Papers by Author: N. Ortega

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Authors: Soraya Plaza, N. Ortega, Ainhoa Celaya, Jose Antonio Sánchez, Luis Norberto López de Lacalle, Borja Izquierdo
Abstract: The European Higher Education Area has entailed some upheaval since it has involved deep changes in university education. Among the subjects taught in technical education such as Manufacturing Technologies, which involve strong experimental contents, the use of specific tools is helpful for better understanding of such subjects. This article highlights the need for the use of simulation tools in the field of manufacturing processes. The student may achieve optimal understanding and learning from them. They can understand, in a more visual way, complex phenomena that govern different processes and the influence of key variables. Applications related to sheet metal forming, forging and casting processes are presented. The main objective is to enable students to better understand the phenomena that govern the processes of moulding and forming, with the invaluable help of simulation software. The final aim is to ensure that the student reaches an optimum knowledge of moulding and forming processes using simulation software.
Authors: Jose Antonio Sánchez, Luis Norberto López de Lacalle, N. Ortega, Aitzol Lamikiz, Soraya Plaza
Abstract: The paradigm the new European Higher Education Area places us in together with the teaching/learning guidelines and models demands the teacher adapt his/her function considering new methods which locate the students in the centre of this process. In this context the experience of the subject ‘Advanced forming and moulding techniques’ taught in 5th course of the Industrial Engineering qualification at the Bilbao Engineering Faculty (UPV/EHU), is presented. This subject must be taken by students opting for intensification in Mechanical Manufacturing. The subject is taught over tour months with 30 students per group on average, where a methodology based on Scoring Rubrics was set up.
Authors: N. Ortega, Inigo Pombo, Jose Antonio Sánchez, Soraya Plaza, B. Izquierdo
Abstract: Grinding process using superabrasive metal-bonded wheels is unavoidably linked to long and inefficient truing and dressing processes. This document presents the application of electro-discharge dressing process as an alternative to form wheels. The accuracy of the process and its efficiency has been analyzed on wheels of different grit size. To do so, complex geometry has been completely profiled to a 1A1 type wheels. Results show that the process can provide the desired geometry at the cost of a high processing time. The comparison between fine and large grit size grinding wheels shows that there is apparently no geometric limitation imposed by the grit size apart from that associated to grit diameter in corners and inner radii.
Authors: Inigo Pombo, Jose Antonio Sánchez, N. Ortega, B. Izquierdo, S. Plaza
Abstract: Temperature measurement in grinding has been a widely analyzed field in the study of the process. Temperatures in grinding are too difficult to measure due to the high gradients in the ground workpiece. A lot of different methods have been employed by many researches in the last years. In this paper the use of thermocouples is analyzed attending to the mathematical characterization of their response. It will be shown that correct modeling of the thermocouple’s response permits the avoidance of the problem of thermal inertia, making thus possible the use commercial thermocouples for temperature measurement in grinding.
Authors: N. Ortega, Ainhoa Celaya, Soraya Plaza, Aitzol Lamikiz, Inigo Pombo, Jose Antonio Sánchez
Abstract: The adaptation of universities to the European Higher Education Area (EHEA) plays an essential role in society, creating new knowledge, transferring it to students by means of new and more active methodologies aimed at learning that will enable students to put everything they learn into practice. However, such methodologies are not equally applicable in all subjects. Subjects such as Manufacturing Technology, taught at different levels in both undergraduate and graduate levels, are descriptive to a great extent. This descriptive nature must be supported by new technologies if these subjects claim to be more attractive to students. In this paper some examples of successful case studies are presented. They represent the new way of understanding the teaching replacing the old concept of traditional classroom lecture by more interactive ones and, therefore, more attractive to students.
Authors: Inigo Pombo, Jose Antonio Sánchez, E. García, N. Ortega, B. Izquierdo, Soraya Plaza
Abstract: The use of fluids in grinding is necessary to carry out an optimized process that avoids any kind of damage in the ground workpieces. However, the use of fluids in machining processes presents some problems as the economic one and the environmental one. The present work analyzes the industrial viability of a new solution to avoid the use of fluids in grinding, the MCG system. This system combines the use of a MQL (Minimum Quantity Lubricant) commercial system and a gas supplied at low temperatures. In this case the grinding of a component of the engine of a competition motorcycle with the MCG (Minimum Coolant Grinding) system is compared with the classic fluid flow system.
Authors: Jose Antonio Sánchez, Soraya Plaza, J.M. Ramos, B. Izquierdo, N. Ortega, I. Pombo
Abstract: The process of Wire Electrical Discharge Machining (WEDM) has experienced a dramatic growth in the last years. Together with the new requirements imposed by customer needs, globalization of the markets has brought about a new scenario in which competitiveness is the keyword. In the case of WEDM, it is only possible from a perspective that integrates developments in hardware, software and know-how, to generate the required added-value with respect to competitors. For instance, it is not enough to give an answer to the demand of a high-speed first cut: economy must be achieved together with a high accuracy and using low-cost wires. In this paper the research actions currently running aiming at the development of a new generation of WEDM machines are presented. The objective of this paper is to present an integrated research approach focused on industrial needs, covering the following aspects: Accuracy and productivity; automation and machine intelligence; eco-efficiency.
Authors: N. Ortega, Inigo Pombo, U. Alonso, J.A. Sánchez, B. Izquierdo, Soraya Plaza
Abstract: Grinding is a stochastic process applied in the last stages of the manufacturing cycle. In last decades, grinding research has focused on prediction of thermal damage on ground workpiece since it is of considerable importance from both research and industrial perspectives. A number of numerical and analytical thermal models have been carried out so far. However, new grinding processes such as peel grinding, creep feed grinding and others such as plongee grinding need new models which consider the effect of higher depth of cuts, but there is no information about the minimum depth of cut to consider the elimination of grounded material in FEM models. This article establishes the frontier from which the removed ground material should be physically eliminated to obtain an accurate FEM thermal model. Results show valuable information to decide which kind of model (with or without element elimination) is enough accurate for their purpose and application.
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