• Transactions of Materials Processing
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• v.24 no.2
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• pp.107-114
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• 2015

The current study presents a geometric measurement and analysis of the section profile for a feature line surface on an automotive outer panel. A feature line surface is the geometry which is a visually noticeable creased line on a smooth panel. In the current study the section profile of a feature line surface is analyzed geometrically. The section profile on the real press panel was measured using a coordinate measuring machine. The section profiles from the CAD model and the real panel are aligned using the same coordinate system defined by two holes near the feature line. In the aligned section profiles the chord length and height of the curved part were measured and analyzed. The results show that the feature line surface on the real panel is doubled in width size.

• Korean Journal of Computational Design and Engineering
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• v.6 no.4
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• pp.244-253
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• 2001

For more complete process planning, machining sequence determination is critical to attain machining economics. Although many studies have been conducted in recent years, most of them suggests the non-unique machining sequences. When the tool approach directions(TAD) are considered fur a feature, both machining time and number of setups can be reduced. Then, the unique machining sequence can be extracted from alternate(non-unique) sequences by minimizing the idle time between operations within a sequence. This study develops an algorithm to generate the best machining sequence for composite prismatic features in a vertical milling operation. The algorithm contains five steps to produce an unique sequence: a precedence relation matrix(PRM) development, tool approach direction determination, machining time calculation, alternate machining sequence generation, and finally, best machining sequence generation with idle times. As a result, the study shows that the algorithm is effective for a given composite feature and can be applicable fur other prismatic parts.

• Journal of the Society of Naval Architects of Korea
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• v.35 no.2
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• pp.104-113
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• 1998

The line heating method is a popular technique used to form ship hull in shipyards. In order to promote shipbuilding productivity, some researchers have made progress in their studies on automatic fabrication system for plate forming. These researches have, however, focused on heat-induced plate deformation with particular mechanical modelings, and do not yet propose the heating paths applicable to actual plate forming process. In this paper, a new algorithm to determine heating lines is developed to simulate the line heating process. The important feature of this algorithm is that it calculates principal curvatures of deflection difference surface which represents difference between target surface and surface in fabrication. Several trials to typical surface types show its usefulness and good applicability to tactical use.

• Journal of the Korea Convergence Society
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• v.8 no.11
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• pp.115-121
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• 2017

The present study aimed to obtain basic knowledge of a customized artificial joint based on the convergence research of Digital Imaging and Communications in Medicine(DICOM) and 5-axis machining technology. In the case of the research method, three-dimensional modeling was generated based on the medical image of the humerus bone, and the shape was machined using a chemical wood material. Then, the anatomical characteristics and the modeling machining computation times were compared. The results showed that the Stereolithography (STL) modeling required twice more time for semi-finishing and 10 times more time for finishing compared to the Initial Graphics Exchange Specification(IGES) modeling. For the 5-axis machining humerus bone, the anatomical structures of the anatomic neck, greater tubercle, lesser tubercle, and intertubercular groove were similar to those in the three-dimensional medical image. In the future, the convergence machining technology, where 5-axis machining of various structures(e.g., the surgical neck undercut of the humerus bone) is performed as described above, can be efficiently applied to the manufacture of a customized joint that pursues the precise model of a human body.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.107-114
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• 2017

A turbocharger is an engine supercharger that is driven by exhaust gas. It improves the output and fuel efficiency by increasing the charging efficiency of the mixture gas, which is achieved by changing the rotatory power of the turbine connected to the exhaust passage. It is important to control the supercharging for this purpose. A nozzle slide joint is one of the core parts. Austenitic stainless steel is currently used as the material for this part, and its excellent mechanical properties include high heat resistance and corrosion resistance. However, because of its poor machinability, there are many difficulties in producing products with complicated shapes. Machining is used in the production of nozzle slide joints for high dimensional accuracy after metal powder injection molding. As design variables in this study, we investigated the sintering temperature, product stress, deformation rate, radius of curvature of the punch, and angle of the chamfer punch, which are related to the strain and shapes. The goal is to suggest a forming process using Nitronic 60 that does not require machining to manufacture a nozzle slide joint for a turbocharger. Accordingly, we determined the best process environment using finite-element analysis, the signal-noise ratio, and the Taguchi method for experiment design. The relative density and hydrostatic pressure of the final product were in accordance with the results of the finite element analysis. Therefore, we conclude that the Taguchi method can be applied to the design process of metal powder injection molding.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.12
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• pp.36-43
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• 2021

