High speed processes the application in aviation industry

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The technical development trend that high speed machines is to use the cutting with rate of rapidder cutting rate, feed and smaller negative charge, and conventional treatment uses bear normally heavier, cut deep bigger low speed cutting. Successful high speed treatment needs to take cutting tool, main shaft and machine tool seriously kinetic tool technology and the progress that the machine tool controls capacity make high speed treatment is in the production of aviation component won wider and wider application. Although high speed processing technique suits the treatment of aluminium alloy particularly, but the land that there also is its use force in the treatment of composite material and hard metal stuff. Competitive pressure is forcing manufacturer to machine a spare parts with more efficient way ceaselessly. Meanwhile, business of production of aviation structural member also needs strength taller, quality the component with stricter requirement of lighter, public errand. Use high speed processing technique to be able to make manufacturer shortens treatment cycle time, still can machine at the same time piece than before the part with more exquisite, smaller wall. According to Ha Si (the view of Wayne Reilly of manager of Haas) company treatment, a lot of people are not rigorous when use high speed machines this one term. Look in Reilly, although a few people think any main shaft rotate speed exceed the treatment of 10000rpm to calculate high speed treatment, but another some of person has a few more complex definition however to this. He says, "Actually this depends on the use setting of this term. Tool manufacturer may be its definition rotate speed, and machine tool manufacturer defines his possibly in be system of CNC numerical control certain before look up handles program block. The technical development trend that high speed machines is to use the cutting with rate of rapidder cutting rate, feed and smaller negative charge, and conventional treatment uses bear normally heavier, cut deep bigger low speed cutting. " for example, the vertical machining center that Ha Si company produces (VMC) offerred the rated main shaft that is as high as 30000rpm for high speed treatment rotate speed and 30 horsepower (22.

The drive system rated power of 4kW) . Xinxinnadi (the aluminium of MAG Cincinnati) company Randy Von Moll of treatment platform manager expresses, "Discuss main shaft rotate speed isolatedly with its, I prefer efficient treatment this term. " his definition besides main shaft rotate speed, the trends that still includes a machine tool is answered. He used 5 parameter to define efficient treatment: Rotate speed of ① main shaft; Power of ② main shaft; The feed rate with high ③ and cutter track rate; ④ is added high, reduce rate; ⑤ high accuracy. Hind the trends that 3 conditions defined a machine tool technically is answered and not be main shaft character. Von Moll says, "For effectively cutting alloy material (be like aluminium alloy) , the tall trends that needs will high-powered main shaft and machine tool really answers union to rise. " if aviation spare parts cent is " thin panel " and " thick panel " two kinds big, he thinks to be able to machine high speed cent to fasten a definition to be: Be in to ply the thin panel of 50mm less than, main shaft rotate speed is 30000rpm, rated power is 80 horsepower (60kW) ; Be in to ply the thick panel of 50mm above, main shaft rotate speed is 18000rpm, rated power is 135 horsepower (100kW) . Von Moll explanation says, "When cutting machines thin panel and thick panel, the highest trends of the machine tool answers parameter and do not have too big different. To two kinds of workpiece, acceleration / decrease speed to should be in 0.

5g left and right sides, should offer as far as possible fast (blame cutting) reciprocate, achieve 1500ipm(38m/min) at least. " machining complex sunken antrum kind when workpiece, acceleration / decelerate spends pair of cutting time to have very big effect, because cutting tool is in treatment must for many times haul. The reciprocating translation time of the machine tool can affect cutting time, assist time especially (the 20%) that time assists to be able to take full treatment cycle time when cutting aluminium alloy. Auxiliary time includes cutting the fixed position time of the cutting tool when a new work or the time that cutting tool moves to change knife manipulator. According to the point of view that seed profit makes, auxiliary time is the waste that a kind of need eliminates. A few years ago, the company rolled out Xinxinnadi to be able to come true fast reciprocating translation and add high / the series of milling machine of HyperMach vertical profile modeling that decelerate spends perfect couple. The speed of fast reciprocating translation of these machine tools is as high as 4000ipm(101m/min) , its purpose assists time to shorten namely. Journey of axis of the X of HyperMach, Y, Z achieves 33m, 3500mm and 1250mm respectively, configured additional A, B or C axis, the main shaft rotate speed of the machine tool is as high as 30000rpm. Milling machine of profile modeling of major HyperMach vertical is to be in the main shaft that two mutual independence install on structure of common door of X axis dragon. Improve large work to answer (the market demand that dimension can amount to 2000mm × 4000mm) to machine efficiency, the company will be in Xinxinnadi IMTS 2008(2008 year exhibition of production technology of American Chicago international) go up to exhibit and demonstrate HyperMach horizontal series. "Cutting goes out small cut bits and as far as possible apace is machined " it is Mu Ye (the definition that Alan Hollatz of engineer of Makino) company design machines to high speed. He thinks, high rotate speed, small cut deep treatment method to be able to reduce the heat in metal cutting in passing into workpiece or cutting tool, workpiece and the cutting power that the machine tool gets are lesser also. It is traditional low rotate speed, easy to cut deep treatment method greatly make thickness of the wall in contemporary design comes 0.

