摘要:
The invention relates to an intake system (1) for the combustion air (2) of an internal combustion engine (3) in a portable handheld work apparatus (4). The intake system (19) includes a filter housing (5) having an air filter (6) for purifying the combustion air (2). The clean space (8) of the air filter (6) is fluidly connected to an outlet opening (10) of the filter housing (5). The outlet opening (10) communicates with a carburetor (7) of the engine (3). A centrifugal-force separator (13) is mounted forward of the air filter (6) for separating large amounts of dust in the inducted combustion air (2). The separator (13) is so positioned ahead of the filter housing (5) that a central core flow (14) of the separator has a lower particle density (15) and is supplied to the filter (6). A tangential flow (16) surrounds the central core flow (14) in the interior of the separator (13). The tangential flow (16) has a great amount of dust or dirt and is conducted away via the suction side (11) of a blower (12), especially of a cooling-air blower (19) of the engine (3) having vanes on the back side thereof.
摘要:
A two-stroke engine for a portable two-stroke engine in a portable handheld work apparatus includes a combustion chamber (3) formed in a cylinder (2). The combustion chamber (3) is delimited by the piston (5) which drives the crankshaft (7) via a connecting rod (6). The two-stroke engine includes several transfer channels (14), which, referred to a symmetry plane (49), lie on opposite sides (47, 48) with the plane partitioning approximately the outlet (10). The transfer channels (14) connect the crankcase (4) to the combustion chamber (3). A first end (20) of each transfer channel (14) opens via an entry window (12, 15) into the combustion chamber (3) and the second end (19) of each transfer channel opens to the crankcase (4). Each transfer channel (14) is connected, between its ends (19, 20), to an air channel (22a, 22b) via a membrane valve (21). Air is supplied by the air channel (22a, 22b) via an adjustable throttle (31, 32).
摘要:
The invention relates to a two-stroke engine for a portable handheld work apparatus such as a motor chain saw. The combustion chamber (3), which is configured in a cylinder (2), is delimited by a piston (5) which drives a crankshaft (7) rotatably journalled in a crankcase (4). The crankcase (4) is connected to the combustion chamber (3) via a transfer channel (14). A first end (20) of the transfer channel (14) opens into the combustion chamber (3) via an entry window (12, 15) lying in the cylinder wall (16); whereas, the second end (19) of this transfer channel (14) is open toward the crankcase (4). The transfer channel (14) is connected between its ends (19, 20) to an air channel (22a, 22b) via a check valve (21). The air channel (22a, 22b) supplies essentially fuel-free gas via a throttle (31) having an adjustable throttle element (33). A mixture-preparation device (8) is provided for the air/fuel mixture downstream of an air filter (42) in the flow direction of the combustion air. The air/fuel mixture is supplied via an inlet (11) to the crankcase (4). In order to meter clean air to the air channels in a controlled manner, an adjustable throttle element (33) is mounted in a throttle channel (36) of an independent throttle housing (31) and the throttle channel (36) is connected upstream of the throttle element to the clean space (51) of the air filter (42) connected ahead of the mixture-preparation device (8).