• Proceedings of the KSME Conference
• /
• 2004.11a
• /
• pp.805-810
• /
• 2004

The model is verified thorough simulations and experiments. And then the developed model is applied to a half car model and automobile vibrations are analyzed. The effects of tire design parameters on the automobile vibration energy are investigated. The results from laboratory and field tests confirm the validity of the analytical model. The 17-DOF half-car model is built to analyze the automobile vibration. The characteristics of the nonlinear model for a shock absorber are applied to this model. The results from the present 17-DOF half car model incorporating the analytical tire model with tire design parameters, are compared with a 5-DOF half car model where the tire is modeled with linear springs. The results of the 17-DOF model are closed to experimental results. Using the 17-DOF model, the influences of tire design parameter are considered. According to the results of analyses, the vibrations at seat/body/wheel are predicted by simulation and experiment.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.518-523
• /
• 1995

To improve the set comfort of commercial vehicles in various road conditions, it is necessary to design a seat shock absorber which can avoid the vibration zone imposing the discomfort feeling and fatigue on drivers. Through the vibration and dynamic analysis, a shock absorber that has 4 steps of damping ability is developed. Dynamic characteristics analysis of the seat damper is performed considering each valve and oil path for the design purpose.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2008.10a
• /
• pp.286-289
• /
• 2008

Production Information System make it possible to check and control the information of manufacturing processes. Based on this information companies are able to act to the price strategy and marketing strategy timely. In this study we will examine developing the MES(Manufacturing Execution System) as Production Information System in the Automobile Shock Absorber Piston rod Manufacturing Process of which processes are composed of heat treatment, lathing, grooving, milling, rolling, inspection and packing processes in order to control its production information efficiently.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.11a
• /
• pp.362-370
• /
• 1996

Even if the shock absorber is developed to Variable S/A or Active S/A, it is necessary to construct data-base or build the dynamic performance characteristic program of Oil S/A. Since both Variable S/A and Active S/A are based on the principle of Oil S/A. To obtain the design technique of Oil S/A, we model the damping mechanism and characteristics of an Oil S/A whose performance was testified. And then it is analyzed the dynamic behaviour characteristics of damping mechanism.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.11a
• /
• pp.371-376
• /
• 1996

The damping force of shock absorber in an automobile is determined by the components which construct the S/A. In this study we investigate the individual effect of these components on damping force. In addition, opening of important valve doling compression and tension cycle due to up-down reciprocation movement is also researched. Thus we are to strictly control the properties and tolerance of components having important effects on tile damping force and to produce S/A of better quality.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.05a
• /
• pp.477-482
• /
• 2002

This research is concerned with the study of an active vibration absorber using piezoelectric actuators and Isolation pad. The active isolation system consists of 4-pairs of PZT actuators bonded on the surface of an aluminum plate and a passive damping material. The active system is connected to the passive system in series. The Signals of the accelerometers are fed into the PZT actuator through the controller. We proposed a new control technique which can deal with the shock as well as the base excitation in this study. The Positive Acceleration Feedback(PAE) tuned to the natural frequency of the vibration isolation system is used to suppress the vibrations caused by the shock using the top accelerometer signal. The Negative Acceleration Feedback (NAF) based on the base acceleration signal is used to counteract the base motion. Experimental results show that the proposed active vibration isolation system can suppress vibrations.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.4 s.97
• /
• pp.46-56
• /
• 1999

A semi-actively controlled impact system which adjusts an impulse exerted by the external impact is studies. The main control variables are internal pressure difference inside the cylinder and the shock absorber displacement while it travels. Compared to a conventional one so called a passive system with a variable orifice inside the cylinder, a semi-actively controlled system utilizes an external orifice controlled by a highly fast responding electrical proportional valve. This device overcomes the temperature and viscosity change due to continuous operating and keeps the desired pressure difference and displacement in every operation. In this article a new prototype impact system is designed and manufactured based on a semi-actively control system. Through computer simulations and experiments, we verify the possibility of controlling the shock absorber pressure and displacement. After investigating the control performance a modified semi-actively controlled system with better control performance is also proposed.

• Proceedings of the KSME Conference
• /
• 2004.04a
• /
• pp.973-977
• /
• 2004

A pneumatic cylinder used to sliding seal which seal the element one to another in relative motion. It is difficult to accuracy control because of adhesion phenomenon. To confirm this phenomenon, it is carried to friction force test and analysis for bellows type rodless cylinder. In the rodless cylinder of this type, friction force test is very important. Through the theoretical analysis of shock absorber obtained the optimal design of bellows type rodless cylinder. As the result of the friction force test, LM Guide type is suitable for work under low friction force.

• Journal of the Korean Society for Precision Engineering
• /
• v.14 no.6
• /
• pp.28-36
• /
• 1997

Even if the shock absorber is developed to Variable S/V or Active S/A, it is necrssary to construct database or bulid the dynamic performance characteristic program of Oil S/A. Since both Variable S/A and Active S/A are based on the principle of Oil S/A. To obtain the design technique of Oil S/A, we model the daping mechanism and characteristics of an Oil S/A whose performance was testified. And then it is analyzed the dynamic behaviour characteristics of damping mechanism.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.39 no.5
• /
• pp.391-399
• /
• 2011

The purpose of this paper is to predict the shock absorbing characteristics of the aluminum honeycomb in a lunar lander. Aluminum honeycomb has been used for shock absorbers of lunar lander due to its characteristics such as light weight, high energy absorption efficiency and applicability under severe space environments. Crush strength of the honeycomb should have strength to endure during shock energy absorbing process. In this paper, the crush strength, which depends on the shape of honeycomb and impact velocity, is estimated using FEM. Ls-dyna is used for finite element analysis of the honeycomb shock absorber. The unit cells of the honeycomb shape are modeled and used for the finite element analysis. Energy absorption characteristics are decided considering several conditions such as impact velocity, foil thickness and branch angle of the honeycomb.