| 摘要 |
PROBLEM TO BE SOLVED: To improve the productivity of a fuel injection valve. SOLUTION: A composite magnetic pipe 20 is magnetized, and the intermediate part alone is non-magnetized, whereby a magnetic pipe part 21, a non- magnetic pipe part 22 and a magnetic valve storage part 23 are integrally formed up. A slide-contact ring 47 sliding on an inner circumferential surface of the non-magnetic pipe part 11 is formed on an outer circumferential surface of a moving iron core 38 by means of cutting work (machining), and a nearly uniform air gap is formed in a space between the outer circumferential surface of the moving iron core 38 and the inner circumferential surface of the valve storage part 23. This air gap serves to separate magnetic flux lying between the moving iron core 38 and the valve storage part 23 when the moving iron core 38 attracted to a fixed iron core 26 is peeled off, and to improve the responsiveness of a needle valve 30 in closing the valve, and to reduce lateral electromagnetic force (eccentric load) working on the fixed iron core 26. The slide- contact ring 47 is formed on the outer circumferential surface of the moving iron core 38, whereby machinability is improved.
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