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Crankshafts of motorcycles require high strength, high reliability and low manufacturing cost. Recently, a reduction of Pb content in the free-cutting steel, which is harmful substance, is required. In order to satisfy such requirements, we started the development of Pb-free free-cutting steel which simultaneously enabled the omission of the normalizing process. For the omission of normalizing process, we adjusted the content of Carbon, Manganese and Nitrogen of the steel. This developed steel can obtain adequate hardness and fine microstructure by air-cooling after forging. Pb-free free-cutting steel was developed based on Calcium-sulfur free-cutting steel. Pb free-cutting steel is excellent in cutting chips frangibility in lathe process. We thought that it was necessary that cutting chips frangibility of developed steel was equal to Pb free-cutting steel. It was found that cutting chips frangibility depend on a non-metallic inclusion's composition, shape and dispersion.

There is a movement to apply emission control in a marine engine as well due to high public awareness of environmental concern in the United States. We started at the development of 3-seater Personal Watercraft (PWC) equipped with 4-stroke engines in taking environment conformity and potential into account. The PWC employed series 4-cylinder 1100cc displacement engine that has been used for mass production motorcycles. The engine was modified to satisfy requirements for PWC, as a marine engine, such as performance function and corrosion. In order to achieve greater or equal power/weight ratio as against two-stroke PWCs, a four-stroke engine for PWC with an exhaust turbo charger was developed. As a result, we succeeded in developing an engine that attained top-level running performance and durability superior to competitors' 2-stroke engines.

Once the design of a door sheetmetal and accessories is confirmed, the acoustics of the door system depends on the sound package assembly. This essentially consists of a watershield which acts as a barrier and a porous material which acts as an absorber. The acoustical performance of the watershield and the reverberant sound build-up in the door cavity control the performance. This paper discusses the findings of a design study that was developed based on design of experiments (DOE) concepts to determine which parameters of the door sound package assembly are important to the door acoustics. The study was based on conducting a minimum number of tests on a five factor - two level design that covered over 16 different design configurations. In addition, other measurements were made that aided in developing a SEA model which is also compared with the findings of the results of the design study.

Four forces act in rings for a metal pushing V-belt. These forces are: two kinds of intercepting forces which prevent blocks from going outside of pulleys (one caused by pulley thrust, the other caused by centrifugal force), frictional force acting between the rings and the blocks, and bending force in longitudinal direction. In the previous paper (1)(2)(3)(5), distribution of three forces, excluding centrifugal force, were presented at low belt speed. We successfully measured all four kinds of forces including centrifugal force continuously at practical operation conditions for layered rings. In this paper, distribution of these four forces on the innermost ring is described at steady states.

In this study, distributions of block compression force on the driving and driven pulleys were measured using a tiny load-cell inserted between two blocks and a telemeter system, under several constant speed ratios. Ring tension distributions were also measured using a specially devised block. From the experimental results, the following conclusions were drawn: (1) Block compression force distribution on the driving pulley is significantly different from that on the driven pulley. (2) Ring tension takes different value at each side of strings. It is considered that this phenomenon is caused by difference of saddle surface speed between two pulleys.

Devices for use in control of exhaust emissions have become indispensable to motorcycles. In order to evaluate quantitatively the effect of each device, the modal analysis system has to be required. The Modal Analysis System is one that classifies any driving schedule which is used for emissions measurement into four modes: idle, acceleration, cruise, and deceleration; then measures the emissions continuously using a mini-computer which accumulates the results of the analysis by mode. Instead of CO2 tracer method, we introduced the method of diluted exhaust gas measurement. In order for the system to produce reliable measurements, the accuracy of the total installation must be ensured. This paper describes the improvements of accuracy of analysers, technique on handling delay time and the verifications on the modal analysis system.

As the hybrid automotive market becomes quickly saturated with highly competitive products and vehicles, auto manufacturers struggle with business models and the combination of current manufacturing with next generation development. The hybrid development cooperation amongst General Motors, DaimlerChrysler, and BMW offers a new business model that promotes the advancement of the state of strong hybrid technology while maintaining the strong global leadership and competition.

A model of a timing belt analyzed by FEM (a general non-linear finite element program:ABAQUS) successfully confirmed the mechanism that generates belt cord stress. Analysis revealed a good correlation between the experimental and computed results of stress distribution of the belt cord. Through calculation, it was discovered that belts broke near the tooth root, which is the point of maximum stress of the cord.

The Vehicle Stability Assist (VSA) system can generate sufficient forces to rapidly change the vehicle's motion. We can use this capability to effectively control the vehicle's behavior, but we must pay careful attention to ensure its reliability. The VSA system should be precisely tuned for each vehicle's characteristics in order to satisfactorily control performance without any unnecessary intervention or any excessive warnings. Usually extensive field tests are necessary to precisely tune the VSA system. This paper presents a practical method to tune the VSA system with Hardware-In-the-Loop (HIL) simulations in the final stage of its development. Due to the application of this procedure, both high control capabilities and reliability of the VSA system can be achieved.

The aim discussed in this paper is to show a technique to predict loads input to the wheels, essential to determining input conditions for evaluation of suspension durability, by means of full vehicle simulations using multi body analysis software Adams/Car. In this process, model environments were built to enable reproduction of driving modes, and a method of reproducing the set-up conditions of a durability test vehicle was developed. As the result of verification of the accuracy of the simulations in the target driving modes, good correlation for waveforms can be confirmed. And also confirm a good correlation in relation to changes of input load due to changes in suspension specifications.

