Cambolt that has two slot shape in thread, have been widely used to adjust wheel alignment in Hyundai and Kia motors. These slots in thread make stress more concentrated, and lead to yield more easily. This paper describes the optimizing process of the Cambolt figure, to maximize the yield load. Contribution of the Cambolt design factors to yield load was verified, through actual test and finite element analysis. Using the DFSS (Design for Six Sigma) method, we optimized the design factors of Cambolt, and confirmed the yield load was enhanced. This new Cambolt can provide more stable wheel alignment joints, by using a higher range of preload.

The worsening environmental pollution has increased the interest in developing eco-friendly technologies. The purpose of this study is to develop an aero-heat exchanger to reduce the emission of environmental pollutants. The operating conditions of an aircraft are extremely harsh, leading to challenges with the determination of appropriate materials and structures that can withstand the severe conditions. In addition, since the tubes brazed to the tube-sheet are structurally fragile, it is essential to assess the structural integrity of tubes. In this study, the overall structural integrity of the tubular heat exchanger under development was evaluated. An appraisal of the junctions between tubes and tube-sheet, which are the most critical parts, was conducted. A finite element (FE) analysis was employed for the assessment of structural integrity. FE analysis was used to evaluate the brazed joint of tubes using a model in which specific tubes were designed to withstand the high temperature of the tube-sheet. The evaluation was carried out compared with the fatigue strength of Inconel 625, the material constituting the heat exchanger.

A thin sheet of metal with corrugated structures has been utilized in various devices: heat exchangers, separators in fuel cells, and many others. However, it is not easy to fabricate thin corrugated structures using a single-step stamping process due to their geometrical complexity. To solve this problem, firstly, a plate type heat exchanger was redesigned to attain the optimal value of aspect ratio and the optimal shape of corrugated structures for the actual loading conditions. A forming analysis of the corrugated plate was then carried out to determine the process parameters. From this work, the optimal value of aspect ratio was found to be 4.6. In addition, the process parameters of heat exchanger forming were optimized using the optimal value of aspect ratio, and the analytical results were evaluated through experiments. The results obtained indicated good agreements between them.

The long neck flange is used to connect piping arrangements where the lap joint is applied. Generally, the component can be manufactured by welding, but this method is both time and cost intensive. Embrittlement at the heat affected zones was also considered. A spinning method developed to improve the manufacturing process and solve the problems of welding. The flange area of the long neck flange can be formed by changing the direction of the metal flow, from axial to radial, while maintaining pressure by using an outer mold and a lap roller. A modified process was additionally developed using a round roller rather than the outer mold. In this modification, the round roller can form the shape of all sizes of long neck flange. Using these flexible methodologies, the cost to prepare outer molds and the time to install and remove the molds can be significantly reduced.

In this study, to avoid surging in the system as a way to ensure the proper discharge requires the design of the valve capacity rating objective is to develop a program. Approximation algorithm for the capacity evaluation is suggested. Loss coefficients obtained by the algorithm is calculated put in the governing equation for the valve flow coefficient and capacity. Calculated values were compared with numerical analysis results for the verifying their validity. The proven formula is created using Excel and it can be easily available the valve design engineers. Creation of analysis models were using a version of Unigraphics NX 4.0, numerical analysis were using a flow analysis commercial program ANSYS CFX 12.0 version. Equations were referenced ‘Handbook of Hydraulic Resistance - 3rd Edition’.

Under extreme test or operation condition, refrigerator endures complicated stresses state and thermal bowing deformation arises on the sidewall. Shelf rails designed in the inner case provide increased surface area to permit expansion without bowing, and also increase structural rigidity to resist bowing. In this study, we designed six different shelf patterns of refrigerator model and studied the bead on refrigerator deformation using finite element method (FEM). Analysis result shows that increasing the numbers of beads properly in refrigerator is more helpful to reduce thermal bowing deformation. In addition, the beads would decrease stress on refrigerator sidewall. However, vertical beads have no effect to reduce thermal deformation of the bowing.

In order to improve the recyclability and to reduce the recycling cost and time, the disassembly technology should be systemized because the worn out products can be reused or recycled after disassembly processes. This paper attempts to propose the integrated CATIA-based DfD (Design for Disassembly) support system to promote the disassemblability of products. The system is composed of two modules; evaluation of disassemblability, generation of DID alternatives. The disassemblability of current vehicle is evaluated to identify the weak point in terms of disassembly using the DELMIA and developed evaluation system. Furthermore a new expert system is developed to propose the optimal redesign rule and principle for generating the DfD alternatives. In order to generate the DfD alternatives, a CATIA-based design support system is implemented. The system can provide quick results and ensure consistency and completeness of the redesign alternatives.

In this study, the casting/forging process was applied in manufacturing a low control arm, in order to prove that application of casting/forging process to Al6061 is likely to get the effect of light weight compared with existing steel products and to reduce the cost of materials. Firstly, In order to set up the optimum casting condition of the forging material, Al6061, casting experiments were carried out by controlling pouring temperature of the aluminum for casting, mold temperature, and pouring time. 700℃ pouring temperature, 300℃ mold temperature and 10-second pouring time were taken into account as the optimum casting conditions. With respect to a hot forging test, it is practiced on the basis of a temperature of materials, strain rate, and reduction rate so as to observe each microstructure and examine strain-stress curve simultaneously; examine tensile test and hardness test; eventually set up the optimum hot forging condition. A hot forging test, tensile test, hardness experiment, and microstructure observation were carried out on condition of 70% reduction rate, 500℃ temperature of materials, and 1 strain rate. As a result of those experiments, 330MPa tensile strength, 16.4% elongation, and 122.8Hv hardness were recorded. In oder to get a sound preform which has no unfilling cavity and less flash, two preforms were proposed on the basis of volume rate of the final product; the optimum volume rate of preform for the low control arm was 115%.
In conclusion, it is confirmed that using the forging material rather than casting materials in casting/forging process is likely to get more superior mechanical properties. Compared with Al6061, performed by means of general forging, moreover, cast/forged Al6061 can not only stimulate productivity by reducing production processes, but cut down the cost of materials by reusing forging scraps.

As the industrial development is accelerated, a new machining process and system are keenly required to achieve super precision surface finish. Especially to get ground surface finish for complicated and narrow inner shape of molds, it is impossible with the existing methods so that a new method is being required to be developed. A new material; called Magic(MAGnetic Intelligent Compounds), is finally made and it is called Magic machining that uses this material. There is a way to make a material as follows, the mixture of magnetic particles, bonding material and particles of abrasive grain should be melt down by proper heat, and then this mixture put in a mold and cool down in magnetic field which has a uniform direction. This new polishing method is spotlighted as an excellent solution to the existing problems. However it hasn't reported any study about the influence of the machining conditions of polishing velocity, amplitude and polishing pressure to the surface roughness yet. This study would examine closely the influence of polishing conditions of. the Magic polishing tool to the surface finish to decide the optimum polishing condition and to standardize the Magic polishing work.