In this study, the optimal feed system and process conditions that can simultaneously minimize each warpage occurring in the two shape features of the 2P Header HSG, a connector part for automobiles, were determined through injection molding simulation analysis. First, we defined each warping deformation of the two features geometrically and quantified them approximately using the injection molding simulation data. For design optimization, a full factorial experiment was conducted considering the feed system, resin temperature, and packing pressure as design variables, and a follow-up experiment was conducted based on the analysis of the average warpage. In this study, an optimal design was generated considering both the warpage result and resin-saving effect. In the optimal design, the warpages of the two shape features were predicted to be 0.18 and 0.29 mm, and these warpages were found to meet the allowable limit of warpage, which is 0.3 mm, for part assembly.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.1
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• pp.98-103
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• 2001

Machining is the commonly used process in the manufacturing of prototypes. This process offers several advantages, such as rigidity of the machine, precision of the machine, precision of the operation and specially a quick delivery. The weight and immobility of the machine support and immobilize the part during the operation. However, despite these advantages it shows, machining still presents several limitations. The immobilization, location and support of the part are referred to as fixturing or workholding and present the biggest challenge for time efficient machining. So it is important to select and design the appropriate fixturing assembly. This assembly depends on the complexity of the part and the tool paths and may require the construction of dedicated fixtures. With traditional techniques, the range of fixturable shapes is limited and the identification of suitable fixtures in a given setup involves complex reasoning. To solve this limitation and to apply the automation, this paper presents the Reference Free Part Encapsulation(RFPE) and implementation of the encapsulation system. The feature-based modeling system and the encapsulation system are implemented. The small part of which it is difficult to find out the appropriate fixturing assembly is made by this system.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.1
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• pp.118-125
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• 2003

As consumer's desire becomes various, agility of mold manufacturing is the most important factor for competitive mold manufacturer. Decision making process is required to produce optimal result of CAM systems in using commercial CAM system to generate tool path. The paper proposes a methodology fur computer-assisted tool selection procedures for various cutting type of rough, semi-rough and finish cuts. The procedure provides assistance for machining tool selection by analyzing sliced CAD model section of die cavity and core. Information about machining time for the generated NC-code is used to aid the tool selection. The module is developed with commercial CAM API. This module will be used fur the optimization of tool selection and planning process.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.703-712
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• 1994

This paper presents an automatic conversion of machining data from the orthographic views of press mold by feature recognition rule. The system includes following 6 modules : separation of views, function support, dimension text recognition, feature recognition, dimension text check and feature processing modules. The characteristic of this system is that with minimum user intervention, it recognizes basic features such as holes, slots, pockets and clamping parts and thus automatically converts CAD drawing details of press mold into machining data using 2D CAD system instead of using an expensive 3D Modeler. The system is developed by using IBM-PC in the environment of AutoCAD R12, AutoLISP and MetaWare High C. Performance of the system is verified as a good interfacing of CAD and CAM when applied to a lot of sample drawings.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.905-910
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• 2003

Most of previous research on machining process planning has not fully included consideration on fixturing. With fixture components properly assembled with the part workpiece in a CAD modeling environment, necessary geometric information of fixture elements and their interrelations with the part model can be obtained so that machining process plans could incorporate fixturing considerations. This paper introduces an interactive fixturing system called I-Fix. I-Fix is a dowel-pin based modular fixture system, and it has been developed using Solid Edge CAD system and Visual Basic. Through customized operations of the assembly commands of the CAD system, I-Fix significantly simplifies user operations and thus reduces fixturing time. Furthermore, I-Fix enhances user convenience by providing general guidance about the fixture components and fixturing methods.