• Title/Summary/Keyword: Cylinder-cut

Search Result 76, Processing Time 0.033 seconds

A study on the stress Distributions and magnetic properties during Hot-pressing according to Strain Rate of Nd-Fe-B-Cu Alloys (Nd-Fe-B-Cu합금의 변형속도에 따른 열간압축시 응력분포와 자기적 특성에 관한 연구)

  • Park, J.D.;Jeung, W.Y.;Kwak, C.S.
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.10 no.2
    • /
    • pp.146-153
    • /
    • 1993
  • Thd specimens were melited in high frequency induction furnace. The samples for measurements were prepared by machining cylinder of 9.5mm diameter and 15mm height. These samples were then hot-pressed according to strain rate ( .epsilon. ). These samples were decanned and cut out, and subsequently heat treated at 1000 .deg. C for 4hours. These were investigated for the change of microstructure, domain pattern, X-ray diffraction and magnetic properties. The stress distributions in the specimens during compressing process were calculated by a finite element method program(SPID). The calculated stresses were effective stress( .sigma. $_{eff}$), compressive direction stress( .sigma. $_{z}$), and shear stress( .tau. $_{rz}$ ). These stresses were compared with the experimental data.a.a.

  • PDF

Electronic Control of Braking Force Distribution for Vehicles Using a Direct Adaptive Fuzzy Controller

  • Kim, Hunmo;Kim, Seungdae;Sung, Yoon-Gyeoung
    • Journal of Mechanical Science and Technology
    • /
    • v.15 no.1
    • /
    • pp.66-80
    • /
    • 2001
  • In brake systems, a proportioning valve(P. V), which reduces the brake line pressure on each wheel cylinder for the anti-locking of rear wheels, is closely related to the safety of vehicles. However, it is impossible for current P. V. s to completely control brake line pressure because, mechanically, it is an open loop control system. In this paper we describe an electronic brake force distribution system using a direct adaptive fuzzy controller in order to completely control brake line pressure using a closed loop control system. The objective of the electronic brake force distribution system is to change the cut-in-pressure and the valve slop of the P. V in order to obtain better performance of the brake system than with mechanical systems.

  • PDF

Appearance Characteristics of a Velvet Fabric and 3-Dimensional Modeling of Pile Fibers (벨벳직물(織物)의 외관특성(外觀特性)과 파일섬유(纖維)의 삼차원적(三次元的)모델링)

  • Kim, Jong-Jun;Jeon, Dong-Won;Lee, Jung-Min
    • Journal of Fashion Business
    • /
    • v.9 no.4
    • /
    • pp.170-177
    • /
    • 2005
  • Velvet fabric has soft touch, subtle luster, and good draping property. Threedimensional simulated models of cylindrical monofilaments constituting the velvet fabric were prepared. Image analysis techniques were used to measure the reflected light from the surface of velvet fabrics and the simulated images of the pile fibers. As the angle of incidence increased, the reflectance from the velvet surface became lower. Most of the reflection came from the tips of the cut piles. Crushed velvet type also was modeled using slant cylinder models on top of a base plate.

A Study on the Machining Charcterisitics of Milling of cylinderical Rod Materials for Passenger Car (승용차용 CYLINDER ROD 소재의 밀링 적삭 특성 연구)

  • 채왕석
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
    • /
    • 1996.03a
    • /
    • pp.143-148
    • /
    • 1996
  • In this paper, we have studied internal quality including chemical compositions, microscopic structure and nonmetalic inclusion of test materials. We have analyzed dynamic characteristics of cutting force of milling including tensile strength value hardness etcs. Test materials are used the tempered carbon steel and the non-tempered carbon steel. The obtained results are as follows: 1.In analyzing internal quality, the tempered carbon steel have typical martensite structure and the non-tempered carbon steel have ferrite+pearlite structure. 2.Yield strength, tensile strength and hardness value are in the non-tempered carbon steel but elongation is maximum value in the tempered carbon steel. 3.Cutting force is smaller non-tempered carbon steel than tempered carbon steel when feed speed and depth of cut is constant. 4.Cutting force is smaller to the tempered carbon steel and smaller non-tempered carbon steel than tempered carbon steel when cutting conditions

