Thermal correction fixture and thermal correction method for aircraft engine air duct inner tube assembly

Abstract

The present invention relates to a thermal correction fixture and a thermal correction method for an aircraft engine air duct inner tube assembly, belonging to the field of mechanical processing technology, and comprising a core shaft, a base, and a hoop assembly; a first flange is provided at one end of the core shaft, the first flange is connected to a groove on the base surface and is clearance-matched, the air duct inner tube assembly is sleeved and connected to the core shaft surface, one end of which is inserted into the gap between the first flange and the groove, and a plurality of hoop assemblies are coated on the surface of the air duct inner tube assembly. The present invention implements clamping restriction of the air duct inner tube assembly through a thermal correction fixture, performs position limiting protection on a damping ring on the surface of the air duct inner tube assembly through a convex groove on the inner wall of the hoop assembly, and implements correction of wave deformation and bamboo-joint deformation of the air duct inner tube assembly through a thermal correction method, and the whole set of fixtures has a simple structure and is easy to operate, which can meet the needs of production and use.

Description

Technical Field

[0001] The invention relates to a thermal correction fixture and a thermal correction method, in particular to a thermal correction fixture and a thermal correction method for an inner tube assembly of an aero-engine air duct, and belongs to the technical field of mechanical processing. Background Art

[0002] The air duct inner tube assembly is welded by a heat shield and a damping ring. As an important component of the aircraft engine turbine component, it constitutes a part of the double-layer air duct of the turbine component. It belongs to the rotor part and plays a vital role in the cooling process of the turbine component. The heat shield is a thin-walled long cylindrical structure with an axial opening. Compared with conventional cylindrical parts, the structure is more complex; the opening size of the heat shield cylinder in the free state is 15 to 50 mm, and the cross-section is circular in the clamped state. The damping rings are equidistantly distributed on the outer surface of the heat shield cylinder along the axial direction. The cross-section of the damping ring is arched and maintains a certain angle relationship with the axial opening. The edge is welded to the heat shield cylinder by laser welding.

[0003] The wall thickness of the supporting parts involved in the air duct inner tube assembly is 0.5mm, and the material is GH4169. Although the welding process is completed using laser welding with relatively small deformation, large wave deformation and bamboo deformation will still occur after welding. The wave deformation is concentrated on both sides of the axial opening of the heat insulation cover, and the bamboo deformation is manifested as a depression of the heat insulation cover between adjacent damping rings. The ordinary cold correction method cannot effectively eliminate the welding deformation.

[0004] The Chinese utility model patent with authorization announcement number CN216655843U discloses a heat treatment correction hanging tool for thin-walled barrel-shaped structural parts of different heights, which includes a hanging rod and a correction ring; the correction ring includes a correction half ring and a lifting screw. The device uses a correction ring clamp to extrude the outer surface of the thin-walled barrel-shaped structural parts to control deformation during the heat treatment process. However, it is not applicable to air duct inner tube components with special structures on the surface, and correction cannot be performed under the premise of protecting the tube wall. Therefore, it is necessary to invent a thermal correction fixture and thermal correction method for air duct inner tube components to eliminate post-weld deformation of laser welding. Summary of the invention

[0005] In order to overcome the deficiencies in the prior art, the present invention provides a thermal correction fixture and a thermal correction method for an aircraft engine air duct inner tube assembly. The air duct inner tube assembly is first limited by the thermal correction fixture, and then the air duct inner tube assembly is subjected to vacuum heat treatment together with the thermal correction fixture to eliminate deformation stress and stabilize the shape.

[0006] To achieve the above-mentioned purpose, the present invention discloses a thermal correction fixture for an aircraft engine air duct inner tube assembly, comprising a core shaft, a base and a hoop assembly; a first flange is provided at one end of the core shaft, the first flange is connected to a groove on the base surface and is clearance-fitted, the air duct inner tube assembly is sleeved and connected to the core shaft surface, one end of the air duct inner tube assembly is inserted into the gap between the first flange and the groove, and a plurality of the hoop assemblies are coated on the surface of the air duct inner tube assembly.