030 ″ (0.

The workpiece generation of 76mm) is out of shape. Lesser cutting force still means the demand that can reduce pair of workpiece clip to hold. Hollatz proposal, when finish machining aluminium alloy, answer to use high speed cutting as far as possible, "If main shaft is rated,rotate speed is 30000rpm, we run the trial amain. In the meantime, we still can restrict the diameter that uses cutting tool. Consider cutting tool is lopsided the centrifugal strength that cause, when machine tool rotate speed is higher, cutting tool diameter should be jumped over small. " as an example, a kind of large machine tool that Mu Ye manufactures (33000rpm of main shaft rotate speed, electric machinery power 107 horsepower [80kW]) does not recommend the cutting tool that uses any diameters to be more than 50mm. To most cutting treatment, the diameter is 25mm or efficiency of less cutting tool cutting is highest. Like supplier of most machine tool, hollatz is recommended in main shaft use when rotate speed is higher hollow short awl handle () of HSK knife handle, and do not use CAT knife handle. He points out, CAT knife handle may pose the precision problem of Z direction when high speed is machined. When undertaking machining with high rotate speed, once had appeared the extreme circumstance that CAT knife handle blocks main shaft. The design characteristic of HSK knife handle is to use cone and end panel double contact, because this can control the precision of Z direction. "It is when main shaft rotate speed when 20000rpm is the following, can use CAT knife handle, but when rotate speed is as high as 30000rpm, besides use HSK have no alternative beyond knife handle. " another crucial factor that high speed machines is CNC controller and the capacity that its control a machine tool accurately below high speed condition to move. Have " before look up " functional controller can control cutting tool according to the place that cutting tool will reach current rate and add / reduce rate, this function and main shaft of high speed drive are likewise important. According to Introduction Hollatz, the standard of controller of herd wild machine tool " before look up " the function has more than 60 - 80 G pile up module. Among them Super GI.

Be machined for high speed and package of 4 controller program is designed technically, have more than 180 - 250 module. To same cutting tool way, super GI.

The athletic speed of 4 compares the SGI that it replaces.

3 controller rose 15% - 30% . According to Ha Si the company machines manager Reilly to introduce, ha Si machine tool machined control to offer scheme for selection for high speed. High speed treatment of Ha Si controls module to allow to use higher feed rate and more complex knife track, and won't make the machine tool appears stop the breakdown such as machine. Ha Si machine tool is used call " the acceleration before interpolation " motion is algorithmic, and as complete as what amount to 80 module " before look up " functional photograph is united in wedlock, treatment of its high speed controls module to be able to offer the contour line feed that is as high as 500ipm(13m/min) to move, and the risk with the knife lack fidelity course that need not risk process designing. "When the biggest profit that such doing executes an order namely, have ' before look up ' quality, and can maintain when athletic way produces any change as far as possible rapid athletic rate. " Reilly explanation says, "If athletic way change is not big, athletic speed also needs a change scarcely. The change of speed is the metabolic proportionate with direction. " in aviation industry, use more composite material to reduce weight as new-style plane, to the treatment of composite material demand is becoming increasingly pressing. 787 planes use Boeing the typical example that synthesizes material to expect production airframe and wing are this one trend. The high speed treatment of aluminium alloy will make standard technology before long, at other application of high speed treatment material of commonly used aviation also has a sense it seems that, not exceptional also of course to composite material. "Should use shape completely nearly when craft makes composite material part, cooperate to achieve, join and cave the precision requirement of place, have machine treatment with respect to need. " explanation of Jeff Crick of manager of platform of treatment of company composite material says Xinxinnadi, "For example, use a layer to accumulate treatment to be able to make enter hole in wing surface, but can achieve only about ± 0.

The precision of 5mm (layer accumulating treatment can achieve) of this kind of precision only. Achieve for the place that asking more high accuracy, undertake fabricating with respect to need (like machine treatment) , resemble having precision work to alloy of aluminium alloy, titanium or rolled steel same. " introduce according to Crick, with treatment aluminium alloy photograph is compared, the power that place of composite material of high speed treatment needs and torque are lesser, the machine tool that machine tool itself need not resemble cutting titanium alloy in that way massiness is strong, but still need to have enough tigidity in order to overcome vibration and resonance. The rotate speed limits of main shaft of most machine tool is in 10 - 13000rpm(although they are OK) of higher rate movement. For example, manufacturer of component of a large aviation of American is the machine tool of 24000rpm to go up in a rotate speed, use 0.

012 - 0.

016 ″ (0.

3 - 0.

