| 摘要 |
PURPOSE:To enable to detect the fuel injection timing with high sensitivity and excellent temperature characteristics, by leading an optical fiber having a high heat resistance into a fuel injection valve, and detecting the injection timing from the change in the quantity of light. CONSTITUTION:When the fuel pressure becomes higher than the pressing force of a valve spring 1 by a fuel injection pump, a valve element 2 and a pressure pin 11 are moved upward and the gap between the top 6 of an optical fiber and the top of a pressure pin is changed, so that the quantity of reflected light received by a light receiving element 5, i.e., the optical electromotive force of the element 5 is changed. By comparing the level of the optical electromotive force by a comparator in a detector section 18, the fuel injection starting period can be detected with high sensitivity from the change in the output of said comparator. |
