Abstract: In a rockable-cam equipped reciprocating internal combustion engine, a rockable cam is rotatably fitted on the outer periphery of an intake-valve drive shaft that is rotatable in synchronism with rotation of a crankshaft. The rockable cam oscillates within predetermined limits during rotation of the intake-valve drive shaft so as to directly push an intake-valve lifter. As viewed from an axial direction of the crankshaft, an axis of the intake-valve drive shaft is offset from a centerline of the intake-valve stem in a first direction that is normal to both the cylinder centerline and the crankshaft axis and directed from the cylinder centerline to the intake valve side. The crankshaft axis is also offset from the cylinder centerline in the first direction.

Abstract: A variable compression ratio mechanism of a reciprocating engine includes at least an upper link connected at one end to a piston pin and a lower link connecting the other end of the upper link to a crankpin. At top dead center, when hypothetical connecting points between the upper and lower links are able to be supposed on both sides of the line segment connecting the piston-pin center and the crankpin center, and the first one of the connecting points has a smaller inclination angle, measured in the same direction as a direction of rotation of the crankshaft, from the axial line of reciprocating motion of the piston-pin center and to a line segment connecting the piston-pin center and the first connecting point; as compared to the second connecting point, the first connecting point is selected as the actual connecting point.

Abstract: A control system of an internal combustion engine is comprised of an operation angle adjustment mechanism which continuously varies an operation angle of intake valves of the engine, an air-fuel ratio detector which detects an exhaust parameter indicative of air-fuel ratio information, and a control unit which are coupled to the operation angle adjustment mechanism and the air-fuel ratio detector. The control unit feedback-controls an air-fuel ratio of the engine on the basis of the exhaust parameter and corrects the operation angle on the basis of the exhaust parameter.

Abstract: In a VVA apparatus, when an actual lift amount detected by a lift-amount detecting sensor exceeds a basic lift-amount target value by a predetermined value or more, ECU corrects a lift phase through a lift-phase varying mechanism to separate from a piston TDC with respect to a basic lift-phase target value.

Abstract: In a variable compression ratio mechanism for an internal combustion engine employing an upper link, a lower link, and a control link, the lower link includes a crankpin bearing portion into which a crankpin is fitted, a first connecting-pin bearing portion into which a first connecting pin for the upper link is fitted, and a second connecting-pin bearing portion into which a second connecting pin for the control link is fitted. A central connecting portion is provided to connect an axial central portion of at least one of the first and second connecting-pin bearing portions to an axial central portion of the crankpin bearing portion. The central connecting portion has an axial length L1 shorter than each of an axial length L2 of the crankpin bearing portion, an axial length L3 of the first connecting-pin bearing portion, and an axial length L4 of the second connecting-pin bearing portion.

Abstract: A control system for an internal combustion engine is provided. The engine includes a compression ratio control mechanism and an ignition timing control system. The control system comprises an engine control for controlling the compression ratio control mechanism and the ignition timing control system so that when the engine is cold, the ignition timing is retarded largely from an MBT point and the compression ratio is set higher than that obtained when the engine is cold and operated at corresponding engine rpm and engine load. A method for controlling such an internal combustion engine is also provided.

Abstract: In an internal combustion engine of variable compression ratio type, a piston control mechanism is employed which comprises a lower link rotatably disposed on a crank pin of a crankshaft of the engine, an upper link having one end pivotally connected to the lower link and the other end pivotally connected to a piston of the engine, a control link having one end pivotally connected to the lower link; and a position changing mechanism which changes a supporting axis about which the other end of the control link turns. When the piston comes up to a top dead center, a compression load is applied to the control link in an axial direction of the control link in accordance with an upward inertial load of the piston.

Abstract: A collector equipped intake system of an internal combustion engine, the collector is fixedly connected directly to either of a cylinder-head side wall and a collector mounting bracket hermetically covering perimeters of intake-port opening end portions of a plurality of intake ports opening through the side wall. A plurality of intake-manifold branches respectively communicating with the plurality of intake ports, are protruded into the interior space of the collector.

Abstract: In a piston actuation system of a V-type internal combustion engine with two cylinder banks having at least one pair of cylinders, a piston pin, an upper link, a lower link, and a control link are mechanically linked to each other for each cylinder bank. When changing a compression ratio of the engine, ends of the control links of the two cylinder banks are moved in synchronism. The lower links of the two cylinder banks are coaxially rotatably fitted on the outer periphery of the same crankpin whose axis is eccentric to the axis of the crankshaft.

Abstract: In an engine capable of continuously controlling an intake air quantity by varying an intake valve operating characteristic, an intake valve lift is sensed as well as an engine speed. Then, an intake air quantity is calculated in accordance with the engine speed and intake valve lift when an engine operating point is in a very low lift state.

Abstract: Intake valve drive shaft and exhaust valve drive shaft are arranged in parallel to each other and provided with sprockets, respectively, for receiving engine rotation from a crank shaft. A rocker cam is swingably mounted on the intake valve drive shaft to push the intake valve, and connected mechanically by a link mechanism with the intake valve drive shaft. The axis of the intake valve drive shaft is offset from the axis of the intake valve to one side. The rocker cam includes a cam nose which projects to the other side of the axis of the intake valve when the intake valve is in the closed state.

