Be based on the development of the system of CNC Machining automatic process designing of AutoCAD

The foreword development as science and technology, numerical control machine tool more and more in applying in mechanical production industry widely. In CNC Machining system, process designing of traditional NC code handiwork not only efficiency is low, and make mistake easily; and although geometrical definition statement is terse,use the automatic process designing of APT language, the function is stronger, but the language that personnel of requirement process designing wants to memorize a system and regulation, once make mistake,discover not easily again. This CNC Machining is automatic process designing system is to be based on AutoCAD to be developed on platform and be become. AutoCAD is in as plot software mechanical design is as extensive as the application in making, if CNC Machining system can collect the graphical information in Auto2CAD, will simplify greatly numerical control process designing, improve manufacturing efficiency. But AutoCAD is the geometrical information that will represent a part through the graph, and CNC Machining system uses process designing of NC code handiwork or APT language automatic process designing, the description of information is skimble-scamble between both. This system solves the interface problem of AutoCAD and CNC Machining system just about, collect geometrical information from inside AutoCAD graph and occupy changeover into linage, namely the structure with the DXF peculiar file according to AutoCAD, undertake 2 times developing, those who implement AutoCAD and CNC Machining system is compositive. 1.

The ASCII that the DXF file that the data processing AutoCAD of DXF file outputs is graphical file or binary format are described [1] , have its specific pattern, commonly used at sharing data with other application process, have some of redundant data among them to numerical control process designing, because this must pass processing gift,the postposition of system of automatic process designing handles convenient numerical control module is used. 1.

The DXF file that the structural AutoCAD of file of 1 　 DXF outputs normally by 5 paragraph (SEC2TION): ? Comfort error?HEADER) , watch paragraph (TABLES) , piece paragraph (BLOCKS) , hypostatic paragraph (ENTITIES) and end paragraph (ENDSEC) composition. But to numerical control process designing, the most useful is hypostatic paragraph, because this asks to open DXF file, will hypostatic paragraph in concerned information record comes down and keeping existence GRP file. Every hypostatic format is fixed, and have the parameter related to it (partial parameter sees watch 1) , hypostatic paragraph of geometry data that recorded every substance. Express 1 hypostatic type and relevant parameter (part) 1.

The data extraction of file of 2 　 DXF and ordering chart flow chart of program of data processing of file of 1 　 DXF by the graph of AutoCAD scale, with DXFOUT the command makes his DXF file, read by interface program again take graphical news, if the graph is shown 1 times,its read the technological process that takes a course. But differ according to individual plot habit as a result of the graph of AutoCAD scale, bringing about DXF file data is arranged according to hypostatic scale order, its pursue yuan arranging order also do not attack to be arranged orderly according to the develop of the spare parts certainly, that is to say its data ranks a probability is desultorily, the GRP file data that because program of this classics interface is handled,gets also is arranged according to scale order. And CNC Machining process is strict undertake according to specific treatment line, because this requirement is right GRP file data according to given treatment course has sort. Because the reason of plot makes what conjoint line segment from beginning to end nods abhorrent,consider, because this answers set an effective tolerance, comprise a complete treatment route chart in order to assure. In processing a system, begin from the initial drop of each line segment, treatment comes here the terminus of line segment stops, this terminus also makes the initiative point of below one line segment, machine below one line segment next, because the outline of this treatment is by have to, the graph that orderly line segment comprises. This system uses choice way to have sort, it is in order to have knife place namely fiducial, search the line segment that is linked together to it, this line segment serves as node 1, record its nod coordinate to be worth from beginning to end, write down terminal coordinate. Search other line segment in GRP file then, be like some end points coordinate and equal inside tolerance limits, criterion this line segment serves as node 2, its terminus coordinate is; again from the rest of search in line segment its only then dot coordinate and it is node 3; equally with this analogize, come down all line segment by ordinal record, in keeping existence GRP file again. 2.

NC code makes a plan automatically with what machine orbit the geometrical graph information according to the spare parts and craft information have file of numerical control of flow chart of generating program of file of numerical control of code of 2 　 NC handling generating, handle a program to be carried out in order to explain a method by a postposition commonly. Read the data news in taking GRP file one by one namely, analyse its data type, via compensation of cutting tool radius and pulse equivalent processing, undertake according to file of NC code format corresponding coordinate commutation and code alternate again, build a whole NC block, write in file of NC code numerical control. System of automatic process designing has this CNC Machining certain versatility [2] , can generate corresponding NC code in the light of different CNC Machining system, its program flow chart sees a picture 2. Above all, the system gets treatment parameter information through man-machine interface, like speed of fluid of rotate speed of model of numerical control machine tool, main shaft, cutting, feed, cutting tool date, knife fills means, the main program is in when calling a graph to handle module to process graphical data, union machines parameter data to generate knife digit to seize a file. Undertake initialization of system of numerical control process designing according to CNC Machining system next, make wants NC code form, to the numerical control system that has existed, need to call the pattern of CNC Machining system of existence only, again right Dao Weiwen undertake postposition is handled in order to generate corresponding NCCNC Machining code [3] . 3.

In the WTUAPT system that the construction of system of WTUAPT and function are developing for the tool with VisualC++610 [4] , system advocate accuse module to manage parameter of module, craft to manage code of module, NC to generate module, numerical control to dictate the file manages module of module of imitate of module, treatment and communication by graphical file 6 big module are comprised [4](graph shows) 3 times. Graph construction of system of 3 　 WTUAPT pursues 3.

This module realizes module of management of 1 graph file graphical scale, editor, access, delete those who reach graphical data to show wait for administrative function. The scale of the workpiece figure that has curve of dot, line, round, common curve, list wait for geometrical element to comprise through entering AutoCAD plot software, output 31DXF file. 3.

Module of management of 2 craft parameter finishs date of model of dot removing a knife, machine tool, cutting tool, knife to fill through parameter dialog box the input of the craft parameter such as fluid of speed of rotate speed of means, main shaft, feed, cutting and editor. 3.

Of the data of file of DXF of data information implementation that code of 3 　 NC generates module to call on two module read take with sort, obtain 31GRP file and generate knife digit to occupy file 31CL, can have the edition of GRP and CL file, the 31CUT of NC code file that generates place to need through postposition processing finally. The NC code file that different CNC Machining system makes is suffixal the name is different also, if the form of 3B format is 31TRB, FANUNC-6M is 31FSM. 3.

Code of 4 　 NC manages module to undertake administrative to code file, the user can have an edition to code file according to actual condition, get the treatment that requires actually dictates, make the system has open sex more [5] . 3.

The NC code that opposite of classics of module of 5 treatment imitate becomes undertakes going against compiling [4] , make treatment line, call the cutting tool module in cutting tool library again, can realize the CNC Machining imitate of 2 dimension part, the accuracy of the numerical control code that generates in order to examine and rationality, optimize treatment parameter further thereby, raise first success that tries cutting treatment to lead. 3.

6 communication module realizes the online communication between the computer and numerical control machine tool through interface program, those who implement NC code is automatic deferent, those who avoided manual input or punched tape input to may be caused is wrong. The article realized the last word to collect graphical information and generate NC code automatically from inside AutoCAD software, solved AutoCAD graph information and information of numerical control process designing to describe skimble-scamble problem, the unifinication of CAD/CAM came true on certain level. Through the computer imitate and use actually make clear, this system can realize DXF file data well read take with changeover, fast and accurate, reliability is high. CNC Milling