How does numerical control machine tool choose cutting tool and process designing correctly

Published on 2017-12-21

Summary: ? Knock at be ignorant of of Yong of Xing of decadent of difficult ≡ Yao instrument of cover of ひ of す of commonplace of Piao of  of scabbard of ㄊ of Kang Na model is troubled by  of  of plaque  Chen Jin to call out collect of refute of  of Tao of  of catfish postscript enthalpy to need Liu of postscript of bless of benzene of curb of  of  of ば  remnant needs ぶ persimmon handsome , make the design data that uses CAD directly in numerical control treatment becomes a possibility, especially the connection of DNC system personal computer and numerical control machine tool, make the whole process of program of design, technology and process designing whole finish on the computer, do not need to output special craft file commonly. Current, the choice that a lot of C have and cutting dosage are the serious content in craft of numerical control treatment surely really, it affects the treatment efficiency of numerical control machine tool not only, and immediate impact machines quality. The development of CAD/CAM technology, make the design data that uses CAD directly in numerical control treatment becomes a possibility, especially the connection of DNC system personal computer and numerical control machine tool, make the whole process of program of design, technology and process designing whole finish on the computer, do not need to output special craft file commonly. Current, a lot of CAD/CAM software packages provide function of automatic process designing, these software are the concerned problem that plans in craft of the clew in process designing interface commonly, be like, dosage of program of method of cutting tool choice, treatment, cutting set, process designing personnel should set the parameter that concern only, can create NC program automatically and transmit complete treatment to numerical control machine tool. Accordingly, the cutting tool choice in numerical control treatment and cutting dosage are finished below interactive condition certainly, this and treatment of general accuracy machine tool form bright contrast, also ask process designing personnel must master the basic principle with cutting tool choice and cutting affirmatory dosage at the same time, in the characteristic that mature numerical control machines when process designing, can choose knife cutting tool and cutting dosage correctly. One, the sort that numerical control machines commonly used cutting tool and characteristicCutting tool of numerical control treatment must get used to numerical control machine tool high speed, efficient with the characteristic with automation high rate, should include knife handle of general cutting tool, general join to reach a few special knife handle commonly. Knife handle wants connection cutting tool and install go up in machine tool head, already was standardized gradually accordingly and seriation. The classification of cutting tool of 1. numerical controlCan divide according to cutting tool structure for: Rectify form of characters or letters; Set pattern, use solder or connection of machine clip type, machine clip type can be divided again for not dislocation and but dislocation two kinds; Special type, wait like complex formula cutting tool, damping type cutting tool. It is according to making the data that cutting tool place uses can divide: High-speed steel cutting tool; Hard alloy cutting tool; Diamond cutting tool; Other data cutting tool, if cubic nitrogen turns cutting tool of boracic cutting tool, pottery and porcelain,wait. Can divide from cutting craft for: Turning cutting tool, especially round, inside cutting tool of aperture, whorl, cut a variety of; Auger cut cutting tool, include broach, reamer, tap to wait; Boring cutting tool; Milling cutting tool. Move durably to cutting tool, steadily, easily to get used to numerical control machine tool, can change the requirement that wait, in last few years machine clip type but dislocation cutting tool receives wide application, the 30% ~ that achieve cutting tool of whole numerical control on the amount 40% , the 80% ~ that the metal excises a quantity to hold sum total 90% . 2.The characteristic of numerical control cutting toolThe cutting tool photograph that uses on numerical control cutting tool and general accuracy machine tool is compared, have a lot of diverse demands, basically have the following characteristic: Tigidity is good (especially rough machining cutting tool) , precision is tall, fight brace up reach heat to be out of shape small; Interchangeability is good, facilitate change a knife quickly; Life is tall, cutting function is stable, reliable; The dimension of cutting tool facilitates adjust, with reducing the settling time that change a knife; Cutting tool should break bits reliably or coil bits, with benefit at cutting bits eliminate; Seriation, standardization, manage at process designing and cutting tool with benefit. 2, the choice of cutting tool of numerical control treatmentThe choice of cutting tool has below the interactive condition of numerical control process designing. Should the element is correct related dosage of working procedure of the function of material of the process capability according to the machine tool, workpiece, treatment, cutting and other choose cutting tool and knife handle. Cutting tool chooses total principle is: Installation adjusts convenient, tigidity good, durability and precision are tall. Below the premise that asks in contented treatment, choose shorter knife handle as far as possible, in order to raise the tigidity that cutting tool machines. When choosing cutting tool, should make the dimension of cutting tool and be gotten used to by the exterior dimension photograph of treatment workpiece. In production, the treatment of outline of cincture of week of planar spare parts, often use establish milling cutter; When milling is planar, should choose milling cutter of hard alloy razor blade; When machining protruding stage, groove, choose high-speed steel to establish milling cutter; When machining semifinished product surface or rough machining aperture, can choose the corn milling cutter that sets hard alloy bit; A few righter establish bodily form face and change the treatment of appearance of bevel angle outline, often use ball head milling cutter, annular milling cutter, cone-shaped milling cutter is mixed dish of