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Transmitted torque, thrusts of driving and driven pulleys, and axial force between two pulleys were measured on a metal pushing V-belt type CVT. Thrust ratios between driving and driven pulleys at several different speed ratios were plotted with respect to torque ratio and compared with each other. It was found that the relation between thrust ratio and speed ratio was almost independent of rotational speed of the pulley and the maximum transmittable torque at a constant torque ratio. The thrust ratio is primarily a function of speed ratio. It also depends on torque ratio and coefficient of friction between blocks and a pulley. An empirical equation for pulley thrust balance was derived. The equation is expressed in an explicit form. It is so simple that it can be applicable for electronic control of CVT.

Described in this paper is the design and development of an electronically controlled continuously variable transmission. The development was carried out by a Japanese and American partnership for use in vehicles with l000cc and 1300cc engines. The paper describes the technical features of the transmission and the development of the starting clutch, hydraulic control, electronic control, and the chain belt sheave system. The test results of vehicle performance and fuel economy are included.

After many years of joint development with Van Doorne's Transmissie BV, FORD has put a modern continuously variable transmission (CTX) for small FWD passenger cars in the market-place. Since May 1987 the CTX is offered in the 1.1 ltr. Fiesta as a low-volume pilot program. The very encouraging customer acceptance has strengthened FORD plans to launch high-volume production of the CTX for 1.1 ltr. Fiesta up to 1.6 ltr. Escort applications in foreseeable future. The CTX also forms the base for further CVT-developments, covering larger vehicles, bigger engines and electronic controls. The first part of this paper deals with initial field experience of the hydraulically controlled CTX in regard to driveability, comfort, performance and fuel economy. In the second part, improved control systems to fully utilize the potential of CVT's are described, including integrated powertrain management concepts.

A continuously variable chain transmission (cvt) used as main drive in motor-cars offers less fuel consumption, noise and toxic exhaust emission, combined with easy handling and comfortable driving. Design features, especially chain design and focal points of development are explained.

The Continuous Variable Transmission, though not new, may have attracted the reader's attention now several manufacturers have announced an automotive application. After 1.5 years experience in producing CV-Transmissions and the VDT-all metal CVT belt, VDT will give the reader a first insight in considerations that were made in the concept of the belt. A short overview of the actual way of applicating the belt in a transmission with respect to operating parameters is given in the last part of this contribution.

With the popularization of easy driving in Japan, the quest to improve the fuel economy and vehicle performance of a small car with a torque converter automatic transmission (AT) has led to the development of the Electro Continuously Variable Transmission (ECVT). The Subaru ECVT which combines an electronically controlled magnetic powder clutch with the van Doorne's steel belt drive system employs a couple of conventional synchromeshes as a means of forward/reverse change-over mechanism and simple hydraulic control valves. This combination has realized smoothness and quick response of CVT operation and provides a compact size for the CVT with the weight of 45.4 kg. Fuel economy of Subaru Justy ECVT car with the one liter engine is thus improved by 15 to 20 % in Japanese 10-mode test cycle and at the 60 km/H constant speed respectively in comparison with that of three speeds torque converter AT.

A transient three-dimensional model has been developed to simulate the thermal and conversion characteristics of nonadiabatic monolithic converters operating under flow maldistribution conditions. The model accounts for convective heat and mass transport, gas-solid heat and mass transfer, axial and radial heat conduction, chemical reactions and the attendant heat release, and heat loss to the surroundings. The model was used to analyze the transient response of an axisymmetric ceramic monolith system (catalyzed monolith, mat, and steel shell) during converter warm-up, sustained heavy load, and engine misfiring. The simulation indicates that high solid temperatures are encountered during sustained heavy load or engine misfiring, while steep temperature gradients are developed during the converter warm-up period. Flow maldistribution and radial heat loss are major sources for the thermal gradients.

Automotive thermal reactors have obtained high conversion efficiencies on engines with very rich carburetion, but fuel economy and reactor durability have suffered. Improved mixing of exhaust gas and secondary air in the engine exhaust port was examined as a means of improving reactor efficiency at less rich engine air-fuel ratios. Three air-injection systems which span a broad range of mixing capabilities were examined. Mixing characteristics were deduced from anemometry measurements of instantaneous secondary airflow, and emission performance of each system was generalized by a test program employing four steady-state conditions. High-pressure, timed air injection provides the best mixing and the best reactor performance. Sparger (radial discharge) air injection tubes provide fair mixing and better performance than conventional open-ended air injection tubes, which exhibit poor mixing characteristics.

