Thermal correction fixture and thermal correction method for multi-layer thin-walled annular laser welding assembly

Abstract

The present invention relates to the field of thermal correction technology, and in particular to a thermal correction fixture and a thermal correction method for a multi-layer thin-walled annular laser welding component, comprising: a base, the base is provided with a storage cavity for placing the thin-walled annular welding component, and a first through hole located in the center; a pressure ring, the pressure ring is provided with a convex shaft, the convex shaft can be embedded in the storage cavity to form a clearance fit, the pressure ring is also provided with a second through hole at the center, and a gasket is also provided between the thin-walled annular welding component and the convex shaft; a pull rod, the pull rod is provided with a limiting boss and a core shaft, the core shaft can pass through the first through hole and the second through hole and extend outward, the core shaft is also provided with an anti-loosening limiting block at the extended end, the core shaft forms a clearance fit with the second through hole, the thermal correction method and fixture of the multi-layer thin-walled annular laser welding component can eliminate the deformation of parts through the combined action of cold correction and hot correction, obtain parts with smooth end faces and retaining elasticity, and avoid the later rebound deformation of the parts.

Description

Technical Field

[0001] The invention relates to the technical field of thermal correction, in particular to a thermal correction fixture and a thermal correction method for a multi-layer thin-walled annular laser welding assembly. Background Art

[0002] As a common annular laser welding component, the fingertip sheet assembly is a precision part of the aircraft engine turbine. Its usual manufacturing process is to overlap multiple layers of annular sheets (made of GH605) and then laser weld the outer cylindrical surface. The fingertip beam located on the inner cylindrical surface of the fingertip sheet assembly contacts the shaft to form a seal. After the fingertip sheet assembly is welded, the end face of the part must be flat, and the adjacent layers must not stick together. The fingertip beam can rebound after being pressed radially to maintain elasticity. The fingertip beam is easily warped due to scratches during the transportation and processing of the parts. During welding, due to the shrinkage of the weld, the weldment as a whole will be distorted or deformed, which will affect the sealing effect after the parts are assembled, resulting in the parts being unable to be used normally and a high scrap rate.

[0003] The Chinese invention patent with authorization announcement number CN111531325B discloses a method for processing split fingertip pieces, including the following steps: S1: blanking, leveling the raw materials by heat treatment, and blanking the split fingertip pieces according to the preset split size and number of split fingertip pieces to form a group of workpieces; S2: rough processing, loading the workpieces into a tooling plate, fixing the tooling plate and the workpieces together through screw clamping holes with screws, milling out the reference angle ruler surface on the tooling plate, using the correction reference hole on the tooling plate as the processing center, drilling the grooves of the process holes at the preset positions of the process holes of the workpiece, and using a punch to punch holes in the process holes. A threading hole is punched in the groove; S3: wire cutting processing, the dimension lines of the inner diameter and outer circle of the workpiece are determined by the correction reference hole, and the workpiece is cut according to the dimension lines, and the joint surfaces of the workpiece are grinded respectively; the workpiece is assembled into a plurality of full circles by splicing the joint surfaces, and laser welding points are used at the joint surfaces to fix the joint surfaces and grind the welding points; the above-mentioned public scheme divides the large fingertip sheet into multiple petals, processes them separately, and welds them into a whole at the joint surfaces with a laser, and combines them with tooling for subsequent detailed processing to improve the utilization rate of materials, but the above-mentioned public scheme does not propose a solution for the deformation of the fingertip sheet assembly during subsequent transportation and processing. Summary of the invention

[0004] Technical purpose: In order to overcome the deficiencies in the prior art, the present invention provides a thermal correction fixture and a thermal correction method for a multi-layer thin-walled annular laser welding assembly.

[0005] Technical solution: To achieve the above purpose, the thermal correction fixture of the multi-layer thin-walled annular laser welding assembly disclosed in the present invention comprises:

[0006] A base, wherein the base is provided with a storage cavity for placing the thin-walled annular welding assembly, and a first through hole located in the center;

[0007] A pressure ring, wherein the pressure ring is provided with a convex shaft, the convex shaft can be embedded in the storage cavity to form a clearance fit, the pressure ring is also provided with a second through hole at the center, and a gasket is also provided between the thin-walled annular welding assembly and the convex shaft;

[0008] The pull rod is provided with a limiting boss and a core shaft, the core shaft can pass through the first through hole and the second through hole and extend outward, the core shaft is also provided with an anti-loosening limiting block at the extended end, and the core shaft forms a clearance fit with the second through hole.

[0009] Preferably, the length of the convex shaft is defined as L, the depth of the storage cavity is defined as H, and L satisfies 0.5H<L≤H. A convex disk is provided at the outer end of the convex shaft.

