Hon-Zong Choi

The effect of high pressure air jet on form accuracy in slot grinding

Abstract Slot grinding used for slot machining of high hardness materials needs high form accuracy and high surface integrity, such as ceramics that are difficult to do cutting and electric discharged machining, and non-conducting materials like high-polymer materials. Generally, the end of a slot grinding wheel has a “V” shape, so the end step is broken by the increase of a grinding resistance such as the clogging. To solve this problem, a high pressure air jet was put in the opposite position of grinding point and form accuracy and wheel wear by the various grinding parameters were measured. The object of this study is to analyze the effects of high pressure air jet to improve form accuracy when the brittle materials were slot grind with a V-shaped cast iron-bonded diamond wheel. High pressure air jet seems to result in the reductions of the wheel wear and enhancement of form accuracy. It is because high pressure air jet blows out the chips between the grains and so the clogging is decreased. The wheel wear becomes reduced by the decrease of the grinding resistance followed by the decrease of clogging. From the above results, we can show the grinding mechanism in slot grinding process.

i-Manufacturing project for collaboration-based Korean manufacturing innovation

Unpredictable customer needs strongly require for manufacturing enterprises to produce quality products satisfying cost and time constraints. To cope with such dynamically changing manufacturing environment and to get higher competitiveness, the manufacturing industry needs to equip with advanced technologies including IT as well as substantial infrastructure. ldquoi-Manufacturingrdquo is the name of the project funded by the Korea government, but on the other it is the strategy for achieving manufacturing innovation in Korea. The most basic but important concept of the i-Manufacturing is ldquocollaborationrdquo. As a part of the project, we are developing various kinds of web-based collaboration systems. We applied IT into conventional manufacturing industry by developing strategic business models and collaboration systems. As a consequence, more than 300 companies are currently using 7 different collaboration systems and they are reducing manufacturing cost and delivery time while increasing product quality and profit. In this paper, therefore, we first introduce the i-Manufacturing and collaboration systems we have developed. The architecture and functions of systems will also be described in detail with case studies.

Simultaneous 3D machining with real-time NURBS interpolation

Increasing demand on precision machining using computerized numerical control (CNC) machines have necessitated that the tool move not only with the smallest possible position error but also with smoothly varying feedrates in 3-dimensional (3D) space. This paper presents the simultaneous 3D machining process investigated using a retrofitted PC-NC milling machine. To achieve the simultaneous 3-axis motions, a new precision interpolation algorithm for 3D Non-Uniform Rational B-Spline (NURBS) curve is proposed. With this accurate and efficient algorithm for the generation of complex 3D shapes, a real-time NURBS interpolator was developed using a PC and the simultaneous 3D machining was accomplished satisfactorily.

Rapid fabrication of aluminum shoe mold using vacuum sealed casting process

Abstract Rapid prototyping and manufacturing (RP&M) is the most appropriate technology for the small-lot production system, because the production cycle is getting shorter owing to various needs of the consumer. Recently RP products, which are made of plastics, wax, and paper, were used to examine the design of samples. These samples, however, cannot be applied to the real mold because soft materials, such as plastics lack the necessary strength to be a mold. So the materials have been changed from RP products to a metal powder filled mold like an epoxy-metal powder composite mold or metal mold, which is called rapid tooling (RT) technology. In this paper, RT technology is applied to the casting process. The casting process has the ability to reflect complicated shapes in one process. But it has not been widely used to make a die and mold because of the poor surface quality caused by air bubbles on the surface of the casting product. In this study, the porous casting mold is fabricated from a mixture of ceramic powder and water-soluble binder. The porous casting mold can improve the characteristics of aluminum casting products with the help of the vacuum sealed casting process. The vacuum sealed casting process is an advanced technology that removes the air bubbles between the porous casting mold and the liquid metal, thus making the surface of the aluminum casting product finer. The purpose of this paper is to develop a high quality shoe mold using porous casting mold and to apply the RP&M technology to the shoe industry.

A Study on BSC-based Evaluation System for Collaborative Information System in Manufacturing Industry

Recently, in order to swiftly satisfy the various product demands by customers reinforced collaboration among industries or business types as well as increased outsourcing have emerged as indispensable constitutive elements of modern manufacturing. An i-Manufacturing project for supporting design collaboration of a domestic mould company is now underway. To drive efficiently the project, different evaluation frameworks per stakeholder in the i-Manufacturing project are required. The purpose of this research is to develop a BSC-based evaluation system for the evaluation of the collaborative information system that will support new product development of mould companies in KOREA. For these, we derived the CSFs and KPIs for evaluating the collaborative information system. And, the derived KPIs are applied to the design collaborative information system, the outcome of the i-Manufacturing project. Evaluation indexes are evaluated through the web-based evaluation system.

