Measurement, control and evaluation of the pneumatic system in buses

Some critical systems in the buses are operated with pneumatic devices. Brake, suspension and door driving mechanisms of all busses are designed as pneumatically. In order to operate efficiently pneumatic systems has to work above a limit pressure given by the regulations (71/320/At). The operating system pressure should not drop below this limit. The main reason for this pressure drop is the leakage in the pneumatic systems. In order to prevent these leakages, the line that has leakage has to be detected by a sensitive measurement device. The system that is used in buses is too old and not sensitive enough. The device that developed, checks the problems in the pneumatic systems and electric circuits connected to them, that are arrayed in a 14 line and reports the places of the problems to the quality control personel. With this device, measurement process revised and new efficient methods to interfere the problems studied. Also, the statistics of the problems made and feedbacks related to the departments can be done. With the PLC automation system in-body quality control device, bus pneumatic line has been tested as air tightneess and brake circuit in two stage. With test results, pressure leak in the brake circuit of the bus line has been determined in production facilities. For example, pressure decrease was detected with air tightness test as 0,35 bar, with brake circuit line test as 0,50 bar at brake pressure control point.