• Journal of the Korea Institute of Military Science and Technology
• /
• v.15 no.3
• /
• pp.315-321
• /
• 2012

In the study, corrosion characteristics of AZ31 magnesium alloy under various environments exposed during machining(immersion in cutting oil, 5 % cutting oil aqueous solution and distilled water & contact with dissimilar metals, SPC4 and A5052-H32) were investigated. A corrosion test was performed AZ31 magnesium alloy was immersed in each electrolyte solution after contacting with each dissimilar metals, and the results were observed by an electron microscope. In immersion tests, corrosion of AZ31 magnesium alloy showed to be in the sequence of distilled water> 5 % cutting oil aqueous solution> cutting oil> air, and in the test of contact with dissimilar metals, corrosion showed to be in the sequence of SPC4> A5052-H32> AZ31. It can be concluded that to prevent corrosion during machining, AZ31 magnesium alloy must prevent contacting water and use magnesium alloy for raw material of Jig & Fixture.

• Journal of the Korean Society for Precision Engineering
• /
• v.28 no.6
• /
• pp.709-715
• /
• 2011

Chattering in cutting operations are usually a cumbersome part of the manufacturing process in mechanical. Particular, machining performance such as that of the boring process is limited by cutting condition at the movable components. Among various sources of chatter vibration, detrimental point in cutting condition is found a mechanical condition on overhang. It limits cutting speed, depth, surface roughness and tool wear failure as result because the all properties are varying with the metal removal process. In this case, we have to observe the resonance frequencies of a boring bar for continuous cutting. In the established research, boring bar vibration of cutting system has been measured with the aid of accelerometer. However, the inherent parameters of internal turning operations are severely limit for the real time monitoring on accelerometers. At this point, this paper is proposed other method for real time monitoring during continuous cutting with optical fiber at the inside of boring bar. This method has been used a plastic fiber in the special jig on boring bar by based on experimental modal analysis. In this study, improvement of monitoring system on continuous internal cutting was attempted using optical fiber sensor of inside type because usually chattering is investigated experimentally measuring the variation in chip thickness. It is demonstrated that the optical fiber sensor is possibility to measure of chattering with real time in boring process.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.21 no.3
• /
• pp.56-62
• /
• 2022

The tank engine clutch flange constitutes a tank on which the engine and transmission of the tank are mounted. The engine clutch flange is fabricated using a difficult-to-cut material that exhibits high strength and hardness. It is difficult to process and requires considerable processing expertise. In addition, the engine clutch flange for the tank requires high machining precision because it is a system in which the connection is detachable. Because it requires high processing precision, the measurement of products equally important as processing. However, productivity is low owing to the significant amount of time required to measure each product using a three-dimensional coordinate measuring machine. Hence, this study is conducted to improve the productivity of the female tank engine clutch flange. Dedicated hobs and jigs are designed and manufactured to convert the existing end-mill cutting processing into hobbing cutting processing. An engine clutch for the tanks is manufactured using the manufactured dedicated hob and jig, and the shortening time is verified by measuring the processing time. In addition, a jig for inspection is designed and manufactured to measure the precision of the product. To verify the inspected product, the product precision is measured using a contact-type three-dimensional coordinate measuring machine and a surface roughness measuring instrument. The study confirmed that the productivity of the engine clutch flange product for tanks can be improved by simplifying the process, reducing the processing time, and simplifying product inspection.

• Journal of the Korea Convergence Society
• /
• v.11 no.11
• /
• pp.183-187
• /
• 2020

The molybdenum cup and molybdenum pin, which are the main materials of the molybdenum electrode used for the LCD BLU CCFL electrode, have not been developed in Japan and all of them are imported and used from Japan, is giving a competitive burden. In this research, to develop the manufacturing technology of molybdenum pin used for CCFL electrode of LCD BLU, development of linear processing technology, development of molybdenum wire surface treatment technology, development of wire cutting technology, production of molybdenum pin, design and fabrication of JIG and Fixture for inspection, molybdenum pin prototyping and analysis, and development of 100% molybdenum pin inspection technology. In this paper, especially, In this paper, especially, research on the convergency design for total inspection machine is treated. is treated.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.21 no.2
• /
• pp.209-216
• /
• 1997

A feature is well known as a medium to integrate CAD, CAPP and CAM systems. For a part drawing including both simple geometry and compound geometry, a process plan such as the selection of process, machine tool, cutting tool etc. normally needs simple geometry data and non-geometry data of the feature as the input. However, a extended process plan such as the generation of process sequence, operation sequence, jig & fixture, NC program etc. necessarily needs the compound geometry data as well as the simple geometry data and non-geometry data. In this paper, we propose a feature data model according to the result of analyzing necessary data, including the compound geometry data, the simple geometry data and the non-geometry data. Also, an example of the feature data model in milling process planning is described.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2021.05a
• /
• pp.38-39
• /
• 2021

The use of temporary container classrooms has increased in recent years due to the development of the construction industry and renovation or rehabilitation of schools. Therefore, various problems, such as errors during assembling, design and insulation issues, and noise problems, have surfaced during the construction of temporary container classrooms. This study analyzes the causes of assembly errors during the manufacturing and installation processes to improve the quality of temporary container classrooms. Assembly errors are caused by non-level planes and inaccurate cutting during the manufacturing process. In the installation process, poor leveling is a major factor that causes errors during the assembly of temporary container classrooms. These causes result in uneven horizontal or vertical planes and uneven height. To solve these problems, quality improvement measures, such as pin connection, jig, joint coupling, and surface plates are proposed in this study.

