摘要:
A portable, handheld work apparatus such as a chain saw has a handle (5, 7) to guide the work apparatus (1) and has an air-cooled, mixture-lubricated combustion engine (10) arranged in a casing as a drive for a work tool (3). The cylinder (11) has a combustion chamber (13) formed therein to which an air/fuel mixture is supplied. The air/fuel mixture is ignited by a spark plug (23) which projects into the combustion chamber (13). An ignition control (30) triggers a spark in dependence on the angular position of the crankshaft (15). A temperature sensor (35, 45, 55) is provided to control the cylinder temperature. The temperature signal of the temperature sensor (35, 45, 55) is connected to a power control (40). When a predetermined temperature is exceeded, the power control (40) changes the operating parameters of the combustion engine (10) in such a manner that the power of the combustion engine (10) is changed.
摘要:
A two-stroke engine (1) has a cylinder (2) defining a combustion chamber (3) delimited by a piston (5). The piston (5) drives a crankshaft (7) which is rotatably journalled in a crankcase (4). The crankcase (4) is connected to the combustion chamber (3) via a transfer channel (17) at at least one position of the piston. The two-stroke engine has an inlet (11) into the crankcase (4) and an outlet (19) from the combustion chamber. There is an arrangement to supply fuel, a control, and a device to determine the crankcase pressure (pKGH). A method to operate the two-stroke engine (1) includes determining the crankcase pressure (pKGH) during every engine cycle. The fluctuation in the crankcase pressure (pKGH) is determined and the fluctuation is compared to a limit value (Δplimit) to determine whether a combustion occurs during every engine cycle. In this way, a determination can be reliably made as to whether the two-stroke engine is running in a four-stroke mode.
摘要:
A two-stroke engine (1) has a cylinder (2) defining a combustion chamber (3) delimited by a piston (5). The piston (5) drives a crankshaft (7) which is rotatably journalled in a crankcase (4). The crankcase (4) is connected to the combustion chamber (3) via a transfer channel (17) at at least one position of the piston. The two-stroke engine has an inlet (11) into the crankcase (4) and an outlet (19) from the combustion chamber. There is an arrangement to supply fuel, a control, and a device to determine the crankcase pressure (pKGH). A method to operate the two-stroke engine (1) includes determining the crankcase pressure (pKGH) during every engine cycle. The fluctuation in the crankcase pressure (pKGH) is determined and the fluctuation is compared to a limit value (Δplimit) to determine whether a combustion occurs during every engine cycle. In this way, a determination can be reliably made as to whether the two-stroke engine is running in a four-stroke mode.
摘要:
The invention relates to a portable, handheld work apparatus such as a chain saw having a handle (5, 7) to guide the work apparatus (1) and having an air-cooled, mixture lubricated combustion engine (10) arranged in a casing as a drive for a work tool (3). The cylinder (11) has a combustion chamber (13) formed therein to which an air/fuel mixture is supplied. The air/fuel mixture is ignited by a spark plug (23) which projects into the combustion chamber (13). An ignition control (30) triggers a spark in dependence on the angular position of the crankshaft (15). A temperature sensor (34, 45, 55) is provided to control the cylinder temperature. The temperature signal of the temperature sensor (34, 45, 55) is connected to a power control (40). When a predetermined temperature is exceeded, the power control (40) changes the operating parameters of the combustion engine (10) in such a manner that the power of the combustion engine (10) is changed.
摘要:
A hand-held working apparatus has an internal combustion engine having a crankshaft which is driven in rotation. The crankshaft drives at least one tool of the working apparatus via a centrifugal clutch. The working apparatus has a device for determining the speed of the internal combustion engine and a control device which controls the internal combustion engine. It is provided that the profile of the speed of the internal combustion engine is evaluated by the control device, and that the engagement speed of the centrifugal clutch is determined from the profile of the speed of the internal combustion engine. A method of operation is also provided.
摘要:
A laser-based device for non-mechanical, three-dimensional trepanation during cornea transplants comprises a computer-assisted control and regulation unit (4) provided with at least one control computer (5, 6, 7) and at least one display unit (8, 9), as well as a laser source (2) for generating a working laser beam (3) as well as a multi-sensor processing head (1) integrated into which are: an axial beam positioning system (11) into which the working laser beam (3) can be coupled, a focal point tracking unit (12) for the z-position displacement of the focal point (13) of the working laser beam (3) an x-y-scanner unit (14, 15) for the x and y-position displacement of the working laser beam (3), an eye position sensor unit (23, 24, 35, 36) for detection of the position of the eye, and a plasma sensor unit (16, 25) for detection of the plasma glow that occurs during the cornea trepanation.