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A new wind tunnel was developed and adopted by Toyota Motor Corporation in March 2013. This wind tunnel is equipped with a 5-belt rolling road system with a platform balance that enables the flow simulation under the floor and around the tires in on-road conditions. It also minimizes the characteristic pulsation that occurs in wind tunnels to enable the evaluation of unsteady aerodynamic performance aspects. This paper describes the technology developed for this new wind tunnel and its performance verification results. In addition, after verifying the stand-alone performance of the wind tunnel, a vehicle was placed in the tunnel to verify the utility of the wind tunnel performance. Tests simulated flow fields around the vehicle in on-road conditions and confirmed that the wind tunnel is capable of evaluating unsteady flows.

This research developed a new measurement technology for thermal analysis of the heat radiation from a hybrid transaxle case surface to the air and improved the heat radiation performance. This heat flux measurement technology provides the method to measure heat flux without wiring of sensors. The method does not have effects of wiring on the temperature field and the flow field unlike the conventional methods. Therefore, multipoint measurement of heat flux on the case surface was enabled, and the distribution of heat flux was quantified. To measure heat flux, thermal resistances made of plastic plates were attached to the case surface and the infrared thermography was used for the temperature measurement. The preliminary examination was performed to confirm the accuracy of the thermal evaluation through heat flux measurement. The oil in the transaxle was heated and the amount of heat radiation from the case surface was measured.

Previous studies and recent practical aerodynamic evaluations have shown that aerodynamic drag of passenger vehicles with “ground simulation” with moving ground and rotating wheels may increase in some cases and decrease in other cases relative to the fixed ground and stationary wheel conditions. Accordingly, the effects of the ground simulation on the aerodynamic drag should be deeply understood for further drag reduction. Although the previous studies demonstrated what is changed by the ground simulation, the reason for the change has not been fully understood. In this article, the effects of wheels and wheel houses attachment and those by the ground simulation with ground movement and wheel rotation on the aerodynamic drag were investigated by quantification of the underfloor flow that plays a crucially important role on the formation of vortical structure around vehicles.

A high reliability and low cost temperature sensor for motor vehicle has been developed. The principle of measuring temperature is based on the NTC thermistor. And novel production techniques for sealing and electric connection are presented.

This research proposes an automatic measuring method for the impulse noise of the valve system in engine production line. This research is composed of the following two parts. (1) The most suitable method for indicating the impulse noise of the valve system - the representative characteristic values - is selected from the general measuring methods for impulse noise. As the result, the crest factor in the frequency band above 1kHz became optimal. (2) By detailed sensory characteristic analysis it was found that impulse noise can be heard better with increasing frequency and that there is little influence in the frequency band with the same frequency as the background noise. Thus the crest factor was obtained for each frequency, and the sensory test for the impulse noise of the valve system is deduced by this linear coupling. As the result of multiple reguression analysis, a high accuracy prediction equetion with a multiple correlation coefficient of 0.91 has been obtained.

This paper describes the development of one-piece die cast magnesium steering wheel frame for a steering wheel incorporating an air bag system. The light weight magnesium frame was designed to have proper stiffness, strength and characteristics of energy absorption. Magnesium alloys with various aluminum contents were tested, and AM60B alloy was selected because of its favorable properties of strength and elongation. New manufacturing techniques, for example, a vacuum hot chamber die casting system and a surface defect inspection system were developed in order to produce high quality castings. The characteristics of energy absorption were evaluated in the laboratory and on actual vehicle crash test, and the results were satisfactory. The magnesium steering wheel frame is about 45% (550g) lighter than the steel one. It has been in production in Toyota passenger cars with driver side air bags.

This paper describes a new plastic coloring and forming system. The system greatly reduces the time and amount of raw materials necessary for color changes, and eliminates the need for manual cleaning during a color change. This system is well-suited for small-lot production with frequent color changes, as well as for automated production systems. The system is being used by auto parts makers, and is practical in a variety of other fields involved with the coloring and forming of plastics.

An unprecedented phenomenon that achieves high NOx conversion was found over an NSR catalyst. This phenomenon occurs when continuous short cycle injections of hydrocarbons (HCs) are supplied at a predetermined concentration in lean conditions. Furthermore, this phenomenon has a wider range of applicability for different catalyst temperatures (up to 800 degrees Celsius) and SVs, and for extending thermal and sulfur durability than a conventional NOx storage and reduction system. This paper analyzes the reaction mechanism and concludes it to be highly active HC-deNOx by intermediates generated from adsorbed NOx over the base catalysts and HCs partially oxidized by oscillated HC injection. Subsequently, a high performance deNOx system named Di-Air (diesel NOx aftertreatment by adsorbed intermediate reductants) was demonstrated that applies this concept to high speed driving cycles.

