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Titanium alloy for forging and pure titanium material for exhaust systems have been developed. The forging alloy will be applied to production of lightweight motorcycle frames and the pure titanium will be applied to improve engine performance. The materials have been made inexpensive by the use of off-grade sponge that includes many impurities for production of titanium ingot. Stable characteristics have been obtained by controlling oxygen equivalent after setting the volume of tolerable impurities by considering mechanical properties and production engineering. In spite of low-cost, the material provides the same design strength compared to conventional material, and enables parts production with existing equipment. A review of manufacturing and surface treatment processes indicated a reduction in the price of titanium parts produced with this new material.

In this research, a material model was developed that has orthotropic properties with respect to in-plane damage to support finite element strength analysis of components manufactured from a randomly oriented long-fiber thermoplastic composite. This is a composite material with randomly oriented bundles of carbon fibers that are approximately one inch in length. A macroscopic characteristic of the material is isotropic in in-plane terms, but there are differences in the tension and compression damage properties. In consideration of these characteristics, a material model was developed in which the damage evolution rate is correlated with thermodynamic force and stress triaxiality. In-plane damage was assumed to be isotropic with respect to the elements. In order to validate this material model, the results from simulation and three-point bending tests of closed-hat-section beams were compared and found to present a close correlation.

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).

The PVC(poly-vinyl chloride) underbody coating was specifically designed for the automotive underfloor area in order to prevent chipping damage as well as the onset of rust propagation from a scratched point. This superior anti-chipping performance can also be achieved without increasing film thickness of the PVC by balancing film strength and adhesion strength. Also, by incorporating plastic balloons in the PVC formulation, a dried film specific gravity of less than 1.0 is achieved, and consequently a 2 kg weight reduction becomes possible when compared to conventional materials used for underbody coating.

In recent years along with stringent the regulations, vehicles equipped with gasoline particulate filter (GPF) have started to launch. Compared to bare GPF, coated GPF (cGPF) requires not only PN filtration efficiency, low pressure drop, but also purification performance. In the wall flow type cGPF having a complicated the pore shape, the pore structure further irregularly changes depending on the coated state of the catalyst, so it is difficult to understand the matter of in-wall. In order to advance of cGPF function, it was researched that revealing the relevance between pore structure change in the wall and GPF function. Therefore, to understand the catalyst coated state difference, cGPF of several coating methods were prepared, and their properties were evaluated by various analyses, and performance was tested.

A hexavalent-chromium-free metal gasket for PWC engines was developed to correspond to the ELV (End of Life Vehicle) directive. In order to enhance the adhesive property, the ion capture to trap the chloride ion, an anti-rust pigment to reform the chemical coating, and an inorganic sealer to stop the passage of chloride ion were added to the adhesive and rubber raw material. A good adhesive property and rubber physical property was obtained through the addition of an anticorrosive pigment. The rubber vulcanization condition in the manufacturing process was reviewed. As a result, without modifying the current compound coating line for mass-production, a gasket with a blistering resistance more than hexavalent chromium conversion coating equivalence and coating adhesion was developed when using salt water for engine cooling.

4C3B (4 coat 3 bake) painting system (see Figure 1) which needs a bake process after the primer surfacer paint was very general and common process for the automotive body painting system. In the beginning of the 2000s, 4C2B painting system (Reference 1) was developed which changed the oven after the primer surfacer paint to a pre heat area, so it can reduce the carbon dioxide (Figure 1, and Figure 2). But unfortunately in this 4C2B painting system, the base coat will be painted on the primer surfacer paint wet-on-wet. By that reason, the appearance deterioration will occur often. The authors used a low temperature crosslinking agent “Polycarbodiimide” to a water born primer surfacer paint, to control the viscosity of primer surfacer paint at the pre heat area. Controlling the viscosity is important to avoid the layer mixing of the primer surfacer paint and the base coat which makes appearance deterioration.

