Unloading device and air compressor

An unloading device, which is applied to an air compressor comprising a plurality of cylinders, the unloading device comprising:

• a plurality of unloading valves, each of the unloading valves movably covering an unloading hole of one of the cylinders;
• an unloading cavity in communication with the unloading hole;
• an intake cavity in communication with the unloading cavity;
• a piston member connected to the plurality of unloading valves by means of a shift fork;
• and
• a valve seat plate covering the cylinder, wherein the unloading hole is formed in the valve seat plate, and the unloading cavity is located on the side of the valve seat plate facing away from the cylinder;
• wherein the shift fork comprises a main body portion located in the unloading cavity and abutting against the valve seat plate, the main body portion being provided with a plurality of open slots;
• wherein each of the unloading valves has a distal end rotatably connected to the valve seat plate by means of a pin shaft, and a proximal end connected to a pilot pin, the pilot pin extending into the open slot;
• wherein, in an unloading state, the piston member is capable of driving, via the shift fork, the unloading valve to move to uncover the unloading hole, so that air in the plurality of cylinders circulates back and forth through the unloading cavity.