CN110434357B

CN110434357B - Numerical control machining method for high-temperature alloy labyrinth sealing parts

Info

Publication number: CN110434357B
Application number: CN201910613489.2A
Authority: CN
Inventors: 杨雪峰; 谭贻文; 黄雪; 宋秀峰; 张洪彬; 程明; 顾志勇; 方正强; 李春雨
Original assignee: AECC Harbin Dongan Engine Co Ltd
Current assignee: AECC Harbin Dongan Engine Co Ltd
Priority date: 2019-07-09
Filing date: 2019-07-09
Publication date: 2021-09-10
Anticipated expiration: 2039-07-09
Also published as: CN110434357A

Abstract

The invention belongs to a labyrinth machining technology, and particularly relates to a numerical control machining method for a high-temperature alloy labyrinth sealing part. When the grid teeth are machined by the grid tooth cutter, a numerical control layer-by-layer progressive machining mode is adopted, the first layer of each tooth is machined one by one according to the arrangement sequence of the teeth of the grid teeth, and after the first layer is completely machined, the second layer and the third layer of each tooth are machined until the machining of each grid tooth is completed. According to the invention, by improving the clamp pressing plate, selecting a proper cutter and optimizing the part processing route, the processing difficulty of the high-temperature alloy labyrinth sealing part is effectively reduced, the production efficiency of the part and the product percent of pass are greatly improved, and the processing percent of pass of the high-temperature alloy labyrinth sealing part is 100% after actual processing verification.

Description

Numerical control machining method for high-temperature alloy labyrinth sealing parts

Technical Field

The invention belongs to a labyrinth machining technology, and particularly relates to a numerical control machining method for a high-temperature alloy labyrinth sealing part.

Background

As shown in fig. 1, the labyrinth seal is a non-contact type sealing structure widely used in aircraft engines, which increases the flow resistance by using sudden expansion and contraction of a channel to limit the fluid leakage. High tooth profiles are often used in the comb design because they are better for thermal stability than short tooth profiles. And the turbine group parts are often in high-temperature and high-pressure working environments, so the parts forming the turbine part of the aircraft engine are made of high-temperature alloy materials in many cases. However, the high-temperature alloy material has poor cutting performance, serious work hardening and serious tool abrasion, and particularly, the conventional labyrinth seal part is generally machined by a common lathe.

When a common lathe in the prior art is used for machining the grate-like part, as shown in fig. 2, the grate-like part is clamped, and the round pressing plate on the end face on the right side has a small diameter and cannot completely cover the first grate, so that the phenomenon of grate toppling, bending and deformation caused by extrusion of a cutter during machining is generated.

The axial dimension needs to be guaranteed by the scale feeding of the small planker dial during the common lathe machining, and the axial dimension needs to be guaranteed by one-time tool setting, so that the machining needs to be carried out one by one. As shown in fig. 3, the No. 1 tooth (the grate-tooth knife is a black outer frame) is firstly processed, then the No. 2 tooth (the grate-tooth knife is a red outer frame) is processed, and the dotted line area is the tooth profile change trend after the grate-tooth knife is processed along the X direction. For example, after the right flank of the No. 1 tooth is machined, when the left flank of the No. 1 tooth is machined, the cutter can generate right cutting force on the grate, the grate is thin, the turning belongs to turning tool forming machining, the cutting force is large, the grate is seriously bent and deformed, the axial size, the grate angle and the tooth top thickness are all out of tolerance, and the same problem can be caused when the No. 2 grate is machined.

Disclosure of Invention

The invention aims to provide a numerical control machining method for a temperature alloy labyrinth sealing part, which has high production efficiency and high product qualification rate.

The technical scheme of the invention is as follows: a method for processing a high-temperature alloy labyrinth sealing part is characterized in that when a labyrinth is processed by a labyrinth cutter, a layer-by-layer progressive processing mode is adopted, according to the arrangement sequence of all the teeth of the labyrinth, the first layer of each tooth is processed one by one, and after the first layer is completely processed, the second layer and the third layer of each tooth are processed until the processing of each labyrinth is completed.

When the grid-toothed cutter is used for processing each grid-toothed section layer by layer, the feed and the withdrawal of the cutter are controlled by a numerical control program.

And (4) during the progressive machining layer by layer, correcting the deformation of the previous layer during the subsequent layer machining.

The tooth side end face of the first high-temperature alloy labyrinth sealing part is arranged on the pressing plate which is parallel and level with the tooth side end face.

The edge of the pressing plate is provided with a notch.

The depth of the notch does not exceed the depth of the comb teeth, and the radian of the notch does not exceed 8 degrees under the condition of meeting the measurement and observation requirements.

The comb tooth cutter is made of hard alloy.

The two back angles of the comb tooth cutter are both 9-10 degrees, the angles are specially designed for the processing method, the processing modes are easy to match, and adverse deformation influence caused by processing is reduced to the maximum extent while high processing efficiency is achieved.

The invention has the technical effects that: according to the invention, the purposes of reducing the processing difficulty of high-temperature alloy labyrinth seal parts and improving the production efficiency and the product percent of pass of the parts are realized by improving the clamp pressing plate, selecting a proper cutter and optimizing the part processing route. The practical processing verifies that the processing qualification rate of the high-temperature alloy labyrinth sealing parts is 100 percent. Meanwhile, the numerical control machine tool is used for machining, about 5.5 hours are needed for machining 1 workpiece in the past, only 2.5 hours are needed for machining 1 workpiece at present, and the production efficiency is improved by 54.5%.

