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The Vapor Reducing Fuel Tank System (Bladder Tank System) using a flexible plastic membrane (Bladder Membrane) was newly developed in order to reduce the amount of vaporized gasoline in a steel fuel tank. This Bladder Membrane is flexible to expand in proportion to a fuel volume and prevents the permeation of the vaporized gasoline. As a result of our initial study for various materials, we decided to apply a multi-layer plastic material which could achieve both low fuel permeability and good flexibility. This multi-layer material consists of polyethylene(PE) for structural material and polyamide(PA) for low permeability. The modulus of the PE needs to achieve a sufficient flexibility in order to keep the movement of the membrane. While PA material must have not only low fuel permeability but also strong adhesion with the structural material of PE. We also clarify the membrane design to keep a good flexibility and to reduce a strain.

This paper contains an explanation of a Multiplex Wiring System with Optical Data-Link for cars, which has been installed in the Toyota “Century” since 1982. In this system, a total of 64 signals related to door wiring are transmitted in a multiplex fashion, and the number of wires from the front right-hand door to the interior could be reduced from 46 wires, which were used with conventional wiring techniques, to 10 wires including 2 plastic optical fibers. This system also has various control functions which includes a door-lock control function. In order to give high reliability to this system, we have developed a new optical data-link as well as a new custom micro-computer. And in the automobile industry, such a large scale multiplex wiring system having high reliability is very innovative in our opinion and will surely have a large impact in the future.

It is important to reduce the viscosity of automatic transmission fluid (ATF) in order to improve fuel economy. However, in general, low viscosity fluid can cause metal fatigue, wear, and seizure. It is necessary to increase the viscosity of the fluid at higher temperatures to maintain the durability of the automatic transmission (AT). The key point is the selection of the base oil and the viscosity index improver (VII) with both a high viscosity index (VI) and excellent shear stability. On the basis of this concept, a new generation high performance ATF named WS was developed. WS can achieve the highest level of fuel economy, while maintaining the durability of the AT.

In the field of automotive gasoline engines, new products aiming at greater fuel economy and cleaner exhaust gases are under development with the aim of preventing environmental destruction. Severe ignition environments such as lean combustion, stronger charge motion, and large quantities of EGR require ever greater combustion stability. In an effort to meet these requirements, an iridium plug has been developed that achieves high ignitability and long service life through reduction of its diameter, using a highly wear-resistant iridium alloy as the center electrode.(1)(2) Recently, direct injection engines have attracted attention. In stratified combustion, a feature of the direct injection engine, the introduction of rich air-fuel mixtures in the vicinity of the plug ignition region tends to cause carbon fouling. This necessitates plug carbon fouling resistance.

We developed a new Manual Transmission Gear Oil (MTF) named LV for improved fuel economy and CO2 reduction. MTF LV is a low viscosity fluid to reduce stir losses at lower temperatures. In general, low viscosity fluids can cause metal fatigue, wear and seizure. The MTF LV was designed to overcome these problems by maintaining the oil film thickness after it is deteriorated and improving the wear characteristics with additives. As a result, the MTF LV provides equal or better durability than the current MTF. In addition, it also has good performance at low temperatures, better shift feeling characteristics, and improved oxidation stability.

The shock absorber of suspension has two important basic functions. One is to control vehicle attitude changes when steering and when accelerating and decelerating, and the other is to dampen forces transmitted from the road by its damping effect, thus softening shocks. The characteristics of these two demands in performance, driving stability and riding comfort, conflict with each other but are selected from the concept of a car and from coaching by users. Namely, someone puts stress on driving stability and the other puts stress on riding comfort. Electronics have advanced in recent years and the use of electronic absorber control systems in order to achieve both driving stability and riding comfort has become widespread first of all in Japanese vehicles and also in European and American vehicles. Toyota first developed its TEMS (TOYOTA ELECTRONIC MODULATED SUSPENSION) in 1983 (1) and since then many improvements have been added.

