To the knife the principle reachs pair of knife methods before numerical control lathe

It is the main operation in CNC Machining and main mastery of a skill or technique to the knife. Below certain condition, the precision to the knife can decide the treatment precision of the spare parts, in the meantime, still affect CNC Machining efficiency directly to knife efficiency. Know to the knife the method is insufficient merely, know all sorts of is opposite to count those who control a system even the knife sets pattern, and these means call a method mediumly in machine program, should know all sorts of actor defect to knife means, use condition at the same time (the treatise below is it is with system of FANUC OiMate numerical control exemple) etc. 1 why to want pair of knives generally speaking, the CNC Machining process designing of the spare parts and go up machine tool treatment has apart. Numerical control process designing member the blueprint paper according to the spare parts, the coordinate department of a convenient process designing reachs make choice of its origin, we say for program coordinate department and program origin. Program origin is common as fiducial as the craft of the spare parts or the design is standard coincide, because this calls workpiece origin again. After electrify of numerical control lathe, must undertake answering 0 (reference point) operation, its purpose is to build numerical control lathe to undertake the position is measured, control, indication unity is fiducial, it is origin of so called machine tool this bits, its position is decided by sensor of machine tool position. Because the machine tool is answered 0 hind, cutting tool (point of a knife) origin of positional distance machine tool is changeless, accordingly, mix to the knife to facilitate treatment, can answer the machine tool 0 hind the position of point of a knife regards machine tool origin. In the graph 1 in, o is program origin, o is the machine tool is answered 0 hind it is the machine tool origin that consult with position of point of a knife. Process designing member the cutting tool of coordinate data authorized strength in be being fastened by program coordinate (point of a knife) moving contrail. The initiative position as a result of point of a knife (machine tool origin) with program origin existence X is apart from to deflection and Z is apart from to deflection, make position of real point of a knife and the position that the program dictates have same deflection space, accordingly, this distance measures beard general to come out and be installed into numerical control system, make the system adjusts the athletic contrail of point of a knife accordingly. Alleged to the knife, pledge actually even if install program origin to be in fasten the coordinate in for the machine tool coordinate that consult with point of a knife. 2 try cut pair of knife principles to have a lot of kinds to the method of the knife, the precision that presses pair of knives can be divided be opposite accurately to be mixed roughly to the knife knife; By whether to use pair of Dao Yi to be able to be divided move for the hand pair of knives and be opposite automatically knife; By whether to use fiducial knife, can divide again wait to the knife relatively to be mixed to the knife absolutely. But no matter which use to plant pair of knife means, cannot leave to try cut pair of knives, try cutting is pair of the basiccest knife methods to the knife. To in an attempt to 2 for exemple, try cut pair of knife measure to be as follows: ① moves mode of operation to fall in the hand, with place choosing cutting tool tries the circle outside cutting work inside mental allowance limits, note the X coordinate cost in displaying screen right now, write down for Xa. (attention: Numerical control lathe shows and the X coordinate of process designing is worth for the diameter commonly) . Go back of direction of Z of ＋ of edge of ② general cutting tool is in to surplus of workpiece end panel a bit (assume the dot that it is α ) cutting end panel, the record shows the Z coordinate in screen is worth right now, write down for Za. ③ measures diameter of the circle outside trying the workpiece after cutting, write down for φ . If program origin O is set in workpiece end panel (must be commonly already the end panel that finish machining ends) the node with centre of turning circle, criterion program origin O fastens medium coordinate to be φ of Xo ＝ Xa- in machine tool coordinate (1) attention of Zo ＝ Za: The coordinate value in formula all is negative worth. Xo, Zo the setting finishs pair of knives to install namely into numerical control system. 3 programs origin (workpiece origin) setting means is in system of FANUC numerical control, have the following kinds of kind that set program origin: ① installs cutting tool deflection to measure compensation; ② sets cutting tool start with G50; ③ installs program origin with G54~G59; ④ is used " workpiece moves " setting program origin. Program origin setting is indispensable to the knife component. Method of every kinds of setting has different process designing to use means, different application condition and different work efficiency. All sorts of setting means can be combined use. (Deflection of 1) setting cutting tool measures the cutting tool compensation that compensates lathe to include cutting tool " wear extent " compensating parameter and " appearance " compensating parameter, both the sum forms lathe tool deflection to measure compensating parameter. Try the deflection that cuts pair of knives to obtain general setting is in " appearance " in compensating parameter. Try to cut pair of knives and install a knife to slant move is as follows: ① is used outside test-drive of round lathe tool - outside round, axis of edge ＋ Z is exited and maintain X coordinate changeless. ② is measured outside round diameter, write down for φ . ③ is pressed " OFSET SET " (deflection is installed) key → is entered " appearance " → of interface of compensating parameter set moves cursor with the knife a position that answers relatively hind, φ of X losing a person (attention: The φ of here represents diametical value, is not one symbol, be the same as below) , by " measure " key, the system presses formula automatically (deflection of cutting tool of direction of X of 1) plan cipher out is measured (if pursue,3 are shown) . Attention: Also can lose person classics computation or the numerical value that get from indication screen directly in corresponding position office, by " lose a person " key setting. ④ is used outside end panel of workpiece of test-drive of round lathe tool, axis of edge ＋ X is exited and maintain Z coordinate changeless. ⑤ is pressed " OFSET SET " key → takes a person " appearance " → of interface of compensating parameter set moves cursor with the knife a position that answers relatively hind, be defeated by person Zo, by " measure " key, the system presses formula automatically (quantity of deflection of cutting tool of direction of Z of 1) plan cipher out. Same OK also by oneself " input " deflection quantity. The amount of cutting tool deflection that ⑥ sets is in numerical control program call with T code. This kind of means is had understand easily, operation simple, process designing and can part completely to the knife undertake waiting for an advantage. In the meantime, in all sorts of combination the metropolis in setting pattern uses a knife to slant setting, because this is opposite,apply in the knife most general. (2) test-drive of lathe tool of the circle outside installing ① of cutting tool start to use with G50 a paragraph outside round, axis of edge ＋ Z is retreated to end panel surplus inside a bit (assume nod for A) . ② is measured outside round diameter, write down for φ . ③ chooses " MDI " (the hand moves an instruction to input) mode, one φ of GO1 U losing a person F0.

