• Title/Summary/Keyword: machined surface

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Analysis of the Characteristics of the Feed motor Current for the Estimation of the Cutting Force in General Cutting Environment (일반적 상황에서 2차원 절삭력 추정을 위한 이송모터 전류의 거동분석)

  • Jeong, Young-Hun;Yun, Seong-Hyun;Cho, Dong-Woo
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.4
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    • pp.93-100
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    • 2002
  • The current from the feed motor of a machine tool contains substantial information about the machining state. There have been many researches that investigated the current as a measure for the cutting farces. However it has been reported that this indirect measurement of the cutting farces from the feed motor current is only feasible in low frequency. In this research, it was presented that the bandwidth of the current monitoring can be expanded to 130 Hz. And the unusual behavior of the current was examined in this bandwidth. The cross-feed directional cutting force influences the machined surface of the workpiece, which makes it necessary to estimate this force to control the roughness of the machined sulfate. The current exists in the stationary feed motor, and it can give the useful information on the quality of the machined surface. But the unpredictable behavior of the current prevents applying the current to prediction of the cutting state. Empirical approach was conducted to resolve the problem. As a result, the current was shown to be related to the accumulation of the accumulation of the infinitesimal rotation of the motor. rotation of the motor. Subsequently the relationship between the current and the cutting force was identified.

The Probabilistic Forcasting of Product's Surface Quality (제품 표면품질의 확률적 예측)

  • 여명구;양정회
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.20 no.43
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    • pp.47-57
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    • 1997
  • As a general index in surface quality of machined products, surface roughness is to measure worker's skill level, a ground product quality and machining accuracy, etc. The surface roughness is defined by a function of rotational speed and radius of a grinding wheel, distances of active grains composed of the wheel, and feed of a grinder's worktable. To predict surface roughness in horizontal surface grinding operations, probability distributions were used. Probability distribution functions(p.d.f.) of surface roughness were found as results when the size of active grains(=the radius of a grinding wheel) is given as uniform, exponential distribution, and the distance between active grains follows the distributions of uniform, exponential. For each pdf case, probabilistic features of surface roughness were also analyzed and presented. This study is a substantial step for determining mathematically the surface roughness instead of using empirical approaches. More works should be presented to develop a general model by which an accurate roughness value can be obtained in horizontal surface grinding operations.

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A Study on Machining for Bearing Rubber Seal Die by Flank of Formed Insert Type Tool (Insert type 총형공구 여유각 영향에 따른 베어링 Rubber Seal 금형의 가공성 평가)

  • Li-Hai Li
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.04a
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    • pp.42-47
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    • 2004
  • Formed insert type tool satisfy both the surface roughness and geometric accuracy, so that cutting edge of formed tool can duplicate final feature. For experiment the formed tools with various clearance angles are machined. And the tools are evaluated with respect cutting force, flank rear and surface roughness to optimistic condition.

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Cutting Process Monitoring Using Tool Dynamometer in End-Milling Process (엔드밀 공정에서 공구 동력계를 이용한 절삭상태 감시)

  • 김홍겸;양호석;이건복
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2001.10a
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    • pp.14-18
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    • 2001
  • Rise in cutting force causes tool damage and worsens product quality resulting in machining accuracy deterioration. Especially, fragile material cutting brings about breakage of material and worsens product surface quality. In this study, we trace the locus of cutting force and examine the machined surface corresponding to the cutting force loci. and build up a monitoring system for deciding normal operation or not of cutting process.

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A Study on the Optimal Cutting conditions for Mild Materials (연질재료의 최적 절삭조건설정에 관한 연구)

  • 최상련
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.8 no.1
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    • pp.112-118
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    • 1999
  • Aluminum alloy, which is advantageous to machining and injection, makes a great contribution to shortening in delivery time, infection cycle time and reducing expense. This study presents machining conditions for mild materials and describes the difference between theoretical and practical machined surface roughnesses affected by various machining conditions. Machining results have been evaluated and analyzed under varying machining conditions. Special properties of the mild materials have been presented by the quantitative analysis and the optimal machining condition has been proposed for the mild materials.

