RU2803617C1 - Method for manufacturing welded butt joints of multilayer thin-walled structures of sound-absorbing panels - Google Patents

Abstract

FIELD: welding.

SUBSTANCE: invention relates to a method for manufacturing welded butt joints of multilayer thin-walled structures of sound-absorbing panels made of steels and titanium alloys. The lining is made in one piece with the filler protrusion. The lining is made in the form of stiffener shelves in the form of an I-beam. Cutting edges are made on welding parts. The assembly is carried out by installing a stiffener between the panels to be joined, ensuring that the welded edges rest against the filler protrusion, which is rectangular in shape in the centre on its shelves. Welding is performed in the centre of the filler protrusion with its complete melting and fusion of the edges to be welded over the entire thickness. The distance between the outer surfaces of the shelves is equal to the distance between the inner surfaces of the welded sheets of sound-absorbing panels. The filler protrusion is made with a width determined from the condition of ensuring its complete melting and fusion of the edges to be welded over the entire thickness, and a height exceeding the thickness of the edges to be welded by the value A, determined by the formula: A=b+g⋅1.5 + 0.3, where b is the flatness of the edges to be welded, mm, g is the minimum value of the required reinforcement of the weld, mm.

EFFECT: improving the manufacturability of the welding method, increasing the accuracy of assembling the structure for welding, the quality of welding and the strength of the welded joint.

1 cl, 2 dwg, 2 tbl

Description

The invention relates to welding of butt joints of multilayer thin-walled structures made of steels and titanium alloys.

Known OST 92-1021-81. ELR621/721/052 9083/74 “Welded connections. Types and design”, which shows the design of the C89 butt joint. This type of welded joint is used when welding assembly units made of steel in an inert gas with a non-consumable electrode without an additive, in an inert gas with a non-consumable electrode with an additive, electron beam welding with a thickness of 0.5 to 4 mm.

The disadvantages of the C89 connection type are:

- limited technological capabilities - can be used for welding steel parts;

- edge preparation parameters in OST are specified in a wide range; when choosing parameter values in a wide range, unfavorable combinations of the width and height of the filler collar are possible, which will lead to weld defects, for example, lack of weld penetration;

- electron beam welding is performed without a protruding filler lip, which, as a rule, leads to an understatement of the weld and a decrease in its strength.

There is a known method for manufacturing a hollow blade of a stator or rotor component (patent No. 2268130, MPK V23R 15/04, V23K 26/30, publ. 06/10/2005.)

A method for manufacturing a hollow blade is designed for a stator component or a rotor component and having at least one load-bearing stiffener located between and connected to two opposing side walls of the blade. The supporting stiffener is connected to at least one wall of the blade from the outside by laser welding in such a way that the interconnected sections of the supporting stiffener and the blade wall form a T-shaped connection.

The load-bearing stiffener has the form of a plate and is located substantially perpendicular to the middle plane of the blade.

The edge of the plate, which forms the load-bearing stiffening element, is connected to the wall of the blade.

First, a hollow blade is made, after which a load-bearing stiffening element is inserted inside the blade, which is then firmly welded to the wall of the blade.

The disadvantages of this method are:

- displacement of the welded edges in height, which is due to the implementation of the load-bearing stiffening element in the form of a plate;

- the difficulty of holding the weld pool in the center of the stiffener; at the slightest displacement of the welding arc from the center of the plate towards one of the welding edges of the part being welded, the weld pool will leak out and burn-throughs will occur;

- the weld has an understatement (shown in Fig. 2 of patent No. 2268130), caused by the flow of part of the molten metal into the root part of the weld to form smooth transitions between the stiffener and the walls of the blade of the T-shaped joint.

