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Tests and analyses are presented on bulldozer blade oscillation configurations for improving dozing productivity. The purpose of oscillation is to decrease the ratio of tractive force to blade force, since dozing costs are so strongly dependent upon tractive force. The oscillating blade mass, frequency, amplitude, and direction of motion for optimum performance are determined using an approximate theoretical analysis. The theoretical results are compared with experimental results obtained from the literature. Reasonable agreement is obtained. Oscillating blade configurations are presented which should realize double the present dozer performance. In addition, those configurations provide complete isolation of the dozer from the inertial forces of the oscillation system. Prior to obtaining the analysis, full scale configurations for a U.S. Army D5 dozer were designed, built, and tested. The tests showed around 20% and 30% improvement with the two configurations.

A new generation of “Super-Stabilized” antiwear hydraulic oils has been developed to meet the stringent requirements of modern high-performance hydraulic systems. Outstanding performance properties of this type of heavy-duty industrial hydraulic oil include: multi-metal compatibility, “keep-clean” performance, antiwear retention, thin oil film inhibition, controlled demulsibility, and wide-temperature-range pumpability. A review of power transmission fluids used in earlier equipment designs is presented going from the “Water Age” to the “Mineral Oil Age.”

The driveline in an application can be the source of vibrations. This paper explains and gives corrective procedures for driveline vibrations caused by unbalance, torsional excitation, inertia excitation and secondary couple effect. It also briefly explains the influence of the driveline on the system bending resonance of the engine-transmission package.

Peak oil film pressure is cited as the parameter controlling the fatigue life of a sleeve bearing. Variables affecting peak film pressure, and the freedom to control them, are discussed. Bearing clearance is the variable most readily controllable, and has the greatest impact on film pressure. Through a simple design change to the conventional sleeve bearing, substantial improvements in fatigue life can be realized for any bearing alloy. Tests in both engines and bearing fatigue rigs have confirmed the validity of the theory on which the design is based. Advantages and implications of the new bearing design with respect to heavy-duty diesel engines are discussed.

Along with the increase in specific output of internal combustion engines the determination of piston temperatures in diesel engines and the possibility of influencing these temperatures has attained greater and greater significance. After a survey of the temperature conditions of pistons in non-turbocharged and turbocharged diesel engines and the various temperature measurement techniques used to determine piston temperatures, this paper will concentrate on some of the different parameters in pistons for diesel engines in the diameter range of 100 to 140 mm and will present their effects with the aid of comparative investigations.

The recent advent of small remotely piloted aircraft as tools for both military and civilian missions has set a requirement for reliable, low vibration, compact, reciprocating engines in a power range where such engines have not previously been available. A new twin crank, geared output engine is being developed to satisfy this requirement. The special feature of this engine is its very low vibration. An analysis and the resulting balance criterion that gives this low vibration is presented.

An engine for providing 10.4 kW (14 hp) with efficient throttled performance has been developed for use in a small, remotely piloted airplane. A requirement for operation at very high altitudes resulted in the choice of an oxidizer-independent, monopropellant gas generator to supply energy. One unique feature is a valving concept by which the working piston is used to actuate the gas-inlet-valve poppets. A pneumatic spring is used to provide the proper valve closing force. The exhaust is ported through the lower cylinder. Good life characteristics have been demonstrated by nearly 20 hours of ground and flight testing.

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.

Previous publications from The Queen's University of Belfast have described the unsteady gas flow through a naturally aspirated two-cycle engine and the most recent of these have detailed the scavenge process, the combustion model and muffler design. It is thus now possible to predict the unsteady gas flow behaviour through and the performance and noise characteristics in this type of engine with a good degree of accuracy. This paper describes a mathematical model which has been formulated to simulate the action of the two-cycle engine fitted with a reed valve due to the unsteady gas dynamic behaviour in the inlet tract and makes comparisons with measurements. A complete simulation on the computer of a two-cycle engine fitted with a reed intake valve is thus now possible.

The Robert Bosch series of In-Line Pumps currently serves engine output requirements ranging from 13 to 268 BHP per cylinder. In this family of injection pumps, the type P in-line pump is mainly applied to heavy-duty, direct injected truck engines, with power output up to 80 BHP per cylinder. Since 1962 approximately 1.5 million pumps of this type have been supplied to the field. Advanced development of the Diesel engine aimed toward increased power output and more favorable exhaust emissions have made further development of the injection system necessary. Conversely, however, the continued development of the injection system provides the possibility of realizing these improvements to the engine. As a contribution to this development, Robert Bosch has redesigned the “P” pump.

