| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an opening structure of a blow molded body, with which flatness of the opening is retained, by thinning the wall of the opening of a fuel tank etc. and improving stiffness of the opening, and to provide a method for forming the same.SOLUTION: An opening 10 of a blow molded body has an opening outer wall section 15, an opening upper wall section 13, and an opening inner wall section 11, and the opening inner wall section 11 has been formed continuously and circumferentially along the opening with a width nearly equal to the width of the opening. A blow molding mold 20 is equipped with an opening outer wall forming section 25 for forming the opening outer wall section 15 and the opening upper wall section 13. A slidable and cylindrical opening cutting blade 30 is installed on a side more inner than the opening outer wall forming section 25. The opening cutting blade 30 has a cutting blade root section 31 and a cutting blade tip section 32, and an outer diameter of the cutting blade root section 31 is larger than that of the cutting blade tip section 32. A parison is cut off with the cutting blade tip section 32 while leaving a width for forming the opening inner wall section 11, and the opening inner wall section 11 is formed by bending a section for forming the opening inner wall section 11 to the inside with the cutting blade root section 31.</p> |
