Abstract: In an injector for intermittently injecting liquid fuel by supplying a pulse signal to an actuator for reciprocating a valve body, a method of controlling the injector comprises the steps of changing the width of the pulse signal to thereby control an open time of the injector, and also changing a voltage of the pulse signal to thereby control a stroke of the valve body.

Abstract: In an injector for intermittently injecting liquid fuel by supplying a pulse signal to an actuator and reciprocating an injector valve, a method of controlling the injector valve comprising the steps of temporarily cutting supply of a pulse signal to the actuator to suppress inertia of the injector valve and thereby stabilize opening characteristics of the valve just before full opening of the valve during an opening stroke of the valve, and temporarily supplying the pulse signal after the cutting step of the pulse signal to the actuator to suppress inertia of the injector valve and thereby stabilize closing characteristics of the valve just before full closing of the valve during a closing stroke of the valve.

Abstract: A fuel injection valve using a stacked piezoelectric ceramics displacement magnifying device as a valve actuator. The piezoelectric actuator comprises a stacked piezoelectric ceramics expandable upon application of an electric field thereto; a lever member having a base portion fixed to the central portion of the casing, an inner portion contacting with an end of the stacked piezoelectric ceramics and receiving an expansion force from the stacked piezoelectric ceramics, a fulcrum portion fixed to the base portion, and at least two outer portions adapted to be outwardly displaced when the inner portion receives the expansion force from the stacked piezoelectric ceramics; and a flexing member formed of an elastic material and connected at its both ends to the outer portions of the lever member under the condition where a central portion thereof is flexed frontwardly, the central portion of the flexing member being connected to a rear end of the valve body.

Abstract: A variable venturi-type carburetor comprising a main fuel passage which is open to the intake passage of the carburetor. An air bleed passage is connected to the main fuel passage. The inlet of the air bleed passage is divided into a first passage and a second passage. A first control valve and a first jet are arranged in the first passage. A second control valve and a second jet are arranged in the second passage. The second jet has a flow area which is larger than that of the first jet. The first control valve opens the first passage only when the engine is operating under an idling state. The second control valve opens the second passage only during the cruising operation of a vehicle.

Abstract: A fuel supplying device for use in fuel injection type internal combustion engine. The device has a fuel metering device operatively connected to an air valve device disposed in the air horn upstream of a throttle valve, fuel supplying means adapted to supply the fuel at a constant supplying pressure to the fuel metering device, a constant differential pressure valve arranged to maintain a predetermined differential pressure across the fuel metering device, and an injector for discharging the metered fuel into the air horn in the vicinity of the throttle valve. The constant differential pressure valve includes a diaphragm type valve arranged to sense and amplify differential pressure across the fuel metering device, and a variable orifice type flow control device arranged to charge flow resistance of the metered fuel.

Abstract: An exhaust gas recirculating device having a regulator integrally formed with an air horn of the carburetor, a throttle body and an insulator, both secured to a carburetor flange, a groove cut on the underside of the carburetor flange, a plate interposed between the flange and the suction manifold, said groove and plate forming an exhaust gas recirculating passage, a variable throttle valve, a throttle valve, and a link means interconnecting the variable throttle valve and the throttle valve, whereby exhaust gas from the engine is recirculated to downstream of the throttle valve. With this invention the exhaust gas recirculating device can be incorporated into conventional carburetors with minor modifications on the carburetor.

Abstract: A fuel supply apparatus for internal combustion engines of a type including an air valve disposed in an intake conduit of the engine upstream of a throttle valve. A sensor is used for sensing the pressure in an air pressure chamber defined within the intake conduit between the air valve and the throttle valve and a feedback control unit is used for controlling the air valve in response to the pressure sensed by the sensor in order to maintain the pressure in the air pressure chamber at a preset value. A fuel flow metering valve is disposed in a fuel feed channel leading from a source of fuel under pressure to the intake conduit and the metering value is interlocked with the air valve in such a manner that the opening degree of the fuel metering valve is in proportion to that of the air valve.

Abstract: In a fuel supply apparatus for an internal combustion engine, a fuel discharging apparatus includes a fuel discharge port opened in an air intake conduit and a fuel valve for injecting a controlled quantity of fuel into the air intake passage through the discharge port. An annular fuel whirling chamber is formed around the fuel valve to receive fuel flow in a tangential direction to cause the fuel flow to whirl within the annular chamber. On the other hand, an annular recess is formed in a passage communicating the discharge port and the fuel valve with each other to forcively feed air to the fuel flowing through the passage. The fuel is thus intensively mixed with air and can be easily atomized upon being injected into the air intake passage through the discharge orifice.

