The Research On The Tool Condition Monitoring Based On Infrared Temperature

In the metal cutting,the tool always happen wear or broken.The wear condition make the precision of the workpiece low,the surface of the workpiece coarse and the quality of the workpiece worsen.The tool will lose the cutting skill and even damage the machine when it wear badly.So,research on the tool condition monitoring has both the important academic signification and the practical value.The key to the success in tool condition monitoring is to find the characteristics data that correspond to the tool condtion well.These characteristics data can identify the tool condition.Though many scholars have researched in the tool conditon monitoring these years,it is hard to find the characteristics data due to the variety of maching condition and the asymmetry of the workpiece.For tool wear has near relationship with the cutting temperature,the temperature will increase along with the increasing of the tool wear.In this thesis,the infrared method is uesd to analyze the tool surface temperature under the different condition of the tool wear,and get characteristics data with good relationship to tool condition.In this thesis,the main efforts are on end milling.Firstly,the hardware of the tool monitoring system is built,the software of the system is programmed,the specialty of the system is analyzed and the error of the system is calibrated based on the principle of the infrared temperature.Secondly,the 3D model of the tool is built,the boundary condition is confirmed,the temperature distribution of the tool is analyzed under the steadily milling.The result of the distribution analyse show that the surface temperature can reflect the cutting temperature,also reflect the tool wear condition indirectly and approve the feasibility of the method of measuring the surface temperature. Then,characteristics of the tool condition and worn process are analyzed,the standard of tool wear is introduced and the system is used to do the milling experiment. The effects of cutting parameter and tool wear on surface temperature are studied and the curve formula is infered.The experiment show that the increasing of the cutting speed v,feed rate fz and radial depth of cut aw make the increasing of the surface temperature.And the effect of v is most,fz is next and aw is least.The conclusions of the experiment can provide production practice with the useful data.At last,the BP nerval network is used to build the relationship bwtween the tool wear condition and the surface temperature.It increase the identify ability,possess the multiplication ability and is propitious to the online monitoring.