Search Results

Machining Powder Metallurgy (P/M) components have been regarded as one of the main issues due to its unique porous structure. Porosity can cause regional vibration and decrease tool life. It can also lower the standard of surface finish. Manufacturers and researchers have searched for different machining technique to overcome the difficulties, such as P/M densities, hardness or the free machining additive. The CVD deposition TiCN/Al2O3 coating cutting tool has been used in this experiment to search its improved capability in the P/M components machining. This paper will attempt to discuss the cutting force measurement, chip formation, and surface finish analysis. A general analysis of the machinability in the specific workpiece has been shown to compare the same machining condition by using different cutting tools.

Recently, the concept of Mizen Boushi (reliability problem prevention) has been applied in automotive development as a tool to refine drawings to the greatest completion possible by the prototype stage. GD3 is a quality innovation process that supports this objective, based on the pillars of Good Design, Good Discussion, and Good Design Review. Good Design tries to nip problems in the bud, and Good Discussion and Good Design Review are used to formulate the best countermeasures to those problems. The process utilizes creative FMEA (Failure Mode & Effects Analysis), FTA (Fault Tree Analysis), and a System Design Review. These tools focus attention on the many potential problems that could occur due to a change in design or environment. The System Design Review is especially useful to examine potential failure modes, root causes, part drawings, and prototype part designs. This is followed by a Design Review Based on Failure Mode (DRBFM for short), as a tool to guide discussion.

One aim of all companies worldwide is the fast building of new tools or parts to start a new series of production. However, in reaching the goal of fast production, many changes may arise between the idea and the final product due to new ideas, unforeseen difficulties, changes in design, etc. These changes often cost valuable time. The goal remains to find a technology which offers fast building of parts or tools with high quality results. Which technologies can be used and offer a good solution to this problem? In my presentation, I will show how it is possible to build tools or parts within the molding technology using the Rapid-Prototyping method, “3-D-Printing with wax.”

In this paper the fatigue life of welded steel sheet structures is predicted by using FE-Fatigue, which is one of fatigue analysis software tools on the market, and these predicted results are evaluated by reference to corresponding experimental results. Also, we try to predict these structures by using two fatigue life prediction theories established by the JSAE fatigue and reliability committee to compare prediction results. It was confirmed that spot welds fatigue life predictions agree qualitatively with corresponding experimental results and arc welds fatigue life predictions are in good agreement with corresponding experimental results in cases where the SN curve database is modified appropriately.

The main operations for the manufacturing of auto parts are the cutting of the flange and the stamping. In order to perform accurate fatigue calculation it is necessary to have the material properties for each point of the structure. Usually, only the fatigue curve obtained on the flat sheet with polished edges is used because it represents the basic metal behaviour. The real edge quality decreases the fatigue limit while the hardening induced by the stamping increases it. To take these effects into account allows a better fatigue calculation of the structural part.

The status of recycling in Korea was reviewed, including the status of ELV(End-Life-Vehicle) and activities of the recycling industry. Also the Korean regulation for recycling was explained, focusing the unique system of Korea. Hereby, the unique system means that all the car makers have to summit the report which shows their activity of the design improvement for recycling to the government in annual year. Finally, the development items and contents was introduced, which RSM(Renault-Samsung Motors) are tackling. These items were selected on the basis of Renault-Nissan Alliance's policy which promotes increasing recycle rate and eliminating the hazardous materials.

The influence of tensile strength on fatigue strength and the effect of microstructure on fatigue notch factor were investigated into conventional mild steels, HSLA steels, DP steels and TRIP steels. The grade of studied steels was altered from 440MPa to 780MPa. Not only smooth fatigue specimens with side surface ground but also fatigue specimens with a pierced hole were prepared for each of steel sheets. Fatigue tests were conducted in an axial load method. These experiments made it clear that the fatigue limits of smooth specimen increase along the tensile strength approximately independent of microstructure but those of notched specimen do not necessarily increase along the tensile strength. Namely, fatigue limits of DP steels and TRIP steels with notch increase in proportion to tensile strength although those of HSLA steels with notch do not increase.

In this paper, we investigate a forming process and formability of the hydroformed front side member designed in the ULSAB-AVC project. The forming process consists of bending, preforming and hydroforming. We carried out a feasibility study of these processes by FEM analysis. We then found a path by which we could form the front side member without it buckling or bursting. In addition, because the front side member designed in the ULSAB-AVC project is a highly specific one, we designed a front side member more generic to actual car body structures. We carried out trials and evaluations of the crash absorption energy of this generic front side member using various thicknesses and strengths of tubes and tailored tubes.

In recent years, improving fuel efficiency and collision safety are important issue. We have worked on a new construction method to develop body structure which is light weight and strong/stiff. We adopt multi type Tailor-Welded Blanks (TWB) which is formed after welding several steel sheets for ATENZA (MAZDA 6), NEW DEMIO (MAZDA 2), and RX-8. This is a technology to consistently improve of such product properties and to reduce costs. Laser welding is a common TWB welding method, but for further equipment cost reductions and productivity improvements, we have developed a higher welding speed and robust plasma welding and introduced this to mass production. We introduce this activity and results in this report.

Information system has been developed and implemented for the purpose of managing motor vehicles maintenance system which includes maintenance of body of motor vehicles. The databases have been developed for the maintenance system regarding workers, locations, failures, vehicles, maintenance operations, spare parts and reports on maintenance, for the purpose of providing valid information required for managing the maintenance system. This paper describes the basic common solution and the individual bus-maintenance software solution for the “Fix-it” process used for “on the road” maintenance. For this process, the mode of operation and the results of its application are shown.