We have developed a new measurement apparatus designed to take orange-peel quality-assessment measurements of paint-finished surfaces on a non-contact basis. This apparatus was developed to determine the relationship between in-line spray-coating conditions and the resulting orange peel surface, and to optimally control/manage the conditions of our existing facilities to ensure the best possible coating results based on the obtained data. The apparatus has been implemented by adopting image analysis, which combines an optical system design based on human inspectors’ visual-checking conditions and a set of straightforward algorithms.

A new, free-cutting steel, hereafter referred to as “non-lead-added free-cutting steel”, has been developed with the intention of replacing currently applied lead containing free cutting steel. The ultimate goal of this project is to provide a new lead-free steel grade that will contribute to the removal of environmentally harmful substances from automobile parts. In this project, we have targeted the development of a material that would demonstrate levels of machinability and other mechanical properties equivalent to those of the conventional free-cutting steel to which sulfur (S), lead (Pb) and calcium (Ca) or combinations, thereof have been added. The fine dispersion of sulfide, modified by adding Mg and Ca, is most effective in enhancing the chip breakability that would otherwise deteriorate due to the absence of lead. The practical application of the non-lead-added free-cutting steel has rendered the goal of total removal of lead from special steel products highly obtainable.

In developing an oxidation catalyst for reducing diesel particulates, it is necessary to balance two conflicting characteristics. One is high oxidizing activity so that the catalyst can reduce the Soluble Organic Fraction (SOF) efficiency even at low exhaust temperatures. The other is the suppression of sulphate formation at high exhaust temperatures. First it was studied that active metals and coating materials are given effects on the reduction of SOF, the formulation of sulphate and durability, by using catalysts equivalent in composition to the oxidation catalyst for gasoline-engines. Based on these findings, a two-stage catalyst wasdeveloped. It satisfies the two characteristics at a comparatively high levelby slecting materials and optimizing the catalyst composition.

In October 1998, a new mass-produced car with titanium engine-valves was released from TOYOTA Motor Corporation. Both intake and exhaust valves were manufactured via a newly developed cost-effective P/M forging process. Furthermore, the material which was specially designed for the exhaust one is a unique titanium metal matrix composite (MMC). This paper discusses the materials and manufacturing methods used. The tensile, fatigue strength and creep resistance of the MMC are always superior to those for the typical heat-resistant steel of 21-4N. Both valves have achieved sufficient durability and reliability with a manufacturing cost acceptable for mass-produced automobile parts.

In automotive plastic parts, bumpers are rather bigger parts and easy to be detached. And there is growing need to develop bumpers recycling technology. Now we developed the recycling technology for waste painted Super Olefin Polymer (SOP) bumpers from car dealers in production. This technology consists of discriminating from the repair in market by dyeing, and of melting SOP resin and hydrolysis of the paint film which are carried out simultaneously in a twin-screw extruder Reactive Processing System.

We have developed a new semi-active suspension, called Piezo TEMS, that uses piezoelectric ceramic for suspension control with sensor and actuator. It improves remarkably driveability with the firm damping force mode and enhances the ride comfort with the soft damping force mode immediately after the road surface input exceeding the threshold level.

Newly designed gears are subject to higher loads that demand a steel that is capable of greater pitting resistance. The application of shot peening to gears has been increasing to improve tooth root strength, but pitting resistance had not been necessarily high. This study examines the effect of alloying additions mainly on tempering resistance and the formation of a non-martensitic layer. The developed high Si-Mo type steel shows excellent pitting resistance, even in shot peened gears, as compared to that of conventional steels due to high tempering resistance and the thin, uniform non-martensitic layer. This new steel is of practical use in some multi-speed automatic transmission gears.

