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The wear mechanisms of the methanol engine were studied using dynamometer tests. Formic acid from methanol combustion mixes with the lubricant oil and attacks the metal surfaces. The iso tacho prorissis method was successfully applied to analyze the formic acid content of the used oil. A large amount of condensed water is also formed by methanol combustion and accelerates the wear. Wear can be effectively reduced by shortening lubricant oil change intervals, by using a special oil and by durable surface treatment of engine parts.

Rankine bottoming system, which operates on waste heat of engine cooling, has been developped to improve the fuel economy of a passenger car. Evaporative engine cooling system is utilized to obtain high thermal efficiency and simplicity of the Rankine bottoming system. The bottoming system uses HCFC123 as a working fluid, and scroll expander as a power conversion unit. The results indicate that energy recovery, which depends on the ambient temperature, is almost 3 percent of engine output power at ambient temperature of 25°C.

In this study, it is purpose to make clear the effect of cavitation phenomenon on the spray atomization. In this report, the cavitation phenomenon inside the nozzle hole was visualized and the pressure measurements along the wall of the nozzle hole were carried out by use of 25-times enlarged acrylic nozzle. For the representatives of regular gasoline, single and two-component fuels were used as a test fuel. In addition, various cavitating flow patterns same as experimental conditions were simulated by use of Barotropic model incorporated in commercial code of Star-CD scheme, and compared with experimental results.

This paper describes and confirms the effect of low frequency sinusoidal steering torque input on vehicle response and steering behavior using vehicle test, analysis with equations of motion and simulations. The vehicle response by low frequency torque input is quite different to the vehicle response by low frequency steer angle input. Steering system parameters such as moment of inertia, damping, friction and power steering assist torque have an effect on low frequency torque input steering system dynamics. The dynamic response of the vehicle with electric power steering (EPS) system, which has a big moment of inertia with electric motor and friction of the reduction gear, is affected by the steering system dynamic properties. The vehicle response by low frequency torque input test has capability for contribute to vehicle evaluation such as steer feel or maneuverability of handling.

A phosphor thermometry, for measurements of two-dimensional gas-phase temperature was examined in turbulent combustion in an engine. The reasonable temperature deviation and the agreement with calculated data within 5% precision were achieved by single-shot images in the ignition process of compression ignition engine. Focusing on the local flame kernel, the flame structure could be quantitatively given by the temperature. It became evident that the HCCI flame kernels had 1-3 mm diameter and the isolated island structures. Subsequently, the HTR zone consisted of the combined flame kernels near TDC.

TOYOTA has developed the world's first eight-speed automatic transmission (AA80E) for front-engine, rear-drive passenger cars. The AA80E developed for high-torque engines raises the level of power performance and fuel efficiency. To meet the size requirements needed for mounting in a passenger car application, an 8-speed geartrain, torque converter, transmission case and hydraulic control device were all newly-developed. Furthermore, the AA80E has benefited from technical developments to achieve an extremely high level of quietness and shifting performance. In this paper, the details of the AA80E are introduced.

TOYOTA has designed a new family of automatic transaxles named the “Super ECT”. These are the next generation of automatic transaxles (AT), for FWD passenger cars. The aim of this development was compactness, lightness, and improvements in fuel economy and shift quality. There are several kinds of transaxles included in this group to match each of the FWD passenger cars and engines. The “U340E,” a four-speed automatic transaxle, has been developed as one member of this family. This is one of the most compact and light AT in its class, and has greatly contributed to the fuel economy of vehicles. This paper will give an overview of the “Super ECT” and the major features and performance of the U340E.

Toyota Motor Corporation has developed a new six-speed automatic transmission AB60E for longitudinal front engine rear wheel drive (RWD) vehicles. This transmission development was aimed at an improvement of power performance and fuel economy, while achieving a lightweight, compact package and a high torque capacity. In order to achieve this target, a high-capacity ultra-flat torque converter, a highly-rigid transmission case, and an ATF warmer with a valve to switch ATF circuits to an air-cooled ATF cooler have been newly developed. Moreover, a new transmission mode control logic “TOW / HAUL” has been developed to improve power performance and driveability during trailer towing. This automatic transmission has adopted the same gear train and hydraulic control system as the conventional six-speed automatic transmission A760E. This paper describes the structure, major features and performance of the transmission in detail.

Toyota Motor Corporation has recently developed a new six-speed automatic transmission (A761E) for Front Engine Rear Wheel Drive (FR) vehicles. Following the general trend of increased shift stages and a wider range of gear ratios, this six-speed automatic transmission has been developed with attention paid to the gear steps and a wider range of gear ratios. By balanced selection of close-ratio gears in a wider range, the change greatly improves the power performance and fuel economy of the vehicle. To further improve fuel economy we have adopted new technologies such as low-viscosity ATF, neutral control, and deceleration control by extending the fuel cut range (reset speed). We have also adopted a flat-shaped torque converter, small solenoids, an aluminum oil pump cover, etc. to realize the lightest six-speed automatic transmission in the world.

Toyota Motor Corporation has developed a new six-speed automatic transaxle (U660E) for Front Wheel Drive (FWD) vehicles. Component parts of U660E are completely redesigned. By combining an innovative gear train which Toyota originally invented and newer technologies, U660E has achieved outstanding fuel economy, smooth and quick shift performance and quietness in a lightweight package among Automatic Transaxles (AT) with similar torque capacity.

