Negative pressure relief valve and be equipped with negative pressure sputum aspirator of this relief valve

The utility model relates to a negative pressure relief valve and be equipped with negative pressure sputum aspirator of this relief valve, the negative pressure relief valve includes: the main valve body, main valve body one end has been seted up and has been connected external atmospheric first air vent, and the second air vent has been seted up to the other end, elastic component, accept in the main valve internal, along main valve body axial motion under the effect of the internal negative pressure of main valve, the regulating part is located between elastic element and the first air vent, can seal or open first air vent under elastic component's drive. Above -mentioned negative pressure relief valve, when the internal negative pressure pressure value of main valve was greater than the preset pressure value, elastic component drove the regulating part to the direction motion of keeping away from first air vent to open first air vent, the value to preset pressure is resumeed to the internal negative pressure pressure value of main valve. When the internal negative pressure pressure value of main valve was less than the preset pressure value, elastic component drove the regulating part and moves to the direction of being close to first air vent, and then made it seal first air vent to holding the regulating part, prevented outside air entering main valve internal.