公开(公告)号：DE3675831D1

公开(公告)日：1991-01-10

申请号：DE3675831

申请日：1986-05-28

Applicant: IBM

Inventor： JOHNSON ERIC A ,  PRICE II

IPC: B23Q17/09 ,  B23B47/24 ,  B23B49/00 ,  G01H17/00

Abstract: A failure detector (12) detects breakage in a machine tool cutting element (22), such as a drill bit, by use of an accelerameter (62, 58) supported against a workpiece (16) being operated on by the cutting element. Vibrations are induced in the workpiece by the cutting operation, the vibrations having spectral components in the audio frequency range which are characteristic of proper operation of the cutting element (22), the spectral components changing upon a breakage of the cutting element. A voltage (40) produced by a positioning mechanism (38, 36) of the cutting element identifies the location of the cutting element relative to the workpiece. A bandpass filter (46) separates the spectral components associated with proper operation from spectral components associated with faulty operation. Logic circuitry (52) monitors the joint occurrence (122, 100) of the spectral components of proper operation with the position of the cutting element at the site of the workpiece so as to permit the signaling (56) of a cutting tool failure during operation on the workpiece.