This paper outlines the problems posed to the designer of fuel injection equipment suited to engines developing from 11 Kw (15 bhp) to 75 Kw (100 bhp) per cylinder and deals in detail with the improvements made to several highly-stressed components in order to make significant increases in service life. The paper then reviews the resultant Lucas CAV range of equipment, concentrating on the Maximec pump and the associated ancillary equipment.

The influence of residual stress and retained austenite on the fracture behavior of bend test specimens of carburized steels was evaluated. The test results are part of an ongoing research effort intended to compare the relative fracture properties of alternate grades of steel and their respective standard grades having similar hardenability. In general, steels of equal hardenability and core carbon content exhibited similar fracture behavior. Compressive residual stress in the carburized case was found to significantly influence the impact fracture stress which, in turn, was correlated with impact fatigue properties. High levels of retained austenite at the surface caused the peak compressive residual stress to occur further into the case. The occurrence of residual stress peaks further into the case was not necessarily detrimental to impact fracture stress or impact fatigue properties.

Robert Bosch GmbH has been developing and manufacturing electrical equipment for automobiles for approximately 80 years and electronic equipment for over 20 years. The first section of this paper describes the beginnings of automotive electronics and their early products. The second section deals with the most important current products which include, in particular, electronic fuel injection, breakerless ignition, and the antiskid. The last part describes the development of future products which consistently use digital technology and in many cases a microcomputer. The most significant project in this series is the digital engine control to manage gasoline injection, ignition and automatic transmission.

The increased usage of electronics in automobiles, especially in critical engine control and safety related applications, makes electronic component reliability a major concern. As the automobile customer becomes more quality conscious, reliability becomes a more and more important sales factor. This paper addresses the needs for improved and predictable reliability for automotive electronics. Reliability enhancement will require improvements in packaging, testability, device design and fabrication processes. Electronic components will have to have reliability designed-in rather than “yielded-in.” There are also needs for improvement in predictions of reliability performance in the field and for alternatives to screening techniques to eliminate infant mortality. Improvement of automotive electronics reliability will require better communication and more joint efforts on the part of individual vehicle manufacturers and members of the electronics industry.

The Japanese automotive industry is greatly concerned with meeting the 1978 Japanese emission standards. Many electronic approaches are used as a powerful tool in solving the emission control problem. There are also many other examples of automotive application of electronics. This paper describes the recent development of automotive electronics in Japan.

Automotive engine control is one of the fastest growing electronic applications in the industry stimulated by legislative requirements on emissions and fuel economy. All of the systems in use or under development will add cost as compared to historical components used for control of fuel, spark and EGR. As the most complex problem, fuel control offers the best example to suggest some of the directions for cost reductions and the most likely areas where continued development will uncover benefits associated with the more complex but expensive electronic control systems. The availability of low cost, high speed semiconductor electronics and the development of fast response sensors and actuators compatible with feedback control concepts will play an important role in this evolution. The rate of growth for electronic engine control will be limited only by our effectiveness as suppliers in meeting these challenges.

Faced with the necessity of controlling of emissions and improved mileage, the automotive industry is turning to the increased use of semiconductor electronics. This paper describes the trends in semiconductor technology over the past two decades, and projects these trends out through the mid-1980's. A systems approach to the design of automotive electronics utilizing a digital information system is presented. The benefits in performance and reliability improvements together with reduced costs are defined. A strategic approach to implementing this digital information systems approach into automotive systems is presented.

The electronic industry and the automotive industry are trying to learn how to work together to achieve reliable, complex electronic control systems. To date however, the emphasis appears to be on initial component cost rather than on system life cycle costs. It is predicted that in the long run, the more complex CMOS technology will prove to be more cost effective than simpler NMOS technology.

The impact of the electronics industry, specifically the semiconductor industry, on automotive engine controls is evident in engineering programs at Ford Motor Company. Within the last four years, a new engineering organization has been established to design and develop these new electronic engine control systems. Additionally, the control system engineers are bridging the gap between engine system engineers and semi-conductor designers to create microcomputers, sensors and actuators with the latest technology. The tangible results of this new engineering activity are seen in the applications of electronics to engine controls at Ford. Starting with the 1978 model year and continuing with the announced 1979 model year applications, approximately twelve new components have been developed and released for manufacturing through the cooperative support of the semi-conductor and automotive industries.

General Motors has developed a computer controlled catalytic converter system. The C-4 system is the primary element in the GM effort to meet the twin goals of higher vehicle fuel economy and lower exhaust emissions. Major system components include a catalytic converter, electro-mechanical carburetor, exhaust oxygen sensor, coolant temperature sensor and electronic control module. The primary function of these components is to provide a precisely controlled air-fuel ratio to the catalytic converter for efficient reduction of regulated exhaust constituents.