Screw cap height detection device for filling machine

The utility model discloses a screw cap height detection device for a filling machine, which comprises a first mounting rack, a second mounting rack, an air cylinder, a push plate, a pressing plate and a top plate, the horizontally arranged air cylinder is mounted on the first mounting rack, a piston rod of the air cylinder is connected with a vertically arranged first connecting plate, the horizontally arranged push plate is connected to the connecting plate, and the pressing plate is mounted on the second mounting rack. A second mounting frame is arranged on one side of the first mounting frame and comprises a blocking part, a pressing plate is arranged below the blocking part, a spring is arranged between the pressing plate and the blocking part, the spring is in a compressed state, and a part of the baffle is located under the cylinder body of the air cylinder. And a button or a pressure sensing device for controlling the cylinder is arranged at the bottom of the cylinder body. According to the utility mo