PROBLEM TO BE SOLVED: To provide an automatic water seal type suction device for a dental unit chair.SOLUTION: An automatic water seal type suction device for a dental unit chair includes: a water seal vacuum pump 10 having a sealing water inflow port 11, an air inflow port 12, and an exhaust port 13 from which sealing water and fluid suctioned through the air inflow port are exhausted； cyclone centrifugal separation means 20 in which the upper end is connected to an air inflow port of the water seal vacuum pump and the circumference of the upper end part is connected to a suction tip of a unit chair, and which separates foul water containing foreign matter suctioned from the oral cavity of a patient from air, and removes it； and a sealing water re-circulation unit 30 having a sealing water tank 31 in which the lower end is connected to a sealing water inlet port of the water seal vacuum pump, and the circumference of the upper end part is connected to the exhaust port of the water seal vacuum pump, and which includes an air outlet at the upper end, cooling means 22 for cooling sealing water to be supplied from the sealing water tank to the water seal vacuum pump, and a fixed sealing water amount supply pump 32 for supplying the sealing water in the sealing water tank in a predetermined amount by the water seal vacuum pump.SELECTED DRAWING: Figure 1【課題】歯科ユニットチェア用全自動湿式サクション装置を提供する。【解決手段】封水流入口１１、空気流入口１２と、封水及び空気流入口を介して吸入された流体が排出される排出口１３を有する水封式真空ポンプ１０、上端が水封式真空ポンプの空気流入口と連結、上端部周りがユニットチェアのサクションチップに連結され、患者の口腔から吸入された異物が含まれている汚水を空気と分離除去するサイクロンの遠心分離手段２０、下端が水封式真空ポンプの封水入口に連結し、上端部の周りが水封式真空ポンプの排出口に連結、上端に排気口を有する封水タンク３１と、この封水タンクから水封式真空ポンプに供給される封水を冷却させる冷却手段２２と封水タンク内封水を水封式真空ポンプで所定量給水する封水定量供給ポンプ３２を具備する封水再循環ユニット３０、を含む。【選択図】図１
