유동성형의 성형변수가 금속유동에 미치는 영향

남경오,염성호,박현진,홍성인 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

The flow forming has been used to produce long thin walled tube parts, with reduced forming force and enhanced mechanical and surface quality for a good finished part, compared with other method formed parts. Therefore, spinning and flow forming techniques are used frequently in automotive, aerial, defense industry. Forming parameters effecting metal flow in the flow forming are lead angle, feed rate, thickness reduction ratio, mandrel revolution and material property etc. Especially, lead angle and feed rate of the working roller are important parameters for the formed metal flow. In this paper, finite element method analysis of one-roller two-path backward and forward flow forming is carried out to study effects of lead angle and feed rate on the formed workpiece geometry. Various lead angles and feed rates are applied in flow forming process analysis. As a result of analysis, build-up, bulging and bell-mouth dimensions on various forming conditions are obtained and compared with each analysis cases.

후방유동성형에서 빌드업 생성이 성형력에 미치는 영향

장승용(Jang Seung Yong),박현진(Park Hyun Jin),우호길(Woo Ho Kil),남경오(Nam Kyoung O) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.10

The flow forming has been used to produce long thin walled tube parts with reduced forming force and enhanced mechanical and surface quality for a good finished part compared with other method. The forming parameters affecting metal flow and forming force in the flow forming are lead angle, feed rate, thickness reduction ratio, mandrel revolution and material property etc. Especially, lead angle, feed rate of the working roller, build-up and thickness reduction ratio are important parameters for the flow forming. In this paper, one-roller backward flow forming analysis is carried out to study effects of the build-up creation affecting the contact area. The forming force is related to the contact area between roller and workpiece. To calculate accurate contact area and forming force, the geometric method and numerical analysis was proposed in this paper.

유동성형의 성형변수가 금속유동에 미치는 영향

남경오(Nam Kyoung O),염성호(Yeom Sung Ho),박현진(Park Hyeon Jin),홍성인(Hong Sung In) 한국생산제조학회 2006 한국공작기계학회 춘계학술대회논문집 Vol.2006 No.-

The flow forming has been used to produce long thin walled tube parts, with reduced forming force and enhanced mechanical and surface quality for a good finished part, compared with other method formed parts. Therefore, spinning and flow forming techniques are used frequently in automotive, aerial, defense industry. Forming parameters effecting metal flow in the flow forming are lead angle, feed rate, thickness reduction ratio, mandrel revolution and material property etc. Especially, lead angle and feed rate of the working roller are important parameters for the formed metal flow. In this paper, finite element method analysis of one-roller two-path backward and forward flow forming is carried out to study effects of lead angle and feed rate on the formed workpiece geometry. Various lead angles and feed rates are applied in flow forming process analysis. As a result of analysis, build-up, bulging and bell-mouth dimensions on various forming conditions are obtained and compared with each analysis cases.

다양한 롤러 단면형상을 적용한 유동성형의 성형력에 관한 평가

남경오,원종호 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

The flow forming has been used to produce long thin walled tube parts, with reduced forming force and enhanced mechanical and surface quality for a good finished part, compared with other method formed parts. Therefore, flow forming technique is used widely in industrial production. Spinning and flow forming techniques are used frequently in automotive, aerial, defense industry. Factors for the flow forming machine design are consist of motor power, bed rigidity, mandrel stiffness, spindle power, roller profile, etc. Especially, mandrel, spindle power and roller are important factors for flow forming machine capacity. In this paper, three dimensional finite element method analysis of one-roller backward flow forming of a workpiece is carried out to study effects of roller profile on forming force. Applied roller profile have roller lead geometries of angle 20°, 30°, 40°, concave and convex. Axial and radial forming forces on various roller profiles are obtained and compared with each analysis cases.

