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Although idling vibration is usually caused by 1st order of engine combustion force, other engine forces also occur at frequencies lower than the 1st order of combustion (called low frequency idling vibration in this paper). The drive-line of the Toyota Hybrid System II (THS II) has different torsional vibration characteristics compared to a conventional gasoline engine vehicle with an automatic transmission. Nonlinear characteristics caused by the state of backlash of pinions and splines influence changes in the torsional resonance frequency. The torsional resonance frequency of the drive-line can be controlled utilizing the hybrid system controls of the THS II.

The aim of this work is to investigate the possibility of heat insulation by “Temperature Swing”, that is temperature fluctuation, on combustion chamber walls coated with low-heat-conductivity and low-heat-capacity materials. Adiabatic engines studied in the 1980s, such as ceramic coated engines, caused constantly high temperature on combustion wall surface during the whole cycle including the intake stroke, even if it employed ceramic thermal barrier coating methods. This resulted in increase in NOx and Soot, decrease in volumetric efficiency and combustion efficiency, and facilitated the occurrence of engine knock. On the other hand, “Temperature Swing” coat on the combustion chamber walls leads to a large change in surface temperature. In this case, the surface temperature with this insulation coat follows the transient gas temperature, which decreases heat loss with the prevention of intake air heating, and also which is expected to prevent NOx and Soot from increasing.

Computational fluid dynamics (CFD) shape optimization technology is playing an increasingly significant role in the development of products that satisfy various demands, including trade-off relationships. It offers the possibility of designing or improving product shape with respect to a given cost function, subject to geometrical constraints. However, conventional CFD shape optimization technology that uses parametric shape modification has two following issues: (1) expensive computational cost to obtain the final shape, (2) performance variations of the obtained shape depends on the skill or experience of the designer who determined the locations to be modified. In this study, to resolve those problems, an efficient shape optimization technology was developed that uses the adjoint method to perform sensitivity analysis of a cost function on the design parameters. It is composed of a combination of topology optimization and surface geometry optimization.

It has been long established fact that fuel economy is a key driving force of low viscosity gasoline engine oil research and development considered by the original equipment manufacturers (OEMs) and lubricant companies. The development of low viscosity gasoline engine oils should not only focus on fuel economy improvement, but also on the low speed pre-ignition (LSPI) prevention property. In previous LSPI prevention literatures, the necessity of applying Ca/Mg-based detergents system in the engine oil formulations was proposed. In this paper, we adopted a specific Group III base oil containing Ca-salicylate detergent, borated dispersant, Mo-DTC in the formulation and investigated the various effects of Mg-salicylate and Mg-sulfonate on the performance of engine oil. It was found that Mg-sulfonate showed a significant detrimental impact on silicone rubber compatibility while the influence from Mg-salicylate remains acceptable.

Abnormal combustion referred to as Low Speed Pre-Ignition (LSPI) may restrict low speed torque improvements in turbocharged Direct Injection (DI) - Spark Ignition (SI) Engines. Recent investigations have reported that the auto-ignition of an engine oil droplet from the piston crevice in the combustion chamber may cause unexpected and random LSPI. This study shows that engine oil formulations have significant effects on LSPI. We found that the spontaneous ignition temperature of engine oil, as determined using High-Pressure Differential Scanning Calorimetry (HP-DSC) correlates with LSPI frequency in a prototype turbocharged DI-SI engine. Based on these findings, we believe that the oxidation reaction of the oil is very important factor to the LSPI. Our test data, using a prototype engine, shows both preventative and contributory effects of base oil and metal-based engine oil additives.

The new concept catalyst for diesel engine has been developed. When the exhaust temperature is low, SOF and HC are temporarily adsorbed by the adsorbent within the catalyst and are oxidized as the temperature rise. This is a different that the low-temperature oxidation activity is appeared by the noble metal loading of the catalyst. The process of this development have manifested as follows. 1. The coating material is important factor to govern the oxidation activity. 2. SOF is reduced by the coating material in low temperature less than 200 3. The coating material, which has low SO2 adsorbing rate suppress the sulfate formation at high temperature. 4. To reduce NOx in the diesel engine exhaust gas is possibility by utilizing adsorptive characteristics of the catalyst.

