Mechanical automatic exhaust valve

The utility model discloses a mechanical automatic exhaust valve, which comprises a valve body, a valve seat, a valve core, a spring and an adjusting screw, wherein the valve seat consists of an upper part and a lower part; the inner diameter of the upper part is less than that of the lower part; the valve core is cylindrical, is located in the lower part of the valve seat ns is in clearance fit with the valve seat; the length of the valve core is less than the depth of the lower part of the valve seat, so that the valve core is capable of vertically sliding on the lower part of the valve seat, and moreover, when the upper end face of the valve core is contacted with the upper part of the valve seat, the lower end face of the upper part of the valve seat can be closed; the spring is located in the upper part of the valve seat; the upper end of the spring is connected with the valve seat; and the lower end of the spring is connected with the valve core. The mechanical automatic exhaust valve disclosed by the u