Intermediate case assembly welding deformation control method and welding clamp

Abstract

The invention belongs to the field of machining, and particularly relates to an intermediate case assembly welding deformation control method and a welding clamp. According to the method, a rigid welding clamp is adopted for limiting and fixing an inner casing large-end spigot, an inner casing small-end spigot, an outer casing large-end spigot and an outer casing small-end spigot of an assembly, and a star-shaped support is arranged at a boss of an inner cavity of the inner casing; then the strut part is positioned and welded between the inner casing and the outer casing; according to the planned welding sequence and the set formal welding parameters, the strut parts are welded between the inner casing and the outer casing from the rectangular welding windows of the inner casing and the outer casing, so that the overall displacement deformation of the inner casing and the outer casing of the intermediate casing assembly in the axial direction, the radial direction, the inclined direction and the like is effectively controlled, and the welding quality is improved. And the welding shrinkage deformation at the boss of the inner cavity of the inner casing when the strut part is welded to the inner casing is reduced.

Description

Technical Field

[0001] The present invention belongs to the field of machining, and particularly relates to a method for controlling welding deformation of an intermediate casing assembly and a welding fixture. Background Art

[0002] As an overall supporting component of the engine, the intermediate casing assembly is an important part of the compressor unit of a marine gas turbine, and plays a role in guiding the inner and outer flow paths of the air to the inner and outer ducts and starting to do work when the engine is operating.

[0003] The main structure of the intermediate casing assembly referred to in this application is composed of an inner casing (1 piece), an outer casing (1 piece) and a plurality of strut parts. The plurality of strut parts are circumferentially and evenly connected to rectangular welding windows at various positions on the inner and outer casings by argon arc welding. The materials of the parts to be welded are all 1Cr18Ni9Ti. After welding, there are relatively high coaxiality requirements between the inner and outer casings of the assembly, and a kerosene leakage inspection needs to be carried out on the welds. Since the overall structural dimensions of the intermediate casing assembly referred to in this application are larger than those of the previous type of welding assembly (the diameter is about 350 mm larger and the axial height is about 200 mm higher), the welding rigidity of the assembly is weaker, making it difficult to control the relatively high coaxiality between the inner and outer casings of the assembly, which is manifested as displacement deformation in various directions such as axial, radial, and inclined between the inner and outer casings of the assembly; in addition, when implementing the argon arc welding fillet welding process for the large "V" - shaped grooves on both sides of the inner cavity boss of the inner casing for welding the strut parts, the weld bead build - up amount of the weld is very large, resulting in more welding heat input and welding stress. Since this inner cavity welding structure of the inner casing in the intermediate casing assembly is the first of its kind, there is no reference for fixtures, welding sequences, and welding parameters for controlling the welding deformation of this component structure, making it more difficult to control the shrinkage deformation of the inner cavity weld of the inner casing of the assembly, and even the plate walls on both sides of the weld at the inner cavity boss part of the inner casing may be pulled into straight surfaces. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for controlling welding deformation of an intermediate casing assembly and a welding fixture to solve the technical problem of difficult control of shrinkage deformation of the inner cavity weld of the inner casing of the assembly existing in the prior art.

[0005] To achieve the above - mentioned purpose, the present invention adopts the following technical solutions: In a first aspect, the present application discloses a method for controlling welding deformation of an intermediate casing assembly, including the following steps: S1: Use a welding fixture to limit and fix the large - end stop of the inner casing, the small - end stop of the inner casing, the large - end stop of the outer casing, and the small - end stop of the outer casing; arrange a star - shaped support at the inner cavity boss of the inner casing; S2: Position - weld the strut parts between the inner casing and the outer casing; S3: Perform formal welding according to the planned welding sequence and the set welding parameters, and weld the strut parts between the inner casing and the outer casing.

[0006] Preferably, the welding fixture includes an upper chassis, a lower chassis, an upper chassis outer casing large end stop pressing plate, a lower chassis outer casing small end stop pressing plate, an upper chassis inner casing large end stop pressing plate, a lower chassis inner casing small end stop pressing plate, an upper chassis reinforcing rib, and a lower chassis reinforcing rib; then S1 is specifically: S101: Axially and radially position the large end stop of the inner casing and the large end stop of the outer casing on the upper chassis; axially and radially position the small end stop of the inner casing and the small end stop of the outer casing on the lower chassis; S102: Press the large end stop of the inner casing and the large end stop of the outer casing against the upper chassis inner casing large end stop pressing plate and the upper chassis outer casing large end stop pressing plate respectively; press the small end stop of the inner casing and the small end stop of the outer casing against the lower chassis inner casing small end stop pressing plate and the lower chassis outer casing small end stop pressing plate respectively; S103: Place the strut parts between the inner casing and the outer casing, and ensure that the strut parts and the upper chassis reinforcing rib and the lower chassis reinforcing rib on the welding fixture are in the same angular direction.

