High speed cutting machines research of cutting tool technology

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Represent the high speed cutting of direction of contemporary machining mainstream to machine, because complied with 21 centuries machinery,add next efficient, high accuracy, flexible ask with what green changes and got swift and violent development. The biggest characteristic that high speed machines is in great and contented efficient production while, also rose to be machined greatly the treatment precision of the spare parts and exterior quality. Use high speed treatment " pass " technology, can process traditional thick precision work finish, can gain the treatment face of high quality already, leave out a certain number of traditional working procedure, make machine efficiency be able to great rise. As the general application of electric main shaft in the machine tool, restricting the element that rate of machine tool cutting rises ceaselessly already was itself of machine tool main shaft not just, the research of the cutting tool system that treatment of cutting of appropriate high speed asks and technology already became influence high speed to machine the main factor of ceaseless development. Accordingly, study high speed machines the new requirement that raises to cutting tool system deep, the cutting tool system that develops appropriate high speed to impose next requirements has very important sense. The malpractice that the article is aimed at traditional cutting tool to exist in high speed treatment, in serious analysis high speed machines the foundation that asks to cutting tool system to go up, discussed appropriate high speed to machine the technics of the cutting tool system of the requirement. Cutting of 1 high speed machines to the knife the treatment of cutting of requirement high speed of its system is main shaft rotate speed not just to rise, point to integral handling time however shorten. Accordingly, treatment of high speed cutting asks cutting cutting tool has character of very tall tigidity, security, flexible, dynamic balancing and operation not only convenient sex, and the join stiffness to cutting tool system and machine tool interface, precision and knife handle hold force and clip to hold precision to waited to raise very tall requirement to the clip of cutting tool. The system of complete cutting tool that system of alleged cutting tool forms by the knife handle that hold clip and place of cutting cutting tool namely. The knife handle that hold clip and machine tool interface are suitable, cutting cutting tool is machined directly by treatment spare parts, both very important. High speed cutting machines cutting tool system to must satisfy the following requirement: The high security of cutting tool structure regards application as the cutting tool system that processes at high speed cutting, its structure must have high security, fly off in order to avoid the bit when circumgyrate of cutting tool high speed, assure to rotate bit is in 2 times at top rotate speed not burst. The dynamic balancing function of the cutting tool system that the dynamic balancing sex with cutting tool excellent system uses at high speed to machine is crucial. By theory mechanical knowledge is knowable, from mental efforts F=mrw2, when dynamic balancing of cutting tool system when performance is poorer, the cutting tool that high speed rotates can produce very great centrifugal power, cause arbor to bend thereby and generation shakes, its will make be machined as a result spare parts diminution of quality, cause cutting tool damage even. Of system of expensive systematic tigidity cutting tool the static, main factor that moving tigidity is influence treatment precision and cutting function. Inadequacy of tigidity of cutting tool system will bring about vibration of cutting tool system or tilt, make machine precision and treatment loss of efficiency. In the meantime, systematic vibration can make cutting tool wears away again aggravate, lower cutting tool and machine tool service life. Precision of tall systematic precision system includes a system to locate clip holds precision and cutting tool to repeat fixed position precision and good precision to maintain a gender. Have the cutting tool system that above precision asks, the static state that ability assures to high speed processes whole system and dynamic stability, satisfy the requirement of workpiece of high speed, expensive precision work thereby. Tall interchangeability is right system of module type cutting tool, system of need cutting tool has taller flexibility, so that pass,assemble, get used to the treatment need of different spare parts quickly. In addition, the interface of cutting tool and machine tool should use same knife handle system, in order to reduce needless inventory. System of efficient sex cutting tool must have the cutting tool of high quality, tall service life, in order to satisfy high speed the requirement of efficient treatment workpiece. System of tall adaptability cutting tool should have the