다양한 롤러 단면형상을 적용한 유동성형의 성형력 비교

남경오(Nam Kyoung O),김범년(Kim Bum Nyun),원종호(Won Jong Ho) 한국생산제조학회 2007 한국생산제조학회지 Vol.16 No.4

The flow forming has been used to produce long thin walled tube parts, with the reduced forming force and the enhanced mechanical and surface quality for a good finished part, compared with the formed parts using other method. Therefore, flow forming technique is used widely in industrial production. Spinning and flow forming techniques are used frequently in automotive, aerial and defense industries. The main factors for the flow forming machine design are motor power, bed rigidity, mandrel stiffness, spindle power, roller profile, etc. Especially, mandrel, spindle power and roller are important factors for flow forming machine capacity. In this paper, three dimensional finite element method for analysis of one-roller backward flow forming of a workpiece has been carried out to study effects of roller profile on forming force. Applied roller profile have roller lead geometries of angle 20°, 30°, 40°, concave and convex. Axial and radial forming forces on various roller profiles are obtained and compared with each analysis cases.

다양한 롤러 단면형상을 적용한 유동성형의 성형력에 관한 평가

남경오(Nam Kyoung O),원종호(Won Jong Ho) 한국생산제조학회 2006 한국공작기계학회 춘계학술대회논문집 Vol.2006 No.-

The flow fanning has been used to produce long thin walled tube parts, with reduced fanning force and enhanced mechanical and surface quality for a good finished part, compared with other method formed parts. Therefore, flow forming technique is used widely in industrial production. Spinning and flow forming techniques are used frequently in automotive, aerial, defense industry. Factors for the flow forming machine design are consist of motor power, bed rigidity, mandrel stiffness, spindle power, roller profile, etc. Especially, mandrel, spindle power and roller are important factors for flow forming machine capacity. In this paper, three dimensional finite element method analysis of one-roller backward flow forming of a workpiece is carried out to study effects of roller profile on forming force. Applied roller profile have roller lead geometries of angle 20°, 30°, 40°, concave and convex. Axial and radial forming forces on various roller profiles are obtained and compared with each analysis cases.

Deformation Behavior of Haynes230 Superalloy during Backward Flow Forming

Xing-kun Wang,Qinxiang Xia,Xiu-quan Cheng 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.1

Flow forming manufacturing technique has a unique advantage in producing thin-walled cylindrical parts, witnessing a growing demand in defense, aerospace and other fields. However, some of mechanisms of flow forming have not been deeply understood yet. Aiming at easily appearing problems of the crack and expanding, a finite element model with implicit code has been developed to simulate backward flow forming process for production of thin-walled superalloy tubular parts. The material displacement and stressstrain field distribution were obtained, impact of material displacement to dimensional accuracy and residual stress of spun part was analyzed; distribution of strain vector along thickness of spun part and its influence on the occurrence of fracture was analyzed. The results indicate that inhomogeneous distribution of material displacement in thickness brings about residual tensile stress in outer layer and residual compressive stress in inner layer of spun part; plastic deformation occurs mainly in the outer layer; shear plastic strain on the outer surface is much larger than the inner, which may lead to fracture on the outer surface. Above research can play an active role in understanding the mechanism of backward flow forming and deepening the understanding of fracture and the optimization of the process parameters.

보스-리브 시험 시 펀치 형상 및 마찰 조건데 따른 변형 양상에 대한 연구

윤여웅(Y. W. Yun),강성훈(S. H .Kang) 한국소성가공학회 2009 한국소성가공학회 학술대회 논문집 Vol.2009 No.10

Recently, boss and rib test based on backward extrusion process was proposed to quantitative evaluate the interfacial friction condition in bulk forming process. In this test, the tube-shaped punch with hole pressurizes the workpiece so that the boss and rib are formed along the hole and outer surface of the punch. It was experimentally and numerically revealed that the height of boss is higher than that of the rib under the severe friction condition. This work is focused on the effect of the punch design and friction condition on deformation pattern in boss and rib test. From the boss and rib test simulations, it was found that there is slight variation in both the heights of boss and rib according to the length of punch land, nose radius, and face angle. However the hole diameter of the punch and the clearance between the punch and die have a significant influence on the heights of the boss and rib. In addition, the effect of flow stress was also investigated on the deformation pattern through FE simulations.