In preparation for compliance with California's SULEV standard and Euro STAGE 4 standard, which will take effect in 2002 and 2005, respectively, we have developed a laminated planar oxygen sensor. The developed sensor has the following characteristics: high thermal conductivity and superior dielectric characteristic, due to direct joining of the heater element alumina substrate and the sensor element zirconia electrolyte; low heat stress at temperature rise, due to optimized heater design; superior sensor protection from water droplets, and improved sensor response, due to optimized arrangement of intake holes in the sensor cover. With these characteristics, the developed oxygen sensor can be activated in 10 seconds after cold start. This report describes the technologies we used to develop the early-activation oxygen sensor.

In comparison with conventional hot forging process, powder forging process has much advantage such as good dimensional accuracy, minimum scattering of weight, etc. In spite of much advantage, the powder forged parts have not been mass-produced except for relatively simple shape parts because of technical and economic problems such as low productivity. Solving these problems, powder forging process was applied to connecting rods which required fatigue strength and minimum scattering of weight, and which were complex in shape. As a result, for the first time in the world, mass-production of powder forged connecting rods was carried out, and its properties are as follows; (1) Sufficient fatigue strength (2) Minimum scattering of weight (3) Good dimensional accuracy

The transfer efficiency for painting processes utilizing water-borne materials is low, and the residual paint is disposed of as waste. In this study, we focused on a recycling system to collect and dissolve the paint over-spray in the booth water, and to concentrate and regenerate it by means of an ultra filter (UF). Paint adaptable to the recycling system has been developed by providing compatibility between the high hydrophilicity of liquid paint and the high hydrophobicity of the paint film, in order to ensure the recyclability and the high anti-corrosion performance required of paint on automobile underbody parts. This recycling technology is used in an actual propeller shaft painting process and provides large waste reduction and a decrease in painting cost.

Public awareness toward the environment has been increasing recently. Accordingly, volatile organic compounds from automotive coating processes must be decreased to protect the environment. Various environmental regulations are already being enforced in many countries and it's expected that the rules will become tighter every year. For this reason, the usage of waterborne basecoats has increased recently. But the introduction of waterborne basecoats has some difficulties such as the requirement of strict temperature and humidity control. So, the application of waterborne basecoats has been inferior to that of solventborne basecoats. We have conducted an investigation, putting emphasis on the viscosity characteristics of waterborne basecoats and reached the conclusion that the following factors are important for applying waterborne basecoats: During spray application, the paint indicates shear thinning behavior.

The camshaft for an automobile engine is generally made of chilled cast iron. Due to increasing demand for higher performance, lawer maintenance and better fuel economy, it is difficult to make the cast iron camshaft lighter and/or more durable. In order to overcome these problems, development of an integral camshaft comprised of a sintered alloy cam piece for better wear resistance and steel tube for weight saving has been accomplished. In 1981 Toyota Motor Corporation successively started the mass-production of the sintered intergral camshaft for the new 1.8 liter ls engine. The significant advantages are as follows; (1) Weight saving (2) Excellent wear resistance (3) Improvement of lubrication system (4) Saving machining cost

The EMT (Elastomer Modified Thermoplastics) currently used in passenger car bumper fascia are limited in retaining low CLTE (Coefficient of Linear Thermal Expansion) and impact resistance, although they are highly rigid, which allows a reduction in weight, and also have high flowability during injection molding. We have developed a new bumper material called “Super Olefin Polymer” using a unique theory based upon a reversal of the current concept. The current polymer design concept of the EMT material is to compound and disperse the EPR (Ethylene Propylene Rubber) into the resin matrix such as polypropylene. We reversed the domain and the matrix, and treated the resin phase as the filler and the elastomer phase as the matrix.

Automotive Shredder Residue (ASR), the waste generated by shredding operations in the recycling of metals from scrapped automobiles, is currently disposed of in landfill sites. In Japan, disposal regulations such as leachable lead control have been changed, and moreover landfill sites are getting scarce. Therefore how to control, treat and decrease ASR is a serious matter. This study presents methods for the recycling of automotive shredder residue into automobile components by dry mechanical processing steps. These steps sort the material into several categories accrding to its properties. The material fineness is improved by further, thorough, sorting steps.