• Title/Summary/Keyword: Pin shape

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A Study on the Ancient Fibulae

  • Kim Moon-Ja
    • The International Journal of Costume Culture
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    • v.8 no.2
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    • pp.71-84
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    • 2005
  • Fibulae have been used as clothing fasteners throughout history. They were especially popular with the Celts, but were also used by the Greeks, Romans, Saxons, and Vikings, to name a few. The earliest examples are found in the Mediterranean and Middle East, and date from 800 B. C. and earlier. Their use continues today, in the form of the modern safety pin. The first fibulae of the Bronze Age were very simple, much like modern safety pins. The form of this small functional object varies from simple to extravagant since it is also seen as a piece of jewelry, and is thus subject to the evolution of style. Its size depends on the thick/Jess of the clothing to be attached. Its fabrication demonstrates a great mastery of metal work. Fibulae would vary with the taste and wealth of the wearer. The Fibulae were divided into 10 styles according to the shape, Fibulae with Safety pin shaped style, Penannular shaped style, Animal shaped style, Diamond shaped style, Radiated head shaped style, Horsefly shaped style, Arched bow shaped style, Fan-shaped style, Trumpet shaped style, Arched-fan shaped style.

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A Study on 6 Edges Reamer for the Improvement of Accuracy of Automotive Cylinder Head Guide Pin (자동차 실린더헤드 가이드 핀의 정밀도 향상을 위한 6날 리머에 관한 연구)

  • Kim Hae-Ji;Kim Nam-Kyung
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.13 no.6
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    • pp.81-86
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    • 2004
  • Generally, automotive cylinder head is manufactured by FCD45 material that is hard to cutting materials, and it needs the accurate machining tool fir higher output of engine. This paper is concerned with a study on TiN coated 6 edges reamer for improving machining accuracy of cylinder head guide pin. The reamer shape is changed from 4 edges to 6 edges for the improvement of machining accuracy. Also, TiN coating is applied to the improvement of surface roughness of cylinder head guide pin and tool life of 6 edges reamer. It is noted that 6 edges reamer are effective in controlling the dimensional accuracy and surface roughness as well as increasing tool life.

Design and Fabrication of Micro Mirror with Staple and Pin (경첩과 핀을 사용한 가동 마이크로 미러의 설계와 제작)

  • Ji, Chang-Hyeon;Kim, Yong-Kweon;Yoon, Eui-Joon;Choi, Bum-Kyoo
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1950-1953
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    • 1996
  • A $1\;{\times}\;4$ micro mirror array is designed and fabricated. In contrast to other micro mirrors which utilize torsional flexure hinges or cantilevers for restoring torque and supporting purpose, we have placed a substrate hinge structure under each mirror. Each micro mirror consists of address electrode, substrate hinge consisting of pin and staple, supporter post, and mirror plate. Electrical connection between mirror plate and ground electrode is established by substrate hinge. Mirror undergoes a rotational motion due to electrostatic force when voltage difference is applied between address electrode and mirror plate. Micro mirrors with two different types of staple shape and two different pin sizes are designed and fabricated. Each mirror is designed to have ${\pm}\;10^{\circ}$ of deflection angle and have $100\;{\times}\;110\;{\mu}m^2$ of size.

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Design of Reconfigurable Desk Based on Pin Art Technology (핀 아트 기술을 활용한 재구성 가능한 데스크 설계)

  • Jeong, Seungdo
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.15 no.2
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    • pp.63-70
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    • 2019
  • To increase the efficiency of task on the desk, this paper proposes a reconfigurable desk. The proposed reconfigurable desk is based on the Pin Art technology. For the design of the proposed desk, the upper surface of the desk is divided into small units, and then the user easily controls the height of the divided pieces to make desk a desired shape by using the proposed user interface. The Arduino module controls the hardware and the user interface is configured by using Android applications, making it easy for anyone to use. Through extensive experiments, the proposed system shows that various types of deformations are possible and thus the utilization is very high by mounting diverse devices.

A Study on the Durability due to Fork Shape of Excavator Bucket (굴삭기 버켓의 포크 형상에 따른 내구성 연구)

  • Han, Moonsik;Cho, Jaeung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.2
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    • pp.54-59
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    • 2018
  • In this study, the durability due to the fork shape of excavator bucket is investigated. The analysis is carried out by modelling the fork shape used in general. As the analysis condition, the pin is constrained as fixed support at the bucket and the load of 12000N is applied at the fork. As the study result, the maximum equivalent stresses at models 1 and 2 are shown as 56.895MPa and 54.722MPa respectively. Model 1 is shown to have the most deformation of 5.6686 mm among four models. Model 3 has the least deformation among four models and the maximum deformation of model 3 is shown as 4.948mm. The fatigue analyses are also carried out with three models. Each model shows the same fatigue lives under the identical fatigue loads. The damage part at each model is shown at the bucket pork or the pin connected with bucket. As this study result, the data is thought to contribute to the safety design at excavator bucket.

A Study on the Chucking of Ferrule using Cone-type Centers and Ball-type Centers in Co-Axial Grinding - Chucking Error Analysis (원추형 센터와 볼형 센터를 이용한 페룰 동축 연삭시 척킹에 관한 연구-척킹 오차 해석)

  • 김동길;박성준;김영태;이상조
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.2
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    • pp.40-49
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    • 2003
  • Ferrule is widely used as fiber optic connecters. In fiber-optic communications. the shape accuracy such as coaxiality and cylindricity of ferrule affects insertion loss. When coaxial grinding of ferrule supported by two pin. pin alignment and chucking accuracy are very important. In this research, the kinematic behavior of the ferrule centers are investigated in the case where the ferrule is chucked with the cone-shaped center pins and bail centers, With homogeneous coordinate transformation and numerical analysis, the obtained results are as follows: In the case of cone-type center, the alignment errors between center pins alone do not affect the rotation accuracy of ferrule. The alignment errors between center holes cause sinusoidal displacement of ferrule. And the maximum displacement of ferrule centers is proportional to the center pin angle. In the case of ball-type center, the displacements of ferrule centers has similar pattern as cone-type center, and the alignment errors art proportional to ball diameters.

