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The rotary engine provides high power density compared to piston engine, but one of its downside is higher oil consumption. In order to better understand oil transport, a laser induced fluorescence technique is used to visualize oil motion on the side of the rotor during engine operation. Oil transport from both metered oil and internal oil is observed. Starting from inside, oil accumulates in the rotor land during inward motion of the rotor created by its eccentric motion. Oil seals are then scraping the oil outward due to seal-housing clearance asymmetry between inward and outward motion. Cut-off seal does not provide an additional barrier to internal oil consumption. Internal oil then mixes with metered oil brought to the side of the rotor by gas leakage. Oil is finally pushed outward by centrifugal force, passes the side seals, and is thrown off in the combustion chamber.

Understanding of the oil film formation mechanism around a piston skirt is very important to reduce the friction loss at piston skirt. We have investigated lubricant oil film behavior around piston skirt which is affected by piston slap under motoring condition. In this study, a cylinder liner of a commercial engine is displaced with a quartz cylinder. Photographic observations of oil film behavior between the cylinder liner and the piston skirt were performed with two kinds of methods; direct monochromatic photography and LIF (Laser Induced Fluorescence) image using a high speed camera. The oil film distributions were determined from oil boundary observed by the direct photography, and oil film thickness was estimated from the LIF intensity. Differences of the oil film distributions and the oil film thickness depending on piston shapes were investigated for four types of pistons.

A structure which effectively improves compatibility in a vehicle-to-vehicle frontal impact has been considered focusing on sub-frame structure that disperses applied force with multiple load paths. Evolved sub-frame structure has been studied by CAE with RADIOSS to search the possibility to reduce aggressivity and to improve self-protection at the same time. Vehicle models used for this compatibility study were a large saloon car with sub-frame and a small family car without sub-frame. The large saloon car had three different front structures: original, forward-extended sub-frame, and original with 25%-stiffness reduced structures. The types of collision contained four different crash modes in a combination of lateral overlap rate difference and side member height difference.

A system for stratifying recycled exhaust gas (EGR) to substantially increase dilution tolerance has been applied to a port injected four-valve gasoline engine. This system, known as Combustion Control through Vortex Stratification (CCVS), has shown greatly improved fuel consumption at a stoichiometric air/fuel ratio. Both burnrate (10-90% burn angle) and HC emissions are almost completely insensitive to EGR up to best economy EGR rate. Cycle to cycle combustion variation is also excellent with a coefficient of variation of IMEP of less than 2% at best economy EGR rate. This paper describes a research programme aimed at gaining a better understanding of the in-cylinder processes in this combustion system.

The thermal fluid field in a vehicle cabin model is analyzed by the mesh free method as well as mentioned in the Part 1. This paper focuses on the steady state indoor climate in the vehicle cabin including the effect of the buoyancy, the heat generation of the driver and heat conduction through the vehicle body surface under the maximum air-cooling condition soaked in a climate chamber in the summer condition for the demonstration of the mesh free method without not only the deformation of the 3D-CAD model but mesh generation. The solar radiation distribution and heat generation through the exhaust pipe from the engine room are simply included in the analysis. Simulated results are compared with experiments in the conditions of both moving and idling states. As a result, no significant difference in air temperature between simulation and experiments can be obtained in both conditions.

A brief study has been undertaken with exhaust gas recirculation (EGR) applied to a prototype low emission, heavy duty, direct injection (DI) diesel engine aimed at evaluating the potential for low nitrogen oxide (NOx) emissions. By virtue of the very low smoke levels achieved with the prototype engine, EGR can be applied at full load for substantial reductions in NOx down to c. 2.5 g/kWh (1.9 g/hph) over the European R-49 13-Mode test. These results were achieved with competitive particulates and fuel consumption and without recourse to engine de-rating. Compliance with the NOx emissions proposed for the year 2000 Japanese market was also demonstrated. These results are summarised in this paper and justify the need for a major research programme aimed at demonstrating the full potential of using EGR to develop a fuel efficient, low emission truck engine concept for the 1990's and beyond.

