Abstract: A gasoline in a material fuel tank is separated into a high-RON fuel having a higher octane value than the material fuel and a low-RON fuel having a lower octane value than the material fuel, by a separator device equipped with a separation membrane. Using a fuel switching mechanism, one or both of the high-RON fuel and the low-RON fuel are supplied to the engine in accordance with the state of operation of the engine. As the octane value of a fuel can be changed in accordance with the engine operation state, the state of combustion in the engine improves, so that both an increase in engine output and an improvement in an exhaust property can be achieved.

Abstract: An internal combustion engine includes two intake side solenoid driving valve mechanisms for opening and closing intake valves by cooperation of an electromagnetic coil and a spring, and/or two exhaust side solenoid driving valve mechanisms for opening and closing exhaust valves provided on each cylinder. A controller commands a driving circuit to cause the valve-opening timing of the exhaust valves or the intake valves to be different.

Abstract: An electromagnetic drive valve always maintains an optimal waveform of a current supplied to electromagnets for driving an armature. The waveform of an instruction current to each coil is changed in accordance with changes of external disturbances affecting a valve body based on the pressure in the cylinders of an internal combustion engine, the sliding resistance on a bearing, and the like.

Abstract: A solenoid valve device includes an engine valve which can move in an axial direction thereof, an armature which moves with the engine valve, an electromagnet which attracts the engine valve so that the engine valve moves in the axial direction, and a zero-lash adjuster mechanism which is interposed between the engine valve and the armature. Thus, the solenoid valve can positively actuate an engine valve between a fully closed position and a fully opened position without formation of a clearance between the engine valve and the armature. A current supplied to the electromagnet may be set in accordance with a value which is related to a relative position of the armature and the electromagnet.

Abstract: An apparatus is provided which includes an internal combustion engine of a lean-burn type, an NOx catalyst disposed in an exhaust passage of the engine so as to remove nitrogen oxides contained in exhaust gas emitted from the engine, and a variable valve control system capable of changing the opening and closing timing and/or a lift of the intake valve and/or the exhaust valve for each cylinder of the engine. The variable valve control system is controlled so that the exhaust gas to which the NOx catalyst is exposed is controlled so as to be suitable for removing a selected gaseous component from the NOx catalyst when the selected gaseous component should be removed. A method of purifying an exhaust gas emitted from the above engine is also provided.

Abstract: An internal combustion engine includes two intake side solenoid driving valve mechanisms for opening and closing intake valves by cooperation of an electromagnetic coil and a spring, and/or two exhaust side solenoid driving valve mechanisms for opening and closing exhaust valves provided on each cylinder. A controller commands a driving circuit to cause the valve-opening timing of the exhaust valves or the intake valves to be different.

Abstract: The variable valve timing control device according to the present invention controls the valve timing of the intake valves of the engine based on the optimum valve timing at the full load operation of the engine. Namely, the variable valve timing control device of the present invention determines the valve timing in accordance with the combination of the present engine load and the present engine speed in such a manner that the deviation of the valve timing from the optimum valve timing when the engine is operated in full load at the present speed does not exceed a predetermined maximum allowable value. Since the valve timing of the engine is always set within a range determined by the maximum allowable deviation from the optimum valve timing for the full load operation, when the engine is accelerated to the full load condition the amount of the change, i.e., the amount of the operation of the variable valve timing control device is kept always within the range determined by the maximum allowable deviation.

Abstract: A control method and apparatus of an engine for driving a generator. When a weight W of a charcoal canister is greater than a predetermined value W.sub.1 ` and a vehicle runs, the engine is actuated. As the result of the actuation of the engine, when a gasoline vapor within a fuel tank is purged and the weight W of the charcoal canister is lower than a second predetermined value W.sub.2, a vacuum switching valve for purging the canister is turned off and the engine is stopped. Even when the vehicle runs while a battery is frequently charged by an external charger, the occurrence of a certain amount of the fuel vapor which can not be caught and collected by the charcoal canister can be prevented and a low pollution vehicle can be obtained. In place of the vehicle running state, a vehicle running distance, or a vehicle running time can be used. In place of the predetermined value W.sub.2, a fuel purge amount can be used.

Abstract: An internal combustion engine having a valve overlapping period control device for controlling a valve overlapping period during which both the intake valve and the exhaust valve are open, and an equivalent length adjustment device for controlling an equivalent length of an exhaust passage necessary to cause an exhaust gas pulsation to return to an exhaust port in the form of a vacuum during the valve overlapping period, to thereby reduce the equivalent length as an engine speed increases when the valve overlapping period is longer than a predetermined period, and for stopping a control of the equivalent length when the valve overlapping period is shorter than the predetermined period.

