Abstract: An intake system of an internal combustion engine including a power cylinder having an intake valve and a fuel injection nozzle, comprising: a throttle chamber upstream open to the atmosphere; primary and secondary throttle valves provided in parallel with each other in the throttle chamber; primary and secondary air passageways leading from the throttle chamber past the primary and secondary throttle valves, respectively, and conjoined together upstream of the intake valve, the secondary passageway being larger in cross sectional area than the primary air passageway and having a reservoir chamber portion larger in cross sectional area than the remaining portion of the secondary passageway; and air heating means provided in the primary air intake pipe and operative to preheat the air to be passed through the primary air intake pipe.

Abstract: An air/fuel mixture heating device for an internal combustion engine comprises a riser portion located at a relatively high position in the riser space in an intake manifold and having air/fuel mixture heating means and a barrier formed on a circumference of a riser surface of the riser portion, and an intake air inlet arranged in opposition to the riser surface for introducing intake air to the riser surface, thereby promoting the atomization of fuel particles by heating by the riser surface and by causing the fuel to pass by the barrier to distribute the fuel uniformly to respective cylinders of the engine.

Abstract: Disclosed is a fuel/air mixture supply system for an internal combustion engine of the single-point fuel injection type wherein, the intake manifold system is formed with a first fuel/air supply passage which inspires atmospheric air and which has fitted generally at a midpoint thereof a fuel injection valve which injects fuel into the inspired air. The fuel/air mixture then proceeds to a first set of branched passages, each one of which conducts the fuel/air mixture to a cylinder of the engine. Further, there is provided a second air supply passage which inspires atmospheric air and which branches into a second set of branched passages, each one of which conducts air to a cylinder of the engine. The first fuel/air supply passage is smaller than the second air supply passage, and the first set of branched passages are smaller than the second set of branched passages.

Abstract: There is disclosed a fuel feeding device for an internal combustion engine equipped with an air regulator for feeding air through a bypass around a throttle valve and a fuel jetting valve for feeding fuel. An air passage outlet of said air regulator is open opposite to and facing said fuel jetting valve. The opening degree of said air regulator is controlled by a coil bimetal functioning in proportion to the temperature of the engine or through a step motor being driven through a controlling circuit detecting operation conditions of the engine.

Abstract: A carburetor is disclosed of the variable venturi type, which has a bypass passage bypassing the throttle valve, which is controlled during starting and warming up of the engine by a piston which adjusts its flow resistance, and which is urged against the biasing action of a spring by the vacuum suction downstream of the throttle valve. The maximum open position of this piston is controlled by a heat-sensitive element which advances this position in the direction of closing the bypass passage as the engine warms up, until it is completely closed when the engine is warm. Air is fed into a supplier which supplies fuel to the carburetor inlet passage to mix with the fuel supplied thereby in an amount which varies from a minimum when the vacuum downstream of the throttle valve is minimum to a maximum when the vacuum downstream of the throttle valve is maximum. Further, the amount of fuel supplied by the fuel supplier is adjusted to be greater when the engine temperature is lower than when it is higher.

Abstract: A carburetor with a circular air valve, in which the fuel metering needle is connected to a bracket on the downstream face of the air valve.

Abstract: A fuel supply system for a multi-cylinder internal combustion engine, comprises an intake passageway which is provided therein with a throttle valve, a fuel injector whose nozzle is located in the intake passageway downstream of the throttle valve, and a fuel reflector against which at least a part of the fuel injected from the fuel injector strikes to be reflected, the fuel reflector being located opposite to the nozzle tip of said fuel injector, so that fuel distribution to a plurality of engine cylinders can be uniformalized.

Abstract: A carburetor in which a fuel evaporator using a "porous ceramic body" is disclosed. The "porous ceramic body" has a three-dimensional porous structure with open boxes. The three-dimensional porous structure comprises an electrically conductive ceramic with a positive temperature coefficient. The carburetor is provided with an electrical arrangement so as to permit current to flow through the "porous ceramic body" to cause it to produce heat.

Abstract: An intake system of an internal combustion engine having a carburetor with a primary venturi and a secondary venturi concentrically disposed within the primary venturi by a bridge member which extends into contact with an inner wall of a throat portion of the primary venturi. A fuel delivery conduit is disposed within the bridge member and spans the secondary venturi with its leading end sealingly received in the side of the secondary venturi opposite the bridge member. The fuel delivery conduit is inclined with respect to the axis of the secondary venturi so that the leading end portion of the conduit extends in an upstream direction. The fuel delivery conduit also has an opening through which fuel is dischargable. A single needle member is fixedly attached to the bottom of the secondary venturi and projects in a downstream direction with respect to the flow of the air passing through the secondary venturi.

Abstract: Heat is rapidly conducted to the induction manifold from the exhaust manifold via heat pipes, the heat absorbing ends of which have exhaust gases controllably directed thereagainst by a bimetallic operated butterfly valve and the heat emitting ends of which can be formed with, fins hollow or solid to increase the surface area thereof which contactingly and radiatingly heats all of the air fuel mixture passing through the induction manifold.

Abstract: Air drawn into a carburetor main fuel passage for adjustment of the air-fuel ratio of an engine air-fuel mixture is either stepwise or continuously prevented from being undesirably increased with increases in the engine load by either closing an additional passage for the air at an engine load above a predetermined value or continuously reducing the effective cross sectional area of a variable orifice in a passage or an additional passage for the air with increases in the engine load.