Method for evaluating diagnosis function of a variable valve mechanism and apparatus for diagnosing a variable valve mechanism
AssigneeHitachi, Ltd.
InventorsRyo Miyakoshi, Kenichi Machida
Life of this patent
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Abstract
Gains of a feedback control of a variable valve mechanism are varied so that a response delay occurs. As a result that a transient response is diagnosed under this state, in the case where the occurrence of response delay is not judged, it is judged that a response diagnosis function is abnormal.
Claims29
A method of evaluating a diagnosis function to diagnose a transient response of a variable valve mechanism that varies an operating characteristic of an engine valve, comprising the steps of:
- degrading the transient response of said variable valve mechanism in a forcible manner;
- diagnosing the transient response of said variable valve mechanism under a state where the transient response is degraded in a forcible manner;
- and
- evaluating the diagnosis function of the transient response based on a result of diagnosing of the transient response.
A diagnosis apparatus for diagnosing a transient response of a variable valve mechanism which varies an operating characteristic of an engine valve, comprising:
- a response delay generating section that degrades the transient response of said variable valve mechanism in a forcible manner;
- a diagnosing section that diagnoses the transient response of said variable valve mechanism under a state where said response delay generating section is being operated;
- and
- an evaluating section that evaluates the diagnosis function of said diagnosis section based on a diagnosis result of said diagnosis section.
Dependencies are inferred from the claim text.