| 摘要 |
<p>PROBLEM TO BE SOLVED: To facilitate press fitting of an inner core member to the inside in an upper part of a peripheral wall of an outer core member. SOLUTION: An internal diameter of an upper part 50 in a peripheral wall 1 of an outer core member 3 is formed in a size preventing a peripheral surface 5a of a second bottom plate 5 from coming into close contact when the second bottom plate 5 of an inner core member 6 is press fitted, and an internal diameter of a lower part 51 in a peripheral wall 1 is formed in a size bringing the peripheral wall 5a of the second bottom plate 5 into close contact when it is press fitted. Each of the outer/inner core members 3, 6 is molded by press work of a metal plate. A first bottom plate 2 of the outer core member 3 and the second bottom plate 5 of the inner core member 6 superposed in each other to be press fitted are fixed by the other fixing means.</p> |
