::: Brake valve test and adjustment bench
::: CHALLENGE :::
Develop a bench for testing and adjustment of hand brake valves for heavy duty vehicles, reaching 100% of production test with a capacity exceeding 60 parts per hour. The bench must have an acquisition and control software executed by a real-time hardware and a supervisory control software for presentation and data management. All hardware involved in data acquisition and control should be from the National Instruments PXI family, according to the standard set by the parent company. The system vendor should be able to design and manufacture all the mechanical system of the bench as well as the control system and data acquisition from them.
::: SOLUTION :::
Design and manufacture a bench with stations operating independently performing all the movements necessary to perform the test routines. The whole bench automation was controlled by the architecture formed by a National Instruments PXI computer operating in real time and the respective data acquisition boards. The monitoring software was developed in LabVIEW, and was instructed to submit the test data, and allow user interaction with the operation, configuration and datalogging of the measurements acquired in the system.
::: Description :::
Knorr Bremse, brake valve manufacturer for commercial vehicles contracted DAQSYS for the development of a test bench for tuning and adjusting brake valves. The tests on the hand brake valves are made up of three basic routines test: Analysis of air response, handle the drive torque and leakage test. In the pneumatic response analysis the system analyzes the pressure response valve according to the fist drive angle. Thus, the PXI computer and its associated software are responsible for the following operations:
• Drive Control and position of the servomotors used to handle the drive and setup the adjustment screw.
• Measurement of the angular position of the handle.
• Measurement of drive torque, unlocking torque and displacement of the handle.
• Pressure Control through a pneumatic proportional valve.
• Pressure measurement which must be synchronized with the angular position measurement.
During the pneumatic response of the valve and the measured torque of the valve, the tests are compared with the registered values of the test valve to make adjustments in the setup of screw or rejecting the valve if you cannot adjust it. The bench also runs a tightness test of the valves, which is run by a dedicated equipment built into the test bench.
In addition to the test steps described above, the system is also responsible for control of 128 inputs and 128 digital outputs, used to drive valves and pneumatic cylinders, monitoring sensor signals, etc.
The bench also has a microcomputer such as a Panel PC running a supervisory software system, which was also developed in LabVIEW and it communicates with the embedded software in real-time controller PXI system using the technology of shared variables. This software enables the visualization of graphs and data measured during the tests, in addition to modules such as logging of valves types, maintenance module, calibration module, configuration screens, user management and automatic report generation. The registration information and results are stored in the database, allowing flexibility in the query and manipulation of it.
Once it is a production line test equipment, anti-failures routines were developed for the parts rejection operation and a tool to ensure traceability of the produced parts.
For more information about this application or others developed by DAQSYS, contact by phone +55 (41) 9967-6977 or info@daqsys.com.br.
