Abstract: A power tool has an internal combustion engine with an injection valve through which fuel is supplied to the internal combustion engine; a crankcase; and a crankshaft arranged in the crankcase so as to be rotatable about an axis of rotation. A fan wheel housing is provided and a fan wheel is arranged in the fan wheel housing and conveys cooling air to the internal combustion engine. In the fan wheel housing a connecting opening is formed. The injection valve is arranged in a cooling area, wherein cooling air is supplied by the fan wheel through the connecting opening to the cooling area.

Abstract: A power tool has a guide bar with clamping area to secure the guide bar to a power tool housing and with guide groove guiding a chain. The guide bar has side elements delimiting a main fluid channel and an auxiliary fluid channel. The main fluid channel has a main fluid inlet at the first side element in the clamping area, a first main fluid outlet at the deflection area of the guide bar, and a second main fluid outlet that opens into the guide groove at a first longitudinal side of the guide bar. A fluid quantity flowing in operation through the main fluid channel is greater than a fluid quantity flowing through the auxiliary fluid channel. The auxiliary fluid channel has a first auxiliary fluid outlet at the deflection area and a second auxiliary fluid outlet that opens at a second longitudinal side into the guide groove.

Abstract: A power tool has an internal combustion engine with a piston supported in the cylinder and delimiting a combustion chamber. A crankshaft is rotatably supported in the crankcase and driven by the piston. Combustion air is supplied to the combustion chamber via an intake passage that has a piston-controlled inlet opening and an intake section formed within the cylinder. The bottom of the intake section, when the cylinder axis is vertical and the crankcase is beneath the combustion chamber, connects lowermost points of passage cross-sections arranged in the intake section perpendicular to the flow direction. The bottom descends toward the crankcase when the longitudinal cylinder axis is vertical. A ramp arranged in the intake passage next to the inlet opening deflects a portion of flow flowing within the intake passage. The ramp, when the longitudinal cylinder axis is vertical, ascends in flow direction toward the crankcase.

Abstract: The invention relates to a portable, hand-held work apparatus such as a chain saw, a cut-off machine, a brush cutter or the like with an air cooled combustion engine. A cooling air blower (4) which includes a cooling air spiral (6) and a fan wheel (5), moves a cooling air flow (13) for cooling the combustion engine. Further a combustion air channel (30) leads from the cooling air blower (4) to the combustion engine (2) and branches off from an air output window (20) provided in the base (14) of the cooling air spiral (6). The diverting device (21) includes a guide wall (22) which extends into the cooling air spiral (6) between the fan wheel (5) and the air output window (20). In order to divert a large volume of combustion air (19) with minimal disruption to the cooling air flow, the pass-through cross-section of the air output window (20) tapers in the direction of the diverted combustion air (19) from a first pass-through area (29) to a second pass-through area (31).

Abstract: An internal combustion engine has a cylinder (2) and a crankcase (4). A combustion chamber (3) is formed in the cylinder (2) and is delimited by a piston (5). The piston (5) rotationally drives a crankshaft (7) in a rotational direction (21) via a connecting rod (6). The crankshaft (7) is arranged in a crankcase interior space (17). A mixture inlet (9) is provided in the crankcase interior space (17). In the crankcase interior space (17), at least one flow conducting element (23, 33, 43, 53, 63, 73) is provided which is spatially fixed and this flow conducting element projects into the crankcase interior space (17) and lies opposite to the rotational direction (21) of the crankshaft (7).

Abstract: The invention relates to a portable, hand-held work apparatus such as a chain saw, a cut-off machine, a brush cutter or the like with an air cooled combustion engine. A cooling air blower (4) which includes a cooling air spiral (6) and a fan wheel (5), moves a cooling air flow (13) for cooling the combustion engine. Further a combustion air channel (30) leads from the cooling air blower (4) to the combustion engine (2) is provided and branches off from an air output window (20) provided in the base (14) of the cooling air spiral (6). The diverting device (21) includes a guide wall (22) which extends into the cooling air spiral (6) between the fan wheel (5) and the air output window (20). In order to divert a large volume of combustion air (19) with minimal disruption to the cooling air flow, the pass-through cross-section of the air output window (20) tapers in the direction of the diverted combustion air (19) from a first pass-through area (29) to a second pass-through area (31).

Abstract: An internal combustion engine has a cylinder with a combustion chamber delimited by a reciprocating piston that drives a crankshaft rotatably supported in a crankcase. The internal combustion engine has an intake passage, an exhaust connected to the combustion chamber, a device supplying fuel, and a control device controlling at least one operating parameter of the internal combustion engine. The internal combustion engine is operated in that a pressure is measured in operation of the internal combustion engine, an adjustable value for at least one operating parameter of the internal combustion engine is deteremined based on the measured pressure, and the determined adjustable value is set for optimized running of the engine.

Abstract: An internal combustion engine has a cylinder (2) and a crankcase (4). A combustion chamber (3) is formed in the cylinder (2) and is delimited by a piston (5). The piston (5) rotationally drives a crankshaft (7) in a rotational direction (21) via a connecting rod (6). The crankshaft (7) is arranged in a crankcase interior space (17). A mixture inlet (9) is provided in the crankcase interior space (17). In the crankcase interior space (17), at least one flow conducting element (23, 33, 43, 53, 63, 73) is provided which is spatially fixed and this flow conducting element projects into the crankcase interior space (17) and lies opposite to the rotational direction (21) of the crankshaft (7).

Abstract: An internal combustion engine has a cylinder with a combustion chamber delimited by a reciprocating piston that drives a crankshaft rotatably supported in a crankcase. The internal combustion engine has an intake passage, an exhaust connected to the combustion chamber, a device supplying fuel, and a control device controlling at least one operating parameter of the internal combustion engine. The internal combustion engine is operated in that a pressure is measured in operation of the internal combustion engine, an adjustable value for at least one operating parameter of the internal combustion engine is deteremined based on the measured pressure, and the determined adjustable value is set for optimized running of the engine.

Abstract: An intake system for the combustion air of a motor of a hand held implement is provided. The system includes an air filter and a centrifugal separator. The air filter has a dirt chamber and a clean chamber that is separated therefrom by a filter medium. The clean chamber is fluidically connected with a carburetor of the motor to convey combustion air to the motor. The centrifugal separator splits the air stream into a core flow having low particle density and a peripheral flow having high particle density. The centrifugal separator includes at least two cyclones, wherein the discharged flows from the cyclones are respectively combined in pairs and open out into a common suction tube.

Abstract: An intake system for the combustion air of a motor of a hand held implement is provided. The system includes an air filter and a centrifugal separator. The air filter has a dirt chamber and a clean chamber that is separated therefrom by a filter medium. The clean chamber is fluidically connected with a carburetor of the motor to convey combustion air to the motor. The centrifugal separator splits the air stream into a core flow having low particle density and a peripheral flow having high particle density. The centrifugal separator includes at least two cyclones, wherein the discharged flows from the cyclones are respectively combined in pairs and open out into a common suction tube.