Abstract: The invention relates to an internal combustion engine comprising a fuel injector (2) for each cylinder; a fuel injection control unit (4) for controlling fuel injection quantity and a piston (5) in each cylinder whose compression action causes a mixture of air and fuel to be ignited. The engine is further provided with inlet and outlet valves (6, 7) and various sensors (12-16) for measuring various engine operating parameters. During compression ignition mode, the control unit (4) is arranged to select a ?-value from a map stored in the control unit, which value is a function of engine load and engine speed, and to compare the actual ?-value with the selected ?-value; whereby the control unit is arranged to adjust the intake manifold pressure as a function of the difference between the said ?-values in order to obtain the selected ?-value. The invention further relates to a method for operating the engine and a computer readable storage device (4).

Abstract: The invention relates to an internal combustion engine comprising a fuel injector (2) for each cylinder; a fuel injection control unit (4) for controlling fuel injection quantity and a piston (5) in each cylinder whose compression action causes a mixture of air and fuel to be ignited. The engine is further provided with inlet and outlet valves (6, 7) and various sensors (12-16) for measuring various engine operating parameters. During compression ignition mode, the control unit (4) is arranged to select a ?-value from a map stored in the control unit, which value is a function of engine load and engine speed, and to compare the actual ?-value with the selected ?-value; whereby the control unit is arranged to adjust the intake manifold pressure as a function of the difference between the said ?-values in order to obtain the selected ?-value. The invention further relates to a method for operating the engine and a computer readable storage device (4).

Abstract: An internal combustion engine that can be operated in compression ignition mode, comprising a fuel injector (2) for each cylinder; a fuel injection control unit (4) for controlling fuel injection quantity and a piston (5) in each cylinder whose compression action causes a mixture of air and fuel to be ignited. The engine is further provided with inlet and outlet valves (6, 7) and sensors (12-16) for measuring various engine operating parameters, is disclosed. During compression ignition mode, the control unit controls the fuel injector to perform a first fuel injection before, and a second fuel injection after top dead center of the piston stroke during or after a negative valve overlap period. A method for operating the engine and a computer readable storage device (4) having stored therein data representing instructions executable by a computer to implement a compression ignition for an internal combustion engine is also described.

Abstract: The invention relates to an internal combustion engine comprising a fuel injector (2) for each cylinder; a fuel injection control unit (4) for controlling fuel injection quantity and a piston (5) in each cylinder whose compression action causes a mixture of air and fuel to be ignited. The engine is further provided with inlet and outlet valves (6, 7) and various sensors (12-16) for measuring various engine operating parameters. During compression ignition mode, the control unit (4) is arranged to select a &lgr;-value from a map stored in the control unit, which value is a function of engine load and engine speed, and to compare the actual &lgr;-value with the selected &lgr;-value; whereby the control unit is arranged to adjust the intake manifold pressure as a function of the difference between the said &lgr;-values in order to obtain the selected &lgr;-value. The invention further relates to a method for operating the engine and a computer readable storage device (4).

Abstract: Crankcase scavenged two-stroke internal combustion engine, in which at least one piston ported air passage, with length Lai, is arranged between an air inlet (2) and each scavenging port (31, 31′) of a number of transfer ducts (3, 3′), with length Ls, from the scavenging port to the crankcase. The air passage is arranged from an air inlet (2) equipped with a restriction valve (4), controlled by at least one engine parameter, for instance the carburetor throttle control. The air inlet extends via at least one connecting duct (6, 6′) to at least one connecting port (8, 8′) in the engine's cylinder wall (12). The connecting port (8, 8′) is arranged so that it in connection with piston positions at the top dead center is connected with flow paths (10, 10′) embodied in the piston (13), which extend to the upper part of a number of transfer ducts (3, 3′).

Abstract: A muffler (1) intended for portable working tools, preferably chain saws, in which the muffler is mounted directly to the exhaust gas outlet (3) of the cylinder (2). The muffler is provided with at least one upstream partition wall (4, 5) at the muffler's inlet (6) from the cylinder and arranged essentially laterally in relation to the engine's cylinder bore (7), so that the partition wall (4) separates an upper fraction (8) above it, i.e. in the direction towards the upper side of the cylinder, and a lower fraction below it, i.e. in the opposite direction, and this dividing into two or several fractions (8, 9, 10) is kept maintained through a great deal of the muffler from the inlet to a number of outlets (11, 12, 13).

Abstract: A two-stroke internal combustion engine comprising a cylinder (10; 50) with a movable piston (11; 52) in it, which cylinder at its one end has a combustion chamber (16; 51) and at its other end is connected to a crankcase (15; 53). The crankcase and the combustion chamber are mutually connected via a scavenging duct (17; 56), whose opening and closing is controlled by the movement of the piston, and a carburetor (20; 55) is via an inlet port (21) connected to the crankcase. In order to simplify starting the engine it is provided with a device (23-6; 61-65; 70-72) for supply of fuel to the scavenging duct (17; 56) adjacent the combustion chamber.

