• Title/Summary/Keyword: Co-grinding

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Structural Optimization and Performance Evaluation of Ultra Precision Co-axial Ferrule Grinding Machining System (초미세 고기능 동축가공 연삭 시스템의 구조 최적화 및 특성 평가)

  • Ahn K.J.;Lee H.J.;Kim G.J.;Kim G.H.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.559-560
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    • 2006
  • Fiber optic connector, ferrule, is a device to connect and align fiber optics cable on fiber-optic communication system. In general $ZrO_2$ ceramic ferrule is manufactured by grinding process because the demands precision is very high. For the precision grinding machining, it is very important that structure of co-axial ferrule grinding system is optimized. In this paper, Structural analysis was performed to analyze bed and frame structure of co-axial grinding machine. Deformation and modal analysis for natural frequency was performed using ANSYS design space program to analyze structural characteristics. New improved model of bed and frame structure was proposed based on initial basic model. Therefore, we estimated the structural characteristics precision co-axial grinding machining system.

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Study on Ultra-Precision Grinding Condition of WC-Co (금형용 WC-Co의 초정밀 연삭 가공 조건에 관한 연구)

  • S.J. Heo;J.H. Kang;W.I. KIm
    • Journal of the Korean Society for Precision Engineering
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    • v.10 no.1
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    • pp.42-51
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    • 1993
  • Recently, WC-Co have some excellent properities as the material for the mechanical component such as metallic moulding parts, ball dies parts, and punch parts. This paper describes the surface roughness and grinding force caused by experimental study on the surface grinding of WC-Co with ultra-precision like a mirror shape using diamond wheel. Also, some investigations are carried out using WA grinding wheel to increase improved ground surface roughness such as polishing, lapping effect. Some important results obtained here are summarized as follow. 1) Within this experimental grinding condition, we can be obtained $R_{max}.\;2\mu\textrm{m}\;R_a\;0.3\mu\textrm{m}$ whichare the most favourable ground surface roughness using #140 diamond wheel, and improved surface roughness values about 20 .approx. 25% throughout 5 times sparkout grinding 2) The value of surface roughness is Rmax. $0.49\mu\textrm{m},\;R_a\;0.06\mu\textrm{m}$ using #600 diamond wheel. 3) The area of no rack zone is less than $F_{n}$ 0.27N/mm, Ft 0.009N/mm

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Amorphous Ultrafine Particle Preparation for Improvement of Bioabailability of Insolube Drugs: Effect of Co-Grinding of UDCA with SLS (난용성 의약품의 생체이용률 증진을 위한 무정형 초미립자의 조제 : UDCA와 SLS의 혼합분쇄 효과)

  • 정한영;곽성신;김현일;최우식
    • YAKHAK HOEJI
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    • v.46 no.2
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    • pp.102-107
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    • 2002
  • The particle size of medicinal materials is an important physical property which affects the pharmaceutical behaviors such as dissolution, chemical stability, compressibility and bioavailability of solid dosage forms. The size reduction of raw pharmaceutical powder is needed to formulize insoluble drugs or slightly soluble drugs and to improve the pharmaceutical properties such as the solubility, the pharmaceutical mixing and the dispersion. The objective of the present study is to evaluate the grinding characteristics of ursodeoxycholic acid(UDCA) as a model of insoluble drugs. The effects of the grinding time and the amount of additive on particle size distribution of ground UDCA were investigated. Grinding of insoluble drug, UDCA and a series of dry co-grinding experiments of UDCA with sodium lauryl sulfate(SLS) as an additive were carried out using a planetary ball mill. It was measured that the median diameter and the particle size distribution of ground products with grinding UDCA and additive SLS by Mastersizer. As a result of co-grinding of UDCA and SLS, the particle size of co-grinding products was decreased more than single grinding one. However, it was observed that co-grinding products were reaggregated to larger particles after 120 min.

Surface grinding of WC-Co with high quality (WC-Co의 고품위 평면 연삭가공)

  • Heo, S.J.;Kang, J.H.;Kim, W.I.
    • Journal of the Korean Society for Precision Engineering
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    • v.11 no.5
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    • pp.42-55
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    • 1994
  • Presently, abrasive processing is on eof several methods for cutting and grinding brittle materials, and high quality in dimensional accuracy and surface roughness are often required as a structural components, therefore most of them has to be ground. In manufacturing of tungsten-carbide components, grinding by diamond wheel is usually adopted in order to provide configurational and dimensional accuracy to the components. The present study proposes the experi- mental research of optimum condition to the high quality surface grinding of the WC-Co material using diamond abrasive wheel in order to minimize the damage on the ground surface and to pursue the precise dimension by conventional grinding machine. Brief investigation is carried out to decrease the dressing is constant, theoretical grinding effect such as machining precision is changed according to the speed of workpiece. Accordingly, normal and tangential grinding forces, which are Fn, Ft were analyzed for the machining processes of WC-Co material to obtain optimum grinding conditions, 3-point bending test is carried out to check machining damage on the ground surface layer, which is one of sintered brittle materials.