[0007] Preferably, in S2, the tack welding is carried out along the edges of the rectangular welding windows of the inner casing and the outer casing in the order of the symmetric point positions, and the welding torch for the tack welding is 8 - 15 L / min; the welding current is 150 - 180 A.

[0008] Preferably, in S3, the welding sequence for welding the strut parts between the inner casing and the outer casing is: welding the 6 strut parts along the circumferential direction of the intermediate casing assembly in the order of the symmetric point positions respectively; and the 6 strut parts correspond to 6 groups of welding windows.

[0009] Preferably, in S3, each group of welding windows includes a corresponding rectangular welding window of the inner casing and a rectangular welding window of the outer casing, and formal welding of the strut parts is carried out at each group of welding windows; the order of the formal welding is successively: the inner side of the outer casing, the inner side of the inner casing, the outer side of the outer casing, and the outer side of the inner casing.

[0010] Preferably, the formal welding at the inner side of the inner casing includes: formal welding of the strut parts and the inner side wall of the inner casing, formal welding of the strut parts and the inner cavity boss of the inner casing; when carrying out formal welding of the strut parts with the inner side wall of the inner casing and the inner side of the outer casing, the set welding parameters include: the welding torch is 8 - 15 L / min; the welding current is 150 - 160 A.

[0011] Preferably, when the pillar parts are officially welded to the inner casing inner cavity boss, there are 12 welding points between the 6 pillar parts and the inner casing inner cavity boss. The welding sequence of the 12 welding points is to weld along the circumferential direction of the inner casing in the order of the symmetrical point positions. And this fixed welding includes back welding and cover welding; the welding torch for the back welding is 8 - 15 L / min; the welding current is 150 - 180 A; the welding torch for the cover welding is 8 - 15 L / min; the welding current is 180 - 200 A.

[0012] Preferably, in the step S3, the official welding of the outer side of the outer casing and the outer side of the inner casing includes back welding and cover welding; the welding torch for the back welding is 8 - 15 L / min; the welding current is 150 - 180 A; the welding torch for the cover welding is 8 - 15 L / min; the welding current is 180 - 200 A.

[0013] Preferably, the star - shaped support includes a connecting part and a supporting part. The supporting parts are symmetrically arranged along the circumferential direction of the connecting part. One end of the supporting part is arranged on the connecting part, and the other end contacts the inner casing inner cavity boss during use.

[0014] In a second aspect, the present application discloses a welding fixture, which is applied to the welding and forming method of the intermediate casing assembly described in any one of the above. The welding fixture includes an upper chassis and a lower chassis. Both the upper chassis and the lower chassis are in a concentric ring - shaped structure. Between the inner ring and the outer ring of the upper chassis, a plurality of upper chassis reinforcing ribs are evenly arranged along the circumferential direction; between the inner ring and the outer ring of the lower chassis, a plurality of lower chassis reinforcing ribs are evenly arranged along the circumferential direction; along the outer circumference of the upper chassis, a plurality of upper chassis outer casing large - end stop - mouth pressing plates are evenly arranged for pressing the outer casing large - end stop - mouth; on each of the upper chassis reinforcing ribs, an upper chassis inner casing large - end stop - mouth pressing plate is arranged for pressing the inner casing large - end stop - mouth; along the outer circumference of the lower chassis, a plurality of lower chassis outer casing small - end stop - mouth pressing plates are evenly arranged for pressing the outer casing small - end stop - mouth; on each of the lower chassis reinforcing ribs, a lower chassis inner casing small - end stop - mouth pressing plate is arranged for pressing the inner casing small - end stop - mouth.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1) The present application adopts a welding fixture with a rigid structure, and combines the planned welding sequence and the welding parameters optimized through tests described in the above - mentioned key technical solutions when argon - arc welding the pillar parts to the inner and outer casings. It can achieve a 100% qualified rate of coaxiality detection between the inner and outer casings of the intermediate casing assembly after welding, and a 100% qualified rate of kerosene leakage inspection of the welds, effectively controlling the displacement and deformation in all directions such as axial, radial, and tilt between the inner and outer casings of the assembly.

[0016] 2) During the welding of the intermediate casing, in combination with the use of the star-shaped support, the straightening deformation of the plate walls on both sides of the weld seam at the boss part in the inner cavity of the inner casing is effectively reduced, and the deformation is further reduced by 0.5 mm on the basis of meeting the design allowable deformation.

