• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.195-198
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• 2000

It can be acquired the high effective productivity through of high speed, precision of machine tools, and then, machine tools will be got a competitive power. Industrially advanced countries already developed that the high speed feed is 60m/min using the high speed ball screw. Also, a lot of problems have happened the feed drive system. It is necessary to study about the characteristics of thermal deformation played a more critical role than static stiffness and dynamic rigidity in controlling the level of machining accuracy. In spite of the improving the thermal deformation characteristics of machine tools at the design stage, there are always some residual errors that have to be compensated for during machining. In this study, thermal deformation error automated compensation device with multiple linear regression is proposed that thermal deformation error can be eliminated at the machining stage. The developed device has been practically applied to the feed drive unit.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.5
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• pp.729-737
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• 2009

This paper introduces the machine tools feed system, which can be optimized the control's performance through simulation and the adjustment of the mechanical components. One method simulates the frequency response of the speed-loop with the design value using the MATLAB application, so that all of the interpolation axis can be equal to the response bandwidth, resulting in a high accuracy rate. The other method sees the mechanical component being adjusted by analyzing the results of various experiments. Lastly, this client's program is able to change the parameters that are related to the FFD, as well as the parameters in the friction compensation of the OPEN-CNC.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.71-72
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• 2006

In this study, automatic assembly and evaluation system fer phone camera module is conceptually designed. The designed core(Auto focus & UV curing, Image Test) equipments adopts a clustering mechanism and compactible structure using index table for minimum tact time. Using a ball screw actuator and absolute encoder in each axis, we can verifies the repeatability and position accuracy of system within ${\pm}3{\mu}m$. In result of simulation test, the proposed system is expected up to 30% in productivity than manual operation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.271-271
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• 2004

다양한 목적으로 개발이 요구되는 로봇의 작업환경과 운동능력에 맞게 로봇을 개발하기 위해서는 다음의 설계 과정을 필요로 한다. 하나, 로봇의 전체 설계 중 개념설계/기초설계로 로봇링크의 길이나, 작업영역에 대한 설계 변수를 결정하는 로봇 기구설계. 둘, 로봇 상세설계로 작업을 실행하는데 필요한 운동능력에 대한 설계 변수를 결정하는 로봇 동역학 설계. 셋, 로봇 기구, 동역학 설계를 기초로 하여 로봇이 최적의 성능을 발휘할 수 있는 로봇 부품들에 대한 요소품 설계가 있다.(중략)

• Journal of the Korean Society for Precision Engineering
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• v.25 no.6
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• pp.126-133
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• 2008

Linear motors are efficient mechanism that offers high speed and positioning accuracy. By eliminating mechanical transmission mechanisms such as ball screw or rack-pinion, much higher speed and greater acceleration can be achieved without backlash or excessive friction. However, an important disadvantage of linear motor system is its high power loss and heating up of motor and neighboring machine components on operation. For the application of the linear motors to precision machine tools an effective cooling method and thermal optimizing measures are required. This paper presents an investigation into the thermal behavior of linear motors with the objective of deriving the optimum cooling conditions. To reach these goals several experiments were carried out, varying operating and cooling conditions. From the experimental results, this research proposed cooling conditions to improve the thermal characteristics of the linear motors.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.18 no.1
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• pp.36-41
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• 2009

This paper presents the development of a micro punching system with modified cymbal mechanism. To realize the micro punching, we introduced the hybrid system with a macro moving part and micro punching part. The macro moving part consists of a ball screw, a linear guide and the micro step motor and micro punching part includes the PZT actuators and displacement amplification device with modified cymbal mechanism. The PZT actuator is capable of producing very large force, but they provide only limited displacements which are several micro meters. Thus the displacement amplification device is necessary to make those actuators more efficient and useful. For this purpose, a cymbal mechanism in series is proposed. The finite element method was used to design the cymbal mechanism and to analyze the mode shape of the one. The displacement and mode shape error between the FEM results and experiments are within 10%. A considerable design effort has been focused on optimizing the flexure hinge to increase the output displacement and punching force.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.11
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• pp.1129-1137
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• 2013

We report a centerless grinding machine which can perform multi-function with 600 mm wide grinding wheels. By increasing manufacturing area, long workpiece such as camshaft and steering shaft, is allowed to grind more quickly, compared with cylindrical grinding system. In this paper, the design of centerless grinding machine puts emphasis on symmetry to exploit the thermal stability. Results of finite element analysis shows that the difference of the structural deflection in the front and rear guideways is less than $1.5{\mu}m$ due to symmetric design. The difference is less than $3.0{\mu}m$, even though the thermal deformation is considered. According to the performance evaluation, the radial error motion of the G/W spindle, which is measured by applying Donaldson Ball Reversal, is about 1.1${\mu}m$. The yaw error of the G/W slide is improved from 2.1 arcsec to 0.5 arcsec by readjusting the slide preload and ball screw.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.2
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• pp.343-350
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• 2008

In this paper, a six degree-of-freedom robot arm which is very light but capable of delivering heavy loads was studied. The proposed robot arm has much higher load capacity than conventional robot arms actuated by motors with speed reducers such as the harmonic drive since a new type of robot actuator based on a closed chain mechanism driven by the ball screw was adopted. Analysis on the design scheme and on the mechanism of the joint actuator of the robot arm were made. Since the robot arm was designed very light, it has deflection in the links. To analyze this, a finite element analysis on the structure of the designed robot links was made using ANSYS software. Verifying experiments on the performance of high load capacity of the robot arm was performed by loading heavy weights on the robot arm. Through experiments. the correctness of the numerical analysis was also verified.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.449-450
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• 2006

Development of a feed drive system with high speed, positioning accuracy and thrust has been an important issue in modern automation systems and machine tools. Linear motors can be used as an efficient system to achieve such technical demands. By eliminating mechanical transmission mechanisms such as ball screw or rack-pinion, much higher speeds and greater acceleration can be achieved without backlash or excessive friction. However, an important disadvantage of linear motor system is its high power loss and heating up of motor and neighboring machine components on operation. For the application of the linear motors to precision machine tools an effective cooling method and thermal optimizing measures are required. In this paper presents an investigation into a thermal behavior of linear motor cooling plate. FVM employed to analyze the thermal behavior of the linear motor cooling plate, using the ANSYS-CFX.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.8
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• pp.687-692
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• 2015

LAM (Laser-Assisted Machining) is an effective method for processing difficult-to-cut workpieces. The focal length of a LAM system is changed by the change of the workpiece shape during laser preheating; this problem is solved by changing the lens of the laser module. Linear- and rotary-type lens changers were developed to change the laser lens of a LAM system. The linear-type lens changer is operated by a motor with a ball-screw, and the rotary type is operated by a stepping motor. The natural frequency and structural stability of the laser lens changers were confirmed by using a finite element analysis; in addition, the functions of the lens changers were verified by measuring the iterative accuracy. The measured results show that the rotary-type lens changer is more accurate than the linear-type changer.