SYSTEM AND METHOD FOR FORMING OPENING SECTION IN HOLLOW PIPE

摘要

PROBLEM TO BE SOLVED: To provide a system by which an opening section is formed on a surface of a metallic hollow pipe. SOLUTION: The opening section forming system to form the opening section 2 in a hollow pipe 1 comprises: a first groove cutting means 20 to cut on an outer surface section 3 of a hollow pipe 1 located in its outermost diametrical portion such a first groove 5 as having a fixed length in the longitudinal direction N of the hollow pipe 1 and a fixed depth h from its outer surface portion 3 to its axis O and remained with a remnant connection portion having a thickness s of several mms or below on an inner wall portion 6 of the pipe 1; a second cutting means 30 to cut on the outer surface section 3 a second groove 10 having the same structure as the first groove 5 along its cross section running crosswise with the axis O and at least over a semi-circumferential portion of the pipe 1; and a remnant portion breaking means 12 to rupture or sever the remnant connection portion of the first and second grooves 5 and 10 respectively. COPYRIGHT: (C)2009,JPO&INPIT