This thesis presents cutter swept volume generation, in-process workpiece modeling and Cutter Workpiece Engagement (CWE) algorithms for finding the instantaneous intersections between cutter and workpiece in milling. One of the steps in simulating machining operations is the accurate extraction of the intersection geometry between cutter and workpiece. This geometry is a key input to force calculations and feed rate scheduling in milling. Given that industrial machined components can have highly complex geometries, extracting intersections accurately and efficiently is challenging. Three main steps are needed to obtain the intersection geometry between cutter and workpiece. These are the Swept volume generation, in-process workpiece modeling and CWE extraction respectively. In this thesis an analytical methodology for determining the shapes of the cutter swept envelopes is developed. In this methodology, cutter surfaces performing 5-axis tool motions are decomposed into a set of characteristic circles. For obtaining these circles a concept of two-parameter-family of spheres is introduced. Considering relationships among the circles the swept envelopes are defined analytically. The implementation of methodology is simple, especially when the cutter geometries are represented by pipe surfaces. During the machining simulation the workpiece update is required to keep track of the material removal process. Several choices for workpiece updates exist. These are the solid, facetted and vector model based methodologies. For updating the workpiece surfaces represented by the solid or faceted models third party software can be used. In this thesis multi-axis milling update methodologies are developed for workpieces defined by discrete vectors with different orientations. For simplifying the intersection calculations between discrete vectors and the tool envelope the properties of canal surfaces are utilized. A typical NC cutter has different surfaces with varying geometries and during the material removal process restricted regions of these surfaces are eligible to contact the in-process workpiece. In this thesis these regions are analyzed with respect to different tool motions. Later using the results from these analyses the solid, polyhedral and vector based CWE methodologies are developed for a range of different types of cutters and multi-axis tool motions. The workpiece surfaces cover a wide range of surface geometries including sculptured surfaces.

This thesis presents cutter swept volume generation, in-process workpiece modeling and Cutter Workpiece Engagement (CWE) algorithms for finding the instantaneous intersections between cutter and workpiece in milling. One of the steps in simulating machining operations is the accurate extraction of the intersection geometry between cutter and workpiece. This geometry is a key input to force calculations and feed rate scheduling in milling. Given that industrial machined components can have highly complex geometries, extracting intersections accurately and efficiently is challenging. Three main steps are needed to obtain the intersection geometry between cutter and workpiece. These are the Swept volume generation, in-process workpiece modeling and CWE extraction respectively. In this thesis an analytical methodology for determining the shapes of the cutter swept envelopes is developed. In this methodology, cutter surfaces performing 5-axis tool motions are decomposed into a set of characteristic circles. For obtaining these circles a concept of two-parameter-family of spheres is introduced. Considering relationships among the circles the swept envelopes are defined analytically. The implementation of methodology is simple, especially when the cutter geometries are represented by pipe surfaces. During the machining simulation the workpiece update is required to keep track of the material removal process. Several choices for workpiece updates exist. These are the solid, facetted and vector model based methodologies. For updating the workpiece surfaces represented by the solid or faceted models third party software can be used. In this thesis multi-axis milling update methodologies are developed for workpieces defined by discrete vectors with different orientations. For simplifying the intersection calculations between discrete vectors and the tool envelope the properties of canal surfaces are utilized. A typical NC cutter has different surfaces with varying geometries and during the material removal process restricted regions of these surfaces are eligible to contact the in-process workpiece. In this thesis these regions are analyzed with respect to different tool motions. Later using the results from these analyses the solid, polyhedral and vector based CWE methodologies are developed for a range of different types of cutters and multi-axis tool motions. The workpiece surfaces cover a wide range of surface geometries including sculptured surfaces.

