Apparatus and method of abnormality diagnosis for supercharging pressure control system
First Claim
1. An abnormality diagnosis apparatus for a supercharging pressure control system including a throttle valve located in an intake system to adjust an intake air quantity, a supercharger located upstream of the throttle valve in the intake system to supercharge intake air, and a bypass valve located in a passage bypassing the supercharger in the intake system, the bypass valve being opened when a predetermined operating condition is established, the abnormality diagnosis apparatus comprising:
- a pressure monitoring means which monitors a pressure upstream of the throttle valve over a period of time; and
an abnormality determination means which determines whether or not there occurs abnormality of the bypass valve based on the pressure monitored by the pressure monitoring means after the operating condition is established with the throttle valve fully closed.
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Accused Products
Abstract
An opening of a waste gate vale is adjusted to control an actual supercharging pressure of intake air. Abnormality in a changing characteristic of the actual supercharging pressure relative to a change in a TCV control duty value can be detected. When an engine is in a steady operation condition, the TCV control duty value is forcibly changed repeatedly by a predetermined amount from 0% to 100%. A deviation between a target supercharging pressure corresponding to the TCV control duty value and an actual supercharging pressure is calculated each time the TCV control duty value is changed by the predetermined amount. This deviation is compared with an abnormality determination value to determine presence/absence of the abnormality in the changing characteristic of the actual supercharging pressure relative to the change in the TCV control duty value.
45 Citations
20 Claims
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1. An abnormality diagnosis apparatus for a supercharging pressure control system including a throttle valve located in an intake system to adjust an intake air quantity, a supercharger located upstream of the throttle valve in the intake system to supercharge intake air, and a bypass valve located in a passage bypassing the supercharger in the intake system, the bypass valve being opened when a predetermined operating condition is established, the abnormality diagnosis apparatus comprising:
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a pressure monitoring means which monitors a pressure upstream of the throttle valve over a period of time; and an abnormality determination means which determines whether or not there occurs abnormality of the bypass valve based on the pressure monitored by the pressure monitoring means after the operating condition is established with the throttle valve fully closed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 19)
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10. An abnormality diagnosis method for a supercharging pressure control system provided with a throttle valve located in an intake system to adjust an intake air quantity, a supercharger located in the intake system upstream of the throttle valve to supercharge intake air, and a bypass valve located in a passage bypassing the supercharger in the intake system, the supercharging pressure control system opening the bypass valve when a predetermined operating condition is met, the abnormality diagnosis method comprising:
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monitoring a pressure upstream of the throttle valve over a period of time; and determining whether or not there occurs abnormality of the bypass valve based upon the monitored pressure upstream of the throttle valve after the operating condition is met with the throttle valve fully closed. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 20)
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Specification