AIR/FUEL RATIO CONTROL APPARATUS FOR GENERAL-PURPOSE ENGINE
First Claim
1. An apparatus for controlling an air/fuel ratio of a general-purpose internal combustion engine that is connectable to a load, having a desired engine speed input switch adapted for an operator to input a desired speed of the engine, an engine speed detector that detects a speed of the engine, a throttle opening regulator that regulates an opening of a throttle valve installed in an air intake pipe of the engine such that the detected engine speed converges to the inputted desired engine speed, a fuel injection amount calculator that calculates a fuel injection amount of the engine based on the detected engine speed and the regulated throttle opening in accordance with fuel injection amount characteristics, and an injector that injects mixed fuel containing alcohol and gasoline based on the calculated fuel injection amount,wherein the improvement comprises:
- a load determiner that determines whether the load connected to the engine is kept constant;
a fuel injection amount injecting increasing/decreasing unit that increases/decreases the calculated fuel injection amount to be injected when the load connected to the engine is determined to be kept constant;
an air/fuel ratio estimator that estimates an air/fuel ratio at which an output of the engine becomes maximum based on the throttle opening regulated when the fuel injection amount is fuel of the increased/decreased;
an alcohol rate estimator that estimates a rate of the alcohol contained in the mixed fuel based on the estimated air/fuel ratio and the calculated fuel injection amount; and
a fuel injection amount corrector that corrects the fuel injection amount based on the estimated alcohol rate.
1 Assignment
0 Petitions
Accused Products
Abstract
In an apparatus for controlling an air/fuel ratio of a general-purpose internal combustion engine using mixed fuel containing alcohol and gasoline and operated at a desired engine speed inputted by the operator while a throttle opening is regulated such that a detected engine speed converges to the inputted desired engine speed, a fuel injection amount prepared for mixed fuel is increased/decreased when a load is kept constant and the output air/fuel ratio (at which an output of the engine becomes maximum) is estimated. A rate of alcohol contained in the fuel is estimated from the estimated air/fuel ratio and the fuel injection amount is corrected based on the estimated alcohol rate, thereby determining the fuel injection amount appropriately in accordance with the estimated alcohol rate.
-
Citations
20 Claims
-
1. An apparatus for controlling an air/fuel ratio of a general-purpose internal combustion engine that is connectable to a load, having a desired engine speed input switch adapted for an operator to input a desired speed of the engine, an engine speed detector that detects a speed of the engine, a throttle opening regulator that regulates an opening of a throttle valve installed in an air intake pipe of the engine such that the detected engine speed converges to the inputted desired engine speed, a fuel injection amount calculator that calculates a fuel injection amount of the engine based on the detected engine speed and the regulated throttle opening in accordance with fuel injection amount characteristics, and an injector that injects mixed fuel containing alcohol and gasoline based on the calculated fuel injection amount,
wherein the improvement comprises: -
a load determiner that determines whether the load connected to the engine is kept constant; a fuel injection amount injecting increasing/decreasing unit that increases/decreases the calculated fuel injection amount to be injected when the load connected to the engine is determined to be kept constant; an air/fuel ratio estimator that estimates an air/fuel ratio at which an output of the engine becomes maximum based on the throttle opening regulated when the fuel injection amount is fuel of the increased/decreased; an alcohol rate estimator that estimates a rate of the alcohol contained in the mixed fuel based on the estimated air/fuel ratio and the calculated fuel injection amount; and a fuel injection amount corrector that corrects the fuel injection amount based on the estimated alcohol rate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method for controlling an air/fuel ratio of a general-purpose internal combustion engine that is connectable to a load, having a desired engine speed input switch adapted for an operator to input a desired speed of the engine, an engine speed detector that detects a speed of the engine, a throttle opening regulator that regulates an opening of a throttle valve installed in an air intake pipe of the engine such that the detected engine speed converges to the inputted desired engine speed, a fuel injection amount calculator that calculates a fuel injection amount of the engine based on the detected engine speed and the regulated throttle opening in accordance with fuel injection amount characteristics, and an injector that injects mixed fuel containing alcohol and gasoline based on the calculated fuel injection amount,
wherein the improvement comprises the steps of: -
determining whether the load connected to the engine is kept constant; increasing/decreasing the calculated fuel injection amount to be injected when the load connected to the engine is determined to be kept constant; estimating an air/fuel ratio at which an output of the engine becomes maximum based on the throttle opening regulated when the fuel injection amount is fuel of the increased/decreased; estimating a rate of the alcohol contained in the mixed fuel based on the estimated air/fuel ratio and the calculated fuel injection amount; and correcting the fuel injection amount based on the estimated alcohol rate. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
-
Specification