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The automotive seating industry will always be interested in understanding what the end-consumer expects and wants in terms of comfort. Even in the face of a movement towards comfort quantification through various measurement technologies, surveys are, and will always be, the best way to understand comfort. With this said, it is surprising that the published seat comfort research does not provide a standard survey demonstrated to be reliable and valid. Based on the fact that seat comfort development relies so heavily on subjective data, one would think that, in order to make design decisions with minimal risk, a reliable and valid survey is a prerequisite. This paper’s contribution is significant in that it provides a survey with acceptable test-retest reliability, internal consistency, criterion-related validity, and construct validity. It also details a more suitable approach to data analysis that should markedly improve the process of designing a comfortable seat.

This paper describes the development and use of new types of Physical Vapor Deposition (PVD) equipment and deposition technology for thin film hard coatings on a variety of large heavy duty stamping tools. The life of the tools increased significantly, beyond the limits of the presently available coating technologies (Chemical Vapor Deposition - CVD and Thermal Diffusion - TD). The pick-up is eliminated, the surface finish of the parts is improved and the process friction is reduced. Coated stock is handled better, as well as hot rolled high strength heavy gage steel up to 10 mm. thickness. This technique allowed parts up to 725 × 725 × 250 mm. and 450 kg. to be coated, while coating of parts twice the size and mass is possible in the near future.

Hot Metal Gas Forming is an innovative metal forming technique with the potential to leapfrog conventional metal forming techniques of structural steel components for automotive and aerospace industry. HMGF is an outgrowth of superplastic forming (SPF) and hot blow forming (HBF) techniques that the aerospace industry developed to form aluminum and titanium structures. The goal of this program is to develop the HMGF process and prove its production readiness for wide spread use in the Automotive and Aerospace industries by proving process robustness. An early process concept is shown below.

The future development of two-stroke engines will be conditioned by the drastic reduction of pollutant emission, especially of hydrocarbon. This goal is not achievable only by scavenging improvement, rather a new quality of mixture formation using direct injection is imposed. However, the internal mixture formation in a large range of speed and load, considering the scavenge flow particularities of two-stroke engines as well, appears as an extremely complex process. Thereby a numerical simulation is in this case very effective for the adaptation of a direct injection method at the engine. The paper presents a concept for modeling and optimization of the mixture formation process within a high-speed two-stroke engine with liquid fuel injection system. The injection system generates a pressure pulse which is not dependent on the engine speed.

High specific power output two-stroke engine for snowmobile use was converted to a Direct Fuel Injection (DFI) engine, in order to achieve lower HC emission by avoiding fuel short circuiting and to obtain higher specific power output by increasing induction air and optimizing A/F. High pressure single fluid fuel system was chosen because of extremely high fuel delivery rate. The fuel injector and its location were investigated and optimized for better mixture formation and lower HC emission. 140kW/L level specific power output, maximum engine speed of 9000 rpm, and 1/2 the level of HC emissions were obtained.

An attempt to reduce the HC emission of a two-stroke engine was carried out. A simple homogeneous charge combustion created with a Direct Fuel Injection (DFI) system was applied to a Personal Water Craft (PWC) engine. 1/4 HC emission of the base carbureted engine was obtained in International Council of Marine Industry Association (ICOMIA) driving mode due to the exclusion of fuel short-circuiting. Then stratified charge combustion was introduced. A numerical simulation of air and spray motion was performed and mixture formation was optimized. The low load misfiring was completely overcome and finally, less than 1/8 HC emission was achieved.

The IAPAC Direct fuel Injection (DI) system, developed by IFP, has already well proven its capability to reduce pollutants emissions and fuel consumption of 2-stroke engines. This crankcase Compressed Air Assisted Fuel Injection Process allowing the introduction of the fuel separately from the scavenging air, minimizes the fuel short-circuiting. In earlier works, results of the implementation of the IAPAC system on cylinder displacement from 125 cc to 400 cc have been presented in various papers. These first prototypes were all using a camshaft to drive the IAPAC DI poppet valve, which was considered as a limitation for applying this system to small displacement 2-stroke engines. The new SCIP™ system is no more using a camshaft neither driveshaft, or any electric power supply to drive the DI air assisted injection valve.

