| 摘要 |
<p>PURPOSE:To prevent a hollow from its generation in a surface of a synthetic resin pipe when a riseup branch part is obliquely formed in the synthetic resin pipe. CONSTITUTION:In a branch work method for a synthetic resin pipe 1, a riseup branch part 1a is formed to tilt to a side of one pipe end part in the synthetic resin pipe 1. First, a branch hole 12 is formed in a pipe wall 11 of the synthetic resin pipe 1, and a riseup margin 13 of predetermined width L is left in a peripheral edge part of the branch hole 12 to closely attach a correcting jig 2 of shape agreeing with the internal surface shape to the internal surface in a position to a pipe end part of the riseup margin 13 by a predetermined pressure. Thereafter, the peripheral edge part of the branch hole 12 is heated and softened and also diagonally pulling up a burring metal mold 3, inserted into the synthetic resin pipe 1, to a side of the correcting jig 2, to form the riseup branch part 1a.</p> |
