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Intake manifold is a part of an engine that supplies fuel/air mixture to the cylinder heads. Recently, silicone FIPG has been used for the two part design of the intake manifold. It is known that a small, but significant, amount of gasoline fuel can penetrate through silicone FIPG layer due to the flexible nature of the siloxane backbone. Since gasoline permeation is becoming more important because of more severe regulations, it is found that a new polyacrylate based FIPG dramatically reduces the gasoline fuel permeation. This study compares this new technology, polyacrylate FIPG sealant with silicone FIPG sealant used today for vehicle powertrain gasketing applications. Adhesion investigation on both aluminum and magnesium alloys, and oil resistance are also discussed in this study.

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.

In recent years, adhesive bonding is increasingly being applied in the construction of vehicle frames in order to improve body stiffness and crash performance. Regarding crash performance, the behavior of impacted components is affected by the fracture energy value of the adhesive. However, the relationship between the ductility and fracture energy values under mixed-mode loadings has not been sufficiently evaluated. In this paper, the fracture energy of three structural adhesives in a static mixed-mode loading using Double Cantilever Beam (DCB) specimens is presented. To derive the fracture energy values, the Compliance Based Beam Method (CBBM) was used, which allowed for precise determination of fracture energy values. Static mixed-mode loading tests were performed in six configurations of mixed-mode loading, ranging from pure peel mode state to almost pure shear mode state.

Infinitely variable transmission (IVT) is one of the methods used to extend the ratio coverage. In this paper, a dynamic behavior analysis technology was developed for an IVT utilizing a half-toroidal variator as the shifting device. The traction coefficient of traction fluid used for the half-toroidal IVT varies greatly according to contact surface slip rate, contact pressure and fluid temperature. This paper used measurement values from a four-roller machine to identify the coefficient, and then applied it to the dynamic behavior analysis. Use of the identified traction coefficient enabled power transmission characteristic predictions of a half-toroidal variator. To reproduce the elastic deformation in actual operation, the research used the Finite Element Method (FEM) for modeling. This model was also used to visualize the frictional state of traction surfaces during operation.

In recent years, the contribution of tires on vehicle fuel economy has been garnering attention. Up until now, rolling resistance coefficient (RRC) has been the standard way of measuring the amount of impact the tire has on fuel economy. We devised a new method for evaluating the impact of tires on fuel economy that incorporates the concept of tire “driving transmission efficiency” (hereinafter referred to as “driving stiffness”). In doing so, we have clarified the technology direction for contributing to the improvement of fuel economy while maintaining vehicle maneuverability by reducing RRC and improving tire driving stiffness.

Honda’s purpose is to realize the joy and freedom of mobility and a sustainable society in which people can enjoy life. As such, three series of environmental vehicles-FCVs, BEVs, and PHEVs-have been developed so that users in communities around the world can select the ones best suited to their local energy circumstances and individual lifestyles. This paper discusses a structure that enhances both the motive power performance and quietness of a newly developed FCV/BEV traction motor. To enhance motive power performance, the research focused on the stator lamination technique. As for methods of affixing the stator’s layers, the practice with previous models has been adhesion lamination, using electric steel sheets that come pre-made with adhesive layers. Having adhesive layers, however, lowers the ratio (space factor) of steel sheet layers. The new motor uses electric steel sheets without an adhesive layer in order to enhance motive power performance.

The moment of inertia of the crankshaft cannot be ignored when analyzing the dynamics of a motorcycle. In this research, the tire friction force (calculated by drag and tire side force) was used as an index of the drive performance. The ratio of roll rate and steering torque (here after referred to as a roll rate gain) was used as an index of the cornering performance, and it was analyzed as the influence of the moment of inertia of a crankshaft on the drive performance as well as cornering performance. As a result, the influence on drive performance and cornering performance by the moment of inertia has been found.

The use of low-density materials in body panels is increasing as a measure to reduce the weight of the vehicle body. Honda has developed an aluminum/steel sheet hybrid door that is more effective in reducing weight than an all-aluminum door. Because aluminum was used in the door skin, bimetallic corrosion at the connection between the aluminum and the steel sheets represented an issue. It was possible that the difference in the electrical potential of the two metals might promote corrosion at the connection between the aluminum door skin and the steel sheet door panel, in particular at the lower edge of the door, where rainwater and other moisture tend to accumulate, with the result that the appeal of the exterior of the door might decline.

