Aisan Industry Co., Ltd.

Toyota Jidosha Kogyo Kabushiki Kaisha

Toyota Jidosha Kabushiki Kaisha

Asian Industry Co., Ltd.

Mikio Minoura

Masaharu Sumiyoshi

Katsuhiko Motosugi

Setsuro Sekiya

Junzo Uozumi

Yuzo Takeuchi

Tsuneo Ando

Masatami Takimoto

Takeru Yasuda

Mitsuyoshi Teramura

Keigo Yorioka

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.

Air-fuel ratio control device of a variable venturi-type carburetor

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. The diaphragm type valve has a function to detect and amplify the differential pressure across the fuel metering device, while the pressure of the metered fuel is controlled by the variable orifice type flow control device which is actuated in response to the differential pressure sensed and amplified by the diaphragm type valve.

Fuel supplying device for use in fuel injection type internal combustion

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.

Exhaust gas recirculating device

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. Also a pressure difference control unit is employed for maintaining the pressure difference of fuel across the fuel metering valve at a preset value, whereby the air-fuel ratio of an air-fuel mixture is maintained constant independently of the engine speed. The fuel supply apparatus of the above type further comprises a variable volume chamber defined by a cylinder and a piston slidably disposed within the cylinder and interlocked with the throttle valve. The pressure variation in the variable volume chamber according to operation of the throttle valve for acceleration or deceleration of the engine is transmitted to either the pressure difference control unit or the air valve control unit to correct the preset pressure difference across the fuel metering valve or the preset pressure in the air pressure chamber, whereby the air-fuel ratio is made richer or leaner during acceleration or deceleration of the engine.

Fuel supply apparatus for internal combustion engines

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.

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.

Exhaust gas recirculation system

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. The air valve controlling device includes a feedback control system which comprises a device for producing a signal of a level corresponding to the pressure prevailing in the air pressure chamber in the intake conduit, and a device responding to the signal for controlling the air valve so that the pressure within the air pressure chamber be maintained at a set valve, and further includes a device for automatically changing the level of the signal representative of the pressure level in the air pressure chamber in dependence on the environmental and operating conditions of the engine such as embient temperature, atmospheric pressure, engine temperature, deceleration and acceleration of the engine and the like, thereby to vary the intake air quantity to attain an optimum air-fuel ratio for the instantaneous operating condition of the engine.

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. The position of the piston relative to the cylinder is varied when the engine operating condition is varied. The movement of the piston varies the fuel-flowing section of the differential fuel pressure valve thereby to vary the fuel pressure difference across the fuel-metering orifice whereby the air-fuel ratio is varied when the engine operating condition is varied.

Air-fuel ratio control apparatus of a fuel supply system for an internal

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.

Internal combustion engine

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. The fuel pressure differential device comprises a first pressure chamber applied with a fuel pressure prevailing at the downstream side of the variable slit, a second pressure chamber having a constant pressure difference relative to the first pressure chamber and a constant differential pressure valve disposed in the fuel feed conduit downstream of the variable slit for controlling the pressure at the downstream side of the variable throttle passage to have the aforementioned pressure difference relative to the second pressure chamber. Further the pressure of the second pressure chamber is arranged to be automatically varied dependent on environmental and operating conditions of the engine such as atmospheric pressure, ambient temperature, engine temperature, acceleration and deceleration of the engine, whereby the pressure difference across the variable slit is varied so as to correct the air-fuel ratio.

Air-fuel ratio control system for an internal combustion engine

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.

Air-fuel ratio controlling system for an internal combustion engine

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. The pilot valve is actuated in response to a pressure in the pressure chamber, a pressure in a venturi portion in a carburetor, and a pressure in an intake passage downstream of a throttle valve, thereby maintaining the pressure in the pressure chamber at the same level as that in the venturi portion, when the pressure in the intake passage downstream of the throttle valve is over a given pressure level, and maintaining the pressure in the pressure chamber higher than the pressure in the venturi portion, when a pressure in the intake passage downstream of the throttle valve is below a given pressure level (at the time of light load running of an engine). Accordingly, the ratio of recirculating exhaust gas to the intake air is maintained constant, when the pressure in the intake passage is over a given pressure level, and reduced when the aforesaid pressure is below the given pressure level (at the time of light load running of an engine.)

Growing community of inventors

Nagoya, Japan

Mikio Minoura