Apply treatment of process designing of grand program variable to be able to use function formula to describe the outline of workpiece or curved surface, it is system of contemporary numerical control a main new function and new method, also be one of main knowledge dots of treatment of numerical control production and contest of numerical control skill. The article with China system of mediaeval star HNC-21TCNC Turning is platform, introduce parabola the work out method of grand program, research the crucial technology of grand program process designing through example, example program can be used as pattern plate promotion. In numerical control lathe, treatment object basically is the circumgyrate face of all sorts of types, mix to face of columnar face, cone, circular arc among them spherical the treatment that wait, can use linear interpolation and instruction of circular arc interpolation to finish, and the swing tower that round to a few blame such as elliptical, parabola curve forms, treatment rises have certain difficulty. The linear interpolation that itself of numerical control system offers and circular arc interpolation cannot be used at be not the treatment of face of round curve circumgyrate directly, accordingly, the method that on numerical control machine tool the treatment to elliptical, parabola uses arc of paragraphs of small linear small perhaps Duan Yuan to approach mostly will weave machine program. Choose in the article China system of mediaeval star HNC-21TCNC Turning, combinative production exercitation and skill contest train the work out method of the grand program of pair of turning parabola outline to undertake discussing, hope each reader can raise precious opinion more. One, the introduction of Hua Zhonghong program uses variable work out to be able to have arithmetic or logistic operation, can control the process that block flows to, call an user grand program. In CNC Turning, grand program can realize use user 2 times conveniently curve (elliptical, parabola) treatment of 2 dimension process designing, orifice pours treatment of horny process designing to wait, can simplify program, improve process designing efficiency, utmost ground produces the advantage of manual process designing. China system of mediaeval star HNC-21TCNC Turning provided the strong grand program function that is similar to advanced language for the user, the user can use variable to have the mixture operation of arithmetic manipulation, logistic operation and function, in addition grand program still offerred circular statement, branch statement and subprogram to call a statement, benefit at the work out all sorts of complex spare parts machine program, decrease and even when absolving manual process designing, undertake trival numerical value is calculated, and compact program volume. Commonly used statement has the following two kinds. (IF of statement of 1) condition differentiate, ELSE. ① : IF condition expression... ELSE... END IF; ② : IF condition expression... ENDIF. (WHILE of 2) loop statement: WHILE condition expression... ENDW. Article example uses WHILE statement process designing. 2, formulary curve grand grand program is in the basic measure of to program in process of real authorized strength, according to process designing person the element such as reserve of practice experience, knowledge and habit can differ somewhat, the article offers grand to program is main measure learns for reader reference. (1) basis is given independent variable of standard equation make choice of defines variable scope. The X in 1) formulary curve and Z coordinate all can make choice of is independent variable, general we choose a span is bigger. 2) goes to the lavatory according to expression the case comes X of make choice of or Z are independent variable. If the graph is shown 1 times, formulary curve expression is Z=-X2/12, compare X choosing for independent variable appropriate. If choose Z to still need expression shift, 2 evolution expression is not quite convenient. After make choice of of 3) independent variable, we decide its variable limits is worth even. Graph 1 independent variable is X, radius change is worth from 6 to 12, other example variable is worth choose redo concrete analysis. (2) basis is given because variable is opposite,standard equation decides the expression at independent variable. Graph 1 in, parabola fastens medium standard equation expression to be in workpiece coordinate: Z=-X2/12, independent variable is X, because variable is Z, criterion the expression of Z is: Z=-X2/12, of sign choose as sunken as parabola protruding about. (3) basis is given the deflection that firm posture fastens to workpiece coordinate measures standard equation. In machining a process actually, the formulary curve position that we encounter is put in a variety of forms, the center of the center of the center that is like formulary curve and coincide of origin of workpiece coordinate department, formulary curve and Z axis or X axis coincide, formulary curve is in the protruding sunken appearance of the aleatoric position in workpiece coordinate department and formulary curve, this asks we are in editor when consideration curve center and the relative position relation that workpiece coordinate fastens. Nextpage is in graph 1 in, parabola Z fastens zero shift quantity to be to workpiece coordinate to center photograph to 3, in block " G01 X[2*#1] Z[3+#2] " body reveals Z to deflection quantity. Consult to curve of other center position example analysis. (Program of 4) work out. Relevant expression and variable element value are already certain, we plan work out program. Lathe swing tower kind the semifinished product surplus with large presence of spare parts treatment, we use G71 loop instruction and grand program nest to complete curved surface treatment. 3, formulary curve the specific application example of grand program process designing is analytic 1. Z machines N50 G71 U1 of of of N40 X31 Z3 of of of N30 G00 X80 Z80 of of of N20 T0101 M03 S800 of of of N10 G90 G94 of of %0001 to spare parts of deflection protruding parabola.