3, cut end panel to reach a center (program origin) . ④ chooses " MDI " mode, be defeated by person G50 X0 ZO, by " start " pushbutton. point of a knife current position sets the coordinate in be being fastened for machine tool coordinate (0, 0) , right now program origin and coincide of machine tool origin. ⑤ chooses " MDI " mode, input GO X150 2200, make point of a knife moves to have knife place. Leave work at this o'clock for cutting tool, facilitate the aleatoric position that changes a knife, it is B dot suppose here, coordinate is (1.

50, 200) . ⑥ the begin of machine program must be G50 X150 2200, set buy of v/arc be on the throne of place of point of a knife namely the coordinate that fastens for machine tool coordinate (150, 200) . Right now the program coordinate of point of a knife (150, the machine tool coordinate of 200) and point of a knife (150, 200) is in same position, program origin still with coincide of machine tool origin. When ⑦ should install coordinate of cutting tool start with G50 X150 2200, position of start of fiducial knife program and terminal position must identical, it is namely before program end, need to make with instruction GO X150 2200 fiducial cutting tool returns same point, ability assures to repeat treatment not random knife. If ⑧ uses G30 of the 2nd reference point, establish the 2nd reference point in the parameter of numerical control system choose the place to remove a knife, can assure to repeat treatment not random knife, right now program begin is: G30 UO WO; G50 X150 Z200. ⑨ if need not the F0 of GO1 U~ φ in measure of afore-mentioned ③ , ④ , ⑤ .

3, G50 XO ZO.

Instruction of GO X150 2200 will win seat of dot removing a knife, usable also and undermentioned formulary computation appoints dot removing a knife to fasten in machine tool coordinate (indication screen) medium coordinate: Xb=Xa- φ ＋ 150 (2) Zb=Za+200 is moved with the dot next or pulse is operated, make point of a knife moves (Xb, zb) the position. Attention: The position of set should move fiducial knife first before moving program. When the start that sets cutting tool with G50, should slant the knife of this knife commonly the value is set for 0. The defect of this means is position of spot removing a knife should install in machine program, and the operation is relatively complex. But it provided the mode of operation that adjusts dot removing a knife accurately with handiwork, some people are preferred to this. (3) tries to cut and measure measure ibid to narrate with ① of origin of G54~G59 setting program same. ② is pressed " OFSET SET " key, take a person " coordinate is " setting, mobile cursor arrives corresponding position, input the coordinate value of program origin, by " measure " or " input " key undertakes installing. If pursue,4 are shown. ③ is called in machine program, for example: G55 X100 Z5.

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. G54 is called for acquiesce. Attention: If the setting is mixed,used a knife to slant compensation, had better set each parameter of G54~G59 for 0, lest repeat,make mistake. To much knife treatment, can be worth the deflection of fiducial knife the setting to be in of G54~G59 among them one of, the knife of will fiducial knife slants compensation is set for 0, and slant the knife of other knife compensation is set measure relative to the deflection at fiducial knife for its. This kind of means applies to batch to produce and the treatment that workpiece has the fixed place that hold clip on chuck. Milling treatment is used morer. Executive G54~G59 instruction is equivalent to moving machine tool origin program origin. (4) is used " workpiece moves " the circle outside installing program origin ① to cut work through trying, end panel, measure a diameter, the basis is formulary (origin of program of 1) plan cipher out (workpiece origin) X coordinate, the record shows the origin Z coordinate that screen shows. ② is pressed " OFSET SET " key, enter " workpiece moves " setting, move cursor corresponding position, input gotten X respectively.