capacity that machines a variety of hardness material to pledge, in order to satisfy the requirement that high speed processes all sorts of work. The precision of fixed position of problem cutting tool that system of 2 traditional cutting tool exists and when repeating low high speed of fixed position precision to machine, because leave the action of mental efforts, main shaft taper hole and handle of cutting tool awl all produce radial dilate. Be less than dilate of main shaft taper hole when tensor of awl handle enlarge when the quantity, appear cooperate clearance. Then, in taut bolt the action of taut force falls, awl handle drives displacement of cutting tool axial, bring about cutting tool to add loss of accuracy of fixed position of the axial when in high speed. In the meantime. Knife handle and main shaft taper hole rely on cone to cooperate join only, axial stiffness is inferior, bring about cutting tool to repeat fixed position precision inferior. When high speed of low cutting tool of cutting tool trends and static stiffness rotates, below centrifugal force effect, the difference of tensor of enlarge of axial of main shaft taper hole, make the stiffness of low rigid connective that is united in wedlock by cone originally farther reduce. Ministry of knife handle awl is longer, go against the miniaturization that changes knife and machine tool main shaft quickly. As a result of above reason, system of traditional cutting tool already cannot satisfy the need that high speed cutting machines, must consider to develop the cutting tool system that cutting of appropriate high speed processes. Cutting of high speed of technology of material of technical cutting tool machines the 3 cutting tool that are based on treatment of high speed cutting is to the main demand of material: Performance of good high temperature chemistry, hot physics function, chemical stability, fight coating burst sex, fight stick receive gender and heatproof brace up quality. Material of treatment cutting tool must press high speed cutting to be machined workpiece material undertakes choosing with fabricating characteristics character, match with reasonable cutting condition, ability develops exceedingly good cutting property. To steel, cast-iron wait for black metal, appropriate chooses pottery and porcelain, cermet and cubic nitrogen to turn boracic cutting tool, wait for nonferrous metal to aluminous, magnesium, appropriate chooses the cutting tool material such as PCD and CVD. Current, in industry of American spaceflight aviation, the cutting speed of milling aluminium alloy already was amounted to 7, 500m/min, , its cutting speed basically suffers rotate speed of main shaft of machine tool of be confined to. To steel, cast-iron wait for black metal, the cutting rate that achieves in high speed cutting is the 1/3 ～ 1/5 that machines aluminium alloy, it is about 1, 000 ～ 1, 200m/min, its speed basically gets the hear resistance of material of cutting tool of be confined to, and the target of cutting of prospective high speed is: The cutting speed of milling aluminium alloy is 10, 000m/min. Cast-iron for 5, 000m/min, common rolled steel is 2, 500m/min, and get the rate that cuts aluminium alloy, cast-iron, common steel for 30, 000m/in, 20, 000m/min and 10, 000m/min, mix in prospective high speed in exceeding high speed to machine, exceed material of strong cutting tool (like cutting tool of PCD, PCBN) , pottery and porcelain, coating cutting tool, TiC(N) base the cutting tool material such as hard alloy cutting tool will produce main effect. Technology of interface of system of cutting tool of technology of its system interface includes the sword cutting tool, technology of machine tool interface and cutting tool, technology of knife handle interface. Cutting tool, the adverse effect that technology of machine tool interface relies on cone fixed position to bring about merely to overcome traditional knife handle, orgnaization of a few scientific research and tool manufacturer research developed a kind to be able to make knife handle is inside main shaft the new-style join means that aperture cone and end panel locate at the same time, two sides tie locates clip runs a system too. This system has very tall contact stiffness and repeat fixed position precision, clamp is reliable. Current, this system basically has short awl handle and 7:2Handle of 4 long awl two kinds of forms. Although 7:2It is as OK as traditional BT knife handle that 4 awls handle is had crossing-over, can go to the lavatory installation is 7:2 at taper of main shaft taper holeOn the machine tool of 4, can increase the good point such as the join stiffness of knife handle and main shaft and precision, but in light of the development trend that the high speed that increases with each passing day from cutting speed machines, taper is 1:1The development perspective of the knife handle structure of the short awl handle of 0 is more wide. Current, the two sides of short awl handle restrains knife handle to basically HSK, KM, NT, BIG-PLUS waits for a few kinds. 1.

Knife handle 2.

Pull rod 3.

Main shaft 4.

Bedspring covers graph 1 1.

Knife handle 2.

Pull rod 3.

Locking steel ball 4.

The lock shuts lever to pursue the awl handle part of knife handle of 2 graphs 3HSK uses taper to be 1:1Of 0 hollow short awl handle, its structure is shown 1 times like the graph. When knife handle and main shaft join, knife handle of support short awl is in heart of decided at the higher level but not officially announced of main shaft taper hole. When short awl knife handle and main shaft taper hole are contacted cheek by jowl. There still is 0 between end panel.

1 right-and-left clearance, below taut strength effect, the flexibility that uses hollow knife handle is out of shape compensate this clearance, in order to realize fixed position of as double-faced as main shaft cone and end panel tie. Right now, the interference between snickersnee handle and main shaft taper hole makes an appointment with 3 ～ 10 µm. Because hollow knife handle has bigger flexibility to be out of shape, because this is right the production precision requirement of knife handle is relatively inferior. In addition, as a result of petiole of system of HSK cutting tool short, quality is small, be helpful for a machine tool changing knife and machine tool miniaturization automatically. But its are hollow structure of short awl power also can make systematic stiffness and intensity are affected. HSK knife handle has a variety of forms such as A, B, C, D, E, among them the limited speed of HSK40A, HSK40E, HSK63E can be achieved 4, 200r/min, 5, 5000r/min, 3, 2500r/min. Agree by the United States the system of KM(Kennametal) module that offer company studies to develop -- system of cutting tool of two sides clip, its structure is shown 2 times like the graph. It was used located at 3 o'clock means, can use at lathe to be able to be used at turning center and machining center again already. Because its structure is unique, have the advantage of high speed, tall tigidity, high accuracy, be being used by place of more and more machine tool manufacturer. Compare with photograph of HSK knife handle, the interference between KM knife handle and main shaft taper hole makes an appointment with 2 ～ high 5 times, if KM6350(is equivalent to the interference of BT40) be 10 ～ 25µm, border application is actually medium, the rotate speed of KM6350 and KM4032 is achieved respectively 36, 000r/min and 50, 000r/min. The stiffness of two systems of HSK and KM is like a graph quite 3. System of BIG-PLUS cutting tool uses 7:24 taper, the clearance that its structure design can assure knife handle main shaft and main shaft end panel is made an appointment with 0.

