Patent ID: 7028975

Claim:
A flush valve structure to control water flow through a pressure difference, comprising: a case which has a housing chamber, a main water inlet, a main water discharge opening, a water outlet and a pressure release passage; a solenoid assembly having a rod; an upper intermediate board fastened to a lower side of the solenoid assembly and the case having a small water pressure release hole which is opened or closed by the rod of the solenoid assembly and a small water passage; a lower intermediate board fastened to the upper intermediate board having a holding trough which contains a medium water pressure release hole and a medium water passage and couples with a mating medium water valve to control opening and closing of the medium water pressure release hole; and a main water ball located in the housing chamber to control opening and closing of the main water discharge opening having a bore; wherein the rod of the solenoid assembly opens the small water pressure release hole to generate a pressure difference to actuate the medium water valve to open the medium water pressure release hole to form a greater pressure difference so that the main water ball rapidly and fully opens the main water discharge opening; and wherein the main water ball has a pressure release stem, a pressure release opening and a second water outlet, the case having a button opening to couple with a button which is depressable to push the pressure release stem and open the pressure release opening to generate a pressure difference so that the main water ball rapidly and fully opens the main water discharge opening to flush water, and the main water ball returns to its original position when the pressure is balanced to close the main water discharge opening and stop flushing.