Patent ID: 9618112
Date: 2017-04-11
CPC Classifications: F16H

Claim:
1. An apparatus for detecting abnormal hydraulic pressure of an automatic transmission, the automatic transmission comprising: first and second input shafts that input rotation of a prime mover mounted on a vehicle through first and second clutches; an idler shaft that inputs the rotation of the prime mover through a third clutch; at least one output shaft arranged in parallel to the first and second input shafts; and a plurality of gear engaging mechanisms that engages one of speed gears of either the first or second input shafts to either the first or second input shafts and the output shaft, comprising: an oil pump driven by the prime mover; a hydraulic pressure supply circuit comprising: a first pressure-regulating valve that pressure-regulates hydraulic pressure discharged from the oil pump to line pressure; a line pressure-regulating valve that controls operation of the first pressure-regulating valve based on a line pressure command value; second pressure-regulating valve that pressure-regulates the line pressure regulated by the first pressure-regulating valve to clutch pressure; first and second oil passages that supply the clutch pressure regulated by the second pressure-regulating valve through first and second shift valves to the first and second clutches of the automatic transmission; a third oil passage that directly supplies the line pressure through the first and second shift valves to the third clutch of the automatic transmission; and first, second and third hydraulic pressure detectors that detect the hydraulic pressures of the first, second and third oil passages respectively, and a line-pressure regulating valve abnormality determiner that determines whether an abnormality has occurred in the line pressure-regulating valve under predetermined operating conditions based on at least the hydraulic pressures detected by at least one of the first, second and third hydraulic pressure detectors and the line pressure command value, the line pressure being greater than the line pressure command value in the abnormality.