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This paper proposes a rolling machine that forms fine corrugated section patterns for thin sheets. A prototype of the machine was made and the performance of the machine was tested. As compared with press forming, rolling has the advantages of the high forming limit, the low forming reaction force, the easy control of the thin sheet's curve and high productivity. We confirmed these four advantages by using finite element analyses and the prototype rolling machine. Stainless steel sheets and titanium sheets, which were one of the materials with a low forming limit, were used. Firstly, the rolling showed a 1.3-times higher forming limit than the press forming in the case that a fine corrugated section pattern was formed in a stainless steel sheet of 22-mm square sizes. Secondly, the forming reaction force of the rolling was about one-twentieth of the press forming without coining, and the experimental results agreed with the finite element simulation.

It has been required recently that diesel engines for passenger cars meet various requirements, such as low noise, low fuel consumption, low emissions and high power. The key to improve the noise is to reduce a combustion noise known as “Diesel knock noise”. Conventional approaches to reduce the diesel knock are decreasing combustion excitation force due to pilot/pre fuel injection, adding ribs to engine blocks or improving noise transfer characteristics by using insulation covers. However, these approaches have negative effects, such as deterioration in fuel economy and increase in cost/weight. Therefore, modification of engine structures is required to reduce it. We analyzed noise transfer paths from a piston, a connecting rod, a crank shaft to an engine block and vibration behavior during engine operation experimentally, and identified that piston resonance was a noise source.

Automotive fenders is one such example where specialized thermoplastic material Noryl GTX* (blend of Polyphenyleneoxide (PPO) + Polyamide (PA)) has successfully replaced metal by meeting functional requirements. The evolution of a fender design to fulfill these requirements is often obtained through a combination of unique material properties and predictive engineering backed design process that accounts for fender behavior during the various phases of its lifecycle. This paper gives an overview of the collaborative design process between Mitsubishi Motors Corporation and SABIC Innovative Plastics and the role of predictive engineering in the evolution of a thermoplastic fender design of Mitsubishi Motors Corporation's compact SUV RVR fender launched recently. While significant predictive work was done on manufacturing and use stage design aspects, the focus of this paper is the design work related to identifying support configuration during the paint bake cycle.

In this paper, emissions reduction technologies applied to high-speed direct injection (HSDI) diesel passenger car engines to meet the stricter exhaust emission legislation are described. To reduce smoke, the F.I.E. has been improved by using a radial-piston distributor pump which delivers fuel-injection-pressure up to 120MPa. Cooled exhaust gas re-circulation (EGR) system and increase in volume ratio of the combustion chamber has made it possible to increase EGR ratio and reduced nitrogen oxides (NOx) and smoke simultaneously. Furthermore, improvements in the oxidation catalyst activating temperature reduces PM at lower exhaust gas temperatures. As a result of applying these technologies, a clean and economical HSDI diesel engine for passenger cars, which complies with Japanese '98 exhaust emissions legislation and has better fuel economy than indirect injection (IDI) diesel engines (above 15%), has been developed.

To apply a fuel economy performance to AT&CVT fluid for common use (hereinafter AT/CVT fluid) and manual transmission fluid, by optimizing fluid viscosity, a fundamental study was investigated. Generally, it is well known that the viscosity of polymer-added transmission fluids is gradually reduced, due to deterioration of the viscosity index improver caused by shear stress. An excessive viscosity reduction causes an operation failure or damage to the transmission. Considering above factor, the authors focused attention on the potential of a low viscosity formulation to improve fuel efficiency by reducing an internal stirring-resistance of the transmission. Also from the viewpoint of friction characteristics, the performance of a base oil was studied. Utilizing the EHL (Elast-Hydrodynamic Lubrication) tester [1] and vehicle tests, the performance of base oils was evaluated for the fluid development.

