Cetane number estimation device

Patent metadata

Field	Value
Publication number	US-9423390-B2
Application number	US-201114004221-A
Country	US
Kind code	B2
Filing date	Mar 29, 2011
Priority date	Mar 29, 2011
Publication date	Aug 23, 2016
Grant date	Aug 23, 2016

Abstract

In order to estimate the cetane number of a fuel, fuel injection is executed by controlling the driving of a fuel injection valve by a prescribed amount. The amount of change in the rotation of a diesel engine generated in response to the fuel injection is detected, and the cetane number of the fuel is estimated on the basis of this amount of change in the rotation. The actual amount of fuel injected from the fuel injection valve is detected, and when the difference between the amount actually detected and the prescribed amount is equal to or greater than a threshold value, the execution of the fuel cetane number estimation process is restricted.

First claim

The invention claimed is:

1. A cetane number estimation device, comprising:
a fuel injection sensor configured to detect an actual amount of fuel injection, which is the actual amount of fuel injection through a fuel injection valve, through drive control of the fuel injection valve based on a target amount of fuel injection; and
an electronic control unit, configured to:
after determining that a fuel cutoff condition has been satisfied, perform a fuel injection for estimation of the cetane number of fuel supplied to a diesel engine through drive control of the fuel injection valve based on the target amount of fuel injection and detect an index value of an output torque of the diesel engine produced as a result of the fuel injection to estimate the cetane number of the fuel based on the detected index value; and
calculate a difference between the target amount of fuel injection and the actual amount of fuel injection through the fuel injection valve through the drive control of the fuel injection valve,
wherein, based on the target amount of fuel injection being equal to or greater than a determination value, prevent estimation of the cetane number, and based on the target amount of fuel injection being less than the determination value, perform estimation of the cetane number; and
change an injection timing based on an engine rotational speed to reduce a variation in a rotational fluctuation amount due to a difference in the engine rotational speed.

2. The cetane number estimation device according to claim 1 , wherein the fuel injection sensor is a pressure sensor for detecting a fuel pressure serving as an index of the fuel pressure inside the fuel injection valve, and the electronic control unit is configured to detect the actual amount of fuel injection based on the manner in which the fuel pressure detected by the pressure sensor fluctuates.

3. The cetane number estimation device according to claim 2 , wherein the pressure sensor is mounted on the fuel injection valve.

4. The cetane number estimation device according to claim 1 , wherein the electronic control unit is further configured to execute estimation of the cetane number on the condition that the fuel injection for operation of the diesel engine is stopped.

Assignees

• Tsuchiyama Makio
• Ito Yoshiyasu
• Miyaura Takeshi
• Toyota Motor Co Ltd

Inventors

• Tsuchiyama Makio
• Ito Yoshiyasu
• Miyaura Takeshi

Classifications

• F02D2200/0602

  Fuel pressure · CPC title

• F02D1/16

  Adjustment of injection timing (F02D1/02 takes precedence) · CPC title

• F02D2200/1012

  Engine speed gradient · CPC title

• F02D41/1497

  With detection of the mechanical response of the engine · CPC title

• F02D41/0025

  Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures · CPC title