An Integrated Multi-BOM System for Product Data Management

Bill of material (BOM), which structurally represents the relation among parts constructing a product, is usually created when enterprises start to develop a new product. And it is shown as various types of BOM according to business needs and usage such as eBOM (engineering BOM), gBOM (green BOM), mBOM (manufacturing BOM), pBOM (process BOM), etc. eBOM, generally called BOM and created in the design stage of the new product, includes the drawing information of parts in the view of product function. eBOM is extended to gBOM adding the material information of parts to cope with international regulations for environment. eBOM is transformed to mBOM, which includes manufacturing sequence of parts and adds some parts required to fabricate parts and to assemble the product. mBOM is also extended to pBOM adding the process information of each part and additional assembly processes. This study introduces the concept of multi-BOM covering eBOM, gBOM, mBOM and pBOM, and proposes an advanced way to manage product data using multi-BOM system. The multi-BOM system proposed is to manage their relations using transformation function of BOM and master information of all BOMs.

Quality management system for web-based collaboration in mold & die industry

Mold and die are frequently used to manufacture the same products rapidly in a great quantity. The qualities of the products, especially the appearance and the functionality of the inner parts of the products, are mostly determined by the quality of the molds which are used to manufacture them. In that sense, It is very important to improve the quality of the molds in order to improve the quality of the products, but it is very difficult to control the quality of the molds because the molds were generally made by the collaboration of many companies. This problem lead to the need of effective collaboration naturally, and this paper deals with the construction and application of the web-based quality control system of molds. In order to control the quality of the molds, we construct the quality information DB for, management of the standard of the product quality and quality element by the buyers guideline, and the quality element management system of molds and the inspection system was constructed. By using this quality management system, the quality standard and quality information could be shared by collaborating companies and applied to inspection, and consequently, the qualities of the molds were improved.

WEB-BASED COLLABORATIVE ENGINEERING FOR INJECTION MOLD DEVELOPMENT

Injection molding is one of the most important manufacturing processes enabling present mass-production. The recent evolutions of technology related to injection molding result in the difficulties in developing the molds. As a result, a higher level of engineering technology should be considered for the developmental stage. This paper presents the web-based engineering collaboration among mold makers, experts, and product makers. Pre-examination and post-verification in the moldmaking process were investigated carefully and implemented in the web environment. Hundreds of engineering collaborations were conducted via developed systems. Surveyed results show that these collaborations help small and medium sized moldmaking enterprises reduce cost and delivery time, while they increase the quality of molds.

FIB-Sputtering Characteristic of Mold Material and Nano Grid Pattern Fabrication

Recently, FIB-Sputtering process has been applied to many micro-manufacturing fields such as semi-conductor industries, display industries and IT industries etc. because it is available to fabricate the micro 3D shape structure directly and more effectively than other machining processes. However, currently FIB is not applied in the fabrication of this micro mold because of some problems such as redeposition and charging effect relating to shape accuracy and productivity. Furthermore, the prediction of the material removal rate is difficult for micro structure fabrication. In this paper, we studied the FIB-Sputtering rate according to mold materials. As well, surface roughness characteristics were analyzed for micro and nano mold fabrication. Si wafer, G.C (glassy carbon), STAVAX, and DLC that have been normally considered as good micro or nano mold materials were used in this study. And also we have known the pattern by pattern procedure has more good fib-sputtering shape than layer by layer procedure.

Win-Win Model between Large Enterprises and Small and Medium Enterprises based on Engineering Collaboration

As a strategy for survival in the recent global competition environment, the collaborations between enterprises are more important than the past. This paper presents the engineering collaboration model between the large and the SMEs (small and medium enterprises) in the field of injection molds. The proposed model was designed based on the needs of fields and was implemented in the form of portal site. It provides the integrated visualization system of analysis results of CAE (computer aided engineering)/CAI (computer aided inspection) and Web-based conferencing system. The developed model contributed to both of large and SMEs in the way of good quality, cost saving, and delivery shortening.