| US 7,552,720 B2 | ||
| Fuel pump control for a direct injection internal combustion engine | ||
| Jonathan Borg, Erding (Germany); Harsha Badarinarayan, Novi, Mich. (US); Donald J. McCune, Farmington Hills, Mich. (US); Atsushi Watanabe, Novi, Mich. (US); Takuya Shiraishi, West Bloomfield, Mich. (US); and George Saikalis, West Bloomfield, Mich. (US) | ||
| Assigned to Hitachi, Ltd, Tokyo (Japan) | ||
| Filed on Nov. 20, 2007, as Appl. No. 11/943,087. | ||
| Prior Publication US 2009/0126688 A1, May 21, 2009 | ||
| Int. Cl. F02M 37/04 (2006.01); F02M 37/06 (2006.01) | ||
| U.S. Cl. 123—508 [123/506] | 12 Claims |
| 1. A fuel pump for a direct injection internal combustion engine comprising:
a body having a valve seat,
a valve having a valve head, said valve movably mounted to said body between an open position in which said valve head is
spaced from said valve seat, and a closed position in which said valve head abuts against said valve seat,
an electric coil which, upon energization, moves said valve to said open position and, upon deenergization, allows said valve
to move to said closed position,
a control circuit which controls the energization of said coil to reduce the pump noise during operation of the engine,
wherein said control circuit deenergizes said coil in a ramp function whenever the speed of the engine is less than a predetermined
threshold to thereby reduce the speed of closure of said valve head from said open to said closed position.
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