[0017] 3) For the first time, a small-deformation argon arc welding fillet joint process for the large "V" groove welding structure of the argon arc welding support pillar parts on both sides of the boss in the inner cavity of the intermediate casing type components is realized; technical experiences such as the rigid welding fixture structure reference, welding planning sequence, and welding parameters adopted when small-deformation welding can be achieved for the intermediate casing components of the same type are provided. Brief Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is a schematic diagram of the overall structure of the intermediate casing assembly of the embodiment of the present invention; Figure 2 It is a schematic diagram of the welding deformation displacement direction of the inner and outer casings of the component in the embodiment of the present invention; Figure 3 It is a schematic diagram of the weld shrinkage deformation position in the inner cavity of the inner casing in the embodiment of the present invention; Figure 4 It is a schematic diagram of the rigid structure welding fixture for argon arc welding of the component in the embodiment of the present invention, where (a) is a cross-sectional view of the welding fixture; (b) is an axonometric view of the welding fixture; Figure 5 It is a schematic diagram of the use of the star-shaped support structure in the embodiment of the present invention; Figure 6 It is a schematic diagram of the positioning welding sequence when the support pillar parts are welded to the inner and outer casings of the component by argon arc welding in the embodiment of the present invention; where (a) is a schematic diagram of the position of a single rectangular welding window on the inner and outer casings; (b) is a schematic diagram of the symmetric welding position setting sequence when positioning welding is performed on a single rectangular welding window of the inner and outer casings; Figure 7 It is a schematic diagram of the formal welding sequence when 6 support pillar parts are welded to the inner and outer casings of the component by argon arc welding in the embodiment of the present invention; where (a) is a schematic diagram of the symmetric welding position setting sequence when the 6 support pillar parts are formally welded along the circumferential direction of the component; Figure 8 It is a schematic diagram of the starting and ending arc positions of the formal welding of a single rectangular welding window in the embodiment of the present invention; Figure 9It is a schematic diagram for controlling the forming dimensions of the inner and outer weld beads of the formal welding of the inner and outer casings of the components in the embodiments of the present invention. Among them, (a) is a schematic diagram for controlling the dimensions of the inner weld bead of the inner and outer casings. m represents that the width of the weld bead is 6 - 10 mm, and n represents that the height of the weld bead is 0 - 2 mm; (b) is a schematic diagram for controlling the dimensions of the outer weld bead of the inner and outer casings. P represents that the width of the weld bead is 10 - 14 mm, and Q represents that the height of the weld bead is 0 - 2 mm; Figure 10 It is a schematic diagram of the setting sequence of the symmetric welding positions when 6 strut parts are argon arc welded at an angle between the two large "V" - shaped welding grooves on both sides of the convex platform part in the inner cavity of the inner casing in the embodiments of the present invention; Figure 11 It is a schematic diagram for controlling the forming dimensions of the inner weld bead at the large "V" - shaped welding groove of the convex platform part in the inner cavity of the inner casing of the components in the embodiments of the present invention. Among them, X represents that the width of the weld bead is 15 - 20 mm, and Y represents that the height of the weld bead is 0 - 2 mm.

[0020] Wherein: 1 - intermediate casing assembly; 2 - inner casing; 3 - outer casing; 4 - strut part; 5 - rectangular welding window of the inner casing; 6 - rectangular welding window of the outer casing; 7 - inner cavity of the inner casing; 8 - convex platform in the inner cavity of the inner casing; 9 - welds on both sides of the convex platform in the inner cavity of the inner casing; 10 - side plates on both sides of the weld of the convex platform in the inner cavity of the inner casing; 11 - upper chassis; 12 - lower chassis; 13 - large - end stop of the inner casing; 14 - large - end stop of the outer casing; 15 - small - end stop of the inner casing; 16 - small - end stop of the outer casing; 17 - upper - chassis outer - casing large - end stop pressing plate; 18 - lower - chassis outer - casing small - end stop pressing plate; 19 - upper - chassis inner - casing large - end stop pressing plate; 20 - lower - chassis inner - casing small - end stop pressing plate; 21 - upper - chassis reinforcing rib; 22 - upper - chassis reinforcing rib; 23 - star - shaped support; 2301 - connecting part; 2302 - supporting part; 24 - inside of the rectangular welding window of the outer casing; 25 - inside of the rectangular welding window of the inner casing; 26 - outside of the rectangular welding window of the outer casing; 27 - outside of the rectangular welding window of the inner casing; 28 - argon arc formal - weld bead on the inner side of the inner and outer casings (excluding the convex platform part in the inner cavity of the inner casing); 29 - argon arc formal - weld bead on the outer side of the inner and outer casings; 30 - argon arc formal - weld bead at the convex platform part in the inner cavity of the inner casing; 31 - large "V" - shaped welding grooves on both sides of the convex platform part in the inner cavity of the inner casing. Detailed implementation manners

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0022] Accordingly, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0023] It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not require further definition and explanation in subsequent drawings.

[0024] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper", "lower", "horizontal", "inner", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present invention. In addition, terms such as "first", "second", etc. are only used for distinguishing descriptions and cannot be construed as indicating or implying relative importance.

[0025] In addition, if the term "horizontal" appears, it does not mean that the component is required to be absolutely horizontal, but it can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but it can be slightly inclined.

