High-precision hole machining detection method for easily-deformed aero-engine annular part

Abstract

The invention discloses a high-precision hole machining detection method for an easily-deformed aero-engine annular part, and the method comprises the steps: controlling the flatness, roundness and coaxiality of the part before machining, determining the clamping requirements, and using a low-stress machining program. The problem that the part state difference is large in the radial precision hole machining state, the machining state, the using state and the detecting state of the easily-deformed aero-engine annular part, especially the titanium alloy annular part is solved, the consistency of the using state and the detecting state of the part and the part machining state is improved, and the part quality is guaranteed. The method has the advantages that the machining precision of the precision hole of the annular titanium alloy part is greatly improved, the machining and using consistency is guaranteed, the part quality is improved, the part using interference frequency and the part rejection rate are reduced, the machining cost performance ratio is high, and the method has wide application prospects in machining of other parts of similar structures.

Description

Technical Field

[0001] The invention relates to the field of mechanical manufacturing, in particular to a finishing method for gap positioning parts. Background Art

[0002] Among the annular parts of aircraft engines, there is a type of parts that are connected to rotating parts for synchronous movement. Although these parts are static parts, they will have a certain parallel displacement with the rotating parts during engine operation, so the machining accuracy of the holes connecting the rotating parts is required to be high. These parts are usually weak rigid parts, and the parts processing process, inspection, and use status vary greatly, resulting in poor quality of the parts after processing, and no mature technology is available. Summary of the invention

[0003] In order to solve the above problems, the present invention discloses a high-precision hole processing and detection method for easily deformable aero-engine annular parts;

[0004] The specific technical solutions are as follows:

[0005] A method for high-precision hole machining and detection of easily deformable aero-engine annular parts, characterized by comprising the following steps:

[0006] 1) Pre-processing control: end face reference, improve the flatness of the end face to 0.05mm during the process; circumferential reference, improve the roundness of the circumferential reference to 0.1mm during the process, and require the coaxiality of the alignment reference and the evaluation reference to be no more than 0.02mm;

[0007] 2) Process control:

[0008] a) Use fiber oilstone to remove tiny burrs on parts and blow them clean;

[0009] b) The parts are leveled and pressed to make the processing state of the parts consistent with the free state or the detection state;

[0010] c) After alignment, mark the alignment points with a marker;

[0011] d) Use a fixture with an internal stop, and the stop gap must be confirmed by calculation;

[0012] e) The program cutting adopts symmetrical hole processing, and the single hole processing adopts bottom hole drilling and expansion boring to ensure the single hole accuracy. The rotation of the parts during processing adopts the method of clockwise and counterclockwise interlacing;

[0013] f) If burrs are generated during processing, use a wire brush on the equipment to remove the chamfer burrs according to the processing sequence of the holes in the processing program;

[0014] 3) Detection process control:

[0015] a) Check the parts to make sure there are no burrs that may affect the inspection of the parts. If there are burrs, remove them with fiber oilstone and blow the parts clean;

[0016] b) The parts are placed on the testing platform as a whole and must not be raised. The probe should be an extended probe, which should be 60 degrees from the hole to avoid interference between the probe and the testing table. The circumferential reference points should be taken from the alignment position of the processing mark.

[0017] Further, the clamp with an inner stop in step 2) includes a pressure plate, an end face of one side of the part abuts against the pressure plate, the pressure plate is fixedly connected to a screw rod, the screw rod is screwed into a base, and a fixing nut is screwed together with the screw rod.

[0018] Furthermore, step 2) is a method for calculating the stop gap: during the boring process, the part is subjected to a force from the outside to the inside, the part deforms inward, and the springback of the part is repeatedly measured, and the middle value of the springback measured multiple times is taken as the clamping clearance.

[0019] The advantages of the present invention are: the method greatly improves the processing accuracy of the precision hole of the annular titanium alloy part, ensures the consistency of processing and use, improves the quality of the part, and reduces the interference frequency of the part use and the scrap rate of the part.

[0020] Annular titanium alloy parts are commonly used in engine structures. The processing of precision holes has always been a difficult point in the processing of such parts. This technology can effectively improve the quality of parts, reduce the scrap rate of parts, and has a high cost-effectiveness in processing costs. It has broad application prospects in the processing of other similar structural parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] A high-precision hole machining detection method for easily deformable aero-engine annular parts;

[0024] 1. Control before processing: During hole processing, the clamped end face and circumferential datum are formed by turning, and the angular and axial datums are formed during the processing process. Although the end face 1 datum does not participate in the position evaluation of the hole, it affects the difference between the clamped state and the free state of part 6. Therefore, the flatness of the end face 1 needs to be improved to 0.05mm during the process; the circumferential datum participates in the evaluation of the position, so the roundness of the circumferential datum 7 is increased to 0.1mm during the process, and the coaxiality of the alignment datum and the evaluation datum is required to be no more than 0.02mm.

