| 摘要 |
PURPOSE:To reduce the model cost of a core and the cost of formation by arranging a plurality of locking structures so that they oppose each other at the symmetrical positions with respect to the central line in the axial direction of an outer drum and the axial direction of the locking structures forms the right angle with the central lines of the axial direction. CONSTITUTION:A protruded hollow terminal box connecting part 7 is formed at the outer periphery of the outer drum 1 so as to form one body. The protruded central line of the part 7 is crossed with the central line of the axial direction of the outer drum 1 at a right angle. Four connecting parts 8, wherein the locking structures 9 are provided at the inner ends, are protruded from parts of the outer periphery of the outer drum 1 so as to form one body. The locking structures 9 oppose at the symmetric positions with respect to the central line in the axial direction of the outer drum. The axial line of the locking structure forms the right angle with the central line of the axial direction of the outer drum. Four reinforcing ribs 12 are formed at the outer periphery of the outer drum 1 in the axial direction, with an equal pitch. The center between the two ribs 12 coincides with the central line of the axial direction. In this constitution, the model cost of the core and the cost of formation can be reduced. |