[0026] In the description of the embodiments of the present invention, it should also be noted that unless otherwise clearly specified and limited, if terms such as "set", "installed", "connected", "connected" are used, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0027] The present invention will be further described in detail below with reference to the accompanying drawings: The present application discloses a method for controlling the welding deformation of an intermediate casing assembly, including the following steps: S1: Use a welding fixture to limit and fix the large-end stop 13 of the inner casing, the small-end stop 15 of the inner casing, the large-end stop 14 of the outer casing, and the small-end stop 16 of the outer casing; arrange the star support 23 at the convex platform 8 in the inner cavity of the inner casing; S2: Position-weld the strut part 4 between the inner casing 2 and the outer casing 3; S3: Perform formal welding according to the planned welding sequence and the set welding parameters, and weld the strut part 4 between the inner casing 2 and the outer casing 3.

[0028] In some embodiments, the welding fixture includes an upper chassis 11, a lower chassis 12, an upper chassis outer casing large-end stop pressing plate 17, a lower chassis outer casing small-end stop pressing plate 18, an upper chassis inner casing large-end stop pressing plate 19, a lower chassis inner casing small-end stop pressing plate 20, an upper chassis reinforcing rib 21, and a lower chassis reinforcing rib 22; then S1 specifically is: S101: Axially and radially position the inner casing large-end stop 13 and the outer casing large-end stop 14 on the upper chassis 11; axially and radially position the inner casing small-end stop 15 and the outer casing small-end stop 16 on the lower chassis 12. S102: Press the inner casing large-end stop 13 and the outer casing large-end stop 14 respectively on the upper chassis inner casing large-end stop pressing plate 19 and the upper chassis outer casing large-end stop pressing plate 17; press the inner casing small-end stop 15 and the outer casing small-end stop 16 respectively on the lower chassis inner casing small-end stop pressing plate 20 and the lower chassis outer casing small-end stop pressing plate 18. S103: Place the strut part 4 between the inner casing 2 and the outer casing 3, and ensure that the strut part 4 and the upper chassis reinforcing rib 21 and the lower chassis reinforcing rib 22 on the welding fixture are in the same angular orientation. The upper and lower fixture chassis reinforcing ribs of the welding fixture and the strut part of the intermediate casing assembly are set in the same angular orientation, completely leaving the welding space between the strut part and the inner casing, and avoiding the component being removed during welding for non-positioned welding.

[0029] In some embodiments, in S2, the tack welding is performed along the edges of the inner casing rectangular welding window 5 and the outer casing rectangular welding window 6 in the order of the symmetric point positions, and the welding torch for the tack welding is 8 - 15 L / min; the welding current is 150 - 180 A.

[0030] In some embodiments, in S3, the welding sequence for welding the strut part 4 between the inner casing 2 and the outer casing 3 is: 6 strut parts 4 are welded separately along the circumferential direction of the intermediate casing assembly 1 in the order of the symmetric point positions; and the 6 strut parts 4 correspond to 6 groups of welding windows.

[0031] In some embodiments, in S3, each group of welding windows includes a corresponding inner casing rectangular welding window 5 and an outer casing rectangular welding window 6, and formal welding of the strut part 4 is performed at each group of welding windows; the sequence of the formal welding is successively: the inner side of the outer casing 24, the inner side of the inner casing 25, the outer side of the outer casing 26, and the outer side of the inner casing 27.

[0032] Further preferably, the formal welding at the inner side 25 of the inner casing includes: the formal welding between the strut part 4 and the inner side wall of the inner casing, and the formal welding between the strut part 4 and the inner cavity boss 8 of the inner casing; when performing formal welding between the strut part 4 and the inner side wall of the inner casing and the outer side 24 of the outer casing, the set welding parameters include: the welding torch is 8 - 15 L / min; the welding current is 150 - 160 A.

[0033] Further preferably, when performing formal welding between the strut part 4 and the inner cavity boss 8 of the inner casing, there are 12 welding points between the 6 strut parts 4 and the inner cavity boss 8 of the inner casing. The welding sequence of the 12 welding points is to perform welding in the order of the symmetric point positions along the circumferential direction of the inner casing 2, and this fixed welding includes backing welding and covering welding; the welding torch for the backing welding is 8 - 15 L / min; the welding current is 150 - 180 A; the welding torch for the covering welding is 8 - 15 L / min; the welding current is 180 - 200 A.

[0034] In some embodiments, in S3, the formal welding of the outer side 26 of the outer casing and the outer side 27 of the inner casing includes backing welding and covering welding; the welding torch for the backing welding is 8 - 15 L / min; the welding current is 150 - 180 A; the welding torch for the covering welding is 8 - 15 L / min; the welding current is 180 - 200 A.

[0035] In some embodiments, the star-shaped support 23 includes a connecting part 2301 and a supporting part 2302. The supporting parts 2302 are symmetrically arranged along the circumferential direction of the connecting part 2301. One end of the supporting part 2302 is arranged on the connecting part 2301, and the other end contacts the inner cavity boss 8 of the inner casing during use.

