Abstract: A method is for the safe starting of a combustion engine in a handheld, portable work apparatus. When starting, start rpm limiting is activated when the rotational speed of the combustion engine exceeds an activation rotational speed that lies above the coupling rotational speed of a centrifugal coupling. After activating the start rpm limiting for at least one working cycle, an intervention in the ignition is carried out such that the rotational speed of the combustion engine decreases. After the rotational speed has decreased below a lower engagement rotational speed, an intervention in the ignition is carried out such that the rotational speed increases. If the rotational speed exceeds an upper engagement rotational speed, an intervention in the ignition is again carried out such that the rotational speed decreases. The upper engagement rotational speed and/or the lower engagement rotational speed is/are changed with an increasing number of consecutive working cycles.

Abstract: A handheld work apparatus has a combustion engine, a pull-rope starter, and a stop button for switching off the combustion engine. A throttle element is arranged in an intake channel of the combustion engine. The work apparatus has a control device for activating a spark plug and a fuel valve. The control device has a starting mode wherein the combustion engine can be started via the pull-rope starter, and an operating mode wherein the operator can adjust the throttle to vary the rotational speed (n) of the combustion engine. The operating and starting mode differ in terms of the control of ignition time and fuel quantity to be supplied. When the combustion engine is started from the switched-off state, the control device is automatically in starting mode, such that after the combustion engine is switched off, the work apparatus is immediately ready for restarting via the pull-rope starter.

Abstract: A method is for the safe starting of a combustion engine in a handheld, portable work apparatus. When starting, start rpm limiting is activated when the rotational speed of the combustion engine exceeds an activation rotational speed that lies above the coupling rotational speed of a centrifugal coupling. After activating the start rpm limiting for at least one working cycle, an intervention in the ignition is carried out such that the rotational speed of the combustion engine decreases. After the rotational speed has decreased below a lower engagement rotational speed, an intervention in the ignition is carried out such that the rotational speed increases. If the rotational speed exceeds an upper engagement rotational speed, an intervention in the ignition is again carried out such that the rotational speed decreases. The upper engagement rotational speed and/or the lower engagement rotational speed is/are changed with an increasing number of consecutive working cycles.

Abstract: A handheld work apparatus has a combustion engine and an ignition device for controlling a spark plug. The ignition device includes an electronic control device having a short circuit button for switching off the combustion engine. A temperature sensor is for capturing an operating temperature. The short circuit button and the temperature sensor are connected to a common signal input of the control device via a common signal line. The temperature sensor is an ohmic resistance variable on the basis of the temperature. A measurement voltage dropped across the resistance of the temperature sensor is supplied, as an analog temperature signal, to a common analog signal input of the control device. The measurement voltage at the temperature sensor collapses in the button position of the short circuit button, as a result of which the analog temperature signal applied to the analog signal input of the control device is extinguished.

Abstract: A handheld work apparatus has a combustion engine, a pull-rope starter, and a stop button for switching off the combustion engine. A throttle element is arranged in an intake channel of the combustion engine. The work apparatus has a control device for activating a spark plug and a fuel valve. The control device has a starting mode wherein the combustion engine can be started via the pull-rope starter, and an operating mode wherein the operator can adjust the throttle to vary the rotational speed (n) of the combustion engine. The operating and starting mode differ in terms of the control of ignition time and fuel quantity to be supplied. When the combustion engine is started from the switched-off state, the control device is automatically in starting mode, such that after the combustion engine is switched off, the work apparatus is immediately ready for restarting via the pull-rope starter.

Abstract: A handheld work apparatus has a combustion engine and an ignition device for controlling a spark plug. The ignition device includes an electronic control device having a short circuit button for switching off the combustion engine. A temperature sensor is for capturing an operating temperature. The short circuit button and the temperature sensor are connected to a common signal input of the control device via a common signal line. The temperature sensor is an ohmic resistance variable on the basis of the temperature. A measurement voltage dropped across the resistance of the temperature sensor is supplied, as an analog temperature signal, to a common analog signal input of the control device. The measurement voltage at the temperature sensor collapses in the button position of the short circuit button, as a result of which the analog temperature signal applied to the analog signal input of the control device is extinguished.

Abstract: A work apparatus has an internal combustion engine and a starter device for starting the engine. Within a housing of the work apparatus, a first electrical component is arranged at a first location and a second electrical component is arranged at a second location. A control unit is provided which is connected to the first electrical component and to the second electrical component. The control unit detects a first temperature-dependent value of the first electrical component at the first location, and a second temperature-dependent value of the second electrical component at the second location, and identifies the starting conditions as a function of these values. The first electrical component is a first actuator and the second electrical component is a second actuator or a sensor.

