• Transactions on Electrical and Electronic Materials
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• v.18 no.1
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• pp.25-29
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• 2017

This paper presents a unique pressure sensor design for environmental applications. The design uses a new geometry for a multi bossed beam-membrane structure with a SOI (silicon-on-insulator) substrate and a mechanical transducer. The Intellisuite MEMS CAD design tool was used to build and analyze the structure with FEM (finite element modeling). The working principle of the multi bossed beam structure is explained. FEM calculations show that a sensing diaphragm with Mises stress can provide superior linear response compared to a stress-free diaphragm. These simulation results are validated by comparing the estimated deflection response. The results show that, the sensitivity is enhanced by using both the novel geometry and the SOI substrate.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.361-366
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• 2000

To make high precision cutting of long materials or a piston for the engines, it must be necessary to keep the stability of spindle and tail stock in CNC lathe. If a object is clamped at the ends, the thermal expansion and cutting generated in cutting process appear as the deflection of in cuttings objects. Especially, of a piston ring, piston ovality and piston profile, the influences are very serious. In order to solve the problems most of piston cutting are worked in simply support. However, the problems exist, yet.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.6
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• pp.98-104
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• 1999

As the accuracy of manufactured goods needed high accuracy processing has made the efficiency of NC and measurement technology development, the innovation of machine tools has influence the development of the semi-conductor and optical technology. The movement errors can be expressed in terms of yaw, roll an pitch etc. In the case of expanding the error range, static, dynamic and servo gain errors can be included. Machining center might have twenty-one movement errs including three types of joint errors. Those errors have been measured on the condition of just loading of standard table. Regarding these measuring methods, the mechanical compliance of the structure has not been considered. In this paper, therefor, the influences of the additional load on the positioning accuracy are investigated. The results and the techniques proposed in this study can be considered very effective and useful to compensate more correctly the positioning motion.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.2
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• pp.228-234
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• 2001

To obtain precise machined surface and high productivity in machining, high speed end milling has beed studied recently. Though high speed end milling is explicitly effective for precision surface generation geometrically, tool deflection, chatter vibration and frequency characteristics of end milling system deteriorate the theoretical surface. In this study, simulation algorithm and programming method are suggested to simulate machined surface using acceleration signal in high speed end milling. This simulation is conducted by considering vibrational effect of spindle system which was not considered by other investigators. Good agreements were obtained between simulated results and experimental results.

• Design & Manufacturing
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• v.2 no.1
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• pp.11-14
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• 2008

we can save a development cost and time as computer was used in tool and die design of car fields in die manufacture process. Dimension accuracy errors such as springback, springgo, overcrown and twist were reduced product accuracy and caused trouble to assembly each parts of car. In this paper, CADCEUS was used to modify and optimize results of deflection for a tail gate panel of car parts in order to reduce dimension accuracy errors by springback in sheet metal forming. As CADCEUS was used to apply for a tail gate panel, the time for quality to improve was reduced to 30%.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1995.03a
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• pp.17-23
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• 1995

This paper describes investigation of the dressing time by laser in the surface grinding operation. Always dressing work is done before grinding operation. And then generates wear and roading on the wheel by contact between the grinding performance but also ground surfaces. On these states dressing work is needed. On this paper contour of the wheel by He-Ne laser is measured. It has also been found that the wheel deflection reduces the actual depth of cut and the roughness of the ground surface.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.314-319
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• 2000

The working surface of a flexible grinding disk was characterized by means of an image processing, in which a picture of a disk surface was taken by the CCD camera and analyzed with the personal computer. As process conditions, depth of cut was changed to be 2 and 4 mm. From the captured image circles marked on the disk was regenerated using the edges detected with scale space filtering. In order to correlate the level of deformation to the distortion of the circles, intervals between each circle have been analyzed. Notable correlation has been observed between the intervals and the process conditions.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.3
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• pp.99-106
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• 1998

Recently, scientists introduced a new type of microscope capable of investigating nonconducting surfaces in an atomic scale, which is called AFM (Atomic Force Microscope). It was an innovative attempt to overcome the limitation of STM (Scanning Tunnelling Microscope) which has been able to obtain the image of conducting surfaces. Surfaces of samples are imaged with atomic resolution. The AFM is an imaging tool or a profiler with unprecedented 3-D resolution for various surface types. The AFM technology, however, leaves a lot of room for improvement due to its delicate and fragile probing mechanism. One of the room for improvements is gap control between probe tip and sample surface. Distance between probe tip and sample surface must be kept in below one Angtrom in order to measure the sample surface in Angstrom resolution. In this paper, AFM system modeling, experimental system identification and control scheme based on system identification are performed and finally sample surface is measured by home-built AFM with such a control scheme.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.944-949
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• 2003

A High-speed cutter, a kind of electric tool is studied to reduce its vibration and noise. The experimental modal analysis, the operational deflection shapes(ODS) and the time domain analysis(TDA) are used in the SMS software to analyze the vibration signals from an operating high-speed cutters under steady state operating condition. The second mode and fifth m,)do of the base plate coincide with the driving frequencies of the motor, And the vibration of the wheel cover is caused by the gap between the main wheel cover and the sub wheel cover. The structural modification for the base plate was done to reduce the vibration. The effect of modification is verified through the test.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.109-114
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• 2005

The large injection molded parts technology such as instrument panel, front and rear bumper are presented for a precision molding. Some lead time and cost are required to product these part from design to mass product. Recently, CAE is widely used in product design, mold design and analysis of molding conditions to reduce time and cost. The optimal molding conditions can be obtained by DOE(Design of Experiment). The optimal design applications with CAE and DOE have been used in small molded parts. However, application to the large molded body is not reported. In this paper, optimization of injection molding process is studied for quality control in mass production of automobile bumper. Mold temperature difference is chosen through robust design of injection molding process, the molding process being optimized in term of shrinkage and deflection. The optimal conditions through DOE are validated by using injection molding analysis.