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- Case-based product development of a high-pressure die casting injection subset using design science researchPublication . Tojal, Matilde; Silva, Francisco J. G.; Campilho, R.D.S.G.; Pinto, Arnaldo; Pinto Ferreira, LuísHigh pressure die casting is widely used in metalworking industry. Many of the components and devices directly linked to the hot parts are subjected to severe wear. However, some design updates can enlarge the lifespan of these components and devices. This paper proposes to show how a sustainable maintenance can be obtained by focusing resources on the analysis of the critical problem and its consequent mitigation, whereas they are originated on the human, machine/process or supplier level. Design science research (DSR) was the iterative research methodology chosen to integrate this work. The completion of the objective with the implementation of this new injection subset concept brought extremely beneficial results, such as reduction of its consumption, reduction of acquisition cost and waste generated, and reduction of the intervention time during maintenance operations, as well as increase in equipment availability time.
- Build-Up an Economical Tool for Machining Operations Cost EstimationPublication . Silva, Francisco J. G.; Sousa, Vitor F. C.; Pinto, Arnaldo; Pinto Ferreira, Luís; Pereira, Maria TeresaCurrently, there is a lack of affordable and simple tools for the estimation of these costs, especially for machining operations. This is particularly true for manufacturing SMEs, in which the cost estimation of machined parts is usually performed based only on required material for part production, or involves a time-consuming, non-standardized technical analysis. Therefore, a cost estimation tool was developed, based on the calculated machining times and amount of required material, based on the final drawing of the requested workpiece. The tool was developed primarily for milling machines, considering milling, drilling, and boring/threading operations. Regarding the considered materials, these were primarily aluminum alloys. However, some polymer materials were also considered. The tool first estimates the required time for total part production and then calculates the total cost. The total production time is estimated based on the required machining operations, as well as drawing, programming, and machine setup time. A part complexity level was also introduced, based on the number of details and operations required for each workpiece, which will inflate the estimated times. The estimation tool was tested in a company setting, comparing the estimated operation time values with the real ones, for a wide variety of parts of differing complexity. An average error of 14% for machining operation times was registered, which is quite satisfactory, as this time is the most impactful in terms of machining cost. However, there are still some problems regarding the accuracy in estimating finishing operation times
- Using an Artificial Neural Network Approach to Predict Machining TimePublication . Rodrigues, André; Silva, Francisco; Sousa, Vitor F. C.; Pinto, Arnaldo; Pinto Ferreira, Luís; Pereira, Maria Teresa RibeiroOne of the most critical factors in producing plastic injection molds is the cost estimation of machining services, which significantly affects the final mold price. These services’ costs are determined according to the machining time, which is usually a long and expensive operation. If it is considered that the injection mold parts are all different, it can be understood that the correct and quick estimation of machining times is of great importance for a company’s success. This article presents a proposal to apply artificial neural networks in machining time estimation for standard injection mold parts. For this purpose, a large set of parts was considered to shape the artificial intelligence model, and machining times were calculated to collect enough data for training the neural networks. The influences of the network architecture, input data, and the variables used in the network’s training were studied to find the neural network with greatest prediction accuracy. The application of neural networks in this work proved to be a quick and efficient way to predict cutting times with a percent error of 2.52% in the best case. The present work can strongly contribute to the research in this and similar sectors, as recent research does not usually focus on the direct prediction of machining times relating to overall production cost. This tool can be used in a quick and efficient manner to obtain information on the total machining cost of mold parts, with the possibility of being applied to other industry sectors
