Abstract: A variable compression ratio control system for an internal combustion engine includes a lubrication system for selectively providing lubricating oil to connecting rods within the engine at either a lubrication pressure or at a control pressure. The oil is provided to compression ratio adjusters so as to cause the adjusters to move from one compression ratio to another, to achieve a desired change in compression ratio. A lubricating pump provides lubricating oil to the connecting rods through the lubrication system. The lubricating pump is selectively operable at one of a lubricating pressure and a control pressure by means of a control valve which is integral with the lubricating pump.

Abstract: The invention aims to provide a compact four-stroke engine with rotary valve control and petroil lubrication which has a simplified construction and allows the engine to be used in any position as a result of an improved lubrication system. To this end, the carburetor is directly connected to the inlet opening and the rotary valve is configured in such a way that in a first position it connects the carburetor to the combustion chamber, in a second position it connects the carburetor to the cylinder chamber/crankcase via the overflow conduit and in a third position it connect the cylinder chamber/crankcase to the combustion chamber via the overflow conduit and the combustion chamber to the outlet opening via the conduit. Said rotary valve is in continuous motion during the operation of the combustion engine and the first, second and third positions only occur at corresponding defined moments.

Abstract: A balancer shaft is supported between a right case and a left case in parallel with a crankshaft. A balancer driven gear and a first balance weight are provided at one end with the balancer driven gear being interlocked with the crankshaft. The outer diameter R2 of a maximum diameter of the first balance weight is larger relative to a root circle diameter R1 of the balancer driven gear. The first balance weight is attached to an outside face of the balancer driven gear. A fitting end of a driving shaft is fitted into a fitting hole provided in the core at the end on the side on which the balancer driven gear is provided of the balancer shaft. The fitting end and the fitting hole are coupled to be integrally rotated and for driving a water pump. A second balance weight is integrated with the other end of the balancer shaft. A gear for driving an accessory is integrated with the base of the second balance weight and is engaged with an oil pump gear for driving an oil pump.

Abstract: An electronically controlled engine management system for an outboard motor, which accurately checks the neutral switch for false operation. The accurate neutral switch detection permits an enjoyable boating environment as well as eliminating unnecessary false neutral switch fault alarms.

Abstract: The invention relates to a motor-driven operating device that comprises a guide handle. Two sensor elements are provided on the guide handle and in two handle areas for detecting the hands of an operator. An ignition device of the motor is controlled by means of a security control device in such a way that the speed can only be increased beyond a security speed when the guide handle is held with both hands, whereby said security control device evaluates the sensor signals. The motor speed is limited to the security speed when the two sensor signals are missing.

Abstract: The present invention has an object to effectively prevent deterioration of combustion characteristics when engine temperature is low. There is provided an intake pressure controller 24 that effects control such that, when an operating condition discriminator 21 that identifies engine temperature identifies low engine temperature after engine start-up, control by an engine controller (feedback controller 23) that performs engine control on fluctuation of intake negative pressure to decrease the intake negative pressure is suppressed until the temperature of the intake passage rises to at or above a predetermined value, and such that the intake negative pressure is made larger.

Abstract: An intake system for an internal-combustion engine has an air line (air pipe) whose end is detachably fastened on a flange of a component. The flange of the component has at least one recess which, in the mounted condition of the connection, engages with fastening elements are provided on the air pipe, so that the air pipe is axially secured on the flange of the component.

Abstract: The oil pan structure of the present invention comprises an oil pan separator 3, disposed within an oil pan 2, for separating a main chamber provided with a suction port disposed therewithin and a sub chamber provided with no suction port from each other, the oil pan separator 3 having a recess forming the main chamber, the main chamber communicating with the inside of an engine block 1, the recess being formed with communication holes 3c, 3d for communicating the main and sub chambers to each other. The sub chamber is formed so as to surround the main chamber as a whole, whereas the outer face of the bottom part of the oil pan separator 3 and the inner face of the bottom part of the oil pan 2 are not in contact with each other. Therefore, raising the temperature of engine oil within the main chamber earlier can lubricate the engine more effectively.

Abstract: A portable power tool includes an internal combustion engine that includes a crankshaft in which a load applied thereto is unevenly distributed along the axis of the crankshaft with respect to the axis of the reciprocating movement of a piston. The portable power tool also includes operational members that are driven by the internal combustion engine, a rotational body fixed to an end of the crankshaft to which a smaller component of the load is applied, and a balancing weight provided on the rotational body for absorbing vibrations generated by the reciprocating movement of the piston. The centroid of the balancing weight is disposed at an angular position from 140 degrees to 180 degrees with respect to the axis of the reciprocating movement of the piston in a rotational direction of the rotational body, when the piston is positioned at a top dead center.

Abstract: Crankshaft main bearing failure in variable compression ratio engines having eccentric main bearing supports is prevented by supporting the bearings in a crankshaft cradle (16) having a high stiffness and a high natural frequency. The crankshaft cradle (16) is rotatable mounted in the engine on a first axis, and the crankshaft (8) is mounted in the crankshaft cradle (16) on a second axis off-set from the first axis, the first axis and the second axis defining a first plane. The crankshaft cradle comprises a primary eccentric member (24) and a plurality of smaller bearing caps (26) separated by a parting line. The crankshaft cradle comprises accentric members (24) that support the bearing element (64), and structural webbing (72) that rigidly holds the eccentric members (24) in alignment with one another at all times.

