Denso Corporation

Hiroaki Nagatomo

Kimitaka Saito

Keita Imai

Eiji Itoh

Masatoshi Kuroyanagi

Makoto Tanaka

Kouichi Mochizuki

A fuel injection control device is adapted for a fuel injection system including an injector and a high-pressure pump that raises pressure of fuel and supplies the fuel to the injector. The fuel injection control device includes a selecting unit for selecting by which one of full lift injection and partial injection to inject fuel, and a pump control unit for controlling operation of the high-pressure pump such that a pressure of fuel supplied to the injector coincides with a target pressure. The selecting unit selects the partial injection when a required injection quantity of fuel is equal to or smaller than a partial maximum injection quantity. A fuel injection system includes the fuel injection control device, the injector, and the high-pressure pump.

Fuel injection control device and fuel injection system

A fuel injection controller includes an energization time period calculation portion adapted to calculate an energization time period of a coil responsive to a target injection amount; and a rise control portion adapted to apply a boosted voltage to the coil, along with start of the energization time period, and to raise an current flowing through the coil to a predetermined threshold value. When a range where timing of the current raised to have a peak value at the threshold value appears in accordance with a range of an operating temperature of the coil is defined as a peak appearance range W, the target injection amount is set such that timing of completion of the energization time period Ti is timing deviated from the peak appearance range W

Fuel injection controller and fuel injection system

A fuel injection control unit includes an injection amount detector and a correction unit. When implementing partial lift injection where a valve closing operation is started after the valve body starts a valve opening operation and before a valve body reaches a maximum valve open position, the injection amount detector detects a physical quantity (valve closing timing) having a correlation with an injection amount. When implementing the partial lift injection, the correction unit corrects an energization time of a fuel injection valve on the basis of a detection value (learning value) that was previously detected by the injection amount detector. An energization time in a small amount region longer than a predetermined time in the partial lift injection is allowed to be corrected on the basis of a value (small amount time detection value) detected in the small amount region by the injection amount detector. On the other hand, an energization time in an extremely small amount region shorter than the predetermined time is prohibited from being corrected on the basis of the above small amount time detection value. As a result, a precision in the injection amount in the partial lift injection is improved.

Fuel injection control unit

A stationary core includes a holding hole that receives and holds a portion of the magnetic spring, which is located on a valve opening side. A solenoid device includes a magnetic yoke that extends in an axial direction and has an axial extent, which overlaps with an entire axial extent of the holding hole. The magnetic yoke has a predetermined portion, which reduces an amount of the magnetic flux that passes through the magnetic yoke in a radial direction in comparison to the rest of the magnetic yoke.

Fuel injection valve for internal combustion engine

A fuel injection valve includes a needle valve having an engagement part, and a movable core having an engagement part to be engaged with the engagement part of the needle valve. One of the engagement part of the needle valve and the engagement part of the movable core is defined by two inner faces of a recess opposing to each other in an axis direction, and the other engagement part is defined by two outer faces of a projection opposing to the inner faces, respectively. The projection is movable between the inner faces in the axis direction in a state that the projection is located in the recess.

Fuel injection valve

A valve body surrounds a first passage connecting with a cylinder of an engine. A valve member is adapted to be seated on and lifted from the valve seat. An injector body connects with the valve body. The injector body has a pressure control chamber for controlling hydraulic pressure applied to the valve member thereby controlling a lift of the valve member. The injector body has a second passage through which fuel in the pressure control chamber is exhausted. An actuator is adapted to communicating the pressure control chamber with the first passage through the second passage and blocking the pressure control chamber from the first passage. The first passage introduces fuel from the pressure control chamber into the cylinder through the second passage.

A fuel injection valve includes a valve body having a valve seat, a valve element adapted to sit on and leave a valve seat, a nozzle hole for the injection of fuel, and an electromagnetic drive section. A holding member surrounds and holds, on one end side thereof, at least a partial area of an opposite-to-nozzle-hole-side end face portion of the valve element. The holding member surrounds and holds, on an opposite end side thereof, a predetermined surface area of a constant position holding portion without being influenced by the pressure of fuel flowing through a fuel passage of the valve body and irrespective of movement of the valve element. An internal area of the holding member is shut off so as not to be influenced by the pressure of fuel present around the internal area.

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Kariya, Japan

Hiroaki Nagatomo