Thin aluminum alloy sheet metal part cutting process method

Abstract

The invention provides a cutting process method for a thin aluminum alloy sheet metal part. The cutting process method comprises the steps that (1) a three-dimensional contour edge line data model of the thin aluminum alloy sheet metal part is obtained to serve as cutting data, programmed and input into a numerical control machine tool; (2) the thin aluminum alloy sheet metal part is fixed to a part three-dimensional carving and cutting clamp, and the part three-dimensional carving and cutting clamp is used for manufacturing a shape-following micro groove along the three-dimensional contour edge of the thin aluminum alloy sheet metal part; (3) a nicking tool is installed on a tool turret of the numerical control machine tool, the center point of a nicking tool point coincides with the part three-dimensional outline edge line normal direction on the part three-dimensional carving and cutting clamp, the nicking tool is controlled to move along the part three-dimensional outline edge according to programming, a certain dip angle is kept between the nicking tool and the normal direction to apply force, and linear grooves are evenly extruded and carved in the surface of the part; and (4) linear grooves are carved along the parts for auxiliary manual cutting and discharging. The problems of cutting defects such as mechanical milling and manual shearing of thin aluminum alloy sheet metal parts are solved, and the service life of the nicking tool can be prolonged.

Description

Technical Field

[0001] The invention relates to a sheet metal parts cutting technology in the field of metal parts manufacturing, in particular to a thin aluminum alloy sheet metal parts cutting process method. Background Art

[0002] Thin aluminum alloy sheet metal parts are widely used in aerospace and other aircraft due to their light weight, high strength, corrosion resistance, and good thermal and electrical conductivity. The correct cutting method is the key to ensure product accuracy, quality and production efficiency.

[0003] Cutting thin aluminum alloy sheet metal parts is a common metal processing method. Common thin aluminum alloy sheet metal cutting methods include: (1) manual shearing, which is usually performed using manual or electric scissors; (2) mechanical milling, which uses mechanical equipment and mechanical tools to perform milling operations; (3) laser cutting, which uses a laser to generate a high-energy beam to cut the aluminum plate into the desired shape; (4) water jet cutting, which uses water flow for cutting; and (5) plasma cutting, which uses high-temperature plasma for cutting.

[0004] For thin aluminum alloy sheet metal parts such as aerospace vehicles, the cutting quality requirements are very high, and performance quality problems such as splashing, cracks, pores, and softening are not allowed. Therefore, laser cutting and plasma cutting cannot be directly applied to the final contour edge cutting of parts. As for mechanical milling of three-dimensional contours, due to the poor rigidity and easy deformation of thin sheet metal parts, they are generally not directly milled, and special milling fixtures need to be designed and manufactured. During milling, the edges of the parts are also very easy to vibrate and fluctuate. The edges of the parts after milling become loose, wave deformation occurs and cannot be repaired, and the appearance is out of tolerance, which still has great limitations. In actual production, manual shearing is still widely used for the three-dimensional contour edge cutting of thin aluminum alloy sheet metal parts such as aerospace vehicles. This method relies on the operator's manpower and technical level, is difficult to mark, has low efficiency, poor accuracy and stability, and is a relatively backward production method. Summary of the invention

[0005] In order to overcome the cutting defects of thin aluminum alloy sheet metal parts such as mechanical milling and manual shearing, a cutting process method for thin aluminum alloy sheet metal parts is proposed to eliminate the problems of wavy deformation and looseness of mechanical milling edges of thin aluminum alloy sheet metal parts, and the difficult, time-consuming, labor-intensive and backward cutting methods of manual marking and shearing, so as to provide a part shape that meets the requirements of the design drawings.

[0006] The present invention provides a thin aluminum alloy sheet metal part cutting process method, comprising:

[0007] 1) Obtain the three-dimensional contour edge line data model of the thin aluminum alloy sheet metal part as the cutting data and input it into the CNC machine tool through programming;

[0008] 2) Fix the thin aluminum alloy sheet metal part on the three-dimensional cutting fixture, and the three-dimensional cutting fixture makes a conformal micro groove along the edge of the three-dimensional contour of the thin aluminum alloy sheet metal part;

[0009] 3) Install a carving knife on the turret of the CNC machine tool, and the center point of the carving knife tip coincides with the normal of the edge line of the three-dimensional contour of the part on the three-dimensional carving fixture of the part. According to the programming control, the carving knife moves along the edge of the three-dimensional contour of the part, and the force is applied at an inclination angle α with the normal, and the α value is between 0 and 10°, and a linear groove is evenly squeezed and carved on the surface of the part;

[0010] 4) Assisted manual cutting and unloading is carried out along the linear grooves engraved on the parts.

[0011] Optionally, the thickness of the thin aluminum alloy sheet metal part is between 0 and 3.0 mm.

[0012] Optionally, the cutting edge of the carving knife is in the shape of a cylindrical polygonal pyramid.