Currently, there is a growing demand for application of plastic coverings for motorcycles in the market. Accordingly, decorative features for plastic coverings are increasingly important to enhance the attractiveness of exterior designs of those motorcycles. Under these circumstances, the magnetically formed decorative painting had been adopted to a mass-production model sold in Thailand in 2008. Magnetically formed decorative painting is a method in which the design patterns are formed by painting a material that contains flakes movable along with magnetic fields, while applying magnetic sheets in the ornamenting design shapes underneath the part being painted. It offers a three-dimensional appearance even though its surface has no protrusions or indentations. The degree of three-dimensionality on the paint surface appearance was defined as “plasticity” [1] (a term used in pictorial arts).

Most types of paint materials currently used for motorcycles contain large amounts of VOCs (Volatile Organic Compounds). VOCs are environmental load substances, and there is a demand to reduce emissions in recent years. Many of a motorcycle's exterior parts are made of ABS (Acrylonitrile-Butadiene-Styrene) plastics (henceforth ABS) or PA (Polyamid) plastics (henceforth PA). These two plastic materials have different film adhesion mechanisms and adhesion strength. Therefore it was necessary to use different conductive primers and that's was one of the factors which made time and material losses in the painting processes. We solved those two issues, the reduction of VOCs and the common use of the same conductive primer for different parts materials, by combining two kinds of resins originally designed as the conductive primers, i.e., urethane resins with carboxylic acid groups and acrylic resins with amide groups, which are different in properties.

The reciprocating frictional test is a common approach for screening the materials of the piston and sleeve of an automobile engine. The frictional speed of this test is, however, limited mainly by the vibration of test apparatus due to the absence of damping factors in engines. Considering that the frictional velocity between the piston and sleeve reaches around 20 m/s, common test conditions at less than 2 m/s are not sufficient to understand the real phenomena at a frictional interface. We therefore developed a high-speed reciprocating test apparatus that can operate at a much higher speed range and examined two materials used for piston rings and sleeves. For the piston ring material, nitrided SUS440C was used. Plates were made of centrifugal cast iron FC250 or cast aluminum AC2B, which were coated with Nikasil. The experimental results showed that the lubrication regimes of the two plate materials were different even at the same reciprocating speeds.

Recent trends to downsize engines have resulted in lighter weight and greater compactness. At the same time, however, power density has increased due to the addition of turbocharger and other such means to supplement engine power and torque, and this has increased the thermal and mechanical load. In this kind of environment, corrosion of the copper alloy bushing (piston pin bushing) that is press-fitted in the small end of the connecting rod becomes an issue. The material used in automobile bearings, of which the bushing is a typical example, is known to undergo sulfidation corrosion through reaction with an extreme-pressure additive Zinc Dialkyldithiophosphate (ZnDTP) in the lubricating oil. However, that reaction path has not been clarified. The purpose of the present research, therefore, is to clarify the reaction path of ZnDTP and copper in an actual engine environment.

Several attempts have been reported in the past decade or so which measured the sizes of particles in lubricant oil in order to monitor sliding conditions (1). Laser light extinction is typically used for the measurement. It would be an ideal if only wear debris particles in lubricant oil could be measured. However, in addition to wear debris, particles such as air bubbles, sludge and foreign contaminants in lubricant oil are also measured. The wear debris particles couldn't have been separated from other particles, and therefore this method couldn't have been applied to measurement devices for detection when maintenance service is required and how the wear state goes on. It is not possible to grasp the abnormal wear in real time by the conventional techniques such as intermittent Ferro graphic analysis. In addition, it is no way to detect which particle size to be measured by the particle counter alone.

To develop ideal oil circuits, it was necessary to establish technology that would accurately predict lubrication oil pressure and flow rates. Therefore, the oil flow rate was predicted by applying load fluctuations, calculated using multi body dynamics, to an oil film model. In addition, the pressure loss of complex oil passages was obtained using 3-dimensional computational fluid dynamics (hereafter, “3D-CFD”). Furthermore, the pressure loss of the oil pressure switching valves and other parts that are difficult to predict using 3D-CFD were measured as single parts, and these results were linked with one-dimensional internal flow analysis to develop a prediction method for lubrication oil pressure and flow rate distributions. Verification tests were ultimately performed using a completed engine, and the results confirmed that this simulation method accurately reproduces the oil pressure and oil flow rate in each part.

