A method for processing a surface-coated thin-walled circular ring part

Abstract

The present application relates to the technical field of machining, in particular to a machining method for a thin-walled ring part with a coating on the surface, which is used for machining of a thin-walled ring part with circumferential deformation and a coating on the surface. The present application can improve work efficiency and effectively ensure that the coating thickness is uniform and the shape and position of the sprayed area are qualified after machining. The present application can quickly and effectively constrain the thin-walled ring part with circumferential deformation in the machining process to a true circle, and then adopt machining methods such as turning, grinding, milling, electrical machining and hole machining, so that: (1) the coating thickness of the part is uniform and qualified; (2) the shape of the area where the coating of the part is located is qualified in constraint detection; (3) the position of the area where the coating of the part is located to the reference is qualified in constraint detection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of machining, in particular to a machining method for a thin-walled ring part with a coating on the surface. BACKGROUND

[0002] In order to improve the service life, modern aero-engines specially increase a spraying layer on the surface of many thin-walled ring parts, such as sealing rings, sealing shaft sleeves, sealing bearing seats and the like. The base materials of such parts are mostly high-temperature alloy, titanium alloy or stainless steel and the like, which have strong rigidity and poor cutting performance, and the deformation is large during cutting. The following two problems often occur during machining:

[0003] (1) the spraying layer part:

[0004] (a) the thickness of the spraying layer is uneven;

[0005] (b) the roundness of the inner hole or the outer circle where the spraying layer is located is difficult to meet the requirements;

[0006] (c) the shape (or position) of the inner hole or the outer circle where the spraying layer is located to the part reference A and B is difficult to meet the requirements;

[0007] The reason for the problem is that after spraying, the spraying layer needs to be ground (or turned) to meet the final design requirements. However, due to the grinding (or turning) of the inner hole of the part before spraying and the grinding (or turning) of the inner hole of the coating after spraying, the deformation amount and deformation form of the part after the second clamping are inconsistent, which leads to uneven thickness of the spraying layer after grinding (or turning) the spraying layer, and the shape and position of the coating area change greatly, which is difficult to meet the requirements.

[0008] (2) complicated process and long machining time

[0009] Reason: The base material will be deformed in each process of part machining. The conventional method is to take all possible measures to reduce the deformation of the part in each process to ensure that the thickness and size of the spraying layer part meet the requirements, such as adding a "stress relief heat treatment process" after rough machining, increasing a "multiple reference correction machining process", taking "smaller cutting parameters", and taking "high-quality tool cutting" measures.

[0010] Therefore, it is necessary to find a machining method that can quickly and accurately improve work efficiency and coating thickness uniformity after machining. SUMMARY

[0011] Therefore, the present application provides a machining method for a thin-walled ring part with a coating on the surface, which can improve work efficiency and effectively ensure that the coating thickness after machining is uniform and the shape and position of the spraying area meet the requirements.

[0012] To address the problems existing in the prior art, the technical solution of this invention is: (same as in the claims)

[0013] Compared with the prior art, the advantages of the present invention are as follows:

[0014] 1) The method of the present invention has fewer processing steps, shorter processing time, higher processing efficiency, and lower cost. Compared with existing methods, it is no longer necessary to take measures to reduce the deformation of parts in every process, such as adding a "stress relief heat treatment process" after rough machining, adding a "machining process with multiple datum repairs", using "cutting with smaller cutting parameters", or using "cutting with high-quality materials and tools".

[0015] 2) The method of the present invention can effectively ensure the uniformity of coating thickness when processing thin-walled annular parts with coating on the inner hole or outer circle.

[0016] 3) The present invention has the advantage of integrating the machining fixture and the inspection constraint measuring tool (i.e., the machining fixture can be used as the inspection constraint measuring tool). Applying the present invention can make the deformation state of the part consistent with that of the part after constraint machining in the process and the part during final constraint inspection (i.e., the part can reproduce the state during machining when it is inspected as a finished product). Therefore, it has the advantages of reliable machining quality, reliable constraint inspection, and high pass rate.

