Monitoring of a cam profile switching system in internal combustion engines
AssigneesFord Global Technologies, LLC, Jaguar Cars Limited
InventorBrian Anthony Varney
Life of this patent
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Abstract
A method and apparatus for detecting degradation in the cam profile switching system in either bank 2, 3 of a V-engine 1 relies on a comparison of the lambda values in each exhaust bank 4, 5 immediately prior to and subsequent to a cam profile switching event in one of the banks. If there is little or no change after switching, then the apparatus deduces that the switched bank has experienced degradation. The method is easy to calibrate and does not require continuous monitoring of engine behavior.
Claims15
A system for detecting degradation in a cam profile switching system of an internal combustion engine having a plurality of cylinder banks, the system comprising:
- at least a cam profile switching system;
- an engine having a first and second cylinder bank, each cylinder bank having an exhaust pipe coupled thereto;
- a first sensor placed in the exhaust path of said first cylinder bank and a second sensor placed in the exhaust path of said second cylinder bank;
- and
- a controller for monitoring the output of said first sensor and the output of said second sensor and providing an indication of degradation of said at least a cam profile switching system in response to a comparison of said output of said first sensor and of said output of said second sensor.
A method for detecting degradation in a cam profile switching system of an internal combustion engine having a first cylinder bank and a second cylinder bank, the method comprising:
- indicating degradation of the cam profile switching system as the output of a first sensor located in the exhaust path of said first cylinder bank varies from the output of a second sensor located in the exhaust path of said second cylinder bank.
A method for detecting degradation in a cam profile switching system of an internal combustion engine having a first cylinder bank and a second cylinder bank, the method comprising:
- applying a switching signal to a cam profile switching system of said first cylinder bank;
- and
- indicating degradation of said cam profile switching system if the air-fuel ratios of said first cylinder bank and said second cylinder bank remain substantially unchanged after applying said switching signal.
Dependencies are inferred from the claim text.