Of 4mm) cut deep implementation the high speed treatment to composite material. Now, major composite material uses the treatment unit that designs for metallic cutting at the outset to machine. Crick thinks, ultimate goal is the special machine tool that makes a weight be designed gentlier, technically to process composite material. The design must notice a kind of trend when this kind of machine tool, namely the size of component of aviation composite material is larger and larger. Crick says, "The size of composite material component may be very large, if be as long as 100 ′ (the Fu outside 30m) wing, include whole airframe part even, like new-style Boeing the diameter of engine room section plane of 787 exceeds 20 ′ (6m) , length exceeds 30 ′ (9m) . In this kind of large construction, the requirement of combines an aspect secondhand treatment public errand to an airframe and another airframe is very strict. Other component may grow to contain muscle board again already, the bridge that be like an ala, carling, pillar and floor beam. Grow already to machine these thin and easy bent spare parts (Crick visualize the ground describes them for " wet noodle " ) , xin Xin carried a company to develop a kind of special extruding then milling machine. This machine tool can machine aluminium alloy to also can process composite material already, treatment size scope 13 ′ × 8 ′ (4 × 2.

4m) , 24000rpm of main shaft rotate speed, 12 kinds of cutting tool that use a diameter not to exceed 25mm undertake machining, workpiece can is as long as 40 ′ (12m) . "When when almost all treatment means can pass high speed to machine benefit with workpiece material, free cutting material (like aluminium alloy or composite material) be benefited the biggest, " Reilly of manager of treatment of Ha Si company says, "Because use high rotate speed, big feed, small cut deep hard milling technology, steel of strong pattern of temper by dipping in water also can be machined from high speed in benefit. Titanium alloy regards aviation industry as more and more important workpiece material, also be one of person that be benefited of course. " " if say machine tool of aluminium alloy cutting resembles F1 racing bicycle, machine tool of titanium alloy cutting more resemble bulldozer, " manager Dan Cooper says the productivity solution of company of MAG maintenance technology, "They have in respect of main shaft rotate speed very big different, although high speed machines a principle -- high rotate speed, small cut also provide greatly sometimes to titanium alloy significant, especially thin wall spare parts had better use high speed to machine principle treatment. E.g. , the spare parts ply of an user is 0.

030 ″ (0.

76mm) , height is 3 ″ (76mm) , thin wall of this kind of great height cannot use vintage and conventional technology to undertake rough machining, low rotate speed, big cut cutting of deep, big torque to will bring about workpiece to be out of shape with cutting tool deflection, to new-style the treatment of spare parts of 5553 titanium alloy especially such. " Cooper points out, quantity of the low thermal conductivity of titanium alloy, high stretch standard and high strenth photograph are united in wedlock, make its make material of a kind of difficult cutting, "Although cutting torque and trends are rigid it is too not important perhaps to be machined to composite material and aluminium alloy, but very important however to titanium alloy treatment. Machine photograph comparing with aluminium alloy, this meets those who restrict titanium alloy to machine speed rise. " be led with exterior speed and feed and Cooper auxes would rather is not main shaft rotate speed will measure high speed treatment. Exterior speed is the function of main shaft rotate speed and cutting tool diameter; Feed leads the function that is main shaft rotate speed and tooth density. Because tooth exceeds rate of close, surface (SFM) is taller, mean feed rate is higher, the design of cutting tool is accordingly crucial. Cooper says, the cutting tool of new-style hard alloy of MAG is OK the exterior speed of 390fpm undertakes machining. "With a diameter 25.

Chamfer of 4mm, knife counts most cutting tool, we can be mixed with the rotate speed of 1500rpm only 2.

The speed of 5m/min is machined, and this is machined to titanium alloy already was quite high rate. " the advantage that high speed processing technique already proved him in aluminium alloy treatment, people expects it resembles titanium alloy in treatment this also can be accomplished when newer, harder data euqally. "Nowadays, the high speed treatment of aluminium alloy is making standard technology. " campstool is overcome (division headquarters mixes Mazak) company on the west the treatment manager Rudy Canchola of aviation technology center says. To him, at present the biggest treatment challenge is high temperature alloy (be like 15-5 stainless steel, 5553 or) of 6Al4V titanium alloy, these material are in the use of aviation industry is increasing. Recently, his plan uses all sorts of cutting tool to undertake cutting experiments on campstool gram machine tool (include to go up to machine experiment) into travel titanium alloy in machining center of Mazak VCN-510C vertical. Canchola says, "The speed that we had proved to establish milling cutter to machine titanium alloy with integral hard alloy can be amounted to 500 - 600fpm. We think this is very pretty good. " they still are used respectively hill is tall (Seco) , Ingersoll (Ingersoll) , agree accept (Kennameta) and Shanteweike (the cutting tool of Sandvik) is in 5 axes of Mazak Vortex 815-II undertook processing 15-5 stainless steel on machining center. The experiment uses suitable mill to machine means, exterior cutting speed is achieved 400 - 600fpm. Canchola says, "Our most machine tool has the capacity that achieves rate of feed of this kind of fast face. If the user needs cutting this kind of material, we can provide the data that obtains in these experiments to them " . When machining high temperature alloy, of machine tool controller " before look up " function unlike treatment when aluminium alloy so important, because right now cutting rate is not quite high. The mainest control function is to measure main shaft and load of shafting place susceptive to undertake adjustment accordingly. Campstool overcomes a machine tool to be able to receive the feedback telecommunication order that comes from servo electric machinery, adjust speed to make its and cutting condition match each other, if be necessary,still can stop machine change cutting tool. CNC Milling