| 摘要 |
<p>PURPOSE: To utilize an air gap sufficiently while preventing saturation by a structure wherein the wall end part is coupled with a core means spaced apart in the axial direction, an axially extending means is couples magnetically with the wall end part and a coaxially extending means extends only partially in the circumferential direction of secondary winding. CONSTITUTION: The firing coil comprises an axially extending core means 16 made of a magnetic material, a primary winding 18 arranged around the core means 16, and a secondary winding 22 arranged around the primary winding 18. The firing coil further comprises end wall parts 12D, 14D made of a binder of electric insulating material and iron particles, and axially extending means 12B, 14B made of a magnetic material and arranged on the outside of the secondary winding 22. The electric insulating material is interposed between the iron particles and a plurality of gaps serving as air gaps are formed between the iron particles. More specifically, the electric insulating material constitutes a binder for the iron particles and can form an insulating gap between the iron particles while insulating them electrically from each other.</p> |
