Current collector shape adjusting device

A current collector shape adjusting device squashing a projected object on bent portions of current collectors of a battery unit before housing the battery unit in a metallic battery case of a prismatic battery,

• the battery unit comprising:
• an electrode plate group composed of a plurality of square-shaped positive electrode plates and negative electrode plates stacked via separators in which side edge portions of the electrode plates on the opposite sides are protruded from facing areas of both the electrode plates;
• and
• the current collectors having lead portion joint surfaces, which are respectively provided corresponding to lead portions of positive electrode plates and negative electrode plates in sides of the electrode plate group, face to end portions of the lead portions, and have at least a part to be welded and fixed to the lead portions, and bent portions bend from both side edges of respective lead portion joint surfaces to lie over outer surfaces of the electrode plate group in a stack direction of the positive electrode plates and the negative electrode plates, and
• the current collector shape adjusting device comprising:
• a work placement unit on which the battery unit is placed;
• a pair of pressing pieces provided in both sides of the battery unit in a thickness direction to squash and deform, in the thickness direction, a projected object on the bent portions of the current collectors of the battery unit disposed on said work placement unit;
• a pair of piece fixing plates fixing and supporting said respective pressing pieces;
• and
• a moving mechanism moving said pair of piece fixing plates and pressing pieces toward the battery unit placed on said work placement unit,
• wherein each of said pressing pieces comprises a head portion made of iron or steel contacting with the bent portion of the current collector, a main body fixed to said piece fixing plate, and a spring disposed between the head portion and the main body,
• wherein said pressing pieces are respectively provided corresponding to welding line correspondent portions on the bent portions, which are in extensions of welding lines on lead portion joint surfaces, of the current collectors,
• wherein said moving mechanism includes a pair of pressure arms, which are provided corresponding to each of the piece fixing plates to press the piece fixing plates toward the battery unit, and a pressure cylinder having a piston which is connected to one of the pressure arms and a cylinder which is connected to the other of the pressure arms, and
• wherein a distance between the pressure arms is adjusted by the piston, which moves forward and backward relative to the cylinder, and when both of the pressure arms are moved to be close to each other, each of the pressing pieces supported by the piece fixing plates are moved toward the battery unit.