Abstract: A valve actuating mechanism for an engine having a rocker arm movement restraining device which controls opening and closing an engine valve. The rocker arm movement restraining device includes a timing arm which engages left and right rocker arms for constraining the axial movement thereof, and a timing cam disposed on an intake-side camshaft. The rocker arm movement restraining device releases the engagement of the timing arm with the left and right rocker arms by activating the timing arm when the intake-side camshaft is rotated, and when the timing arm releases the engagement with the left and right rocker arms, the left and right rocker arms move to a predetermined operating position.

Abstract: A hydraulic pressure warning system for an internal combustion engine including a hydraulic pressure sensor that is prevented from being influenced by the heat of the engine and by the pulsation of an oil pump. A hydraulic pressure sensor detects hydraulic pressure in a lubricating oil passage of the engine and issues a warning based on hydraulic pressure detected by the hydraulic pressure sensor when the hydraulic pressure drops. The hydraulic pressure sensor is provided on a wall surface of a water jacket of a rear cylinder block so as to project therefrom.

Abstract: To effectively arrange actuators for control by individually controlling an intake valve and an exhaust valve in an internal combustion engine which includes a variable valve operating device for controlling valve operating characteristics. An internal combustion engine includes a variable valve operating device having a valve characteristic variable mechanism for controlling valve operating characteristics of engine valves consisting of an intake valve and an exhaust valve. The valve characteristic variable mechanism includes electrically operated motors for changing operational timings and lift quantities of the above-mentioned engine valves. The electrically operated motors are arranged outside a valve operating chamber. At the same time, the electrically operated motors are arranged close to the throttle body on a cylinder intake side.

Abstract: A twin clutch device wherein a second clutch is arranged coaxially and radially inside of a first clutch outer which forms an annular plate portion. One clutch inners of both clutches is arranged between a clutch member which constitutes a portion of the outer of the first and second clutches and an annular plate portion. Lifter pins have axes arranged parallel to a rotary axis of first and second clutches and axially movably penetrate both clutch inners to bring one ends thereof into contact with pressure plates. First and second drive control members are capable of applying control forces to disconnect the first and second clutches against spring forces of first and second clutch springs. A second clutch outer is rotated together with the first clutch outer and is arranged coaxially with the first clutch. A pair of clutch outers are connected in a relatively non-rotatable manner with each other.

Abstract: A twin clutch device wherein a second clutch is arranged coaxially and radially inside of a first clutch outer which forms an annular plate portion. One clutch inners of both clutches is arranged between a clutch member which constitutes a portion of the outer of the first and second clutches and an annular plate portion. Lifter pins have axes arranged parallel to a rotary axis of first and second clutches and axially movably penetrate both clutch inners to bring one ends thereof into contact with pressure plates. First and second drive control members are capable of applying control forces to disconnect the first and second clutches against spring forces of first and second clutch springs. A second clutch outer is rotated together with the first clutch outer and is arranged coaxially with the first clutch. A pair of clutch outers are connected in a relatively non-rotatable manner with each other.

Abstract: A twin clutch gear transmission for a vehicle is provided for improving speed change control. The twin clutch gear transmission includes an even-numbered-gear-change gear transmission mechanism having a plurality of even-numbered gear-change gear trains which can be selectively established, and an odd-numbered-gear-change gear transmission mechanism having a plurality of odd-numbered gear-change gear trains which can be selectively established. The pair of clutches are capable of individually changing over the disconnection and the connection of power transmission between input shafts, which both gear transmission mechanisms include respectively, and a power source.

Abstract: A valve actuating mechanism for an engine having a rocker arm movement restraining device which controls opening and closing an engine valve. The rocker arm movement restraining device includes a timing arm which engages left and right rocker arms for constraining the axial movement thereof, and a timing cam disposed on an intake-side camshaft. The rocker arm movement restraining device releases the engagement of the timing arm with the left and right rocker arms by activating the timing arm when the intake-side camshaft is rotated, and when the timing arm releases the engagement with the left and right rocker arms, the left and right rocker arms move to a predetermined operating position.