[0025] 2. Process control:

[0026] Titanium alloy parts have good elasticity and are prone to chamfering burrs at the edges and corners. Using a fiber oilstone to remove tiny burrs on the parts and then blowing them clean can effectively reduce clamping differences.

[0027] The parts are leveled and pressed. The end faces of the parts have flatness, which will cause the parts to deform during clamping. The method of leveling and pressing can reduce the clamping deformation and keep the parts processing state consistent with the free state, that is, the detection state.

[0028] After alignment, mark the alignment points with a marker.

[0029] A fixture 8 with an inner stop is used. During the boring process, the part is subjected to a force from the outside to the inside, deforming inward. The springback of the part is measured repeatedly, and the middle value of the springback measured multiple times is taken as the clamping clearance. The clearance is minimized to control the deformation of the part while ensuring smooth clamping of the part.

[0030] The programmed tool path adopts symmetrical hole processing to reduce the deformation of parts caused by processing. The single hole processing adopts bottom drilling and expansion boring to ensure the single hole accuracy. The rotation of the part during processing adopts the method of clockwise and counterclockwise interlacing to reduce the processing stress, so that the deformation of the processed parts can be controlled;

[0031] The processing produces burrs, and a wire brush is used on the equipment to remove the chamfer burrs according to the processing order of the holes in the processing program.

[0032] 3. Detection process control:

[0033] Check the parts to make sure there are no burrs that may affect the inspection of the parts. If there are burrs, use a fiber oilstone to remove them and blow the parts clean.

[0034] The evaluation of part hole position involves the benchmark. The part is small in height and weak in rigidity. The part cannot be raised with a pad (the benchmark state detected at this time is quite different from the actual state). Probe 9 uses an extended probe that is 60 degrees to the hole (as shown in the figure to avoid interference between the probe and the detection table). The circular benchmark sampling points start from the alignment position of the processing mark.

[0035] The clamp with inner stop in step 2): the clamp with inner stop 8 comprises a pressure plate 2, the end face of one side of the part abuts against the pressure plate 2, the pressure plate 2 is fixedly connected to the screw 3, the screw 3 is screwed into the base 4, the fixing nut 5 is screwed together with the screw 3, and the inner stop 81 abuts against the end face of the other side of the part.

Claims

1. A high-precision hole processing and detection method for easily deformable aero-engine annular parts, characterized in that: The steps include: 1) Pre-processing control: end face reference, improve the flatness of the end face to 0.05mm during the process; circumferential reference, improve the roundness of the circumferential reference to 0.1mm during the process, and require the coaxiality of the alignment reference and the evaluation reference to be no more than 0.02mm; 2) Process control: a) Use fiber oilstone to remove tiny burrs on parts and blow them clean; b) The parts are leveled and pressed to make the processing state of the parts consistent with the free state or the detection state; c) After alignment, mark the alignment points with a marker; d) Use a fixture with an internal stop, and the stop gap must be confirmed by calculation; e) The program cutting adopts symmetrical hole processing, and the single hole processing adopts bottom hole drilling and expansion boring to ensure the single hole accuracy. The rotation of the parts during processing adopts the method of clockwise and counterclockwise interlacing; f) If burrs are generated during processing, use a wire brush on the equipment to remove the chamfer burrs according to the processing sequence of the holes in the processing program; 3) Detection process control: a) Check the parts to make sure there are no burrs that may affect the inspection of the parts. If there are burrs, remove them with fiber oilstone and blow the parts clean; b) The whole part is placed on the testing platform and must not be raised. The probe should be an extended probe, which should be 60 degrees to the hole to avoid interference between the probe and the testing table. The circular reference point sampling starts from the alignment position of the processing mark.

2. The high-precision hole processing detection method for easily deformable aerospace engine annular parts according to claim 1 is characterized in that: The clamp with an inner stop in step 2): the clamp with an inner stop includes a pressure plate, the end face of one side of the part abuts against the pressure plate, the pressure plate is fixedly connected to the screw, the screw is screwed into the base, and the fixing nut is screwed together with the screw.

3. The high-precision hole processing and detection method for deformable aero-engine annular parts according to claim 1 is characterized in that: Step 2) Calculation method of stop gap: During the boring process, the part is subjected to force from the outside to the inside, and the part deforms inward. The springback of the part is measured repeatedly, and the middle value of the springback measured multiple times is taken as the clamping clearance.

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