摘要:
A valve train device for an engine for driving a valve which opens and closes a valve opening of a combustion chamber comprises: a valve drive device comprising a drive member and driving force transmission mechanism. The drive force transmission mechanism is configured to transmit a driving force from the drive member to the valve. The drive force transmission mechanism comprises a transmission portion configured to transmit the driving force from the drive member to the valve and a variable portion configured to continuously change a state of the transmission portion to thereby continuously change an opening duration of the valve or the amount of valve lift. At least part of the variable portion is positioned within in the transmission portion.
摘要:
A variable stroke valve drive for an internal combustion engine, including an intermediate lever which is slidingly arranged on a crank path of a crank arm the intermediate lever has a working cam with null lifting cam and lifting cam portions. The working cam contacts a gas exchange valve via an intermediate element. A first adjustment element rotates the intermediate lever against a spring element around a point located near the crank, the intermediate lever being displaceable along the crank path by a second adjustment element. The first adjustment element is provided with a cam plate whose radius continuously increases or reduces on a circumference with respect to an axis of rotation. The inventive variable stroke valve drive substantially reduces wear in a valve drive.
摘要:
A valve actuating assembly for opening and closing a valve includes a cam mounted on a camshaft and enclosed by a pair of rotary cam guides each of which includes a roller channel having an outer race for receiving opposed ends of a roller that extends transversely from the lowermost end of a valve lifter disposed between the cam guides with the lifter being mounted to a connecting rod. The lifter has a radius at the lowermost end for engagement with the cam during certain engine phases, and the connecting rod is pivotally attached to a rocker arm, and the rocker arm attached to a valve. A valve spring mounted on the stem of the valve extends and compresses coincident with the rotation of the cam guides and contact of the roller ends with the outer races of the cam guides thereby actuating the lifter to open and close the valve with positive force and wherein the point of contact for valve opening and closing transfers between the engagement of the roller ends with the outer races and the radius against the cam during the various engine phases with the valve spring holding the valve in the closed position during certain phases through the exertion of positive force.
摘要:
An engine control apparatus includes a valve operating mechanism for transmitting the rotation of a crankshaft to camshafts through a timing wrapping member. A control unit includes a phase detection section that detects the phase of a camshaft relative to the crankshaft, an abnormality determination section that makes, based on the detected phase, a determination whether the valve operating mechanism is abnormal, a threshold storage section that stores determination references as a lower limit threshold and an upper limit threshold, an initial phase storage section that stores, as an initial phase, a phase detected at the time of engine installation, and a phase correction section that corrects the phase detected during engine operation by using the initial phase thereby to calculate a corrected phase. The abnormality determination section outputs an abnormality determination signal when the corrected phase deviates from a determination reference range of from the lower to upper limit thresholds.
摘要:
A three-dimensional cam of a three-dimensional map state, having uncountable cam profiles continuously ranged along a rotation axis direction, and a valve lifter following a cam surface of the three-dimensional cam are included, and a lift characteristic of a valve is continuously controlled by relative motions of the three-dimensional cam and the valve lifter. The three-dimensional cam has cam top portions formed to have a smoothly ranged edge line substantially along the rotation axis direction thereof, and a part of the edge line includes at least one valley portion to take on a row of peaks. The cam peak portion of the cam top portion which forms the valley portion of the edge line is moderately set to be deviated toward a delayed side with reference to the rotation direction of the cam from the other cam peak portions.
摘要:
Swivel actuator device for lift control of a gas exchange valve in a cylinder head of an internal combustion engine comprising a swivel motor having a shaft on which is provided a first operating element having a control path for opening the gas exchange valve, whereby a second operating element having a second control path provided on the first operating element. Due to the arrangement of the swivel actuator device, less electric power is needed at low rotational speeds and processing of the fuel mixture is improved.
摘要:
A valve drive mechanism for actuating a valve of an internal combustion engine includes a camshaft that is rotated by a crankshaft of the internal combustion engine. The crankshaft has a cam with positive and negative acceleration portions. A swing member rocked on a support shaft by rotation of the cam. The swing member has a cam surface configured to drive the valve. The cam surface has a base circle portion, a lift portion, and a ramp portion extending between the base circle portion and the lift portion. The ramp portion is configured such that when the positive or negative acceleration portions of the cam actuate the swing member, a lift speed of the valve is substantially constant.
摘要:
A valve drive mechanism is provided for opening and closing a valve of an engine. The device comprises a valve drive device and a swing member pivotally supported on a swing member support shaft. The swing member is driven to pivot about the swing member support shaft by the valve drive device. A cam surface is formed on the swing member. The cam surface is configured to transfer motion of the swing member to a second member of the valve drive device. The cam surface comprises a first portion that is configured to contact the second member while the valve is moving from a closed or substantially closed position to an open position and a second portion configured to contact the second member when the valve is closed or substantially closed. A width of the second portion of the cam surface is smaller than a width of the first portion of the cam surface.
摘要:
There is provided a valve gear of an internal combustion engine, comprising a cam mechanism for converting rotational motion of an electric motor into linear motion to drive a valve for opening and closing a cylinder against a valve spring, and a torque reduction mechanism for adding an opposite torque, which serves so as to reduce a torque applied to the cam mechanism from the valve spring at the time of driving the valve, to the cam mechanism.
摘要:
The invention relates to a valve drive, in particular for internal combustion engines of motor vehicles, comprising at least one cam element (2) that is located on a driven shaft (1) and at least one lifting valve (10), which has a valve stem (11) and can be displaced by the cam element (2). The cam element (2) is pivotally mounted inside a flexible encapsulation element (4), which is connected to one end of the valve stem (11). The end of the valve stem (11) is guided in the displacement direction of the valve (10).