With the method of contrail of center of cutting tool of AutoCAD graph computation

0 wrote an application program, the program obtains the coordinate information of spare parts outline from inside AutoCAD graph, give the athletic contrail of cutting tool center according to these information and other parameter computation, generate treatment code directly. This process works to improvement the quality, validity that assures process designing and the economic value with raise the ability that handles task of more sophisticated treatment to have better. One, of information of coordinate of spare parts outline get obtain information from inside the graph, should press the spare parts above all actual size is exact undertake scale, make graphical coordinate and coordinate of machine tool treatment consistent. Go to the lavatory to choose, want to set spare parts contour line into one whole normally, to closing outline, can form a many justice line with what Bloly command makes (Polyline) , close to be not outline, can use Pedit child command what Join makes to form many justice line. Many justice line is the special logo substance in AutoCAD, it by a series of end to end comprise with circular arc point-blank, in graphical database with acme (be linked together namely dot) the form of seed body saves information, the information that concerns with the position, appearance basically has two: It is apical coordinate numerical value, maintain presence in 10 group code; 2 it is apical protruding is spent (Bulge) , maintain presence in 42 group code. The agreement in AutoCAD: Protruding is spent for 0 it is linear acme, it and next apical join are all the time line; Protruding is spent do not be 0 it is circular arc acme, it and next apical join are one circular arc; Protruding spends a value to express clockwise arc to lose, protruding spends a value to be expressing anticlockwise circular arc; Protruding spends absolute value to be less than 1 state circular arc wraps horn to be less than 180 ° , protruding spends absolute value to be more than 1 state circular arc wraps horn to be more than 180 ° . Protruding spends the concern that includes part with circular arc is: Circular arc wraps Arctan of horny =4 × | Protruding spends a worth | . The linear acme of many justice line and circular arc acme were saved only indicate with the start of circular arc point-blank, terminal coordinate protects existence the next in acme. Autolisp language was offerred read the function that takes data of apical and hypostatic group code, accordingly, can very know each apical coordinate is worth many justice line to spend a worth with protruding conveniently, repass coordinate fastens changeover and computation, got the start of straight line segment on spare parts contour line, terminal coordinate and circular arc paragraph the geometrical information such as start, terminal, radius, the centre of a circle. 2, the element that concerns with contrail of cutting tool motion pursues the contrail of motion of relation cutting tool of motion of 1 cutting tool and spare parts surface and treatment method is concerned with appearance of spare parts outline not only, still with this outline be a spare parts inside means of the surface or outside face, treatment is arrange mill or go against dimension of radius of mill, milling cutter, public errand, treatment to be out of shape wait for all elements to concern. Machine the surface inside the spare parts: When suitable mill, cutting tool moves by anticlockwise direction (main shaft is turning, similarly hereinafter) (1a) seeing a picture, when going against mill, criterion cutting tool moves by the clockwise (1b) seeing a picture. Machine the surface outside the spare parts: As it happens is contrary, when suitable mill, cutting tool suitable hour hand moves (1c) seeing a picture, when going against mill, criterion cutting tool is anticlockwise motion (the distance of center of cutting tool of 1d) seeing a picture and spare parts contour line besides milling cutter radius, when considering dimension public errand and treatment even " let a knife " metabolic circumstance, if press nominal dimension to undertake machining, general inside exterior dimension slants small, outside area size slants big, accordingly, must install to adjust variable, use at undertaking adjustment to nominal dimension. In addition, to be not the joint that makes the same score glide to cross, should consider circular arc to transfer means (usable also other transfers means) . 3, the contrail of center of computational computation cutting tool of contrail of cutting tool center is to press way of cutting tool movement, ordinal the data that takes out substance of acme of many justice line has computation and transition. Spend a value to judge apical quality according to protruding above all, deciding the object is linear from this still is circular arc. If be linear acme, obtain this acme and the coordinate value with apical the next first, again the basis machines means, part to reach starting point of sharp edge of two end points with Polar function terminal direction adds 90 ° (suitable mill) or decrease 90 ° (go against mill) hind, radius of mobile cutting tool and the distance that adjust variable difference, get the start of cutting tool center and terminal coordinate. If be circular arc acme, the coordinate value that obtains this acme first and protruding spend value and the coordinate with apical the next to be worth, computation gives the centre of a circle and radius, again direction of the centre of a circle of edge of two end points (sunken arc) or as opposite as the centre of a circle way (protruding arc) radius of mobile cutting tool and the distance that adjust variable difference. One Duan Zhi line or a paragraph of circular arc are afore-mentioned algorithm, when they are combined together, the circumstance wants a few more complex, basically be to judge them to whether need to transfer in joint circular arc and whether to repeat calculation. Will tell commonly, two join point-blank, should have transfer circular arc; Mix point-blank circular arc or two circular arc join, tangent when do not need to transfer circular arc, and tangent place requires calculation only a bit, not tangent when need transfers circular arc. Below special situation, the sunken circular arc with circular arc radius and cutting tool equal radius, receive after tangent and linear or circular arc, all can not require calculation. Notable is, it is consistent that the acme that afore-mentioned calculative premise are many justice line ranges order and way of cutting tool movement. And the acme that commands formation many justice line with Bpoly always presses anticlockwise direction to arrange in graphical database save, and permutation starting point and the selected element when making many justice line are concerned, accordingly, must determine direction of cutting tool motion first before computation. When cutting tool it is suitable hour hand when motion, need conversed acme original permutation is ordinal, and the character that should change acme, namely circular arc of linear and apical instead is apical, instead of circular arc acme is linear and apical. 4, 2 parameter input blueprint of operation dialog box the dialog box goes to the lavatory to use an operation, want to design an operation dialog box with DCL language, if pursue,2 are shown. In this dialog box, choose outline pushbutton through pressing (treatment contour line is chosen on the graph, obtain coordinate information) , surface of choice spare parts and treatment means (in order to determine the athletic direction of cutting tool) , the input adjusts parameter and cutting tool number (the deflection of center of affirmatory cutting tool and contour line is measured) after waiting for an operation, usable imitate shows pushbutton, the 2 safeguard that undertake in AutoCAD graph editor cutting tool moves directly emulate imitate to show; After observation is satisfactory, input cutting deepness respectively again, every time the process designing such as rotate speed of speed of speed of feed quantity, cutting, feed speed, mill of essence of life, main shaft machines parameter, press affirm pushbutton, in can outputting whole CNC Machining process designation text file. 5, the last word undertakes numerical control process designing with this kind of method, want to pursue correct formerly only, can make sure process designing succeeds, and the work that place of process designing personnel should do chooses to machine an object namely and the input machines parameter. Can reduce labor intensity already, shorten process designing time, can reduce accident again, make process designing work simple, efficiency rises. CNC Milling