PROBLEM TO BE SOLVED: To provide an automatic water supply system capable of operating over a wide scope of an effective head from the lowest effective head of about 20 cmAq to the effective head of about 350 cmAq.SOLUTION: This automatic water supply system is provided with a water conducting pipe 102 whose opening on one side is communicated with a channel 101 being a water supply source, a valve body 103 provided in an opening on the other side of the water conducting pipe 102, a valve element 108 moving vertically by using an optional fulcrum 112a as a pivotal shaft and coming into pressure-contact with or leaving from a valve seat part 104 of the valve body 103, and a tank 111 having an air vent 115 in an end part of an arm 110 provided opposingly to the fulcrum 112a around the valve element 108 and/or at the valve element 108. The automatic water supply system is provided with a flow-in pipe 117 for communicating the inside of the valve body 103 with the inside of the tank 111 and a drain pipe 119 for communicating the inside of the tank 111 with a water level sensor 120. The center of gravity of the tank 111 filled with water to its capacity is on a valve element 108 side.COPYRIGHT: (C)2008,JPO&INPIT【課題】 本発明は、上記の課題を解決するためになされたものであり、自動給水装置を作動させる最低有効水頭が、概ね20cmAq.程度から、350cmAq.程度の有効水頭まで広範囲にわたり作動させることのできる自動給水装置を提供する。【解決手段】一方の開口が用水の供給源である水路101に連通された導水管102と、導水管102の他方の開口に設けられた弁本体103と、任意の支点112aを枢軸に上下動し、弁本体103の弁座部104に圧接離間する弁体108と、弁体108を中心にして支点112aと対向して設けられたアーム110の端部及び/又は弁体108にエアー抜き115を有するタンク111を設ける。弁本体108内とタンク111内とを連通する流入管117と、タンク111内と水位センサ120とを連通する排水管119とを設け、タンク111の満水時の重心を支点112aよりも弁体108側に設ける。【選択図】図1
