High-temperature alloy processing method for thin plate with small-diameter inclined hole and multi-convex hull characteristics

Abstract

The invention belongs to the field of thin plate high-temperature alloy machining and manufacturing, and relates to a machining method for a thin plate high-temperature alloy with the small-diameter inclined hole multi-convex-hull characteristic. According to the method, the machining efficiency and quality of the sheet high-temperature alloy are improved, the hole forming position is determined on an unfolded graph through a hole-axis positioning method, non-contact laser cutting is adopted, manufacturing of a two-dimensional unfolded blank contour, a characteristic small hole and a process positioning hole is completed on a component base material plate, and a local step-by-step forming method is adopted for the blank. According to the method, the process positioning hole is used for positioning to carry out integral molded surface die forming, then the convex hull characteristics of the parts are formed one by one through the bending die with the local molded surface, and finally the parts are positioned and clamped in the heat treatment clamp through the process positioning hole, so that accurate shape correction is realized. And the accuracy of the convex hull is ensured.

Description

Technical Field

[0001] The invention belongs to the field of thin plate high temperature alloy processing and manufacturing, and relates to a thin plate high temperature alloy processing method with small diameter inclined holes and multiple convex hull features. Background Art

[0002] In order to adapt to the service environment and load conditions of the combined effects of force, heat, sound and vibration, especially to overcome the new problems brought by the high-temperature service environment conditions of the structure, the commonly used titanium alloys and composite materials are no longer competent. As a result, more and more high-temperature alloy materials are used in aircraft. In addition to the iteration of part materials, many active cooling technologies are adopted in the product structure, among which the small-diameter inclined hole feature is a commonly used active cooling structure. Since the hole diameter distributed on the entire surface of the thin plate part is as small as 2mm and the central axis of the hole is at a certain angle to the normal of the surface, drilling is the preferred method, but the poor cutting performance of the high-temperature alloy, the large number of small-diameter inclined holes, and the need to ensure the angle between the central axis and the normal require not only special drilling jigs but also special high-temperature alloy steel drill bits, and a lot of manpower is required. In addition, in order to meet the assembly requirements of this type of thin plate high-temperature alloy, multiple convex hull structures for screw connection appear on the surface of the part. This type of convex hull structure is suitable for one-time molding by die pressing, and can accurately ensure the spatial position of each convex hull. In fact, due to the constraints of the part structure, the convex hull axis forms a negative angle, and the molding cannot be completed in one time. At the same time, in order to eliminate the springback generated after the thin plate is molded, the part needs to be corrected twice, and the convex hull will inevitably become a stumbling block for correcting the springback. In order to quickly, accurately and efficiently realize the forming of thin-plate high-temperature alloys with small-diameter inclined holes and multiple convex hulls, it is urgent to find a suitable processing method. Summary of the invention

[0003] According to the above-mentioned problems of large number of small-diameter inclined holes in thin plate high-temperature alloy, poor machinability, large labor workload, and contradiction between the structure of parts with multiple convex hull features and the forming process, a method for processing thin plate high-temperature alloy with small-diameter inclined holes and multiple convex hull features is provided to improve the processing efficiency and quality of thin plate high-temperature alloy, and the hole axis positioning method is used to determine the hole making position on the unfolded graph, and non-contact laser cutting is used to complete the manufacture of two-dimensional unfolded rough material contour, characteristic small holes and process positioning holes on the component substrate sheet. The rough material is formed by a local step-by-step forming method, and the process positioning holes are first used to position the overall surface for die pressing. Then, the convex hull features of the parts are formed one by one through a bending die with a local surface. Finally, the parts are first positioned and clamped in a heat treatment fixture with the process positioning holes to achieve precise correction. The normal direction of the convex hull can be flexibly adjusted during the forming process to ensure the accuracy of the convex hull.

