Cutting dosage is decided really

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  • source:MARSTEN CNC Machining
Dosage of logical choice cutting is having crucial concern to producing the optimal beneficial result of numerical control machine tool. The principle that chooses cutting dosage 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 tool manual, cutting manual, combine experience and decide. 1. Its also call cutting deepness T quantity of back penetration of a cutting tool, below the condition that allows in machine tool, workpiece and cutting tool stiffness, t 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. 2. Cutting width L calls step pitch in width of the cutting in process designing, l of general cutting width and D of cutting tool diameter become direct ratio, become inverse ratio with cutting deepness. In rough machining, step pitch is obtained be helpful for improving treatment efficiency greatly. When using flat bottom knife to undertake cutting, the extraction of general L is worth limits to be: L= (0.

6 ~ 0.

9) D. And use circle nose knife undertakes machining, cutting tool diameter should recoup the round part part of point of a knife, namely D=D-2r, (D is cutting tool diameter, r is radius of round horn of point of a knife) , and L can be obtained (0.

8 ~ 0.

9) D. And when using ball head knife to have precision work, step pitch should consider the precision that can achieve and exterior surface roughness above all surely really. 3. VC also calls cutting linear velocity quantity of odd tine cutting, the unit is M/min. Raising VC to be worth also is a when improve productivity significant step, but the relationship of VC and cutting tool durability is closer. As the accretion of VC, cutting tool durability drops quickly, the choice of reason VC basically depends on cutting tool durability. General good tool supplier is met in its the cutting rate that manual perhaps offers cutting tool in cutting tool manual recommends parameter VC. Additional, value of cutting speed VC comes according to the material hardness of workpiece even proper adjustment. Use for example when establishing milling cutter milling to add up to King Kong 30CrNi2MoVA, VC can use 8m/min left and right sides; And with when establishing aluminium alloy of milling cutter milling likewise, VC is optional 200m/min above. 4. The unit of rotate speed of main shaft of N of main shaft rotate speed is R/min, come according to cutting speed VC commonly make choice of. Computational formula is: Among them, DC is cutting tool diameter (Mm) . Should make when knife of use ball head a few adjust, the computational diameter Deff of ball head milling cutter should be less than DC of milling cutter diameter, actually border rotate speed should not press friend computation of DC of milling cutter diameter, and should calculate by computational diameter Deff. Rotate speed of common stock main shaft writes melody on the Control Panel of numerical control machine tool (fold) switch, the circumstance can be machined actually to undertake adjustment to main shaft rotate speed in the basis in machining a process. 5. Speed of feed of feed speed Vf is to show machine tool workbench is in insert a feed speed when, the unit of Vf is Mm/min. 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, but the durability of cutting tool also can be reduced. When demand of treatment surface surface roughness is low, vf can choose some more greatly. Feed speed can press face formula has consideration: Among them: Vf expresses workbench feed, the unit is Mm/min; N shows main shaft rotate speed, the unit is turn / cent; Z states cutting tool tine is counted, the unit is tine; FZ expresses feed, the unit is Mm/ tine; Fz value is offerred by tool supplier. In numerical control process designing, still should consider to choose different feed career below different situation. If be when initiative cutting feed, especially when the knife below Z axis, because undertake Duan Xi, get power bigger, consider the security issue of the program at the same time, answer so with relative to slower speed feed. The feed of direction of axis of additional explicit Z by go to high low when going, generation carries cutting, can set different feed rate. In cutting process, feed of some planar side direction, the possibility arises complete knife cutting namely the periphery of cutting tool wants cutting, cutting condition is opposite more abominable, can set inferior feed rate. 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. In actual treatment process, likelihood to each cutting dosage parameter undertakes adjustment, if use higher feed rate to undertake machining, although the life of cutting tool is reduced somewhat, but saved handling time, can have better beneficial result instead. To the change that produces ceaselessly in treatment, the cutting dosage in CNC Machining chooses to rely on the experience of process designing personnel greatly, accordingly, process designing personnel must be familiar with the affirmatory principle of the use of cutting tool and cutting dosage, accumulate experience ceaselessly, assure the treatment quality of the spare parts and efficiency thereby, produce the advantage of numerical control machine tool adequately, raise the economic benefits of the enterprise and manufacturing level. CNC Milling