Search Results

Honda has developed, in collaboration with Hitachi Metals and Daido Steel, two types of low-nickel heat-resistant alloys for exhaust valves which are more cost effective than the conventional nickel alloys. They are NCF4015 that contains approximately 40% nickel and NCF3015 with approximately 30% nickel content. The two types of new alloys were developed based on our unique alloy design concept. Both alloys feature superb high-temperature strength and are capable of maintaining favorable material properties, even after an high-temperature exposure. The NCF4015 is compatible with the conventional Inconel 751 and 60Ni alloys in terms of high-temperature strength. The NCF3015 falls slightly behind the two metals, but overwhelms the 21-4N (SUH35) in high-temperature strength. The exhaust valves made of the two alloys developed have been used for mass production engines.

The 4T65-E transmission produced by General Motors is the third evolution of GM's original 4-speed F.W.D. automatic. This most recent redesign introduced for the 1997 model year meets new corporate goals for fuel economy and reduced noise, along with the ability to adjust shift character to meet the brand image of the various nameplates. Improving fuel economy and cooling at increased engine power levels was enabled by designing a larger diameter torque converter with the aid of 3-D modeling. The new converter has reduced internal leakage and incorporates a controlled slip clutch. Improvements in NVH have been achieved through a revised oil pump design and the use of the new phased drive chain, made affordable by the joint development of powdered metal technology required for the unique sprocket design.

A CNG bi-fuel version of the GMC and Chevrolet C2500 pick up trucks was developed as an OEM (Original Equipment Manufacturer) vehicle. The converted bi-fuel vehicles use the same engine with modifications for use with gaseous fuels, and the same catalytic converters as the gasoline baseline. The fuel management system is an automatic switching bi-fuel system which is able to control fuel flow rate, spark timing, EGR, and perform OBD-II (On-Board Diagnostics II) on both gasoline and CNG. This system has been extensively tested and validated for durability, electro magnetic compatibility requirements, crash integrity, corrosion resistance, emissions performance and powertrain performance under extreme environmental conditions and different CNG fuel compositions. The CNG fuel storage technology of the bi-fuel system was validated to the most stringent safety and durability requirements in the industry.

The gas velocity through an automotive catalyst has been determined by measuring the time of flight of a pulse of propane injected at the inlet plane of the catalyst. The arrival time at the exit plane was detected by a fast flame ionization detector. By synchronizing and delaying the injection of propane with respect to the engine crankshaft position, the fluctuations of the exhaust gas velocity during the engine cycle were investigated. A number of tests at different engine load and speed points were carried out. The results show a complex velocity/time characteristic, including flow reversals. The technique is shown to be a viable option for flow measurement in this harsh environment.

This paper describes an effort by the US Army Tank-automotive & Armaments Command, Research, Development & Engineering Center (TACOM-TARDEC) to model, simulate, and validate a dynamic model of a Medium Tactical Vehicle (MTV) truck towing a M105A2 trailer, both fully payloaded at 5-ton and 1-1/2 tons, respectively (see figure 1). Prior to the simulation analysis, a set of carefully controlled and instrumented field tests were conducted with the truck / trailer combination to understand inherent stability problems, determine performance limits, and to collect instrumented data to validate the dynamic models. This paper documents these efforts.

In this study a mathematical model was developed for the BIOSID dummy using the CAL3D simulation program. This model was correlated to the dummy impact response using pendulum tests on various body regions, and a side sled test. Favorable comparisons were achieved between the test results and the model responses. This model was then used for identifying optimal side airbag designs for a large car.

The primary purpose of using a plastic material instead of conventional aluminum cast for intake manifold is to reduce its weight and cost. Moreover, the use of plastic for intake manifold is regarded as a key for further development of so called an “intake modular system”. As a secondary effect, the engine power can be increased with the help of improved interior surface roughness and lowered air temperature. With regard to NVH, however, plastic intake manifold is considered somewhat negative since it is less rigid and less dense than aluminum one. In this paper, the mechanism that plastic intake manifold affects the performance and NVH of in-line 4 cylinder gasoline engine is presented. In connection with engine performance, air flow efficiency of not only intake manifold itself but also other components of intake system and also cylinder head is evaluated.

Managing engine oil temperatures and extending service intervals has caused many engine designers to consider crankshaft windage trays. With benefits such as reducing oil aeration and oil temperature while improving engine performance, windage trays have long been used in performance engines. Most automotive engines would benefit from the introduction of windage trays. This paper outlines a new approach in the form of an oil management module for the lower engine, a one piece glass-reinforced nylon composite system which integrates a windage tray with other oil system components such as: pan gasket, pick-up/strainer, baffling and sensor interface. The oil management module is very near to reality since it is the integration of proven nylon composite applications and not a totally new application.

The problems of Two-Stroke SI engines regarding high fuel consumption and unburned hydrocarbon emissions, both caused by the short circuiting of fresh homogeneous mixture during the scavenge process, are well-known. The progress of Piaggio since 1977 in state-of-art direct fuel injection systems, oriented to development of Hi-Tech solutions for 2T SI engines to overcome the above drawbacks, is analyzed. The analysis includes several streams of research ranging from conventional crankcase scavenged engines with direct solid mechanically controlled fuel injection to solutions with separate scavenging pump with electronically controlled injection units, and from low pressure injectors to air-assisted fuel injection with stratified charge. Each solution is examined with presentation of typical engine parameters and cost data.