[0004] The technical solution of the present invention:

[0005] A processing method for a thin plate high-temperature alloy with small-diameter inclined holes and multiple convex hull features is used to determine the position of the process positioning hole according to the shape of the thin plate high-temperature alloy part, and the hole axis positioning method is used to determine the hole position, and the two-dimensional manufacturing data set used for component blanking is determined. The laser cutting process is used to complete the manufacturing of the rough material contour, characteristic small holes and process positioning holes on the substrate sheet. During the bending process, the process positioning holes are used for positioning, and the part profile is bent and formed. After that, the part is clamped in a mold with a theoretical position of the convex hull hole, and the convex hull center hole is drilled. The convex hull center hole is used as the positioning reference, and the convex hull feature is formed on the local bending die. Finally, the positioning hole is still used as the processing reference, and the processed part is clamped in the heat treatment tooling to achieve precise shape correction, as follows:

[0006] Step 1: Process positioning hole setting

[0007] The positioning holes serve as the processing reference for each processing step in the component manufacturing process and run through the entire process of thin plate high-temperature alloy parts processing. In order to reduce the calculation deviation, the positioning holes are selected on the same edge where the curvature of the part changes little. The positioning holes are attached to the ear pieces, and the number of positioning holes is selected to be 2 to 3. In order to better constrain the degree of freedom of the parts, the spacing between the positioning holes is not less than 200 mm, and the diameter of the positioning holes is selected to be 2.7 to 5.2 mm.

[0008] Step 2: 2D unfolding data set and unfolding rough material production

[0009] The two-dimensional unfolding data set is the flattening of the theoretical profile of the part. As the important data for generating the laser cutting trajectory, the three-dimensional data set containing all the features of the part with the positioning lugs and positioning holes added, including the small-diameter inclined holes, convex hulls, etc., is proportionally unfolded through the CATIA data unfolding module;

[0010] The hole-axis positioning method extracts the intersection of the axis of the inclined hole and the upper surface of the component in the digital model of the component, and projects the point onto the pre-expanded surface, and uses the unfolding function to unfold the center point, locating hole, convex hull center and other features along with the selected unfolding surface to form a two-dimensional unfolding data set;

[0011] The laser cutting machine generates processing codes based on the two-dimensional unfolded data set. The angle between the laser and the thin plate is the same as the inclined hole. It cuts small-diameter inclined holes, positioning holes, and part shapes on the thin plate to achieve the processing of unfolded raw materials.

[0012] Step 3: Bending the Part

[0013] The bending part forming described above clamps the upper and lower bending dies that are in harmony with the part profile at the center of the upper and lower platforms of the hydraulic press by bolts. According to the characteristics of the part profile, the unfolded rough material is preformed by laser impact forming technology so that the positioning holes can be coordinated and fitted with the positioning pins on the bending die to achieve effective positioning. After the preformed unfolded rough material is stably positioned on the lower die, the upper die is slowly lowered to achieve effective closure and pressure maintenance of the upper and lower dies to complete the bending forming of the part;

[0014] Step 4: Convex hull feature processing

[0015] The convex hulls are evenly distributed on the surface of the entire part. In order to determine the theoretical position of the convex hulls, a mold with the theoretical position of the convex hulls is designed. The mold surface is coordinated with the part surface. The positioning pin A is also arranged on the tire body to coordinate with the positioning hole of the rough material. A drilling mechanism is arranged on the tire cover at the center of the convex hull. The drilling mechanism is lined with a drill sleeve, and the axis thereof coincides with the center line of the convex hull. In order to facilitate drilling, the thickness of the tire cover of the drilling mechanism is thinned.

