Abstract: An internal combustion piston engine having a plurality of intake valves and a plurality of exhaust valves per cylinder employs apparatus for disabling the operation of at least one exhaust valve upon decrease in speed of the engine below a predetermined level.

Abstract: An internal combustion piston engine having a plurality of intake valves and a plurality of exhaust valves per cylinder employs apparatus for disabling the operation of at least one exhaust valve upon decrease in speed of the engine below a predetermined level.

Abstract: An apparatus and a method for controlling the operation of intake and exhaust valves of an internal combustion engine having a plurality of intake and exhaust valves for each cylinder to provide an optimum engine output at all operating speeds. When the engine is rotating at a low speed, a part of both of the intake and exhaust valves are rendered inoperative. When the engine is rotating at a medium speed, all of the intake valves are made operative and a part of the exhaust valves are rendered inoperative. Finally, when the engine is rotating at a high speed, all of both of the intake and exhaust valves are rendered operative.

Abstract: Herein disclosed is a valve actuating mechanism having a stopping function for use in an internal combustion engine of the type, in which at least one pair of intake or exhaust valves having an identical function and disposed adjacent to each other are arranged for one cylinder. First and second rocker arms respectively having arms abutting against the upper ends of the paired intake or exhaust valves are rockingly supported on a common support shaft which is fixed on the engine body while having an axis perpendicular to the operating directions of the valves. The first rocker arm is formed with a cylinder bore which is opened toward the second rocker arm to bear a plunger therein whereas the second rocker arm is formed with a guide bore which is opened toward the first rocker arm to fit the plunger therein.

Abstract: A valve disabling device for use in an internal combustion engine having inlet valve means, exhaust valve means, at least one of which comprises a plurality of valves. Disabling means selectively holds the at least one of the inlet valve means and the exhaust valve means in a first state wherein part of the valves thereof are inoperative, and in a second state wherein all the valves thereof are operative for alternate closing and opening actions. Transmission state detecting means detects whether power transmission means of the engine is in a connected state wherein power transmission between the engine output shaft and a load on the engine is allowed, and in a disconnected state wherein the power transmission is inhibited.

Abstract: A valve disabling device has an engaging member and an urging member slidably disposed, respectively, in first and second axial bores formed within, respectively, first and second rocker arm means, one of which engages a valve actuating cam. The engaging member is displaceable within the first axial bore by means of pressure applying means, into the second axial bore for driving coupling of the first and second rocker arm means whereby a pair of inlet valves or exhaust valves corresponding to the first and second rocker arm means make valving motions in unison with each other, or out of the second axial bore for disconnection of the first and second rocker arm means from each other to disable part of the valves. Biasing means biases the engaging member into the second axial bore irrespective of operation of the pressure applying means, to correspondingly bias the urging member into a predetermined position where a portion thereof is projected out of the second axial bore.

Abstract: A valve driving control apparatus in an internal combustion engine comprises a plurality of power cylinders each having a plurality of intake and exhaust reciprocating valves which are made operative or inoperative depending upon the load conditions of the engine.This apparatus selectively makes the valves operative or inoperative according to a control signal which is generated in a control circuit in response to the engine rotational speed. A part of the intake valves and a part of the exhaust valves are made inoperative in a low rotational speed range of the internal combustion engine. A part of the intake valves is made inoperative and all of the exhaust valves are made operative in a medium rotational speed range. All of the intake and exhaust valves are made operative in a high rotational speed range.

Abstract: An intake device for an engine including the first intake valve located at the downstream end of the first intake passage that is connected to the primary carburetor. A second intake valve is located at the downstream end of the second intake passage that is connected to the secondary carburetor in a cylinder. Both intake passages are connected to each other through a pathway situated in the middle of said intake passages. A check valve located in said pathway allows flow from the first intake passage to the second intake passage. In accordance with a second embodiment, the primary and secondary carburetors are configured so that operation of the secondary carburetor is a function of negative pressure in the primary system to remain closed under minimal load conditions.

Abstract: The present invention is directed to a valve operation control apparatus for use in an internal combustion engine. The device comprises a cylinder with at least two intake or two exhaust valves, one of the two valves including a pause member for holding the valve in a closed position. The control apparatus comprises a control circuit operatively coupled to the pause member. The control circuit has at least two open degree sensors responsive to two different degrees of opening of a throttle valve of the engine and at least two engine speed sensors responsive to two different speeds of the engine, wherein the control circuit controls the operation of the pause member in response to predetermined combinations of the operation of the open degree sensors and the engine speed sensors.

Abstract: An acceleration device including an acceleration fuel spray nozzle arranged on the upstream side of the choke valve and a through aperture formed in the latter to allow the fuel spray from the nozzle to freely proceed to the engine even when the choke valve is closed. There is no unwanted squirt of fuel during engine starting or high speed operation and formation of any overrich fuel-air mixture or depletion of the fuel passage extending to the nozzle is effectively prevented.

Abstract: A starter assist device for internal combustion engines which includes a supplemental air supply passage for the intake manifold arranged to bypass the carburetor, and a thermo-sensitive switch incorporated in the starter circuit and arranged to cause introduction of supplemental air into the intake manifold when the engine is started under conditions in which the engine is warm so that an oversupply of fuel is avoided, and to close off the supplemental air when the engine is started when cold to provide an adequate amount of fuel.

Abstract: An apparatus and a method for controlling the operation of intake and exhaust valves of an internal combustion engine having a plurality of intake and exhaust valves for each cylinder to provide an optimum engine output at all operating speeds. When the engine is rotating at a low speed, a part of both of the intake and exhaust valves are rendered inoperative. When the engine is rotating at a medium speed, all of the intake valves are made operative and a part of the exhaust valves are rendered inoperative. Finally, when the engine is rotating at a high speed, all of both of the intake and exhaust valves are rendered operative.

Abstract: A valve .[.disabling.]. .Iadd.operation control .Iaddend.device for use in an internal combustion engine having inlet valve means, exhaust valve means, at least one of which comprises a plurality of valves. Disabling means selectively holds the at least one of the inlet valve means and the exhaust valve means in a first state wherein part of the valves thereof are inoperative, and in a second state wherein all the valves thereof are operative for alternate closing and opening actions. Transmission state detecting means detects whether power transmission means of the engine is in a connected state wherein power transmission between the engine output shaft and a load on the engine is allowed, and is a disconnected state wherein the power transmission is inhibited.

Abstract: Herein disclosed is a valve actuating mechanism having a stopping function for use in an internal combustion engine of the type, in which at least one pair of intake or exhaust valves having an identical function and disposed adjacent to each other are arranged for one cylinder. First and second rocker arms respectively having arms abutting against the upper ends of the paired intake or exhaust valves are rockingly supported on a common support shaft which is fixed on the engine body while having an axis perpendicular to the operating directions of the valves. The first rocker arm is formed with a cylinder bore which is opened toward the second rocker arm to bear a plunger therein whereas the second rocker arm is formed with a guide bore which is opened toward the first rocker arm to fit the plunger therein.