• 소성∙가공
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• 제4권1호
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• pp.17-27
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• 1995

The tact switch is widely used in electric and electronic products. The dome type tact spring is produced by stamping. Stamping of the tact spring and operation of the tact switch have been simulated by the elasto-plastic finite element method. The operating characteristics of the switch may be given by the relation between the operating force and stroke. For a given material, this is affected by two main factors. One is the geometry of dome spring which is determined by the geometry of stamping dies and the stamping pressure, and another one is the dimension of switch. From the calculation, it was possible to obtain the stamping conditions and switch dimension for a predetermined force-stroki relation And, the hoop stresses and effective strains distributions due to the stamping and during the operation of the switch indicate a possibility of cracking in the center and rim of dome spring.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.18-20
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• 2002

In this paper, various forces generated in the Gas Circuit Breaker(GCB) such as operating force, repulsive force, spring force, and dashpot force are analyzed with the fluid properties and the mechanical structure. The operation of GCB can be understood. A stroke curve from the result of simulation is compared with experimental one.

• 한국자동차공학회논문집
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• 제8권5호
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• pp.114-120
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• 2000

Friction forces of piston rings for a typical SI engine were independently measured while excluding the effects of cylinder pressure, oil starvation and piston secondary motion using a floating liner system. Friction patterns, represented by the measured friction forces, were classified into five frictional modes with regard to the combination of predominant lubrication regimes(boundary, mixed and hydrodynamic lubrication) and stroke regions(mid-stroke and dead centers). The modes were identified on the Stribeck diagram of the dimensionless bearing parameter and friction coefficients which were evaluated at the mid-stroke and at the dead centers. And the frictional modes were estimated to the full operation range. The compression rings behave in the mode where hydrodynamic lubrication is dominant at the mid-stroke and mixed lubrication is dominant at the dead centers under steady operating conditions. However, the oil control ring behave in the mode where mixed lubrication is dominant throughout the entire stroke.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권4호
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• pp.317-323
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• 2005

To increase the operating speed of the solenoid actuator, this paper proposed a modified model using a non-magnetic ring, which is welded on the magnetic guide tube, and also presents the characteristic equations, results of Finite Element Method (FEM) analysis for magnetic flux distribution and density in magnetic flux paths, and computer simulation results for the dynamic characteristics of plunger motion according to the stroke and time variation. As well, we proved the non-magnetic ring effect by experiments using prototypes.

• 한국생산제조학회지
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• 제5권3호
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• pp.22-30
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• 1996

In order to compensate for out-of-straightness of shafts, an automatic straightening process composed of an automatic measuring module, an automatic control unit and operating softwares was developed with a hydraulic press. The out-of-sraightness of each shaft was measured automatically in the measuring stage. An optimal pressure point was determined to minimize TIR value of the shaft according to press count of 3-points bending process. In the geometric adaptive control procedure, punch stroke and springback of the shaft were predicted by an observer using on-line measured values of press force and deflection amount I each press count. An automatic straightening machine was realized with the measuring module, the GAC module, PLD, IBM-PC and the operating software on the hydraulic press. the validity of the proposed straightening process was confirmed through a series of experiments with cam shafts.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.50-52
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• 1996

The exiting apparatus for rectilinear reciprocating motion has low efficiency because of various mechanical converting equipments from rotary motion. The LOA(Linear Oscillation Actuator) is the rectilinear reciprocating actuator. This paper shows the operating principle of bifiler winding LOA and the comparison the characteristics of thrust force of no tapered moving core type LOA with the tapered one. Through FEM analysis tapered LOA has the lower peak force and longer stroke than no tapered LOA.

• Journal of Biosystems Engineering
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• 제38권3호
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• pp.171-179
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• 2013

Purpose: A simulator for the design and performance evaluation of a tractor with a hydro-mechanical transmission (HMT) was developed. Methods: The HMT consists of a hydro-static unit (HSU), a swash plate control system, and a planetary gear. It was modeled considering the input/output relationship of the torque and speed, and efficiency of HSU. Furthermore, a dynamic model of a tractor was developed considering the traction force, running resistance, and PTO (power take off) output power, and a tractor performance simulator was developed in the co-simulation environment of AMESim and MATLAB/Simulink. Results: The behaviors of the design parameters of the HMT tractor in the working and driving modes were investigated as follows; For the stepwise change of the drawbar load in the working mode, the tractor and engine speeds were maintained at the desired values by the engine torque and HSU stroke control. In the driving mode, the tractor followed the desired speed through the control of the engine torque and HSU stroke. In this case, the engine operated near the OOL (optimal operating line) for the minimum fuel consumption within the shift range of HMT. Conclusions: A simulator for the HMT tractor was developed. The simulations were conducted under two operation conditions. It was found that the tractor speed and the engine speed are maintained at the desired values through the control of the engine torque and the HSU stroke.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
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• pp.227-230
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• 2003

There are many practical applization that require motorless actuation. The purpose of the paper is to develop an actuator using the shape memory alloys(SMA) that operates is linear motion. We consider several design specifications as driving force of above 5kgf, driving stroke length 15mm, supply voltage DC 9-l2V and operating time less than 0.5sec etc. Design procedure and experimental results of a mock-up model are Presented. It has been also applied to the door locking system.

• 한국정밀공학회지
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• 제30권9호
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• pp.961-968
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• 2013

In this paper, we propose an optimal design for starfish capturing manipulator module with four-bar linkage mechanism. A tool link with compliance is attached on the four-bar linkage, and the tool repeats detaching starfish from the ground and putting it into the storage box. Since the tool is not rigid and the manipulator is operating underwater, the trajectory of the tool tip is determined by its dynamics as well as kinematics. We analyzed the trajectory of the manipulator tool tip by quasi-static analysis considering both kinematics and dynamics. In optimization, the lengths of each link and the tool stiffness are considered as control variables. To maximize the capturing ability, capturing stroke of the four-bar manipulator trajectory is maximized. Reaction force and reaction moment, and other kinematic constraints were considered as inequality constraints.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권9호
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• pp.538-544
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• 2004

This paper presents the interruption capability of serial-hybrid type GCB (gas circuit breaker) compared with that of puffer type. First a puffer type model interrupter which has the stroke length of 80 mm has been designed and manufactured. And also, a serial-hybrid type interrupter which has the same design parameters as the puffer type interrupter except the serially arranged thermal-expansion chamber and puffer cylinder has been fabricated. Using a simplified synthetic test facility, the critical interruption capabilities of the two GCBs have been estimated. The critical di/dt, the critical dV/dt of ITRV (initial transient recovery voltage) and the minimum arcing time of the puffer type model GCB were 10.7 A/${\mu}\textrm{s}$, 5.5 kV/${\mu}\textrm{s}$, and 15.0 ms respectively. In the case of serial-hybrid type model GCB, each of the values was 16.6A/${\mu}\textrm{s}$, 11.5 kV/${\mu}\textrm{s}$ and 13.0 ms. As a conclusion of this work, it has been quantitatively confirmed that the hybrid type interrupter can obtain the sufficient interruption capability at the operating force which is so low that puffer type interrupter has not the interruption capability.