Patent ID: 8066090
Filing Date: 2011-11-29
Classification: B60K,B60L,B60W,F16H,Y02T,Y10T

Abstract:
1. A hydraulic control apparatus for an automatic transmission, comprising: a forward travel engaging element that engages when changing from a non-travel shift position or shift range to a forward travel shift position or shift range and disengages when changing from the forward travel shift position or shift range to the non-travel shift position or shift range; a reverse travel engaging element that engages when changing from the non-travel shift position or shift range to a reverse travel shift position or shift range and disengages when changing from the reverse travel shift position or shift range to the non-travel shift position or shift range; a first signal electromagnetic valve that can output a signal pressure; a first switching valve that is interposed on a reverse travel engagement oil path that supplies an engagement pressure to a hydraulic servo of the reverse travel engaging element, and that switches between an engagement position that communicates the reverse travel engagement oil path and a discharge position that enables quicker draining than by simply draining using the reverse travel engagement oil path based on an output state of the signal pressure of the first signal electromagnetic valve; and a second switching valve that is interposed on a forward travel engagement oil path that supplies an engagement pressure to a hydraulic servo of the forward travel engaging element, and that switches between an engagement position that communicates the forward travel engagement oil path and a discharge position that enables quicker draining than by simply draining using the forward travel engagement oil path based on the output state of the signal pressure of the first signal electromagnetic valve, wherein: