Because the crosshead-pin bearing for large size two-stroke diesel engines oscillates within a small angle at a low speed and is always subject to a high downward-load, the hydrodynamic oil film is very thin. It is important to improve the load carrying capacity of the crosshead-pin bearing in the context of raising engine power in recent years. In the present study, calculations were carried out to clarify the lubrication characteristics of the crosshead-pin bearing to which an externally pressurized lubrication system was applied. Because the externally pressurized crosshead-pin bearing forms a very thick oil film at the bottom dead center, an improved hydrodynamic squeeze action is produced, thereby greatly increasing the minimum oil film thickness. Increasing the hydrostatic lift as well as extending the oil pocket pitch angle are effective means to improve the squeeze action, and thereby to increase the minimum oil film thickness.

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The purpose of this paper is to clarify the mechanism and lubricating effects of the outflow behavior of lubricant trapped in pits. The pits regularly arranged on a workpiece surface were produced by coining a die surface topograghy. The effects of pit size, array and area ratio of pits on the friction behavior were investigated by using a roiling type tribometer. Lubricant flows out from oil pits in the direction of the friction stress. The outflow trace becomes deeper for the lubricant of higher viscosity or for the annealed workpiece. With increasing the area ratio of pits or decreasing the pit size or arranging the pits to cross array, the outflow lubricant from pits covers wider surface area and the lubricating effects of the pits become larger. The lubricating effects of the pit also become larger with decreasing viscosity of the lubricant or roughness of the surface around the pit and with increasing the hardness of the workpiece.

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Effects of the wire shape in bundles and the wire feeding conditions on the shape of formed coils are analyzed theoretically and experimentally, which derives the relations between the reel plane inclination and the shape of the formed coils. In these relations, the effects of combined loads on the yield point load of the wire are considered qualitatively. As a result of the analysis, it is clarified that the shape of the formed coils is not affected by the feeding conditions in case of straight wire. On the other hand, the shape of the formed coils is influenced by the wire shape and the wire feeding conditions in case of curved wires. In other words, the more the feed roller force increases and the smaller spring index becomes, the smaller the shape change of formed coils becomes. Furthermore, it is clarified that the torsion of the formed coils is mainly processed by coiling tools compared with wire shape.

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This paper deals with deformation characteristics of textile composite tubes in spherical shape thermoforming process. The composite tubes are made of cowoven braid, which consists of polyamide resin and carbon braid with thin thickness and high fiber volume fraction, and are fabricated by internal pressure bonding method. Spherical shape closed dies of two different sizes are used in the experiment. The specimen is deformed at a temperature that makes the specimen soft enough to be deformed. Several combinations of internal pressure and axial displacement, which are controlled by a personal computer, are applied to the specimen during forming. An expression to predict a required axial displacement for the forming was derived from geometric deformation model of a braid. A spherical shape part being about two times as large as original tube diameter is obtained under suitable forming conditions. Calculated axial displacements agree with experimental results. It is proved that the derived equation is valid to predict required axial displacements for spherical shape forming. Experimental results reveal that this forming process has a potential as one of thermoforming techniques for the composite tubes.

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In the product planning procedure of machine tools, mature designers always analyze and consider various customer's requirements and also conduct necessary information processing so as to obtain the most suitable product specifications. In order to rationally systematize such a procedure, it is necessary and indispensable to analyze and establish the decision making in the product planning of machine tools. Thus, in this paper, a product evaluation method using customer satisfaction degree has been proposed to establish a product development methodology for machine tools. The validity and effectiveness of the proposed evaluation method are verified through some case studies.

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When the spindle buits in machine tool rotates with very high speed, it may be shortened by the centrifugal force, and in contrast elongated by the thermal effect, resulting in the deterioration of the machning accuracy Whilst the speed is in low or moderate range, the displacement behavior is rather simple, therfore its compensation is easy. In very high speed range, the spindle shows complicated behavior in its displacement because of the additional effect of the centrifugal force, and duty the conventional compensation becomes erroneous. This paper describes that the spindle displacement can be represented with a linear equation considering the historical data for function values of the spindle speed. A multiple regression analysis is used to determine the coefficients in the linear equations.

