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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.

A hardening depth evaluation technique using eddy current has been developed, which can be applied to a mass production line for destructive (cutting) inspections. Using this technique, changes in the hardness of the induction-hardened structure can be detected based on the changes in magnetic permeability. This technique reduces the thermal effect and improves measurement accuracy through a multi-frequency exciting method and a difference method algorithm.

We have developed a Hall effect device based height sensor of a smaller size, and with higher temperature operation durability, as compared to conventional devices. Downsizing of the sensor is realized by decreasing a number of parts, and by employing a short bearing. Improvement in heat resistance is achieved by adopting an IC with sufficient heat resistance and a SmCo magnet with high coercive force. In addition, a sensor of a high degree of accuracy is accomplished by improvements in linearity and robustness of magnetic characteristics. Development of a small, heat-resistant and accurate height sensor will promote the spread of systems using a height sensor, such as a High Intensity Discharge (HID) headlamp.

Port fuel injection (PFI) injector and direct fuel injection (DI) injector clogging from deposits caused by poor fuel quality, is a concern in emerging countries. Then DI injector deposits are sometimes cleaned by injector cleaners in such situation. However deposit cleaners for PFI injectors have not been developed, because of the lack of research of PFI injector deposits. Through chemical analysis, this study showed them to be water-soluble deposits. Subsequently success was achieved in developing a new gasoline injector cleaner applicable to injector deposits in both types of injectors, through optimization of a surface active agent.

It is critical to develop high performance three-way catalysts to meet increasing regulations around the world. It was found that a double-layered catalyst loaded with Pt and Rh suppresses Pt-Rh alloying, thereby improving catalytic performance. A double-layered catalyst has the effect of decreasing OSC performance, but this has been overcome by a newly developed Rh support and suppressed Pt grain growth. The developed catalyst is capable of lowering the amount of PGM required by approximately 40%.

Due to regulations for even lower levels of pollutants in exhaust gas, development of advanced combustion techniques and increasingly efficient catalysts has become more crucial than ever. One of the essential technologies to achieve this goal is an advanced measurement method, which can detect the characteristics of exhaust gas, such as temperature and chemical compositions, in real-time to clarify their reaction mechanisms. A direct and fast response (1ms) measurement technique was developed based on diode laser absorption spectroscopy and applied to practical engine exhaust measurement to prove the validity of this technology for various applications such as clarification of engine start phenomena and improvement of EGR controls.

In the automobile industry, interest in the prevention of global warming has always been high. The development of eco cars (HV, EV etc.), aimed at reducing CO2 emissions during operation, has been progressing. In the announcement of its "Toyota Environmental Challenge 2050", Toyota declared its commitment to creating a future in which people, cars, and nature coexist in harmony. In this declaration, Toyota committed to reducing CO2 emissions not only during operation but also over the entire life cycle of vehicles, and to using resources effectively based on a 4 R’s approach (refuse, reduce, reuse, and recycle). Although eco cars decrease CO2 emissions during operation, most of them increase CO2 emissions during manufacturing. For example, the rare-earths (Nd, Dy etc.) used in the magnets of driving motors are extracted through processes that produce a significant amount of CO2 emissions.

In recent years the regulations governing emissions from automobiles have been strengthened as awareness of global environmental problems has increased. Furthermore, the amount of precious metals being used has continued to decrease due to concerns over the exhaustion of natural resources and worries about the risk of fluctuations in the price of these precious metals. As a result, a high performance three-way catalyst that can satisfy the emissions regulations is now required. By applying zone-coating and carrier degradation control technology, a high performance three-way catalyst has been developed. The zone-coating technology improves the conversion performance of the catalyst through improvement of HC and NOx conversion reactions and oxygen storage capacity (OSC) reactions. The addition of an Nd surface-enriched layer strengthened the mutual interactions between the carrier and Rh.

