Cutting tool breaks the case study with fluky bits and means of settlement
- source:NEWRGY CNC Machining
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7) B, b is the width of bits chamfer. 2, linear model the chamfer that break bits (5b seeing a picture) intersect point-blank by two paragraphs and become, horn of its bottom land is 180 ° - σ (σ calls part of bits stage wedge) , bottom land horn (180 ° - σ ) the action that replaced circular arc Rn. Bottom land part is small, the curly radius that cuts bits is small, cut bits to be out of shape big; Bottom land part is large, the curly radius that cuts bits is big (see a picture 7) cut bits to be out of shape small. In medium cut fall greatly, horn of wedge of the stage that break bits chooses 60 ° ～ commonly 70 ° . Two kinds of afore-mentioned appearance break bits chamfer to apply to treatment carbon steel and alloy structure steel, general before horn is in γ . Inside 5-15 ° limits. The 3, complete circular arc chamfer that break bits (5c seeing a picture) γ of the horn before Rn of radius of circular arc of wide B of main parameter chamfer, bottom land is mixed. The relation between is: (when seeing graph 5C) wait for tall plasticity material when cutting red copper, stainless steel, often choose the complete circular arc chamfer that break bits. Because process tall plasticity data when, the horn before cutting tool is chosen more greatly (γ 0=25 ° - 30 ° ) likewise big before horn, the cutting blade that complete circular arc breaks bits chamfer cutting tool is solidder, groove is additionally more shallow also, facilitate shed bits, on purpose is more practical (8) seeing a picture (2) the width of the chamfer that break bits breaks Ap of deepness of B of bits chamfer width and feed F, cutting to concern, when feed F increases, cutting ply increases, break the width of bits chamfer to answer corresponding broaden; Cutting deepness is big, groove also answer proper broaden. Changeless, the change of B of width of the chamfer that break bits is curly to cutting bits affect with metabolic. Graph 9a is groove wide suit basically with feed, the classics that cut bits is curly the collision after be out of shape breaks off C form; Graph 9b is groove not quite wide, cut bits curly radius is small, be out of shape big, short C breaks off after collision form or form collapse broken flake; Graph 9c is groove too narrow, it is very difficult in groove to cut bits to squeeze Cheng Xiaojuan to jam flow, cause hold back bits to be met even batter cutting blade; Graph 9d, E is groove too wide, cut bits curly radius is too big, be out of shape insufficient. Break off not easily. Do not shed classics bottom land even sometimes and form freely banding bits. If use feed primary election to break the width of bits chamfer, say roughly, to cutting medium carbon steel, the relation of width B and feed F is B=10f about; And when cutting alloy steel, cut bits to be out of shape to increase, desirable B ＝ 7f. The width B of the chamfer that break bits also should suit with photograph of cutting deepness Ap. Choose groovy wide B roughly commonly according to Ap, when Ap is big, b also ought to somes big; And Ap is small, criterion B should be reduced appropriately. Because should be cut deep when big and groove is too narrow, cut bits wide, it is not easy in groove curly, such, cut bits often does not flow into bottom land and form by oneself banding bits; Should cut deep when small and groove is too wide, cut bits narrow, flow is freer, be out of shape not quite sufficient, break off not easily also. (3) the chamfer that break bits and advocate the banking angle of cutting blade breaks bits groove and advocate of cutting blade tilt the outside having inclined with commonly used means, parallel form, and inside inclined 3 kinds (the inclined outside 10) 1 seeing a picture sees a picture (10a) , outside the chamfer breaking bits of inclined, before wide hind narrow, before deep hind shallow. Inclined breaks bits chamfer outside cut bits curly be out of shape big, if the graph is shown 11 times, the cutting rate that A of round outside approaching work face manages is top and groove is narrow, cut bits most first suffocate suffocate and curly, and curly radius is small, be out of shape big; And be in in B of point of a knife, cutting rate is low and groove is wide, cut bits finally with bigger curly radius curly, this can produce a power, on face of the knife after making cut bits to retroflexion or work surface, via break off after collision and forming C form bits. The chamfer breaking bits of this kind of form. In medium cut deep when the range that break bits is wider, the effect that break bits is stable and reliable, the application in production is relatively wide. The numerical value of banking angle τ basically decides by workpiece material, when general cutting medium carbon steel, ° of =8 extraction τ - when alloy steel of 10 ° cutting, cut bits to be out of shape to increase, take τ =10 ° - 15 ° . But cutting greatly deep when, because stand by A of surface of the circle outside workpiece to be in (11 seeing a picture) width of the chamfer that break bits is too small, cut bits easy block, cut blade of bits batter cutting even, convert more commonly so parallel form. 2, parallel form (L0b) seeing a picture: Parallel form breaks bits chamfer cut bits to be out of shape the inclined outside be inferior to is big, cutting bits is to touch mostly machine in workpiece apparently break off. When the medium carbon steel that cut bits, the result breaking bits that parallel form breaks bits chamfer and outside inclined is basic similar, but feed should be increased slightly a few, what cut bits in order to increase is add and curly be out of shape. 