Search Results

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.

Research has been conducted on Controlled Auto-Ignition (CAI) engine with natural gas. CAI engine has the potential to be highly efficient and to produce low emissions. CAI engine is potentially applicable to automobile engine. However due to narrow operating range, CAI engine for automobile engine which require various speed and load in real world operation is still remaining at research level. In comparison some natural gas engines for electricity generation only require continuous operation at constant load. There is possibility of efficiency enhancement by CAI combustion which is running same speed at constant load. Since natural gas is primary consisting of methane (CH4), high auto-ignition temperature is required to occur stable auto-ignition. Usually additional intake heat required to keep stable auto-ignition. To keep high compression temperature, single cylinder natural gas engine with high compression ratio (CR=26) was constructed.

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.

The suitability of FM radio receivers for automobiles has conventionally been rated by evaluating reception characteristics for broadcast waves in repeated driving tests in specific test environments. The evaluation of sound quality has relied on the auditory judgment due to difficulties to conduct quantitative evaluations by experiments. Thus the method had issues in terms of the reproducibility and objectivity of the evaluations. To address these issues, a two-stage method generating a virtual radio wave environment on a PC was developed. The research further defined the multipath distortion rate, MDr, as an index for the sound quality evaluation of FM receivers, and the findings concerning the suitability of the evaluation of FM terminals for automobiles were reported at the 2015 SAE World Congress.

A compact, low-cost fuel pump module has been developed for use in motorcycles with a small-displacement engine. Various considerations are given to make the module as compact as possible. The pump motor, which is one of the major component parts, is down-sized specifically for applications to small-displacement engines. The pressure regulator uses a simple construction consisting only of a ball and a spring without a diaphragm. Especially noteworthy is that with the volume reduced by approximately 40% from the conventional pressure regulator while using the construction that reduces self-excited vibrations caused by fuel pressure pulsations, the pressure regulator contributes significantly to the down-sizing and cost reduction of the module. Furthermore, the down-sized module remarkably reduces the size of fuel pump mount surface, allowing a modification from the flat-surface sealing to the radial sealing.

Gasoline includes various kinds of chemical species. Thus, the reaction model of gasoline components that includes the low-temperature oxidation and ignition reaction is necessary to investigate the method to control the combustion process of the gasoline engine. In this study, a gasoline combustion reaction model including n-paraffin, iso-paraffin, olefin, naphthene, alcohol, ether, and aromatic compound was developed. KUCRS (Knowledge-basing Utilities for Complex Reaction Systems) [1] was modified to produce paraffin, olefin, naphthene, alcohol automatically. Also, the toluene reactions of gasoline surrogate model developed by Sakai et al. [2] including toluene, PRF (Primary Reference Fuel), ethanol, and ETBE (Ethyl-tert-butyl-ether) were modified. The universal rule of the reaction mechanisms and rate constants were clarified by using quantum chemical calculation.

A multi-use road simulator for reproducing various road loads on motorcycles and buggies has been developed on a test bench by using computer-controlled hydraulic actuators. The device is controlled by a low-priced personal computer and an interface system with custom software. An unique feature is the capability to simulate loads related to such phenomena as the bottoming of suspension and the movement of a telescopic type front fork on the road.

A new hydrogen fueling protocol named MC Formula Moto was developed for fuel cell motorcycles (FCM) with a smaller hydrogen storage capacity than those of light duty FC vehicles (FCV) currently covered in the SAE J2601 standard (over than 2kg storage). Building on the MC Formula based protocol from the 2016 SAE J2601 standard, numerous new techniques were developed and tested to accommodate the smaller storage capacity: an initial pressure estimation using the connection pulse, a fueling time counter which begins the main fueling time prior to the connection pulse, a pressure ramp rate fallback control, and other techniques. The MC Formula Moto fueling protocol has the potential to be implemented at current hydrogen stations intended for fueling of FCVs using protocols such as SAE J2601. This will allow FCMs to use the existing and rapidly growing hydrogen infrastructure, precluding the need for exclusive dispensers or stations.

A highly efficient two-motor plug-in hybrid system is developed to satisfy the global demands of CO2 reduction. This system switches three operation modes, what is called “EV Drive”, “Hybrid Drive” and “Engine Drive”, to maximize fuel efficiency according to the driving condition of the vehicle. Practical plug-in EV (Electric Vehicle) capability is also realized by adding a high-power on-board charger and a high capacity Li-ion battery to the original system. The outlines of the system components including a newly developed Atkinson cycle engine, a highly efficient electric coupled CVT (Continuously Variable Transmission) with built-in motor and generator, an integrated PCU (Power Control Unit) and an exclusive battery for plug-in HEV (Hybrid Electric Vehicle) are described in this paper. In addition to the switching of three driving modes and the efficiency improvement of each device, cooperative control of the hybrid system is introduced.

This paper explains the new methodology for post-crash fuel leakage testing of Fuel Cell Vehicles (FCVs) and other hydrogen vehicles utilizing compressed hydrogen storage systems. This methodology was incorporated into SAE J2578 that was revised and published in January, 2009. The new methodology is based on the concept in FMVSS 303 that specifies post-crash fuel leakage test method and criteria for CNG vehicle and adopted some modifications. Specifically, the following items are addressed: (1) Allowable leakage can be accurately evaluated in test even with large size tank that obtains only small pressure drop when a given amount of leakage occurs. A new method to deal with the influence of measurement errors was devised. (2) Even though only one option of test gas and initial filling pressure is accepted in FMVSS 303, new methodology for hydrogen system allows helium and hydrogen at reduced pressure as alternatives in addition to hydrogen at service pressure.

