Design Of Embedded Crankshaft Stress Test System For Engine

The crankshaft of internal combustion engine is under the action of alternating load for a long time,and the accident of shaft breaking due to fatigue failure happens from time to time,which causes great loss of life and property.Therefore,the research on the force of crankshaft to provide theoretical and data support for the reliability design of crankshaft has been the focus of scholars at home and abroad.However,due to the poor working environment of crankshaft,the relevant research work is mainly focused on the finite element analysis,calculation and simulation,and the lack of measured data support.In this paper,a 4 channel crankshaft dynamic stress testing system is developed based on the design principles of miniaturization,low power consumption,high temperature resistance and anti-vibration.System level chip hardware all use cars,with low power consumption PIC singlechip as the core,in view of the strain bridge unbalanced output DAC is designed bridge automatic zero circuit,first through the signal conditioning circuit switch after zero strain bridge output amplification processing,signal filtering by microcontroller built-in high-speed 12 bit ADC converts the signal to the digital quantity,finally will test data in the F-RAM memory as a backup.The low-power ZigBee wireless communication technology is adopted,and the test data in the memory is uploaded to the receiving end of the upper computer outside the crankcase by wireless control chip.The system software designed the DAC automatic zero setting program for the unbalanced output of the bridge,and added the program of automatic sleep,timing acquisition and intermittent power on during the system operation to reduce the power consumption of the system.In order to verify the overall performance of the test system,the crankshaft dynamic stress test experiment was carried out on the diesel engine bench after testing the function of each module.The results show that the system has good stability and reliability,can accurately measure the crankshaft dynamic stress signal and display the stress change curve of the crankshaft spindle neck fillet,and can provide the practical data support for the design and optimization of the crankshaft.