| 摘要 |
PURPOSE:To facilitate machining of sliding surfaces improve starting characteristics when it is cold by providing two needles which are slidably installed keeping a certain space apart in parallel with each other, and feeding secondary fuel which is heated while being circulated. CONSTITUTION:A needle 6 for primary fuel and a needle 7 for secondary fuel are slidably provided keeping a certain space apart in parallel with the shaft axis of a needle holder. The needles 6 and 7 are in a closed position while they are pressed by springs 22 and 23. when secondary fuel which is heated by a circulating mechanism in a head 2, is fed from a feeding hole 38 by an injection pump, the tapered portion 7g is subjected to a back pressure allowing the needle 7 to be elevated overcoming a spring (35) force so as to inject the secondary fuel into a cylinder 10 from a passage 14. Subsequently, pressurized control oil is fed to an oil chamber 23 from a feeding hole 25 so as to allow a large diameter portion 6d to press the spring 22 because of a back pressure. Then the needle 6 is elevated allowing the primary fuel to be injected into the cylinder 10 from a passage 13. Thus, machining of sliding surface is facilitated and start-up characteristics when it is cold is improved. |
