Command of commonly used and compound G71, G72, G73 uses numerical control car method

Numerical control lathe is compound command (classics of G71, G72, G73, G74, G75, G76) is commonly used arrive, suit mental allowance bigger the treatment process designing that reachs forging, cast. Compound command does not need to write the program paragraph of finish machining, not only program paragraph is little, and shortened effectively the auxiliary time of process designing. Compound command is the loop of rough machining, need has precision work with G70 command. Be opposite below the use method of commonly used compound command G71, G72, G73 and treatment course undertake an analysis (it is below it is exemple) with FANUC system. 1. G71, inside, outside the semifinished product workpiece that thick car commands G71 of round loop of thick finish machining to basically be used at radial dimension to ask dimension of taller, axial is more than radial dimension circularly undertakes thick car circulates. (△ D) R(e) of 1) format G7l U(; ω of △ of U)W(of G71 P(ns)Q(n)u(△ ) F()S(s)T(t) ; G70 P(ns)Q(n) ; In the format, △ D is cutting deepness (radius value is appointed, do not take losing a mark, and for mode instruction) ; E is measured to retreat a knife (mode instruction) ; The beginning that Ns is fine vehicle block phase date; N is the end phase date of fine vehicle block; The fine vehicle surplus that △ U is X axis direction (have losing a mark, diametical instruction) ; The fine vehicle surplus that △ ω is Z axis direction (have losing symbolic) ; , S, T is rotate speed of the feed speed in rough machining loop, main shaft and cutting tool function; G70 circulates for fine vehicle, this command cannot be used alone, need to follow in thick car after compound loop dictates. (If the graph is shown 1 times,2) graphic representation shows circular contrail, AB is workpiece contour line, cutting tool begins sudden shift to be nodded to D from C dot, mobile distance is fine vehicle allowance, next the basis is given feed of axis of cutting deepness X, undertake axial turning, when retreating a knife, by the quantity that retreat a knife E undertakes 45. After retreating a knife, sudden shift reachs circular starting point, finish loop of a thick car, cutting deepness undertakes ordinal basis for many times circulate, the last loop of thick car is the figuration turning loop that finishs according to fine vehicle allowance. Nextpage need attention is the following at 2 o'clock: Command of ① G71 loop is in only outline appearance is when increasing by degrees, use, cannot be in in order to use have when decreasing successively, can appear otherwise degressive part undertakes statified turning, turning deepness is too big. The mobile command of ② block can be X axis shift only, can not appear Z axis is mobile, appear otherwise call the police. (If the graph is shown 3 times,2) graphic representation shows circular contrail, AB is workpiece outline, cutting tool begins to nod sudden shift to arrive from C, ) , mobile quantity is fine vehicle allowance, be worth feed of Z axis direction by Ad, undertake radial turning, by E the value undertakes 45. Retreat a knife, start of go back loop, finish a loop, it is a figuration outline that leaves surplus of car having essence of life circularly for the last time, with G70 the command has the treatment of allowance of purify fine vehicle. The beginning that those who need an attention is circular block allows the shift of Z axis only, appear otherwise call the police. 3. G73 -- profile modeling loop of thick car of compound loop G73 basically uses car of thick, essence at already the thick car of figuration workpiece circulates, be like forging, cast. (κ of △ of △ I)w(of 1) format G73 U() R(d) ; ω of △ of U)w(of G73 P(ns)Q(nf)u(△ ) F()s(s)T(t) ; In G70 P(ns)Q(nf) format, the quantity retreating a knife that △ I is X axis direction (radius is worth an instruction, have losing symbolic) ; Show the amount retreating a knife for Z axis direction (have losing symbolic) ; D is counted to divide administrative levels (the frequency) that shows thick car repeats treatment. (If the graph is shown 5 times,2) graphic representation shows circular contrail, cutting tool is begun to move quickly by C dot, j dot, next the D of number of cent administrative levels of surplus of thick car of cutting tool basis is calculated every time cutting deepness, circular time decides cutting deepness; Turning loop contrail and G71, G72 is different, it is a complete workpiece outline contrail circularly every time, this command can have the treatment of degressive outline. Suit the form cutting of forging cast. Nextpage GOX200.

Z100.

; 4. Epilogue is complex command process designing circularly, the meaning that should notice κ of I of ω of △ U, △ , △ , △ to be represented respectively from numerical value, ω of △ U, △ is finish machining surplus, have way, its are losing a value decide according to means of knife of advance and retreat, choose reasonable order according to semifinished product appearance, after the F in the command, S, T dictates, in Ns ～ N the instruction disables. CNC Milling