[0010] Preferably, the diameter of the storage cavity is defined as A, the outer diameter of the thin-walled annular welding assembly is defined as B, then A=B+1mm, and a backing groove is provided at the root of the storage cavity.

[0011] Preferably, the upper and lower end surfaces of the gasket are parallel, the thickness is not less than 3 mm, the outer diameter of the gasket is C, and C=B.

[0012] Preferably, the inner hole size D of the gasket and the diameter size of the first through hole are both smaller than the inner hole size E of the thin-walled annular welding assembly.

[0013] Preferably, the limiting block is wedge-shaped, and the core shaft is provided with a wedge-shaped hole that cooperates with the limiting block.

[0014] The present invention also provides a thermal correction method based on a thermal correction fixture of a multi-layer thin-walled annular laser welding assembly, the steps of which are as follows:

[0015] S1: Clean the impurities on the base, pressure ring, pull rod and gasket, and wipe them with absorbent cotton dipped in acetone and air dry;

[0016] S2: Clean the thin-walled annular welded components with acetone and air dry;

[0017] S3: insert the pull rod into the first through hole of the base, place it horizontally on the platform, put the thin-walled annular welding assembly into the storage cavity, put the gasket in, install the pressure ring, and lock it with a limit block;

[0018] S4: placing a plurality of thermal correction fixtures equipped with the thin-walled annular welding components into a furnace at intervals, with the base located at the bottom, and not being inverted or stacked, for vacuum heat treatment;

[0019] S5: After the vacuum heat treatment, the thermal calibration fixture is air-cooled to room temperature, and the thin-walled annular welded components are opened and taken out one by one. The surfaces of the thin-walled annular welded components are wiped clean with a silk cloth dipped in acetone or by ultrasonic cleaning.

[0020] Preferably, in step S3, when there are multiple groups of thin-walled annular welding components placed in the storage cavity, a gasket ring needs to be placed between every two groups of thin-walled annular welding components.

[0021] Preferably, the vacuum heat treatment in step S4 comprises the following steps:

[0022] S201: Vacuuming: vacuum degree during operation 1×10 -3 Pa;

[0023] S202: Heating: heating to 700°C to 800°C;

[0024] S203: Insulation: Insulation for 2h to 4h;

[0025] S204: Cooling: After the furnace is cooled to 80°C, the vacuum state is removed and the furnace is air-cooled.

[0026] The beneficial effects of the present invention are:

[0027] 1. The thin-walled annular welded assembly to be corrected is placed in the thermal correction fixture. Through the cooperation of the pull rod and the limit block, the pressure ring applies vertical force to the thin-walled annular welded assembly to be corrected, performs cold correction, eliminates deformation, and can also be locked to prevent loosening for easy disassembly.

[0028] 2. The assembled thermal correction fixture is subjected to vacuum heat treatment to eliminate the deformation stress of the thin-walled annular welded components to be corrected, ensuring that no springback deformation will occur after the thermal correction fixture is removed after cooling; through the combined action of the thermal correction fixture and vacuum heat treatment, the thin-walled annular welded components to be corrected can eliminate the opening deformation, end face distortion, and warping deformation, and obtain parts with smooth end faces and retained elasticity.

[0029] 3. One or more groups of thin-walled annular welded assemblies to be corrected can be installed in one thermal correction fixture to improve the efficiency of single thermal correction. At the same time, inserting gaskets between two thin-walled annular welded assemblies to be corrected can prevent adhesion between adjacent parts and provide a flat force interface for the thin-walled annular welded assemblies to ensure the flatness of the rear end surface after thermal correction. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a cross-sectional view of the overall structure of the thermal correction fixture of the present invention;

[0031] Figure 2 It is a stereoscopic diagram of the overall structure of the thermal correction fixture of the present invention;

[0032] Figure 3 is a cross-sectional view of the base in the present invention;

[0033] Figure 4 for Figure 3 Magnified view of area F in the middle;

[0034] Figure 5 This is a schematic diagram of the structure of a thin-walled annular welding assembly in the present invention;

[0035] Figure 6 is a cross-sectional view of the gasket ring in the present invention;

[0036] Figure 7 It is a cross-sectional view of the pressure ring of the present invention;

[0037] Figure 8 It is a cross-sectional view of the pull rod in the present invention.

