CN114603297A

CN114603297A - Assembly welding fixture for upper pipe seat of fuel assembly structure without positioning table

Info

Publication number: CN114603297A
Application number: CN202011451703.8A
Authority: CN
Inventors: 李莎; 李先平; 袁野; 王保军; 张海发
Original assignee: China Jianzhong Nuclear Fuel Co Ltd
Current assignee: China Jianzhong Nuclear Fuel Co Ltd
Priority date: 2020-12-09
Filing date: 2020-12-09
Publication date: 2022-06-10

Abstract

The invention belongs to a clamp, and particularly relates to a welding clamp for assembling a pipe seat on a fuel assembly structure without a positioning table. A fuel assembly welding fixture for assembly of a structural pipe seat without a positioning table comprises a positioning bottom plate and a fixture pressing plate (10) which are arranged in parallel, and a positioning connecting rod is arranged between the positioning bottom plate and the fixture pressing plate (10). The invention has the following remarkable effects: 1) the newly designed pipe seat assembling spot welding clamp does not need to independently assemble and spot weld the coaming, and only needs to be assembled with other parts in one clamp at one time, so that twice repeated positioning errors are reduced, and the assembling efficiency and the assembling precision are improved. After assembly, the deviation of the gaps of all welding seams of the lower pipe seat is less than 0.10 mm. 2) By adopting the welding fixture, a positioning-free table on a tube seat structure is cancelled, the problems that the gap of an inner cavity seam is out of tolerance after the tube seat is welded and the groove section of a plate spring is wrinkled after the tube seat is machined are solved, the subsequent welding quality is ensured, and the production efficiency and the yield are improved.

Description

Assembly welding fixture for upper pipe seat of fuel assembly structure without positioning table

Technical Field

The invention belongs to a clamp, and particularly relates to a welding clamp for assembling a pipe seat on a fuel assembly structure without a positioning table.

Background

The special fuel assembly upper pipe seat is formed by assembling and welding 1

upper frame plate

1, 4

coamings

2 and 1 upper connecting plate 3 (as shown in figure 1), and has the following problems.

1) At present, an assembly and welding clamp of a pipe seat needs to assemble and spot-weld a surrounding plate and then other parts, and the assembly and spot welding of the pipe seat needs to be completed by two steps and two clamps (the surrounding plate assembly clamp and the pipe seat assembly clamp). Not only the assembly steps are tedious, and repeated clamping many times, assembly error accumulation easily appears, leads to final assembly precision low.

2) The welding joint form (as shown in figure 3) with a 1.3 +/-0.1 mm positioning table is adopted among all parts, the gap of an inner cavity seam is formed after the pipe seat is welded, and the wrinkle of the groove section of the plate spring of the inner cavity is easy to appear after machining, so that the product is scrapped, the yield is low, the coaming is thermally expanded at the position close to the welding seam when the gap at the inner side of the welding seam is welded, the lap joint of the upper connecting plate is extruded towards the direction of the inner cavity, and after the welding is finished, the coaming close to the welding seam is cooled and shrunk, so that the lap joints of the coaming, the upper connecting plate and the coaming and the upper frame plate are positioned at the inner side of the welding seam close to the inner cavity to form gaps.

3) The groove width of the special spring groove section on the front surface and the back surface is different, and the front surface and the back surface are required to be processed twice. The welded joint form is a form with a positioning table, so that the upper frame plate spring groove position section has a base material with the thickness of 0.4 +/-0.1 (shown in figure 2). The accumulated machining tolerance and the welding deformation cause the thickness change of the base material at the spring groove positioning table to fluctuate within the range of 0-0.5 mm, and when a back spring groove is machined, the milling cutter rotates at high speed to possibly cause the following conditions:

a) the parent metal is machined off and smoothly transited;

b) when the parent metal is thin, an extremely thin wrinkle is formed and can be removed by a small tool;

c) when the base material is thick (less than 0.5mm), it is difficult to remove the base material with a tool. Because the wrinkle formation position is special, only manual removal can be adopted, and in the removal process, the removal amount is large, and the risk that peripheral base materials (such as a coaming, an upper frame plate and an upper connecting plate) are possibly damaged exists, so that the appearance quality of the tube seat is poor.

Disclosure of Invention

The invention aims at the defects of the prior art and provides a welding fixture for assembling a pipe seat on a fuel assembly positioning-table-free structure.

The invention is realized by the following steps: a welding fixture for assembling a structural pipe seat on a fuel assembly without a positioning table comprises a positioning bottom plate and a fixture pressing plate which are arranged in parallel, and a positioning connecting rod is arranged between the positioning bottom plate and the fixture pressing plate.

The welding fixture for assembling the pipe seat on the fuel assembly positioning-table-free structure is characterized in that a jacking connecting rod is further arranged between the positioning bottom plate and the fixture pressing plate.

According to the welding fixture for assembling the pipe seat on the fuel assembly positioning-table-free structure, the jacking connecting rod is arranged on the positioning bottom plate through the eccentric wheel.

The welding fixture for assembling the pipe seat on the fuel assembly positioning-table-free structure is characterized in that a coaming jacking block is further arranged between the positioning bottom plate and the fixture pressing plate.

The pipe seat assembling and welding fixture for the fuel assembly structure without the positioning table is characterized in that the positioning bottom plate is provided with a positioning pin.

The welding fixture for assembling the pipe seat on the fuel assembly positioning-table-free structure is characterized in that a tightening nut is arranged on the top surface of the fixture pressing plate.

