Papers by Author: King Sun Lee

Abstract: This system is a self-developed real-time thickness inspection system including high-precision laser sensors and a mobile platform for on-line detection of tire rubber skin. The measurement data is used to calculate the standard deviation and process capability indices, and to evaluate measurement capacity. The system is a real-time measurement system in which the obtained measuring data compare with the standard value and show any errors. A technician can adjust the process parameters precisely on-line to improve product quality. The standard deviation of repeatability of the system for height is within +/- 0.0081 mm. The repeatability error of the horizontal sliding rail is within 0.0145mm, while the measurement error between this system and a coordinated measuring machine is within 0.028mm.

Abstract: The unibody of LED lampshade is the expansion of a lampshade array from single-LED in order to decrease assembly time, the forming technique is complicated. This study employ solid model to build micro mold, and find out the optimal design parameters, such as gate position, running system, cooling system and holding pressure system. The improvement of gate system can reach flowing equilibrium when molten plastic flows into cavity, and no welding line is produced. In the cooling stage, the cooling speed at each cavity is also steady and balance in order to reduce residual stress and lens defects. This study utilizes multi-gate system and multi-stage holding pressure aided forming to decrease welding line and residual stress. This study improves traditional mold design to fit more multi-cavity LED mold design which includes cooling system redesigning, cavities layout, flowing balance in runner and reducing shear stress. The Taguchi method and orthogonal array are used in the study for each group of experiment; many factors are applied to obtain the minimum shear stress, minimum warp, reduction of flow mark and uniform stress distribution. The results can provide for industry reference.

Abstract: After the automobile made an emergency brake or bumped by accident, the baby car seat will be deformed and cracked by great force, the baby car seat have became a very important topic for years. This study focuses on analyzing the state of baby car seat after receiving forces, propose the improvement of structure strength and safety factors, enhance the structural strength of baby car seat and improve collision resistance. The internal skeleton was a backbone of baby car seat structural design, this research utilized simulation that combined CAD software (Pro-E) with finite element analysis software (Ansys\Workbench) to analyze the bumping situation, the high-speed camera was also applied to record the bumping situation of baby car seat. The comparison between these two results was used to design the skeleton within safety seat in order to approach the anticipative structure strength. Therefore, structure analysis will enable baby car seat to reach a high level of collision resistance.

Abstract: The key of qualities of optical lens created by injection molding are geometric errors and distribution of residual stress. This study analyses a mobile phone camera lens with aspheric optical lens created by one mold and 16 cavities. Mold flow analysis was used to simulate geometric shapes of different gates and design cooling systems to control mold temperatures. Mold temperature was controlled during the actual injection process and simulation results were used as the basis for mold design. The effects of cold-wall-mold on lens residual stress are discussed. The experiment result showed that higher mold temperatures are helpful to reduce residual stress. An aspheric mould measurement system was used to measure both the mold and the product. The results showed that the replicating capacity is satisfactory with a molding error of 3.604μm.

Abstract: This study is subject to 3D virtual simulation and experiment design method application in the optimal clearance design in the 3D shell punched processing. During the simulation stage, the PAM-CRASH and 3D-CAD (Pro/E) system are used to model the punching processing. The results of the punching maximum punched burr from the 3D virtual punching simulation were input to a neural network to establish a model corresponding to the 3D shell punched variables. Once the metal punching control parameters, such as punch/die radius, punch/die clearance, punch cutting angle and different material thickness, were given, the punching processing performance (the punching maximum burr and maximum stress) can be accurately predicted by this developed network. Therefore, in this research, a satisfactory result based on the simulation verification is established.

Abstract: This study aimed to create a multi-cavity and non-uniform thickness die casting for flowing balance. The die casting processes involved a hot-chamber die casting experiment and computer aided simulation to explore the flowing condition of the molten metal in the metal molding process. Computer-aided mould flow analysis software FLOW 3D V9.2 was applied to simulate the filling stage of zinc alloy in the mould cavities. The design parameters of the mould included four variables relating to the gate: width, position, shape, and thickness of cross-section. Analysis results shows that the primary goals of balance design include two things: (1) the flowing path of molten metal was shortest; (2) the mould cavity was easiest to fill with molten metal. The flowing balance design used analysis software to simulate the flowing condition of the air, which produced an air trap. The melting metal motive force pushed air into the slug well in order to reduce the production of pores. The experiment confirms the actual flowing situation of zinc alloy with a nearly 95% accuracy.

Abstract: Chips scraping each other during transportation, and chips coming into contact with water or air will cause oxidization resulting in poor quality products. The chips need to be well packed and to be protected from the environment. The method of Surface Mount Component (SMC) packing using plastic carrier tape can reduce chip damage. This study focuses on the extrusion process parameters optimization of plastic carrier tape. Because each extrusion process produces 270 pieces of carrier tape, the tape size is 1.35mmX2.25mmX1.35mm and is extremely difficult to reach the tolerance standard. This study utilized a practical test to explore various factors on the quality of the carrier tape, such as the rotational speed of extruder screw motor and extrusion mold; the negative pressure of extrusion mold; and the temperature of the extrusion mold. These experiments could find out an optimal extrusion process.

Abstract: This research applies 3D mesh mold-flow analysis to analyze the SD (Secure Digital) card. It aims at temperature of the mold and plastic. The proper mold filling temperature is found by simulation analysis to improve the short shot situation, and seeks the cause of warping via various processed conditions. SD memory card clip has a big variation in thickness. Due to the bigger flow resistance the plastic is difficult to reach thinner portion, even hot plastic is also difficult to supply. The temperature of plastic goes down as a result of the cold mold cavity. Thus, the plastic does not reach certain portions before solidifying. The cooling system of injection machine was controlled by constant temperature oil cooling. This study explored the optimum injection condition by utilizing experiment to control the temperature of the plastic, the temperature of mold, the packing pressure process and so on. It is valuable to companies which utilize injection mold applications.

Abstract: This research utilizes an image-vision-system to measure the size of the product-burr. The relational expression was established between the clearance of micro punching die and burr size after blanking the composite material via a neural network. This can help to anticipate the burr size under any clearance and used cycles of punching die. The purposes of this research are: (1) it can predict the used cycles of punching die at any clearance between the punch and die, the engineer can change the punching dies at right moment to prevent the bad product from producing; (2) it can utilize this research to find out the optimum clearance condition which can avoid bad design of the punching die, which will take long time to repaired the punching die.