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Vehicle interior wind noise is typically managed through the overall exterior geometry of the vehicle, mirror shape and mounting location, sealing features and glass thickness and damping. Prior research has distinguished between contribution of fluctuating pressure due to air turbulence as compared to acoustic pressure to a passenger vehicles exterior at highway speeds. Because of the large difference in propagation speed between turbulent and acoustic pressure for on-road passenger vehicles, the structural response of the glass to turbulent versus acoustic pressure is not the same. The acoustic coincidence frequency of door glass is typically in the 2-3 kHz range. Turbulent coincidence frequency is much lower, and the effective transmission loss (TL) of the glass depends on the mix of turbulent and acoustic pressure on the exterior surface of the glass.

This paper describes the development of an innovative AWD system called Dynamic Torque Vectoring AWD for all-wheel drive (AWD) vehicles based on a front-wheel drive configuration. The Dynamic Torque Vectoring AWD system helps to achieve high levels of both dynamic performance and fuel efficiency. Significant fuel economy savings are achieved by using a new compact disconnection mechanism at the transfer and rear units, which prevents any unnecessary rotation of the propeller shaft. In addition, the system is also capable of independently distributing torque to the rear wheels by utilizing electronically controlled couplings on the left and right sides of the rear differential. This greatly enhances both on-road cornering performance and off-road driving performance.

The SEA model of wind noise requires the quantification of both the acoustic as well as the turbulent flow contributions to the exterior pressure. The acoustic pressure is difficult to measure because it is usually much lower in amplitude than the turbulent pressure. However, the coupling of the acoustic pressure to the surface vibration is usually much stronger than the turbulent pressure, especially in the acoustic coincidence frequency range. The coupling is determined by the spatial matching between the pressure and the vibration which can be described by the wavenumber spectra. This paper uses measured vibration modes of a vehicle window to determine the coupling to both acoustic and turbulent pressure fields and compares these to the results from an SEA model. The interior acoustic intensity radiating from the window during road tests is also used to validate the results.

In recent years, a number of different Blind Spot Monitor (BSM) systems have become more and more popular in North American automotive market. The BSM system advises the driver of vehicles travelling in adjacent lanes when these vehicles are also in the driver's outside rearview mirror blind spots. Similarly, when the vehicle is backing up from a parking spot, cross-traffic vehicles can be in the driver's outside mirror blind spots. In this situation, the Rear Cross Traffic Alert (RCTA) system alerts the driver when the driver shifts the vehicle in the reverse gear and there are approaching cross-traffic vehicles. The benefits of RCTA system was presented by [1]. The RCTA alert studied in this paper is given by playing an audible sound and by flashing the outside mirror indicators. The RCTA and BSM systems share the same vehicle sensors and most of their vehicle components.

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 full vehicle multi-body dynamic (MBD) model with suspension control system is developed for fatigue life prediction under rough road condition. The model consists of tires, a trimmed body, heavy attached parts, powertrain, suspension, joints, and a driver model, and includes a suspension control system that varies characteristics of the suspension according to the rough road inputs. For tires, a commercial MBD tire model is employed with identifiable parameters. The models are simulated to run on the optically measured road surface of the proving ground. Apart from the trimmed body, several important heavy attached parts are modeled separately, that represent dynamic behavior that induces complex body input load. These parts, along with suspension and powertrain systems are connected to the body using nonlinear elements such as joints, springs, and dampers. Contact conditions are used to represent mount bushing, hood lock, stopper rubber, etc.

In conventional gasoline engine vehicles, three-way catalysts are used to simultaneously remove HC, CO and NOx from the exhaust gas. The effectiveness of the catalyst to remove these harmful species depends strongly on the oxygen concentration in the exhaust gas. Deterioration of three-way catalyst results in a reduction in its purification activity and OSC (oxygen storage capacity). In this investigation, additive elements were used to enhance the durability and OSC of the catalyst support material. An optimized formulation of a CeO2-ZrO2 and a ZrO2 material was developed to have excellent durability, improved OSC, enhanced interaction between precious metals and support materials, and increase thermal stability. Using these newly developed support materials, catalysts with increased performance was designed.

A new rubber recycling technology to produce a thermoplastic elastomer (TPE) based on ethylene-propylene-diene rubber (EPDM) waste was developed. In this technology, the developed process consists of devulcanization of EPDM waste, blending of the devulcanized EPDM and polypropylene (PP), and dynamic vulcanization of the rubber component. All three are set up in as a continuous process in which the Recycled Rubber based Thermoplastic Elastomer (which is indicated as “RR-TPE” henceforth) is finally obtained. The RR-TPE exhibits elasticity and mechanical properties similar to those of commercial Thermoplastic olefins (TPO). These properties may be due to a suitably formed phase structure. Automotive parts are being developed and are going to be produced with the RR-TPE manufactured by this new technology. This technology will contribute to both protecting the environment and saving resources.