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Modeling of surface roughness in electro-discharge machining using artificial neural networks

  • Cavaleri, Liborio;Chatzarakis, George E.;Trapani, Fabio Di;Douvika, Maria G.;Roinos, Konstantinos;Vaxevanidis, Nikolaos M.;Asteris, Panagiotis G.
    • Advances in materials Research
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    • v.6 no.2
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    • pp.169-184
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    • 2017
  • Electro-Discharge machining (EDM) is a thermal process comprising a complex metal removal mechanism. This method works by forming of a plasma channel between the tool and the workpiece electrodes leading to the melting and evaporation of the material to be removed. EDM is considered especially suitable for machining complex contours with high accuracy, as well as for materials that are not amenable to conventional removal methods. However, several phenomena can arise and adversely affect the surface integrity of EDMed workpieces. These have to be taken into account and studied in order to optimize the process. Recently, artificial neural networks (ANN) have emerged as a novel modeling technique that can provide reliable results and readily, be integrated into several technological areas. In this paper, we use an ANN, namely, the multi-layer perceptron and the back propagation network (BPNN) to predict the mean surface roughness of electro-discharge machined surfaces. The comparison of the derived results with experimental findings demonstrates the promising potential of using back propagation neural networks (BPNNs) for getting a reliable and robust approximation of the Surface Roughness of Electro-discharge Machined Components.

COMPARISON OF RESONANCE FREQUENCY ANALYSIS BETWEEN VARIOUS SURFACE PROPERTIES (임프란트 표면 처리에 따른 공명주파수 변화에 대한 연구)

  • Bae, Sang-Bum;Lee, Seong-Hyun;Song, Seung-Il
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.32 no.2
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    • pp.107-111
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    • 2010
  • Purpose: The aim of this study is to compare the stability between Mg-incorporated implant, TiUnite and Machined implant. Materials and Methods: Premolars of 3 Mini pigs (24 months) were extracted. After 2 months later, total 27 fixtures of implants (9 of each design : Machined/ TiUnite/ Mg-incorporated) were inserted into the mandible of 3 mini-pig. Implant stability was estimated by RFA in installation to 2, 4 & 6 weeks. Statistical analysis of RFA values was performed with time and between groups using repeated measure ANOVA and turkey's multiple comparison test. Results: In analyzing the mean value for the observation periods, three types of implants yielded a slight decrease in RFA mean value after 2 week, followed by increase at 4-6 weeks. Mg incorporated oxidized implants demonstrated significantly higher RFA mean values at 6 weeks comparing other groups. The difference of RFA value with time and between groups was statistically significant. Conclusion: We concluded that Mg implants may reduce failure rates of clinical implants In the early period of bone healing and Mg implants may shorten the bone healing time from surgery to functional loading.

Development of a Virtual Machine Tool-Part 4: Mechanistic Cutting Force Model, Machined Surface Error Model, and Feed Rate Scheduling Model

  • Yun, Won-Soo;Ko, Jeong-Hoon;Cho, Dong-Woo
    • International Journal of Precision Engineering and Manufacturing
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    • v.4 no.2
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    • pp.71-76
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    • 2003
  • A virtual machine tool (VMT) is presented in this two-part paper. In Part 1, the analytical foundation for a virtual machining system is developed, which is envisioned as the foundation for a comprehensive simulation environment capable of predicting the outcome of cutting processes. The VHT system undergoes "pseudo-real machining", before actual cutting with a CNC machine tool takes place, to provide the proper cutting conditions for process planners and to compensate or control the machining process in terms of the productivity and attributes of the products. The attributes can be characterized by the machined surface error, dimensional accuracy, roughness, integrity, and so forth. The main components of the VMT are the cutting process, application, thermal behavior, and feed drive modules. In Part 1, the cutting process module is presented. When verified experimentally, the proposed models gave significantly better prediction results than any other methods. In Part 2 of this paper, the thermal behavior and feed drive modules are developed, and the models are integrated into a comprehensive software environment.vironment.

Fabrication of LGP Micro-Channels by Micro End-Milling and MR Fluid Jet Polishing (Micro End-Milling과 MR Fluid Jet Polishing을 이용한 도광판 마이크로 채널 제작)

  • Lee, J.W.;Ha, S.J.;Hong, K.P.;Cho, M.W.;Kim, G.H.;Yoon, G.S.;Je, T.J.
    • Transactions of Materials Processing
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    • v.22 no.2
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    • pp.80-85
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    • 2013
  • The surface integrity of micro-machined products affects the performance of products significantly. Micro-burrs resulting from micro-cutting degrades the surface quality. Therefore it is desired to eliminate them completely and many studies have been undertaken for this purpose. In this study, micro-end-milling was carried out on nickel alloy and brass materials commercially used for light guide plate mold in 3-D optical devices. After completing this micro-machining, the burr heights were measured with a microscope. Then, deburring was done on the machined edges using the MR jet polishing method. A jet angle of $0^{\circ}$ and deburring times of 1, 3, and 5 min. were chosen. It was found that burrs were completely eliminated after 5 min of MR fluid jet polishing.