Mechanical valve automatic-control device, valve system and water purifier

The utility model relates to a mechanical valve automatic-control device, a valve system and a water purifier. The mechanical valve automatic-control device comprises a triggering mechanism, a mechanical power output mechanism, a mechanical transmission mechanism and a switching driving mechanism, wherein the triggering mechanism is used for limiting the power output of the mechanical power output mechanism; the mechanical power output mechanism is in driving connection with the mechanical transmission mechanism; the mechanical transmission mechanism is in driving connection with the switching driving mechanism. When the device is used, the switching driving mechanism is in driving connection with a valve, the triggering mechanism is triggered to release limitation to the mechanical power output mechanism, the mechanical power output mechanism outputs power, the power is transmitted to the switching driving mechanism through the mechanical transmission mechanism, and the switching driving mechanism acts to close the valve. The device is of a purely mechanical structure, and is power-free, control safety and reliability are achieved, the valve can be automatically closed, and a water leakage protection function can be realized. The utility model further discloses the valve system comprising the mechanical valve automatic-control device and the water purifier.