Patent ID: 8132438

Claim:
A closing machine for closing an open end of a work piece that rotates about an axial center thereof by pressing a heated die against the work piece, the axial center being in a first horizontal direction that is substantially perpendicular to the direction of gravity, comprising: a chuck spindle that rotates the work piece; a moving device that moves the chuck spindle, together with the work piece, along a second horizontal direction to a processing position in which the heated die is pressed against the work piece, the second horizontal direction being substantially perpendicular to the direction of gravity and being perpendicular to the first horizontal direction; an air purge box disposed vertically above the processing position with respect to the direction of gravity and having an opening portion that opens vertically downwards towards the work piece in the processing position along the direction of gravity; a sensor provided in the interior of the air purge box to detect a state of the work piece that has moved to the processing position; and air supply means for supplying air to an interior of the air purge box, so as to prevent the sensor from being exposed to lampblack generated by a processed portion of the work piece by the heated die.