Search Results

The paper traces from the introduction of the internal combustion engine the numerous attempts that have been made to understand the fundamental origins of noise. It relates the progress made from very early subjective assessments to the present day sophisticated experimental and theoretical analyses.

A general pupose LCD driver chip set employing a (2/3) multiplexing scheme is presented. Mask programmable options of either four (4) or (3) common backplanes are provided. A master/slave approach is employed to yield a more optimum system expansion of frontplanes. Temperature tracking of liquid crystal threshold shift can readily be implemented off chip. Internal clock timing can be generated by either an on board oscillator circuit or an external clock source.

Systematically reviewed are the fundamentals of Electronic Fuel Management (EFM). Included is a discussion of five EFM areas: 1) air sensing concepts 2) fuel metering concepts 3) fuel delivery to the cylinders 4) fuel preparation with the air 5) calculation hardware (ECM) Presented as a part of the air sensing section is a summary of the physical principles that may be applied to compressible fluid mass air flow rate measurement. Finally, an example of digital computer control of a timed speed density system is reviewed.

This paper provides information on theory and design methods used to tailor pneumatic spring rate and natural frequency. Equations utilized in the design procedure are presented, and the interaction of the important variables is discussed. The vital role of laboratory testing and validation is emphasized. Although the paper is restricted to pneumatic spring design, peripheral equipment such as leveling valves and auxiliary reservoirs are addressed

This paper presents the results of statistically designed machinability tests for single point turning of aluminum casting alloys using several different cutting tool materials. A methodology is presented which is aimed at providing machinability data for both performance comparisons over a wide range of machining conditions and individual process modeling and optimization. Anew type of graphical summary is used to display machining performance in terms of wear rate, tool life, surface roughness and surface integrity to enable the process planner to analyze the trade-offs in cutting condition selection. Performance predictions for several tools and materials are presented and discussed.

Automotive components made from advanced composite materials result in significant weight savings over steel and aluminum. However, already a few components have been developed in composite materials which have been unsuccessful in meeting the requirement s. Not all components can successfully be designed from advanced composite materials. One of the problem areas is the application involving torsion members. Specifically those applications where torsional shear strength, shear fatigue, or shear strain are limiting factors. In automotive components this includes torsion bars, coil springs, and the shorter drive shafts. In this paper the strain limitations of advanced composites are compared to other materials and this effect demonstrated in the design of a torsion bar. A parametric analysis will be shown which will directly indicate when, for a particular application, advanced composite materials can or cannot be utilized.

Machinability of popular automotive casting alloys is determined by (1) alloy chemistry, microstructure and properties, (2) the casting method employed, (3) various treatments that alter the microstructure, cleanliness or strength of the alloy, and (4) metallic and non-metallic impurities. Silicon and other hard phases act as abrasives in a relatively soft alloy matrix and tend to reduce cutting tool life. Copper and magnesium increase alloy hardness, improve machined surface finish and decrease the tendency of an alloy to build up on a cutting tool edge. Sand castings require more machining stock and have a coarser microstructure than either permanent mold castings or die castings and therefore are more costly to machine. Die castings are the least costly to machine. Treatments to refine primary silicon or modify the eutectic silicon morphology substantially improve tool life.

AISI 5160 and modified 5160, the most commonly used steels for automotive suspension coil springs, contain chromium. In the event this metal becomes hard to get, our industries should have the information basis for introducing spring steels with less or no chromium. This paper reviews existing spring-steel grades and summarizes a laboratory study aimed at finding new alloys with an optimum combination of properties. New alloy approaches that are potentially competitive with 5160 and modified 5160 during normal times are identified as well as substitutes that could be used during an emergency.

This paper is intended to review what air suspensions should accomplish and how closer attention to principles and ideas presented here can result in greater user satisfaction. Some new and potentially helpful ideas are also presented which may set trends for future designs.

This paper is directed to those engineers who sense a need for custom integrated circuits, but who are not familiar with the options available to them. Custom integrated circuits are invariably unique to a particular customer. In automotive applications they are seen as interface units between microprocessors and controlled systems, also as independent functional elements. They are used for reasons of economy, reliability and security. The CMOS (Complementary Symmetry Metal Oxide Semiconductor) technology has a number of virtues that make it especially suitable to the automotive environment. A technique exists for rapidly converting conventional logic diagrams into computer-designed custom CMOS integrated circuits. The technique is described.

The performance and cost advantages of custom integrated circuits for automotive electronics have been established. The most effective design technique for a particular application may encompass both linear and digital custom ICs. A bipolar design technique that is used to advantage in combining both linear and digital functions on the same chip is called linear-compatible Integrated Injection Logic (I2L). This paper describes several automotive applications for linear-compatible I2L custom ICs. Advantages and benefits, as well as limitations, are discussed and illustrated with actual chip development efforts. The paper concludes with a discussion of advanced development programs utilizing this technique to enhance future product design.

