Andreas Stihl Ag & Co.

Andreas Stihl

Other

Andreas Stihl Ag Co. Kg

Firma Andreas Stihl

Reinhard Gerhardy

Klaus Geyer

Gerhard Osburg

Werner Vonderau

Michael Wissmann

Heiko Rosskamp

Peter Linsbauer

Arno Kinnen

Reinhard Friedrich

Wolfgang Luithardt

Lars Bergmann

Hans Holderle

Peter Schmidt

Jurgen Wolf

Jan Borchardt

Jochen Gantert

Bernhard Kiefel

Eberhard Bohnacker

Erich Krauter

Mohamed Abou-Aly

An operating mechanism is provided and has an operating lever, an adjusting lever, and a valve element that is rotatably disposed in a channel, wherein the adjusting lever is connected with the valve element via a shaft. A coupling element is provided for interconnecting the positions of the operating lever and the adjusting lever. The distance of the pivot axis of the adjusting lever from a connection of the coupling element with the adjusting lever is variable as a function of the position of the adjusting lever.

Operating mechanism

An intake device having an intake channel that includes an intake channel section is provided. A butterfly valve is pivotably mounted in the intake channel section. A dividing wall is disposed downstream of the butterfly valve and divides the intake channel section into an air duct and a mixture duct. The air duct has a flow cross-section that is greater than the flow cross-section of the mixture duct. A fuel jet opens into the mixture duct.

Intake device

A carburetor for an internal combustion engine includes an intake channel section () as well as a throttle element journalled in the intake channel section (). The throttle element is adjustable between a full-load position () and an idle position (). A pump () is provided for additional fuel metering and this pump includes a pumping chamber () and a pump piston () guided in the pumping chamber (). The position of the pump piston () is coupled to the position of the throttle element. To ensure an optimal supply of the internal combustion engine with fuel in each operating state, the pump piston () is so coupled to the throttle element that fuel is pumped from the pumping chamber () into the intake channel section () when there is a displacement of the throttle element from the full throttle position () into the idle position ().

Carburetor

A carburetor arrangement for an internal combustion engine in a manually guided implement, such as a power chainsaw, a cut-off machine, etc. is provided. A regulating chamber delimited by a regulating diaphragm is provided. Upon deflection of the diaphragm due to underpressure in the regulating chamber, the latter is connected with a fuel tank. Via at least one nozzle, the regulating chamber opens into an air channel that supplies fuel/air mixture to the engine. The carburetor arrangement includes a scavenging pump that is disposed in a return line from the regulating chamber to the fuel tank, and in which is formed a pump chamber. The scavenging pump serves to completely fill the regulating chamber with fuel before start-up of the engine. To prevent the fuel/air mixture from becoming too lean after start-up, especially upon opening of the choke valve, a supply line is provided from the pump chamber into the air channel and supplies additional fuel to the air channel during the run-up phase.

Carburetor arrangement

A carburetor arrangement is provided for an internal combustion engine of a manually guided implement, and includes a carburetor that is embodied in particular as a diaphragm carburetor. A butterfly valve is pivotably mounted in an air channel that is disposed in the carburetor and leads to the internal combustion engine. Also provided is an accelerator pump that includes a pump chamber and an accelerator piston that is guided in the pump chamber. The accelerator piston is coupled with the butterfly valve. The pump chamber can be connected with a fuel tank via a pump line. A first pressure-controlled check valve is provided in the pump line.

Carburetor arrangement having an accelerator pump

A membrane carburetor for an internal combustion engine in a portable handheld work apparatus includes a control chamber ( ) delimited by a membrane ( ). The control chamber ( ) is connected via a feed line ( ) to a fuel tank ( ). The feed line ( ) is cleared via a valve body ( ) when there is a deflection of the membrane ( ) because of an underpressure in the control chamber ( ). The control chamber ( ) is connected to an air channel ( ) via at least one fuel nozzle ( ) and at least one ancillary chamber ( ). The air channel ( ) passes through the membrane carburetor ( ) and leads to the internal combustion engine. A purge pump ( ) is provided in a fuel line ( ) connecting the control chamber ( ) to the fuel tank ( ). The fuel path between the control chamber ( ) and the purge pump ( ) is guided through at least one ancillary chamber ( ).

Membrane carburetor

A carburetor for an internal combustion engine is provided and includes at least one adjusting screw disposed in a housing for regulating the fuel/air mixture. The adjusting screw is screwed into a bore of the carburetor housing. The adjusting screw is embodied as a cheese head screw, whereby one end of the screw is provided with two slots that are cross-shaped relative to one another and extend over the diameter of the cheese head screw.

Carburetor for an internal combustion engine and including at least one adjusting screw

The invention relates to a two-stroke engine for a portable handheld work apparatus such as a motor chain saw. The combustion chamber ( ), which is configured in a cylinder ( ), is delimited by a piston ( ) which drives a crankshaft ( ) rotatably journalled in a crankcase ( ). The crankcase ( ) is connected to the combustion chamber ( ) via a transfer channel ( ). A first end ( ) of the transfer channel ( ) opens into the combustion chamber ( ) via an entry window ( ) lying in the cylinder wall ( ); whereas, the second end ( ) of this transfer channel ( ) is open toward the crankcase ( ). The transfer channel ( ) is connected between its ends ( ) to an air channel ( a, b) via a check valve ( ). The air channel ( a, b) supplies essentially fuel-free gas via a throttle ( ) having an adjustable throttle element ( ). A mixture-preparation device ( ) is provided for the air/fuel mixture downstream of an air filter ( ) in the flow direction of the combustion air. The air/fuel mixture is supplied via an inlet ( ) to the crankcase ( ). In order to meter clean air to the air channels in a controlled manner, an adjustable throttle element ( ) is mounted in a throttle channel ( ) of an independent throttle housing ( ) and the throttle channel ( ) is connected upstream of the throttle element to the clean space ( ) of the air filter ( ) connected ahead of the mixture-preparation device ( ).

