Automated Core And Cavity Design System For Mould Works Using Generative Method Of Computer Aided Process Planning

In recent years, many efforts have been made for core and cavity design system to be fully automated. Three profound limitations in the previous automated core and cavity design systems are (i) the lack in parting direction flexibility, (ii) inability to detect and generate parting direction for both inner and outer undercuts and (iii) no information transfer from automated core and cavity design system to machining system. To overcome these limitations, automated core and cavity design system (ACCDS) is developed. This system acts as a component in computer aided process planning system where it takes information from any 3D CAD model and provides information to the machining system. Generative method is the basis of this system where core and cavity models are generated from scratch. The outputs from the system are (i) the generated core, cavity and side-cores with parting direction and (ii) the information of zero tool-face collision angle range of core and cavity mould pieces. By comparing ACCDS with a recent system proposed by a researcher, improvements such as better core and cavity design and the reduction of system computational time were observed. This shows that ACCDS were able to contribute in the betterment of the core and cavity design system in automatic manner

Manufacturing technologies in mould industry and future challenges

This report is based on the manufacturing technologies actively used in the industry. The mould industry in Portugal is one of the biggest and considered the best in quality of moulds in various types of industries like Automobile, Medical and Aerospace. The State of the art mould manufacturing technologies like conformal cooling in complex parts, multi cavity moulds are taking over the industry standards to a new level of competitiveness in terms of business and quality achievement. The industry in Portugal is very well known for the quality of the moulds and the process fabrication of mould tools. The future is becoming more and more competitive with advancement in lean manufacturing and the enormous advancement in the 3D printers. With more time the advance in these technologies will help the requirement of polymer parts be met with high power and high capability of print quality achievable it is seen to be posing a threat to the mould manufacturers. They are in dire need to update the manufacturing process and to be in touch with the developments of production technologies in the world of polymers to stay in the competitive market for a long time. This report will touch upon the present manufacturing techniques and state of the art technologies that are coming into use in the industry and the challenges this industry will face due to increase in use of 3D printers

Construction Of Hybrid Geometric Modelling For Injection Mould Using Cadcam System

This project describes a procedure for automatic feature recognition to help in mould designing. Hybrid representation approach is used in automatic feature recognition to extract the geometric information of the feature in order to identify the undercut features. Boundary representation(B-rep) is applied in the shape representation by using the topology and geometry. The proposed approach that used the Face Adjacency Hypergraph describes the shape of the undercut features by representing the relationships among the faces of the features. The Face-to-Face Composition is applied to study the relationship between the main feature and undercut features. Part A, Part B and Part C were created and used the automatic feature recognition to classify the depression and protrusion feature. The algorithms based on the heuristic rule is used to determine the best parting line and parting direction of the parts by comparing their geometric information of the feature. These automatic feature recognition identified their shape of concave and convex feature according their depression or protrusion faces and their face adjacency relationship. These approaches are helpful in creating the core and cavity automatically. It will help to simplify the process of mould designing and reduce the time of moulding designing. Therefore, these approaches will have significant effect on increasing the productivity in manufacturing industry

Automated Core And Cavity Design System For Mould Works Using Generative Method Of Computer Aided Process Planning

In recent years, many efforts have been made for core and cavity design system to be fully automated. Three profound limitations in the previous automated core and cavity design systems are (i) the lack in parting direction flexibility, (ii) inability to detect and generate parting direction for both inner and outer undercuts and (iii) no information transfer from automated core and cavity design system to machining system. To overcome these limitations, automated core and cavity design system (ACCDS) is developed. This system acts as a component in computer aided process planning system where it takes information from any 3D CAD model and provides information to the machining system. Generative method is the basis of this system where core and cavity models are generated from scratch. The outputs from the system are (i) the generated core, cavity and side-cores with parting direction and (ii) the information of zero tool-face collision angle range of core and cavity mould pieces. By comparing ACCDS with a recent system proposed by a researcher, improvements such as better core and cavity design and the reduction of system computational time were observed. This shows that ACCDS were able to contribute in the betterment of the core and cavity design system in automatic manner

Automated Parting Methodologies for Injection Moulds

Ph.DDOCTOR OF PHILOSOPH

Application of statistical process control in injection mould manufacturing

Master'sMASTER OF ENGINEERIN

Impact of rapid manufacturing on design for manufacture for injection moulding

Rapid manufacturing (RM) employs similar technologies and processes to rapid prototyping (RP), hence resulting in a tool-less manufacturing process. This is achieved by assuming that RP machines have been converted to proper manufacturing machines. The current approaches to the design process, product development cycle and manufacturing considerations at the design stage within a concurrent engineering environment are closely examined. An attempt is then made to investigate the effect of the RM processes on the design process and product development cycle. This is further expanded to consider the impact of RM on rules and guidelines that have been established for design for manufacturing (DFM). This paper is limited to a comparison of RM with regards to injection moulding as RM is most likely to compete with this process in the first instance. This is the first research work to investigate the impact of RM on the design process

