| 摘要 |
PROBLEM TO BE SOLVED: To provide a battery case in which process is easy, small-sized, having a high strength. SOLUTION: A cap 12 is fitted to a battery case body 10, and a battery electrode 16 is protruded in the cap 12. On the top face of the cap 12, a groove 18 is formed close to the joint part 14 of the battery case 10 with the cap 12 along the circumference of the cap 12. As the material for the battery case 10 and the cap 12, aluminum or aluminum alloy, etc. is preferable for example. Because of presence of this groove 18, welding heat is prevented from escaping to the cap 12 in welding after fitting the cap 12 to the battery case body 10. Accordingly, the joint 14 needs not be made into a protruded shape. Therefore, even if the cap 12 is increased in thickness to enhance its strength, enlargement of the battery case is avoided. Furthermore, as laser power for welding is small because the welding heat does not escape to the cap 12, production cost for the battery case is suppressed by reducing the facility cost and electric power expense. Furthermore, as the surface area of the cap 12 becomes larger by portion of making the groove 18, a heat radiation characteristic in operation of the battery is improved. In addition, if the grove 18 is used for adjusting the position of the laser for welding, the productivity of the battery case is further improved. COPYRIGHT: (C)2004,JPO |