When we develop the new car, the conditions under which vehicles are used in the market is an important factor in assuring vehicle durability. Because of Asia and Oceania etc. that will increase number of the car has much gravel road(The cruel areas), calculating the severity of road load is most important factor. In this work, we show you simple measurement and analytical method for the severity of road load in the cruel areas, that use the principle of road power spectrum.

YAG laser welding for body in white has been developed and applied to the joint of the roof and body side of new L-class car. By comparison with the resistance spot welding, which is conventional joining method, the laser welding has some advantages, such as one-side welding and continues welding. So the joint structure can be improved to lightweight with high strength and stiffness. And the appearance of joint also is improved. We use two 3KW YAG lasers and robots with fiber optics. The roof and body side panel are galvanized zinc coated steel, and lap welded. The most critical factor for mass production is the gap control technique, and we developed the gap control system with special pressure device. And in-process monitoring system is also developed which analyzed the intensity of plume and back reflection of YAG laser.

Rollover testing evaluates whether a vehicle will roll over or slide in emergency steering maneuvers. The results may depend upon consistent tire performance through consecutive runs. Researchers in the past have concluded that tire shoulder wear greatly affects the maximum lateral acceleration capability of the tires. This research, however, was performed in the 1970's on bias-ply tires. Tire technology has improved significantly since these results were published. Recent test results on Firestone Wilderness radial tires suggest that as tire shoulder wear increases, the maximum lateral capacity of the tires does not. This paper presents data from thirty J-turn tests performed through the shoulder life of a tire. Results show that maximum tire adhesion levels were independent of run number or tire shoulder wear level. Vehicle dynamics were also consistent throughout the tire's shoulder wear life.

A high-quality die-casting technology has been developed for lightweight aluminum frame structures that produces high-strength aluminum parts that are also weldable. This new technology has been used in casting frames for motorcycles and snowmobiles and has enabled improved frame designs with far fewer component parts than was possible before. This die-casting technology also results in a significant reduction in energy consumption during the manufacturing process.

The objective of this study is to develop a more precise springback prediction technique by means of finite elements method for the optimization of forming process design. The approach includes a new material modeling method to calculate accurate residual stresses inherent in forming processes, and a new analytical method to calculate springback shape by releasing residual stresses in a sequence of releasing steps. This paper proposed the new analytical method in springback simulation for actual automotive components with complex shapes. A new algorism, Multi-Step-Springback method was developed to improve the accuracy of springback simulation. In order to determine the material parameter, compression-tension tests were carried out. The impact on springback results is shown. The effect of modeling a more complex material behavior is presented.

The Free Piston Power Pack (FP3) represents a new concept in the design of free piston engines. The FP3 is a free piston engine with an integral generator for electrical power output. Its novel features are an integral compressor and a passive intake valve located in the head of the piston. These improvements eliminate undesirable problems that affect conventional free piston engine designs, such as piston ring wear and the need for an external compressor, and allow a significant increase in power density. The FP3 is designed to meet the highest levels of fuel efficiency and exhaust emissions performance in a compact size for use in hybrid electric vehicles (HEVs). This paper describes the design of the FP3 and gives details of the operation and construction of a prototype.

LCA is a powerful tool for analyzing the competition between materials used in the design of an automobile. Presented here from the viewpoint of the Steel Industry, are the impacts of using steel and light metals on the construction, use and end-of-life phases of an automobile. Steel is lean in energy and GHG emissions during the construction-phase. High-strength steels make it fairly easy to reduce vehicle weight, which has a strong influence on the use phase impacts, and the indefinite recyclability of steel also influences the end-of-life. Steel is well positioned in this comparison, all the more so that the input data for such sensitive parameters as the recycling level are chosen to reflect real-life data. Ecodesign thus emerges as a powerful tool that forces competing metals to improve their properties even further.

It is important to reduce the viscosity of automatic transmission fluid (ATF) in order to improve fuel economy. However, in general, low viscosity fluid can cause metal fatigue, wear, and seizure. It is necessary to increase the viscosity of the fluid at higher temperatures to maintain the durability of the automatic transmission (AT). The key point is the selection of the base oil and the viscosity index improver (VII) with both a high viscosity index (VI) and excellent shear stability. On the basis of this concept, a new generation high performance ATF named WS was developed. WS can achieve the highest level of fuel economy, while maintaining the durability of the AT.

This study examined the evolution of the surface topography of imperfections in response to painting. Critically-sized imperfections on industrially produced coated sheet steel surfaces were sampled, and carefully characterized. Changes in the surface topography were measured after painting simulations, and visibility after painting was assessed. Three-dimensional optical profilometry was demonstrated to be a powerful technique for assessing imperfection topographies and their evolution during painting; several imperfections that were completely invisible through human inspection after painting were still measurable by 3-D topography. Two primer surfacer systems were used, to compare a conventional liquid system with a high-build anti-chip powder system.

The oven shock test is an accelerated test which is often used to quantify the thermal durability of both coated and uncoated ceramic substrates. The test calls for heating the substrate for 30 minutes in an oven, which is preheated to specified temperature, and then cooling it in ambient environment for 30 minutes. Such a cycle induces axial and tangential stresses, during cooling, in the skin region whose magnitude depends on physical properties, oven temperature, radial temperature gradient and the aspect ratio of substrate. In addition, these stresses vary with time; their maximum values occur as soon as the substrate is taken out of the oven. This paper evaluates the severity of thermal stresses as function of above factors and estimates the probability and mode of failure during cooling using thermocouple data. Methods to reduce these stresses are discussed.