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The anodic oxide films are formed to improve the corrosion resistance on aluminum alloy that used as the parts of engines and car bodies. Because these films are porous structure, it is necessary to seal the pores to further improve the corrosion resistance. The pores are sealed with hydrated alumina by treating the films in boiling water or solution that added sealing additives. These hydration sealing has a problem that energy consumption is large because of long sealing time and high temperature of solution. In this study, the authors have developed a new sealing treatment (Lithium sealing) using a lithium hydroxide solution to solve above problem. Lithium sealing mainly sealed the pores with lithium aluminate double salt (LiH(AlO2)2·5H2O). This salt was rapidly formed in strong alkaline solution at room temperature, so that the sealing time was reduced to about 1/10 compared with the conventional sealing.

Anodizing is applied to improve the durability and the corrosion resistance of aluminum alloy parts of engines and car bodies. Generally, anodic oxide film is formed using direct current anodizing (DCA). However, in the case of anodizing high silicon aluminum alloy cast parts, it is difficult to derive uniform film thickness distribution. Furthermore, it takes a long treatment time which causes low productivity. In this study, the authors have developed an anodizing method by using high-frequency switching anodizing (HSA) to solve these problems. The growth process of anodic oxide film is susceptible to the metallographic structure. Thus, the typical DCA application to the high silicon aluminum alloy produces a non-uniform film thickness, while HSA has the potential to form uniform film without being affected by metallographic structure. Moreover, the current density of HSA is higher than that of DCA which reduces treatment time to 1/5 as the film formation enhances.

A seal ring of PEEK material was developed and shown to withstand high pressure and high shaft velocity. This was made possible by cooling the ring material using leakage through an engineered passage at the cut junction. The cooling effect of leakage rate was modeled thermodynamically, and calculated leakage rates were compared to measured results.

Lean-burn is the most attractive way to lower emissions of NOx while improving the fuel consumption simultaneously in spark ignition engines. A Pulsed Combustion Jet (PCJ) ignition system has a great potential to enhance ignition reliability and burning rate of lean fuel-air mixtures. Its action is based on the utilization of turbulent plumes formed by jets produced by generators, in the shape and size of an ordinary spark plug, that embody a small (500 mm3 or less) cavity, capped with an orifice plate and outfitted with a hollow electrode. Performance characteristics of PCJ were established by combustion tests carried out in a diskshaped, constant volume combustion chamber using lean methane-air mixtures. The results were compared to those obtained with Pulsed Plasma Jet (PPJ) an standard spark plug ignition systems. Lean limit was extended most by PCJ ignition under both quiescent and swirl conditions.

Recent trends in automotive design and aerodynamics increasingly lead to a “oneness” or unified image of the bumper with the body. This leads to requirements that the bumper meet the same high surface quality as the body, be capable of more complex geometry, while at the same time becoming larger. Currently in Japan, the typical approach is to use PP or PUR as a base material. As for the painting operation, a primer is applied and then the bumper must be painted off-line separately from the body. The purpose of this development effort was to 1) improve color matching, 2) improve distinctness of image, 3) improve impact performance, 4) simplify the process, while at the same time, 5) achieving a large cost reduction. The focus of this program was to develop a PPE (polyphenylene ether) / PA (polyamide) bumper material, paint on-line with the body, and eliminate the primer system. The first step of this program was to establish the on-line paintability of the PPE/PA bumper system.

In order to confirm quantitatively the performance and characteristics of the plasma jet ignition in turbulent lean mixtures, combustion tests were carried out in a disk-shaped combustion chamber with lean turbulent methane-air mixtures. In the tests, the governing parameters of the plasma jet ignition such as the plasma cavity size, the orifice diameter, and the discharge energy were varied. A characteristic lifetime and a characteristic length of the plasma jet and an entrainment volume of the mixture into the plasma jet are defined theoretically and expressed by the parameters of the plasma jet ignition. A series of combustion tests revealed that lean flammability limits, a comparing parameter, and a combustion index are correlated with these characteristic values, where the comparing parameter shows the degree of combustion enhancement by the plasma jet ignition in its initial stage and the combustion index represents the total combustion performance of the plasma jet ignition.

A simple new method of prediction of a change in gas motion in an engine cylinder during the compression stroke has been developed for both flat piston and bowl-in-piston typed combustion chambers. The availability of this method was ascertained by comparing the results of predictions with several measured ones. In order to show the effects of engine variables on the gas motion during the compression stroke quantitatively, calculations have been made also with some typical engine dimensions.