Patent ID: 6223706
Filing Date: 2001-05-01
Classification: F01L

Abstract:
Valve train of an internal combustion engine comprising a tappet (1) that can be coupled for different valve lifts of at least one gas exchange valve, said tappet (1) comprising an outer annular section (2) which concentrically surrounds a circular section (3) which is axially movable relative thereto, said sections (2, 3) are contacted in the region of their bottoms (4, 5) by cams of different lifts having at lest one signal track, or said annular section (2) is contacted in the region of its bottom (4) by at least one cam having a signal track, said sections (2, 3) comprising within their bottoms (4, 5) or in adjoining regions, at least one reception (6a, 6b, 7) arranged radially and aligned to each other in the base circle phase of the cams, a first and a third slide (8, 9) being disposed in said receptions (6a, 6b) of the annular section (2), said slides (8, 9) extending in the uncoupled state of the tappet (1) with their radially inner end faces (10, 11) immediately in front of an annular surface (12) between the sections (2, 3), a second slide (13) extending in the uncoupled state of the tappet (1) over an entire length of the reception (7) of the circular section (3), the third slide (9) delimiting with its radially outer end face (15), a pressure chamber (16) for hydraulic medium, and locking means (14) for the slides (8, 9, 13) being associated to the tappet (1), said locking means (14) cooperate with the signal track on the opposing cam, wherein the first slide (8) is loaded on its radially outer end face by a compression spring (33) and cooperates with the locking means (14) which comprise a transmitting member (21) and a locking member (22), said locking member (22) penetrating in cam direction into a respective one of the receptions (6a) while being arranged axially below this reception (6a) on a ring (23) supported on a compression spring (17) which extends in an annular chamber (18) of the annular section (2) axially below the respective receptions (6a, 6b) and acts at the other end, on a support means (20) connected to the circular section (3), the transmitting member (21) extends on one or on both sides of the reception (6a) exteriorly thereof and parallel to the longitudinal axis of the tappet (1) and scans the signal track of the opposing cam with one end while acting with the other end on the ring (23), and the first slide (8) comprises, at least on a side facing the locking means (22), two locking recesses (24, 25) for the locking member (22), said locking recesses being spaced from each other at a distance corresponding to coupling and uncoupling positions of the slides (8, 9, 13).