Processing technique of milling of mould high speed and example of process designing of its numerical control apply

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High speed is machined not only can twice land improves manufacturing efficiency, return the treatment precision that can improve a spare parts further and exterior quality, the efficient treatment problem of the certain and special material that in solving a few convention to machine, solves hard, accordingly, high speed processing technique caused height to take seriously on the world. The article reached the crucial technique that the respect such as process designing of CAM numerical control processes to high speed to undertake elaborating from machine tool, cutting tool, material, the article returns the example that gave treatment of two high speed finally. One, the pivotal tool that introductive mould manufactures as mould pressing product, its design and manufacturing cycle make the payoff that decides new product development cycle increasingly. At present the industry such as the aerospace of industrial developed country, car, mechanical, mould, machine tool above all profit from this new technology, make the product quality of afore-mentioned industries rises apparently, cost is reduced substantially, gained market competition advantage. In auto industry, the development cycle of new in the past model is 10 years commonly, shorten now it is 2 ～ 3 years. The new model development cycle of the company such as Ford, general, Feng Tian is 1 year only half, all these of design of pattern of profit from industry and the modern level of production method rise. Technology of high speed cutting applies at treatment gradually cast-iron with duralumin alloy, machine especially large enclothe model of a punch model, forging die, Die Casting and injection mould, the purpose is to reducing handling time and development time while raise dimension public errand and exterior consistency. At present processing technique of cutting of the high speed on international basically applies at industry of auto industry, mould, aerospace industry, machining the domain of complex curved surface especially, the treatment domain with workpiece itself or higher demand of tigidity of cutting tool system, displayed powerful function. The research of processing technique of cutting of domestic high speed and application only then at 20 centuries 90 time, also be to basically apply at mould, aviation, spaceflight and auto industry, but cutting tool of cutting of machine tool of adoption CNC of high speed cutting, high speed and CAD/CAM software give priority to in order to import. 2, the cutting of high speed of crucial technology numerical control that treatment of high speed cutting applies machines a most important advanced production technology in be being made as the mould, it is collect efficient, high grade, low cost the advanced production technology at a suit. Get a series of problems of the worry fully in groovy cutting treatment, the application that processes through high speed cutting gets understanding definitely. Photograph of its cutting speed, feed speed is machined to traditional cutting, rise with progressional class, cutting mechanism also produced fundamental change. Machine photograph comparing with traditional cutting, cutting machines the leap that produced substaintial sex, the metallic excision rate of its unit power rose 30% ～ 40% , cutting force was reduced 30% , the cutting life of cutting tool rose 70% , the heat in metal cutting that stays at workpiece is reduced substantially, low rank cutting vibration disappears almost. As cutting speed rise, the purify rate of material of unit time semifinished product increases, cutting time decreases, treatment efficiency rises, shortened thereby the production of the product is periodic, enhanced the market competition ability of the product. In the meantime, the grain speed that high speed machines makes cutting power decreases, the high speed that cuts bits eliminates, the cutting force that reduced workpiece and thermal stress are out of shape, raised the possibility of rigid difference and treatment of cutting of thin wall spare parts. As a result of cutting force reduce, of rotate speed rise those who make the working frequency of cutting system is far from a machine tool is low rank natural frequency, and the exterior surface roughness of workpiece is right low rank frequency is most sensitive, reduced exterior surface roughness from this. The hard steel of high temper by dipping in water in the mould (HRC45 ～ 65) in machining a process, use high speed cutting to be able to replace the working procedure of electric treatment and grinding polish, the report of the production that avoided electrode and take time handling time, reduced the burnish of benchwork and polishing amount substantially. The Bao Bimo that needs more and more on a few markets provides work, high speed milling can be finished smoothly. And go up in machining center of CNC of high speed milling, the mould holds clip treatment of achievable multitask pace. These advantages ask in capital circumgyrate time of fast, delivery is critical, the industry such as the pattern with product intense competition is very appropriate. 1.

