Abstract: The invention relates to an electromagnetic valve having a valve housing (2) and a valve opening (29) with a valve seat (8) and an electric drive coil (3) and a magnetic yoke (11) and a longitudinal centre axis (14). The magnetic yoke (11) is assigned a metallic plate armature (5) which is mounted movably and has an armature disc (48). The armature disc (48) lies sealingly with a sealing surface (9) against the valve seat (8) in a first switching position of the valve, and opens the valve seat (8) in a second switching position of the valve. According to the invention, the valve seat (8) is configured on a valve component (18), wherein the valve component (18) has at least one valve opening (29) which lies at a radial spacing (r) from the longitudinal centre axis (14). The valve seat (8) of the valve opening (29), which valve seat (8) corresponds with direct body contact with the sealing surface (9) of the armature disc (48) of the plate armature (7), consists of metal.

Abstract: The invention relates to an electromagnetic valve having a valve housing (2) and a valve opening (29) with a valve seat (8) and an electric drive coil (3) and a magnetic yoke (11) and a longitudinal centre axis (14). The magnetic yoke (11) is assigned a metallic plate armature (5) which is mounted movably and has an armature disc (48). The armature disc (48) lies sealingly with a sealing surface (9) against the valve seat (8) in a first switching position of the valve, and opens the valve seat (8) in a second switching position of the valve. According to the invention, the valve seat (8) is configured on a valve component (18), wherein the valve component (18) has at least one valve opening (29) which lies at a radial spacing (r) from the longitudinal centre axis (14). The valve seat (8) of the valve opening (29), which valve seat (8) corresponds with direct body contact with the sealing surface (9) of the armature disc (48) of the plate armature (7), consists of metal.

Abstract: An electromagnetic fuel valve has a valve chamber, a valve element and a valve seat assigned to the valve element. The valve chamber is delimited by an electromagnetic drive which moves the valve element relative to the valve seat. The drive includes a receiving housing for a coil carrier with an electrical coil. A magnet core is inserted into the coil carrier and has an end section facing the valve element. At an open sealing end facing toward the valve chamber, a sealing element is arranged between the end section of the magnet core and the receiving housing. To achieve good sealing, that end section of the magnet core situated in the sealing element expands the sealing element and compresses the material thereof radially against the edge of the sealing end of the receiving housing to seal the valve chamber to the interior space of the receiving housing.

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 handheld work apparatus includes a fuel tank, into which a flexible fuel line projects. A suction head is arranged at the free end of the fuel line. The suction head is connected via the fuel line to a fuel supply device of an internal combustion engine of the work apparatus. The suction head has at least one weight member. The weight member is formed at least partially as a magnet to achieve good cleaning of the fuel without a substantial increase in the weight of the work apparatus.

Abstract: A power tool has an internal combustion engine with a cylinder. An injection valve supplies fuel to the internal combustion engine. A fuel pump conveys fuel from a fuel tank to the injection valve. A fan wheel is provided that is driven by the internal combustion engine. The cylinder is arranged in a first cooling zone of the power tool and the fan wheel conveys cooling air through the first cooling zone. The fuel pump is arranged in a second cooling zone of the power tool. Between the first cooling zone and the second cooling zone a buffer zone is arranged. The buffer zone is separated by at least one first partition from the first cooling zone and by at least one second petition from the second cooling zone.

Abstract: An electromagnetic fuel valve has a valve chamber, a valve element and a valve seat assigned to the valve element. The valve chamber is delimited by an electromagnetic drive which moves the valve element relative to the valve seat. The drive includes a receiving housing for a coil carrier with an electrical coil. A magnet core is inserted into the coil carrier and has an end section facing the valve element. At an open sealing end facing toward the valve chamber, a sealing element is arranged between the end section of the magnet core and the receiving housing. To achieve good sealing, that end section of the magnet core situated in the sealing element expands the sealing element and compresses the material thereof radially against the edge of the sealing end of the receiving housing to seal the valve chamber to the interior space of the receiving housing.

Abstract: A hand-guided work apparatus includes a combustion engine to drive a work tool. The combustion engine includes a crankcase (14) in which a crankshaft (16) is rotatably mounted about a rotational axis (44). A pressure sensor (27) and a temperature sensor (26) are arranged on the crankcase (14). The pressure sensor (27) and the temperature sensor (26) are arranged in a common sensor housing (31). In the typical put-down position (8) of the work apparatus, the pressure sensor (27) and the temperature sensor (26) are arranged below a plane (45) which is parallel to the horizontal storage surface (7) and contains the rotational axis (44) of the crankshaft (16). A connecting channel (25) is formed in the sensor housing (31). The connecting channel (25) connects the pressure sensor (27) to the crankcase interior (20) and the base (35) of the connecting channel (25) slopes down toward the crankcase interior (20) in the typical put-down position (8) of the work apparatus.

Abstract: A power tool has an internal combustion engine with a cylinder. An injection valve supplies fuel to the internal combustion engine. A fuel pump conveys fuel from a fuel tank to the injection valve. A fan wheel is provided that is driven by the internal combustion engine. The cylinder is arranged in a first cooling zone of the power tool and the fan wheel conveys cooling air through the first cooling zone. The fuel pump is arranged in a second cooling zone of the power tool. Between the first cooling zone and the second cooling zone a buffer zone is arranged. The buffer zone is separated by at least one first partition from the first cooling zone and by at least one second petition from the second cooling zone.

