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To meet the requirements for lower fuel consumption and emissions as well as higher performances, a “Variable Valve Timing - intelligent by Electric motor (VVT-iE)” system has been newly developed. The system has been firstly adopted to the intake valve train of the Toyota's new 4.6 and 5.0 litter V8 SI engine series. The VVT-iE is composed of a cam phasing mechanism connected to the intake camshaft and brushless motor integrated with its intelligent driver. The motor-actuated system is completely free from operating limitation caused from hydraulic conditions. This enjoys an advantage for reducing cold HC. The system also presents further reduction in fuel consumption.

Ever since the creation of the spark plug, improvements have continually been made to achieve high ignitability and long life. To fulfill these requirements, “Iridium Spark Plug” was introduced in 1997 with fine-wire center electrode technology to promote ignitability and long life. Then in 2003 “Super Ignition Spark Plug” was developed which uses fine-wire precious metal alloys on both the center and ground electrodes to achieve supreme ignitability and long life. Currently, the global technology trend is focusing more and more on the regulation of emissions and fuel consumption. This is driven by increased awareness for environmental conservation. These regulations are becoming stricter, which leads to a higher demand for spark plug ignitability from all kinds of vehicles ranging from luxury cars through compact sized cars. Particularly in the small vehicle category, both ignitability and low cost are a requirement.

Recently many automotive components have become electrified and an ultra high speed drive (over 150,000 rpm) is now expected in applications such as a turbocharger. In these applications, a robust induction motor (IM) with a rectangular wave drive is generally adopted. A speed sensor is required to control the IM, but it can cause problems concerning cost, space and reliability. Thus, a sensorless speed detection method is required. Because general sensorless methods based on a sinusoidal wave drive are not applicable to a rectangular wave drive, we propose a method utilizing slot harmonics that are generated by the mechanical structure of the IM. Signal-to-noise (S/N) ratio of slot harmonics is very small, and hence we suggest three techniques: a detection circuit, a digital filter with a variable passband, and a detection method to restart the motor while rotating.

In order to clarify the combustion behavior in the ultra high engine speed range, a new technique has been developed. This technique is composed of ionization current detection and flame observation, and is highly heat-resistant, vibration-resistant, and has a quick response. From analyzing the flame front propagation in the high-speed research engine, it was found that the flame propagated throughout the entire cylinder over almost the same crank angle period irrespective of engine speed introduction.

In order to clarify the diesel fuel spray characteristics inside the cylinder, we developed two novel techniques, which are preparation of same level of temperature and pressure ambient as inside cylinder and quantitative measurement of vapor concentration. The first one utilizes combustion-type constant-volume chamber (inner volume 110cc), which allows 5 MPa and 873K by igniting the pre-mixture (n-pentane and air) with two spark plugs. In the second technique, TMPD vapor concentration is measured by using Laser Induced Exciplex Fluorescence method (LIEF). The concentration is compensated by investigation of the influence of ambient pressure (from 3 to 5 MPa) and temperature (from 550 to 900 K) on TMPD fluorescence intensity. By using two techniques, we investigated the influence of nozzle hole diameter, injection pressure and ambient condition on spray characteristics.

Inverter type electric compressors capable of providing cooling capability during engine stop and that do not cause fuel efficiency drop during air conditioning system use are recently being used in hybrid vehicles that have been drawing attention for their low fuel consumption and low emissions. Conventionally, the electric compressor inverter, like other high-voltage devices, was located in a cooling unit known as a power control unit (PCU) box because it requires cooling. However, inverter installation in the PCU box is subject to rigid installation constraints, and there is increasing need to integrate it with the electric compressors. In the present development, we adopted inverter-integrated construction in which the inverter is cooled using suction refrigerant etc., so as to make the electric compressor compact.

In a common rail type fuel injection system installed in recent diesel engines, a supply pump is needed to accumulate high pressure fuel. In this supply pump, a bushing is used for the outer cam system. The bushing is lubricated by diesel fuel with relatively low viscosity and unit load of the bushing is higher. Therefore, lubricating film thickness of the bushing is extremely thin. In order to ensure the bushing function under such severe sliding conditions, the bushing is required higher seizure resistance and higher fatigue resistance. Conventionally, lead bronze alloys are applied for the bushing material. We developed a new high performance copper alloy material without lead, which is one of substances of environmental concern. The newly developed bushing contains bismuth instead of lead for tribological component.

We developed a high performance automotive lithium-ion battery and applied it to our new Toyota Intelligent Idling Stop System. This hybrid power management system has been introduced in the “intelligent package” of Toyota Vitz vehicles sold in Japan. The lithium-ion battery is installed under the seat on the passenger-side. The battery supplies electric power to the auxiliary electrical systems during the “idling stop” mode, and when restarting the engine. The main requirements of this battery are to supply high electric power output even at low temperatures and at the same time, maintain continuous power during charge and discharge cycling, and have long storage life. This performance has been accomplished successfully through a series of improvements in battery materials and structures.

