Focusing is efficient milling, improve manufacturing efficiency

Ae.

Vf =ap.

Ae.

Fz.

Z.

N (cm3/min) can see in these two relation that we machine from milling, should use bigger cutting deepness (amount to 1-2 the milling cutter diameter of times) , the quantity of side penetration of a cutting tool of size of milling cutter diameter and higher feed rate (corresponding higher milling rate) when, the excision that can improve data greatly is led. Use craft of this kind of treatment to have particularly important sense to making structural member of whole of plane thin wall. Because want aluminium alloy of plasticity of will whole high strenth,treatment becomes integral component part to need to excise the material of 90%-95% . So big treatment is measured, pass only use particularly efficient cutting technology, with the shortest time excision is dropped as far as possible much material ability reduces manufacturing cost. Such demand also promoted aircraft manufacturing industry to took the lead in using efficient cutting technology, for example European aviation matters pertaining to defense and spaceflight company (EADS) the integral component part that producing plane of for military use (2000) when, machine 25 hours when what need to shorten 12 hours by previous convention through using efficient treatment, shortened handling time half above (pursue 1) . Craft of this kind of efficient treatment uses efficient milling at the treatment of all sorts of whole structural member of the plane not only, and return application to machine blade from good stuff, more and more even ground is used expect from material of a sincere the compressor leaf of engine of efficient treatment aircraft dish (graph 2) , need not make luggage of individual lamina reentry match. In milling steel, cast-iron with alloy steel shoulder of groove, stage and groovy antrum and when having heavy cut, often also use efficient milling technology. When mill chamfer, quantity of back penetration of a cutting tool is amounted to commonly 1.

5D-2D. Reduce power to use up to undertake cutting is mixed smoothly, use commonly have not tooth of divide into equal parts, different helix angle and before horny milling cutter. Efficient milling craft, aim to make full use of main shaft most the oldest material excision rate is achieved as far as possible below the circumstance of high-power. Current, the material excision rate of efficient milling aluminium alloy can be as high as 8000-10000 Cm3/min (8-10 to rise commonly / Min) . However, as time elapse, taller material excision is led with shortening further handling time, make the bigger demand on the market. Engineering of production of Darmstadt industry university and the milling test that machine tool institute has make clear, weigh when workpiece 1.

5 tons, want the material portion of excision to be component part weight 70% when, if raise material excision rate 12 L/min from 8 L/min, criterion the time of rough machining can shorten 33% (graph 3) . And need of tall material excision rate is enough high main shaft power. The JHP490 efficient milling cutter that uses Seco firm for example is when the groovy antrum of structural member of milling aluminium alloy, make through using bigger radial and axial cutting deepness material excision rate achieves 9557 Cm3/min, and cutting power is as high as 117 KW (graph 4) . Can see from inside this example, the electric main shaft of high rotate speed, high-power and tall torsion is the fundamental requirement that raises excision of aluminium alloy material to lead, current, like the manufacturer of electric main shaft such as GMN and Fischer the home rolled out main shaft of new high rotate speed, high-power report in succession. Be like the HCS170-40000/100 (n=40000 R/min of GMN, p=100 KW) , the MFW-2715/20 (n=20000r/min of Fischer, ps1/s6-40%=150/187 KW) . When the power of electric main shaft is 150 KW, the material excision rate of its milling can achieve 12750 Cm3/min. For structural member of whole of aluminium alloy of efficient treatment plane, DST company rolled out ECOSPEED F efficient machining center technically in recent years (graph 5) , 120 KW of main shaft power, turn up 30000r/min.

The machine tool is used and the Sprint-Z3 of compose of through traffic motive machines a head, athletic quality is light, dynamic performance is good, can realize first-rate of complex structural member treatment of 5 axes couplet. And the new generation of Mu Ye company is large 4-A20 of A of horizontal machining center, main shaft power amounts to 120 KW, and the AeroCell horizontal machining center that Handtmann company is led to achieve extremely expensive stuff to excise and designs technically, power of its main shaft is as high as 150 KW (when S6, power: 180kW) , most the material excision rate when high-power can be amounted to 12.