As the electric vehicle (EV) market expands and we enter the period of fully fledged diffusion of the vehicles, evaluation of battery performance when secondhand vehicles are sold and when batteries are put to alternative uses will become increasingly important. However, the accurate measurement of battery performance for the purpose of battery evaluation represents a challenge when the batteries are fitted in a battery pack consisting of multiple cells. The authors therefore formulated a degradation estimation model for the evaluation of battery performance based on battery usage history. To formulate the model, parameters expressing the internal state of the battery are estimated from the battery's usage history; battery capacity is estimated with consideration of these parameters.

Research to respond to demands for improving usability of passenger vehicles has played important roles. Some aspects can be attributed to friction behavior of the steering and suspension components. In this study, we focus on an approach to improve handling, steering feel and ride-comfort of a vehicle by applying the appropriate friction behavior to tie-rod end ball joint. To control not only friction coefficient but also static-kinetic transient behavior, we investigate the potential use of diamond-like carbon (DLC) coatings. Different DLC coatings varied widely in hydrogen content, mechanical properties and micro-surface roughness are applied to the ball studs. Friction behavior corresponds to material characteristics and surface roughness of DLC.

A new 6-speed automatic transmission (AT) has been developed with the aim of enhancing fuel economy, raising efficiency, and achieving greater compactness. The unit was built on a parallel-shaft structure similar to the previous Honda AT, which has high torque transmission efficiency. The new AT was given more gear speeds and the ability to handle higher input torque from the engine. On the one hand, bolt structure for shaft tightening was implemented, the forward-reverse shift mechanism was placed on the input shaft and common gear trains are provided. As a result of these and other measures, the total length of the new transmission is 18 mm shorter than the previous model 5-speed AT. A multi-plate lock-up clutch (LC) structure with a separate chamber in the torque converter was also adopted so that the lock-up torque capacity could be increased and the LC control range expanded.

Honda has been taking measures since the late 1990s to address three issues raised by the automobile, from air pollution, which was already a matter of regulation, to the additional issues of global warming and energy. With observation of recent trends in society, what had been our concern about these three matters appears to have gradually been turning into certainty instead. Meanwhile, the demand for automobiles is expected to increase with the population growth in newly emerging countries, economic growth, and other such factors. At present, with automobiles dependent on oil for the greater part of their energy, it has become a challenge to secure a stable supply of reasonably priced oil while the global warming perspective requires reduction of CO2 emissions. This article will review the history of development of the fuel cell vehicle (FCV) equipped with the next-generation power plant capable of simultaneously providing the solutions demanded for all three automobile issues.

A simple method is frequently used to calculate a reciprocating engine’s bearing load from the measured cylinder pressure. However, it has become apparent that engine downsizing and weight reduction cannot be achieved easily if an engine is designed based on the simple method. Because of this, an actual load on a bearing was measured, and the measured load values were compared with a bearing load distribution calculated from cylinder pressure. As a result, it was found that some of actual loads were about half of the calculated ones at certain crank angles. The connecting rod’s elastic deformation was focused on as a factor behind such differences, and the rod’s deformation due to the engine’s explosion load was studied. As a result, it was found that the rod part of the engine’s connecting rod was bent by 0.2 mm and became doglegged. Additional investigation regarding these findings would allow further engine downsizing.

An apparatus that automatically samples lubricating oil and measures the size distribution of particles in the oil has been developed in order to monitor the state of engines and transmissions in operation. It is a widely known fact that when an engine or transmission seizes or experiences unusual wear, comparatively large pieces of wear debris are released. The goal of the use of the apparatus is to detect these particles of wear debris, stop testing before damage occurs, and clarify the causes. Seizure was, therefore, artificially induced in a transmission, and the wear debris in the oil was closely analyzed following the test. The results showed that when the simulated seizure occurred, large, elongated particles of wear debris were produced. Similar wear debris was observed in oil recovered from the market following the seizure of a component, and at present this is believed to be a type of wear debris characteristic of seizure.

The Honda NSX, made entirely of aluminum, introduces a concept of using chromium chromate as a method of chemical pretreatment. For other parts that contain a different type of metal, such as various parts of the chassis, a DACRO coating system as well as many other inventions are used. For the paint process itself, a new waterborne basecoat technology is also introduced to obtain a high-class appearance level for the NSX.