• 한국기계가공학회지
• /
• 제16권4호
• /
• pp.83-88
• /
• 2017

Recently, the use of advanced materials with light weight significantly increases because of global regulation on CO2 emission. Especially, CFRP (carbon fiber reinforced plastics) one of the most promising advanced materials. Since CFRP has pretty higher strength per unit weight than steel, it is one of most popular materials in aviation industry and its application to automobile rises sharply. Especially, one of the frequent machining processes for CFRP is drilling to make a hole, however, CFRP drilling has troublesome limitations in hole quality and productivity induced due to delamination, splintering and severe tool wear. Particularly, cutting loads increase caused by tool wear makes delamination and splintering even severer. Therefore, tool wear monitoring or reduction in CFRP drilling must be considered seriously. In this study, we measured thrust force, flank wear, and tool surface temperature in drilling using various tools with different sizes and materials. Consequently, it was presented the effects of tool properties on drilled hole quality, thrust force and tool surface temperature.

• 한국레이저가공학회지
• /
• 제15권3호
• /
• pp.1-6
• /
• 2012

The friction force of patterned needle in elastomer have been investigated to verify the application for bio and plastic industry. The micro pattern on the needle surface were prepared by 266 nm, 20 ns laser and 800 nm, 220 fs laser, which were able to generate the different surface roughness. The friction force was measured by the load cell of 10 N capacity. As the results, the friction force of no patterned needle is almost constant during the needle penetrates the silicone rubber sample. However, the needle having asperities shows the variation of the friction force. The higher the surface roughness is, the smaller the friction force is until the surface roughness is very high. In our experiment conditions, the reduction of the friction force by 20 % compared to no pattern needle was achieved with straight and $50{\mu}m$ discrete line generated by 266 nm, 20 ns laser.

• Journal of Welding and Joining
• /
• 제31권2호
• /
• pp.30-36
• /
• 2013

Recently the use of ultra high strength steels(UHSS) in structural and safety component is rapidly increasing in the automotive industry. Furthermore, it commonly use in tailor welded blank laser welding process before hot stamping to reduce lightweight vehicle. However TWB process is to be a problem about welded strength after hot stamping because it's welded before heat treatment. Therefore, in this study, laser welds of TWB after heat treatment were analyzed for changes in the characteristics, especially the impact on the oxidation and decarburization in order to prevent pre-coated Al-Si layer welds on the properties for intensive investigation. As a result, the degradation of the TWB weldments changes in the heat treatment conditions alone, without any pre-treatment of the coating layer has confirmed that there is a limitation on the improvement. Furthermore Al-Si elements are overall distributed on the weldment and it specially concentrated along the fusion line. Hardness value of Al-Si segregation area is less than 350Hv and tensile strength showed just 78~83% compared with substrate. Accordingly, we proved that both side Al-Si coating should be removed in order to ensure the strength of the substrate.

• 한국기계가공학회지
• /
• 제21권4호
• /
• pp.60-69
• /
• 2022

To keep pace with Industry 4.0, it is imperative for companies to redesign their working environments by adopting robotic automation systems. Automation lines are facilitating the latest cutting-edge technologies, such as 3D vision and industrial robots, to outdo competitors by reducing costs. Considering the nature of the manufacturing industry, a time-saving workflow and smooth linkwork between processes is vital. At Dellics, without any additional new installation in the automation lines, only a few improvements to the working process could raise productivity. Three requirements are the development of gripping technology by utilizing a 3D vision system for the recognition of the material shape and location, research on lighting projectors to target long distances and high illumination, and testing of algorithms/software to improve measurement accuracy and identify products. With some of the functional requisites mentioned above, improved robotic automation systems should provide an improved working environment to maximize overall production efficiency. In this article, the ways in which such a system can become the groundwork for establishing an unmanned working infrastructure are discussed.

• 한국기계가공학회지
• /
• 제15권1호
• /
• pp.136-144
• /
• 2016

The air-conditioning industry is closely related to types of lifestyles, climate, and products. With the improvement of national income, the pursuit of pleasant living and working environments, and South Korea's four seasons and distinct climatic conditions, demand for air conditioning has increased. In addition, the industry is becoming increasingly precise and cooperative, and the increase in the domestic production of sophisticated air conditioning and continued growth of future industrial cooperation are expected to rapidly rise. Accordingly, the study of air piping systems can improve the productivity and quality of products and cost savings and can achieve vibration reduction. Additionally, using a heat treatment furnace for copper tube annealing treatment reduces the risk of using an oxy-acetylene torch.