A new test machine has been developed which can evaluate vibration due to stick-slip using an actual full-scale clutch pack. Using this machine, a static breakaway friction coefficient measurement test method and a stick-slip test method have been established. Both methods have been shown to provide results which correlate with the results from both a full-scale assembly test and a vehicle shudder evaluation test. The evaluation of the frictional properties of commercial oils using these test methods showed that the static breakaway friction coefficient and the stick-slip properties have generally contradictory performance to each other for automatic transmission. The study of the frictional properties for typical additives and an analysis of the surface of the steel plates with ESCA (Electron Spectroscopy for Chemical Analysis) showed that the frictional properties are significantly affected by the additives adsorbed on the clutch plate sliding surface.

In today's manufacturing environment, it has become necessary to develop intelligent robots which are adaptable to changing process requirements. To attain this goal, a key robot technology involving new real time control algorithms has been developed. The algorithms govern the 3D position and orientation of the robot. Initially, a simulation method was used to study the achievable system accuracy. From the results of computer simulations, it was determined that the algorithms can achieve a high tracking accuracy of ± 0.5 mm at a velocity of 300 mm/sec (4 times higher than conventional sensory control speeds). For a sensory feedback system, delays in tracking movements are inherent. This is due to the calculation time required for control and to the servo response. To solve this problem, a sensor is positioned at a predetermined distance in advance of the tool in the direction of travel.

The behavior of spray injections to turbulent duct flows from a slit injector for direct-injection gasoline engines was investigated using a combination of large eddy simulation (LES) and Lagrangian discrete droplet model (DDM). As a result, diffusion of droplets in stronger turbulent flows was observed at a later stage of the injection. Moreover, we compared calculation and experimental results by generating a pseudo-particle image from the calculation result.

The structure of HCCI (homogeneous charge compression ignition) combustion flames was quantitatively analyzed by measuring the two-dimensional gas temperature distribution using phosphor thermometry. It was found from the relation between a turbulent Reynolds number and Karlovitz number that, when compared with the flame propagation in an S.I. engine, HCCI combustion has a wider flame structure with respect to the turbulence scale. As a result of our experimentation for the influence of low temperature reaction (LTR) using two types of fuel, it was also confirmed that different types of fuel produce different histories of flame kernel structure.

This paper describes the development of alloy cast iron that can be used for the cutting edges of the trimming die of a press die. Usually, a block of tool steel or steel casting is inserted at the cutting edge of the trimming die of a press die. However, we unified the structure part and the cutting-edge part of a press die with alloy cast iron. As it can''t bear as the cutting edge in this state, the cutting edge is processed by flame-hardening. After the flame- hardening, we developed the alloy cast iron so that enough hardness may be obtained by natural air cooling. Thereby, the machining of the installation seat of the cutting edge decreased and the expense of dies has been reduced.

Model-Based Development (MBD) has become an automotive industry standard process in vehicle control systems development due to the potential to reduce development time and improve engineering quality. This has become even more important as control systems are becoming increasingly complex while development cycle timelines shorten. Toyota utilized Hardware-in-the-Loop Simulations (HILS) techniques when developing the latest Fuel Cell Hybrid Vehicle, FCHV-adv. These MBD techniques contributed to the overall development process, but applications were limited to verifying control specifications. It was recognized that if MBD could be utilized beyond its current role in the control system design process to include functional specification validation, specification quality could be improved while decreasing development time and cost.

Mass reduction of parts is growing in importance as a means for reducing CO2 emissions from vehicles.The aim of the present research was to contribute to further mass reduction of pistons by developing a new aluminum casting material with highest level of fatigue strength. This goal was achieved using a development concept of creating a homogeneous structure in which Ti was added to create a fine structure and appropriate quantities of Fe and Mn were added to form a compound that is stable at high temperatures. Stand-alone tests of prototype pistons fabricated using the developed material show that the material is 14% stronger than the conventional material, thereby enabling increases in power and mass reduction.

We have developed a New Black-face Cluster with Transparent EL Display, positioned on the speedometer, to display driver support information within the cluster; mass production of this DUAL VISION CLUSTER commenced in September 1999. The following were two requirements for implementing this cluster. 1) Selection of display device 2) Positioning of cluster in front of speedometer, using Transparent EL Display In this session, we will explain how we resolved the issues involved in development of this new Black-face Cluster. We will also describe the structure of the cluster.

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.

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.

Two effects of rich-spike duration on NOx-storing have been analyzed. The first one, that NOx-storing speed decreases as rich-spike duration increases, is explained as the influence of NOx diffusion in wash-coat layer, which is quantified by a simple mathematical expression for NOx-storing rate. The second one, a peculiar behavior of NOx-storing in appearance of the outlet NOx concentration, is clarified: Heat produced directly or indirectly (via oxygen storage in ceria) by rich-spike warms up the downstream part, which releases excess NOx at the raised temperature. Contributions of the oxygen storage and the carbonate of NOx-storage material are also discussed.

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.