Between 4mm. Gear law sees a picture to curve of Fm of modulus M factor 2. Curve of Fz2 of factor of Z2 of number of tine teeth of a cogwheel sees a picture 3. When Z2 ≤ 120 when, the curve that uses B=0 1. When Z2>120, the value that presses B of helix angle of gear reference circle is in with insertion correspondence is gotten between the curve at B=0 ° , B=30 ° and B=60 ° . Curve of Fd of factor of D(mm) of hob external diameter sees a picture 4. Fd value uses insertion get between the curve from ° of B=0 of helix angle of corresponding gear reference circle and B=60 ° . Graph A of 6 hob penetration and gear choose N of number of tine of 5 hob blade and graph of F(N/z0) of factor of Z0 of hob head number curve of Fa of factor of Xp of form displacement correction coefficient (take hob penetration =2.
25m and N of number of tine of Xp=0) hob blade and F(N/z0) of factor of Z0 of hob head number see a picture 5. Fa of factor of Xp of correction coefficient of hob penetration A(mm) and displacement of form of tine teeth of a cogwheel sees a picture 6. Be in from the graph 1 ～ 6 on after the numerical value that gains 6 factor of influence such as Fh1, era enters type (the value of Fa(mm/r) of hob axial feed that 1) can use so that answer. The data SU factory that works of tool of gear of Fa(1)2 SU of · of F(N/z0) of · of Fd of · of Fz2 of · of Fm of Fa= Fh1 · decides gear hobbing feed is manufacturer of Italian gear tool. Will to our country export gear hob for years. Went up in conference of tool industry chief engineer 1995, SU factory holds technical chair, the figure cutting bits that gear hobbing of refer gear hob produces is more complex, and constant change, with " cut bits ply Hz on average " go up on behalf of tine of gear hob blade " average machine is laden " . Its computation type is the Fa in Hz=faz0N(2) type -- gear every turn hob axial feed, mm/r Z0 -- gear hob head counts N -- number of tine of gear hob blade uses formula in domestic and international data (2) person quite much. When the comparison that SU factory has angrily efficiency and angrily cost in the hob that plans different structure, use same Hz value to be premise. Efficient to cutting the high-speed steel of sedan gear hob, its Hz value is chosen 0.
) of 6mm(subordinate list. 3 gear hob uses identical " cut bits ply on average, Hz " : But with type (1) calculates " the biggest ply that cut bits, H1max " it is different. Circle of TiN of 1003155% cobaltic high-speed steel grinds ° of Vc(m/min)a(mm)fa(mm/r)hz(mm)h1max(mm)124715 of structure of coating of material of M(mm)z2bd(mm)z0N of parameter of cutting of hob of hob of gear, gear and gear of gear of number of hob of table of cutting parameter data law gear hob 204.
Hob of gear of tine of 23228 whole much blade 5.
Tine of blade of 1835022 whole slue does not grind gear hob again 4.
23 note: 1.
Hz is the numerical value that arranges before the experiment, be worth computation to give the Fa that experiment of each gear hobbing uses to be worth from this. H1max value is to use formula (the value of numerate of estimation of 1) basis Fa. 2.
The H1max value of 1# and 3# hob is real be 0.
225mm and 0.
What 229mm differs twice is numeric, take 2 fraction to change whole all become 0.
23mm. 1# and 3# hob are taking Hz=0.
When 6mm arranges feed, the H1max of earning is achieved 0.
23mm, the H1max ≤ that gives with German hob factory 0.
25mm is very adjacent. The H1max of 2# hob is 0.
18mm, from hob function consideration, its Fa value still can use greater value, in order to improve gear hobbing efficiency. Appear the reason of afore-mentioned reasons is: Type 2 in Hz and (Z0/N) becomes direct ratio, and H1max and (Z0/N)1.
762 into direct ratio, hob blade tine increases to count in latter in order to improve the result of gear hobbing efficiency more apparent. When the author thinks to arranging big batch gear hobbing, to feed choose, compare Hz with H1max more reasonable, also suit slam the door of industry of current and Euramerican automobile to the round hob that grind a way turns and use hob of gear of integral much blade more in order to improve the current situation of gear hobbing efficiency. CNC Milling