A New Feedback Carburetor with Air Jet Collision Control

A new type closed loop A/F control carburetor has been developed. In the carburetor, an air jet, a by-pass stream of an intake air flow, is made to collide with a fuel flow to suppress the flow rate. Studies were made of the basic features of the method such as fuel controlling capability and the factors affecting it from phenomenological consideration and schlieren observation. For comparison, three types of carburetors were prepared for the conbination of main and idle fuel circuits. In driving mode tests on a dynamometer, a new carburetor which employs the new method for the main fuel circuit, provides 30 % lower emission level than an air bleed control carburetor. Higher controlling frequencies were obtained for the new carburetors. The high controllability of the air jet collision control method is attributable to the smaller fluctuation in both the controlling air and the spouting fuel.