[0016] The corresponding carcass parts are set to avoid;

[0017] The formed blank is clamped in the mold with the positioning hole as the positioning reference and pressed tightly, so that the blank tends to the theoretical position in the mold. A handheld electric drill forms a bottom hole on the part through the drill sleeve on the tire cover. Due to the poor cutting performance of thin plate high-temperature alloy, a positive punch can also be used to print a center hole on the part through the drilling mechanism, and then the part is taken out and placed on a bench drilling machine to finally complete the drilling of the bottom hole;

[0018] The local bending die is designed with the bottom hole of each convex hull as the positioning reference. The local bending model surface is in the same proportion as the convex hull profile surface, and is in the form of a male and female die, and is installed on an ordinary punching machine. A cylindrical positioning pin A is set at the center of the male and female dies, and its diameter is the same as the bottom hole of the hull. The matching relationship of the local bending model surface is aligned by the male and female model surfaces and the cylindrical positioning pin A, and there is no need to set up a guide mechanism for guiding the male and female dies, so as to avoid interference with the raw material during the convex hull process;

[0019] Install the local bending die on the punch press and align the matching surface. Hold the raw material, identify the direction of the convex hull, insert the bottom hole of the convex hull into the cylindrical positioning pin A, and keep the normal line of the curved surface parallel to the vertical direction, that is, the normal line of the convex hull hole is parallel to the vertical direction. Start the punch press to complete the convex hull forming. Repeat the above steps to complete all convex hull forming.

[0020] After the convex hull is formed, the bottom hole of the convex hull is enlarged by drawing, and the enlarged bottom hole is used as the positioning reference to design a punching die, and the final processing of the upper hole of the convex hull is completed by the punching method;

[0021] Step 5: Precise calibration

[0022] The precise shape correction described above still uses the positioning hole as the processing reference, and the parts are mounted on a stable heat treatment fixture through the positioning pins, and the surface springback and internal stress generated during the forming process are eliminated by heating and heat preservation in the clamped state;

[0023] The heat treatment fixture has high temperature resistance. The area of ​​the clamping profile is set according to the springback state of the part, and the convex hull feature on its surface is avoided. In order to improve the use efficiency of the heat treatment furnace, the upper surface of the heat treatment fixture is processed into a flat surface, which can be stacked and placed. The thin plate high-temperature alloy parts that are precisely shaped by heat treatment completely eliminate the springback and internal stress, and further improve the forming accuracy.

[0024] Through the above precise calculation simplification of parts before forming, discrete processing thinking and unchanged processing datum during forming, and precise correction of stable heat treatment after forming, the processing and forming of thin plate high-temperature alloy with small-diameter inclined holes and multiple convex hulls is achieved.

[0025] Beneficial effects of the present invention:

[0026] (1) The hole-axis positioning method was proposed to accurately determine the hole position through the conversion between the three-dimensional digital model and the two-dimensional diagram, thereby improving the manufacturing quality and precision of the product;

[0027] (2) The step-by-step forming method improves the manufacturing accuracy of the components. The step-by-step forming method uses a unified theoretical positioning reference for forming positioning, which reduces the error caused by repeated positioning. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Select schematic diagrams for the positioning holes and lugs;

[0029] Figure 2 It is a two-dimensional expansion schematic diagram;

[0030] Figure 3 is a schematic diagram of the bending die;

[0031] Figure 4 Schematic diagram of tire type;

[0032] Figure 5 Schematic diagram of the convex die and concave die and processing status;

[0033] Figure 6 Schematic diagram of the heat treatment fixture.

[0034] Among them: 1 positioning hole, 2 ear piece, 3 edge with small curvature change, 4 lower die of bending die, 5 positioning pin, 6 tire cover, 7 drilling mechanism, 8 positioning pin A, 9 convex hull. DETAILED DESCRIPTION

[0035] The present invention is explained below with reference to figures and examples for easier understanding.

[0036] 1. Setting of positioning holes

[0037] The positioning holes 1 are used throughout the entire process of thin plate high temperature alloy parts processing, and serve as the processing reference for each processing step. In order to reduce the calculation deviation and facilitate positioning during forming, the positioning holes 1 are selected as much as possible on the same edge 3 with small curvature change of the part. The positioning holes 1 are attached to the ear pieces 2, and the number of positioning holes 1 is selected to be 2. In order to better constrain the degree of freedom of the parts, the spacing between the positioning holes 1 is not less than 200mm, and the diameter of the positioning holes 1 is selected to be 5.2mm. Figure 1 shown.