8 L/min, be equivalent to one minute cutting the aluminium alloy with next heavy 35 Kg. It is facilitating platoon bits, treatment workbench made vertical configuration. To carry out structural member of efficient milling aluminium alloy reliably, besides deserving to have the electric main shaft of high-power tall torsion, what still need to clip of cutting tool, knife and machine tool wait for each part that shares cutting is harmonious cooperate. Shake to prevent the generation when efficient milling, the helix that milling cutter uses the hard alloy film of careful grain to divide into equal parts ages or do not differ discharges bits chamfer (like 350/380) . When efficient milling, can produce very great cutting power and torque, adoption knife clip should have very big clip to hold power, fall off in order to prevent milling cutter from inside knife clip. And the machine tool is divided outside having very tall tigidity and working stability, still should facilitate a bits, deserve to have the efficient system that discharge bits. Nextpage raises material excision to lead with lesser K and bigger Fz craft parameter with lesser tool cutting edge angle (K) with bigger every tine feed (Fz) the craft of big feed milling that is a feature, be after what efficient milling craft narrating above afterwards, make an appointment with the efficient milling new technology that in the mould 2003 the development in making rises. In a few years subsequently, this kind of craft is in the production domain such as the model of such as forging die, figuration, model that note model and model, received promotion application. With before the basically differs point that states efficient milling craft, it is latter used the milling cutter that having radius of lesser tool cutting edge angle or arc of bigger edge garden, can be being used is much better than orthogonal milling cutter multiple feed speed, raised the excision rate of material significantly from this. Tool cutting edge angle (K) be but of dislocation razor blade advocate an included angle between cutting blade and workpiece treatment surface, the size of this angle affects the life of force of the ply that cuts bits, cutting and cutting tool directly. And the numerous advantage of craft of big feed milling is profit from used lesser tool cutting edge angle. Very apparent, tool cutting edge angle is smaller, cut bits ply on average thinner (H=fz Sin K) , action is jumped over at the radial cutting component of force on edge small, treatment is smoother. And corresponding bigger axial action of axial of edge of criterion of component of force go up at the main shaft bearing of the machine tool (graph 6, graph 7 with watch 1) . Such, when milling is machined, milling cutter is unapt happen bend be out of shape, and treatment is deeper model when antrum, what what use is longer hang the risk that extends milling cutter to also won't generation shakes, raised process dependability greatly, still improved the service life of cutting tool, allow to raise the every tine feed of milling cutter significantly thereby, raise feed rate greatly then. In addition, milling cutter is used mostly bigger, the horn before radial and axial, realize soft cutting, reduced the power that consume. Come nearly 10 years, a lot of cutting tool such as such as LMT, Ingersoll, Seco, Walter and Franken Fette made a manufacturer develop numerous big feed in succession efficient milling cutter, although the structure of these milling cutter is endless identical, but their common characteristic is to be had agree with the edge geometry appearance that achieves high speed feed. The characteristic of appearance of this kind of geometry is cutting edge have a very big garden arc radius or have an evener tool cutting edge angle. Among them if LMT Fette square is big,3 blade milling cutter mixes the 3 arris form of the milling cutter of radius of garden arc edge, Walter Horn triangle is big the milling cutter of radius of garden arc edge, these milling cutter used lesser tool cutting edge angle (10 ° - 20 ° ) , can use very tall every tine feed and very high feed rate to undertake milling is machined, in order to win very high material excision rate and shorter handling time. Numerous big feed of efficient milling craft use make clear, use efficient milling and use photograph of groovy milling craft to compare, the excision rate of its material can rise 300%-500% , handling time can reduce 100%-150% , treatment charge can reduce 60%-70% about. For example, use of 3 but the convention of dislocation garden razor blade twists steel of mould of thick mill of the milling cutter that fit pattern (40Cr MnMoS86) the vitreous bottle with qualitative material boasts a standard, cutting speed Vc=250 M/min, fz=0 of every tine feed.

3mm, back penetration of a cutting tool measures Ap=0.

75mm, side penetration of a cutting tool measures Ae=18mm, air cooling refrigeration is used in milling process. The handling time of thick mill is 9 minutes. And the Time-S-Cut that uses Franken company to have radius of big garden arc of 3 but the milling cutter of dislocation razor blade, have equal treatment, and in cutting dosage the respect just will carry penetration of a cutting tool on the back to measure Ap to fall to 0.

5mm, and Fz rises 1.

0mm, at this moment handling time used 4 minutes only. Handling time is 45% when using milling of milling cutter of garden razor blade, time was saved 125% . For example, efficient the groovy antrum of orifice plate of thick mill extruder, alloy steel of X5CrNiCuNb15 5 of orifice plate material, machine tool hour uses charge to be 230 euro. The milling cutter treatment that used in the past changes a knife with respect to need after 2 chamfer antrum, convert after milling cutter of the F2330 that Walter company develops to machine a mould technically efficient big feed, the ability after machining 5 chamfer antrum now needs to change a knife. Tool cutting edge angle is very small, cut bits to attenuate, radial cutting force is reduced, can use very high feed rate consequently, achieve remarkable technical economy result thereby (watch 2) : In this example, of its charge through shortening handling time place obtains save. Still rise without what consider cutting tool service life among them and assist time (change a knife) the benefit that reduces place to bring. Cite a case again. German G.

M.

W company uses the milling cutter of SP2L big feed of Ingersoll company, milling is large and marine casing of derv dynamo stainless steel (3200 × of 4400 × 2200mm) end panel and joint face, milling cutter tool cutting edge angle is 13 ° only, every tine feed is amounted to 2.

5mm, speed of milling cutter feed achieves 6000mm/min, material excision rate amounts to 1435cm3/min, than before treatment raised 3 times. One year treatment saved 40000 euro 12 times, reduced the treatment cost of 67% . Should point out, use big feed milling cutter to have efficient treatment, because cut bits very thin, radial cutting force is lesser, power is used up little, reason can be used on groovy general accuracy machine tool, have very good use flexible. Epilogue 10 come for years, develop the is a feature with rate of expensive stuff excision efficient milling technology that rise in succession, no matter be to use tall cutting parameter (Ap, Ae, Vc and Vf) efficient milling, still use the efficient milling of small tool cutting edge angle and big feed, these two kinds of efficient milling, already became the industry such as aviation industry and mould manufacturing industry and car to improve thick mill efficiency apparently, shorten handling time and the very significant step that reduce manufacturing cost. To efficient milling craft, the ceaseless development of cutting tool technology, mix in cutting tool material, coating especially the ceaseless development of geometrical appearance respect and optimize combination, had conclusive effect to developing all sorts of efficient milling cutter. What should allude particularly is, the geometrical appearance that optimizes cutting edge is to raise material of big feed milling cutter to excise the foundation of rate. And the play that clip of main shaft of machine tool, report, knife, refrigeration and the ceaseless development that control a technology are process capability of efficient milling cutter offerred a condition. Henceforth, the 3 element of the high demand of the user and cutting tool (cutting tool material, coating and appearance of cutting tool geometry) and the cooperate withing of the relevant technology such as the machine tool develops will still be the main motive force that promotes development of efficient processing technique. CNC Milling