Compressed air supply apparatus

1. A compressed air supply apparatus comprising:

an air compressor installed in at least one of a plurality of vehicles connected to each other;

a plurality of air tanks connected to the air compressor via a connection flow path and installed in each of the plurality of vehicles in communication with each other;

a pressure measurement unit configured to measure an air pressure in one of the plurality of air tanks connected to the air compressor via a shortest flow path, among the plurality of air tanks;

a control unit configured to operate the air compressor when a measurement value of the pressure measurement unit reaches a first pressure or less, and configured to stop the air compressor when the measurement value reaches a second pressure higher than the first pressure;

a plurality of relief valve apparatuses installed in each of the connection flow path between the air compressor and each of the plurality of air tanks, and

a safety valve configured to release compressed air in the plurality of air tanks into an atmosphere when an air pressure in the plurality of air tanks reaches a pressure higher than the second pressure,

wherein each of the plurality of relief valve apparatuses comprises:

a flow-restricting unit configured to restrict an air flow, and

a valve main body installed nearer to a corresponding one of the plurality of air tanks than the flow-restricting unit, configured to open the connection flow path to the atmosphere when the measurement value reaches a third pressure higher than the second pressure and lower than the pressure at which the safety valve is operated, and configured to close the connection flow path when the measurement value reaches a fourth pressure higher than the second pressure and lower than the third pressure after the opening.

2. The compressed air supply apparatus according to claim 1 , wherein the flow-restricting unit is a throttling flow path having a smaller flow path area than the connection flow path.

3. The compressed air supply apparatus according to claim 2 , wherein each of the plurality of relief valve apparatuses is installed downstream from a flexible pipe installed in the connection flow path.

4. The compressed air supply apparatus according to claim 3 , wherein each of the plurality of relief valve apparatuses is installed downstream from an aftercooler installed in the connection flow path and configured to dehumidify compressed air.

5. The compressed air supply apparatus according to claim 2 , wherein each of the plurality of relief valve apparatuses is installed downstream from an aftercooler installed in the connection flow path and configured to dehumidify compressed air.

6. The compressed air supply apparatus according to claim 1 , wherein each of the plurality of relief valve apparatuses is installed downstream from a flexible pipe installed in the connection flow path.

7. The compressed air supply apparatus according to claim 6 , wherein each of the plurality of relief valve apparatuses is installed downstream from an aftercooler installed in the connection flow path and configured to dehumidify compressed air.

8. The compressed air supply apparatus according to claim 1 , wherein each of the plurality of relief valve apparatuses is installed downstream from an aftercooler installed in the connection flow path and configured to dehumidify compressed air.

9. The compressed air supply apparatus according to claim 8 , wherein the aftercooler is installed in the connection flow path separately from the air compressor.