| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent the erroneous learning of a holding point near the maximum retard or advance angle position of a variable valve timing mechanism. <P>SOLUTION: This engine valve timing control device determines a learning range of the holding point from a current advance angle value (S1, S2), executes holding point learning processing in a range between a learning upper limit value Lmax and a learning lower limit value Lmin in the case of a normal range (S5), and stores an obtained holding point learning value Lh as a learning reference value Lref to be the basis of learning in a region on an advance or retard angle side (S6). In learning processing in a range near the maximum advance angle position and learning processing in a range near the maximum retard angle position, the holding point learning processing is executed in a range limited on the base of the learning reference value Lref (S15, S25) to prevent erroneous learning. When the learning value sticks to the upper or lower limit value, a control range is limited (S18, S28) to prevent the occurrence of noises due to the mechanical contact of the movable part of the variable valve timing mechanism. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
