Research On Monitoring Technique For Cutting Tool’s Wear Based On The Thermoelectric Effect

As the change of market demand, the trend of manufacturing equipment is more automation and integration. During the processing, many deteriorate situations will happen, cause the machining process interrupted. Tool wear and the accidental damage are the typical processing conditions, which not only make the product quality can not meet the security, but also can not meet the ideal requirements, it forces the producers have to increase investment in manufacturing. So, the effective processing condition monitoring technology become the most important task. It is of great significance to improve the machining quality and ensure the normal operation of processing equipment, the extension of the service life of the workpiece, and the guarantee of production safety. Monitoring technique for cutting tool’s wear has been concerned by the middle of the last century, then by a great number of in-depth study, along with the rapid development of computer, sensor, intelligent system and pattern recognition, digital and image signal processing, intelligent control, it has become a course which includes many advanced technology in the field of science.In order to ensure the high efficiency of the uninterrupted processing, the processing condition monitoring technology has become inevitable, and the technology occupies an absolute dominant position in advanced manufacturing technology. Since the middle of the 20th century, many manufacturers have started the research of the issue, and the failure of cutting tool and breakage is the most common failure in the process. So, the use of advanced monitoring technology to predict the change of cutting tool state will become the focus of research.This article is based on thermoelectric effect of tool wear condition monitoring system, and its research object is turning process, but the application object of this system can be expanded to the whole manufacturing system. Purpose is to study the thermoelectric effect between tool and workpiece to monitor machining center tool wear and breakage. The principle of thermoelectric effect produced is:in the process of metal cutting, due to the difference of cutting materials the workpiece materials, it will produce a great quantity of heat because of the friction between metal, so in the process of cutting will produce thermoelectric effect, and there is a certain relationship between the thermal parameter values and the cutting tool wear. Making a brief introduction of the three elements of cutting and the law to the choice of cutting elements. Then, instruct the concept of the orthogonal experiment design and the plan of orthogonal design scheme in detail. Obtaining the rank of the influence degree of the three elements to the thermoelectric parameter value by the processing and analysis of final experiment data, and come to a conclusion:cutting parameter influence on thermal power parameter value rule and rule of cutting parameter to the influence of cutting temperature is the same. Finally, it is concluded that tool wear amount and the corresponding thermal parameter value function and curve by using the least squares method, and then deduce the thermoelectric potential value of the corresponding amount of tool wear based on the polynomial function.We will use thermoelectric parameter values of the cutting tool failure as the basis, when the thermoelectric system monitoring parameters value reaches the critical value, it will remind workers to change the tool in time. At last, verify the amount of tool wear when reaches the critical point in a reasonable scope through a set of experiments illustrates the tool wear condition monitoring system based on thermoelectric effect is reasonable.