摘要:
A hydraulic valve lash adjuster for a valve train of an internal combustion engine, for example for an automotive vehicle, said hydraulic valve lash adjuster comprising a piston (2) that is guided for displacement in a piston housing (4) and elastically supported against said housing, said piston (2) comprising a low pressure chamber (3) that communicates via an axial opening (26) in a piston bottom (19) with a high pressure chamber (5) defined by the piston housing (4) and the piston (2), and further comprising a control valve (6) acting between said pressure chambers (3, 5), said control valve (6) comprising a valve closing body (7) that can be brought to bear sealingly against a valve seat (24) that surrounds the axial opening (26) on a piston body undersurface (28) and is received in a closing body cap (9) whose cap bottom (21) acts as a stroke limitation of the valve closing body (7), and said control valve (6) further comprising a control valve spring (8) that loads the valve closing body (7) in opening direction, and, during a collapsing movement between the piston (2) and the piston housing (4), said valve closing body (7) being hydraulically loadable in closing direction against the biasing force of the control valve spring (8) by a pressure build-up in the high pressure chamber (5).To improve the valve lash adjuster so that undesired operational fluctuations are reduced, the valve closing body (7) is configured as a needle-shaped, elongate sealing piston whose valve seat-proximate end comprises a plate-shaped sealing surface (10) that cooperates with a correspondingly configured sealing surface (25) of the valve seat (24) and whose valve seat-distal end comprises a surface of application (12) for hydraulic loading, and the valve closing body (7) substantially fills a space volume of the closing body cap (9) surrounding the valve closing body (7).
摘要:
A hydraulic valve lash adjuster with idle stroke function for a valve train of an internal combustion engine, said hydraulic valve lash adjuster comprising a piston (2, 2′, 2″) that is guided for displacement in a piston housing (4) and elastically supported against said housing (4), said piston (2, 2′, 2″) comprising a low pressure chamber (3) that communicates via an axial opening (7) in a piston bottom (8) with a high pressure chamber (5) defined by the piston housing (4) and the piston (2, 2′, 2″), and further comprising a control valve (9, 9′, 9″, 9′″) acting between said pressure chambers (3, 5), said control valve (9, 9′, 9″, 9′″) comprising a valve closing body (10, 10′, 10″) that can be brought to bear sealingly against a valve seat (15, 15′) that surrounds the axial opening (7) on a piston body undersurface (18) and is received in an element (12, 12′) that limits a closing body stroke (17), and said control valve (9, 9′, 9″, 9′″) further comprising a control valve spring (11) that loads the valve closing body (10, 10′, 10″) with a spring force in opening direction, and an idle stroke being produced during a collapsing movement between the piston (2, 2′, 2″) and the piston housing (4) during which said valve closing body (10, 10′, 10″) is hydraulically loaded in closing direction against the action of the control valve spring (11) by a pressure build-up in the high pressure chamber (5), whereby a retarded pressure build-up can be obtained through a flow control device (23, 23′) arranged on a high pressure chamber-side and comprising a flow control element (24, 24′) and a medium pressure chamber (19) that extends between the flow control element (24, 24′) and the axial opening (7) of the piston (2).
摘要:
A hydraulic valve lash adjuster with idle stroke function for a valve train of an internal combustion engine, said hydraulic valve lash adjuster comprising a piston (2, 2′, 2″) that is guided for displacement in a piston housing (4) and elastically supported against said housing (4), said piston (2, 2′, 2″) comprising a low pressure chamber (3) that communicates via an axial opening (7) in a piston bottom (8) with a high pressure chamber (5) defined by the piston housing (4) and the piston (2, 2′, 2″), and further comprising a control valve (9, 9′, 9″, 9′″) acting between said pressure chambers (3, 5), said control valve (9, 9′, 9″, 9′″) comprising a valve closing body (10, 10′, 10″) that can be brought to bear sealingly against a valve seat (15, 15′) that surrounds the axial opening (7) on a piston body undersurface (18) and is received in an element (12, 12′) that limits a closing body stroke (17), and said control valve (9, 9′, 9″, 9′″) further comprising a control valve spring (11) that loads the valve closing body (10, 10′, 10″) with a spring force in opening direction, and an idle stroke being produced during a collapsing movement between the piston (2, 2′, 2″) and the piston housing (4) during which said valve closing body (10, 10′, 10″) is hydraulically loaded in closing direction against the action of the control valve spring (11) by a pressure build-up in the high pressure chamber (5), whereby a retarded pressure build-up can be obtained through a flow control device (23, 23′) arranged on a high pressure chamber-side and comprising a flow control element (24, 24′) and a medium pressure chamber (19) that extends between the flow control element (24, 24′) and the axial opening (7) of the piston (2).
摘要:
A four-stroke internal combustion engine, having a brake controller by which pressure is built up in the exhaust system and/or at least one exhaust valve is additionally opened is provided. A hydraulic valve clearance compensation element is incorporated in at least one transmission element between the camshaft and at least one intake and exhaust valve and has at least one piston (3), a cylinder housing part (2) that interacts with the piston (3), a return spring (16) disposed therebetween, a check valve (4), and an actuatable locking device is provided which limits the movement of the piston (3) relative to the cylinder housing part (2) and/or limits the movement of the cylinder housing part (2) relative to an exterior housing (1) connected to one of the transmission elements or relative to a transmission element at least in one direction of movement, and the piston (3) is supported on a stop element (5) connected to the exterior housing (1) or the transmission element.
