The car cuts basic knowledge

High-speed steel high-speed steel weighs high speed steel again, it is the steel of tall alloy tool that is main alloying element with tungsten, chromic, vanadium, molybdenum. The hardness after high-speed steel quenchs is HRC63 ～ 67, its are red hard temperature 600 ℃ of 550 ℃ ～ , permission cutting rate is 25 ～ 30m/min. High-speed steel has higher bending strength and concussion tenacity, can undertake casting, forging, solder, heat treatment and cutting treatment, have good grinding performance, blade grinds quality taller, reason is multi-purpose will make the cutting tool with complex form, wait like broach, reamer, milling cutter, often also use as lathe tool of low speed finish machining and figuration lathe tool. Commonly used high-speed steel brand is W18Cr4V and W6Mo5Cr4V2 two kinds. 2.

Hard alloy hard alloy is the WC that uses tall wearability and tall hear resistance (carbonization tungsten) , TiC (carbonization titanium) with Co (cobaltic) agglomeration of high temperature of travel of the reentry after figuration of pulverous classics high pressure and make, among them action of the felt since Co, the hardness of hard alloy is HRA89 ～ 94 (be equivalent to HRC74 ～ about 82) , have very high red hard temperature. In 800 ～ the high temperature of 1000 ℃ falls to still can maintain the hardness that cutting place needs, cutting of hard alloy cutting tool is general steel cutting speed can amount to 100 ～ 300m/min, can undertake high speed cutting with this kind of cutting tool, its defect is tenacity poorer, more fragile, not impulse withstand, hard alloy makes the bit of all sorts of appearance commonly, solder or place solid to be used on cutter hub. Commonly used hard alloy has tungsten cobalt and tungsten titanium cobalt two kinds big: (1) tungsten is cobaltic kind (YG) comprise by carbonization tungsten and cobalt, apply to treatment the brittleness material such as cast-iron, bronze. Commonly used brand has YG3, YG6, YG8 to wait, the number from the back expresses to contain the per cent of cobaltic quantity, the quantity that contain cobalt heals tall, its bear percussive performance has healed. Accordingly, YG8 is commonly used at rough machining, YG6 and YG3 are commonly used at semifinishing machining and finish machining. (2) tungsten titanium is cobaltic kind (YT) comprise by titanium of carbonization tungsten, carbonization and cobalt, join carbonization titanium to be able to increase the wearability of alloy, can raise the sticking temperature of alloy and plasticity material, reduce cutting tool to wear away, also can raise hardness; Dan Ren sex is poor, more fragile, bear percussive performance is poorer also, use treatment plasticity data commonly, be like all sorts of rolled steel. Commonly used brand has YT5, YT15, YT30 to wait, the number is the percentage of carbonization titanium content from the back, the content of carbonization titanium heals tall, red rigid has healed; But cobaltic content heals accordingly low, tenacity is differred more, more not impulse withstand, YT5 is so commonly used at rough machining, YT15 and YT30 are commonly used at semifinishing machining and finish machining. 2, the composition of lathe tool and configuration 1.

The compositive lathe tool of lathe tool is mixed by knife head two parts form cutter hub. Knife head is used at cutting, cutter hub is used at installation. Knife head is general by 3, two blade, one needle is comprised. Knife face is the surface that cuts bits to shed a course before. Advocate hind knife face is as opposite as workpiece cutting surface surface. Deputy hind knife face is already machined the surface with opposite surface with workpiece. Advocate cutting blade is before knife face and advocate hind of knife face cross a line, load main cutting job. Deputy cutting blade is before knife face and deputy hind of knife face cross a line, load a few cutting works, have the certain effect that repair light. Point of a knife is advocate of cutting blade and deputy cutting blade intersect part, transfer for a paragraph small commonly circular arc. 2.