- Developing a Novel Fully Automated Concept to Produce Bowden Cables for the Automotive IndustryPublication . Sousa, Vitor Fernando Crespim; Silva, Francisco J. G.; Campilho, Raul; Pinto, Arnaldo; Pinto Ferreira, Luís; Martins, NunoThe automotive industry is one of the driving forces of the global industry; thus, it is a very competitive sector which creates a constant need for process improvement, regarding productivity, quality, and flexibility. Automation has proven to be a viable solution for these production problems, with the rising adoption of these automated system by companies that try to design and implement more flexible systems, while reducing costs and improving process quality. Furthermore, the use of automation reduces the manpower factor and its associated variability. In the present work, a new concept for a Bowden cable production process is presented by employing the design science research (DSR) methodology. The project starts with the analysis of the previous production concept, determining possible problems and improvements, as well as setting objectives/requirements for a possible new concept/equipment. This information was used to develop a new automated Bowden cable production equipment, implementing several changes to the old concept and filling a gap in the literature in this field. The developed system was implemented and tested. A considerable reduction in cycle time was registered by 25%, which resulted in an increase of 30% in process productivity
- A Novel Robotic Manipulator Concept for Managing the Winding and Extraction of Yarn CoilsPublication . Costa, Rúben; Sousa, Vitor F. C.; Silva, Francisco J. G.; Campilho, Raul; Pinto, Arnaldo; Pinto Ferreira, Luís; Soares, RuiWire rope manufacturing is an old industry that maintains its place in the market due to the need for products with specific characteristics in different sectors. The necessity for modernization and performance improvement in this industry, where there is still a high amount of labor dedicated to internal logistics operations, led to the development of a new technology method, to overcome uncertainties related to human behaviour and fatigue. The removal of successive yarn coils from a twisting and winding machine, as well as cutting the yarn and connecting the other end to the shaft in order to proceed with the process, constitutes the main problem. As such, a mobile automatic system was created for this process, due to its automation potential, with a project considering the design of a 3D model. This novel robotic manipulator increased the useful production time and decreased the winding coil removal cycle time, resulting in a more competitive, fully automated product with the same quality. This system has led to better productivity and reliability of the manufacturing process, eliminating manual labor and its cost, as in previously developed works in other industries
- Increasing the Sustainability of Manufacturing Processes in Plastic Injection: Recovering Out-Of-Service Robots to Eliminate Manual Assembly OperationsPublication . Costa, Rúben; Sousa, Vitor; Silva, Francisco J. G.; Campilho, Raul; Sá, José Carlos; Pinto, Arnaldo; Pereira, JoãoIn the 20th century, there was a burst concerning the development of the automobile industry, which has become an essential asset for society. With its evolution, this industry created a foundation that based its competitiveness on satisfying people’s needs with the highest possible quality and always respecting the delivery deadlines. With the growth in demand, the improvement of certain processes was needed to achieve the desired production goals, accomplished through automation and robotics, as production and assembly lines increasingly used fully automated processes. In plastic injection lines, production is constant and carried out quickly, so it is desirable to perform component assembly steps that immediately support the output of the injection mould parts. This work consists of adapting an obsolete robotic cell to be implemented in one of the production lines to insert components into the injected parts, replacing labour work. Through a mechanical project and an automation design, the equipment was concluded and is currently in production, fulfilling the necessary requirements and improving the process’ cycle time. This proves that it is possible to recover old equipment, which is able to improve current tasks and common needs in modern industry, increasing the economic sustainability of the processes and saving resources
- Applying the SMED Methodology to Tire Calibration ProceduresPublication . Santos, Vítor; Sousa, Vitor F. C.; Silva, Francisco J. G.; Matias, João C. O.; Costa, Rúben D.; Pinto, Arnaldo; Campilho, RaulDue to the automotive industry’s strict demands, customers submit constant production pressure, leading to the adoption of new methodologies, techniques, and management ideas. The goal is always to minimise losses and waste. These demands also affect the maintenance department, which has to keep the balance between machines’ availability for production and ensuring that the machines’ proper running conditions translate into excellent-quality products. Thus, continuous improvement and correct management of maintenance activities are crucial for a company to maintain effective production, without defects, breakdowns, and accidents. Nevertheless, some maintenance activities should also prevent the degradation of equipment conditions in order to produce high-quality products. This paper presents an improvement of maintenance activities conducted on equipment that produces large tires. The main problems and technical difficulties of Machine Tolerance Check (MTC) activities are explored by analysing existing documents, internal knowledge, and changes to working methods. We discuss the implementation of the SMED (Single-Minute Exchange of Die) methodology in calibration procedures, as this method is commonly applied to machines’ setups to reduce downtime. At the end of the study, a 31% decrease in the duration of machine tolerance check activities was achieved, which led to a significant increase in the equipment’s availability