Summary: With Lee Xiefu model of skid wire field is a foundation, from theoretic derivation knife, bits is close together model the computation that contacts length Ln is formulary, think knife, bits is close together model osculatory length is cutting the first, the 2nd result; that is out of shape collaboration of area put together is used experiments through cutting, discussed cutting parameter to the knife, bits is close together model the influence that contacts length; computation result and test result photograph are compared, analysed this rationality of academic formula and suitable scope. 1 foreword knife, a bits contact length is process of cutting of the influence in metallic cutting treatment main factor, the attrition condition that it reflects cutting process directly affects temperature of cutting force, cutting, cutting tool to wear away thereby, cut bits is formed and already machined exterior quality. According to a large number of research of domestic and international scholar, before the knife of knife face, bits contact area can divide for close together model contact Ou Hefeng dot contact area: Close together model osculatory warden is spent by the knife, decision of bits plasticity district; And when area of peak dot contact mirrors the tigidity that cut bits to pour out of, cut bits and before the attrition condition of knife face. As a result of at present knife, use experimental mensuration of bits contact length mostly certainly, because this is right close together model of contact and peak dot contact limit reach the correlation between both to still have an a lot of problems that did not solve, to the knife, the academic research that the computation of bits contact length and the relation between its and cutting parameter still require to have deep person. Liu Xiangdong, Zhou Zehua is written " metallic cutting knife, bits is close together model the research that spends with warden of peak dot contact " ever was opposite knife, bits is close together model, length of area of peak dot contact has made a system consider, and derivation gives a knife, bits is close together model, the peak dot theoretical calculation that contacts length is formulary, but in formula close together model the shear strength Tint that metal of bits ground floor cuts inside osculatory area cannot from theoretic get, also cannot measure, earning formula can be made with experimental result only qualitative quite with the analysis. Accordingly, although this formula has academic sense, but cannot use Yu Dao, bits is close together model, the peak dot actual computation that contacts length. Because be in actual cutting process the peak dot attrition strength that contacts an area is relative at close together model force of osculatory area attrition can be ignorred, because this is right close together model the research that contacts area attrition force is more important. For this, the article regards workpiece material as ideal firm plasticity body, use Lee Xiefu onefold cut scale model from theoretic derivation knife, bits is close together model the computation that contacts length is formulary, proof knife, bits is close together model osculatory length is cutting the first, the 2nd result that is out of shape collaboration of area put together is used, analysed formulary rationality and suitable scope through the experiment. Graph 1 Lee Xiefu model of skid wire field pursues 2 Lee Xiefu stress of model of slippage money field is round 2 knives, bits is close together model the graph shows the computational formula that contacts length 1 times for Lee Xiefu model of skid wire field. The slippage in process of model hypothesis cutting produces Lee Xiefu in shear plane. On, and the shearing stress on OA face T. Achieve yield point;AB to be out of shape for whole plasticity a hypothesis of the area is attrib border, forming what cut bits and make tigidity to move up in material of AB face above suppose () of the motion that discharge bits, because this AB is free border, 0 load are on its; The dividing line OAB that OA and AB are plasticity area and rigid division is area of a complete plasticity, and make an uniform field. The graph is shown 2 times for Lee Xiefu stress of model of skid wire field is round. The law on AB face all is to stress and shearing stress 0, be located in coordinate origin. On stress circle, AO is by AB edge setting out circumferential clockwise rotates 90 and; By AB anticlockwise rotate 90 ° attainable BC, again by BC anticlockwise rotate BO of face of the knife before 2h horn gets namely. In cutting process, cut is out of shape as a result of the elbow of face of the knife before getting cutting tool to cut bits, next face of the knife before the edge is poured out of. Does because of this knife the attrition on one bits interface include two parts: ? Herd of Cui of that Xing Da shows Yuan Jiaowei of benzyl of call on of of Zhi of poisonous smile of male of reason of tomb figure move Σ of banner of hut of of bead of Lai where Σ apprentice of benzyl of deserted fur coat oh ② of ツ Σ ? transforms when cut material end to cut the course of bits and, right now knife, the contact between bits is peak dot contact. Because this shows Lee Xiefu 1 times by the graph model of skid wire field is knowable, OB is knife bits namely close together model osculatory length Ln. The basis pursues 1, the graph shows geometrical relation 2 times to be able to push derive Ln=aesin(f+b-g0sinfcosb changes brief in getting Ln=ae[L(µ-tang0)+1/cosg0](1) form: Ae -- cutting ply F -- cut horny B -- before knife range is average G0 of angle of friction -- L of the horn before cutting tool -- be out of shape coefficient, l=[cos(f-g0)]/sinf µ -- before knife range is average coefficient of friction, because µ=tanf is out of shape coefficient L basically mirrors cutting the first be out of shape the volume of kiss shear body of the area, before face of the knife before µ of average coefficient of friction reflects knife range integratedly and cut the interaction between bits (namely the 2nd be out of shape the circumstance) of the area, accordingly by type (1) is knowable: Knife, bits is close together model osculatory length is cutting process in the first, the 2nd result that is out of shape collaboration of area put together is used. 3 cutting experiment and analysis are opposite through cutting experiment cutting parameter (the horn before be like ply of cutting speed, cutting, cutting tool) with the knife, bits is close together model the relation between osculatory length undertook study, analysed cutting parameter to the knife, bits is close together model the influence that contacts length. Cutting speed is right knife, bits is close together model the condition of influence cutting experiment that contacts length: High-speed steel cutting tool, g0=5 ° ; A0=8 ° ; Ae=O. 1mm; Aw=2.