[0017] 4) The method of the present invention is applicable to the processing of thin-walled metal parts with a diameter greater than 50 mm and less than 2000 mm.

[0018] 5) In this invention, firstly, the part reference A and reference B must be machined to the required dimensions. Then, before spraying, the inner hole to be sprayed is machined to the required dimensions using the part reference A and reference B as positioning references. Finally, after spraying, the sprayed layer is ground to the required dimensions using the part reference A and reference B as positioning references. This processing sequence must be followed. Furthermore, the positioning form and positioning dimensions of the fixtures used before and after spraying must be consistent. This is the key to ensuring uniform thickness of the sprayed layer. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the part of the present invention;

[0020] Figure 2 for Figure 1 AA section view;

[0021] Figure 3 These are schematic diagrams showing two typical parts after circumferential deformation and constraint by a fixture; where a is a diagram of one type of deformation; and b is a diagram of the other type of deformation.

[0022] Figure 4 A schematic diagram of all surfaces of the rough-machined part (dashed lines indicate a 1mm allowance).

[0023] Figure 5 Fig. 1 is a schematic view of roughing the reference A and B;

[0024] Figure 6 Fig. 2 is a schematic view of roughing the inner hole before spraying;

[0025] Figure 7 Fig. 3 is a schematic view of the inner hole spraying position;

[0026] Figure 8 Fig. 4 is a schematic view of grinding the inner hole coating after spraying;

[0027] Figure 9 Fig. 5 is a schematic view of roughing the coating 2 side surface;

[0028] Figure 10 Fig. 6 is a schematic view of the clamp cross section;

[0029] Reference signs: 1 - part base, 2 - sprayed layer at the inner hole, 3 - clamp constraint point one, 4 - theoretical circle, 5 - clamp constraint point two, 6 - inner hole, 7 - sprayed layer left side surface, 8 - sprayed layer right side surface, 9 - clamp, 10 - pressing plate. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0031] The present application provides a method for processing a "thin-walled annular part with surface coating", so that:

[0032] (1) The coating thickness of the part is uniform and qualified.

[0033] (2) The shape requirements of the part coating area itself are all constrained and detected qualified.

[0034] (3) The position requirements of the part coating area to the reference are all constrained and detected qualified.

[0035] Example 1:

[0036] The steps of a method for processing a thin-walled annular part with surface coating are as follows:

[0037] 1) First, rough all surfaces of the part base 1 to the contour of the part, leaving a 1mm allowance, as shown in Figure 4 ;

[0038] 2) Axially position and clamp the roughed part base 1, then rough reference A and reference B to size, which can ensure that the flatness of reference A is good and the roundness of reference B is good, as shown in Figure 5 ;

[0039] 3) Position the part base 1 in fixture 9 using datum A and datum B. The structural diagram of the fixture is shown below. Figure 10 As shown, datum A and datum B are brought into close contact with the end face and inner circle of fixture 9. The part base 1 is clamped by fixture 9 at fixture constraint point 3 or fixture constraint point 5 and squeezed to form a perfect circle. Then, the inner hole 6 of the part is precision machined to the size before spraying. Figure 6 As shown;

[0040] 4) Remove the part and spray paint the inner hole 6 of the precision-machined part, such as... Figure 7 As shown;

[0041] 5) Position the part substrate 1 using datum A and datum B, ensuring datum A and datum B are in close contact with the end face and inner circle of fixture 9. The part substrate 1 is clamped by fixture 9 at constraint point 3 or constraint point 5, forming a perfect circle. Then, grind the coating material at the inner hole 6 of the part to the specified dimensions. Figure 8 As shown;

[0042] 6) Position the part base 1 using datum A and datum B, ensuring datum A and datum B are in close contact with the end face and inner circle of fixture 9. The part base 1 is clamped by fixture 9 at constraint point 3 or constraint point 5, forming a perfect circle. Then, precision machine the left side 7 and right side 8 of the spray coating 2 to the specified dimensions. Figure 9 As shown.

[0043] 7) Milling, turning, electrical discharge machining and hole machining processes on other surfaces of the part can be arranged after any of the above 6 steps. As long as the order of the above 6 steps remains unchanged, the coating thickness of the part can be guaranteed to be uniform and qualified, the shape and position of the coating area can be qualified, and the constraint test can be qualified.

