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In Japan, environmentally-friendly vehicles, such as HV, PHV, EV, and FCV, have been researched and developed as solutions to the energy and environmental problems, but none of these vehicles have been fully satisfactory in all respects, such as environmental performance, vehicle performance, and adaptability to existing infrastructure. Hino Motors, Ltd. launched a hybrid bus in 1992 as a pioneer in hybrid commercial vehicles and has sold more than 10,000 hybrid buses and trucks. An electric-powered minibus designed under the concept of short travel distance and high charging frequency was developed to make use of Hino’s abundant experience in the development of HV and the past market results it has achieved. Since 2012, these buses have operated in three areas as community buses.

In a tractor-trailer, ride comfort affected by horizontal human body motions, so called “wavy” and “shaky” feelings, is at issue. Insight about “wavy” and “shaky” feelings which is important for efficient vehicle development is not enough. Experiments using 6-axis motion generator and motion capture and inverse-analysis using multi-body human model indicated the characteristics of each feeling. Motion observation and transfer function indicated that while a bad subjective score of “wavy” feeling corresponds to same-phase roll motion of chest and pelvis up to 0.7Hz, “shaky” correlates to an antiphase of them around 2Hz. By multiple regression, dominant vibration components of the human body and the vehicle to subjective evaluation of the feelings above were identified. Explanatory variables for the “wavy” feeling are roll rate and lateral jerk and those for the “shaky” are lateral acceleration and longitudinal acceleration.

To understand relationship between vibration on cargo bay of truck and bruise of strawberries in long transportation, a detail analysis of a strawberry-transport was carried out. Vibration in various locations on the truck box was measured throughout the route, and increase of damage to the strawberries was observed at the end of the journey. Also, S-N diagram of strawberries in various frequencies was measured in shaker tests. From these data, a “degree of damage” which can assess the occurrence of bruise was established.

In this study, we investigated the relationship of indicated mean effective pressure (IMEP) for a spark ignition engine under lean combustion with the cyclic variation of mass fraction burned by measuring the energy release from the spark plug, intensity of the light emmision from the flame and the cylinder pressure at the same time. In order to minimized an error in the initial and late combustion stages of the mass fraction burned to be obtained by cylinder pressure, spark plug energy and intensity of light emission were measured. As a result, it was found that there are three main couses of cyclic variation of IMEP. These consist of the burning speed during the initial stage of combustion, variation in the total mass fraction burned, and variation of the late burning during the late expantion stroke. Thus, we determined that there is a favorable interrelatonship between the IMEPs and the corrected mass fraction burned.

A combustion flame visualization system, for use as an engine diagnostics tool, was developed in order to evaluate combustion chamber shapes in the development stage of mass-produced spark ignition (S.I.) engines. The system consists of an image converter camera and a computer-aided image processing system. The system is capable of high speed photography (10,000 fps) at low intensity light (1,000 cd/m2), and of real-time display of the raw images of combustion flames. By using this system, flame structure estimated from the brightness level on a photograph and direction of flame propagation in a mass-produced 4-valve engine were measured. It was observed that the difference in the structure and the propagation of the flame in the cases of 4-valve and quasi-2-valve combustion chambers, which had the same in the pressure diagram, were detected. The quasi-2-valve configuration was adopted in order to improve swirl intensity.