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A new curemeter, called Cone-Rheometer, has been developed. This instrument simultaneously determines changes in pressure and stiffness in elastomeric compounds during the course of vulcanization. The use of the Cone-Rheometer to evaluate extruded, continuously vulcanized, neoprene and EPDM sponge stocks is described. The effects of changes in blowing agent level, blowing agent type, and test temperature are observed and discussed.

Semirigid urethane-foam specimens of various high densities were evaluated when subjected to simulated heavy-mass impacts such as in low-speed automobile collisions. The dynamic test results showed excellent material-energy absorption with essentially no compression sets, even after many repeated impacts of high deflection. These findings, coupled together with the well-known tough physical properties of urethanes, provide an outstanding candidate material that can be used to effectively reduce the damage to support structures and contact surfaces, not only in automotive applications but in any other application requiring a reduction of shock forces.

A new method for determining the spring and damping constants for elastomer materials is presented. The method relies on three concepts-measurement of force and displacement or velocity across the test specimen, precise control of differential phase shift and sensitivity in transducers and electronics over the full operating frequency and amplitude range, and automatic optimal identification of K and C using analog hardware. The technique may be used in conjunction with either a resonant beam or electrohydraulic system, as demonstrated in the paper. Typical error sources are presented for both systems with indications given of their elimination by the new technique. Hardware implementing the concepts is described and calibration test results given. It is concluded that the system provides an automatic test procedure which has the potential to reduce errors and maintain consistent results for rubber properties, relatively independent of the test machines and operators.

Comfort, styling, and durability of automotive seating is largely due to the excellent performance of flexible urethane foam cushioning elements. This paper reviews the production and properties of current molded urethane foam cushioning, and the total assembly seating performance requirements. The newer developments of “full-depth” cushioning and “high-resilience” foams are examined in some detail.

Driver response and performance can be quantified by observing the stimulus-response environment. Yet the driver's inherent adaptability allows him to have seemingly adequate performance in potentially hazardous driving situations even though he may be operating near the acceptable safety limits. Physiological measures of the driver's internal state can provide further quantification of his performance level and can give a measure of his workload or safety performance margin. Measures of driver physiological and control responses have been made under gust disturbance conditions with the subject's car operating at various speeds. The experimental techniques and data are described, and correlations between the situational parameters and driver stress and control response are shown.

As the evidence of the contribution of intoxicated drivers to vehicular fatalities continues to mount, interest has grown in the development of novel counter-measures. One approach now being considered involves the use of a device installed in the automobile which automatically determines if the driver is intoxicated and prevents the driver from operating the vehicle when intoxication is determined. In this paper such devices are discussed with particular consideration given to the method of determining intoxication, the point in time when the determination is made and their applications. The paper also discusses the Transportation Systems Center's research program directed to dealing with this problem.

This paper is an expansion of a previously presented paper “Ignition Interlocks for Intoxicated Drivers,” with additional data analysis which exposed the basic problems resulting from the operation of automobiles by intoxicated drivers in the United States. Several approaches to the development of ignition interlock systems are discussed. The Phystester,* an ignition interlock developed by General Motors and based on a predriving performance test of short duration, is discussed. Plans for evaluation of its effectiveness are presented, and available data from experiments involving both sober and intoxicated subjects are included. Integration of the Phystester in the operation of the vehicle and additional functional uses of the device are also discussed. Results of the Michigan Breath Testing Program, 1970-1971, are provided as an Appendix.

One of the effects of the existing and proposed European legislation limiting vehicle noise has been to generate a requirement for quieter engines. A simple analysis of the vibration of the external surfaces of several in-line engine structures has shown how the noise from the engine surfaces can be reduced, provided that all the thin-section areas of the external surface are treated. Noise-reduction techniques have been evolved for all the commonly used surface structures for diesel engines, and these are described in this paper. Four in-line diesel engines have been treated by these techniques, and noise reductions of 5-8 dBA have been obtained. In all cases, the same manufacturing plant was used to machine the modified crankcase/cylinder block casting; the valve gear cover and sump were modified versions of those already fitted to the engine.

An evaluation of gaseous fuels was made to determine their capability in reducing emissions from automobiles. The four-part program included tests of propane (LPG) and natural gas in a dynamometer engine (phase one) and in a car parameter study (phase two). Power and spark requirements were compared with those of gasoline on the dynamometer engines. Emissions, economy, performance, and drivability were evaluated on the cars; and air-fuel ratio, spark advance, and exhaust gas recirculation served as variable parameters. The third phase of the program determined the low-emission capability of an LPG car with proposed emission hardware. The economy, performance, and drivability at these low levels were obtained. The final phase tested a dual-fuel car to evaluate the feasibility of using LPG to start and warm up the car, followed by an automatic switch to gasoline. The emissions, drivability, and the LPG fuel consumption were recorded.

A program was conducted to determine the effect of temperature and humidity on exhaust emissions from automotive engines. The objective was to determine if the effects were of sufficient magnitude to require the application of correction factors to measured exhaust emissions to standard humidity and temperature values. Both American and foreign-made vehicles were tested at 20 combinations of ambient temperature and humidity. The effect of temperature and humidity was found to be both unpredictable and of little significance for hydrocarbon and carbon monoxide emissions. No correction factors were developed for these exhaust gas constituents. The effect of temperature was found to be of little significance for oxides of nitrogen. However, humidity effects were found to be significant and predictable for oxides of nitrogen.

