정밀냉간단조 기술을 적용한 자동차 액추에이터용 스퍼기어 부품개발

박동환,한성철 한국소성∙가공학회 2023 소성가공 : 한국소성가공학회지 Vol.32 No.6

Spur Gear parts for automobile actuators using existing former forging technology were produced in a total of three processes on a former forging machine. However, in order to improve cost increase due to frequent mold breakage, Spur Gear parts were designed and manufactured in the cold forging process after forming the preform through former forging. In other words, in the existing former forging mold, product seating defects occurred due to horizontal movement, resulting in many product defects and mold damage, so there was an urgent need to improve mold life and product defects. In order to improve this, we tried to improve the mold life by improving the existing 3 former forging processes to a former forging process and 2 cold forging processes. Therefore, We developed Spur Gear parts for automobile actuators were developed by applying precision cold forging technology through a former forging process and 2 cold forging processes to improve mold life.

계장화 압입시험을 이용한 냉간단조 금형의 예압력 평가기술 개발

김경일(Kyung Il Kim),조규섭(Gue Serb Cho) 한국생산제조학회 2021 한국생산제조학회지 Vol.30 No.6

In cold forging molds, the life of the mold is determined by several factors. Recent studies report that the pre-stress that occurs when the mold is press-fitted to the outer ring has a significant effect on the lifetime of the mold. However, there are many limitations in accurately evaluating the pre-stress of the mold. In this study, we developed a technology to evaluate the pre-stress in the process of sintering, polishing, and press-fitting a WC-Co cold forging mold using the instrument indentation technique, a non-destructive method, referring to the residual stress evaluation technique. In addition, the changes in the stress state after the mold is used in the industrial field were confirmed, and the method to improve the mold life with the evaluation technique proposed in this study was also discussed.

복합단조 공정을 적용한 Outer Support Ring 개발

주원홍(Won Hong Ju),박성영(Sung-young Park) 한국산학기술학회 2017 한국산학기술학회논문지 Vol.18 No.4

본 연구에서는 원웨이 클러치의 핵심 부품인 Outer Support Ring의 복합 단조 공정을 개발하고, 시제품을 제작하여 평가하였다. 기존 공정 즉, 열간 단조와 MCT 가공 공정은 과대한 소재 절삭량과 가공 시간이 길다는 단점이 있다. 이를 극복하고자 열간 단조를 통하여 형상을 구현하고, 냉간 단조를 통하여 정밀한 부품을 성형하였다. 최소한의 가공만을 적용하는 복합 단조 공정을 개발하였다. 상용 소프트웨어인 Deform-3D를 이용하여 단조 해석을 수행하였다. 해석 결과를 바탕으로 열간 단조 및 냉간 단조 공정을 설계하였고, 실제 금형 및 시제품을 제작하였다. 제작한 시제품은 경도, 표면 조도, 내부 결함, 단류선 검사 등의 평가를 수행하였다. 평가결과 특이한 문제점은 발견되지 않았으며, 양산적용이 가능할 것으로 판단된다. 복합 단조를 통하여 열간 단조와 MCT 가공 공정 대비 약 27%의 소재를 절감할 수 있었다. 또한 제품 개당 생산 시간은 약 2.15배 단축되었다. 본 연구를 통하여 원가 절감이 가능한 공정 및 금형 설계 기술을 확립하였고, 이를 통하여 관련 자동차 부품 생산에도 긍정적인 효과가 있을 것으로 기대된다. In this study, the complex forging process of an outer support ring was developed and the prototype was manufactured. The current process, hot forging and MCT machining, has a disadvantage of excessive material removal rates and longer machining hours. To overcome this disadvantage, a general shape is given through hot forging and the precision is achieved through cold forging. The complex forging process was developed with the minimal machining process. Forging analysis was carried out to design a forging process using the commercial program, Deform-3D. The hot and cold forging processes were set up based on the analyzed result. The mold and prototype were manufactured. Hardness, surface roughness, internal defect, the grain low line of the prototype were evaluated. The results showed no particular problems, and there were no problems in mass production. Using complex forging, the material was reduced by approximately 27 % compared to the process using hot forging and MCT machining. In addition, the production speed was improved 2.15 fold compared to that of hot forging and MCT machining. Through this study, a cost-effective process and mold design technology were established, which is expected to have positive effects on other related automotive parts production.

