• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2002.04a
• /
• pp.440-445
• /
• 2002

공압쿠션실린더(${\psi}80{\times}500^{st}$)의 쿠션장치인 쿠션슬리브(${\psi}20{\times}28^{st}$) 4종(Model #a, Model #b, Model #c, Model #d) 모델을 제작하여 수직하강하는 실린더에 각각 장착한 후, 각 모델에 따라 압력과 부하 특성을 비교하였다. 동일한 실험조건인 공급압력($5kg_{f}/$\textrm{cm}^2$)과 부하하중($70kg_{f}$)에서 각 모델별 실험을 실행하였다. 각 모델별 실험에서, Model #c의 쿠션슬리브인 경우가 가장 적합한 형상임을 알 수 있었다.

• Journal of the Korean Society of Industry Convergence
• /
• v.6 no.3
• /
• pp.261-266
• /
• 2003

이 논문에서는 반능동 진동 흡수기를 통합 시트/섀시 현가 장치에 확대, 적용하여 그 성능을 조사하였다. 통함 현가시스템의 성능분석을 위해 집중 인체질량과 함께 실험적으로 입증된 한 비선형 시트 쿠션 모델을 도입하였다. 또한 3 자유도 시트/섀시 현가시스템의 효과적인 진동제어를 위해 리아푸노브 바이스테이트 제어법칙을 사용하였다. 시뮬레이션결과 반능동 통합 현가장치는 시트 쿠션 모델과 관계없이 운전자의 승차감과 관련 있는 시트의 절대가속도 크기와 시트쿠션의 시트 트랙에 대한 상대변위를 상당히 감소시킬 수 있음을 알 수 있었다. 그러나, 주로 사용되어온 선형 쿠션 모델을 사용한 경우보다 비선형쿠션 모델을 사용한 경우의 제진성능이 약간 저조함을 알 수 있었다. 따라서, 자동차 시트 설계시 성능분석을 위해서는 실제의(비선형의) 시트 쿠션 특성을 적용해야 함을 알 수 있다.

• Proceedings of the KAIS Fall Conference
• /
• 2008.11a
• /
• pp.456-458
• /
• 2008

RV 차량의 쿠션 패널을 생산하여 조립하는 공정은 작업자의 오류로 인한 불량이 많이 발생된다. 본 연구에서는 이러한 불량을 제거하기 위한 화상검사장치를 개발함을 목적으로 한다. 이러한 장치개발은 쿠션패널 고정용 지그, 카메라 인식영역, 이송을 위한 X-Y테이블, 카메라 모듈, 제어기 로 구성되어진다. 본 논문에서 제안한 화상검사장치를 설계하고 화상인식 프로그램을 통해 불량을 판정하여 화상검사 시스템의 타당성을 검증하였다.

• Proceedings of the KAIS Fall Conference
• /
• 2006.11a
• /
• pp.73-75
• /
• 2006

본 논문은 현재 운행 하고 있는 과천선의 도시철도를 중심으로 충돌 속도별 인명 상해치를 연구 하였으며 더 나아가 에어쿠션의 유무에 따른 인명 상해치를 저감시켜 많은 인명을 구조하기 위한 에어쿠션의 개념 설계를 하였다. 그 결과 에어쿠션 장착에 따른 높은 인명 구조 효과가 있음을 제시 하였으며 개념 설계를 기초로 하여 시험을 수반한 해석을 실시한다면 선로 침입자를 위한 도치철도 구조장치를 개발 할 수 있을 것이다.

• Journal of the Korean Geotechnical Society
• /
• v.22 no.12
• /
• pp.33-43
• /
• 2006

Driving tests using model plastic piles with different hammer cushion materials were performed in order to evaluate the efficiency of energy transfer ratio from the hammer, degree of vibration of the surrounding ground and noise due to impacting. A small pile driving analyzer (PDA) was composed using straingages and Hopkinson bar which is measuring force signal and pile-head velocity. The hammer cushion (cap block) materials used for the model driving tests were commercial Micarta, plywood, polyurethane, rubber (SBR) and silicone rubber. The highest energy transfer ratio was obtained from Micarta in the same soil and driving conditions. Micarta was followed by polyurethane, plywood, rubber and silicone in descending order. The more efficient energy transfdr ratio of the hammer cushion materials became, the bigger average noisy (sound) level was found. In addition, Micarta and polyurethane provided bigger bearing capacities than other materials compared in the same soil and driving conditions in which the static loading tests were performed at the end of driving.

