Valve seat structure of diaphragm pump and diaphragm pump

A valve seat structure of a diaphragm pump, comprising:

• a water inlet seat provided in a valve seat;
• a water inlet valve mounted in the water inlet seat;
• the water inlet seat is provided with a mounting hole and a water inlet hole;
• the water inlet valve comprises a water inlet valve plate and a water inlet valve stem which are connected to each other;
• the water inlet valve stem is mounted to the mounting hole, and the water inlet valve plate is of a bowl-shaped structure for movably opening and closing the water inlet hole;
• the water inlet valve plate is positioned on a front side of the water inlet seat;
• a guide base is provided at a back side of the water inlet seat;
• the guide base is mounted in the mounting hole in a reciprocating sliding manner;
• the water inlet valve stem has a first end which is fixedly connected to the water inlet valve plate and a second end which penetrates into and is fixed in an intermediate connecting hole of the guide base in the mounting hole;
• the guide base has a first end which is distant from the water inlet valve plate;
• the first end of the guide base extends out of the mounting hole and is provided with a radially protruding restricting portion;
• the guide base is sleeved with a pressure spring, and two ends of the pressure spring respectively abut against the restricting portion and an edge of the mounting hole on the back side of the water inlet seat.