トライボロジスト
Online ISSN : 2189-9967
Print ISSN : 0915-1168
ISSN-L : 0915-1168
66 巻, 8 号
特集・加工のための潤滑技術
選択された号の論文の13件中1~13を表示しています
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目次
連載・トライボロジーを語る
特集・加工のための潤滑技術
解説
  • ―板材の塑性加工用潤滑剤の仕組みと高度化への取組み―
    木村 茂樹
    2021 年 66 巻 8 号 p. 601-607
    発行日: 2021/08/15
    公開日: 2021/08/15
    ジャーナル 認証あり

    Lubricants for plastic working of metals are materials is the chemical substances which penetrates to the interface between a tool and a workpiece, then controls friction and prevent seizure. These lubricants are classified into liquid, semisolid (grease) and solid according to their appearance. Liquid- and semisolid-type lubricants are mainly used in cold-working region, and solid-type ones are often applied to hot-working region. Liquid-type lubricants are the most commonly-used lubricant in the field of metal forming because it's easy to handle from their liquidity (hereinafter referred to as lubricating oils). Such the lubricating oils used in plastic working of metal materials are called by names of forming processes like rolling oil, drawing oil, forging oil, press oil, punching oil and so on. Among those, press oils and punching oils, which are used in processing sheet-metal into final parts, have high complication in application and wide variety in type. For example, based on material and dimension of processed parts, forming difficulty, and suitability on subsequent processes to final parts, the required functions as appropriate lubricants vary in detail. Focusing on press oils and punching oils, their required functions, activities for its advancing and the future outlook are outlined.

  • ―油剤供給方法の観点―
    帯川 利之, 森合 主税
    2021 年 66 巻 8 号 p. 608-613
    発行日: 2021/08/15
    公開日: 2021/08/15
    ジャーナル 認証あり

    Tribology in cutting processes are explained for different cooling methods with flood coolant, MQL, high speed coolant, and high pressure coolant. First, the fundamental modeling of lubrication in cutting processes through gas phase lubrication, which can be applied to all the cooling methods, is depicted. This model explains the efficient lubrication of MQL, which could compensate the poor cooling ability of MQL in comparison with flood cooling. Computational fluid dynamic analysis of coolant flow in turning shows visibly that high speed coolant is much more effective than flood coolant for cooling high temperature area of a tool near the tool tip. Finally, the effects of high and ultrahigh pressure coolant on cutting processes are highlighted. Both kinds of coolant have two main roles in cutting: cooling and chip breaking. Chip breaking is a not-negligible action of these types of coolant, which contributes to the efficient cutting processes by solving one of ill-defined problems of chip control. The influence of coolant pressure on cooling and chip breaking is described comprehensively.

  • 森本 真輔
    2021 年 66 巻 8 号 p. 614-619
    発行日: 2021/08/15
    公開日: 2021/08/15
    ジャーナル 認証あり

    The development of cutting fluids is related to the progress of the metal machining field. The requirement to the performance of cutting fluids is varying due to the trends, and it is important to response to laws and regulations regarding chemical substances in Japan and overseas, and to consider the working environment. The basic functions of cutting fluids are lubricity, cooling ability and anti-build-up ability. Various performances based on these effective functions make it possible to contribute to productivity improvement in the machining field. On the other hand, the environmental problems relating with cutting fluids should be more considered. Many countries have laws and regulations such as PRTR in Japan, REACH in EU, TSCA in USA. Therefore, it is important to response them to prevent environmental pollution and risks for human health. In this paper, it is described the fundamental knowledge regarding performance and properties such as water miscible cutting fluids and straight cutting oils, and the environmental response based on the current trends as well as several requirements.

  • 大森 整, 稲澤 勝史, 江面 篤志, 伊藤 伸英
    2021 年 66 巻 8 号 p. 620-625
    発行日: 2021/08/15
    公開日: 2021/08/15
    ジャーナル 認証あり

    ELID-grinding is well known as an effective mirror surface grinding method, and is expected to be more efficient by addition of new function. Fine bubble is one of its candidates. We attempted to mix air fine bubble for ELID-grinding fluid, and to characterize its effects on interaction between the grinding wheel and the workpiece. Then, the effects of CO2 fine bubble on grinding ratio and wheel wear have also been evaluated. As a result, fine bubble can avoid clogging of grinding wheel and keep the grinding ability together with ELID, and can improve grinding ratio and wheel wear.

  • ―加工液の観点―
    二ノ宮 進一
    2021 年 66 巻 8 号 p. 626-631
    発行日: 2021/08/15
    公開日: 2021/08/15
    ジャーナル 認証あり

    In grinding, grinding fluid is important for improving the processing characteristics. However, in recent years, the components of the grinding fluid have been limited due to environmentally friendly efforts. The authors aim to achieve both reduction of the amount of grinding fluid used and improvement of processing characteristics. In this paper, ultrasonic vibration assisted grinding fluid (kilo-sonic coolant, mega-sonic coolant) and fine bubble-containing grinding fluid (micro bubble coolant, ultra-fine bubble coolant) are introduced. These technologies are expected to be adopted in actual production.

  • 王 志剛
    2021 年 66 巻 8 号 p. 632-637
    発行日: 2021/08/15
    公開日: 2021/08/15
    ジャーナル 認証あり

    This paper describes the concept and basic features of shear forging. The basic idea of shear forging is the application of the flow model in metal cutting into cold forging to reduce the forging load dramatically. The feature of shear forging is to move a part of the workpiece freely by using the flow pattern of the continuous chip in metal cutting. The mechanics and the material movement in shear forging are similar to those in metal cutting, but the tribological issues in shear forging are very different from those in metal cutting since the forging velocity is extremely lower than the cutting velocity.

解説
  • 齊藤 利幸
    2021 年 66 巻 8 号 p. 638-645
    発行日: 2021/08/15
    公開日: 2021/08/15
    ジャーナル 認証あり

    The technological history of machine tool was looked back in this report. Early domestic machine tools were developed to follow the technological leading overseas machine tools. If in need, some machine tools were developed in technical partnerships with foreign companies. High-performance machine tools manufactured excellent parts as a mother machines and, often boosted their national power. In particular, some technologies, such as the appearance of NC machine tools, the incorporation of machining compensation functions on machines and the adoption of high-performance element parts, were innovative in improving machining accuracy and productivity. Machine tools would be continuing to improve their performance by incorporating technological innovations such as material technology, artificial intelligence and Internet of things, and support the industry.

学術論文
  • 津田 武志, 山下 侑里恵, 吉崎 浩二, 黒川 貴則, 新井 大和
    2021 年 66 巻 8 号 p. 646-655
    発行日: 2021/08/15
    公開日: 2021/08/15
    [早期公開] 公開日: 2021/06/09
    ジャーナル フリー

    In recent years, demands for improving energy efficiency in industrial machinery and vehicles are increasing. Especially, bearing rotational torque in motors cannot be ignored and low torque property of ball bearings are required. Generally, rotational torque of ball bearings using grease lubrication is greatly affected by stirring resistance derived from grease. Although studies on torque of rolling bearings were mainly related to soap grease, few studies investigated urea grease. In future, the use of urea grease is expected to increase because of severe operating conditions such as high temperature. Thus, new grease design for low torque and long-life properties are needed. In this study, we evaluated rheological properties and bearing rotational torque of different types of urea grease prepared by changing amine composition, oil types and penetration. We found correlation between the new concept of viscosity reduction energy and stirring loss energy which is the time integral of torque. It is suggested that the higher the viscosity reduction energy, the lower the bearing rotational torque.

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