Fuel injection controller and fuel injection system

Patent metadata

Field	Value
Publication number	US-9970376-B2
Application number	US-201415037447-A
Country	US
Kind code	B2
Filing date	Nov 10, 2014
Priority date	Nov 21, 2013
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

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 1 , 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 1.

First claim

The invention claimed is:

1. A fuel injection controller for a fuel injector adapted to perform a valve-opening operation of a valve body through electromagnetic attraction force generated by energization of a coil, the fuel injector injecting a fuel for use in combustion in an internal combustion engine, the fuel injection controller comprising:
a target injection amount setting portion adapted to set a target injection amount of the fuel through a single opening of the fuel injector;
an energization time period calculation portion adapted to set a base value of an energization time period of the coil responsive to the target injection amount and to correct the base value according to a temperature of the coil to calculate the energization time period;
a booster circuit adapted to boost a battery voltage; and
a rise control portion adapted to apply a boosted voltage, which is a voltage boosted by the booster circuit, 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;
wherein
a peak appearance range is defined as a range which includes a boundary between an increase area in which the injection amount decreases as the temperature of the coil is higher and an increase area in which the injection amount increases as the temperature of the coils is higher, and
the target injection amount setting portion sets the target injection amount such that timing of completion of the energization time period is timing later than the peak appearance range, in a case that the valve body is positioned at a partial area.

2. The fuel injection controller according to claim 1 , wherein
the target injection amount setting portion sets the target injection amount such that the timing of completion of the energization time period is timing later than the peak appearance range.

3. The fuel injection controller according to claim 1 , wherein
in a case where pre-charging for applying the battery voltage to the coil is performed prior to the application of the boosted voltage by the rise control portion, the target injection amount setting portion sets the target injection amount such that the timing of completion of the energization time period is timing deviated from the peak appearance range.

4. A fuel injection controller for a fuel injector adapted to perform a valve-opening operation of a valve body through electromagnetic attraction force generated by energization of a coil, the fuel injector injecting a fuel for use in combustion in an internal combustion engine, the fuel injection controller comprising:
a target injection amount setting portion adapted to set a target injection amount of the fuel through a single opening of the fuel injector;
an energization time period calculation portion adapted to a base value of an energization time period of the coil responsive to the target injection amount and to correct the base value according to a temperature of the coil to calculate the energization time period;
a booster circuit adapted to boost a battery voltage;
a rise control portion adapted to apply a boosted voltage, which is a voltage boosted by the booster circuit, 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;
wherein
when a point where characteristic lines indicating relationships between the energization time period and the injection amount at different coil operating temperatures are intersected with each other is defined as a cross point, at which an increase area in which the injection amount decreases as the temperature of the coil is higher and an increase area in which the injection amount increases as the temperature of the coil is higher are switched to each other, and a range where the cross point appears in accordance with a range of the operating temperature of the coil is defined as a cross-point appearance range,
the target injection amount setting portion sets the target injection amount such that timing of completion of the energization time period is timing deviated from the cross-point appearance range in a case that the valve body is positioned at a partial area.

5. The fuel injection controller according to claim 4 , wherein
in a case where pre-charging for applying the battery voltage to the coil is performed prior to the application of the boosted voltage by the rise control portion,
the target injection amount setting portion sets the target injection amount such that the timing of completion of the energization time period is timing deviated from the cross-point appearance range.

6. The fuel injection controller according to claim 1 , wherein
a resistance value of the coil, the boosted voltage, and the threshold value are set such that a range of the target injection amount set by the target injection amount setting portion includes a small injection amount with which the valve body starts a valve-closing operation before reaching a maximum valve-opening position, after the start of the valve opening operation.

Assignees

• Denso Corp

Inventors

• Nagatomo Hiroaki
• Tanaka Makoto

Classifications

• F02D41/20 Primary

  Output circuits, e.g. for controlling currents in command coils · CPC title

• F02D2041/2006

  by using a boost capacitor · CPC title

• F02M51/061

  using electromagnetic operating means · CPC title

• F02D2041/2065

  the control being related to the coil temperature · CPC title

• F02M51/0671

  the armature having an elongated valve body attached thereto · CPC title