Abstract: A hydraulics unit for an internal combustion engine with a hydraulically variable gas exchange valve gear, is provided that includes a hydraulic housing having a pressure chamber, a pressure relief chamber and a venting duct. The venting duct is connected, on a hydraulic housing inner side, to the pressure relief chamber via a restriction and opens on a hydraulic housing outer side. The venting duct has a siphon with a downward first duct section and an upward second duct section, respectively in the direction of gravity and in the venting direction. When a gas exchange valve is closed, a lowermost section of the siphon is below a boundary of a pressure chamber defined by a slave piston.

Abstract: A hydraulics unit for an internal combustion engine with a hydraulically variable gas exchange valve gear, is provided that includes a hydraulic housing having a pressure chamber, a pressure relief chamber and a venting duct. The venting duct is connected, on a hydraulic housing inner side, to the pressure relief chamber via a restriction and opens on a hydraulic housing outer side. The venting duct has a siphon with a downward first duct section and an upward second duct section, respectively in the direction of gravity and in the venting direction. When a gas exchange valve is closed, a lowermost section of the siphon is below a boundary of a pressure chamber defined by a slave piston.

Abstract: An internal combustion engine (4) having an electrohydraulic valve control (1) for the variable lift drive of a gas exchange valve (3) is provided. The hydraulic valve (15) is actuated by an electronic control module (16) such that a gas exchange valve stroke (19) required for a charge change is adjusted during the cold start phase of the internal combustion engine (4) within a minimum stroke height (h-min) and a maximum closing time (?-max). A method for operating the internal combustion engine (4) is also provided.

Abstract: An internal combustion engine (4) having an electrohydraulic valve control (1) for the variable lift drive of a gas exchange valve (3) is provided. The hydraulic valve (15) is actuated by an electronic control module (16) such that a gas exchange valve stroke (19) required for a charge change is adjusted during the cold start phase of the internal combustion engine (4) within a minimum stroke height (h-min) and a maximum closing time (?-max). A method for operating the internal combustion engine (4) is also provided.

Abstract: A switchable bucket tappet for a valve drive of an internal combustion engine, which has a bucket basic body with a ring-like base. A hollow-cylindrical projection protrudes from an inner edge of the base, and in the bore of the projection an inner body extends. Two coupler pistons lie opposite one another and, to achieve full valve stroke, engage in sections with a driver surface of the bucket basic body which run in a radial hole of the inner body. A zero valve stroke is achieved when the coupler piston is displaced completely into the radial hole of the inner body, which is baseless and free of contact with a cam. The projection has a window-like aperture, with the underside acting as the driver surface for an upper side of the coupler piston during coupling. The region of the base is an approximately symmetrical and continuously thin-walled formation.

Abstract: A hydraulic unit (5) is provided for a cylinder head (2) of an internal combustion engine with a hydraulically variable valve train (1). In the hydraulic unit, a high-pressure chamber (11), a medium-pressure chamber (12), and a low-pressure chamber (16) used as the hydraulic medium reservoir are formed. The low-pressure chamber communicates via a throttle point (17, 17?, 17?, 17??) with the medium-pressure chamber, and the throttle point is formed by a displaceable valve body (19, 19?, 19?, 19??) and has through-flow cross sections of different sizes according to a position of the valve body.

Abstract: The invention proposes a switchable tappet (1) of a valve train of an internal combustion engine, said tappet comprising a hollow cylindrical housing (3) comprising a bottom (2), an inner element (5) being guided for relative axial displacement in a bore (4) of the housing (3), an at least indirect support for a gas exchange valve extending on a cam-distal front end (6) of the inner element (5), two diametrically opposing pistons as coupling elements (8) being arranged in a radial bore (7) of the inner element (5), which coupling elements (8), for effecting coupling [full valve lift], can be displaced partly beyond a parting surface (9) between the housing (3) and the inner element (5) into an entraining surface (12) of the housing (3) by the force of a compression spring (10a) clamped between inner front ends (10) of the coupling elements (8), wherein the entraining surface (12) is an direct constituent of a separate annular member (13) that is fixed in a cam-distal region of the bore (4) of the housing (3),

Abstract: A hydraulic unit (5) is provided for a cylinder head (2) of an internal combustion engine with a hydraulically variable valve train (1). In the hydraulic unit, a high-pressure chamber (11), a medium-pressure chamber (12), and a low-pressure chamber (16) used as the hydraulic medium reservoir are formed. The low-pressure chamber communicates via a throttle point (17, 17?, 17?, 17??) with the medium-pressure chamber, and the throttle point is formed by a displaceable valve body (19, 19?, 19?, 19??) and has through-flow cross sections of different sizes according to a position of the valve body.

