DEVICE FOR ASSEMBLING RING-SHAPED MEMBER

Provided is a device for assembling a ring-shaped member in which the ring-shaped member is not readily brought into contact with an object during a movement process when the ring-shaped member is assembled on the object. The device (1) for assembling a ring-shaped member operates such that when an insertion part (20) that holds an O-ring (90) is inserted into the accommodation part (182) of a workpiece (180), the insertion part (20) and a positioning pin (14) are caused to move while a positional relationship is sustained in which the depth direction of the workpiece (180) and the direction in which the insertion part (20) extends are aligned. In a process for inserting the insertion part (20) into the accommodation part (182), the positioning pin (14) and a through-hole part (192B) are mated before the O-ring (90) being held is caused to move to a placement part (186A). The spacing (L1) between the through-hole part (192B) and the placement part (186A) is kept to a fixed spacing (X),and the spacing (L2) bet