| 摘要 |
PROBLEM TO BE SOLVED: To suppress erroneous determination that an abnormality exists in a supercharger by abnormality determination processing.SOLUTION: In abnormality diagnosis processing which is performed by an electronic control device 21, an abnormality diagnosis device of a supercharger determines that an abnormality exists in a turbocharger 4 on the basis of the fact that actual boost pressure reaches upper limit boost pressure or higher for preventing the excess rotation of the turbocharger 4. When lowering the output torque of an internal combustion engine 1, the abnormality diagnosis device decreases a throttle opening, and on the other hand, the abnormality diagnosis device tries to lower the actual boost pressure while lowering a rotation speed of the turbocharger 4. At this time, since a delay occurs in the lowering of the rotation speed of the turbocharger 4 while the throttle opening is quickly decreased, the actual boost pressure is temporarily raised. The electronic control device 21 prohibits the execution of the abnormality determination processing during the decrease of the throttle opening. By this constitution, it is suppressed that the existence of the abnormality of the turbocharger 4 is erroneously determined by the abnormality diagnosis processing resulting from a temporary rise of the actual boost pressure.SELECTED DRAWING: Figure 1 |
