Search Results

First introduced in 1995, the concept of a temperature-responsive Variable Orifice Valve to control refrigerant flow (patent # 5,479,786) has been further developed for use in automotive refrigerant systems. This device is an alternative, to the expansion devices currently used in automotive refrigerant systems and offers the best features of a thermal expansion valve system (similar high ambient performance ) and of a fixed orifice tube system (low cost, high reliability & performance at lower ambients). Typical automotive refrigerant system operation includes wide variations in condenser air flow and refrigerant pressure. The resultant condenser exit refrigerant temperature is a very stable input parameter for the control of this variable orifice valve (VOV).

An extensive investigation was conducted to assess the influence of steel sheet surface finish (i.e. topography or “texture”) on painted surface appearance. Ten sets of steel panels representing a variety of shot blast, EDT, laser, and bright surface textures were painted simultaneously using advanced solvent-based luxury vehicle paint systems. Paint appearance was measured using a relatively new Autospect instrument and also in terms of conventional Distinctness of Reflected Image (DOI). The results are discussed in detail with respect to 1) the influence of different steel surface textures on paint appearance, 2) the evolution of surface topography during painting, and 3) the implications of this work.

In-cylinder flows in four-valve SI engines were examined by high frame rate flow visualization and two-component LDV measurement. It is believed that the tumble and swirl motion generated during intake breaks down into small-scale turbulence later in the cycle. The exact nature of this relationship is not well known. However, control of the turbulence offers control of the combustion process. To develop a better physical understanding of the in-cylinder flow, the effects of the cylinder head intake port configuration and the piston geometry were examined. For the present study, a 3.5L, four-valve engine was modified to be mounted on an AVL single cylinder research engine type 520. A quartz cylinder was fabricated for optical access to the in-cylinder flow. Piston rings were replaced by Rulon-LD rings. A Rulon-LD ring is advantageous for the optical access as it requires no lubrication.

More stringent Federal Regulations (FMVSS 201 & 208) have been established to limit injuries of car passengers in case of accidents. Materials with good energy management capability, such as Structural Thermoplastic Composites, are being given the first roles in instrument panel, kneebolster and seat applications.

The manufacturing analysis of molded plastic parts is described in detail. A PC based program is presented to analyze the material and capital cost. The program listing is included.

The increased use of a wide variety of recently developed engineered materials and associated processes, for producing vehicular components, has posed a significant challenge to those charged with the responsibility of knowing, developing and/or applying inspection and testing technology to support the quality assurance of these materials, processes and resulting products. This challenge can be more easily and effectively met, within the constraints of time, expertise and other available resources, if computerized knowledge-based systems are employed to enhance the identification, acquisition and application of advanced inspection technology. This paper provides an overview of developments underway to implement this approach in an automotive environment.

THIS STUDY WAS DEVELOPED in response to a component fatigue strength test which determined that if the current #3 engine bearing cap were used in the 2.5L Turbo application, it would be over stressed. Proposed solutions for solving this problem included: a redesigned grey iron cap with additional material in the highly stressed areas, or a cap made from either nodular iron or a free machining steel using current specifications. One of the manufacturing concerns about switching materials is the perceived difference in the machinability of nodular iron and steel. A single point turning evaluation was carried out by Chrysler Motors' Machinability Development Laboratory to compare the machinability of various materials proposed for use in engine bearing caps. Materials tested included: SAE G2500 grey cast iron, the current production material; SAE D45-12 nodular cast iron; and SAE steel grades 1117, 1137, 1215, 12L14, 1215, and 1215 modified (Incut 200).

Material properties of niobium (Nb)-treated SAE I 141 steel connecting rod produced by control cooling were evaluated in comparison with quenched and tempered connecting rod of the same steel. The microstructure of the control cooled connecting rod is predominantly bainitic compared with tempered martensite for the quenched and tempered rod. Tensile strengths are comparable, while yield strength and ductility are lower for the control cooled connecting rod. There are small variations in hardness of the control cooled connecting rod depending on the section thickness in contrast with the uniform hardness for the quenched and tempered rod. Component high-cycle fatigue resistance is lower for the control cooled connecting rod due to the lower yield strength. Both connecting rods meet the fatigue strength performance requirements for the rod design evaluated.

THE NEW CHRYSLER ULTRADRIVE four-speed transaxle is the first production transmission to employ fully-adaptive electronic controls. Adaptive controls are those which perform their functions based on real-time feedback sensor information, just as is done by electronic anti-skid brake controls. Although the transmission is conventional in that it uses hydraulically-applied clutches to shift a planetary geartrain, its use of electronic logic to replace the function of many mechanical and hydraulic components is unique. This paper describes the adaptive controls, how they function in upshifts and downshifts, the simplicity they permit in the clutch and geartrain arrangement, their effect on the design of certain components, and the advantages they offer in diagnostics. It also describes the hydraulics and how certain unique challenges are met in the Ultradrive transmission.

A new kind of four-speed automatic transaxle, engineered from concept specifically for real-time closed-loop electronic control, has been designed, developed, and put into production by Chrysler Motors Corporation. This overdrive transaxle combines two simple planetary gear sets with five disc-clutches, five hydraulic spool valves, and four direct-acting three-way solenoid valves to achieve all operating modes. It uses no bands and only the torque converter stator has a freewheel element. It provides both a fourth ratio and increased engine torque capacity in the same package space used by the previous three-speed transaxle. At the same time, fewer parts are required and manufacturing is more readily automated.

Process Driven Design yields proven benefits in automotive product design. The use of plastics is expanding in the automotive industry. The designer requires a knowledge of the methods of processing plastic parts. This work provides this information by giving a brief description of plastic processing techniques. Included in this is an extensive table of processing techniques and current parts fabricated by these methods. Extension of the process to future automotive products is included.

Product Engineering, Component Supply and Vehicle Assembly are the main forces that transform ideas, customer research and technical information into products. Quality professionals, and others, have advanced many concept models about improved Product and Process Development based upon the application of new tools and systems to Engineering, Procurement/ Supply and Manufacturing/Assembly relationships. Regardless of the concept model, the problem of effecting operating change in U.S. automotive business practices has both behavioral and technical implications. While many studies have emphasized the application of quality tools and systems as a means to improve Product/Process development, they often overlook the cultural change that is necessary to transition from a 75-year history of strong vertical organizations to the “Networking” implicit with new concept models. The availability of improved tools and systems alone will not insure behavioral change.

The scope of Finite Element Analysis in the Product Development Cycle is given. A brief review of the development process is given. A brief description of the analysis method is presented. A description of how it works, how is it implemented, and where do I use it are included. The entire range of questions are answered through, how do I train for it, how do I manage it, along with what are the limitations and what are the benefits of this analysis method.