Abstract: The invention relates to a two-stroke engine for a portable handheld work apparatus such as a motor-driven chain saw, cutoff machine, brushcutter or the like. A crankcase (4) is formed below the engine cylinder (2). A piston (5) moves up and down in the cylinder (2) and drives a crankshaft (7) rotatably journalled in the crankcase (4). A fuel-containing mixture is supplied via a membrane carburetor (8) to the combustion chamber (3) delimited between the piston (5) and the cylinder (2). A bypass channel (22) is provided parallel thereto and supplies essentially fuel-free air to the combustion chamber (3). The bypass channel (22) opens into a channel segment (21) via a connecting piece (24) fixedly attached to the cylinder (2). The channel segment (21) is formed in the cylinder wall (16). A spark plug (20) and an ignition control device (34) are assigned to the combustion chamber (3).

Abstract: A cylinder is produced of die cast metal and is for a two-stroke engine in a portable handheld work apparatus such as a motor chain saw. A combustion chamber (3) is formed in the cylinder (2) and this combustion chamber is delimited by a piston (5). In the cylinder wall (16), there is an outlet (10) for conducting away the combustion gases from the combustion chamber (3). Transfer channels (14a, 14b) are provided which open into the combustion chamber (3) via transfer windows (12, 15) and supply the operating medium from the crankcase (4) needed for operating the two-stroke engine. The transfer channels (14a, 14b) are configured in the cylinder wall (16) as channels opening radially to the outside and are closed by a seated cover (23).

Abstract: The invention relates to a two-stroke engine in a portable handheld work apparatus such as a motor chain saw. A combustion chamber (3) is formed in a cylinder (2) and is delimited by a piston (5). The piston (5) drives a crankshaft (7) via a connecting rod (6). The crankshaft is journalled in a crankcase (4). Air is supplied to the combustion chamber (3) via a first outlet-near transfer channel (15); whereas, the air/fuel mixture, which is needed for operation, flows in via a second outlet-remote transfer channel (12) from the crankcase (4). The constructive volume of the outlet-near transfer channel (15) is designed to be approximately 20% to 60% of the volumetric total air input of the engine (1) in order to achieve a complete charge of the combustion chamber while having low scavenging losses.

Abstract: A connector between a carburetor and a cylinder connection of an internal combustion engine of an implement is provided. The flow channel formed in the connector is provided with raised portions over the inner periphery of the channel. To avoid fluctuations in the speed of the engine as a function of changes in position of the implement, the raised portions are embodied as wall portions that are oriented approximately transverse to the center line of the channel. The wall portions provide a flow cross-section for the channel that varies in a step-shape or terrace-shaped manner.

Abstract: An internal combustion engine, for example a two-stroke engine having scavenging collection, is provided. The combustion chamber formed in the cylinder is delimited by a reciprocating piston. A fuel/air mixture prepared in the Venturi section of a diaphragm carburetor is supplied to the engine. The air portion of the mixture is conveyed to the Venturi section via an intake channel, and the fuel portion is conveyed to the Venturi section via a main nozzle path that branches off from a fuel-filled control chamber to which fuel is supplied via a fuel line and a feed valve that is controlled by a control diaphragm that delimits the control chamber. A device is provided for varying the air portion and/or the fuel portion at full load. Connected to the device is a control unit that receives, as an input variable, an operating parameter of the engine that varies as a function of engine speed. The device is actuated as a function of the output signal of the control unit.

Abstract: The invention relates to a two-stroke engine in a portable handheld work apparatus. A combustion chamber (3) is formed in a cylinder (2) and the chamber is delimited by a piston (5). At least one transfer channel (14) is provided which connects the crankcase (4) to the combustion chamber (3). An air channel (22) opens into the transfer channel (14) and this channel supplies essentially fuel-free gas, preferably air. The intake channel (28) of a carburetor (8) is connected to an intake opening (45) in the housing base (41) of the air filter housing (43) upstream of a carburetor throttle flap. The intake channel (28) connects downstream of the carburetor throttle flap to an intake channel (9) to the crankcase (4).

Abstract: The invention relates to a two-stroke engine for a portable handheld work apparatus such as a motor-driven chain saw, cutoff machine, brushcutter or the like. A crankcase (4) is formed below the engine cylinder (2). A piston (5) moves up and down in the cylinder (2) and drives a crankshaft (7) rotatably journalled in the crankcase (4). A fuel-containing mixture is supplied via a membrane carburetor (8) to the combustion chamber (3) delimited between the piston (5) and the cylinder (2). A bypass channel (22) is provided parallel thereto and supplies essentially fuel-free air to the combustion chamber (3). The bypass channel (22) opens into a channel segment (21) via a connecting piece (24) fixedly attached to the cylinder (2). The channel segment (21) is formed in the cylinder wall (16). A spark plug (20) and an ignition control device (34) are assigned to the combustion chamber (3).

Abstract: The invention relates to a cylinder which can be produced of die cast metal. The cylinder is for a two-stroke engine in a portable handheld work apparatus such as a motor chain saw. A combustion chamber (3) is formed in the cylinder (2) and this combustion chamber is delimited by a piston (5). In the cylinder wall (16), there is an outlet (10) for conducting away the combustion gases from the combustion chamber (3). Furthermore, transfer channels (14a, 14b) are provided which open into the combustion chamber (3) via transfer windows (12, 15) and supply the operating medium from the crankcase (4) needed for operating the two-stroke engine. The transfer channels (14a, 14b) are configured in the cylinder wall (16) as channels opening radially to the outside. These channels are closed by a seated cover (23).

Abstract: The invention relates to a two-stroke engine in a portable handheld work apparatus such as a motor chain saw. A combustion chamber (3) is formed in a cylinder (2) and is delimited by a piston (5). The piston (5) drives a crankshaft (7) via a connecting rod (6). The crankshaft is journalled in a crankcase (4). Air is supplied to the combustion chamber (3) via a first outlet-near transfer channel (15); whereas, the air/fuel mixture, which is needed for operation, flows in via a second outlet-remote transfer channel (12) from the crankcase (4). The constructive volume of the outlet-near transfer channel (15) is designed to approximately 20% to 60% of the volumetric total air input of the engine (1) in order to achieve a complete charge of the combustion chamber while having low scavenging losses.

Abstract: The invention relates to a two-stroke engine in a portable handheld work apparatus. A combustion chamber (3) is formed in a cylinder (2) and the chamber is delimited by a piston (5). At least one transfer channel (14) is provided which connects the crankcase (4) to the combustion chamber (3). An air channel (22) opens into the transfer channel (14) and this channel supplies essentially fuel-free gas, preferably air. The intake channel (28) of a carburetor (8) is connected to an intake opening (45) in the housing base (41) of the air filter housing (43) upstream of a carburetor throttle flap. The intake channel (28) connects downstream of the carburetor throttle flap to an intake channel (9) to the crankcase (4).