[0038] In the figure, 1. base; 101. storage cavity; 102. first through hole; 103. tool withdrawal groove; 2. thin-walled annular welding assembly; 3. pressure ring; 301. convex shaft; 302. second through hole; 303. convex disk; 4. gasket; 5. pull rod; 501. limiting boss; 502. core shaft; 503. wedge-shaped hole; 6. limiting block. DETAILED DESCRIPTION

[0039] The following is combined with Figure 1 To Attachment Figure 8 The principles and features of the present invention are described, and the examples given are only used to explain the present invention, not to limit the scope of the present invention.

[0040] Example 1: Thermal correction fixture for multi-layer thin-walled annular laser welding components, such as Figure 1 — Figure 5 As shown, it includes a base 1, a pressure ring 3 and a pull rod 5. The base 1 is provided with a storage cavity 101 for placing a thin-walled annular welding component 2, and a first through hole 102 located in the center; in this embodiment, the thin-walled annular welding component 2 is a fingertip sheet component, which is formed by laser welding the outer circumference of seven layers of annular sheets, the thickness of a single-layer annular sheet is 0.25mm, the thickness of the fingertip sheet component after welding is 2mm~2.3mm, and the material of the fingertip sheet component is GH605. The diameter size of the storage cavity 101 is defined as A, and the outer diameter size of the thin-walled annular welding component 2 is defined as B, then A=B+1mm, and the gap reserved in the diameter direction of the storage cavity 101 gives the thin-walled annular welding component 2 a certain deformation space and limits the change of its outer circle. In this embodiment, the B value is 100mm and the A value is 101mm. In order to ensure that the thin-walled annular welding component 2 is placed flat in the storage cavity 101, a backing groove 103 for root cleaning is provided at the root of the storage cavity 101.

[0041] like Figure 6 — Figure 7 As shown, the pressing ring 3 is provided with a convex shaft 301, which can be embedded in the storage cavity 101 to form a clearance fit. The pressing ring 3 is also provided with a second through hole 302 at the center. The length of the convex shaft 301 is defined as L, and the depth of the storage cavity 101 is defined as H. L satisfies 0.5H<L≤H. In this embodiment, the H value is 16mm and the L value is 10mm. In another embodiment, the H value is 16mm and the L value can also be 16mm. In order to facilitate the subsequent separation of the pressing ring 3 and the base 1, a convex disc 303 is provided at the outer end of the convex shaft 301.

[0042] A gasket 4 is also provided between the thin-walled annular welding component 2 and the convex shaft 301. The upper and lower end surfaces of the gasket 4 are parallel and the outer surface is smooth. The vertical pressure from the convex shaft 301 is evenly applied to the thin-walled annular welding component 2 through the gasket 4. The thickness of the gasket 4 is not less than 3 mm. The outer diameter of the gasket 4 is C, C=B. In this embodiment, the C value is 100 mm. The inner hole size D of the gasket 4 and the diameter size of the first through hole 102 are both smaller than the inner hole size E of the thin-walled annular welding component 2. In this embodiment, the E value is 78 mm, and the diameter sizes of D and the first through hole 102 are both 60 mm.

[0043] like Figure 8 As shown, the pull rod 5 is provided with a limiting boss 501 and a core shaft 502. The core shaft 502 can pass through the first through hole 102 and the second through hole 302 and extend outward. The core shaft 502 is also provided with a loose-proof limiting block 6 at the extended end. The core shaft 502 forms a tight clearance fit with the second through hole 302 to ensure that the pull rod 5 and the pressure ring 3 are coaxial after assembly. Since the convex shaft 301 can be embedded in the storage cavity 101 to form a clearance fit, the pull rod 5, the pressure ring 3 and the base 1 are coaxial after assembly. In order to facilitate the disassembly and assembly of the limiting block 6 and improve the anti-loosening effect, the limiting block 6 is wedge-shaped, and the core shaft 502 is provided with a wedge-shaped hole 503 that cooperates with the limiting block 6. When the limiting block 6 is installed in the wedge-shaped hole 503, a self-locking effect is generated and it will not loosen. Moreover, through the cooperation with the pull rod 5, pressure can be generated on the thin-walled annular welding assembly 2 to perform cold correction and eliminate the opening deformation and fingertip beam warping. The material selection of the base 1, pressure ring 3, gasket 4, pull rod 5 and limit block 6 is related to the material of the thin-walled annular welding component 2, and the thermal expansion coefficients of the materials should be the same or similar. In this embodiment, the material of the thin-walled annular welding component 2 is GH605, and the optimal material of the base 1, pressure ring 3, gasket 4, pull rod 5 and limit block 6 is GH605. However, the thermal expansion coefficients of the fixture made of 1Cr18Ni9Ti material are similar and can also meet the requirements of correcting part deformation.

