• Title/Summary/Keyword: clamping

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Investigation for Clamping Properties of the Tool Clamping Device Based on the Shape Memory Alloy for Application of a Micro Spindle System (소형 스핀들 시스템 적용을 위한 형상기억합금 기반 공구 클램핑 장치의 체결특성 고찰)

  • Shin, Woo-Cheol;Ro, Seung-Kook;Park, Jong-Kweon;Lee, Deug-Woo;Chung, Jun-Mo
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.16 no.6
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    • pp.9-14
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    • 2007
  • In this paper, a rotating tool clamping device was developed based on a shape memory alloy(SMA) and its feasibility as a tool holder was experimentally explored. The SMA-based device was able to alter clamping to unclamping through temperature control within 1 second. The means and repeatability(${\sigma}$) of the tool clamping force were 185.5N and 6N respectively and its drifts were less than 3% for an hour. Considering the temperature hysteresis of the SMA-based tool clamping device, it is necessary to heat the SMA ring to around $50^{\circ}C$ after tool change to obtain more clamping force.

The Effect of Clamping Angle of a Locker on the Clamping Force of the Wedge Type Rail Clamp (Locker 의 물림각이 쐐기형 레일클램프의 압착력에 미치는 영향 평가)

  • Han D.S.;Lee S.W.;Han G.J.;Ahn C.W.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.1042-1045
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    • 2005
  • The wedge type rail clamp has the operating mechanism: First, the jaw pad clamps a rail with small clamping force. Next as the wind speed increases, the clamping force of the Jaw pad Is Increased by the wedge. The initial clamping force of a jaw pad was determined by the clamping angle of a locker. In this study, we carried out the finite element analysis to evaluate the relationship between the clamping angle of a locker and the clamping force of a jaw pad with respect to the design wind speed, such as 2, 4, 6, 8, and 10m/s, we adopted the wedge type rail clamp fur 50tons class container crane with the wedge angle of $10^{\circ}$.

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Clamping effects on the dynamic characteristics of composite tool bars (고정부 조건이 복합재료 공구용 바의 동적 특성에 미치는 영향)

  • 황희윤;김병철;이대길
    • Proceedings of the Korean Society For Composite Materials Conference
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    • pp.199-202
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    • 2003
  • The dynamic characteristics of composite tool bars depend on the clamping conditions such as clamping force, stiffness and surface characteristics of clamping parts as well as the basic structures. Therefore, in this work, the effects of clamping part conditions on the dynamic characteristics of cantilever type composite machine tool structures with clamped joint were investigated because the cantilever type machine tool structures are ideal cases for composite application to increase the natural frequency and damping of structures. New design of the clamping part was developed in order to improve shear properties of the clamping part and dynamic characteristics of composite tool bars. From FE analysis and Impulse response tests, dynamic characteristics were obtained with respect to the clamping part conditions of the new design.

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A Comparative Study on the Clamping Protocols of a Biliary External Drainage Tube in Adult Living-donor Liver Transplant Recipients (성인 생체 간이식 수혜자에서 담도 외-배액관 잠그기 훈련 방법 비교)

  • Chung, Jin Ah;Choi, Hye Ran
    • Journal of Korean Critical Care Nursing
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    • v.7 no.1
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    • pp.33-39
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    • 2014
  • Purpose: The propose of this study was to introduce the clamping protocols for a biliary external drainage tube and trace the results of using clamping protocols to prevent some possible biliary complications or enable their early detection in living-donor liver transplantation. Method: This study was a retrospective study to analyze the cases of 97 subjects who had undergone liver transplantation in a hospital in Seoul, Korea. Clamping protocol 1 was applied to 47 patients, and clamping protocol 2 was applied to 50 patients. Results: In the case of protocol 1, the success rate of the clamping protocol was 74.5%, while that of protocol 2 was 84.0%. However, there was no significant difference in the compiled statistics from authentic sources (p = .246). Conclusions: The difference in the success rate between the two protocols was not significant for the clamping protocols of the biliary external drainage tube. However protocol 2 is suggested for the clamping method due to the simplicity of application. Further study with a large sample size is suggested.

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A Study on the Transmitted Torque of Self Clamping Friction Clutch (자기 체결 마찰 클러치의 전달 토크에 관한 연구)

  • Wang, Jee-Seok;Kim, Jong-Do;Yoon, Hee-Jong
    • Journal of Advanced Marine Engineering and Technology
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    • v.32 no.8
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    • pp.1149-1156
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    • 2008
  • The principle of self clamping friction clutch is presented in this paper and the transmitted torque capacity is also calculated. In order to enlarge the friction force, a part of rotating force of driving side is converted to normal force of friction materials by clamping arm. The increased normal force of friction materials assures the large friction force and the transmitted torque capacity of clutch becomes large. The self clamping friction clutch is adopted in the tube type air pressure clutch and the condition of stability is investigated. It is proven that the inclined angle of clamping arm and the friction factor of friction materials are the essential elements in stability and torque capacity of self clamping friction clutch. The transmitted torque capacity of self clamping friction clutch is compared with air pressure clutch. The normal force of friction lining is magnified by 1/(1-k) and the transmitted torque capacity is also magnified with same proportion comparing with air pressure clutch. The larger the friction factor of friction lining, the larger the magnification factor. The longer the clamping arm, the smaller the magnification factor. It must be also noted that the value of k=${\mu}Y/X$ is the criterion of stability. If the value of k=${\mu}Y/X$ is greater than or equal to 1, the self clamping friction clutch is unstable and it can not be used as clutch.

