Summary: Of face of the knife after studying cone twist drill shape, built the mathematical model that gets a tip, the computation of the horn after deciding from this is formulary. Built parameter to change computational interface through C++Builder, with this analysis each blade grinds the influence of the horn after parameter is right, decided through backdate law below the horn after giving blade grinds the process seeking solution of parameter. 1 preface is current, the twist drill that using is ground again without special device, heavy blade grinds main armrest labour to operate. Very apparent, manual operation precision is not tall, asymmetry of blade of cutting of meeting generation such as, hind horny left and right sides differs, hind knife face is absent same curved surface is classy a series of problems. Mass-produced practice makes clear, the geometrical appearance of face of the knife after twist drill and blade grind quality to affect the cutting function of broach and service life directly, after so broach wears away, basically be face of the knife after blade grinds those who get a tip. The article gets pointed mathematical model through studying cone twist drill namely, counterpoise blade is ground undertake parameter is calculated, blade is ground piece reasonable hind knife face, to design a kind of simple and easy broach heavy blade grinds appearance to provide academic basis. Graph 1 cone blade grinds geometry to pursue blade of face of the knife after 2 cone twist drill grinds motion to analyse to assure the good cutting of cone twist drill function is mixed honest service life, twist drill sets the horn after timing is change. When face of the knife after blade is ground will advocate nod each on cutting blade hind part of the predestined relationship outside horny wear is small, stand by more auger the heart is bigger. If the graph is shown 1 times, want to wear face of the knife after giving cone on emery wheel, must have the following campaign. Emery wheel revolving advocate motion. Grinding awl moves. To form grinding awl, make broach circles awl axis to rotate, this motion is one is moved toward compound pendulum. Workpiece feed moves. For abrasion workpiece surplus, need edge workpiece axial or with advocate the directional feed with perpendicular blade. Emery wheel nap moves. By the graph 1 knowable, should make broach around the hypothesis include advocate when the conic axes of cutting blade rotates, face of the knife after the taper seat of the horn after be being had at cutting blade relatively is formed namely. Model of maths of face of the knife after model of maths of face of the knife after 3 cone is built above all, if the graph is shown 1 times, broach circles Z axis circumgyrate to form grinding awl, its half cone angle is D. Get axis and awl axis not to intersect, awl top is S to the distance of broach axes, get axis and awl axis axes slant be apart from for E, the included angle that gets axis and awl shaft is Q. Go up in taper seat every as perpendicular as its axes section plane profile is round, closer awl top jumps over its curvature radius small, namely curvature is bigger. Use this one characteristic, consummate of face of the knife after broach the one part of conic surface, the horn after according with broach stands by the place that get core to exceed big requirement more. It is in coordinate department OXYZ, build cone equation above all: X2+Y2=Z2tan2d(1) by coordinate translation, {X=X-eY=YZ=Z-(S/sinq)(2) fastens coordinate 0XYZ to circle OX, (Ox) rotates Q horn arrives Oxyz, criterion the relation in two coordinate department is: {X=xY=ycosq-zsinqZ=ysinq+zcosq(3) will (3) type acting person (2) , (1) , have the equation of straight taper seat: (The equation couplet of X-e)2+(ycosq-zsinq)2=(ysinq+zcosq- S)2tan2dsinq(4) and straight cylinder stands, the {(x-e)2+(ycosq-zsinq)2=(ysinq+zcosq- S)2tan2dsinqx2+y2=r2(5) of the equation that cross a line that gets cone and cylinder is set advocate the angle parameter that the A on cutting blade nods is T, criterion afore-mentioned parameter equation that cross a line pursue for {(rcosq-e)2+(rsintcosq-zsinq)2=(rsintsinq+zcosq- S)2tan2d4sinqx=rcosty=rsint(6) of 2 broach hind horn pursues plane of the horn after 3 columnar section plane develops a plan the mathematical model of the horn after section plane of prop drawing of 4 twist drill is medium is ground in blade in of magnanimity is Afe(of the horn after the structure is circumferential namely hind horny A) , this angle is the broach that measures inside the columnar face that shows through cutting the make choice of on blade is nodded transverse plane and hind the included angle between knife face. If the graph is shown 2 times, to advocate the A point on cutting blade will tell, face of the knife after the AC crossing a line of broach taper seat and the columnar section plane that pass this a little bit is what should nod namely. AC and AB(of cutting speed direction are in perpendicular inside the transverse