Search Results

The Corrosion Task Force of the Automotive/Steel Partnership (A/SP) and the Society of Automotive Engineers' Automotive Corrosion and Prevention (SAE/ACAP) committee are working cooperatively on the development of an improved laboratory test for perforation corrosion. This paper gives the results of testing a set of standard SAE perforation corrosion test specimens for up to 160 cycles in the environment of J 2334, the new SAE cyclic test for cosmetic corrosion. SAE J 2334 was found to provide a clear distinction among the test materials. In general, the results indicate that the perforation corrosion resistance of coated products is much greater than that of cold rolled steel, and that it also increases with coating mass, as well as with application of a barrier organic coating. Magnetite (Fe3O4) was the predominant iron corrosion product found in the crevices of the perforation corrosion test specimens. Smaller amounts of goethite (α-FeOOH) were also found.

The use of cyclic corrosion tests which consist of salt spraying, humidifying, and drying phases is desirable in the evaluation of the corrosion performance of automotive body panels. In this work, coupons of zinc-coated steel and of cold rolled steel were exposed to a defined cyclic corrosion test (CCT) which has shown to be suitable for simulating diverse outdoor conditions for evaluating the cosmetic corrosion of precoated steel. Micro-environment data in the gap of lapped panel specimens, such as wetness, corrosion rate of test materials, pH value, chloride content, have been obtained during the CCT test. The galvanic current flowing between a gold electrode and the test materials was measured to monitor the degree of wetness inside the crevice. The results show that the surface of the test materials never became really dry even during the dry period of the CCT cycle. Furthermore, the wetness during wet and dry periods in the crevice increased with increasing number of CCT cycle.

The presence of marred and scratched areas detract from the appearance of current automotive topcoat systems. Although the final determination of the extent of the damage to the paint surfaces must be made by human visual evaluation, machine estimation of this damage has value in being a tool for screening large numbers of different paint technologies. Scattered light from marred regions (both single and multiple scratches) in an automotive basecoat/clearcoat system was generated and collected in a goniophotometer. The areas under the intensity/angle curves were obtained using an extended trapezoidal rule for numerical integration. This technique shows promise in correlating goniophotometric data with human evaluation of marred areas. This technique may be of value in screening different paint technologies and chemistries.

A simple method and apparatus have proven useful for examining the quality of air-caps manufactured for paint spray guns. The technique combines accurate measurement of atomizing and fan air volumes, with velocity measurements taken through the axes of the flow pattern downstream of the cap. Initial comparisons of velocity profiles to actual spray patterns indicate that the profile symmetry (or lack of symmetry) correlates well with the resulting geometry of the spray pattern. This paper centers on the variation measured among supposedly identical air-caps. The conclusion proposes a standard method for specification of air-cap performance and manufacturing tolerances which would be beneficial to the finishing industry.

The use of automotive waterborne paint is an industry trend aimed at minimizing environmental impact through reduced VOC's, while providing increased paint appearance and quality. These benefits are greatly increased when the paint is applied electrostatically. This paper will provide an explanation of an electrostatic waterborne base coat application system, a review of its components, and the integration with an electric robot. The system performance is then discussed citing actual production experience including data relative to paint savings, quality improvements, and reliability.

It has been proposed that an automated remote color inspection of automobile body panels is possible with a reasonably precise color measurement. This paper outlines a test of a new 3D color measurement technology as applied to this task and presents the results of the first test. A camera is set up several feet away from a car body; a 3D orientation measuring system takes both 3D and color data from the car. The raw data is presented as a set of 3D graphs; the geometry-corrected data is also provided. Statistical analysis is presented to indicate system precision.

This paper describes fundamental developments in two-component (two-pack, 2K) waterborne polyurethanes for autmotive OEM clearcoats. The focus is on work in progress concerning: raw materials relevant chemistry application considerations

The Paint Technology Globalization effort is recognized as an important step of accomplishing the leveraging of worldwide resources of both engineering and purchasing in order to improve General Motor's competitiveness. The process used, the benefits derived, the current status of the effort, and the expected results (deliverables) are discussed. These include common materials, processing, and equipment paint specifications to be included in purchasing bid packages.