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A Study on the Comparison of Internal Plunge Grinding and Internal Thrust Grinding (내면 플런지 연삭과 스러스트 연삭의 비교)

  • Choi, Hwan;Seo, Chang-Yeon;Seo, Young-Il;Lee, Choong-Seok
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.15 no.1
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    • pp.68-73
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    • 2016
  • In this paper, the grinding characteristics in internal grinding methods(plunge, thrust) were studied with vitreous CBN wheels using machining center. Grinding experiments were performed according to the same material removal rate conditions such as a wheel speed, depth of cut and workpiece speed. And the grinding force, machining error and grinding ratio were investigated though these experiments. Based on the experimental results, the grinding characteristics on internal grinding methods were compared.

A Study on the Precision of a Machined Surface in Thrust Internal Grinding (스러스트 내면 연삭가공의 가공면 정도에 관한 연구)

  • Choi, Hwan;Seo, Chang-Yeon;Seo, Young-Il;Lee, Choong-Seok
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.15 no.5
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    • pp.73-79
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    • 2016
  • In this paper, the grinding characteristics in thrust internal grinding have been studied using vitreous CBN wheels with a machining center. Grinding experiments have been performed according to grinding conditions such as wheel feed speed, cut depth, workpiece speed, rate of grinding width and number of grinding passes. The machining error, shape of machined surfaces, grinding force, and surface roughness have been investigated though these experiments. Based on the experimental results, the grinding characteristics on the machined surface in the internal thrust grinding are discussed.

The Development of Ultra-precision Centerless Grinding Machine (초정밀 CNC 센터리스 연삭기 개발)

  • Cho S.J.;EBIHARA EBIHARA;Yoon J.S.;Cho C.R.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.557-558
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    • 2006
  • In this study, the ultra precision centerless grinder for ferrule grinding was designed. As the good-qualified ferrule is required a precise and fine grinding, grinding machine for ferrule must have a high accuracy and a sufficient stiffness. The centerless grinder is composed of the high damping concrete bed, grinding wheel spindle unit, regulating wheel spindle unit, feeding table and dressing unit. For a newly developed centerless grinder, hydrostatic system with high precision feeding and high stiffness was proposed.

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Temperature Distribution of Tungsten Carbide Alloy Steel(WC-Co) for Surface Grinding (초경합금재의 평명연삭에 의한 온도분포)

  • Nam, Joon Woo;Kim, Won Il;Heo, Seoung Jung
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.7
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    • pp.178-188
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    • 1995
  • A study on the temperature distribution of tungsten carbide alloy steel(WC-Co) in surface grinding was conducted to improve the surface finish and to find optimum grinding conditions which would lead to efficient grinding operation by theoretical finite element method analysis and experimental test of workpiece under various conditions. Based on the comparixion of test results and FEM analysis data, it is concluded that the FEM computer simulation of heat transfer is useful in predicting the temperature distribution of test material that the increase of temperature is more infuleneced by the grinding depth than the grinding speed. And that the grinding energy flux of dey grinding is 4 to 6 time greater than wet grinding regardless of grinding speed and finally that the heat transfer does not take place in depth deeper than 3mm from the grinding surface.

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A Study on Precision Infeed Grinding for the Silicon Wafer (실리콘 웨이퍼의 고정밀 단면 연삭에 관한 연구)

  • Ahn D.K.;Hwang J.Y.;Choi S.J.;Kwak C.Y.;Ha S.B.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1-5
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    • 2005
  • The grinding process is replacing lapping and etching process because significant cost savings and performance improvemnets is possible. This paper presents the experimental results of wafer grinding. A three-variable two-level full factorial design was employed to reveal the main effects as well as the interaction effects of three process parameters such as wheel rotational speed, chuck table rotational speed and feed rate on TTV and STIR of wafers. The chuck table rotaional speed was a significant factor and the interaction effects was significant. The ground wafer shape was affected by surface shape of chuck table.

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A Study of Grinding Characteristic of Ferrule (페룰의 연삭 가공 특성에 관한 연구)

  • Lee, S.W.;Choi, H.Z.;Choi, Y.J.;Ahn, G.J.
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.974-979
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    • 2003
  • As recently optical communication industry is developed, request of optical communication part is increased. Ferrule is very important part which determines transmission efficiency and quality of information in the optical communication part. Most of ferrule processes are grinding which request high processing precision. Particularly, concentricity and cylindricity of inner and outer diameter is very important. The co-axle grinding process of ferrule is to make its concentricity all of uniform before centerless grinding. Surface integrity of ferrule is affected by kind of grinding wheels, grinding conditions, and characteristic of workpiece and equipment. In this study, surface integrity of workpiece according to change of grinding wheel speed, feed rate, regulating wheel speed and grinding force is investigate to improve the concentricity and roundness of ferrule from many experiments.

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