Abstract: A composite container is provided where FRP layers are formed by winding FRP around a metal liner so that the dome sections are reinforced while limiting an increase in the weight. The FRP layers include a hoop layer that covers the entirety of the cylindrical section in hoop winding, and dome section reinforcing layers that also cover as least the portions of the cylindrical section near the dome sections. In the dome section reinforcing layers, FRP are wound in helical form in such a manner that the orientation angle of the FRP over the cylindrical section relative to the direction of the axis of the liner continuously changes towards the center of the cylindrical section, and thus, the weight of FRP near the center of the cylindrical section is reduced.

Abstract: A composite container is provided where FRP layers are formed by winding FRP around a metal liner so that the dome sections are reinforced while limiting an increase in the weight. The FRP layers include a hoop layer that covers the entirety of the cylindrical section in hoop winding, and dome section reinforcing layers and that also cover as least the portions of the cylindrical section near the dome sections and. In the dome section reinforcing layers and, FRP are wound in helical form in such a manner that the orientation angle of the FRP over the cylindrical section relative to the direction of the axis of the liner continuously changes towards the center of the cylindrical section, and thus, the weight of FRP near the center of the cylindrical section is reduced.

Abstract: In an engine having a propeller mounted on one end of a crankshaft, the vibrations on an end portion of the crankshaft opposite to the propeller are effectively suppressed with a pair of vibration pendulum type weights arranged outside the crankcase whereby it is possible to easily perform a change of the vibration suppression structure in conformity with the property of the propeller.

Abstract: To reduce the number of parts, improve the mountability and maintainability, and allow for a reduction in the size and weight an engine is provided having a crankshaft, a crankcase having a plurality of bearing portions for rotatably supporting the crankshaft with each of the bearing portions being dividable along a divisional plane arranged on the axis of the crankshaft. Cylinder barrels are connected to the crankcase and include cylinder bores with cylinder heads connected to the cylinder barrels. The cylinder heads are integrated with portions of the cylinder barrels forming at least the cylinder bores to form cylinder blocks. The cylinder blocks and the crankcase are fastened together by a plurality of fastening bolts having axes parallel to the axes of the cylinder bores and extending through at least the cylinder blocks, with a compressive structure in the axial direction of the fastening bolts.

Abstract: To attain downsizing and weight reduction of a starter motor and starting power transmission in an engine starting apparatus. The starting power transmission decelerates rotation power of the starter motor and transmits the power to a crankshaft, even in a multi-cylinder engine. The starting power transmission is provided between the starter motor that starts rotation by electric power supplied from a battery and the crankshaft. An exhaust valve is depressed and opened by actuation of an actuator in accordance with actuation of the starter motor. The actuation of the actuator is continued until the number of revolutions of the crankshaft detected by a revolution detector reaches a predetermined number of revolutions.

Abstract: In an engine having a propeller mounted on one end of a crankshaft, the vibrations on an end portion of the crankshaft opposite to the propeller are effectively suppressed with a pair of vibration pendulum type weights arranged outside the crankcase whereby it is possible to easily perform a change of the vibration suppression structure in conformity with the property of the propeller.

Abstract: To reduce the size and weight of an engine body and improve the mountability and maintainability of transmitting rods in a valve train for an OHV engine having a crankshaft, a crankcase for rotatably supporting the crankshaft, a camshaft incorporated in the crankcase, cylinder heads connected to the crankcase, engine valves operably provided in the cylinder heads, and the transmitting rods for transmitting a valve operating force due to the rotation of the camshaft to the engine valves. The transmitting rods as pull rods are arranged on one side of cylinder barrels. One end portion of each transmitting rod is formed with an engaging portion disengageably engaged with a hook portion of a mating member. An engine body or a guide member, fixed to the engine body, is provided with a guide portion for guiding the engaging portion to the hook portion of the mating member.