[0007] Furthermore, the inner wall of the hoop assembly is provided with convex grooves spaced apart along the circumferential direction, and the convex grooves correspond one to one with the arc-shaped protrusions on the surface of the inner tube assembly of the air duct, and are clearance-matched.

[0008] Furthermore, the hoop assembly is a plurality of semicircular arc hoop bodies with different widths, connecting ears extend from the ends of the hoop bodies, two hoop bodies form a group, and wedges are clamped on the surfaces of the two connecting ears.

[0009] Furthermore, a second flange is provided at one end of the core shaft away from the base, a fixing rod for limiting is radially connected to the side wall of the second flange, a gasket is clamped between the fixing rod and the core shaft; and a hook is connected to the surface of the second flange.

[0010] Furthermore, it also includes a gasket, which is crescent-shaped; when the convex grooves and the arc-shaped protrusions on the surface of the air duct inner tube assembly do not correspond one to one, gaskets are inserted between adjacent groups of hoop bodies.

[0011] A thermal correction method based on the thermal correction fixture for the inner tube assembly of an aircraft engine air duct comprises the following steps:

[0012] Step S1: Check whether the thermal calibration fixture is missing any parts and keep it clean. Before clamping, the bulges and depressions of the air duct inner tube assembly should be stretched as much as possible, and the shell should be flattened as much as possible to facilitate the clamping of the air duct inner tube assembly;

[0013] Step S2: Assemble the mandrel and the base to limit one end of the air duct inner tube assembly. Since the gap between the base and the mandrel is small, the air duct inner tube assembly cannot be directly inserted into the gap when it is directly fixed. In order to ensure the shape of the openings at both ends of the air duct inner tube assembly, the base can be removed first, and the air duct inner tube assembly can be hooped in the base before inserting the mandrel;

[0014] Step S3: assembling the hoop assembly layer by layer from one end of the base, with two hoop bodies as one group. During assembly, it is important to make sure that the convex groove matches the damping ring position on the surface of the air duct inner tube assembly, that is, the arc-shaped protrusion. The two ends of the convex groove are pressed on the damping ring welding section as much as possible. The axial position between layers is adjusted by a gasket. After the position is adjusted, close a group of hoop bodies and gently wedge them with a wedge.

[0015] Step S4: assembling the hoop assembly layer by layer, and repeating the operation of step S3 to complete the initial assembly of the hoop assembly;

[0016] Step S5: Use the fixing rod and the mandrel to press the gasket tightly to complete the axial limit of all assembly parts;

[0017] Step S6: tighten the wedges in sequence to complete the final positioning of the hoop assembly;

[0018] Step S7: The air duct inner tube assembly in the clamped state is subjected to vacuum heat treatment together with the clamp, and the whole is adjusted to a vertical state, and hoisted and heat treated in the vertical state;

[0019] Step S8: After the heat treatment is completed, the fixtures are removed piece by piece to finally obtain the air duct inner tube assembly that has been heat-corrected.

[0020] Furthermore, in step S7, the heat treatment parameters are: heating to 710°C-730°C, keeping warm for 8 hours, then cooling to 613°C-629°C, keeping warm for another 8 hours, cooling to 80°C with an argon fan, and then air cooling out of the furnace.

[0021] Beneficial effects: The present invention realizes clamping restriction of the air duct inner tube assembly through the thermal correction fixture, limits the damping ring on the surface of the air duct inner tube assembly through the convex groove on the inner wall of the hoop assembly, and realizes the correction of the wave deformation and bamboo deformation of the air duct inner tube assembly through the thermal correction method; after correction, the surface of the heat insulation cover is smooth, the radial dimensions of the outer cylindrical surface of the damping ring are consistent, which is conducive to the assembly of the assembly and the realization of the assembly function, the axial opening dimensions of the air duct inner tube assembly in the free state are consistent, the assembly retains elasticity, can meet the performance and use requirements, and the whole set of fixtures has a simple structure and is easy to operate, which can meet the production and use needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The structure of the present invention is schematically shown Figure 1 ;