Toyota succeeded in the fall of 1984 in manufacturing a complex engine and transmission control system using a newly developed single-chip microcomputer. This microcomputer, equipped with an 8K-byte ROM ( Read Only Memory) and a 256-byte RAM ( Random Access Memory), a powerful real time processing function, and a high-speed optimum instruction set, is better suited for automobiles. Application of the latest CMOS technology has enabled lower power consumption and improved noise immunity. The new system, which includes a new function; the electronic spark advance with knock control in addition to the conventional sophisticated system, has greatly improved the performance and driveability of vehicles.

Toyota has developed a new system, which uses integrated control of powertrain by PowerTrain Management (PTM), in order to improve driving comfort and reliability. This system is currently in use on Lexus's new LS460. This system is composed of 4 parts: a generation part, a mediating part, a modification part and a distribution part. In each part, processes are based on drive power and torque. In the generation part, requests from a programmed model driver, Driving Support Computer and Vehicle Dynamics Integrated Management (VDIM) are generated and expressed by drive power. In the mediating part, most suitable vehicle drive power was selected among the requests. In the modification part, the selected request is modified using a programmed powertrain model, which considers internal combustion engine condition and powertrain response and transmission's tolerance. In the distribution part, optimized engine torque and gear ratio are processed.

Toyota Motor Corporation has developed a new four-speed automatic transaxle U140E named “Super ECT”. The U140E has achieved compactness which enables it to mount on many new platforms, achieved high efficiency, which contributes to improve fuel economy, and it achieved good shift feeling, response, and reduce noise. This paper shows the major features and performance of the U140E.

Toyota Motor Corporation has developed a new five-speed automatic transmission (A750E/A750F) for longitudinal front engine rear wheel drive (RWD) vehicles. The development of this transmission has been aimed at improving fuel economy and power performance, achieving the world's top-level weight and compactness, while maintaining high torque capacity. In order to achieve this purpose, the gear train, torque converter, and other components are completely changed, and advanced technology has been applied. Moreover, this automatic transmission has achieved high-quality shift feel and quiet performance. This paper describes the major features and performance of this transmission in detail.

A new five-speed automatic transaxle, U150E, has been developed for FWD passenger cars. The goals of the development of this transaxle are fuel economy improvement, better acceleration performance, and a smoother shift feel. U150E achieved its targets by adopting a wide gearing range and using hydraulic control system design based on various simulations. This paper describes the major features, performance of this automatic transaxle, and technical points of the development.

The design requirement for more efficient vehicle moves a compact car toward front wheel drive arrangement, which requires an entire redesign of its power train. Toyota, with systematic approach from its planning stage, has developed a new automatic transmission series including one 3-speed and two 4-speed transmissions. An extensive examination on gear train arrangements enabled the 3-speed light, compact and highly reliable under the arrangement of Simpson gear train, and freewheel shifts with one-way clutches at every shifting. Two different 4th gear packages with freewheel shift are combined with the 3-speed unit to provide the versatility for the 4-speed units in various installations. Besides, these transmissions feature lock-up clutch converter, oil pump of a new tooth profile and two different control systems: hydraulic and electro-hydraulic.

A new compact five-speed automatic transmission (A650E) has been developed for front engine rear wheel drive cars. The development of this transmission has been aimed at improving fuel consumption, power performance, engine noise reduction during highway cruising and smooth acceleration by employing a wide range of gearing and close gear ratios. Generally a five-speed automatic transmission is larger than a four-speed, because of additional friction elements and gears. This can result in a change in the floor panel of the car body. However, by removing a one-way clutch for second gear and employing a unique gear-train layout, this transmission has the same circumference and length as the conventional four-speed automatic transmission (A340E)(1).1 In order to reduce first or second gear noise, gear specification and supporting structures of planetary gears have been optimized by FEM analysis.

The third generation four valve lean combustion engine controlled by newly designed combustion pressure sensor has been developed. This combustion sensor composed of a metal diaphragm and a thin silicone layer formed on devitron piece detects the combustion pressure in the No.1 cylinder. Comparing with the lean mixture sensor equipped in the first and second generation lean combustion engine, the lean misfire limit was detected directly with this sensor, and the lean operation range was expanded, which realized lower fuel consumption and NOx emission. The output torque fluctuation was minimized by precisely compensating the fuel supplied to individual cylinder based on the crank angle sensor signal. Separated dual intake ports, one with the swirl control valve and the other with helical port shape was designed and a twin spray injection nozzle was equipped between those ports. The swirl ratio was lowered from 2.2 to 1.7.

A compact and high-performance five-speed automatic transmission(A350E) has been developed for passenger cars. The development of this transmission has been aimed at improvement in acceleration performance in the low and medium speed range and at smooth acceleration. A five-speed automatic transmission with a simple gear train has been completed by means of the industry's first modern control theory aided shifting technique.

Toyota has developed a new full time 4WD system, called “EC-HYMATIC” or Electronically Controlled - HYdraulic Multi-plate clutch Active Traction Intelligent Control. This system permits an automatic torque transfer, depending on driving conditions, for front and rear wheels under control of the speed difference between the two. The system developed consists of a center differential, a speed difference control clutch system employing multi-plate clutch, and a gear set for rear axle drive. The speed difference control clutch system is controlled by a unique electro-hydraulic system using a microcomputer. An extensive use of computer simulations and vehicle test and evaluation has successfully developed an appropriate control strategy for the clutch system. The new 4WD system, EC-HYMATIC, considerably improves handling characteristics, traction performance and stability of a 4WD vehicle.