摘要:
In a method for controlling a composition of a fuel/air mixture supplied to an internal combustion engine, which engine has a speed control circuit maintaining an actual rotary speed of the crankshaft within preset limits and a controllable metering device for at least one component of the fuel/air mixture, a disruptive variable is introduced into the valve control circuit at a predeterminable point in time, the activity of an engine speed control circuit is monitored and evaluated immediately after introducing the disruptive variable, and, depending on the evaluation result, at least one parameter having an effect on the operation of the internal combustion engine is adjusted.
摘要:
A method is for controlling the metering of fuel in a fuel system (30) of an internal combustion engine (1) which is to be started manually. This control is with a currentless open electromagnetic valve (21). The electromagnetic valve (21) is only switched into the closed state when a supply voltage (Uv) is applied and current flows. Within a blocking time (47), which is pregiven by an engine control (13), a supply voltage (Uv) is switched onto the excitation coil of the electromagnetic valve (21) only and the valve (21) is supplied with current only when an underpressure is present in the intake channel (11) of the fuel system (30); whereas, in the remaining time span (50) of the blocking time (47), wherein no underpressure is present, the control unit (20) switches off the supply voltage (Uv) and the valve (21) is in the currentless open state.
摘要:
An electromagnetic valve (1, 21) includes a coil (2) which is fixedly connected to an iron core (3). An armature plate (5) is movably journalled in the direction of the coil longitudinal axis (22) relative to the iron core (3). At least two flow channels (8, 9; 26, 27, 28, 29) open at the armature plate (5) and are fluidly separated from each other when a current flows in the coil (2). A small structural size with a simple manufacture of the electromagnetic valve (1, 21) is achieved in that a flow channel (8; 26, 27, 28) opens in the peripheral region (32) of the armature plate (5) at the end (33) of the armature plate (5) facing toward the coil (2).
摘要:
A carburetor arrangement is provided for an internal combustion engine that is to be started with a pull cord. A fuel channel that is connected with a fuel-filled storage space opens into and supplies fuel to an intake channel portion as a function of the underpressure in the intake channel portion. The underpressure in the intake channel portion is increased during the start-up process via a start-up mechanism. To keep the engine ready to run with the start-up mechanism engaged, a control valve is disposed between the storage space and where the fuel channel opens into the intake channel portion. The control valve is opened or closed by a control unit as a function of the speed of the internal combustion engine.
摘要:
An ignition circuit is for an internal combustion engine in a handheld portable work apparatus. A combustion chamber (4) is configured in the cylinder (3) of the engine (1) which is delimited by a piston (5) driving a crankshaft (7). An electromagnetic induction loop (13) and a pole wheel (10) are provided. The pole wheel (10) revolves with the crankshaft (7) and is assigned to the induction loop (13). The pole wheel (10) periodically changes the magnetic flux in the induction loop (13). An ignition capacitor (16) is charged by a charge coil (14) of the induction loop (13) and is discharged via a discharge circuit (15) via an ignition coil (17). The ignition coil (17) is connected to a spark plug (19) projecting into the combustion chamber (4). For achieving a powerful ignition spark, the discharge of the ignition capacitor (16) is prevented by an rpm evaluation circuit (23) when the rpm curve (30) exhibits an rpm change (Δn) which exceeds a pregiven threshold value.
摘要:
An arrangement for decanting liquids includes a tubular-shaped support (1) having a flow channel (2). The flow channel (2) is blocked by a valve plate (3) which is coupled via axial connecting elements (4, 4′) to the relative movement of an inner sleeve (5) and an outer sleeve (6) of the support (1). The outer sleeve (6) lies in overlapment and the axial connecting elements (4, 4′) extend into the interior of the support. The valve plate (3) can be lifted from its valve seat against a spring force engaging at the inner sleeve (5) and at the outer sleeve (6). A radial flange collar (13) is formed on the outer sleeve (6). To ensure an accurate metering at the highest possible volume flow of the discharged liquid at low manufacturing costs, the valve plate (3) is mounted at a free end (9) of the support (1) and the axial connecting elements are configured as tension rods (4, 4′) and are arranged next to an edge of the valve plate (3).
摘要:
A portable handheld work apparatus such as a motor-driven chain saw (1) includes a housing (2) wherein an internal combustion engine (10) and a carburetor (11) are mounted. A throttle lever (6) is provided which is pivotally journalled on a handle (3). The handle (3) is connected to the housing (2) via at least one antivibration element (33). A vibration gap (9) is configured between the handle (3) and the housing (2). A transmitting unit (13) is provided for transmitting the pivot movement of the throttle lever (6) to the carburetor (11). The transmitting unit includes a rigid transmitting element (17, 37) which bridges the vibration gap (9). A simple configuration and a substantial decoupling of the relative movement between the housing (2) and the handle (3) from the actuating movement of the carburetor is achieved in that the transmitting element (17, 37) is rotatably journalled and the pivot movement of the throttle lever (6) is transmitted as a rotation about a rotational axis (22) lying transverse to the vibration gap (9).
摘要:
The invention relates to a carburetor arrangement for an internal combustion engine (1), especially for a drive motor of a work apparatus such as a motor-driven chain saw, a brushcutter, a cutoff machine or the like. The carburetor arrangement includes a carburetor (2) having an intake channel (3) and an air filter (4) mounted upstream of the intake channel (3). The air filter (4) has an air filter housing (5). The intake channel (3) opens with an intake opening (6) in a housing base (7) of the air filter housing (5). The intake opening (6) can be covered at least partially by a choke element (8). The choke element (8) is held on a choke carrier (9) so as to permit a limited movement of the choke element.
摘要:
The invention is directed to a tensioning arrangement for saw chains of motor-driven chain saws which include a device for longitudinally displacing the guide bar. The clamped guide bar is released so that the adjusting arrangement can be actuated for the longitudinal displacement of the guide bar. By rotating a disc having a spiral slot, a slide piece, which is coupled to the guide bar, is displaced in the longitudinal direction. Assembly is simplified and handling facilitated when the tension in the saw chain is adjusted. This is achieved by making the slide piece on the spiral disc so that it is not released therefrom but instead is held so as to be rotationally and longitudinally displaceable. The slide piece is fixedly connected to the guide bar by using appropriate attachment devices.
摘要:
The invention is directed to a tensioning arrangement for a saw chain of a motor-driven chain saw. The saw chain runs on a guide bar mounted on the motor housing of the chain saw. The tensioning arrangement includes a rotatable disc having a spirally-shaped guide slot in which a lug of a slide piece engages. The longitudinal displacement of the guide bar is provided by rotating the disc. The guide slot in the disc extends over a rotational angle of at least 270.degree.. A still lesser slope of the guide slot is provided with a rotational angle in the range of 360.degree. to 450.degree.. The tensioning arrangement is especially suitable for adjusting the guide bar in motor-driven chain saws thereby adjusting the tension in the saw chain.