| 摘要 |
<P>PROBLEM TO BE SOLVED: To change pressure of fuel injected into an intake passage in a fuel injection system for an internal combustion engine including a low-pressure fuel pump and a high-pressure fuel pump. <P>SOLUTION: The fuel injection system for the internal combustion engine sequentially includes: the low-pressure fuel pump 1; the high-pressure fuel pump 2; a high-pressure fuel injection valve 7; a pressure reduction device 9 for reducing the pressure of the fuel to a setting pressure; and a low-pressure fuel injection valve 12. Moreover, the fuel injection system includes a communication passage 17 which communicates the low-pressure fuel pump 1 with the low-pressure fuel injection valve 12 by bypassing the high-pressure fuel pump 2, a check valve 18 which is provided in the communication passage 17 and only passes the fuel from the side of the low-pressure fuel pump 1 to the side of the low-pressure fuel injection valve, a return passage 13 which connects an upstream side and an downstream side from the low-pressure fuel pump 1, and a safety valve 14 which is provided in the return passage 13 and is opened to make the fuel flow when the pressure of the fuel at the downstream side from the low-pressure fuel pump 1 is not lower than a predetermined pressure that is higher than the setting pressure, and is closed to interrupt the flow of the fuel when the pressure is lower than the predetermined one. <P>COPYRIGHT: (C)2013,JPO&INPIT |