Abstract: A variable valve characteristic mechanism has a valve operation cam pivotally supported on a camshaft and a driving mechanism rocking an interlocking mechanism around the camshaft, the interlocking mechanism rocking the valve operation cam by a driving cam integrated into the camshaft. The engine valve starts to open and close in a damping portion of the valve operation cam, and the driving mechanism rocks the valve operation cam via the interlocking mechanism, thereby controlling an opening timing and a closing timing of the engine valve. A cam swelled portion of the driving cam has a constant velocity portion in which a lift velocity is constant, and the constant velocity portion is provided over an angular width where the opening timing in a most advanced angle position of the opening timing of the engine valve and the opening timing in a most retarded angle position of the opening timing are included.

Abstract: A twin-clutch transmission system in a power unit for a vehicle includes a clutch system with a pair of hydraulic clutches, which respectively include clutch pistons. A gear transmission includes a first main shaft, which has a first end portion linked to a first one of the two hydraulic clutches. The gear transmission also includes a second main shaft, which has a first end portion linked with the other one of the two hydraulic clutches. A pair of hydraulic passages are concentrically formed inside the second main shaft, and apply hydraulic pressure respectively to the clutch pistons. An operating fluid is supplied from a second end side of the second main shaft. The resulting configuration enables the protrusion of the power unit toward the clutch system to be minimized.

Abstract: A variable valve characteristic mechanism has a valve operation cam pivotally supported on a camshaft and a driving mechanism rocking an interlocking mechanism around the camshaft, the interlocking mechanism rocking the valve operation cam by a driving cam integrated into the camshaft. The engine valve starts to open and close in a damping portion of the valve operation cam, and the driving mechanism rocks the valve operation cam via the interlocking mechanism, thereby controlling an opening timing and a closing timing of the engine valve. A cam swelled portion of the driving cam has a constant velocity portion in which a lift velocity is constant, and the constant velocity portion is provided over an angular width where the opening timing in a most advanced angle position of the opening timing of the engine valve and the opening timing in a most retarded angle position of the opening timing are included.

Abstract: To provide a smaller clutch system with fewer component parts, the clutch system includes a first hydraulic clutch, which is provided between a power source and a first driven shaft, and a second hydraulic clutch, which is provided between the power source and a second driven shaft. An input member includes an annular plate portion, an inner cylindrical portion, and an outer cylindrical portion. The input member is provided commonly to a first and a second hydraulic clutches, while the inner and the outer cylindrical portions are made to be the input sides respectively of the first and the second hydraulic clutches. First and a second clutch pistons, which are included respectively in the first and the second hydraulic clutches, are placed on an opening end side of the input member.

Abstract: To effectively arrange actuators for control by individually controlling an intake valve and an exhaust valve in an internal combustion engine which includes a variable valve operating device for controling valve operating characteristics. An internal combustion engine includes a variable valve operating device having a valve characteristic variable mechanism for controling valve operating characteristics of engine valves consisting of an intake valve and an exhaust valve. The valve characteristic variable mechanism includes electrically operated motors for changing operational timings and lift quantities of the above-mentioned engine valves. The electrically operated motors are arranged outside a valve operating chamber. At the same time, the electrically operated motors are arranged close to the throttle body on a cylinder intake side.

Abstract: A control apparatus for a continuously variable transmission ensures good acceleration performance during staffing operations, and following an engine stall occurring before a gear ratio of the continuously variable transmission is shifted back to a low speed. The control apparatus includes sensors, a gear ratio return control unit, and a one-way clutch. One sensor detects a gear ratio of a continuously variable transmission. Another sensor detects whether an engine is in a stationary state. The gear ratio return control unit drives a motor in a backward direction when the engine is in the stationary state and the gear ratio of the continuously variable transmission is other than a low gear ratio. The one-way clutch turns idly relative to a backward drive of the output shaft. The gear ratio return control unit brings the motor to a stop when the gear ratio of the continuously variable transmission lowers sufficiently.

