Controller and control method for fuel injection timing of internal combustion engine

Patent metadata

Field	Value
Publication number	US-10704489-B2
Application number	US-201916258779-A
Country	US
Kind code	B2
Filing date	Jan 28, 2019
Priority date	Mar 6, 2018
Publication date	Jul 7, 2020
Grant date	Jul 7, 2020

Abstract

A controller executes an advancement process for advancing an injection start timing by a direct injection valve to a larger extent when a coolant temperature that is a temperature of coolant in an internal combustion engine is greater than or equal to a preset temperature than when the coolant temperature is lower than the preset temperature. The advancement process includes a retardation process for setting a smaller advancement amount at the injection start timing when a lubricant temperature that is a temperature of lubricant is lower than a predetermined temperature than when the lubricant temperature is greater than or equal to the predetermined temperature.

First claim

The invention claimed is:

1. A controller for an internal combustion engine, the controller comprising a processor that controls a fuel injection timing of the internal combustion engine, the internal combustion engine including a direct injection valve that injects fuel into a combustion chamber and a lubrication device that discharges lubricant toward a rear surface of a piston, wherein
the processor is configured to execute
a start timing setting process for setting, through at least one of two processes, an injection start timing of fuel by the direct injection valve, wherein one of the two processes is a process for setting the injection start timing to be more advanced when a rotation speed of a crankshaft of the internal combustion engine is high than when the rotation speed is low, and the other one of the two processes is a process for setting the injection start timing to be more advanced when a load on the internal combustion engine is large than when the load is small, and
an injection valve operation process for operating the direct injection valve in order to start injecting fuel from the direct injection valve at the injection start timing,

the start timing setting process includes an advancement process for advancing the injection start timing to a larger extent when a coolant temperature that is a temperature of coolant in the internal combustion engine is greater than or equal to a preset temperature than when the coolant temperature is lower than the preset temperature, and
the advancement process includes a retardation process, wherein in a case in which the coolant temperature is greater than or equal to the preset temperature, the retardation process sets a smaller advancement amount at the injection start timing when a lubricant temperature that is a temperature of the lubricant is lower than a predetermined temperature than when the lubricant temperature is greater than or equal to the predetermined temperature.

2. The controller according to claim 1 , wherein
the processor is configured to execute, when the coolant temperature is lower than or equal to an increase threshold value, a low-temperature fuel-increasing process for increasing an amount of fuel supplied to the combustion chamber in a single combustion cycle to a larger extent when the coolant temperature is low than when the coolant temperature is high, and
the preset temperature is a value greater than or equal to the increase threshold value.

3. The controller according to claim 1 , wherein
the start timing setting process includes a cold-time process, wherein when the coolant temperature is less than a cold-time threshold value that is less than the preset temperature, the cold-time process advances the injection start timing to a larger extent than when the coolant temperature is greater than or equal to the cold-time threshold value, and
in a case in which the coolant temperature is greater than or equal to the preset temperature, the advancement process advances the injection start timing to a larger extent, in a range in which the injection start timing is not set to be more advanced than when the coolant temperature is less than the cold-time threshold value, than when the coolant temperature is lower than or equal to the preset temperature and greater than or equal to the cold-time threshold value.

4. The controller according to claim 1 , wherein
the processor is configured to execute a fuel cut-off process for stopping supplying fuel to the combustion chamber, and
the retardation process includes a process for setting a small advancement amount at the injection start timing in the same manner as a case in which the coolant temperature is greater than or equal to the preset temperature and the lubricant temperature is lower than the predetermined temperature on condition that the fuel cut-off process has been continued for a predetermined period even if the coolant temperature is greater than or equal to the preset temperature and the lubricant temperature is greater than or equal to the predetermined temperature.

5. The controller according to claim 1 , wherein
the processor is configured to execute an idling process for controlling the rotation speed of the crankshaft to a target rotation speed on condition that an accelerator operation amount is zero, and
the retardation process includes a process for setting a small advancement amount at the injection start timing in the same manner as a case in which the coolant temperature is greater than or equal to the preset temperature and the lubricant temperature is lower than the predetermined temperature on condition that the idling process has been continued for a certain period even if the coolant temperature is greater than or equal to the preset temperature and the lubricant temperature is greater than or equal to the predetermined temperature.

6. The controller according to claim 1 , further comprising a storage device that stores map data sets, the map data sets each including the rotation speed and the load as an input variable and including the injection start timing as an output variable, wherein
the map data sets include
a map data set selected when the coolant temperature is lower than the preset temperature,
a map data set selected when the coolant temperature is greater than or equal to the preset temperature and the lubricant temperature is lower than the predetermined temperature, and
a map data set selected when the coolant temperature is greater than or equal to the preset temperature and the lubricant temperature is greater than or equal to the predetermined temperature, and

the start timing setting process includes a process for setting the injection start timing using the map data sets.

7. A control method for controlling a fuel injection timing of an internal combustion engine, wherein the internal combustion engine includes a direct injection valve that injects fuel into a combustion chamber and a lubrication device that discharges lubricant toward a rear surface of a piston,
the control method comprising:
setting, through at least one of two processes, an injection start timing of fuel by the direct injection valve, wherein one of the two processes is a process for setting the injection start timing to be more advanced when a rotation speed of a crankshaft of the internal combustion engine is high than when the rotation speed is low, and the other one of the two processes is a process for setting the injection start timing to be more advanced when a load on the internal combustion engine is large than when the load is small; and
operating the direct injection valve in order to start injecting fuel from the direct injection valve at the injection start timing,

the control method further comprising:
advancing the injection start timing to a larger extent when a coolant temperature that is a temperature of coolant in the internal combustion engine is greater than or equal to a preset temperature than when the coolant temperature is lower than the preset temperature; and
setting, in a case in which the coolant temperature is greater than or equal to the preset temperature, a smaller advancement amount at the injection start timing when a lubricant temperature that is a temperature of the lubricant is lower than a predetermined temperature than when the lubricant temperature is greater than or equal to the predetermined temperature.

8. A non-transitory computer-readable storage medium that stores a program causing a processor to execute a control process for controlling a fuel injection timing of an internal combustion engine, wherein the internal combustion engine includes a direct injection valve that injects fuel into a combustion chamber and a lubrication device that disch

Assignees

• Toyota Motor Co Ltd

Inventors

• Mitsuishi Yasuhiro

Classifications

• F02D41/068

  for warming-up · CPC title

• F02D41/401 Primary

  Controlling injection timing (F02D41/402 takes precedence) · CPC title

• F02D2200/021

  Engine temperature · CPC title

• F02D41/3094

  the fuel injection being effected by at least two different injectors, e.g. one in the intake manifold and one in the cylinder · CPC title

• F02D2200/023

  Temperature of lubricating oil or working fluid · CPC title