| 摘要 |
PURPOSE:To reduce the initial fuel injection rate by providing an injection valve body opening or closing an injection valve port and a valve port releasing the pressure so that the force to open an injection valve when the valve port is opened is made smaller than the force to close the injection valve when the valve port is closed. CONSTITUTION:The fuel injection port 2 of a high-pressure fuel injection device is opened on an accumulator chamber 7, and an injection valve body 13 is arranged. The center passage 16 of the injection valve body 13 is communicated to a small chamber 23, and a large-diameter section 14 is held slidably with a cylinder 21. A valve body 31 is provided at the valve port 24 of the small chamber 23 and operated by an electromagnet. A coil spring 41 is fitted in the direction that the injection valve body 13 closes the injection port 2. Fuel is fed through a passage 28. The load of the coil spring 41 is set so that the lifting speed of the injection valve body 13 when the valve port 24 is opened is made slower than the lowering speed of the injection valve body 13 when the valve port 24 is closed based on the relation among the pressure of the accumulator chamber 7, the pressure of the small chamber 23 when the valve port 24 is opened, and cross section areas of a small-diameter section 15 and the large-diameter section 14 applied with the pressure. The initial fuel injection rate is reduced with a simple structure.
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