Abstract: The invention relates to a power unit, in particular for a hybrid vehicle, comprising a two-cylinder reciprocating piston engine comprising two pistons guided in two cylinders in tandem arrangement, and two counter-rotating crankshafts connected to the pistons by connecting rods, a generator which is rotatable in the same direction as the first crankshaft and in the opposite direction to the second crankshaft, and a balancer shaft which is rotatable in the same direction as the second crankshaft and in the opposite direction to the first crankshaft. The generator is operatively connected directly to the first crankshaft by a first traction mechanism and the balancer shaft is operatively connected directly to the second crankshaft by a second traction mechanism. The balancer shaft and/or the second crankshaft support(s) a flywheel mass element. The invention further relates to a vehicle, in particular a hybrid vehicle, having such a power unit.

Abstract: The invention relates to a power unit, in particular for a hybrid vehicle, comprising a reciprocating piston engine and comprising a generator which can be in driving engagement therewith, wherein the reciprocating piston engine has at least two pistons, which are guided in at least two cylinders in tandem arrangement, and two counter-rotating crankshafts, which are connected to the pistons by connecting rods and which are mechanically coupled so as to be in phase, wherein a first generator can be driven by the first crankshaft and a second generator can be driven by the second crankshaft.

Abstract: The invention relates to a power unit, in particular for a hybrid vehicle, comprising a two-cylinder reciprocating piston engine comprising two pistons guided in two cylinders in tandem arrangement, and two counter-rotating crankshafts connected to the pistons by connecting rods, a generator which is rotatable in the same direction as the first crankshaft and in the opposite direction to the second crankshaft, and a balancer shaft which is rotatable in the same direction as the second crankshaft and in the opposite direction to the first crankshaft. The generator is operatively connected directly to the first crankshaft by a first traction mechanism and the balancer shaft is operatively connected directly to the second crankshaft by a second traction mechanism. The balancer shaft and/or the second crankshaft support(s) a flywheel mass element. The invention further relates to a vehicle, in particular a hybrid vehicle, having such a power unit.

Abstract: The invention relates to a power unit, in particular for a hybrid vehicle, comprising a reciprocating piston engine and comprising a generator which can be in driving engagement therewith, wherein the reciprocating piston engine has at least two pistons, which are guided in at least two cylinders in tandem arrangement, and two counter-rotating crankshafts, which are connected to the pistons by connecting rods and which are mechanically coupled so as to be in phase, wherein a first generator can be driven by the first crankshaft and a second generator can be driven by the second crankshaft.

Abstract: The invention relates to a power unit, in particular for a hybrid vehicle, comprising a reciprocating piston engine and comprising a generator which can be in driving engagement therewith, wherein the reciprocating piston engine has at least two pistons, which are guided in at least two cylinders in tandem arrangement, and two counter-rotating crankshafts, which are connected to the pistons by connecting rods and which are mechanically coupled so as to be in phase, wherein a first generator can be driven by the first crankshaft and a second generator can be driven by the second crankshaft.

Abstract: The invention relates to a power unit, in particular for a hybrid vehicle, comprising a reciprocating piston engine and comprising a generator which can be in driving engagement therewith, wherein the reciprocating piston engine has at least two pistons, which are guided in at least two cylinders in tandem arrangement, and two counter-rotating crankshafts, which are connected to the pistons by connecting rods and which are mechanically coupled so as to be in phase, wherein a first generator can be driven by the first crankshaft and a second generator can be driven by the second crankshaft.

Abstract: An engine valve operating device includes rocker arms, cams on a cam shaft corresponding to the rocker arms, and a connection switchover device for switching over between the connection and disconnection of the rocker arms. The switchover device includes a piston slidably fitted into the first rocker arm operatively connected to an engine valve with one end facing a hydraulic pressure chamber, a pin slidably fitted into the second rocker arm adjacent the first rocker arm with one end abutting against the other end of the piston, a limiting mechanism slidably fitted into the third rocker arm operatively connected to another engine valve and adjoining the second rocker arm on the opposite side from the first rocker arm and which limiting mechanism abuts against the other end of the pin, and a spring biasing mechanism in the third rocker arm for biasing the limiting mechanism toward the pressure chamber.

Abstract: In a cooling system for a multi-cylinder engine, a main gallery is provided around outer peripheral portions of the plurality of cylinder bores upstream a block-side coolant jacket to commonly surround the cylinder bores, and an upstream coolant gallery is provided between the block-side coolant jacket and the main coolant gallery to separately surround each of outer peripheries of the cylinder bores. The upstream coolant gallery and the main coolant gallery is in communication with each other through a constriction communication passage provided around the outer periphery of each of the cylinder bores, and the upstream coolant gallery is further in communication with an upstream end of the block-side coolant jacket.

Abstract: A power unit mounting structure in a motor vehicle includes a power unit comprising an engine having a crankshaft, a transmission coupled to the crankshaft of the engine, and a differential interposed between drive axles connected to a pair of laterally spaced front road wheels of the motor vehicle and the transmission. The power unit is mounted in a front portion of the motor vehicle with its center of gravity positioned rearwardly of the drive axles extending from the differential toward front road wheels serving as the drive road wheels. A steering gearbox extends parallel to the drive axles and is disposed forwardly of the drive axles.

Abstract: A valve operating device for an internal combustion engine in which a selective coupling mechanism is operable to control the lift and opening interval of the valve includes a hydraulically operated phase adjusting mechanism disposed between the timing wheel and the camshaft to effect relative angular movement therebetween for timing control of valve operation.

