| Description |
With the importance of environmentally benign manufacturing processes growing globally, metal machining processes are one of the candidates for increased sustainability initiatives. One strategy that has been proposed is drastic reduction in the use of cutting fluids, which are usually applied as a flood, and are known to pose several environmental and economic issues, such as toxic mist generation, liquid waste disposal, reduced recyclability of scrap/chips, and high maintenance cost. The Minimum Quantity Lubrication (MQL) concept of using small amounts of lubricant in an atomized spray has been researched and advocated extensively in the literature. However, since the typical flood cooling medium has been eliminated and only a lubricant is present, problems caused by thermal build-up, such as increased tool-wear and thermal distortion of work parts, continue to exist. The generic application of a flood of cutting fluid has masked the need for precisely estimating minimum amounts of coolant and lubricant needed for different work materials that are being machined. In order to experimentally and theoretically model the minimum amounts of coolant or lubricant needed, a system capable of controlling and delivering specific amounts of cutting fluids need to be designed. There are a few products available in the market that cater to controlled fluid application needs but these systems are unable to dispense a separate coolant and lubricant, and are also unable to precisely control the quantity of fluid used. Moreover, there has been little effort to explore the feasibility of interfacing cutting fluid application systems with CNC (Computer Numerical Control) machine controllers. In this thesis, a novel multiple fluid dispensing system has been designed, and this system is capable of providing a simultaneous supply of small amounts of coolant and lubricant in an independent manner. The focus was on designing a system that is modular in nature and can be interfaced with the CNC machine controller or sensors or both. Initial design iterations were explored and a solution to meet the budget and time constraints was developed. The MQCF dispensing system is designed to output metered quantities of multiple fluids simultaneously and independently, based on real-time digital signals of measured physical quantities (such as machining forces). By using the system presented in this thesis, manufacturing process planners have a device that can maintain process quality by utilizing an appropriate system response in the form of instantaneous application of coolant and/or lubricant. |
