Machining method for large-size aero-engine precise clamping ring

Abstract

The invention discloses a machining method for a large-size aero-engine precise clamping ring. The machining method sequentially comprises the steps of blanking, edge rolling, polishing welding, vacuum heat setting, slow wire cutting, acid pickling, appearance machining, magnetic flaw detection and chemical passivation. During blanking, a rectangular plate is adopted, vacuum heat setting is carried out to obtain the hardness required by the precision snap ring, roundness correction is carried out, slow wire cutting is carried out to obtain the precision snap ring middleware meeting the flatness and parallelism requirements, the required thickness and surface roughness are obtained after acid pickling, the final boundary dimension is obtained through machining, and finally flaw detection and surface passivation treatment are carried out. According to the machining method, the loss of raw materials can be greatly reduced, the size precision of the precise clamping ring can be guaranteed, and the application range is wide.

Description

Technical Field

[0001] The invention belongs to the field of mechanical processing, and in particular relates to a processing method for a large-size precision clamping ring. Background Art

[0002] A snap ring is a device used to fix mechanical parts in aircraft engines. Its structure is as follows: Figure 1 As shown, it is a precision annular part with an outer diameter of The width is B, the flatness is 0.3mm, the parallelism is 0.03mm, the material thickness is C, the surface roughness is Ra0.8, and the hardness must also be guaranteed.

[0003] At present, there are three main processing solutions for this type of precision retaining ring:

[0004] The first method uses a plate with a thickness of C to cut and process to obtain a circular precision clamping ring, but the flatness size after cutting is difficult to guarantee, and a large amount of raw material in the middle of the ring material is wasted during the cutting process.

[0005] The second method is to use bar processing, cut the bar into sheets, and then remove the middle circular part to obtain the ring-shaped part, but this method also has the problem of a large amount of raw materials being wasted.

[0006] The third method is to use pipe processing. However, since there are no thin-walled pipes of such large sizes on the current market, they need to be customized, resulting in high material procurement costs.

[0007] After searching, except for the above three processing ideas, no public literature has been found on other processing methods for this type of large-sized aircraft engine precision retaining rings. Summary of the invention

[0008] The invention aims to provide a method for processing a large-sized aircraft engine precision retaining ring, which can reduce the waste of raw materials and ensure the processing accuracy of the part size.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] A method for processing a large-size aircraft engine precision retaining ring comprises the following steps:

[0011] S1, cutting, using rectangular plate, the thickness of the plate is greater than the width of the precision clamping ring, and the width of the plate is greater than the thickness of the precision clamping ring;

[0012] S2, rolling, rolling the rectangular plate in S1 along the length direction;

[0013] S3, polishing and welding, polishing the two ends of the rectangular plate in the length direction after being rolled in S2, and then splicing and welding them into a ring-shaped part;

[0014] S4, vacuum heat setting, heating the annular component in S3 under vacuum environment, expanding the annular component from the inner ring surface to the outside, ensuring the hardness of the annular component and calibrating the roundness of the annular component;

[0015] S5, wire cutting, cutting the ring in S4 along a plane perpendicular to the axis of the ring, and obtaining at least one precision clamping ring intermediate under the premise of ensuring the flatness and parallelism of the two axial end faces of the ring;

[0016] S6, pickling, pickling the precision clamping ring intermediate obtained in S5 to remove the ablation layer on its surface and ensure that its surface roughness meets the requirements;

[0017] S7, machining the shape, machining the precision clamping ring intermediate piece after pickling in S6 according to the requirements of the precision clamping ring part drawing, and obtaining a precision clamping ring with the shape size and characteristic structure in the part drawing;

[0018] S8, magnetic flaw detection, check whether the precision clamping ring in S7 has defects;

[0019] S9, chemical passivation, performs surface chemical passivation treatment on the precision clamping ring that does not have defects in S8.

[0020] As an option, in S2, a rolling bed is used to roll the rectangular sheet material in S1.

[0021] As an option, in S4, a heat setting mold is used for heating in a vacuum environment, the heat setting mold includes a cylindrical surface for inserting the inner ring of the annular part in S3, and the material thermal expansion linear velocity of the heat setting mold is greater than the thermal expansion linear velocity of the rectangular sheet in S1.

[0022] As an option, in S6, the middle of the precision snap ring is pickled to obtain the thickness required by the precision snap ring part drawing.

[0023] As an option, in S7, the inner and outer cylindrical surfaces of the precision clamping ring intermediate piece after pickling in S6 are machined according to the requirements of the precision clamping ring part drawing to ensure that the outer diameter and width required by the precision clamping ring part drawing are obtained, and the notch required by the precision clamping ring part drawing is machined along the weld position in S3.

[0024] Compared with the prior art, the processing method provided by the present invention greatly reduces the waste of raw materials compared with parts processed by traditional solutions (such as circular cutting on sheet materials and processing using rods), while ensuring the processing accuracy of the precision retaining ring size.

[0025] Compared with the prior art, the processing method provided by the present invention is more reliable, and the processed precision clamping ring has better consistency and higher quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the parts structure of a large-sized aircraft engine precision retaining ring;

[0027] Figure 2 This is a schematic diagram of the raw material;

[0028] Figure 3 This is a schematic diagram of curling welding;

[0029] Figure 4 It is a schematic diagram of heat setting;

[0030] Figure 5 This is a schematic diagram of wire cutting;

[0031] Figure 6 This is a schematic diagram of the machine appearance. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with specific embodiments, but it should not be understood that the scope of the subject matter described in the present invention is limited to the following embodiments. Without departing from the above-mentioned technical ideas of the present invention, various modifications, substitutions and changes made according to common technical knowledge and customary means in the field are included in the scope of the present invention.