Resolving internal undercuts of parts in mould design.

by Li Kai Man.Thesis (M.Phil.)--Chinese University of Hong Kong, 1996.Includes bibliographical references (leaves [112]-[113]).Chapter chapter 1 --- INTRODUCTION --- p.1-1Chapter 1.1. --- Research objective --- p.1-1Chapter 1.2. --- Thesis organisation --- p.1-2Chapter chapter 2 --- BACKGROUND ON MOULD DESIGN --- p.2 1Chapter 2.1. --- Mould design process --- p.2-2Chapter 2.2. --- Basic structure of a simple two-piece mould --- p.2-4Chapter 2.3. --- Undercuts --- p.2-5Chapter 2.3.1. --- External undercut --- p.2-6Chapter 2.3.2. --- Internal undercut --- p.2-8Chapter chapter 3 --- RELATED WORKS --- p.3 1Chapter 3.1. --- Previous works --- p.3-1Chapter 3.2. --- Overview of the proposed approach --- p.3-2Chapter chapter 4 --- BACKGROUND THEORIES --- p.4 1Chapter 4.1. --- Mouldability of a part --- p.4-1Chapter 4.1.1. --- Mouldability with a simple 2-piece mould --- p.4-1Chapter 4.1.2. --- Mouldability with side core --- p.4-1Chapter 4.1.3. --- Mouldability with split core --- p.4-2Chapter 4.2. --- Solid sweep --- p.4-2Chapter 4.3. --- Application of solid sweep in mould design --- p.4-5Chapter 4.4. --- Spherical mapping and visibility mapping --- p.4-6Chapter 4.4.1. --- Spherical mapping --- p.4-6Chapter 4.4.2. --- Visibility mapping --- p.4-8Chapter chapter 5 --- DETERMINATION OF MAIN PARTING DIRECTION FOR SIMPLE 2-PIECE MOULD --- p.5 1Chapter 5.1. --- Extraction of possible main parting directions --- p.5-2Chapter 5.2. --- Main parting direction --- p.5-3Chapter 5.3. --- Ranking of main parting direction --- p.5-4Chapter 5.4. --- Calculation of projected area of a moulded part --- p.5-5Chapter 5.5. --- Creation of cavity solid --- p.5-8Chapter 5.6. --- Cleavage of cavity solid --- p.5-10Chapter 5.7. --- Undercut solid determination --- p.5-12Chapter 5.8. --- Difference in the application area of solid sweep and Visibility map --- p.5-13Chapter 5.9. --- Search strategy for parting direction of a 2-piece mould --- p.5-18Chapter chapter 6 --- DETERMINATION OF MAIN PARTING DIRECTION AND SIDE CORE --- p.6-1Chapter 6.1. --- Undercut evaluation --- p.6-2Chapter 6.2. --- Determination of main parting direction --- p.6-4Chapter 6.3. --- Determination of side core for a given main parting direction --- p.6-4Chapter 6.4. --- Search strategy for main parting direction and side core direction --- p.6-7Chapter 6.4.1. --- The search for single side core --- p.6-7Chapter 6.4.2. --- The search for multiple side cores --- p.6-9Chapter chapter 7 --- DETERMINATION OF SPLIT CORE DIRECTION --- p.7-1Chapter 7.1. --- Determination of split core direction --- p.7-1Chapter 7.2. --- Visibility check for split core --- p.7-3Chapter 7.3. --- Selection of split core --- p.7-3Chapter 7.4. --- Trajectory of split core --- p.7-5Chapter 7.4.1. --- Primary solid sweep --- p.7-5Chapter 7.4.2. --- Secondary solid sweep --- p.7-7Chapter 7.5. --- Interference check between split cores --- p.7-9Chapter 7.6. --- Search strategy for split core --- p.7-9Chapter chapter 8 --- HEURISTIC\DEPTH-FIRST SEARCH STRATEGY --- p.8-1Chapter 8.1. --- Side core determination --- p.8-1Chapter 8.2. --- Split core determination --- p.8-3Chapter chapter 9 --- EXPERIMENTAL RESULTS --- p.9-1Chapter chapter 10 --- COMPLEXITY ANALYSIS --- p.10-1Chapter 10.1. --- Determination of main parting direction and side cores --- p.10-2Chapter 10.2. --- Determination of side core directions --- p.10-5Chapter chapter 11 --- CONCLUSIONS --- p.11-1REFERENCE

