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In recent years, the slip lock-up mechanism has been adopted widely, because of its fuel efficiency and its ability to improve NVH. This necessitates that the automatic transmission fluid (ATF) used in automatic transmissions with slip lock-up clutches requires anti-shudder performance characteristics. The test methods used to evaluate the anti-shudder performance of an ATF can be classified roughly into two types. One is specified to measure whether a μ-V slope of the ATF is positive or negative, the other is the evaluation of the shudder occurrence in the practical vehicle. The former are μ-V property tests from MERCON® V, ATF+4®, and JASO M349-98, the latter is the vehicle test from DEXRON®-III. Additionally, in the evaluation of the μ-V property, there are two tests using the modified SAE No.2 friction machine and the modified low velocity friction apparatus (LVFA).

In diesel engines with a straight intake port and a lipless cavity to restrict in-cylinder flow, an injector with numerous small-diameter orifices with a narrow angle can be used to create a highly homogeneous air-fuel mixture that, during PCCI combustion, dramatically reduces the NOX and soot without the addition of expensive new devices. To further improve this new combustion concept, this research focused on cooling losses, which are generally thought to account for 16 to 35% of the total energy of the fuel, and approaches to reducing fuel consumption were explored. First, to clarify the proportions of convective heat transfer and radiation in the cooling losses, a Rapid Compression Machine (RCM) was used to measure the local heat flux and radiation to the combustion chamber wall. The results showed that though larger amounts of injected fuel increased the proportion of heat losses from radiation, the primary factor in cooling losses is convective heat transfer.

Fuel economy measurement test is one of important engine tests to establish fuel economy engine oil performance standard to support CO2 emission reduction efforts in the automotive industry. On the other hand, it is difficult to develop an engine test without appropriate engine hardware that is designed to utilize low viscosity engine oils. A new firing fuel economy test was developed based on 2ZR-FXE engine designed for hybrid powertrain. The new test procedure aimed to provide the tool to evaluate new low viscosity grades such as 0W-8 and 0W-12 that were adapted in SAE J300 in 2015.

One primary result of the reduction of platinum group metals (PGM) within a catalytic converter is the decline in NOx conversion efficiency. This paper hypothesizes that the primary factor of this decline to be hydrocarbon (HC) poisoning. To maintain high NOx conversion efficiency as the PGM reduces, Rh activation improvement becomes significant to overcome the HC poisoning. Analysis of the Rh deterioration mechanism found that it is effective to separately arrange Rh and CeO2 on the converter, avoiding the Rh deactivation. By this improvement, we improved the catalyst activity at less than 25% of the original Rh loading.

We report in this paper our newly developed technology applied to ILSAC GF-5 0W-20 engine oil that offers great fuel economy improvement over GF-4 counterpart, which is a key performance requirement of modern engine oil to reduce CO2 emissions from a vehicle. Our development strategy of the oil consisted of two elements: (1) further friction reduction under mixed and hydrodynamic lubrication conditions considering use of roller rocker arm type valve train system and (2) lowering viscosity at low temperature conditions to improve fuel economy under cold cycles. Use of roller rocker arm type valve train system has been spreading, because of its advantage of reducing mechanical friction. Unlike engine with conventional direct-acting type valve train system, lubrication condition of engine with the roller rocker arm type valve train system has higher contribution of mixed or hydrodynamic lubrication conditions rather than boundary lubrication condition.

A molded headliner made from polypropylene, which we developed for the first time in the world, was adopted in May 1987 for TOYOTA COROLLA. The new material with high stiffness and light weights, has a sandwich structure consisting of PP-sheets and a PP-foam sheet. We have thus succeeded in the production of the new headliner in which each layer is laminated without any adhesive. A unique resin used for PP-sheets as surface skins was developed with high impact, thermal and fire resistances. Further, a PP-form core sheet with soft-feel and good moldability was also developed. As a result, we established proper conditions of molding this material and succeeded in producing stable superior parts with high quality and short cycle-time. Finally new molded headliner is comparable to the suspended type headliner in respect to weight and production cost.

