Patent ID: 6729988
Filing Date: 2004-05-04
Classification: F16H,Y10T

Abstract:
A hydraulic system for a vehicle with:an engine having idle-stop control, the idle-stop control controlling idle-start and idle-stop of the engine in accordance with preset idle-stop conditions; and an automatic transmission which carries out speed change using a hydraulic pressure supplied from a hydraulic-pressure source, the automatic transmission comprising a forward engagement element, the hydraulic system comprising: a control valve unit which controls the speed change of the automatic transmission, the control valve unit including a manual valve; a bypass passage which allows communication between a first hydraulic passage downstream of the manual valve and the forward engagement element; a first switching valve arranged on the bypass passage, the first switching valve being switched between a communicating state and a non-communicating state; and a first switching device which switches the first switching valve between the communicating state and the non-communicating state, the first switching device switching the first switching valve to the communicating state when the hydraulic pressure is lower than a predetermined pressure.