[0038] 2. Production of 2D unfolded data set and unfolded wool material

[0039] The two-dimensional unfolded data set is a flattened theoretical profile of the part. It is a three-dimensional data set of all features including small-diameter inclined holes, convex hulls 9, etc., which is proportionally unfolded through the CATIA data unfolding module using the selected reference plane as the unfolding reference. The two-dimensional unfolded data set is reversible with the three-dimensional data set, that is, the three-dimensional data set can be unfolded into a two-dimensional unfolded data set through the CATIA software. At the same time, the two-dimensional unfolded data set can achieve a three-dimensional data set state after forming. The two-dimensional unfolded data set is important data for the generation of laser cutting trajectories. The laser cutting machine uses the processing code generated by the two-dimensional unfolded data set. The angle between the laser and the thin plate is the same as the inclined hole. The small-diameter inclined hole, the locating hole 1, and the part shape and other features are cut on the thin plate to realize the processing of the unfolded rough material. Figure 2 shown.

[0040] 3. Bending parts forming

[0041] The bending part forming described above will coordinate with the upper and lower bending dies of the part profile. The upper die is not shown and is clamped in the center of the upper and lower platforms of the hydraulic press by bolts. According to the characteristics of the part profile, the laser impact forming technology is used to preform the expanded raw material so that the positioning hole 1 can coordinate with the positioning pin 5 on the bending die to achieve effective positioning. After the preformed expanded raw material is stably positioned on the lower die, the upper die is slowly lowered to achieve effective closure and pressure maintenance of the upper and lower dies to complete the bending forming of the part. Figure 3 shown.

[0042] 4. Convex hull feature processing

[0043] The convex hull 9 is evenly distributed on the surface of the entire part. In order to determine the theoretical position of the convex hull 9, a mold with the theoretical position of the convex hull 9 is designed. The mold surface is coordinated with the part surface. The positioning pin is also arranged on the tire body to coordinate with the positioning hole 1 of the rough material. A drilling mechanism 7 is arranged at the center of the convex hull 9 on the tire cover 6. The drilling mechanism 7 is lined with a drill sleeve, and the axis thereof coincides with the center line of the convex hull 9. In order to facilitate drilling, the thickness of the tire cover 6 of the drilling mechanism 7 is thinned. The corresponding tire body part is provided with a avoidance.

[0044] The formed blank is clamped in the mold with the positioning hole 1 as the positioning reference and pressed tightly, so that the blank tends to the theoretical position in the mold. A handheld electric drill forms a bottom hole on the part through the drill sleeve on the tire cover 6. Due to the poor cutting performance of thin plate high-temperature alloy, a positive punch can also be used to print a center hole on the part through the drilling mechanism 7, and then the part is taken out and placed on a bench drilling machine to finally complete the drilling of the bottom hole. Figure 4 shown.

[0045] The local bending die is designed with the bottom hole of each convex hump 9 as the positioning reference. The local bending model surface is in the same proportion as the convex hump 9 profile, and is in the form of a male and female die, and is installed on an ordinary punching machine. A cylindrical positioning pin 8 is set at the center of the male and female die, and its diameter is the same as the bottom hole of the convex hump 9. The matching relationship of the local bending model surface is aligned by the male and female model surfaces and the cylindrical positioning pin 8, and there is no need to set up a guiding mechanism for guiding the male and female dies, so as to avoid interference with the raw material during the convex hump 9 process.

[0046] Install the local bending die on the punch press and align the matching surface. Hold the raw material, identify the direction of the convex 9, insert the bottom hole of the convex 9 into the cylindrical positioning pin 8, and keep the normal line of the curved surface parallel to the vertical direction, that is, the normal line of the convex 9 hole is parallel to the vertical direction. Start the punch press to complete the convex 9 forming. Repeat the above steps to complete the forming of all convex 9. Figure 5 shown.

