This paper proposes an evaluation index of motion transmissibility of N degree-of-freedom (dof) in-parallel wire-driven mechanisms with N+1 wires. Utilizing the relationship between input force and output force of N dof in-parallel actuated mechanism with only rigid links, a transmission index for in parallel wire-driven mechanism has been defined. The effectiveness of the index has been confirmed through the comparison of the index with the magnitude of tension force caused by external forces. A six dof spatial mechanism with high motion transmissibility has been obtained.

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For the purpose of improving tribological properties of FRP sliding pads, an investigation was made on the friction and wear properties of glass fibre reinforced vinylester composite materials with various kinds of fillers. Three types of composites with fillers (pitch based carbon fabric mat: RCM, pitch based short carbon fibre and polyester felt: RPC, and graphite particles and polyester felt: RPG) and a vinylester resin for a comparison specimen were prepared in this experiment. It was also surveyed that the surface roughness of the steel counterface was influenced by the fillers. The tribological properties of these composites were determined with a reciprocating-slider frictional testing machine under a dry condition. Experimental results showed that the coefficient of friction and abrasion loss of these composites reduced in comparison with those of a vinylester resin. RPC presented lower frictional coefficient, particularly. The specimen for maximum wear resistance was RPC during short distance, and RPG for later. The steel surface roughness to RPG was unchanged. On the other hand, the surface roughness value increased with both RPC and RCM at far sliding distance, because carbon fibre injured a steel surface.

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In one direction of improving the material strength of a piston-ring of a marine diesel engine, a new wear resisting steel has been made efforts to develop in the expectation that it may supersede high phosphorus gray cast iron. For the newly developed wear resisting steel (later, wear resisting steel) we carried out wear tests and scuffing tests, and analyzed its test results in comparison with those of gray cast iron. After that we manufactured piston-rings using wear resisting steel. Piston rings made from wear resisting steel were installed the actual engine, and the actual engine test was carried out for 160.8 hours. We inspected the sliding surfaces of piston-rings after 29 hours and 160.8 hours. According to the test results, the wear amount of wear resisting steel was the same or smaller than that of gray cast iron, and the sliding surfaces of piston rings were normal and no severe wear such as scuffing was observed on them.

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In the traction drive of reciprocating motions, three properties such as the traction forces, the frequency responses and the surface damages after times of 10⁶ had been driven were investigated for the precision feed mechanism. Steel, Si₃N₄ and PSZ were used as the material of the driver rollers and the follower fiat plates. Traction oil Daphne 7074 was used for the lubricant. The traction force of reciprocating motion was mainly decided by the limiting shear stress of lubricant in the case of three materials. The lower the frequency of the motion, the larger the surface damages of the plates, but that of Si₃N₄ and PSZ was very little. Therefore it was evident that the traction drive should be well applied for the precision feed mechanism.

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"Opposed dies shearing process" is based on the idea of smooth surface formation by cutting mechanism and can be applied to brittle materials in principle. This feature is considered to be available for finishing of cast products and new demand for this process is expected. In this paper, precision shearing of cast materials by "Opposed dies shearing process" was studied. Four kinds of cast iron and cast aluminum under practical use were tested and unique characteristics in applying this process to brittle materials were cleared. Influences of working conditions on sheared surface were investigated and optimum conditions to obtain fracture-free sheared surface were given for each material. In comparison with other shearing processes, it was cleared that the sheared surface quality of this process was much better than that of conventional shearing process and almost equal to that of shaving process.

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The purpose of this research is to develop a new die forging process to form machine parts which satisfy the strength requirements like a gear or a spline. The major point of this new process is the feasibility of the increase in the thickness without buckling since the initial material shape for the new process is a thick sheet and an intermediate product before die forging is a drawn cup. The new process is composed of deep drawing, redrawing with ironing, ear-trimming, and final die forging. In the redrawing, intermediate second process, the outer profile is the same to that of the final product. In the final die forging the increase in the wall thickness of the drawn cup is promoted mainly by centripetal metal flOW. The feasibility of the new plastic forming process was confirmed through a series of experimental simulation with a final product that had a wavy cross-sectional profile. As a result of an experiment the increase in the wall thickness without severe buckling has been confirmed.