To prevent global warming, many countries are making efforts to reduce CO2 emissions toward achieving 2050 carbon neutrality. In order to reduce CO2 concentration quickly, in addition to spread of renewable energy and expansion of BEV, it is also important to reduce CO2 emissions by improving thermal efficiency of ICE (internal combustion engine) and utilizing carbon neutral fuels such as synthetic fuels and biofuels. It is well known that lean burn is an effective technology to increase thermal efficiency of engine highly. However, since NOx emission from lean burn engine cannot be reduced with three-way catalyst, there have been issues such as complicated system configuration due to the addition of NOx reduction catalyst or limiting lean operation to narrow engine speed and load in order to meet emission regulation of each country.

The effects of intake dilution with various dilution gases including nitrogen, argon, and carbon dioxide on low temperature diesel combustion were investigated in a naturally aspirated DI diesel engine to understand the mechanism of the simultaneous reductions in smoke and NOx with ultra-high EGR. NOx almost completely disappears with the intake oxygen concentration diluted below 16% regardless of the kind of dilution gas. Smoke emissions decrease with increased heat capacity of the charged gas due to promotion of mixture homogeneity with longer ignition delays. Intake dilution with the 36% CO2 + 64% Ar mixture which has a similar specific heat capacity as N2 shows lower smoke emissions than with N2. Chemical kinetics analysis shows that carbon dioxide may help to reduce NOx and soot by lowering the reaction temperature as well as by changing the concentrations of some radicals or/and species related to soot and NOx formation.

To meet future stringent emission regulations such as Euro6, the design and control of diesel exhaust after-treatment systems will become more complex in order to ensure their optimum operation over time. Moreover, because of the strong pressure for CO₂ emissions reduction, the average exhaust temperature is expected to decrease, posing significant challenges on exhaust after-treatment. Diesel Oxidation Catalysts (DOCs) are already widely used to reduce CO and hydrocarbons (HC) from diesel engine emissions. In addition, DOC is also used to control the NO₂/NOx ratio and to generate the exothermic reactions necessary for the thermal regeneration of Diesel Particulate Filter (DPF) and NOx Storage and Reduction catalysts (NSR). The expected temperature decrease of diesel exhaust will adversely affect the CO and unburned hydrocarbons (UHC) conversion efficiency of the catalysts. Therefore, the development cost for the design and control of new DOCs is increasing.

This paper considers an application of reference governor (RG) to automotive diesel aftertreatment temperature control. Recently, regulations on vehicle emissions have become more stringent, and engine hardware and software are expected to be more complicated. It is getting more difficult to guarantee constraints in control systems as well as good control performance. Among model-based control methods that can directly treat constraints, this paper focuses on the RG, which has recently attracted a lot of attention as one method of model prediction-based control. In the RG, references in tracking control are modified based on future prediction so that the predicted outputs in a closed-loop system satisfy the constraints. This paper proposes an online RG algorithm, taking account of the real-time implementation on engine embedded controllers.

In a Diesel engine with a Diesel particulate filter (DPF) system, high-sulfur fuel causes white smoke containing odorous and harmful pollutants during DPF regeneration. This study investigates the conditions and mechanisms of sulfur-related white smoke generation. Engine and vehicle tests found that sulfur compounds emitted from the engine accumulated on the catalysts in the DPF system and were emitted as white smoke during DPF regeneration. The white smoke was observed when the catalyst temperature was more than 450°C, under conditions such as the early stage of DPF regeneration. Model gas tests were conducted to clarify the mechanism of the white smoke. It was found that SO2 emitted from the engine was oxidized to SO3 on the catalyst, which was then mainly absorbed on the oxidation catalyst support (Al2O3). Then, the absorbed SO3 was desorbed and converted into white smoke.

