The paper also explores and discusses the implementation and application perspectives of those smart tools against the smart machining requirements from a number of industrial applications, such as micromachining maintained with constant cutting force, extra-high speed micro drilling, and contamination-free machining of medical device or explosive materials [Smart cutting tools are built with autonomous sensing and self-learning capabilities, and operate in-process sensoring and actuation and will thus likely lead to improved part quality and surface roughness, reduced production costs and higher manufacturing productivity.
They are characterized with some distinguished features such as plug-and-play, autonomous operation, self-condition monitoring, self-positioning adjustment, self-learning, compatible with highly automated CNC environments.
Cutting force can be generally measured by three methods, i.e., using force shunt, direct force measurement and indirect force measurement.
Regarding direct cutting force measurement method, a sensoring unit is mounted directly in the force path in order to measure the entire process force.
Smart machining has tremendous potential and is becoming one of new generation high value precision manufacturing technologies in line with the advance of Industry 4.0 concepts.
This paper presents some innovative design concepts and, in particular, the development of four types of smart cutting tools, including a force-based smart cutting tool, a temperature-based internally-cooled cutting tool, a fast tool servo (FTS) and smart collets for ultraprecision and micro manufacturing purposes.Some high value components require to be machined in a contamination-free environment, which means coolant cannot be applied during the machining.However, dry cutting condition would lead to tool wear and high cutting temperature, and poor surface quality would thus occur and tool life be shortened.In order to produce a strong signal in the low frequency range, a plastic tip head of the impact hammer is applied in the hammer test.Both signal outputs from the digital impact hammer and the piezoelectric sensor were converted from the time domain into the frequency domain.For instance, ultra-precision and micro machining, with the surface roughness normally at the nanometric scale and features/patterns at the micrometer level, is increasingly and continuously demanded particularly for high precision components and products with improved functionality and performance.The smart precision and micro manufacturing in a ‘proactive’ manner will be the way forward .Four types of smart toolings have been developed by the authors as highlighted in Figure .They include the cutting force measurement based smart cutting tool, cutting temperature oriented smart cutting tool, fast tool servo (FTS), and the smart fixtures and smart collets, which are applicable to measure cutting force, cutting temperature, tool positioning and actuation in process, respectively or combined.In high precision machining, however, to position the cutting tool with such high accuracy and repeatability is the key and this is normally undertaken in a “passive” manner, i.e., the tool’s position relying on the slideways’ positioning accuracy but without measuring the tool cutting behaviour and process conditions.Furthermore, for many high value precision machining processes, it is important to use smart cutting tools to carry out the processes in a ‘proactive’ manner, in order to cope with machining dynamics, process variations and complexity.