• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.4
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• pp.164-170
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• 2017

The CNC machine tool field is showing a growing trend with the recent rapid development of manufacturing industries such as semiconductors, automobiles, medical devices, various inspection and test equipment, mechanical metal processing equipment, aircraft, shipbuilding and electronic equipment. However, small and medium-sized machining companies that use CNC machine tools are experiencing difficulties in increasingly intense competition. Especially, small companies which are receiving orders from 3rd or 4th venders are very difficult in business management. In recent years, company S experienced difficulty to make product quality and delivery time due to the ignorance of the processing method when manufacturing cooling plate jig made of SUS304 material used for cell phone liquid crystal glass processing. In order to solve these problems, we redesigned the process according to the size of our company and tried to manage all processes with quantified data. In the meantime, we have found that there is a need to improve the cutter process, which accounts for most of the machining process. Therefore, we have investigated the correlation between RPM and FEED of three cutters that have been used in the past. As a result, we found that it is the most urgent problem to solve the roughing process during the cutter operation which occupies more than 70% of the total machining. In order to shorten the machining time and improve the quality in machining of SUS304 cooling plate jig, we select the main factors such as price, tool life, maintenance cost, productivity, quality, RPM, and FEED and use AHP to find the most suitable milling cutter. We also tried to solve the problem of delivery, quality and production capacity which was a big problem of S company through experiment operation with selected cutter tool. As a result, the following conclusions were drawn. First, the most efficient of the three cutters currently available in the machining center has proven to be an M-cutter. Second, although one additional facility was required, it was possible to produce the existing facilities without additional investment by supplementing the lack of production capacity due to productivity improvement. Third, the Company's difficulties in delivery and capacity shortfalls have been resolved. Fourth, annual sales increased by KRW 109 million and profits increased by KRW 32 million annually. Fifth, it can confirm the usefulness of AHP method in corporate decision making and it can be utilized in various facility investment and process improvement in the future.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.3
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• pp.430-438
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• 1997

Deburring and edge finishing technology as the final process of machining operation is required for manufacturing of advanced precise conponents. But, deburring is considered as a difficult problem on going to the high efficient production and automation in the FMS. Removal of burr couldn't have a standard of its definition because of its various shapes, dimensions and properties and mostly depends on manual treatment. Especially, deburring for cross hole inside is very difficult owing to its shape passing through out perpendicular to a main hole. The electrochemical method is suggested as its solution in practical aspect. Therefore, electrochemical deburring technology needs to be developed for the high efficiency and automation of internal deburring in the cross hole. In this study, the new process in the eliminating burr inside cross hole, electrochemical deburring by the wheel electroplated with Cubic-Boron-Nitrade abrasives, is suggested. Its deburring mechanism is described and machining performances is investigated. Also, CBN electroplated wheel is designed and manufactured and then characteristics of electrochemical deburring are investigated through experiments. Overall electrochemical deburring performance against burr inside cross hole is examined in the various power sources such as peak current and direct current.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.4
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• pp.297-301
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• 2014

The biggest factors, which lower the machining accuracy of machine, are thermal deformation and chatter vibration. In this article, we introduce the development case of a device and technology that can automatically compensate thermal deformation errors of machine during long-time processing on the machine tool's CNC (Computerized Numerical Controller) in real time. In machine processing, the data acquisition of temperature signal in real time and auto-compensation of the machine origin of machine tools depending on thermal deformation have significant influence on improving the machining accuracy and the rate of operation. Thus, we attempts to introduce the related contents of the development we have made in this article : The development of a device that embedded the acquisition part of temperature data, linear regression to get compensation value, compensation model of neural network and a system that compensates the machine origin of machine tool automatically during manufacturing process on the CNC.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.6
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• pp.128-135
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• 2002

Burr is a projected part of finished workpiece. It is unavoidable and undesirable by-product of most metal cutting or shearing process. Also, it must be removed to improve the fit of machined parts, safety of workers, and the effectiveness of finishing operation. But deburring process Is one of manufacturing processes that have not been successfully automated, so deburring automation is strongly needed. This paper focused on developing a basic algorithm to find edge of workpiece and match two different image data for deburring automation which includes automatic recognition of parts, generation of deburring tool paths and edge/comer finding ability by analyzing the DXF drawing file which contains information of part geometry. As an algorithm fur corner finding, SUSAN method was chosen. It makes good performance in finding edge and corner in suitable time. And this paper suggested a simple algorithm to find matching point between CCD image and drawing file.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.491-494
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• 2002

The real-time industrial network often referred to as fieldbus, is an important element for building automated manufacturing systems. Thus, in order to satisfy the real-time requirements of field devices such as sensors, actuators, and controllers. numerous standard organizations and vendors have developed various fieldbus protocols such as Profibus, WorldFIP and Foundation Fieldbus. However, the application of fieldbus has been limited due to the high cost of hardware and the difficulty in interfacing with multi-vendor products. In order to solve these problems, the computer network technology, especially Ethernet (IEEE 802.3), is being adopted lo the industrial environment. The crucial technical obstacle for Ethernet is that its non-deterministic behavior makes it inadequate for industrial applications where real-time data such as control command and alarm signal hale to be delivered within a certain time limit. Recently, the development of switched Ethernet shows a very promising prospect for industrial application due to the elimination of uncertainties in the network operation resulting in much improved performance. This paper focuses on the application of the switched Ethernet for industrial comm unications.

