摘要:
A cylinder head includes a cylinder head body provided with intake and exhaust ports opened toward a combustion chamber and capable of being closed by valves, the intake and exhaust ports being separated from each other in a circumferential direction around a cylinder central axis. An opening section of at least one of the intake or exhaust ports facing the combustion chamber is provided with a seat surface centered on a valve axis and a tapered surface is disposed closer to the combustion chamber than the seat surface, the tapered surface gradually increasing in diameter closer to the combustion chamber. A central axis of the tapered surface is disposed eccentrically from the valve axis toward the cylinder central axis.
摘要:
A device for controlling at least one valve, the device comprising a body having a non-deformable cavity communicating exclusively with the outside via at least four rectilinear cylinders that are closed respectively by an opening piston (P1) actuated by an opening cam (C1), a closing piston (P2) actuated by a closing cam (C2), a shuttle piston (Pa) serving to load or unload the device, and a piston (Ps) that is mechanically connected to the valve. By adjusting the angular phase shift between the opening and closing cams (C1, C2), the control device of the invention makes it possible in operation to adjust the lift of the valve, the angular duration of the opening of the valve, and if necessary, to deactivate the valve completely throughout the duration of a cycle.
摘要:
Valve control for at least one valve of an internal combustion engine, in which the movement of at least one cam (2) of a camshaft (3) can be transmitted to a valve stem (5) of the valve (1) by a transmission mechanism (4), the transmission mechanism (4) including at least one transmission element (7) which is mounted rotatably on an axis (6) and is preferably designed as a rocker arm (10) or drag lever and which is connected to the camshaft (3) via a contact element (8) arranged on the transmission element (7), the contact surface (19) of the contact element (8) and the circumferential surface (20) of the cam (2) having, at least in regions, curved and mutually corresponding contours in the axial direction (21), and the transmission element (7) being mounted axially moveably on an axial body (11) of the axis (6).
摘要:
A variable valve lift apparatus may include a rocker arm coupled with a rocker arm shaft, a valve bridge disposed to be pressed by one end portion of the rocker arm, the valve bridge including a piston insertion hole and at least one pin insertion hole connecting to the piston insertion hole, a valve disposed to be pressed by the valve bridge, and a variable lift unit disposed in the valve bridge and variably controlling an amount that the rocker arm presses the valve bridge. The variable lift unit includes a variable piston of which the lower portion is inserted into the piston insertion hole, and a check pin disposed in the pin insertion hole to be selectively inserted into the pin groove formed on a side surface of the variable piston according to the hydraulic pressure supplied to the piston oil passage formed in the variable piston.
摘要:
A valve bridge assembly is disclosed for use with an internal combustion engine. The valve bridge assembly may have a valve bridge with a center portion, opposing lateral extensions, a central cavity formed within the center portion, and a bore formed within each of the opposing lateral extensions. The valve bridge assembly may also have a lash adjuster disposed within the central cavity, and a sleeve insert disposed within each bore of the opposing lateral extensions. Each sleeve insert may be configured to receive a corresponding valve stem.
摘要:
A system for actuating one or more engine valves comprises a lost motion assembly including locking elements to selectively lock and unlock a locking mechanism disposed within a valve train such that motions may be likewise selectively applied to, or prevented from being applied to, one or more engine valves. In an embodiment, the locking elements comprise wedges having at least one wedge inclined surface defined according to a cone frustum and configured to engage an outer recess formed in a housing, the outer recess comprising an outer recess inclined surface also defined according to the cone frustum. The device may comprise a locking mechanism disposed within a housing bore in the housing and a snubber also disposed in the housing bore. Furthermore, the outer recess may be configured to permit movement of the locking element along a longitudinal axis of the housing bore.
摘要:
A method of lubricating one or more valve train (100) components includes delivering a lubricating fluid to the inner cavity (156) of a fluid collecting member (152) through a radially extending discharge portion (182) of a fluid passage (176) in a rocker arm insert. The insert fluid passage (176) is in fluid communication with a lubricating fluid source to dispense a controlled amount of lubricating fluid to one or more valve train components during operation of an engine. The radially extending discharge portion of the fluid passage in the insert may be positioned adjacent to a spherical end cap that is received in the inner cavity of the fluid collecting member.
摘要:
A valve mechanism is disclosed for a cylinder of an internal combustion engine which comprises two gas exchange poppet valves mounted in a cylinder head, a bridge 122 acting on the two valves, a cam for actuating the two valves, a slider 124 movable by the cam and slidable relative to the bridge 122, and a hydraulically controlled locking system having a latched position in which the slider transmits the force of the cam to the bridge 122 to actuate the two valves and a released position in which the valves are deactivated and the slider slides freely relative to the bridge. In the invention, the slider 124 is urged towards the cam by a spring 134 acting between the slider 124 and the cylinder head.
摘要:
A multi-mode valve control mechanism for an engine includes a primary cam follower rotatably mounted within a mount and having one end engaging a camshaft. One or more secondary cam followers are rotatably mounted within the mount and having one end engaging the camshaft. Each secondary cam follower is operatively coupled to a shaft. A follower is dedicated to each cam lobe. A frequency and a duration at which valves in a valve train are actuated is changed by activating only the primary cam follower in a first mode of operation, or activating both the primary cam follower and the one more than one secondary cam followers in a second mode of operation, depending on whether the control mechanism has been activated or not. In either mode of operation, the entire valve train assembly is actuated.
摘要:
A supercharged internal combustion engine having at least two exhaust-gas turbochargers is provided. The engine includes a first exhaust manifold and a second exhaust manifold which are permanently connected to one another upstream of the two turbines of the turbochargers via at least one connecting duct which cannot be closed off. In this way, overflow of exhaust from the one exhaust manifold may be transferred to the other exhaust manifold.