System of cutting of treatment of high speed of treatment of high speed cutting is main the system of software of CAM of high speed cutting that runs cutting tool of cutting of system, high speed, on the safe side by the high speed machining center that can satisfy high speed cutting, high-powered cutting tool clip form, accordingly, high speed treatment is a big systematic project essentially. As the progress of technology of cutting cutting tool, high speed treatment already can apply at wrought alloy steel (HRC>30) , the treatment of the spare parts such as the strong tool set that uses in car and electronic component product widely, Injection Mold Tooling. The definition that high speed machines relies on the type of the workpiece data that is processed. Graph 1 it is the uses generally to different material cutting rate when using high speed to machine. For example, the cutting rate that steel of high speed wrought alloy uses is 500m/min, and the suitable mill rate that when this one speed is machining aluminium alloy, uses for convention. The applied limits that machines as high speed expands, the improvement of the generation of new strategy of method of cutting tool of the improvement that designs a structure to the research of material of new-style cutting tool, cutting tool, numerical control and cutting condition also rise somewhat. And, the computer of cutting process assisted imitate technology to also appear, this technology is right forecast cutting tool temperature, stress, prolong cutting tool service life very significant. Cast, the high speed cutting that model of die, hot pressing and the application that the model that note model processes represented cast-iron, cast steel and alloy steel uses range expand. The country with banner industry creates a field in die and casting moulding, much expends development time to machine working procedure to go up in machining and polish, if pursue,1 is shown. The machining of die or mould and polishing treatment occupy the 2/3 of whole treatment charge about, and high speed mill but as it happens is used shorten development is periodic, reduce treatment cost. Graph production cycle of milling of 1 high speed and speed of cutting of commonly used material 2.

High speed milling machines a machine tool to exceed technology of high speed cutting is the development direction that cutting machines, also be the product that the times develops. Technology of high speed cutting is one of main development direction of cutting processing technique, it waits for fundamental technology as CNC technology, microelectronics technology, new material and new structure develop and stride higher chance to extricateoneself from an awkward position. However, oneself of technology of high speed cutting also is existing a few treat emergency problem urgently, if the cutting mechanism of tall hardness material, cutting tool is in,the damaged in load change process, monitoring technology that builds database of high speed cutting, development to apply to high speed cutting to machine condition and green make a technology wait. The CNC machine tool that place of high speed cutting uses, cutting tool and CAD/CAM software, technical content is high, the price is high, make investment of high speed cutting very large, this restricted the promotion application of technology of high speed cutting on certain level. The component in the system of machine tool of efficient application requirement of high speed cutting must advanced, main show is in the following respects: (The driver that the tigidity of structure of 1) machine tool asks to offer high speed feed (speed speed makes an appointment with 40m/min, 3D outline machines speed to be 10m/min) , can offer 0.

4m/s2 is spent to the acceleration of 10m/s2 and decelerate. (The rigid requirement of 2) main shaft and knife handle satisfies 10000r/min to the rotate speed of 50000r/min, through main shaft compresses air or cooling the system controls the axial clearance between knife handle and main shaft to be more than 0.

0002 inches. (3) controls unit demand 32 or 64 collateral processor, have high number to occupy transmission rate, can add decelerate automatically. (4) dependability and the utilization rate that treatment is versed in skill raises a machine tool quite (6000h/y) the dependability that operates with nobody, craft model conduces to the understanding that concerns between pair of cutting conditions and cutting tool life. If the delegate of machining center of common domestic and international high speed expresses 1 to show. Compare with photograph of machine tool of traditional and ordinary numerical control, speed of structure of its machine tool, treatment and property performance are more excellent, be like machining center of DMC85 high speed, use linear electric machinery and electric main shaft, rotate speed of its main shaft achieves 30000r/min, feed speed achieves 120m/min, acceleration exceeds 1g (gravitational acceleration) . The machine tool structure of the main shaft unit with high-powered requirement of high speed machine tool and cooling system, tall tigidity, safe device and supervisory system and good static motivation character, have technical content tall, machine tool makes difficulty wait for a characteristic greatly. At present high speed machine tool of home, its function and foreign photograph compare the difference with still exist certain. Express machining center of 1 domestic and international high speed 3.