[0044] The fixture 9 used in this invention can also be used as a constraint measuring tool for testing, so that the deformation state of the part after constraint processing in the process is consistent with that of the part during final constraint testing. That is, the part can reproduce the state during processing when it is inspected as a finished product, thus having the advantages of reliable processing quality, reliable constraint testing, and high pass rate.

[0045] The aforementioned fixture 9 presses and constrains the outer circle of the reference B part through constraint point 3 or constraint point 5, such as... Figure 3 As shown in a and b, the part reference A is constrained by the joint pressing of the end face of the fixture 9 and the corresponding pressure plate 10, as shown in the figure. Figure 10 As shown, the flatness of the fixture positioning end face must be within 0.02 mm, the roundness of the fixture positioning circle must be within 0.01 mm, and the theoretical size of the fixture positioning circle should be the maximum material size of part datum B. Tolerance: 0. +0.01In this way, the fixture can effectively constrain the part reference B to a true circle.

[0046] The fixture 9 used in steps 3, 5 and 6 needs to be consistent in positioning and size.

[0047] According to the above steps, the machining of the part can be completed, ensuring that the thickness of the sprayed layer is uniform and that the shape and position requirements of the area where the coating is located are qualified.

[0048] Of course, the above description is not a limitation of the present application, and the present application is not limited to the above examples. Changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present application are all within the scope of the present application.

Claims

1. A method of machining a surface-coated thin-walled annular part, characterized in that: The method steps are: 1) First, rough turning all surfaces of the part base (1) to the profile of the part, leaving a 1mm allowance; 2) Axially positioning and clamping the rough-turned part base (1), and finish turning the part's reference A and reference B to size; 3) Positioning the part's reference A and reference B, placing the part base (1) into the fixture (9) so that the part's reference A and reference B are in close contact with the end face and inner circle of the fixture (9), and the part base (1) is squeezed and constrained to be a perfect circle at the fixture constraint point one (3) or the fixture constraint point two (5) by the fixture (9), and then finish turning the part inner hole (6) to the size before spraying; 4) Removing the part, and spraying the finish-turned part inner hole (6); 5) Positioning the part's reference A and reference B, placing the part base (1) into the fixture (9) so that the part's reference A and reference B are in close contact with the end face and inner circle of the fixture (9), and the part base (1) is squeezed and constrained to be a perfect circle at the fixture constraint point one (3) or the fixture constraint point two (5) by the fixture (9), and then grinding the sprayed layer at the part inner hole (6) to size; 6) Positioning the part's reference A and reference B, placing the part base (1) into the fixture (9) so that the part's reference A and reference B are in close contact with the end face and inner circle of the fixture (9), and the part base (1) is squeezed and constrained to be a perfect circle at the fixture constraint point one (3) or the fixture constraint point two (5) by the fixture (9), and then finish turning the left side of the sprayed layer (7) and the right side of the sprayed layer (8) of the sprayed layer (2) to size; 7) The milling, turning, electrical processing and hole processing procedures of other surfaces of the part are arranged after any of the above 6 steps; that is, it can ensure that the part coating thickness is uniform and qualified, the coating area shape and position requirements are qualified, and the constraint detection is qualified.

2. A method of machining a surface-coated thin-walled annular part according to claim 1, characterized in that: The positioning form and size of the fixture (9) used in steps 3), 5) and 6) need to be consistent.

3. A method of machining a surface-coated thin-walled circular ring part according to claim 1 or 2, characterized in that: The clamp (9) extrudes the constraint part reference B outer circle through the clamp constraint point one (3) or the clamp constraint point two (5), and extrudes the constraint part reference A through the end face of the clamp (9) and the corresponding pressing plate (10), and the clamp positioning end face flatness needs to be within 0.02 millimeters, the roundness of the clamp positioning circle needs to be within 0.01 millimeters, and the theoretical size of the clamp positioning circle should be the maximum physical size of the part reference B, and the tolerance is: ０ ＋０．０1 .

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