| Following a great prosperity in the aviation engines industries, the application ofaircraft engine has increased dramatically in recent decades. The industrial demands forblades have also greatly increased because they are the vital components in theabove-mentioned equipments. There exist a great variety of different types of bladeswith various complex surfaces, which are very difficult to machine. The designing leveland manufacturing quality of blade surfaces have great influences on the workingefficiency and serve life of the above equipments. However, the blade manufactureenterprise is also used the traditional manual way of blade precision finishing in ourcountry, which Seriously restricted the promotion of national defense equipment’soverall level. Therefore, it has practical significance to develop a set of automaticgrinding equipment with high efficiency, economical, proprietary intellectual propertyrights,to realize grinding with higt efficiency, high precision.CNC auto-programming system is an important part of the process of blademachining, which decides the efficiency of machining equipment. At present, commonused CAM softwares are not only expensive, but also not suitable for blade. so wedevelop customized CAD/CAM software for turbine blade is the optimal way to realizeblade machining. The main research in my topic is the technology of CNCauto-programming in abrasive belt grinding, the main idea is to realize NC Machiningof aircraft blade.The main contents in this paper are as following:1)Under the assistance of CAD models of blade, we can get the information suchas the coordinates of point and normal vector of any point locating on the the blade, andalso including some geometrical characteristics on the surface by analyzing the surfaceof blade, based on which we carry out tool-path planning, picking up cutter contactpoint and cutter loeation data, caculating the direction of wheel gyroaxis with grindingcharacteristic of abrasive belt.2)We proposed machining technology problem in inlet edge and exhaust edge ofaircraft blade, build the normal axis mechanical model by analyzing the structuralfeatures. Build the grinding depth and normal grinding force function model byanalyzing abrasive belt character. caculate the grinding force in cutter contact point tocontrol the grinding force during the process by picking up machining allowance, compensate for normal axis location by caculating grinding static defection throughfinite element method.3)Take full consideration the character of abrasive belt grinding, starting fromresearching the relative position and pose between tool and workpiece in grinding.analyzed the machine structure characteristic and motion of each axis, build thekinematics model, solved motion parameters with D-H method. Take research onmove speed of machine axis for high efficiency and high quality. check themismachining tolerance and make relevant compensation. Convert the format andgenerate NC code by CNC character. Guarantee the exactness, we carry out Interferencechecking and motion simulatuion.4)As UG for platform, We adopt VC++programming language and UG/OPEN APIfor the re-development tool. with the help of differential geometry knowledge, wefinished the aircraft blade development of CNC auto-programming system which havesix main modules, such as input and output module, machining area division module,cutter location and grinding tool path generation module, blade edge machiningallowance picking up module, post-processing module and machining simulationmodule. The system can realize auto-generation of NC code and abrasive belt grindingmachining simulation with machining parameters and blade module input by users. |
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