The treatment means of the goods such as electrode of black lead mould, black lead basically is given priority to with turning, milling, bore, and black lead product is simple firm and fragile, if,be in in treatment process cutting tool (PCD cutting tool) the choice is incorrect, produce collapse caustic phenomenon very easily, the author joins real case today, how should the PCD cutting tool that will machine black lead a little choose ~
One, the cutting tool material that processes black lead product chooses character
Cutting tool material is the prime factor that decides function of cutting tool cutting character, to machining efficiency, treatment quality, finished cost and cutting tool durability have very big effect. But because black lead makes character firm and fragile, so cutting cutting tool needs to have tall hardness and tall wearability, enough strength and concussion tenacity, the function such as good machinability, commonly used cutting tool material is at present qualitative main with diamond (PCD) give priority to.
Diamond (PCD) cutting tool has a lot of kinds of structures, be like PCD milling cutter, PCD reamer, PCD broach, PCD lathe tool, cutting tool of CVD diamond coating, but in domain of black lead goods, basically give priority to with PCD lathe tool and diamond coating milling cutter, at present commonly used PCD lathe tool has CDW302 material to pledge with CDW010 material pledges, treatment efficiency is tall, milling cutter of CVD diamond coating with HPD black lead special milling cutter is given priority to.
Diamond (PCD) cutting tool graphic representation
2, the cutting parameter choice of cutting tool of black lead treatment
Parameter of so called cutting is cutting speed, feed and deepness of penetration of a cutting tool 3 element, in machining black lead process, the basis controls cutting 3 element, will assure black lead mould / the requirement of efficient high accuracy of the goods such as black lead electrode.
High rotate speed is used in machining black lead process (cutting speed Vc) , fast feed (feed Fr) , small cut deep (Ap of deepness of penetration of a cutting tool) undertake machining, limits of specific cutting parameter expresses as follows:
Black lead machines the cutting parameter choice of diamond cutting tool
3, the geometrical angle choice of cutting tool of black lead treatment
Choose proper geometrical point of view, machine the can reduce cutting tool effectively vibration when black lead goods, conversely, not easy also collapse is short of black lead workpiece.
Hind horn: If hind horny accretion, criterion intensity of cutting tool point is reduced, knife face wears away after the area increases gradually. After the part after cutting tool is too large, cutting vibration is strengthened.
Before horn: Use the part before losing (6-10 ° ) mould of treatment black lead / when the goods such as black lead electrode, strength of cutting tool point is better, impulse withstand as good as the function of attrition.
Helix angle: When helix angle is lesser, the knife that black lead work cuts at the same time on same cutting blade is long, cutting resistance is great, wallop of cutting of cutting tool susceptive is big, consequently cutting tool wears away, milling force and cutting vibration are very big when helix angle is bigger, the rate of the surface of directional deviate workpiece of milling join forces is old, the cutting that graphite material causes because of collapse caustic pounds aggravate, consequently cutting tool wears away, milling force and cutting vibration also increase somewhat.
Check through having much science to the fabricating characteristics of graphite material, milling cutter of HPD black lead and CDW302/CDW010 material pledge PCD car razor blade optimized the geometrical angle of relevant cutting tool, make thereby the integral cutting function of cutting tool rises greatly.
4, the coating choice of cutting tool of black lead treatment
Cutting tool of treatment black lead should choose diamond coating, milling cutter of HPD black lead uses brand-new coating technology, advanced coating aftertreatment technology, make its and matrix union more close together, wear-resisting function, fight oxidation function and lubricant function exceedingly good, attrition force is smaller, treatment surface quality more actor, it is the good choice of cutting tool of black lead treatment, also can reflect the performance characteristics with black lead advantageous cutting tool.
Wear-resisting of benefit of blade of mill of HPD black lead, reduce the number that change a knife, can raise close 10-20 service life of times cutting tool; Point course is special optimize, reduce cutting resistance effectively, efficiency is taller; Can compare tall 2-3 of hard alloy cutting tool in cutting speed at the same time efficient treatment has to black lead goods below the circumstance of times, the treatment of big batch of contented machining center, efficient, high accuracy asks.
Black lead machines graphic representation of diamond coating cutting tool
5, the point aggrandizement of cutting tool of black lead treatment
Technology of passivation of cutting tool point is one still is not taken seriously generally by people, and it is very serious problem. The point of hard alloy cutting tool after blade of diamond emery wheel is ground, the microcosmic breach with existence different level (namely tiny collapse blade and curium buccal) . Cutting of black lead high speed machined cutting tool function and stability to raise taller requirement, especially diamond coating cutting tool must be handled through the passivation of blade before coating, ability assures the firm sex of coating and service life.
6, the plan of electrode of black lead of treatment of milling cutter of HPD black lead
Be in when black lead electrode EDM (electric spark is machined) when, have two or two above direction has electric effect to be stereo electrode namely at the same time. Following plan institute show: 5 faces when stereo electrode EDM have discharge effect at the same time, the electrode of this type does not come out from treatment of a direction, need to be machined from a few direction commonly (namely many treatment) , EROWA clamping apparatus is used as far as possible when treatment in order to assure precision, treatment also goes to the lavatory in the meantime, the treatment method of stereo electrode introduces below:
Leave from end face whole with φ 12R0.5 first thick, give 3R0.3 of Φ of electrode base → 2 times to fly thick small chamfer and ball of 10R5 of indentation → Φ solely end face of with nothing left of head milling cutter and mill of 10R0.5 essence of Φ of → of side of bag of essence of life average a copy, below side of bag of essence of life 5mm (the round horn R5 that knife of cut away ball leaves) knife of ball of → Φ 2R1 and φ 1R0.1 part clear round part and interest part (only smooth end face and approach end face part) part to be machined from 4 flank after → , the 1R0.1 that use φ and Qing Dynasty of milling cutter of head of φ 1R0.5 ball give side all round horn and interest part.
Milling cutter of HPD black lead processes work of black lead electrode
7, the norms model with commonly used milling cutter of HPD black lead
The norms model with commonly used milling cutter of diamond of HPD of black lead milling
Above is the author machines black lead goods to use diamond about milling (PCD) the alternative with cutting tool simple material, and treatment parameter analysis, if you also concern the issue of and so on of the milling that waits for goods at black lead electrode, mould, bore, can communicate together, discuss oh ~