[0013] Optionally, the three-dimensional contour edge line data of the thin aluminum alloy sheet metal part is obtained by extracting the neutral plane edge line data of the part, and includes extended additional positioning hole ear edge data.

[0014] Optionally, the three-dimensional part cutting fixture and the part are positioned and connected by a plurality of positioning pins;

[0015] A cover plate is also arranged on the upper surface of the part, and the outer shape of the cover plate is contracted within the peripheral edge of the part to avoid the movement trajectory of the engraving tool and prevent collision and interference.

[0016] Optionally, the cross section of the micro groove is semicircular or rectangular.

[0017] Optionally, the linear groove depth h is between 2 / 3 and 4 / 5 of the part material thickness δ.

[0018] Optionally, the three-dimensional cutting fixture for parts is a rectangular block, the bottom surface of the rectangular block is fixed on the CNC machine tool, and the top surface and side surfaces are provided with contact surfaces, which match the part profile to provide support for the part.

[0019] The present invention provides a cutting process for thin aluminum alloy sheet metal parts, which has the beneficial effect that since most of the aircraft thin aluminum alloy sheet metal parts have a thickness between 0 and 3.0 mm, the method has a wide range of applications. Since the hardness of thin aluminum alloy in a soft state or a newly quenched state is generally low, the use of a cutting process at this time can further extend the service life of the cutter. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of a thin aluminum alloy sheet metal part;

[0021] Figure 2 It is the extracted edge line graph of the three-dimensional contour of the part;

[0022] Figure 3 is a schematic diagram of the engraving fixture;

[0023] Figure 4 yes Figure 3 A cross-sectional view of

[0024] Figure 5 It is a schematic diagram of the engraving process method;

[0025] Figure 6 yes Figure 5 A partial enlarged view of

[0026] Figure 7 yes Figure 6 A partial enlarged view of

[0027] Figure 8 Schematic diagram of cutting when the cutting fixture has a cover plate;

[0028] Fig. 9 Schematic diagram of knife movement during engraving;

[0029] Fig.10 Schematic diagram of the completed parts;

[0030] Description of reference numerals:

[0031] 1. Sheet metal parts, 2. Engraving and cutting fixtures, 3. Grooves, 4. Engraving and cutting tool points, 5. CNC machine tools, 6. Positioning holes, 7. Engraving knives, 8. Positioning pins, 9. Cover plates, 10. Linear grooves, 11. Parts engraving and cutting blanks. DETAILED DESCRIPTION

[0032] The present application is further described in detail below with reference to the accompanying drawings.

[0033] See attached Figure 1-7 The present invention provides a thin aluminum alloy sheet metal part cutting process method, which mainly includes a thin aluminum alloy sheet metal part, a carving knife, a carving fixture, a CNC machine tool and a turret, and is mainly suitable for cutting the three-dimensional contour edge of a thin aluminum sheet metal part with a thickness between 0 and 3.0 mm. A metal tool is used to carve a three-dimensional contour edge of the part on the surface of the part by a carving method to form a nearly penetrating groove, so that the part and the rough material are in a state of being disconnected but not separated, and then manual auxiliary cutting is performed, which specifically includes:

[0034] 1) Establish or extract the three-dimensional contour edge line data model of thin aluminum alloy sheet metal parts as cutting data and program it; 2) Design and manufacture a three-dimensional cutting fixture for parts according to thin aluminum alloy sheet metal parts, and make a conformal groove along the three-dimensional contour edge of the part; 3) Design and manufacture a carving knife, and the cutting knife has a cylindrical multi-faceted pyramid shape; 4) Install the carving knife on the turret of the CNC machine tool, and the center point of the carving knife tip coincides with the normal of the three-dimensional contour edge line of the part, move along the three-dimensional contour edge of the part, maintain a certain inclination angle with the normal, and evenly squeeze and carve a nearly penetrating linear groove on the surface of the part, so that the part and the rough material are separated but not separated, maintaining a weak connection; 5) Carve the linear groove along the part for auxiliary manual cutting and unloading.

[0035] Exemplarily, the three-dimensional contour edge line data of the part is obtained by extracting the neutral plane edge line data of the part, and includes extended additional positioning hole ear piece edge data.

[0036] Exemplarily, the shape of the three-dimensional cutting fixture for parts protrudes beyond the edge of the part's circumference; the three-dimensional cutting fixture for parts is conformal at the edge of the part's circumference and has a certain width, so as to keep the shape in close contact with the part's circumference and support the overall rigidity of the part without being changed by external forces; the three-dimensional cutting fixture for parts and the part are positioned and connected with a number of locating pins, which can be provided by the part or added by supplementary means; when the part is unstable, the cutting fixture can add a cover plate to assist in clamping and keep the part in a rigid state during cutting, and the cover plate's shape shrinks within the edge of the part's circumference to avoid the movement trajectory of the cutting tool and prevent collision and interference.

[0037] For example, the depth h of the nearly penetrating linear groove is generally controlled between 2 / 3 and 4 / 5 of the part material thickness δ, and penetration and shedding are allowed at local line segments.

