Abstract:
An engine with intake and exhaust valves that may be controlled with a circular cam lobe is provided. The rotating axis of the circular cam lobe is offset from the physical center of the cam lobe. This permits the cam lobe to impart a reciprocal opening and closing of the valve. To maintain the valve in the closed position, the interconnection between the cam lobe and the valve 12 may have a spring which is compressed to allow the valve to remain closed for a set duration of time while the cam lobe continues to rotate.
Abstract:
A valve operating device for an internal combustion engine enabling both valve timing and valve lift characteristic to be varied depending on engine operating conditions includes intake and exhaust camshafts, an eccentric cam fixed to a first one of the intake and exhaust camshafts so that an axis of the eccentric cam is eccentric to an axis of the first camshaft. A rockable cam is supported on the first camshaft so that the rockable cam rotates or oscillates about the axis of the first camshaft. A rocker arm is oscillatingly supported on an outer periphery of the eccentric cam so that a center of an oscillating motion of the rocker arm revolves around the axis of the first camshaft. Also provided is a control shaft variably controlling the center of the oscillating motion of the rocker arm.
Abstract:
The invention relates to a valve mechanism for controlling a disc valve (1) of an internal combustion engine and comprises a control shaft (2) which is driven by the engine crankshaft, and a push rod (3) which is driven by the control shaft (2) and which for the purpose of transmitting reciprocating movement is connected to one arm (14) of a two-arm rocker (4) which is pivotable about a rocker shaft (15) and the other arm (16) of which rocker transmits these movements to the valve (1). The valve mechanism according to the invention is characterized in that the control shaft (2) is intended to act upon the push rod (3) in both directions of movement thereof; in that the first arm (14) of the rocker (4) extends essentially at right angles to the push rod (3) and the second arm (16) of the rocker extends essentially parallel with the longitudinal geometric axis of the valve (1); and in that a lifting arm (5) is provided for transferring rocker movement to the valve (1). The other arm (16) of the rocker (4) is provided with activating means (18) for coaction with the lifting arm (5), one end of which is pivotally mounted on a lifting arm shaft (19) and the other end of which is provided with means for activating the valve (1). The lifting arm surface (20) which co-acts with the second arm (16) of the rocker (4) is profiled in a manner to achieve the desired pattern of movement of the second end of the lifting arm (5) in response to movement of the rocker (4).
Abstract:
PROBLEM TO BE SOLVED: To provide a variable valve device of a multi-cylinder internal combustion engine capable of ensuring high startability due to improved combustion and improving responsiveness to switchover to cylinder deactivation.SOLUTION: A variable valve device includes: a pair of intake valves 3a or 3b and a pair of exhaust valves 71a or 71b provided at #1 or #2 cylinder. respectively; and first valve stop mechanisms 11b and 11c switching a state of one of the paired intake valves over between a valve operative state and a valve stop state; a second valve stop mechanism 11a switching a state of the other intake valve over between the valve operative state and the valve stop state. The first valve mechanisms are configured to switch one of the intake valves to the valve operative state if a hydraulic pressure is supplied, and to the valve stop state if supply of the hydraulic pressure stops. The second valve mechanism is configured to switch the other intake valve to the valve stop state if a hydraulic pressure is supplied, and to the valve operative state if supply of the hydraulic pressure stops.