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Nowadays, Bismuth (Bi) is being applied as an overlay material for engine bearings instead of Lead (Pb) which is an environmentally harmful material. Bi overlay has already been a solid performer in some automotive engine sectors due to its superior load carrying capacity and good robustness characteristic which are necessary to maintain its longevity during the lifetime of engines. The replacement is also seen on relatively larger size engines, such as Trucks and Off-highway heavy duty applications. Basically, these applications require higher power output than passenger cars, and the expected component lifecycle becomes longer. Though Bi has similar material characteristic to traditional Pb, it becomes challenging for the material alone to satisfy these requirements. Polymer overlay is known for its superior anti-wear performance and longer lifetime due to less adhesion against a steel counterpart than metallic materials (included Bi).

In recent years, the removal of lead (Pb), which is an environmentally hazardous material often used in bearings for automotive engines, has been continuously promoted. Bismuth (Bi) is attracting attention as a substitute for lead, and it is currently being used mainly for passenger cars and trucks as a lead replacement. However, lead has not been replaced for motorcycles where the bearings are exposed to high temperatures at high rotation speeds, and trucks and generators where high loading capacity, long lifetime and good corrosion resistance are required. It has been difficult to achieve both high load and corrosion resistant for a bearing overlay material. The purpose of this development is to improve the corrosion resistance and fatigue resistance of bismuth overlay by developing a bismuth- antimony alloy overlay in which antimony (Sb) is added to the bismuth matrix.

A new hybrid system has been developed to increase the permissible system weight and raise dynamic performance/system efficiency for the global rollout of Honda's electric vehicles. The powertrain consists of a 2.0L direct injection engine, a Front Drive Unit (FDU) with a built-in traction motor/generator and gear that directly transmit engine torque to the wheels (engine driving gear), a Power Control Unit (PCU) mounted on the FDU, and an Intelligent Power Unit (IPU) mounted under the cargo area. The FDU has a higher RPM (+12%) and higher torque (+6%) traction motor for enhanced launch acceleration performance and maximum vehicle speed settings tailored to regional needs. In addition, a new engine driving gear for low-speed driving has been added to heighten system efficiency by avoiding traction motor driving in low-speed, high-load areas where electrical losses are high, and instead using a driving mode with an engine driving gear (ENGINE MODE).

The mechanical loss reduction of the bearing reduces the fuel consumption of the engine, which can help realize a sustainable society. Thus, a bearing friction reduction technique has been studied. There have been many studies related to friction-reduction techniques for mixing and boundary lubrication. However, there are few studies on hydrodynamic lubrication, and the main methods have been related to changing the low-viscosity oil and bearing size. In driving passenger cars in urban areas, the lubricant condition of the engine bearings is largely dependent on hydrodynamic lubrication. Therefore, the power loss under this operating condition cannot be ignored. In this study, the reduction of the friction loss under hydrodynamic lubrication was focused. A method for reducing the shear resistance of oil was examined and its effect was confirmed through experiments and calculations.

The superior formability and local ductility of the emerging class of third generation of advanced high-strength steels (3rd Gen AHSS) compared to their conventional counterparts of the same strength level offer significant advantages for automotive lightweighting and enhanced crash performance. Nevertheless, studies on the material behavior of 3rd Gen AHSS have been limited and there is some uncertainty surrounding the applicability of developed methodologies for conventional dual-phase (DP) steels to this new class of AHSS. The present paper provides a comprehensive study on the quasi-static and dynamic constitutive behavior, formability characterization and prediction, and the fracture behavior of two commercial 3rd Gen AHSS with an ultimate strength of 1180 MPa that will be contrasted with a conventional DP1180. The hardening response to large strain levels was determined experimentally using tensile and shear tests and then validated with 3-D simulations of tensile tests.

Bismuth has been applied successfully as sliding bearing overlay material in internal combustion engines, where a good combination of sliding properties, mechanical strength and corrosion resistance can be attained. However, environmental pressures driving towards lower emission and higher fuel efficiency are set to raise firing loads above the capability of many state-of-the-art bismuth materials in the market. At the same time, in order to meet increasingly stringent environmental regulations modern engines are adapting to more efficient and economic designs which put bearing materials under ever growing pressure to provide enhanced oxidation resistance and robustness to cope with elevated engine operating temperature and tighter oil clearance.

