Fuel injection apparatus
AssigneeDenso Corporation
InventorsMasahiro Okajima, Satoru Asai
Life of this patent
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Abstract
In an electromagnetic fuel injector, when an opening valve pulse is turned ON by a command from an ECU, a first coil is energized and a first fixed core attracts a moving core and unseats a valve member from a valve seat to open a valve of the fuel injector. A time Tx before the opening valve pulse becomes OFF, a closing valve pulse is turned ON, whereby a second coil is energized and a second fixed core attracts the moving core toward a valve closing direction. As a result, after the valve starts to close, the urging force in the valve closing direction increases rapidly, the time delay from the start of valve closing to the end is shortened, and the valve closing responsiveness improves.
Claims10
A fuel injector, comprising:
- a valve member for opening and closing a fuel injection hole by leaving a valve seat and seating on the valve seat;
- a moving core provided integrally with the valve member;
- a first coil, mounted at one end of the moving core, for magnetizing a first fixed core when the first coil is energized by an electrical current and attracting the moving core toward a valve opening direction;
- and
- a second coil, mounted at the other end of the moving core, for magnetizing a second fixed core and attracting the moving core toward a valve closing direction, wherein
- energizing of the second coil is started before an end of energizing of the first coil for holding the valve open, and
- in a valve-closing stroke, energizing of the second coil is ended before the valve member seats on the valve seat.
Dependencies are inferred from the claim text.