(5)Transverse sectionPf,longitudinal sectionPn,transversesectionorlongitudinal sectionsystemTransverse section Pis aplane passing through adesignated point on cutting组成进给部面参考系P-P-Ppedge and parallel to thedirection of feeding motionand perpendicular to the toolreference plane Pr NormallyP, is a section parallel ornormalto a certain plane oraxis of the tool easy forgrindingandsetup,shown asFig.1.9. Longitudinal sectionPp is a planepassing througha designated point on thecuttingedgeandperpendicular to the toolreference plane Pr and theFig.1.9Transverse sectionPftransverse section Pf.longitudinal sectionP上页下页退出
(5) Transverse section Pf , longitudinal section Pp , transverse section or longitudinal section system Transverse section Pf is a plane passin g through a designated point on cutting edge and parallel to the direction of feeding motion and perpendicular to the tool reference plane Pr. . Normally, Pf is a section parallel or normal to a certain plane or axis of the tool easy for grinding and setup,shown as Fig.1.9. Longitudinal section Pp is a plane passing through a designated point on the c u t t i n g e d g e a n d perpendicular to the tool reference plane Pr and the Fig.1.9 Transverse section Pf t r a n s ve r s e s e c t i o n P f . , longitudinal section Pp Pr －Pf－Pp
1.1.2.3 Reference system fortheworking anglesofcuttingtoolsInthedefinitionoftoolreferenceplaneP,thefeedingmotionisnotconsidered,i.e.the marked angles ofthe cuttingtoolis determined underthepredetermined conditions.It is notrue inpractice,whereonlytheresultantvreflectsthe situation.Forexample,Fig.l.10 shows threetoolshaving the same marked angles,but the practical conditions,likethecontactandfrictionareverydifferentIt is same consideringthe affection of thetool setupposition,exceptthat vis replacedby e, where ve is the practical feedingdirectioninsteadofthepredetermineddirection上页下页退出
1.1.2.3 Reference system for the working angles of cutting tools In the definition of tool reference plane Pr the feeding motion is not considered, i.e. the marked angles of the cutting tool is determined under the predetermined conditions . It is no true in practice,where only the resultant ve reflects the situation. For example，Fig.1.10 shows three tools having the same marked angles,but the practical conditions,like the contact and friction,are very different It is same considering the affection of the tool setup position, except that ve is replaced by vc，where vc is the practical feeding direction instead of the predetermined direction
Fig.(a) itis normal,where thereis clearancebetweentheflank andtheworkpieceVe+0aFig.1.10the workingangleofthetool下页上页退出二返回
Fig.（a）it is normal, where there is clearance between the flank and the workpiece. (a) Fig.1.10 the working angle of the tool
Fig.(b) ,two surfaces are completelycontacted.causing serious friction;00-0(b)Fig.1.10 Working angles of thetool上页下页退出
Fig.（b）, two surfaces are completely contacted, causing serious friction； (b) Fig.1.10 Working angles of the tool
inFig.(c),thecuttingedgecannotenterintothemetal.Therefore.onlyconsiderthemain motion isnotproper.The working angles ofthetoolmust bedecided bytheworking reference system, i.e.,considerthedirectionoftheresultantmotionVoFig.1.10 the working angles ofthetool上页下页退出二
刀具工 作角度 示意图 in Fig.（c）,the cutting edge can not enter into the metal.Therefore, only consider the main motion is not proper. The working angles of the tool must be decided by the working reference system, i.e.,consider the direction of the resultant motion Fig.1.10 the working angles of the tool