Abstract: A method and a device for setting the valve lash to a desired value at I.C. engines, including application of a motor driven coaxial double spindle (22) on each valve adjusting screw (18) and lock nut (19) followed by a number of consecutive operation steps comprising: tightening the adjuster screw (18) of each valve (11;111) to a snug torque level (Ts) , open the valve (11;111) by tightening the adjuster screw (18) through a predetermined angle while checking the torque magnitude required therefor, reverse the adjuster screw (18) through an angle exceeding the previous predetermined angle, re-tighten the adjuster screw (18) to the snug torque level (Ts), reverse the adjuster screw (18) through an angular interval corresponding to the desired valve lash, and tighten the lock nut (19) while holding the adjuster screw (18) stationary.

Abstract: In an internal combustion engine comprising an hydraulic system for the variable driving of valves, one tappet comprises two separate piston sections that are connected to two distinct pressure chambers, which control the driving pistons of two separate valves of the same engine cylinder.

Abstract: What is proposed is a switchable tappet (1) for the direct transmission of a cam lift to a tappet push rod. The tappet (1) comprises a hydraulic clearance compensation element (31) and has an excellent hydraulic rigidity compared to the prior art. This is achieved by a leak gap positioned radially very far outwards. This leak gap is situated directly between a housing (2) and a pressure piston (4) which, in its turn, encloses an inner element (11) that acts on a tappet push rod.

Abstract: In an internal-combustion engine with a hydraulic system for variable operation of the valves, the tappet actuated by each cam of the camshaft is slidably mounted in a tubular body which is made of a single piece with a bushing for guiding the valve-actuating piston.

Abstract: In an internal-combustion engine with a hydraulic system for variable operation of the valves, associated to the tappet controlled by each cam of the cam shaft is a passage for bleeding the hydraulic system.

Abstract: In a valve train (1) of an internal combustion engine (10), a tappet push rod (2) comprises on its first end (3), a tappet (5) and an uncoupling device (8) made as a single component, and on its second end (4), a hydraulic lash adjuster (15) that acts on a rocker arm. Due to this spatial separation of the lash adjuster (15) from the single component (5, 8), a component (5, 8) is obtained that has a reduced mass and a smaller diameter as well as a relatively simple structure. In addition, the lash adjuster (15) can now be supplied with hydraulic medium directly out of the rocker arm.

Abstract: Valve clearance adjusting shims in an internal combustion engine having an overhead cam, are removed and replaced by compressing a valve spring through a cam follower forcibly held against the spring pressure by a valve clearance tool. A method for relieving pressure against the valve spring and for replacing the valve clearance adjusting shims is described.

Abstract: A hydraulic lash adjuster includes a leak down land and a support land that are substantially cylindrical. The support land is substantially coaxial relative to the leak down land, and at least a portion of the support land is disposed radially opposite the leak down land.

Abstract: The invention relates to a variable valve train (1) for a cam-actuated lifting valve (13) of an internal combustion engine, which valve (13) is loaded by a closing spring (13a) acting against the direction of opening, with an approximately cylindrical force application element (2) located between a cam (14) and the valve (13), whose length can be adjusted hydraulically and whose exterior cylindrical wall face (3) is slidable in a fixed guide cylinder (4), said element (2) being provided with a pressure piston (6) longitudinally slidable in a cylinder (5), which piston (6) is adjacent to a pressure chamber (7) into which opens a pressure channel (8) departing from a port (9) in the wall face (3) of the force application element (2), a fixed pressure line (11) opening into the guide cylinder (4) in the area of the port (9), which line (11) can be subjected to hydraulic high pressure (pH) permitting hydraulic activation of the valve (13).

Abstract: The invention proposes a switchable support element (1) requiring only a small design space. For this purpose, a slide (12) that serves to couple an inner element (6) to an outer housing (3) in the support element (1) is positioned laterally in a housing (2) arranged in the cylinder head (5). At the same time, a bore (8) in the inner element (6) for the slide (12) is made as a pocket bore, the housing (2) being seated through an annular extension (11) directly in a bore (9) of the outer housing (3). The slide (12) can be displaced electromagnetically or hydraulically in at least one direction.

Abstract: A switchable, hydraulic support element (1) requiring only a small design space is proposed. For achieving this, a bore (16) for a slide (23) is arranged laterally of a pressure piston (10) of a hydraulic clearance compensation element (11) in the inner element (7) and is configured as a pocket bore. This dispenses with the stacked arrangement of the bore in the inner element and the clearance compensation element on top of each other as seen in prior art. At the same time, the slide (23) is installed in a housing (19) that extends in the cylinder head (5).

Abstract: In a device for operating a gas exchange valve of an internal combustion engine having an electromagnetic actuator including a valve opening magnet and a valve closing magnet, between which there is arranged an armature which, together with an opening spring, engages a valve stem against the force of a closing spring, and a hydraulic play-compensating element is arranged in the valve operating force transmission structure, the hydraulic play-compensating element is installed in the transmission structure together with a mechanical adjusting element providing for minimal valve play when the engine is shut down.

Abstract: An electromagnetic actuator for the actuation of the intake or exhaust valves of an internal combustion engine, in which an oscillating arm has a first end hinged on a support frame secured to the head of the engine and a second end in abutment on the upper end of the stem of the intake or exhaust valve; two electromagnets being provided in order to move, on command, the oscillating arm so as axially to displace this valve between a closed position and a position of maximum opening; the frame being connected to the head of the engine so as to be able to oscillate about an axis of rotation perpendicular to the axis of movement of the intake or exhaust valve and the electromagnetic actuator further being provided with a device for adjusting the position of the frame with respect to the head, which is adapted to rotate, on command, the frame about the axis of rotation so as to maintain the mechanical play between the second end of the oscillating arm and the upper end of the stem of the valve at a predetermined

Abstract: A method for setting clearance between a tappet screw and a valve wherein the movement of the valve during opening and closing is monitored and used to calculate further linear movement of the tappet screw to provide a desired tappet clearance. In one embodiment, a predetermined imaginary zero point, which falls in a band of linear displacement during closing of the valve, is used to determine a distance the tappet screw must be further moved to provide the desired tappet clearance. In another embodiment, plural valve displacement measurements are taken and the true zero point or valve closed position, and further movement of the tappet screw to provide the desired tappet clearance is determined based upon these plural measurements. In a further embodiment, movement of the valve head is directly monitored and used to set the tappet clearance.