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AS temperature sensing elements, thermistors have been in use for more than four decades. They have become quite useful in stabilizing electronic circuits and measuring temperature. They are used as surge protectors for electric motors and electrical power devices as well as fluid level sensing elements. Improvements in technology and manufacturing methods expanded their usefulness for higher temperature applications. This paper will offer an overview of various oil level sensing technologies and then will examine the characteristics of thermistors and their use as low oil level sensors for engines.

Environmental regulations for reduced hydrocarbon permeation from gasoline powered vehicles and devices encourage development of better fuel hose and tubing as well as improved materials of construction. A review of hydrocarbon permeation regulations will highlight the utility of two new Viton® fluoroelastomer materials for hose and tubing components - VTR-7551 and VTR-9217.

Plastic materials are used for fuel tanks for automobiles because they are lightweight and highly durable and help these tanks ensure a capacity. However, plastic fuel tanks have the disadvantage of easily allowing the fuel to permeate through. To solve this problem, HDPE is used nowadays as the main material, and fuel tanks using EVOH for a barrier material and formed by multi-layer blowing are installed in the majority of automobiles conforming to the Tier 1 regulations set by EPA and the LEV I regulations set by CARB. In view of EPA's Tier 2 regulations and CARB's LEV II regulations, both of which will be launched in the near future, plastic fuel tanks with a lower level of fuel vapor permeability (hereinafter referred to as “permeability”) are desired. We thus developed a plastic fuel tank that is much lower than conventional plastic fuel tanks in permeability. This low-permeation plastic fuel tank may easily conform to the Tier 2 and LEV II regulations.

This paper presents research into a novel autoselective electric discharge method for regenerating monolithic wall flow diesel particulate filters using low power over the entire range of temperatures and oxygen concentrations experienced within the exhaust systems of modern diesel engines. The ability to regenerate the filter independently of exhaust gas temperature and composition significantly reduces system complexity compared to other systems. In addition, the system does not require catalyst loading and uses only mass- produced electronic and electrical components, thus reducing the cost of the after-treatment package. Purpose built exhaust gas simulation test rigs were used to evaluate, develop and optimise the autoselective regeneration system. On-engine testing demonstrated the performance of the autoselective regeneration process under real engine conditions.

Halogen light sources for automotive forward lighting applications are designed for a nominal DC voltage and power, typically in the range of 13 volts and 55 to 65 watts. However some applications attempt multifunctional use, such as a high beam – day time running lamp (DRL) combination, by regulating the power. This can be done by pulse width modulation (PWM) or by simply lowering the applied DC voltage. More advanced applications, such as smart headlamps or advanced forward lighting systems, might also operate the bulb only for a short period of time. This can have a similar effect as PWM. In either case the halogen bulb will perform differently than at the DC design voltage. The valid power or voltage ranges do not only depend on the light source itself, but strongly on environmental conditions. Thermal management and external temperatures of the system can influence or prevent the halogen cycle activation and cause problems, such as bulb wall blackening.

Intelligent Transportation Systems (ITS) require reliable location information with emphasis being put on sensor level integration and low power consumption. The Global Positioning System (GPS) has been proposed as a potential technology to provide this information but has been hampered by poor performance (in urban environments) and power hungry board level solutions. Increased pressure on in-vehicle sensor power consumption has driven SiRF Technology Inc. to develop the SiRFstar1/LX GPS chip set (GSP1LX and GRF1LX). This improved chip set architecture enables lower power consumption without sacrificing tracking or navigation performance specifically in difficult urban canyons. Most GPS systems have been designed as stand-alone board level solutions that can be used in high-level system integration.

The paper discusses the property of rolling resistance as applied to pneumatic tires. Reference is made to the low power source vehicles presently under development and the importance of providing a tire compatible with this type of vehicle. The emphasis is placed on minimizing the power consumption in tires and the relationship of this minimization to the other performance properties of the tire. Basic relationships of rolling resistance are discussed as associated with structural and environmental factors in both low and high speed operation. The discussion covers only tire service over hard surfaces and is primarily concerned with passenger car tires.