摘要:
An internal combustion piston engine comprising at least one cylinder head, said cylinder head closing at least one cylinder, inlet and outlet channels of said cylinder head being regulated, each one, by at least one inlet and outlet valve that is loaded by a closing spring, said inlet and outlet valves being activated by roller tappets (1) driven by cams of a camshaft and, if appropriate, by further transmission elements, said roller tappets (1) comprising at ends oriented away from rollers (7) of the roller tappets, two flattened portions (2) that are arranged substantially parallel to each other while being operatively connected to two matching inner surfaces (9) of an anti-rotation bridge (10) made typically of plastic, a spacing dimension of said flattened portions (2) at least partially overlapping a distance between said inner surfaces (9) and, starting from a mounting position of the roller tappet (1) in the anti-rotation bridge (10), an adjustment between the flattened portions. (2) of the roller tappets (1) and the inner surfaces (9) of the anti-rotation bridge (10) is varied with a tendency to adjustment with lash in direction of an operating position of the roller tappet (1).
摘要:
The hydraulic play compensation device, having an outer cylinder part which is closed on one side by a base and in which a piston element which lies on its inside is guided so as to be longitudinally displaceable, with a guide gap, having an oil pressure space having an oil inlet which supplies the oil supply space, and having a connecting duct controlled by a nonreturn valve between the oil supply space and the oil pressure space. For optimized removal of air which is introduced via the oil inlet, it is proposed that a ventilation path which connects the oil supply space and the guide gap is formed in the piston element downstream of the oil inlet and upstream of the connecting duct.
摘要:
A switch element (1) is proposed for valve shut-off, fabricated as cam follower for a plunger rod valve drive of an internal combustion engine, having an outer part (2) and an inner element (4) axially movable in its bore (3) and with rotational security (15) relative to the guided inner element (4). The outer part (2), inside the bore (3), has an annular groove (6), and the inner element (4) has a radial bore (7) with two diametrically opposed pistons (8), which to couple the elements (2, 4) in their axially remote relative position achieved by a lost-motion spring (5) are displaceable towards the annular groove (6). On their cam-side under side, emanating from their radially outward, bulbous face, the pistons (8) segmentwise comprise a plane transverse surface as contact area for a facing under side (27) of the annular groove (6). The latter is intersected by two diametrically opposed oil ports (11) running offset 90° from the pistons (8) in circumferential direction. In addition, the outer part (2) has means (13) for rotationally secured guidance of the switch element (1) relative to a surrounding structure.
摘要:
The invention relates to a method of setting the ball travel of a valve-closing body, designed as valve ball (6), of a control valve (7) of a hydraulic valve-lash-adjusting element which has a plunger (1) with a plunger head (2) and a central bore (3) in the same, a valve seat (5) being provided at the outer end (4) of this central bore (3), this valve seat (5) being controlled by a valve ball (6), the ball travel of which is limited by a valve cap (8) which has a cap flange (9) and a cap base (11), the cap flange (9) resting with its bearing surface (10) on a base (17) of a recess (13) of the plunger head (2), and a stop (12) of the cap base (11) serving as a travel limit for the valve ball (6). The identical ball travel of the valve balls (6), which is so important for the operating behaviour of the internal combustion engine and for the wear and noise behaviour of its valve train, is achieved in that, after an internal depth dimension (a) of the valve cap (8) has been measured, this internal depth dimension (a) extending from the bearing surface (10) of the cap flange (9) up to the stop (12) of the cap base (11), and after a projecting dimension (b) of a measuring ball (16), lying in the valve seat (5), relative to the base (17) of the recess (13) has been measured, a calculated value of the ball travel (c=a−b) is determined, and in that, after that, a matched valve ball (6) having the ball diameter required for the desired ball travel is selected from a number of valve balls of different, known diameter and is fitted together with the measured plunger (1) and the measured valve cap (8). The measured actual values of the ball travel of the valve balls (6) can also be corrected by subsequently pressing the valve caps (8) in a controlled manner.
摘要:
The invention proposes a switching element (1) for a valve train of an internal combustion engine, particularly for valve deactivation, with a simple-to-implement measure for adjusting the coupling lash of its coupling means (8) in a receptacle (6) using two retaining rings (19, 20), one of which is stocked in a variety of thicknesses.
摘要:
An internal combustion piston engine based on a four-stroke process, including a crankcase in which at least one cylinder/piston assembly is arranged, the piston being guided by a connecting rod connected to a crankshaft. At least one cylinder head closes the cylinder, each of whose intake and exhaust channels are controlled by at least one intake valve and one exhaust valve (13, 13a). The intake and exhaust valves (13, 13a) are actuable by a rocker arm (5) or a finger lever driven by a camshaft (1) through intake and exhaust cams (2). The rocker arms or finger levers are guided on at least one axle (6). A brake control device is provided which includes, in the region of the base circle of the exhaust cam (2), at least one additional cam (1) for an additional opening of at least one of the exhaust valves (13, 13a). A control element (12, 12a) is installed between the rocker arm (5) or finger lever and the exhaust valve or valves (13, 13a), which control element (12, 12a) can be connected to the pressurized oil circulation system of the internal combustion piston engine and whose length can be varied, so that the additional cam (3) is active during a braking operation and inactive during a pure engine operation. The control element (12) is arranged in a bridge (11) that is associated with a plurality of exhaust valves (13, 13a).