PROBLEM TO BE SOLVED: To provide an automatic watering device producing dilute liquid manure at high dilute accuracy in real time.SOLUTION: This automatic watering device 1 includes a liquid manure supply part 2 supplying liquid manure F, a water supply part 3 supplying pressurized water W, a mixture tank 4 storing dilute liquid manure Wf made by mixing the liquid manure F and the water W from both the supply parts, a liquid manure flowing quantity sensor 6 measuring the flowing quantity of the liquid manure F, a water flowing quantity sensor 7 measuring the flowing quantity of the water W, a liquid level sensor 8 measuring the liquid level in the mixture tank 4, and a control part 9 controlling both the supply parts. When the control part 9 detects that the liquid level is less than a prescribed lower limit, the control part opens a water supply valve 18 to measure the flowing quantity of the water W with the water flowing quantity sensor 7, calculates the quantity of the liquid manure F with a necessary dilute magnification, and operates a minute discharge pump 13 so as to discharge the amount of the liquid manure F, and at the same time, instantly calculates the difference between the flowing quantity of the liquid manure F with the liquid manure flowing quantity sensor 6, and the flowing quantity of the liquid manure F by the calculation, and gives feedback to operation of the minute discharge pump 13.COPYRIGHT: (C)2013,JPO&INPIT【課題】 高い希釈精度でリアルタイムに希釈液肥を生成すること。【解決手段】 本発明の自動潅水装置1は、液肥Fを供給する液肥供給部2と、加圧された水Wを供給する水供給部3と、該両供給部からの液肥F及び水Wを混合してなる希釈液肥Wfを貯留する混合タンク4と、液肥Fの流量を計測する液肥流量センサー6と、水Wの流量を計測する水流量センサー7と、該混合タンク4内の液位を計測する液位センサー8と、該両供給部を制御する制御部9とを備えている。制御部9は、前記液位が所定の下限を下回っていることを検知すると、給水バルブ18を開かせて水Wの流量を水流量センサー7で計測し、所要の希釈倍数による液肥Fの量を演算し、該量の液肥Fを吐出するように微少吐出ポンプ13を作動させる。同時に液肥流量センサー6による液肥Fの流量及び前記演算による液肥Fの流量の差違を即時に演算し、微少吐出ポンプ13の作動にフィードバックする。【選択図】 図1