• Journal of ILASS-Korea
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• v.16 no.1
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• pp.1-6
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• 2011

In recent years, the need for more fuel-efficient and lower-emission vehicles has driven the technical development of alternative fuels such as LPG (Liquefied Petroleum Gas) which is able to meet the limits of better emission levels without many modifications to current engine design. LPG has a high vapor pressure and lower viscosity and surface tension than diesel and gasoline fuels. These different fuel characteristics make it difficult to directly apply the conventional gasoline or diesel fuel pump. Self acting lubricated groove design or coating can be used in high-speed and high precision spindle system like a roller-vane type fuel pump, because of its advantages such as low frictional loss, low heat generation, averaging effect leading better running accuracy and simplicity in manufacturing. Those design method can also affect the atomization of fuel from the injector and the formation of fuel film on the intake manifold. In this study, experiments are carried out to get performance characteristics of initial and steady state operation, The characteristics of vane type fuel pump were investigated to access the applicability on LPLi engine.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.425-428
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• 2005

본 연구는 건설장비 차량 조립부품을 제작하는 가공공장의 계획 및 운영 시스템 개발에 대한 내용이다. 연구의 대상은 건설장비 차량인 굴삭기, 휠로더, 지게차의 조립부품을 제작하는 공장으로 제작품별 제작라인이 구성되어 있다. 그리고 각 제작라인에는 여러 개의 공정이 있으며, 일부 공정은 작업자에 의해 작업이 이루어지고, 용접 및 가공 등은 자동화된 장비 및 설비에 의해 작업이 된다. 가공공장에서 관리 및 운영의 주요 관점은 이후 공정인 조립공장의 조립 착수일에 늦지 않게 제작된 부품을 공급하는 것이다. 그리고 공장 자체적으로 제작라인 내의 재공재고 감소, 작업일간 작업부하평준화, 자동화 장비 및 설비의 효율 극대화 등이 공장의 주요 관리 사항이다. 따라서 본 연구에서는 가공공장에서 제작되는 조립부품의 납기일 준수, 재고 감소, 부하 평준화, 장비효율의 극대화를 위해 공장을 체계적으로 관리하기 위한 계획 및 운영 시스템을 개발하였다. 개발시스템에는 제작라인별 제작 착수 및 자재발주${\cdot}$입고 관리, 공정별 실적관리, 실시간 작업 진행 관리, 용접 불량 관리 기능 등이 있다. 시스템은 MSSQL 서버, 오라클과 Visual Basic, Visual C# ASP로 개발되었다.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.6 s.183
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• pp.151-159
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• 2006

This paper describes a design process of end-milling cutters: solid model of the designed cutter is constructed along with computation of cutter geometry, and the wheel geometry as well as wheel positioning data f3r fabricating end-mills with required cutter geometry is calculated. In the process, the main idea is to use the cutting simulation method by which the machined shape of an end-milling cutter is obtained via Boolean operation between a given grinding wheel and a cylindrical workpiece (raw stock). Major design parameters of a cutter such as rake angle, inner radius can be verified by interrogating the section profile of its solid model. We studied relations between various dimensional parameters and proposed an iterative approach to obtain the required geometry of a grinding wheel and the CL data for machining an end-milling cutter satisfying the design parameters. This research has been implemented on a commercial CAD system by use of the API function programming, and is currently used by a tool maker in Korea. It can eliminate producing a physical prototype during the design stage, and it can be used for virtual cutting test and analysis as well.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.2 s.95
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• pp.123-129
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• 1999

Ball-end milling process is widely used in the die and mold manufacturing because of suitable one for the machining of free-form surface. During the process, the pencil cutting operation can be adopted before finish cut to eliminate overload in uncut area caused by large diameter of ball-end mill. The ball-end mill cutter for the pencil cutting is easily deflected by cutting force due to the long and thin shape, and the tool deflection in pencil cutting is one of the main reason of the machining errors in a free-form surface. The purpose of this study is to find the characteristics of deflected cutter trajectory by constructing measurement system with eddy-current sensor. It was found that the severe reduction of corner radius produced the overcut during the plane cutting. Up cutting method induced the overcut both plane and slope cutting, but down cutting one induced the undercut. From the experiments, down cutting with upward cutting path can generate the small undercut surface.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2004.11a
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• pp.249-254
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• 2004

The pressing of car body parts is one of the most important sheet metal drawing processes. The corrosion protection oil applied by the steel mills plays a part in every sheet metal forming operation and also makes up the largest proportion of lubricants used. The idea to combine the corrosion protection properties of a corrosion preventive oil with the lubricity of a drawing oil lead to the development of the Anticorit prelubes. Applied at the finishing lines of the steel mills, they finally serve as lubricant in the press shops. A prerequisite for the suitability of a prelube-type oil is the absolute compatibility with all single processes from the coil to the Body in White. The use of prelubes in steel mills reduces the number and quantity of spot lubricants for additional press shop oiling dramatically. But their true benefits can only be fully achieved if the compatibility principle is applied throughout the manufacturing chain. Therefore, modem prelubes systems are modular, even different viscosities can be part of the same concept. This results in a far-reaching multifunctionality of the Anticorit prelube system for all applications.