Abstract: To reduce the number of parts, improve the mountability and maintainability, and allow for a reduction in the size and weight an engine is provided having a crankshaft, a crankcase having a plurality of bearing portions for rotatably supporting the crankshaft with each of the bearing portions being dividable along a divisional plane arranged on the axis of the crankshaft. Cylinder barrels are connected to the crankcase and include cylinder bores with cylinder heads connected to the cylinder barrels. The cylinder heads are integrated with portions of the cylinder barrels forming at least the cylinder bores to form cylinder blocks. The cylinder blocks and the crankcase are fastened together by a plurality of fastening bolts having axes parallel to the axes of the cylinder bores and extending through at least the cylinder blocks, with a compressive structure in the axial direction of the fastening bolts.

Abstract: To reduce the size and weight of an engine body and improve the mountability and maintainability of transmitting rods in a valve train for an OHV engine having a crankshaft, a crankcase for rotatably supporting the crankshaft, a camshaft incorporated in the crankcase, cylinder heads connected to the crankcase, engine valves operably provided in the cylinder heads, and the transmitting rods for transmitting a valve operating force due to the rotation of the camshaft to the engine valves. The transmitting rods as pull rods are arranged on one side of cylinder barrels. One end portion of each transmitting rod is formed with an engaging portion disengageably engaged with a hook portion of a mating member. An engine body or a guide member, fixed to the engine body, is provided with a guide portion for guiding the engaging portion to the hook portion of the mating member.

Abstract: In a valve system for a OHV horizontally-opposed, four-cycle internal combustion engine, valve camshafts are provided at crankcase portions for supporting a crankshaft, of left and right cylinder banks disposed on opposite sides of the crankshaft. Intake and exhaust valves are provided at cylinder heads and are opened and closed by pull rods operated by the valve camshafts. The aforementioned valve system achieves large reductions in the size and weight of the piston heads where the intake and exhaust valves of the internal combustion engine are disposed.

Abstract: To provide a four-cycle engine, in which a pair of intake valve ports is openable/closable by respective intake valves and a pair of exhaust valve ports is openable/closable by respective exhaust valves. The pair of intake valve ports and the pair of exhaust valve ports are provided in a cylinder head such that they are positioned on both sides of a first virtual plane which contains the axial line of the cylinder bore and passes through an approximately central portion of the combustion chamber. A pair of ignition plugs is mounted in the cylinder head. The pair of ignition plugs is mounted such that the degradation of a flame propagation condition is minimized, even if accidental firing of either of the ignition plugs occurs. The pair of ignition plugs is disposed substantially symmetrically with respect to a second virtual plane which passes through the center of a combustion chamber and is perpendicular to the first virtual plane.

Abstract: To provide an oil pump mounting structure for an engine. The engine includes a crankcase rotatably supporting a crankshaft, an oil pan connected to a lower portion of the crankcase, and an oil pump interlocked for rotation with the crankshaft. The oil pump mounting structure lowers the center of gravity of the engine and improves the suction efficiency and maintenance characteristic of the oil pump. A pump housing of the oil pump is removably mounted on a mounting portion provided on the bottom of an oil pan.

Abstract: To provide a valve system for an engine, in which a rocker arm is interlocked with an engine valve and is supported on a rocker shaft fixedly mounted to a cylinder head such that it is rockable with the rotation of a camshaft. Accordingly, the size and weight of the engine can be reduced. The posture of a rocker shaft is set to have an axial line crossing an axial line of a crankshaft on the projection plane perpendicular to an axial line of a cylinder bore. A rocker arm is rockably supported by the rocker shaft and is provided with an input arm extending, on the above projection plane, from the rocker arm to the camshaft side. A pull rod reciprocates in the axial direction with the rotation of the camshaft and is connected to the input arm.

Abstract: In a horizontally opposed type internal combustion engine, to enable rigid support of a middle journal of a crankshaft through rational utilization of first and second case halves constituting a crankcase, and to thereby contribute to a simplification in structure and a reduction in weight. In a horizontally opposed type internal combustion engine, a crankcase is split at a plane containing the axis line of a crankshaft into first and second case halves connected with first and second cylinder blocks. The first and second case halves are integrally provided with first and second journal supporting walls for supporting a middle journal of the crankshaft. The first and second journal supporting walls front cylinder bores of the first and second cylinder blocks. The first and second journal supporting walls are coupled by a plurality of first bolts inserted from the side of the cylinder bores of the first cylinder block and disposed on opposite sides of and in proximity to the middle journal.

