(5) Transverse section Pf, longitudinal section Pp, transverse section or
longitudinal section system
Pr －Pf－Pp
Fig.1.9 Transverse section Pf,
longitudinal section Pp
TransversesectionPfisaplanepassingthroughadesignatedpointoncuttingedgeandparalleltothedirectionoffeedingmotionandperpendiculartothetoolreferenceplanePr..Normally,Pfisasectionparallelornormaltoacertainplaneoraxisofthetooleasyforgrindingandsetup,shownasFig.1.9.LongitudinalsectionPpisaplanepassingthroughadesignatedpointonthecuttingedgeandperpendiculartothetoolreferenceplanePrandthetransversesectionPf.
1.1.2.3 Reference system for the working angles of cutting tools
In the definition of tool reference plane Prthe 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 veis replaced by vc，where vcis the practical feeding direction instead of the predetermined direction.
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 completely contacted, causing serious friction；
(b)
Fig.1.10 Working angles of the tool
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
刀具工作角度示意图
Fig.1.10 the working angles of the tool