While there has been an empirical rule telling suspension designers that a slight rearward inclination of the wheel travel locus could improve ride harshness performance, there has not been any quantitative proof on it, to the extent of authors' knowledge. The authors planned to analyze the phenomenon by quantitatively measuring the force transmission via suspension, to find out that the amplitude of longitudinal force transmission to the sprung mass changes significantly depending on the above inclination angle. Further investigation has lead to a conclusion that the force transmission from ground to tire has a sharp directivity. And that the relationship between this direction and the direction of wheel travel is a dominant factor, which decides the magnitude of longitudinal force transmission to the sprung mass. In order to make use of the finding, the optimal wheel center locus inclination in side view has been studied, to minimize the longitudinal force transmission.

The tires are one of the most important parts of the vehicle chassis, as they significantly influence aspects such as vehicle's directional stability, braking performance, ride comfort, NVH, and fuel consumption. The tires are also a part whose size affects the vehicle's essential specifications such as wheelbase and track width. The size of the tires should therefore be determined in the initial stage of vehicle development, taking into account whether the size allows the vehicle to achieve the targeted overall performance. In estimations of vehicle performance, computer simulation plays more of an important role, and simulated tire models are designed to reproduce the measured tire characteristics of existing tires. But to estimate the chassis performance with various tire sizes or with tires of uncommon sizes, the prevailing modeling approach, “individual models for individual tires,” would not function well because of limited ability to expand tire models to unfamiliar sizes.

At present, measurements of running resistance are conducted outdoors as a matter of course. Because of this, the ambient temperature at the time of the measurements has a considerable impact on the measurement data. The research discussed in this paper focused on the temperature characteristic of the tires and developed a new correction technique using a special rolling test apparatus. Specifically, using a tire rolling test apparatus that made it possible to vary the ambient temperature, measurements were conducted while varying the levels of factors other than temperature that affect rolling resistance (load, inflation pressure, and speed). Next, a regression analysis was applied to the data for each factor, and coefficients for a relational expression were derived, making it possible to derive a quadratic equation for the tire rolling resistance correction formula.

Vehicle dynamic performance on snow-covered roads is one aspect of performance that is influenced by tire performance. Much research concerning a vehicle's performance on snow-covered roads has focused on being directed to vehicle control technology that increases control when the tire-slip ratio is larger, such as anti-lock braking systems (ABS) and electronic stability control (ESC). There has been little research, regarding performance when the slip ratio on a snow- covered road is smaller. We studied the friction performance of tires on snow-covered roads to predict vehicle performance within the grip range. We propose a technology for predicting vehicle performance within the small slipangle range and also verify its effectiveness. We established the tire characteristics that assure the grip range on a snow-covered road using performance indicators.

Adhesive bonding is a key technology for the lighter weight of battery pack trays using aluminum material. A robust design method of adhesive bonding with the required strength for battery pack structure after degradation was developed to minimize variability of strength under various noise conditions. The parameter design based on Taguchi methods determined the optimum adhesive condition of the bonding process. To guarantee strength after degradation, it is essential to select a robust adhesive material and to minimize the strength variation derived from the adhesive material. The functional evaluation, which includes experimental design method, determined adhesive material with the minimum strength variation among material candidates. Then, robustness of the adhesive material itself has been evaluated as the result of collaboration with the adhesive material supplier. This analysis was able to regulate the compound ratio of raw materials without reducing the adhesive strength.

A new DC brushless motor, which has an almost equivalent driving performance to a 50 cm₃ scooter engine, has been developed to be used in a new electric motorcycle for business. The traction motor is compact enough to be mounted close to the driveshaft of the transmission, which helps reduce friction in the drive train. Consequently, in the downsized motor, by mounting the drive train unit with the PDU (Power Drive Unit) on the wheel side by applying reduction gears, it enables the reduction of maximum motor torque requirement. It also enables other parts of the drive system to be integrated into one unit. In this motor, IPM (Interior Permanent Magnet) structure has been implemented to cope with the high rotation of the motor, and the concentrated winding stator coil has been implemented for downsizing. As for the rotor, the magnets were placed in sections and the yoke shapes were improved to achieve higher rotation speeds that provide the higher power.

This paper studies various wheel stiffness configurations, with the aim of enhancing driving stability while minimizing the increase in weight associated with an increase in stiffness. Reinforcement was added to the wheel disk and the wheel rim of standard aluminum wheels for passenger vehicles in order to produce four wheels with different stiffness configurations. The effects of disk stiffness and rim stiffness on tire contact patch profiles and driving stability were quantitatively evaluated. From the results of tests with the four wheels, it was observed that disk stiffness and rim stiffness have differing effects on tire contact patch profiles, and on driving stability. Disk stiffness influences especially tire contact patch length, and tire contact patch length influences especially maneuverability in driving stability. Rim stiffness influences especially tire contact patch area, and tire contact patch area influences especially stability in driving stability.