Abstract: A two-stroke internal combustion engine comprising a cylinder (10; 50) with a movable piston (11; 52) in it, which cylinder at its one end has a combustion chamber (16: 51) and at its other end is connected to a crankcase (15; 53). The crankcase and the combustion chamber are mutually connected via a scavenging duct (17; 56), whose opening and closing is controlled by the movement of the piston, and a carburetor (20; 55) is via an inlet port (21) connected to the crankcase. In order to simplify starting the engine it is provided with a device (23-26; 61-65; 70-72) for supply of fuel to the scavenging duct (17; 56) adjacent the combustion chamber.

Abstract: Crankcase scavenged two-stroke internal combustion engine, in which at least one piston ported air passage, with length Lai, is arranged between an air inlet (2) and each scavenging port (31, 31′) of a number of transfer ducts (3, 3′), with length L s, from the scavenging port to the crankcase. The air passage is arranged from an air inlet (2) equipped with a restriction valve (4), controlled by at least one engine parameter, for instance the carburetor throttle control. The air inlet extends via at least one connecting duct (6, 6′) to at least one connecting port (8, 8′) in the engine's cylinder wall (12). The connecting port (8, 8′) is arranged so that it in connection with piston positions at the top dead center is connected with flow paths (10, 10′) embodied in the piston (13), which extend to the upper part of a number of transfer ducts (3, 3′).

Abstract: Crankcase scavenged two-stroke internal combustion engine (1), in which a piston ported air passage is arranged between an air inlet (2) and the upper part of a number of transfer ducts (3, 3′). The air passage is arranged from an air inlet (2) equipped with a restriction valve (4), controlled by at least one engine parameter, for instance the carburetor throttle control. The air inlet extends via at least one connecting duct (6, 6′) to at least one connecting port (8, 8′) in the engine's cylinder wall (12). The connecting port (8, 8′) is arranged so that it in connection with piston positions at the top dead center is connected with flow paths (10, 10′) embodied in the piston (13), which extend to the upper part of a number of transfer ducts (3, 3′).

Abstract: Crankcase scavenged internal combustion engine (1) of two-stroke type, intended for a working tool, preferably a chain saw or a trimmer, and provided with a light-weight and compact muffler (2). The engine is arranged with a particularly high crankcase compression created in that at least one filling (3, 4, 5, 6) is placed into the compression area (7) under the engine piston (8) in form of a filled balance (3) and/or a piston filling (4) and/or a piston washer (5) and/or a stationary filling (6), at the same time as the engine is provided with an especially strong throttling created in the engine's exhaust side, i.e. in its exhaust port (9) and/or in a possible exhaust duct (10) and/or in the muffler (2).

Abstract: Emission gasses from an engine exhaust pipe are collected through an inlet of a dilution tunnel which is an elongated, hollow tube. The inlet is spaced from the exhaust pipe to also admit surrounding air. Ambient air and emissions are mixed in the tunnel by a screen in the tunnel. A probe in the tunnel diverts a portion of the mixture to gas analyzers. Prior to analysis the mixture may be condensed, filtered or otherwise processed. The analysis determines a CO/CO.sub.2 ratio which is used to determine the air/fuel ratio in the engine based on characteristics of the fuel. The air/fuel mixture of the engine is then adjusted to achieve desired performance.

Abstract: Emission gasses from an engine exhaust pipe are collected through an inlet of a dilution tunnel which is an elongated, hollow tube. The inlet is spaced from the exhaust pipe to also admit surrounding air. The air and emissions are mixed in the tunnel by a screen in the tunnel. A probe in the tunnel diverts a portion of the mixture to gas analyzers. Prior to analysis the mixture may be condensed, filtered or otherwise processed.

Abstract: In a method and device for controlling a carburetor (1) of an i. c. engine, the A/F ratio thereof is automatically adjusted to a preferred level during varying operating conditions. An adjusting means (5) is continuously actuated by a first control unit (4) of a first control circuit (3) to provide a A/F ratio having a modified dependency on the speed of rotation. An adjusting means (9) is periodically actuated for a short period by a second control unit (7) of a second control circuit (6), said second control unit receiving speed information (8) from the engine (2), to provide a short-term change of the mixture ratio, and the change of speed of rotation caused thereby is measured. With regard to the obtained result and stored information the second control unit (7) performs an adjustment of the mixture ratio by a predetermined step towards leaner or richer mixture by actuating an adjusting means (5).

Abstract: Door constructions are provided including a frame, a core, and on both the inner and outer faces of the core an iron plate at least 0.2 millimeters thick with a wooden layer adhesively secured to the outer surfaces thereof. Preferably the core provided is a material having superior heat insulating properties with a heat conductivity of between about 0.15 and 0.05 as well as a diffusion resistance at least 20 times greater than that of air. In a preferred embodiment, each of the iron plates has a wooden layer adhesively secured to both the inner and outer surfaces thereof.