PROBLEM TO BE SOLVED: To provide a paddy field valve for semiautomatically supplying a predetermined amount of water which automatically stops water supply when the predetermined amount of water is supplied, and which is surely opened or closed owing to a large valve-opening degree even when the water-supply pressure is low.SOLUTION: The paddy field valve is structured as follows: a cylinder chamber 4 is separated into a diaphragm chamber 45 and an auxiliary chamber 46 via a diaphragm body 42 the diaphragm body 42 is set up in one chamber so as to be expandable and displaceable the diaphragm chamber 45 and the auxiliary chamber 46 are respectively communicated with the air and the side of a water supply port 30 of a valve chamber 3 via a switching valve 8 linked with a water supply flow amount-integrating meter 6 the auxiliary chamber 46 is communicated with the side of the water supply port 30 via the switching valve 8, and the diaphragm chamber 45 is switched so as to be communicated with the air, so that the valve body 40 is opened due to displacement of the diaphragm body 42 when the water supply flow amount is under a preset amount and the diaphragm chamber 45 and the side of the water supply port 30 are communicated with each other via the switching valve 8 and the auxiliary chamber 46 is communicated with the air, so that the valve body 40 is closed due to displacement of the diaphragm body 42 when the water supply flow amount reaches to a preset amount.COPYRIGHT: (C)2009,JPO&INPIT【課題】設定された給水量が給水されると自動的に給水を停止し、給水圧が低い時でも、開弁度を大きく弁体の開閉を確実に行う。【解決手段】水田バルブにおいて、シリンダ室4が、ダイヤフラム体42によりダイヤフラム室45と補助室46とに分割されて、該ダイヤフラム体42は一方の室内に膨張変位可能に配設され、前記ダイヤフラム室45と補助室46はそれぞれ給水流量積算計6に連係される切替バルブ8を介して大気とバルブ室3の給水口30側と連通可能とされ、給水流量が設定量未満の場合、切替バルブ8により補助室46と給水口30側が連通され、ダイヤフラム室45が大気に連通されるように切替られ、ダイヤフラム体42の変位により弁体40を開け、給水流量が設定量に達した場合、切替バルブ8によりダイヤフラム室45と給水口30側とが連通され、補助室46が大気に連通され、ダイヤフラム体42の変位により弁体40を閉じるように構成した。【選択図】図1
