A high-precision hole processing and detection method for a deformed aero-engine annular part

Abstract

This invention discloses a high-precision hole machining and inspection method for easily deformable aero-engine ring parts. By controlling the flatness, roundness, and coaxiality of the part before machining, clarifying clamping requirements, and using low-stress machining programs, this method solves the problem of significant differences in the condition of easily deformable aero-engine ring parts, especially titanium alloy ring parts, when machining radial precision holes, and between the machined and used / inspected states. This improves the consistency between the used / inspected state and the machined state of the part, ensuring part quality. The advantages of this invention are: it significantly improves the machining accuracy of precision holes in ring-shaped titanium alloy parts, ensures consistency between machining and use, improves part quality, reduces the interference frequency and scrap rate during use, and offers high cost-effectiveness. It also has broad application prospects in the machining of other similar structural parts.

Description

Technical Field

[0001] This invention relates to the field of mechanical manufacturing, specifically to a precision machining method for gap positioning parts. Background Technology

[0002] Among the ring-shaped parts in aero-engines, there is a type of part that connects to rotating components and moves synchronously. Although these parts are considered stationary components, they undergo a certain parallel displacement with the rotating components during engine operation. Therefore, the machining accuracy requirements for the holes connecting to the rotating components are relatively high. These parts are usually weakly rigid, and the differences between the machining process and the inspection and usage conditions are significant, resulting in poor quality of the machined parts. There is no mature technology available for this purpose. Summary of the Invention

[0003] To address the above problems, this invention discloses a method for high-precision hole machining and inspection of easily deformable ring-shaped parts for aero-engines;

[0004] The specific technical solution is as follows:

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

[0006] 1) Pre-processing control: end face datum, improve the flatness of the end face to 0.05mm during the process; circumferential datum, improve the roundness of the circumferential datum to 0.1mm during the process, and at the same time require that the coaxiality of the alignment datum and the evaluation datum is not greater than 0.02mm;

[0007] 2) Process control:

[0008] a) Use a fiber whetstone to remove minor burrs from the parts and blow them clean;

[0009] b) The parts are leveled and pressed with a gauge block to ensure that the part's machining state is consistent with its free state, i.e., its inspection state;

[0010] c) Mark the alignment points with a marker after alignment;

[0011] d) A fixture with an inner stop is used, and the stop clearance is calculated and confirmed;

[0012] e) The program uses symmetrical hole machining, and single hole machining uses drilling the bottom hole and boring to ensure the accuracy of the single hole. The rotation of the part during the machining process adopts a clockwise and counterclockwise alternating method.

[0013] f) Burrs generated during processing are removed by using a wire brush on the equipment in the order of hole processing in the processing program.

[0014] 3) Detection process control:

[0015] a) Inspect the parts to ensure there are no burrs that would affect the inspection. If any are present, remove them with a fiber-reinforced oilstone and blow the parts clean.

[0016] b) The part is placed on the inspection platform without being raised. The probe is an extended probe, which is at a 60-degree angle to the hole to avoid interference between the probe and the inspection platform. The circumferential reference points are taken from the alignment position of the machining mark.

[0017] Further, in step 2), the fixture with an inner stop: the fixture 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 a screw, the screw is screwed into the base, and the set nut is screwed together with the screw.

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

[0019] The advantages of this invention are: the method significantly improves the machining accuracy of precision holes in annular titanium alloy parts, ensures consistency in machining and use, improves part quality, and reduces the interference frequency and scrap rate of parts.

