On-line Monitoring Research And Application Of Tool Wear For Milling Process Of Car Engine Production

In CNC machining, Tool wear has a serious impact on the surface quality, machining accuracy and the processing efficiency of the workpiece. Assembly line production methods are adopted in automobile engine production. Error is usually happen to the machine if Worn tool can not be discovered and changed timely. This will cause the whole production line can’t work normally. Combined with the actual situation and demand of the car engine production, This paper presents a tool wear condition monitoring method based on the analysis of spindle motor current signals. The main research content is as follows:Firstly, Based on the analysis of car engine production process and tool wear form and mechanism, this paper present a tool wear monitoring method by monitoring the current signal. The Research plan and experiment platform are established.Then, Based on the analysis of process of car engine, Pretreatment method of current signals and choice of smoothing parameter are discussed. The variation regular of signals in time domain and frequency domain is analyzed.the sensitive characteristics for the tool wear conditions are extracted. Their scope of application is discussed. By studying regular of tool wear, tool wear condition identification model is established.Finally, this paper present the concrete realization method of tool monitoring. The PMC programmer is developed to connect the device with CNC machine tool. The identification result of the model is validated. And most of the damage of parts can be avoided using the tool monitoring device. And the production efficiency is greatly increased.