[0023] Figure 2 The structure of the present invention is schematically shown Figure 2 ;

[0024] Figure 3 is a cross-sectional view of the present invention;

[0025] Figure 4 for Figure 3 A schematic diagram of the enlarged structure of part A;

[0026] Figure 5 for Figure 3 A schematic diagram of the enlarged structure of part B;

[0027] Figure 6It is a structural schematic diagram of the mandrel of the present invention;

[0028] Figure 7 It is a structural schematic diagram of the base of the present invention;

[0029] Figure 8 It is a structural schematic diagram of the inner tube assembly of the air duct of the present invention;

[0030] Fig. 9 It is a structural schematic diagram of the hoop body of the present invention;

[0031] Fig.10 It is a schematic diagram of the structure of the gasket of the present invention;

[0032] Fig.11 It is a schematic structural diagram of the wedge block of the present invention.

[0033] In the figure, 1, core shaft; 2, base; 3, hoop assembly; 301, hoop body; 4, first flange; 5, groove; 6, air duct inner tube assembly; 7, convex groove; 8, connecting ear; 9, wedge block; 10, second flange; 11, fixing rod; 12, gasket; 13, hook; 14, gasket; 15, damping ring. DETAILED DESCRIPTION

[0034] The following is combined with Figure 1 To Attachment Fig.11 The principles and features of the present invention are described, and the examples given are only used to explain the present invention, rather than to limit the scope of the present invention.

[0035] A thermal correction fixture for an aircraft engine air duct inner tube assembly comprises a core shaft 1, a base 2 and a hoop assembly 3; a first flange 4 is provided at one end of the core shaft 1, the first flange 4 is connected to a groove 5 on the surface of the base 2 and is clearance-fitted, and the base 2 and the core shaft 1 are connected by bolts; an air duct inner tube assembly 6 is sleeved and connected to the surface of the core shaft 1, and one end of the air duct inner tube assembly 6 is inserted into the gap between the first flange 4 and the groove 5, and a plurality of the hoop assemblies 3 are coated on the surface of the air duct inner tube assembly 6 to limit the overall outer circumferential surface of the air duct inner tube assembly 6.

[0036] The inner wall of the hoop assembly 3 is provided with convex grooves 7 at intervals along the circumferential direction, and the convex grooves 7 correspond one to one with the arc-shaped protrusions on the surface of the air duct inner tube assembly 6, and are clearance-matched to ensure that when the outer surface of the air duct inner tube assembly 6 is tightened, each arc-shaped protrusion, i.e., the arc segment at the top of the damping ring 15, is protected.

[0037] The hoop assembly 3 is composed of several semicircular hoop bodies 301 with different widths, which are convenient for adjusting the axial clearance using the gasket 14. When in use, the hoop body 301 with a suitable width can be matched according to the length of the air duct inner tube assembly 6 to form the hoop assembly 3. Each group of hoop bodies 301 can limit the deformation of 1 to 2 damping rings 15 and their surroundings.

[0038] A connecting ear 8 extends from the end of the hoop body 301, and two hoop bodies 301 form a group. Wedge blocks 9 are clamped on the surfaces of the two connecting ears 8 to lock the hoop body 301. The clamping part between the wedge block 9 and the connecting ear 8 is designed to be narrow at the top and wide at the bottom. This design can produce a self-locking effect after heating, thereby improving the clamping effect.

[0039] A second flange 10 is provided at one end of the core shaft 1 away from the base 2, and a fixing rod 11 for limiting is radially connected to the side wall of the second flange 10, and a gasket 12 is clamped between the fixing rod 11 and the core shaft 1; a hook 13 is connected to the surface of the second flange 10, and the two hooks 13 are symmetrically arranged for hoisting the entire device.