3, inside inclined (10c seeing a picture) : Inclined breaks bits chamfer inside (12 seeing a picture) place of A of round outside workpiece face is the widest. And be in in B of point of a knife the narrowest. Cut bits to often be in in B so first curly Cheng Xiaojuan, and in A place criterion roll into coils greatly. When advocate the blade dip of cutting blade takes 3 ° - when 5 ° , cut bits to form successive length easily to tighten a bits. Inclined breaks bits inside groove and advocate the banking angle of cutting blade takes τ =8 ° commonly - 10 ° , inclined breaks bits chamfer form to grow to coil closely inside the cutting dosage of bits range is quite narrow, so its aborning uses the inclined outside be inferior to and parallel formula general, basically be to apply at fine vehicle or half fine vehicle. 4, a few kinds of commonly used methods that break bits (one) use bits chamfer: The place before be like is narrated, the chamfer that break bits has add metabolic effect to cutting bits not only. And what still can realize control to cut bits is curly with break off. The form that wants bits chamfer only, dimension and the chamfer that break bits and advocate the banking angle of cutting blade is appropriate, breaking bits is reliable. It is to solder no matter type cutting tool or cutting tool of machine clip type, it is to grind type cutting tool to still do not weigh the cutting tool that wear type to be able to be used again. For applicable and different cutting dosage limits. Hard alloy can squelch on dislocation razor blade the chamfer breaking bits that has a variety of appearance and different measure, facilitate choose, such already economy handy. This kind of method is the method that first selection answers in cutting treatment, also be the method with the widest application. Insufficient place is cutting tool reasonable geometry parameter is decided really, those who get bits asks is diversionary (2) use bit implement break bits implement have stationary and adjustable type two kinds. Graph the 13 adjustable type that go up for lathe tool break bits implement. Before lathe tool knife cover jacket blocks bits board 1, when be being poured out of before cutting tool of the edge that cut bits, because suffer,block bits board a block and the turn is broken zigzag. Break bits implement parameter Ln and α can be designed by need and adjust, be in in order to assure given below cutting condition, the stability that break bits is reliable. Loose bolt 3, in bedspring the action of 4 falls, can make block bits board 1 with pressing plate 2 raise together, facilitate block bits board to adjust the fast dislocation with bit and change. This kind breaks bits implement commonly used go up at the cutting tool of big, medium-sized machine tool. (3) , use bit unit to snap bit unit type a lot of, can divide commonly for mechanical, fluid pressure type and electric type, cost of the plant that break bits is high, but breaking bits is stable and reliable, use on transfer matic only commonly. Graph the sketch map of 14 the device that break bits that contain amputator to use those who go up at lathe tool. When turning, cut bits to pass guide bits passageway 2 pour out of, dish of form amputator that is rotated ceaselessly 3 cut off forcibly, after be being cut off cut bits to from platoon bits 6 eduction. Amputator is by transmission shaft 4 drive. In the graph 1 for lathe tool. (4) use in workpiece the apparently method that opens slot beforehand: Differ by workpiece diameter size, be being machined beforehand apparently edge workpiece axial leaves to give or count a groove, its deepness is less than cutting deepness slightly, those who make be cut cut bits to form weakness sectional, break off thereby. Such, assured to break bits reliably already, do not affect workpiece to already machined exterior surface roughness again. Although machine tenacity when older stuff, the effect that break bits is very good also. Be in for example the workpiece stuff with older tenacity of boring of essence of life (wait like 40Cr) when, when breaking bits very hard with other method, can be being machined apparently broaching gives fore-and-aft groove, undertake boring again. Use this kind of method to be able to show its distinct advantage. (5) parameter of geometry of change cutting tool and adjust cutting dosage by in front what narrate cut bits to break off the principle is knowable, reduce the role before cutting tool; Increase tool cutting edge angle; In advocate grind on cutting blade piece lose edge; Lower cutting rate; Increase feed and change advocate cutting blade appearance can make cut bits to break off. But, adopt these methods to break bits, regular meeting brings a few undesirable consequence, if productivity drops, force of aggravation of workpiece surface quality, cutting increases etc, this kind of method, use rarely on transfer matic, serve as the auxiliary method of bits only sometimes. In addition, use cutting fluid to be able to reduce the plasticity that cuts bits and tenacity, also be helpful for breaking bits. Raise force of cutting hydraulic pressure to be able to be made more cut bits to break off, in aperture treatment, use this kind of method sometimes. CNC Milling CNC Machining