GB1439445A - Internal combustion engine and carburettor assembly - Google Patents

Abstract

1439445 Spray carburetters NISSAN MOTOR CO Ltd 1 May 1974 [7 May 1973] 19140/74 Heading F1B An I.C. engine and a carburetter assembly, the engine having pre-combustion chambers each connected with a main combustion chamber, the carburetter assembly comprising a first throttle valve mounted on a rotatable shaft in a main carburetter primary barrel connected to the main combustion chambers, a second throttle valve mounted on a rotatable shaft in an auxiliary carburetter barrel connected to the pre-combustion chambers, a third throttle valve mounted on a rotatable shaft in a main carburetter secondary barrel also connected to the main combustion chambers, the third throttle valve being rotatable in response to Venturi vacuums in the barrels of the first and third throttle valves and a mechanical linkage between the two shafts of the first and second throttle valves the two shafts being parallel to each other and perpendicular to the respective longitudinal axes of said main and auxiliary carburetter barrels. Auxiliary barrel 18 has butterfly throttle valve 34 mounted on shaft 36, main carburetter primary barrel 14 has throttle valve 24 mounted on shaft 28 and main carburetter secondary barrel 16 has throttle valve 26 mounted on shaft 30. Valves 34 and 24 are connected by levers 50 and 48 and adjustable link 52 and are actuated simultaneously by a control pedal. Throttle valve 26 is connected by lever 68 and rod 66 to diaphragm 62. Spring 70 biases the valve to the closed position and the vacuum at Venturis 20 and 22 acts on the diaphragm through passage 64 to open the valve as the airflow through the carburetter assembly increases. The assembly is mounted on a manifold 42, 44 having separate ducts leading to the main and precombustion chambers. The longitudinal axes of the barrels are in a common plane (X-X<SP>1</SP>) Fig. 2 (not shown) which is perpendicular to a plane y-y<SP>1</SP> which includes the axes of a bank of engine cylinders 40a ... d and which intersects the plane y-y<SP>1</SP> at a point equidistant from the axes of the two outermost cylinders.