Two-stroke engine having a bypass branching from an air filter housing

A membrane carburetor ( ) for an internal combustion engine includes a control chamber ( ) delimited by a membrane. The control chamber ( ) is connected via a feed line ( ) to a fuel tank ( ). The feed line ( ) is cleared with the deflection of the membrane ( ) because of underpressure in the control chamber ( ). The control chamber ( ) is connected via at least one intake opening ( ) with an air-intake channel ( ) to the engine. As start-assist devices for the engine, a scavenging pump ( ) and an injection pump ( ) are provided. The scavenging pump ( ) is provided in a return line ( ) between the control chamber ( ) and the fuel tank ( ). The fuel can be pumped into the air-intake channel ( 4) with a displacement piston ( ) of the injection pump ( ). The displacement piston ( ) is longitudinally guided in a cylinder ( ) and delimits a pump chamber ( ). The pump chamber ( ) is connected via an injection line ( ) to a feed ( ) of the intake openings ( ). The piston stroke of the displacement piston ( ) is limited by a stop ( ) which is adjusted in stroke direction ( ) by an adjusting element ( ) in dependence upon temperature. This arrangement ensures a reliable start of the engine with an easy operability of the start-assist devices.

A diaphragm-type carburetor is provided for a two-cycle engine, in a manually guided implement, that operates with layered scavenging. Formed in the carburetor housing is an intake channel portion in which is disposed a butterfly valve that is pivotably held by a shaft. Opening into the intake channel portion are fuel-conveying channels supplied from a fuel-filled control chamber that is formed on a longitudinal side of the intake channel portion in the carburetor housing and is separated from a compensation chamber by a diaphragm. Air for combustion is additionally supplied to the engine via an air channel formed in a functional component of the carburetor fixed on the housing thereof on a longitudinal side of the intake channel portion. The air channel is disposed approximately parallel to the intake channel portion and is guided from that end face of the carburetor that faces an air filter to the connecting side of the carburetor that faces the internal combustion engine. Disposed in the air channel is a throttle member that is rotatably held by a shaft, which is coupled together with the shaft of the butterfly valve by means of a transmission connection.

Diaphragm-type carburetor for a two-cycle engine that operates with layered scavenging

A carburetor for an internal combustion engine of a hand-held working tool has a housing and a suction channel with a venturi section arranged in the housing. The suction channel has an inlet and an outlet for allowing air flow therethrough. A throttle is connected in the suction channel so as to be pivotable. A control chamber is provided and a main fuel channel connects the suction channel and the control chamber. An idle fuel channel connects the suction channel and the control chamber. A bypass, having an air supply line and a fuel supply line, is provided for introducing an auxiliary fuel/air mixture during a starting operation of the internal combustion engine to a location of the suction channel downstream of the throttle in a direction of air flow. A closure device for separately closing off in a closed position of the piston the air supply line and the fuel supply line of the bypass is provided so that simultaneously the fuel supply and air supply are shut off before formation of the auxiliary fuel/air mixture.

Carburetor for an internal combustion engine of a hand-held working tool

A carburetor for an internal combustion engine of a hand-held working tool has a housing having an intake channel and a fuel-filled control chamber mounted in the housing. A fuel channel is connected to the control chamber and the intake channel. A control valve is mounted in the fuel channel and has a valve member. A control screw is mounted in the carburetor housing and acts on the valve member for adjusting it. A cap is fixedly mounted on the control screw and has a stop. A counter stop is mounted on the housing in a rotational path of the stop of the cap. A locking device for securing the cap relative to the housing is provided. The locking device has a locking member and counter locking members cooperating with the locking member for locking the cap in one of various preset positions relative to the housing.

Carburetor with secured control screw

A diaphragm carburetor for an internal combustion engine has a carburetor housing having an intake channel with a venturi section. A plate valve is positioned in the intake channel. A fuel outlet valve is mounted in the venturi section. A fuel-filled control chamber is provided and delimited at one side by a diaphragm. A fuel supply channel is connected to the control chamber. A supply valve is mounted in the fuel supply channel and actuated by the diaphragm. A first fuel channel connects the control chamber and the fuel outlet valve. At least one fixed main throttle is mounted in the first fuel channel for fixedly determining a fuel flow cross-section to the fuel outlet valve. A lever is provided for actuating the valve plate. An adjustable stop cooperates with the lever. The flow cross-section of the intake air is adjusted by the stop to a desired air/fuel ratio and is changeable, in a limited range, in a direction of increasing the flow cross-section.

Diaphragm carburetor

A diaphragm carburetor for an internal combustion engine of a portable hand-held working tool has a housing with a control chamber. A suction channel extends through the housing and has a venturi section. An inlet valve is connected to the control chamber and supplies the control chamber with fuel. A main valve channel connects the control chamber to the venturi section of the suction channel. A check valve is positioned in the main valve channel adjacent to the control chamber and closes the main valve channel toward the control chamber. The main valve channel has a straight and elongate portion extending from the check valve into the venturi section and projecting into the suction channel.

Diaphragm carburetor for an internal combustion engine of a hand-held

The invention is directed to a membrane carburetor which includes an intake channel having a throttle flap which is pivotally journalled. The carburetor also includes a control chamber from which fuel can be supplied to the intake channel. A valve is mounted in an ancillary channel and a corresponding adjustment of the throttle flap results in dependence upon the opening and closing position.

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Korb, Germany

Reinhard Gerhardy