Abstract:
Vorgeschlagen ist ein schaltbarer Schlepphebel (1) eines Ventiltriebs einer Brennkraftmaschine, mit einem Außen- und einem zwischen dessen Seitenwänden (2) angeordneten Innenhebel (3, 4). Zwischen Armen (7) des Innenhebels (4) verläuft eine auf einem "fliegend" gelagerten Bolzen (5) angeordnete Rolle als Gegenlauffläche (6) für einen Hubnocken. Die Hebel (3, 4) sind an einem Ende (9) auf einer gemeinsamen Achse (12a) angeordnet. Am abgewandten Ende (11) haben sie sich längs erstreckende, im Nockengrundkreis zueinander fluchtende Aufnahmen (13, 14). In der Aufnahme (13) des Außenhebels (3) ist ein Koppelmittel (15) angeordnet, das für eine Kopplung abschnittsweise in die Aufnahme (14) (hier Mitnehmerfläche) des Innenhebels (4) verlagerbar ist. Der Bolzen (5) im Innenhebel (4) steht mit je einem Ansatz (15a) geringfügig über die Arme (7) des Innenhebels (4) hinaus, wobei im Koppelfall Oberseiten (16) der Ansätze (15) an Unterseiten (17) von Anschlagflächen (18) anliegen, die an Innenflächen (19) der Seitenwände (2) des Außenhebels (3) appliziert sind.
Abstract:
The invention relates to an apparatus for achieving internal EGR in a four-stroke internal combustion engine which, for each cylinder, has at least one inlet valve and at least one exhaust valve (10) for controlling the connection between combustion chambers in the cylinder and an inlet system and exhaust system respectively. A rotary camshaft (18) with a cam curve (22) is designed to interact with a follower member and has a first lobe portion for generating the normal exhaust valve lift of the engine. The camshaft is provided with a second lobe portion, which has a height measurement over and above its basic curve which falls short of the measurement for normal exhaust valve clearance when driving at low load and accompanying low heat development in the engine. As a result of thermal expansion in the valve mechanism, the height measurement exceeds the measurement for normal exhaust valve clearance when driving at high load and accompanying high heat development in the engine. The second lobe portion is situated within a crankshaft angular range of about 360-480 degrees.
Abstract:
Systems and methods for actuating engine valves are disclosed. The systems may include primary and auxiliary rocker arms disposed adjacent to each other on a rocker arm shaft. A rocker arm coupling assembly may be disposed between the auxiliary rocker arm and the primary rocker arm. The coupling assembly may include a piston having a curved surface disposed in a bore formed in the primary rocker arm, and a slot having a second radius of curvature formed in the auxiliary rocker arm. The piston may be selectively hydraulically locked into an extended position between the primary and auxiliary rocker arms so as to selectively transfer one or more auxiliary valve actuation motions from the auxiliary rocker arm to the primary rocker arm.
Abstract:
In order to produce a variable valve lift device for the lift adjustment of the gas-exchange valves of an internal combustion engine, by means of which with adjustment forces and holding forces, independently from whether said holding forces and adjustment forces are applied mechanically, hydraulically or electrically, with an adjustment of the valve lift being as cost-effective as possible, and with maximum accuracy of the adjustment or control of the valve lift to be taken between the individual cylinders of a multi-cylinder internal combustion engine, and, moreover, the adjustment possibility of the valve lift of the valves of an internal combustion engine with several cylinders is obtained within smallest tolerances, it is suggested that a valve lift device (1) has a rotatable eccentric shaft (3), which consists of several eccentrics (4, 5) and whereby all possible contours of the eccentrics (4, 5) are positioned within a circle, which is formed by means of the external diameters of a bearing (6, 7) of the eccentric shaft (3).
Abstract:
A cylinder operation control apparatus includes: an internal combustion engine (E) which is adapted to operate in an all-cylinder activation mode and in a cylinder deactivation mode; a lift amount changing device (VT) which is associated with the internal combustion engine (E), and which enables switching between the all-cylinder activation mode and the cylinder deactivation mode by changing the amount of lifts of intake and exhaust valves (IV, EV) associated with the cylinders; a lift operating device (33) which is associated with the lift amount changing device (VT) to operate the same; a cylinder activation enforcing device (33') which is operatively disposed between the lift amount changing device (VT) and the lift operating device (33) so as to enforce the all-cylinder activation mode as necessary.
Abstract:
Lost motion systems and methods for providing engine valves with variable valve actuation for engine valve events are disclosed. The system may include a master piston hydraulically linked to a slave piston, and a dedicated cam operatively connected to the master piston. The slave piston may be disposed substantially perpendicular to the master piston in a common housing. The slave piston is adapted to actuate one or more engine valves. The slave piston may incorporate an optical valve seating assembly into its upper end. A trigger valve may be operatively connected to the master-slave hydraulic circuit to selectively release and add hydraulic fluid to the circuit.
Abstract:
An adjustable valve gear of an internal combustion engine capable of continuously changing the opened lift amounts and opened operating angles of valves by a three-dimensional cam, wherein the three-dimensional cam (48) converts the cam lift and operating angle of the three-dimensional cam (48) into the opened lift amounts and opened operating angles of the valves (52) and (53) through a cam follower (49) moved within a specified width and rotated in contact with the three-dimensional cam (48) and a sliding holder (51) in contact with the lower surface of the cam follower (49), the cam follower (49) is swingably and rotatably held on the sliding holder (5) since the spherical projected part (64) thereof provided on the lower side is inserted into the center recessed part (66) of the sliding holder (51), and the cam follower (49) is rotated and swung on the cam surface of the three-dimensional cam (48) and a projected surface (62) through lubricating oil, whereby the friction and wear of the valve gear can be reduced, a high speed rotation can be performed with a simple structure, and a low fuel consumption and high torque can be achieved by a variable intake by the valves.