公开(公告)号：US20200206828A1

公开(公告)日：2020-07-02

申请号：US16631305

申请日：2018-05-11

Applicant: NGK SPARK PLUG CO., LTD.

Inventor： Naoki ANDOH ,  Takuya HASEGAWA ,  Takashi FUJIMOTO

IPC: B23B27/16 ,  B23B27/22

Abstract: A cutting insert has cutting edges having the same shape and provided at respective corners of a polygon in rotational symmetry about the center axis of the polygon, is clamped in an upright position to a holder, and has a negative side rake angle on a rake face of a side cutting edge. A side cutting edge is present at an intersection ridge between a polygonal face and an outer peripheral face. The outer peripheral face includes a rake face of the cutting edge and a flank of an end cutting edge of another cutting edge different from the side cutting edge. The flank has a positive slope angle in opposition to a negative side rake angle of the side cutting edge. A breaker groove extending in a front-rear direction is formed in the rake face and cuts into the flank, in such a manner as to divide the rake face.

公开(公告)号：US20170266732A1

公开(公告)日：2017-09-21

申请号：US15505146

申请日：2015-10-16

Applicant: NGK SPARK PLUG CO., LTD.

Inventor： Naoki ANDOH ,  Minoru KOIDE ,  Takashi FUJIMOTO

IPC: B23B27/04 ,  B23B27/22 ,  B23B27/14

CPC classification number: B23B27/04 ,  B23B27/14 ,  B23B27/22

Abstract: Inclined surfaces are formed on a rake face and a recessed groove is formed in the central portion between the inclined surfaces. A groove width of the recessed groove gradually increases from the position of the end cutting edge toward the rear, then gradually decreases such that the recessed groove has a narrowest portion at a position P2 forward of the position P3 of an upper end of a breaker wall and rearward of a positive rake angle rear end position P1, and then gradually increases toward the rear up to the position P3 of the upper end of the breaker wall. The dimensional relation W1