An experimental study for weight balance evaluation using rail vehicle weighting system

초록

Rail vehicle consists of a car body to take passengers on board, two bogies to support the load of the car body firmly and deliver the force of traction, various electronic equipments such as storage battery, air compressor, power supply for air conditioner which are installed under the bottom of the train and a pantograph to collect the overhead current on the roof. Among the components of the rail vehicle, bogie remarkably influences the railway safety. If the bogie is damaged, the diagonal balance may break down which can induce the derailment of the train and unevenly wear down the rail. To guarantee the structural health of bogie, it is necessary to monitor the weight balance periodically. In the present article, a rail vehicle weighting system which can be used to measure the wheel load easily and effectively is developed and parameters to break down the weight balance of the bogie are evaluated. A vehicle weighting system consists of a hydraulic pump, mechanical component to lift a wheel and digital load display. The hydraulic pressure from the hydraulic cylinder is pumped through a pressure hosepipe to a lifting component mechanically for the wheel. The wheel load is measured by the pressure sensor and displayed by the digital indicator which can show a digit of 0.01 ton. The system relying on the hydraulic pressure was improved for the present application. Four wheel weighting systems were installed simultaneously at each wheel of a bogie on the track. The rail vehicle for this experiment is a commuter train of KORAIL in Korea. Diagonal weight balance of bogie was measured when the height of an air spring situated on the left side of the bogie was lowered to 20mm in increments of 5mm. Wheel loads at the position where the height of an air spring was lowered were decreased to 21.7%, 23.7%, respectively. At the opposite position, wheel loads were increased to 23.6%, 27.2%, respectively. Wheel loads at each wheel were changed linearly to the height of air spring. When an air spring situated on the left side is lowered, the other one situated on the right side takes the load more. Thus the wheel loads at the right side were increased. From the experimental study in this paper, a vehicle weighting system for the measurement of weight balance has been realized and tested. Also, we found that the height of air spring influences the weight balance of bogie. In the next study, we’ll quantify the effects of weight balance from the various experimental cases.