As above a structural pipe seat equipment welding jig of fuel assembly no location platform, wherein, bounding wall top tight piece total two, every all roughly is right angled triangle, two triangle-shaped's bounding wall top tight piece hypotenuses set up relatively, set up the location connecting rod between two triangle-shaped's bounding wall top tight piece, on the right angle of two triangle-shaped's bounding wall top tight piece, set up 1 on every right angle and push up tight connecting rod.

The invention has the following remarkable effects: 1) the newly designed pipe seat assembling spot welding clamp does not need to independently assemble and spot weld the coaming, and only needs to be assembled with other parts in one clamp at one time, so that twice repeated positioning errors are reduced, and the assembling efficiency and the assembling precision are improved. After assembly, the deviation of the gaps of all welding seams of the lower pipe seat is less than 0.10 mm. 2) By adopting the welding fixture, a positioning-free table on a tube seat structure is cancelled, the problems that the gap of an inner cavity seam is out of tolerance after the tube seat is welded and the groove section of a plate spring is wrinkled after the tube seat is machined are solved, the subsequent welding quality is ensured, and the production efficiency and the yield are improved.

Drawings

FIG. 1 is a schematic view of the assembly of the header

FIG. 2 is a schematic view of a tape positioning table

FIG. 3 is a schematic view of a structure without a positioning table

FIG. 4 upper pipe seat assembling and welding fixture

FIG. 5 is a schematic view of a panel tightening block

Detailed Description

The utility model provides a structural nozzle assembly welding jig of fuel assembly does not have location platform, utilize the locating pin hole of two diagonal positions on the upper ledge board 1, anchor clamps design positioning bottom plate 4, locating pin 5 is fixed with upper ledge board 1, the displacement of two directions of restriction horizontal plane, 2 bounding

wall puller block

6, 4

puller connecting rods

8, 4 eccentric wheel 9 can be convenient to the 2 horizontal direction puller spacing of 4 bounding walls, reuse the guide tube hole on the upper ledge board 3 that has processed, design 4 positioning connecting rods 7 and to connecting plate 3 horizontal and axial direction spacing, finally screw up the nut 11 with anchor

clamps pressure strip

10 and 4 and screw up to vertical Z direction, simple operation can be with nozzle one-step assembly shaping, keep higher assembly accuracy simultaneously.

Because the upper frame plate 1 has a special structure and the inner cavity is provided with the lug boss, the enclosing plate jacking blocks 6 are designed into 2 independent L-shaped jacking blocks for facilitating assembly and disassembly, enough clearance is reserved between the two jacking blocks after assembly, and the two jacking blocks can be obliquely pushed out after the pipe seat is assembled and welded. The coaming puller block utilizes the size of the inner cavity of the assembled tube seat to design the puller block so as to limit the size and the position of the inner cavity of the tube seat.

The innovation points or technical points to be protected of the application are as follows

1) A1.3 +/-0.1 mm positioning table is cancelled, and under the condition of no positioning reference limit, a plurality of parts are assembled at one time.

2) In order to avoid the situation that the upper boss of the part is shielded and the upper tube seat cannot be taken down after the assembly is finished, 2 independent L-shaped jacking blocks are adopted, enough clearance is reserved between the two jacking blocks after the assembly, and the two jacking blocks can be obliquely pushed out after the tube seat is assembled and welded.

3) The design is applied to the assembly welding of the pipe seat on the structure without the positioning table for the first time, and a plurality of parts of the same pipe seat are assembled and welded at one time, so that the error accumulation of repeated assembly in the assembly process is solved, and the assembly precision is improved.

4) A positioning table-free structure on the tube seat is omitted, the problem that the gap of an inner cavity seam is out of tolerance after the tube seat is welded is solved, the groove section of the plate spring is wrinkled after the plate spring is machined, the subsequent welding quality is guaranteed, and the production efficiency and the yield are improved.

Claims

1. The utility model provides a structural upper pipe base assembly welding jig of fuel assembly does not have locating station which characterized in that: the clamp comprises a positioning bottom plate (4) and a clamp pressing plate (10) which are arranged in parallel, and a positioning connecting rod (7) is arranged between the positioning bottom plate (4) and the clamp pressing plate (10).

2. The structural nozzle mount assembly welding fixture of a fuel assembly no-locating table of claim 1, characterized in that: a jacking connecting rod (8) is also arranged between the positioning bottom plate (4) and the clamp pressing plate (10).

3. The structural nozzle assembly welding fixture of a fuel assembly no-positioning-table as set forth in claim 2, wherein: the jacking connecting rod (8) is arranged on the positioning bottom plate (4) through an eccentric wheel (9).

4. The structural nozzle assembly welding fixture of a fuel assembly no-positioning-table as in claim 3, wherein: and a coaming jacking block (6) is also arranged between the positioning bottom plate (4) and the clamp pressing plate (10).

5. The structural nozzle mount assembly welding fixture of a fuel assembly no location table of claim 4, wherein: the positioning bottom plate (4) is provided with a positioning pin (5).

6. The structural nozzle mount assembly welding fixture of a fuel assembly no location table of claim 5, characterized in that: the top surface of the clamp pressing plate (10) is provided with a tightening nut (11).

7. The structural nozzle mount assembly welding fixture of a fuel assembly no-locating table of claim 6, wherein: the coaming compact heap (6) total two, every approximately is right triangle, two triangle's coaming compact heap (6) hypotenuse sets up relatively, sets up location connecting rod (7) between two triangle's coaming compact heap (6), sets up 1 on every right angle and pushes up compact heap (6) right angle edge, every right angle.