Welding joining method and welding joined body
AssigneeToyota Jidosha Kabushiki Kaisha
InventorYouichiro Baba
Life of this patent
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Abstract
Provided is a welding joining method for joining end portions of first and second pipes made of polyamide resin by bonding the end portions to each other by pressure in a molten state. The welding joining method includes: a placing step of placing an infrared radiation lamp between the first and second pipes placed to face each other at an interval; a heating and melting step of heating and melting the end portions of the first and second pipes by emitting infrared; and a pressure bonding step of cooling down the molten end portions in a state where the molten end portions are bonded to each other by pressure.
Claims2
A welding joined body including a joined portion obtained by bonding, by pressure, end portions of tubular members made of crystalline resin to each other in a molten state, wherein:
- a weld bead remains in a vicinity of the joined portion and in a shape folded onto an inner peripheral surface of one of the tubular members from a root of the weld bead, the weld bead being discharged from the joined portion in pressure bonding such that the weld bead projects inwardly in a tubular radial direction and falls down toward the one of the tubular members;
- a rate of change in crystallinity in the tubular radial direction in a belt-shaped predetermined region extending outwardly in the tubular radial direction when the predetermined region is viewed in a circumferential direction is a predetermined value or less, the predetermined region being set in a corresponding one of the tubular members so as to start from a boundary portion between the weld bead and the inner peripheral surface of the corresponding one of the tubular members.
Dependencies are inferred from the claim text.