• Tribology and Lubricants
• /
• v.29 no.1
• /
• pp.7-12
• /
• 2013

Turbine power control devices at a nuclear / thermoelectric power plant lead to failure by creating mechanical shocks and strong vibrations that are due to the strong elasticity of a spring and the inertia of the valve face during its rapid movement to block steam. To ensure durability of the turbine power control device, which is the main component in the power plant, it is necessary to develop a device that can prevent such vibrations. In this study, a cushion mechanism is added to the head of the hydraulic servo actuator, which is a turbine power control device. Moreover, the cushion mechanism, which includes various modifies shapes and orifices is investigated dynamically through modeling and simulations.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.17 no.1
• /
• pp.42-47
• /
• 2018

This paper describes the dynamical behavior of the bicycle and its nonlinear effect when magnetic repulsive forces are applied to the bicycle cushion system. A finite-element method was used to obtain its reliabilities by comparing the experimental and numerical values and select the proper magnet sizes. The Equivalent spring stiffness values were evaluated in terms of both linear and nonlinear approximations, where the nonlinear effect was specifically investigated for the ride comfort. The corresponding equations of linear and nonlinear motion were derived for the numerical model with three degrees of freedom. Dynamic behaviors were observed when the bicycle ran over a curvilinear road in the form of a sinusoidal curve. The analysis in this paper for the observed nonlinearity of magnetic repulsive forces will be a useful guide to more accurately predict the cushion design for any vehicle system.

• Journal of rehabilitation welfare engineering & assistive technology
• /
• v.3 no.1
• /
• pp.49-53
• /
• 2009

In this paper, we compared wheelchair seating system between wheelchair users with cerebral palsy and spinal cord injuries. Wheelchair seating system is divided into three parts, seating components, seating cushion, and special functions. Seating components are composed of 10 sections, such as headrest, footrest, etc. There are 4 seating cushions including gel, form, hybrid, and air. Also leg elevation, seat elevation, tilt-in-space, reclining, and standing are special function of the wheelchair. There are 10 wheelchair users, 5 with celebral palsy, and 5 with spinal cord injuries who have participated in this study. 10 wheelchair users have been customers of rehabilitation technology center in national rehabilitation center. On the result, SCI group mostly uses headrest, and Humeral blocks (seating components), air cushion (seating cushion), and tilt in space, reclining (special functions). On the other hand, CP group uses adductor, abductor, and pommel (seating components), form cushion (seating cushion), and some of CP group uses reclining (special functions)

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.15 no.6
• /
• pp.64-69
• /
• 2016

Vehicle clutch measurement for disc cushion variation was developed for the production of high quality Dual clutch transmissions. The developed device is composed of load cells for load measurement and LVDT for measuring the distance variation measurement in cushion variation. The servo motor-driven electric press for flexible loads that was developed was controlled by a PC-based HMI system, LabVIEW, and the device was able to continuously record real time measurement data with the accuracies of ${\pm}0.1\;kgf$ load and ${\pm}5{\mu}m$ cushion amount, which is far above the requirements of commercial vehicle standards.

• International Journal of Highway Engineering
• /
• v.10 no.1
• /
• pp.87-95
• /
• 2008

One way to shield an atypical structure to secure the occupant safety of an impact vehicle is to stack energy absorbing material modules around the structure. To be applicable to a cushion module, material must have enough energy absorbing capabilities while satisfying the safety requirements of the vehicle occupant. Static compression test of the potential materials gives a good indication which material is good for a slacking module. This paper presents the mechanical properties that a cushion material must have to satisfy the safety requirements. Static tests are performed for Quard-Guard system module, sand bag, recycled tires, Geo-Container, Geo-Cell and Expanded Polystyren (EPS) Blocks. Static test results are discussed and EPS block of $30kg/m^{3}$ density showed good potential for a cushion module. To check the dynamic effect of EPS block, drop tests have been made up to 35.6km/h impact speed. Drop test results are compared with static test results and no appreciable difference was found. To improve the EPS module property, making holes to the block is suggested and drop test are performed for the modified blocks. From the drop test results, design values are suggested.