Method for improving milling precision of barrel part mounting seat

Abstract

The invention provides a method for improving the milling precision of a cylinder part mounting seat. The method comprises the following steps: measuring the size from the surface to the center of the mounting seat in a relative measurement mode; all other mounting bases are machined to be in the qualified size; replacing a cutter; the mounting seat with the planeness of 0.01 mm is subjected to finish machining; a threaded hole is machined, specifically, the threaded hole is milled in a spiral milling mode, and the cutting depth of an inner layer is 0.4 mm; and chamfering the threaded hole by using a chamfering tool. As the mounting base is of an asymmetric structure, the size from the surface to the center of the mounting base can be measured without a measuring tool and a standard component, and the size from the surface to the center of the mounting base is measured through a relative measurement method. By adjusting the machining sequence, the allowance distribution, the cutter selection and the cutting amount, the machining size of the part meets the requirements of a design drawing. The method has the advantages that the quality fluctuation of products is effectively eradicated, the generation of out-of-tolerance quality is eradicated, the bench worker plane grinding procedure is canceled, and the part machining efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of aeroengines, and in particular to a method for improving the milling precision of a barrel-type part mounting seat. Background Art

[0002] A cylindrical part is a large thin-walled welding part with a diameter of more than 1200mm and a height of more than 1400mm. The size from the surface of the mounting seat to the center cannot be directly measured, and the accuracy is usually guaranteed by CNC equipment. There is a 200mmX180mm stepped mounting seat with a flatness of 0.01mm and a parallelism of 0.01mm between the two stepped planes. During the development process, this type tolerance poses a huge challenge to processing. In the early stage, the flatness requirements of the outer plane were guaranteed by plane grinding, but the parallelism of the inner plane was out of tolerance. The above practical problems were solved by adjusting the processing sequence, replacing the tool and adjusting the processing parameters. Summary of the invention

[0003] The purpose of the present invention is to solve the problems of cylindrical parts, the size from the mounting seat surface to the center and the flatness and parallelism of the mounting seat plane, and a method for improving the milling accuracy of the mounting seat of cylindrical parts is provided.

[0004] The present invention provides a method for improving the milling precision of a cylindrical part mounting seat, which is characterized by the following steps:

[0005] 1. Measure the size from the mounting surface to the center by relative measurement

[0006] Use a ceramic standard ball to make it coaxial with the rotation center of the part, and use a machine tool to measure the size from the mounting seat surface to the center.

[0007] Process one side of the square worktable or the outer circle of the circular worktable, then accurately measure the true size of one side or the outer circle, and use the machine tool to measure the size from the surface of the mounting seat to the center;

[0008] 2. Process all other mounting seats to qualified dimensions

[0009] The mounting seat with a flatness of 0.01 mm is semi-finished;

[0010] Plane A and plane B have a 0.2mm margin in the plane;

[0011] Leave 0.2mm margin for inner contour 1 (4) and inner contour 2 (5);

[0012] 3. Replace the tool

[0013] Replacement of 3-edged tool;

[0014] Use uncoated tools;

[0015] Use non-blade blunt knives;

[0016] The radius of the replaced tool should be smaller than the transition radius of the inner contour 14 and the inner contour 25;

[0017] 4. Finishing the mounting seat with a flatness of 0.01 mm

[0018] Process the inner contour 1 4 and the inner contour 2 5 to the qualified size;

[0019] Chamfer inner contour 1 4, inner contour 2 5, at this time the chamfer size is the nominal size + 0.2mm;

[0020] Processing plane A, the first cutting depth is 0.1mm, the second cutting depth is 0.05mm, leaving a 0.05mm margin;

[0021] When machining plane B, the first cut has a depth of 0.1 mm, the second cut has a depth of 0.05 mm, and a 0.05 mm margin is left. When machining plane B, the tool compensation is expanded by 0.03 mm to ensure that the side edge of the tool does not cut the inner contour 5 during the machining process;

[0022] The reverse milling tool path is used to process plane B, and the flatness of the processed plane B is within 0.006;

[0023] After plane B is processed to be qualified, plane A is processed by reverse milling until plane A is processed to be qualified;

[0024] 5. Processing threaded holes 1

[0025] The threaded hole 1 is milled by spiral milling, and the inner layer cutting depth is 0.4 mm;

[0026] Use a chamfering cutter to chamfer threaded hole 1.

[0027] Since the mounting seat is an asymmetric structure, there are no measuring tools or standard parts to measure the size from the mounting seat surface to the center. The relative measurement method is used to measure the size from the mounting seat surface to the center. By adjusting the processing sequence, the allocation of allowances, the selection of tools, and the adjustment of cutting parameters, the processing dimensions of the parts meet the requirements of the design drawing.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] The method for improving the milling accuracy of the cylindrical part mounting seat described in the present invention can effectively prevent product quality fluctuations, prevent the generation of quality out-of-tolerance orders, cancel the bench plane grinding process, and improve part processing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments:

[0031] Figure 1 Schematic diagram of the mounting base.