The global warming has been recognized as a potential hazard in the 21st century and all the power plants are asked to be more clean and energy saving, which is still the toughest problem. On the other hand, people are more anxious about the quality and longer useful life and higher maneuverability of their cars. A so called “Intelligent Engine” must become a reality in the not-too-distant future. Progress in the technologies of the three major elements of the engine control: (1)Sensors and Actuators (2)ECU (3)Control strategies continues. The application of modern control theory offers the big advancements and it expands from engine itself to the engine/vehicle system. As for sensors, combustion pressure sensors may become one of the key sensors for directly defectomg the fundamental signal from the mechanical phenomena of the engine.

A newly developed AR series 4-cylinder engine has achieved high fuel efficiency through the following: adopting roller rocker arms for the valvetrain system and a variable output oil pump to reduce the friction losses, optimizing the combustion chamber and its cooling system for high compression ratio, and adopting VVT-i (Variable Valve Timing-intelligent) for both intake and exhaust camshafts to enhance thermal efficiency of the engine. Engine torque has been enhanced across the entire range of engine speeds while high performance at low engine speed is achieved by adopting a variable induction intake manifold system (ACIS-III). Output power has been enhanced by making the intake and exhaust systems highly efficient. A hinge type tumble control valves were developed to improve emissions at low temperature by improving combustion when the engine is cold in order to comply with the U.S. Cold-NMHC.

The Fuel Cell is a highly efficient device that when integrated with hybrid technology yields even higher system-level efficiencies. This impressive efficiency is one of the key reasons fuel cell technology is one of the most promising future power sources. However, this benefit creates a significant challenge in cold climates. With so much of the energy converted directly to power, there is little waste heat compared to conventional internal combustion engine (ICE) technologies. This challenge is particularly apparent at system start up from ambient sub-freezing temperatures due to the fact that the fuel cell heats-up slower than internal combustion engines (ICEs). Clearly, the amount of heat generation can be increased if the total power produced by the system is increased proportionally, but this method can be challenging because the excess power must be consumed in some manner (such as by a cabin heater).

CO2 reduction, energy security and emission reduction in urban areas are some of the issues surrounding the future of the automobile. One high profile solution for these issues is Plug-In Hybrid Vehicles (PHV). It combines the advantages of Electric Vehicles (EV), which can use electricity for vehicle propulsion and Hybrid Vehicles (HV), which has high environmental benefit potential combined with cruising range comparable to conventional vehicles. This paper describes a newly developed plug-in hybrid system and vehicle performance. The system adopts Li-batteries with high energy density and has an affordable EV range without greatly sacrificing cabin space. The vehicle achieved 1.7 times better fuel consumption with 30 miles driving range. Additionally, the vehicle has met the most stringent emissions regulations in the world.

In order to adapt to energy security and the changes of global-scale environment, further improvement of fuel economy and adaptation to each country’s severer exhaust gas emission regulation are required in an automotive engine. To achieve higher power performance with lower fuel consumption, the engine’s basic internal design such as an engine block and cylinder head were changed and the combustion speed was dramatically increased. Consequently, stroke-bore ratio and valve layout were optimized. Also, both flow coefficient and intake tumble ratio port were improved by adopting a laser cladded valve seat. In addition, several new technologies were adopted. The Atkinson cycle using a new Electrical VVT (Variable Valve Timing) and new combustion technology adopting new multi-hole type Direct fuel Injector (DI) improved engine power and fuel economy and reduced exhaust emissions.

Objective: Opposite-direction crashes can be extremely severe because opposing vehicles often have high relative speeds. The most common opposite direction crash scenario occurs when a driver departs their lane driving over the centerline and impacts a vehicle traveling in the opposite direction. This cross-centerline crash mode accounts for only 4% of all non-junction non-interchange crashes but 25% of serious injury crashes of the same type. One potential solution to this problem is the Lane Departure Warning (LDW) system which can monitor the position of the vehicle and provide a warning to the driver if they detect the vehicle is moving out of the lane. The objective of this study was to determine the potential benefits of deploying LDW systems fleet-wide for avoidance of cross-centerline crashes. Methods: In order to estimate the potential benefits of LDW for reduction of cross-centerline crashes, a comprehensive crash simulation model was developed.

Down-sizing and dielectric insulation were required for the traction motors of hybrid vehicles. By utilizing the newly developed coil with thick resin insulation atop the conventional enamel film, the use of conventional inter-phase insulation paper was abolished. Furthermore, by adopting the stair-shaped coil structure and spiral winding configuration, the stator size was minimized. With the above technologies, the motor installation to smaller hybrid vehicles was realized, thus contributing to weight reduction of hybrid vehicles.