• 디지털융복합연구
• /
• 제19권2호
• /
• pp.161-168
• /
• 2021

지식기반경제로의 이행이 가속화되기 시작하면서 기업 환경에 많은 변화가 일어나고 있다. 중국제조 2025 전략을 시작으로 중국 산업에도 변화가 일어나기 시작하였다. 제조공장으로서의 역할이 아닌, 첨단기술 기반의 산업을 선도하기 위한 노력을 경주하고 있다. 본 연구의 목적은 중국 기업의 혁신에 대한 결과물인 전유 메커니즘을 파악하는데 있다. 이를 위해 본 연구에서는 선행연구를 기반으로 델파이 조사를 통해 8개 요인을 최종적으로 도출하고, 8개 요인을 중국 기업의 실무자들을 대상으로 전유 메커니즘에 대해 설문조사를 하였다. 분석결과, 전체산업을 기준으로 전유 메커니즘의 중요성은 특허, 의장등록, 리드타임, 비밀유지, 보완적 제조, 보완적 판매 및 서비스, 디자인의 복잡성, 학습곡선 효과/규모의 경제 순으로 그 중요도가 나타났다. 본 연구의 결과는 기업의 실무자들이 자사에게 맞는 전유 메커니즘을 통해 기업의 지식재산 전략의 계획을 수립하는데 도움을 줄 수 있을 것으로 보인다.

• 한국기계가공학회지
• /
• 제1권1호
• /
• pp.48-54
• /
• 2002

In industrially advanced countries, environmentally conscious machining was eagerly studied because of ecological and economical reasons. As the environmental regulations become stricter, new machining technologies which take environmental aspects into consideration are being developed Industry and research institutions established applications for dry, semi-dry, oil-mist and compressed cold air machining. This paper investigates the performance of new compressed cold air system for environmentally conscious machining and evaluates machinability of dry and new compressed cold air machining. A series of tests are carried out using measuring eqipments under dry and compressed cold air machining.

• 한국생산제조학회지
• /
• 제6권1호
• /
• pp.59-68
• /
• 1997

Recently, the cases of using bonded dissimiliar materials which have each of the different components tend to increase for the purpose of developing new materials and using the special objects in the field of industry. Among the cases the strength evaluation of the joining materials of vehicle engine and the structural materials with ceramic/metal bonded joints becomes more important. But the residual stress occurs, because the joining of ceramics and metals is performed in extremely high temperature. It becomes a dominant cause to reduce the strength of the ceramic/metal bonded joints. In this paper, strength evaluation method of ceramic/metal bonded joints considering stress singularity was investigated by boundary element method and 4-point bending test. An advanced method of quantitative strength evaluation for ceramin/metal bonded joints is to be suggested.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2002년도 춘계학술대회 논문집
• /
• pp.134-139
• /
• 2002

Motorcycle industry, for its competitive position, depends on part design technology. This part design has a bulky amount of data and asks the accumulation of advanced technical skill and experience, and fragmentary technical application is not enough to get to the kernel of a problem. Therefore, the improvement of proper productivity - the starting point of engineering design - and useful Design Methodology for products manufacturing are needed. Thus this paper is aimed to create a program that outputs dynamic characteristics of a vehicle when the data from fully understanding on motorcycle's brake system and induced formula for brake design are inputted.

• 한국정밀공학회지
• /
• 제17권4호
• /
• pp.48-68
• /
• 2000

The high-speed machining technology of difficult-to-cut material is needed to achieve the high-efficiency of die manufacturing. The high-speed machining is applied in automobile, airplane and electricityㆍelectro industry etc, because it can improve machining efficiency and productivity with high speed, high power and high rotation. In this study, high speed machinability, tool wear characteristics and its monitoring, characteristics of damaged layer, machinability of difficult-to-cut material, characteristics of a free curved surface and method of CAD/CAM system were introduced to acquire the shortening of machining time, the improvement of machining efficiency and the high quality of machined surface. Therefore, we establish the stabilization condition of difficult-to-cut material machining and present the optimal cutting condition for high-efficiency cutting.