Systems and methods for real-time monitoring of micromilling tool wear

#The present disclosure relates to micromilling, and in particular to monitoring of tool wear in connection with the same.

#Micromilling is a material-removal manufacturing process for producing parts that typically are less than 1 mm in size, with features measured in microns, and sub-micron manufacturing tolerances. A micromilling machine typically consists of a tool known as a micro-endmill placed in a spindle. The micro-endmill contains one or more teeth. The spindle typically rotates the micro-endmill at speeds exceeding 50,000 RPM while advancing the tool through the material. Each time a tooth of the micro-endmill passes through the material, a chip is produced and removed from the material. As the micro-endmill removes chips, the teeth become dull. Dull micro-endmill teeth cause a manufacturing defect known as “burring” and eventually cause the micro-endmill to break.

#Measuring the state of wear of a micro-endmill is typically done by halting the cutting process, removing the micro-endmill from the machine, and examining it under a microscope. The radius of the cutting edge of the teeth is measured visually, and is used as a quantification of tool wear. This process is cumbersome and time-consuming; accordingly, improved systems and methods for assessing tool wear are desirable.

#With reference to the following description and accompanying drawings:

#FIG. 1 illustrates a block diagram of an exemplary micromilling tool wear monitoring system in accordance with an exemplary embodiment;

#FIG. 2 illustrates a block diagram of exemplary components of a micromilling tool wear monitoring system in accordance with an exemplary embodiment;

#The following description is of various exemplary embodiments only, and is not intended to limit the scope, applicability or configuration of the present disclosure in any way. Rather, the following description is intended to provide a convenient illustration for implementing various embodiments including the best mode. As will become apparent, various changes may be made in the function and arrangement of the elements described in these embodiments without departing from the scope of the present disclosure.

#For the sake of brevity, conventional techniques for machining, micromilling, microscopy, and/or the like may not be described in detail herein. Furthermore, the connecting lines shown in various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in a practical tool wear monitoring system.

#In accordance with principles of the present disclosure, tool wear may be monitored during the cutting process via measuring the rate of chip production. The “minimum chip thickness” principle indicates that a tooth cannot produce a chip that is thinner than ⅓ of the cutting edge radius of that tooth. Accordingly, principles of the present disclosure contemplate real-time monitoring of the state of wear of a micro-endmill; this may be accomplished by recognizing the existence of a relationship between the state of tool wear and a discrepancy between the number of chips that should be produced (based, for example, on machining parameters) and the number of chips that are actually produced. An exemplary tool wear monitoring system may be configured to measure this discrepancy and thus infer the state of tool wear.