The treatment craft of aperture of large surplus semifinished product and cutting tool are designed

5. Workpiece Kong Weizhu builds bottom outlet, workpiece material ZG270-500, hardness > HB143. Decide 5mm of unilateral mental allowance formerly, and differ actually as a result of semifinished product quality, cast aperture prejudicial and serious, mental allowance is extremely inhomogenous, unilateral surplus most greatly 9mm, the smallest for 1mm) , the treatment that gives fixed position opening brings very great difficulty, treatment percent defective is taller. We are passed " body of around axle housing machines technical reformation of lathe of boring of aperture of two upright fixed position " the project undertook tackling key problem to this, machine the contrast of plan through differring, the choice gets reaming technology and designed special reamer, solved the treatment difficult problem of this large surplus aperture. 2 bore hole craft asks according to the treatment of workpiece, can choose plan of 3 kinds of boring. In the arrangement on lever of a boring thick, essence cuts boring cutter to partake the excision of surplus, wine cup pours again after boring hole. To do not affect manufacturing metre, two thick, essence cut boring cutter to need to work at the same time. Because bore diameter has Ø60mm only, hole depth 65mm, because this boring shank diameter is the biggest,do not exceed Ø46mm, the largest sectional size is boring cutter lever 14 × 14mm, impaction bolt is the biggest the diameter is M8. Because be,on boring lever bore reachs tap, weakened the tigidity of boring lever and intensity further. And of boring surplus inhomogenous distributing make cutting power very great, two boring cutter work at the same time make machine tool power insufficient, because this wants inevitably to cause cutting vibration, cannot satisfy workpiece to machine precision and requirement of exterior surface roughness. In the arrangement on lever of same root boring thick, essence cuts boring cutter to partake the purify of surplus: With the first boring cutter first boring goes the surplus of 5 ～ 6mm, boring of the 2nd boring cutter goes to reoccupy odd surplus, pour wine cup with what pour horny knife to machine 30 ° of 4 × finally, but among them two any knives must not work at the same time. Although can reduce cutting force,adopt this plan, but boring lever length increased double, cause boring lever tigidity to be not worth; At the same time odd treatment man-hour also increased one times, guarantee against manufacturing metre. Arrange two machine tools, increase boring machine of a half essence to partake namely the finish machining of surplus. Although this plan can solve a problem, but workpiece finished cost is too high. In addition, because workpiece is cast steel, its cut bits to show consecutive record, because this machines the platoon in the process,bits also is a very serious problem. And use bore hole craft, the space between boring lever and workpiece hole wall is very little, bits is cut when be machined on horizontal boring machine easy jam around blade of boring cutter cutting, often appear so the phenomenon that hit a knife. When cutting, 3 reaming craft is being gotten as a result of reamer is 4 tine attend cutting at the same time, its cutting force can be balanced each other in cutting process, below identical cutting feed, reamer 1/4 the cutting surplus of every tine is boring cutter, every age cutting bear is reduced greatly; The integral tigidity of reamer is ambitious at boring cutter, the durability of cutting tool also rises greatly; In addition, reamer contains helix chamfer, have the enough space that hold bit, bits is cut in machining a process eduction of chamfer of helix of can successful edge, can satisfy workpiece to machine precision and requirement of exterior surface roughness. Accordingly, below identical mental allowance, the tigidity that wants a machine tool only has assure, use the efficiency that the efficiency far outclass of reaming craft bores hole. The structural characteristic reamer of reamer design reamer has whole, set a variety of forms such as tine, suit, answer to undertake choosing according to different use situation. Be aimed at the treatment condition of this workpiece, we choose suit type reamer, cutting tool uses impaction of bolt of a M16. This cutting tool has the following advantage: Cutting tool can bear bigger cutting load. Suit reamer uses core axis centering, bear by end panel cutting load, key delivers torque, because this is in,cutting tool won't appear to skid below cutting load greatly relatively phenomenon. Cutting tool length is small, weight is light, make handy. Cutting tool is adjusted easily, assemble and unassemble convenient. The cutting parameter of reamer chooses to consider cast aperture is prejudicial and serious, its unilateral mental allowance is more than the mental allowance that craft asks, because this chooses the lathe tool bit with bit old width, leave on reamer end panel end panel blade and cutting pour horny blade. Blade pouring wine cup has main cutting effect, cut major surplus; End panel blade has auxiliary cutting effect, partake aperture is prejudicial the surplus that create (the biggest amount to 9mm) . As a result of advocate the metropolis influence such as dimension of chamfer of bits of look of the geometrical parameter of cutting blade, cutter hub is machined the precision of aperture and exterior quality, accordingly Ying Shen chooses again. Tool cutting edge angle. Advocate cutting blade slants part should be decided according to the cutting function of workpiece. Advocate cutting blade slants horny size, not only the ply that affects cut, also affect the linearity of the cutting stability when reaming and aperture. Increase advocate cutting blade slants horn, make the linearity of aperture ameliorates, have corrective effect to the linearity of prefab aperture, but as advocate cutting blade slants horny accretion, cutting ply increases subsequently, the oriented sex when cutting blade enters hole and stability will become poor. So, use commonly when reaming bigger advocate cutting blade slants horn. Horn is casting pig as a result of workpiece material before, cutting tool takes the part before 0 ° , facilitate cutting tool is made already, the appearance that can enhance cutting blade tigidity and cutting blade again heats up function, can improve cutting tool life significantly. Hind of horny cutting tool hind horn basically should satisfy face of the knife after reducing and the requirement that already machined exterior attrition. Take the part after 12 ° , what can assure cutting blade already is sharp, the intensity that can satisfy cutting blade again asks. Helix angle and look bits chamfer for corrective and prefab aperture not accuracy in order to get accurate aperture, the helix angle of reamer cannot too big, take 10 ° . Considering look bits and the need that discharge bits, on broach besides leave outside having helix chamfer, still leave on cutting tool end panel have horny blade to allow bits chamfer and end panel blade to allow bits chamfer, in order to assure the enough space that hold bit, avoid to jam because of cutting bits and hit a knife. The choice cutting dosage of cutting dosage machines quality of durability of efficiency, cutting tool, treatment to be able to produce an effect to cutting. Classics spot is debugged, decide rotate speed N=200r /min; Cutting deepness Ap decides according to mental allowance, the demand goes a knife to excise overall surplus, choose Ap=9mm according to the largest unilateral surplus; Because workpiece bottom outlet is,cast aperture, crusty, clip is arenaceous wait for blemish, workpiece mental allowance is big at the same time and surplus is inhomogenous, to reduce concussion and thermal stress, choose inferior cutting career, take V=37.

5m/min; The element such as tigidity of diameter of integrated workpiece material, workpiece, cutting tool, choose feed F=0 according to experience.

4mm/r. In machining the effect to machine the experiment of afore-mentioned workpiece in choice reaming craft, because technology program choice is right, in workpiece in debugging cutting, the machine tool moves smooth, avoided main shaft completely shake, make the existing tigidity of the machine tool and intensity completely contented the treatment craft requirement of workpiece. Although cast aperture to slant,Kong Yan is weighed, but reamer cutting is light, the eduction that cut bits is fluent, the treatment surface surface roughness of aperture and precision all achieve a requirement, and quality of the product in using all the time very stable, the machine tool debugs check to receive a success, achieve expectant result completely. CNC Milling CNC Machining