CN110722334A

CN110722334A - Method for broaching deformation of large axial mortise notch and eliminating tool connecting edge

Info

Publication number: CN110722334A
Application number: CN201911169583.XA
Authority: CN
Inventors: 孟震威; 史前凯; 庞丹; 田晓龙; 刘峻宇
Original assignee: AECC Shenyang Liming Aero Engine Co Ltd
Current assignee: AECC Shenyang Liming Aero Engine Co Ltd
Priority date: 2019-11-26
Filing date: 2019-11-26
Publication date: 2020-01-24
Anticipated expiration: 2039-11-26
Also published as: CN110722334B

Abstract

The invention discloses a method for broaching deformation of a large axial mortise notch and eliminating a tool connecting edge, which is characterized in that a broaching tool is used on a numerical control broaching machine to perform rough broaching of a square groove, groove expanding, forming and fine broaching on the mortise groove layer by layer to the final size required by the design by adopting a gradual cutting broaching mode to finish the final broaching machining; roughly drawing the mortise flash structure, reserving a machining allowance of 0.2mm-0.3mm, after finishing the finish broaching machining of the mortise and the rough drawing machining of the flash, finely milling the axial tool connecting edge of the flash allowance part which appears due to tool relieving by a broach, and finely milling by adopting an end mill to finish the fine milling machining of the flash allowance of a single mortise. According to the technical scheme, the processing quality of the mortise is better, the processing period is relatively stable and controllable, and the requirements of most production units in large-scale axial mortise processing are met.

Description

Method for broaching deformation of large axial mortise notch and eliminating tool connecting edge

Technical Field

The invention relates to the field of machining, in particular to a method for broaching deformation of a large axial mortise notch and eliminating a tool connecting edge.

Background

A certain aircraft engine fan disc part has the axial tongue-and-groove of big overlap structure, can divide the tongue-and-groove into tongue-and-groove district and overlap district according to structural feature, and the key effect of being connected with the blade cooperation is carried in the tongue-and-groove district, and size, technical conditions are very strict, generally adopt the broaching processing mode, though overlap district need not connect the cooperation, but because its radial dimension change is great, the relative relation, the dimensional variation and the roughness requirement of two planes can't be guaranteed in the broaching.

The large axial mortises are typical structures of disc parts in the fan rotor unit body of the modern aircraft engine, and the machining of the mortises is usually carried out in a broaching mode due to the severe size and technical conditions of the mortises. Along with the promotion of aeroengine performance, the part of novel structure constantly appears, and the tongue-and-groove structure that the big precision of size is high is more and more, especially for the big overlap formula structure tongue-and-groove that control engine vibrations and design, because the radial dimension span of this type of tongue-and-groove is big, often with broach height value settlement great in the design of broach, and cutter quantity is also comparatively huge. The broaching processing mode is gradually cut processing, a plurality of groups of broaches are often needed to be combined and processed on broaching of the notch flash part, due to the release of processing stress, a plurality of tool connecting edges can appear on the inner surface of the mortise flash part, the size change range of the same surface is large, the qualification of the size cannot be guaranteed, the design requirements can be met through later-stage manual pliers repair, and the part quality and the processing period cannot be guaranteed.

Disclosure of Invention

In order to solve the technical problems, the invention provides a method for broaching deformation and removing a connecting edge of a large axial mortise notch, which has the following specific technical scheme:

a method for broaching deformation and eliminating tool connecting edges of a large-scale axial mortise notch is characterized in that a large-scale axial mortise structure made of TC4 titanium alloy is divided into a mortise groove type main body and a wheel disc outer side flash structure; the length of the flash is more than 70mm, and the axial thickness is 5-22 mm;

the groove-shaped part of the mortise is used for mounting a blade, and the working surface of the mortise is tightly matched with the blade;

the outer side flash structure is single and thin;

the method comprises the following steps: performing rough broaching processing on the mortise groove type layer by layer through rough broaching of the square groove, the expanded groove and the forming by using a broach in a gradual cutting type broaching mode on a numerical control broaching machine;

step two: replacing the finish broach to remove allowance of the mortise groove type for processing, and directly processing the mortise groove type part to the final size required by the design to finish the final broaching processing;

step three: roughly drawing the tenon groove flash structure, machining the tenon groove flash structure layer by layer through roughly drawing a square groove, expanding the groove and forming by using a broach, reserving machining allowance of 0.2-0.3 mm, and uniformly reserving allowance for flashes on two sides;

step four: after finishing the finish broaching of the mortise and the rough broaching of the flash, finish milling is carried out on the axial tool connecting edge of the flash allowance part due to the cutter relieving, an end mill is adopted for finish milling, the side edge of the end mill is used for realizing inner hole end feed along the diameter direction of the flash, an arc is cut out after the straight line segment is finished, then the other side is turned, the arc is cut in and fed from the inner hole end to the outer circle end, and the finish milling of the flash allowance of a single mortise is finished.

The method for broaching deformation of the large axial mortise notch and eliminating the tool connecting edge has the preferred scheme that due to the fact that two different machining modes are adopted, machining equipment and stations are required to be replaced for parts, in order to guarantee machining consistency, the same positioning is required for machining of two sides, angular relations are transferred through precision holes, and therefore drilling is generally arranged on the process method and then broaching grooves are arranged.

