Skill of CNC Turning process designing

Shorten as far as possible feed course, reduce empty travel taking a knife, improve manufacturing efficiency. (1) uses knife site opportunely. If be in circular treatment, according to the effective treatment circumstance of workpiece, will remove a knife dot and detached to knife dot, in ensure safety and the premise condition of the contented need that change a knife fall, make dot removing a knife approachs work as far as possible, reduce empty travel taking a knife, shorten feed course, save the executive time in machining a process. (2) is weaving when the machine program of complex outline, adopt reasonable arrangement " time 0 " course, the terminus of before making one knife and hind the distance between the start of one knife as far as possible short, perhaps be 0, in order to shorten feed course, improve manufacturing efficiency. (When 3) rough machining or semifinishing machining, semifinished product surplus is larger, should use appropriate loop to machine means, be reached to machine the requirement such as craft sex to fall by the tigidity of treatment spare parts in give attention to two or morethings, take the shortest cutting feed course, reduce idle stroke time, improve manufacturing efficiency, reduce cutting tool to wear away. 2.

Assure to machine the requirement of the precision of the spare parts and exterior surface roughness. (1) is reasonable select site removing a knife, cut nod and cut way, assure to cut a course smooth, without concussion. To make sure the surface roughness after workpiece outline surface is machined asks, when finish machining, final outline should be arranged the knife goes to be machined continuously in the last time. Consider cutting tool seriously cut and cut outlet line, decrease to stop a knife in outline place as far as possible, abrupt change causes flexibility to be out of shape and leave knife mark in order to avoid cutting strength. Answer commonly along spare parts surface tangential cut and cut, avoid edge workpiece outline as far as possible perpendicular direction is entered, retreat a knife and cut workpiece. (2) choice workpiece is out of shape after treatment lesser course. To long and thin spare parts or laminose spare parts, should use divide treatment taking a knife to final measure, or adopt semmetry to go course of feed of surplus law arrangement. When dimension of affirmatory axial shift, of cutting tool of Lv of take an examination introduce length and surmount length. (3) is used to special spare parts " first hind of essence of life is thick " treatment working procedure. Below certain and special situation, treatment working procedure is not pressed " first close hind far " , " first thick hind essence of life " principle consideration, and make " first hind of essence of life is thick " special processing, can make sure the dimension public errand of workpiece asks better instead. 3.

The security that assures to machine a process should avert the interference of cutting tool and blame treatment face, prevent cutting tool and workpiece in collision. If groove is encountered to need to machine in workpiece, dot of knife of advance and retreat should notice to answer when process designing as perpendicular as groovy direction, feed speed cannot be used " G0 " speed. "G0 " the instruction avoids as far as possible when retreating a knife " X, Z " at the same time shift is used. 4.

Be helpful for simplifying numeric computation, in reducing block amount and workload of work out program to be operated in actual production, the treatment operation that secures via often can coming up against some reappears again now, can write this part operation into the subprogram, in stocking memory beforehand, the basis needs to be called at any time, make the program is written become simple, quick. To those graphs same, dimension differs or craft way is same, the process designing that is the series spare parts with positional different data only, can use macroinstruction process designing, decrease and even the numeric consideration that loaded down with trivial details has when absolving process designing, reduce program amount. 3, accurate control the treatment characteristic that all sorts of loop cutting dictate and the influence that its machine precision place to arise to workpiece, hand-in-hand travel is reasonable choose. In system of FANUC0-TD numerical control, numerical control lathe has more than 10 kinds of cutting to process an instruction circularly, instruction of avery kind of has respective treatment characteristic, the treatment precision after workpiece is machined also differs somewhat, respective process designing method is different also, we want anatomize when choose, reasonable choose, strive for treatment to give the part with tall precision. If the loop machines whorl cutting to have statement of two kinds of treatment: G92 enters type cutting and G76 continuously the inclined cutting that take form. As a result of means of feed of cutting cutting tool different, make method of these two kinds of treatment is distinguished somewhat, respective process designing method is different also, cause machining error to also differ, the whorl after workpiece is machined paragraph treatment precision also differs somewhat. G92 whorl cutting uses means of the straight feed that take form to undertake whorl cutting circularly. Error of screw center diameter is bigger. But tooth form precision is taller, general and multi-purpose the treatment at whorl of small pitch high accuracy. Machine program is longer, want to often be measured in treatment; G76 whorl cutting uses means of the inclined feed that take form to undertake whorl cutting circularly. Tooth form precision is poorer. But craft sex is more reasonable, process designing efficiency is taller. This treatment method applies to the treatment of whorl of big pitch low precision commonly. Ask in whorl precision not high case falls, this machines a method more forthright is convenient. So, we should master respective treatment characteristic and suitable scope, the precision that asks according to the treatment characteristic of workpiece and workpiece chooses these cutting loop statements neatly correctly. Need to machine the whorl of high accuracy, big pitch for instance, can use G92, G76 to mix used method, undertake whorl rough machining with G76 first namely, reoccupy G92 has precision work. Those who need an attention is the dot removing a knife when thick finish machining wants identical, in order to prevent the generation that whorl chaos buckles. 4, use special G code neatly, the treatment quality that assures a spare parts and precision 1.