Abstract: In a three-wheeled vehicle provided with a power transmission mechanism for transmitting the output of an engine to left and right rear wheels via a continuously variable transmission, a gear box and inner shafts of drive shafts as left and right output shafts, the inner shafts which are output shafts of the gear box are provided apart in a longitudinal direction of the body. The overall length of the drive shafts can be increased. When the rear wheel is vertically moved, an angle of the bend of the drive shaft can be minimized. Further, the tread of the wheels can be reduced. Therefore, the width of the body can be reduced and the mobility of the vehicle can be enhanced. In addition, the gear case can be separate from the crankcase and attached to the crankcase with the differential mechanism being housed in the separate gear case.

Abstract: In order to do away with the need for a power source switching operation, and to improve motor regeneration charge efficiency in a hybrid vehicle, a one-way clutch is provided between an internal combustion engine and an electric drive motor.

Abstract: A power plant includes an internal combustion engine having a crankshaft to which a piston is connected and a variable compression ratio system for changing the position of the axis of rotation of the crankshaft. The power plant includes a transmission having a main shaft which is connected to the crankshaft through a first deceleration system. The variable compression ratio system includes a crankshaft holder, which rotatably supports the crankshaft and which is swingably supported on a main shaft, and a drive system which swings the crankshaft holder. Thus, the power plant retains unchanged the distance of shafts between the crankshaft and the main shaft, even when the combustion engine has a variable compression ratio system, by changing the position of the axis of rotation of the crankshaft.

Abstract: A twin clutch gear transmission for a vehicle is provided for improving speed change control. The twin clutch gear transmission includes an even-numbered-gear-change gear transmission mechanism having a plurality of even-numbered gear-change gear trains which can be selectively established, and an odd-numbered-gear-change gear transmission mechanism having a plurality of odd-numbered gear-change gear trains which can be selectively established. The pair of clutches are capable of individually changing over the disconnection and the connection of power transmission between input shafts, which both gear transmission mechanisms include respectively, and a power source.

Abstract: A twin clutch device wherein a second clutch is arranged coaxially and radially inside of a first clutch outer which forms an annular plate portion. One clutch inners of both clutches is arranged between a clutch member which constitutes a portion of the outer of the first and second clutches and an annular plate portion. Lifter pins have axes arranged parallel to a rotary axis of first and second clutches and axially movably penetrate both clutch inners to bring one ends thereof into contact with pressure plates. First and second drive control members are capable of applying control forces to disconnect the first and second clutches against spring forces of first and second clutch springs. A second clutch outer is rotated together with the first clutch outer and is arranged coaxially with the first clutch. A pair of clutch outers are connected in a relatively non-rotatable manner with each other.

Abstract: A three-wheeled motor vehicle includes a through coupling situated between right and left internal shafts and rear wheels, each via a drive shaft. The axial lines of right and left internal shafts are both intersected with a straight line as a rocking axis. If the right and left internal shafts are placed away from each other in the front and rear of the vehicle body, the drive shaft can be placed extensively in the diagonal direction from the right and left internal shafts to the rear wheel side. Using the described structure, the total length of the drive shaft can be increased. In consideration thereof, the bending angle of the drive shaft can be minimized when the rear drive wheels move in the vertical direction, and the track of the rear wheels can be reduced because the drive shaft is placed extensively in the diagonal direction.

Abstract: A differential mechanism is arranged below an infinitely variable transmission and a reduction gear mechanism. Front fitting parts and rear fitting parts for fitting suspension arms to a vehicle frame are arranged to the front and rear of the deferential mechanism. Even though the left and right suspension arms swing up and down, or a transmission and a reduction gear mechanism attached on a vehicle frame swing left and right with respect to the suspension arms, there is no interference of the transmission and the reduction gear mechanism with the suspension arms due to a space at the front and the rear of a differential mechanism, so that the vehicle frame can swing left and right and it is also possible to easily constitute a vehicle having an independent suspension.