Andreas Stihl Ag Co. Kg

Other

Andreas Stihl

Eberhard Schieber

Heinrich Leufen

Mohamed Abou-Aly

Georg Maier

Hans Nickel

Heiko Rosskamp

Jörg Schlossarczyk

Wolfgang Layher

Klaus Geyer

Ernst Gorenflo

Franz Mandl

Roland Schierling

Claus Naegele

Andreas Neubauer

Jurgen Trost

Gunter Dietzsch

Andreas Hägele

Ina Weimer

Manfred Bortfeld

Thomas Neumaier

Michael Harrer

Thomas Frank

The invention relates to an ignition device for triggering an ignition spark at a spark plug by way of an ignition generator. The latter includes a magnet wheel, which has two permanent magnets arranged at a spacing from each other in the peripheral direction and a magnetic yoke. The magnetic yoke carries a charging coil which charges an ignition capacitor, a primary coil and a secondary coil connected to the spark plug. During every passing of a permanent magnet, a voltage is induced in the coils, wherein, in order to trigger the ignition spark, the ignition capacitor is discharged via a switch element. In order to avoid an unwanted ignition at the bottom dead center of the piston, a device for reducing the voltage that occurs at the spark plug is provided.

Ignition device for a two-stroke engine

A portable, handheld work apparatus such as a chain saw has a handle () to guide the work apparatus () and has an air-cooled, mixture-lubricated combustion engine () arranged in a casing as a drive for a work tool (). The cylinder () has a combustion chamber () formed therein to which an air/fuel mixture is supplied. The air/fuel mixture is ignited by a spark plug () which projects into the combustion chamber (). An ignition control () triggers a spark in dependence on the angular position of the crankshaft (). A temperature sensor () is provided to control the cylinder temperature. The temperature signal of the temperature sensor () is connected to a power control (). When a predetermined temperature is exceeded, the power control () changes the operating parameters of the combustion engine () in such a manner that the power of the combustion engine () is changed.

Handheld work apparatus having an air-cooled combustion engine

In a method for providing in a hand-held power tool electric energy for an engine control unit before start of an internal combustion engine of the power tool that is to be started by a rope starter, a voltage source is provided that generates electric energy electro-dynamically or photovoltaically before starting the internal combustion engine. The thus generated electric energy is stored in a rechargeable energy storage device arranged within the power tool. The electric energy stored in the energy storage device is supplied to the engine control unit upon first rope starter pull for start of the internal combustion engine. The device for performing the method has an electro-dynamic or photovoltaic voltage source and an energy storage device electrically conductingly connected to the voltage source, wherein the energy storage device has an output that is electrically conductingly connected to the engine control unit.

Method and device for providing electric energy for an engine control unit

The invention relates to a portable hand-guided work apparatus having an internal combustion engine () for driving a work tool (). A combustion chamber () is formed in a cylinder () of the engine () and is delimited by a piston () which drives a crankshaft () in rotation. A spark plug () is held in the cylinder () and is driven by an ignition module () to ignite a compressed air/fuel mixture in the combustion chamber () to drive the piston (). A short circuit line () is provided on the ignition module () for switching off the ignition. The short circuit line () is configured as a bus line () in order to make available, in a simple manner, a plurality of further operating parameters to the ignition module. An external control apparatus () and/or sensors () are connected to the bus line (). The ignition module (), as master, controls data traffic on the bus line () and permits a data communication on the bus line () only when a minimum crankshaft angular distance (A, B) is present at an ignition time point (Z, Z) of the ignition module ().

Ignition module having a bus line

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.

Method for detecting operating parameters of a power tool comprising an internal combustion engine

An internal combustion engine has a combustion chamber having a spark plug arranged thereat. A crankcase supports a crankshaft. An intake for introducing fuel and combustion air into the combustion chamber is provided. An exhaust for exhausting combustion gases from the combustion chamber is provided. A piston is connected to the crankshaft and drives the crankshaft in rotation. A wheel member is connected to the crankshaft and rotates with the crankshaft. An alternator driven by the crankshaft supplies electric power to a consumer. The alternator is arranged within a radial boundary of the wheel member and external to the crankcase. The alternator has a stator and a rotor, wherein the crankshaft penetrates the stator and wherein the rotor is fixedly connected to the wheel member.