The lathe tool configuration with the most commonly used configuration of lathe tool has the following two kinds: (1) the cutting part of head of knife of integral lathe tool is to rely on blade to grind those who get, the material of integral lathe tool is multi-purpose high-speed steel is made, use at low speed cutting commonly. (2) solder lathe tool is in solder of hard alloy razor blade knife head place, the lathe tool of different sort can use the bit of different figure. Soldering hard alloy lathe tool, can use at high speed cutting. 3, the horn before the main angle of the main angle of lathe tool and its action lathe tool has (γ 0) , hind horn (α 0) , chief editor horn (Kr) , deputy slant horn (Kr ' ) with blade dip (λ S) . To define the point of view of lathe tool, want to build 3 coordinate plane: Tool cutting edge plane, tool reference plane and advocate section plane. To turning character, if take no account of lathe tool installation and the influence that cutting moves, tool cutting edge plane can consider as lead vertical plane; Tool reference plane is horizontal; When advocate when cutting blade level, perpendicular at advocate the section plane that cutting blade place makes gives priority to section plane. (1) before horny γ 0 in advocate measure in section plane, be before the included angle between knife face and tool reference plane. Its action is to make the crucial point sharp, facilitating cutting. But before horn cannot too big, can weaken the intensity of edge otherwise, wear away easily to molder even. When processing plasticity data, before horn is somes big more optional, if use steel of cutting of hard alloy lathe tool desirable γ 0=10 ～ 20, process brittleness data, of lathe tool before horny γ 0 should compare rough machining big, with benefit at edge sharp, the surface roughness of workpiece is small. (2) hind horny α 0 in advocate measure in section plane, be advocate from the back with the included angle between tool cutting edge plane. Its action is when reducing turning advocate from the back the attrition with workpiece, 12 ° of ～ of general 0=6 extraction α , small cost is taken when thick car, big cost is taken when fine vehicle. (3) Kr of tool cutting edge angle is measured in tool reference plane, it is advocate cutting blade is in of tool reference plane umbriferous the included angle with feed direction. Its action is: 1) changeable advocate the length that cutting blade attends cutting, affect cutting tool life. 2) the size that affects radial cutting force. Small tool cutting edge angle can increase advocate the length that cutting blade attends cutting, come loose consequently heat is better, advantageous to prolonging cutting tool service life. But when processing long and thin rod, workpiece stiffness is insufficient, small tool cutting edge angle can make cutting tool action increases in the radial load on workpiece, easy generation bends and oscillatory, accordingly, tool cutting edge angle should choose a little bit big. The tool cutting edge angle with commonly used lathe tool has 45 ° , 60 ° , 75 ° , 90 ° to wait for a few kinds, among them 45 ° are much. (4) deputy slant horny Kr ' measure in tool reference plane, it is deputy cutting blade what go up in tool reference plane is umbriferous the included angle that returns way with feed. Its main effect is to reduce deputy cutting blade and already machined the attrition between the surface, the coarse of essence of life that already machined the surface in order to improve is spent. In Kr of F of cutting deepness Ap, feed, tool cutting edge angle equal condition falls, reduce deputy slant horny Kr ' , can reduce the rudimental area after turning, reduce exterior surface roughness thereby, choose ～ of Kr ′ =5 commonly 15 ° . (5) blade dip enters λ S to be measured in tool cutting edge plane, be advocate the included angle of cutting blade and tool reference plane. Its action basically is the way of going from place to place that control cuts bits. Advocate cutting blade and parallel of tool reference plane, λ S=0; point of a knife is in advocate the nadir of cutting blade, λ S is negative worth, intensity of point of a knife increases, the flow direction that cut bits already machined the surface, use at rough machining; Point of a knife is in advocate the apogee of cutting blade, λ S is be worth, intensity of point of a knife is weakened, cut bits to flow to work surface, use at finish machining. S of λ of dip of lathe tool blade, be in commonly - choose between 5-+5 ° . 4, the blade of lathe tool grinds lathe tool to use blunt hind, must blade is ground, so that restore its reasonable appearance and angle. Lathe tool is ground in the blade on grinder commonly. Grind high-speed steel lathe tool to use white alumina emery wheel, grind hard alloy lathe tool to use green carborundum emery wheel. When lathe tool is ground again, often the wear out condition according to lathe tool, the knife face that grinding concerns can. The average order that lathe tool blade grinds is: → of face of the knife after grinding is ground deputy hind → of face of the knife before knife face → is ground grinds circular arc of point of a knife. After lathe tool blade is ground, still apply oilstone fine wear each knife faces. Such, can raise the service life of lathe tool and the surface roughness that reduce workpiece surface effectively. The following item should notice when blade grinds lathe tool: (1) when blade is ground, two tactics grasps firm lathe tool, arbor leans at bracket, make aspect getting blown away by wind sticks emery wheel gently. Do not have exerted oneself to do sth. fierce, lest squeeze broken emery wheel, cause an accident. (2) the lathe tool that should grind blade is in emery wheel controls shift on circumferential face, make emery wheel wear and tear even, do not give groove. Avoid in emery wheel two flank exert oneself to do sth. kibble lathe tool, down to emery wheel suffers force to slant place, jumpy, broken even. (3) when knife head grinds heat, should touch water to cool namely, lest knife head because temperature rise is exorbitant and anneal bate. When grinding hard alloy lathe tool, knife head should not touch water, avoid bit to touch water urgent cold and generation crackle. (4) the openly blade that does not stand in emery wheel grinds lathe tool, make handlers gets hurt when emery wheel is broken in case. CNC Milling CNC Machining