[0033] like Figure 1 to Figure 6 As shown, the processing method of the large-sized aircraft engine precision retaining ring given in this embodiment includes the following steps:

[0034] (1) Cutting: Calculate the size of the rough material and use a rectangular sheet with a thickness of 7.5 mm for cutting. Figure 2 The size of the rough material after welding should be consistent with the size of the heat setting mold. Match.

[0035] (2) Rolling: Use a rolling bed to roll the sheet metal. Figure 3 shown.

[0036] (3) Polishing welding: After polishing and rolling, the two ends of the splicing are used as the welding place and the rounded sheet is welded. After welding, there is a weld seam on the ring. Figure 3 shown.

[0037] (4) Vacuum heat setting: Vacuum heat setting ring parts to ensure hardness. The thermal expansion linear velocity of the heat setting mold and the precision clamping ring raw material is different (the thermal expansion linear velocity of the precision clamping ring raw material is smaller than that of the heat setting mold). Through thermal expansion and contraction, the round ring parts are calibrated, such as Figure 4 Dimensions It should be ensured that the welded ring can be placed before thermal expansion, and the inner ring should have a margin for subsequent machining after thermal expansion. Vacuum heat setting is carried out in a vacuum furnace. The heating parameter of the vacuum furnace is the aging temperature, so the temperature window has been determined, and the type of precision clamping ring material has also been determined. Then the expansion amount of the ring at this temperature can be determined, and the material and size of the heat setting mold can be determined, thereby ensuring that the ring is calibrated.

[0038] (5) Slow wire cutting: Slow wire cutting parts, cutting Figure 3 Based on the right picture, multiple rings are cut from left to right (or multiple rings with the same outer diameter and height are cut in the axial direction of the ring), ensuring a flatness of 0.3mm and a parallelism of 0.03mm. Figure 5 As shown. The thickness dimension leaves margin for subsequent pickling.

[0039] (6) Pickling: Pickle the parts and control the process parameters. Remove the surface ablation layer to ensure the surface roughness and the thickness dimension C of the parts. The pickling process ensures both the surface roughness and the thickness. That is to say, the thickness of the middle part after wire cutting must be combined with the pickling process to ensure both the surface quality and the thickness of the middle part after pickling.

[0040] (7) Machining shape: The inner and outer circles of the ring parts are machined according to the dimensions required by the precision retaining ring parts drawing to ensure the size and B, the notch position is cut along the original weld position. Figure 6 shown.

[0041] (8) Magnetic flaw detection: Magnetic flaw detection is performed on precision retaining rings.

[0042] (9) Chemical passivation: surface treatment, chemical passivation of precision clamping rings.

[0043] The contents not described in detail in the specification of the present invention belong to the prior art known to the professional and technical personnel in the field. Although the illustrative specific embodiments of the present invention are described above to facilitate the understanding of the present invention by the technical personnel in the field, it should be clear that the present invention is not limited to the scope of the specific embodiments. For ordinary technicians in the field of this technology, as long as various changes are within the spirit and scope of the present invention defined and determined by the attached claims, these changes are obvious, and all inventions and creations using the concept of the present invention are protected.

Claims

1. A method for processing a large-size aircraft engine precision retaining ring, characterized in that: The following steps are involved: S1, cutting, using rectangular plate, the thickness of the plate is greater than the width of the precision clamping ring, and the width of the plate is greater than the thickness of the precision clamping ring; S2, rolling, rolling the rectangular plate in S1 along the length direction; S3, polishing and welding, polishing the two ends of the rectangular plate in the length direction after being rolled in S2, and then splicing and welding them into a ring-shaped part; S4, vacuum heat setting, heating the annular component in S3 under vacuum environment, expanding the annular component from the inner ring surface to the outside, ensuring the hardness of the annular component and calibrating the roundness of the annular component; S5, wire cutting, cutting the ring in S4 along a plane perpendicular to the axis of the ring, and obtaining at least one precision clamping ring intermediate under the premise of ensuring the flatness and parallelism of the two axial end faces of the ring; S6, pickling, pickling the precision clamping ring intermediate obtained in S5 to remove the ablation layer on its surface and ensure that its surface roughness meets the requirements; S7, machining the shape, machining the precision clamping ring intermediate piece after pickling in S6 according to the requirements of the precision clamping ring part drawing, and obtaining a precision clamping ring with the shape size and characteristic structure in the part drawing; S8, magnetic flaw detection, check whether the precision clamping ring in S7 has defects; S9, chemical passivation, performs surface chemical passivation treatment on the precision clamping ring that does not have defects in S8.

2. The method for processing a large-size aircraft engine precision retaining ring according to claim 1, characterized in that: In S2, the rectangular sheet material in S1 is rolled using a rolling bed.

3. The method for processing a large-size aircraft engine precision retaining ring according to claim 1, characterized in that: In S4, a heat setting mold is used for heating in a vacuum environment. The heat setting mold includes a cylindrical surface for inserting the inner ring of the annular part in S3, and the material thermal expansion linear velocity of the heat setting mold is greater than the thermal expansion linear velocity of the rectangular sheet in S1.

4. The method for processing a large-size aircraft engine precision retaining ring according to claim 1, characterized in that: In S6, the middle of the precision snap ring is pickled to obtain the thickness required by the precision snap ring part drawing.

5. The method for processing a large-size aircraft engine precision retaining ring according to claim 1, characterized in that: In S7, the inner and outer surfaces of the precision clamping ring intermediate piece after pickling in S6 are machined according to the requirements of the precision clamping ring part drawing to ensure that the outer diameter and width required by the precision clamping ring part drawing are obtained, and the notch required by the precision clamping ring part drawing is machined along the weld position in S3.

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