Because when high speed cutting is machined, the knife handle that high speed cutting machines and cutting tool leave mental efforts and oscillatory effect, requirement cutting tool has very tall geometry precision and outfit clip to repeat fixed position precision, the sex of on the safe side of very tall stiffness and high speed dynamic balancing. Because high speed cutting adds the centrifugal power with greater man-hour and vibration to wait for a characteristic, traditional 7:2System of 4 taper knife handle shows apparent rigid inadequacy when undertaking high speed cutting, repeat fixed position precision dimension of not tall, axial is flabby wait surely, of main shaft expand the deviate that causes cutting tool and clamp orgnaization centroid, affect the dynamic balancing ability of cutting tool. The heat that application is at present more is knife handle of HSK high speed and foreign nowadays popularity bilges knife handle of style of cold crimple firm. Heat bilges of knife handle of style of cold crimple firm heat system, its tigidity is better, but cutting tool can change a gender poorer, a knife handle can install the cutting tool of diameter of a kind of join only. Heat as a result of this kind the system is more expensive, HSK is used when initial stage kind knife handle system can. When the amount of high speed machine tool of the enterprise exceeds 3 above, use heat to bilge knife handle of style of cold crimple firm is more appropriate. Cutting tool is one of the most active and main factors in treatment of high speed cutting, it is affecting the treatment precision that processes efficiency, production cost and product directly. Cutting tool should bear in process of high speed treatment the load such as high temperature, high pressure, attrition, concussion and vibration, one of crucial factors that because its hardness and this wearability, intensity is mixed,the basic function such as tenacity, hear resistance, technical properties and economy is treatment of implementation high speed. At the same time the cutting of workpiece high speed of different material is in of cutting tool choose on should notice its and workpiece material match a gender, express the 2 adaptability ability that machine to cutting of different workpiece material for cutting tool of commonly used high speed. The rate of development of cutting tool technology that high speed cutting machines is very rapid, application is more like diamond (PCD) , cubic nitrogen changes boron (CBN) , hard alloy of cutting tool of pottery and porcelain, coating, (carbon) nitrogen changes titanium hard alloy TIC (N) etc. Because high speed machine tool is mixed,at present price of cutting tool material is compared costly it is treatment of influence high speed in domestic all-pervading one of main reasons. Among them coating hard alloy applies in high speed treatment most extensive, the high speed cutting that can be used at heat-resisting alloy, titanium alloy, high temperature alloy, cast-iron, pure steel, aluminium alloy and composite material. Express adaptability of cutting of material of cutting tool of 2 commonly used high speed to be in treatment is cast-iron in the cutting cutting tool with alloy steel, hard alloy is the most commonly used cutting tool material. Wearability of hard alloy cutting tool is good, but hardness changes boron and pottery and porcelain than cubic nitrogen low. To rise hardness is mixed the surface is bright and clean degree, hard alloy cutting tool uses hard coating data to have coat, if nitrogen changes titanium, nitrogen,change titanium aluminium and carbolic nitrogen to change titanium to wait. The diameter is inside limits of 10 ～ 40mm, and the hard alloy bit that carbolic nitrogen changes titanium coating can machine Rockwell hardness to be less than the material of 42; And the cutting tool that nitrogen turns titanium aluminous coating can machine Rockwell hardness to be 42 more expensive even stuff. Can ask according to using, choose different cutting tool material and coating material. Watch 3 gave out the cutting parameter of material of aluminium alloy of treatment of hard alloy cutting tool. The cutting tool that uses at high speed cutting and coating material can divide for: Machine cast-iron cubic nitrogen to change boron and nitrogen to turn silicon cutting tool, the nitrogen that machines Rockwell hardness to amount to the alloy steel of 42 changes titanium and carbolic nitrogen to turn the alloy cutting tool of titanium coating, treatment Rockwell hardness changes titanium aluminium and aluminous nitrogen to change cutting tool of titanium coating alloy to wait for the nitrogen of 42 taller even alloy steel. The course carries out test and verify, because cut bits to present pulverous state,be in in the milling treatment process of composite material, because this asks cutting blade compares sharp wear-resisting, its efficiency and precision compare the cutting tool that uses diamond data common hard alloy is close friends. The cutting of titanium alloy uses the common hard alloy of coating hard alloy and YG8 to compare ideal. The parameter of high speed cutting that expresses aluminium alloy of 3 hard alloy 4.