[0036] In some embodiments, to control the overall welding deformation of the intermediate casing assembly, the technical solution of the present invention uses a welding fixture that limits and compresses both the large and small end stop mouths of the intermediate casing assembly to enhance the overall welding rigidity, and welds the inner and outer casings and the strut parts of the intermediate casing assembly body at one time; the upper and lower fixture chassis reinforcing ribs of the welding fixture are set at the same angular direction as the strut parts of the intermediate casing assembly, so as to completely make way for the welding space between the strut parts and the inner casing, and avoid non-positioned welding due to the removal of the assembly during the welding process; when using this welding fixture to perform argon arc welding fillet welding on the large "V" - shaped grooves on both sides of the inner cavity boss of the inner casing and the strut parts, a star-shaped support is additionally used and placed on the inner cavity boss of the inner casing to reduce the welding shrinkage deformation of the inner cavity of the inner casing when welding the strut parts to the inner casing.

[0037] Meanwhile, in order to further control the welding displacement deformation in various directions such as axial, radial, and tilt between the inner and outer casings when several strut parts of the intermediate casing assembly are circumferentially evenly distributed and welded to the inner and outer casings of the assembly by argon arc welding, and to reduce the shrinkage deformation of the inner cavity of the inner casing during the welding of the strut parts to the inner casing, when several strut parts of the assembly are circumferentially evenly distributed and welded to the inner and outer casings of the assembly by argon arc welding, it is necessary to complete the tack welding, formal welding, and argon arc welding fillet welding of the large "V" groove on both sides of the boss in the inner cavity of the inner casing by the planned symmetric welding sequence and the welding parameters optimized by experiments; at the same time, in order to ensure the weld quality, the starting and ending arc positions of the rectangular single welding window where the strut parts are welded to the inner and outer casings should be set on the long side of the edge of the window.

[0038] The present application also discloses a welding fixture, which is applied to the welding forming method of the intermediate casing assembly described in any one of the above. The welding fixture includes an upper chassis 11 and a lower chassis 12. Both the upper chassis 11 and the lower chassis 12 are concentric ring structures. Between the inner ring and the outer ring of the upper chassis 11, a number of upper chassis stiffeners 21 are evenly arranged along the circumferential direction; between the inner ring and the outer ring of the lower chassis 12, a number of lower chassis stiffeners 22 are evenly arranged along the circumferential direction; along the outer circumference of the upper chassis 11, a number of upper chassis outer casing large end stop pressing plates 17 are evenly arranged, which are used to press the outer casing large end stop 14; on each of the upper chassis stiffeners 21, an upper chassis inner casing large end stop pressing plate 19 is arranged, which is used to press the inner casing large end stop 13; along the outer circumference of the lower chassis 12, a number of lower chassis outer casing small end stop pressing plates 18 are evenly arranged, which are used to press the outer casing small end stop 16; on each of the lower chassis stiffeners 22, a lower chassis inner casing small end stop pressing plate 20 is arranged, which is used to press the inner casing small end stop 15.

[0039]

Embodiment

[0040] As Figures 2 - 3, the intermediate casing assembly 1 has overall structural dimensions larger than those of the previous welding assemblies of this type (about 350 mm larger in diameter and about 200 mm higher axially), making the welding rigidity of the assembly 1 weaker, resulting in difficulty in controlling the high coaxiality between the axes of the inner casing 2 and the outer casing 3 within the assembly, manifested as displacement and deformation of the inner casing 2 and the outer casing 3 within the assembly in various directions such as axial, radial, and tilt; in addition, when implementing the argon arc welding fillet welding process for the large "V" groove 31 on both sides of the inner cavity boss 8 of the inner casing of the assembly, the build-up amount of the weld seam is very large, generating more welding heat input and welding stress. Since the welding structure of this inner cavity boss 8 of the inner casing is the first in the intermediate casing type assemblies, there is no reference for fixtures, welding sequences, welding parameters, etc. for controlling the welding deformation of the component structure at this location, resulting in more difficult control of the shrinkage deformation of the inner cavity 7 of the inner casing, and even the plate walls 10 on both sides of the weld seam at the inner cavity boss part of the inner casing may be pulled into straight surfaces.

