Manufacturing method for pipe structure

Abstract

A manufacturing method for a pipe structure includes a pipe bending step for implementing for a plurality of times a bending process of bending a part of a straight pipe by wrapping the part around a peripheral surface of a rolling block to form a plurality of bend portions in intermediate locations along a longitudinal direction of the pipe. When a final bending process is implemented during the pipe bending step, a position of a rear end portion of the pipe is determined, and relative positions of the pipe and the rolling block in a predetermined y direction are controlled on the basis of the position of the rear end portion so that after the bending process, a y-direction position of the rear end portion is aligned with a y-direction position of the front end portion. According to this configuration, complicated operations such as cutting the respective end portions of the pipe after bending the pipe can be eliminated, and a pipe structure such as a meandering pipe body in which the positions of the respective end portions are aligned can be manufactured appropriately and with favorable productivity.

1 . A manufacturing method for a pipe structure, comprising a pipe bending step for implementing for a plurality of times a bending process of bending a part of a straight pipe by wrapping the part around a peripheral surface of a rolling block to form a plurality of bend portions in intermediate locations along a longitudinal direction of the pipe,
 a region near a front end portion on a bend start side of the pipe and a region near a rear end portion on a bend end side being separated from each other in a predetermined x direction and extending in a y direction that intersects the x direction,   wherein, when a final bending process is implemented during the pipe bending step, a position of the rear end portion of the pipe is determined, and relative y-direction positions of the pipe and the rolling block are controlled on the basis of the position of the rear end portion so that after the final bending process, a y-direction position of the rear end portion is aligned with a y-direction position of the front end portion.   
     
     
         2 . The manufacturing method for a pipe structure according to  claim 1 , wherein the pipe structure is a meandering pipe body. 
     
     
         3 . The manufacturing method for a pipe structure according to  claim 1 , wherein the pipe structure is a spiral pipe body. 
     
     
         4 . The manufacturing method for a pipe structure according to  claim 1 , wherein detecting means for detecting the rear end portion of the pipe is used in an operation for controlling the relative y-direction positions of the pipe and the rolling block on the basis of the position of the rear end portion, and by using the detecting means, the pipe is positioned so that the rear end portion of the pipe is disposed a predetermined dimension away from the rolling block in the y direction. 
     
     
         5 . The manufacturing method for a pipe structure according to  claim 4 , wherein the predetermined dimension is a y-direction dimension from the rolling block to the front end portion of the pipe in a state where the pipe and the rolling block have been positioned to implement a first bending process on the pipe. 
     
     
         6 . The manufacturing method for a pipe structure according to  claim 4 , comprising a step for determining a projection dimension in the y direction from the rolling block to the front end portion of the pipe when positioning the pipe and the rolling block to implement the final bending process,
 wherein the predetermined dimension is set at a value corresponding to the projection dimension.   
     
     
         7 . The manufacturing method for a pipe structure according to  claim 1 , wherein a pipe on which respective longitudinal direction end portions have been laser-cut is used as the straight pipe.