The role of the blank holder in the generation of the restraining forces acting on the metal sheet during the deep drawing is considered. It is well known that the choice of the restraining force distribution is a key point in the definition of the stamping process. The evolution of the blank holder modelling in the finite element simulation of the drawing process is reviewed and the need of deformable model of the blank holder to obtain process realistic simulation is pointed out. The factors that affect the actual restraining force distribution are briefly analyzed, identifying control factors (that are at disposal of the process engineering in order to tune-up the actual tool) and noise factors (that are not practically controllable). In order to have a realistic numerical simulation of the drawing process, these factors have to be included in the finite element model, with particular attention to the different alternatives for the blank holder modelling.

With modern multipoint drawing equipment, it is possible to control the draw pins independently of each other. This gives the possibility to specifically change the normal force distribution between blankholder and workpiece regarding location and time. Investigations show that the effects which are achievable with multipoint drawing technology are only possible in conjunction with a changed blankholder design. The increase in the maximum drawing depth by approximately 57% were achieved. In addition to experimental work, numeric simulation is used to determin the necessary setting parameters.

For current passenger vehicles, multi-point injection (MPI) systems are extensively employed for gasoline engines due to ease of control and rapid response. In these systems, the pressure within the intake manifold to which the injectors are installed can fall below the saturated vapor pressure of some hydrocarbon components present in the fuel. Such a condition leads to an atomization process in which flash boiling occurs. In the present work, the atomization process under flash boiling conditions has been characterized both experimentally and theoretically. The experimental investigation has been carried out with a spray test facility consisting of a variable pressure chamber equipped with a pintle type fuel nozzle. Infrared Extinction/Scattering (IRES) is utilized to provide temporal and spatially resolved distribution of the fuel vapor concentration within the spray.

With the objective of achieving better investigation of engines-fuels by obtaining instantaneous quantitative imaging of in-cylinder processes, several steps have been taken for some years at Rutgers University. They are: (1) Construction of a new multispectral high-speed infrared (IR) digital imaging system; (2) Development of spectrometric analysis methods; (3) Application of the above to real-world in-cylinder engine environments and simple flames. This paper reports some of results from these studies. The one-of-a-kind Rutgers IR imaging system was developed in order to simultaneously capture four geometrically (pixel-to-pixel) identical images in respective spectral bands of IR radiation issued from a combustion chamber at successive instants of time and high frame rates.

NO, OH, and soot in combustion flame produced from burning at high temperature and pressure diesel fuel spray issuing from a single-hole injection nozzle was measured by laser induced fluorescence (LIF) and laser induced incandescence (LII) methods. The LIF images of OH showed that OH radical, distributed in a band-like zone outside the region of the flame luminescence observed, would persist even after the extinction of flame luminescence. The LIF images of NO showed that NO was located slightly outside the flame luminescence zone and that its region was almost the same as that of OH and would tended to increase in the latter period of the combustion process. Also, the LII images showed that the formation of soot would take place near the flame central zone coincident with the flame luminescence zone.

This paper describes research and development activities dealing with a technique which allows the measurement of gaseous and particulate concentrations inside the combustion chamber. This so-called fast-timed gas sampling technique was used for both the observation of the development of gaseous pollutants and soot during combustion and expansion and for getting information about the particle size history. The system has been applied to a modern passenger car DI diesel engine (Volkswagen). The investigation covers the early combustion phase beginning with the start of combustion and throughout the expansion phase until exhaust valve opening. Particles with a size of about 10 nm up to 1 μm were found. Slight variations in the smaller size classes could be observed during the combustion and expansion process.