A novel Fast Response Chemiluminescence Detector and a Fast Flame Ionization detector have been used to examine the instantaneous NO and unburnt hydrocarbon concentration in the cylinder and exhaust port of a DI Diesel engine. The in-cylinder results indicate very high levels of NO in the premixed phase of combustion, followed by generally lower levels during the diffusion burning phase. Hydrocarbon signals also indicate significant detail. The in-cylinder uHC signal is consistent with the probe location being between two of the fuel sprays. Both in-cylinder and exhaust results indicate rather high cyclic variability in the NO levels at steady conditions. Variations in the timing and structure of the exhaust uHC signal during the valve open period with load may give insight into the fuel spray/air motion.

An important component in many hybrid electric vehicle (HEV) concepts is the load leveling device (LLD). The best type of LLD for HEVs is under debate. This paper identifies the important concept selection criteria for the three leading types of LLDs being considered for use in HEVs. The performance of electrochemical batteries, ultracapacitors, and flywheels is compared using these criteria. The concept selection methodology indicates that at the present time flywheels show the most promise for development for use in a hybrid electric vehicle. The use of this type of selection methodology is a powerful tool in identifying concepts worthy of development as well as determining performance criteria in need of improvement within each concept.

A universal computer model simulating the performance and fuel consumption of vehicles operating under both steady and dynamic driving conditions was developed and verified. The model calculations were based on the total vehicle's aerodynamic drag, grade and rolling resistance, atmospheric conditions and other vehicle design parameters. These include engine capacity, fuel injection and ignition method, fuel specification, drivetrain details (manual/automatic transmission), total vehicle weight and type of engine management system. The dynamic driving conditions were simulated by the European driving cycle (80/1268/EWG) which accounts for town and open roads driving conditions. The developed model was of a modular structure and was designed to run on a Pentium personal computer of a minimum of 16 Megabytes of RAM capacity.

The high-pressure direct injection (HPDI) of natural gas (NG) permits diesel engines to retain their high fuel economy while reducing regulated emissions. In the work presented in this paper, directly injected natural gas is ignited by pilot diesel fuel, and both fuels are injected through a single injector. The injector concept is discussed, along with the description of the instrumented Detroit Diesel two-stroke 6V-92TA DDEC II engine used for the experiments. Measurements of the performance and emissions with the HPDI of NG confirm the retention of the high efficiency of the diesel engine and demonstrate reductions in nitrogen oxide (NOx) emissions near 50% at high load using the same injection timing as for diesel fueling. Methane (CH4) and non-methane hydrocarbon (nmHC) emissions were found to be as low as those measured for diesel fueling at high loads, but were higher at low load operation. The gas injection pressure was found to affect the low-load emissions.

A car front energy absorber made of composite materials is analyzed in this work. Mechanical requirements (static and crash behavior), geometry, load and boundary conditions are described in the first part of this study. A finite element simulation has been performed in order to obtain the mechanical behavior of the absorber. The experimental analysis was also carried out: displacements, strains and stresses were obtained by means of mechanical testing of the absorber. An outstanding correlation between the theoretical and experimental results will be shown. Finally, a comparison between metallic and non-metallic car front energy absorbers will be presented in the chapter of conclusions.

A performance map for polyurethane energy managing foam is presented as a heuristic tool in the selection of appropriate formulation and density. Dynamic data was mapped to material characterization data. Material characterization was accomplished by quasi-static compression testing ASTM D-1621. The D-1621 data was correlated with 24.1 km/hr (15 mph) head impact data and 8.05 km/hr (5 mph) bumper impact data. For example, Head Injury Criterion (HIC) values were correlated with D-1621 compressive strengths which were mapped to polyurethane formulations and densities. The performance map can save time and money by identifying appropriate formulation and density.

This article focuses on new findings related to the scratch resistance of two-component polyurethane clear coats under a variety of conditions (methods) and with differing media (dry abrasives, wet abrasives, etc.). The results are discussed in connection with polymer structure data and other important film properties, such as acid etch resistance.

No longer are North American automotive OEMs designing vehicles for their own domestic market. Today's automotive engineer must design and deliver world class quality to a global customer with unprecedented expectations, unlimited choices and little brand loyalty. In automotive interiors, there are distinctions between vehicles designed in North America and their engineered counter-parts in Japan and Europe. One area worthy of examination is the selection of nonwoven automotive interior headliner fabrics. Japanese and European automotive OEM's have recognized nonwovens for their reduced cost, light weight, superior fade resistance and ability to be recycled. Today, nonwoven automotive interior headliner fabrics command over 60% of the Japanese and 50% of the European automotive markets, with less than 5% in North America.

A new core binder system (1) was used to produce foundry cores for casting hollow aluminum suspension parts by the low pressure, gravity flow, semi-permanent mold method. These and other prototype aluminum parts made using the system demonstrate that easy core removal from complex castings, core and sand recycling, and an improved environment in the core making facilities will increase productivity, improve product quality and reduce manufacturing costs.

In order to evaluate the crash-worthiness of a car, the dynamic response of the car body has to be correctly obtained at each level of car velocity. For the dynamic analysis, the dynamic properties of auto-body materials need to be identified for various strain rates. One of the typical high strain rate tensile tests is a split Hopkinson bar test. The present experiment has been carried out with a new split Hopkinson bar apparatus specially designed for the dynamic tensile test of sheet metals. The experiment provides stress-strain curves for various strain rates ranged from 2500 to 5000/sec. The experimental results from the both quasi-static and dynamic test are used to construct the Johnson-Cook equation as a constitutive relation, which can be applied to simulate the dynamic behavior of auto-body structures.