The demand that milling of high speed of process designing of numerical control of high speed cutting machines logarithm to control process designing system is higher and higher, the high speed with high price machined equipment to raise higher security and effectiveness requirement to software. High speed cutting is having more special than traditional cutting craft demand, besides wanting to have machine tool of high speed cutting and cutting tool of high speed cutting, having software of appropriate CAM process designing also is crucial. The numerical control instruction of CNC Machining included all process, a system of excellent process designing of CAM of high speed treatment should have very high computation rate, stronger interpolation function, whole journey to cut examination and processing capability, automatic knife handle and clamping apparatus automatically to interfere rate of examination, feed to optimize processing too function, need treatment contrail of orbit monitoring function, cutting tool. Process designing of high speed cutting should notice to machine methodological security and effectiveness above all; Next, want all likelihoods to make sure cutting tool contrail is smooth and smooth, this can immediate impact machines the life of the spare parts such as quality and machine tool main shaft; Finally, want to make cutting tool load even as far as possible, this meeting affects the life of cutting tool directly. (1)CAM system should have very tall consideration use in treatment of high speed of process designing speed very small cut quantity and cut deep, program of more traditional than be opposite CNC Machining wants the NC order that reason high speed processes to be gotten greatly much, consequently requirement computation speed wants fast, want editor of contrail of convenient and managing cutting tool, optimize the time of process designing. (2) whole journey has been prevented automatically cut processing capability and interference of automatic knife handle to check treatment of ability high speed to machine the cutting speed of nearly 10 times to undertake machining with the tradition, once had happened to cut pair of machine tools, product and cutting tool to will produce disastrous consequence, ask its CAM system must have whole journey to had prevented the capacity that cuts processing automatically so. One of main features that high speed machines can use the cutting tool of lesser diameter namely, machine the detail structure of the mould. The system can hint the briefest clip runs cutting tool length automatically, undertake cutting tool interferes an examination automatically. (High speed machines the strategy of contrail of cutting tool of high speed cutting with rich 3) to walk along knife means to having special demand than traditional pattern function to machining craft, consequently requirement CAM system can satisfy these specific craft requirements. To can ensure the biggest cutting efficiency, assure the security that machines when high speed cutting again, CAM system should the size according to treatment instantaneous surplus, undertake automatically optimizing handling to feed rate, in order to ensure cutting tool of high speed treatment gets the smooth stability of power position, improve the service life of cutting tool. CAM software is in generate respect of cutting tool contrail to should have the following function: ☆ should avoid the abrupt change that knife way takes in cutting tool contrail, lest because of local the damage that be cut too and causes cutting tool or equipment; What ☆ should maintain cutting tool contrail is smooth, avoid to be quickened suddenly or decelerate; ☆ leaves a sword or excessive part had better use the knife below inclined between travel or circular arc leaves a sword, avoid perpendicular next knives are close to workpiece material directly; The end points that cuts all right uses circular arc connection, avoid linear join; ☆ incomplete surplus is machined or clear root treatment is the important step that improves treatment efficiency, should use treatment for many times commonly or use series cutting tool from arrive small minutes greatly second treatment, avoid to be machined with the penknife finish, still should avoid main wide cutting; It is very important that editor of contrail of ☆ cutting tool optimizes a function, avoid redundant sky knife, the mirror that can pass pair of cutting tool contrail, duplicate, rotate wait for an operation, avoid to repeat calculation; Contrail of ☆ cutting tool cuts out repair function is very main also, can reduce empty knife through cutting out accurately, improve efficiency, also can use at a zero process designing when local change, need to revise metabolic part only right now, need not be opposite whole model new-model; ☆ can provide outstanding visible emulation treatment imitate and cut an examination too, if Vericut software can detect well,interfere. 