But blade of dislocation circular arc carries milling cutter to process medium application in frog of tall manganese steel
- source:COCKRIEL CNC Machining
Tall manganese steel of of of character of tall manganese steel is the wear-resisting steel that a kind of single-phase austenite organizes. Classics water pliable but strong is handled (1100 ℃ of 1000 ～ heat the heat treatment means with the cooling water after heat preservation) tall manganese steel has effect of remarkable treatment sclerosis, pound action to fall in tall outside force namely, hardness of its job surface by 170 ～ 220 HB W increases above of 450 ～ 550 HBW, core still maintains extremely tall tenacity, obtain consequently very tall fight bad news of concussion, wear-resisting and the function that fight crackle to expand. <script Src="/ads/js/201.
Frog of tall manganese steel of whole casting of Js"></script> railroad switch (: of the following abbreviation? Guo Tan eventually Yi? uses afore-mentioned characteristic production to make namely. Have integral sex good, wearability strong, on the safe side, low, conserve maintains cost convenient wait for an advantage. Of material of tall manganese steel use the hardness that raised a part, intensity and service life to wait, this is advantageous one side. But because its oneself machines sclerotic and serious, coefficient of thermal conductivity temperature of small, cutting tall, tenacity is tall, outspread lead coefficient of the big, difficulty that break bits, linear expansion the physical function such as muscularity of big, cutting, machine sclerotic phenomenon especially, brought very great difficulty to machining of tall manganese steel. With differentiating on the difficult easy degree that material of spare parts purify machines, tall manganese steel belongs to difficult treatment material. 2.
Frog of tall manganese steel machines of cutting tool to carry the development that faces direction of high speed, burden as railroad, taller and taller also to the requirement of quality of facility for transporting. Frog of tall manganese steel is the equipment crossing path that makes the wheel of engine car crosses another rail by a rail, it is component of key of railroad switch equipment, material is qualitative: ZGMn13, workpiece length is in commonly 4 ～ 6m, ply is in commonly 140 ～ 180 Mm, width is commonly inside limits of 350 ～ 500 Mm. Machining of frog of tall manganese steel, basically be planar treatment. Cutting means is Duan Xi. Cutting tool chooses hard metal commonly but dislocation carries milling cutter. Because be cast of tall manganese steel, together with workpiece is long and thin, be out of shape in treatment bigger, have certain treatment difficulty. My factory begins the history that machining of frog of tall manganese steel already had more than 10 years, accumulated certain experience. Come for years, cutting tool material is machined to go up in frog of tall manganese steel, what we use is bit brand is 767 hard alloy. Cutting tool configuration basically uses wedge piece clamp, type of annulus of axial fixed position. Clamp of this kind of structure is convenient and reliable, fixed position precision is tall. Want to locate component and bit geometry dimension have taller production precision only, can make sure cutting tool has taller fixed position precision, when cutting power is too great, limitative razor blade and razor blade edge axial change is moved, prevent attaint cutter hub. Because milling treatment is interrupted cutting, every tooth should produce impact when cutting work, when entering work to make milling cutter is cut as far as possible, knife face and workpiece are to be in above all before be far from point of a knife and contact of cutting blade point, improve tooth to cut fashionable condition getting power thereby, raise its to fight concussion ability, protect point of a knife, reduce collapse blade, treatment of frog of tall manganese steel carries milling cutter to use forms of pair of the horn before losing, namely: ? Man and γ P all are less than 0, γ F=-5 ° , γ P=-7 ° . Home produces and abroad introduces but dislocation carries milling cutter, it is commonly quadrangular razor blade, great majority of R of κ of tool cutting edge angle is 75 ° . My factory was used in the past old, although be on product quality and manufacturing efficiency,can satisfy a requirement basically quite, but the characteristic that machines as a result of tall manganese steel, the existence of the point of a knife of blade of square razor blade, straight cutting and edges and corners, the knife is hit in production collapse blade phenomenon is relatively serious, wastage of mat of bit, knife, cutter hub is big, cost is exorbitant. In recent years, we change square razor blade to be round razor blade, will but milling cutter of blade of dislocation circular arc introduces in treatment of frog of tall manganese steel, because cutting point is circular arc shape, without fragile point of a knife and edges and corners, nonexistent weak area, can die without point of a knife in cutting process so. Moreover, in cutting process, changed excision figure not only, and the R of κ of tool cutting edge angle of cutting tool also changes along with the change of cutting deepness, improved treatment condition. The course experiments and use a proof, change straight cutting blade to machine frog of tall manganese steel for blade of circular arc cutting, avoiding collapse where a thing can be put to best use, increase cut reach feed greatly, increase production efficiency, reduced the respect such as cost to obtain apparent effect. Should point out, the form that changes cutting point is a kind of when overcome blade of collapse of hard alloy razor blade relatively efficient way. But milling cutter of end panel of blade of dislocation circular arc is basic the structure is shown 1 times like the graph. 3.
