Abstract: 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 (1) comprises a fuel passage (13) including a fuel nozzle (16) for supplying fuel to the intake passage, a first air passage (14) communicating with the fuel passage to supply air to the fuel passage, a variable communication unit (21, 41) 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 (22, 43) for moving the variable communication unit between the open position and the closed position in dependence on a load of the engine.

Abstract: 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 (1) comprises a fuel passage (13) including a fuel nozzle (16) for supplying fuel to the intake passage, a first air passage (14) communicating with the fuel passage to supply air to the fuel passage, a variable communication unit (21, 41) 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 (22, 43) for moving the variable communication unit between the open position and the closed position in dependence on a load of the engine.

Abstract: 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.

Abstract: 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.

Abstract: In a general-purpose internal combustion engine having a throttle valve and a choke valve each installed in an air intake passage connected to a combustion chamber, air sucked in flowing through the air intake passage and mixing with fuel supplied by a carburetor to generate an air-fuel mixture that enters the combustion chamber of a cylinder and is ignited to drive a piston to rotate a crankshaft to be connected to a load such as a generator, there are provided an electric motor (actuator), a throttle valve opening/closing mechanism connected to the motor to open/close the throttle valve and a choke valve opening/closing mechanism connected to the throttle valve opening/closing mechanism to open/close the choke valve in response to operation of the throttle valve opening/closing mechanism, thereby enabling to move a choke valve without need to install an additional actuator.

Abstract: An engine-start is inhibited when a gas engine is tilted, and the engine is immediately stopped. A shutoff valve (21) is provided on a liquefied fuel passage (15) supplying a liquefied fuel to a vaporizing chamber (14) from a cylinder (16). The shutoff valve (21) is provided with a diaphragm (28) to which a pulsation pressure of a crank chamber (4) is applied, and opens the liquefied fuel passage (15) if a negative pressure is applied to the diaphragm (28). A tilting shutoff valve (39) is provided in a pressure passage (34) transmitting the pulsation pressure to the shutoff valve (21). The tilting shutoff valve (39) which has a ball valve releases the pulsation pressure of the crank chamber (4) to an atmospheric air. If the pulsation pressure is open to the atmospheric air, the diaphragm (28) can not operate. Accordingly, the liquefied fuel passage 15 is kept being shut off, and is rapidly shut off in response to the tilt during the operation.

Abstract: In a general-purpose internal combustion engine having a throttle valve and a choke valve each installed in an air intake passage connected to a combustion chamber, air sucked in flowing through the air intake passage and mixing with fuel supplied by a carburetor to generate an air-fuel mixture that enters the combustion chamber of a cylinder and is ignited to drive a piston to rotate a crankshaft to be connected to a load such as a generator, there are provided an electric motor (actuator), a throttle valve opening/closing mechanism connected to the motor to open/close the throttle valve and a choke valve opening/closing mechanism connected to the throttle valve opening/closing mechanism to open/close the choke valve in response to operation of the throttle valve opening/closing mechanism, thereby enabling to move a choke valve without need to install an additional actuator.

Abstract: An engine-start is inhibited when a gas engine is tilted, and the engine is immediately stopped. A shutoff valve (21) is provided on a liquefied fuel passage (15) supplying a liquefied fuel to a vaporizing chamber (14) from a cylinder (16). The shutoff valve (21) is provided with a diaphragm (28) to which a pulsation pressure of a crank chamber (4) is applied, and opens the liquefied fuel passage (15) if a negative pressure is applied to the diaphragm (28). A tilting shutoff valve (39) is provided in a pressure passage (34) transmitting the pulsation pressure to the shutoff valve (21). The tilting shutoff valve (39) which has a ball valve releases the pulsation pressure of the crank chamber (4) to an atmospheric air. If the pulsation pressure is open to the atmospheric air, the diaphragm (28) can not operate. Accordingly, the liquefied fuel passage 15 is kept being shut off, and is rapidly shut off in response to the tilt during the operation.

Abstract: A general-purpose engine fuel tank fuel vapor treatment system includes: a canister mounted on a peripheral part of a fuel filler opening of a fuel tank mounted on a general-purpose engine, the canister housing a fuel adsorbent for adsorbing fuel vapor generated in the interior of the fuel tank; and an air vent provided in a tank cap fitted into the filler opening of the fuel tank. The air vent has an inner end opening in the interior of the fuel tank, and an outer end opening to the atmosphere. The canister is connected to the air vent. The interior of the fuel tank is made open to the atmosphere via the canister and the air vent. Thus, need for special piping is eliminated and fuel vapor within the fuel tank is treated while always stably maintaining the interior of the fuel tank at atmospheric pressure.