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This paper deals with the influence of hob geometry, rake angle and relief angle, on tool wear reduction effect of lubricating additives in cutting oils for bobbing and effect of the additives for improving of finished surface roughness. Experiments were carried out using a fly tool. It was revealed that among the additives used in these experiments, sulfur type's sulfurized fatty oil showed a best performance in terms of an extension of tool life and an improvement of surface roughness for almost of rake angles, relief angles and at all cutting speeds tested. Especially, it was obvious that the sulfurous EP additive is effective for the hob having the geometry of rake angle of 0° and relief angle of 12°. The use of sulfurized fatty oil as an additive is very effective for environmental pollution control and for improving the safety of the operator.

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The fine particle manipulation using optical radiation force has already been investigated in former research. Based upon that, the manufacturing method of the micro parts made up of some fine particles has been developed. However, when the micro parts consist of a lot of fine particles, the manipulation and assembly procedures become time consuming with low work efficiency because of the one by one operation. To solve this problem, a new arrangement method with a single laser beam was realized and proposed in the study, which is able to conduct the assembly procedures efficiently and practically. In detail, the method is to arrange particles by stopping the scanning of a YAG laser beam for a short interval at some appointed positions along the scanning locus to give out a larger amount of input laser energy so that fine particles can be trapped in priority at those stop positions. Therefore it becomes realizable to trap several fine particles at the appointed locations. Furthermore, if the stop positions of the laser scanning are arranged at the same time, the plural trapped fine particles can be manipulated simultaneously. This idea has also been experimentally realized.

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In high accurate and high efficient tooth finishing, a vitrified CBN (cubic boron nitride) wheel or a electro-deposited CBN wheel shows superior performance. And honing by a involute spline tooth meshing is profitable due to the generating motion. However, a lack of wheel rigidity and an inadequate feeding motion of the wheel trend to reduce finishing performance. As a result, it is difficult to keep the tooth surface smooth. In this study, the finishing with a vitrified CBN wheel is carried out using a new honing tool. The finishing performance is compared with that obtained using a electro-deposited wheel. And the finishing by braking a internal spline axis is carried out. The influence of different feeding methods is investigated on the finished tooth surface roughness. The finishing by using a vitrified CBN wheel and braking a internal spline axis shows superior performance.

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This study describes the end milling operation using an articulated robot that is the new machining for extruded aluminum alloys. In this machining operation, it is necessary to reduce a cutting force as far as possible for the improvement of machining speed. In this paper, in order to reduce a chatter vibration in end milling which importantly affects a cutting force, the means of vibration isolation was done by using the rubber vibration isolator at the holder of high-speed spindle. Consequently, the peak of cutting force decreased about 90%, and the limit of feed speed improved over two times in comparison with the case of no vibration isolation.

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The goal of this study is making up CIM of the painting process for large scale steel products. In this process, placer robot system is necessary to approach and spray paint on the workpiece. Unfortunately, dynamic efficiency of a placer is poor as a rule because of its insufficient stiffness. It causes fluctuation of the tool center point (TCP) in the trajectory, which has harmful effect on the film formation. In this paper, cooperative control of the placer-robot system is proposed to improve the TCP painting trajectory. TCP trajectory data and placer trajectory data with the moving pattern for vibration control are generated in the NC data generation system and given to the controller. In the controller, robot trajectory is generated from TCP and placer trajectory data, and compensates TCP trajectory. We studied various methods for such compensation through the dynamic response simulation of the placer-robot system, and found out that the compensation by the robot trajectory of wrist swing is effective in improving TCP trajectory. As a result of experiment in the prototype system for ship hull-block, significant improvement was confirmed in the film formation. In addition, method of the dynamic simulation for the film formation is also proposed. In this simulation, the response simulation above mentioned is linked to the quantitative process of coating.

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