  • PDF

A Study on the Actual Condition for Air Respirators Using Air-breathing (공기호흡기용 압축공기 시스템에 대한 실태 연구)

  • Lee Chang-Woo;Lee Young-Jae;Hyun Seong-Ho;Seong Jae-Man;Song Yun-Suk;Choi Don-Muk;Yoon Myung-O
    • Fire Science and Engineering
    • /
    • v.18 no.4
    • /
    • pp.16-21
    • /
    • 2004
  • This paper has investigated influences of pollutants in air-breathing on the respirators and it by year of disused air respirators that fire fighter is using in domestic cutting done air respirators after collection observed state of cylinder material through instrumental analysis, and cut open pipe to confirm pollution degree of pipe from cylinder of air respirators to airline mask and confirm pollution availability. The metal surface inside the air respirators was corroded by moisture included in the compressed air. The material generated by corrosion is white powder of less then 100㎛, which is analyzed as aluminum hydroxide corroded by moisture. This aluminum hydroxide powder may get into the lung while one breathes in, and it is easy to be attached to the lung so it will cause a serious influences to human health. This study suggests that Korea should set out the standards for components and composition of breathing air as soon as possible.

A Study on Morphological and Pattern Analysis in 2 kinds of Paeoniae Radix (2종(種) 작약류(芍藥類)의 내외부형태(內外部形態)와 패턴분석 연구(硏究))

  • Song, Kyoung-Song;Choi, Go-Ya;Kim, Hong-Jun;Ju, Young-Sung
    • Korean Journal of Oriental Medicine
    • /
    • v.11 no.2
    • /
    • pp.141-154
    • /
    • 2005
  • The following is a taxonomic list of the specific features of external and internal shape and pattern analysis of Paeonia lactiflora PALL. and P. obovata MAX as the standard of herbal medicine. 1. External shape of original plant P. lactiflora has lancelate and elliptical leaves with no hair on both sides. It bears a flower bud at the shoot apex or leaf axil. On the other hand, P. obovata has obovate leaves with hair on the back side. It has a single flower bud at the shoot apex. 2. Physical characteristics of herbal states P. lactiflora has a bright and smooth external surface whose color is light red brown, light gray on its section and it is not easy to cut. On the other hand, P. obovata has a coarse external surface whose color is dark brown, pinkish on its section and it is easy to cut. 3. Physical characteristics of herbal state in currents Paeonia Radix Alba is brown on the external surface, and whitish on its section. On the other hand, Paeonia Radix Rubra is dark brown on the external surface, and yellowish-white on its section. 4. Internal characteristics Internal shape is correspond to that of Paeonia Radix described in literatures. Only P. lactoflora has a concentrated vascular bundle toward centeral cylinder. On the other hand, P. obovata has a scattered vascular bundle at the cortex. 5. Physicochemical pattern by HPLC Both P. lactoflora and P. obovata showed the same pattern. Paeoniforin, a main component, appears upon 13.68 in retention time (Rt) in both. In addition, both contain a large amount of paeoniflorin. Such results will, in the future, be used as basic source for the additional research, such as biological reactions and genetic discrimination.

  • PDF

An experimental study on the roundness effect for the cutting conditions in a cylinder cutting by end mill (엔드밀에 의한 원통 가공시 절삭조건에 따른 진원도의 실험적 연구)

  • 박희견
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.8 no.4
    • /
    • pp.52-60
    • /
    • 1999
  • In this study the effect of roundness error with respect to the cutting conditions using the external cylindrical work piece by end mill cutting in a machining center was studied. the end mill used in this study is HSS coated with Ti-N which is of Ø 12-4 flutes. The material of workpiece is SM20C and cutting oil is used as a cooling flued The cutting experiments were carried out for the several cutting conditions(depth of cut height of end mill feed rate revolution per minute and cutting direction) and their roundness effects were compared using the least squares circle measuring method. The experimental results are summarized as follows : 1) The cutting depth is dominant for the roundness of a cylindrical work piece and the cutting speed must be determined precisely when the cutting depth is large 2) When the cutting direction in circular manufacturing is the same with the spindle rotation i.e up-cutting condition the surface roundness is also improved.