[0044] Embodiment 2: A thermal calibration method based on the thermal calibration fixture of the multi-layer thin-walled annular laser welding assembly, the steps are as follows:

[0045] S1: Cleaning the fixture: clean the impurities on the base 1, the pressure ring 3, the pull rod 5 and the gasket 4, and wipe them further with acetone dipped in absorbent cotton and air-dry them, focusing on cleaning the gasket 4 and the surface of the storage cavity 101.

[0046] Specifically, clean the thermal calibration fixture and remove dirt such as oil that affects the vacuum heat treatment effect. When cleaning the thermal calibration fixture, if it is found that its surface is difficult to clean, it should be polished or replaced with a new thermal calibration fixture. If the thermal calibration fixture is deformed, resulting in failure of the fit between components or poor parallelism of the two end faces of the gasket 4, the failed components should be replaced in time.

[0047] S2: Cleaning parts: Clean the thin-walled annular welding component 2 with acetone and then air-dry it. In the present embodiment, the thin-walled annular welding component 2 is a fingertip sheet component, which is formed by laser welding the outer circumference of seven layers of annular sheets. The thickness of a single-layer annular sheet is 0.25 mm. The thickness of the fingertip sheet component after welding is 2 mm to 2.3 mm. The material of the fingertip sheet component is GH605. Care should be taken to avoid warping of the fingertip beam during cleaning.

[0048] S3: Clamping parts: insert the pull rod 5 into the first through hole 102 of the base 1, place it horizontally on the platform, put the thin-walled annular welding assembly 2 into the storage cavity 101, put in the gasket 4, install the pressure ring 3, and lock it with the limit block 6. When multiple groups of thin-walled annular welding assemblies 2 need to be corrected at a time, put the multiple groups of thin-walled annular welding assemblies 2 into the storage cavity 101, and put a gasket 4 between every two groups of thin-walled annular welding assemblies 2. The gasket 4 can separate adjacent thin-walled annular welding assemblies 2 to prevent adhesion and provide a flat cross section for the application of pressure, so that multiple pieces of thermal correction can be achieved at a time, and the thermal correction efficiency can be improved.

[0049] S4: Place several thermal correction fixtures equipped with thin-walled annular welding components 2 into the furnace at intervals for vacuum heat treatment. During the placement process, ensure that the base 1 is located at the bottom. Do not invert or stack them. No contact is allowed between the thermal correction fixtures.

[0050] Vacuum heat treatment includes the following steps:

[0051] S201: Vacuuming: vacuum degree during operation 1×10 -3 Pa;

[0052] S202: Heating: heating to 700°C;

[0053] As another preferred embodiment of the present invention, the heating temperature may also be 750° C. or 800° C., and the above vacuum heat treatment temperatures may both meet the requirements of the thermal correction process.

[0054] S203: Insulation: Insulation for 2 hours;

[0055] As another preferred embodiment of the present invention, the insulation time can also be adjusted according to the different materials of the thin-walled annular welding component 2. The insulation time can also be 3 hours or 4 hours. The above insulation time can meet the thermal correction process requirements.

[0056] S204: Cooling: After the furnace is cooled to 80°C, the vacuum state is removed and the product is taken out of the furnace for air cooling.

[0057] S5: After the vacuum heat treatment, the thermal correction fixture is air-cooled to room temperature, the limit block 6 is removed, the thermal correction fixture is opened and the thin-walled annular welding components 2 are taken out one by one, and the surface of the thin-walled annular welding components 2 is wiped clean with a silk cloth dipped in acetone or by ultrasonic cleaning. In this embodiment, the surface of the thin-walled annular welding components 2 is wiped clean with a silk cloth dipped in acetone. When the thin-walled annular welding component 2 is a fingertip sheet component, check the activity of the fingertip beam. If the fingertip beam cannot be easily pressed radially, the surface of the fingertip beam can be gently rolled with a round wooden stick to allow air to flow into the gap of the fingertip beam to restore the rebound of the fingertip beam. The above-mentioned thermal correction method is used to correct the deformation of the thin-walled annular welding component 2 and similar structural parts, which can eliminate the opening deformation, end face distortion, and warping deformation of the parts, and obtain a flat end face, non-adhesion between adjacent layers, and the fingertip beam can rebound after being pressed radially, and retains elastic parts, and deformation rebound can be avoided. The vacuum heat treatment parameters can also be adjusted according to the different materials of the thin-walled annular welding component 2.