Abstract: A combustion control system for a spark-ignition internal combustion engine includes a variable piston stroke characteristic mechanism changing a compression ratio of the engine, sensors detecting engine operating conditions, i.e., engine speed and engine load, and at least one of a variable lift and working-angle control mechanism simultaneously continuously changing an intake-valve lift and an intake-valve working angle and a variable phase control mechanism changing an angular phase at a central angle corresponding to a maximum valve lift point of the intake valve. Also provided is a control unit that controls the variable piston stroke characteristic mechanism, and at least one of the variable lift and working-angle control mechanism and the variable phase control mechanism, depending on the engine operating conditions.

Abstract: A paired counterweights of a crankshaft have projected inner surfaces which protrude toward each other defining a given space therebetween. A plurality of links are arranged to convert a reciprocating motion of a piston to a rotational motion of the crankshaft. One of the links is pivotally connected to other links through link connecting portions and swingably disposed on a crank pin of the crankshaft so that upon rotation of the crankshaft, a peripheral portion of the link passes through the given space. At least one of the link connecting portions is placed within an imaginary circle which would be described by a radially innermost part of the projected inner surfaces of the paired counterweights when the paired counterweights turn about an axis of the crank pin.

Abstract: A piston crank mechanism of an internal combustion engine includes an upper link connected to a piston, a lower link connected to both the upper link and a crankpin, and a control link through which the lower link is linked to an eccentric cam of a control shaft to restrict the degree of freedom of the lower link. By varying the angular position of the eccentric cam with respect to the control-shaft axis, the center of oscillating motion of the control link varies, thus varying a compression ratio. The center of gravity of the lower link, determined by an equivalent inertia weight obtained by adding weights of connecting pins and weights of the upper-link boss-shaped end and the control-link boss-shaped end connected to the lower link via the respective connecting pins to the lower-link self-weight, is situated closer to the center of the crankpin.

Abstract: An internal combustion engine has an intake valve control device for controlling at least intake valves. The control device comprises a first mechanism which varies a working angle of the intake valve; a second mechanism which varies an operation phase of the intake valve; and a control unit which controls both the first and second mechanisms in accordance with an operation condition of the engine. The control unit is configured to carry out controlling variation in the open timing of the intake valve effected by the first mechanism to be larger than variation in the open timing of the intake valve effected by the second mechanism.

Abstract: A variable compression ratio mechanism of a reciprocating engine includes at least an upper link connected at one end to a piston pin and a lower link connecting the other end of the upper link to a crankpin. At top dead center, when, of hypothetical connecting points between the upper and lower links, to be able to be supposed on both sides of a line segment connecting a piston-pin center and a crankpin center, a first one of the connecting points has a smaller inclination angle measured in the same direction as a direction of rotation of the crankshaft from an axial line of reciprocating motion of the piston-pin center and formed between a line segment connecting the piston-pin center and the first connecting point as compared to the second connecting point, the first connecting point is selected as an actual connecting point.

Abstract: A supercharged internal combustion engine is provided with a double-link type piston crank mechanism connecting between a piston and a crankshaft. The piston crank mechanism causes the piston to move at a speed which is smaller around a top dead center (TDC) and larger around a bottom dead center (BDC) as compared with respective corresponding piston speeds attained by a comparable single-link type piston crank mechanism. The double-link type piston crank mechanism variably controls a compression ratio by varying an angular position of one of links constituting the piston crank mechanism.

Abstract: A hybrid vehicle propulsion system comprises an electric motor as a first propulsion source, an engine as a second propulsion source and a continuously variable transmission for receiving an input rotation from at least one of the motor and engine and for delivering a driving torque to a drive axle of the vehicle. A controller controls a transmission ratio of the transmission so that the transmission ratio in a motor drive mode is higher than the transmission ratio in an engine drive mode.

Abstract: A drive system for a hybrid drive vehicle, comprises a driving mechanism which includes a clutch, an engine connected the clutch, a first motor for generating power, connected to the clutch, a second motor for driving a drive wheel, connected to the clutch, and a transmission connected to the clutch. A third motor is provided for driving a hydraulic pump of a hydraulic system for the transmission. A first inverter is connected between the first motor and a battery, in which charging and discharging between the first motor and the battery being made through the first inverter. A second inverter is connected between the second motor and the battery, in which charging and discharging between the second motor and the battery being made through the second inverter. A third inverter is connected between the third motor and the battery, in which changing and discharging between the battery and the motor being made through the third inverter.

Abstract: In a hybrid vehicle, an internal combustion engine and a first electric propulsion motor are linked to an input axle of a clutch and an input axle of a continuously variable transmission and a second electric propulsion motor are linked to an output axle of the clutch. A propulsion mechanism for transmitting a power from an output axle of the continuously variable transmission to drive axles, a third electric propulsion motor used to drive a hydraulic system of the continuously variable transmission, a battery supply, a power inverter for charging and discharging between the battery supply and the first, second, and third electric propulsion motors, and a controller for controlling operations of the power inverter, the battery supply, the first, second, and third motors, and the continuously variable transmission are provided in the hybrid vehicle.