Graph the crucial process that belt of 1 foreword treatment overhauls the position of approximate path of contact when 1 hob machines helical gear to insert tine knife to insert tine knife along helical gear is gear hobbing and roll flute, the tooth form of its cutting tool needs to amend. Calculate through amending knowable, this kind of helical gear inserts tine knife the reference circle pressure angle of surface of left, right tooth form is unequal, to satisfy this one requirement, must amend treatment helical gear to insert tine knife place to want the tooth form of hob. In roll flute process, the tooth form that can control the knife that insert tine through roll flute example reachs the relation of the start that build a predestined relationship and transverse tooth thickness, make its can decrease try insert treatment frequency to be achieved even do not need to try the purpose that insert. The consideration of special hob tooth form that 2 treatment repair predestined relationship helical gear to insert tine knife is primary the clench the teeth that the computation of horn of involute tooth form machines helical gear to insert tine knife to be equivalent to gear of crisscross axis helix with hob. Because insert tine knife to still need to grind tooth form finally, reason can think hob machines helical gear to insert tine knife approximately is to age rack is in continuously N-N is sectional in insert tine knife clench the teeth with helical gear, see a picture 1. Path of contact and dentiform of the knife that insert tine are formed all should be in this is sectional inside, the tooth form of the knife that insert tine should be being carried sectional inside measure. Analyse I-I now sectional inside of outline of the tooth that insert tine form. Dot of A1 of root of tooth flank tine is hob is in N-N is sectional inside form, but name a person for a particular job of B of top of tooth flank tine arrives in hob shift when N-N position form. Because hob has radial feed face to cut deep increase, reason ages in tooth flank the top is in transverse tooth thickness to will be decreased thin; Right tooth flank is contrary, in tooth flank transverse tooth thickness of tine root place will be decreased thin, pressure angle of left reference circle will be more than the tooth form of the knife that insert tine that such cutting go out the tooth form horn of hob, reference circle pressure angle is less than the tooth form horn of hob on the right side of. The tooth form of the knife that insert tine that gives to make cut obtains the reference circle pressure angle of the requirement, must undertake correction to hob tooth form. The Aon" of horn of right, left tooth form of the special hob that machines helical gear to insert tine knife and Aon can use form calculation: In Tanaon=tan2antanan+tandesinbgtanaon"=tan2antanan-tandesinbg type: Bg -- the reference circle helix angle of the knife that insert tine An -- the reference circle pressure angle that the knife that insert tine asks De -- the after carrying blade on the head horn of the knife that insert tine should notice, type applies to treatment dextrorotation helical gear to insert tine knife on. When machining left helical gear coming back to insert tine knife, go up the sign in type is contrary. Because helical gear inserts tine knife tooth form left, right the reference circle pressure angle of two side surface is unequal, when because this uses formula,computation rolls tooth body part, answer to use the An in type the reference circle pressure angle that inserts tine knife actually to take the place of to have consideration. The computation of horn of tooth form of the involute that build a predestined relationship machines practice to make clear, involute tooth form of the standard is not good tooth form, to assure the smooth stability of positive drive, improve quality of gear clench the teeth, reduce noise, need undertakes correction to the tooth form of gear, it is this to must have long look to the tooth form of cutting tool. Can use emery wheel to repair predestined relationship law to come commonly grinding inserts tine tooth form, be about to the bevel that round place repairs A outside emery wheel, make grind the point of root of the tooth that insert tine that give to add thick. But, pure grind a long predestined relationship that accords with a requirement very hard to insert tine knife with this kind of method, so, insert tine knife to make those who accord with a requirement, must machine the appearance that gives the share that build a predestined relationship first. For this, the R of effective curvature radius that can offer according to blueprint place is effective (or tine rises horny Q) to calculate what hob builds predestined relationship part to concern dimension, specific computation process is: ° of effective =(qD0p)/360 of the computational Rmax=(Re2-R02)½rmin=(RØ02-R02)½r effective =rmax-rmin(of C of the height that build a predestined relationship or R) in C1=Re-RØ0 type: Rmax -- the Rmin of radius of the biggest curvature that inserts tine knife -- the Re of radius of the smallest curvature of the knife that insert tine -- the tine of the knife that insert tine carries round radius R0(D0) on the head -- the basic circle radius of the knife that insert tine (basic circle