Yamabiko Corporation

Iida Denki Kogyo Co., Ltd.

Lida Denki Kogyo Co., Ltd.

Takamasa Otsuji

Takahiro Yamazaki

Shirou Yamaguchi

Akira Yamazaki

Kosuke Matsumoto

Hidekazu Tsunoda

Shiro Yamaguchi

Hiroyuki Miyaki

Buhei Kobayashi

Buhei Kobayshi

An engine-driven working machine includes a controller, which varies a control value of a solenoid valve so as to decrease or increase an opening degree of the solenoid valve when a rotating speed of an engine is within a predetermined high rotating speed range and the rotating speed of the engine is lower or higher than a predetermined rotating speed, respectively. When the control value of the solenoid valve is varied so as to decrease the opening degree of the solenoid valve and corresponds to a predetermined opening degree larger than a fully-closed state, the control value is set to a limitation value.

Handheld engine-driven working machine

A carburetor achieves better emission characteristics while improving a combustion state by increasing a delivery ratio of a stratified scavenging engine and reducing intake resistance. No dividing wall is provided between a throttle valveand a choke valve, and a gapbetween the valvesandis opened. Intake air in both of an upper region and a lower region of the choke valveflows into an air-fuel mixture passagein a lower region of the fully-open throttle valve. A main nozzleis arranged so as to be inclined toward the throttle valve

Stratified scavenging two-stroke internal combustion engine and carburetor thereof

To allow an intake negative pressure to directly act on a fuel outlet formed on a nozzle tube, and to guide a fuel discharged from the fuel outlet in the nozzle tube to the fuel-air mixture passage. A rotary carburetor () has a guide plate member () downstream of a fuel outlet () located in a through-hole (). The guide plate member () has both side edges () away from an inner wall surface () of the through-hole (). The through-hole () is divided by the guide plate member () into a first passage portion () and a second passage portion (). The first passage portion () communicates through a piston groove with a scavenging passage of a cylinder. The fuel discharged from the fuel outlet () is guided by the guide plate member () to the second passage portion () and is supplied through the second passage portion () to a fuel-air mixture passage () of an engine intake system.

Rotary carburetor for two-stroke internal combustion engine

An engine-driven working machine includes a controller, which varies a control value of a solenoid valve so as to decrease or increase an opening degree of the solenoid valve when a rotating speed of an engine is within a predetermined high rotating speed range and the rotating speed of the engine is lower or higher than a predetermined rotating speed, respectively. In case the controller determines that the engine-driven working machine gets started saw cutting, the controller stops varying the control value of the solenoid valve when the rotating speed of the engine is within the predetermined high rotating speed range and lower than the target rotating speed.

The certainty of supplying air to a scavenging channel through a piston groove is improved. In a cylinder wall, a gas venting portis formed below and adjacent to a scavenging port. The gas venting portis independent from the scavenging port, and is opened/closed by a piston as each of an air portand the scavenging portis. Upon a piston groovebeing brought into communication with the gas venting portas a result of the piston moving up (FIG.(II)), blown-back gas in a piston groovecan move to a crankcase through the gas venting port. Along with this, air can enter the piston groovefrom the air port

Air leading-type stratified scavenging two-stroke internal-combustion engine

The present invention is to prevent mixing of fresh air and an air-fuel mixture when a throttle valve is fully opened and increase a delivery ratio. A main nozzle () is surrounded by a tunnel-like air flow guiding member (). The air flow guiding member () is opened at its front and back sides. A whole amount of fuel discharged via a main nozzle () is sent to a downstream side by an air flow created by the air flow guiding member (). When a throttle valve () and a choke valve () are both in a fully-opened state, fresh air flows into an air-fuel mixture passage () through a gap between these valves ().

Carburetor for stratified scavenging two-stroke engine

It is intended to effectively prevent blow-by with no need for large changes in typical structures of two-cycle internal combustion engines. A main scavenging passage () for supplying air-fuel mixture from a crankcase to a combustion chamber for scavenging purposes has a branch scavenging passage () that extends upward aslant toward an intake port (). The main scavenging passage () communicates with a first scavenging port () located nearer to an exhaust port (). The branch scavenging passage () communicates with a second scavenging port (). A mean cross-sectional area of the branch scavenging passage () is smaller than that of the main scavenging passage (). Cross-sectional area of a portion () next to an inlet port () of the main scavenging passage () opening to the crankcase is smaller than the sum of cross-sectional areas of the first and second scavenging ports ().

Growing community of inventors

Tokyo, Japan

Takamasa Otsuji