Technical presentation, review, and investigation on recent progress in general ground propulsion technologies, including powertrain technology roadmap, regulation review, product development and localization, off-road applications, new technology evaluation, decarbonization, and emission control. PFL 180 covers both conventional and alternative vehicle propulsion system technologies.
A knowledge of ball joints has been applied to the development of a novel improvement in their application to front suspensions. Two functionally different units have been created from the “full ball” type of joint, which has been applied in the past to both upper and lower sockets: 1. A lower socket, hanging on the stud, carries the load on a loose ring of balls and provides a free turning motion for steering. 2. An upper socket, provided with a spring-loaded clutch, dampens the steering motion, and those vibrations resulting from the gyroscopic thrusts of the front wheel. Mr. Booth’s paper delves into the historic background behind the idea of applying ball joints to front suspensions in order to combine suspension and steering action at one point into a neat package. It emphasizes the ability of ball joints to prevent suspension stiffness that results from misalignment.
The current state of the art in truck wheel technology is reviewed with particular emphasis on rims. The salient design features of both single and multipiece rim types are described and the safety of both types in the context of field performance is explored. Some aspects of contemporary design methodology are discussed and possible future directions for the technology are forecast.
A brief history is traced of the stages of development of earthmover rims and wheels. Tubeless earthmover terminology, mountings, applications, and safety tips are discussed. The information is intended primarily for the use of the vehicle designer and the end user of earthmover rims and wheels.
Tire traction performance is dependent on both the tire design and the road surface on which the tire is operated. Measurement of a tire's traction capabilities is indicative of the performance of the tire-road surface combination. Therefore, it is important that the surfaces used to evaluate tire traction capabilities react in a manner similar to those on which the tire will operate. This paper presents a method for categorizing road surface traction properties by evaluating the traction performance of road surfaces when tested with a series of special tires. Data are presented on a series of road surfaces and recommendations are made for traction test surface design.
In a car body painting system, the contribution ratio of phosphate treatment as the paint base coating reaches about 20% in corrosion resistance according to the analysis of variance of experimental results. However, this depends on paint, base steel, etc., used. With the zinc phosphate type conversion treatment, coating mainly consisting of hopeite and phosphophyllite is formed on the surface of steel sheet. With an electrodeposition paint base, corrosion resistance becomes higher as the content of phosphophyllite in the coating becomes higher. The reason for this may be sought in the dissolution of phosphate coating when ED paint is applied (solubility) and when it is decomposed during subsequent baking (heat resistance). We conducted wet-synthesis of hopeite and phosphophyllite crystals. A study was made on the crystals thus obtained relating to their morphology, acid resistance, alkali resistance and heat resistance compared to the phosphate coating formed on steel sheet.
Detachment of wheels from heavy commercial vehicles has been noted in the UK. The mechanism appears to be that of a clamping failure. The compressive force of the wheelnut does not generate enough frictional holding power to prevent microscopic movements taking place between the wheel and nut. When this occurs the studs will be rapidly fatigued in bending and in addition the wheelnuts may loosen. The forces imposed by cornering reduce the compressive forces under the wheelnuts. In-plane forces, such as the ground reaction, may then be sufficient to overcome the frictional hold. The reduction of clamping force is larger when the stud is stiff. Dimensional inaccuracies make a key contribution to the problem. They arbitrarily change the designed flexibilities, they introduce fitting stresses and they create the difference in perimeters necessary for wheelnut loosening.
The results of an empirical study of the dynamic conditions necessary for non-intrusive, plastic deformation of automotive lamp filaments is presented. Both barrier impact and centrifugal techniques were utilized to inertially load the lamp filaments. Numerous tests were conducted under a variety of filament illumination combinations in order to determine threshold values of acceleration necessary for permanent, plastic filament deformation. The study revealed that acceleration levels necessary for permanent filament deformation are well in excess of the average values of deceleration experienced by an automobile, even in very high speed collisions.
Taillight lamp filaments provide valuable information on their illumination status during a collision. This information is contained in the shape of filament deformation, extent and nature of filament fracture, and filament oxidation. The degree of deformation of these filaments, a quantity which may be useful in determining velocities prior to impact, has been documented for headlights but has not been closely examined for taillights. In this paper, a study of the quantification of automobile taillight filament response when subjected to low speed impacts is presented. These studies include two different brands, five velocities up to approximately 19 miles per hour, three filament orientations, and two different deceleration pulses. Recommendations are given for further study in order to provide sufficient data for practical application and use in accident reconstruction.
Real time work cell pressures are incorporated into a dynamic analysis of the gas sealing grid in Rotary Combustion Engines. The analysis which utilizes only first principal concepts accounts for apex seal separation from the trochoidal bore, apex seal shifting between the sides of its restraining channel, and apex seal rotation within the restraining channel. The results predict that apex seals do separate from the trochoidal bore and shift between the sides of their channels. The results also show that these two motions are regularly initiated by a seal rotation. The predicted motion of the apex seals compares favorably with experimental results. Frictional losses associated with the sealing grid are also calculated and compare well with measurements obtained in a similar engine. A comparison of frictional losses when using steel and carbon apex seals has also been made as well as friction losses for single and dual side sealing.
General Motors requires that tires used on its vehicles meet certain performance requirements. Since the establishment of this Tire Performance Criteria (TPC) System, tire design, compounding technology, and testing capabilities have improved. Additional performance parameters important to the total tire/vehicle system have been identified and appropriate additional tire performance requirements have been established. Updated TPC test procedures and specifications are presented. Prior to 1984, three generations of TPC specification tires had been developed for General Motors’ vehicles. For 1984 and 1985 model years, development of a fourth generation of TPC specification tires was completed. The considerations which led to establishment of performance goals are discussed. Test data in major tire performance categories is presented in general summary form comparing fourth generation to third generation TPC specification tires.
This paper examines the development of a two-piece collared flange nut for dual stud mounted wheels. These steel wheels have a 10 hole 11-1/4″ (285.75mm) bolt circle diameter with .875 spherical countersinks. Development was done using standard heavy truck dual wheels. The wheels used were 22.5×8.25 and 24.5×8.25. The objective of the laboratory testing was to compare the current inner and outer cap nuts to the two-piece collared flange nuts. The comparison involved torque retension, clamping force, stud loading, stud durability, and assembly runout. The field testing on the two-piece collared flange nuts was conducted to determine torque retension under field conditions. The test results indicate that wheel clamping forces increase and the torque retension improves with the use of two-piece collared flange nuts.
ISO 26262, an international functional safety standard of electrical and/or electronic systems (E/E systems) for motor vehicles, was published in November 2011 and it is expected that the scope will be extended to motorcycles in a second edition of ISO 26262 going to be published in 2018. ISO/DIS 26262 second edition published in 2016 has Part 12 as a new part in order to apply ISO 26262 to motorcycle. Proper estimation of Exposure, Controllability, and Severity in accordance with ISO/DIS 26262 Part 12, are key factors to determine Motorcycle Safety Integrity Level. To estimate precise these factors, there would be a case that it might not be appropriate to apply studies done for passenger car to motorcycle, and it would be necessary to apply motorcycle specific knowledge and estimation methods. In our previous studies we clarified these motorcycle specific issues and studied the method for the adaptation.