TYSCI Technologies ’ spring compression tester was designed and developed for testing of railway car bogie springs. These springs are dynamically tested and the results are not only plotted but compared to the ideal spring rate curve.
The testing is automatic with the procedures comprising of several tests depending on the spring type.
The majority of the springs are steel and are nested, thus the spring rate changes with displacement. Some of the springs are rubber which react differently and give more of a curve as they are compressed.
The load is applied hydraulically using proportional valves whilst the guarding and other labour saving functions are pneumatically operated.
Data acquisition and control of the machine is done through National Instruments’ LabVIEW, and the desktop computer uses a PCI card also from National Instruments.
The accuracy of the readings is important as the machine has to meet Australian standard AS2193 grade A. Calibration can done through the program or through physical adjustments of the signal conditioners. Either way it is a task that is done annually.
Several sub routines are incorporated in the main VI (virtual instrument). These are for different spring sets and each is tested according to the test schedule. The plotted results are printed and are kept with the spring sets while the test results are written to file.
Using high quality PC cards and a stable operating system the machine is in use daily without undue problems.