Fuel injection apparatus

Patent metadata

Field	Value
Publication number	US-9470172-B2
Application number	US-201414164284-A
Country	US
Kind code	B2
Filing date	Jan 27, 2014
Priority date	Feb 1, 2013
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

An individual difference index is obtained based on the slope of variation ratios between a plurality of actual injection quantity and a target injection quantity. The individual difference index is stored as a learning value. An individual difference correction of the fuel injector is conducted based on the individual difference index. By using the individual difference index, a shot-dispersion is removed and individual-difference correction of the fuel injector can be conducted.

First claim

What is claimed is:

1. A fuel injection apparatus comprising:
a common rail accumulating a fuel;
a fuel injector injecting the fuel in the common-rail;
a pressure sensor detecting a fuel pressure accumulated in the common-rail; and
a control unit performing an injection control of the fuel injector based on a driving condition which includes the fuel pressure detected by the pressure sensor, wherein
the control unit computes actual injection quantity based on a fuel pressure drop detected by the pressure sensor when the fuel is injected,
the control unit computes an individual difference index based on a slope of variation ratios between a plurality of actual injection quantity and a target injection quantity, and
the control unit performs an individual-difference correction of the fuel injector based on the individual difference index as a learning value.

2. A fuel injection apparatus according to claim 1 , wherein
the individual difference index is expressed by the slope of the variation ratios in a relation between the target injection quantity and an individual difference, and
the control unit computes a correction injection quantity based on the individual difference index and the target injection quantity.

3. A fuel injection apparatus according to claim 2 , wherein:
the control unit computes an energization period of the fuel injector based on a corrected target injection quantity which is corrected based on the correction injection quantity.

4. A fuel injection apparatus according to claim 1 , wherein:
the control unit computes the actual injection quantity in view of a fuel leak from the fuel injector to a fuel tank.

5. A fuel injection apparatus according to claim 1 , wherein:
the control unit employs the individual difference index as a constant value with respect to any target injection quantity.

6. A fuel injection apparatus according to claim 1 , wherein:
the control unit employs the individual difference index as a constant value with respect to any target pressure of the common-rail.

Assignees

• Denso Corp

Inventors

• Katsura Ryou

Classifications

• F02D2200/0616

  determined by estimation · CPC title

• F02D41/247

  Behaviour for small quantities · CPC title

• F02D41/0085

  Balancing of cylinder outputs, e.g. speed, torque or air-fuel ratio · CPC title

• F02D41/3809 Primary

  Common rail control systems (common rail apparatus F02M55/025, F02M63/0225) · CPC title

• F02D41/2467

  for injectors · CPC title