금형 냉각을 고려한 다단 열간 단조 공정의 유한요소해석

최두순(Du-Soon Choi),강형부(Hyoungboo Kang) 한국기계가공학회 2020 한국기계가공학회지 Vol.19 No.5

Multistage hot forging process enables mass production of various parts at a high speed, wherein, it is important to design the forging steps in an optimal way. Finite element methods are widely applied for optimizing the forging process design; however, they present inaccurate results due to the rapid change in the mold temperature during multistage hot forging. In this study, the temperature distributions of the mold in a steady state were calculated via heat transfer analysis during mold cooling. The flow stress and friction coefficient of the material were measured according to the temperature and were applied for numerical analysis of the multistage hot forging process. Eventually, the accuracy of the analysis results is verified by comparing these results with the experiments.

유한요소법을 이용한 SCM435 Bolt의 성형 공정에 관한 해석 및 공정 개선 방안

안교철(Ahn, Kyo-Chul),최취경(Choi, Chui-Kyung) 한국산학기술학회 2012 한국산학기술학회논문지 Vol.13 No.11

볼트의 제작 공정은 연속적인 단조 작업에 의해서 완성되는데 각 공정의 기술적, 경제적인 성공은 적절한 공정설계와 각 작업에 필요한 금형 설계에서 좌우된다. 본 연구에서는 다단 공정에 의해서 이루어지는 SCM435 볼 트의 성형과정 중에서 1, 2단계의 성형을 유한요소법을 이용하여 해석하여 합리적인 공정이 이루어지도록 개선 방향 을 제시하고자 하며 유한요소법을 이용하여 해석한 1, 2단계의 공정은 축대칭이 성립되므로 소재의 변형 형상이 공 정에서 기대했던 치수를 만족할 수 있었으며 소재에 형성된 단류선이 전 공정을 통하여 부드럽게 연속적으로 형성됨 을 알 수 있었으므로 소재의 성형 뿐 아니라 내부의 결함도 없을 것으로 예상되었다. A bolt manufacturing process is completed with continuous forging. Technical and economical success of each process will depend on the appropriate process design and metal mold design for each procedure. This study aims to analyze the moldings of first and second steps among the multi-step molding processes of SCM435 bolt by use of the finite element method in order to achieve the reasonable process. Since the processes of first and second steps analyzed by use of the finite element method consist of axial symmetry, the transformed configuration of material satisfy the dimensions expected in process. In addition, the uniflow line formed in material becomes smooth and consistent over the entire process. Therefore neither molding of material nor inherent defect is expected.

러시아 단조금형의 수입에 따른 우리나라 통관제도의 개선방안

최해범(Hae-Bum Choi),신성식(Sung-Shik Shin) 한국관세학회 2013 관세학회지 Vol.14 No.1

In recent years, forging mold of imports from the Russian Federation and the rapid increase in the trend, and the reason than were imported from Germany the existing strengths in terms of price competitiveness and improve the quality of the product. The reason the industry is at the discretion of the FTA agreement is not imports from the FTA was signed in Germany than in Russia, forging mold of the basic tariff to pay 8%. Especially South Korea, because the importance of forging mold it is very large parts assembled by shipbuilders and car companies that supply structure. Eventually say so inefficient, but because this domestic manufacture or imports of raw materials from supply to price competitiveness in the process leading to the assembled falling. Corporate positions rather forging mold is preferable to utilize industrial imports. Considering these points, the income related trade procedures, review the contents of the relevant laws and regulations, Further studies on the direction of the current on the revision of the Tariff Act as kind of machine mold forging equipment introduced to Korea and now imports almost negligible from Russia.