3, the commonly used strategy in process designing of high speed milling and the rough machining that high speed treatment includes CAM software to be a purpose with purify surplus, remain rough machining, and the semifinishing machining that is a purpose in order to get the treatment surface of high quality and fine structure, finish machining and lens face treatment. The craft plan that the rough machining place in high speed treatment should adopt is the combination of rate of tall cutting speed, tall feed and small cutting quantity. Waiting for tall treatment means is the means of a kind of treatment that numerous CAM software uses generally. Application is more is helix wait to be mixed high wait for Z axis two kinds tall means, machining area namely only feed, carrying successive and slick cutting tool way is made below the circumstance of the knife, into, the means that retreat a knife uses circular arc to be cut, cut. The characteristic of the high fashion such as helix is, did not wait for the cutter track shift between the high level, avoid to carry often the consume with the influence of knife, feed to quality of spare parts surface and mechanical needless equipment. Handle respectively to area of abrupt peace calm, computation suits to wait to be reached high suit to use similar 3D to slant the area of buy, and can use helix means at the same time, carrying rarely optimized cutting tool way is made below the circumstance of the knife, acquire better exterior quality. Apply in high speed treatment, must adopt circular arc to be cut, cut join way, and turning point circular arc transfers. Taboo issues the order that the join means a future life of the knife processes into high speed directly. Strategy of high speed finish machining includes three-dimensional slant buy, etc expensive precision work and optimal wait for the strategy such as the expensive precision work, expensive precision work such as helix. These strategy can make sure cutting process light is suitable, stable, ensure the material on workpiece of can fast excision, get high accuracy, slick cutting surface. The main demand of finish machining is to should acquire quality of very tall precision, smooth spare parts surface, realize the treatment of careful area easily, wait like small round part, groove. To a lot of appearance, the strategy with the most significant precision work is to use three-dimensional helix strategy. Use this kind of strategy to be able to avoid to use parallel strategy and slant the frequent directional change that the conference in strategy of buy finish machining appears, raise treatment rate thereby, reduce cutting tool to wear away. This strategy is carrying rarely successive and slick cutting tool way is made below the circumstance of the knife. This kind of processing technique is integrated helix treatment and the advantage that wait for tall treatment strategy, cutting tool bear is stabler, the frequency that carry a sword is fewer, can shorten handling time, reduce machine of cutting tool attaint to lead. It returns quality of ameliorable treatment surface, the biggest be restricted the need of manual burnish after the ground reduces finish machining. Area of calm of peace of expensive precision work waits in what a lot of circumstances need will abrupt area union of method of three-dimensional and equidistant finish machining rises use. After using high speed to machine equipment, to process designing the demand of personnel will increase, because requirement of craft of high speed treatment is strict, it is more important to cut protection too, reason needs to spend much time to undertake emulation examining to NC instruction. Usually, high speed machines process designing time to want to grow more than machining process designing time commonly. Machine the utilization rate with enough equipment to assure high speed, need to deploy more CAM staff. Show some CAM software, the Cimatron E of the CATIA of the UnigraphicsNX of MasterCAM of the PowerMILL that is like DELCAM, United States, UGS, Dassualt, Israel high speed that provided relevant function contrail of milling cutting tool is politic. Graph 2 ～ pursue the high speed milling of the 5 Bao Bi spare partses that are platform of UnigraphicsNX, CATIA, MasterCAM to fall respectively