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In order to correspond to the exhaust emissions regulations that become severe every year, more advanced engine control becomes necessary. Engine engineers are concerned about the Hydrocarbons (HCs) that flow through the air-intake ports and that are difficult to precisely control. The main sources of the HCs are, the canister purge, PCV, back-flow gas through the intake valves, and Air / Fuel ratio (A/F) may be aggravated when they flow into the combustion chambers. The influences HCs give on the A/F may also grow even greater, which is due to the increasingly stringent EVAP emission regulations, by more effective ventilation in the crankcase, and also by the growth of the VVT-operated angle and timing, respectively. In order to control the A/F more correctly, it is important to estimate the amount of HCs that are difficult to manage, and seek for suitable controls over fuel injection and so on.

A multi-dimensional numerical method for predicting the warm-up characteristic of automobile catalytic converter systems was developed to effectively design catalytic converter systems which achieve low tail pipe emissions with satisfactory packagebility. The features of the method are; (1) consideration of the governing phenomena such as gas flow, heat transfer, and chemical reactions (2) capability of predicting warm-up characteristic for not only the catalytic converters but also the system as a whole during emission test modes such as the USA LA-4 mode. The description of the method is presented. The experimental verifications of the method were conducted to assure the accuracy of it. The effect of design parameters such as electrically heated catalyst (EHC), high loading of noble metal and thin honeycomb wall on warm-up characteristic of the catalyst are analyzed in the paper.

A new 4.5 liter in-line 6 cylinder engine,1 FZ-FE has been developed for the Toyota Land Cruiser. To obtain high power, fuel efficient engine, we adopted the most advanced Toyota technologies, such as Toyota original 4 Valve DOHC system with scissors gear between camshafts, compact combustion chamber with smooth inlet and outlet system, KCS and so on. The engine produces 212 HP at 4600 rpm and 275 ft-lbs at 3200 rpm. Aluminum cylinder head,short skirt cylinder block stiffened with aluminum oil pan give the engine light weight and make it rigid enough to have low vibration and quietness. And we also designed every engine part appropriately so as to make the engine durable enough in severe operating condition of off-road vehicle.

A new proportional collection system for extremely low tailpipe emission measurement in transient conditions has been developed. The new system can continuously sample a minute flow of exhaust gas, at a rate that is proportional to the engine exhaust rate. A zero grade gas dilution technique is utilized to prevent the influence of pollutants in atmospheric air that are the same concentration level as those in the exhaust gas. The system has accuracy within ±5%. For the direct exhaust gas flow meter, a pitot tube type flow meter is utilized as it is simple, heat resistant, sufficiently accurate and has low flow-resistance characteristic. For the collection and dilution controllers, two mass flow controllers (MFC) were adopted. The MFCs' output can be adversely influenced by variation of the specific heat of the sample gas, resulting in flow reporting error.

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 the field of automobile disk wheels, demands for aluminum wheels have been increasing for the reason of ride comfort and better appearance. And over 90 percent of luxurious passenger cars are equipped with aluminum wheels. This trend is spurred also by the demand for higher fuel efficiency for the cause of environmental protection, which calls for weight reduction of automobiles. This paper reports our research on manufacturing light-weight, high-quality aluminum cast wheels; covering the entire process from basic design to casting, and placing emphasis on the following three points. 1) Determination of optimum wheel configuration through computer simulation 2) Selection of optimum material composition 3) Optimization of the thin plate casting conditions Combination of the above technologies developed for the purpose of weight reduction resulted in the weight reduction of approximately 20% over the conventional aluminum wheels.

Methyl esters of saturated/unsaturated higher aliphatic acids (FAMEs) and a FAME of waste cooking oil (WCOME) were heated at 120°C in an air gas flow. The samples were analyzed before and after heating, using six different methods including electrospray ionization mass spectrometry. As a result, the samples after heating were found to contain low molecular weight aliphatic compounds and oligomers of the FAME. Based on the chemical structure of these oxidation products, reaction schemes were proposed for the deterioration of FAMEs. In addition, two unsaturated FAMEs containing 2,6-di-t-butyl-p-cresol (BHT) were similarly heated and analyzed to examine the effect of BHT on the oxidation of these FAME.