Abstract: An exhaust gas recirculation system for cleaning exhaust gas from an internal combustion engine is provided in which a variable constriction is provided between an intake pipe and a pressure control valve in operative connection to a throttle valve in the carburetor and the pressure differential across said variable constriction is maintained constant to keep off any influence of the exhaust gas pressure while the ratio of the exhaust gas flow rate to the air intake into the engine is varied in correspondence to the intake pipe negative pressure. This exhaust gas recirculation system can be adapted to a fuel injection type intake system as well as other intake systems provided with an air valve for regulating air intake or having no venturi constriction such as employed in an SU type carburetor.

Abstract: A fuel supply apparatus for an internal combustion engines comprises a throttle valve disposed in an intake conduit leading to the internal combustion engine, an air valve disposed in the intake conduit upstream of the throttle valve so as to define an air pressure chamber in the intake conduit in cooperation with the throttle valve, a device for controlling the air valve in response to the pressure prevailing in the air pressure chamber so that the pressure be maintained at a substantially constant level, and a fuel metering device including a variable throttle passage provided in a fuel feed conduit opening in the intake conduit through a fuel injection valve and interlocked with the air valve to be controlled so that the flow section area of the throttle passage may be proportional to the opening degree of the air valve, and a device for maintaining difference in pressure produced across the variable throttle passage at a predetermined value.

Abstract: An air-fuel ratio control apparatus for an internal combustion engine has an air valve disposed in an intake passage downstream of a throttle valve to cooperate therewith to define an air pressure chamber and operative to maintain a substantially constant pressure therein. A fuel circuit includes a fuel discharge port open to the intake passage and a fuel-metering orifice operatively associated with the air valve such that the fuel-flowing section of the orifice is varied in proportion to the air-flowing section of the air valve. A constant differential fuel pressure valve is disposed in the fuel circuit to maintain a substantially constant fuel pressure difference across the fuel metering orifice during normal engine operation. The differential fuel pressure valve is mechanically operatively connected to a piston-cylinder assembly into which the fuel pressure upstream of the fuel-metering orifice is introduced.

Abstract: An internal combustion engine has a secondary air supply system and a fuel injection system including a two-fluid injection nozzle operative to inject air and fuel both under pressure into engine intake system. The secondary air supply system includes an air pump and a secondary air supply line extending between the pump and the engine exhaust system. The two-fluid injection nozzle is pneumatically connected to an air distributor provided on the secondary air supply line whereby pressurized air from the air pump is also supplied to the two-fluid injection nozzle and injected thereby together with the fuel to facilitate atomization of the injected fuel as well as to supercharge the engine.

Abstract: A fuel supply apparatus for an internal combustion engine comprises an air valve disposed in an intake air conduit upstream of a throttle valve and caused to rotate in accordance with the quantity of intake air through the intake conduit, a fuel supply source for supplying fuel under a substantially constant pressure through a fuel feed conduit to a fuel discharge port opened to the intake conduit, and a fuel metering device including a variable slit provided in the fuel feed conduit and interlocked with the air valve to be controlled such that the flow area of the variable slit may be proportional to the quantity of intake air and a fuel differential device for maintaining pressure difference across the variable slit at a predetermined value.

Abstract: An air-fuel ratio controlling system for a fuel-injection type internal combustion engine has an air valve disposed in an air intake duct upstream of a throttle valve and a fuel-metering variable orifice disposed in a fuel circuit. The air valve and the fuel-metering variable orifice are operatively associated with each other and controlled normally to maintain the air-fuel ratio at a substantially constant value. Pressurized fuel is used as a working fluid to operate the air valve. O.sub.2 sensor detects the oxygen content of exhaust gases to actuate a valve which varies the pressure of the working fluid to change the degree of opening of the air valve whereby the air-fuel ratio is adjusted in accordance with the output of the O.sub.2 sensor.

Abstract: A system for returning part of exhaust gases from an internal combustion engine through a return passage into an intake passage. Provided in the return passage are a fixed orifice, a pressure chamber downstream thereof, and a regulating valve downstream of the chamber. The regulating valve controls the pressure in the pressure chamber for a proper flow rate of exhaust gases being returned or recirculated. An opening of the regulating valve is so designed as to respond to the movement of a pilot valve provided separately.