BORING APPARATUS AND CORE CUTTER FOR BORING

摘要

PURPOSE: A punching device and core cutter for punching is provided to facilitate carrying and assembling of core cutter and punching part by adjusting the diameter of core cutter. CONSTITUTION: A punching device comprises a core cutter(2), a driving member and supporting device. The core cutter arranges a cutter portion arranging tips in circular arc direction. The driving member rotates each cutter portion of the core cutter according to arc. The supporting device supports the core cutter and driving member in order to accord the core cutter rotary shaft to the column line of a sewerage pipe(11). The cutter portion is fixed to a manhole wall of the outer circumference of the sewerage pipe.