Sintered silicon nitride, particularly in structural ceramics, has superior properties such as low weight, heat resistance, wear resistance, etc. It is already being applied to automobile engine parts such as the swirl chamber and the turbine rotor. In recent years, the strength of silicon nitride has shown to be above 1000MPa. This has been achieved through advances in manufacturing technology such as materials powder, forming, sintering and so on. But the silicon nitride is easily damaged during grinding because it has less fracture toughness than metal. Consequently, the inherent strength of the material is not demonstrated in the actual products presently produced. It is assumed that the main cause of strength reduction is microcrack. In ordinary grinding methods, the length of microcrack has been estimated at approximately twenty micrometers by fracture mechanics analysis.

The anti-shudder effect of ATF additives and their mechanisms have been investigated. Anti-shudder durability was evaluated using an automatic transmission (AT) on an engine stand under continuously slip-controlled condition. The addition of over-based Ca-sulfonate and friction modifier (FM) remarkably improved the anti-shudder durability of ATF. The surface roughness of the contact area (contact area roughness) of the clutch plates was measured by an electron probe surface roughness analyzer. To evaluate the boundary frictional properties of the adsorbed film formed, the friction coefficient of the clutch plates in the absence of oil was examined after the anti-shudder durability test. It was found that shudder occurrence was strongly correlated with the contact area roughness and the boundary frictional property of the steel plate surface. Large contact area roughness and low boundary friction were preferred to prevent shudder.

The recent growth of available computational resources has enabled the automotive industry to utilize unsteady Computational Fluid Dynamics (CFD) for their product development on a regular basis. Over the past years, it has been confirmed that unsteady CFD can accurately simulate the transient flow field around complex geometries. Concerning the aerodynamic properties of road vehicles, the detailed analysis of the transient flow field can help to improve the driving stability. Until now, however, there haven’t been many investigations that successfully identified a specific transient phenomenon from a simulated flow field corresponding to driving stability. This is because the unsteady flow field around a vehicle consists of various time and length scales and is therefore too complex to be analyzed with the same strategies as for steady state results.

A communication system that uses roadside beacons to broadcast road and traffic information and private messages to vehicles has been developed. The system, called Road/Automobile Communication System (RACS), was the result of a joint research project involving the Public Works Research Institute and 25 private-sector corporations. This paper contains an outline of RACS and of an onboard system developed by TOYOTA and presents the results of field tests conducted in the Tokyo area. The results not only verify the capability of the RACS system and the effectiveness of the in-vehicle equipment but also indicate the potential of such a beacon based network to improve traffic jam and driving safety whilst providing enhanced communication facilities without increasing radio-wave congestion.

In recent years Road Departure Mitigation Systems (RDMS) is introduced to the market for avoiding roadway departure collisions. To support the performance testing of the RDMS, the most commonly seen road edge, grass, is studied in this paper for the development of standard surrogate grass. This paper proposes a method for defining the resembling grass color and height features due to significant variations of grass appearances in different seasons, temperatures and environments. Randomly selected Google Street View images with grass road edges are gathered and analyzed. Image processing techniques are deployed to obtain the grass color distributions. The height of the grass is determined by referencing the gathered images with measured grass heights. The representative colors and heights of grass are derived as the specifications of surrogate grass for the standard evaluation of RDMS.

This paper investigates a new approach to the quantification technique for road induced vehicle interior noise and vibration within the frequency range up to 40 Hz. By employing the least squares method, both vertical and fore-aft load to each wheel were quantified using transfer function and actual vibration response of the vehicle driven on a road. The coupled structural-acoustic vehicle model using the finite element method, which is also detailed in this paper, is combined with the quantified input load to simulate road induced interior noise and vibration response. Experimental verification, which indicates reasonable accuracy of the simulation, and an application for the prototype development are also presented.

