Search Results

Two types of particulate trap systems for heavy duty diesel truck have been newly designed and bench tests were conducted. The first is single wall flow type trap and a burner assisted regeneration system in which exhaust gas is by-passed during regeneration. Even though maximum temperature in the trap could be kept low by controlling both burner gas temperature and the amount of particulate collection, there was a problem of trap failure, cracks developing after a certain period. The other type is a cross flow type trap where collected particulate is blown out periodically by high pressure air from rear side of trap for burning by an electric heater. This system features that the trap can be regenerated without heating the trap body itself. After conducting basic tests it was found that this system had a high potential. This paper details this new concept.

The adoption of stringent emission control requirements for diesel powered vehicles has generated the need for emission reducing engine controls. An exhaust gas recirculation system controlled by a true mass airflow sensor has been developed for a light duty truck equipped with a 2.2 liter, naturally aspirated, diesel engine to satisfy these requirements. An intake air throttle provides a method of reducing the intake mass airflow to the engine. The air/fuel ratio, which will simultaneously obtain the desired NOx emission level and minimize any increase in particulates, is achieved by a combination of intake air throttling and introduction of exhaust gas recirculation. The control system reduces emission output in a simple, cost effective manner, without adversely affecting fuel economy or driveability.

Isuzu Motors Limited has recently-developed 2.5 liter and 2.8 liter diesel engines to power Isuzu “ELF” trucks (payload 1-2 tons). These two engines are high fuel economy direct injection diesels featuring a square cavity combustion chamber and Bosch VE distributor type injection pump. To reduce the D.I. diesel engine noises, the combustion chamber, fuel injection system, and cylinder block construction have been improved. In addition, a vibration damping sheet oil pan, timing belt drive, and cylinder block, cover are employed. The two diesel engines are small size, light weight, highly reliable engines to be successors to the 2.0, 2.2 and 2.4 liter Isuzu “C”-series diesel engines. To date, 2 million of these engines have been produced to power the Isuzu “ELF” trucks and other vehicles as well as a wide variety of industrial and marine applications.