The main characteristic of milling cutter of end panel of circular arc blade and of of of milling experiment analysis (tool cutting edge angle of milling cutter of end panel of blade of 1) circular arc the characteristic tool cutting edge angle of κ R is cutting tool one of important angle. Its size, affect the figure of cut on one hand, on the other hand immediate impact participates in the bear of cutting blade length of the job and unit cutting blade at the same time, affect cutting tool directly namely wear away and life. When quantity of back penetration of a cutting tool and feed are certain, angle of change tool cutting edge angle can make cut bits to attenuate or thickening, the influence comes loose the change of hot circumstance and cutting force. That is to say, the change of size of R of κ of tool cutting edge angle, the collapse blade that affects cutting tool directly and hit a knife. General tool cutting edge angle of milling cutter of straight blade end panel is calm value, great majority is κ R=75 ° , r of κ of tool cutting edge angle is worth certain end panel milling cutter, how does no matter carry penetration of a cutting tool on the back,the quantity change in milling process, r of κ of tool cutting edge angle is basic won't change. <script Src="/ads/js/201.
Js"></script> and the R of κ of tool cutting edge angle of cutting tool of circular arc blade criterion otherwise, its size changes along with what bear amount of penetration of a cutting tool and change. With 16mm circle bit is exemple, like: ? Make a noise when the predestined relationship reads class?mm, r of κ of tool cutting edge angle is 30 ° , when quantity of back penetration of a cutting tool is 2 Mm, r of κ of tool cutting edge angle is 20 ° 17 ″ of 42 ′ , when quantity of back penetration of a cutting tool is 1mm, r of κ of tool cutting edge angle is 14 ° 39 ″ of 28 ′ . (2) but is the analytic cutting force of force of cutting of milling cutter of end panel of blade of dislocation circular arc basically to point to: ? The change that P0; of PV of component of force of P H of component of force of Z of of condyle of a surname Xing, fore-and-aft milling, transverse milling and axial milling component of force follows size of R of κ of tool cutting edge angle, the size of 3 cutting component of force and allocate scale to concern to also can produce change. Concerned technology data introduces, when R of κ of tool cutting edge angle is 75 ° , the milling power theory of straight edge milling cutter allocates for: , PH=(0 of fore-and-aft milling force.
3 ～ 0.
4)PZ, p V=(0 of transverse milling force.
85 ～ 0.
95)PZ, p0=(0 of axial milling force.
5 ～ 0.
55)PZ. Pass milling experiment actual measurement, can is the allocation of force of milling of milling cutter of end panel of blade of dislocation circular arc: basically? H=(0 of of Zu Si sincere condyle.
33 ～ 0.
37)PZ, PV=(0 of transverse milling force.
45 ～ 0.
53)PZ, axial milling force is P0=(0.
78 ～ 0.
84)PZ(sees graph 2) . Test specimen material: ZGMn13, =160mm of milling cutter diameter, z=10, γ F=-5 ° , λ P=-7 ° , bit brand: 767. Cutting dosage: N=140r/min, v=70m/min, fn=168mm/min, fz=0.
12mm/z. Can see from inside above test data, when cutting, because knife of circular arc blade is straighter the knife of workpiece of blade knife contact is long increase (increase 40% or so) , make axial force P0 increases, and R of κ of tool cutting edge angle measures along with back penetration of a cutting tool change and change, make PV of transverse milling force drops substantially. And the size of PV of transverse milling force, it is to affect edge to cut workpiece to pound point of a knife and edge tatty fitly main factor, the ply cutting bits that cuts plus place of circular arc edge differs, improved thereby medicinal powder hot condition. The cutting area that still has circular arc bit is the round arc that does not have edges and corners without point of a knife, nonexistent weak area, this makes concussion of machinery of susceptive of the place in cutting process, thermal shock lesser, accordingly, the cutting tool life of circular arc blade can rise greatly. 4.
The when choosing milling cutting dosage of cutting dosage should the basis is pledged by treatment workpiece material, combine the integrated consideration such as the economic life of the tigidity of clamping apparatus of machine tool power, tool and cutting tool, in order to achieve first-rate economy result. Demand of precision of machining of frog of tall manganese steel is not very high, belong to rough machining. In cutting process, be out of shape as a result of plasticity and the influence of cutting force, the meeting inside certain depth range produces serious sclerotic phenomenon below cut and surface. The sclerotic layer that creates to take a knife before surface of escape semifinished product is mixed one times, amount of larger back penetration of a cutting tool and feed chose in cutting process. Straighter blade carries milling cutter, when blade of use circular arc carries milling cutter, reduce somewhat on cutting speed. With circular arc blade the knife that carry mill machines frog of tall manganese steel, quantity of general back penetration of a cutting tool takes Ap=3-5mm, feed takes Fz=0.
15mm/z, cutting speed takes V=60 ～ 80m/min. The course produces practice, integrated result is favorable. 5.
Structure of knife of Duan Xi of blade of hard alloy circular arc of epilogue is simple, accessory is little, outfit clip is convenient, precision is tall, use at treatment of frog of tall manganese steel, overcome straight blade effectively to carry milling cutter intensity low, wear away, collapse blade is serious wait for inadequacy. Compare with photograph of square razor blade, of circular razor blade but much dislocation 2 ～ 3, make full use of cutting tool material, reduce manufacturing cost thereby. Carry out a proof, blade of hard alloy circular arc the knife that carry mill is used at frog of tall manganese steel treatment is practical. CNC Milling CNC Machining