Abstract: A technique for enabling reduction of fuel consumption without greatly changing an engine structure and without impairing a feeling of operation of a vehicle as a motorcycle. An engine includes a crankshaft and a primary gear integrated with the crankshaft that is attached such that the power of the engine is transmitted to a wheel. A one-way clutch transmits the power from the crankshaft to the primary gear but does not transmit the power from the primary gear to the crankshaft. The one-way clutch is provided between the crankshaft and the primary gear with a regenerative brake motor being provided on the primary gear. The engine is non-swingable mounted on the vehicle body with a cylinder extending in a substantially horizontal direction and a crankshaft provided to be oriented in a vehicle width direction. An electric motor is located in front of and above the crankshaft of the engine.

Abstract: A hybrid vehicle in which an electric motor is disposed in the vicinity of a center of a vehicle body to reduce lateral expansion. The hybrid vehicle includes an engine, a motor, and a power transmission mechanism for transmitting power of the engine and the motor to a rear wheel. The engine is suspended on the vehicle body in a non-swingable manner with a cylinder extending in a substantially horizontal direction and a crankshaft provided to be oriented in a vehicle width direction. The electric motor is located in front of and above the crankshaft of the engine.

Abstract: A piston with transverse-rib through holes formed easily therein for reducing the cost of manufacturing. A piston includes a pair of mutually opposed longitudinal ribs individually formed with piston pin bosses interconnecting a pair of piston skirt portions on a back side of a piston head. A pair of transverse ribs interconnect the mutually opposed longitudinal ribs with the transverse ribs. The pair of transverse ribs are formed with transverse-rib through holes at places proximal to the back side of the piston head. A skirt opening is formed by cutting away a part of the piston skirt portion that is opposed to the transverse rib and faces the transverse-rib through hole.

Abstract: A coolant air bleed structure is provided for a water-cooled internal combustion engine having a plurality of cylinders and a cylinder head, formed at upper portion of the cylinders. The cylinder head includes a coolant jacket formed therein. The coolant air bleed structure is disposed in an air bleed hole formed in a protrusion formed at a substantially central vertical portion of a sidewall of the cylinder head. The coolant air bleed structure is operatively connected to the coolant jacket, and includes a jiggle valve which is configured to open during a coolant changing operation.

Abstract: A coolant air bleed structure is provided for a water-cooled internal combustion engine having a plurality of cylinders and a cylinder head, formed at upper portion of the cylinders. The cylinder head includes a coolant jacket formed therein. The coolant air bleed structure is disposed in an air bleed hole formed in a protrusion formed at a substantially central vertical portion of a sidewall of the cylinder head. The coolant air bleed structure is operatively connected to the coolant jacket, and includes a jiggle valve which is configured to open during a coolant changing operation.

Abstract: A vehicular power unit including a drive-side transmission sprocket wheel provided on an end of an output shaft that protrudes from one side of a crankcase, an endless transmission belt for transmitting power to a driving wheel wound the sprocket wheel. The endless transmission belt transmits power from the crankshaft to a transmission housed in the crankcase. A water pump is arranged on the same side of the crankcase in a position between the crankshaft and the output shaft. Further, the water pump is disposed inside the drive-side transmission sprocket wheel in a direction along the axis of an output shaft. This configuration enables the vehicular power unit to be formed in a compact size in a direction along an axis of a crankshaft.

Abstract: A sub-gallery for leading oil to a cylinder head side of an engine is provided in a crankcase in such a manner as to be connected to an outlet of an oil filter and in parallel with a main gallery. A lubricating device is also provided to equally feed oil to each of portions to be lubricated in the engine, including the main gallery connected to a discharge port of an oil pump via the oil filter. This lubricating device sufficiently feeds oil to even the cylinder head side of the engine while avoiding increased pressure loss of the oil.

Abstract: A sub-gallery for leading oil to a cylinder head side of an engine is provided in a crankcase in such a manner as to be connected to an outlet of an oil filter and in parallel with a main gallery. A lubricating device is also provided to equally feed oil to each of portions to be lubricated in the engine, including the main gallery connected to a discharge port of an oil pump via the oil filter. This lubricating device sufficiently feeds oil to even the cylinder head side of the engine while avoiding increased pressure loss of the oil.

Abstract: In a volumetric gas adsorption measuring method, an initial dead volume of the sample cell and an initial dead volume of a reference cell at the same time point are preliminarily determined. When the gas adsorption on the solid sample is to be measured, a change in the dead volume of the sample cell is calculated on the basis of an internal gas with the sample cell and reference cell immersed in a pressure of the reference cell measured at this time point cryogenic fluid temperature bath, the initial dead volume of the reference cell, and an initial gas pressure of the reference cell measured at a time point of the measurement of the initial dead volume of the reference cell. Then, the initial dead volume of the sample cell preliminarily measured is corrected on the basis of the change in the dead volume of the sample cell for the calculation of the amount of the gas adsorbed on the solid sample.