| 摘要 |
PURPOSE:To control the machining length accurately and to facilitate the precise machining by detecting and storing the position where a tool comes into contact with an object to be machined by a controller by a variation of a signal from an AE sensor abutted on the stationary object to be machined. CONSTITUTION:The material 17 with the already known thickness is held to one of plural chuck tables 18 provided to a peripheral part of a rotating disc 22. The AE sensor 12 fitted to a sensor supporting means 14 via a rod 15 and an intermediating means 13 is abutted on the material 17. Then, the tool 36 is lowered while being rotated by a spindle 33 and an elastic wave which generates when the tool 36 contacts with the material is received by the AE sensor 12 and sent to the controller 44 as the tool position information and stored there. Then, the material 17 is replaced with the object 16 to be machined and while the object 16 to be machined is ground by the tool 36, the same operation as the measurement of the thickness of the material 17 is repeated to finish up the object to be machined to the prescribed thickness. Hereby, the elastic wave is received with high sensitivity and the accurate position of the tool is calculated and the accurate machining can be performed. |
