Intermittent air-generating device

An intermittent air generating device configured to intermittently output compressed air from an air device, comprising:

• a supply source configured to supply the compressed air;
• and
• a switching device disposed downstream of the supply source,
• wherein the switching device includes:
• a body provided with an inlet port to which the compressed air guided from the supply source is supplied, an outlet port for outputting the compressed air to the air device, a pilot input port to which pilot air is supplied, and an exhaust port for discharging the pilot air which is supplied to the pilot input port;
• and
• a valve element disposed inside the body so as to be movable to an air-stop position to stop supply of the compressed air to the air device and an air-supply position to supply the compressed air to the air device;
• wherein:
• when the valve element is located at the air-stop position, communication between the inlet port and the outlet port and communication between the pilot input port and the exhaust port are respectively blocked off by the valve element, and the pilot air is supplied to the pilot input port,
• when the valve element is located at the air-supply position, the inlet port and the outlet port communicate with each other via the valve element, and the pilot input port and the exhaust port communicate with each other via the valve element,
• when the pilot air is supplied to the pilot input port in a state where the valve element is located at the air-stop position, the valve element is moved from the air-stop position to the air-supply position by a pressure of the pilot air against a biasing force which is biased from the air-supply position to the air-stop position,
• while supplying the compressed air to the air device by causing the inlet port and the outlet port to communicate with each other via the valve element in a state where the valve element is located at the air-supply position, the valve element discharges the pilot air by causing the pilot input port and the exhaust port to communicate with each other via the valve element, and
• as the pilot air is discharged via the valve element, the valve element is automatically returned from the air-supply position to the air-stop position by the biasing force, and the communication between the pilot input port and the exhaust port is blocked off by the valve element.