5R1 P90 Q200 X0.
Z0 of 5 .
1N110 #1=6;X of of of N100 Z0 of of of N90 G01 X12 of of of N80 G42 G00 X31 Z3 of of of N70 M03 S1500 F100 of of of N60 G00 X80 Z80 of F200 is worth N120 #2=-3;Z to initial drop radius to initial drop (opposite at parabola acme) whether does judgement of N130 WHILE #1 LE 12; walk along X to terminus (relatively at parabola, approach parabola outline (the deflection that should consider center here is measured) because N150 #2=-[#1*#1]/12; is variable Z to value N160 #1=#1+0.
1; step pitch 0.
1, namely Z is worth degressive quantity for 0.
1, this value affects appearance precision greatly too, pass burden of operation of small aggravating system, should take N230 M30 of of N220 M05 of of of N210 G40 G00 X80 Z80 of of of N200 Z-50 of of of N190 G01 X30 of of of N180 G01 Z-40 of of of N170 ENDW of the big that be worth to use VNUC numerical control to emulate software imitate treatment as far as possible below the premise of contented appearance precision, if pursue,as a result 2 are shown. Afore-mentioned Nextpage example we already did brief analysis in front, patulous example can communicate study for everybody below. 2.
Xiang Jun of X, Z has spare parts of deflection sunken parabola to if the graph is shown 3 times,be machined, this spare parts is when process designing, we are OK apply mechanically example the process designing format of 1, the deflection position of sunken, center and variable remove the protruding that both distinction depends on parabola appearance the computation of dead centre. ... #1=12.
5;X is worth to initial drop radius (get according to parabola center and mouth direction computation) #2=15.
626;Z to initial drop (the photograph is apical to parabola) whether does judgement of WHILE#1GE4; walk along X to terminus (relative to the numerical value at parabola center) G01X[40-2*[#1]] Z[#2-25.
626] ; linear interpolation, approach parabola outline (the deflection amount that should consider center here, sunken parabola takes negative worth) because #2=[#1*#1]/10; is variable Z to the #1=#1-0 that be worth .
1; step pitch 0.
1, namely Z is worth degressive quantity for 0.
1, this value affects appearance precision greatly too, pass burden of operation of small aggravating system, should take of of great value ENDW as far as possible below the premise of contented appearance precision... 4, when the last word uses numerical control lathe to machine parabola curve, should notice the following: (The step pitch that chooses when the precision of the workpiece after 1) turning and process designing is concerned. Step pitch value is less, treatment precision jumps over tall; but reduce step pitch to be able to cause workload of numerical control system to increase, operation is busy, affect feed rate rise, reduce treatment efficiency thereby. Accordingly, must ask according to treatment logical choice step pitch, ask in contented treatment premise falls commonly, choose bigger step pitch as far as possible. (2) to parabola center and Z axis not the spare parts of coincide, need has workpiece coordinate department slanting after buy, the method that narrates by place of the example in article next undertakes machining. (Protruding sunken case of the curve should consider when 3) process designing, both distinction depends on linear interpolation approaching the X coordinate in curvilinear block to change. (Process designing of turning of the outline inside 4) parabola and outside outline is similar, position of main consideration center, concave and convex circumstance reachs a dead centre place, the reader can weave according to apply mechanically of afore-mentioned example proper motion. The example that the article chooses already was in configuration China is mediaeval on the numerical control lathe of astral HNC-21T system run treatment actually to pass (among them radius of circular arc of point of a knife is 0.
4mm) , wait for parameter to be able to have set according to machining real environment to the F in process designing, S and Ap, set-point can offer reference. Afore-mentioned programs can regard formulary curve as pattern plate of grand program process designing use, need to change individual parameter to be worth only can. CNC Milling
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