Study On The Fault Diagnosis And Design Improvements About The Water Temperature Monitoring System Of Excavator Engine

Display instrument for temperature excavator is a water temperature sensor adoptsanalog voltage signal of the feedback controller to realize after treatment, the watertemperature sensor is a negative temperature coefficient of the resistance, the resistancevalue is changing with the engine temperature, the controller will send a signal voltageto the water temperature sensor. The changes of the resistance at the same time, thevoltage is used as feedback signal is also changing, but when the other loop vehiclecircuit system in conducting at the same time, to a certain extent, also can bring certaininfluence to the feedback signal of the water temperature.In this paper, a fault excavator produced by the systematic analysis of thephenomenon of fault and its performance is when excavator in bright lights or airconditioning, excavator instrument display3-6℃higher than that of water instantly.When the headlights or air conditioning and other electrical equipment is turned off,excavator instrument display temperature can drop moment before. That at the time ofopen the electricity equipment, the instrument shows false high temperature condition.Data were analyzed according to the excavator shown by the actual fault and thedata collection. A comprehensive analysis of sensor types, factors of the changeof circuit of the system before and after the start, fault analysis and comprehensive.According to the possibility of failure causes inferred, one by one in the faultpossibilityof excavator fault point processing, processing after re test machine,again for datacollection and analysis, observe the change of fault phenomena.After the processing for each of the point of failure, will draw a fundamentalreason leading to failure phenomenon, thus draw a effective technicalreformprogram, the application of fault machine tested technical reform program,theestablishment of the new machine mass production technology rectification standardsAccording to the water temperature sensor signal voltage received interferenceproblem, this paper adopts the method to treat the failure problem of voltagecorrection, the integrated operational amplifier to be amended, and achieve goodresults in the real vehicle test.