GB292229A - Improvements in or relating to apparatus for supplying air to the carburettors of internal combustion engines - Google Patents

Abstract

292,229. Ricardo, H. R. March 14, 1927. Spray carburettors.-The temperature of the air supplied to a carburettor is varied substantially in inverse proportion to the torque of the engine. The temperature control may be effected directly from the throttle lever or more conveniently, in accordance with the pressur in the induction pipe but in either case a dashpot or like device is provided to introduce a time lag in such a manner that the extent of the lag will be reduced automatically as the temperature of the engine rises. Air is supplied to the inlet A<1> of the carburettor A from a casing C having inlets C<2> for cold air and inlets C<3> for air heated in a casing F<1> around the exhaust pipe A<2>, or by other means. Formed integrally with the upper cover D of the is a cylinder D<2> containing a piston G which is subjected, at its upper face, through a pipe O to the pressure existing in the induction pipe B. The lower cover E comprises a dashpot cylinder E<4> the piston E<5> in which is loaded by a spring J and is connected to the piston G by a, rod H which carries a valve N having a disc-like portion N<2> and a coned portion N<1>. The hot-air pipe F is connected to or integral with a ring F<3> engaging walls C<3>, C<6> and forming a chamber C<4>. The cold air passes through the throat of a substantially Venturi-shaped member L, and the hot air through the throat M<1> of a member M. The cylinder E<4> is filled with a liquid which becomes less viscous as its temperature increases. With closed throttle and therefore small engine torque, the suction through pipe O is large, the piston G is raised, the cold air is cut off by disc N<2> and heated air only is admitted through M<1>. With throttle fully open and torque at a maximum, the cone N' closes hot-air inlet M<1>, and the throat in cold-air inlet L is fully open. With intermediate throttle positions, varying proportions of both hot and cold air are admitted. The dashpot prevents a too sudden reduction of air temperature upon sudden opening of the throttle, and the throat M<1> at the same time causes an increase of depression at the fuel orifice and a somewhat richer mixture to be supplied. The rod H may, alternatively, be connected through resilient means with the throttle valve.