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Using skirt-liner clearance and cylinder pressure measurements provided by Isuzu Motors, Ltd. of a production type gasoline automotive engine, a validation study was done of Ricardo's PISDYN code, which predicts the secondary motions and skirt liner elastohydrodynamic lubrication of pistons. Predictions using the computer code of the skirt liner clearance at two locations on the skirt were compared with measured results. Using the code, parametric studies were done. Very good qualitative and quantitative agreement was found for the baseline cases. In the parametric studies using the code only, the following were found: The predicted clearances were very sensitive to variation in cold minimum clearance. The effect of cylinder induced pressure deformation was significant, especially near the point of peak cylinder pressure. Increasing the cylinder pressure increased the peak clearances. Changing the asperity roughness height affected the clearances near a point of asperity contact only.

This paper offers a brief explanation of Isuzu Transport Auto Control (I-TAC), a system used to accurately collect and control information in-transit. I-TAC was developed as a means to meet needs for transportation by truck.

Countour Induction Hardening (CIH) method is in the limelight as a new possible surface refining method for gears as it reduces quenching distortion considerably and increases compressive residual stress. Also, Double Shot Peening (DSP) method, especially its advanced technique of using extensively small shots (less than 100 m) at the secondary peening, enables increased compressive residual stress under the surface of the gears. Therefore, the new Compound Surface Refining Method of using CIH + DSP is expected to give much higher compressive residual stress than the conventional methods. On studying the application of this new method, the authors evaluated their surface-refining characteristics and the fatigue limits.

Supercharging system is obviously a necessary technology for heavy duty vehicular diesel to meet future stringent emission regulation as well as to improve fuel consumption characteristics. Although the conventional exhaust turbocharger system improves fuel consumption, there are some problems such as having a difficulty in improving starting acceleration and smoke emission characteristic because the response of an exhaust supercharger is not enough. On the other hand, the conventional mechanical supercharging system seems to be a quite effective aid for acceleration ability. However, it does not satisfy demand for low fuel consumption characteristic.

The growing need for improved fuel economy is a global challenge due to continuously tightening environmental regulations targeting lower CO2 emission levels via reduced fuel consumption in vehicles. In order to reach these fuel efficiency targets, it necessitates improvements in vehicle transmission hardware components by applying advanced technologies in design, materials and surface treatments etc., as well as matching lubricant formulations with appropriate additive chemistry. Axle lubricants have a considerable impact on fuel economy. More importantly, they can be tailored to deliver maximum operational efficiency over specific or wide ranges of operating conditions. The proper lubricant technology with well-balanced chemistries can simultaneously realize both fuel economy and hardware protection, which are perceived to have a trade-off relationship.

Every year the trucking industry demands lighter weight and lower cost truck components. But it is very difficult to achieve both these targets. This paper describes the example of a suspension system design which was conducted by computer simulation, so called CAE. The computer simulation by FEM was used completely to decide the detailed shape of each part. This paper also introduces a casting method to strengthen the aluminum alloy cast using high pressure during casting. By using this method, products have a precise metallographic structure. As a result, both the development cost and period were reduced by over the half the time required of the current system and lighter and strong parts were created.

When a heavy duty truck with 2 rear axles is turning a curve at slow speed, a large side bending force to the chassis frame occurres as vehicle turning radius becomes smaller. In the past, the stress produced by side bending forces was little analyzed. By our research work of FEM, side bending stress of heavy duty truck could be analyzed accurately.

To check sharply increasing traffic accident casualties, activities have been underway to analyze accidents and develop safety equipment Automobile makers have placed a great emphasis on improving safety in collision. In this situation, a new side impact standard was introduced in FMVSS 214 in October 1990 and will be applied to passenger cars in 1993 model year. The standard requires an additional full scale dynamic test in which an aluminum honeycomb moving deformable barrier (MDB) simulating the front end of a car is crashed at 33.5 mph into the side of a standstill car at an angle of 27 degrees. The Side impact Dummy's (SID) Thoracic Trauma index (TTI(d)), which is the average of the maximum rib acceleration and the maximum lower spine acceleration, is limited to 90 g's for a 2-door passenger car and 85 g's for a 4-door car. The dummy's pelvic maximum acceleration must remain no greater than 130 g's for both types of cars.

GVW 20 ton class cargo trucks were mainly powerd by L6 turbocharged engines ISUZU 6SD1TC and ISUZU 6RB1TC, and this time new 6WA1TC turbocharged engine with intercooler as a successor to 6RB1TC went into production in July 1992. In the recent cargo vehicle market in Japan, demand is increasing for higher out-put power, light weight, long service life, high reliability and low fuel consumption. Under such circumstances special engineering attention was paid to exhaust emissions and noise regulations which are expected to become even stricter in future. The basic engine structure consists of an OHC 4-valve type cylinder head and a ladder frame type cylinder block which satisfies the requirements for the high out-put power, low fuel consumption and light weight. Also, adopted are various variable structures such as a high pressure fuel injection pump with a variable injection timing and rate control device, variable swirl system and variable geometry turbocharger.