and mould machines sketch map of cutting tool contrail. Sketch map of contrail of milling of high speed of graph 2 UG NX/CAM pursues sketch map of contrail of milling of 3 CATIA high speed pursues milling of high speed of graph 5 MasterCAM emulates sketch map of contrail of milling of 4 MasterCAM high speed treatment sketch map 4, the high speed processing technique that treatment of high speed cutting creates pattern of medium representative application example in the mould becomes technology of our country mould to transform one of the mainest content gradually. The efficiency that high speed machines decides not only at main shaft speed and cutting tool diameter, still reach the integrated element such as treatment craft to concern with life of the material of place cutting, cutting tool. The hardness that the alloy mould rolled steel such as mould of Injection Mold Tooling, Die Casting, punch mould and forging die expects exceeds HRC50 commonly. The limitative element that high speed of this kind of mould machines basically is cutting tool life, aluminium alloy of and rather than machines medium main shaft speed. To the treatment of the detail structure of small-sized mould, main shaft speed can amount to 40000r/min above. And the treatment that large car covers a mould, the treatment of above of 12000r/min of speed of general main shaft can call high speed treatment. Injection mould, mould, forging die and the mould machining time that cover a strong tool set to wait basically are expended go up in the component such as manufacturing punch and sunken model. Be in the United States, the most commonly used mould material is 3Cr2Mo mould steel (HRC30) , commonly used material is forging die and mould 4Cr5MoV1Si steel, have HRC45 ～ the forging die of 60 and HRC46 ～ the mould of 50. Watch 4 listed the most commonly used mould material, steel of 40Cr, 45 ＃ quenchs tone is the material with commonly used injection mould character, the die manufacturer of 50% machines injection mould to use high speed cutting to finish. 3Cr2Mo mould steel is the steel with treatment the most commonly used injection mould, because contain carbon the amount is small, normally beforehand heat treatment arrives when HRC30 treatment, be in next quench HRC50 ～ 55. In the application of Die Casting model, 4Cr5MoV1Si of steel of hot forge mould still can have precision work when HRC46 condition. Expressing what material of commonly used mould of 4 United States and picture of tolerancepublic errand demand show 6 times is what in what weave below UGNX environment some is based on SMC to shape is large the sketch map of contrail of cutting tool of treatment of milling of numerical control high speed that covers a sunken model of hot pressing model. Its rough machining uses those who be based on rudimental semifinished product to wait tall statified milling, semifinishing machining uses 3D parallel milling. Material of model of this hot pressing is 55 ＃ cast steel, Ф was used when rough machining the milling cutter of the helix that mount a tooth-like part of anything of 40, cutting parameter is Z axis for deepness of main shaft 800r/min, cutting rate of width of diameter of 90% cutting tool, feed is width of every 2mm, cutting 2000mm/min. Graph 6 enclothing a sketch map of milling of high speed of hot pressing model to pursue is 7 to be below MasterCAM platform, the cutting tool contrail that the injection mould that uses 40Cr to some undertakes high speed cutting is machined and emulation treatment sketch map. What use here is traditional numerical control machine tool, as a result of the limitation of rotate speed of its main shaft, dosage of cutting of its high speed: Rough machining uses Ф 2mm of deepness of 2000mm/min of rate of 2000r/min of the cutting tool of 20, rotate speed, feed, cutting; Deepness of the cutting tool that finish machining uses Ф 12mm, cutting 0.

3500r/min of rotate speed of 2mm/min, main shaft, feed leads 3000mm/min. Graph sketch map of contrail of cutting tool of milling of high speed of 7 injection mould 5, processing technique of last word high speed is worldwide inside the times forward position technology that gets attention, it improves the efficiency that promotes treatment greatly the improvement with product quality. Place of preamble of no less than is narrated, high speed treatment is project of a system, he asks to reach all-around reform of equipment respect from software, hardware, but because its have a tradition to machine unparalleled dominant position, will be henceforth processing technique develops way necessarily. CNC Milling CNC Machining