Further fuel economy improvement of the internal combustion engine is indispensable for CO2 reduction in order to cope with serious global environmental problems. Although lowering the viscosity of engine oil is an effective way to improve fuel economy, it may reduce the wear resistance. Therefore, it is important to achieve both improved fuel economy and reliability. We have developed new 0W- 8 engine oil of ultra-low viscosity and achieved an improvement in fuel economy by 0.8% compared to the commercial 0W-16 engine oil. For this new oil, we reduced the friction coefficient under boundary lubrication regime by applying an oil film former and calcium borate detergent. The film former increased the oil film thickness without increasing the oil viscosity. The calcium borate detergent enhanced the friction reduction effect of molybdenum dithiocarbamate (MoDTC).

The study described in this paper covers the development of the Sequence IVB low-temperature valvetrain wear test as a replacement test platform for the existing ASTM D6891 Sequence IVA for the new engine oil category, ILSAC GF-6. The Sequence IVB Test uses a Toyota engine with dual overhead camshafts, direct-acting mechanical lifter valvetrain system. The original intent for the new test was to be a direct replacement for the Sequence IVA. Due to inherent differences in valvetrain system design between the Sequence IVA and IVB engines, it was necessary to alter existing test conditions to ensure adequate wear was produced on the valvetrain components to allow discrimination among the different lubricant formulations. A variety of test conditions and wear parameters were evaluated in the test development. Radioactive tracer technique (RATT) was used to determine the wear response of the test platform to various test conditions.

Since drowsy driving is a major cause of serious traffic accidents, there is a growing requirement for drowsiness prevention technologies. This study proposes a drowsy driving prediction method based on eye opening time. One issue of using eye opening time is predicting strong drowsiness before the driver actually feels sleepy. Because overlooking potential hazards is one of the causes of traffic accidents and is closely related to driver cognition and drowsiness, this study focuses on eye opening movements during driving. First, this report describes hypotheses concerning drowsiness and eye opening time based on the results of previous studies. It is assumed that the standard deviation of eye opening time (SDEOP) indicates driver drowsiness and the following two transitions are considered: increasing and decreasing SDEOP. To confirm the hypotheses, the relationship between drowsiness and SDEOP was investigated.

Fluoroelastmers are well known for their resistance to heat and fluids, and have become major material for crankcase oil seals. On the other hand, new additive formulations are developed for engine lubricants used for fuel economic gasoline engines. In this paper, the effects of those additives on properties of fluoroelastmers are investigated. The results of the immersion tests of both test plaques and oil seal products indicate that dithiocarbamates, friction modifier, have hardening effects on fluoroelastmers. The fluoroelastmer deterioration mechanism is determined by analysis of elastmer samples after immersion in oil.

Torque loss reduction at differential gear unit is important to improve the fuel economy of automobiles. One effective way is to decrease the viscosity of lubricants as it results in less churning loss. However, this option creates a higher potential for thin oil films, which could damage the mechanical parts. At tapered roller bearings, in particular, wear at the large end face of rollers and its counterpart, known as bearing bottom wear is one of major failure modes. To understand the wear mechanism, wear at the rolling contact surface of rollers and its counterpart, known as bearing side wear, was also observed to confirm the wear impact on the tapered roller bearings. Because gear oils are also required to avoid seizure under extreme pressure, the combination of a phosphorus anti-wear agent and a sulfurous extreme pressure agent are formulated.

Due to the advancement of engine performance, large volumes of oil circulate within a narrow internal space of passenger car engines. This phenomenon often leads to oil foaming and aeration problems. In this study, we developed a method for predicting the rate of engine oil aeration from specific engine parameters and running conditions. Engine tests show that the rate of oil aeration is stable throughout the process between bubble release from the oil surface and aeration. Additionally, bubble size affects its release rate from the oil surface. Utilizing both of these assumptions, our prediction method calculates aeration rate by evaluating bubble number and size.

Two types of new conceptual lead free overlays are developed for automotive internal combustion(IC) engine bearings. The overlays are consisted of molybdenum disulfide(MoS2) and polyamideimide(PAI) resin for binding. One of the overlays is suitable for diesel engines with higher unit load and the other overlay is suitable for gasoline engines with higher sliding velocity. Both overlays indicate good corrosion resistance and wear resistance comparing with conventional lead base overlay. Moreover, higher fatigue resistance is obtained in combination with high performance lead free bearing alloy. These new bearings have the potential to become alternative materials to conventional copper lead bearings with lead base overlay.