In order to further improve the performance of NOx storage-reduction catalysts (NSR catalysts), focus was placed on their high temperature performance deterioration via sulfur poisoning and heat deterioration. The reactions between the basicity or acidity of supports and the storage element, potassium, were analyzed. It was determined that the high temperature performance of NSR catalysts is enhanced by the interaction between potassium and zirconia, which is a basic metal oxide. Also, a new zirconia-titania complex metal oxides was developed to improve high temperature performance and to promote the desorption of sulfur from the supports after aging.

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.

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.

One of the key elements of vehicle safety requires a constantly uninterrupted visible view especially during unexpected weather conditions. Our present development of a light reflection type rain sensor is a key device of our automatic windshield wiper system. The design concept of the sensor is based on the quantification on both detected rainfalls and wiping modes in order to match the wiping mode in an operator's mind by optimizing the optical sensing system and establishing an algorithm for controlling wiping. In addition, auto-initialization of the system has been achieved first in the world.

A method of fatigue life estimation for the spot-welds of vehicle body structures by means of Finite Element Analysis (FEA) was studied. 6 general forces applied to a nugget of spot-weld under multiaxial loads were determined and the Nominal Structural Stress (σns) was calculated from them. It was confirmed that fatigue strength of the spot-welds under various multiaxial loads could be estimated universally by using σns. Based on the theory of elasticity of plates, stress of spot-weld nugget was analyzed. The theoretical equations for determining the principal stress at the nugget edge from6 general forces acting on a nugget were derived. And the principal stress was defined as the σns. The value of σns was determined by FEM that used a solid model and compared with the theoretical calculation value. They agreed quite well. Fatigue tests of DC specimens under various multiaxial loads (shear plus cross tension and tensile shear plus torsion) were conducted.

Two-layered surface materials composed of a thermoplastic olefin elastomer (TPO) skin and a cross-linked polypropylene (PP)foam are increasingly replacing the conventional PVC skin/PVC foam for interior trims. In the past, recycled material obtained by melt-blending TPO skin and PP foam could not be re-used for TPO skin because of its appearance. A new recycling technology using the reaction biaxial extruder with a reaction agent can decompose the network structure of PP foam. As a result, PP foam is dispersed into TPO uniformly and the recycled material has properties and an appearance similar to virgin TPO. These new properties may allow the application of the recycled material as a surface material.

So far in conventional automotive meter, reflection of the incident light on a cover glass is prevented by a hood and a curved cover glass. Anti-reflection coating (hereafter abbreviated as AR coating) on the surface of cover glass can offer a meter without the hood. Thin films of AR coating are uniformly deposited on a large polymethylmethacrylate substrate in an ambient atmosphere by sol-gel dip coating and cured at low temperature. The AR coated panel shows a very low reflectance. In addition, the AR coating has a high reliability for the instrument panels of automobiles. The AR coating meter offers new instrument panel design for Toyota Prius.

In a stage of designing a CVJ boot, analytic conditions of FEA method are established so that values calculated with the FEA method coincide with the actually measured values. This has made it possible to predict the life of the boot under bench testing. Furthermore, the boot field life can also be predicted by the minor rule based on the joint-angle frequencies of a vehicle. As a result, it has become possible to determine an optimal configuration in the design stage and to decrease the number of test cycles, resulting in reduced development lead time.

A slip-controlled lock-up clutch system Is very efficient in improving the fuel economy of automatic transmission (AT) equipped vehicles. However, a special automatic transmission fluid (ATF) which combines an anti-shudder property with high torque capacity is required for this system. In this study, we established additive technology for ATF having a sufficient anti-shudder property and high torque capacity. Based on the technology, new ATF: ATF-T4 was developed. It was confirmed in actual AT tests that ATF-T4 has excellent anti-shudder durability and high torque capacity. Furthermore, ATF-T4 has good SAE No. 2 friction characteristics, oxidation stability, compatibility with materials (elastomers, nylons, etc.) and viscosity at low temperatures.

Airflow effect is one of the important functions demanded of a rear spoiler. It helps prevent mud or dust from swirling up behind the running vehicle, or in the case of driving in the rain or snow, helps prevent rain or snow from adhering to the rear window. During the design process, we often decide on the shape of a spoiler in a relatively short time, focusing primarily on its appearance. Therefore, we established a design method using the recently developed computational fluid dynamics (CFD) to determine the central cross sectional shape of a spoiler that produces a desired airflow effect. We verified its effectiveness through testing.

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.

Conventionally, sound insulation materials have been applied to control interior noise above 500 Hz, and damping materials to control interior noise below 500 Hz. In this paper, the noise control component for vehicle panels, which consists of damping material and sound insulation material, is investigated by using a two-degrees-of-freedom system. The investigation shows that sound insulation material can be effective in reducing interior noise below 500 Hz if its stiffness is reduced. This stiffness depends not only on the spring of the material itself but also on its pneumatic spring which is determined by air-flow resistance. This paper concludes with applications of techniques to reduce interior noise below 500 Hz by improving sound insulation materials.