Abstract:
An hydraulic valve clearance compensation element comprising a housing in which a pressure piston is guided and a pressure space is disposed behind the pressure piston, an oil inlet chamber with an oil inlet opening to supply oil to the pressure space, characterized in that the pressure space (13) and guide means (5) for the pressure piston (6,7) is formed by the base (1), the oil inlet chamber (23) is provided between the base (1) and a housing sleeve (18) which is arranged concentrically at the piston side of the base (1) and the oil inlet opening (26) is provided on the housing sleeve (18).
Abstract:
A hydraulic valve clearance compensation element comprising a hydraulic censation element (2) in a bore of a rocker arm (1) or similar actuating mechanism extending coaxially from a stem (4) of an engine valve, a longitudinally moveable, adjusting piston (3) ending towards the valve stem (4) in a spherical projection (5) and between said projection and the end face (6) of the valve stem (4) a guide shoe (7,14) is arranged, comprising, on the one hand, a spherical cavity (8) which engages the spherical projection (5) of the adjusting piston (3) and, on the other hand, being supported with a plane surface (9) on the end face (6) of the valve stem (4), characterized in that, on the adjusting piston (3), a cage portion (11) emanates from a location situated behind the spherical projection (5), and extends in the direction of the valve stem (4) and ends there in radially inwardly directed locating zones (13), which engage behind an outer surface (15) of the guide shoe (7,14) and projections (10), respectively, of this surface so that the guide shoe is securely held onto adjusting piston (3) while being angularly freely moveable to said piston.
Abstract:
A novel inner element for a hydraulic valve play compensation element for ternal combustion engines is comprised of a cylindrical element (3) closed at one end and having a reduced outer diameter (7) and a peripheral groove (8) therein at the other open end and a piston element (5) guided therein for longitudinal displacement and projecting from the open end of cylindrical element (3) beyond the latter with a reduced outer diameter (6) in this region, a sheet metal cap (9) with a radial flange (10) engaging the reduced diameter (6) region of piston element (5) and with a cylindrical collar (13) on the open end of cylindrical element (3) engaging on at least some points of its circumference with groove (8), characterized in that sheet metal cap (9) has at least one projection (11,14,15) radially projecting at at least one point about its circumference beyond the outer diameter of cylindrical element (3).
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:
A tappet (1) with a hydraulic clearance compensation element (7), a positive opening of a one-way valve (15) being effected during a base circle region &agr; of the contacting cam (5) whereby a closing member (16) of the one-way valve (15) is loaded by an adjusting element (21), the adjusting element (21) extends through a bottom (3) of the tappet (1) and cooperates with a groove (22) on the outer peripheral surface (23) of the cam (5), the groove (22) extends over the entire periphery of the cam (5) with the exception of its base circle region so that when the base circle region &agr; comes to be situated opposite the bottom (3), a positive opening of the closing member (16) is effected whereby no undesired relieving of the gas exchange valve actuated by the tappet (1) nor its opening due to a transmission of undesired opening movements from the cam (5) to the clearance compensation element (7) can occur in the base circle region &agr; of the cam (5).
Abstract:
A hydraulic clearance compensation element actuated by a cam of a camshaft and adapted for use with a valve drive, includes a casing closed on one end by a bottom which bears upon one end of a gas exchange valve, a pressure piston so received in the interior of the casing that a leakage gap for hydraulic fluid is formed between an outer surface area of the pressure piston and an adjacent side wall of the casing for enabling the clearance compensating function. The pressure piston and the casing are movable relative to one another in axial direction, with a high pressure chamber being defined between the bottom and a confronting end face of the pressure piston for receiving a hydraulic fluid. In order to provide the leakage gap of optimum size over the entire temperature range adjacent structural components of the pressure piston and the casing in the area of the leakage gap are configured in accordance with the following equation: ##EQU1## wherein C is a characteristic ratio number,S is the width of the leakage gap,.epsilon.' is the quotient of the thermal expansion coefficient .epsilon..sub.D of the pressure piston to the thermal expansion coefficient .epsilon..sub.G of the casing,
Abstract:
A valve tappet actuated by a cam of an internal combustion engine comprises a cup (1) having a hollow cylindrical skirt (2) and a cup bottom (3) which closes the skirt (2) at one end. On an outer surface, the skirt (2) comprises a peripheral groove (4), and on an inner surface, at least one bead (5). Concentrically arranged within the cup (1) is an inner element (6) whose casing (9) bears against the bead (5, 21). A hydraulic valve clearance compensation element (10) is guided for axial displacement in the inner element (6). To simplify the manufacturing of this valve tappet, it is proposed that the cup (1) is hardened in a heat treatment process, and the inner element (5) is unhardened.
Abstract:
The outer peripheral surface of the housing (2) of a support element (1) for a finger lever of a valve drive of an internal combustion engine comprises a serration toothing (13) which is pressed into a reception bore (4) of a cylinder head (5) during mounting. During pressing-in, material is sheared off the tooth tips and displaced wholly or partly into the gaps between the teeth towards the root of the toothing. In this way, the clearance compensation element (1) is retained secure against rotation in the reception bore (4).
Abstract:
In a valve drive (1) for the simultaneous actuation of, for instance, three equally acting gas exchange valves (2), longitudinal axes of the gas exchange valves (2) are arranged so as to include an angle therebetween wherein a bridge (4) is arranged between the cams of a camshaft (3) and the gas exchange valves (2), and the longitudinal axis (9) of the guide means (5) of the bridge (4) extends parallel to a bisectrix (10) between the longitudinal axes of the gas exchange valves (2a, 2b).
Abstract:
A tappet (1) is to be engageable on to at least three different cam profiles with an optional zero lift. To this end the tappet (1) consists of an annular base section (2) enclosing a circular base section (3). Both base sections (2, 3) can be coupled together via radially adjustable coupling devices (10). An additional, axially movable inner piston (18) is fitted in a guide sleeve (7) of the circular base section (3). The inner piston (18) can be decoupled via further coupling means (23) so that the tappet (1) can be completely decoupled from the guide sleeve (7).