An experimental investigation was carried out to highlight the impact of different catalytic exhaust systems of a typical European two-stroke engine for small scooters on exhaust emissions and on engine performances. In particular different chemical compositions of the active coating materials and different precious metal loads were tested, and several geometries of the monolith in the exhaust system were analyzed. The influence of different carburetor settings on the efficiency of the catalyst and on engine performance was also evaluated. Finally, durability tests were performed, by monitoring the efficiency of the catalyst during a 12000 km aging test.

A project was conducted by Southwest Research Institute on behalf of the California Air Resources Board and the South Coast Air Quality Management District to demonstrate the technical feasibility of utilizing closed-loop three-way catalyst technology in off-road equipment applications. Five representative engines were selected, and baseline emission-tested using both gasoline and LPG. Emission reduction systems, employing three-way catalyst technology with electronic fuel control, were designed and installed on two of the engines. The engines were then installed in a fork lift and a pump system, and limited durability testing was performed. Results showed that low emission levels, easily meeting CARB's newly adopted large spark-ignited engine emission standards, could be achieved.

The motorcycle Industry is one of the advantageous industries with developing potentialities in China. Depending on chassis dynamometer test results from more than 100 motorcycles a motorcycle emission data–base was set up. By using this motorcycle emission data–base the status overview of Chinese motorcycle emissions is given. Unleaded gasoline will be used throughout china in 2000, which creates essential prerequisite for application of catalytic converter technique. Catalytic control of motorcycle emissions requires that the catalytic converter must be carefully integrated into the exhaust system. Optimal matching between catalytic converter position and engine performance was achieved through engine tests. Evaluation of catalytic converters was made through chassis dynamometer tests. Emission results from motorcycle with the optimum catalytic converter can meet the present Europe motorcycle limitations (The so called motorcycle EURO–1 were taken into force in June 17th 1999[1])

The rocker arm has a function to lead the cam shaft rotation to the valve operation. There are cases when damages are caused due to abnormal wear at the sliding part, causing certain problems. Authors classified the wear phenomenon, and realized a systematic analysis on the possible cause of the damage. As a result, it was revealed that the damage was of two types, and to prevent the hard wear, it is effective to apply shot peening before plating. The prototype rocker arm was test under various lubricating conditions, thus actually confirming that the occurrence of wear was largely reduced.

The basic Semi-Direct-Injection System (SDIS) which is already in production for PWC and applied to small 2-wheeler engines features a low-pressure fuel injection system injecting through the rear scavenge port window in the cylinder symmetry plane onto the piston crown. The patented new SDIS Mk.II System [1] injects through an (additional) scavenge port window that is positioned above the scavenge ports and is controlled by a window in the piston skirt. This new arrangement allows longer injection duration and also other injector positions and directions. A CFD simulation by AVL's FIRE-CFD-code with moving piston and exhaust gas dynamics compares the different injector positions and directions for WOT and rated speed and for a part throttle low speed case. The SDIS Mk.II injection system consists of mass-produced automotive parts thus giving a low cost approach for present 2-stroke engines requiring only moderate engine modifications.

In general, welding of high-pressure die casting (DC) parts has been difficult due to gases trapped in the castings. This is a result of the high-speed turbulent flow condition of the DC process. These gases are liberated during welding and produce porosity in the weld joint. The Author had found the range where an enough welding quality was obtained without great drop in castability to the middle of the laminar flow and turbulent flow. This range has been defined as the transition zone. Moreover high strength Al-Mg-Ni alloy was developed by non-heat-treatment. The Transition Flow Filling Method(TFFM) has been developed, that can not only reduce the amount of trapped gases but also is applicable to standard high pressure die casting equipment. With this method, high quality DC parts can be produced that are weldable, strong and have high toughness.