5mm; Test specimen material is 10 steel; Orthogonal and free cutting. Pass cutting experiment and computation, get 3 show cutting rate pursueing respectively. With the knife, bits is close together model the two relations curve that contacts length Ln (computational result and) of actual measurement result. Compare two curves knowable, when cutting speed V>68m/min, computational result and be identical of actual measurement result are gotten very good, both tends consistent; is become when V<68m/min, actual measurement result is more than computational result; When V=35m/min both differs the biggest (amount to 24%) . The main reason that creates this kind of difference is Lee Xiefu material of workpiece of hypothesis of model of skid wire field is body of ideal firm plasticity, oversight in cutting process by the treatment sclerosis of cutting material. And in actual cutting process, on one hand the treatment that meet an emergency can cause workpiece material is sclerotic, the heat in metal cutting with the many on the other hand generation when cutting makes again workpiece material bate, the action of both is weakened each other. When V>68m/min, the heat in metal cutting of the generation when cutting makes workpiece material bate, effect can ignor the treatment sclerosis of the material that be cut to be cut right now material can regard ideal firm plasticity as body, computational result and be identical of actual measurement result are accordingly better. By the graph 4 show cutting rate. The relation curve with B of angle of friction is knowable, when V>68m/min, b of angle of friction tends fair value. When V<68m/min, machine sclerotic effect to take dominant place, right now material cannot regard ideal firm plasticity as body, the knife because of this actual measurement, bits is close together model osculatory length cost is more than computational value. To the graph 4 make further analysis knowable, when V=35m/min, b of angle of friction is the biggest, show treatment sclerosis effect is most right now distinct, because of this knife, bits is close together model osculatory length Ln has maximum, its computation value and actual measurement value differ the biggest also. Pursue V of 3 cutting speed and knife, bits is close together model the relation graph that contacts length Ln the relation graph of V of 4 cutting speed and B of angle of friction Ae of 5 cutting ply and knife, bits is close together model the relation graph that contacts length Ln G0 of the horn before 6 cutting tool and knife, bits is close together: High-speed steel cutting tool, g0=5 ° , a0=8 ° ; V=8.
64m/min, aw=2.
5mm; Test specimen material is cutting of orthogonal freedom of 10 steel; . Pass cutting experiment and computation, get 5 show cutting ply Ae and knife pursueing respectively, bits is close together model the two relations curve that contacts length Ln (computational result and) of solid side result. Compare two curves knowable, when cutting ply Ae<0.
When 2mm, two curves are basic be identical; Increase as cutting ply, the difference of both also increases ceaselessly, and actual measurement result is more than computational result. Its reason basically is: ① is being calculated knife bits is close together model when contacting length, assume the material that be cut is body of ideal firm plasticity, and the place before be like is narrated, machine sclerotic effect to take dominant place right now, material cannot regard ideal firm plasticity as body; What ② cuts bits is transverse be out of shape increase along with the accretion of cutting ply, when Ae>0.
When 2mm, cut bits transverse be out of shape cannot oversight, because this does not accord with Lee Xiefu cutting skid wire the hypothesis condition of condition of meet an emergency of field model plane. The horn before cutting tool is right knife, bits is close together model the condition of influence cutting experiment that contacts length: High-speed steel cutting tool, a0=8 ° ; Ae=0.
1mm, aw=2.
5mm, v=110.
58m/min; Test data is cutting of orthogonal freedom of 10 steel; . Pass cutting experiment and computation, g0 of the horn before getting 6 show cutting tool pursueing respectively and knife, bits is close together model the two relations curve that contacts length Ln (computational result and) of actual measurement result. By the graph 6 knowable, the metabolic trend of two curves is consistent. Experiment according to afore-mentioned cutting integration analysis result is knowable, below certain cutting condition, with Lee Xiefu field model is cutting skid wire the formula that fundamental derivation gives (the computational value of 1) and actual measurement are worth basic be identical, as a kind of similar processing technique, use formula (1) computation knife, bits is close together model osculatory length has real sense. The article uses 4 verdict Lee Xiefu field model derivation gives cutting skid wire knife, bits is close together model osculatory length gauge calculates formula to be. This type makes clear a knife one bits is close together model osculatory length is cutting process in the first, the 3rd result that is out of shape collaboration of area put together is used. Below certain cutting condition, when by the treatment sclerosis effect of cutting material but by oversight when, type (the knife of 1) plan cipher out, bits is close together model value of osculatory length Ln and be identical of photograph of actual measurement value. Cutting tries check proof, lee Xiefu field model just is in cutting skid wire the approximate method below certain cutting condition, but still have academic guidance and actual application sense. CNC Milling