Linkage turning precision machining method for narrow cavities of disc parts

Abstract

The linkage turning precision machining method comprises the following steps: firstly, carrying out manufacturability analysis on the narrow cavity of a part, and measuring the sizes such as an opening and the depth; drawing a mid-difference model; then designing a cutter structure, dividing a processing area to determine the specification and shape of the cutter, for example, the area A is formed by a rectangle, and the cutter 1 is used for processing; secondly, a machining program is programmed and simulated, reasonable cutting parameters are set, tool retracting and high-pressure cooling are conducted every time 1-2 layers are cut, and chip extrusion and tool hitting are prevented; according to the method, the problems of scrap extrusion, tool hitting and the like of a traditional machining tool are solved, the machining precision and stability are improved, the method is successfully applied to machining of the non-bolt-connection baffle installation groove of the powder alloy turbine disc, qualified delivery of multiple turbine discs is completed, and remarkable economic benefits are created; and the method is suitable for machining narrow groove-shaped structures of various disc parts, and has a wide prospect in the manufacturing field of aero-engines and the like.

Description

Technical Field

[0001] The invention relates to the technical field of aviation engine manufacturing, in particular to a precision machining method for narrow cavity linkage turning. Background Art

[0002] In the field of aviation engine manufacturing, disc parts are key components of turbine rotor components, and their performance and quality play a vital role in the overall operation of the engine.

[0003] With the continuous development of aero-engine technology, the requirements for disc parts are becoming increasingly stringent. Such parts usually have the characteristics of high material hardness, which leads to significant work hardening during processing. What is more complicated is that their structure contains a variety of narrow cavities, which brings great challenges to processing.

[0004] Traditional CNC lathes and tool structures have exposed many limitations when facing the processing of such parts. Due to the special structure of the narrow cavity, it is very easy for the tool to squeeze chips and hit the tool during the processing. The chip squeezing phenomenon not only affects the surface quality of the processing, but also may cause damage to the tool and increase the processing cost. The problem of hitting the tool may directly cause the tool to be scrapped, and at the same time cause damage to the parts, resulting in the parts being scrapped due to out-of-tolerance. In addition, the narrow cavity is also prone to interference and collision problems, which further increases the processing risk, making it difficult to ensure the processing accuracy of the parts, and unable to meet the high-precision and high-quality requirements of aircraft engines for disc parts. Summary of the invention

[0005] In order to solve the above problems, the present invention discloses a method for precision machining of a narrow cavity of a disc-like component by linkage turning.

[0006] The specific technical solutions are as follows:

[0007] A method for precision machining of a narrow cavity of a disc-like component by linkage turning, comprising the following steps:

[0008] Step 1: Processability analysis of the narrow cavity of the part, measuring the opening, depth, length, and transfer radius of the cavity of the part;

[0009] Step 2, draw the mean difference model of the narrow cavity of the part, and establish the mean difference model of the narrow cavity of the part;

[0010] Step 3: Tool structure design: divide the processing area according to the established mean difference model, and determine the processing area, tool shape, and tool specifications of the tool;

[0011] Step 4: Processing program compilation and simulation: program compilation of each tool is completed in sequence according to the processing area of ​​the tool, and trajectory simulation is completed;

[0012] Step five: Part processing, call the CNC program to complete part processing verification.

[0013] In step three: the specification of the tool is determined by the size measured by the minimum fillet in the groove.

[0014] In step three: first, the rectangular area of ​​the cavity is machined, and the groove depth is machined by the tool. The transfer groove is used as the dividing point, and the straight line segment area on the right side of the dividing point is machined. Then the semicircular area is machined, and finally the remaining area in the cavity is completed by tool machining.

[0015] In step 4: the cutting depth of the tool each time is not greater than 0.4mm, the tool feed speed is not greater than 0.15mm, the linear speed is not greater than 50m / min, and the cutting time of a single blade is not greater than 40min.

[0016] The advantages of the present invention are: it is suitable for machining parts with complex groove structures, especially for narrow cavity structures like disc-like parts, and can effectively ensure machining accuracy and quality. It is widely applicable in the fields of aerospace, machinery manufacturing, etc., and adopts linkage turning, reasonable tool design and machining procedures, and anti-chip measures for narrow structures, etc., to improve machining efficiency. According to actual applications, it has created a value of 7.5 million yuan, and subsequent parts of the same family can achieve an annual production value of more than 30 million yuan, which can achieve stable delivery of parts of this family and have batch production processing capabilities to meet production needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Flow chart of the processing method of the present invention;

[0018] Figure 2 It is a schematic diagram of the dimensional analysis and measurement of the narrow cavity of the turbine disk in the case of the present invention;

[0019] Figure 3 It is a schematic diagram of the mean difference model of the narrow cavity of the turbine disk in the case of the present invention;

[0020] Figure 4 It is a schematic diagram of the tool structure in the case of the present invention;

[0021] Figure 5 Schematic diagram corresponding to the processing area of ​​the tool in the case 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] Taking a certain type of powder alloy turbine disk part of an aircraft engine as an example, a narrow cavity linkage turning processing scheme is introduced. The present invention is further explained below in conjunction with the accompanying drawings and embodiments.

