• 연구논문집
• /
• s.29
• /
• pp.111-121
• /
• 1999

Weft insertion and Beating mechanism which weaves fabric with completion the pattern of warp yarn and weft yarn in the high speed rapier loom is driven by cam operating method. This mechanism has 4 cams on the coaxial line for driving. These cams form a pair by two. and perform a conjugate motion with each other. By this reason, it is necessary for two pairs to realize the synchronized motion through exact and optimal design. From this viewpoint, to analysis the whole cams' movement and to realize the high speed of rapier loom, I tried to develop the computer aided simulation program. In this study, I would like to introduce the simulation program about above-mentioned 4 kinds of cam mechanism which can display the profiles of 2 pairs of cam mechanism not to speak of mutual relationships of their movement on the monitor.

• Journal of Advanced Marine Engineering and Technology
• /
• v.37 no.6
• /
• pp.611-616
• /
• 2013

Many researches have been carried out consistently for the green ship owing to its economic increasement, efficiency and convenience. One of them is an electronic controlled marine diesel engine. However, we are suffered from dissemination of above engine, due to its anxiety about safety and reliability. In order to solve these problems in this study, emission characteristics test of main propulsive two-stroke diesel engine, equipped both electronic control and cam drive fuel injection systems, has been performed and evaluated under the various load conditions. From the test results, we have confirmed that exhaust gas emission characteristics of the electronic control system is similar to the cam drive system in eco-mode operation, but NOx in emission mode has been decreased 100ppm or more in full load condition. HC emission from the electronic control system is decreased 10~20ppm at 50% load, and 35~40ppm at 25% load in comparison to cam drive system. In fuel consumption, it is considered that 7g/kWh is decreased than the value of cam drive system at 700bar of injection pressure, which is 200bar higher than cam drive system.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.5
• /
• pp.591-596
• /
• 2022

Since 4-bar linkage widely used in various industrial fields has a fixed link length, it is inconvenient to add an independent link structure or control device to change the movement of output link. Therefore, this paper proposes a new concept of variable 4-bar linkage mechanism to selectively adjust the movement of the output link to fit desired situations, and applied to the commercial table fans, which is a representative product using a 4-bar linkage system. The optimal rotation angle steps for efficiency are determined experimentally and the appropriate lengths of linkage to fit each step are calculated analytically. Changes in the linkage length are implemented by the rotational motion using a grooved cylindrical cam and the feasibility of the proposed variable linkage mechanism is verified through fabrication and measurement. The presented variable link mechanism is expected to improve the efficiency of industrial robots and fuel valve systems.

• Tribology and Lubricants
• /
• v.16 no.4
• /
• pp.289-294
• /
• 2000

This paper present the contact stresses, which considers the shear stress at the cam and follower interface in the direct acting type valve train system of a high speed engine. To determine the contact condition, the normal contact forces are calculated by using the lumped mass dynamic modeling. The line contact is considered between the cam and follower interface. The variations of dynamic stresses are presented as a function of camshaft rotational angle. Also the effects of various design parameters are investigated.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.9
• /
• pp.732-736
• /
• 2016

Air conditioning part designs are moving towards higher efficiency and productivity. The expansion device is one of the core parts of an air conditioning system and controls the refrigerant quantity, evaporation load, compression capacity, and condensation capacity. In this study, an electronic expansion valve for two working fluids ($CO_2$ and R134a) was developed for air conditioning systems in vehicles. The valve uses an eccentric cam driving structure instead of a lead screw to decrease manufacturing costs and increase productivity. The pressure resistance and flow rate performance was evaluated using numerical analysis. At maximum operation conditions and burst pressure conditions with $CO_2$, the maximum stresses on the valve model were about 98 MPa and 223 MPa, respectively. The maximum flow rates of $CO_2$ and R134a with different orifice openings were about 550 kg/h and 386 kg/h, respectively. The performance with R134a was verified by experiments.