There is ever an increasing need for weight reduction and high performance of engine (clean smoke and improving fuel economy) To achieve this, recently aluminum castings are used for engine parts such as cylinder heads that construct combustion chamber and are required thermal resistance. This paper describes thermal fatigue tests of aluminum castings that are made under various conditions of cooling rate during solidification, heat treatment, and chemical compositions. It further investigates the influence of material (such as cooling rate, chemical conmposition and heat treatment) and mechanical properties (such as σB, δ, E ) on thermal fatigue life of aluminum castings.

Application of alternate fuels to diesel engine is much desired. A new and unique dual-fuel injection system has been developed for high speed automotive diesel engines. This system has two features. One is that alternate fuels such as methanol, ethanol and biomass, are directly inducted into the fuel injection pipe through one-way check valve under pressure, and blended fuels are simultaneously injected into the combustion chamber. The other is that various kinds of fuel can be easily adapted to this system not dependent upon the fuel properties such as viscosity. Using a single cylinder direct injection diesel engine and ethanol as an alternate fuel, injection characteristics and exhaust gas emissions were investigated. The results showed that ethanol could replace up to 50% of diesel fuel while keeping the normal engine operating stability. A better fuel economy was also obtained by applying both higher compression ratio and advanced injection timing.

The P’UP has been on the markets worldwide since 1972, both in Japan and overseas, including for the U.S., in which case, with model designation as the Chevrolet LUV. In 1980, for the first time since its market introduction, it was fully remodelled with detail improvements reflected thereon in every aspect. This new model continues to be on the U.S. market as the Chevrolet LUV as it has been, but, beginning from spring of 1981, the similar model has been introduced to the market by the American Isuzu Motors Inc. (AIM) as the Isuzu P’UP. Taking this opportunity, a diesel version has been added to its model lineup. The diesel engine mounted on this version features its 20 to 30% better fuel efficiency over its gasoline counterpart. In the first half of this paper, the engineering concepts of its full remodelling and their onvehicle reflection will be introduced.

A pre-combustion chamber (hot plug) made of the silicon nitride ceramics has been developed. The hot plug constitutes a component of the combustion chamber of swirl chamber diesel engines. And it is subjected to the severest thermal load of all the diesel engine operating components. Unlike metal hot plugs, the ceramic hot plug application requires a unique design approach to meet the ability of the ceramic materials. That is, the soft engine mounting is necessary to avoid the concentraction of mechanical stress resulting from the high Young's Modulus of the ceramic and control of temperature distribution is also required to reduce thermal stress. Due to the heat insulating construction, the ceramic hot plug permits the combustion performance to be improved at a low speed and load, resulting in improved noise, startability, and HC emission. In additional the ceramic hot plugs are already being produced for diesel passenger car.

Eight kinds of the spot-welded test specimens were studied to obtain the basic fatigue data on steel sheets for car bodies. Analytical methods such as the strain amplitude at outside and inside plates close to the nugget, the maximum nominal stress and Kθmax criteria of fracture mechanics were used. The authors propose that the ratio of strains at two points around the nugget can provide evaluation of the bending load and estimation of the fatigue strength.

This paper describe the metal-to-ceramic joining method which is important for building ceramic adiabatic engine and deals with the potential of pistons for use for adiabatic ceramic engine. Although various ceramic-to-metal joining methods have been developed, the chemical bonding method such as brazing and diffusion bonding is not only inferior in complex joining process and heat resistance, but also incapable of attaining the bonding strength of 196Mpa required of engineering ceramics. The ceramic-to-metal bonding attained generally by mechanical method such as staking results in the failure of ceramic bonding face due to a strong shearing force accompanied by the plastic deformation of metal. Therefore, the reduction of the shearing force between the ceramic and metal materials and the improvement of plasticity of the metal are necessary.

In order to meet the demands for reduced emissions and improved fuel consumption, a subport-type variable swirl system (Isuzu Variable Electronic Economy Swirl, or IVES) was developed by Isuzu for medium- and heavy-duty direct-injection-type diesel engines. The main characteristics of IVES are: (1) It is simple in structure and only minor changes to the cylinder head are required. (2) Modular design is possible for three different swept volume engines due to the use of a common actuator and sensor. (3) The problem of air flow coefficient drop when swirl is varied has been successfully eliminated.

Two working groups in the JSAE Committee of Fatigue–Reliability Section1 are currently researching the issue of fatigue life by both experimental and the CAE approach. Information regarding frequent critical problems on arc–welded structures were sought from auto–manufacturers, vehicle component suppliers, and material suppliers. The method for anti–fatigue design on arc–welded structures was established not only by a database created by physical test results in accordance with the collected information but also with design procedure taking Fracture–Mechanics into consideration. This method will be applied to vehicle development as one of the virtual laboratories in the digital prototype phase. In this paper, both the database from bench–test results on arc welded structures and FEA algorithm unique to JSAE are proposed some of the analysis results associated with the latter proposal are also reported.

In fleet uses, heavy-duty trucks with turbo, inter-cooled engines are popular in Japan. These trucks usually experience congested traffic and/or frequent road grade change in expressways. As a result, frequent vehicle speed and engine load fluctuations are observed. This paper describes the typical, on road driving data from the field and presents one sample of engine control optimization for better fuel economy in actual road conditions.