| 摘要 |
PURPOSE:To keep fuel pressure high even just before a needle valve takes its seat as well as to make a backflow of combustion gas not occur, by installing a pressure-regulating sleeve and also a pressure-regulating spring which energizes it so as to do its slide motion with the fuel pressure being somewhat lower than valve opening pressure. CONSTITUTION:A pressure-requlating sleeve 8 is provided with a pressure receiving surface 9, adjoining an oil sump 4, at its tip end, and one end of a pressure- regulating spring 12 comes into contact with its base end part with pressure, energizing it toward the tip end side. Working pressure in the pressure-regulating spring is set to be slightly lower than valve opening pressure in a needle valve 13. When fuel is fed to the oil sump 4 with pressure, the pressure-regulating sleeve 8 slides upward as in illustration, and in time of injection ending, it slides downward by dint of energizing force of the pressure-regulating spring 12 whereby substantial capacity in the oil sump decreases. In consequence, a sudden drop in fuel pressure is relieved to some extent so that such a pressure-regulating effect as being sufficient to prevent a backflow of fuel gas surely from occurring, is securable.
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