Recent automotive engine developments have made great progress in protecting the global environment and in meeting exhaust gas regulations and fuel economy regulations. As a result, engine bearings tend to be used under severe conditions such as higher specific load onto the bearings and with low viscosity of lubricating oil. Aluminum alloy bearings are widely adopted as main bearings and connecting rod bearings in gasoline and diesel engines for passenger cars, and generally Al-Sn-Si alloy bearings without an additional overlay are used. Although these Al-Sn-Si alloy bearings have good anti-seizure properties and excellent running-in-properties, their material strength under high temperature conditions is not sufficient because of the low melting point of Sn phase contained in the alloy, and they could potentially result in damage to the bearing as seizure and fatigue under these conditions. In such cases, Cu-Pb-Sn alloy bearings with lead-based overlay are usually applied.

The development and calibration of stress state-dependent failure criteria for advanced high-strength steel (AHSS) and aluminum alloys requires characterization under proportional loading conditions. Traditional tests to construct a forming limit diagram (FLD), such as Marciniak or Nakazima tests, are based upon identifying the onset of strain localization or a tensile instability (neck). However, the onset of localization is strongly dependent on the through-thickness strain gradient that can delay or suppress the formation of a tensile instability so that cracking may occur before localization. As a result, the material fracture limit becomes the effective forming limit in deformation modes with severe through-thickness strain gradients, and this is not considered in the traditional FLD. In this study, a novel bending test apparatus was developed based upon the VDA 238-100 specification to characterize fracture in plane strain bending using digital image correlation (DIC).

Practical evaluation and reduction of edge cracking are two challenging issues in stamping AHSS for automotive body structures. In this paper, the effects of the shear clearance and shear rake angle on edge cracking were investigated with three different grades of AHSS; TRIP780, DP 980, and DP 1180. Five different shear clearances, between 5% and 25% of material thickness, were applied to the flexible shearing machine to generate samples for the half specimen dome test (HSDT). The shear loads and the shear edge quality were thoroughly characterized and compared. The HSDT created the edge forming limits as compared to the base material forming limit diagram. The load-displacement curve was acquired by the load-cell and the strain distribution was measured using a digital image correlation (DIC) system during the dome test.

The number of vehicles with engines using idling stop systems and hybrid systems to improve fuel consumption has recently been increasing. However, with such systems the frequent starts and stops of the engine, where the oil film between the bearings and shaft is squeezed out and direct contact between the components is more likely, can result in increased wear of the engine bearings, particularly in the main bearing. Bearings with resin overlays have been shown to display superior resistance to wear from such start-stop cycles. Moreover, cast iron shafts without quenching treatment have also been used in engines for cost reduction. Because the cast shaft has low hardness and unstable surface graphite after abrasive finishing, increase in the wear amount cannot be suppressed by conventional resin overlay in comparison with steel shaft. Therefore, the resin overlay with improved wear resistance achieved by adding hard particles was developed.

This study developed technology for simultaneously welding heterogeneous resin tubes in order to weld and integrate resin tubes with two different specifications (low temperature and high temperature). The aim of integration was cost and weight reduction. The cost reduction due to reducing the number of parts exceeded the increase in material cost due to a change to resin materials. Base material fracture of the resin tubes was set as the breaking format condition, and the welding parameters of the joint part rotations and the friction time between the joint part and the resin tubes were specified as the weld strength judgment standard. In addition, the fused thickness determined by observing the cross-section after welding was specified as the weld quality judgment standard. The range over which weld boundary peeling does not occur and weld strength is manifest was clarified by controlling the welding parameters and the fused thickness.

The CAE method to predict the vibration transfer function of the hydraulic engine mount on a vehicle with sufficient precision and calculation time without prototype cars was developed. The transfer function is given in the following steps. First, rubber deformation form under the power train weight loaded must be predicted. It’s obtained by using a reduction model of an engine mount, as a unit, which doesn’t have its fluid sealed inside, with the technique to get the static spring characteristics in a non-linear relationship. Second, Young’s modulus and structural damping coefficient for the deformed rubber must be given. As for these characteristics, ignoring the relations between these values and strain, the constant values are used. This considerably reduces computation time and model size. Next, the reduction model and the fluid model have must be combined to express actual product. In this step, coupled analysis for fluid and structure is used.

In order to determine the seizure limit of the main bearings of passenger vehicles under actual operating conditions, evaluations were conducted in environments containing noise factors (Various factors which designer cannot adjust and which make function vary were defined as noise factors in this paper.) [1,2] It was shown that noise factors have an effect on seizure limit performance in relation to performance under ideal test conditions (test conditions in which no noise is present). In relation to oil properties, the results showed that a reduction in viscosity as a result of dilution affected seizure limit performance. In relation to the shape of the sliding sections of the test shaft, seizure limit performance declined in a shaft in which the central section was swollen (“convex shaft” below).

