Mikuni Corporation

Hiroshi Mizui

Ryoji Ehara

Shogo Hashimoto

Tadashi Nichogi

Junichiro Takahashi

Osamu Miura

To secure detection accuracy of a temperature sensor in a general purpose engine. A general purpose engine includes an engine main body (), an output shaft () that outputs a rotation force of the engine main body, a cooling fan () that is rotated and driven by the output shaft, a cooling cover () that is fixed to the engine main body to define a cooling air passage (CP) which guides cooling air generated by the cooling fan along an exterior wall () of the engine main body, and a temperature sensor () that is fixed to the engine main body in a region away from the cooling air passage (CP). Accordingly, it is possible to measure a temperature of the engine main body with high accuracy and perform electronic control of fuel injection with high accuracy.

General purpose engine

In a fuel injection system, a fuel tank is disposed below an electronically controlled fuel injection apparatus. A fuel reservoir chamber for supplying fuel from the fuel tank is disposed above the electronically controlled fuel injection apparatus, and the fuel stored in the fuel reservoir chamber is supplied to the electronically controlled fuel injection apparatus via a fuel supply passage. The fuel reservoir chamber and the fuel tank are connected by a first fuel return passage through which vapor is ejected and fuel in the fuel reservoir chamber overflows. A second fuel return passage for returning surplus fuel from the electronically controlled fuel injection apparatus is connected to either of the fuel reservoir chamber and the first fuel return passage at the position above the connecting position at which the fuel reservoir chamber connects with the first fuel return passage.

Fuel injection system

An internal combustion engine fuel supply system includes a fuel discharge apparatus having a vapor removal system. The fuel discharge apparatus includes an apparatus body, a fuel chamber defined in the body, a fuel inlet connected to a fuel tank, a fuel supply path partially defined by the fuel inlet and connecting the fuel chamber to the fuel tank, a fuel discharge outlet, a fuel return outlet for return of excess fuel to the fuel tank, and a reflux path connecting the fuel supply path to the fuel return outlet. A vapor blocking member is provided in the fuel supply path at a bifurcation point at which the reflux path branches from the fuel supply path. The reflux path is arranged such that vapor blocked by the vapor blocking member rises from the bifurcation point and through the reflux path to the fuel return outlet due to self-buoyancy of the vapor.

Fuel discharge apparatus having a vapor removal system, and internal combustion engine fuel supply system having such fuel discharge apparatus

An electronically controlled fuel injection device includes a plunger pump constituted by a cylinder, a plunger is slidably mounted within the cylinder to form a pressure chamber, and a solenoid coil for driving the plunger. At a lower section of a body that encases the plunger pump, an intake section is coupled to the pressure chamber to cause intake of fuel into the pressure chamber upon operation of the plunger. At an upper section of the body, a return section is arranged to return surplus fuel to a fuel tank. A circulation passage branches off from the intake section and is provided between the cylinder and the solenoid coil for guiding a portion of the fuel toward the return section. With this arrangement, penetration of vapor into the fuel injection device is suppressed, and an inexpensive and highly durable electronically controlled fuel injection device is provided.

Electronically controlled fuel injection device

An electronically controlled fuel injection device includes a plunger pump, a circulation passage which circulates fuel that has been pressurized in the initial stage of a pressure-feeding stroke, a valve body which blocks the circulation passage in the later stage of the pressure-feeding stroke, an inlet orifice nozzle which allows the passage of fuel whose pressure has been increased in the later stage of the pressure-feeding stroke, an outlet orifice nozzle which is used to circulate some of the fuel that has passed through the inlet orifice nozzle back into the fuel tank, an injection nozzle which injects an amount of fuel equal to the difference between the fuel that has passed through the inlet orifice nozzle and the fuel that has passed through the outlet orifice nozzle, and a control arrangement for controlling the plunger pump in response to the cycle of the engine.

Growing community of inventors

Kanagawa, Japan

Hiroshi Mizui