Returning reference point of instruction of reference point G28, G29 is a machine tool one when go up secures a place, return functional cutting tool to move easily through reference point this position. Reference point basically uses as changing knife or set coordinate automatically is, cutting tool whether return reference point well and truly, it is the main index that measures its to repeat fixed position precision, also be the premise condition that CNC Machining assures its size consistency. In be being machined actually, clever use return reference point instruction, can raise the precision of the product. To repeating the machine tool with fixed position very tall precision, to assure the treatment precision of main measure, before machining main measure, cutting tool can return reference point to move to machine the position afresh again first. The purpose of such way is new officer nucleus actually fiducial, in order to decide the dimension precision of treatment. 2.

Delay time G04 dictates delay time G04 dictates, its action is the machine program that artificially temporary limitation runs, besides common general use situation, in actual CNC Machining, instruction of delay time G04 still can make a few special use: (1) big batch is odd in the spare parts treatment with a shorter handling time, the pushbutton that start is used often, to reduce the misoperation that handlers brings as a result of exhaustion or frequent pushbutton, of the spare parts after with G04 the instruction replaces first start. Delay time time assembles and unassemble by what complete a part time set, after operation personnel masters CNC Machining program adroitly, the instruction time of delay time can shorten gradually, but the safe time that needs to assure to be decided firstly. Spare parts machine program designs circular subprogram, g04 instruction is with respect to the design in the main program that calls this loop subprogram, design a choice to plan to stop M01 instruction to serve as the end of the program or examination when necessary. (When 2) attacks central whorl with tap, need to attack a tooth with stretch collet head, come in order to make sure tap is attacked won't die when whorl is bottom, set instruction of G04 delay time in whorl bottom, make tap makes treatment of blame feed cutting, the time of delay time needs to ensure main shaft dead stop, press after main shaft dead stop turning formerly speed inverts, tap backs down by former lead. (3) has bigger change in main shaft rotate speed when, can set G04 instruction. The purpose is after making main shaft rotate speed stable, undertake the cutting of the spare parts is machined again, in order to improve the exterior quality of the spare parts. 3.

G91 of opposite process designing and G90 of absolutely process designing dictate opposite process designing is with point of a knife location position is coordinate origin, point of a knife comes with undertaking displacement at coordinate origin relatively process designing. That is to say, the coordinate origin of opposite process designing often is in commutation, moving is with showing point of a knife the dot is fiducial control displacement, when so successive displacement, inevitable generation accumulates an error. Absolutely process designing is in the whole process of treatment, all have relatively unified datum mark, namely coordinate origin, so its accumulate an error more opposite process designing is small. When CNC Turning is machined, the precision of workpiece radial dimension is taller than axial dimension, it is so when work out program, radial dimension had better use absolutely process designing, go to the lavatory considering what add man-hour, axial dimension uses opposite process designing, but to important axial measure, also can use absolutely process designing. Additional, to assure the certain and relative position of the spare parts, according to the requirement of craft, use what undertake opposite process designing and absolutely process designing neatly. Anyhow, as the flying development of science and technology, because numerical control lathe has advantageous treatment characteristic, the application in mechanical manufacturing industry is wider and wider, to produce the effect of numerical control lathe adequately, we need to master certain skill in process designing, the work out gives reasonable, efficient machine program, make sure treatment gives the eligible work that accords with blueprint requirement, can make the function of numerical control lathe gets rational application and sufficient play at the same time, make numerical control lathe works can safely, reliably, efficiently. CNC Milling CNC Machining