[0032] In the figure, 1 is a threaded hole, 2 is plane A, with a flatness tolerance of 0.01mm, 3 is plane B, with a parallelism tolerance of 0.01mm to plane A, 4 is an inner contour, 5 is an inner contour, and 6 is an inner contour transition R. DETAILED DESCRIPTION

[0033] The present invention will be further explained below in conjunction with specific implementation plans, but the present invention is not limited thereto. The structures, proportions, sizes, etc. illustrated in the drawings of the specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the restrictive conditions under which the present invention can be implemented. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0034] The present invention provides a method for improving the milling precision of a cylindrical part mounting seat, which is characterized by the following steps:

[0035] 1. Measure the size from the mounting surface to the center by relative measurement

[0036] Use a ceramic standard ball to make it coaxial with the rotation center of the part, and use a machine tool to measure the size from the mounting seat surface to the center.

[0037] Process one side of the square worktable or the outer circle of the circular worktable, then accurately measure the true size of one side or the outer circle, and use the machine tool to measure the size from the surface of the mounting seat to the center;

[0038] 2. Process all other mounting seats to qualified dimensions

[0039] The mounting seat with a flatness of 0.01 mm is semi-finished;

[0040] Plane A and plane B have a 0.2mm margin in the plane;

[0041] Leave 0.2mm margin for inner contour 1 (4) and inner contour 2 (5);

[0042] 3. Replace the tool

[0043] Replacement of 3-edged tool;

[0044] Use uncoated tools;

[0045] Use non-blade blunt knives;

[0046] The radius of the replaced tool should be smaller than the transition radius of the inner contour 14 and the inner contour 25;

[0047] 4. Finishing the mounting seat with a flatness of 0.01 mm

[0048] Process the inner contour 1 4 and the inner contour 2 5 to the qualified size;

[0049] Chamfer inner contour 1 4, inner contour 2 5, at this time the chamfer size is the nominal size + 0.2mm;

[0050] Processing plane A, the first cutting depth is 0.1mm, the second cutting depth is 0.05mm, leaving a 0.05mm margin;

[0051] When machining plane B, the first cut has a depth of 0.1 mm, the second cut has a depth of 0.05 mm, and a 0.05 mm margin is left. When machining plane B, the tool compensation is expanded by 0.03 mm to ensure that the side edge of the tool does not cut the inner contour 5 during the machining process;

[0052] The reverse milling tool path is used to process plane B, and the flatness of the processed plane B is within 0.006;

[0053] After plane B is processed to be qualified, plane A is processed by reverse milling until plane A is processed to be qualified;

[0054] 5. Processing threaded holes 1

[0055] The threaded hole 1 is milled by spiral milling, and the inner layer cutting depth is 0.4 mm;

[0056] Use a chamfering cutter to chamfer threaded hole 1.

[0057] Since the mounting seat is an asymmetric structure, there are no measuring tools or standard parts to measure the size from the mounting seat surface to the center. The relative measurement method is used to measure the size from the mounting seat surface to the center. By adjusting the processing sequence, the allocation of allowances, the selection of tools, and the adjustment of cutting parameters, the processing dimensions of the parts meet the requirements of the design drawing.

[0058] Matters not covered by the present invention are known technologies.

[0059] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for improving the milling accuracy of a cylindrical part mounting seat, characterized in that: Here are the steps:

1. Measure the size from the mounting surface to the center by relative measurement Use a ceramic standard ball to make it coaxial with the rotation center of the part, and use a machine tool to measure the size from the mounting seat surface to the center. Process one side of the square worktable or the outer circle of the circular worktable, then accurately measure the true size of one side or the outer circle, and use the machine tool to measure the size from the surface of the mounting seat to the center; 2. Process all other mounting seats to qualified dimensions The mounting seat with a flatness of 0.01 mm is semi-finished; Plane A and plane B have a 0.2mm margin in the plane; Leave a 0.2mm margin for inner contour 1 (4) and inner contour 2 (5); 3. Replace the tool Replacement of 3-edged tool; Use uncoated tools; Use non-blade blunt knives; The radius of the replaced tool should be smaller than the transition radius of inner contour 1 (4) and inner contour 2 (5); 4. Finishing the mounting seat with a flatness of 0.01 mm Processing inner contour 1 (4) and inner contour 2 (5) to the qualified size; Chamfer inner contour 1 (4) and inner contour 2 (5), where the chamfer size is the nominal size + 0.2 mm; Processing plane A, the first cutting depth is 0.1mm, the second cutting depth is 0.05mm, leaving a 0.05mm margin; When machining plane B, the first cut has a depth of 0.1 mm, the second cut has a depth of 0.05 mm, and a 0.05 mm margin is left. When machining plane B, the tool compensation is expanded by 0.03 mm to ensure that the side edge of the tool does not cut the inner contour 5 during the machining process; The reverse milling tool path is used to process plane B, and the flatness of the processed plane B is within 0.006; After plane B is processed to be qualified, plane A is processed by reverse milling until plane A is processed to be qualified; 5. Processing threaded holes (1) The threaded hole (1) is milled by spiral milling, and the inner layer cutting depth is 0.4 mm; Use a chamfering cutter to chamfer the threaded hole (1).

Images