| 摘要 |
PROBLEM TO BE SOLVED: To provide a fuel injection valve capable of detecting the lift amount of a nozzle needle with a high response and having a sufficient strength in a structure in which the entire nozzle needle is positioned in high-pressure fuel. SOLUTION: A stop pin 61 is installed so as to come into contact with the upper end of the nozzle needle 1 having the lift controlled by a hydraulic pressure in a control chamber 2, and a magnetic plate 62 is fixed to the outer periphery of the stop pin. Magnetic chips 63a and 63b are installed above the magnetic plate 62, and a detection coil 67 allowing a permanent magnet 64 and a magnetic bar 65 to be inserted therein is installed on the outer peripheral side of the magnetic chips 63a and 63b. Also a magnetic ring 68 to surround all of these chips and detection coil is installed to form a lift amount detection part 6. The magnetic plate 62, magnetic chips 63a and 63b, magnetic bar 65, and magnetic ring 68 forming a magnetic circuit are formed of a high permeable material to vary, with high response, a magnetic circuit resistance when the magnetic plate 62 is displaced together with the nozzle needle 1 so as to detect the lift amount of the nozzle needle 1 with high response.
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