Electronic Control of Air/Fuel Ratios in a carburettor for 2-Wheeler Application 2008-28-0057
Carburettors are widely used for control of Air/fuel mixture in 2/3 wheeler vehicles in India as well as other countries. Carburettor technology has improved over the years to meet stringent emission requirements as well as fuel economy demands of customer.
With the introduction of Euro-III regulations in 2006 and proposed BS IV requirements in India, emphasis is laid on the transient control capability of carburettor. A project was undertaken at Ucal Fuel Systems to understand the transient characteristics of carburettor and develop electronic control to achieve programmable control of Air/Fuel ratio on the driving cycle.
Several tests were conducted on carburettor flow test bench and on chassis dynamometer to understand the transient control response and develop control strategy. It is observed that the Air/fuel ratio measured at steady speed trials, have a marked influence on the transient Air/Fuel ratio behavior as measured on drive cycles. It is possible to control the same with electronic control system.
This paper gives the details of carburettor modifications, Electronic controls employed and results obtained.