Zama Japan Kabushiki Kaisha

Z Ama Japan Co., Ltd.

Iida Denki Kogyo Co., Ltd.

Hideki Watanabe

Takumi Nonaka

Akira Yamazaki

Ryouhei Yamashita

Tamotsu Saitou

Hiroyuki Oka

Tamotsu Saito

A fuel injection device comprising electricity-generating means generating electricity by rotation of an engine and outputting a predetermined signal, and a solenoid valve injecting fuel; the valve being opened as a result of a drive current applied to a coil, and the fuel being injected into an intake passage of the engine at a predetermined timing during the rotation of the engine; to ensure that the flow rate required during high-speed operation ca be adequately provided in a fuel injection device for injecting/supplying fuel to an engine. The electricity-generating means is an alternating current generation means attached to the engine in a crank angle position at which an output is generated in synchronization with the intake timing of the engine; the signal is an injection command signal applied to the solenoid valve as an alternating-current drive current; and the applied voltage increases with increased engine speed.

Fuel injection device

A fuel injection device for smooth discharge of a gas accumulated therein comprising a fuel pump, a solenoid valve for injecting pressurized fuel into the intake passage of an engine, a high-pressure fuel passage extending from the fuel pump to the solenoid valve and has a medially positioned constant-pressure chamber, and a fuel return passage connected to a fuel return pipe, with the fuel return passage extending from the constant-pressure chamber and having a medially positioned priming pump. The constant-pressure chamber is configured with the top wall in the upper space thereof disposed above the opening of the high-pressure fuel passage opposite the solenoid valve, the fuel return passage opens into the upper space at a position above the opening of the high-pressure fuel passage, and the gas accumulating in the constant-pressure chamber is discharged from the upper space toward the fuel tank via the fuel return passage.

An attachment structure for a solenoid valve which can be stably attached to and removed from a carburetor unit with a single movement and without increasing the number of parts. A rod-like supporting portion is disposed a predetermined distance away from a surface of a carburetor unit and extending in a direction substantially perpendicular to a direction of and installed near an opening in the surface of the carburetor unit. A cylindrical engaging portion extends from a circumferential face of a cylindrical body fitted on the solenoid valve substantially perpendicular to an axial line of the rod-like supporting portion, and forms a groove-like engagement portion which is narrower in diameter than the rod-like supporting portion, whereby the engaging portion, via the groove-like engagement portion, is coupled to and supported by rod-like supporting portion when an insertion portion of the solenoid valve is inserted into the opening.

Attachment structure for solenoid valve to carburetor unit

A starting device for feeding a quantity of fuel from the fixed-quantity fuel chamber to an intake passage during start-up having a manually operated primary pump for suctioning/pumping fuel and arranged on a fuel introduction path connected along a fuel-feeding path; and a fixed-quantity fuel chamber for temporarily storing fuel delivered from the primary pump. An internal wall of the fixed-quantity fuel chamber undergoes elastic displacement, allowing its internal capacity to expand/shrink within a predetermined range; the fixed-quantity fuel chamber is connected to a fuel delivery path that communicates with the intake passage side and has a manually operated open/close valve; the valve is opened in a state in which, due to the primary pump being operated, the fixed-quantity fuel chamber is filled with a predetermined quantity of fuel while enlarging its internal capacity, whereby it shrinks due to an elastic contraction force and the fuel.

Starting device and carburetor supplying fixed amount of fuel

A speed reduction method for a hand-carried engine-driven working machine is provided in which a speed reduction of an engine can be attained reliably and safely by preventing the occurrence of lean come-down phenomenon in such a state that the engine is operating in a practical revolution speed range. An acceleration is calculated based on a change in revolution speed, and when the acceleration becomes smaller than a predetermined threshold, an ignition timing is retarded by a desired amount based on a determination that the engine is being decelerated, and further, a fuel flow rate is also increased, whereby the decelerated state of the engine is maintained without fail, so that the occurrence of lean come-down phenomenon is prevented in the process of reducing the revolution speed of the engine.

Speed reduction method for hand-carried engine-driven working machine

The opening of a solenoid valve is automatically adjusted after an engine is started and before actual work is performed for an appropriate air-fuel ratio, whereby it is possible to attain a good and stable driving of the engine without any delay even for an abrupt change in load. After the engine is started, when a rotation speed enters a 'fuel flow rate adjusting rotation speed range' in which a definite load is applied to the engine in a working rotation speed range of the engine in which a throttle valve is opened to a definite opening, a detected rotation speed is fed back to a target rotation speed, and the opening of the solenoid valve is controlled to adjust a fuel flow rate, so that the combustion state in the engine is optimized at the valve opening so determined.

Fuel control method for hand-carried engine-driven working machine

A method for making an optimum combustion during engine operating time changes a fuel flow rate of the solenoid valve on the basis of engine rotational speed feedback control during engine idling time at low engine rotational speed and low electric power consumption. During engine idling time of an engine are carried out a rotational speed detecting process, an idle rotation adjusting process of making a rotational speed detected by the rotational speed detecting process equal to an initial value of rotational speed by controlling an ignition timing while comparing the detected rotational speed with the initial value of rotational speed as target value, and a valve opening correction process according to idle ignition timing change (I.I.T.C.) obtained by the idle rotation adjusting process. The valve opening is set to an adjusted valve opening (A.V.O.) plus a correction valve opening (C.V.O.) by the valve opening correction process.

Fuel control method for handheld engine operating machine

A fuel injection device comprising electricity-generating means generating electricity by rotation of an engine and outputting a predetermined signal, and a solenoid valve injecting fuel; the valve being opened as a result of a drive current applied to a coil, and the fuel being injected into an intake passage of the engine at a predetermined timing during the rotation of the engine; to ensure that the flow rate required during high-speed operation can be adequately provided in a fuel injection device for injecting/supplying fuel to an engine. The electricity-generating means is an alternating current generation means attached to the engine in a crank angle position at which an output is generated in synchronization with the intake timing of the engine; the signal is an injection command signal applied to the solenoid valve as an alternating-current drive current; and the applied voltage increases with increased engine speed.

Growing community of inventors

Iwate, Japan

Hideki Watanabe