Abstract: An internal combustion engine has a fuel system that has a fuel valve with a housing, wherein in the housing a fuel chamber is formed. A fuel pump pumps fuel from a fuel tank into the fuel chamber. A conveying pump provides forced conveyance of fuel into the fuel system. A feed line is connected to the fuel chamber of the fuel valve. The conveying pump is arranged in the feed line and supplies fuel to the fuel chamber. A relief line is connected to the fuel chamber of the fuel valve and a first valve is arranged in the relief line.

Abstract: A work apparatus has an internal combustion engine and a starter device for starting the engine. Within a housing of the work apparatus, a first electrical component is arranged at a first location and a second electrical component is arranged at a second location. A control unit is provided which is connected to the first electrical component and to the second electrical component. The control unit detects a first temperature-dependent value of the first electrical component at the first location, and a second temperature-dependent value of the second electrical component at the second location, and identifies the starting conditions as a function of these values. The first electrical component is a first actuator and the second electrical component is a second actuator or a sensor.

Abstract: An internal combustion engine has a cylinder in which a combustion chamber, bounded on one side by a reciprocating piston, is formed. The piston drives a crankshaft rotatably mounted in a crank casing. The internal combustion engine has an inlet opening for combustion air into the crank casing, and an outlet opening out of the combustion chamber. The internal combustion engine has at least one overflow duct which connects the crank casing interior to the combustion chamber. The internal combustion engine has a crank casing pressure sensor for measuring the crank casing pressure, a device for determining the rotational position of the crankshaft, and an evaluation device which evaluates the measurements of the crank casing pressure sensor. A method for operating the internal combustion engine is provided where the ambient pressure is determined using the crank casing pressure measured by the crank casing pressure sensor.

Abstract: An internal combustion engine includes a cylinder and a piston journalled to reciprocate therein. The cylinder and piston conjointly delimit a combustion chamber into which a spark plug projects. Ignition of the spark plug occurs at an ignition time point controlled by a control unit. The ignition time point is controlled in an idle speed range according to an idle control having a most advanced ignition time point. The engine has a decompression valve which, when open, connects the combustion chamber to a pressure relief space. The valve is open during engine start and closes when pressure in the combustion chamber exceeds a closing pressure. To close the valve, the ignition occurs in the idle speed range for an engine cycle departing from the idle control at a closing ignition time point lying approximately 5° crankshaft angle ahead of the most advanced ignition time point.

Abstract: An internal combustion engine has a fuel system that has a fuel valve with a housing, wherein in the housing a fuel chamber is formed. A fuel pump pumps fuel from a fuel tank into the fuel chamber. A conveying pump provides forced conveyance of fuel into the fuel system. A feed line is connected to the fuel chamber of the fuel valve. The conveying pump is arranged in the feed line and supplies fuel to the fuel chamber. A relief line is connected to the fuel chamber of the fuel valve and a first valve is arranged in the relief line.

Abstract: An internal combustion engine of a hand-held power tool has a crankcase having a circumferential wall extending in a circumferential direction of the crankcase. A crankshaft is supported so as to be rotatable about an axis of rotation within the crankcase. At least one transfer passage extends from the crankcase into the cylinder of the engine, wherein the transfer passage has an inlet port at the crankcase. At least one fuel retaining device is disposed on the circumferential wall of the crankcase. A radial direction, starting at the axis of rotation of the crankshaft and extending outwardly, extends through the at least one fuel retaining device. The at least one fuel retaining device has a depth in the radial direction and a length in the circumferential direction. The at least one fuel retaining device, relative to the radial direction, has an asymmetric cross-section in the circumferential direction.

Abstract: An internal combustion engine has a cylinder in which a combustion chamber, bounded on one side by a reciprocating piston, is formed. The piston drives a crankshaft rotatably mounted in a crank casing. The internal combustion engine has an inlet opening for combustion air into the crank casing, and an outlet opening out of the combustion chamber. The internal combustion engine has at least one overflow duct which connects the crank casing interior to the combustion chamber. The internal combustion engine has a crank casing pressure sensor for measuring the crank casing pressure, a device for determining the rotational position of the crankshaft, and an evaluation device which evaluates the measurements of the crank casing pressure sensor. A method for operating the internal combustion engine is provided where the ambient pressure is determined using the crank casing pressure measured by the crank casing pressure sensor.