Minoru Ohsuga

A study on the oxygen-biased wide range air-fuel ratio sensor for rich and lean air-fuel ratios

Abstract Using computer simulations and experiments, we have studied a method of meausring automobile air-fuel ratios over a wide range from rich to lean. The method utilizes the oxygen pumping action of solid oxide electroyte in an air-fuel ratio sensor. The air-fuel ratios were experimentally confirmed as being measurable from 0.8

High Performance Engine Control System

The basic structure of a new engine control system for highly accurate air-fuel ratio control is introduced. Improved engine power and decreased fuel consumption are required for todays engines. Better air-fuel ratio control must be attained to set the air-fuel ratio to that of the maximum power and minimum fuel consumption. In order to enhance the accuracy of the air-fuel ratio control, the air flow meter, air-fuel ratio sensor, and fuel supply device are improved in the new system. Accuracy is lost in conventional system owing to the sensors deterioration over long-term use. So prevention of air flow meter deterioration and compensation of air-fuel ratio sensor deterioration are taken into consideration. Fuel atomization of the fuel supply device is improved in order to reduce the air-fuel ratio fluctuation in the transient operating state. High power and decreased fuel consumption over long-term use are made possible with the new system.

Influence of mixture preparation on HC emission of SI engine with high swirl ratio under cold conditions

Abstract This study investigates the effects of injection timing and fuel atomization on engine-out HC emission of an Sl engine with a high swirl ratio under cold conditions. To study the air-fuel mixture formation process inside the intake port and cylinder, laser visualization techniques were applied and their results were compared with the measured HC emission. Although the performance test indicated that the HC emission deteriorated in the case of one-intake-port operation, the HC emission was recovered by fuel atomization by an air-assisted injector and backflow from the cylinder into the intake port at the beginning of the intake stroke.

Measurement of In-Cylinder Air-Fuel Ratio at Early Combustion Stroke Using an Optical Combustion Sensor.

Achieving the expected future exhaust emission and fuel consumption standards for passenger cars will require fundamental improvements in the combustion process for spark ignition engines. Improvements must be made in the fuel-injection device based on precise studies of the engine-combustion process. Real-time measurements of light emission from inside the cylinder in an actual automotive engine are currently very few. In this paper, a real-time method utilizing an optical combustion sensor that combines fiber optics with a conventional spark plug is presented. The incylinder air-fuel ratio of the flame at an early combustion stroke is measured by means of spectroscopy of the combustion luminosity in not only the steady but the transient state. The fuel-injection device is evaluated in terms of these measured parameters.

Pulsating Flow Characteristics of Hot-Wire Air Flow Meter for Gasoline Fuel-Injection System

Pulsating flow characteristics of hot-wire air flow meters for gasoline fuelinjection systems were investigated to analyze simple methods of measuring data processing. It was clarified that backward flow components due to pulsation are detected as forward flow by the probe in the conventional meters, increasing errors. The errors due to pulsation can be reduced by using a meter with a hot-wire probe located in a bypass passage, compensating aerodynamically forward and backward flow components.

Measurement and Evaluation of In-Cylinder Combustion Using an Optical Combustion Sensor.

Compliance with future exhaust emission and fuel consumption standards for passenger cars will require fundamental improvements in the combustion process for spark ignition engines. Improvements must be made in fuel-injection devices based on precise studies of the engine combustion process. Real-time measurement of light emission from inside the cylinder in an actual automotive engine is currently scarce. In this paper, a real-time measurement method using an optical combustion sensor that combines fiber optics with a conventional spark plug is presented. Diffusion combustion, air-fuel ratio and temperature of the flame are measured by means of spectroscopy of the combustion luminosity. The fuel injection device is evaluated in terms of these measured parameters.