Abstract: A general-purpose engine fuel tank fuel vapor treatment system includes: a canister mounted on a peripheral part of a fuel filler opening of a fuel tank mounted on a general-purpose engine, the canister housing a fuel adsorbent for adsorbing fuel vapor generated in the interior of the fuel tank; and an air vent provided in a tank cap fitted into the filler opening of the fuel tank. The air vent has an inner end opening in the interior of the fuel tank, and an outer end opening to the atmosphere. The canister is connected to the air vent. The interior of the fuel tank is made open to the atmosphere via the canister and the air vent. Thus, need for special piping is eliminated and fuel vapor within the fuel tank is treated while always stably maintaining the interior of the fuel tank at atmospheric pressure.

Abstract: A general-purpose engine includes a canister which adsorbs fuel vapor that has evaporated within a fuel tank. The fuel vapor is desorbed from the canister and guided to an intake system communicating with an engine main body. The engine main body includes a crankcase and a cylinder block joined to the crankcase to have an upwardly inclined cylinder axis (C). The canister is disposed to one side of the crankcase and beneath the cylinder block to avoid any increase in the dimensions of the general-purpose engine.

Abstract: A composite control valve is constructed by a valve housing, first and second diaphragms mounted to the valve housing and disposed to be opposed to each other, a negative pressure working chamber defined between the first and second diaphragms to communicate with a negative pressure generating section in an engine, a first control valve adapted to be opened and closed by advancing and returning of the first diaphragm, and a second control valve adapted to be opened and closed by advancing and returning of the second diaphragm. The first control valve is incorporated into an air vent system for a fuel tank, and the second control valve is incorporated into a fuel passage system extending from the fuel tank to a fuel supply section in the engine.

Abstract: A general-purpose engine includes a canister which adsorbs fuel vapor that has evaporated within a fuel tank. The fuel vapor is desorbed from the canister and guided to an intake system communicating with an engine main body. The engine main body includes a crankcase and a cylinder block joined to the crankcase to have an upwardly inclined cylinder axis (C). The canister is disposed to one side of the crankcase and beneath the cylinder block to avoid any increase in the dimensions of the general-purpose engine.

Abstract: A composite control valve is constructed by a valve housing, first and second diaphragms mounted to the valve housing and disposed to be opposed to each other, a negative pressure working chamber defined between the first and second diaphragms to communicate with a negative pressure generating section in an engine, a first control valve adapted to be opened and closed by advancing and returning of the first diaphragm, and a second control valve adapted to be opened and closed by advancing and returning of the second diaphragm. The first control valve is incorporated into an air vent system for a fuel tank, and the second control valve is incorporated into a fuel passage system extending from the fuel tank to a fuel supply section in the engine.

Abstract: A gas-turbine engine having means capable of determining the temperature inside a combustion chamber without mounting a special temperature sensor therein and of controlling the operation of the components according to the detected inside temperature of the combustion chamber, which is provided with means for measuring a resistance value of a glow plug driven with a constant current, means for measuring a flow rate of air supplied to the combustion chamber and means for determining an inside temperature of the combustion chamber by searching a specified temperature corresponding to a measured value of glow-plug-resistance and a measured air-flow-rate from a table holding therein resistance-temperature characteristic data of the glow plug predetermined for airflow rate as parameter.

Abstract: A premixing section for supplying a fuel-air mixture to a homogeneous combustion chamber includes a first fuel nozzle disposed along an axis, a second fuel nozzle disposed to surround the outer periphery of the first fuel nozzle, and a premixing/pre-evaporating chamber. The first fuel nozzle is a diffusion combustion type nozzle and supplies the fuel-air mixture from an air blast-type nozzle tip directly to the homogeneous combustion chamber. The second fuel nozzle is a premixing/pre-evaporating type nozzle and supplies the fuel-air mixture from an air blast-type nozzle tip to the premixing/pre-evaporating chamber, so that the fuel-air mixture promoted in mixing and evaporation in the premixing/pre-evaporating chamber, is supplied via a swirler to the homogeneous combustion chamber. With the above arrangement, the atomization of the fuel enhances the emission characteristics.