diameter) RØ0 -- the knife that insert tine: Rmax=(Re2-R02)½rmin1=rmax-(r effective 1+r is effective) in =(RØ2-R02)½C2=Re-RØ type: Rmin1 -- the R of radius of the smallest curvature of part of the Dao Xiuyuan that insert tine is effective 1 -- the RØ of effective curvature radius of part of the Dao Xiuyuan that insert tine -- the Dao Xiuyuan that insert tine stops place radius to be able to reach from this partly the long predestined relationship that inserts tine knife, the C of the height that build a predestined relationship of attainable other a side. The helical gear that build a predestined relationship inserts those who age tooth root increases large amount to give out have two kinds of cases, if pursue 2, the graph is shown 3 times. Graph 2 graphs 3 show 2 times like the graph, what give out to go up in the height that build a predestined relationship directly is left, on the right side of tine root is added large amount and, accordingly its repair predestined relationship involute left, on the right side of Bon of tooth form horn and Bon" can press form is direct cipher out: Tanbon=/Ctanbon"=/C is shown 3 times like the graph, left, on the right side of tine root increases large amount, those who give out is to insert the nadir that cutting participates in on tine tooth form to basic involute (extension line) the distance that go up. In computational process, should first cipher out is in those who repair predestined relationship height to go up to increase large amount 1 with 1, accordingly, the involute that build a predestined relationship is left, on the right side of Bon of tooth form horn, Bon" is {tanbon=(+1)/tanbon"=(+1)/ among them 1=Ctanaon1=Ctanaon" needs to explain, although method of this kind of calculation is theoretic,apply to the tooth form part that manages in reference circle to calculate only, be under reference circle or the result of above plan cipher out all has deviation, but the tooth form of the knife that insert tine that the hob treatment that we use this kind of method to design gives basically accords with treatment to ask. The roll flute model that the design of example of 3 roll flute uses before my factory basically is the height of teeth top that inserts tine knife according to helical gear and design of dimension of transverse tooth thickness, this kind of example can control the transverse tooth thickness that carries sectional part only, uncontrollable to grinding the transverse tooth thickness of the knife that insert tine after again, because insert the horn after tine knife has,this is, round diameter of round diameter of its tine top and tine root chases the end panel after inserting tine knife to arrive from front face so to be reduced gradually, corresponding ground transverse tooth thickness also is reduced. Be aimed at this kind of circumstance, designed two pairs of model especially, one pair is used at assuring to repair predestined relationship helical gear to insert the unilateral tooth form of tine knife; Another pair is to be used at controlling its bilateral tooth form and the card example of the start that build a predestined relationship and relation of transverse tooth thickness. The design of bosseyed example. Bosseyed example is to be used at assuring to begin to come from the start that build a predestined relationship to stop the tooth form of round place (the left, tooth form on the right side of each not identical) . Transverse tooth thickness is the alveolar width design that inserts tine knife according to repairing predestined relationship helical gear, to facilitate unilateral examines, the alveolar width that its transverse tooth thickness should compare the knife that insert tine slightly small, example appearance sees a picture 4. Graph 4 bosseyed example pursue the design of example of card of transverse tooth thickness of example of card of 5 transverse tooth thickness. The either of the knife that insert tine is sectional all can process a proper involute tooth form. When the design blocks example, be cut considering the likelihood end the tooth that insert tine difficult situation and can detect carry requirement of sectional and the following dentiform, in end round point (standard external diameter) stay have one empty chamfer, from long predestined relationship initiative line begins, the tooth form that inserts tine knife according to helical gear and dimension of transverse tooth thickness undertake designing, example appearance sees a picture 5. Treatment carries out a proof, the helical gear building a predestined relationship that the hob that uses this method design and example treatment give inserts tine knife to accord with treatment requirement. Graph form of the 6 tooth that insert tine 4 designs example is foregone: Law to modulus Mn=3. 5mm, ° of Ae=7 of the horn after carrying blade on the head 30; On the right side of right =144 of D0 of basic circle diameter.
354mm, left =145 of D0 of diameter of left basic circle.
230mm; Standard tooth form spreads out horny Q=15 ° on the right side of 10, left standard tooth form spreads out horny Q=15 ° 40; Tooth form of long predestined relationship spreads out horny Q1=3 ° on the right side of 35, the left tooth form that build a predestined relationship spreads out horny Q1=4 ° ; Dg=158 of reference circle diameter.