High speed natural light motion picture records synchronized with head gasket ionization probe and in-cylinder pressure data have been made in the transparent engine of different combustion chamber configurations. For knocking cycles, the head gasket ionization current method simultaneously taken with pressure data was able to find the location of knocking occurrence. To investigate the effects of combustion chamber configurations, the flame propagation experiments for pent-roof combustion chamber with center ignition ( Modified Type I engine ) and modified pent-roof ( Type II engine ) combustion chamber were performed with high speed natural light photography technique. The flame propagation of Modified Type I engine represents more uniform patterns than that of Type II engine. The investigation of knocking combustion was also made possible by observing flame propagation with the measuring techniques that use head gasket ionization probe and in-cylinder pressure data.

To investigate NO formation in a combustion flame, PLIF (Planar Laser-Induced-Fluorescence) technique was applied to measure the NO fluorescence distribution in a constant-volume combustion chamber and in a sparkignition engine. The NO fluorescence distribution was taken by an image intensified CCD camera. In the constant-volume combustion chamber, the high NO fluorescence intensity was concentrically observed in the thin flame zone along the flame front. In postflame gas behind the flame zone, the NO fluorescence was widely distributed with weak intensity. In the case of the engine, the fluorescence was distributed in the broad flame zone. The fluorescence intensity had high value near the flame front, and decreased from the flame front to the postflame gas. As the equivalence ratio was changed, the fluorescence intensity reached maximum value at slightly lean condition.

Three-dimensional numerical analysis of fuel liquid and mixture behavior in a port-injection gasoline engine is assessed by comparing calculations with measurements. The fuel mass distributed in the intake port and cylinder is measured using an engine with hydraulic valve and gas sampling system. The experimental results show that about half of the fuel mass per injection enters the cylinder, and the rest stays in the port. The difference of the mass fraction of injected fuel directly entering the cylinder is small between the cases of single pulse injection and serial injection. Therefore, three-dimensional calculation presupposing single pulse injection has difficulty in predicting the in-cylinder mixture formation process, although it can analyze the amount of fuel wetting the port wall. The calculations are performed for a port-injection engine, and the differences of fuel behavior with respect to swirl control valve opening and wall temperature are discussed.

By using engine controlled gear shifting, a manual transmission can be automated without using the clutch during the shift event. The main contribution of this paper is a novel extension of the existing system using active handling of driveline resonances. The strategy is based on a model of the transmission torque, which is derived by using experimental data from a heavy truck. A key step is the design of a criterion for a controller that drives the transmission torque to zero with damped resonances and with a control signal realizable by the engine. The proposed solution offers a possibility to optimize the time needed for a gear shift, which is important since the vehicle is free rolling when in gear-shift condition. Furthermore, neutral gear can successfully be engaged also when facing initial driveline oscillations and load disturbances.

The occurrence of liquid fuel in the cylinder of automotive internal combustion engines is believed to be an important source of exhaust hydrocarbon (HC) emissions, especially during the warm-up process following an engine start up. In this study a Phase Doppler Particle Analyzer (PDPA) has been used in a transparent flow visualization combustion engine in order to investigate the phenomena which govern the transport of liquid fuel into the cylinder during a simulated engine start up process. Using indolene fuel, the engine was started up from room temperature and run for 90 sec on each start up simulation. The size and velocity of the liquid fuel droplets entering the cylinder were measured as a function of time and crank angle position during these start up processes. The square-piston transparent engine used gave full optical access to the cylinder head region, so that these droplet characteristics could be measured in the immediate vicinity of the intake valve.

Video imaging has been used to investigate the evolution of liquid fuel films on combustion chamber walls during a simulated cold start of a port fuel-injected engine. The experiments were performed in a single-cylinder research engine with a production, four-valve head and a window in the piston crown. Flood-illuminated laser-induced fluorescence was used to observe the fuel films directly, and color video recording of visible emission from pool fires due to burning fuel films was used as an indirect measure of film location. The imaging techniques were applied to a comparative study of open and closed valve injection, for coolant temperatures of 20, 40 and 60 °C. In general, for all cases it is shown that fuel films form in the vicinity of the intake valve seats.