Valve drive for an internal combustion engine

#This application claims priority to German Patent Application No. DE 10 2017 205 572.3, filed on Mar. 31, 2017, the contents of which are hereby incorporated by reference in its entirety.

#The invention relates to a valve drive for an internal combustion engine comprising a cam shaft and comprising at least one cam follower.

#Generic valve drives for an internal combustion engine comprising a cam shaft and comprising at least one cam follower as well as comprising at least one cam group, which is mounted to the cam shaft in a rotatably fixed manner, comprising a first cam and comprising a second cam axially adjacent to the first cam, are already known. In a first position, the cam follower is thereby drivingly connected to the first cam of the respective cam group and, in a second position, to the second cam of the respective cam group.

#In each case schematically,

#FIG. 1 shows a view of a valve drive according to the invention;

#FIG. 2 shows a view of a valve drive according to the invention comprising a switching arrangement, wherein control elements have a through groove and are mounted by engagement elements in the upper area;

#According to FIG. 1, a valve drive 1 according to the invention has a cam shaft 2 and a cam follower 3 comprising a first roller 3a and comprising a second roller 3b. The cam shaft 2 has a first cam group 4 and a second cam group 5, which are mounted to the cam shaft 2 in a rotationally fixed manner. The first cam group 4 and the second cam group 5 each have a first cam 4a and 5a as well as a second cam 4b and 5b, which is axially adjacent to the respective first cam 4a and 5a. In a first position, the rollers 3a and 3b of the cam follower 3 are drivingly connected to the first cams 4a and 5a of the cam groups 4 and 5, and in a second position, the rollers 3a and 3b of the cam follower 3 are drivingly connected to the second cams 4b and 5b of the cam groups 4 and 5.

#To adjust the cam follower 3 into the first position or into the second position, the valve drive 1 has an adjusting device 6, which has a first adjustable engagement element 7a and a second adjustable engagement element 7b. The first engagement element 7a thereby cooperates with a first guide 8a, which is mounted to the cam shaft 2, and the second engagement element 7b cooperates with a second guide 8b of a slide guide 8, which is mounted to the cam shaft 2. The first engagement element 7a and the second engagement element 7b can alternately be adjusted between an initial position and a switching position, whereby there is no contact with the corresponding guide 8a or 8b in the initial position and the respective engagement element 7a or 7b cooperates with the corresponding guide 8a or 8b in the switching position. The valve drive 1 also has a rocker arm 9, on which the cam follower 3 is arranged so as to be capable of being displaced. The rocker arm 9 is rotatably mounted to a rocker arm shaft 10.

#To adjust the engagement elements 7a and 7b, the adjusting device 6 has a switching arrangement 11 comprising a first stop area 12a for a first control element 13a and comprising a second stop area 12b for a second control element 13b. In this exemplary embodiment, the switching arrangement 11 is a linearly guided shifting arrangement, which is controlled by means of an individual—for example hydraulic or electromagnetic or pneumatic—actuator. In response to a displacement of the switching arrangement 11 along the rocker arm shaft 10, the stop area 12a or 12b is moved to the control element 13a or 13b and the respective control element 13a or 13b is displaced perpendicular to the rocker arm shaft 10 by means of a downwards movement of the rocker arm 9. The adjustment of the control element 13a or 13b with the respective engagement element 7a or 7b thereby occurs in that the control element 13a or 13b abuts on the stop area 12a or 12b of the switching arrangement 11 and is prevented from the upwards or downwards movement of the cam follower 3 with the rocker arm 9 on the rocker arm shaft 10. The control element 13a or 13b is thus adjusted relative to the cam follower 3 in response to the upwards or downwards movement of the cam follower 3 with the rocker arm 9.