[0038] For example, the engraving tool is made of the same material and has a similar structure to a traditional CNC milling tool, and can be installed interchangeably on a general CNC machine tool. The only difference is the cutting edge, which is a cylindrical multi-faceted pyramid shape and is suitable for 360° cutting in any direction.

[0039] For example, assisted manual cutting and unloading generally adopts manual shearing, and can also adopt band sawing or pneumatic tool manual milling, but all of them are guided by the linear groove to move forward.

[0040] Referring to the attached drawings, the specific steps are as follows: first, evaluate the conformity of the contour of the sheet metal part 1 to be engraved, including the material type and thickness, the structural characteristics of the part and its programming and processing capabilities, select a suitable CNC machine tool 5, establish or extract the three-dimensional contour edge line data model of the sheet metal part 1 as the engraving data and program it, and design and manufacture the engraving knife 7. The three-dimensional blank shape of the sheet metal part 1 is pre-formed on the tooling mold such as the forming mold, and the engraving fixture 2 is designed and manufactured according to the sheet metal part 1. The positioning hole 6 of the engraving fixture 2 is coordinated with the tooling mold such as the forming mold of the sheet metal part 1. The part engraving blank 11 of the sheet metal part 1 is installed on the engraving fixture 2 using the positioning hole 6 and the positioning pin 8. When the stability of the part is poor and the rigidity is insufficient, the cover plate 9 needs to be clamped again. The engraving fixture 2 is installed on the CNC machine tool 5, and the engraving knife 7 is installed on the turret of the CNC machine tool 5. Adjust the machine tool, and perform cutting processing on the groove 3 of the cutting fixture 2 along the contour edge of the part from the cutting point 4. After completing a cycle, the tool returns to the cutting point 4 to complete the cutting of a sheet metal part 1. Remove the sheet metal part 1 and perform auxiliary manual cutting and unloading along the linear groove 10 cut by the part.

[0041] It should be noted that the structures of thin aluminum alloy sheet metal parts vary greatly. During the engraving process, the forces at each point of the contour are not exactly the same, and the depth of the engraved grooves is not completely uniform. It is allowed that some line segments are separated, but the overall connection should be weak to maintain the rigidity of the parts. After the engraving and cutting are completed, manual assisted cutting and unloading are carried out.

Claims

1. A thin aluminum alloy sheet metal parts cutting process, characterized in that: include: 1) Obtain the three-dimensional contour edge line data model of the thin aluminum alloy sheet metal part as the cutting data and input it into the CNC machine tool through programming; 2) Fix the thin aluminum alloy sheet metal part on the three-dimensional cutting fixture, and the three-dimensional cutting fixture makes a conformal micro groove along the edge of the three-dimensional contour of the thin aluminum alloy sheet metal part; 3) Install a carving knife on the turret of the CNC machine tool, and the center point of the carving knife tip coincides with the normal of the edge line of the three-dimensional contour of the part on the three-dimensional carving fixture of the part. According to the programming control, the carving knife moves along the edge of the three-dimensional contour of the part, and the force is applied at an inclination angle α with the normal, and the α value is between 0 and 10°, and a linear groove is evenly squeezed and carved on the surface of the part; 4) Perform auxiliary manual cutting and unloading along the linear grooves engraved on the parts.

2. The thin aluminum alloy sheet metal parts cutting process according to claim 1 is characterized in that: The thickness of thin aluminum alloy sheet metal parts is between 0 and 3.0 mm.

3. The thin aluminum alloy sheet metal parts cutting process according to claim 1 is characterized in that: The cutting edge of the carving knife is in the shape of a cylindrical polygonal pyramid.

4. The thin aluminum alloy sheet metal parts cutting process according to claim 1 is characterized in that: The three-dimensional contour edge line data of the thin aluminum alloy sheet metal part is obtained by extracting the neutral layer edge line data of the part, and includes the extended additional positioning hole ear edge data.

5. The thin aluminum alloy sheet metal parts cutting process according to claim 1 is characterized in that: The three-dimensional cutting fixture of the parts is positioned and connected with the parts by a number of positioning pins; A cover plate is also arranged on the upper surface of the part, and the outer shape of the cover plate is contracted within the peripheral edge of the part to avoid the movement trajectory of the engraving tool and prevent collision and interference.

6. The thin aluminum alloy sheet metal parts cutting process according to claim 1 is characterized in that: The cross section of the micro groove is semicircular or rectangular.

7. The thin aluminum alloy sheet metal parts cutting process according to claim 1 is characterized in that: The linear groove depth h is between 2 / 3 and 4 / 5 of the part material thickness δ.

8. The thin aluminum alloy sheet metal parts cutting process according to claim 1, characterized in that: The three-dimensional cutting fixture for parts is a rectangular block, the bottom surface of which is fixed on the CNC machine tool, and the top surface and side surfaces are provided with contact surfaces, which match the part profile to provide support for the part.

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