[0020] Ring-shaped titanium alloy parts are commonly used in engine structures. Machining precision holes has always been a challenge for these parts. This technology can effectively improve part quality, reduce scrap rate, and offers high cost-effectiveness. It has broad application prospects in the machining of other similar structural parts. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] A method for high-precision hole machining and inspection of easily deformable aero-engine ring parts;

[0024] 1. Pre-machining control: During hole machining, the clamping end face and circumferential datum are formed by turning, while the angular and axial datums are formed by the machining process itself. Although end face 1 datum does not participate in the hole position evaluation, it affects the difference between the clamping state and the free state of part 6. Therefore, the flatness of end face 1 needs to be improved to 0.05mm during the process. The circumferential datum participates in the position evaluation. Therefore, the roundness of circumferential datum 7 needs to be improved to 0.1mm during the process. At the same time, the coaxiality between 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, but their edges and corners are prone to burrs. Using a fiber oilstone to remove the tiny burrs and blowing them clean can effectively reduce clamping differences.

[0027] Using dial gauges to level and clamp parts can reduce clamping deformation due to the flatness of the part's end face during clamping. This ensures that the part's machining state is consistent with its free state, i.e., its inspection state.

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

[0029] Using a fixture 8 with an inner stop, the part is subjected to a force from the outside to the inside during the boring process, and deforms inward. The springback of the part is repeatedly measured, and the middle value of the springback measured multiple times is taken as the clamping gap. While ensuring smooth clamping of the part, the gap is minimized as much as possible to control the deformation of the part.

[0030] The program uses symmetrical hole machining to reduce part deformation caused by machining. Single hole machining uses drilling the pilot hole and reaming to ensure single hole accuracy. The rotation of the part during the machining process adopts a clockwise and counterclockwise interleaving method to reduce machining stress, thereby controlling the deformation of the machined part.

[0031] Burrs are generated during processing. The burrs are removed by using a wire brush on the equipment in the order of hole processing in the processing program.

[0032] 3. Testing process control:

[0033] Inspect the parts to ensure there are no burrs that could affect the inspection. If any are found, remove them with a fiber whetstone and blow the parts clean.

[0034] The evaluation of the hole position accuracy of the part involves a reference. The part is relatively short and has weak rigidity, so a shim cannot be used to raise the part (in this case, the reference state detected will differ greatly from the actual state). Probe 9 is an extended probe, which is at a 60-degree angle to the hole (as shown in the figure, to avoid interference between the probe and the detection table). The circumferential reference sampling point starts from the alignment position of the machining mark.

[0035] Step 2) The fixture with an inner stop: The fixture 8 with an inner stop includes 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 set 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 method for high-precision hole machining and inspection of easily deformable aero-engine ring parts, characterized in that, Includes the following steps: 1) Pre-processing control: end face datum, improve the flatness of the end face to 0.05mm during the process; circumferential datum, improve the roundness of the circumferential datum to 0.1mm during the process, and at the same time require that the coaxiality of the alignment datum and the evaluation datum is not greater than 0.02mm; 2) Process control: a) Use a fiber whetstone to remove minor burrs from the parts and blow them clean; b) The parts are leveled and pressed with a gauge block to ensure that the part's machining state is consistent with its free state, i.e., its inspection state; c) Mark the alignment points with a marker after alignment; d) A fixture with an inner stop is used, and the stop clearance is calculated and confirmed; e) The program uses symmetrical hole machining, and single hole machining uses drilling the bottom hole and boring to ensure the accuracy of the single hole. The rotation of the part during the machining process adopts a clockwise and counterclockwise alternating method. f) Burrs generated during processing are removed by using a wire brush on the equipment in the order of hole processing in the processing program. 3) Detection process control: a) Inspect the parts to ensure there are no burrs that would affect the inspection. If any are present, remove them with a fiber-reinforced oilstone and blow the parts clean. b) The part is placed on the inspection platform without being raised. The probe is an extended probe, which is at a 60-degree angle to the hole to avoid interference between the probe and the inspection platform. The circumferential reference points are taken from the alignment position of the machining mark.

2. The method for high-precision hole machining and inspection of easily deformable aero-engine annular parts according to claim 1, characterized in that, Step 2) The fixture with an inner stop: The fixture with an inner stop includes a pressure plate, one end face of the part abuts against the pressure plate, the pressure plate is fixedly connected to a screw, the screw is screwed into the base, and the set nut is screwed together with the screw.

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

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