대형엔진용 자유단조품 생산을 위한 공정 자동화장비 개발

지명국(Myoung Kuk Ji),김영근(Young Keun Kim),장백선(Baek Seon Jang),최창수(Chang Su Choi),김철표(Churl Pyo Kim),정한식(Han Shik Chung),정효민(Hyo Min Jeong) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.10

In mechanical industries, forging is one of the basic process. But comparing the other developed industries, forging industries can not reach at the level of that development. In forging industries, the quality of the products are totally depends on the skills of workers and also the precision of the equipments. Especially in case of open die forging, all processes are manual and the workforce are always exposed to danger. So keeping in view the aspect of danger during open die forging, a development of system has been made in this research, which is based on forklift. In the regard some additional device has been made especially. After than it is fitted with the forklift for safe and easy handling of jobs and products during open die forging process. First of all, development system mold has been assembled to the system, after than it is assembled with forklift. This development system has been applied for handling of large scale products over 300Kg, and the satisfactory result with uniform quality of the products have been achieved due to this mechanical setup.

LPI 차량용 연료필터하우징 개발

이병훈(Lee, Byeong-Hoon),박성영(Park, Sung-Young) 한국산학기술학회 2014 한국산학기술학회논문지 Vol.15 No.2

자동차용 LPI 연료필터 하우징의 냉간단조 공정에 대한 성형해석을 수행하였다. 변형과 하중의 분배를 고려 하여 금형과 시제품을 제작하였다. 또한 기존 모델과 신규 모델의 유동 특성을 분석하기 위하여, 유동해석을 수행하 였다. 유동해석 결과, 두 모델은 동등한 압력강하량을 나타내었다. 기존 제품 대비, 상부 하우징은 16 g, 하부 하우징 은 30.5 g이 감소하여, 총 46.5 g의 중량이 감소하였다. 안정성을 검증하기 위해서 기밀시험 및 내압시험을 수행하였 으며, 시험 기준을 만족하였다. Computer simulation has been performed to optimize cold forging process of automotive LPI fuel filter housing. A mold and the test product have been manufactured considering the strain and load distribution during the cold forging process. Also, fuel flow simulation has been performed to analyze flow characteristics of existing model and new model. Simulation result shows that two models have equivalent pressure drop. Compared with the mass of existing product, raw material reduction of 16 g and 30.5 g has been achieved from the upper and lower housing, respectively. Total mass reduction of the new housing was 46.5 g. Leak test and internal pressure test have been performed to verify the safety standard and test results were satisfactory.

반경단조 공법을 이용한 사각봉재 제조공정의 최적 금형설계

장성민(S. M. Jang),김홍태(H. T. Kim),장시진(S. J. Jang),전만수(M. S. Joun),문호근(H. K. Moon) 한국소성가공학회 2012 한국소성가공학회 학술대회 논문집 Vol.2012 No.5

In conventional open die forging press, the material is formed by up and down motion of punch and thus the longitudinal elongation per stroke is relatively small, resulting in long manufacturing time. In addition, the center of material is exposed to decisive defects generated during cogging due to Mannesmann’s effect, that is, repeated deformation in compression after tension. To the contrary, four punches or dies in radial forging press the material in four perpendicular directions at the same time, which results in better quality as well as short manufacturing time. In the paper, the manufacturing process of a square bar using radial forging press is simulated to optimize die design and a set of optimized dies are given

헬리컬기어 단조금형의 마찰저감에 관한 연구

최원식(W.S. Choi),이영선(Y.S. Lee),남중희(J.H. Nam),권주리(J.R. Kwon) 한국소성가공학회 2011 한국소성가공학회 학술대회 논문집 Vol.2011 No.5

The purpose of this study is to find of tribologic characteristics on the drag reduction in helical forging mold which is new development part in mobile auto-transmission. The test materials were SCr420H and SKD61. This study has used the pin-on-disk type of friction wear test system and has used the normal load in the range of 20-100N. It was operated at the speed range of 0.06-0.34m/s. The friction coefficient of helical gear and mold materials was a range of 0.02-0.12. When the velocity increases and the load decrease, the friction coefficient increased. On the other hand, the friction coefficient of dimple patterning materials was a range of 0.012-0.03. When the load increases, the friction coefficient decreased and the changes in velocity were not affected. The specimen of dimple processing was corresponding to 30% of the friction coefficient for not processing specimens. It is dimple effect.