| 摘要 |
Methods for machining control shafts on variable valvetrains are known in which a control shaft (34) to be machined is inserted into a grinding machine (26) and the control shaft cams (36) are ground down in accordance with stored values. Often, control shafts machined in this manner fail to achieve equal valve lifts. According to the invention, to achieve this aim, intermediate levers (28) and roller idler arms (30) to be installed are first inserted into a measuring device (10) in which a reference cam shaft (12), a reference control shaft (14) and reference slots (16) are arranged, the resulting valve lifts then being measured in the measuring device (10) as the reference cam shaft (12) is rotated, and the gas exchange valve (18) with the smallest valve lift being determined. Subsequently, the valve lift differences &Dgr;x between the gas exchange valve (18) with the smallest valve lift &Dgr;x and the respective valve lifts of all the other gas exchange valves (18) are measured and the individual valve lift differences &Dgr;x are converted into axial spacing differences Ad for the control shaft (34) to be machined, by means of a characteristic map &Dgr;x/&Dgr;d which allocates a valve lift difference &Dgr;x of a gas exchange valve (18) to an axial spacing difference &Dgr;d of the control shaft (34). Finally, the control shaft cam (36) to be associated with the gas exchange valve (18) with the smallest valve lift is ground down to attain nominal dimensions, and the other control shaft cams (36) are ground down to said nominal dimensions reduced by the respective axial spacing difference &Dgr;d of the control shaft (34) of the associated gas exchange valve (18) in question, said difference having been determined by means of the characteristic map. |