[0040] It also includes a gasket 14, which is crescent-shaped and is used to adjust the axial position of each group of hoop bodies 301; when the convex grooves 7 and the arc-shaped protrusions on the surface of the air duct inner tube assembly 6 do not correspond one to one, gaskets 14 are inserted between adjacent groups of hoop bodies 301 to avoid assembly gaps caused by axial misalignment.

[0041] The thermal correction method based on the thermal correction fixture for the inner tube assembly of the aircraft engine air duct comprises the following steps:

[0042] Step S1: Check whether the thermal calibration fixture is missing any parts and keep it clean. Before clamping, the bulge and depression of the air duct inner tube assembly 6 should be stretched as much as possible, and the shell should be flattened as much as possible to facilitate the clamping of the air duct inner tube assembly 6;

[0043] Step S2: Assemble the mandrel 1 and the base 2 to limit one end of the air duct inner tube assembly 6. Since the gap between the base 2 and the mandrel 1 is small, the air duct inner tube assembly 6 cannot be directly inserted into the gap when it is directly fixed. In order to ensure the shape of the openings at both ends of the air duct inner tube assembly 6, the base 2 can be removed first, and the air duct inner tube assembly 6 can be hooped in the base 2 before being inserted into the mandrel 1.

[0044] Step S3: assemble the hoop assembly 3 layer by layer from one end of the base 2, two hoop bodies 301 form a group, and during assembly, pay attention to make the convex groove 7 match the position of the damping ring 15 on the surface of the air duct inner tube assembly 6, that is, the arc-shaped protrusion, and the two ends of the convex groove 7 are pressed on the welding section of the damping ring 15 as much as possible. The axial position between layers is adjusted by the gasket 14. After adjusting the position, close a group of hoop bodies 301 and use the wedge block 9 to gently wedge them;

[0045] Step S4: assembling the hoop assembly 3 layer by layer, and repeating the operation of step S3 to complete the initial assembly of the hoop assembly 3;

[0046] Step S5: Use the fixing rod 11 to cooperate with the core shaft 1 to press the gasket 12 tightly, so as to complete the axial limiting of all the assembly parts;

[0047] Step S6: tighten the wedge blocks 9 in sequence to complete the final position limiting of the hoop assembly 3;

[0048] Step S7: The air duct inner tube assembly 6 in the clamped state is subjected to vacuum heat treatment together with the clamp, and the whole is adjusted to a vertical state, and hoisted and heat treated in the vertical state; the heat treatment parameters are: heating to 710°C, keeping warm for 8 hours, then cooling to 620°C, keeping warm for another 8 hours, cooling to 80°C with an argon fan, and then taking out of the furnace for air cooling;

[0049] Step S8: After the heat treatment is completed, the fixtures are removed piece by piece to finally obtain the air duct inner tube assembly 6 that has been heat-corrected.

[0050] The present invention realizes clamping restriction of the air duct inner tube component 6 through a thermal correction fixture, limits the damping ring 15 on the surface of the air duct inner tube component 6 through the convex groove 7 on the inner wall of the hoop assembly 3, and realizes the correction of the wave deformation and bamboo deformation of the air duct inner tube component 6 through a thermal correction method; after correction, the surface of the heat insulation cover is smooth, the radial dimensions of the outer cylindrical surface of the damping ring 15 are consistent, which is conducive to the assembly of the component and the realization of the component function, the axial opening dimensions of the air duct inner tube component 6 in the free state are consistent, the component retains elasticity, can meet the performance and use requirements, and the whole set of fixtures has a simple structure and is easy to operate, which can meet the production and use needs.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A thermal correction fixture for an inner tube assembly of an aircraft engine air duct, characterized in that: The invention comprises a core shaft (1), a base (2) and a hoop assembly (3); a first flange (4) is arranged at one end of the core shaft (1), the first flange (4) is connected to a groove (5) on the surface of the base (2) and is clearance-fitted; an air duct inner tube assembly (6) is sleeved and connected to the surface of the core shaft (1), one end of which is inserted into the gap between the first flange (4) and the groove (5); a plurality of hoop assemblies (3) are covered on the surface of the air duct inner tube assembly (6); convex grooves (7) are distributed at intervals along the circumferential direction on the inner wall of the hoop assembly (3), the convex grooves (7) correspond one to one to arc-shaped protrusions on the surface of the air duct inner tube assembly (6) and are clearance-fitted.