We develop a new metal-belt continuously variable transmission fluid (CVTF) named FE to improve fuel economy and help reduce CO2 emissions. FE is a low-viscosity fluid that reduces friction loss at low temperatures. Low-viscosity fluids generally reduce hardware durability, resulting in reduced metal fatigue life. Therefore, FE is designed for maintaining oil film thickness throughout the life of a vehicle by optimizing the base oil and viscosity modifier. FE also exhibits long-term anti-shudder performance that enables frequent use of controlled-slip torque converter clutches for improving fuel economy, represented by the flex start system, without decreasing torque capacity between the belt and pulley. The key point in the formulation of design is the selection of a suitable friction modifier. A friction modifier is an additive that improves friction properties.

After the Great East Japan Earthquake on March 11, 2011, Toyota Motor Corporation received considerable public response regarding the role of vehicles in emergencies from a large number of customers. These included comments about the usefulness of the electricity supply system in the Estima Hybrid during the long power outages caused by the earthquake. In response, Toyota decided to install this system in its other hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs). This system is capable of supplying power up to 1,500 watts, which means that it can be used to operate virtually every household electrical device. Since the engine starts automatically when the main battery capacity is depleted, a single vehicle can supply the daily power needs of a normal house in Japan for about four days, providing that the battery is fully charged and the fuel tank is full.

Reducing powertrain losses is an important technical challenge to further improve the efficiency of electric vehicles as part of measures toward achieving carbon neutrality. One effective method of accomplishing this goal is to reduce the viscosity of transaxle lubricating oil. However, it is generally known that lowering viscosity can cause durability issues such as wear and seizure if the thickness of the lubricating oil film on metal sliding surfaces is insufficient. In gears and bearings, reducing the oil film thickness can increase direct contact with the base metal and may cause surface fatigue peeling. A new additive formulation for lubricating oil specifically for electrified vehicles has been designed in anticipation of the wider adoption of such vehicles in the future. The result has been a new transaxle fluid that ensures unit durability while reducing viscosity of 40°C to 12.2[mm2/sec].

Recently, diesel engine manufacturers have been improving the tolerance of fuel injection quantity and timing in response to the strengthening of emissions regulations and the introduction of various kinds of diesel fuels. This paper describes the Intelligent Accuracy Refinement Technology (i-ART) system, which has been developed as a way of achieving substantially improved tolerances. The i-ART system consists of a fuel pressure sensor installed in the injectors. It calculates the injection quantity and timing at high speed using a dedicated microcomputer designed for pressure waveform analysis. As the injector can directly measure the fuel injection pressure waveform for each injection, it can compensate the injection quantity and timing tolerance at any time. Toyota Motor Corporation has introduced this system in Brazilian market vehicles. In Brazil, the PROCONVE L6 emissions regulations will be introduced in 2012, and the market also uses various kinds of diesel fuels.

An investigation was made into the effects of valve lifter material on fuel consumption and engine noise. It was found that the use of aluminum not only improves fuel economy but also reduces valve-train chatter because it is lighter in weight and less hard than steel. The stresses to which the valve lifters are subjected and their surface temperatures were measured in bench tests, and durability tests were conducted to ascertain the problems which might be expected. Based on the results of these tests, the shape was modified, a new aluminum alloy was developed and a coating was applied to the surface. The aluminum valve lifters thus developed were found to be as durable as conventional steel lifters and have been used in the new Toyota V8 engine (IUZ type).

We have developed a new automotive instrument cluster consisting of a dial made of a glossy natural metal in order to enhance the high-quality appearance of the cluster. The glass covering the cluster contains an electrochromic device (ECD) to reduce the glare of natural light reflecting off the dial. The ECD automatically controls light transmittance in steps based on the brightness of the surrounding environment. We had to solve the following two problems before successfully completing the new cluster development: (1) Selection of a transparent device that can change the light transmittance; and (2) Finding a method for sensing the intensity of sunlight reflected from the dial surface.

Since the monolithic ceramic substrate was introduced for automotive catalytic converters, the reduction of the substrate wall thickness has been a continuing requirement to reduce pressure drop and improve catalytic performance. The thin wall substrate of 0.10 mm (4 mil) thick wall/400 cpsi cell density has been introduced to production by achieving mechanical strength equivalent to a conventional 0.15 mm (6 mil)/400 cpsi substrate. Although a round cross-section substrate can have a reduced catalyst volume compared to an oval cross-section substrate because of uniform gas flow distribution, the smaller cross-section of the round substrate increases pressure drop. The thin wall technology was applied to the round substrate to offset the pressure drop increase and to further improve catalytic performance.