Abstract:
A switchable support element (1) for a valve train of an internal combustion engine, said switchable support element (1) comprising a housing (2) that can be arranged with an outer peripheral wall (3) in a reception of the internal combustion engine, an axially displaceable pressure piston (5) extending in a bore (4) of the housing (2), said pressure piston (5) being loaded by a lost motion spring means (6) in a direction leading out of the housing (2), a head (7) of the pressure piston (5) extending beyond an edge (8) of the housing (2), and at least one coupling piston (10) extending in a cross-bore (9) of the pressure piston (5), which coupling piston (10) can be brought partially into engagement with an entraining surface (11) of the housing (2) for achieving coupling, wherein, starting from an outer front end (12) of the at least one coupling piston (10), a flattened portion (14) is arranged on an underside (13) of the coupling piston (10), the entraining surface (11) in the housing (2) per coupling piston (10) is constituted by an underside (15) of a window-like aperture (16) in the bore (4) of the housing (2), on which underside (15) the at least one coupling piston (10) can be displaced with said flattened portion (14) for achieving coupling, and the pressure piston (5) comprises an anti-rotation device (17) relative to the housing (2), while the at least one coupling piston (10) comprises an anti-rotation device (18) relative to the cross-bore (9).
Abstract:
A switchable support element for a valve train of an internal combustion engine, comprising a housing that can be arranged with an outer peripheral wall in a reception of the internal combustion engine, an axially displaceable pressure piston extending in a bore of the housing, said pressure piston being loaded by a lost motion spring means in a direction leading out of the housing, a head of the pressure piston extending beyond an edge of the housing, and at least one coupling piston extending in a cross-bore of the pressure piston, which can be brought partially into engagement with an entraining surface of the housing for achieving coupling, wherein, starting from an outer front end of the at least one coupling piston, a flattened portion is arranged on an underside of the coupling piston wherein a flattened portion is arranged on an underside of the coupling piston, the entraining surface in the housing per coupling piston is constituted by an underside of a window-like aperture in the bore of the housing, on which underside the at least one coupling piston can be displaced with said flattened portion for achieving coupling, and the pressure piston comprises an anti-rotation device relative to the housing, while the at least one coupling piston comprises an anti-rotation device relative to the cross-bore.
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), wherein only one compression spring as a lost motion spring means (16) extends in a cylindrical hollow space (15) formed between an underside (14) of the bottom (2) of the housing (3) and a cam-side flat front end (14a) of the inner element (5), and wherein the inner element (5) is substantially disk-shaped and the parting surface (9) between the housing (3) and the inner element (5) does not comprise any vertical stop means.
Abstract:
The invention proposes a tappet (1) in a valve train of an internal combustion engine having a bottom camshaft for acting on a tappet push rod, said tappet being arranged with a housing (2) for axial displacement, but secured against rotation, in a guide bore (3) of the internal combustion engine (3a) or of a component connected to the internal combustion engine, said housing (2) comprising on one front end (4), two cheek-like extensions (5) that are situated diametrically opposite each other and are connected by an axle (6) on which a rotary roller (7) extends for making direct contact with a cam, said front end (4) comprising a transverse region (8) that connects the extensions (5) axially inside and has a cylindrical shape in a length direction of the roller (7), and said guide bore (3) being intersected by two passages (12, 13) for routing hydraulic medium to the tappet (1), wherein a radius center point (M) of the transverse region (8) of the one front end (4) is situated with a lateral offset to a longitudinal axis of the tappet (1), so that one side (14) of a periphery of the housing (2) between the extensions (5) is distinctly longer than an opposite side (15), and the two passages (12, 13) are led to the housing (2) at least approximately on the longer one side (14) of the periphery.
Abstract:
A switchable tappet for directly transmitting a cam lift onto a tappet push rod, includes a housing having a push rod distal end which is formed with a ramp surface for contact by a cam. An inner element is placed in a recess of thehousing and has a push rod proximal end formed with an abutment for the push rod. Secured to the push rod proximal end of the inner element is an attachment to extend the inner element beyond the recess of the housing, wherein the attachment has a housing-distal end formed with a shoulder. A helical compression spring extends between the shoulder of the attachment and a rim of the housing for urging the inner element in a direction of the push rod, and conically expands, at least partly, in the direction of the push rod and is wrapped around the attachment of complementary conical configuration.
Abstract:
In a switching element (1) for a valve train of an internal combustion engine for switching to different valve lifts, said switching element (1) comprising an outer element (2) having an inner element (4) arranged for axial displacement therein, each of the outer and the inner element (2, 4) comprising a reception (11, 9) aligned to each other in a relative position, at least one piston (10) being arranged in at least one of the receptions (11, 9) for sliding toward the other of the receptions (9, 11) to couple the inner element (4) to the outer element (2) in said relative position, and a high-position stop for defining said relative position being arranged between the inner and the outer element (4, 2), at least one part of the high-position stop is configured as an adjustable, separate element (13). This element (13) cooperates through a preferably conical section (15) of its outer periphery with a complementary chamfer (18) on one end (17) of a guide (16) in the outer element (2). By these extremely simple fabrication measures, an aligned adjustment of the receptions (9, 11) is created for effecting coupling.
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 connection of a bearing bolt (6) in a cylindrical housing (1) of a roller tappet (2) that is actuated in a direction of a longitudinal axis (Z) is provided, especially for a tappet push-rod valve drive of an internal combustion engine. The bearing bolt (6) is supported in bore holes (7) of the housing (1), which extend in a transverse plane (XY) to the roller tappet (2), perpendicular to the longitudinal axis (Z), and is connected with a positive and/or non-positive fit to the housing (1) through material deformation. The material deformation is provided as one or more segments (9, 10), of which at least one segment (9) completely encloses a radial load zone (16) of the bearing bolt (6), and a section (15) of the bearing bolt (6) extending about the transverse plane (XY) is free from material deformation.
Abstract:
In a switching element (1) for a valve train of an internal combustion engine for switching to different valve lifts, said switching element (1) comprising an outer element (2) having an inner element (4) arranged for axial displacement therein, each of the outer and the inner element (2, 4) comprising a reception (11, 9) aligned to each other in a relative position, at least one piston (10) being arranged in at least one of the receptions (11, 9) for sliding toward the other of the receptions (9, 11) to couple the inner element (4) to the outer element (2) in said relative position, and a high-position stop for defining said relative position being arranged between the inner and the outer element (4, 2), at least one part of the high-position stop is configured as an adjustable, separate element (13). This element (13) cooperates through a preferably conical section (15) of its outer periphery with a complementary chamfer (18) on one end (17) of a guide (16) in the outer element (2). By these extremely simple fabrication measures, an aligned adjustment of the receptions (9, 11) is created for effecting coupling.
Abstract:
A switchable cup tappet for a valve timing mechanism of an internal combustion engine, which has a cup basic body with an annular base loaded by large-lift cams. A hollow-cylindrical projection protrudes from an inner edge of the base and an inner body extends in the hole of the projection. The disc-like base is contacted by a small-lift cam. In a hole of the inner body two coupler pistons are coupled in sections with a driver surface of the cup basic body for a large valve stroke. The small stroke occurs by complete displacement into the radial hole. An annular web, spaced from its end faces at both ends, is attached integrally, in which the radial hole extends with the coupler pistons. The driver surface for the pistons is formed by a lower edge of the projection, which is spaced from the bases.