Abstract: A cylinder block as a main part of an engine block includes a cylinder barrel assembly block, a skeleton-like frame surrounding the outer periphery of the cylinder barrel assembly block and a plate-like rigid film member, within a fluid passage in the skeleton-like frame. The skeleton-like frame is integrally joined to the outer surfaces of left and right side walls of the assembly block along the crankshaft axis and includes crossbeam bone members, longitudinal beam bone members and post bone members which are rigid and unitarily assembled into a three-dimensional latticework structure. A cylinder head is integrally coupled to the deck surface of the cylinder block and a lower case is integrally coupled to the lower surface of the cylinder block, lateral outer surfaces of the block and lower case along the crankshaft axis being formed flush with each other in parallel with the cylinder bore axis.

Abstract: A valve operating mechanism for an internal combustion engine having a valve disposed in an intake port or an exhaust port of a combustion chamber and being openable by a rotatable cam and cam follower in synchronism with the engine crankshaft rotation. The valve is normally urged toward the closed position by a spring means encircling the valve. Various embodiments are disclosed for varying the resilient force urging the valve toward the closed position during different engine operating conditions, such as, increasing the resilient valve closing force during high-speed operation for ensuring proper valve operation and decreasing the resilient valve closing force during low-speed operation for reducing friction in the valve operating mechanism. The valve operating mechanism includes means for switching between actuation by a low-speed cam or a high-speed cam. One form of the spring means includes a mechanism for increasing the spring force on the high-speed cam follower only during high-speed operation.

Abstract: A valve operating mechanism for an internal combustion engine having a valve disposed in an intake port or an exhaust port of a combustion chamber and being openable by a rotatable cam and cam follower in synchronism with the engine crankshaft rotation. The valve is normally urged toward the closed position by a spring means encircling the valve. Various embodiments are disclosed for varying the resilient force urging the valve toward the closed position during different engine operating conditions, such as, increasing the resilient valve closing force during high-speed operation for ensuring proper valve operation and decreasing the resilient valve closing force during low-speed operation for reducing friction in the valve operating mechanism. The valve operating mechanism includes means for switching between actuation by a low-speed cam or a high-speed cam. One form of the spring means includes a mechanism for increasing the spring force on the high-speed cam follower only during high-speed operation.

Abstract: Valve operating apparatus is disclosed in which intake or exhaust valves of an internal combustion engine are operated by rocker arms driven by cams having different cam profiles and hydraulically operated coupling mechanisms for selectively connecting or disconnecting adjacent rocker arms to vary the operation of the valves under different engine operating conditions. Sensing means in the form of a piston displacement detecting device is included in the apparatus to monitor its operating condition.

Abstract: A device for switching valve operation modes in an internal combustion engine with a rotatable camshaft having cams integral therewith, valves disposed in intake or exhaust ports of the combustion chamber and normally urged closed by a spring, and the valves being openable by the cams through a plurality of rocker arms disposed adjacent to each other for imparting the cam lifts to the valves. A coupling mechanism selectively connects and disconnects the rocker arms by means of pistons in aligned guide holes in the rocker arms movable between positions to either extend across the adjacent sides of the rocker arms or be aligned with such sides. A solenoid is provided in one rocker arm and surrounds a piston to selectively cause movement of that piston. Springs urge the pistons to the position controlled by the solenoid.

Abstract: A valve operating mechanism for an internal combustion engine wherein a plurality of rotatable cams have different cam profiles for operating an intake or exhaust valve differently in high and low speed ranges of the engine. A plurality of rocker arms are selectively connected or disconnected for transmitting the appropriate cam lift to the valve depending on the engine speed range. The cam profiles have dampening areas at the start of opening and the finish of closing of the valve. The dampening areas of the high speed cam have a smaller rate of change than the dampening areas of the low speed cam to minimize the possibility of engagement by a rocker arm with a cam for one speed while the engine is operating at another speed by another cam and rocker arm.

Abstract: Valve operating apparatus is disclosed in which the valves are operated by transmitting members in the form of rocker arms or bucket lifters driven by cams having different cam profiles and coupling devices for selectively connecting or disconnecting adjacent transmitting members to vary the operation of the valves under different engine operating conditions. The transmitting member that is not directly associated with a valve and that idles when not coupled to an adjacent transmitting member is spring biased toward the operating cam by an abutment member and means are provided to limit the stroke of the abutment member.

Abstract: Apparatus for controlling the operation of intake or exhaust valves of an internal combustion engine in which cam-driven rocker arms that operate the valves are selectively connected or disconnected for movement in unision or for independent movement in order to open and close the valves in accordance with the various modes of engine operation. Control of the valves is produced by the cooperative effect of hydraulic pressure and variable spring forces whereby more accurate valve operation over a greater number of engine operating modes is achieved.

Abstract: A valve operating device for an internal combustion engine, including a plurality of cams or a camshaft having different cam profiles corresponding to operating conditions of the engine for opening and closing the intake valves according to the operating conditions of the engine. The high-speed cam has a cam lobe which projects from a base-circle portion of the cam by a distance smaller than the distance by which the cam lobe of a low-speed cam projects from the base-circle portion. The cam lobe of the high-speed cam also subtends a larger angle on the base circle of the camshaft than the cam lobe of the low-speed cam.

Abstract: Valve operating apparatus is disclosed in which the valves are operated by rocker arms driven by cams having different cam profiles and hydraulically operated coupling mechanisms for selectively connecting or disconnecting adjacent rocker arms to vary the operation of the valves under different engine operating conditions. The coupling mechanisms are operated by fluid supplied through the rocker shaft mounting the rocker arms. The rocker shaft is divided into independent fluid supply passages whereby the couplings can be supplied independently with operating fluid in order to expand the number of available valve operating control modes. Variations are described in which operating fluid can be independently supplied to various ancillary hydraulically-operated equipment, as well as to the selective coupling mechanisms.