Optimum Design of a Pin-Fins Type Heat Sink Using the CFD and Mathematical Optimization

  • Park, Kyoung-Woo;Oh, Park-Kyoun;Lim, Hyo-Jae
    • International Journal of Air-Conditioning and Refrigeration
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    • v.13 no.2
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    • pp.71-82
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    • 2005
  • The shape of $7\times7$ pin-fins heat sink is optimized numerically to obtain the minimum pressure drop and thermal resistance. In this study, the fin height (h), fin width (w), and fan-to-heat sink distance (c) are chosen as the design variables and the pressure drop $({\Delta}P)$ and thermal resistance $(\theta_j)$ are adopted as the objective functions. To obtain the optimum design values, we used the finite volume method for calculating the objective functions, the BFGS method for solving the unconstrained non-linear optimization problem, and the weighting method for predicting the multi-objective problem. The results show that the optimum design variables for the weighting coefficient of 0.5 are as follows: W=4.653 mm, h=59.215mm, and c=2.667mm. The objective functions corresponding to the optimal design are calculated as ${\Delta}P=6.82$ Pa and $(\theta_j)=0.56K/W$. The Pareto solutions are also presented for various weighting coefficients and they will offer very useful data to design the pin-fins heat sink.

Weldability and properties of lap joints by pin FSW with 1050 Al sheet (1050 Al판재의 핀 마찰 교반용접에 의한 실험적 연구)

  • Jang, Seok-Ki;Park, Jong-Seek;Han, Min-Su
    • Journal of Advanced Marine Engineering and Technology
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    • v.31 no.4
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    • pp.394-400
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    • 2007
  • The properties and weldability of lap joints by PFSW with 1050 Al sheet was investigated according to tool shape. dimension and welding condition. Tensile shear test was carried out for lap jointed specimen, and the hardness in the joint regions was examined. Moreover interfacial joining length, metallograph and failure location of the lap-jointed cross section were discussed. Two tool types were a simple cylindrical type and a notched cylindrical type. Under joining conditions such as plunging depth of 2.2mm. rotating speed of 1600rpm and dwelling time of 3s, the tensile shear strength of lap-jointed specimen by the notched type tool was superior to that by simple cylindrical type tool. The maximum tensile shear load of lap jointed specimen was 5807N. Optimal dimensions of the notched type tool were as follows : diameters of the shoulder and pin were $18{\phi}mm$ and $10{\phi}mm$, and pin length was 2.2mm.

Pull-off Strength of Jagged Pin-reinforced Composite Hat Joints (요철핀으로 보강된 복합재 모자형 체결부 구조의 강도 연구)

  • Kwak, Byeong-Su;Kim, Dong-Gwan;Kweon, Jin-Hwe
    • Composites Research
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    • v.31 no.6
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    • pp.323-331
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    • 2018
  • The effect of stainless steel jagged-pin reinforcement on the pull-off strength of the composite hat-joint was studied by the test. The pins were physically and chemically surface-treated and inserted in the thickness direction over the interface where the skin and stiffener meet. The specimens including the jagged-pins were made by co-curing process. Diameters of the jagged-pins were 0.3, 0.5 and 0.7 mm. The pin areal densities were set to 0.5 and 2.0% based on the interface area where the skin and stiffener meet. The specimens using 0.3 mm diameter normal (un-jagged) pins with 2.0% areal density were additionally fabricated and tested to investigate the pin shape effect on the pull-off strength. The pull-off strengths of specimens reinforced with 0.5% areal density by 0.3, 0.5, and 0.7 mm diameter pins were 45, 19 and 9% higher than those of un-reinforced specimens, respectively. In case with 2.0% pin areal density, the strengths were 127, 45, and 11% higher than those of un-reinforced specimens, respectively. The test results show that the higher pin areal density results in the higher strength when the pin diameter is the same. When the pin areal density is the same, the smaller pin diameter leads to higher strength. When the joints using jagged-pins and normal pins in 2.0% areal density with 0.3 mm diameter, the joints of jagged-pins showed the 64% higher strength. From the results of this study, it was confirmed that jagged-pin reinforcement can be an effective method for improving the pull-off strength of composite hat-joint.

Shape Optimization of a Rotating Cooling Channel with Pin-Fins (핀휜이 부착된 회전하는 냉각유로의 최적설계)

  • Moon, Mi-Ae;Husain, Afzal;Kim, Kwang-Yong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.7
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    • pp.703-714
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    • 2010
  • This paper describes the design optimization of a rotating rectangular channel with staggered arrays of pin-fins by Kriging metamodeling technique. Two non-dimensional variables, the ratio of the height to the diameter of the pin-fins and the ratio of the spacing between the pin-fins to the diameter of the pin-fins are chosen as the design variables. The objective function that is a linear combination of heat transfer and friction loss related terms with a weighting factor is selected for the optimization. To construct the Kriging model, objective function values at 20 training points generated by Latin hypercube sampling are evaluated by a three-dimensional Reynolds-averaged Navier-Stokes (RANS) analysis method with the SST turbulence model. The Kriging model predicts the objective function value that agrees well with the value calculated by the RANS analysis at the optimum point. The objective function is reduced by 11% by the optimization of the channel.