Air supply structure of pneumatic tool

An air supply structure of a pneumatic tool, comprising:

• a housing, comprising an operating portion, a connecting portion and a holding portion, the operating portion comprising an air chamber, the holding portion comprising an air entering channel and an air exiting channel, the connecting portion being in communication with the air chamber, the air entering channel and the air exiting channel;
• a ventilation module, disposed in the connecting portion, the ventilation module separately manufactured into a first assembly member and a second assembly member connected to the first assembly member, and the ventilation module comprising a ventilation space between the first assembly member and the second assembly member, wherein the first assembly member comprises an air outlet and a first air opening, and the second assembly member comprises an air inlet and a second air opening, and the ventilation space is communicated with the air inlet, the air outlet, the first air opening and the second air opening;
• a piston, disposed in the operating portion;
• a first air valve, disposed in the ventilation module;
• and
• a second air valve, disposed in the ventilation module;
• wherein in a first state, the first air valve is open and the second air valve is closed, such that the first air opening communication with the air inlet and the air chamber, and the piston is located at a forward position;
• wherein in a second state, the first air valve is closed and the second air valve is open, such that the second air opening is in communication with the air inlet and the air chamber, and the piston is located at a withdrawn position.