This paper presents the results of an exploratory study examining the production of particulate matter (PM) by 2-wheel vehicles and the impact of catalytic aftertreatment on these emissions. Information is presented demonstrating the efficacy of catalytic aftertreatment for significantly reducing not only hydrocarbons (HC) and carbon monoxide (CO), but also PM emissions from motorcycles equipped with small 2-stroke engines. The generation of PM by 5 test vehicles during realistic driving conditions is discussed and the impact of catalyst performance characteristics on the reduction of these releases is examined. Vehicle based test data, obtained with a mini-dilution tunnel, clearly demonstrates the benefits to the environment achievable through the use of catalytic aftertreatment.

The use of catalytic aftertreatment to reduce harmful gases in the exhaust streams of 2-wheel vehicles powered by small engines is becoming widespread as increasingly restrictive emissions standards are enacted. The primary exhaust gas pollutants are carbon monoxide (CO) and hydrocarbons (HC) for vehicles equipped with 2-stroke engines and CO for those using 4-stroke power plants. Because the exhaust streams of these small engines also contain significant concentrations of oxygen, catalytic aftertreatment is a very effective approach for oxidizing these contaminants to carbon dioxide and water. In order to assure the maximum long term benefits of catalytic aftertreatment, it is necessary to understand not only the factors responsible for high initial activity, but also the mechanisms by which a catalyst's performance is negatively impacted.

The first part of the paper gives an overview of the environmental conditions with which a future two stroke powered vehicle must comply and explains the reasons for which a direct gasoline injection into the combustion chamber offers a potential solution. The paper continues with a description of the fuel/air mixture injection used in the F.A.S.T. concept and gives a detailed overview of the layout of the 125 cc engine to which it is applied. The structure of its electronic engine management system, mandatory for the necessary control precision, is presented. Hereafter is made a short introduction to the visualization and numerical computation tools used for the engine design optimization. The paper concludes with a detailed presentation and discussion of the experimental results obtained with the engine operated, either in steady state and transient conditions on an engine test rig, and mounted in a classic small dimension two-wheel vehicle submitted to road tests.

In order to see the effect of injection timing and directions on the performance of a DI gas engine, an experimental engine was prepared, and firing tests were carried out. Also a laser induced fluorescence method was used to see in-cylinder fuel distribution. As the result, following conclusions were obtained. 1) NO2 could be used as a tracer substance to visualize in-cylinder gaseous fuel distribution. 2) Injection timing had large influence on the fuel distribution and the performance of the DI engine. 3) In-cylinder fuel distribution and operation stability of the DI engine was also affected by injection directions.

The influence of injection timing on the performance of a manifold injection gas engine was investigated with the results of firing tests. Also the in-cylinder fuel distribution of the engine was measured by a tracer LIF method and used to understand the results of the firing tests. These results showed that the in-cylinder fuel distribution of the engine in the direction of a cylinder axis was changed by the variations of injection timing.

The development and preliminary results of a low cost electronic fuel injection (EFI) system for one and two cylinder 4-cycle gasoline engines is described. The feasibility of reducing system cost by minimizing the number of sensors is explored. The objective is to use only the following signals to determine the operational state of the engine: Magneto Voltage Signal (Speed/Load) Engine Temperature Lambda Exhaust Gas Oxygen (Optional) Another objective in the on-going development is to maintain the performance enhancements that EFI offers over carbureted engines: cold starting, fuel economy, and reduced emissions. Special focus is applied to the creation and analysis of a load signal that is related to the torque produced by the engine. Constrained by certain conditions, the load signal is related to the air charge entering the cylinder. The load signal, along with the engine speed signal, provides a basis for a fueling look-up table.

The application of low cost stratified scavenging systems to the two-stroke engine is described. Previous results from multi-stream systems tested at The Queen's University of Belfast are reviewed and results from single- and double-entry air-head engines are presented. The most promising results relate to a 270cm3 single cylinder cross-scavenged engine with the single-entry air-head system. Effective trapping was obtained by injecting fuel into the crankcase and inducing air through an inlet at the top of the transfer ducts. The results showed significant improvements over the standard homogeneous scavenged engine. The brake specific fuel consumption was reduced by up to 22% and the brake specific hydrocarbons by up to 55%.