The choice of the cutting tool in CNC Machining and cutting dosage are decided really

Summary: The innovation that the characteristic with contemporary marked cutting tool is a structure fast go accelerate. Expand of the domain ceaselessly as computer application, machining also begins to apply number to help a technology, at this moment cutting tool choice and cutting dosage raised taller requirement. The article buckles the cutting tool choice in why deciding CNC Machining and cutting to use undertook discussing completely. Keyword: Numerical control technology; Machining; Cutting tool chooses one, cutting tool of scientific choice numerical control 1, the life of principle cutting tool that chooses numerical control cutting tool and cutting dosage have affinity. When making cutting dosage, answer to choose reasonable cutting tool life above all, and reasonable cutting tool life should be decided according to optimized target. Divide life of highest productivity cutting tool and life of lowermost cost cutting tool commonly two kinds, former foundation is single the objective with a least man-hour is firm, latter decides according to the target of lowest of working procedure cost. Following a few ground can consider when choosing cutting tool life cutting tool is complex degree, make and grind knife cost to choose. Complex with precision tall cutting tool life should be chosen cutting tool of the blade that compare sheet is some higher. To machine clip but dislocation cutting tool, because change knife time short, to develop its cutting property adequately, improve manufacturing efficiency, cutting tool life is optional some lower, take 15-30min commonly. To holding a knife, change knife and tone knife to compare complex much knife machine tool, modular machine tool and automation to machine cutting tool, cutting tool life should be chosen some higher, should assure cutting tool dependability especially. Of the productivity that the productivity of working procedure of the some inside the workshop restricted whole workshop when rising, when the M of entire plant expenses that life should choose the cutting tool of this working procedure some lowlier to partake when the place inside time of unit of some working procedure is bigger, cutting tool life also should be chosen some lowlier. When big finish machining, take a knife to assure to be finished at least, the midway when avoiding cutting changes a knife, cutting tool life should decide by spare parts precision and exterior surface roughness. With general accuracy machine tool treatment method photograph is compared, CNC Machining raised taller requirement to cutting tool, need ridge animal sacrifice not only good, precision is tall, and requirement measure is stable, durability is tall, break and discharge function altar to ask installation is adjusted at the same time convenient, such coming that satisfy the requirement with numerical control efficient machine tool. The cutting tool that chooses on numerical control machine tool often uses the cutting tool data that gets used to high speed cutting (like high-speed steel, exceed fine granuality hard alloy) use but dislocation razor blade. 2, choice CNC Turning uses the general component with commonly used lathe tool of cutting tool CNC Turning to shape lathe tool of lathe tool, sharp contrast lathe tool, circular arc form and 3 kinds. Shape lathe tool also calls example lathe tool, the outline form that its process a spare parts is complete decide by the form bend over of lathe tool edge and dimension. In CNC Turning treatment, shape commonly lathe tool has lathe tool of circular arc of smaller part diameter, blame rectangular recessing knife and whorl knife. In CNC Machining, should be used less as far as possible or need not shape lathe tool. Sharp contrast lathe tool is with straight the lathe tool that cutting blade is a feature. The point of a knife of this kind of lathe tool by straight advocate deputy cutting blade is formed, if 900 inside and outside are round lathe tool of lathe tool, or so end panel, grooving (cut off) lathe tool and point of a knife pour arris very small all sorts of outside circle and inside aperture lathe tool. Parameter of geometry of sharp contrast lathe tool (basically be geometrical angle) when choosing method and common turning basic and identical, but the characteristic that should combine CNC Machining (if machine interference of course, treatment to wait) have comprehensive consideration, answer the intensity of itself of point of a knife of give attention to two or morethings. 2 it is lathe tool of circular arc form. Lathe tool of circular arc form is with one circularity or line outline spends the circular arc with very small error the lathe tool that form cutting blade is a feature. Blade of circular arc of this lathe tool is the point of a knife of lathe tool of circular arc form each bits, should this, knife the dot is not on circular arc, and go up in the centre of a circle of this circular arc. Lathe tool of circular arc form can be used at surface of turning inside and outside, special agree with turning all sorts of smooth join (sunken form) shape face. The radius of the smallest curvature that when choosing radius of lathe tool circular arc, should consider to the circular arc radius of blade of lathe tool cutting should was less than at 2 o'clock or be equal to outline of spare parts sunken form to go up, lest produce treatment to work shallow this radius is unfavorable the choice is too little, otherwise not only production difficulty, because intensity of point of a knife is too weak,still meet or cutter hub comes loose to heat energy force is differred and bring about lathe tool to damage. 3, milling of choice numerical control is with cutting tool in CNC Machining, outline of inside and outside of milling plane part and milling plane are commonly used flat bottom establishs milling cutter, this cutting tool is as follows about the experience data of parameter: It is RD of milling cutter radius the Rmin of radius of the smallest curvature that should be less than face of the outline inside the spare parts, take RD=(0 commonly.