Internal combustion engine with alternator

An ignition device for a motor unit with an internal combustion engine provided with a piston, a combustion chamber with a spark plug, a crankshaft driven by the piston, an intake port supplying combustion air to the combustion chamber, an exhaust for removing combustion gases from the combustion chamber, a signal generator driven by the crankshaft and emitting for one crankshaft revolution an alternating voltage signal, has an ignition unit that triggers a spark at the spark plug at a preselectable timing. The ignition unit is a module separate from the motor unit. An alternating voltage signal generated by the signal generator is supplied to the ignition unit as an information signal sufficient for operating the internal combustion engine. The alternating voltage signal is supplied to a first unit for energy processing and to a second unit for processing information for control of the internal combustion engine.

Ignition device for an internal combustion engine and method for its operation

An ignition circuit is for an internal combustion engine in a handheld portable work apparatus. A combustion chamber () is configured in the cylinder () of the engine () which is delimited by a piston () driving a crankshaft (). A pole wheel () revolves with the crankshaft () and is assigned to an induction loop (). The pole wheel periodically changes the magnetic flux in the induction loop. An ignition capacitor () is charged by a charge coil () of the induction loop and is discharged via a discharge circuit () via an ignition coil (). The ignition coil is connected to a spark plug () projecting into the combustion chamber. For achieving a powerful ignition spark, the discharge of the ignition capacitor is prevented by an rpm evaluation circuit () when the rpm curve () exhibits an rpm change (&#x394;n) which exceeds a pregiven threshold value.

Ignition circuit having a high-energy spark for an internal combustion engine

The invention is directed to a method for operating a two-stroke engine having a cylinder in which a combustion chamber is formed and which includes devices for metering fuel and supplying combustion air as well as an ignition device for igniting a mixture in the combustion chamber. In the method, fuel and combustion air are supplied to the engine and the mixture in the combustion chamber is ignited. The combustion chamber is delimited by a piston which drives a crankshaft rotatably journalled in a crankcase. A control is provided which controls the metering of fuel and the ignition of the mixture in the combustion chamber. In the method, the two-stroke engine is controlled in at least one operating state so that the number of combustions is less than the number of revolutions of the crankshaft in the same time interval.

Method of operating a single cylinder two-stroke engine

An internal combustion engine is provided, and has a throttle element mounted in the intake channel of the engine so as to be pivotable, via a throttle shaft, between an idling position and a full-load position. An abutment is fixedly connected with the throttle shaft. In the idling position, the abutment rests against a stop element that is fixed in position on the intake channel. The stop element is adjustable and establishes the idling position of the throttle element. The abutment forms, with the stop element, a switch that is actuated in the idling position of the throttle element.

Internal combustion engine

The invention is directed to an ignition circuit for a two-stroke engine in a portable handheld work apparatus. A spark plug () is connected via a switch () to a voltage source (). The ignition switch () is actuated by an electronic control circuit () which closes the ignition switch () in dependence upon the crankshaft angle and additional operating parameters such as the rpm of the engine () in order to trigger an ignition spark per revolution of the crankshaft (). To limit rpm, the ignition switch () is held open when a pregiven end rpm is exceeded in order to suppress an ignition spark over at least one crankshaft revolution. In order to prevent that additional vibrations are excited by the limiting of rpm, the ignition switch () is closed after an end rpm is exceeded in accordance with the random principle and in dependence upon the position of the crankshaft () in such a manner that an ignition spark, which corresponds to a crankshaft revolution, is triggered in accordance with the random principle.

Ignition circuit having RPM limitation for an internal combustion engine

A magnetic ignition system for an internal combustion engine has a magnet wheel revolving with the crankshaft of the engine. At least one permanent magnet rotates with the magnet wheel. A stationary armature with a coil is provided. The permanent magnet induces a voltage in the coil, and the voltage is supplied to an energy storage. The magnet wheel has a magnet support made of a magnetically conducting material. A section of the magnet support that is in magnetic shunt is magnetically saturated.

Magnetic ignition system

The invention is directed to a safety arrangement for a power-driven portable tool such as a motor-driven chain saw or the like. The portable tool has a housing equipped with two handles both of which are grasped by the operator to hold and guide the tool during use thereof. One of the handles is a bail handle mounted at the forward part of the housing. The safety arrangement includes two switches associated with respective ones of the handles. The switches are operatively connected to the motor so as to cause the same to be operative only when both switches are closed. At least a portion of one of the contacts of the bail handle switch is displaceable from a first position whereat the bail handle switch is open to a second position whereat the switch contacts come into mutual contact and the bail handle switch is closed. An elastic body associated with the bail handle acts on the one contact to effect the displacement to the second position in response to pressure applied to the elastic body by the operator of the tool when grasping the bail handle.

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Backnang, Germany

Eberhard Schieber