plane at getting a shaft) AA of the horn after places angle is what should nod namely. Develop afore-mentioned round cylinder plane, the curvilinear AC of former columnar section plane turns into flat curve AC, the included angle of the tangent AD that AA of the horn after the tagging that A nods nods in A for curvilinear AC namely and linear AB. If the graph is shown 3 times, it is the abscissa for ordinate Rt with Z, z=f(r · T) , have TanaA=(dz/d(r · T) | A, nod A to appointing for, era enters (the horn after 6) type gets twist drill is formulary: The Z in type of Tana=1(ycosq-zsinq)xcosq-y(x-e)-tan2d(zcosq+ysinq- S)xsinqsinq(x2+y2)½ (ycosq-zsinq)sinq+tan2d(zcosq+ysinq- S)cosqsinq(7) is worth but by type (6) is gotten. Couplet establishs afore-mentioned equation (6) , (7) , era enters Z value, can beg the random on winner cutting blade of a bit hind horn. As a result of hind horn is about broach diameter D, awl half horn D, make choice of nods radius R, get axis and cone axis of top of Q of axial included angle, awl and S of the distance that get a shaft, awl and get an axis to slant the function that is apart from E, reason but parameter is changed seek solution. Use C++Builder5. 0 undertake designing begging solving. C++Builder regards visible process designing as the tool, friendly, function uses face of outside of can rapid development formidably program. The program interface of the design is shown 4 times like the graph. Graph 4 hind block diagram of horny computation dialog 5 hind horn changes along with S sketch map 5 hind knife face blade grinds parameter to design computation the influence of the horn after D of half cone angle checks the shadow part of the day of the horn after each blade grinds parameter to be opposite by hind horny computation dialog box, change D, each value regards the others as constant, as the accretion of half cone angle, horn is reduced after. To standard twist drill, vertex angle 2F=118 ° , and Q+d=F, reason Q=59 ° - D, increase and increase what horn follows Q after place. The influence of the horn after awl top is opposite to the distance that get a shaft changes the value of S, each value takes the rest constant, can get the accretion as S, horn is reduced after. Slant the influence that is apart from the horn after E is right can be gotten with manage slant the action result that is apart from the horn after E is right, increase as E, horn also increases subsequently after, and extent is remarkable. Knife face blade grinds parameter to examine data of relevant cutting tool surely really after, the predestined relationship outside twist drill is in hind closely related horn and diameter, 14 ° of Do<15mmae=11 ～ 12 ° of Do=15 ～ 30mmae=9 ～ 11 ° of Do>30mmae=8 ～ in type, do is broach diameter; The horn after what Ae is broach is reasonable. Graph 6 blade grind number to beg blade of basis of solution principle graph to grind practice, change of Q of axial included angle is not big, it is 45 ° left and right sides commonly, reason can set his for constant. Q+d=F, vertex angle asks to be 59&feg; commonly, reason D also comes down certainly. Need to be in only so give broach diameter to fall, beg solution to give E, the horn after S makes is in reasonable hind inside horny range can. As a result of general E=0.
05 ～ 0.
07d, reason can take one cost inside this limits. By before the analysis is knowable, horn follows the accretion of S after and reduce, its change curve is shown 5 times like the graph. Oneself use backdate method (weigh heuristic again) undertake begging solving. When E is given, give an initiative dot S1 first, the horn after era is entered is formulary (7) , cipher out an A1, compare this A1 and Ae photograph, be like A1<ae, show S1>Se, let the 2nd S grow by particular situation right now reduce, namely S2<S1, criterion cipher out A2>ae, compare A2 and Ae photograph again, be like A2<ae, continue to reduce S cost, be like A2>ae, grow to increase S accordingly by the pace, when be worth till certain S, the A as it happens of cipher out is equal to Ae, give the combination of a pair of E, S with respect to the search right now, corresponding flow chart is shown 6 times like the graph. Next backdate can let E grow to increase or be reduced by particular situation produce a change, continue to search combination of below one pair of E, S ahead. According to principle of this kind of computation, write this flow chart the program, can beg a S that matchs with E photograph immediately, a=ae of the horn after this E, S combines what make the predestined relationship outside this broach is in. Can decide all blade grind parameter from this, such because controlled variable amount, in be being adjusted actually, need to change E, S only, also come true easily, the metabolic rule of the horn after face of the knife after can assuring those who go out to blade is ground thereby is abided by, and abrade of face of the knife after be not being caused already got has cut workpiece face. CNC Milling
CNC Machining