8-0.

9)Rmin. The 2 treatment height H<(1/4-1/6)RD that are a spare parts, in order to make sure the knife has enough stiffness. 3 be when establishing department of the bottom land inside milling cutter milling with flat bottom, because bottom land walks along a knife twice to need to build,receive, and the radius Re=R-r with effective blade of cutting tool bottom, namely the diameter is D=2Re=2(R-r) , cutting tool radius is taken to be Re=0 when process designing.

95(Rr) . To a few establish bodily form face and change the treatment of appearance of bevel angle outline, commonly used and globose milling cutter, annular milling cutter, bosomy form milling cutter, cone-shaped milling cutter He Panxi knife. Current, cutting tool of seriation, standardization is used mostly on numerical control machine tool, right but the knife handle that wait and knife head have lathe tool of the circle outside dislocation machine clip, end panel lathe tool national level and seriation model are reached to machining center have the machine tool that trades knife unit automatically, the knife handle of cutting tool already had the regulation of seriation and standardization, if the standard code name of system of awl power cutting tool is TSG-JT, the standard code name of system of straight power cutting tool is DSG-JZ, in addition, to chooses cutting tool, need to undertake strict measurement to cutting tool dimension before use in order to obtain accurate data, and by handlers these data data-in systems, classics program is called and complete treatment process, process the work that gives qualification thereby. 2, Where is setting knife dot and the position that change a knife to nod cutting tool to from what position begin to move to appoint after all? Carry out in the program so at the beginning, must decide cutting tool fastens next positions that begin campaign in workpiece coordinate, the start that photograph of the cutting tool when this one position is carried out for the program namely moves to workpiece, say the order is bit more initial so or have knife place. This is bit more initiative decide through coming to the knife commonly, so, say at this o'clock to be nodded to the knife again. When work out program, want to choose the place that chooses to the knife correctly. To the knife place setting principle is: Facilitating numerical value is handled and simplify to program. Search to facilitating in machining a process easily examination; The machining error that cause is small. To the knife the dot can be installed go up in treatment spare parts, also can install go up in clamping apparatus or on the machine tool, to raise the treatment precision of the spare parts, to the knife the dot should install the design in the spare parts as far as possible fiducial or who gets on craft radical. When operating a machine tool actually, the sword that can carry handiwork to operate a cutting tool to the knife the dot puts pair of knives to nod, namely " knife dot " with " nod to the knife " coincide. Alleged " knife dot " it is the fixed position datum mark that points to cutting tool, the knife of lathe tool the dot is point of a knife or center of circular arc of point of a knife. Making the same score a bottom to establish milling cutter is the node of cutting tool axes and cutting tool underside; Ball head milling cutter is the ball heart of ball head, broach is to get a needle to wait. Move pair of knife operations with the hand, inferior to knife precision, and efficiency is low. And some factories use optics to be opposite Dao Jing, right wait Dao Yi, automatically to knife device, in order to reduce pair of knife time, raise pair of knife precision. When the need in machining a process changes a knife, should provide the point that change a knife. Alleged " the dot that change a knife " it is the position when showing tool carrier roll changes a knife, what the dot that change a knife should set in workpiece or clamping apparatus is exterior, workpiece and other component are not touched in order to change to be when the knife accurate. 