In order to investigate the corrosion resistance of organic composite-coated steel sheets ( OCS ) in a real automotive environment, many kinds of corrosion tests were performed on test pieces and real automotive doors. Tests with a corrosive solution including iron rust were introduced to simulate the real corrosive environment of automotive doors. The relationship between the components of OCS and the corrosion resistance in the rust-including tests was examined. In addition, electrochemical studies were performed. Results indicate OCS has much better corrosion resistance than plated steel sheets with heavier coating weight in all tests. OCS shows excellent corrosion resistance in rust-free corrosive solution, however, some types of OCS do have corrosion concerns in rust-including tests. It became clear that these OCS types have an organic coating with lower cross-linking.

The supercharged diesel engine with a pressure wave supercharger (PWS) has achieved a high torque over the entire speed range in a quick response while maintaining the low fuel consumption as a small diesel engine. This is the result of adopting a high efficient supercharger based on the unique construction of PWS. Lower inlet and exhaust flow resistance, earlier inlet-close timing, etc., are specially important for engine with PWS. Another advantage is less unturned fuel emissions.

Mazda has been pursuing the research of side exhaust porting for its rotary engine in an effort to improve the engine's fuel efficiency and exhaust emissions characteristics. The side exhaust porting configuration provides greater flexibility in setting port timing and shape, as compared to the peripheral exhaust porting configuration, which is in use in the current-generation rotary engines; the side exhaust porting configuration enables the selection of a port timing more favorable to reduced fuel consumption and exhaust emissions. The side exhaust port rotary engine used in this research has its exhaust port closure timing around the top dead center (TDC) and has no intake-exhaust timing overlap. As a result, burnt gasses entering the next cycle of combustion are reduced, thus enhancing combustion stability; also, the air-fuel ratio can be set leaner for improved fuel consumption.

Both NOx and unburned HC were reduced by changing the direction of the flame propagation. It is generally said that the optimum ignition position of spark ignition engine is in the center of combustion chamber. However by igniting arround the chamber and propagating the flame toward the center, a smooth heat release pattern due to the decrease in the flame area and a decrease in the unburned gas entering the ring crevise can be anticipated. These effects of this combustion process, which was named the surrounding combustion process (SCP), were experimntally confirmed using the constant volume combustion vessels and the spark ignition engine equipped with six spark plugs per cylinder. Next, the steps for decreasing the number of ignitions TCre considered, and additional three spark plugs for SCP were installed in the four valve pentroof combustion chamber. With this engine, the NOx reduction and the capability of SCP to further improve the lean burn engine fuel economy were confirmed.

To coat flexible parts such as R-RIM Urethane Fascia baked at low temperatures, a different painting approach from one for steel parts is employed. Since paint color differences between the fascia and the body would downgrade the product, a color matching technique is required. For better color matching, matching of color shades was attempted with improvement of paint resin, optimal pigment blending and analysis of how color is affected by varying conditions. Application of a primer for finishing has brought about the desired paint film distinctness. Introduced was also the high weatherablilty paint for plastic parts. All such techniques were utilized on R-RIM Urethane Fascia to achieve high-grade color matching.

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.

Speciated hydrocarbon emissions were measured at steady-state conditions in pre- and post-catalyst exhaust from a modern multi-valve fuel-injected and closed-loop controlled European gasoline engine tested on toluene, isooctane and diisobutylene. Unburned fuel contributed 70-80% of the total engine-out hydrocarbon emissions on toluene, but only 24% and <10% on isooctane and diisobutylene respectively except at idle where values were 71% and 47% respectively. Emissions from both of the aliphatic fuels were dominated by photochemically-reactive olefins such as isobutene and propene, plus ethyne, methane and formaldehyde. With the exception of ethyne, emissions of these compounds were much less from toluene. Even at rich conditions, most hydrocarbons were catalytically controlled to some extent, but the catalyst efficiency was dependant upon hydrocarbon composition.

An investigation into the application of electronically controlled solenoid activated high pressure in-cylinder gasoline injection systems has been carried out in both conventional and novel four-valve four-stroke pent-roof chamber single-cylinder engines. Air motion requirements were studied and their effects on port design and layout were assessed. Alternative injector types, locations and spray characteristics were investigated. Transient and steady-state comparisons of the engines were made under both normal and cold running conditions. The outlook for the use of in-cylinder injection technology compatible with ULEV emissions requirements is discussed in the light of the results obtained.

