To secure necessary air tightness and joining strength, further to prevent breakage, etc., of a joined part due to secular change after completion by joining the joining part of a can and lid with cold welding and not leaving a flange to the outer circumference of can in which the joined part is formed flat along the side face of can.
Cold welding is executed in the processes in which a pressure welding die 5 is inserted in a can 2, a lid 1 is placed on its opening part, a pressure welding punch 4 pressurizes from the upper face of lid 1 and the lid 1/can 2 are pushed into the die 5. The joined part of can 2 and lid 1 is pressurized while ironing with both the pressurizing part of tip of pressure welding punch 4 and the inner face of pressure welding die 5. By this method, friction and base metal crack due to plastic deformation are generated to both contact faces. As a result, an active face is exposed to both contact faces and maintained while pressurized, interatomic bonding is generated to the joined face to have cold pressure welding bonding. At the same time, the joined part is formed flat along the side face circumference of can 2, the side face of enclosed container is turned to flageless.
SUZUKI KAZUO
KONNO KEIICHI
