CN110883540A

CN110883540A - Welding assembly process for thin-wall spray pipe shell of engine

Info

Publication number: CN110883540A
Application number: CN201911180753.4A
Authority: CN
Inventors: 郑莉; 孟强; 张鹏博; 刘涛
Original assignee: Xi'an Changfeng Electromechanical Research Institute
Current assignee: Xi'an Changfeng Electromechanical Research Institute
Priority date: 2019-11-27
Filing date: 2019-11-27
Publication date: 2020-03-17

Abstract

The invention provides a welding assembly process for a thin-wall nozzle shell of an engine, which changes a butt joint interface of a workpiece to be welded from a flat port to a spigot port. The butt joint of the workpieces to be welded adopts a spigot butt joint structure tool, the spigot butt joint structure tool comprises a mandrel, a chassis, a blocking cover and a nut, the large end of the mandrel is downwards and vertically arranged on an assembly platform, a convergent section is sleeved on the mandrel and is tightly attached to the chassis, a tail pipe is sleeved on the mandrel, then a tail ring is installed, the blocking cover is sleeved, and the nut is screwed down, so that the assembly can be completed. The invention can simplify the welding assembly process, improve the production efficiency and improve the assembly precision before welding.

Description

Welding assembly process for thin-wall spray pipe shell of engine

Technical Field

The invention relates to an improved technology for welding and assembling a thin-wall spray pipe shell of an aerospace engine.

Background

The thin-wall nozzle shell of the engine is formed by assembling and welding a convergence section, a tail pipe and a tail ring by a vacuum electron beam welding method. The wall thickness of the shell is about 1.5mm, a crater adopts a flat butt joint mode, an internal support type tool must be used for guaranteeing the assembly precision of a welding line, and the structure of the existing tool is shown in figure 1. The tool is complex in structure and comprises a core shaft, a check ring, a front expansion sleeve, a middle sleeve, a taper sleeve, a rear expansion sleeve, a compression nut, a back cap and the like. The welding assembly process is tedious and time-consuming, and along with the increase of the use times, the front and rear expansion sleeves matched with the tool mandrel can deform, and the three parts are not concentric in the axis direction during internal bracing, so that the dislocation of the butt joint of the welding openings of the parts and the over-tolerance of the radial runout are caused. Products which are unqualified in welding can only be degraded for use or scrapped, so that the economic cost and the labor cost are greatly increased, and the production efficiency is severely restricted.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a welding assembly process of an engine thin-wall spray pipe shell, which improves the welding assembly mode by changing the butt joint mode of a welding opening and adjusting a tool structure, prevents assembly dislocation from being out of tolerance and improves the production efficiency.

The technical scheme adopted by the invention for solving the technical problems is as follows: the butt joint interface of the workpiece to be welded is changed from a flat port to a spigot port.

The workpiece to be welded sequentially comprises a tail ring, a tail pipe and a convergence section, wherein the tail ring and the convergence section are female spigot ends, and the tail pipe is a male spigot end.

And when the tail pipe is used for processing the spigot, a tail pipe end face turning tool is adopted to support the tail pipe.

And the tail ring, the tail pipe and the convergence section are assembled by using a pull rod type tool.

The butt joint of the workpieces to be welded adopts a spigot butt joint structure tool, the spigot butt joint structure tool comprises a mandrel, a chassis, a blocking cover and a nut, the large end of the mandrel is downwards and vertically arranged on an assembly platform, a convergent section is sleeved on the mandrel and is tightly attached to the chassis, a tail pipe is sleeved on the mandrel, then a tail ring is installed, the blocking cover is sleeved, and the nut is screwed down, so that the assembly can be completed.

The invention has the beneficial effects that:

1) simplify the welding assembly process, improve production efficiency: when the original tool is adopted for assembly, the working hours required by the assembly of a single workpiece are 0.4h under the condition of qualified assembly dislocation before welding, if the assembly is not qualified, the assembly and the adjustment must be carried out again, the working hours are consumed for a long time, the maximum time reaches 6h, and the production efficiency is extremely low; the assembly is carried out by adopting a pull rod type tool in a mode of changing a spigot butt joint into a mode of only needing less than 0.15h, so that the production efficiency is improved by 1.7 times;

2) the assembly precision before welding is improved, the radial and port runout of the welded part is improved, the welding seam quality and the mechanical performance of the joint can meet the design index requirements, and the capacity of producing qualified products is realized.

Drawings

FIG. 1 is a schematic structural view of a nozzle shell plain end butt welding tool;

FIG. 2 is a schematic view of a male (tail pipe) and female (tail ring, convergent section) butt joint;

FIG. 3 is a schematic view of a tail pipe end turning tool;

FIG. 4 is a schematic view of a modified spigot-butt assembly;

in the figure, 1-internal bracing tooling mandrel, 2-check ring, 3-front expansion sleeve, 4-middle sleeve, 5-taper sleeve, 6-rear expansion sleeve, 7-compression nut, 8-nut, 9-tail ring, 10-tail pipe, 11-convergence section, 12-tail pipe end face mandrel, 13-locking cap, 14-compression cap, 15-small taper sleeve, 16-clamp spring, 17-pressing ring, 18-gasket, 19-back cap, 20-flat key, 21-spring, 22-pull rod tooling mandrel, 23-chassis, 24-blocking cover and 25-nut.

Detailed Description

The present invention will be further described with reference to the following drawings and examples, which include, but are not limited to, the following examples.

