Combined valve

The utility model provides a combination valve which comprises a valve base, a first pilot head, a second pilot head and a third pilot head. The first pilot head, the second pilot head and the third pilot head are installed on the valve base. Wherein the valve base is provided with a main air inlet, a working air pipe, a first pilot port, a second pilot port and a third pilot port; the first pilothead, the second pilot head and the third pilot head are respectively used for opening and closing the first pilot port, the second pilot port and the third pilot port; a negative pressure opening and a positive pressure opening are formed in the working air pipe, a vacuum nozzle is arranged in the valve base, the input end of the vacuum nozzle communicates with the main air inlet through a firstpilot opening, and the output end of the vacuum nozzle communicates with the outside; an adsorption cavity is formed in the output end of the vacuum nozzle and communicates with the negative pressureopening through a second p