The common features of the analogue and the claimed invention are:

- installation of a stiffener in the area of the welded butt joint;

- connection by welding of the stiffener with parts

The analogue closest in technical essence and achieved result to the invention is patent SU 1159741, IPC B23K 33/00, publ. 06/07/1985, adopted as a prototype - a method for manufacturing welded butt joints, in which the butt edges of the pipes being connected are cut at an acute angle to the longitudinal axis of the pipes, making an outer cone, while at the end of the pipe a blunting can be made, the size of which is not exceeds 0.2 pipe wall thickness, and then assembly and welding is carried out on the remaining lining containing a filler protrusion made in the form of an equitrapezoidal ring, which is located between the mating edges. The smaller base of the filler protrusion is combined with the outer surface of the lining or is made integral with the lining.

The disadvantages of this method are:

- high complexity of the process of manufacturing a trapezoidal annular filler protrusion in one piece with the remaining lining, due to the complex geometric shape;

- the high complexity of the process of preparing the welded edges of the joined parts due to the need to bevel them with an angle corresponding to the bevel angle of the trapezoidal annular filler protrusion to form a conical surface;

- inaccurate assembly of the structure for welding in the form of wedge-shaped gaps due to possible deviations in the actual values of the angles of the filler protrusion and the bevel of the welded edges, which leads to a decrease in the quality of the weld in the form of non-fusion of the welded edges;

- the method relates to welding, mainly, butt circumferential welds of pipes.

The common features of the prototype and the invention are:

- the filler collar is made integral with the lining;

- welding of the joint is carried out in the center of the filler protrusion with complete penetration of the filler protrusion and the welded edges.

The objectives of the invention are:

- increasing the manufacturability of the method, ensuring high-quality welds with complete penetration of the welded edges;

- improving welding quality;

- reducing the cost of implementing the method.

When solving the problem, the following technical results are achieved:

- increasing the manufacturability of the method for manufacturing the remaining lining;

- simplification of the process of assembling a structure for welding;

- increasing the accuracy of assembly for welding;

- improving the quality of welding, the strength of the welded joint (by increasing the accuracy of assembly, ensuring complete fusion of the welded edges).

The technical result is achieved by the fact that in the method of manufacturing welded butt joints of multilayer thin-walled structures of sound-absorbing panels, in which the lining is made in one piece with the filler protrusion, the edges of the parts are prepared for welding, the filler protrusion is placed between the edges to be welded, and welding is performed in the center of the filler protrusion with its complete melting and fusion of the welded edges over the entire thickness, according to the claimed invention, a stiffening rib is made in the form of an I-beam, and the filler protrusion is made rectangular in shape in the center on its shelves, while the shelves serve as a lining, and the distance between the outer surfaces of the shelves is equal to the distance between internal surfaces of the welded sheets of sound-absorbing panels, assembly is performed by installing a stiffener between the panels being joined, ensuring that the welded edges rest against the filler protrusion, while the filler protrusion is made with a width determined from the condition of ensuring its complete melting and fusion of the welded edges to the full thickness, and height, exceeding the thickness of the welded edges by value A, determined by the formula:

A=b+g*1.5+0.3,

where b is the flatness of the welded edges, mm;

g is the minimum value of the required weld reinforcement, mm.

When assembling parts to be welded - sound-absorbing panels, the stiffener aligns the welded edges in height, and the rectangular-shaped filler protrusion ensures the parallelism of the panels along the joint and the location of the stiffener along the axis of symmetry of the plane of the joint of the panels, which results in assembly accuracy. The excess of the protrusion by the amount A above the surface of the welded edges ensures the strengthening of the weld.

The claimed method in its new set and relationship of features in comparison with the prototype allows:

- reduce the labor intensity of manufacturing a lining with an filler collar;

- reduce the labor intensity of assembly;

- increase the accuracy of assembling parts for welding, improve the quality of the weld and the strength of the welded joint;

- weld longitudinal and circumferential joints.

In fig. Figure 1 shows a view of the assembly of a welded butt joint of sound-absorbing panels.

In fig. 2 - shows a view of the welded joint after welding the sound-absorbing panels.

The method is carried out as follows.