[0058] The working principle of the present invention is as follows: the surfaces of the thermal correction fixture and the thin-walled annular welding component 2 are cleaned to ensure that the base 1, the pressure ring 3, the gasket 4 and the pull rod 5 are well matched and free of deformation. The thin-walled annular welding component 2 to be corrected is placed in the storage cavity 101 and the gasket 4 is placed in it, and the pressure ring 3 is installed. The limit block 6 is knocked into the wedge-shaped hole 503 for locking, so as to provide cold correction pressure for the thin-walled annular welding component 2. After assembly, thermal correction is performed through vacuum heat treatment. The thin-walled annular welding component 2 after thermal correction can eliminate the opening deformation, end face twisting and warping deformation of the part, obtain a flat end face, non-adhesion between adjacent layers, and obtain a part with elasticity.

[0059] 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. Thermal correction fixture for multi-layer thin-walled annular laser welding components, characterized in that: include: A base (1), the base (1) being provided with a storage cavity (101) for accommodating a thin-walled annular welding component (2), and a first through hole (102) located at the center; A pressure ring (3), the pressure ring (3) being provided with a convex shaft (301), the convex shaft (301) being capable of being embedded in the storage cavity (101) to form a clearance fit, the pressure ring (3) being further provided with a second through hole (302) at the center, and a gasket (4) being further provided between the thin-walled annular welding component (2) and the convex shaft (301); A pull rod (5), the pull rod (5) being provided with a limiting boss (501) and a core shaft (502), the core shaft (502) being able to penetrate the first through hole (102) and the second through hole (302) and extend outwards, the core shaft (502) being further provided with an anti-loosening limiting block (6) at the extended end, the core shaft (502) and the second through hole (302) forming a clearance fit; The thermal correction method based on the thermal correction fixture of the multi-layer thin-walled annular laser welding assembly comprises the following steps: S1: clean the impurities on the base (1), the pressure ring (3), the pull rod (5) and the gasket (4), and wipe them further with absorbent cotton dipped in acetone and air-dry them; S2: Clean the thin-walled annular welded component (2) with acetone and then air dry; S3: inserting the pull rod (5) into the first through hole (102) of the base (1), placing it horizontally on the platform, placing the thin-walled annular welding assembly (2) into the storage cavity (101), placing the gasket (4), installing the pressure ring (3), and locking it with a limit block (6); S4: placing a plurality of heat correction fixtures equipped with the thin-walled annular welding components (2) into a furnace at intervals, with the base (1) located at the bottom, and not being inverted or stacked, for vacuum heat treatment; S5: After the heat calibration fixture has been subjected to vacuum heat treatment, it is air-cooled to room temperature, the thin-walled annular welded components (2) are opened and taken out one by one, and the surface of the thin-walled annular welded components (2) is wiped clean with a silk cloth dipped in acetone or by ultrasonic cleaning; The vacuum heat treatment in step S4 comprises the following steps: S201: Vacuuming: vacuum degree during operation 1×10 -3 Pa; S202: Heating: heating to 700°C to 800°C; S203: Insulation: Insulation for 2h to 4h; S204: Cooling: After the furnace is cooled to 80°C, the vacuum state is removed and the furnace is air-cooled.

2. The thermal correction fixture for a multi-layer thin-walled annular laser welding assembly according to claim 1, characterized in that: The length of the convex shaft (301) is defined as L, the depth of the storage chamber (101) is defined as H, and L satisfies 0.5H<L≤H. A convex disc (303) is provided at the outer end of the convex shaft (301).

3. The thermal correction fixture for a multi-layer thin-walled annular laser welding assembly according to claim 2, characterized in that: The diameter of the storage cavity (101) is defined as A, and the outer diameter of the thin-walled annular welding component (2) is defined as B, then A=B+1 mm, and a backing groove (103) is provided at the root of the storage cavity (101).

4. The thermal correction fixture for a multi-layer thin-walled annular laser welding assembly according to claim 3, characterized in that: The upper and lower end surfaces of the gasket (4) are parallel, the thickness is not less than 3 mm, the outer diameter of the gasket (4) is C, and C=B.

5. The thermal correction fixture for the multi-layer thin-walled annular laser welding assembly according to claim 4 is characterized in that: The inner hole size D of the gasket ring (4) and the diameter size of the first through hole (102) are both smaller than the inner hole size E of the thin-walled annular welding component (2).

6. The thermal correction fixture for a multi-layer thin-walled annular laser welding assembly according to claim 1, characterized in that: The limiting block (6) is wedge-shaped, and the core shaft (502) is provided with a wedge-shaped hole (503) that matches the limiting block (6).

7. The thermal correction fixture for a multi-layer thin-walled annular laser welding assembly according to claim 1, characterized in that: In the step S3, when there are multiple groups of the thin-walled annular welding components (2) placed in the storage cavity (101), a gasket (4) needs to be placed between every two groups of the thin-walled annular welding components (2).

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