Low Pressure Cooled Exhaust Gas Recirculation (LP EGR) is an attractive technology to reduce fuel consumption for a spark-ignition (SI) engine, particularly at medium-to-high load conditions, due to its knock suppression and combustion cooling effects. However, the long LP EGR transport path presents a significant challenge to the transient control of LP EGR for the engine management system. With a turbocharged engine, this is especially challenging due to the much longer intake induction system path compared with a naturally aspirated engine. Characterizing and modeling the EGR, intake air mixing and transport delay behavior is important for proper control. The model of the intake air path includes the compressor, intercooler and intake plenum. It is important to estimate and track the final EGR concentration at the intake plenum location, as it plays a key role in combustion control. This paper describes the development of a real-time, implementable model for LP EGR estimation.

Downsizing is regarded as a promising strategy to reduce the fuel consumption of gasoline engines. But downsized turbocharged engines need to take knocking into account to avoid engine damage. Low Pressure (LP) cooled exhaust gas recirculation (EGR) is an effective suppressant of knocking at boosted high load and EGR could reduce pumping loss at low loads. Both of them are helpful to improve fuel economy. In the research, a LP cooled EGR system is added to a 1.5L turbocharged PFI production gasoline engine and the compression ratio is changed from 9.3 to 11.5. The results show that the fuel reduction is 4.5% at 2000rpm 5bar (20% EGR ratio) and 9.7 % at 3000rpm 10bar (20% EGR ratio) compared with no EGR case. But at boosted high loads the fuel consumption is almost same to the production engine due to high compression ratio which results in severe knocking. In order to further reduce fuel consumption, the engine is operated in lean burn conditions.

A fundamental problem with methanol fueled engines is poor cold startability and high formaldehyde emissions during engine warm-up. Direct injection has the potential to solve these problems. The design and development of an electronically controlled low pressure injector which provides an alternative to high pressure “diesel” type injection is reviewed.

A low pressure fuel distillation system is proposed for extracting a high-volatility fraction of gasoline, and to improve start-up and warm-up behavior of SI engines. More complicated methods for generating high-volatility start-up fuels have demonstrated improved cold start driveability and reduced HC emissions, but so far they have not been put into mass production. In this project, a ‘bench-top’ apparatus was used to investigate the feasibility of using sub-atmospheric pressures to extract a lighter and more volatile fraction from the parent gasoline. A series of experiments was conducted to evaluate the characteristics of the extracted fuel vapor as a function of temperature and pressure. The sensitivity to different brands and grades of gasoline was also explored. The results show that the extracted fuel consists mostly of C5 and C6 compounds, and that its Molecular Weight and Stoichiometric A/F ratio show little sensitivity to the pressure level used for the extraction.

Low pressure Exhaust Gas Re-circulation (EGR) can be used along with Diesel Particulate Filter (DPF) systems to reduce NOx emissions from heavy-duty diesel engines. Normally the use of EGR decreases NOx emissions and increases soot emissions. The effect of low pressure EGR on DPF regeneration has been investigated in connection with two passive DPF systems. One system contained a catalyst followed by an uncatalyzed DPF and one system was a Catalyzed DPF (CDPF). The objective was to obtain a better understanding of soot oxidation and to develop EGR calibration strategies that would ensure reliable DPF regeneration. Formation of NO2 and the subsequent reaction of NO2 with soot in the DPF, was studied as a function of temperature, EGR rate, and exhaust gas flow rate under steady state conditions for a range of DPF soot preloads. For the catalyst plus uncatalyzed DPF, NO2 emissions after the catalyst reached their highest levels at intermediate loads.

AFTER MAKING A QUICK GENERAL SURVEY of the different injection systems which have been testing for some years, the author describes a new direct low pressure fuel electronic injection system specially adapted to the two stroke engine. Very short time of about a millisecond can be obtained at high flow variation by controlling electromagnetically the balistic movement of the injector needle. The monitoring electronic control can be carried out by an opto-electronic memory or a static one (M. O. S.) by microprocessing. The performances of such system are specially interesting with regards to the specific fuel consumption decreases about 30 to 40 per cent compared with an engine fed through a carburettor. The unburnt H.C. emission level, which until now condemned the two-stroke engine, are greatly decreased.