The application of tailored blanks to autobody parts has progressed because of its numerous advantages. The forming of tailored blanks has, however, a lot of technical problems. Among the problems, weld-line movement and formability deterioration are the most significant ones in case of deep drawing. The weld-line movement and formability change were examined experimentally as a function of weld-line location in square cup deep drawing. The weld-line movement of tailored blank consists of two sources. One is the geometrical reason, and the other is due to the hardening of weld bead. The formability of tailored blank is inferior to that of an original blank by the existence of hardened weld region. The mode of fracture changes from wall breakage to a fracture adjacent to punch radius when the weld-line was close to the punch corner.

This paper describes a calculating method to predict the quasi-static collapsing behaviors of spot-welded closed-hat section curved beams under axial compression. The overall deformat ions and the local buckling modes of beams were calculated using a geometrical model. Force-displacement relations were predicted by a elastic-plastic structural analysis method using the ‘plastic hinge’ concept. Collapsing tests were made on beams which are differenting section size, rotation angle, and metal sheet thickness. Comparisons between the calculated and experimental results of deformed shapes of beams, the local buckling modes and the force displacement relations are discussed.

Spot friction welding (SFW) is a cost-effective spot joining technology for aluminum sheets compared with resistance spot welding (RSW) [1]. In this study, coated mild steel was spot friction welded to 6000 series aluminum using a tool with shoulder diameter of 10 mm and welding conditions of 1500-2000 rpm and time of 5 s. Testing showed that tensile shear strength increased as the solidus temperature of the coating on the steel decreased. Microstructure characterizations of steel/Al joint interfaces showed that zinc from the coatings was incorporated into the stir nuggets and that intermetallic phases may have formed but not in continuous layers. Some Al-Zn oxides that appeared to be amorphous were also found in the joint interfaces.

As part of the International Lubricant Standardization and Approval Committee's (ILSAC) goal of developing a global automatic transmission fluid (ATF) specification, members have been evaluating test methods that are currently used by various automotive manufacturers for qualifying ATF for use in their respective transmissions. This report deals with comparing test methods used for determining torque capacity in friction systems (shifting clutches). Three test methods were compared, the Plate Friction Test from the General Motors DEXRON®-III Specification, the Friction Durability Test from the Ford MERCON® Specification, and the Japanese Automotive Manufacturers Association Friction Test - JASO Method 348-95. Eight different fluids were evaluated. Friction parameters used in the comparison were breakaway friction, dynamic friction torque at midpoint and the end of engagement, and the ratio of end torque to midpoint torque.

For fuel economy improvement by lean-burn gasoline engines, extension of their lean operation range to higher loads is desirable as more fuel is consumed during acceleration. Urgently needed therefore is development of emission control systems having as high NOx conversion efficiency as three-way catalysts (TWC) even with more frequent lean operation. The authors conducted a study using catalysts loaded with potassium (K) as the only NOx trapping agent in an emission control system of a lean-burn gasoline engine.

For a crash analysis using FEM with respect to a structure that is composed of thin plates, we developed a new structure study method (plastic strain equalization method). This method defines the optimality criteria as in the linear analysis of a fully stressed design and indirectly finds an optimal solution. We assume that a structure with both a lightweight and high collapse load should have sufficient strength corresponding to impact loads in each area. This means that at any area the load value and the strength are balanced at a certain value. For the criteria that the plastic strain value is equal over the whole area, a solution can be found by repeating computations. The design variable is the thickness of shell elements and the computation is iterated until plastic strain values are almost equal. In this paper, a structure with both a lightweight and a high collapse load could be optimized by equalizing the plastic strain value.

A technique to strengthen body frame with a polymeric structural foam has been developed with benefits of reducing vehicle weight and improving drivability and fuel economy. The idea of this new technology was evolved from the concept that body frame strength will increase drastically if the body frames are prevented from folding on collision. The energy of a collision impact would be effectively absorbed if weak portions of body frames are reinforced by a high strength structural foam. The new technology composed of the high strength structural foam and a light-weight frame structure with partial foam filling is reported here.

