• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.3
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• pp.37-43
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• 2007

Recent technological developments in machine tools have been focused on high speed, low vibration machining and high precision machining. And the concern with multi-functional machining has been increased for the last several years. Multi-tasking machines are widely used in machine tool industries. Laser multi-tasking machine has been developed for high precision and fewer vibration machining. The purpose of this study is to evaluate the effects of structural reinforcement on Laser multi-tasking machine which is comprehensively combined turning center and laser machine. Up to date, for the structural stability evaluation of a multi-tasking machine, the analysis model has been considered only the weight of the upper parts. The positions of upper parts on multi-tasking machine have not been considered in the model. So, the results of the present FE model have revealed some difference with measurement data in case of multi-tasking machine. Design of the machine and structural analysis is carried out by FEM simulation using the commercial software CATIA V5. In the result of the structural analysis, effectiveness of reinforcement of the bed was confirmed.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.2
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• pp.129-138
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• 2012

In this study, three types of large scale multi-tasking machine tools together with core technologies involved have been developed and introduced; a multi-tasking machine tool for large scale marine engine crankshafts, a multi-tasking vertical lathe for windmill parts, and a large scale 5-axis machine tool of gantry type. Several special purpose devices has been necessarily developed for the purpose of handling and machining big and heavy workpieces accurately, such as PTD (Pin Turning Device) with revolving ring spindle for machining eccentric crankshaft pins, hydrostatic rotary table and steady rest for supporting and resting heavy workpieces, and 2-axis automatic swiveling head for high-quality free surface machining. Core technologies have been also developed and adopted on their detail design stage; 1) structural design optimization with FEM structural analysis, 2) theoretical hydrostatic analysis for the PTD and rotary table bearings, 3) box-in-box type cross-rail and octagonal ram design to secure machine rigidity and accuracy, 4) constant spindle rpm control against gravitational torque due to unbalanced workpiece.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.1
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• pp.9-14
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• 2015

To build a high precision machine tool and increase its productivity, structural analysis needs to be carried out for vibration and stiffness of the machine tools before any detailed design. Therefore, in this paper, static and dynamic analysis is carried out to evaluate 8-axis multi tasking machining beds for automotive power train shafts; then, selection of an appropriate device is made for application to bed design. The results of structural and modal analysis confirmed the structural characteristics of the 8-axis multi tasking machine for automotive power train shaft beds: and the second shape bed is the safest is considered secure.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.2
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• pp.156-160
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• 2012

Recently, the demands of the large scale machine tools gradually increase to machine the large parts, such as large scale crankshaft, yaw and pitch bearings for the wind power generator and the vehicle or aircraft components. But the high technology is necessary in order to develop the huge machine tools. Furthermore, the global market of it has been monopolized by a few companies. So, we need to develop the large scale machine tools and study its core technology to rush into the increasing market. In this study, we carried out the researches for the important core technology of a multi-tasking, machine tool; a large scale 5-axis machine tool of gantry type for multi-task machining. This study is focused on the design of large size gantry type multi-axis machine. In the case of large size of machine the cross rail deflection in the X-axis is significant. To reduce the deflection due to the eccentric spindle head, a special hollow type design in the cross rail with outside ram is adapted in this study. Also, the Zig-Zag motion in the Y-axis is inevitable with the gantry geometry, which is by the un-balancing, different motion at the left and the right columns moving. We tried to reduce the influence of Zig-Zag motion using FEM with different loading conditions at the left and the right side column.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.1006-1011
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• 1993

In this study, a DNC(Distributed Numerical Control) management system is designed that can directly control and manage hybrid CNC machine tools on real-time. And management software is developed to inter-communicate field informations with CNC controllers using an interface processor(Intelligent Multi Communication Board, IMCB). Especially, IMCB supports that DNC system sends and receives part program with CNC controllers in the form of real-time multi-tasking.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.453-454
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• 2012

• Journal of the Korean Society for Precision Engineering
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• v.12 no.12
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• pp.19-29
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• 1995

The basic technology for a production system represented by design, machining, assembly, and inspection, is machining technology such as CNC machine tools. etc. Direct Numerical Control, that effeciently manages NC programs is developing into Distributed Numerical Control that increases the utilization of the machining cell. It has the ability of monitoring and control, in real time, for CNC and periperial equipment. In this study, we develop a Distributed Numerical Control system that has real time and multitasking operation capability for the machining cell with various CNC's. With the consideration of economy, generalization and extension, the system is interfaced with CNC machine tools and periperial device using RS-485 network and RS-232C communication methods.

• Journal of the Korea Safety Management & Science
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• v.5 no.2
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• pp.87-98
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• 2003

With the development of CNC(Computer Numerical Control) and communication technology, the connotation and functions of Distributed Numerical Control have been greatly enlarged. In this study, we develop and implement a Distributed Numerical Control system that has real time and multi-tasking operation capability for the machining cell with various NC(Numerical Control) and CNC machines. With the consideration of economy, generalization and extension, this system is interfaced with Shop Floor Control System, Machine Control System and Tool Preparation System using advanced networking method. In the implementation phase, we use the ORACLE DBMS (Database Management System) as the DBMS and Microsoft Visual C++ as the programming tools.