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 (8) has an ignition device, a device for supplying fuel and a device for detecting the rpm of the engine (8). The engine (8) includes a permissible limit rpm (ng) and a control range (A) of the rpm (n) above the limit rpm (ng). A method for operating the engine (8) provides that the rpm of the engine (8) is limited in the control range (A) because of suppression of the ignition in individual engine cycles wherein the rpm (n) lies above a control rpm (na) lying in the control range (A). In the control range, and to improve the exhaust-gas values, the noncombustion engine cycle ratio (NECR) is adjusted. The NECR indicates the ratio of the number of engine cycles wherein the ignition is suppressed to the total number of ignitions.

Abstract: A water supplying device of a hand-held power tool has a water-conveying line and a valve arrangement arranged in the line for controlling the water flow through the line. The valve arrangement has a control valve with a valve body adjustable across a positioning travel. The opening cross-section of the control valve, as a function of the positioning travel, has a progressive characteristic line. An arrangement for actuating the water supplying device has an actuator that is separate from additional control elements of the power tool.

Abstract: In a method for priming a fuel metering device for an internal combustion engine with a piston arranged in a combustion chamber and driving a crankshaft that is rotatably supported in a crankcase, with a fuel pump that conveys fuel from a fuel tank to a metering valve that opens into a metering chamber at alternating operating pressure, and with a control unit that calculates and controls timing for the metering valve for metering a fuel quantity corresponding to a load situation of the internal combustion engine, the metering valve is kept open, independent of the calculated timing for the metering valve, for a priming duration in a starting phase of the internal combustion engine when the alternating operating pressure of the metering chamber at the mouth of the metering valve is negative and when a fuel system pressure in the fuel metering device is below a target pressure.

Abstract: A hand-guided work apparatus includes a combustion engine to drive a work tool. The combustion engine includes a crankcase (14) in which a crankshaft (16) is rotatably mounted about a rotational axis (44). A pressure sensor (27) and a temperature sensor (26) are arranged on the crankcase (14). The pressure sensor (27) and the temperature sensor (26) are arranged in a common sensor housing (31). In the typical put-down position (8) of the work apparatus, the pressure sensor (27) and the temperature sensor (26) are arranged below a plane (45) which is parallel to the horizontal storage surface (7) and contains the rotational axis (44) of the crankshaft (16). A connecting channel (25) is formed in the sensor housing (31). The connecting channel (25) connects the pressure sensor (27) to the crankcase interior (20) and the base (35) of the connecting channel (25) slopes down toward the crankcase interior (20) in the typical put-down position (8) of the work apparatus.

Abstract: In a method for detecting an operating parameter of a power tool having an internal combustion engine with a cylinder, a piston delimiting a combustion chamber in the cylinder and driving a crankshaft supported rotatably in a crankcase, an intake supplying combustion air to the combustion chamber, an exhaust removing combustion gases from the combustion chamber, and a signal generator driven in rotation by the crankshaft emitting sequential alternating voltage signals, a period duration of the voltage signal is selected to correspond to the n-th portion of a crankshaft revolution with n greater than 2. The n-th portion of the crankshaft revolution provides a crankshaft angle interval. For each crankshaft angle interval at least one information is detected that represents a course plotted against the crankshaft angle. The course is scanned with regard to characteristic features that are correlated with an operating parameter of the power tool.

Abstract: A manually guided suction apparatus for suctioning up material via a suction air stream, comprising a suction fan having a fan housing surrounding a fan wheel and provided with an intake opening. A centrifugal separator is disposed upstream of the intake opening and produces a curved path of the suction air stream. The centrifugal separator has a curved peripheral wall in which is disposed a removal opening for material that is to be sucked up. The intake opening is disposed approximately in a central portion of the centrifugal separator.

Abstract: A method for operating an internal combustion engine having a fuel system which feeds fuel at a given pressure to a metering valve provides that a controller defines the opening time and the closing time of the metering valve and correspondingly actuates the metering valve so that the metering valve opens and closes at the defined times. In order to permit precise metering of fuel even in high-speed internal combustion engines there is provision for the controller to define at least one of the times for the opening or closing of the metering valve while taking into account the counterpressure actually prevailing at the outlet opening of the metering valve.

Abstract: A device for supplying water to a cutting wheel of a hand-held cut-off machine has a water-conducting line and a valve arrangement arranged in the line. The valve arrangement has a shut-off valve for controlling the water flow flowing through the line. The shut-off valve is actuated as a function of an operating signal of the cut-off machine such that in operation of the cut-off machine the water flow through the line is released by the shut-off valve. The shut-off valve interrupts the water flow through the line when the operating signal is absent.

Abstract: In a method for priming a fuel metering device for an internal combustion engine with a piston arranged in a combustion chamber and driving a crankshaft that is rotatably supported in a crankcase, with a fuel pump that conveys fuel from a fuel tank to a metering valve that opens into a metering chamber at alternating operating pressure, and with a control unit that calculates and controls timing for the metering valve for metering a fuel quantity corresponding to a load situation of the internal combustion engine, the metering valve is kept open, independent of the calculated timing for the metering valve, for a priming duration in a starting phase of the internal combustion engine when the alternating operating pressure of the metering chamber at the mouth of the metering valve is negative and when a fuel system pressure in the fuel metering device is below a target pressure.

Abstract: A water supplying device of a hand-held power tool has a water-conveying line and a valve arrangement arranged in the line for controlling the water flow through the line. The valve arrangement has a control valve with a valve body adjustable across a positioning travel. The opening cross-section of the control valve, as a function of the positioning travel, has a progressive characteristic line. An arrangement for actuating the water supplying device has an actuator that is separate from additional control elements of the power tool.