Semiconductor, ROM-based microcomputers have one of two heritages - calculators or microprocessors. Similar paths were followed in the evolution of the automobile. The Model-T Ford and mid-range autos like the Buick, led to the consolidated automobile designs of the 1930’s. By 1930 the basic inventions were past, and numerous refinements were in the future. The evolution of ROM-based microcomputers have reached the same point in 1980. The coming era will take advantage of features that are available now. The Motorola M6805 Family is typical of a modern program architecture with flexible system configurations. Among the program benefits are multilevel subroutines, look-up tables, interrupts, timers, flexible addressing modes and multifunction instructions. The systems configurer gets a variety of ROM and RAM sizes, various I/O features, plus a choice of HMOS or CMOS technologies.

With electronic fuel injection systems accurate control of air to fuel ratio primarily requires knowledge of the quantity of air mass taken into the engine. Above all it is the unfavorable automotive engine environment which renders the few known transducer capable of measuring this quantity little attractive. This paper describes a new mass air flow meter which besides being perfectly insensitive to that environment meets all other important requirements.

FABRICATION AND TESTING OF COMPLEX MOS large scale integrated circuitry is changing as the semiconductor industry positions itself for the next generation. Mostek’s discussion will highlight some of the advances in technology, production methods, and equipment necessary to the challenges of manufacturing MDS circuits of complexities similar to the 64K RAM. The timing and leadtimes necessary for this technology will be illustrated by historical example. The example will be Mostek’s 3870 which in 1977 was the state of the art. This discussion will center around an automotive application now in production and mention the various revision and their timing and impact on manufacturability of the MK3870.

The CVCC engine requires a small amount of rich mixture for the auxiliary combustion chamber and a greater amount of lean mixture proportioned to the load for the main combustion chamber, with the overall air-fuel ratio which has to be properly controlled. In order to fulfill the above requirements, the carburetor has to provide both the main and auxiliary fuel system independently and connect their throttle valve shafts with each other by a link mechanism. Besides this, the carburetor is confronted by the problems that are introduced by the leaner mixture, i.e., idle stability, surging, transient performance, cornering problems, and starting performance. It is also required to be equipped with exhaust emission control devices so as to meet stringent official regulations. It is not too much to say, indeed, that the development of the carburetor was the key to the success of the CVCC engine.

The solenoid fuel injector's dynamic behavior has been modelled by digital simulation techniques. The results help to explain the injector's non-linear flow calibration at short control pulse widths. This behavior is reproduced in an experimental comparison, and recommendations are made for reducing these calibration non-linearities based on model predictions.

This paper outlines the history and development of a new small injector which is especially suitable for passenger car diesel engines. Engine Performance, Durabiliby, Field Test and Emissions are covered in the paper. The main features of this new injector are as follows: 1) A small screw-in injector having a 14 mm sparking plug thread 2) Gives quieter running than pintle or hole type nozzles 3) Gives emissions comparable with pintle nozzles 4) Gives lower fuel consumption than pintle or hole type nozzles over most of the operating range. 5) No back leakage pipes required 6) No heat shield required It has been exhaustively tested in a number of engines and vehicles, and is now in volume production.

Piezomotors are a form of electromechanical interface device that have unique properties with regard to response capability and proportionate control. They employ ferroelectric materials that undergo a lattice distortion when subjected to an electric field. This paper gives a brief review of material properties desirable for this type of high-strain actuator and explains why these properties are important. It describes a material developed by the authors’ company and shows the extent to which this material satisfies requirements. The significant factors in coupling energy from a Piezomotor are examined, and methods for addressing them are described. Current state of the art is quantified in a design guide diagram that permits the performance of any size of Piezomotor to be predicted under various electric field energizations. A selection of applications in automotive fuel systems, pumps, valves, industrial hydraulics, and optical systems is presented.

Identification of the noise generating mechanisms of gravity action and vibrator stimulated sliding chutes has resulted in the development of practical and effective noise abatement treatments for both. In the case of gravity action chutes the application of foam-backed thin and narrow spring steel plates on the chute surface achieves the desired effect with noise reduction of 14 to 25 dB(A). With vibrator stimulated chutes progressive steps were taken to attenuate source noise, chute radiation noise and the non-productive component of the force vector from the vibrator, resulting in noise reduction of 25 to 30 dB(A).

Three principal noise-generating mechanisms were identified in the vibratory feeder as structural vibrations, interaction between the conveyed parts and the track surface and radiation from the bowl cavity. Treatment of the track surface based on theoretical analysis of the vibration-stimulated conveyance, structural damping treatment of the bowl and “see through, load through, reach through” acoustical screen have been developed. These treatments lead to 20–25 dBA reduction of the sound pressure level accompanied by substantial reduction of part delivery time.