Hitachi, Ltd.

Masamitsu Okumura

Torazo Nishimiya

Seisaku Numakura

Tadao Osawa

Tomo Ito

Takashige Kohno

Tokihiko Sakuma

Toru Nakagawa

Yuichi Tobita

An air-fuel ratio control device for an internal combustion engine equipped with a plurality of variable venturi type carburetors each having a slow system, in which the flow rate of air supplied to the slow systems of the carburetors is controlled depending on the engine operation parameters including, for example, the temperature of intake air, temperature of engine oil and atmospheric pressure to improve the rate of atomization of fuel, thereby improving the idling performance of the engine and therefore improving the fuel consumption of the engine.

Air-fuel ratio control device for internal combustion engines

A proportional type electromagnetic valve comprises a flow rate control valve secured to a movable core which moves a stroke in proportion to the input current, and a valve seat portion cooperative with the flow rate control valve to control the flow rate. In addition to a bias spring providing for urging the flow rate control valve toward the valve seat portion, a second spring is disposed on the movable core for urging the flow rate control valve to release it from the valve seat portion. The resultant force of the two springs makes the stroke of the flow rate control valve proportional to the input current.

Proportional type electromagnetic valve

A fuel vapor trapping device for trapping the fuel vapors evaporated in a fuel feed system such as a float chamber of a carburetor and a fuel tank of an internal combustion engine, said device comprising a first canister whose one end is communicated with the float chamber and the high suction in the carburetor and whose the other end is communicated with the surrounding atmosphere and which is filled with a first absorbent capable of absorbing the vapors of hydrocarbons having carbon numbers up to and including seven (C.sub.7), and a second canister whose one end is communicated with the fuel tank and with the high suction in the carburetor and whose the other end is communicated with the surrounding atmosphere and which is filled with a second absorbent capable of absorbing the vapors of hydrocarbons having the carbon numbers up to and including four (C.sub.4). A single canister type is also disclosed wherein the first and second canisters are constructed as a unitary assembly.

Device for trapping fuel vapor vaporized in fuel feed system of internal

A current-stroke proportional type solenoid valve has a movable plunger disposed around the inner peripheral wall of a bobbin with a coil therearound, a stator core disposed face to face with the movable plunger and forming the magnetic circuit, a bias spring for always biasing the movable plunger in one direction and the stroke of the movable plunger being determined by magnitude of the current flowing through the coil. In the solenoid valve, the output rod is axially supported by a first lubricant resin and the movable plunger also by a second lubricant resin.

Current-stroke proportional type solenoid valve

An exhaust gas recirculation control system for controlling the amount of exhaust gas subjected to recirculation to the air inlet depending on the amount of inlet air of an internal combustion engine. This system comprises a control valve disposed in an exhaust gas recirculation passage, for controlling the amount of exhaust gas recirculation, an orifice disposed in the recirculation passage, for creating a negative pressure upstream of the control valve, and a solenoid valve for generating a pressure which controls the control valve. The solenoid valve comprises a core formed therein with a hollow passage opened at one end to a valve portion, a plunger made of a magnetic material and having a valve seat opposing the open end to define the valve portion, a spring biasing the plunger in the opening direction of the valve portion, a first exciting coil generating, when passing therethrough a current proportional to the amount of inlet air, a force acting on the plunger to close the valve portion, and a second exciting coil generating, when passing therethrough a current in inverse proportion to the pressure downstream of the orifice, a force opposite to the force on the plunger due to the first exciting coil.

Growing community of inventors

Katsuta, Japan

Masamitsu Okumura