Abstract: In a multi-cylinder internal combustion engine, a hydraulic valve rest mechanism is mounted on a valve operating device, which performs open-close driving of an engine valve which is arranged in a cylinder head of an engine body having a plurality of cylinders in an openable-and-closable manner. The hydraulic valve rest mechanism is operated with an oil pressure that is controlled by a hydraulic control device so as to close and rest engine valves of a plurality of cylinders for bringing the cylinders into a rest state Therefore, the miniaturization of the multi-cylinder internal combustion engine along an axis of a crankshaft and can shorten a length of an oil passage which connects a hydraulic valve rest mechanism and a hydraulic control device. A hydraulic control device is arranged on an engine body directly above a portion thereof corresponding to a cylinder that is expected to assume a cylinder rest state.

Abstract: An electronic throttle control device in a internal combustion engine for a vehicle can be improved in maintainability and can be reduced in size. An electronic throttle control device in a V-type internal combustion engine for a vehicle has a fuel injection valve and throttle valves in an intake passage. A throttle driving motor controls the opening angle of each throttle valve according to the amount of operation of a throttle grip performed by an operator of the vehicle. The throttle driving motor is located outside a region surrounded by the throttle bodies that are respectively connected to all of intake ports as viewed in plan.

Abstract: An air intake control system is provided for an internal combustion engine of a vehicle. The control system includes an intake port of a cylinder head for an engine main body, a throttle body having a throttle valve and connected to the intake port, an electric actuator having an electric motor and arranged on the throttle body to drive open or close the throttle valve, and a connector disposed on a housing of the electric actuator in a position facing toward one axial end of a crankshaft. The connector is provided in order to connect to an outside conductor to the electric motor of the electric actuator. The resulting configuration facilitates the work to connecting the outside conductor to the connector.

Abstract: A multicylinder internal combustion engine, which can simplify its control and is advantageous against thermal loads or vibrations includes a cylinder head with intake valves and exhaust valves arranged therein. Valve actuators are provided for openably operating the intake valves and exhaust valves, respectively. A cylinder head cover forms, in combination with the cylinder head, a valve actuator chamber with the valve actuators accommodated therein. At least some of the valve actuators are deactivatable to disable their corresponding cylinders. The multicylinder internal combustion engine is a V-shaped internal combustion engine provided with a front bank and rear bank. The cylinders on opposite ends in a direction of a crankshaft are set as full-time operating cylinders.

Abstract: An internal combustion engine having cylinders capable of selectively resting during engine operation is capable of eliminating step increases in engine output when the number of operative cylinders is changed. The internal combustion engine includes a plurality of cylinders divided into two or more groups, at least some of the cylinders being restable. A throttle valve of each of the cylinders is independently operable on the basis of the group to which the cylinder belongs, and the number of resting cylinders is controlled according to the throttle grip opening. The throttle valve opening is different between the groups, except for the full opening condition and the full closure condition of the throttle valve, and an ECU is provided for opening the throttle valve of the next cylinder group before the throttle valve opening of the former cylinder group reaches the full opening condition.

Abstract: An internal combustion engine incorporating rest cylinders is provided which does not need a high response performance when operating a throttle valve and which can eliminate engine output variations as the number of operable cylinders changes. In the internal combustion engine, some of a plurality of cylinders is configured to rest during normal operation of the engine. The cylinders are divided into a plurality of cylinder groups, and each of the cylinders is provided with an independent throttle valve. An ECU for increasing the number of operative cylinder groups according to at least the throttle handgrip opening is provided. Also provided are motors for bringing the throttle valves in the cylinder in the rest state into a fully closed state on the basis of each cylinder group, a throttle valve position sensor, and the like.

Abstract: An internal combustion engine incorporating rest cylinders is provided which does not need a high response performance when operating a throttle valve and which can eliminate engine output variations as the number of operable cylinders changes. In the internal combustion engine, some of a plurality of cylinders is configured to rest during normal operation of the engine. The cylinders are divided into a plurality of cylinder groups, and each of the cylinders is provided with an independent throttle valve. An ECU for increasing the number of operative cylinder groups according to at least the throttle handgrip opening is provided. Also provided are motors for bringing the throttle valves in the cylinder in the rest state into a fully closed state on the basis of each cylinder group, a throttle valve position sensor, and the like.

Abstract: A throttle body for controlling a plurality of throttle valves in a multi-cylinder engine. The throttle valves of at least two of the cylinders are structurally connected to each other.

Abstract: The invention provides a multi-cylinder engine wherein, even where it is structured such that a cam chain case is provided on a side portion of the engine, a working fluid supply path can be simplified and the weight and size of a cylinder head reduced. According to the invention, a multi-cylinder engine is provided wherein at least one of a plurality of engine valves of a cylinder head can be cut off from its corresponding combustion chambers such that a first intake valve, a second intake valve, a first exhaust valve, and a second exhaust valve are positioned on the opposite side to a cam chain case.

Abstract: In a multi-cylinder internal combustion engine having throttle valves to be opened and closed by electric motors, output control is enabled in various ways according to the state of usage of an object to be driven by the multi-cylinder internal combustion engine with a simple structure with the scope of application of shared components being expanded to reduce the cost. In addition, a throttle body assembly is downsized in the direction of the arrangement of the cylinders. A multi-cylinder internal combustion engine includes a predetermined number of cylinders, a throttle body assembly including the throttle bodies formed with intake-air channels and throttle valves. The respective throttle valves are opened and closed by the electric motors provided independently for each throttle valve. Air-intake ports of the first and fourth cylinders are formed so as to approach a center plane in the direction of the arrangement as they approach entrances.

