1,008 research outputs found
Development of working procedures of a 5 Axis CNC milling machine
Dissertação de mestrado em Mechanical EngineeringThe work developed and presented on this dissertation tends to the installation and configurations of a 5-axis CNC machine with the creation of working procedures intended to build a stable workflow that can be employed by any individual expected to use the machine.
Being a large field within mechanical engineering as well as being involved in a large selection of different industrial sectors, the concept of 5-axis machining will be explored to develop knowledge in terms of CAM programming and manipulation/optimization of toolpaths.
The importance/functioning of the transmission of information both from post-processor to the controller and from the controller to the actual machine is also a critical point in this work as they are directly related to the quality of the parts produced.
To accomplish this, the theoretical knowledge foundations regarding CNC machining work were researched, studied, and explained.
Furthermore, the machine model in question (HY-6040 5-axis CNC Router) was meticulously analysed regarding to the machines structure, post-processor, and controller.
Upon assembling all this information, and through the production of some test parts, a permanent manufacture workflow for different machining approaches was established and described.O trabalho desenvolvido e apresentado nesta dissertação tende à instalação e configuração de uma máquina CNC de 5-eixos, com a criação de procedimentos de trabalho destinados a criar um fluxo de trabalho estável que possa ser empregue por qualquer individuo que pretenda utilizar a máquina.
Sendo um grande campo dentro da engenharia mecânica e estando também envolvido numa grande seleção de diferentes setores industriais, o conceito de maquinagem em 5-eixos será explorado com a finalidade de desenvolver conhecimentos a nível de programação CAM e manipulação/otimização de trajetórias de corte.
A importância/funcionamento da transmissão de informação quer do pôs-processador para o controlador, quer do controlador para a máquina constituem também um ponto critico neste trabalho já que estão diretamente relacionados com a qualidade das peças produzidas.
Para a realização de tal, foram pesquisados, estudados e explicados os fundamentos do conhecimento teórico relativamente ao trabalho de maquinagem CNC.
Para além disso, o modelo da máquina em questão (HY-6040 5-axis CNC Router) foi meticulosamente analisado quanto à estrutura da máquina, pós-processador e controlador.
Após reunir toda esta informação, e través da produção de peças teste, foi estabelecido um fluxo de trabalho de manufatura (CAD/CAM/Maquinagem) para diferentes abordagens de maquinagem
Generalization of mathematical representation for tool path based on boundary representation (BREPS) data structure
A generic representation of linear and curvilinear entities with embedded motion attributes is possible via the integration of a Hermite curve and dynamic of motion. A Hermite curve will form the curve, while a dynamic of motion will position the vertices on the curves with the introduction of a delta distance (Δs). A three-phase algorithm is introduced to examine the applicability of generic representation in tool-path generation. The preprocessing stage will examine the input model prior to Phase I. Phase I will extract the BReps data, and these BReps data will be used in Phase II to develop the generalized mathematical representation of the tool path. Finally, the tool path is drawn in Phase III
Machine planning in a product model environment
The aim of this research was to understand and solve problems associated with the
integration of a Machine Planner within a product model environment. This work
was carried out in conjunction with other researchers, pursuing parallel integration
issues related to pre-production proving and product data representation.
Product data representations of component level planned, processes and feature
level process data have been explored as sub-sets of -a product data model to aid
integration. Geometric queries on a cell decomposition solid, model. have been
explored as a means of providing feature geometric interaction data, while the
dimensional interactions between features have also been addressed.
Product data representations have been modelled using a prototype software tool, providing an environment for the exploration of the integration of a Machine Planner using a feature based design approach. Necessary Machine Planning functions have been implemented, using the ADA programming language, to explore the integrating capability of the product model environment, concentrating on the
use of a prismatic benchmark component. Using the experimental implementation,
setup and operation plans have been produced and machining part programs generated
from product model representations of variants on the benchmark component. These have been successfully machined using a3 axis vertical machining centre. Such experiments, as well as others in conjunction with co-researchers, have shown
that a product data model can provide a common base of data for the integration of
a range of design and manufacturing activities
Process planning by recognizing and learning machining features
We present two methods for process planning of 2.5D machined parts. The first method is based on feature recognition from a 3D model. We embedded the shape and the machining method of two generic classes of machining features in a set of OPS5 rules to form a machining feature recognizer. When successfully recognizing a machining feature, machining instructions, in terms of the tool entrance face, drive face and part face, for cutting the machining feature will be generated and further processed to produce NC codes.
The second method is based on learning the shape and the machining method of the machining feature. When a machining feature cannot be recognized by the former feature recognizer, the user can use the machining feature as a positive training example to instruct the system about the tool entrance face, drive face and part face of the machining feature. The system then builds a new rule, using the boundary shape of the unrecognized machining feature as the rule's matching condition and the acquired machining instruction as the rule's action. The new rule can be used subsequently for process planning of machining features that have shapes similar to the memorized one
Analysis of Different Tool Path Strategies for Free Form Machining with Computer Aided Surface Milling Operations
[EN] Free form surfaces are commonly used to generate aesthetic parts. These parts can be manufactured directly by material removal techniques or indirectly with molding or forming techniques. In any case, these surfaces must be commonly machined with traditional processes, at least until certain degree of surface finishing, and the tool path must be generated with computer aided applications. In doing so, developers are implementing new theoretical strategy operations for controlling tool path and trajectories. These new options have so many combinations that it is difficult to know which is the best one to choose when defining the tool movements. Apart from the traditional strategies fixed angle method, principal axis method and multipoint machining, combined with tool orientation, there are many other strategies to explore due to machine tool and numerical control improvements. What is need now is a validation of these new strategies in computer aided applications regarding time minimizing and how the cutting parameters affects in the surface final result.The authors would like to thanks Universitat Politècnica de València, La Fondation Dassault Systèmes, Carolina Foundation and the National Polytechnic School for the support of this article through the 2017 call and project PIS 16-15 - PIS 16-22.Vila, C.; Ayabaca-Sarria, C.; Torres Carot, R.; Gutiérrez, SC.; Meseguer, M.; Yang, X. (2019). Analysis of Different Tool Path Strategies for Free Form Machining with Computer Aided Surface Milling Operations. Procedia Manufacturing. 41:843-850. https://doi.org/10.1016/j.promfg.2019.10.006S8438504
A knowledge-based approach for the extraction of machining features from solid models
Computer understanding of machining features such as holes and pockets is
essential for bridging the communication gap between Computer Aided Design and
Computer Aided Manufacture. This thesis describes a prototype machining feature
extraction system that is implemented by integrating the VAX-OPS5 rule-based
artificial intelligence environment with the PADL-2 solid modeller. Specification of
original stock and finished part geometry within the solid modeller is followed by
determination of the nominal surface boundary of the corresponding cavity volume
model by means of Boolean subtraction and boundary evaluation. The boundary model
of the cavity volume is managed by using winged-edge and frame-based data
structures. Machining features are extracted using two methods : (1) automatic feature
recognition, and (2) machine learning of features for subsequent recognition. [Continues.
Productivity Improvement in CNC Machining Process by using DCMT 11 T304 Tool Bit
Productivity improvements in terms getting high quality at low cost with greater accuracy are much important in the global market competition. In these empirical study at first conventional machining process been carried out for step turning operation with the help of HSS tool bit, where the accuracy of the product and quality is not been achieved. After the root cause analysis improvements has been done with the machine and there after the tool bit has been changed to DCMT11T304. Both the process after collecting the data in SQC charts has plotted and shown where a remarkable improvement has been achieved in terms of accuracy, quality and productivity
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