This paper describes the application of the modal compliance method to a complex structure such as a vehicle body in white, and the extension of the method from normal modes to the complex modes of a complete vehicle. In addition to the usual bending and torsion calculations, the paper also describes the application of the method to less usual tests such as second torsion, match-boxing and breathing. We also show how the method can be used to investigate the distribution of compliance throughout the structure.

The durability of fuel tank straps is essential for vehicle safety. Extensive physical tests are conducted to verify designs for durability. Due to the complexity of the loads and the fuel-to-tank interaction, computer-aided-engineering (CAE) simulation has had limited application in this area. This paper presents a CAE method for fuel tank strap durability prediction. It discusses the analytical loads, modeling of fuel-to-tank interaction, dynamic analysis methods, and fatigue analysis methods. Analysis results are compared to physical test results. This method can be used in either a fuel-tank-system model or a full vehicle model. It can give directional design guidance for fuel tank strap durability in the early stages of product development to reduce vehicle development costs.

One of the major NVH concerns for automobile manufacturers is the response of a vehicle to the impact of the tire as it encounters a road discontinuity or bump. This paper describes methods for analyzing the impact response of a vehicle to such events. The test vehicle is driven on a dynamometer, on which a bump simulating cleat is mounted. The time histories of the cleat impact response of the vehicle can be classified as a transient and a repeated signal, which should be processed in a special way. This paper describes the related signal processing issues, which include converting the time data into a continous spectrum, determination of the correct scaling factor for the analyzed spectrum, and smoothing out harmonics and fluctuations in the signal. This procedure yields a smooth frequency spectrum with a correctly scaled amplitude, in which the frequency contents can be easily identified.

Vehicle design and packaging is a repetitive and tedious process that involves frequent engineering and design changes. To improve design efficiency, a standard naming vehicle design methodology is proposed in this paper. For the geometric or the functional object used in the vehicle context, a standard name is assigned and also used as a unique object feature through its life cycle. With the proposed standard naming design methodology, the engineering knowledge can be efficiently embedded into the CAD design, and hence, vehicle design can be executed in a more automated fashion. Work case of the standard naming design methodology is illustrated by a vehicle design and packaging application using CATIA V5.

New supplier / manufacturer relationship are necessary to produce products quickly, cost-effectively, and with features expected by the customer. However, the need for a new relationship is not universally accepted and endorsed. Resistance can be minimized through supplier self-assessment (such as Ford Motor Company's web-based instruments), management initiatives, and incentives. Trust and sharing are hallmarks. This strategy requires a new workplace paradigm affecting culture and people issues. Teams, extend across companies, share ideas and innovations. Decisions need to be mutually beneficial and the long-term value, for supplier and manufacturer, needs to be considered.

Combined Brake System for small motorcycles has been developed. In small motorcycles, some models have a hydraulic disc brake both in the front and rear wheels but many of them have a hydraulic disc front brake and a mechanical drum rear brake. Accordingly, it was necessary to develop a new system to link the hydraulic system with the mechanical system to allow an application of Combined Brake System to these models. In this paper, a CBS having a new configuration is described where a disc brake and a drum brake are linked in a simple lever structure of an input force distributor, and an inhibitor spring at the foot pedal. With this mechanism equipped, the distribution of brake forces is controlled. When a large input force is applied, a large proportion of brake force is applied to the front brake to obtain adequate deceleration. When a mild input force is applied, which is frequently operated, the brake force proportion is large in the rear compared to the front.

The environmental performance of automobiles and automobile engines in particular is the foremost issue in the automotive industry today. In addition, engine durability performance is an essential aspect of engine oil performance. Four-cycle motorcycle engine oils formulated with dialkyl phosphate, a sulfur-free additive developed as an alternative to ZDDP, provide excellent environmental and durability performance in terms of longer drain intervals, cleanliness and low corrosion properties.

Using sand cores, the weld-able, hollow die-cast parts have been developed. For casting, the transition flow filling method is applied to reduce gas containment and to minimize damages to the core. In designing the products, the newly developed core stress prediction system by melt pressure distribution and the newly developed in-product gas containment prediction system have been applied. The hollow die-cast frame made by the new method attains a 30% increase in rigidity and 1kg reduction of weight.

The 2-Stroke Engine Oil Subcommittee of the JSAE has developed the following five JASO (Japan Automobile Standards Organization) 2-Stroke Gasoline Engine Oil Quality Standards for motorcycle, utility and outboard engines: 1) JASO M340-92 Lubricity test procedure for evaluating two stroke gasoline engine oils 2) JASO M341-92 Detergency test procedure for evaluating two stroke gasoline engine oils 3) JASO M342-92 Smoke test procedure for evaluating two stroke gasoline engine oils 4) JASO M343-92 Exhaust system blocking test procedure for evaluating two stroke gasoline engine oils 5) JASO M345-93 Two stroke gasoline engine oils These standards consist of four kinds of engine test procedure and a classification system which includes three physico chemical properties of an oil.

Conventional HEV motors use neodymium magnets with added heavy rare earths, to realize high output and size reduction. However, deposits of heavy rare earths such as Dysprosium (Dy) and Terbium (Tb) are unevenly distributed, so it is important to reduce the amount used, because of supply issue and material cost. In this paper, the application of a heavy rare earth-free magnet is considered on the new motor for a two-motor hybrid system. Compared to conventional neodymium magnets, heavy rare earth free magnets tend to have low coercivity. Also, heavy rare earth-free magnet have low thermal durability, so it is not easy to apply them to motors for a two-motor hybrid system, which requires high output and small size. The motor requires twice as much torque and six times output than one-motor hybrid system. Increase demagnetization resistance and magnet cooling performance is studied by development of the new motor.