• Journal of the Korean Magnetics Society
• /
• v.20 no.6
• /
• pp.234-238
• /
• 2010

Solenoid diaphragm fuel pump, which to replace mechanical fuel pump system by utilizing cam-shaft driving force, is in the spotlight for being a high efficient green car component. However, there is a drawback in power consumption as a solenoid diaphragm fuel pump only relies on solenoid for its flux needed in reciprocating motion. Therefore, this research proposes permanent magnet type VCM (Voice Coil Motor) fuel pump system to minimized power consumption. Furthermore, the study compares and analyzes power consumption and dynamic performance between the current and the former solenoid diaphragm pump by conducting finite element analysis with the commercial electromagnetic solver, MAXWELL.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.11
• /
• pp.1453-1459
• /
• 2011

A roller pinion gear (RPG) system composed of either a pin or a roller and its conjugated cam gear can improve the gear endurance from that of a conventional gear system by reducing the sliding contact while increasing the rolling motion. In this paper, we first proposed the exact cam gear profile and the self-intersection condition obtained when the profile shift coefficient is introduced. Then, we investigated the Hertzian contact stresses and the load stress factors while the varying the shape design parameters to predict the gear surface fatigue life, which is strongly related to the gear noise and vibration at the contact patch. The results show that the pitting life can be extended significantly by increasing the profile shift coefficient.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.6 no.3
• /
• pp.78-87
• /
• 1998

A dynamic model of direct-acting OHC valve train system has been used to determine the load conditions in the system. The modified equations for calculating the friction forces between cam and HLA, and at a camshaft bearing have been defined considering the lubrication conditions. Then, to understand the frictional characteristics in the system, a parameter study has been performed. As the results of the analysis, valve spring stiffness and preload have great effects on the friction in the system, but the effects of other parameters are negligible. So, how to design the valve train system with respect to the reduction of friction is to minimize the valve spring stiffness and preload in the limit of satisfying the dynamic constraints.

• Journal of KSNVE
• /
• v.4 no.1
• /
• pp.83-88
• /
• 1994

In many circumstances, it is desired to move a mass from one position to another without inducing and vibration in the mass being moved. Two such problems are considered here : the motion of a mass initiated by another mass, nd the motion of a pendulum initiated by the specified motion of its support. In each case, it is dosired that the system start at rest and come to rest in the second position. A simple strategy for the specified motion is given here. The method is motivated by engine cam-follower design. The force required to move the system in question is determined as well as the maximum value of the force required(and the times at which these forces take place).

• Transactions of the Korean Society of Automotive Engineers
• /
• v.24 no.5
• /
• pp.527-537
• /
• 2016

Recent automakers are trying to be more precise with the dimension check and moving parts to guarantee high quality and satisfy customer requirements. The aim of this paper is to investigate the design tolerance suitability of door operating mechanism linked arms, lever, and cam-shaft in a mobile air handling unit. These parts are complicated because doors, arms, lever and cam-shaft are connected nonlinearly in 3D. The current tolerance analysis method poses problems in design analysis because the moving doors are reasonably suitable for the AHU function. The 3-DCS analysis method provided useful results not only in establishing the inspection criteria for the quality control of products but also in enabling economical production. As a result, the vent door had $1.62^{\circ}{\sim}1.72^{\circ}$ and the defrost door had $0.84^{\circ}{\sim}0.9^{\circ}$ for the directly connected arms operating-type. For the lever connected arm operating-type, the foot door had $2.0^{\circ}{\sim}2.24^{\circ}$ tolerance, while the tolerance values satisfied the air flow volume distribution rate criteria in the AHU. Finally, the results have confirmed the design's tolerance suitability by using 3-DCS analysis at the early design stages. Reliability can be achieved by analyzing accumulated tolerance during the sub-parts assembly process and the moving mechanism linked especially by arms, lever, and cam-shaft.