A Novel Feature-Based Manufacturability Assessment System for Evaluating Selective Laser Melting and Subtractive Manufacturing Injection Moulding Tool Inserts

Challenges caused by design complexities during the design stages of a product must be coordinated and overcome by the selection of a suitable manufacturing approach. Additive manufacturing (AM) is capable of fabricating complex shapes, yet there are limiting aspects to surface integrity, dimensional accuracy, and, in some instances, design restrictions. Therefore, the goal is essentially to establish the complex areas of a tool during the design stage to achieve the desired quality levels for the corresponding injection moulding tool insert. When adopting a manufacturing approach, it is essential to acknowledge limitations and restrictions. This paper presents the development of a feature-based manufacturability assessment system (FBMAS) to demonstrate the feasibility of integrating selective laser melting (SLM), a metal-based AM technology, with subtractive manufacturing for any given part. The areas on the tool inserts that hold the most geometrical complexities to manufacture are focused on the FBMAS and the design features that are critical for the FBMAS are defined. Furthermore, the structural approach used for developing the FBMAS graphical user interface is defined while explaining how it can be operated effectively and in a user-friendly approach. The systematic approach established is successful in capturing the benefits of SLM and subtractive methods of manufacturing, whilst defining design limitations of each manufacturing method. Finally, the FBMAS developed was validated and verified against the criteria set by experts in the field, and the system’s logic was proven to be accurate when tested. The decision recommendations proved to correlate with the determined recommendations of the field experts in evaluating the feature manufacturability of the tool inserts

Mold Feature Recognition using Accessibility Analysis for Automated Design of Core, Cavity, and Side-Cores and Tool-Path Generation of Mold Segments

Injection molding is widely used to manufacture plastic parts with good surface finish, dimensional stability and low cost. The common examples of parts manufactured by injection molding include toys, utensils, and casings of various electronic products. The process of mold design to generate these complex shapes is iterative and time consuming, and requires great expertise in the field. As a result, a significant amount of the final product cost can be attributed to the expenses incurred during the product’s design. After designing the mold segments, it is necessary to machine these segments with minimum cost using an efficient tool-path. The tool-path planning process also adds to the overall mold cost. The process of injection molding can be simplified and made to be more cost effective if the processes of mold design and tool-path generation can be automated. This work focuses on the automation of mold design from a given part design and the automation of tool-path generation for manufacturing mold segments. The hypothesis examined in this thesis is that the automatic identification of mold features can reduce the human efforts required to design molds. It is further hypothesised that the human effort required in many downstream processes such as mold component machining can also be reduced with algorithmic automation of otherwise time consuming decisions. Automatic design of dies and molds begins with the part design being provided as a solid model. The solid model of a part is a database of its geometry and topology. The automatic mold design process uses this database to identify an undercut-free parting direction, for recognition of mold features and identification of parting lines for a given parting direction, and for generation of entities such as parting surfaces, core, cavity and side-cores. The methods presented in this work are analytical in nature and work with the extended set of part topologies and geometries unlike those found in the literature. Moreover, the methods do not require discretizing the part geometry to design its mold segments, unlike those found in the literature that result in losing the part definition. Once the mold features are recognized and parting lines are defined, core, cavity and side-cores are generated. This work presents algorithms that recognize the entities in the part solid model that contribute to the design of the core, cavity and side-cores, extract the entities, and use them in the design of these elements. The developed algorithms are demonstrated on a variety of parts that cover a wide range of features. The work also presents a method for automatic tool-path generation that takes the designed core/cavity and produces a multi-stage tool-path to machine it from raw stock. The tool-path generation process begins by determining tool-path profiles and tool positions for the rough machining of the part in layers. Typically roughing is done with large aggressive tools to reduce the machining time; and roughing leaves uncut material. After generating a roughing tool-path for each layer, the machining is simulated and the areas left uncut are identified to generate a clean-up tool-path for smaller sized tools. The tool-path planning is demonstrated using a part having obstacles within the machining region. The simulated machining is presented in this work. This work extends the accessibility analysis by retaining the topology information and using it to recognize a larger domain of features including intersecting features, filling a void in the literature regarding a method that could recognize complex intersecting features during an automated mold design process. Using this information, a larger variety of new mold intersecting features are classified and recognized in this approach. The second major contribution of the work was to demonstrate that the downstream operations can also benefit from algorithmic decision making. This is shown by automatically generating roughing and clean-up tool-paths, while reducing the machining time by machining only those areas that have uncut material. The algorithm can handle cavities with obstacles in them. The methodology has been tested on a number of parts