Abstract:
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.
Abstract:
A carburetor for an internal combustion engine includes an intake channel section (2) as well as a throttle element journalled in the intake channel section (2). The throttle element is adjustable between a full-load position (25) and an idle position (26). A pump (20, 30) is provided for additional fuel metering and this pump includes a pumping chamber (24, 34) and a pump piston (21, 31) guided in the pumping chamber (24, 34). The position of the pump piston (21, 31) 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 (21, 31) is so coupled to the throttle element that fuel is pumped from the pumping chamber (24, 34) into the intake channel section (2) when there is a displacement of the throttle element from the full throttle position (25) into the idle position (26).
Abstract:
A membrane carburetor (1) for an internal combustion engine includes a control chamber (2) delimited by a membrane. The control chamber (2) is connected via a feed line (8) to a fuel tank (9). The feed line (8) is cleared with the deflection of the membrane (3) because of underpressure in the control chamber (2). The control chamber (2) is connected via at least one intake opening (16, 17) with an air-intake channel (14) to the engine. As start-assist devices for the engine, a scavenging pump (10) and an injection pump (20) are provided. The scavenging pump (10) is provided in a return line (13) between the control chamber (2) and the fuel tank (9). The fuel can be pumped into the air-intake channel (14) with a displacement piston (21) of the injection pump (20). The displacement piston (21) is longitudinally guided in a cylinder (22) and delimits a pump chamber (24). The pump chamber (24) is connected via an injection line (30) to a feed (18) of the intake openings (16, 17). The piston stroke of the displacement piston (21) is limited by a stop (26) which is adjusted in stroke direction (31) by an adjusting element (23) in dependence upon temperature. This arrangement ensures a reliable start of the engine with an easy operability of the start-assist devices.
Abstract:
The invention is directed to a membrane carburetor for an internal combustion engine such as a two-stroke engine having an intake for drawing the mixture in by suction. The membrane carburetor has a venturi section wherein the mixture is formed. A main nozzle opening opens forward of a throttle flap and an idle nozzle opening opens rearward of the throttle flap both viewed in flow direction. Both openings are connected via channels to a fuel-filled control chamber to which fuel flows via an inflow channel. An inlet valve is mounted in the inflow channel and has a valve body disposed opposite a valve seat fixed in the housing. The inlet valve is actuated in the opening direction via a control lever by a control membrane delimiting the control chamber. Transverse accelerations are prevented from leading to an opening of the inlet valve by providing a sealing surface on the valve body which coacts with an annular sealing surface disposed on the valve seat and lying parallel to the flat sealing surface on the valve body. The flat sealing surface lies essentially at right angles to the opening direction.
Abstract:
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.
Abstract:
A membrane carburetor for an internal combustion engine in a portable handheld work apparatus includes a control chamber (3) delimited by a membrane (2). The control chamber (3) is connected via a feed line (4) to a fuel tank (5). The feed line (4) is cleared via a valve body (6) when there is a deflection of the membrane (2) because of an underpressure in the control chamber (3). The control chamber (3) is connected to an air channel (10) via at least one fuel nozzle (7) and at least one ancillary chamber (9). The air channel (10) passes through the membrane carburetor (1) and leads to the internal combustion engine. A purge pump (11) is provided in a fuel line (12) connecting the control chamber (3) to the fuel tank (5). The fuel path between the control chamber (3) and the purge pump (11) is guided through at least one ancillary chamber (9).
Abstract:
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.
Abstract:
Disturbances can occur in handheld portable tools driven by internal combustion engines because the idle-nozzle system and the main-nozzle system influence each other. The carburetor of the invention prevents this disturbing influence and provides a control of the engine which is proportional to speed. The carburetor includes a control member which closes off the main nozzle during idle operation and the idle nozzle during operation under load in dependence upon the position of the throttle flap.
Abstract:
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.
Abstract:
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.