To gain a better understanding of the exhaust emissions impact of olefins in a low aromatic, full boiling range gasoline, an evaluation of the before and after catalyst emissions of three highly olefinic refinery streams and three highly paraffinic refinery streams, blended 50/50 in motor alkylate, was conducted using a 3.1 L GM engine. The test fuels were also selected to consider the effects of volatility in addition to olefin concentration. The fuels were evaluated under three steady state engine operating conditions. The results of the tests indicate essentially only small differences in the before and after catalyst total hydrocarbons (THC) between the pairs of highly olefinic streams and the highly paraffinic streams at relatively the same volatility level, for two of the test conditions (2400RPM-light and moderate/heavy loads. The ozone forming potentials (OFP) for these fuels, across all three speed and load conditions, also show relatively small differences.

The rotary engine provides high power density compared to piston engine, but one of its downside is higher oil consumption. A model of the oil seals is developed to calculate internal oil consumption (oil leakage from the crankcase through the oil seals) as a function of engine geometry and operating conditions. The deformation of the oil seals trying to conform to housing distortion is calculated to balance spring force, O-ring and groove friction, and asperity contact and hydrodynamic pressure at the interface. A control volume approach is used to track the oil over a cycle on the seals, the rotor and the housing as the seals are moving following the eccentric rotation of the rotor. The dominant cause of internal oil consumption is the non-conformability of the oil seals to the housing distortion generating net outward scraping, particularly next to the intake and exhaust port where the housing distortion valleys are deep and narrow.

Mazda announced that all customers who purchase Mazda cars are provided with the joy of driving and excellent environmental and safety performance under slogan of "Sustainable Zoom-Zoom" long-term vision for technology development. The purpose of this study is to develop a new approach of Life Cycle Assessment (abbreviated to LCA) to be applied to clean energy vehicles and new car models. The improvement of both environmental performance, e.g., fuel consumption, exhaust emissions, vehicle weight reduction, and LCA that is a useful methodology to assess the environmental load of automobiles for their lifecycles has become more important. LCA by inventory analysis, for RX-8 Hydrogen RE as a rotary engine vehicle used hydrogen as clean energy, was carried out and disclosed the world for the first time. LCA for new Mazda 5 was carried out as the portfolio of all models, previously only the specific model equipped with fuel efficiency device based on ISO14040.

The Wankel rotary engine is more compact than conventional piston engines, but its oil and fuel consumption must be reduced to satisfy emission standards and customer expectations. A key step toward this goal is to develop a better understanding of the apex seal lubrication to reduce oil injection while reducing friction and maintaining adequate wear. This paper presents an apex seal dynamics model capable of estimating relative wear and predicting friction, by modeling the gas and oil flows at the seal interfaces with the rotor housing and groove flanks. Model predictions show that a thin oil film can reduce wear and friction, but to a limited extent as the apex seal running face profile is sharp due to the engine kinematics.

We have introduced a supercharged Miller Cycle gasoline engine into the market in 1993 as an answer to the requirement of reduction in CO2 emission of vehicles. Improvement in the fuel economy of a supercharged Miller Cycle engine is achieved by the reduction of friction loss due to a smaller displacement. The biggest problem of a conventional supercharged engine is knocking. In order to avoid the knocking, lower compression ratio, which accompanies lower expansion ratio, has been adopted by the conventonal engines and achieved insufficient fuel economy improvement. The Miller Cycle obtains superior anti-knocking performance as well as lowering compression ratio, while keeping the high expansion ratio. The decreased friction loss by the smaller displacement has completely lead to the improvement of fuel economy.

Recently, an audible clattering noise has been noticed in some vehicles during cold engine starts, mainly in the U.S. The clattering is referred to by various names, such as “carbon knock,” “carbon rap,” “mechanical knock” and “combustion chamber deposit interference (CCDI).” CCDI is believed to be caused by the deposit formation in the combustion chamber. In the research effort described here, CCDI was successfully reproduced in a 2.5-liter multipoint injection engine with a polyolefin amine gasoline additive. It was determined that the CCDI was caused by mechanical contact between the piston top and the cylinder head deposits. The vibration due to CCDI originated mainly at the thrust side of the piston right after top-dead-center on compression stroke and was characterized by a high frequency response. Combustion chamber deposit (CCD) formation depends on many factors, including gasoline additives.