Low-pressure molding processes have been presented for numerous applications on automobiles. While some suppliers of these technologies provide entire systems, some potential applications only require moderate alteration of current injection molding equipment. This area of technology includes low-pressure insert molding, injection compression molding, compression molding, and extrusion-compression molding. As a reduced pressure molding process, gas-assisted injection molding can even be applied as a low-pressure technique. The processes can be described using the sequence of operation for each. Overall, there are advantages and limitations for each process and cost considerations that may limit successful application.

Passenger car suspension components have traditionally been manufactured from ductile iron castings or welded steel fabrications. Although, as fuel economy and emission concerns become more important, passenger car component designers are looking to aluminum suspension components for a reduction in unsprung weight. The advancements in the Low Pressure Permanent Mold (LPPM) Casting Process has made it one of the most cost and quality effective methods for producing production quantities of premium grade aluminum castings for the suspension component industry. This paper presents the advantages, the weight savings potential, the physical and mechanical property data that categorizes low-pressure casting as a state of the art premium grade casting process.

A system for low pressure permanent mold casting of magnesium alloys is presented. The equipment exploits new concepts of transfer of molten metal, eliminating the risks for melt contamination. Consistent quality is secured by extensive recording of process parameters and the use of a flexible computer system to operate and monitor the system. Properties of a successful permanent mold casting alloy is discussed in general. These principles are applied in the selection of suitable magnesium alloys. An example of application of the present low pressure die casting technology is provided by wheel castings for the automotive industry.

Natural gas is an attractive fuel for vehicles because it is a relatively clean-burning fuel compared with gasoline. Moreover, methane can be stored in the physically adsorbed state [at a pressure of 3.5 MPa (500 psi)] at energy densities comparable to methane compressed at 24.8 MPa (3600 psi). Here we report the development of natural gas storage monoliths [1]. The monolith manufacture and activation methods are reported along with pore structure characterization data. The storage capacities of these monoliths are measured gravimetrically at a pressure of 3.5 MPa (500 psi) and ambient temperature, and storage capacities of >150 V/V have been demonstrated and are reported.

The present use of the carburetor to supply fuel to the Otto cycle engine has placed it in a difficult competitive position with the diesel engine, which has successfully operated with a fuel injection system. The purpose of this study was to consider the feasibility of utilizing a low pressure injection system for the Otto cycle engine. The proposed design is discussed in detail. As the author points out, this system will allow design changes in the engine that would be impossible if the carburetor were retained, and thus considerable improvement in performance and efficiency can be realized for the Otto cycle engine.

Aqueous Urea is a non-toxic and stable ammonia carrier and its injection and mixing represent the basis for the most common de-NOx technology for mobile applications. The reactant feed preparation process is defined by evaporation, thermolysis and hydrolysis of the liquid mixture upstream the Selective Catalytic Reduction reactor, and it is strongly dependent on the interaction between spray and gaseous flow. Low-pressure driven injectors are the common industrial standard for these applications, and their behavior in almost-ambient pressure cross flows is significantly different from any in-cylinder application. For this reason, two substantially different injectors in terms of geometry and design are experimentally studied, characterizing drop sizes and velocities through Phase Doppler Anemometry (PDA) and liquid mass spatial distribution through Shadow Imaging (SI).

A low profile wideband Planar Inverted-F antenna (PIFA) is presented in this paper for automotive application in the sub-6 GHz 5G system and Dedicated Short Range Communication (DSRC) bands that operates in the frequency range from 617 MHz to 6 GHz while having an acceptable rejection in the GNSS bands. The proposed antenna is suitable for low profile applications in the automotive industry due to its physical dimensions and performance. Simulation results are presented along with measured data on a ground plane (GND) and on a vehicle from properly cut metal sheet prototype. The results are discussed in terms of return loss, radiation patterns, and efficiency.