Patent ID: 6966536

Claim:
A flush valve device of a flush toilet, the flush valve device comprising: a flush valve body having: a main valve that is disposed in a main water conduit to open and close the main water conduit; a pilot valve that presses the main valve in a closing direction and parts a back pressure chamber; and a driving rod that is attached to the pilot valve, wherein the driving rod is inclined to lower water pressure in the back pressure chamber and thereby open the main valve; and a manual operation unit that functions to open the pilot valve, wherein a supply of washing water is flown into a toilet bowl in response to an operation of the manual operation unit, wherein the manual operation unit includes: a flexible transmission member; an operation button that is pushed up and down in response to a pressing operation; an operating force conversion mechanism that is coupled with one end of the transmission member and converts an operating force generated by the pressing operation of the operation button into a tensile force of pulling the transmission member, wherein the operating force conversion mechanism includes a spring that restores the operation button, which has been subjected to the pressing operation, to an original position thereof, and a slide member that pulls the transmission member in a sliding direction, the slide member having an inclined plane to convert the operating force of the operation button into a moving force in a direction substantially perpendicular to a direction of the operating force; and a tilting mechanism that is coupled with the other end of the transmission member and moves to incline the driving rod in response to a pull of the transmission member.