Patent ID: 7462131

Claim:
A pressure control system of an automatic transmission comprising: a control-pressure regulating valve to regulate a reducing pressure to an appropriate control pressure in accordance with the control of a transmission control unit; a path switching valve to output the control pressure regulated in the control-pressure regulating valve during gear shifting, and to output a line pressure after completion of the gear shifting; and a coupling-pressure regulating valve to regulate a coupling pressure to be supplied to a frictional element based on the control pressure or the line pressure outputted from the path switching valve; wherein the path switching valve includes: a pressure receiving port and a first input port to receive the control pressure of the control-pressure regulating valve, respectively; a second input port to receive the line pressure; an output port connected to the coupling-pressure regulating valve; a first reaction force portion to provide a reaction force against the control pressure inputted via the pressure receiving port; and a first switching land to connect the output port to one of the first and second input ports in accordance with a force-equilibrium relationship between the first reaction force portion and the control pressure inputted via the pressure receiving port.