form milling cutter. Having free curved surface (mould) when treatment, as a result of the cutting carrying a department of ball head cutting tool speed is 0, accordingly, to assure to machine precision, cutting row spacing uses top to be apart from closely commonly, reason ball head is commonly used the finish machining at curved surface. And crop cutting tool machines quality and cutting efficiency respect in the surface knife of excel ball head, accordingly, below the premise that wants to be cut too in guarantee against only, no matter be the rough machining of curved surface or finish machining, answer knife of first choice crop. Additional, the durability of cutting tool and precision and impact of cutting tool price are great, must of bring to sb’s attention is, below most circumstance, although the cutting tool that has chosen raised cutting tool cost, but of the treatment quality that brings from this and treatment efficiency rise, can make whole finished cost is reduced greatly. On machining center, all sorts of cutting tool are installed respectively go up in knife library, by the program the regulation undertakes the knife is mixed choosing at any time the movement that change a knife. Because this must use standard knife handle, so that make,get, the standard cutting tool that the working procedure such as boring, enlarge, milling uses installs machine tool main shaft well and truly or knife library goes up. The structural measure that process designing personnel should use knife handle on understanding machine tool, adjust method and adjust range, so that the radial of cutting tool and axial size determine when process designing. At present the machining center of our country uses TSG tool system, its knife handle has straight power (3 kinds of norms) with awl handle (4 kinds of norms) 2 kinds, include the knife handle of 16 kinds of different utility in all. In the treatment process of machine tool of economy numerical control, because the blade of cutting tool is ground, measure and change to be moved for artificial hand more undertake, take up auxiliary time is longer, accordingly, must the permutation of reasonable arrangement cutting tool is ordinal. Should follow the following principle commonly: ① reduces cutting tool amount as far as possible; After ② places cutting tool outfit, should finish all treatment move that its can have; The commencement of cutting tool part of one’s job of ③ thick finish machining is used, even if the cutting tool of same size standards; ④ is gotten after mill first; ⑤ has curved surface precision work first, precision work of 2 dimension outline has after; ⑥ falls in probable condition, what should use numerical control machine tool as far as possible is automatic the function that change a knife, wait in order to improve manufacturing efficiency. 3, those who machine dosage of the cutting in the process is affirmatoryThe principle of dosage of logical choice cutting is: When rough machining, give priority to in order to improve productivity commonly, but also should consider economy and finished cost; When semifinishing machining and finish machining, answer to fall in the premise that assures to machine quality, efficiency of cutting of give attention to two or morethings, economy and finished cost. Particular numerical value should according to dosage of machine tool manual, cutting manual, combine experience and decide. Specific should consider the following factors: Cutting deepness Ap. Below the condition that allows in machine tool, workpiece and cutting tool stiffness, ap is equal to mental allowance, this is a when improve productivity significant step. To assure the treatment precision of the spare parts and exterior surface roughness, should leave certain surplus to have precision work commonly. The finish machining surplus of numerical control machine tool can be less than general accuracy machine tool slightly. Cutting width L. General L and D of cutting tool diameter become direct ratio, become inverse ratio with cutting deepness. In the treatment process of machine tool of economy numerical control, the extraction of general L is worth limits to be: L=(0.6 ~ 0.9)d. Cutting speed V. Raising V also is a measure that improves productivity, but the relationship of V and cutting tool durability is closer. As the accretion of V, cutting tool durability drops quickly, the choice of reason V basically depends on cutting tool durability. Additional, cutting speed and treatment material also have very big concern, use for example when establishing milling cutter milling to add up to King Kong 30CrNi2MoVA, v can use 8m/min left and right sides; And with when establishing aluminium alloy of milling cutter milling likewise, above of V optional 200m/min. N(r/min) of main shaft rotate speed. Main shaft rotate speed comes according to cutting speed V commonly make choice of. Computational formula is: V=pnd/1000. Rotate speed of common stock main shaft writes melody on the Control Panel of numerical control machine tool (fold) switch, can undertake to main shaft rotate speed in machining a process multiple is adjusted rectifying. Feed speed Vf. VF should be mixed according to the treatment precision of the spare parts requirement of exterior surface roughness and cutting tool and workpiece data will choose. The addition of Vf also can improve manufacturing efficiency. When demand of treatment surface surface roughness is low, vf can choose some more greatly. In machining a process, vf also can pass the switch writing melody on machine tool Control Panel to undertake be adjustmented artificially, but speed of the biggest feed should get equipment stiffness and feed system performance sexual limitation. Producing as numerical control machine tool actual medium wide application, quantify the formation of product line, numerical control process designing has accused to machine one of medium crucial questions into amount to. In the work out process of numerical control program, want cutting tool of instant below interactive condition choice and affirmatory cutting dosage. Accordingly, process designing personnel must be familiar with the affirmatory principle of the selection method of cutting tool and cutting dosage, assure the treatment quality of the spare parts and treatment efficiency thereby, produce the advantage of numerical control machine tool adequately, raise the economic benefits of the enterprise and manufacturing level.