This report presents the results of a three-year study designed to collect analyze, and reduce selected anthropometric data on 4027 infants and children representative of the current U.S. population ranging in age from newborn to 12 years of age. Since the major purpose was to provide basic measurement data most useful and critical to consumer product design, regulatory consideration, or other direct applications, 12 of the 41 measurements taken were applied measurements which have not been previously available. As an example of the direct application to product design, measurement of buttock depth on 3-to 6-month-old infants provided an objective basis for establishment of crib interslat distances. A substantial portion of the study involved the design, fabrication, development, and testing of a new generation of anthropometric measuring devices which transmit measurement signals to a portable mini-computer data acquisition system or to a set of readout meters.

A primary concern in the development of a passenger inflatable restraint system is the possibility that a child could be in the path of the deploying cushion either due to initial position at the time of an accident or due to precrash braking accompanying an accident. Previous studies by General Motors and Volvo have indicated that serious injuries to children are possible if the cushion/child interaction forces are not controlled by system design. This paper describes an instrumented child dummy which was developed to provide measurements of the various cushion/child interaction forces. An analysis is given describing the types of injuries which could be associated with the various types of interaction forces. These results were used to develop appropriate dummy instrumentation for indicating the severity of the cushion/child interaction. A description of the modifications made to an existing three-year-old child dummy are described.

The design and development of Mark II GT brake system within the parameters dictated by the Mark I chassis presented many problems. The Mark II GT with its larger 427 cubic inch engine had more weight and much higher performance than the Mark I. Space limitations of the carryover wheels and suspension imposed a severe handicap on individual brake component design. This was compounded by shortening the normal one year development time to a three month period. Part I of this paper is devoted to the consideration of factors which control the design of a brake. The concept of kinetic energy and its effects on brake performance is reviewed briefly. Use of the ventilated rotor design is explained for applications where severe heat is a problem, as in the case of the Mark II GT. The development of the brake system from the 24 hour Daytona endurance race to the Le Mans Grand Prix race is reviewed.

Mark II GT Transaxles - This paper provides a description of the Ford Mark II GT transaxle as used in the 1966 Le Mans race. The functional requirements, as established by a simulated Le Mans dynamometer test cycle, are summarized through integration of the engine torque and speed data and compared with gear and bearing design parameters to reflect their capacities in hours of Le Mans usage. The areas where the development work was particularly important are highlighted in the discussion. MARK II GT TRANSAXLES* - While the specific subject of this paper, in a sense, did not exist as little as two years ago all of the mechanics for its functional needs were available. All of the mechanics, in fact, have been well developed for several years; the arrangement, however, is not in common use in this country and its application is treated as new.

There is no handbook of vehicle electrical system design or no secret formula which can serve as a guide in the development of electrical components for competitive events. The basic approach to the extent possible, therefore, was to use production components or components for which we had considerable background experience.

Among the factors attributable to Ford's success at Le Mans, France in 1966 is the high efficiency air induction system of the 427 GT engine. Contrary to the basic design parameters of passenger car engine induction systems, which consider part-throttle transitions and fuel economy, induction systems for high speed, high-output competitive engines are quite the opposite. These engines demand maximum airflow capacity, and equal balance of air/fuel mixture to each cylinder to insure high efficiency throughout the engine speed range under full-throttle conditions. Recognition of this need, its resolution, and the application of resultant techniques to the Ford 427 engine since its inception in 1963, are the basis for this paper. The GT induction system is the product of a new development technique that involved the extended use of an induction flow-stand, as well as extensive studies of various types of manifolds and cylinder heads.

Compared with in-line 4-cylinder engines, V-6 engines show a slower rise in exhaust gas temperature, requiring a longer time for catalysts to become active, and they also emit higher levels of engine-out emissions. In this study, The combination of a new type of catalyst, and optimized ignition timing and air-fuel ratio control achieved quicker catalyst light-off. Additionally, engine-out emissions were substantially reduced by using a swirl control valve to strengthen in-cylinder gas flow, adopting electronically controlled exhaust gas recirculation (EGR), and reducing the crevice volume by decreasing the top land height of the pistons. A vehicle incorporating these emission reduction technologies reduced the emission level through the first phase of the Federal Test Procedure (FTP) by 60-70% compared with the Tier 1 vehicle.

The mechanism causing the micro slip characteristic of a metal CVT belt during torque transmission was analyzed, focusing on the gap distribution between the elements. It was hypothesized that gaps between the elements cause slip to occur between the elements and the pulleys when the belt is squeezed between the two halves of the pulleys, and the slip ratio was calculated theoretically on that assumption. The μ-v (friction coefficient versus sliding velocity) characteristic between the elements and the pulleys was measured and the results were used in calculating the slip ratio. As a result, a simulation procedure was developed for predicting the slip-limit torque of the belt on the basis of calculations. The slip ratio found by simulation and the calculated slip-limit torque showed good quantitative agreement with the experimental data, thereby confirming the validity of the simulation procedure.