• Journal of the Korean Society of Costume
• /
• v.30
• /
• pp.69-84
• /
• 1996

The main current of ancient Korean thought is based on Yuk(易) : which solves the principle of creation of universe letter(文字) which is the principle of geometry and three elements thought of circle square . It's related to the creation principle of the universe and regarded as a sign that demons-trates shows the way to read the mathematical principle. The original form of Korean clothes(Han-Bock, 韓服) is represents the structure of hu-man body which reflects a small universe. So a good structure and meaning of the human body is well read in the formation of Korean clothes(Han-Bock, 韓服) and that is a good symbolization of the clothes(Han-Bock, 韓服) as the space of small universe. The good formation of Korean clothes(Han-Bock, 韓服) could be shown by cutting out straight bending twisting and turning each straitly cutting piece is applied to its trans-tormation. Geametical formation with obvious sym-metric dividing of front-back left-right and top-bottom is well shown in Korean clothes by twisting Yuk(易) or m bius strips. So we can find out whole formation by representing only either 'front and back' or 'left and right' and also sa-pok(사폭) of man's trousers seop(섶) of jeo-go-ri(short jacket 저고리) kyut-ma-gi(곁마기) of Sam-hwai-jang jeo-go-ri (삼회장 저고리), mu(무) of jig-ryung(straight collar and long and wide sleeved robe, 直領) trouser wide and ga-rae-ba-dae(가래바대) of dan-cok-kok(woman's under trousers). The formation line of Korean clothes(Han-Bock, 韓服) is based on theprinciple of unlimited m bius strips by twisting of turning direction from universal principle and original basic form is not changd even by turning in-side out. Unity of the whole and part in Korean clothes(Han-Bock, 韓服) could be found in nonorientable thought(非始原思想) which represents the unity and dependence kil(길) of jeo-go-ri(short jacket, 저고리) and po(long and wide sleeved robe, 袍). Selva-gewise(식서방향) of sleeves and seam of out-side of kil(길) and outside of seop(섶) are directed to outside of seop(섶) inside of seop(섶) is to kil and direction of inseam of kheut-dong(끝동) and kyut-ma-gi(곁마기) is directed to sleeves. Korean clothes(Han-Bock, 韓服) is usually made by cutting fabric for several parts and sewing them and the way to make Korean clothes is deeply related to the theory of chon-pu-kyung jong-il and il-seok -sam-geuk. As the development of men's consciousness is pro-gressed from total separation to separation and superseparation. Sewing process of korean clothes(Han-Bock, 韓服) can be make single dimension to double or triple dimension of korean clothes(Han-Bock, 韓服) silhoutte bacause it can be include principle of topology as noneuclity.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.12 no.1 s.26
• /
• pp.1-11
• /
• 1988

This study dealt with the Dopo, one of the representative ceremonial dress that acclasical scholar used after the middle of the period of the Chosun dynasty. This study represents the period of Dopo's formation and its origin, and the characteristics of the weary of Dopo in Young Dong Province Area is arranged by folkloric method on the base of the exisitng facilities. Dopo has worn since the middle of the period of the Chosun dynasty. It is the kind of Jig young Po that its back is cuffed for convenience and has another cloth as a ceremonial dress. It is thought to be one of the national customs pos formed by the mixture of the big sleeve type which is influenced by confusion life feeling. It seemed that the name of DoPo comes from the Jigchal, an ordinary dress of a high official in China, which is call Dopo. This Dopo is changed and received and so disappeared but it is still used such as ceremonial dress, the necessary articles for marriage of the bride, a bridegroom's liturgical vestments of a memorial service held on the anniversary of the death of a person, mourning dress and a shroud grave clothes. This area has different characters on wearing customs. It is changed into the kind of Dopo, with its back not cutting. The hemp sack is almost used as its subject matter. It doesn't have collar strip for the classification of one's family in any case, and Dopo which is prepared for necessary articles for marriage can not be taken tack after seperating by divorce.

• Journal of the Korea Safety Management & Science
• /
• v.15 no.4
• /
• pp.179-184
• /
• 2013

An accident from machine work is often fatal to the worker. This accident is mostly preventable through perfect process jig. In case of this machine work, however, the disaster frequently occurred because of the design which is not considered the beginning of product design, post-process and mass process of production. As for sand casting method, this has the merits of the production; the product is easily produced by manual labor. On the other hand, this method has the demerits of a bigger dimensional error contrary to other mass process of production. When the sand casting product is in machine work, there are various problems such as unsafe fix and excessive cutting, product desorption and rapid life depreciation of equipment and tools. Considering the characteristics of sand casting method, it is accepted as difficulty to improve the problems. In this study, it suggests shell mold method for mold instead of the machine work after the sand casting of the circle shape container product. And the surface accomplishes the following average of surface roughness Ra$9.94{\mu}m$ of machine work with the casting of flask mold by shell mold method. In accordance with the simplification of processing process and reducing the average thickness variation by mass production of product with detailed appearance, it has a good influence on safety accident prevention caused by production and damaged product. It is confirmed that making higher degree of size precision of all machine work product is possible to increase the safety and productivity, reduce the processing process and improve environment.

• Composites Research
• /
• v.23 no.6
• /
• pp.61-66
• /
• 2010

In this paper, the variation of mechanical properties of T800 carbon/epoxy composites according to the forming pressure, which was referred to previous studies on a filament winding process, were investigated. The specimens of all the tests were fabricated by an autoclave de-gassing molding process controlling forming pressure (absolute pressures of 0.1MPa, 0.3MPa, 0.7MPa including vacuum) and water jet cutting after fabricating composite laminates. Various tensile tests were performed for in-plane properties and interlaminar properties were also measured by using Iosipescu test jig. Fiber volume fraction was measured to correlate the property variation and the forming pressure. This properties are expected to be utilized in the design of Type III pressure vessel for hydrogen vehicles which uses the same carbon fiber (T800 carbon fiber) for the filament winding process.