  • PDF

A Chancteristic of Thermal Efficiency in Order to High Expansion Realization with a Retard of Intake Valve Closing Time in the Low Speed Diesel Engine (저속 디젤기관에서 흡기밸브 닫힘시기 지연시 고팽창 실현을 위한 열효율 특성)

  • Jang Tae-Ik
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.30 no.1
    • /
    • pp.42-49
    • /
    • 2006
  • In this research. the diesel cycle was thermodynamically interpreted to evaluate the possibility of high efficiency by converting diesel engines to the high expansion diesel cycle, and general cycle features were analyzed after comparing these two cycles. Based on these analyses. an experimental single cylinder a long stroke with high expansion-diesel engine. of which S/B ratio was more than 3, was manufactured. After evaluating the base engine through basic experiments, a diesel engine was converted into the high expansion diesel engine by establish VCR device and VVT system Accordingly, the high expansion diesel cycle can be implemented when the quantity of intake air is compensated by supercharge and the effective compression ratio is maintained at its initial level through the reduction of the clearance volume. In this case, heat efficiency increased by $5.0\%$ at the same expansion-compression ratio when the apparent compression ratio was 20 and the fuel cut off ratio was 2. As explained above, when the atkinson cycle was used for diesel cycle, heat efficiency was improved. In order to realize high expansion through retarding the intake value closing time, the engine needs to be equipped with variable valve timing equipment, variable compression ratio equipment and supercharged pressure equipment. Then a high expansion diesel cycle engine is realized.

Characteristics of Coupled Acoustic Wave Propagation in Metal Pipe (금속 배관의 연성된 음향 전파 특성)

  • Kim, Ho-Wuk;Kim, Min-Soo;Lee, Sang-Kwon
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.32 no.3
    • /
    • pp.267-273
    • /
    • 2008
  • The circular cylinder pipes are used in the many industrial areas. In this paper, the acoustic wave propagation in the pipe containing a gas is researched. First of all, the theory for the coupled acoustic wave propagation in a pipe is investigated. Acoustic wave propagation in pipe can not be occurred independently between the wave of the fluid and the shell. It requires complicated analysis. However, as a special case, the coupled wave in a high density pipe containing a light density medium is corresponded closely to the uncoupled in-vacuo shell waves and to the rigid-walled duct fluid waves. The coincidence frequencies of acoustic and shell modes contribute to the predominant energy transmission. The coincidence frequency means the frequency corresponding to the coincidence of the wavenumber in both acoustic and shell. In this paper, it is assumed that the internal medium is much lighter than the pipe shell. After the uncoupled acoustic wave in the internal medium and uncoupled shell wave are considered, the coincidence frequencies are found. The analysis is successfully confirmed by the verification of the experiment using the real long steel pipe. This work verifies that the coupled wave characteristic of the shell and the fluid is occurred as predominant energy transmission at the coincidence frequencies.

A Study of Dynamic Characteristics of Stacking and Transferring System for the Solid Freeform Fabrication System (임의형상가공시스템의 적층 및 이송장치 동특성연구)

  • 엄태준;주영철;민상현;김승우;공용해;천인국;방재철
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.3 no.4
    • /
    • pp.280-284
    • /
    • 2002
  • This paper presents computer simulations of the stacking and transferring system for the fast freeform fabrication system. The stacking and transferring system is essential for the fast freeform fabrication system and its stable motion is very important for consistent stacking of the cut slices. The stacking and transferring system can be modeled as a pneumatic system. The system consists of air compressor, the control valve, and the cylinder. The governing parameters have been changed and the simulation results are shown to predict the time response of the system. The results show some parameters should be correctly tuned to obtain stable system response.

  • PDF