Abstract:
A switchable cam follower (1) or a switchable support element of a valve train of an internal combustion engine, said cam follower or support element comprising an outer part (2) which is assembled together with an inner part (4) that is displaceable relative thereto in a direction of cam lift, said inner part (4) comprising, at a parting gap (5) to the outer part (2), two spaced apart or opposing openings (6, 7) for coupling means, each of said openings (6, 7) being aligned, at one cam position, to a further opening (10, 11) for coupling means in the outer part (2), the coupling means being configured and arranged so that, in a coupled state, each coupling means extends beyond the parting gap (5) on one coupling side (12, 13) while simultaneously extending in the opening (10, 6) of the outer and the inner part (2, 4) which in an uncoupled position of the coupling means (14, 15), an axial idle stroke of the coupling means (15) on the one coupling side (12) till coupling is achieved is large and the axial idle stroke of the coupling means (14) on the further coupling side (13) till coupling is achieved is small. In this way, a switchable cam follower (1) or a switchable support element is crated in which the manufacturing costs, the complexity and also the risk of faulty couplings are drastically reduced.
Abstract:
A rocker arm (6) that can be uncoupled from the cam lift, the axle (11) of this rocker arm (6) is guided for longitudinal movement in a slot (12) of a pedestal (13), and the rocker arm (6) can be coupled to the pedestal (13) by locking elements (20, 21, 22) or it can be uncoupled from the pedestal (13) by these locking elements (20, 21, 22) for achieving a zero lift of an associated gas exchange valve (9).
Abstract:
A hydraulic clearance compensation element free of prior art disadvantages and manifesting substantially higher sink values over a wide range of temperatures.
Abstract:
A valve actuating mechanism which can be set to three different strokes for a gas exchange valve includes a finger lever actuated by a control cam with a single lift curve, with the finger lever being selectively connectable to a longitudinal guide in the region of its bearing member via incorporation of a piston that is movable in various positions. In a first coupling position of the piston, the bearing member is fixed to the longitudinal guide so that the finger lever executes a maximum pivot during the lift phase of the cam. In a second coupling position of the piston the finger lever is moved axially along the longitudinal guide during a complete cam lift so that the opening cross section of the gas exchange valve is smaller than in the first coupling step. In a third coupling step of the piston, the finger lever executes an idle stroke-pivoting movement on its point of contact on the gas exchange valve which remains closed.
Abstract:
A cam follower (1) comprises an annular and a circular bottom portion (2, 3). The two bottom portions (2, 3) are concentric to each other, and a low lift cam (4) is arranged opposite the circular bottom portion (3) while at least one high lift cam (5) is arranged opposite the annular bottom portion (2). The cams (4, 5) are arranged out-of-phase with each other in circumferential direction. Since, therefore, when the cam follower (1) is coupled to the high lift cam (5), the low lift cam (4) would disadvantageously actuate the cam follower (1) with its excess lift, a means is provided in the cam follower for compensating this undesired lift.
Abstract:
A device for the simultaneous actuation of two gas exchange valves (10) of an internal combustion engine by a camshaft (11) rotatably supported in a camshaft bearing (15,16), said device comprising a bridge (3) which, with the interposition of hydraulic valve clearance compensation elements (7), is in contact with valve shaft ends (9) of the gas exchange valves (10), and a guide rail (2) on which the bridge (3) is guided for longitudinal displacement by a linear bearing (5), said guide rail (2) comprising a first oil duct (18) which opens into the linear bearing (5) and a second oil duct (22) implemented in the bridge (3), which connects the valve clearance compensation elements (7) to the linear bearing (5), and the oil passes phase-wise from the first oil duct (18) into the second oil duct (22), characterized in that a third oil duct (21) branches from the first oil duct (18) and opens into the camshaft bearing (15,16).
Abstract:
A mechanical valve tappet arranged in a guide bore of a cylinder head of an internal combustion engine, which valve tappet comprises a cup-shaped housing with a hollow cylindrical wall (1) closed at one end by a bottom (2) against which a control cam runs from the outside while an adjusting element (5) bears against the inner surface of the bottom by a first flat end face and is in contact with the end of a valve stem of a two-way gas valve by a second end face which is parallel to said first end face, characterized in that the adjusting element (5) is a solid component with a cylindrical outer peripheral surface and parallel end faces, projections being provided on the cup-shaped housing to cooperate with the cylindrical outer peripheral surface of the adjusting element so that the adjusting element (5) is retained by interlocking or by force engagement on the cup-shaped housing.
Abstract:
A self-adjusting hydraulic valve tappet arranged in a guide bore of a cylinder head of an internal combustion engine and comprising a cup-shaped housing which surrounds a hollow cylindrical wall which is closed at one end by a bottom against which a control cam bears on the outside, the housing comprising a cylindrical guide sleeve which is concentric with the hollow cylindrical wall and which at its end facing away from the bottom opens into the center of a disc member which at its outer periphery merges into the hollow cylindrical wall of the housing, the actual hydraulic clearance compensation element being guided longitudinally displaceably in the guide sleeve and an annular oil reservoir being defined by the hollow cylindrical wall, the cylindrical guide sleeve, the bottom and the disc member and supplied with oil from the lubricating oil circuit of the internal combustion engine via a bore arranged in the hollow cylindrical wall, the annular oil reservoir being provided with an air vent bore in one of its delimiting walls, characterized in that at one point of a wall delimiting the oil reservoir and which is in sliding contact with an adjacent structural component at least during the phase in which the base circle of the control cam bears against the bottom of the valve tappet, a bore is provided which opens into the sliding gap defined by these components.
Abstract:
An outer guide means for a valve tappet receiving an automatic, hydraulic earance compensation element of use in internal combustion engines, the tappet being disposed directly between a cam of a camshaft and a valve stem, the guide means comprising a wear-resistant end member co-operating with the cam, a hollow cylindrical stem part made of an extrudable polymeric substance and closed at one end by the end member and sliding in a guide bore in a cylinder head, and means coaxially disposed in the stem part thereof and adapted to receive the clearance compensation element, characterized in that a thin-walled unitary reinforcing element (10, 22, 41) is provided which is drawn from sheet metal and which, on the one hand, is secured to the end member (8, 26, 42) and, on the other hand, is positively connected to the stem part (9, 32, 36).
Abstract:
A ball-and-socket joint interposed between a rocker arm and a valve shaft of an internal combustion engine including a journal cooperating with the rocker arm and having a crowned end face which cooperates with a spherical cavity of a joint socket provided at its side opposing the spherical cavity with a plane surface by which it bears against the valve shaft wherein a restraining element is linked to the journal or to a structural element connected to the journal for grasping from behind the circumferential surface of the joint socket thereby securely holding the latter at the journal, characterized in that the restraining element is a spring element (10,19) which bears by elastic prestress against the joint socket (7) thereby holding the crowned end face (5) of the journal (4) in play free contact with the spherical cavity (6).