• 한국기계가공학회지
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• 제6권3호
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• pp.85-91
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• 2007

This study was carried out to minimize the lifting force of a two hinge type stand mechanism. This unit is designed for the display devices in order to enhance the ergonomics for effective height adjustment and maintenance at any preferred position. The unit will be very useful for the mechanism fabricated with a coil spring and disc springs as a torque generator. The maximum and the minimum torque value should be calculated initially for the smooth lift. And the reasonable torque distribution is necessary to prevent any auto lift and auto dropping at any position because the torque generated by coil spring is more sensitive than disc spring in tilting the position. Therefore, the analysis of the coil spring is requisite to issue the specific torque value depending on the distorted angle with securing reliability of a long time storage condition. After the theoretical torque value was calculated, the evaluation was carried out by making a proto-type sample, then distorted angle was updated by experiment. The result of this study can readily be applied to various units for the optimization of the smooth lift.

• 한국기계가공학회지
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• 제5권2호
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• pp.36-41
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• 2006

This study was carried out to install the lifting force of a two hinge type stand mechanism by 6 Sigma process in advance. This unit is designed for the display device in order to enhance the ergonomics for effective height adjustment and maintenance at any preferred position. The unit will be very useful for the mechanism fabricated with coil springs and disc springs as a torque generator. The 6 Sigma process was applied to select two key factors among 7 elements to lift the head unit and to find out applicable tolerance securing the 3.4 ppm of defects as well as what deviation of lifting force we can expect between calculation and experiment at the design stage of development. The result of this study can be applied to various units for the optimization of the smooth lift.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1454-1457
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• 2003

This study was carried out to minimize the lifting force of a two hinge type stand mechanism. This unit is designed for the display devices in order to enhance the ergonomics for effective height adjustment and maintenance at any preferred position. The unit will be very useful for the mechanism fabricated with a coil spring and disc springs as a torque generator. The maximum and the minimum torque value should be calculated initially for the smooth lift. And the reasonable torque distribution is necessary to prevent any AUTO LIFT and AUTO Drooping at any position because the torque generated by coil spring is more sensitive than disc spring in tilting the position. Therefore, the analysis of the coil spring is requisite to issue the specific torque value depending on the distorted angle with securing reliability of a long time storage condition. After the theoretical torque value was calculated, the evaluation was carried out by making a proto-type sample, then distorted angle was updated by experiment. The result of this study can readily be applied to various units for the optimization of the smooth lift.

• 한국공작기계학회논문집
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• 제16권1호
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• pp.92-97
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• 2007

This study was carried out to minimize the lifting force and to design the slim sized frame of a height adjustment mechanism. This unit is designed for the display devices in order to enhance the ergonomics for effective height adjustment as well as to achieve much slimmer frame for the pedestal. A tolerance analysis of 6 sigma was applied to achieve smooth lift at design stage not to change the tolerance specification of gap several times in a roller type of lifting mechanism at mass production stage. The specification of minimum gap and the target of production yield ratio were agreed with a quality team before tooling. A DFSS simulation on drawings had been done with reasonable tolerance and achievable standard deviation(${\sigma}$) several times until the target specification of gap and yield ratio was met. Once tolerance and deviation(${\sigma}$) were fixed tooling start was done successfully. A CAE method was applied to achieve a slim design. Design parameters were frozen when those parameters matched the reference strength data of standard model. Through those tolerance analysis and CAE simulation the number of tool modification was reduced and production yield ratio was raised up without arguing quality specification at production stage in the end.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2002년도 추계공동학술대회논문집
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• pp.155-159
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• 2002

Wire ropes are used in a myriad of various industrial applications such as elevator, mine hoist, construction machinery, lift, and suspension bridge. Especially, wire rope of crane is important component to container transfer. If it happens wire rope failures in operating, it may lead to safety accident, economic power loss by productivity decline, competitive power decline of container terminal and so on. To solve this problem, we developed wire rope fault detecting system as a portable instrument, and this system is consisted of 3 parts that fault detecting part using hall sensor, permanent magnets and analog unit, and digital signal processing part using data acquisition card, monitoring part using wavelet transform, denoising method. In this paper, a wire rope is scanned by this system after makes several broken parts on the surface of wire rope artificially. All detected signal has external noise or disturbance according to circumstances. So, we applied to discrete wavelet transform to extract a signal from noisy data that was used filter. In practical applications of denoising, it is shown that wavelet pursue it with little information loss and smooth signal display. It is verified that the detecting system by denoising has good efficiency for inspecting faults of wire ropes in service. As a result, by developing this system, container terminal could reduce expense because of extension of wire ropes exchange period and could competitive power. Also, this system is possible to apply in several fields like that elevator, lift and so on.