摘要:
A two-stroke engine has a cylinder with a combustion chamber that is delimited by a reciprocating piston that drives with a connecting rod a crankshaft rotatably supported in a crankcase. In predetermined positions of the piston, the crankcase is connected by at least one transfer channel to the combustion chamber. The two-stroke engine has a mixture channel for supplying a fuel/air mixture and an air channel that supplies substantially fuel-free air to the transfer channel. In order to provide a simple adjustment of the air channel to different two-stroke engines of a model range, a component in which the air channel is formed has a throttle member that is arranged at an end face of the component. The throttle member throttles the air flow through the air channel in at least one operating state of the two-stroke engine.
摘要:
A two-stroke engine has a cylinder in which a combustion chamber is provided. The combustion chamber is delimited by a reciprocating piston that drives with a connecting rod a crankshaft rotatably supported in a crankcase. In predetermined positions of the piston, the crankcase is connected by at least one transfer channel to the combustion chamber. The two-stroke engine has a mixture channel for supplying a fuel/air mixture and an air channel that supplies substantially fuel-free air to the transfer channel. In order to enable in a simple way an adjustment of an air channel to different two-stroke engines of a model range, at one end face of a component in which the air channel is formed a throttle member is arranged that throttles the air flow through the air channel in at least one operating state of the two-stroke engine.
摘要:
A blower (1) has a housing (10) to which a blower pipe (2) may be removably connected. An internal combustion engine located within the housing (10) drives a blower wheel. The blower wheel, in turn, generates an air flow (11) within the blower pipe. To reduce the exhaust gases and the fuel consumption during idle operation of the combustion engine, a reduction device (12, 22), located in the blower pipe downstream of the blower wheel reduces the clear cross section of flow during idle operation of the engine.
摘要:
A membrane carburetor for an internal combustion engine in a portable handheld work apparatus includes a control chamber (3) delimited by a membrane (2). The control chamber (3) is connected via a feed line (4) to a fuel tank (5). The feed line (4) is cleared via a valve body (6) when there is a deflection of the membrane (2) because of an underpressure in the control chamber (3). The control chamber (3) is connected to an air channel (10) via at least one fuel nozzle (7) and at least one ancillary chamber (9). The air channel (10) passes through the membrane carburetor (1) and leads to the internal combustion engine. A purge pump (11) is provided in a fuel line (12) connecting the control chamber (3) to the fuel tank (5). The fuel path between the control chamber (3) and the purge pump (11) is guided through at least one ancillary chamber (9).
摘要:
A two-stroke engine (1) is especially for a handheld work apparatus such as a motor-driven chain saw, a cutoff machine or the like and has a cylinder (2) wherein a combustion chamber (3) is formed. The combustion chamber (3) is delimited by a reciprocating piston (5). The piston (5) drives a crankshaft (7) via a connecting rod (6). The crankshaft (7) is rotatably journalled in the crankcase (4). The combustion chamber (3) is connected to the crankcase (4) at pregiven piston positions via at least one transfer channel (11). The combustion chamber (3) has an outlet (10) for exhaust gases. An air channel (9) is provided which conducts combustion air into the crankcase (4) and a throttle element is mounted in the air channel (9). A compact configuration of the two-stroke engine (1) can be achieved when a separate fuel inlet (13) is provided in the crankcase (4) which is fed by a fuel metering system (15). The fuel metering system (15) has means for supplying fuel in dependence upon the position of the throttle element and/or in dependence upon the engine rpm. A method for operating the two-stroke engine (1) provides that the fuel is prepared to an air/fuel mixture in the crankcase (4) with the combustion air supplied via the air inlet (14).
摘要:
A two-stroke engine has an intake channel via which the engine (1) is supplied with an air/fuel mixture prepared in a carburetor (12). The engine also has a starting device (19, 40) for enrichment of the air/fuel mixture during the start operation. The starting device (19, 40) is disposed in the region of the carburetor (12). To avoid an overenrichment of the mixture after start-up of the engine, a bypass channel (20) is provided which branches off upstream of the starting device (19, 40) viewed in the flow direction (30) of the air/fuel mixture and opens downstream of the starting device (19, 40). A switching valve (23) is mounted in the bypass channel (20) and is essentially closed when the engine (1) is started. When the engine (1) runs up, the switching valve (23) automatically switches into a position where less throttling occurs.
摘要:
A two-stroke engine (1) has a combustion chamber (3) configured in a cylinder (2). The combustion chamber (3) is delimited by a reciprocating piston (5) and drives a crankshaft (7) which is rotatably journalled in a crankcase (4). The two-stroke engine (1) has an outlet (10) out of the combustion chamber (3) and at least one transfer channel (12, 15) which connects the crankcase (4) to the combustion chamber (3) at pregiven piston positions. The transfer channels (12, 15) open with transfer windows (13, 16) into the combustion chamber (3). To obtain a good start and good idle performance and low exhaust-gas values, an ancillary channel (14) is provided which is connected into the combustion chamber (3) at one end (37) and into the transfer channel (15) with the other end (36). During operation, the ancillary channel (14) opens into the combustion chamber (3) during the downward stroke of the piston (5) while the transfer window (16) to the combustion chamber (3) is still closed.
摘要:
A two-stroke engine has an intake channel via which the engine (1) is supplied with an air/fuel mixture prepared in a carburetor (12). The engine also has a starting device (19, 40) for enrichment of the air/fuel mixture during the start operation. The starting device (19, 40) is disposed in the region of the carburetor (12). To avoid an overenrichment of the mixture after start-up of the engine, a bypass channel (20) is provided which branches off upstream of the starting device (19, 40) viewed in the flow direction (30) of the air/fuel mixture and opens downstream of the starting device (19, 40). A switching valve (23) is mounted in the bypass channel (20) and is essentially closed when the engine (1) is started. When the engine (1) runs up, the switching valve (23) automatically switches into a position where less throttling occurs.
摘要:
A two-stroke engine (1) has a combustion chamber (3) configured in a cylinder (2). The combustion chamber (3) is delimited by a reciprocating piston (5) and drives a crankshaft (7) which is rotatably journalled in a crankcase (4). The two-stroke engine (1) has an outlet (10) out of the combustion chamber (3) and at least one transfer channel (12, 15) which connects the crankcase (4) to the combustion chamber (3) at pregiven piston positions. The transfer channels (12, 15) open with transfer windows (13, 16) into the combustion chamber (3). To obtain a good start and good idle performance and low exhaust-gas values, an ancillary channel (14) is provided which is connected into the combustion chamber (3) at one end (37) and into the transfer channel (15) with the other end (36). During operation, the ancillary channel (14) opens into the combustion chamber (3) during the downward stroke of the piston (5) while the transfer window (16) to the combustion chamber (3) is still closed.
摘要:
A carburetor has a housing with an intake channel section. A throttle element and a choke element are arranged in the intake channel section and are adjustable between a closed position in which a flow cross-section of the intake channel is substantially closed and an open position in which the flow cross-section of the intake channel is substantially released. The choke element has a start position in which the flow cross-section of the intake channel is at least partially closed. A coupling device couples the throttle element to the choke element when the choke element is in the start position. The choke element has an enriching position. The coupling device has an actuator that moves the choke element into the enriching position when the throttle element is moved, starting from the start positions of the throttle element and of the choke element, toward the open throttle position of the throttle element.