This thesis presents cutter swept volume generation, in-process workpiece modeling and Cutter Workpiece Engagement (CWE) algorithms for finding the instantaneous intersections between cutter and workpiece in milling. One of the steps in simulating machining operations is the accurate extraction of the intersection geometry between cutter and workpiece. This geometry is a key input to force calculations and feed rate scheduling in milling. Given that industrial machined components can have highly complex geometries, extracting intersections accurately and efficiently is challenging. Three main steps are needed to obtain the intersection geometry between cutter and workpiece. These are the Swept volume generation, in-process workpiece modeling and CWE extraction respectively. In this thesis an analytical methodology for determining the shapes of the cutter swept envelopes is developed. In this methodology, cutter surfaces performing 5-axis tool motions are decomposed into a set of characteristic circles. For obtaining these circles a concept of two-parameter-family of spheres is introduced. Considering relationships among the circles the swept envelopes are defined analytically. The implementation of methodology is simple, especially when the cutter geometries are represented by pipe surfaces. During the machining simulation the workpiece update is required to keep track of the material removal process. Several choices for workpiece updates exist. These are the solid, facetted and vector model based methodologies. For updating the workpiece surfaces represented by the solid or faceted models third party software can be used. In this thesis multi-axis milling update methodologies are developed for workpieces defined by discrete vectors with different orientations. For simplifying the intersection calculations between discrete vectors and the tool envelope the properties of canal surfaces are utilized. A typical NC cutter has different surfaces with varying geometries and during the material removal process restricted regions of these surfaces are eligible to contact the in-process workpiece. In this thesis these regions are analyzed with respect to different tool motions. Later using the results from these analyses the solid, polyhedral and vector based CWE methodologies are developed for a range of different types of cutters and multi-axis tool motions. The workpiece surfaces cover a wide range of surface geometries including sculptured surfaces. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

Process planning is a task comprising a broad range of activities to design and develop an appropriate manufacturing process for producing a part. Interpretation of the part design, selection of manufacturing processes, definition of operations, operation sequences, machining datums, geometrical dimensions and tolerances are some common activities associated with the task. Process planning is also “the link between product design and manufacturing” with the supplementary commission to support design of competitive products. Process planning is of a complex and dynamic nature, often managed by a skilled person with few, or no, explicit methods to solve the task. The work is heuristic and the result is depending on personal experiences and decisions. Since decades, there have been plenty of attempts to develop systems for computer-aided process planning (CAPP). CAPP is still awaiting its breakthrough and one reason is the gap between the functionality of the CAPP systems and the industrial process planning practice. This thesis has an all-embracing aim of finding methods that cover essential activities for process planning, including abilities to predict the outcome of a proposed manufacturing process. This is realised by gathering supporting methods suitable to manage both qualitative and quantitative characterisation and analyses of a manufacturing process. The production research community has requested systematisation and deeper understanding of industrial process planning. This thesis contributes with a flow chart describing the process planning process (PPP), in consequence of the methodological studies. The flow chart includes process planning activities and information flows between these activities. The research has been performed in an industrial environment for high volume manufacturing of gear parts. Though gear manufacturing has many distinctive features, the methods and results presented in this thesis are generally applicable to precision manufacturing of many kinds of mechanical parts. / <p>QC 20140522</p>

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22438号 / 工博第4699号 / 新制||工||1734(附属図書館) / 京都大学大学院工学研究科マイクロエンジニアリング専攻 / (主査)教授 松原 厚, 教授 西脇 眞二, 教授 小森 雅晴 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

The aim of the diploma thesis is to describe influences of selected production technologies on geometrical and dimensional accuracy of workpieces. Specific technologies - turning, milling and grinding and the machines on which these technologies will be implemented - a vertical lathe, a portal milling machine and a center grinder are described in this thesis. Additionally a procedure is created for adding geometric errors to a tri-axial machine tool to describe the entire working area of the machine in terms of errors. Subsequently an analysis of each geometric error is created for each machine and their influence on the resulting workpiece is determined.

The aim of this thesis was to design the robotic handling system of CNC production line based on requirements of Valeo Compressor Europe in Humpolec. The theoretical part of this thesis includes the profile of the company, analysis of handling system and automated workstations used in production system. The practical part of this thesis includes analysis of the current state and design of handling system for CNC production line. There is recovery of investment analysis for the designed line and summary at the last part of diploma project.