The invention changes the butt joint interface of the workpiece to be welded from a flat port to a spigot port. The tail ring and the convergent section are concave spigot, and the tail pipe is convex spigot. The spigot is difficult to process due to the thin wall and the long size of the tail pipe, and the spigot of the tail pipe can be processed by supporting the tail pipe by adopting a tail pipe end turning tool. After the butt joint interface is changed, the assembly among the convergence section, the tail pipe and the tail ring can be completed by using the pull rod type tool, and the problem of assembly dislocation and over-tolerance caused by the expansion valve of the tool and the non-concentricity of the shaft is avoided. The spigot butt joint structure tool mainly comprises a mandrel, a chassis, a blocking cover and a nut. And vertically standing the large end of the mandrel on an assembly platform downwards, sleeving the convergent section on the mandrel to be tightly attached to the chassis, sleeving the tail pipe on the mandrel, then installing the tail ring, finally sleeving the plug cover, and screwing the nut to finish assembly.

The welding process parameters of the improved method are confirmed by using the butt-joint test piece, and a multi-nozzle shell simulation piece (full-size product) is welded, wherein the welding parameters conform to the parameter range specified by a process file. The shrinkage of the nozzle shell simulation piece after welding is basically consistent with the shrinkage before optimization, which shows that the improved assembly method has no obvious influence on the shrinkage of welding.

After welding, the appearance quality inspection and X-ray photographic inspection of the welding seam of the spray pipe shell test piece are carried out according to the I-grade welding seam requirement of QJ972-86 electron beam welding technical condition, the tensile test is carried out on the test piece welded along with the furnace, the welding seam quality and the mechanical property both meet the design requirement, and the improved assembly method can ensure the welding seam quality and the mechanical property.

The invention changes the butt joint interface of the workpiece to be welded from a flat port to a spigot port, as shown in figure 2. The tail ring and the convergent section are concave spigot, and the tail pipe is convex spigot. The tail pipe has thin wall and long size, so the tail pipe has low rigidity and is easy to deform, the tail pipe is not easy to clamp and align on a lathe, and the form and position tolerance (namely the perpendicularity of the end surface) cannot be ensured when the end surface spigot is turned, so the tail pipe end surface turning tool is used, as shown in figure 3. The specific operation method comprises the following steps: sequentially sleeving four pressing rings, three gaskets and a back cap into a mandrel, sleeving a tail pipe into the mandrel, and fastening the back cap by using a chisel; the small taper sleeves, the clamping springs and the springs at the two ends are respectively arranged, the pressing cap is screwed down, and the locking cap is screwed down finally.

After the butt joint interface is changed, the assembly among the convergence section, the tail pipe and the tail ring can be completed by using the pull rod type tool, and the problem of assembly dislocation and over-tolerance caused by the expansion valve of the tool and the non-concentricity of the shaft is avoided. The seam allowance abutting structure tool is shown in fig. 4 and mainly comprises a pull rod tool mandrel 22, a chassis 23, a blanking cover 24 and a nut 25. And vertically standing the large end of the mandrel on an assembly platform downwards, sleeving the convergent section on the mandrel to be tightly attached to the chassis, sleeving the tail pipe on the mandrel, then installing the tail ring, finally sleeving the plug cover, and screwing the nut to finish assembly.

The optimized butt test piece is used for confirming welding process parameters, a four-nozzle shell simulation piece (full-size product) is welded, the number of the four-nozzle shell simulation piece is PSY 01-PSY 04, the assembly dislocation amount before welding is shown in the table 1, and the assembly quality completely meets the process requirements.

TABLE 1 nozzle Shell simulation Pre-weld Assembly misplacement

And (3) after welding, performing weld appearance quality inspection on the simulation piece according to the I-grade weld joint requirement of QJ972-86 Electron Beam welding technical Condition, wherein the front and back quality of the weld joint is shown in Table 2. The quality of the welding seam meets the design requirement and the standard requirement.

Table 2 nozzle shell simulant weld front and back quality

Claims

1. The welding assembly process of the thin-wall spray pipe shell of the engine is characterized in that: the butt joint interface of the workpiece to be welded is changed from a flat port to a spigot port.

2. The welding assembly process of the thin-wall nozzle shell of the engine according to claim 1, characterized in that: the workpiece to be welded sequentially comprises a tail ring, a tail pipe and a convergence section, wherein the tail ring and the convergence section are female spigot ends, and the tail pipe is a male spigot end.

3. The welding assembly process of the thin-wall nozzle shell of the engine according to claim 2, characterized in that: and when the tail pipe is used for processing the spigot, a tail pipe end face turning tool is adopted to support the tail pipe.

4. The welding assembly process of the thin-wall nozzle shell of the engine according to claim 2, characterized in that: and the tail ring, the tail pipe and the convergence section are assembled by using a pull rod type tool.

5. The welding assembly process of the thin-wall nozzle shell of the engine according to claim 2, characterized in that: the butt joint of the workpieces to be welded adopts a spigot butt joint structure tool, the spigot butt joint structure tool comprises a mandrel, a chassis, a blocking cover and a nut, the large end of the mandrel is downwards and vertically arranged on an assembly platform, a convergent section is sleeved on the mandrel and is tightly attached to the chassis, a tail pipe is sleeved on the mandrel, then a tail ring is installed, the blocking cover is sleeved, and the nut is screwed down, so that the assembly can be completed.