Warm-up control apparatus for general-purpose engine

Patent metadata

Field	Value
Publication number	US-9926870-B2
Application number	US-201113219162-A
Country	US
Kind code	B2
Filing date	Aug 26, 2011
Priority date	Sep 8, 2010
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

In an apparatus for controlling warm-up operation of a general-purpose internal combustion engine having a throttle valve installed in an air intake pipe and connectable to an operating machine to be used as a prime mover of the machine, it is configured to calculate a basic fuel injection amount based on an engine speed and a throttle opening and control engine warm-up operation by calculating a warm-up time fuel injection amount by correcting the calculated basic fuel injection amount based on one of a temperature change amount of a spark plug seat of the engine, the throttle opening and an output of the operating machine and injecting fuel from an injector by the calculated warm-up time fuel injection amount. With this, it becomes possible to calculate a fuel injection amount suitable for the engine warm-up condition by using an appropriate parameter in place of the lubricating oil temperature.

First claim

What is claimed is:

1. An apparatus for controlling warm-up operation of a general-purpose internal combustion engine, the internal combustion engine being an air-cooled engine and connectable to an operating machine to be used as a prime mover of the operating machine, the apparatus comprising:
a basic fuel injection amount calculator adapted to calculate a basic fuel injection amount based on a speed of the air-cooled engine and a throttle opening of a throttle valve; and
a warm-up controller adapted to control warm-up operation of the air-cooled engine by calculating a warm-up time fuel injection amount by correcting the calculated basic fuel injection amount based on a warm-up correction coefficient calculated based on a temperature of a cylinder head of the air-cooled engine and one of a temperature change amount of a spark plug seat of the air-cooled engine, the throttle opening and an output of the operating machine, and injecting fuel from an injector by the calculated warm-up time fuel injection amount, wherein
the warm-up controller calculates a first coefficient based on the one of the temperature change amount of the spark plug seat, the throttle opening and the output of the operating machine,
calculates a second coefficient based on the temperature of the cylinder head,
calculates the warm-up correction coefficient by subtracting a value determined by multiplying the first coefficient by the second coefficient from an initial value calculated based on the temperature of the cylinder head, and
the warm-up correction coefficient becomes smaller as the first coefficient increases along with an increase of a load acting on the air-cooled engine.

2. The apparatus according to claim 1 , wherein the warm-up controller calculates the warm-up time fuel injection amount by correcting the basic fuel injection amount with the calculated warm-up correction coefficient after start operation of the air-cooled engine is completed.

3. The apparatus according to claim 1 , wherein the warm-up correction coefficient is calculated every time the air-cooled engine is rotated a predetermined number of times or every time a predetermined time period elapses.

4. The apparatus according to claim 1 , wherein the warm-up correction coefficient is composed of a multiplication term equal to or greater than 1.0 and is calculated such that it decreases toward 1.0 by a predetermined value every time the air-cooled engine is rotated a predetermined number of times or every time a predetermined time period elapses, and the warm-up controller continues the warm-up operation until the warm-up correction coefficient reaches 1.0.

5. The apparatus according to claim 1 , wherein the air-cooled engine has an actuator adapted to open and close the throttle valve such that the speed of the air-cooled engine is converged to a desired engine speed set by an operator.

6. The apparatus according to claim 1 , wherein the air-cooled engine has an actuator adapted to open and close the throttle valve such that the speed of the air-cooled engine is converged to a desired engine speed determined based on the output of the operating machine.

7. The apparatus according to claim 1 , wherein the operating machine comprises a generator, and the output of the operating machine comprises a power output of the generator.

8. The apparatus according to claim 1 , wherein the operating machine comprises a pump, and the output of the operating machine comprises a discharge amount of the pump.

9. The apparatus according to claim 1 , wherein the operating machine comprises a high-pressure washing machine, and the output of the operating machine comprises a discharge amount of the washing machine.

10. The apparatus according to claim 1 , wherein the operating machine comprises a power sprayer, and the output of the operating machine comprises a discharge amount of the power sprayer.

11. The apparatus according to claim 1 , wherein the initial value decreases along with an increase of the temperature of the cylinder head.

12. The apparatus according to claim 1 , wherein the second coefficient increases along with an increase of the temperature of the cylinder head when the temperature of the cylinder head is smaller than a predetermined temperature.

13. The apparatus according to claim 12 , wherein the second coefficient is 0 when the temperature of the cylinder head is equal to or greater than the predetermined temperature.

14. The apparatus according to claim 1 , wherein the first coefficient increases along with an increase of the temperature change amount of the spark plug seat, an increase of the throttle opening, or an increase of the output of the operating machine.

15. The apparatus according to claim 1 , wherein when the first coefficient is calculated based on the temperature change amount of the spark plug seat, the first coefficient is 1.0 when the temperature change amount of the spark plug seat is smaller than a first predetermined value, increases along with an increase of the temperature change amount of the spark plug seat when the temperature change amount of the spark plug seat is equal to or greater than the first predetermined value and smaller than a second predetermined value, and is a predetermined upper limit when the temperature change amount of the spark plug seat is equal to or greater than the second predetermined value.

16. The apparatus according to claim 1 , wherein when the first coefficient is calculated based on the throttle opening, the first coefficient is 1.0 when the throttle opening is smaller than a first predetermined value, increases along with an increase of the throttle opening when the throttle opening is equal to or greater than the first predetermined value and smaller than a second predetermined value, and is a predetermined upper limit when the throttle opening is equal to or greater than the second predetermined value.

17. The apparatus according to claim 1 , wherein when the first coefficient is calculated based on the output of the operating machine, the first coefficient is 1.0 when the output of the operating machine is smaller than a first predetermined value, increases along with an increase of the output of the operating machine when the output of the operating machine is equal to or greater than the first predetermined value and smaller than a second predetermined value, and is a predetermined upper limit when the output of the operating machine is equal to or greater than the second predetermined value.

18. A method for controlling warm-up operation of a general-purpose internal combustion engine, the internal combustion engine being an air-cooled engine and connectable to an operating machine to be used as a prime mover of the operating machine, the method comprising the steps of:
calculating a basic fuel injection amount based on a speed of the air-cooled engine and a throttle opening of a throttle valve; and
controlling warm-up operation of the air-cooled engine by calculating a warm-up time fuel injection amount by correcting the calculated basic fuel injection amount based on a warm-up correction coefficient calculated based on a temperature of a cylinder head of the air-cooled engine and one of a temperature change amount of a spark plug seat of the air-cooled engine, the throttle opening and an output of the operating machine, and injecting fuel from an injector by the calculated warm-up time fuel injection amount,
wherein the step of controlling warm-up operation of the air-cooled engine comprises:
calculating a first coefficient based on the one of the

Assignees

• Hashizume Takashi
• Fukushima Tomoki
• Saito Shigeru
• Honda Motor Co Ltd

Inventors

• Hashizume Takashi
• Fukushima Tomoki
• Saito Shigeru

Classifications

• F02D2200/0404

  Throttle position · CPC title

• F02D41/068 Primary

  for warming-up · CPC title

• F02D2200/021

  Engine temperature · CPC title

• F02D2200/10

  Parameters related to the engine output, e.g. engine torque or engine speed · CPC title