded with the support bolts. Tighten the pressure plate with the second tensioner to fix the end cap and tighten the nozzle with the support bolts. Start the argon arc welding machine and rotate the electrode around the weld. The weld runout should not exceed 0.2mm. Argon gas was introduced for protection; After welding is completed, X-ray flaw detection is performed.

7. The method for welding the curved end cap with double bevels and the nozzle according to claim 6, characterized in that, In step S2, when determining the fit between the inspection block and the nozzle and positioning flange surfaces, visually check with a feeler gauge that the bottom edge of the nozzle weld is 0.2 to 0.3 mm lower than the bottom edge of the head weld.

8. The welding method for the curved end cap with double bevels and the nozzle according to claim 6, characterized in that, In step S2, when performing manual argon arc welding, the weld points are evenly distributed in 4 to 8 points.

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