Abstract: An internal combustion engine having cylinders capable of selectively resting during engine operation is capable of eliminating step increases in engine output when the number of operative cylinders is changed. The internal combustion engine includes a plurality of cylinders divided into two or more groups, at least some of the cylinders being restable. A throttle valve of each of the cylinders is independently operable on the basis of the group to which the cylinder belongs, and the number of resting cylinders is controlled according to the throttle grip opening. The throttle valve opening is different between the groups, except for the full opening condition and the full closure condition of the throttle valve, and an ECU is provided for opening the throttle valve of the next cylinder group before the throttle valve opening of the former cylinder group reaches the full opening condition.

Abstract: In a multi-cylinder internal combustion engine having throttle valves to be opened and closed by electric motors, output control is enabled in various ways according to the state of usage of an object to be driven by the multi-cylinder internal combustion engine with a simple structure with the scope of application of shared components being expanded to reduce the cost. In addition, a throttle body assembly is downsized in the direction of the arrangement of the cylinders. A multi-cylinder internal combustion engine includes a predetermined number of cylinders, a throttle body assembly including the throttle bodies formed with intake-air channels and throttle valves. The respective throttle valves are opened and closed by the electric motors provided independently for each throttle valve. Air-intake ports of the first and fourth cylinders are formed so as to approach a center plane in the direction of the arrangement as they approach entrances.

Abstract: To provide an internal combustion engine that can generate a strong swirl by increasing the amount of intake air for generating the swirl in a simple structure. In the internal combustion engine provided with a cylinder head formed with an air intake port having first and second ports, when a second intake valve for opening and closing the second port is brought into a halted state by a valve halting mechanism, a swirl is generated by intake air flowing through the first port in a combustion chamber.

Abstract: A throttle body for controlling a plurality of throttle valves in a multi-cylinder engine. The throttle valves of at least two of the cylinders are structurally connected to each other.

Abstract: The invention provides a multi-cylinder engine wherein, even where it is structured such that a cam chain case is provided on a side portion of the engine, a working fluid supply path can be simplified and the weight and size of a cylinder head reduced. According to the invention, a multi-cylinder engine is provided wherein at least one of a plurality of engine valves of a cylinder head can be cut off from its corresponding combustion chambers such that a first intake valve, a second intake valve, a first exhaust valve, and a second exhaust valve are positioned on the opposite side to a cam chain case.

Abstract: To provide an internal combustion engine that can generate a strong swirl by increasing the amount of intake air for generating the swirl in a simple structure. In the internal combustion engine provided with a cylinder head formed with an air intake port having first and second ports, when a second intake valve for opening and closing the second port is brought into a halted state by a valve halting mechanism, a swirl is generated by intake air flowing through the first port in a combustion chamber.

Abstract: To provide a high performance four-stroke internal combustion engine wherein an increase in a side of a cylinder head is prevented and a valve resting mechanism is provided for a valve lifter. In a four-stroke internal combustion engine with a valve resting mechanism includes a valve lifter having a valve resting mechanism interposed between a valve motion cam and a stem of a poppet valve and a valve lifter spring is provided for biasing the valve lifter in a direction in which the valve lifter is normally held in contact with the valve motion cam. A slide pin holder is pressed against the valve lifter by a spring force of the valve lifter spring that is provided on the valve lifter while a shim portion having a predetermined thickness for controlling a relative positional relationship with the valve lifter is formed integrally with a valve lifter top wall.

Abstract: A cylinder head for an internal combustion engine in which any of a plurality of valve guides for guiding intake and exhaust poppet valves provided with valve lifters can be press-fitted in fitting holes of the cylinder head with a substantially uniform press fit force. At least one valve guide is fitted at a different depth in the cylinder head than others of the guides valves. The intake and exhaust poppet valves have substantially uniform thicknesses in the respective longitudinal directions of the valve guides. An idle fitting hole with an inner diameter greater than an outer diameter of the valve guides is formed above one of the fitting holes which is formed deeper in the cylinder head than the other fitting holes, the idle fitting hole extending upward to a lower side of a valve spring.

Abstract: A valve pause mechanism of a four-stroke internal combustion engine includes a valve pause mechanism. A valve lifter fitted between a valve cam and a valve stem of a poppet valve is always pressed in a direction in which the valve lifter contacts the valve cam with a lifter spring. However, a slide pin is fitted into a slide pin holder fitted in the valve lifter so that a slide pin can slide in a direction perpendicular to the valve stem. A stem working face in contact with the valve stem of the poppet valve and a stem through hole that the valve stem pierces are both adjacently formed in the slide pin and a slide pin driving mechanism. The slide pin driving mechanism selectively makes the stem working face and the stem through hole face the valve stem by moving the slide pin. A side of the slide pin at the back of the stem working face is chamfered across the stem through hole.

Abstract: A valve pause mechanism of a four-stroke internal combustion engine includes a valve pause mechanism. A valve lifter fitted between a valve cam and a valve stem of a poppet valve is always pressed in a direction in which the valve lifter contacts the valve cam with a lifter spring. However, a slide pin is fitted into a slide pin holder fitted in the valve lifter so that a slide pin can slide in a direction perpendicular to the valve stem. A stem working face in contact with the valve stem of the poppet valve and a stem through hole that the valve stem pierces are both adjacently formed in the slide pin and a slide pin driving mechanism. The slide pin driving mechanism selectively makes the stem working face and the stem through hole face the valve stem by moving the slide pin. A side of the slide pin at the back of the stem working face is chamfered across the stem through hole.