[0041] 2. Specific implementation method of small-deformation argon arc welding for intermediate casing assembly (1) Welding fixture with rigid structure for controlling argon arc welding deformation of intermediate casing and its use As Figure 4 , a welding fixture for overall enhancing welding rigidity that limits and compresses the large end stop 13 of the inner casing, the large end stop 14 of the outer casing, the small end stop 15 of the inner casing, and the small end stop 16 of the outer casing of the intermediate casing assembly 1 is adopted, and the inner casing 2, the outer casing 3, and the support parts 4 of the main body of the intermediate casing assembly 1 are welded at one time. The structural scheme of the welding fixture is as follows: 1) The large end stop 13 of the inner casing, the large end stop 14 of the outer casing, the small end stop 15 of the inner casing, and the small end stop 16 of the outer casing of the intermediate casing assembly 1 are respectively limited axially and radially by the upper chassis 11 and the lower chassis 12 of the welding fixture. At the same time, the large end stop 13 of the inner casing and the large end stop 14 of the outer casing are respectively pressed by 9 and 18 circumferentially evenly distributed upper chassis inner casing large end stop pressing plates 19 and upper chassis outer casing large end stop pressing plates 17 arranged on the upper fixture chassis 11; the small end stop 15 of the inner casing and the small end stop 16 of the outer casing are respectively pressed by 9 and 18 circumferentially evenly distributed lower chassis inner casing small end stop pressing plates 20 and lower chassis outer casing small end stop pressing plates 18 arranged on the lower fixture chassis 12; 2) Six upper chassis stiffeners 21 and six lower chassis stiffeners 22 of the welding fixture are arranged in the same angular direction as the six support parts 4 of the intermediate casing assembly 1, so that the fixture completely gives up the welding space between the support parts 4 and the inner casing 2, and the purpose of completing the welding at one time can be achieved without removing the entire intermediate casing assembly 1 from the welding fixture whether the support parts 4 are welded from the large end or the small end direction of the inner casing 2 of the assembly.

[0042] 3) As Figure 5, when performing argon arc fillet welding on the large "V" groove 31 on both sides of the boss 8 in the inner cavity of the component of the strut part 4 using the above-mentioned welding fixture, a star support 23 is additionally used and placed on the boss 8 in the inner cavity of the inner casing to reduce the welding shrinkage deformation of the inner cavity 7 of the inner casing when welding the strut part 4 to the inner casing 2.

[0043] (2) Welding sequence planning and welding parameters for controlling the argon arc welding deformation of the intermediate casing 1) Tack welding As Figure 6 , when tack welding the strut part 4 of the intermediate casing assembly 1 to the rectangular welding window 5 of the inner casing and the rectangular welding window 6 of the outer casing, it is necessary to Figure 6 (b) Perform tack welding in the order of the symmetric point positions marked a - j along the edge of the rectangular welding window, combining the welding parameters optimized by the test in Table 1.

[0044] Table 1 Argon arc tack welding parameters for the rectangular welding windows of the inner and outer casings

[0045] 2) Formal welding A. Overall welding sequence of the intermediate casing assembly body As Figure 7 , to reduce the displacement deformation in all directions such as axial, radial, and tilt between the axes of the inner casing 2 and the outer casing 3 after welding the intermediate casing assembly 1, it is necessary to Figure 7 (a) Weld the 6 strut parts 4 in the order of the symmetric point positions marked a - f along the circumferential direction of the assembly 1.

[0046] At the same time, to ensure the quality of the argon arc welding seam and reduce the welding deformation of a single strut part 4, the single strut part needs to be welded to the inner casing 2 and the outer casing 3 of the assembly from both the inner and outer sides of the single rectangular welding window 5 of the inner casing and the rectangular welding window 6 of the outer casing. As Figure 7 (b), the welding sequence of welding the single strut part 4 to the inner casing 2 and the outer casing 3 of the assembly is: inner side of the outer casing 24 → inner side of the inner casing 25 → outer side of the outer casing 26 → outer side of the inner casing 27.

[0047] B. Welding process for a single welding window of the inner and outer casings To ensure the quality of the welding seams of the rectangular welding window 5 of the inner casing and the rectangular welding window 6 of the outer casing of the assembly, when welding from both the inner and outer sides of the rectangular welding window 5 of the inner casing and the rectangular welding window 6 of the outer casing of the intermediate casing assembly 1, the starting and ending arc positions should be set as Figure 8 between the long sides a, c and the long sides b, d marked on the edge of the rectangular window, avoiding the short sides and the R positions. And according to the welding parameters optimized by the test in Table 2 andFigure 9 Weld the weld bead of the shown formed size, where ① is the root pass welding and ② is the cover pass welding.

[0048] Table 2 GTAW formal welding parameters on both sides of a single welding window of the inner and outer casings

[0049] C. Welding process for welding the strut parts to the boss in the inner casing cavity To reduce the welding shrinkage deformation when welding the strut part 4 to the boss 8 in the inner casing cavity of the inner casing cavity 7, especially to reduce the straightening deformation of the plate walls 10 on both sides of the weld at the boss part of the inner casing cavity, as Figure 10 , it is necessary to weld the 12 large "V" - shaped grooves 31 for welding the strut parts on both sides of the boss 8 in the inner casing cavity of the assembly in sequence along the symmetric point positions marked a - l in the circumferential direction a of the inner casing. And carry out welding according to the welding parameters optimized by the test in Table 3 and Figure 11 Weld the weld bead of the shown formed size, where ① is the root pass welding and ② is the cover pass welding.