Z coordinate is worth, go up by clavier of machine tool MDI " INPUT " key undertakes installing. If pursue,5 are shown. ③ makes axis of X, Z answers machine tool origin (reference point) , build program origin coordinate. "Workpiece moves " the setting also is equivalent to moving machine tool origin program origin (workpiece origin) . To short-hilted broadsword treatment, if was installed " workpiece moves " , had better slant its knife compensation is set for 0, reappear again in case wrong; To much knife treatment, "Workpiece moves " medium numerical value is worth for the deflection of fiducial knife, be worth photograph of other cutting tool the setting to slant in corresponding knife to the deflection of fiducial knife in compensation. The combination of much to system of knife FANUC numerical control knife to the knife installs 4 much knives means has: ① is opposite absolutely knife; ＋ of G50 of ② fiducial knife slants relative to the knife; ③ fiducial knife " workpiece moves " ＋ slants relative to the knife; ＋ of G54~G59 of ④ fiducial knife slants relative to the knife. (1) be opposite absolutely the knife is alleged and absolutely it is to use every to undertake the knife trying cutting pair of knives inside mental allowance limits namely to the knife, gotten deflection value setting is in of corresponding knife date slant in buy compensation. Thinking of this kind of means is clear, the operation is simple, each deflection are worth not cross correlation, adjust consequently rise relatively simple also, get applied extensively in be machined actually so. (2) relatively right the knife is alleged and opposite it is make choice of namely to the knife a fiducial knife, undertake trying cutting pair of knives with fiducial knife, the deflection of will fiducial knife uses G50, "Workpiece moves " or G54~G59 will install, the knife of will fiducial knife slants compensation is set for 0, and be worth photograph of other cutting tool the setting to slant in respective knife to the deflection of fiducial knife in compensation. Below to in an attempt to is shown 2 times for exemple, how does the introduction obtain other knife to slant relative to the knife of fiducial knife value. ① should try the circle outside be being cut with fiducial knife, when A of fall back on of edge Z axis is nodded, press monitor lower part " opposite " soft key, distinguish screen shows the opposite coordinate that the machine tool moves. ② chooses " MDI " means, shift gear by "SHIFT" key, choose U by "XU" , at this moment U coordinate is twinkling, press " ORIGIN " buy 0, if pursue,6 are shown. Same W coordinate buy 0. ③ changes other knife, aim point of a knife A place, the U coordinate on indication screen, W coordinate is this knife to slant at the knife of fiducial knife relatively namely value. In addition, still can use pair of blade appearance to determine to slant relative to the knife value. 5 be opposite accurately knife from theoretic say, afore-mentioned cut through trying, measure, computation; Pair of gotten knife data should be accurate, but actually the fixed position precision as a result of the machine tool, influence that repeats a variety of elements such as precision, mode of operation, make the hand is moved trying pair of blade precision that cut pair of knives is finite, because this is returned,must be opposite accurately knife. Alleged and accurate to the knife, design inside limits of spare parts mental allowance namely simple try automatically cut a program, through " try automatically cut → to measure → error to compensate " train of thought, write melody repeatedly deflection quantity, or the program start position of fiducial knife and the force that are not fiducial knife slant buy, make procedure treatment dictates the error of value and real measured value achieves precision requirement. Because make sure start of fiducial knife program is in exact position is to get accurate blame,fiducial knife knife slants the premise of buy, because this was amended commonly former hind amend latter again. The correction formula that measures accurately to knife deflection is: Write down: ? ? theory is worth (order injunction is worth) - real value (measured value) , criterion X of δ of Xo2=xo1 ＋ (3) attention of Zo2=Zo1- δ Z: δ value has sign. For example: Try with the instruction cut one diameter 40, length is the cylinder of 50, the diameter that if measure,gets and length are respectively 040.

25 with 49.

85, criterion this cutting tool is in X, Z to deflection coordinate should be added respectively - 0.

25 and - 0.

15, also can maintain former knife to slant of course the cost is fixed, and add the error wear away column. Author of 6 last words designed a paragraph of many knife machine program, in the test and verify on system of FANUC OiCNC Turning a few kinds of afore-mentioned combination set pattern to the knife, obtained same result. Also have certain promotion value to system of other numerical control. CNC Milling