• 산업기술연구
• /
• 제29권A호
• /
• pp.155-159
• /
• 2009

Recently, a Elevator system is specially important in human life. Also a elevator door is important to a elevator system. In this paper, induction motor drive system using vector control was developed with high performance for elevator door system. For this, velocity pattern generation method was proposed. The proposed system is verified by experimental result with 400[w] induction motor drive system for the elevator door.

• 한국안전학회지
• /
• 제35권1호
• /
• pp.12-17
• /
• 2020

This paper analyzes functions of component parts of D-Urban Railway's door system along with operation obstacle risks on frequency(the number of occurrences/year) and severity(delay time/the number of occurrences). Based on this, the paper presents improvements and current system's problems after obstacle risks of EMU and door system are appled. The obstacle of door system causes corrosion of main parts such as DCU due to heat problem of operation environment, problems of maintenance methods and deterioration. DCUs on PCBs with more than 50% pattern corrosion cause problems. Even though the number of door system's obstacle occurrences for the last 5 years is 42, along with 104 minutes of operation obstacle, EMU operation obstacle risk is low(Level 1), which indicates there is limit in matrix of railway risks presented by the standard of railway safety management system. Therefore, it is necessary to have railway risk matrix suitable for the field. Finally, the paper deducts the obstacle risks through frequency and severity. Since 2017 when the risks of EMU and door system's obstacle, that of EMU has been 24(47% reduced) and that of door system has been average 9.5 per year(23% reduced).

• 한국기계가공학회지
• /
• 제17권2호
• /
• pp.30-36
• /
• 2018

Since the freezer compartment and the refrigerating compartment are located side by side in a side-by-side refrigerator, the problems of the door height difference (DHD) and door flatness difference (DFD) have been constantly raised. Deformation of the cabinet of a built-in side-by-side refrigerator under food and thermal loads was analyzed by the finite element software ANSYS. The DHD and DFD, occurring due to the deformation of the cabinet, evaluated. From the results of the analysis of the cabinet, the 3D CAD software CATIA was used to geometrically translate and rotate the freezing and refrigerating compartment doors, in consideration of the displacement of the hinge fastening point. Then, the coordinates of two points on the upper corner of the doors were determined, and the DHD and DFD were obtained. It found that the thermal load, occurring under normal operation conditions, decreases the door height difference, but increases the door flatness difference. Values of the analyzed DHD and DFD appear smaller than the acceptance criteria used by the refrigerator manufacturer.

• 한국기계가공학회지
• /
• 제17권5호
• /
• pp.76-83
• /
• 2018

A cabinet-door integrated finite element model was constructed for a built-in side-by-side refrigerator with an ice dispenser, and its deformation was analyzed using the ANSYS finite element software. As loads, the food load needed to fill in the cabinet and doors and the thermal load occurring during normal operation conditions were taken into consideration. The door height difference (DHD) and door flatness difference (DFD) between the two doors of the freezing and refrigerating compartments were derived. The DHD and DFD under the assembled condition without applied loads satisfied the acceptance criteria specified by the refrigerator manufacturer. It appeared that the food load increases the DFD slightly. The thermal load tends to increase the differences because of the thermal deformation, especially the DFD, of the cabinet and doors.

• 한국자동차공학회논문집
• /
• 제23권4호
• /
• pp.396-401
• /
• 2015

A door checker holds a car door at several opening angles and limits the maximum door opening, so that the door does not bump against to passengers. Recently, the performance of door checker becomes more important as the feeling of door opening and closing effects on the quality of a car. However, some of door checkers make squealing noise when they are used for ages, which causes consumer's complaints as well as decreasing commercial value of the product. In this study, after various experiments for the noise, we concluded that the major reasons of the noise are acceleration of wearing and loss of lubricant due to impurities in working parts. Therefore, we developed a new mechanism of door checker which can resolve the major reasons of the noise. The developed mechanism is effective to prevent inflow of impurities and loss of lubricant by locating working parts in the case. We also proved that the developed mechanism does not make any noise after the test of 50,000 times of operations.

• 소성∙가공
• /
• 제26권1호
• /
• pp.55-62
• /
• 2017

This paper proposes the process to develop a light-weighting automotive door assembly using high strength steel with low cost penalty. In recent years, the automotive industry is making an effort to reduce the vehicle weight. In this study, inner panels for automotive front door using thinner sheets and quenchable boron steel were designed to reduce the weight of conventional one. In order to evaluate the stiffness properties for the proposed door design, the several static tests were conducted using the finite element method. Based on the simulation results, geometry modifications of the inner panels were taken into account in terms of thickness changes and cost saving. Furthermore, a prototype based on the proposed design has been made, and then static stiffness test carried out. From the results, the proposed door is proved compatible and weight reduction of 11.8% was achieved. It could be a reference process for automotive industry to develop the similar products.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2011년도 춘계학술대회 논문집
• /
• pp.357-360
• /
• 2011

In these days, the passenger vehicles usually have equipped various comfort & security systems to appeal to customers. And then, the importance of emotional quality gives added weight to the noise performance of those system devices. Door inside handle system is one of the most popular devices for passenger. This paper shows developing process about the operating sound of door inside handle. We used DFSS process to develop the door inside handle snap back sound and confirmed the improvement.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
• /
• pp.10-13
• /
• 2009

We have developed variety of LCD technologies for the out-door display, which improve out-door readability as well as reliability from external impacts. This improvement was made possible by new approach on LCD cell optical design and modification of LCD surface, which allows surrounding light to be transmitted to enhance the visibility and at the same time filtering out light, which are considered to be source of noise in terms of visibility. This technology enables users to maintain high display performance in both in-door & out-door environments moreover alternatively choosing in-door/out-door.

• 한국공작기계학회논문집
• /
• 제13권3호
• /
• pp.91-97
• /
• 2004

The door closer is a typical system which consists of spring and damper. The door closer is a device to close the door more slowly. The virtual prototypes of cylinder-type door closer are developed. The simulations of virtual prototype are performed to obtain the load history of the guide pin. The structural strength assessment of the guide pin is performed to verify a design safety. The fatigue life and damage of the guide pin are predicted using a FEMFAT 4.3h based on the finite element analysis.

• 한국자동차공학회논문집
• /
• 제10권3호
• /
• pp.176-184
• /
• 2002

The door stiffness is one of the important factors for the side impact. Generally, the researches have been conducted on the assembled door. A side impact door beam is installed in a door to protect occupants from the side impact. This research is only concentrated on the side impact beam and a side impact beam is designed. The cross section is defined to have an elliptic shape. An optimization problem is defined to find the design maximizing the intrusion stiffness within the specified weight. Design variables are the radii and the thickness of the ellipsoid. The analysis of the side impact is carried out by the nonlinear finite element method. The optimization problem is solved by two methods. One is the experimental design scheme using an orthogonal array. The other is the gradient-based optimization using the response surface method(RSM). Both methods have obtained the better designs than the current one.