Preform conveying device, preform conveying method, and blow molding device

A preform conveying device comprising:

• a continuous conveyor section that continuously conveys a conveyor jig which supports a preform along a heating conveyor path;
• an intermittent conveyor section that intermittently conveys a conveyor arm between a first position and a second position along a direction which is parallel to the heating conveyor path, the preform being transferred from the conveyor jig to the conveyor arm during the conveying of the conveyor arm;
• and
• a control unit that controls the intermittent conveyor section so that the conveyor arm which was waiting in the first position can catch up with the conveyor jig which is being conveyed continuously,
• wherein the continuous conveyor section includes a first motor which applies conveying force to the conveyor jig and a first encoder which detects a rotational angle of the first motor,
• wherein the intermittent conveyor section includes a second motor which applies conveying force to the conveyor arm, and
• wherein the control unit detects an arriving time at which the conveyor jig arrives at a reference position facing the first position based on an output of the first encoder, and commands the second motor to move the conveyor arm to a target position at regular intervals from the arriving time, the target position in each command being a position obtained by adding, to a current position of the conveyor jig which is obtained based on a latest output of the first encoder which was obtained when the command has been issued, a moving distance by which the conveyor jig has advanced during a delay time which spans from a time when the latest output is outputted from the first encoder to a time when the command is received by the second motor.