Regarding the prevention of global warming and ozone layer depletion to protect the global environment, energy conservation and disuse of CFCs are among the recent industrial requirements. An ejector cycle can save power by eliminating expansion energy loss in the conventional vapor compression refrigeration cycle, which uses an expansion valve, and using the otherwise lost energy as compressor power. This technology is useful for almost all kinds of refrigerating and air-conditioning systems, but has not yet been developed to a practical level anywhere in the world. We have developed a practical ejector cycle technology and successfully commercialized it for the first time in the world, as an ejector cycle refrigerator that drastically improves refrigerating capacity and power efficiency while substantially reducing system weight, in comparison with refrigerators using the conventional vapor compression cycle.

The environment is one of the most important issues currently facing the world and the automobile industry is required to respond with eco-cars. To meet this requirement, the hybrid vehicle is one of the most optimal solutions. The hybrid system automatically stops engine idling (idling stop), or stops the engine during deceleration to recover energy. The engine stop however creates a problem concerning the vehicle's climate control system. Because the conventional climate control system incorporates a compressor driven by engine belt, there is almost no cooling performance while the engine is stopped. Until now, when a driver needed more cooling comfort the engine has been switched back on as a compromise measure. To realize cabin comfort that is consistent with fuel saving, a 2-way driven compressor has been developed that can be driven both by engine belt while the engine is running and by electric motor when the engine is stopped.

To meet diesel emission regulations, high injection pressure is demanded for the supply pump of electronically controlled common-rail type injection system. DENSO has produced common-rail type injection system in 1999. Cam and roller to generate high pressure in the supply pump at the system are composed of steel and silicon nitride ceramics, and are rolling contact under light oil lubrication. Therefore, rolling contact fatigue failure had been concerned. In order to assure the components, we estimated the influence on the materials and the lubrication on the rolling fatigue strength of silicon nitride ceramics, the contact fatigue life was tested under oil lubrication.

Phosphating is a surface treatment process widely used for preparing metal surfaces before painting. The phosphate coating plays a very important role in enhancing after-painting corrosion resistance, which is one of the essential quality requirements of painted surfaces. Continued research and development is therefore under way in various parts of the world to increase the corrosion resistance enhancement effect of phosphating. Moreover, because the demand for environmental protection has been increasing in recent years, reducing the amount of waste (sludge) generated during the phosphating process is also strongly required. To meet these requirements, we have developed a novel phosphating technology called the “electrolytic phosphating process,” which drastically enhances corrosion resistance after painting and reduces sludge generation. The developed process has already been put to practical use for surface preparation before cation electrodeposition painting of automotive parts.

Behavior of sprays formed by slit nozzle as well as swirl nozzles with the spray cone angle in the range of 40° ∼110 ° were studied in a constant volume N2 gas chamber. The fuels used are iso-pentane, n-heptane, benzene and gasoline. The ambient pressure and temperature were raised up to 1.0 MPa and 465 K, respectively. The injection pressure was mainly set at 8 MPa. Spray penetrates at an almost constant speed for a while after injection start and begins to decelerate at a certain point. This point was judged as breakup point, based on a momentum theory on spray motion, the observation of spray inside and the analysis of the spray front reacceleration which occurs under highly volatile condition.

The demand for thermal comfort in the passenger vehicle compartment is infinite. As a result, technologically sophisticated options and features continue to be upgraded both in the hardware and software sectors. The personalization of comfort became a priority and led to improvements in automatic room temperature control techniques. Furthermore, the demand is rising not only for thermal comfort but also for cabin air quality improvement. Also, contributions to improve mileage and fuel consumption are a new request at the present time. This paper introduces the latest thermal comfort technologies in temperature and airflow controls as well as air quality improvement features. In addition, this paper introduces fuel consumption reduction technology employed by the A/C configuration of the TOYOTA HYBRID SYSTEM.

In manufacturing technology, the predominant tendency in recent years has been for machine tools, for example, turning-, milling-, and drilling-machines, to employ an electrically operated actuator such as a servo-motor equipped with a ball screw. There are, however, various problems with these electric driving systems; they are excessively large in size and complex. In order to solve these problems, the first purpose of this study was to develop a precision driving system composed of a hydraulic cylinder and high-speed ON/OFF valves. It was confirmed that the developed system had a moving resolution of 1.2 μm. The second purpose of this study was to practice the ability test of turning, drilling and milling by applying the developed driving system to a micro-machine-tool. It was confirmed that the developed machine was compatible with, or even superior to conventional NC-machines.

In the 42V Mild Hybrid System introduced into market by Toyota for the first time in the world, the crankshaft using belt(s) drives the motor/generator (MG). The set-up employs an inverter unit to control the MG electronically. This paper describes the system configuration, operations, characteristic features and development results of the new power control system. The focus is on the MG, the inverter-for-MG-control and energy regeneration, as well as DC/DC converter for the power supply to the 14V devices.

As a means to reduce exhaust emission, narrowing nozzle hole diameter is known to be an effective method of improving fuel atomization. In general, Electrical Discharge Machining (EDM) is more effective than other machining techniques because there is no burring and no machining force is apply to the tool, but the drawback to EDM is a low removal rate. An EDM drilling device by using piezoelectric elements has been newly developed. This device can drive a wire electrode at a high response of 5kHz. As a result of high response, this device can drill holes 0.1-0.5mm in diameter 3 times more efficiently than a conventional electrical discharge machine.