An Experimental Study of Vibrator Amplitude Change for a Clamping Force Dispersion and Friction Coefficient Decrease (체결력 산포와 마찰계수의 감소를 위한 가진기의 진동량 변화 실험)

  • Lee, Geum-Gang;Moon, Seok-Man;Cho, Yong-Joo
    • Tribology and Lubricants
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    • v.27 no.6
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    • pp.332-337
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    • 2011
  • The object of this experimental study is to investigate influences of vibrator amplitude on clamping force in vibration for bolted joint. The experiment is that change the vibrator amplitude to check clamping force. also the friction coefficient calculated by equation to use an obtained in experiments. The main purpose of generation vibrations is decreasing the clamping force dispersion. also If vibration occurs while tightening the bolt is reduced coefficient of friction. In this paper, In experiments to measure the clamping force before vibrator's amplitude changing. Vibrator's amplitude changes to 5.5mm from 4.4mm. As a result, under various vibration condition, relationship of clamping force and Vibrator amplitude.

Implementation of the rotating tool clamping device using a shape memory alloy (형상기억합금을 이용한 회전공구 클램핑 장치 구현)

  • Chung, J.M.;Park, J.K.;Lee, D.J.;Shin, W.C.
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.17 no.1
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    • pp.16-20
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    • 2008
  • This paper presents the construction of micro tool clamping device using a Ni-Ti shape memory alloy(SMA) ring. Clamping force of the device is produced by elastic force of the SMA reverted to its original shape in normal temperature. Phase transformation of the SMA was realized by temperature control using a peltier element. Prototype of the SMA tool clamping device was fabricated and examined its clamping force and clamping/unclamping operation.

Design and Machining Precision Evaluation of Pneumatic Clamping Type Guide-bush System (공압식 소재물림 가이드부쉬 시스템의 설계 및 가공정도 평가)

  • Lee, Jae-Hoon;Yi, Su-Min;Park, Seong-Hun;Lee, Shi-Bok
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.19 no.6
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    • pp.859-866
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    • 2010
  • Generally, a fixed type guide-bush system is installed during machining miniature work-pieces with high precision in the multi-task CNC lathe. But a conventional guide-bush system does not provide a constant clamping force under the condition of varying work-piece diameters. It is important to maintain a constant clamping force for guaranteeing machining precision. This paper proposes a new guide-bush system with a pneumatic clamping device for the CNC Swiss-turn lathe to keep constant clamping force with changes in work-piece diameters. Through performance tests, new clamping system developed in the study showed better machining precision at the cost of a small increase in the temperature of the system than conventional systems due to an increase in the frictional heat and a change in the heat transfer route.

Development of Clamping Probe for Rare DNA Detection using Universal Primers

  • Kim, Meyong Il;Lee, Ki-Young;Cho, Sang-Man
    • Fisheries and Aquatic Sciences
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    • v.17 no.3
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    • pp.339-344
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    • 2014
  • PCR amplification with universal primer is a useful tool for speciation of symbionts in marine eukaryote coupled with robust separation method such as denaturing high performance chromatography (DHPLC). To overcome the biased amplification, clamping PCR is recommended to suppress the amplification of host gene. In this study, we evaluated the efficiency of rare gene detection for two kinds of clamping probes which were successfully utilized for eukaryotic symbiont analysis: C3 linked nucleotide (C3) and peptide nucleic acid (PNA). PNA was 3-4 orders of magnitude higher than that of C3 tested in clamping efficiency and rare gene detection. This represented that PNA could be a more competent clamping probe for the enhancement of PCR amplification for rare symbiont genes.

Finite Element Analysis of Residual Stress by Cold Expansion Method with Clamping Force in the Plate having Adjacent Holes (인접홀에서 홀확장법과 체결력 고려시, 발생하는 잔류응력 분포에 대한 유한요소해석)

  • Yang Won-Ho;Cho Myoung-Rae;Jang Jae-Soon
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.5
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    • pp.149-154
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    • 2006
  • The cold expansion method (CEM) is one of the widely used a method to improve the fatigue behavior of materials in aerospace industry. Such improvement is due to the compressive residual stress developed when a tapered mandrel goes through the fastener holes a little smaller than the mandrel. CEM is retarded of crack initiation due to the compressive residual stress developed on the hole surface. Many researchers are studied a finite element analysis of residual stress around fastener hole. But in case of real model, fastener hole has a clamping force after CE. Therefore, it is respected that residual stress distributions should be changed due to clamping forces. In this paper, it was performed finite element analysis of residual stress by clamping force after CE in the plate having adjacent holes. From this study, it has been found that compressive residual stress near the hole increases according to clamping force. Also, the more increase clamping force, the more increases compressive residual stress. However, tensile residual stress increase beyond clamping force area.