Honda Motor Co., Ltd.

Honda Giken Kogyo Kabushiki Kaisha

Hitoshi Abe

Hirohisa Ishikawa

Eiichi Utsugi

Naoyuki Kamiya

Takashi Suzuki

Kenji Kamimura

Masashi Nakamura

Katsuya Tajima

Kouichi Asai

Shuhei Maruyama

Ryo Saito

Masaki Ando

Teruyuki Saitoh

Yukio Sugimoto

Yoshio Yoshihara

Masayuki Fukuhara

Hideo Kurasawa

Koichi Sakurai

In an automotive carburetor, the time delay in the response of the engine to the change in the cross sectional area of the air passage is minimized, and a high level of freedom in selecting the communication cross section area of the air passage and the air fuel ratio for the given load of the engine. The carburetor () comprises a fuel passage () including a fuel nozzle () for supplying fuel to the intake passage, a first air passage () communicating with the fuel passage to supply air to the fuel passage, a variable communication unit () provided in a part of the first air passage and moveable between an open position for communicating the first air passage and a closed position for shutting off the first air passage and a switch mechanism () for moving the variable communication unit between the open position and the closed position in dependence on a load of the engine.

Carburetor for internal combustion engine

Disclosed is an engine fuel supply apparatus which can be made smaller in size and in which the amount of fuel in an air-fuel mixture can be increased with a fast response in correspondence with the operation of a throttle valve when the engine is accelerated rapidly. The fuel supply apparatus is provided with a fuel booster pump. A portion of an air-fuel mixture is introduced into a negative-pressure chamber of the fuel booster pump via a negative-pressure chamber channel, and the fuel booster pump is actuated. The actuation forces air in a pump chamber to flow into a pressure chamber, and fuel in a fuel storage chamber is temporarily supplied to a carburetor.

Fuel supply device for engine

An engine air intake system for an engine-powered working machine includes a lever cover which covers at least a base portion of an operation control lever mounted on an operation handle for operation by a human operator to control operation of at least one of the working machine and an engine of the working machine, a lower cover disposed inside the lever cover so as to define jointly with the lever cover a hollow space, an air intake portion having an air inlet opening and disposed in the lever cover such that at least the air inlet opening is disposed within the hollow space, and a fresh air guide hose interconnecting the air intake portion and the interior of an air-cleaner case.

Engine air intake system for engine-powered walk-behind working machine

A choke valve is controlled finely suited to the running state of an engine. A throttle valveand a choke valveare provided in series on an intake pipe, and the opening degree of the choke valveis controlled by a stepping motorA choke valve opening degree upon start of engine (start opening degree) and a driving pulse rate of a stepping motorare determined depending on the engine temperature. When lower than the engine temperature TL, the pulse rate is set at first rate, or the lowest rate in a specified range. Depending on the engine temperature, the pulse rate is set higher gradually up to second rate TH. When releasing the choke gradually in warm-up operation, the pulse rate is lowered so as to obtain a choke opening degree of high precision by a high torque.

Automatic choke

In a diaphragm-type carburetor, a fuel vapor treating chamber is provided in a downstream fuel passage which interconnects a fuel pump operated in response to a pulsation pressure from a pulsation pressure generating source and an inlet bore in a constant-pressure fuel chamber. The fuel vapor treating chamber is located before the inlet bore, and a porous element for finely dividing fuel vapor is placed in the fuel vapor treating chamber. Thus, when a fuel vapor is generated in the fuel discharged from the fuel pump, a large amount of fuel vapor can be prevented from being ejected all at one time from a fuel nozzle by finely dividing the fuel vapor and introducing it along with the fuel into the constant-pressure fuel chamber, it is immediately passed toward the fuel nozzle, whereby the variation in air-fuel ratio of a fuel-air mixture can be suppressed to a very small level.

Diaphragm-type carburetor

A diaphragm-type carburetor includes a fuel well communicating with a lower end of a fuel nozzle, a constant-pressure fuel chamber communicating with the fuel well through an outlet bore, and a fuel pump incorporated in fuel passages defined between an inlet bore of the constant-pressure fuel chamber and a fuel tank. A fuel introduction control valve controls the introduction of fuel into the constant-pressure fuel chamber. The fuel introduction control valve includes a valve seat member which communicates at its lower end with the fuel well through a bypass passage extending above the constant-pressure fuel chamber. Thus, when fuel vapor is introduced into the constant-pressure fuel chamber, it immediately passes towards the fuel nozzle, whereby the extreme reduction in air-fuel ratio of a fuel-air mixture can be avoided.

A fuel supply passage leading to a fuel tank is connected to an intake side of a fuel pump of a diaphragm-type carburetor, and a fuel transfer chamber incorporated in an intermediate portion of the fuel supply passage is provided in an insulator interposed between the carburetor and an engine. The fuel pumped from the fuel tank is heated in the chamber moderately, thereby decreasing the difference in temperature between the carburetor and the fuel introduced into the carburetor. Thus, the generation of fuel vapor in the diaphragm-type carburetor can be restrained.

Growing community of inventors

Wako, Japan

Hitoshi Abe