Countries and regions around the world are tightening emissions regulations in reaction to the increasing awareness of environmental conservation. At the same time, growing concerns about the depletion of raw materials as vehicle ownership continues to increase is prompting automakers to look for ways of decreasing the use of platinum-group metals (PGMs) in the exhaust systems. This research has developed a new catalyst with strong robustness against fluctuations in the exhaust gas and excellent nitrogen oxide (NOx) conversion performance. This catalyst incorporates rhodium (Rh) clusters with a particle size of several nanometers, and stabilized CeO2-ZrO2 solid-solution (CZ) with a pyrochlore crystal structure as a high-volume oxygen storage capacity (OSC) material with a slow O2 storage rate.

To more effectively improve the work on a vehicle assembly line, it is desirable to have a method by which the degree of work load on each person can be evaluated quantitatively; enables us to decide the priority order of improvement; and calculates the improvement effect. We developed a quantitative evaluation method of work load by introducing a concept of physiological stress generated regardless of the type of muscles involved. Applying the burden borne by the body to the load evaluation of various assembly operations involved the problem of complex load measuring methods. We solved this problem by categorizing the load conditions for various assembly operations and converting each to a standard state of loads evaluated by experiments.

Recently, there has been a tendency of high power and high speed in automotive engines. In addition they have been also required high reliability. And engine bearings have been required to be advanced in wear resistance as well as seizure resistance. Therefore, copper-lead alloy bearings with overlay, which have better seizure resistance, have been widely used for high speed engines up to the present. But it becomes very important for them to advance the overlay wear resistance. In this paper, the composite overlay is mainly researched to improve wear resistance regarding kind of hard particles and their amounts in the overlay.

Diesel engines with relatively good fuel economy are known as an effective means of reducing CO₂ emissions. It is expected that diesel engines will continue to expand as efforts to slow global warming are intensified. Diesel particulate and NOx reduction system (DPNR), which was first developed in 2003 for introduction in the Japanese and European markets, shows high purification performance which can meet more stringent regulations in the future. However, it is poisoned by sulfur components in exhaust gas derived from fuel and lubricant. We then developed the sulfur trap DPNR with a sulfur trap catalyst that traps sulfur components in the exhaust gas. High purification performance could be achieved with a small amount of platinum group metal (PGM) due to prevention of sulfur poisoning and thermal deterioration.

New ductile cast iron flywheel integrated with gear and its manufacturing process were developed to reduce the manufacturing steps and cost compared with conventional flywheel around which a steel ring gear is fit. In this process, the ring gear teeth around a cast iron flywheel are formed directly in net shape and free from any defect by the hot form-rolling method, followed by the thermomechanical treatment in a short time. The gear is superior to that made by the conventional hobbing and heat treatment in accuracy, strength and anti-wear property.

A new technologies for manufacturing of engine valve seats have been developed. This process, different from the conventional method that valve seats made of sintered alloy were press-fit into the cylinder head, is directly formed valve seats onto cylinder head by using the laser cladding technique. In order to develope the cylinder head with laser cladding valve seats, the laser cladding technology by which copper based alloy is deposited onto aluminum alloy with little dilution and stable bead has been established. And the unique cladding alloy, which is two phases in the liquid stage and in which iron or molybdenum rich hard particles are dispersed in the solid state, has been developed. Based on this technique, the practical process has been successfully completed.

Filiform corrosion phenomenon and its prevention method for 5000 series aluminum alloy sheet have been investigated. The painted aluminum alloy sheets were subject significantly to filiform corrosion caused by formation of a mottled and coarse zinc phosphate film during chemical conversion process. On the other hand, galvanized aluminum alloy sheet showed an uniform and fine phosphate film in a brief time and the filiform corrosion resistance was improved markedly. The test results of press-forming and corrosion for the prototype engine hoods made of this newly developed galvanized sheets have revealed a good formability and an excellent filiform corrosion resistance.