In this research, a three degree-of-freedom (DOF) rack-type electric-based power steering (EPS) model is developed. The model is coupled with a three DOF vehicle model and includes EPS maps as well as non-linear attributes such as vibration and friction characteristics of the steering system. The model is simulated using Matlab's Simulink. The vibration levels are quantified using on-vehicle straight-line test data where strain-gauge transducers are placed in the tie-rod ends. Full vehicle kinematic and compliance tests are used to verify the total steering system stiffness levels. Frequency response tests are used to adjust tire cornering stiffness levels as well as the tire dynamic characteristics such that vehicle static gain and yaw natural frequency are achieved. On-center discrete sinusoidal on-vehicle tests are used to further validate the model.

Recently vehicle development timeline is becoming shorter, so there is an urgent need to be able to develop vehicles with limited resources. This means the efficiency of the body structure development process must be improved. Specifically it is important to reduce the amount of design re-work required to meet performance targets as this can have a large influence on the body development time. In order to reduce the afore mentioned design re-work, we developed simple calculation models to apply a “V-Flow Development Process” to the preliminary stage design of the automobile body structure. The “V-Flow” advantages are as follows: (1) simple and easy to use, (2) defects are found at early stage, (3) avoids the downward flow of the defects. The advantage of preliminary stage design is that there is design flexibility since not many specifications have been determined yet.

Seat vibration when a vehicle is idling or in motion is an issue in automobile development. In order to reduce this vibration, dynamic damper or inertia mass is widely used. These countermeasures increases vehicle's weight and causes bad fuel-efficiency. Some new ways to reduce the vibration without weight increase are needed. One of that is the floating seat. Seat vibration has been reduced by controlling seat resonance frequencies. In order to control resonance frequency, the structures of the seat-mounting unit are replaced with floating structures using rubber bushings. It was demonstrated that partially replacing the mounting unit with floating structures makes it possible to control the resonance frequencies of the entire seat. The issue of balancing vibration reduction with strength and durability and crash safety performance caused by the fitting of rubber bushings to the seat-mounting unit was addressed using stopper structures optimized for each type of input.

Dark, high gloss decorative finishes (i.e. piano black) are gaining increased application and demand in vehicle interiors; due to interior stylists' desire for this look. One significant concern with this trend is that scratches, and other appearance related defects such as orange peel (waviness), are more apparent to the customer. To address this issue, a highly scratch-resistant 2K clearcoat formulation was developed to minimize visible surface scratches, while also yielding minimal orange peel and exceptional DOI (distinctness of image); all while being applied using typical application techniques in the part finishing market. This output was accomplished by first benchmarking the consumer electronics market for appearance and scratch resistance, and then setting targets through that research.

Regulations that limit emissions of pollutants from gasoline-powered cars and trucks continue to tighten. More than 75% of emissions through an FTP-75 regulatory test are released in the first few seconds after cold-start. A factor that controls the time to catalytic light-off is the heat capacity of the catalytic converter substrate. Historically, substrates with thinner walls and lower heat capacity have been developed to improve cold-start performance. Another approach is to increase porosity of the substrate. A new material and process technology has been developed to significantly raise the porosity of thin wall substrates (2-3 mil) from 27-35% to 55% while maintaining strength. The heat capacity of the material is 30-38% lower than existing substrates. The reduction in substrate heat capacity enables faster thermal response and lower tailpipe emissions. The reliance on costly precious metals in the washcoat is demonstrated to be lessened.

We developed a windshield washer system that enhances washing performance while maintaining low consumption of windshield washer fluid. The system reduces user stress by shortening the amount of time required to remove dirt and maintaining visibility through the windshield. We analyzed the mechanism through which the windshield wiper and windshield washer remove dirt from the glass surface to improve cleaning efficiency. The mechanism consists of a sequence in which the windshield washer fluid splashes down on the glass surface and lifts dirt which is then wiped away by the windshield wiper blade. We defined the amount of windshield washer fluid needed and the time from splashdown to wiping required to lift dirt and wipe it away with the wiper. Based on this mechanism, we developed a wiper arm with built-in washer nozzles.

There has been a requirement for automotive bearings materials to be free of the toxic material lead, in accordance with ELV regulations and from the perspective of environmental problems. Currently, bismuth is used as a replacement for lead in copper alloy based main journal bearings and connecting rod bearings for automotive engines. In recent years, there has been changing to lead-free materials for truck engine bearings. Compared with automotive engines, lots of contaminations in the oil and local contact between the shaft and bearings can occur in truck engines. The ability to tolerate contamination and local contact is therefore required for truck engine bearings. In this development, we find that the addition of 8 mass% bismuth and 1.5 mass% molybdenum carbide particles into copper-tin alloy is effective for improving the ability which allow the contamination and local contacts. The development of above mentioned lead-free copper alloy bearing material is described here.