[0024] 1) Processability analysis of narrow cavity of parts. The opening, depth, length and transition fillet of the cavity of the turbine disc were measured, which were 10.5mm, 10.5mm, 7.5mm respectively, and the minimum fillet size was R1.5mm. The fillet size was determined based on the minimum fillet. In order to determine the specifications of the tool and to improve the rigidity of the tool, a tool with a larger diameter was selected as much as possible, such as Figure 2 ;

[0025] 2) Draw the narrow cavity mid-difference model of the part. Complete the mid-difference model construction according to the mid-difference of the design drawing, such as Figure 3 , prepare for tool design and programming;

[0026] 3) Tool structure design. The tool shape design should be completed by minimizing the number of tools and using the linkage turning function as much as possible for the same structure, such as Figure 4 , Figure 5 The following cavity dimensions are in millimeters, and are divided and processed according to the groove processing area as follows:

[0027] Area A is composed of a rectangle formed by a cavity opening size of 10.5 and a depth of 10.5, and this area is processed by tool 1.

[0028] Area B is a rectangular area formed by the straight line area in the cavity length 7.5 (the right part with the transition groove R2 in the figure as the dividing point) to the groove depth 10.5, and this area is processed by tool 2.

[0029] Area D is a semicircle formed by the reverse transfer fillet area in the cavity, and then an area extending in the depth direction of the cavity with the radius of the tool selected for area D as the reference length. These two parts together constitute the processing area of ​​area D, and the processing is completed by tool 4.

[0030] The remaining part except the above-mentioned areas A, B, and D is defined as area C and is processed by tool 3.

[0031] 4) Processing program compilation and simulation. Use a computer to generate program trajectory, and for the risk points where narrow structures are prone to chip squeezing and tool hitting, which may lead to part deviations, the tool is removed from the part after every 1-2 layers of cutting. High-pressure cooling is used to clean up the iron chips on the narrow cavity of the part and the tool to ensure that there is no chip entanglement between the tool and the part. For the part material, the cutting depth of each tool is selected to be ≤0.4mm, the feed speed is ≤0.15mm, the linear speed is ≤50m / min, and the cutting time of a single blade is ≤40min. VERICUT is used to simulate the tool trajectory;

[0032] 5) Parts processing: Clamp the parts on the equipment and call the program to complete the entire processing of the parts.

Claims

1. A method for precision machining of narrow cavity linkage turning of disc-like parts, characterized in that: The steps include: Step 1: Processability analysis of the narrow cavity of the part, measuring the opening, depth, length, and transfer radius of the cavity of the part; Step 2, draw the mean difference model of the narrow cavity of the part, and establish the mean difference model of the narrow cavity of the part; Step 3: Tool structure design: divide the processing area according to the established mean difference model, and determine the processing area, tool shape, and tool specifications of the tool; Step 4: Processing program compilation and simulation: program compilation of each tool is completed in sequence according to the processing area of ​​the tool, and trajectory simulation is completed; Step five: Part processing, call the CNC program to complete part processing verification.

2. The method for precision machining of narrow cavity linkage turning of disc-like parts according to claim 1 is characterized in that: In step three: the specification of the tool is determined by the size measured by the minimum fillet in the groove.

3. The method for precision machining of narrow cavity of disc-like parts by linkage turning according to claim 1, characterized in that: In step three: first, the rectangular area of ​​the cavity is machined, and the groove depth is machined by the tool. The transfer groove is used as the dividing point, and the straight line segment area on the right side of the dividing point is machined. Then the semicircular area is machined, and finally the remaining area in the cavity is completed by tool machining.

4. The method for precision machining of narrow cavity of disc-like parts by linkage turning according to claim 1, characterized in that In step 4: the cutting depth of the tool each time is not greater than 0.4mm, the tool feed speed is not greater than 0.15mm, the linear speed is not greater than 50m / min, and the cutting time of a single blade is not greater than 40min.

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