Hard alloy inserts the horn before losing the teeth shape error of tine knife and tooth form horn are amended

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  • source:EAMOM CNC Machining
When machining gear with cutting of the knife that insert tine, the orbit surface of next motion on cutting blade and by treatment gear clench the teeth, reason cutting blade what go up in tool reference plane is umbriferous should be involute to just won't produce principle error. And the knife that insert tine is the horn after the horn before having is mixed, the tine side surface of the knife that insert tine is involute helicoid, 0 ° of ＝ of γ of the horn before carrying blade on the head like the knife that insert tine, criterion before knife face tooth form is involute, won't cause treatment teeth shape error; Be like a 0 ° of ＜ of γ of the horn before blade, criterion before knife face tooth form is taper seat and tine side surface cross a line, cutting blade what go up in tool reference plane is umbriferous already not was involute, reason will cause teeth shape error (see a picture 1) . Graph the teeth shape error that the horn before the 1 knife that insert tine causes if the Ⅱ in to in an attempt to - Ⅱ is sectional medium involute tooth form is fiducial, be in Ⅲ - Ⅲ is sectional in every side reduces the thickness that tine carries on the head thin Δ Fa, manage together, tine root place will increase Δ Ff, be equivalent to dividing round pressure angle to increase, this will cause bigger teeth shape error. If the graph is shown 2 times, through inserting the top of face of tine knife front blade makes end sectional O-O, get involute CD, with O-O (tool reference plane) for polar coordinates plane, your reference axis Ooy passes involute start C, criterion the polar coordinates equation of involute is Ry of ／ of Rbo of ＝ of Y of α of the Cos in type of Y of α of Inv of θ Y ＝ to pursue the equation with umbriferous on tool reference plane blade of cutting of analysis of error of form of the 2 tooth that insert tine can pass the following method to get. Random is taken to nod M on cutting blade, its radius is Ry, sectional for Ⅰ - Ⅰ , the space that leaves O-O of tool reference plane is Δ B, have Δ B ＝ (Ra - Ry) point of M of 　 of 　 of ｜ of Tg ｜ γ is opposite at M ′ the drop has turned Δ φ horn, its are worth Y of the β in be type -- the polar coordinates equation that M nods arbitrarily on the blade of cutting of helix angle of tine side surface that radius is Ry (namely the equation with cutting umbriferous on tool reference plane blade) Y of θ of ＝ of Y of the ′ that it is θ - 　 of 　 of 　 of 　 of Δ φ 　 , criterion cutting blade is in of end panel umbriferous will have bigger error with academic involute, this kind of error will make top of the tooth that insert tine and tine root ply produce change. Should insert ＝ of α of tine knife parameter 20 ° , m ＝ 8, z ＝ 16, ra ＝ 74. 2168, 6 ° of α O ＝ , γ ＝ - when 5 ° , fa of Δ of error of tine top place can be amounted to 0. 0397mm, the Fb of Δ of teeth shape error that basic circle is in is amounted to - 0. 0121mm. Age to inserting for the knife, so big error is unallowed, and of the knife that insert tine before E of α of the horn after horny γ is mixed is bigger, teeth shape error is bigger also. To reduce teeth shape error, can use the method that revises part of body of the tooth that insert tine, amend the part of end panel tooth form of tine side involute helicoid namely, the O of α of tooth form horn that makes insert tine knife and gear cent round pressure angle α differs. Specific means is to make blade of cutting tool cutting umbriferous the tangent coincide of the tangent that distributing round part and academic involute, derive cutting tool ages from this lateral is primitive α of tooth form horn. The graph shows M 3 times to nod is dot of random of edge music on-line, the included angle ψ between the tangent that already nodded to curvilinear M and radial is a graph the correction of horn of 3 tooth form type (1) medium θ ′ Y is differential to Ry, get among them Y of α of Tg of ＝ of Y of α of Inv of θ Y ＝ - α Y, take the place of to go up because,type is gotten α ＝ Arccos (Rb ／ Ry) , reason namely 　 　 (2) make dividing a circle to be in cutting blade the pressure angle α that the ψ horn of umbriferous curve is equal to academic involute, criterion ψ ＝ α , ry ＝ Ro, generation of O of α of α Y ＝ enters type (2) E of α of Otg of α of Tg of ｜ of γ of ｜ of Tg of ＋ of O of α of Tg of ＝ of the α that get Tg namely 　 　 (3) 　 basis type (3) can request an appearance of side of the knife that insert tine the correction α O of tooth form horn, the as it happens of the pressure angle that divide a circle with umbriferous blade of the cutting after amending is α , accord with the requirement that machines gear. CNC Milling CNC Machining