Failure diagnosis method for internal combustion engine supercharging assist device and internal combustion engine supercharging assist system

摘要

PROBLEM TO BE SOLVED: To provide a failure diagnostic method of a supercharging assist system of an internal combustion engine capable of easily diagnosing a failure state of a flow passage switching device of the supercharging assist system by detecting information from an existing sensor, in the internal combustion engine having a turbo type supercharging system and the supercharging assist system for introducing prestored compressed air into a cylinder, and to provide the supercharging assist system of the internal combustion engine.SOLUTION: In a failure diagnostic method of a supercharging assist system of an internal combustion engine including a turbo type supercharging system 1 and a supercharging assist system 10, the existence of failure of a flow passage switching device 20 and the failure state of the flow passage switching device 20 and the supercharging assist system 10 are determined from a switching state of the flow passage switching device 20, progress of internal pressure Pi of a compressed air tank 18 and a detecting result of the existence of the movement of air in an air suction passage 12a.