Welding of sound-absorbing panels (SAP) 1 and 2 from titanium alloy OT4 was carried out. The thickness of the welded edges: outer sheet 3 (outer cladding of ZPK panels) - 1 mm, inner sheet 4 (inner lining of ZPK panels) - 0.5 mm. The distance between the inner surfaces of the welded sheets 3 and 4 of the sound-absorbing panels 1 and 2 is 20.3 mm. We made a stiffening rib 5 in the shape of an I-beam with rectangular filler protrusions 6 in the center on its flanges 7. The filler protrusion 6 was made 1 mm wide and height exceeding the thickness of the welded edges of sheets 3 and 4 of the ZPK panels by value A, determined by the formula:

A=b+g*1.5+0.3, where

b - flatness of welded edges = 0.1 mm;

g - minimum value of the required weld reinforcement = 0.2 mm.

A=b+g*1.5+0.3=0.1+0.2*1.5+0.3-0.7 mm.

The distance between the outer surfaces of the shelves 7 is equal to the distance between the inner surfaces of the welded sheets 3 and 4 of sound-absorbing panels 1 and 2 - 20.3 mm.

We cut the welded edges of sheets 3 and 4 as part of the sound-absorbing panels 1 and 2. We assembled the welded panels 1 and 2 as follows: installed a stiffener 5 between the welded edges of sheets 3 and 4 of panels 1 and 2, placing them on the outer surface of the shelves 7 to support of the welded edges of sheets 3 and 4 into the filler protrusions 6. As a result of assembling the sound-absorbing panels 1 and 2, the stiffening rib 5 aligns the welded edges of sheets 3 and 4 in height, and the filler protrusion 6 serves as a guide element, is pressed closely against the welding edges and thereby ensures the parallelism of panels 1 and 2 along the joint and the location of the stiffener 5 along the axis of symmetry of the plane of the joint of the panels, which as a result guarantees the accuracy of the assembly.

Taking into account the excess of the collar 6 above the surface of the welded edges of sheets 3 and 4 by 0.7 mm, as well as the thickness of the sheets 3-1.0 mm, sheets 4-0.5 mm, the height of the filler protrusions 6 was 1.7 mm and 1, respectively .2 mm.

The excess of the shoulder 6 by the amount A=0.7 mm above the surface of the welded edges ensures the strengthening of the weld. Electron beam welding was performed in the center of the collar 6 with its complete melting and fusion of the welded edges over the entire thickness. Welding modes are given in Table 1. As a result of welding, high-quality welds No. 1 and No. 2 and strong welded joints were obtained (Fig. 1). Dimensions are given in table 2.

The claimed method, compared to the prototype, is more technologically advanced, easy to implement, ensures assembly accuracy with a tight fit of the welded parts to the pads and filler protrusion, welding quality and reliability of welded joints with minimal labor and economic costs, and the ability to weld longitudinal and circumferential butt joints.

Claims (4)

A method for manufacturing welded butt joints of multilayer thin-walled structures of sound-absorbing panels, in which the lining is made in one piece with the filler lip, the edges on the parts for welding are cut, the filler lip is placed between the edges to be welded, welding is performed in the center of the filler lip with its complete melting and fusion of the welded parts. edges over the entire thickness, characterized in that the stiffener is made in the form of an I-beam, and the filler protrusion is made of a rectangular shape in the center on its shelves, while the shelves serve as a lining, and the distance between the outer surfaces of the shelves is equal to the distance between the inner surfaces of the sheets of sound-absorbing panels being welded , assembly is performed by installing a stiffener between the panels being joined, ensuring that the welded edges rest against the filler protrusion, while the filler protrusion is made with a width determined from the condition of ensuring its complete melting and fusion of the welded edges to the full thickness, and a height exceeding the thickness of the welded edges by an amount A, determined by the formula A=b+g*1.5+0.3, where b - flatness of welded edges, mm; g is the minimum value of the required weld reinforcement, mm.

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