3, affirmatory cutting dosage when numerical control process designing, process designing personnel must determine the cutting dosage of every working procedure, in writing person program with the form of the instruction. Cutting dosage includes quantity of penetration of a cutting tool of main shaft rotate speed, back and feed speed to wait. To different treatment method, need chooses different cutting dosage. The choice principle of cutting dosage is: Make sure the spare parts machines precision and exterior surface roughness, develop property of cutting tool cutting adequately, assure reasonable cutting tool durability, develop the property of the machine tool adequately, utmost improves productivity, reduce cost. 1, rotate speed of main shaft of rotate speed of affirmatory main shaft should be mixed according to permission cutting rate workpiece (or cutting tool) the diameter will choose. Its computation formula is: In N=1000v/71D type: V, cutting speed, the unit is moved for M/m, by the durability decision of cutting tool; N one by one main shaft rotate speed, the unit is R/min, d, workpiece diameter or cutting tool diameter, the unit is Mm. N of rotate speed of calculative main shaft, want to choose machine tool some or more adjacent rotate speed finally. 2, the important parameter in deciding speed of feed speed feed is dosage of cutting of numerical control machine tool, the material property of the treatment precision of the spare parts and requirement of exterior surface roughness and cutting tool, workpiece chooses main ground. Speed of the biggest feed accepts the function restriction of machine tool stiffness and feed system. Decide the principle of feed speed: When the quality of workpiece asks to be able to get assuring, manufacture efficiency to rise, can choose higher feed rate. Choose inside limits of 100 one 200mm/min commonly; In cut off, when machine deep aperture or be being machined with high-speed steel cutting tool, appropriate chooses inferior feed career, choose inside limits of 20 one 50mm/min commonly; When treatment precision, when demand of exterior surface roughness is high, feed speed should choose a little bit small, be in commonly 20- - choose inside 50mm/min limits; When cutting tool idle stroke, especially remote " time 0 " when, can set the highest feed speed of set of system of numerical control of this machine tool. 3, penetration of a cutting tool of back of quantity of affirmatory back penetration of a cutting tool measures the stiffness according to machine tool, workpiece and cutting tool to decide, below the condition that allows in stiffness, answer to make carry penetration of a cutting tool on the back to measure the mental allowance that is equal to workpiece as far as possible, can reduce knife number so, improve manufacturing efficiency. To assure to machine exterior quality, can leave a few finish machining surplus, general 0.

2 one 0.

5mm, anyhow, the particular numerical value of cutting dosage should combine practical experience to decide with analogy method according to machine tool function, relevant manual. In the meantime, make deepness of main shaft rotate speed, cutting reachs feed rate 3 person can suit each other, in order to form optimal cutting dosage. Cutting dosage is the important parameter that must decide before the machine tool is adjusted not only, and its are numeric and reasonable waited for the effect with having very main to machining cost of efficiency of quality, treatment, production. Alleged " reasonable " cutting dosage is to point to make full use of function of cutting tool cutting and performance of machine tool power () of power, torque, below the premise that assures quality, obtain the cutting dosage of tall productivity and low finished cost. Bibliographical reference: 1, association of tool of cutting of Taiyuan city metal.

Metallic cutting is practical cutting tool technology.

Beijing: Machinist trade publishing house.

20022, skill of machine tool treatment trains.

Chinese labor press.

In May 1996 3, luxuriant beautiful, xu Shuo.

CNC Machining technology [IJ ' education reforms exploration CNC Milling