[0050] Table 3 GTAW parameters for the boss part in the inner casing cavity

[0051] 3. Implementation effects (1) By using the rigid - structure welding fixture disclosed in the present invention, when performing integral rigid positioning and clamping on the intermediate casing assembly 1 of the present invention and then carrying out component welding, the welding rigidity of the intermediate casing assembly 1 is greatly enhanced, and it can effectively resist the displacement and deformation in various directions such as axial, radial, and inclined directions generated between the axes of the inner casing 2 and the outer casing 3 when welding the strut part 4 to the inner casing 2 and the outer casing 3. (2) Set the upper fixture chassis reinforcing rib 21 and the lower fixture chassis reinforcing rib 22 of the welding fixture and the strut part 4 of the intermediate casing assembly to have the same angular orientation structure, avoiding the displacement and deformation in various directions such as axial, radial, and inclined directions between the inner casing 2 and the outer casing 3 of the assembly when it is necessary to unload the entire assembly 1 from the welding fixture for non - limited - position welding during the welding process from the large - end and small - end directions of the inner casing 2 of the assembly, and further controlling and improving the welding deformation of the assembly 1.

[0052] Combined with the description of the implementation effects in the above (1) and (2) items, through the actual welding verification of the intermediate casing assembly 1 of the present invention, while ensuring the weld quality of the assembly 1, the qualified rate of the coaxiality detection between the axes of the inner casing 2 and the outer casing 3 is 100%, the qualified rate of the weld kerosene leakage inspection is 100%, and the coaxiality is improved from a maximum of about 3 mm to not more than 1 mm, effectively controlling the displacement and deformation in various directions between the inner casing 2 and the outer casing 3.

[0053] (3) For the rigid structure welding fixture disclosed in the present invention, a star-shaped support 23 is provided at the boss part 8 of the inner casing cavity of the intermediate casing assembly 1, effectively reducing the welding shrinkage deformation of the inner casing cavity 7 when the strut part 4 is welded to the inner casing 2, especially reducing the deformation of the plate walls on both sides of the weld at the boss part of the inner casing cavity being pulled into a straight surface. Through actual welding verification, the welding shrinkage of the inner casing cavity 7 of the assembly is reduced from nearly 2 mm on one side to about 0.7 mm on one side, further reducing the deformation by 0.5 mm on the basis of meeting the design allowable deformation of 1.2 mm.

[0054] (4) For the first time, a small-deformation argon arc welding corner joint process for the large "V" groove 31 welding structure for argon arc welding of strut parts at both sides of the boss 8 of the inner casing cavity of the intermediate casing assembly is realized; technical experiences such as the rigid welding fixture structure reference, welding planning sequence, and welding parameters are provided when the same type of intermediate casing assembly can achieve small-deformation welding.

[0055] In summary, the present invention belongs to the field of machining, and specifically relates to a method for controlling welding deformation of an intermediate casing assembly. This method uses a rigid welding fixture to limit and fix the large-end stop, small-end stop of the inner casing, large-end stop of the outer casing, and small-end stop of the outer casing of the assembly, and arranges a star-shaped support at the boss of the inner casing cavity; then the strut part is tack-welded between the inner and outer casings; according to the planned welding sequence and the set formal welding parameters, the strut part is welded between the inner casing and the outer casing from the rectangular welding windows of the inner and outer casings respectively, effectively controlling the overall displacement deformation in all directions such as axial, radial, and tilt between the inner and outer casings of the intermediate casing assembly, and reducing the welding shrinkage deformation at the boss of the inner casing cavity when the strut part is welded to the inner casing.

[0056] The above is only the preferred embodiment of the present invention and is not used to limit the present invention. For those skilled in the art, various changes and modifications can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for controlling welding deformation of an intermediate casing assembly, characterized in that: The following steps are involved: S1: Use a welding fixture to limit and fix the inner casing large end stop (13), the inner casing small end stop (15), the outer casing large end stop (14) and the outer casing small end stop (16); set the star support (23) at the inner casing inner cavity boss (8); S2: Position welding the support part (4) between the inner casing (2) and the outer casing (3); S3: Perform formal welding according to the planned welding sequence and set welding parameters to weld the support part (4) between the inner casing (2) and the outer casing (3).

