Everything cuts the source of force, cutting join forces reachs his to decompose, the join forces of the origin cutting force of force of cutting power cutting and force of cutting of research of component of force, to making clear further cutting mechanism, to computation power is used up, to the design of cutting tool, machine tool, clamping apparatus, reasonable to making cutting dosage, optimize parameter of cutting tool geometry to wait, have very important sense. When metallic cutting, cutting tool cuts work, make material happening is out of shape and be become to cut the force that bits place requires by treatment, call cutting force. Cutting force originates 3 respects: Overcome metabolic of the flexibility that be opposite by treatment material to fight force; overcomes metabolic of the plasticity that be opposite by treatment material to fight force; Opposite of face of the knife after overcomes the attrition force that cuts area of the knife before bits is right and cutting tool is crossed the surface and already machined the attrition force between the surface. The summation of afore-mentioned each force forms action to be F) in the GB of join forces Fr(on cutting tool. For actual application, fr is dissoluble it is Fp) and Fz(GB to be Fc) for GB of Ff) , Fy(for mutual and perpendicular Fx(GB 3 component of force. When turning: Fz -- cutting force or tangential force. It is cut at transferring the surface is as perpendicular as tool reference plane. Fz is intensity of computational lathe tool, design machine tool part, place of power of affirmatory machine tool is indispensible. Fx -- feed force, axial force or force taking a knife. It is to be in tool reference plane inside as parallel as workpiece axes as contrary as direction taking a knife force. Fx is to design knife orgnaization, place of power of feed of computational lathe tool is indispensible. Fy -- cut fight force greatly, or force of back force, radial load, penetration of a cutting tool. It is to be in the as perpendicular as workpiece axes force inside tool reference plane. Fy uses the workpiece deflection that concerns with workpiece treatment precision certainly, computer bed spare parts and lathe tool intensity. The vibration that it and workpiece produce in cutting process is concerned. Use up the power in cutting process to call GB of cutting power Pm(to be Po) . Cutting power is force Fz and the power the sum that Fx spends, because Fy direction does not have displacement, do not consume power so. Then Pm=(FzV+Fxnwf/1000) × 10-3 among them: Pm, cutting power (KW) ; Fz, cutting force (N) ; V, cutting speed (M/s) ; Fx, feed force (N) ; Nw, workpiece rotate speed (R/s) ; F, feed (Mm/s) . The 2nd on the right side of the equality sign in type is to consume the power in feed motion, for the power that it consumes at F place relatively, general very small (<1% ～ 2%) , can skip not plan, then Pm=FzV × 10-3 is pressed on after type gets cutting power, if want the power of computer bed electromotor (so that PE) chooses machine tool electromotor when, still should consider efficiency of machine tool drive. In type of M of η of PE ≥ Pm/ : η M, the transmission efficiency of the machine tool, take commonly for 0. 75 ～ 0.
85, great value applies to new machine tool, little value applies to old machine tool. The CAT of the measurement of 2 cutting force and cutting force is being produced actual in, the size of cutting force uses the experience formula that establishs by experimental result to calculate commonly. When the cutting power that knows in need condition of some kind of cutting falls well and truly, still need to undertake be metricaled actually. As the modernization that checks an instrument, the measurement technique of cutting force had very great progress, had measured cutting power accurately below a lot of circumstances. The measurement of cutting force became the instrument of the effective that studies cutting force. The cutting power that uses at present measures a method to basically have: Determine machine tool power, computational cutting force measures a machine tool electric machinery to be in in cutting process after the power PE that uses up with dynamometer, can press form calculation gives cutting power Pm: Pm=PE η M falls for foregone circumstance in cutting speed V, use Pm to be able to beg a cutting force F. This kind of method the size of force of cutting of can rough estimation, not quite accurate. When the size that knows cutting power accurately when the requirement, use the appearance that measure power to be measured directly normally. Using those who measure power instrument to measure cutting force to measure power instrument to measure a principle is to use cutting master piece to use what what produce on the stretch component of the appearance that measure power to be out of shape, or after the charge that action generates on piezocrystal passes changeover, numerate the value of Fz, Fx, Fy. In automation production, it is OK to still can use the signal that measures force to pass move plant to arise to optimize the working principle that presses the appearance that measure power with monitoring cutting process cent is mixed for mechanical, hydraulic pressure electric the appearance that measure power. At present commonly used is resistor meet an emergency piece type measures power appearance and press report to measure power instrument. The experience formula of 3 cutting force mixes the CAT of cutting force cutting force estimation is current, people had gathered data of much cutting force test, to machining a method commonly, if turning, aperture adds labour and milling,waited to already established the experience formula that can use directly. Commonly used experience formula can divide about it is two kinds: One kind is exponential formula, one kind is to press unit cutting force to have consideration. Carry out a proof, the influencing factor of cutting force is very much, basically cutting tool of material of parameter of geometry of dosage of workpiece material, cutting, cutting tool, cutting tool wears away condition and cutting fluid. CNC Milling
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