Ignition timing control device for internal combustion engine

Patent metadata

Field	Value
Publication number	US-10054098-B2
Application number	US-201715642429-A
Country	US
Kind code	B2
Filing date	Jul 6, 2017
Priority date	Jul 19, 2016
Publication date	Aug 21, 2018
Grant date	Aug 21, 2018

Abstract

An ignition timing control device for an internal combustion engine including: a setting unit configured to set a target ignition timing of the internal combustion engine based on a reference ignition timing and an advance correction amount; a start determination unit configured to determine, based on change in an alcohol concentration, whether or not the fuel injected from a fuel injection valve starts to switch from a first fuel to a second fuel higher in the alcohol concentration than the first fuel; a completion determination unit configured to determine whether or not switching to the second fuel is completed; a restriction unit configured to restrict the advance correction amount during a switching period to the advance correction amount corresponding to the alcohol concentration of the first fuel or lower; and a cancel unit configured to cancel restriction of the advance correction amount after the completion of the switching is determined.

First claim

What is claimed is:

1. An ignition timing control device for an internal combustion engine configured to use a fuel containing alcohol, the internal combustion engine including
a fuel injection valve,
a delivery pipe configured to supply the fuel to the fuel injection valve,
a fuel pipe configured to communicate with the delivery pipe,
a fuel tank, and
an alcohol concentration sensor provided to one of the fuel pipe and the fuel tank, the alcohol concentration sensor being configured to detect a concentration of alcohol in the fuel,
the ignition timing control device comprising
an electronic control unit configured to:
acquire an operating state of the internal combustion engine;
acquire the concentration of alcohol in the fuel based on the alcohol concentration detected with the alcohol concentration sensor;
calculate a reference ignition timing of the internal combustion engine based on the operating state;
calculate an advance correction amount of an ignition timing such that an advance amount of the ignition timing increases more as the alcohol concentration is higher;
set a target ignition timing of the internal combustion engine based on the reference ignition timing and the advance correction amount;
determine, based on change in the alcohol concentration, whether or not the fuel injected from the fuel injection valve starts to switch from a first fuel to a second fuel higher in the alcohol concentration than the first fuel;
determine whether or not the first fuel remaining in the fuel pipe and the delivery pipe is consumed and switching from the first fuel to the second fuel is completed;
restrict the advance correction amount, during a period from a time when the start of the switching is determined to a time when the completion of the switching is determined, to an advance correction amount corresponding to the alcohol concentration of the first fuel or lower; and
cancel restriction of the advance correction amount after the completion of the switching is determined.

2. The ignition timing control device according to claim 1 , wherein
the electronic control unit is configured to determine whether or not switching from the first fuel to the second fuel is completed based on i) a content volume of a portion of the fuel pipe positioned downstream from the alcohol concentration sensor and the delivery pipe and ii) an integrated value of a fuel injection amount of the fuel injection valve after the start of the switching is determined.

3. An ignition timing control device for an internal combustion engine configured to use a fuel containing alcohol, the internal combustion engine including
a fuel injection valve,
a delivery pipe configured to supply the fuel to the fuel injection valve,
a fuel pipe configured to communicate with the delivery pipe,
a fuel tank, and
an alcohol concentration sensor provided to one of the fuel pipe and the fuel tank, the alcohol concentration sensor being configured to detect a concentration of alcohol in the fuel,
the ignition timing control device comprising
an electronic control unit configured to:
acquire an operating state of the internal combustion engine;
acquire the concentration of alcohol in the fuel based on the alcohol concentration detected with the alcohol concentration sensor;
calculate a reference ignition timing of the internal combustion engine based on the operating state;
calculate an advance correction amount of an ignition timing such that an advance amount of the ignition timing increases more as the alcohol concentration is higher;
set a target ignition timing of the internal combustion engine based on the reference ignition timing and the advance correction amount;
determine, based on change in the alcohol concentration, whether or not the fuel injected from the fuel injection valve starts to switch from a first fuel to a third fuel that is lower in the alcohol concentration than the first fuel;
determine whether or not the first fuel remaining in the fuel pipe and the delivery pipe is consumed and switching from the first fuel to the third fuel is completed;
restrict the advance correction amount, during a period from a time when the start of the switching is determined to a time when the completion of the switching is determined, to an advance correction amount in a case of the alcohol concentration being zero; and
cancel restriction of the advance correction amount after the completion of the switching is determined.

4. The ignition timing control device according to claim 3 , wherein
the electronic control unit is configured to determine whether or not switching from the first fuel to the third fuel is completed based on i) a content volume of a portion of the fuel pipe positioned downstream from the alcohol concentration sensor and the delivery pipe and ii) an integrated value of a fuel injection amount of the fuel injection valve after the start of the switching is determined.

Assignees

• Toyota Motor Co Ltd

Inventors

• Shinohara Yoshitsugu

Classifications

• F02P5/15 Primary

  Digital data processing · CPC title

• F02M37/0064

  for engines being fed with multiple fuels or fuels having special properties, e.g. bio-fuels; varying the fuel composition (controlling engines working with pluralities of fuels F02D19/06) · CPC title

• F02D19/087

  with determination of densities, viscosities, composition, concentration or mixture ratios of fuels · CPC title

• F02D19/084

  Blends of gasoline and alcohols, e.g. E85 · CPC title

• F02D19/061 Primary

  by controlling fuel injectors · CPC title