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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.

In order to reduce traffic accident casualties, sophisticated safety systems have been developed and are continuously being upgraded in today's passenger vehicles. One system showing growth in the global automotive industry is a feature currently available on high-end passenger cars, Vehicle Stability Control (VSC). VSC can control side slipping, an unstable phenomenon which can lead to critical accidents. VSC systems are multi-functional systems that include an acceleration sensor to detect forces applied to the vehicle. Acceleration sensors sometimes referred to as G sensors are indispensable and are one of the key sensors for vehicle safety systems. New safety systems require acceleration sensors with high sensitivity and accuracy. We have achieved these increased requirements by adopting a unique stacked IC structure.

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.

We have developed Li-ion battery heating system which is direct resistance heating for hybrid electric vehicles (HEV), plug-in hybrid vehicles (PHEV) and electric vehicles (EV) by use of an inverter and a motor. One relay is added between a positive terminal of Li-ion battery and one-phase (e.g. U-phase) of a three-phase motor. When additional relay is turned on, the motor coils, IGBTs (Insulated-gate bipolar transistor) and diodes in the inverter and a smoothing capacitor for the inverter constitute buck-boost DC to DC converter. IGBTs are controlled to repeat charging and discharging between the battery and the smoothing capacitor. We made a system prototype and examined battery heating capability. And also we optimized charging and discharging frequency from impedance and current to improve heat generation. This method can increase battery temperature from −20 degrees C to 0 degrees C in 5 minutes and can extend EV driving range.

In today's motorized society, various automotive technologies continue to evolve every day. Amid this trend, a new concept with respect to automatic transaxle gear-shifting has been developed. In order to materialize a new concept for shifting operation with a universal design in mind, a system has been developed: a shift-by-wire system developed specifically for hybrid vehicles. The greatest advantage of this new system is the lack of constraints associated with the conventional mechanical linkage to the transaxle. This allows freedom of design for the gear selection module. A revolutionary improvement in the ease of shifting has been realized by taking full advantage of this design freedom. In addition, this system contributes to an innovative design. For improved ease of operation, the operation force of the shift lever of this system has been dramatically reduced. For parking, the driver can engage the parking mechanism of the transaxle at the touch of a switch.

Evaporator surface treatment technology is important for air conditioners in that it provides resistance to rust, odor and bacteria, while imparting hydrophilicity. However, since the first-layer chromate coating contains hexavalent chromium, an environmental loading substance whose stricter regulation is under consideration, development of an alternative technology is needed. We selected titanium coating for the first-layer non-chromate coating, and added an inhibitor to the second-layer multifunctional resin coating to impart a self-healing effect without undermining the other functions. As a result, we succeeded in developing a non-chromate surface technology that ensures the same level of rust resistance and other qualities as with conventional technology.

Among aluminum heat exchangers used for automotive air conditioning, the evaporator is located in the instrument panel. We have developed a new evaporator by: 1) improving the heat transfer performance through use of thinner tubes and fins; 2) establishing technologies for improving corrosion resistance and enabling reduction in wall thickness (development of highly corrosion-resistant material and control of Zn diffusion by shortening brazing time); and 3) improving refrigerant distribution in the tanks. The new evaporator is equivalent to our conventional MS Evaporator (of Multi-Tank Super-Slim Structure)(1) in cooling performance and corrosion resistance, while being significantly thinner (35% reduction) and lighter in weight (40% reduction).