Drawings

FIG. 1 is a schematic structural view of a high-temperature alloy labyrinth sealing part;

FIG. 2 is a schematic view of clamping of a high-temperature alloy labyrinth sealing part in the prior art;

FIG. 3 is a schematic view of the machining of a high-temperature alloy labyrinth sealing part in the prior art;

FIG. 4 is a schematic view of clamping of high-temperature alloy labyrinth sealing parts;

FIG. 5 is a schematic view of a platen configuration;

FIG. 6 is a schematic view of machining of high-temperature alloy labyrinth sealing parts.

Detailed Description

The invention is further illustrated with reference to the following figures and examples:

the method for processing the high-temperature alloy labyrinth sealing parts can be divided into three links when the high-temperature alloy labyrinth sealing parts given in figure 1 are taken as an example for processing the labyrinth:

1. and aligning and pressing the parts.

Referring to fig. 3, the left end face and the inner diameter are used for positioning, the pressing plate presses the right end face tightly to fix the part, and the alignment reference is the maximum outer diameter of the part. In the embodiment, the pressing plates are improved, and an aluminum circular pressing plate with the diameter being the same as the outer diameter of the grate sealing part is manufactured by self to completely cover the end face of the grate, so that the deformation of the grate is effectively avoided.

Meanwhile, referring to fig. 4, a notch is milled on the end face of the pressure plate, the depth of the notch does not exceed the depth of the comb tooth, and the radian of the notch does not exceed 8 degrees under the condition of meeting the measurement and observation requirements, so as to ensure the protection of the comb tooth structure.

2. And selecting a cutter.

Aiming at the turning characteristics of poor cutting performance, work hardening and the like of high-temperature alloy, the invention selects the formed grate cutter made of hard alloy material to process parts. Meanwhile, the invention is different from the prior art, two back angles of the existing conventional molding grate cutter are greatly improved from 5 degrees to 10 degrees so as to be matched with the processing mode of the invention. Certainly, according to different actual processing objects, the back angle can be adjusted to a certain degree from 9 degrees to 11 degrees, but is obviously larger than the back angle of the conventional forming grate cutter, so that the back angle is matched with a new processing method, the processing resistance is reduced, the temperature generated by cutter processing is reduced, and the cutter abrasion is reduced.

3. And determining a part processing route.

Aiming at the problem of bending deformation of the comb-tooth parts during processing, the invention uses a numerical control lathe to process the comb-tooth parts by adopting a pecking type layered cutting method. Referring to fig. 6, according to the processing sequence of the first tooth, the second tooth and the third tooth, the first layer of the first tooth is processed, then the first layer of the second tooth and the first layer of the third tooth are processed until the first layers of all the comb teeth are completely processed, then the second layer and the third layer of each comb tooth are processed, and progressive processing is performed layer by layer until all the comb teeth are processed. Through the strict control on the processing sequence, the deformation influence of subsequent processing on the prior processing can be effectively avoided.

Meanwhile, when the comb teeth are machined layer by layer, the peck type layered cutting method is adopted for machining the comb teeth in a numerical control mode, each comb tooth of the part can be machined layer by layer one by utilizing a numerical control program, and each tooth side can be machined by a larger comb tooth respectively, so that the cutting resistance during machining of each knife can be reduced, meanwhile, the machining deformation generated in the previous knife can be corrected, the deformation of the comb teeth is reduced, and the sizes of the comb teeth can be guaranteed.

In the embodiment, the grate is processed by adopting a numerical control pecking type layered cutting method, so that the processing precision of the grate is greatly improved, and the processing qualification rate of the high-temperature alloy grate sealing part is 100% after practical processing verification, which is far superior to that of the prior processing technology. Meanwhile, the numerical control machine tool is used for machining, compared with the existing common lathe for machining 1 workpiece in about 5.5 hours, the existing machine tool only needs 2.5 hours for machining 1 workpiece, the production efficiency is improved by 54.5%, and the numerical control machine tool has obvious economic benefit.

Claims

1. A method for processing a high-temperature alloy labyrinth sealing part is characterized in that when a labyrinth is processed by a labyrinth cutter, a layer-by-layer progressive processing mode is adopted, according to the arrangement sequence of all the teeth of the labyrinth, the first layer of each tooth is processed one by one, and after the first layer is completely processed, the second layer and the third layer of each tooth are processed until the processing of each labyrinth is completed;

a pressing plate which is flush with the right end face of the high-temperature alloy labyrinth sealing part is arranged on the right end face of the high-temperature alloy labyrinth sealing part, the diameter of the pressing plate is the same as the outer diameter of the high-temperature alloy labyrinth sealing part, a notch is formed in the edge of the pressing plate, the depth of the notch does not exceed the depth of the labyrinth, and the radian of the notch does not exceed 8 degrees under the condition that the measurement and observation requirements are met;

two back angles of the comb-tooth cutter are both 9-10 degrees.

2. The machining method for the high-temperature alloy labyrinth sealing type part according to claim 1, characterized in that when the labyrinth cutter is used for machining each labyrinth layer by layer in a progressive mode, the cutter feeding and retracting are controlled by a numerical control program.

3. The machining method of the high-temperature alloy labyrinth sealing part as claimed in claim 1, wherein during the progressive machining layer by layer, the deformation of the previous machining layer is corrected by the subsequent machining layer.

4. The machining method for the high-temperature alloy grate seal type part according to claim 1, wherein the grate cutter is made of hard alloy.