Yamaha Hatsudoki Kabushiki Kaisha

Masahiro Uchida

Kenichi Sakurai

Tatsuo Niiyama

Kaoru Okui

Tateo Aoyama

An improved arrangement for controlling the valve operation of an internal combustion engine wherein the control valves are mounted within perpendicularly extending bores formed in the cylinder head and camshaft bearing cap with the bores being deep enough so that the valves do not project significantly beyond the cylinder head. In addition, one or more of the connecting passages are formed by grooves in the mating surfaces of the cylinder head and bearing cap to avoid the necessity of drillings and particularly of drilling blind bores.

Variable valve drive mechanism for an internal combustion engine

An improved compact engine construction that facilitates positioning in close quarters while still affording ease of assembly and servicing. This is accomplished by mounting the camshafts at different heights and by providing a two-piece spark plug tube in the cylinder head that facilitates removal in sections rather than all at once.

Cylinder head spark plug mounting arrangement

Camshaft supporting structure for four-stroke cycle engine

Several embodiments of variable valve timing mechanisms for an internal combustion engine wherein the timing of two valves associated with the same combustion chamber of the engine may be driven at the same time interval and at the same speed from the engine output shaft and both valves may have their timing adjusted simultaneously by a first variable valve timing mechanism and only one of the valves may have its timing adjusted relative to the other valve by a second variable valve timing mechanism to provide a simpler operational control and lower cost assembly.

Variable valve timing mechanism for engine

An improved journaling and sensor mounting arrangement for the VVT mechanisms of a twin overhead cam engine. By utilizing a combined single bearing cap for the VVT ends of the camshafts that mounts the sensors that are associated with timing wheels on the respective camshafts, it is possible to maintain a very neat external appearance and a compact construction. Also, high accuracy can be obtained because of the positive rotation of the components. In addition, a simplified oil supply and control arrangement is also disclosed for lubricating the thrust surfaces of the camshaft bearings and other bearing surfaces as well as supplying hydraulic fluid to the VVT mechanisms.

CAM angle sensor mounting structure for engine

A cylinder head, air intake manifold, fuel injector and fuel rail arrangement for an overhead valve engine that provides a compact assembly. The fuel rail is attached to the cylinder head by fasteners that extend parallel to the fasteners that fix the intake manifold to an adjacent portion of the cylinder head. The layout is such, however, that there is no interference between the various components and thus accessibility is improved while cost is minimized.

Cylinder head and manifold arrangement for injected engine

A control valve arrangement for a three-valve-per-cylinder internal combustion engine. The control valve arrangement controls not only the effective length of the intake passage serving each combustion chamber, but also controls the flow through the intake passage so as to generate turbulence under low-speed and low-load conditions. The control valve further includes a pair of valves which change not only the effective flow area, but also the effective flow direction. In this way varying degrees and types of turbulence can be generated during different engine running conditions. A number of different types of valve arrangements are disclosed.

Intake control system for generating tumble action

A variable valve timing mechanism for an internal combustion engine wherein the camshaft is supported at one end by a combined bearing and valve body member that is detachably connected to the supporting engine body. The connection is such that fluid from the engine lubricating system can be delivered to this body and distributed by control valves mounted in it. This simplifies machining of the engine body and permits a more compact, lower cost construction without sacrificing any function.

Two embodiments of VVT mechanisms for internal combustion engines. The VVT mechanisms are hydraulically operated by the engine lubricating oil through control passages formed in the forward-most bearing portion of the camshaft. However, spaced on both sides of these control passages, there are provided lubricant supplies to the forwardmost and rearward most ends of the forward bearing surfaces of the camshaft so as to provide good lubrication, particularly in the more highly loaded forwardmost portion thereof.

Variable valve timing arrangement

A multiple cylinder, multiple valve internal combustion engine having direct cylinder injection. The cylinder injectors are disposed on a longitudinally extending plane that contains the cylinder bore axis and are inclined at acute angles to planes perpendicular to the longitudinal plane and containing the cylinder bore axis. The spark plugs are located at the intersection of both planes and are inclined to the transverse plane similarly to the fuel injectors. An arrangement is disclosed for controlling the intake charge into the engine so as to be directed primarily on the side of the combustion chamber where the fuel injector injects under at least low speed, low load conditions.

Combustion chamber for engine

A 'V'-type engine having two banks of cylinders with a valley therebetween, an intake air manifold extending between the banks, and a supercharger for charging the air delivered to the engine is disclosed. The supercharger is positioned in the valley formed between the two banks of cylinders and below the intake air manifold. The supercharger has an air inlet and an air outlet, the air outlet extending upwardly to the intake air manifold.

Supercharged engine

This invention is adapted to improve a cam drive system for an overhead camshaft internal combustion engine having a cylinder block defining at least one cylinder bore. A cylinder head assembly is affixed to the cylinder block and closes one end of the cylinder bore to form a combustion chamber therein. The cylinder head assembly comprises a main valve associate with the combustion chamber. The crankshaft is rotatably journalled relative to the cylinder block at the end of the cylinder bore opposite the cylinder head and driven by the piston. The cylinder head assembly includes at least one detachable member to provide at least in part a journal for journalling an intermediate cam drive shaft for rotation about an axis parallel to the axes of rotation of the crankshaft and the camshaft.

Cam drive system for engine

An improved compact oil pump drive arrangement for an internal combustion engine having an auxiliary shaft that is driven by the crankshaft. The oil pump is driven by an oil pump drive shaft that is disposed between the auxiliary shaft and the crankshaft by a helical gear arrangement. The auxiliary drive shaft is also driven by a helical gear arrangement, and the helical gears on the auxiliary drive shaft are of appropriate hands so as to balance the axial thrusts on the auxiliary drive shaft.

Oil pump drive for engine

A two-stage cam shaft drive arrangement for an internal combustion engine employing a pair of flexible transmitters. The two-stage mechanism is driven by an intermediate shaft that is driven off of the crankshaft at a point between its ends. Flexible transmitter tensioners are engaged with the flexible transmitters on the side away from the cylinder block for ease of accessibility and to maintain a more compact engine configuration.

Growing community of inventors

Iwata, Japan

Masahiro Uchida