The aim of this thesis called Design of bar-feeder for CNC lathe is research about workpiece handling and bar feeders. But the most important aim is design of bar feeder by chosen parameters. The first part of thesis includes description of different types of workpiece handling. The second part is formed by bar feeders description and distribution and possibly construction solution. In the last part is performed choice of parameters for designed bar feeder and design of short bar feeder construction itself.

No description available.

Dans ce travail de thèse, une amélioration aussi bien à l’échelle globale qu’à l’échelle locale a été apportée sur la compréhension des mécanismes tribologiques aux interfaces outil-pièce-copeau durant l’usinage à sec de l’acier C45 avec des outils en carbure de tungstène revêtus en TIN. Dans une première partie expérimentale, des essais de frottement ont permis d’étudier la sensibilité des paramètres de frottement sur le comportement tribologique aux interfaces pion-pièce. Ainsi, l’évolution du coefficient de frottement, du flux de chaleur et du coefficient de partage de chaleur aux interfaces outil-pièce-copeau ont été identifiés pour le couple de matériau frottant et frotté. Pour mieux comprendre ces phénomènes, une étude métallographique a été effectuée sur des échantillons. Elle a notamment permis l’obtention des transformations métallurgiques au niveau de la surface superficielle de la pièce : des affinements des grains (déformation plastique) aux basses vitesses de frottement et des couches blanches (durcissement thermique) pour les grandes vitesses. Pour avoir plus de détails, un modèle numérique simulant l’essai de frottement a été développé en se basant sur l’approche Arbitraire Lagrangienne Eulérienne (A.L.E). Ce modèle nous a permis d’avoir plus d’informations sur les grandeurs locales de frottement (pression de contact, température de contact, vitesse locale de glissement, déformation plastique). Un modèle de frottement et un modèle de coefficient de partage de chaleur ont été identifiés à travers cette étude numérique. Dans la deuxième partie expérimentale, deux types d’essais d’usure ont été effectués dans des conditions similaires sur des pions et sur des plaquettes d’outils de coupe de même nuance. Des analyses microscopiques et au MEB couplés à une analyse EDS ont été faites afin de mieux analyser les mécanismes tribologiques durant les essais d’usure. Des similitudes de faciès d’usure ont été observées à différentes échelles d’analyse, sur les pions ainsi que sur les plaquettes d’outils de coupe. Ces similitudes ont permis d’aboutir à une corrélation des phénomènes tribologiques observés sur les pions et ceux observés sur les plaquettes. / In this work, improved both global and local levels has been made on understanding the tribological mechanisms at the chip-tool-workpiece interface in dry machining of a AISI 1045 steel with a TiN coated carbide tool. In the first part, several friction tests have been performed to study the sensitivity of friction parameters on the tribological behavior at pin-workpiece interface. Thus, evolutions of the apparent friction coefficient, of heat flux and of heat flux partition ratio have been identified. To better understand these phenomena, a metallographic study was performed on the samples of the workpiece.It has enabled the achievement of metallurgical transformations in terms of surface area of the room : the refinement of grains (plastic deformation) friction at low speeds and white layers (thermal curing)for high speeds. These results show that the initial state of the steel (ferritic-pearlitic microstructure) has been changed, In fact, two phenomena have been observed. The first phenomenon has been observed for low sliding velocities. In this range of the sliding velocities, the grains have been crushed because of the large plastic deformations. The second phenomenon has been observed by increasing the friction velocity. In fact, the white zones have been identified at the surface layer and which have presented a different structure compared to the initial state of the steel. A 3D A.L.E. numerical model, simulating the friction test, enables to extract local information from the contact area, especially the contact pressure, the contact temperature and the average local sliding velocity. An adhesive friction model and a heat partition coefficient model depending on average local sliding velocity have been identified. These friction models can be utilized in a FEM of the cutting process in order to improve the understanding of the material flow and temperature distribution around cutting tools. In the second part, pin wear in the friction tests and tool wear in machining tests have been performed. To compare the phenomena observed at the tool-chip interfaces during the wear tests in machining with the phenomena observed at the pin-workpiece during the wear tests of friction, similarities of faces have been observed at different scales of analysis on the pins and on the cutting tool inserts.