| 摘要 |
<p>The present invention comprises the steps of: (a) extruding a material into a prismatic hollow material having two open ends; (b) drawing the hollow material multiple times such that the thickness of the hollow material reaches the desired thickness; (c) forming a body by cutting the hollow material, which has been drawn, into a fixed length; (d) manufacturing an airtight cover in a form that corresponds to an open end of the body; and (e) welding the airtight cover to the open end of the body. Manufacturing the body of a prismatic battery case by means of an extrusion and repeated drawings, according to the present invention, allows the body to be manufactured into the desired thickness, and at the same time decreases the defect rate by preventing cracks from forming on the body. In addition, heat treating the drawn hollow material after each drawing process lowers the hardness and strength of the hollow material and improves the moldability of the hollow material, thereby preventing an occurrence of a defect during the subsequent drawing process. Furthermore, a leakage prevention groove and a leakage prevention protrusion are formed on the body and the airtight cover, thereby preventing an electrolyte solution inside the battery case from leaking outside.</p> |