Oil pump down sizing is one of the effective method to improve engine friction loss. Reducing the required amount of lubricating engine oil can be achieved by the application of a new crankshaft bearing with an eccentric oil groove. By adopting a bearing with an eccentric groove, we found the well balanced specification which can keep the necessary amount of oil to the crankshaft pin and reduce leaking oil from crankshaft main journal. Measuring oil amount distribution in engine running condition simultaneously and checking capability of eliminating contamination analytically have achieved.

Recently, engines achieving high power levels are becoming increasingly common. The trend is toward increasing the inflow of lubricating oil into the crankcase through several factors (for example, increasing the flow rate of the cooling oil jets in order to reduce the thermal load of the pistons). In addition, the mechanical losses induced by the motion of the crankshaft and connecting rods through the additional oil are intensified due to the higher engine speeds at maximum power. In this article, we confirmed a method of separating the pumping loss and the agitation loss by measuring the pressure in the crankcase and an empirical formula was found for predicting pumping loss from displacement and ventilating area. We also investigated the effect of reducing the lubrication oil flow rate, as well as other factors affecting the oil flow, on the mechanical loss at high engine speeds.

In recent years, the realization of carbon neutrality has become an activity to be tackled worldwide, and automobile manufacturers are promoting electrification of power train by HEV, PHEV, BEV and FCEV. Although interest in BEV is currently growing, vehicles equipped with internal combustion engines (ICE) including HEV and PHEV will continue to be used in areas where conversion to BEV is not easy due to lack of sufficient infrastructures. For such vehicles, low-viscosity engine oil will be one of the most important means to contribute to further reduction of CO2 emissions. Since HEV requires less work from the engine, the engine oil temperature is lower than that of conventional engine vehicles. Therefore, the reduction of viscous resistance in the mid-to-low temperature range below 80°C is expected to contribute more to fuel economy. On the other hand, the viscosity must be kept above a certain level to ensure the performance of hydraulic devices in the high oil temperature range.

The reduction of CO2 emissions is one of the most important challenges for the automotive industry to contribute to address global warming. Reducing friction of internal combustion engines (ICEs) is one effective countermeasure to realize this objective. The improvement of engine oil can contribute to reduce fuel consumption by reducing friction between engine parts. Electrification of ICE powertrains increases the overall efficiency of powertrains and reduces the average engine oil temperature during vehicle operation, due to intermittent engine operation. An effective way of reducing engine friction is to lower the viscosity of the engine oil in the low to medium temperature range. This can be accomplished while maintaining viscosity at high temperatures by reducing the base oil viscosity and increasing the viscosity modifier (VM) content to raise the viscosity index (so-called “flat viscosity” concept).

In this paper, we will introduce a stereo vision system developed as a sensor for a vehicle's front monitor. This system consists of three parts; namely, a stereo camera that collects video images of the forward view of the vehicle, a stereo ECU that processes its output image, and a near-infrared floodlight for illuminating the front at night. We were able to develop an obstacle detection function for the Pre-Crash Safety System and also a traffic lane detection function for a Lane-Keeping Assist System. Especially in regard to the obstacle detection function, we were able to achieve real-time processing of the disparity image calculations that had formerly required long processing times by using two types of recently developed LSIs.

In order to determine the main factors causing the mileage-related increase in formaldehyde emission from methanol-fueled vehicles, mileage was accumulated on three types of vehicle, each of which had a different air-fuel calibration system. From exhaust emission data obtained during and after the mileage accumulation, it was found that lean burn operation resulted in by far the highest formaldehyde emission increase. An investigation into the reason for the rise in engine-out formaldehyde emission revealed that deposits in the combustion chamber emanating from the lubricating oil promotes formaldehyde formation. Furthermore it was learnt that an increase in engine-out NOx emissions promotes partial oxidation of unburned methanol in the catalyst, leading to a significant increase in catalyst-out formaldehyde emission.

This paper proposes a theory to analyze the collision avoidance capability of automated driving technologies. The theory gives answers to a fundamental question whether automated vehicles fall into extreme conditions at all rather than another question how a vehicle reacts under extreme conditions (is it as safe as driver?). The theory clarifies the following matters: There are two types of hazards to cause collisions, cognitive hazards and behavioral hazards. Cognitive hazards are handled by controlling the upper limit speed of the automated vehicle including when stopped. There are two methods for handling behavioral hazards, preparation and response. The response known well is the coping method activated when the hazard is detected in the dynamic (operational) level. The preparation is the coping method operating at all time in the semantic (tactical) level.