Patent ID: 7015421

Claim:
A fusion joining device for plastic tubes that heats a joint portion of plastic tubes for fusion joining the joint portion, comprising: a fusion joining head for sandwiching said joint portion from both sides to heat the joint portion, wherein said fusion joining head comprises a pair of members for heat conduction, a pair of clampers, and a pair of heaters; said pair of members for heat conduction is disposed so as to be opposed to each other through said joint portion; said pair of clampers is supported to be pivoted between a closed position where said pair of clampers sandwiches said joint portion from both sides through said pair of members for heat conduction, and an open position where a spacing between said pair of members for heat conduction is widened; and said pair of heaters is made of a resistance heat generation material in a sheet shape, and is arranged along said pair of members for heat conduction, respectively, for heating said joint portion through the pair of members for heat conduction, a supporting head for removably supporting the fusion joining head, and a heating circuit for supplying power to the fusion joining head through the supporting head; wherein said supporting head supports the pair of clampers pivotably between the closed position and the open position; said heating circuit comprises a pair of head electrodes; one of said pair of head electrodes is provided on the fusion joining head; the other of said pair of head electrodes is provided on the supporting head; said pair of head electrodes is connected to each other when the fusion joining head is loaded onto the supporting head; and at least one of said pair of head electrodes is energized in a direction in which the one of the pair of head electrodes is connected to the other of the pair of head electrodes.