| 摘要 |
PURPOSE:To enable easy detection of the valve opening pressure value of a fuel injection valve through measurement of a contact time between a needle valve and a nozzle body, by a method wherein, in a state in that the needle valve is brought into contact with a stopper means, the needle valve is electrically connected with the nozzle body. CONSTITUTION:When a fuel injection valve 1 is closed, the level of a voltage signal V0 generated at a resistor 27 is raised to [H]. When the forced feed of fuel is started, a needle valve 8a is separated from a valve seat 10, and the fuel injection valve 1 is opened, the level of the voltage signal V0 is lowered to [L]. When a fuel pressure is further increased and the needle valve 8a is brought into contact with an intermediate plate 3, the needle valve 8a is electrically connected with a nozzle body 6, and thereby the level of the voltage signal V0 is raised to [H] again. In which case, the length of a period in which the voltage signal V0 generated during the starting of injection and at a completion time of injection is increased to [H] depends upon the valve opening pressure value of the fuel injection valve 1. This enables detection of an actual valve opening pressure valve by reference to data indicating relation between said period and the valve opening value.
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