| Transmission is an important part of automotive powertrain which transfers thepower of engine to other drive mechanism through the gear of different ratio in thetransmission to drive the car. Mechanical transmission occupies the largest marketshare in automotive transmissions. Because of the reasonable price and low fuelconsumption, mechanical transmission will continue to play an important role in thetransmission field in the future. In recent years, the number of mini-bus is constantlygrowing. The FR mechanical transmission which is widely used in the mini-bus alsodraws a lot of attention of the mini-bus manufacturers. Development ofhigh-performance FR mechanical transmission test bench is very important forfinding the problem of the design and technology, improving the efficiency of thedevelopment of transmission, reducing the transmission defects and ensuring thequality of vehicle.This research is based on the project that the development of mini-bus FRmechanical transmission performance test bench. According to the technicalrequirements, the research makes the transmission efficiency test and lubricantstemperature rise test as the targets. The research and development work also takesversatility and expansibility into consideration.First, in order to develop the overall plan of the test bench, we analyzed the basicplans from three aspects, bench type, measurement and control system. The testbench uses DC-bus and linear arrangement. Its measurement and control system isbased on PROFIBUS-DP. The PLC works as the master and the inverter controllerand the IPC work as the slaves. Virtual instrument technology and data acquisitioncard are used in the IPC to collect process signals.Second, in order to build the test bench hardware platforms, we designed andselected the hardware also from three aspects, mechanical system, drive system andmeasurement and control system. To ensure the safety of the test and realize theautomated testing, remote automatic shifting robot which is similar to the AMT wasdesigned. In order to make the load motor match the transmission, a high-performance gear box with2:1ratio was designed. To realize the measurementof the temperature sensor output signal, an amplify filter circuit with highcommon-mode rejection ratio, high input impedance and low offset voltage wasdesigned. High-precision sensors, multifunction data acquisition card,high-performance PLC and communication interface card were selected to realizehigh-speed acquisition, precise control and stable communication function.Third, in order to realize the functions of measurement and control of the testbench, we debugged the S120inverter system, and built the PROFIBUS-DP network,and design the software on the IPC. Not only did we use SIZER to complete thehardware configuration of S120variable frequency drive system, but also we used theSTARTER to optimize the motors. We used STEP7to configure each station ofPROFIBUS-DP communication network and communication telegrams and writeprograms of PLC to realize the functions of periodic and aperiodic datacommunication between master station and slave stations. On the IPC we wroteLabVIEW programs to make IPC communicate with the PLC master station throughthe DF PROFI II board and complete the development of data acquisition and userinterface.Fourth, in order to complete transmission efficiency test and lubricantstemperature rise test, we developed specific test procedures. We not only completedthe relevant tests, but also analyzed the results.The electrically closed FR mechanical transmission test bench has a simplestructure and strong expansibility. It uses SIEMENS high-speed motor as drive and itcan carry out a transmission test with a maximum input speed of the6500r/min.Because it uses a common DC bus regenerative electric enclosed structure whoseactual intake of energy from the grid is very limited, the energy-saving effect isobvious compared with the open-type electric power flow mechanical transmissiontest bench. |
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