Method for manufacturing can lid, can lid, and can body

Abstract

In the elongation processing shown in A, the height of the panel ( 11 ) is maintained by supporting the panel ( 11 ) from the bottom side, the curled portion ( 13 ) is held from the top side and the bottom side, and the movement of the curled portion ( 13 ) is restricted in both of the upper direction and the lateral direction. In the elongation processing, external force is applied to the bottom part of the annular groove ( 12 ) in the downward direction in this state, and the bottom part of the annular groove ( 12 ) is pressed down. Accordingly, the panel ( 11 ) is pulled toward the outer direction in the diameter direction of the panel ( 11 ), and the tension is generated in the panel ( 11 ) as shown by the black arrow, which is intended to reduce distortion of a can lid while reducing formation of shapes in the can lid.

1 - 10 . (canceled) 
     
     
         11 . A method for manufacturing a can lid, comprising:
 forming an annular groove in a plate made of a metal;   performing deformation processing on an inner-side region of the plate, the inner-side region being located on an inner side of a part where the annular groove is formed;   applying a tension to the inner-side region by applying external force to a portion where the annular groove has been formed in the panel, after performing the deformation processing.   
     
     
         12 . The method for manufacturing the can lid according to  claim 11 , wherein
 applying the tension to the inner-side region further comprises applying the tension to the inner-side region by applying, to the inner-side region, external force that acts toward an outside in a diameter direction of the inner-side region and that is caused by applying external force increasing a depth of the annular groove to the annular groove and increasing the depth of the annular groove.   
     
     
         13 . The method for manufacturing the can lid according to  claim 11 , wherein
 forming the annular groove causes a protruding portion to be formed in the plate, the protruding portion protruding from a surface of the plate opposite to the other surface where the annular groove is formed and being formed into an annular shape, and   applying the tension to the inner-side region further comprises applying the tension to the inner-side region by applying the external force caused by pressing a side of the protruding portion toward an outer-side direction in a diameter direction of the protruding portion, the side being located on an inner side in the diameter direction of the protruding portion formed into the annular shape.   
     
     
         14 . A method for manufacturing a can lid, comprising:
 performing deformation processing on a plate made of a metal; and   applying external force acting in a thickness direction of the plate, to a portion located on an inner side with respect to an outer-side portion of the plate in a state where the outer-side portion is held, after performing the deformation processing, the outer-side portion being a portion located on an outer peripheral-edge side of the plate and located on an outer side with respect to a processed portion where the deformation processing has been performed.   
     
     
         15 . A method for manufacturing a can lid, comprising:
 performing deformation processing on a plate made of a metal; and   forming an annular groove enclosing a processed portion of the plate by performing another deformation processing on a peripheral area of the processed portion of the plate, after performing the deformation processing on the plate, the processed portion being a portion where the deformation processing has been performed.   
     
     
         16 . A can body comprising:
 a main body of a can comprising an opening part and containing a content; and   a can lid attached to the opening part of the main body, wherein   the can lid is the can lid manufactured by the method for manufacturing the can lid according to  claim 11 .   
     
     
         17 . The can body comprising:
 a main body of a can comprising an opening part and containing a content; and   a can lid attached to the opening part of the main body, wherein   the can lid is the can lid manufactured by the method for manufacturing the can lid according to  claim 12 .   
     
     
         18 . The can body comprising:
 a main body of a can comprising an opening part and containing a content; and   a can lid attached to the opening part of the main body, wherein   the can lid is the can lid manufactured by the method for manufacturing the can lid according to  claim 13 .   
     
     
         19 . The can body comprising:
 a main body of a can comprising an opening part and containing a content; and   a can lid attached to the opening part of the main body, wherein   the can lid is the can lid manufactured by the method for manufacturing the can lid according to  claim 14 .   
     
     
         20 . The can body comprising:
 a main body of a can comprising an opening part and containing a content; and   a can lid attached to the opening part of the main body, wherein   the can lid is the can lid manufactured by the method for manufacturing the can lid according to  claim 15 .   
     
     
         21 . A can lid comprising:
 a base formed into a plate and being to be attached to a main body of a can, the main body containing a content;   a processed portion which is located on an inner side of an outer peripheral edge of the base and on which deformation processing has been performed; and   an annular groove formed along the outer peripheral edge of the base and around the processed portion, wherein   elongation processing is performed on a part of the base by applying external force to the annular groove after the deformation processing is performed on the base, the part being located on the processed portion, or   elongation processing is performed on the part of the base by forming the annular groove by another deformation processing after the deformation processing is performed on the base, the part being located on the processed portion.   
     
     
         22 . A can lid comprising:
 a base that is formed into a plate and is to be attached to a main body of a can, the main body containing a content; and   a processed portion which is located in an inner-side region located on an inner side of an outer peripheral edge of the base, and on which deformation processing has been performed, wherein   elongation processing is performed on a part of the base by pressing at least part of the inner-side region in a thickness direction of the base in a state where an outer peripheral edge of the base is held, after the deformation processing is performed, the part of the base being a portion where the deformation processing has been performed.   
     
     
         23 . The can lid according to  claim 21 , wherein
 a score line is formed in the processed portion by the deformation processing, the score line enhancing cracking of the base when an opening is formed in the base,   the score line comprises one end and the other end on a central-part side in a diameter direction of the base, is formed to expand toward an outer peripheral-edge side of the base, and further comprises a peak on the outer peripheral-edge side, and   the score line is formed so that the one end and the other end are located in one region out of two regions opposite to each other with respect to a central part in the diameter direction of the base and the peak is located in the other region.   
     
     
         24 . The can lid according to  claim 22 , wherein
 a score line is formed in the processed portion by the deformation processing, the score line enhancing cracking of the base when an opening is formed in the base,   the score line comprises one end and the other end on a central-part side in a diameter direction of the base, is formed to expand toward an outer peripheral-edge side of the base, and further comprises a peak on the outer peripheral-edge side, and   the score line is formed so that the one end and the other end are located in one region out of two regions opposite to each other with respect to a central part in the diameter direction of the base and the peak is located in the other region.   
     
     
         25 . A can body comprising:
 a main body of a can comprising an opening part and contains a content; and   a can lid which is attached to the opening part of the main body, wherein   the can lid is the can lid according to  claim 21 .   
     
     
         26 . The can body comprising:
 a main body of a can comprising an opening part and contains a content; and   a can lid which is attached to the opening part of the main body, wherein   the can lid is the can lid according to  claim 22 .   
     
     
         27 . The can body comprising:
 a main body of a can comprising an opening part and contains a content; and   a can lid which is attached to the opening part of the main body, wherein   the can lid is the can lid according to  claim 23 .   
     
     
         28 . The can body comprising:
 a main body of a can comprising an opening part and contains a content; and   a can lid which is attached to the opening part of the main body, wherein   the can lid is the can lid according to  claim 24 .