In this study, in order to relax the pre-cooling regulations at hydrogen fueling stations, we develop a software algorithm to simulate an actual hydrogen fueling process to Fuel Cell Vehicle (FCV) tanks. The simulation model in the software consists of the same filling equipment found at an actual hydrogen fueling station. Additionally, the same supply conditions (pre-cooling temperature, pressure and mass flow rate) as at a hydrogen fueling station were set to the simulation model. Based on the supply conditions, the software simulates the temperature and pressure of hydrogen in each part of filling equipment. In order to verify the accuracy of the software, we compare the temperature and pressure simulated at each stage of the filling process with experimental data. We show that by using the software it is possible to accurately calculate the hydrogen temperature and pressure at each point during the fueling process.

The present study experimentally investigated the performance and emission characteristics of the diesel engine with hydrogen added to the intake air at late diesel-fuel injection timings. The diesel-fuel injection timing and the hydrogen fraction in the intake mixture were varied while the gross heating value per second of diesel fuel and hydrogen was kept constant at a certain value. NO showed minimum at specific hydrogen fraction. The maximum rate of incylinder pressure rise also showed minimum at 10 vol% hydrogen fraction. The indicated thermal efficiency was almost constant or slightly increased with small amount of hydrogen. A combination of hydrogen addition and late diesel-fuel injection timing contributed to low temperature combustion, in which NO decreased without the increase in unburned fuel.

Compression ignition combustion with a lean mixture has high potential in terms of high theoretical thermal efficiency and low NOx emission characteristics due to low combustion temperatures. In particular, a Dual-Fuel concept is proposed to achieve high ignition timing controllability and an extended operation range. This concept controls ignition timing by adjusting the fraction of two fuels with different ignition characteristics. However, a rapid combustion process after initial ignition cannot be avoided due to the homogenous nature of the fuel mixture, because the combustion process depends entirely on the high reaction rate of thermal ignition. In this study, the effect of mixture stratification in the cylinder on the combustion process after ignition based on the Dual-Fuel concept was investigated. Port injection of one fuel creates the homogeneous mixture, while direct injection of the other fuel prepares a stratified mixture in the cylinder at the compression stroke.

In this research, a new wire material made using surface-reforming heat treatment was developed in order to enhance the corrosion fatigue resistance of suspension springs. The aim of surface reforming is to improve hydrogen embrittlement characteristics through grain refinement and to improve crack propagation resistance by partial softening of hardness. The grain refinement method used an α'→γ reversed transformation by rapid short-term heating in repeated induction heating and quenching (R-IHQ) to refine the crystal grain size of SAE 9254 steel spring wire to 4 μm or less. In order to simultaneously improve the fatigue crack propagation characteristics, the possibility of reducing the hardness immediately below the spring surface layer was also examined. By applying contour hardening in the second IHQ cycle, a heat affected zone (HAZ) is obtained immediately below the surface.

The present study experimentally investigated cyclic variation of combustion characteristics of a diesel engine with hydrogen added to the intake air in detail. As the result, there were three ignition modes: (1) hydrogen ignition mode, (2) hydrogen-assisted ignition mode, and (3) diesel-fuel ignition mode. Ignition timing fluctuated from cycle to cycle in each ignition mode and between one ignition mode and another mode. As the coolant temperature was increased, the number of cycles in diesel-fuel ignition mode decreased, and indicated thermal efficiency and cyclic variation was improved. In the case with the blow-by gas introduced to intake port, preflame reaction of blow-by gas first occurred, ignited hydrogen, and then diesel-fuel was ignited by hydrogen combustion in hydrogen ignition mode and hydrogen-assisted ignition mode.

Appendix H of the SAE J2601 standard defines a development hydrogen fueling protocol named the MC Default Fill, which builds upon the foundation of the table based protocol, utilizing the same assumptions, boundary conditions, and process limits as the current standard. The MC Default Fill facilitates the following beyond the table based protocol: 1) the potential to provide faster, more consistent fueling times for fuel cell electric vehicle customers, and 2) the ability to continuously and dynamically adjust to a wide range of dispenser fuel delivery temperatures, allowing for more flexibility in station design. Computer simulations and laboratory bench tests were previously conducted and documented, validating the function and operation of the protocol.

A flexible-fuel system for small motorcycles has been developed that can utilize both gasoline, and ethanol as an alternative to fossil fuel. For practicality, we aimed to develop a system that uses a minimum of additional parts. As a method to make both ethanol and gasoline available with the system, a control algorithm that estimates the ethanol concentration by utilizing the output voltage of an OXYGEN SENSOR and selects the appropriate injection quantity is employed. Usually, in automotive flexible-fuel vehicles (FFV), sub-tanks are mounted to ensure engine startability in cold temperatures. However, in small motorcycles, limitations of mounting space must be addressed. In this system, by clarifying the control logic and determining the difficult cases for cold temperature starts due to high ethanol concentration, configuring the indicator to promote gasoline mixture when the start is difficult enabled the elimination of the sub-tanks.

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.

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.