2 the left and right sides, the flexibility that the opening inside main shaft can use when locking expands to undertake compensating to this clearance, tighten in order to ensure knife handle and main shaft end panel are stuck. Two sides restrains clip to held a system to make up for a lot of inadequacy of traditional tool system, represented cutting tool the mainstream direction of technology of interface of one machine tool, be sure to receive wider and wider application. Current, abroad already research and development the clip of two sides tie of a variety of configuration runs a system, because this system is had,repeat fixed position precision stiffness of tall, activity is advanced a series of advantages, can satisfy the requirement that high speed machines. The bulk that knife handle of technology of interface of one knife handle holds power to the clip of cutting tool and clip hold cutting tool the discretion of precision, very important place is had in high speed cutting. If knife handle is right,cutting tool clip is held not firm, light reduce treatment precision, cause cutting tool and workpiece damage again, cause safe accident even. Raise clip of cutting tool system to hold precision, must try to make cutting tool obtains accurate and reliable fixed position, ensure enough clip holds power, must be controlled strictly and raise cutting tool system to cooperate precision, increase clip to run length, optimize structural design and reasonable select material. Current, the cutting tool collet that cutting of appropriate high speed machines basically has the following kinds: Shrink collet uses knife handle to install tool bore heat to bilge cold shrink make cutting tool reliable clamp. It is a kind of collet that does not have clamping unit, the structure is simple symmetrical, clamping force is large. Collet of high accuracy bedspring the collet of high accuracy bedspring that by Japanese big clear and machine of essence of life the company limited produces, use cone angle 12 ° awl is covered, all collet classics balance nap, in order to get used to the requirement that high speed machines. Current, the rotate speed of this kind of collet can be amounted to 30, 000 ～ 40, 000r/min. The collet of high accuracy hydraulic pressure of system of cutting tool of BlG-PLUS of collet of high accuracy hydraulic pressure uses an organic whole that clip held at 2 o'clock construction, have very tall clip to hold force and clip to hold precision, and reduced collet quality. High accuracy is static pressure expand the high accuracy that type collet overcomes a company to produce by German hero is static pressure expand type collet, through screwing pressurization bolt increases the oil pressure inside oil pocket, make oil pocket wall even and symmetrical expand to axes direction, with clamp cutting tool. This collet clip holds precision extremely tall, its are radial and jumpy be less than 3µm. 3 arris are out of shape this collet uses collet the cutting tool of deformation force clamp of collet itself, its freedom condition is 3 arris form, when the cutting tool that hold clip, use hydraulic action to make the aperture inside collet turns into circle, after cancel outside force, kong Chongxin systole is 3 arris form inside, in order to realize pair of cutting tool at 3 o'clock clamp. This collet has a structure precision of compact, fixed position is tall (can amount to 3µm the following) and symmetrical, cutting tool installs clip to wait for depend on dot simply. Original structure collet by Sandvik company new the Coro Grip collet that roll out, device of hydraulic pressure of have the aid of drives awl to cover, measure in 3D place, its are radial and jumpy can amount to 2 ～ 6µm, clamp of this kind of collet is more reliable, collet of hydraulic pressure of its tigidity prep above, the time that hold clip is short at shrink collet. The columnar handle that ISCAR company rolls out is new-style the means that hold clip, make sure end panel is contacted not only, and clamping force can be formed on half circumferential face, raised clip to hold tigidity. Cutting tool balances technical high speed to machined the dynamic balancing technology to cutting tool to raise very tall requirement. Usually, milling cutter knife handle, pinchcock head can achieve dynamic balancing through balancing nap. The collet of shrink of tall balance grade that rolls out like Japanese NT company (the applicable rotate speed of 6) of ～ of SK3, SK4 can be amounted to 70, 000r/min, SR10 ～ 20 can amount to 50, 000r/min. To carrying the head of boring of essence of life of fine tuning orgnaization, machine the change of the centre of gravity when the diameter for balance adjustment, the company limited rolled out Japanese big clear and machine of essence of life one kind can undertake self-poise compensatory boring head, EWB, use at machining bore diameter to be Ø32 ～ the boring of 105 high speed essence with Ø2 ～ Ø42 head EWB32 ～ 105 with 50 of EWB2 ～ , speed of its limit cutting can be amounted to 20, 000r/min. Cutting tool of cutting of high speed of technology of design of 4 cutting tool designs what the technology includes parameter of cutting tool geometry to optimize choice, knife to rest the technology such as design of safe structure design, bit clamp orgnaization. The main feature that cutting tool of high speed cutting damages is: Heat of cutting tool point of a knife wears away and the breach damaged of border of blade of cutting tool cutting. Accordingly, the horn before be being used at what high speed machines cutting tool should compare common cutting tool Xiao (0 ° of G ≤ ) , horn should compare common cutting tool after big (8 ° of 5 ° ～ ) , advocate, joint of deputy cutting blade should use the point of a knife that repair a circle or pour horny point of a knife, in order to increase cutting tool tigidity and the probability that reduce damaged of cutting cutting tool. Cutting tool structure is designed should according to be being machined material and working procedure optimize material of assorted cutting tool, coating and chamfer function, development has the bit structure of optimal cutting effect. What like ISCAR company and Japan company of 3 water chestnut rolls out is muti_function bit, have side of the knife before dimensional cutting blade and curved surface, cutting force is small, point intensity is high, when high speed is machined, fight wear away capability is strong, high speed of it may be said machines the delegate of blade of cutting cutting tool structure. In addition, structure of cutting tool clamp also should get used to high speed to machine a requirement, use structure of clamp of new-style razor blade for instance in case bit flies off, cutter hub small quality is light-duty change a design, indicate moment of force of top limited speed and bit clamp. Treatment of cutting of 5 epilogue high speed already became the main trend that machinery makes to develop way, accordingly, the research of the technique of cutting tool system that cutting of appropriate high speed processes has very important sense. As the development of advanced production technology and material technology and accept rice technology, the functional material such as the horniness coating of form of new rice of multivariate, compound, accept and CVD diamond film, exceed cutting tool of cutting tool of material of strong cutting tool, pottery and porcelain, coating to wait will get applied extensively, system of cutting tool of high speed cutting will be perfect with each passing day, make the main component that drives treatment of high speed cutting. CNC Milling