[0047] After the convex hull 9 is formed, the bottom hole of the convex hull 9 is enlarged by drawing, and the enlarged bottom hole is used as a positioning reference, and a punching die is designed, and the final processing of the hole on the convex hull 9 is completed by a punching method.

[0048] 5. Accurate calibration

[0049] The precise shaping described above still uses the positioning hole 1 as the processing reference. The parts are installed on a stable heat treatment fixture through the positioning pin 8, and the surface springback and internal stress generated during the forming process are eliminated by heating and heat preservation in the clamped state. The heat treatment fixture described above has high temperature resistance. The area of ​​the clamping surface is set according to the springback state of the part, and the convex hull 9 feature on its surface is set to avoid it. In order to improve the efficiency of the heat treatment furnace, the upper surface of the heat treatment fixture is processed into a plane that can be stacked. The thin-plate high-temperature alloy parts that are precisely shaped through heat treatment completely eliminate springback and internal stress, and further improve the forming accuracy. Figure 6 shown.

[0050] Through the above precise calculation simplification of parts before forming, discrete processing thinking and unchanged processing benchmark during forming, and precise correction of stable heat treatment after forming, the processing and forming of thin plate high-temperature alloy with small-diameter inclined holes and multiple convex hulls 9 features is achieved.

Claims

1. A method for processing a thin plate high temperature alloy having small diameter inclined holes and multiple convex hulls, characterized in that: Here are the steps: Step 1: Process positioning hole setting The positioning hole (1) is used as a processing reference for each processing step in the component manufacturing process and runs through the entire process of thin plate high-temperature alloy part processing. In order to reduce the calculation deviation, the positioning hole (1) is selected on the same edge of the part where the curvature change is small, and is attached to the ear piece (2); Step 2: 2D unfolding data set and unfolding rough material production The two-dimensional unfolding data set is a flattened theoretical profile of the part. As important data for generating the laser cutting trajectory, the three-dimensional data set containing all the features of the small-diameter inclined hole and the convex hull (9) of the part with the positioning lug (2) and the positioning hole (1) added is proportionally unfolded through the CATIA data unfolding module. The hole axis positioning method extracts the intersection point of the inclined hole axis and the upper surface of the component in the digital model of the component, and projects the point onto the pre-expanded surface. The center point, the positioning hole (1), the center of the convex hull (9) and other features are unfolded along the selected unfolded surface using the unfolding function to form a two-dimensional unfolding data set. Step 3: Bending the Part The bending part forming method comprises: clamping the upper and lower bending dies that are consistent with the part profile at the center of the upper and lower platforms of the hydraulic press respectively by bolts; preforming the unfolded raw material by laser impact forming technology according to the characteristics of the part profile, so that the positioning hole (1) can be coordinated and fitted with the positioning pin (5) on the bending die to achieve effective positioning; after the preformed unfolded raw material is stably positioned on the lower die, the upper die is slowly lowered to achieve effective closure and pressure maintenance of the upper and lower dies, thereby completing the bending forming of the part; Step 4: Convex hull feature processing The convex bulge (9) is evenly distributed on the surface of the entire part, the tire profile of the convex bulge (9) is coordinated with the part profile, and the positioning pin A (8) is also arranged on the tire body so as to be coordinated with the rough material positioning hole (1); a drilling mechanism (7) is arranged on the tire cover (6) at the center of the convex bulge (9); The formed blank is clamped in the mold using the positioning hole (1) as a positioning reference and pressed tightly so that the blank tends to the theoretical position in the mold; A hand-held electric drill is used to form a bottom hole on the part through a drill sleeve on the tire cover (6); The local bending die is designed with the bottom hole of each convex hump (9) as the positioning reference; the local bending die surface is in the same proportion as the convex hump (9) profile, in the form of a convex-concave die, and is installed on a common punch press; The local bending die is installed on the punch press, and the matching surface is aligned; the rough material is held, the direction of the convex hull (9) is identified, the bottom hole of the convex hull (9) is inserted into the cylindrical positioning pin A (8), and the normal line of the curved surface at this location is kept parallel to the vertical direction, that is, the normal line of the convex hull (9) hole is parallel to the vertical direction; the punch press is started to complete the forming of the convex hull (9); the above-mentioned actions are repeated to complete the forming of all convex hulls (9); After the convex hull (9) is formed, the bottom hole of the convex hull (9) is enlarged by drawing, and the enlarged bottom hole is used as a positioning reference, a punching die is designed, and a punching method is used to complete the final processing of the upper hole of the convex hull (9); Step 5: Precise calibration The precise shape correction described above still uses the positioning hole (1) as the processing reference, and the part is mounted on a stable heat treatment fixture through the positioning pin (8), and the surface springback and internal stress generated during the forming process are eliminated by heating and heat preservation in the clamped state; The heat treatment fixture has high temperature resistance, the area of ​​the clamping profile is set according to the springback state of the part, the convex hull (9) feature on its surface is avoided, and the upper surface of the heat treatment fixture is processed into a plane; Discrete processing thinking and unchanged processing datum during forming, as well as precise shape correction by stable heat treatment after forming, have achieved the processing and forming of thin-plate high-temperature alloy with small-diameter inclined holes and multiple convex hulls (9).