Abstract: An intake system for a horizontally opposed type internal combustion engine can contribute to an improvement in output performance without sacrificing the intrinsic merit of the horizontally opposed type internal combustion engine. Specifically, the intake system ensures that the overall height of the engine remains small. First and second intake ports are provided at head portions of first and second banks, which are arranged on the left and right sides. First and second intake distribution ports are arranged horizontally at a front wall of an intake surge tank 10, which is disposed on the rear end side of and adjacent to a crankshaft 1. The first and second intake ports are respectively connected with each other through first and second intake pipes disposed along a top surface or bottom surface of the engine E. Throttle valves for controlling intake quantities in the first and second intake pipes are provided in upstream portions of the intake pipes.

Abstract: To provide a valve system for an engine, in which a valve stem for an engine valve is slidably fitted in a guide cylinder provided in a cylinder head. A rocker arm is interlocked to rock with rotation of a camshaft. The rocker arm is also interlocked with the valve stem. With the above construction, local wear, galling, and the like in the guide cylinder can be prevented. Accordingly, the reliability can be improved. A lifter is interposed between a rocker arm and a valve stem. The lifter is formed into a cylindrical shape with a closed bottom and has a diameter larger than an outside diameter of the valve stem. The lifter is fitted in a lifter housing in such a manner as to be slidable in the axial direction of the valve stem. The lifter housing is fixed to a cylinder head.

Abstract: To attain downsizing and weight reduction of a starter motor and starting power transmission in an engine starting apparatus. The starting power transmission decelerates rotation power of the starter motor and transmits the power to a crankshaft, even in a multi-cylinder engine. The starting power transmission is provided between the starter motor that starts rotation by electric power supplied from a battery and the crankshaft. An exhaust valve is depressed and opened by actuation of an actuator in accordance with actuation of the starter motor. The actuation of the actuator is continued until the number of revolutions of the crankshaft detected by a revolution detector reaches a predetermined number of revolutions.

Abstract: To provide a four-cycle engine, in which a pair of intake valve ports is openable/closable by respective intake valves and a pair of exhaust valve ports is openable/closable by respective exhaust valves. The pair of intake valve ports and the pair of exhaust valve ports are provided in a cylinder head such that they are positioned on both sides of a first virtual plane which contains the axial line of the cylinder bore and passes through an approximately central portion of the combustion chamber. A pair of ignition plugs is mounted in the cylinder head. The pair of ignition plugs is mounted such that the degradation of a flame propagation condition is minimized, even if accidental firing of either of the ignition plugs occurs. The pair of ignition plugs is disposed substantially symmetrically with respect to a second virtual plane which passes through the center of a combustion chamber and is perpendicular to the first virtual plane.

Abstract: To provide an oil pump mounting structure for an engine. The engine includes a crankcase rotatably supporting a crankshaft, an oil pan connected to a lower portion of the crankcase, and an oil pump interlocked for rotation with the crankshaft. The oil pump mounting structure lowers the center of gravity of the engine and improves the suction efficiency and maintenance characteristic of the oil pump. A pump housing of the oil pump is removably mounted on a mounting portion provided on the bottom of an oil pan.

Abstract: To provide a valve system for an engine, in which a valve stem for an engine valve is slidably fitted in a guide cylinder provided in a cylinder head. A rocker arm is interlocked to rock with rotation of a camshaft. The rocker arm is also interlocked with the valve stem. With the above construction, local wear, galling, and the like in the guide cylinder can be prevented. Accordingly, the reliability can be improved. A lifter is interposed between a rocker arm and a valve stem. The lifter is formed into a cylindrical shape with a closed bottom and has a diameter larger than an outside diameter of the valve stem. The lifter is fitted in a lifter housing in such a manner as to be slidable in the axial direction of the valve stem. The lifter housing is fixed to a cylinder head.