Patent ID: 7278944

Claim:
A hydraulic control apparatus for an automatic transmission having a gear implemented by engagement of a friction engagement element, comprising: a pressure regulation valve including a first control pressure chamber to which first control pressure is introduced from a first control valve, and a feedback pressure chamber to which oil pressure that is to be supplied to said friction engagement element is branched off and introduced as feedback pressure, said pressure regulation valve being switched between an oil pressure supply state in which oil pressure generated at an oil pressure source is regulated to be supplied to said friction engagement element and an oil pressure cutoff state in which oil pressure is cut off, based on balance between said first control pressure and said feedback pressure, a switching valve including a second control pressure chamber to which second control pressure is introduced from a second control valve and a feedback pressure introduction port through which said feedback pressure is introduced, said switching valve being switched by said second control pressure to one of a feedback pressure supply state in which the oil pressure introduced from said feedback pressure introduction port is supplied to said feedback pressure chamber and a feedback pressure drain state in which oil pressure is drained away from said feedback pressure chamber, and a control unit for controlling said first control valve and said second control valve such that said pressure regulation valve attains said oil pressure cutoff state and said switching valve attains said feedback pressure drain state when a predetermined condition is met.