Toyota Jidosha Kabushiki Kaisha

Aisan Industry Co., Ltd.

Aisin Industry Co., Ltd.

Takashi Katou

Norihiko Nakamura

Takaaki Itoh

Toshiharu Morino

Masatami Takimoto

Mitsuyoshi Teramura

Yozo Ota

Takaaki Itou

Yukinori Isoya

Takaaki Ito

Sunao Kitamura

Takeru Yasuda

Hidenori Hirosawa

Masaharu Hayakawa

Yozo Sakakibara

Youzou Sakakibara

Shunsuke Mizutani

In a variable venturi type carburetor having a slow speed system, a fuel vapor conduit is provided, an inlet of which is open to a main fuel passage, an outlet of which is open to an intake passage. Fuel vapor occurring in the main fuel passage is carried through the fuel vapor conduit, so as not to be introduced into a slow fuel passage; thereby, the engine is rotated stably with a relatively lean air-fuel ratio.

Variable venturi type carburetor

A variable venturi-type carburetor comprising a metering jet and at least one air-bleed bore formed on the cylindrical inner wall of the metering jet. The amount of air fed into the fuel passage of the carburetor from the air-bleed bore is controlled by an output signal from the oxygen concentration detector arranged in the exhaust manifold so that the air-fuel ratio of the mixture fed into the cylinder of the engine becomes equal to the stoichiometric air-fuel ratio. The metering needle is arranged so that it contacts the cylindrical inner wall of the metering jet and partially covers the air-bleed bore.

Variable venturi-type carburetor

An engine comprising a variable venturi-type carburetor which has a raised wall formed on the inner wall of the intake passage thereof. The suction piston of the carburetor has a tip face having a V-shaped cross-sectional upstream end portion which cooperates with the raised wall for defining an approximately isosceles triangle-shaped airflow-restricting opening therebetween when the amount of air flowing within the intake passage is small. An electromagnetic valve is arranged in an air-bleed passage of the carburetor and is periodically opened at a fixed frequency of 1 to 2 Hz so that the air-fuel ratio fluctuates at a fixed frequency within the range of .+-.0.2 A/F unit through a .+-.1.0 A/F unit relative to an approximately stoichiometric air-fuel ratio.

Exhaust gas-purifying device of an internal combustion engine

A variable venturi-type carburetor comprising a main fuel passage, a slow fuel port and a slow fuel passage connecting the main fuel passage to the slow fuel passage. A fuel metering jet is arranged in the slow fuel passage. The slow fuel passage, between the fuel metering jet and the slow fuel port, is connected to the venturi portion of the carburetor via a jet.

A variable venturi-type carburetor comprising a suction piston which has a tip face. A raised wall is formed on the inner wall of the intake passage, which faces the tip face of the suction piston. The raised wall has a substantially straight extending tip edge. The inner wall of the intake passage and the tip edge of the raised wall define a D-shaped air inlet mouth. The connecting portions of the inner wall of the intake passage and the tip edge of the raised wall have an arc shape. The upstream end portion of the tip face of the suction piston and the tip edge of the raised wall define an isosceles triangular air inlet opening therebetween when the amount of air fed into the cylinder of the engine is small.

A variable venturi-type carburetor comprising a vacuum chamber and an atmospheric pressure chamber which are separated by a suction piston. A needle is mounted on the central portion of the tip face of the suction piston. A suction hole, interconnecting the vacuum chamber to a venturi portion of the carburetor, is formed on the tip face of the suction piston at a position located upstream of the needle. The vacuum chamber is open to the atmosphere via a flow rate control valve apparatus when the engine temperature is low. The vacuum chamber is disconnected from the atmosphere by the flow rate control valve apparatus when the engine temperature is high.

A device for controlling the operation of a carburetor comprising a wax valve fitted into a bore formed in the device housing. A wax valve holder is fitted into the bore so as to surround the temperature sensitive portion of the wax valve. A cooling water passage is formed in the bore so as to surround the wax valve holder. A heat insulating space is formed between the outer wall of the temperature sensitive portion and the inner wall of the wax valve holder.

Device for controlling the operation of a carburetor

A variable venturi-type carburetor comprising a hollow cylindrical casing and a suction piston which is movable in the casing. The casing has a support pipe extending along the axis of the suction piston. The suction piston has a piston rod which is inserted into the support pipe. A bearing sleeve, equipped with a plurality of balls, is inserted between the piston rod and the support pipe. The bearing sleeve has a plurality of connecting grooves formed on the outer circumferential wall of the sleeve and extending in the axial direction of the sleeve over the entire length thereof.

A variable venturi-type carburetor comprising a fuel passage which is open to an intake passage. An air bleed passage is connected to the fuel passage. The carburetor comprises an air bleed control valve device for controlling the flow area of the air bleed passage. The air bleed control valve device comprises a bore formed therein, a push rod slidably inserted into the bore for controlling the flow area of the air bleed passage, and a wax valve actuating the push rod. A cooling water passage is formed in the air bleed control valve device so as to surround the air bleed passage and the wax valve.

A variable venturi-type carburetor comprising a suction piston which has a tip face having an upstream end portion. A raised wall is formed on the inner wall of the intake passage. The upstream end portion of the suction piston cooperates with the tip edge of the raised wall to restrict the flow of air flowing within the intake passage. The upstream end portion of the suction piston has a V-shaped central portion and flat opposed end portions. The tip edge of the raised wall has a flat central portion cooperating with the V-shaped central portion of the suction piston and has opposed end portions cooperating with the flat opposed end portions of the suction piston and projecting towards the intake passage.

A variable venturi-type carburetor comprising a suction piston which has a tip face defining a venturi portion. The tip face has a needle-mounting face at the center thereof, and a metering needle is fixed onto the needle-mounting face. The tip face also has a projecting tip face portion located upstream of the needle and projecting from the needle-mounting face towards the venturi portion. A groove, extending along the axis of the intake passage of the carburetor, is formed on the projecting tip face portion. The projecting tip face portion has a V-shaped cross-section which expands from the groove towards the venturi portion.

A control device comprising a push rod and a wax valve actuating the push rod in response to the temperature of the cooling water of an engine. The push rod is connected to the throttle valve of the carburetor so that the degree of opening of the throttle valve becomes smaller as the temperature of the cooling water of the engine is increased. The amount of air fed into the fuel passage from the air bleed passage is controlled by the push rod so that the amount of the air is increased as the temperature of the cooling water of the engine is increased. A vacuum-operated, time-delay valve is connected between the air-bleed passage and the atmosphere and increases the amount of air fed into the fuel passage from the air-bleed passage following a brief time delay period after the engine starts.

A variable venturi-type carburetor comprising a suction piston which has a tip face defining a venturi portion. The tip face has a projecting tip face portion located upstream of the needle and projecting toward the venturi portion. A groove, extending along the axis of the intake passage of the carburetor, is formed on the projecting tip face portion. The projecting tip face portion has a V-shaped cross-section which expands from the groove toward the venturi portion. A projection, having a V-shaped cross-section, is formed on the inner wall of the intake passage, which faces the tip face of the intake passage, which faces the tip face of the suction piston. The projection enters into the V-shaped cross-section of the projecting tip face portion of the suction piston when the amount of air fed into the cylinder of the engine is small.

A variable venturi-type carburetor comprising a suction piston, a fuel passage, and a needle fixed onto the suction piston and extending through the fuel passage. An air bleed passage is connected to the fuel passage. During engine starting, before the engine begins to rotate by its own power, the vacuum chamber of the suction piston is open to the atmosphere and the air bleed passage is shut off. When the engine begins to rotate by its own power, the vacuum chamber of the suction piston is closed from the atmosphere. After this, the air bleed passage is gradually opened. Such control of the closing of the vacuum chamber and the opening of the air bleed passage prevents engine stall by preventing the fuel mixture from becoming excessively lean when the engine first begins to rotate on its own power and then prevents engine misfires by subsequently reducing the air-fuel ratio to a lean mixture.

Growing community of inventors

Mishima, Japan

Takashi Katou