The research that the blade of hob of scrape of hard alloy gear grinds
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- source:LAURENDA CNC Machining
1415926 know, the circle that nods when computation (De) when the diameter changes, its are corresponding hind horn also is different (graph R) hob blade grinds sketch map to grind sketch map to see by hob blade, when hob before blade face blade grinds those who pursue medium " after blade is ground before blade face " this line when, the part carrying blade on the head of new cutting tool arrived A dot, the position of tine root arrived the place that B chooses when, the 2*de that the external diameter Da= of the hob that has ground newly pursues medium (graph A) after hob blade is ground before the coordinate that takes A dot and B to nod is begged to be shown by graph R place below graph of blade face point, age the very width that grinds is U1, of tine root grind width U2.
We know the role after Nextpage1 calculates what hob side shovels a face, after the circumferential chamfer number of the hob of external diameter Z- of the De- hob that the capacity shovelling a back of hob states with K value K=de*pi*tan(13)/z formula is medium gets shovelling back the K of the quantity when us, formula of Ww of the horn after the side edge of hob is as follows: Tan (Ww) =z*k*sin (Am) / (Pi*dx) the tooth form horn that the Am in type is hob, in actual computation, had better use (graph S) the numeric computation of horn of medium or so tooth form. Dx is the formula above basis of computational dot radius, can know, the diameter that the computation of the Am of tooth form horn of Ww of the horn after the side edge of hob and hob and hob nods is concerned. Am is bigger, ww is bigger, dx is bigger, the tine top of face of the blade before Ww jumps over small foregone hob grinds quantity U1 and tine root to grind quantity U2, the top that try a tooth-like part of anything decreases grain Q1 and tine root to decrease grain Q2.
The decrement Q2 of the decrement Q1 that computational tine carries on the head and tine root can be calculated according to the formula of the face the root round diameter that the Dg in Q1=k*u1/(pi*de) Q2=k*u2/(pi*dg) type is hob if each sectional transverse tooth thickness need computational dentiform to weigh the word of Mo, must decide the transverse tooth thickness of corresponding hob. If pursue (graph B) be shown. (graph B) grind principle place to know according to the shovel of hob, be in same it is equal that the shovel grinds on-line tooth transverse tooth thickness. According to this one regulation, can calculate those who give the transverse tooth thickness of corresponding hob to assure dot and corresponding tooth depth. One up-to-date, the computational condition that the blade of hob of scrape of hard alloy gear grinds the horn before losing gradually all ready, when using these conditions, the tooth form part that difference will control is clear about respectively go. From the analysis above, can see, if hob according to before the parallel of blade face grinds a way, of the tooth form horn of face of the blade before can assuring changeless, but, this yes before the eccentric throw of blade face been decreasinging. A. Set, will before blade face blade grinds N second, made eccentric throw =0, the horn of or so tooth form that is hob only is changeless still, with controlling tooth form horn to differ big case looks, (M18) , 19 ° left and right sides is on the right side of its, left it is 13 ° left and right sides. According to the common sense of gear hob, the eccentric throw =0 when hob when, the part of or so tooth form of the hob of hob approachs 20 ° , very apparent, this kind grinds a way cannot be used. B. If the blade of hob is ground,use change of eccentric throw grind a way, need the numeric Q1 with corresponding computation, the coordinate of face of the blade before the hob with Q2 new ground, computation gives corresponding eccentric throw, although use the equation of X and Y, computation gives corresponding eccentric throw. Next, the actual eccentric throw that grinds according to present blade has consideration new now eccentric throw, computation gives coordinate of corresponding hob tooth form, undertake comparative, find metabolic numerical value the smallest, will decide the method that blade grinds. Calculate respectively according to or so tooth form with respect to need so ability decision. Pass the analysis of above, can roughly the partial principle that the blade of hob of the horn before the specification is lost grinds and the method that should use. Actually, want to alternate slightly only, can solve before the blade of hob of the horn before the method that the blade of horny hob grinds and zero grinds a method. As a result of,be only length be caused by, these detailed calculative heavy and complicated, renew in the future. This one comes here end. CNC Milling