Diesel particulate and NOx reduction system (DPNR) is an effective technology for the diesel after-treatment system, which can reduce particulate matter (PM) and nitrogen oxides (NOx) simultaneously. Further improvement of the DPNR is expected for cleaner air in the future. The catalyst for the DPNR (called DPNR catalyst) consists of a NOx Storage Reduction (NSR) catalyst coated onto a Diesel Particulate Filter (DPF). The development of the DPNR catalyst for the decrease of exhaust weight has been considered before now with respect to the PM combustion. But it will be necessary to focus on PM particle number emissions in the future. In this study, the relationship between the pore structure of the DPNR catalyst and the trapping of PM to lower particle number was clarified by evaluating a high-porosity, large-pore cordierite DPF with an average pore size of 20 μm or greater. Furthermore, the optimal pore structure to trap PM particles in a highly effective manner was discussed.

By using analytical techniques (FT-IR, TG-MS, ICP) and DFT calculations, the potassium (K) used as a storage component in NOx Catalysts can be analyzed. The results from this study show that the, K exists as K2CO3, and that the amount, molecular structure, and thermal stability of K2CO3 are different, depending on the support material (ZrO2, Al2O3, or TiO2). If the amount of K that interacts with the support to form an inactive complex oxide is decreased, the amount of K2CO3 and NOx storage is increased. The amount of the inactive K varies with the basicity of the supports. K2CO3 that exists in unstable structures on the supports can be easy to react with NOx to form the nitrate. So, the higher the quantity of unstable K2CO3, the higher the NOx storage capacity. Based on these results, a development guideline was proposed to improve the NOx storage performance.

The dissolution and exfoliation of chromium plating specific to Russia was studied. Investigation and analysis of organic compounds in Russian soil revealed contents of highly concentrated fulvic acid. Additionally, it was found that fulvic acid, together with CaCl2 (a deicing agent), causes chromium plating corrosion. The fulvic acid generates a compound that prevents reformation of a passivation film and deteriorates the sacrificial corrosion effectiveness of nickel.

The use of lead-free (Pb-free) solder and plating in onboard electronic components has accelerated rapidly in recent years, but solutions have yet to be found for the issues of whisker generation in tin (Sn) plating and crack initiation in Pb-free solder, despite widespread research efforts. Analysis of the whisker generation mechanism has focused on internal energy levels and crystal orientation, and analysis of the crack initiation mechanism in Pb-free solder has examined changes in the grain boundaries of Sn crystals.

NO2 sources of roadside atmosphere at Matsubarabashi monitoring station in Tokyo were investigated analytically. The result showed that contribution of urban background is dominant from November to February and NO oxidation with O3 has large contribution from April to September. NO2 air quality standard will be achieved by reducing vehicle NOx emission to post-new long-term regulation level. The analytical method was verified by using our developed simulation system, which consists of micro traffic flow analyzer and CFD-based, unsteady-state diffusion with chemical reaction solver.

Our two types of NOx storage-reduction (NSR) catalyst have been tested under various conditions of thermal endurance; the performance of these catalysts have been regressed to give the formulas that enable to estimate the performance after thermal endurance; and we have found the method to simplify (shorten the duration of) the thermal endurance tests and that the thermal deterioration of NSR catalysts is controlled by the worst condition of endurance (at least approximately). The regression formula for the amount of potassium that contributes to the catalyst performance (active K) after the endurance has also been obtained. These formulas predict that the amount of active K is the least for the worst condition of endurance and suggest a difference in deterioration mechanism that reflects the performance between low and high temperatures and the portion of worse deterioration (front or rear).

As part of the International Lubricant Standardization and Approval Committee's (ILSAC) goal of developing a global automatic transmission fluid (ATF) specification, members have been evaluating test methods that are currently used by various automotive manufacturers for qualifying ATF for use in their respective transmissions. This report deals with comparing test methods used for determining torque capacity in friction systems (shifting clutches). Three test methods were compared, the Plate Friction Test from the General Motors DEXRON®-III Specification, the Friction Durability Test from the Ford MERCON® Specification, and the Japanese Automotive Manufacturers Association Friction Test - JASO Method 348-95. Eight different fluids were evaluated. Friction parameters used in the comparison were breakaway friction, dynamic friction torque at midpoint and the end of engagement, and the ratio of end torque to midpoint torque.