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In automatic inspection of X-ray radiographic testing, it is difficult to detect small and unclear defect images from low contrast film. Generally, these defect images are hidden by noise due to unclear background image, small particles of film, uneven development of film and so On. Furthermore, it is difficult to abstract shape of defects, because the boundaries among defect images and their background images are unclear. Therefore, in order to eliminate background image and detect defect boundaries surely, two dimensional background subtraction method and region growing method are proposed. This paper deals mainly with the algorithms of the background subtraction method and the region growing method, and their effectiveness of these methods in automatic inspection of X-ray films.

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A basic study was carried out to find out the optimal heating and cutting conditions for hot turning of difficult-to-cut materials with YAG laser. A carbon steel of S45C for machine structural use was used to examine the effects of local heating on its roachinability. The machined surface roughness against cutting temperature and the relation between cutting temperature and cutting speed were examined experimentally. Because of the lower laser power of not more than 162 W, the calculated average temperature rise in the cutting region reached less than 70 K, which was not effective to decrease the cutting force. In the cutting speed range where the marked formation and growth of built up edge was appeared, however, about 40 K of the calculated average temperature rise in the cutting region due to laser beam irradiation was effective to improve the surface roughness. In the cutting temperature range of 950 to 1200 K where the built up edge should be disappeared, the surface roughness was less than that in the temperature range of 500 to 950 K and was not affected by the cutting temperature. In the higher cutting temperature range, the slope of cutting temperature against cutting speed was decreased to 50∼75% of that in the lower temperature range.

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This study aims for realizing new assembly process planning methodology to promote agile manufacturing to meet diversified customer orders and shorten product life cycle in the globally competitive market. First, a simplified assembly process planning model composed of three characterized planning items is newly proposed by analyzing 20 actual assembly process. Next, assembly process planning methodology based on the model and unique quantitative evaluation method by information entropy, is newly proposed. The new assembly process planning methodology realizes fast and accurate assembly process planning. Finally, the methodology is demonstrated the effectiveness by applying for the process planning of a blower in an auto air conditioner.

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Reconciling the different desires and requirements of individuals within decision making groups is becoming increasingly important, as corporate structures tend to embody fiat relationships more than hierarchical ones, and as computer networks gain ever more utility. In this paper, a computer aided decision making support system is proposed, that such groups of decision makers can rely on, in order to arrive at the best possible cooperative decisions. First, weighting coefficients for the factors to be evaluated are determined by pair comparisons based on the AHP (Analytic Hierarchy Process) method. The preference structures of the decision makers for these factors are expressed by single-attribute satisfaction functions. Next, these satisfaction functions are classified into two groups having opposite tendencies (positive, and negative) so that when graphed, the intersection of the two curves can be defined as a solution point where the decision makers can compromise. Then, improvement procedures are conducted based on compromise processes, so that the satisfaction level at the solution point becomes as high as possible. Finally, these decision making procedures are demonstrated by analyzing the decision making problems encountered when designing' an industrial robot.

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Container logistics networks need their expansion and the improvement of their efficiency. For this purpose, the container handling carrying system should be optimized in terminals. Then, it is important to reduce the cycle time for container operation. The operation cycle time is effected by machine performance and the arrangement of containers in stacking yard. In this study, the optimum stacking method in the yard is constructed. As the first step, a stacking method based on fuzzy systems theory has been developed. The judgement of container weight and unloading terminal are treated logically for a container. And the optimum location of a container in stacking yard is decided. The container handling applied this stacking method and conventional ones was simulated. The speed and distance of load hoisting, travelling and traversing are considered in this simulation. As the result, this stacking method is superior to convensional ones in shipping operation time.

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