Abstract: A switchable bucket tappet for a valve drive of an internal combustion engine, which has a bucket basic body with a ring-like base. A hollow-cylindrical projection protrudes from an inner edge of the base, and in the bore of the projection an inner body extends. Two coupler pistons lie opposite one another and, to achieve a full valve stroke, engage in sections with a driver surface of the bucket basic body which run in a radial hole of the inner body. A zero valve stroke is achieved when the coupler piston is displaced completely into the radial hole of the inner body, which is baseless and free of contact with a cam. The projection has a window-like aperture, with the underside acting as the driver surface for an upper side of the coupler piston during coupling. The region of the base is an approximately symmetrical and continuously thin-walled formation.

Abstract: A force transmitting device (4) for a valve drive (1) of an internal combustion engine (2) with a hydraulic valve lash compensating device (6) is provided. The force transmitting device (4) has a hollow cylindrical compensating piston (13), which on one end defines a working chamber (35) of the valve lash compensating device (6) and on the other end encloses an internal hydraulic medium reservoir (15) used to supply the working chamber (35). This is connected to a hydraulic medium supply (16) of the internal combustion engine (2) and is protected from a return flow of hydraulic medium in the direction of the hydraulic medium supply (16) by means of a valve plate (26), which can be pressurized and which can move axially, in that the valve plate (26) interacts in a sealing way with an axial annular surface (28) of the compensating piston (13) for a non-pressurized hydraulic medium supply (16).

Abstract: The invention proposes a switchable tappet (1) of a valve train of an internal combustion engine, said tappet comprising a hollow cylindrical housing (3) comprising a bottom (2), an inner element (5) being guided for relative axial displacement in a bore (4) of the housing (3), an at least indirect support for a gas exchange valve extending on a cam-distal front end (6) of the inner element (5), two diametrically opposing pistons as coupling elements (8) being arranged in a radial bore (7) of the inner element (5), which coupling elements (8), for effecting coupling [full valve lift], can be displaced partly beyond a parting surface (9) between the housing (3) and the inner element (5) into an entraining surface (12) of the housing (3) by the force of a compression spring (10a) clamped between inner front ends (10) of the coupling elements (8), wherein the entraining surface (12) is an direct constituent of a separate annular member (13) that is fixed in a cam-distal region of the bore (4) of the housing (3),

Abstract: A force transmitting device (4) for a valve drive (1) of an internal combustion engine (2) with a hydraulic valve lash compensating device (6) is provided. The force transmitting device (4) has a hollow cylindrical compensating piston (13), which on one end defines a working chamber (35) of the valve lash compensating device (6) and on the other end encloses an internal hydraulic medium reservoir (15) used to supply the working chamber (35). This is connected to a hydraulic medium supply (16) of the internal combustion engine (2) and is protected from a return flow of hydraulic medium in the direction of the hydraulic medium supply (16) by means of a valve plate (26), which can be pressurized and which can move axially, in that the valve plate (26) interacts in a sealing way with an axial annular surface (28) of the compensating piston (13) for a non-pressurized hydraulic medium supply (16).

Abstract: A hydraulic system (1) for a switchable valve drive element (10) of an internal combustion engine (33) is provided and includes a throttled connection (13) created from a second channel (9), used to actuate a hydraulic play-compensation element (11) using hydraulic fluid, directly to an external radial side (12) of a coupling element (8). The coupling element (8) is supplied by a first channel (7) with the switching hydraulic pressure. These measures make it possible to keep the first channel (7) as free as possible of undesired air.

Abstract: A hydraulic system (1) for a switchable valve drive element (10) of an internal combustion engine (33) is provided and includes a throttled connection (13) created from a second channel (9), used to actuate a hydraulic play-compensation element (11) using hydraulic fluid, directly to an external radial side (12) of a coupling element (8). The coupling element (8) is supplied by a first channel (7) with the switching hydraulic pressure. These measures make it possible to keep the first channel (7) as free as possible of undesired air.