2. The thermal correction fixture for the inner tube assembly of the aircraft engine air duct according to claim 1, characterized in that: The hoop assembly (3) comprises a plurality of semicircular arc hoop bodies (301) of different widths, a connecting ear (8) extending from the end of the hoop body (301), two hoop bodies (301) form a group, and wedge blocks (9) are clamped on the surfaces of the two connecting ears (8).

3. The thermal correction fixture for the inner tube assembly of the aircraft engine air duct according to claim 2, characterized in that: A second flange (10) is provided at one end of the core shaft (1) away from the base (2); a fixing rod (11) for limiting position is radially connected to the side wall of the second flange (10); a gasket (12) is clamped between the fixing rod (11) and the core shaft (1); and a hook (13) is connected to the surface of the second flange (10).

4. The thermal correction fixture for the inner tube assembly of the aircraft engine air duct according to claim 3, characterized in that: It also includes a gasket (14) which is crescent-shaped; when the convex groove (7) and the arc-shaped protrusion on the surface of the air duct inner tube assembly (6) do not correspond one to one, the gasket (14) is inserted between adjacent groups of hoop bodies (301).

5. The thermal calibration method for the thermal calibration fixture for the inner tube assembly of the air duct of an aircraft engine according to claim 4, characterized in that: The following steps are involved: Step S1: Check whether the thermal calibration fixture is missing any parts and keep it clean. Before clamping, the bulges and depressions of the air duct inner tube assembly (6) should be stretched as much as possible, and the shell should be flattened as much as possible to facilitate the clamping of the air duct inner tube assembly (6); Step S2: The core shaft (1) is combined with the base (2) to complete the positioning of one end of the air duct inner tube assembly (6). Since the gap between the base (2) and the core shaft (1) is small, the air duct inner tube assembly (6) cannot be directly inserted into the gap when it is directly fixed. In order to ensure the shape of the openings at both ends of the air duct inner tube assembly (6), the base (2) is first removed, and the air duct inner tube assembly (6) is hooped in the base (2) before being inserted into the core shaft (1); Step S3: assembling the hoop assembly (3) layer by layer from one end of the base (2), with two hoop bodies (301) forming a group. During assembly, attention should be paid to making the convex groove (7) match the position of the damping ring (15) on the surface of the air duct inner tube assembly (6), that is, the arc-shaped protrusion. The two ends of the convex groove (7) should be pressed as much as possible on the welding section of the damping ring (15). The axial position between the layers is adjusted by the gasket (14). After the position is adjusted, a group of hoop bodies (301) are closed and lightly wedged with a wedge (9); Step S4: assembling the hoop assembly (3) layer by layer, and repeating the operation of step S3 to complete the initial assembly of the hoop assembly (3); Step S5: Use the fixing rod (11) to cooperate with the core shaft (1) to press the gasket (12) tightly, so as to complete the axial limit of all assembly parts; Step S6: tightening the wedge blocks (9) in sequence to complete the final positioning of the hoop assembly (3); Step S7: The air duct inner tube assembly (6) in the clamped state is subjected to vacuum heat treatment together with the clamp, and the whole is adjusted to a vertical state, and hoisted and heat treated in the vertical state; Step S8: After the heat treatment is completed, the fixtures are removed piece by piece, and finally the air duct inner tube assembly (6) that has been heat-corrected is obtained.

6. The thermal calibration method according to claim 5, characterized in that: In step S7, the heat treatment parameters are: heating to 710°C-730°C, keeping warm for 8 hours, then cooling to 613°C-629°C, keeping warm for another 8 hours, cooling to 80°C with an argon fan, and then air cooling out of the furnace.

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