Abstract: A cylinder head for an engine is formed with a first straight intake passage which leads to a first intake port, and with a second helical intake passage which leads to a second intake port and is formed with a helical end vortex portion. A common intake passage leads to the upstream ends of the first and second intake passages. A dividing ridge extends from one side of the inner surface of the cylinder head defining the intake passages towards but not reaching an opposite side of that surface, with a gap being left beween the ridge summit portion and that opposite side. The ridge thus divides the second intake passage into a one side portion remote from the first intake passage and terminating in the helical end vortex portion, and another side portion towards that first intake passage which is a straight bypass passage and is communicated at its downstream end to that helical end vortex portion.

Abstract: In an internal combustion engine cylinder head for being clamped to a cylinder block for defining therewith a plurality of combustion chambers arranged in a row, the cylinder head is formed with three parallel coolant passages along the row of combustion chambers, a first, a second and a third one of those passages successively passing by intake ports, exhaust ports and roofs of the row of combustion chambers, respectively, each passage being independently connected at one end thereof with a coolant jacket of the cylinder block to receive coolant therefrom, so that three parallel coolant flows of a favorable triple distribution of flow rates are optionally established according to certain relative magnitudes of flow resistance of the three coolant passages.

Abstract: An internal combustion engine has a cylinder block formed with first and second cylinder bores, and first and second pistons are fitted in the bores and reciprocate in them. A cylinder head is affixed to the cylinder block and defines first and second combustion chambers in cooperation with the first and second pistons and cylinder bores. This cylinder head is formed with a portion which in cooperation with a portion of the first piston defines a squish area of the first combustion chamber, with a cylinder fixing bolt hole boss being located between the first portion and the second portion of the cylinder head, and being disposed towards the side of the cylinder head on the side of the squish area. Further, the cylinder head is formed with a side wall defining one side of a coolant passage which substantially follows through the cylinder head proximate to the squish area so that a first portion of the coolant passage directly cools the squish area.

Abstract: A variable swirl siamese type intake port structure for an internal combustion engine cylinder head includes a first generally straight intake passage which leads to a first intake port and a second generally helical intake passage which leads to a second intake port which is formed with a helical end vortex portion. A control valve is fitted in the first generally straight intake passage at an upstream portion thereof so as to control its flow resistance. A means is provided to the generally straight intake passage on the side thereof towards the generally helical intake passage, for, when the control valve is in its position to maximize the flow resistance of the generally straight intake passage, diverting a relatively minor proportion of air-fuel mixture sucked into the intake port structure from a point upstream of the control valve to a point near the downstream end of the first generally straight intake passage, thus bypassing the control valve.

Abstract: A variable swirl siamese type intake port structure for an internal combustion engine cylinder head includes a first generally straight intake passage which leads to a first intake port and a second generally helical intake passage which leads to a second intake port which is formed with a helical end vortex portion. A control valve is fitted in the first generally straight intake passage at an upstream portion thereof so as to control its flow resistance. A substantially straight auxiliary passage, opening from a point upstream of the control valve to a point near the downstream end of the first intake port and bypassing the control valve, points through the first intake port, when open, generally at the ignition point of the engine spark plug. Thereby, when the control valve is closed, even then an air-fuel mixture stream is directed straight at the spark plug, and this prevents local weakening of mixture due to centrifugal effects.

Abstract: In an internal combustion engine which is provided with a throttle valve of the type which, when slightly opened, provides a flow of intake gases which is biased towards one particular side of the intake passage, and which is provided with a helical type inlet port which has a helical surface leading to the combustion chamber which imparts swirl to inlet gases, a vane is provided, which particularly directs gases passing near that one particular side of the intake passage towards the start of the helical surface, whereby good swirl and turbulence are generated in the power cylinder, especially during low and medium load operation of the engine.

Abstract: In an internal combustion engine which is provided with a throttle valve of the type which, when slightly opened, provides a flow of intake gases which is biased towards one particular side of the intake passage, a vane is provided, which particularly directs gases passing near that one particular side of the intake passage towards a portion of the edge of the inlet port which is most remote from the central axis of the power cylinder, whereby good swirl and turbulence are generated in the power cylinder, especially during low and medium load operation of the engine.