동부스바 인발 금형설계

권혁홍,이정로 한국공작기계학회 2002 한국생산제조학회지 Vol.11 No.4

Copper bus-bar is made by drawing process and used in many part of industry. When design drawing die for copper bus-bar, design factor is focused on the deformation of die-land by drawing force and shrink fit. In this paper it is analyzed to determine shrink fit value by shrink fit analysis program which is used with APDL/UIDL language in a commercial FEM package, ANSYS. The shrink fit analysis has been developed that enables optimal design of the dies taking into account the elastic deflections. Elastic deflection is generated in shrink fitting the die inserts and that caused by the stresses generated using DEFORM software for drawing process analysis. This data can be processed as load input data for a finite element die-stress analysis. Process simulation and stress analysis are thus combined during the drawing die design. The stress analysis of the dies is used to determine optimized dimension of die-land.

박판스프링 교정시스템 구축에 관한 연구

권혁홍,김선호 대진대학교 1997 大眞論叢 Vol.5 No.-

This paper describes that study which construct a theoretic and experimental algorithm in order to make the automatic correction system of detent spring, and when load for correction pressed at spring, it can be found elastic and plastic deformation quantities by Finite Element Analysis. As a result, it has been found that the simulation datas are in good agreement with experimetal results.

TiB₂ 세라믹 소재를 이용한 열간 압출금형 개발

권혁홍,이정로 대진대학교 2001 大眞論叢 Vol.9 No.-

The use of ceramic inserts in hot extrusion dies offers significant technical and economic advantages over other forms of manufacture. These potential benefits can however only be realized by optimal design of the tools so that the ceramic inserts are not subjected to stresses that lead to their premature failure. In this paper, process simulation and stress analysis are thus combined during the design, and a data exchange program has been developed that enables optimal design of the dies taking into account the elastic deflections generated in shrink fitting the d e inserts and that caused by the stresses generated in the process. The stress analysis of the dies is used to determine the stress conditions on the ceramic insert by considering contact and interference effects under both mechanical and thermal loads. The results are compared with the experimental ones for verification.

디텐트 스프링 교정방법의 적용성 평가

권혁홍 대진대학교 신과학연구소 1998 신과학연구 Vol.1 No.-

A sheet spring such as detent is widely used in machine elements because it is easy to produced in mass with low cost. Since it has several complicated production processes, inspection and correction for spring force is needed after production. To construct automatic spring force correction system, applied force for plastic deformation must be derived from experimental methods. Frequently change of model and spring materials make it diffcult for the experimental methods to be applied. This paper describes the evaluation of analytical method for detent spring force correction as a substitute to experimental method. FEM(Finite Element Method)is used in the analytical method to find elastic and plastic deformation quantities at various conditions. To find the application of automatic spring force correction system, analytical and experimental results are compared with deformation quantities at various applied forces. It is find that the simulation results of the analitical method is good agreement on those of the experimental method whithin the limit 5%.

헬리컬기어 냉간압출금형의 파손해석

권혁홍 한국공작기계학회 2001 한국생산제조학회지 Vol.10 No.2

This paper suggests to predict the failure of helical gear extrusion die. The basic assumption that constitutes the frame-work for any combined stress failure theory is that failure is predicted to occur when the maximum value of stress becomes equal to or exceeds the value of the same modulus that produces failure in a simple uniaxial stress test using the same material. The stresses which were calculated to each critical points are applied maximum normal stress theory and distor-tion energy theory. The theoretical analysis and experimental results for Samanta process and New process dies were com-pared.

Hexagonal 인서드용 열간압출 금형설계

권혁홍,이정로 한국공작기계학회 2002 한국생산제조학회지 Vol.11 No.1

The use of hexagonal ceramic inserts for copper extrusion dies offers significant technical and economic advantages over other forms of manufacture. In this paper the data on the loading of the tools is determined from a commercial FEM package as the contact stress distribution on the die-workpiece interface and as temperature distributions in the die. This data can be processed as load input data for a finite element die-stress analysis. Process simulation and stress analysis are thus combined during the design, and a data exchange program has been developed that enables optimal design of the dies taking into account the elastic deflections generated in shrink fitting the die inserts and that caused by the stresses generated in the process. The stress analysis of the dies is used to determine the stress conditions on the ceramic inset by considering contact and interference effects under both mechanical and thermal loads.

나선형기어 냉간압출금형의 파손해석

권혁홍 대진대학교 생산기술연구소 2000 생산기술연구소 논문집 Vol.3 No.-

This paper suggests to predict the failure of helical gear extrusion die. The basic assumption that constitutes the framework for any combined stress failure theory is that failure is predicted to occur when the maximum value of stress becomes equal to or exceeds the value of the same modulus that produces failure in a simple uniaxial stress test using the same material. The stresses which were calculated to each critical points are applied maximum normal stress theory and distortion energy theory. The theoretical analysis and experimental results for Samanta process and New process dies were compared. 주요기술용어 : Failure Analysis(파손해석), Cold Extrusion Die(냉간압출 금형), 최대수직응력 이론(maximum normal stress theory), 비틀림에너지이론(distortion energy theory)

기어加工用 챔퍼링머신의 構造解析

權赫洪,金善浩 대진대학교 1994 大眞論叢 Vol.2 No.-

In this study the structure analysis of chamfering m/c is developed to improve dynamic characteristics To this purpose a chamfering m/c is mathematically modelled and dynamic response analysis of the model are investigated by use of Finite Element Method(FEM). The investigation procedures are as follows. The finite element modelling of the chamfering m/c is done with triangular and rectangular plate elements and each node of the elements has 6 degrees of freedom. And this model is idealized as a forced vibration system under impulse load by cutting force Model parameters, natural frequency and mode shape, and dynamic response for displacement and stress are analyzed by use of mode superposition method. To reduce computing time of dynamic response analysis, lower vibration mode is analyzed with master-DOF and mass participation factor. In this case maximum relative displacement is occured at 17.483 Hz in the right column. this result

CATIA를 이용한 고속가공용 탭핑머신의 구조해석

권혁홍,김지용,하종국 대진대학교 2002 大眞論叢 Vol.10 No.-

In this study the structure analysis of tapping m/c is developed to improve dynamic characteristics. To this purpose a tapping m/c is mathematically modelled and dynamic response analysis of the model are investigated by use of Finite Element Method(FEM). The investigation procedures are as follows. The finite element modelling of the tapping m/c is done with triangular and rectangular plate elements and each node of the elements has 6 degrees of freedom. And this model is idealized as a forced vibration system under impulse load by cutting force. Model parameters, natural frequency and mode shape, and dynamic response for displacement and stress are analyzed by use of mode superposition method. To reduce computing time of dynamic response analysis, lower vibration mode is analyzed with master-DOF and mass participation factor. In this case maximum relative displacement is occured at 17.483 Hz in the right column.

전주기술을 이용한 로터리스크린 제조에 관한 연구

권혁홍,박상호 대진대학교 2004 大眞論叢 Vol.11 No.-

To simple the manufacturing process of rotary screen, this study was adopted electroforming technology and produced silicon rubber mandrel. Furthermore, to indicate the optimal condition for the acquisition of high-qualified rotary screen product, the experiment was executed with pH, time, sulfamate nickel solution according to density which were the main factors to decide the condition, then compared it with the product made by original "S" Company in Holland. As a result, the figure of Hole was more obvious and correct. Also the open size increased more than 2-3%.