2. The method for controlling welding deformation of an intermediate casing assembly according to claim 1, characterized in that: The welding fixture comprises an upper chassis (11), a lower chassis (12), a stopper pressure plate (17) at the large end of an outer casing of the upper chassis, a stopper pressure plate (18) at the small end of an outer casing of the lower chassis, a stopper pressure plate (19) at the large end of an inner casing of the upper chassis, a stopper pressure plate (20) at the small end of an inner casing of the lower chassis, an upper chassis reinforcement rib (21) and a lower chassis reinforcement rib (22); then S1 is specifically: S101: The upper chassis (11) axially and radially positions the inner casing large end stop (13) and the outer casing large end stop (14); the lower chassis (12) axially and radially positions the inner casing small end stop (15) and the outer casing small end stop (16); S102: Press the inner receiver large end stop (13) and the outer receiver large end stop (14) onto the upper chassis inner receiver large end stop pressure plate (19) and the upper chassis outer receiver large end stop pressure plate (17) respectively; press the inner receiver small end stop (15) and the outer receiver small end stop (16) onto the lower chassis inner receiver small end stop pressure plate (20) and the lower chassis outer receiver small end stop pressure plate (18) respectively; S103: The support part (4) is arranged between the inner casing (2) and the outer casing (3), and it is ensured that the support part (4) is at the same angle as the upper chassis reinforcement rib (21) and the lower chassis reinforcement rib (22) on the welding fixture.

3. The method for controlling welding deformation of an intermediate casing assembly according to claim 1, characterized in that: In S2, tack welding is performed along the edges of the inner casing rectangular welding window (5) and the outer casing rectangular welding window (6) in the order of symmetrical point positions, and the tack welding torch is 8-15 L / min; the welding current is 150-180A.

4. The method for controlling welding deformation of an intermediate casing assembly according to claim 1, characterized in that: In S3, the welding sequence of the support parts (4) between the inner casing (2) and the outer casing (3) is as follows: the six support parts (4) are welded respectively along the circumferential direction of the intermediate casing assembly (1) in the order of the symmetrical point positions; and the six support parts (4) correspond to six groups of welding windows.

5. The method for controlling welding deformation of an intermediate casing assembly according to claim 4, characterized in that: In S3, each group of welding windows includes a corresponding inner casing rectangular welding window (5) and an outer casing rectangular welding window (6), and formal welding is performed on the support part (4) at each group of welding windows; the formal welding is performed in the following order: the inner side of the outer casing (24), the inner side of the inner casing (25), the outer side of the outer casing (26), and the outer side of the inner casing (27).

6. The method for controlling welding deformation of an intermediate casing assembly according to claim 5, characterized in that: The formal welding at the inner side (25) of the inner casing includes: formal welding of the support part (4) and the inner side wall of the inner casing, and formal welding of the support part (4) and the inner cavity boss (8) of the inner casing; when the support part (4) is formally welded with the inner side wall of the inner casing and the inner side (24) of the outer casing, the set welding parameters include: the welding torch is 8-15 L / min; the welding current is 150-160A.

7. The method for controlling welding deformation of an intermediate casing assembly according to claim 6, characterized in that: When the support parts (4) and the inner casing inner cavity boss (8) are formally welded, there are 12 welding points between the six support parts (4) and the inner casing inner cavity boss (8), and the welding order of the 12 welding points is to weld along the circumferential direction of the inner casing (2) in the order of symmetrical point positions, and the fixed welding includes base welding and covering welding; the welding torch of the base welding is 8~15 L / min; the welding current is 150~180A; the welding torch of the covering welding is 8~15 L / min; the welding current is 180~200A.

8. The method for controlling welding deformation of an intermediate casing assembly according to claim 5, characterized in that: In S3, the formal welding of the outer side (26) of the outer casing and the outer side (27) of the inner casing includes base welding and covering welding; the welding torch of the base welding is 8~15 L / min; the welding current is 150~180A; the welding torch of the covering welding is 8~15 L / min; the welding current is 180~200A.

9. The method for controlling welding deformation of an intermediate casing assembly according to claim 1, characterized in that: The star-shaped support (23) comprises a connecting portion (2301) and a supporting portion (2302), wherein the supporting portion (2302) is symmetrically arranged along the circumference of the connecting portion (2301), and one end of the supporting portion (2302) is arranged on the connecting portion (2301), and the other end is in contact with the inner casing inner cavity boss (8) when in use.

10. A welding fixture, characterized in that: In the intermediate casing assembly welding forming method as described in any one of claims 1 to 9, the welding fixture comprises an upper chassis (11) and a lower chassis (12), both of which are concentric ring structures, and a plurality of upper chassis reinforcing ribs (21) are evenly arranged along the circumference between the inner ring and the outer ring of the upper chassis (11); a plurality of lower chassis reinforcing ribs (22) are evenly arranged along the circumference between the inner ring and the outer ring of the lower chassis (12); a plurality of upper chassis outer ribs (22) are evenly arranged along the outer circumference of the upper chassis (11). The large end stop pressure plate (17) of the receiver is used to press the large end stop (14) of the outer receiver; the upper chassis inner receiver large end stop pressure plate (19) is arranged on the upper chassis reinforcement rib (21) to press the large end stop (13) of the inner receiver; a plurality of lower chassis outer receiver small end stop pressure plates (18) are evenly arranged along the outer circumference of the lower chassis (12) to press the small end stop (16) of the outer receiver; and the lower chassis inner receiver small end stop pressure plates (20) are arranged on the lower chassis reinforcement rib (22) to press the small end stop (15) of the inner receiver.

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