2. The method for processing a thin plate high temperature alloy having small diameter inclined holes and multiple convex hulls as claimed in claim 1, characterized in that: The number of the positioning holes (1) is selected to be 2 to 3, the spacing between the positioning holes (1) is not less than 200 mm, and the diameter of the positioning holes (1) is selected to be 2.7 to 5.2 mm.

3. The method for processing a thin plate high temperature alloy having small diameter inclined holes and multiple convex hulls as claimed in claim 1 or 2, characterized in that: In the second step, the laser cutting machine generates a processing code based on the two-dimensional unfolding data set, and the angle between the laser and the thin plate is the same as the inclined hole, so as to cut a small-diameter inclined hole, a positioning hole (1) and a part shape feature on the thin plate material, thereby realizing the processing of the unfolded rough material.

4. The method for processing a thin plate high temperature alloy having small diameter inclined holes and multiple convex hulls as claimed in claim 1 or 2, characterized in that: The drilling mechanism (7) is lined with a drilling sleeve, the axis of which coincides with the center line of the convex hull (9), and the thickness of the tire cover (6) of the drilling mechanism (7) is reduced.

5. The method for processing a thin plate high temperature alloy having small diameter inclined holes and multiple convex hulls as claimed in claim 3, characterized in that: The drilling mechanism (7) is lined with a drilling sleeve, the axis of which coincides with the center line of the convex hull (9), and the thickness of the tire cover (6) of the drilling mechanism (7) is reduced.

6. The method for processing a thin plate high temperature alloy having small diameter inclined holes and multiple convex hulls as claimed in claim 1, 2 or 5, characterized in that: A cylindrical locating pin A (8) is arranged at the center of the male and female molds, and its diameter is the same as the bottom hole of the convex hull (9); the matching relationship of the local bending model surface is aligned through the male and female model surfaces and the cylindrical locating pin A (8).

7. The method for processing a thin plate high temperature alloy having small diameter inclined holes and multiple convex hulls as claimed in claim 3, characterized in that: A cylindrical locating pin A (8) is arranged at the center of the male and female molds, and its diameter is the same as the bottom hole of the convex hull (9); the matching relationship of the local bending model surface is aligned through the male and female model surfaces and the cylindrical locating pin A (8).

8. The method for processing a thin plate high temperature alloy having small diameter inclined holes and multiple convex hulls as claimed in claim 4, characterized in that: A cylindrical locating pin A (8) is arranged at the center of the male and female molds, and its diameter is the same as the bottom hole of the convex hull (9); the matching relationship of the local bending model surface is aligned through the male and female model surfaces and the cylindrical locating pin A (8).

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