Schaeffler Technologies Ag & Co .kg

Arne Manteufel

Norbert Nitz

Andreas Biermann

Ronny Gunnel

Stefan Gemein

Lucia Hinkovska

Christoph Walther

The disclosure relates to a valve train of an internal combustion engine having variable-lift gas exchange valves, comprising: a carrier shaft, a cam piece arranged on the carrier shaft in a rotationally fixed and axially displaceable manner. The cam piece comprises a cam group of axially adjacent cams of different elevations, and an axial slotted link having axially opposite displacement grooves, each having a displacement region and an outlet region. Actuator pins, by engaging with the displacement grooves, displace the cam piece on the carrier shaft. Each displacement groove axially delimits, partially or completely, the outlet region by only one groove wall, and the one groove wall, at which the actuator pin, which is in engagement with the displacement region, positively accelerates the cam piece into a displacement direction. The width of the displacement grooves is smaller in the outlet region than a diameter of the actuator pins.

Variable stroke gas exchange valve train of an internal combustion engine

A method for diagnosing an electromagnetic actuator of a sliding cam valve drive of an internal combustion engine. An actuator pin is released by electrical energizing of the actuator and is introduced into a groove-like sliding slot which passes through a cylindrical slot section of the associated sliding cam-and ends in a slope onto the cylindrical circumference of the slot section. The method includes: energizing the actuator using current parameters of a variable actuator characteristic map so that the actuator pin is released when the cylindrical circumference overlaps the actuator pin circumferentially; determining whether the released actuator pin generates a rejection signal due to the slope from the sliding slot onto the cylindrical circumference; if no rejection signal is detected, repeating step a) whereas at least one current parameter is changed and step b); updating the actuator characteristic map with the changed current parameter.

Diagnostic method for a valve drive actuator

A slide cam unit with a cam region is provided with an adjusting device having an actuator for adjusting the slide cam unit to different axial positions via slide grooves on the circumference of the slide cam unit. The adjusting device is arranged in a stationary manner and a device for fastening the slide cam unit in the different axial positions is provided. The cam region and the slide groove region of the slide cam unit are designed as separate cam and slide groove components which are fastened to each other with a positive-fit connection and fixed in place to each other by their support on the base shaft.

Constructed slide cam unit

A cam part () is provided for a variable sliding cam valve drive of an internal combustion engine, which cam part () can be mounted on a basic shaft of the sliding cam valve drive fixedly so as to rotate with it but axially displaceably, and has one or more cam groups () and at least one connecting link piece () with at least one spiral groove () for an actuator pin engagement. At least one weight-reducing groove () which does not coincide with the spiral groove () is formed on the outer casing () of the cam part ().

Cam part for a variable sliding cam valve drive

A valve drive system () having a support element () and a switchable cam follower () that is linked on this support element in an articulated way is provided. The cam follower () is made from an outer lever () between whose arms () runs an inner lever (), wherein at least the outer lever () is provided on its top side () with a contact surface () for a lifting cam, n the inner lever () has, on a bottom side () on a first end (), a contact () for a gas-exchange valve and at least on the other end () two side walls () that are spaced apart and in which extend opposing boreholes (). The side walls () are bridged by a tubular axle piece () that sits in the boreholes () and in whose opening () run two diametrically opposed coupling pistons (). The axle piece () sits between the side walls () in a cross borehole () of a head () of the support element (), and in the region of the first end (), the levers () sit on a common swivel pin () and the arms () of the outer lever () have, on the other end (), a catch surface () for the coupling pistons () that can be brought out from its opening () in engagement with the catch surface () section-wise in the coupled state, such that a large valve stroke is realized, and for decoupling, a comparatively smaller valve stroke is presented. The outer lever () is forced back by a restoring spring () from its pivot mode.

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Bamberg, Germany

Arne Manteufel