Published test results have established that the recirculation of a portion of an engine's exhaust gas is an effective means of reducing oxides of nitrogen in the exhaust. Many methods of flow control have been tried; some require extensive revisions to the carburetion system. A retrofit system in which recirculation and spark advance are selectively controlled by vehicle speed and vacuum level has been tested on various cars to give 30-70% reductions in NOx as well as significant reductions in HC and CO. Revisions to the existing power train are minimal, while changes in driveability and fuel economy are hardly noticeable.

Reactions of sulfur, present in small amounts in gasoline, with catalyst and catalyst support materials are discussed. GMR studies have shown that sulfur accumulates in catalysts and support materials at temperatures of 600-1300 F under both oxidizing and reducing conditions. Partial sulfur release has been observed at 1200-1600 F. Concurrent with sulfur accumulation, there is a marked reduction in the carbon monoxide (CO) reactivity of noble metal, promoted and base metal catalysts. Lesser highly variable effects on hydrocarbon (HC) reactivity were noted. Studies of nitrogen oxide (NOx) reducing, noble metal catalysts also showed an adverse effect of sulfur accumulation on the NOx reactivity. These results indicate that steps must be taken to reduce or eliminate sulfur poisoning of automotive emission control systems. Approaches for achieving this objective are discussed.

This paper shows that the rise in engine temperatures of automobiles has created a need for elastomers which can resist the deleterious effects of the higher heat. In addition to the high temperature requirement, a material with high tear and high modulus was also needed, as it is anticipated that there will be an increased use of silicone rubber fabricated parts. It is also pointed out that silicones have continued to improve their physical properties so that they are now being used in many automotive applications, and will be the answer to many design problems confronting the industry today. It is further predicted that there will be a need of silicone rubber adhesive/sealants to replace preformed gaskets and as bonding agents for trim and automotive ornaments.

The high-temperature properties of silicone rubber are compared to those of six organic rubbers. New data on properties at temperature, as distinct from standard heat aging data, are presented to guide the designer and materials engineer. The properties of fluorosilicone rubber are also discussed. Current automotive applications of both silicone rubber and fluorosilicone rubber are described.

This paper describes the implementation of Title 2 of the Clean Air Act, with special emphasis on the emission standards and test procedures which will apply to 1975 and 1976 light-duty vehicles. Discussed are the new test procedure to measure an average car's emissions, and the EPA's tests and analysis-particularly the baseline study of emissions from 1971 cars-which became the basis for setting the new standards. The complex control systems being designed to meet the 1975 standards are expected to require more maintenance attention than the control systems currently in use. The EPA expects to allow more maintenance on durability vehicles than is allowed by the currently-applicable regulations, but will condition its approval of more maintenance on its reasonableness; reasonableness is discussed.

The CO2 tracer technique is a method of measuring automotive exhaust mass emissions during arbitrary modes of operation of a car on the 1972 federal emission test driving schedule. This technique allows modal mass measurements of low-emission cars based on undiluted exhaust gas concentrations. The CO2 concentration at the tailpipe is compared with the CO2 in the diluted stream to obtain exhaust flow. This flow, multiplied by tailpipe concentrations of hydrocarbon, carbon monoxide, and nitric oxide, and integrated over the driving mode, gives modal mass emissions. Problems associated with the lag between the time at which a transient maneuver takes place in the engine and the time at which measurements are recorded are also discussed.

The problems encountered in mounting fire pumps, fire truck bodies, and related equipment on chassis are discussed. The problem area is defined and recommendations are offered for each of the following areas of the chassis: frame, electrical systems, fuel systems, brake systems, transmission and PTO systems, exhaust systems, drivelines, and lights. More technical cooperation between body builders and chassis manufacturers is suggested.

The formed-in-place gasket concept consists of using a paste-type liquid silicone RTV (room temperature vulcanizing rubber) applied to the flange area of the components to be sealed and having the flanges squeeze out and form the liquid gasket on assembly. This system offers several advantages over the conventional precut or preformed gaskets. This system can replace all the static gaskets on a drive train (except head and manifold) and perform as well or better than the gaskets it replaces. Material cost can be reduced as can handling costs when the RTV is automatically applied.

Miniaturization of terminals, connectors, springs, and other contacts in automotive electric systems has imposed rigorous demands upon the principal materials used in their manufacture-copper alloys. This paper surveys the more important copper alloys and presents available data, including that from current research, which bear upon the problem of material selection. Various coppers, copper alloys, and groups of copper alloys are described, and a brief description of mechanical and electrical properties, corrosion performance, surface characteristics, and economics is presented. Comparative data for the various representative copper alloy groups are also presented. Such data includes comparison of mechanical strength-ultimate tensile, offset yield, and fatigue strengths, modulus of elasticity; corrosion resistance-general, stress, and crevice corrosion, dezincification; and surface characteristics-contact resistance, solderability, plating performance.

Adjustment and inspection of headlamp aim may be accomplished by four methods: visual, optical, photoelectric, and mechanical. Visual aim is the simplest but the least accurate. Lateral accuracy is restricted by the ability of the driver to align the vehicle perpendicular to the aiming board and the difficulty of determining the edge of the high-intensity zone of the low-beam lamps. The precision of visual aim is considerably less than the tolerances prescribed in the SAE J599b, Lighting Inspection Code. An optical aimer projects a reduced image of the headlamp beam on a screen. Difficulty in visually determining the edge of the high-intensity zone of the low-beam lamps and inability to accurately align the aimer to the vehicle results in inaccurate measurement of headlamp aim. Two photoelectric aim systems are available.