25mm, ° of Bg=18 of reference circle helix angle (left) ; Tine counts Z=43, outside round diameter De=164.
46mm, divide St=4 of transverse tooth thickness of arc of round end panel.
305mm, form of the tooth that insert tine sees a picture 6. Design computation move is as follows: The pressure angle of end panel of design computation hob of hob At left =arccos(D0 of At right At is left, left / Dg)=arccos(145.
230/158.
25)=23.
Right =arccos(D0 of 40425658 ° At is right / Dg)=24.
Law of 19028998 ° hob to pressure angle An left Cosbg)=22 of left =arctan(tanat of right An of left, An.
Right Cosbg)=23 of right =arctan(tanat of 37416241 ° An.
Aon of horn of tooth form of 13353158 ° hob left =arctan[tan2an of Aon right " Aon is left, left / (Tanan is left - Tanaesinbg)] =arctan[tan222.
37416241 ° / (Tan22.
37416241 ° - ° of Tan7 ° 30sin18) ] right "=arctan[tan2an of =24 ° 3233" Aon is right / (Tanan is right + Tanaesinbg)]=21 ° 1807" repairs C of predestined relationship height to part of basic tooth form, right: Rmax=(Re2-Ro2)½=[(164.
46/2)2-(144.
354/2)2]½=39.
10 × of ° of =(15 of ° of 40 R effective =(qD0p)/360 144.
354 × 3.
141592654)/360 ° =19.
10 Rmin=rmax-r effective =20.
30=(RØ02-R 02)½ computation can get RØ0=74.
98mm, because this has C1=Re-RØ0=(164.
46/2)-74.
98=7.
25mm to building predestined relationship part, right: ° =23 of right P]/360 of R effective 1=[(q1+q)D0.
62 Rmin1=rmax-r effective 1=39.
40-23.
62=(RØ2-R02)½ computation can get RØ=73.
88mm, because this has C2=Re-RØ=8.
35mm repairs predestined relationship height to be C=C2-C1=1.
1mm uses same method calculable the C=1 of the height that build a predestined relationship that gives left.
1mm. Right " of left, Bon is like Bon of horn of tooth form of the involute that build a predestined relationship the graph is shown 6 times, those who age the root increases large amount give out accord with a graph the circumstance of 3, because this has 1=Ctanaon right "=1.
1807"=0 of ° of 1 × Tan21.
43mm Bon right "=arctan[(+1)/C]=arctan[(0.
17+0.
43)/1.
1]=28 ° 3638" uses same method calculable a 2516" of ° of Bon left =31. Graph the designs parameter of other of tooth form graph design of 7 hob and treatment are common the parameter design that inserts tine knife place to use hob is identical, be omitted. Graph the 7 design tooth form that are hob pursue. The design At left =23 of the designs computation to control transverse tooth thickness card model of roll flute example.
Left =tanat of 40425658 ° Invat is left - [(Pat is left) / 180 ° ] =0.
024345512 right: Invat right =0.
027013926(also can consult involute function table) long edge is initial diametical D=150mm. Tanb=(Dsin18 ° / Zm knife) =150sin[18 ° / (43 × 3.
5)]cosb=0.
955698907 left: A=arccos(145.
230/150)=14.
48801342 ° Inva=0.
005530862LTX=½D[(St/Dg)+invat-inva]cosb =(150/2)[(4.
305/158.
25)+0.
024345521-0.
005530862] × 0.
955698907 =3.
298mm right: A=arccos(144.
354/150)=15.
77009006 ° Inva=0.
007167738RTX=3.
The design basis of 372mm bosseyed example L=pD/Z-S, can get left: L=½(150p/43)-(3.
298/cosb)=2.
029mm right: L=1.
951mm reachs thereby law to dimension: Left: Ln=lcosb=1.
939mm right: Ln=1.
865mm criterion the left, right transverse tooth thickness of example is LTX=1 respectively.
939-0.
5=1.
439mmRTX=1.
865-0.
5=1.
365mm to make sure tooth form is more exact, when can take more commonly, the dimension computation process of these dots and afore-mentioned algorithm kind with. Should notice, the end panel that the computation of all parameter all takes is worth, but be to use a method in roll flute process to roll flute, so example should be a law to example, for this, the law should become parameter conversion when the example that make to the value. CNC Milling
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