A new single-brick Ba + alkali metals NOx-Trap catalyst has been developed to replace a two-brick NOx-Trap system containing a downstream three-way catalyst. Major development efforts include: 1) platinum group metals selection for higher HC oxidation with potassium-containing washcoat, 2) alumina and ceria selection, and Rh architecture design for more efficient NOx reduction and 3) NiO to suppress H2S odor. Mitsubishi Motors' 1.8L GDI™ with this Delphi new NOx-Trap catalyst with H2S control achieves J-LEV standard with less cost and lower backpressure compared to the previous model. It is further discovered that incorporation of NiO into the NOx-Trap washcoat is effective for H2S control during sulfur purge but has a negative impact on thermal durability and sulfur resistance. Further study to improve this trade-off has been made and preliminary results of an advanced washcoat design are presented in this paper. Details will be reported in a future publication.

Recently, it has been expected that titanium alloy valves will be adopted at extremely high rate to motorcycle engines where higher engine performance is required than in automobiles. However, there were difficulties with respect to reliability required for motorcycle engines. The reason for this is that engine valves of motorcycle engines are not only smaller in stem diameter, but also used at a higher maximum engine speed than those of automobile engines. This study is about a development of titanium alloy engine valves that meet reliability requirements in motorcycle engines.

With society demanding automobiles that provide higher fuel efficiency, safety of occupants in collisions and that at the end of their service life can be recycled with low environmental impact, the steel industry is tackling the needs of the automobile industry by developing ever-higher performance steel materials and simulation technologies that can demonstrate the performance of steel materials at the development stage without the need for costly prototype testing. In this paper, weight reduction of automobile body in Japan will be discussed. The main items will be as follows: (1) Development of Automobile Steel Sheets, (2) Materials for Automobile Bodies, (3) Materials and Technologies (Tailored Blanks, Hydroforming and Locally Quenching) for Reducing the Weight of Panels and Reinforcing members, (4) Future Prospects.

The International Lubricant Standardization and Approval Committee (ILSAC) ATF subcommittee members have compared the two oxidation bench test methods, Aluminum Beaker Oxidation Test (ABOT) and Indiana Stirring Oxidation Stability Test (ISOT), using a number of factory-fill and service-fill ATFs obtained in Japan and in the US. In many cases, the ATFs were more severely oxidized after the ABOT procedure than after the same duration of the ISOT procedure. The relative severity of these two tests was influenced by the composition of the ATFs. The bench test oxidation data were compared with the transmission and the vehicle oxidation test data.

A method of fatigue life prediction of spot welded joint under multi-axial loads has been developed by fatigue life estimation working groups in the committee on fatigue strength and structural reliability of JSAE. This method is based on the concept of nominal structural stress ( σ ns) proposed by Radaj and Rupp, and improved so that D value is not involved in stress calculation. The result of fatigue life estimation of actual vehicle with nominal structural stress which was calculated through newly developed method had very good correlation with the result of multi-axial loads fatigue test carried out with test piece including high strength steel.

New 440MPa class high-strength steel, which had high r-value(1.6) and elongation(38%), was applied to outer-panel for the first time in the world. In this development FEM simulation was carried out to clarify the necessary steel properties, and the production conditions in strip mill were established. 10-kg weight reduction was realized by using this steel.

In this paper the fatigue life of welded steel sheet structures is predicted by using FE-Fatigue, which is one of fatigue analysis software tools on the market, and these predicted results are evaluated by reference to corresponding experimental results. Also, we try to predict these structures by using two fatigue life prediction theories established by the JSAE fatigue and reliability committee to compare prediction results. It was confirmed that spot welds fatigue life predictions agree qualitatively with corresponding experimental results and arc welds fatigue life predictions are in good agreement with corresponding experimental results in cases where the SN curve database is modified appropriately.

The main operations for the manufacturing of auto parts are the cutting of the flange and the stamping. In order to perform accurate fatigue calculation it is necessary to have the material properties for each point of the structure. Usually, only the fatigue curve obtained on the flat sheet with polished edges is used because it represents the basic metal behaviour. The real edge quality decreases the fatigue limit while the hardening induced by the stamping increases it. To take these effects into account allows a better fatigue calculation of the structural part.