Abstract: A device for recycling exhaust gases from an internal combustion engine via an exhaust gas line in its intake area is equipped with an exhaust gas valve that is positioned within a valve chamber and closes off or opens up the connection to a combustion chamber of an internal combustion engine. A valve actuating mechanism is located within the valve chamber. The valve chamber is equipped with at least one cooling channel.

Abstract: An improved method and system for the control of an engine system such as the spark timing. The control senses the speed variations either during a portion of a complete cycle and a complete cycle and/or from cycle to cycle in order to determine the load on the engine from preprogrammed maps based upon the engine characteristics. From this load and the speed reading, it is possible to obtain the desired engine control. This not only reduces the costs of the system by reducing the number of sensors, but also permits adjustments to be made more rapidly.

Abstract: A variable compression ratio control system for an internal combustion engine includes an engine driven accessory hydraulic pump and a hydraulic accumulator system for receiving hydraulic fluid from the engine driven accessory pump. The hydraulic accumulator also receives engine oil from an engine oil pump. A variable compression ratio actuator is supplied with high pressure engine lubricating oil from the hydraulic accumulator system so as to control the compression ratio of the engine.

Abstract: A control apparatus controls the opening and closing timings of the intake and exhaust valves and the fuel injection timing. When the water temperature of the engine is equal to or below a predetermined value, the exhaust valve closes before the top dead center, and the intake valve opens after the top dead center. At the same time, if the pressure inside the intake passage is equal to or below a predetermined value, the fuel injection is conducted during the intake process. Furthermore, the intake fuel injection timing is changed according to the rotational speed of the engine. In this manner, the vaporization of the injected fuel is promoted, and stability of the combustion is improved. Also the exhaust emission is improved, while the fuel consumption is reduced.

Abstract: The invention relates to a method for operating an internal combustion engine operated with a self-ignitable fuel, with an approximately homogeneous fuel-air mixture being produced in the combustion chamber in the self-ignition ranges (CI), a high compression ratio suitable for a self-ignition of the fuel being provided and the combustion occurring in the self-ignition ranges (CI) predominantly by self-ignition. In order to control the start of combustion in the self-ignition range (CI) in the easiest possible way it is provided that in the self-ignition range (CI) the pressure and/or temperature of the homogeneous fuel-air mixture are set in such a way, preferably depending on the charge composition and/or charge temperature, that the self-ignition would be achieved only after the actually desired start of combustion in the zone of the upper dead center and the combustion of the homogeneous fuel-air mixture is initiated locally in the self-ignition range (CI) by an external energy impulse.

Abstract: The invention relates to a method of operating a direct injection internal combustion engine operated on both spark-ignitable and autoignitable fuel, more specifically on gasoline, wherein the operational range of the engine is allocated autoignition ranges and spark-ignition ranges, an at least nearly homogeneous fuel-air mixture being produced in the combustion chamber in autoignition ranges, a high compression ratio suitable for spontaneous ignition of the fuel being provided and the combustion in the autoignition range being mostly initiated by spontaneous ignition, and wherein, in the ranges of spark ignition, combustion is initiated by spark ignition of said air-fuel mixture and a spark ignition range is assigned to the full load range and an autoignition range assigned to at least part of the part load range and wherein the effective compression ratio is lowered in spark ignition ranges and combustion controlled by regulating the residual gas content in the ranges of spontaneous ignition.

Abstract: An engine is operated in a homogeneous charge combustion mode or a stratified charge combustion mode. An intensive target throttle angle is computed based on the running state of the engine, regardless of a combustion mode which is underway. The intensive target throttle angle reflects an engine torque which is demanded at the time of executing the homogeneous charge combustion mode. At the time of executing the homogeneous charge combustion mode, the degree of opening of a throttle valve is adjusted based on the intensive target throttle angle to adjust the engine torque. At the time of executing the stratified charge combustion mode, a fuel injection amount is adjusted based on the intensive target throttle angle to adjust the engine torque. In other words, even in case where either of the two combustion modes is executed, the engine torque is adjusted based on the intensive target throttle angle.

Abstract: An intake air quantity detected by an air flow meter is corrected based on a change speed of an engine load and on a change speed of an engine rotation speed, and an oxygen quantity stored in a catalytic converter is estimated based on the corrected intake air quantity and an oxygen concentration in the exhaust gas.

Abstract: An engine employs a dual mode combustion process including a first combustion mode for light loads utilizing premixed charge forced auto ignition (PCFA) wherein a pulse jet of reacting fuel mixture from a prechamber mixes with an ultra dilute premixed fuel-air charge in a main chamber, causing rapidly expanding combustion that ignites the remaining ultra dilute mixture by compression ignition. This improves efficiency, allows combustion phasing control and reduced NOx emissions. For higher speeds and loads, a conventional second combustion mode is utilized wherein a strong premixed mixture is ignited conventionally with spark ignition and/or pulse jet ignition. Cylinder pressures which would result from compression ignition at the higher speeds and loads are thus reduced providing overall engine operation with reduced emissions, improved fuel economy, and reduced noise through improved control of the combustion process.

Abstract: A control system for an internal combustion engine is provided which comprises a compression ratio control mechanism and a control unit for controlling the compression ratio control mechanism. The control unit including an acceleration parameter obtaining section for obtaining an acceleration parameter corresponding to a change of an engine speed, an acceleration determining section for determining whether the engine is in a slow or fast acceleration state on the basis of the acceleration parameter, and a control section for controlling at least one of a compression ratio change speed at which the engine compression ratio during engine acceleration is changed and a compression ratio change start time at which a change of the engine compression ratio during engine acceleration is started, on the basis of whether the engine is in a slow or fast acceleration state. A control method is also provided.