The invention has the beneficial effects that: the technical scheme of the invention is a method for solving broaching deformation of a rabbet of a mortise and eliminating a tool connecting edge, which is made for an axial mortise with a large flash structure; the method comprises the following steps of dividing a mortise into two parts, namely a mortise area and a flash area according to the special structural characteristics of the mortise, wherein the mortise area bears the key function of being in matched connection with a blade, the size, technical conditions and surface roughness requirements of the mortise are very strict, and the common milling cannot meet the design requirements and is generally carried out in a broaching machining mode; the flash part does not need to be connected and matched and consists of two parallel surfaces, the size and technical requirements are easier to achieve relative to the mortise area, but because the radial size change of the flash part is larger, the relative relation, the size change and the surface roughness requirements of two planes cannot be ensured by broaching gradual cutting type processing. Therefore, aiming at the special structure, the technical scheme of the patent is carried out by combining two processing methods, the broaching processing progress is high, the efficiency is high, but the large allowance removal amount also brings large stress deformation amount, a small amount of deformation of the mortise part can be eliminated by rough and fine broaching, and a large amount of shrinkage and distortion deformation caused by single thin structure of the flash part and poor structure rigidity can be processed by adopting a milling mode, so that good relative size and surface quality can be obtained; compared with the existing large-scale mortise by simple broaching or milling, the method has the advantages that on the basis of keeping the precision control of the broaching on the dimensional tolerance of the mortise groove, the phenomenon that the two faces which should be parallel are in a football shape due to the fact that a large allowance is removed from a flash structure of the notch is avoided, and multiple tool connecting edges exist on the surface is avoided. The method has innovative thinking, uses a simpler process method, ensures that the popularization of projects and the materialization transformation of products are relatively simpler, has small investment and quick response, effectively combines various processing modes together, makes up for deficiencies to obtain better mortise processing quality and a relatively stable and controllable processing period, and meets the requirements of most production units in the mortise processing with special structures.

Drawings

FIG. 1 is a schematic view of a tongue and groove and flash configuration;

FIG. 2 is a schematic diagram of a flash milling track;

FIG. 3 is a schematic view of a burr-receiving edge;

fig. 4 is a schematic view of a finish end mill.

In the figure, 1-mortise, 2-flash, 3-flash allowance, 4-tool connecting edge, 5-end milling cutter and 6-finish milling processing track.

Detailed Description

According to the method for broaching deformation and eliminating the tool connecting edges of the large axial mortise notch, which is shown in the figures 1-4, the large axial mortise structure made of TC4 titanium alloy is divided into a mortise 1 groove-shaped main body and a wheel disc outer side flash 2 structure; the length of the flash 2 is more than 70mm, and the axial thickness is 5-22 mm;

the groove-shaped part of the mortise 1 is used for mounting a blade, and the working surface of the mortise is tightly matched with the blade;

the outer side flash 2 is single-thin in structure;

the method comprises the following steps: performing rough broaching processing on the groove shape of the mortise 1 layer by layer through rough broaching square grooves, expanding grooves and forming by using a broach in a gradual cutting type broaching mode on a numerical control broaching machine;

step two: replacing a finish broach to remove allowance of the groove type of the mortise 1, and directly processing the groove type part of the mortise 1 to the final size required by the design to finish the final broaching;

step three: roughly drawing the structure of the tenon groove flash 2, machining the structure layer by layer through roughly drawing a square groove, expanding the groove and forming by using a broach, reserving machining allowance 3 of 0.2-0.3 mm, and uniformly reserving allowance for the flash 3 at two sides;

step four: after finishing the finish broaching of the mortise 1 and the rough broaching of the flash 2, finish milling the margin part of the flash 2 due to an axial tool connecting edge 4 which appears due to broach relieving, finish milling by adopting an end mill 5, using a side edge of the end mill 5 to feed from a large outer circular end to an inner circular end along the diameter direction of the flash, cutting an arc after the straight line segment is finished, turning to the other side, cutting the arc and feeding from the inner circular end to the outer circular end, and finishing the finish milling of the margin of the single mortise according to a finish milling processing track 6.

Because two different processing modes are adopted, processing equipment and stations are required to be replaced for parts, in order to ensure the processing consistency, the processing on two sides needs to have the same positioning, and angular relation is transferred through precise holes, therefore, the process method generally arranges drilling and then arranges pull grooves.

Claims

1. A method for broaching deformation and eliminating tool connecting edges of a large-scale axial mortise notch is characterized in that a large-scale axial mortise structure made of TC4 titanium alloy is divided into a mortise groove type main body and a wheel disc outer side flash structure; the length of the flash is more than 70mm, and the axial thickness is 5-22 mm;

the outer side flash structure is single and thin;

2. The method as claimed in claim 1, wherein the broaching deformation and the removal of the tool-receiving edge are performed by two different machining methods, wherein the machining equipment and the machining stations are replaced, the same positioning is performed on the two sides for the machining consistency, and the angular relationship is transferred through the precision holes, so that the drilling is generally performed before the grooving.