Abstract:
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.
Abstract:
A lifter assembly for an internal combustion engine, including an elongate sleeve having an upper radial wall portion provided with oil feed and oil bleed holes through which oil respectively enters and exits the lifter assembly. An elongate, hollow lifter body closed at one end is reciprocatingly disposed within the sleeve, and has a plunger reciprocatingly disposed therein. The plunger has an internal cavity at least partially defining a low pressure oil reservoir which is in at least periodic fluid communication with the oil feed hole. A high pressure oil reservoir is at least partially defined by the plunger and the lifter body closed end, and is in one-way fluid communication with the low pressure oil reservoir. A cap is reciprocatingly disposed within the sleeve and engaged with the plunger. Seals are provided which preclude oil from exiting the lifter assembly through the ends of the sleeve.
Abstract:
Hydraulic engine valve lifter includes a pair of pistons defining a pressure chamber therebetween and a separate lash adjusting piston which defines a lash adjustment chamber with one of the pistons in the pair. One-way valve structures permit fluid to flow from the pressure chamber into the lash adjustment chamber thereby displacing the lash adjusting piston to, in turn, adjust valve lash. Motion damping functions during a downstroke of the lifter pistons are also provided by a valve damper chamber and fluid passageways between the pressure and damper chambers. Structure is provided which opens communication between the pressure and damper chambers during upstroke of the lifter pistons (thereby precluding motion damping) and then closes communication at a predetermined location during downstroke (thereby providing motion damping).
Abstract:
A hydraulic lash adjuster has a generally cylindrical, hollow body having a closed end, an open end and a top land at the open end. A plunger is positioned in the body and is held in place by a retainer. The retainer is fastened to the exterior of the body. The retainer has a rim supported on the top land of the body and is held in place by tabs which are folded under into grooves in the side of the body.
Abstract:
A device for actuating valves in an internal combustion engine comprise four valves (9, 10, 11, 12) inclined in a V configuration and a central spark plug (3) per cylinder (6), each cylinder (6) being associated with two pairs of valves (9, 10; 11, 12) inclined on each side of an axial plane (PP) of the cylinder (6), while a spark plug pit (4) is provided between the two valves (9, 10) of one of the pairs, roughly parallel to the latter, this device comprising a central camshaft (13) located in the vicinity of the axial plane (PP) and, for each cylinder (6), at least two rockers (14, 15). There is interposed between each rocker (14, 15) and the camshaft (13) a pushrod (21) parallel to the cylinder (6), and, for each cylinder, the pin (18) of the rocker(s) disposed on the same side as the pit (4) is carried, as the other pin (19), by two bearings (26) located on each side of the rockers (14, 15) and is disposed between the pit (4) and the axial plane (PP). This device is of small overall size and particularly reliable.
Abstract:
A hydraulic lash adjusting tappet for an internal combustion engine of the type supplying oil to a passage communicating with the tappet-receiving guide bore in the engine. The tappet has a roller follower on the cam end and a registration means adjacent the opposite end for orienting the roller with respect to the engine cam. The tappet body has at least one localized collector recess disposed longitudinally coincident and peripherally spaced with the registration means. In one embodiment the registration comprises a pair of oppositely disposed flats and the tappet has a pair of diametrically opposed collector recesses interconnected by a peripheral groove spaced longitudinally therefrom to by-pass the flats and provide sufficient surface for leakage control. An oil inlet hole is formed in one of the collector recesses for supplying the lash adjuster valve in the tappet. The localized recess is aligned with the engine supply passage by the orientation of the registration surface.
Abstract:
A hydraulic lifter has an upper plunger member and a lower plunger member slidably received in a bore of a casing. A reservoir chamber is formed in the upper and lower plunger members for receiving hydraulic fluid, and a pressure chamber is formed between a blind bottom end of the casing and the bottom of the lower plunger. Both chambers are fluidly connected through a check valve. In order to vent air in the reservoir chamber and thereby to prevent air from entering the pressure chamber, there is formed in the upper plunger member at least one air vent hole located above a fluid inlet of the reservoir chamber. There is further formed a fluid passage between the upper plunger and the lower plunger for allowing fluid in the clearance between the casing and the plunger members to return to the reservoir chamber. This fluid passage may comprises a plurality of radially extending grooves formed either in the face of the bottom end of the upper plunger or in the face of the top end of the lower plunger.
Abstract:
A hydraulic tappet is used in a variable valve lift engine. The tappet comprises an outer case having a pressure chamber formed therein, an inner case having an oil chamber formed therein and engaged within the outer case, and a check valve disposed between the pressure chamber and the oil chamber. The pressure chamber is communicated with an electromagnetic valve via an additional check valve. The electromagnetic valve is actuated in accordance with changes in operating conditions of an engine, i.e. the engine load and the temperature of the engine, so that the oil pressure between the additional check valve and the electromagnetic valve is maintained at a predetermined level. As a result, the valve lift of the engine can be varied at an optimum level in accordance with changes in the operating conditions of the engine.
Abstract:
A hydraulic valve gear includes a novel rocker arm and support structure and lubrication means therefor. The rocker arm is mounted for oscillating motion in the plane defined by the axes of the valve stem and hydraulic valve lifter only, which permits the use of a simple, reliable and inexpensive lubrication system for the valve gear.