• 제목/요약/키워드: 타원궤적 진동절삭

검색결과 16건 처리시간 0.021초

미세 초음파 타원궤적 진동절삭 (II) 타원진동 절삭운동을 이용한 미세 홈 초음파 가공 (Micro Ultrasonic Elliptical Vibration Cutting (II) Ultrasonic Micro V-grooving Using Elliptical Vibration Cutting)

  • 김기대;노병국;황경식
    • 한국정밀공학회지
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    • 제22권12호
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    • pp.198-204
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    • 2005
  • For precise micro V-grooving, ultrasonic elliptical vibration cutting (UEVC) is proposed using two parallel piezoelectric actuators, which are energized by sinusoidal voltages with a phase difference of 90 degrees. Experimental setup is composed of stacked PZT actuators, a single crystal diamond cutting tool, and a precision motorized xyz stage. It is found that the chip formed in the process of UEVC is discontinuous because of the periodic contacts and non-contacts occurring between the tool and workpiece. It is experimentally observed that the cutting force in the process of UEVC significantly reduces compared to the ordinary non-vibration cutting. In addition, the creation of burr during UEVC is significantly suppressed, which is attributable to the decrease in the specific cutting energy.

미세 초음파 타원궤적 진동절삭 (I) 미세 초음파 가공을 위한 타원 절삭경로 생성 (Micro Ultrasonic Elliptical Vibration Cutting (I) The Generation of a Elliptical Vibration Cutting Motion for Micro Ultrasonic Machining)

  • 노병국;김기대
    • 한국정밀공학회지
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    • 제22권12호
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    • pp.190-197
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    • 2005
  • For precise micro-grooving and surface machining, a mechanism for creating elliptical vibration cutting (EVC) motion is proposed which uses two parallel piezoelectric actuators. And based on its kinematical analysis, variations of EVC path are investigated as a function of dimensional changes in the mechanism, phase difference and amplitude of excitation sinusoidal voltages. Using the proposed PZT mechanism, various types of two dimensional EVC paths including one dimensional vibration cutting path along the cutting direction and thrust direction can be easily obtained by changing the phase lag, the amplitude of the piezoelectric actuators, and the dimension of the mechanism.

타원궤적 진동절삭 가공기를 이용한 미세 형상 가공 (Machining of Micro Structure using Elliptical Vibration Grooving Machine)

  • 김기대;노병국
    • 한국정밀공학회지
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    • 제25권11호
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    • pp.45-51
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    • 2008
  • Successive micro-scale V-grooves and a grid of pyramids were machined by elliptical vibration tufting (EVC) to investigate feasibility of using EVC as an alternative method of creating micro-molds to photo-lithography and electroforming, which have been commonly employed. An elliptical vibration grooving machine was developed which consists of two orthogonally-arranged piezoelectric actuators, a diamond cutting tool, and a motorized xyz stage. The micro-scale features were machined on materials of copper, duralumin, nickel, and hastelloy and it was found that EVC significantly reduces cutting resistance and prohibits generation of side burrs and rollover burrs, thus resulting in improving machining qualify of micro-molds in ail experimented workpiece materials.

타원궤적 진동절삭기의 타원궤적 보정 (Compensating the Elliptical Trajectory of Elliptical Vibration Cutting Device)

  • 노병국;김기대
    • 한국정밀공학회지
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    • 제28권7호
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    • pp.789-795
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    • 2011
  • In elliptical vibration cutting (EVC), cutting performance is largely affected by the shape of an elliptical path of the cutting tool. In this study, two parallel piezoelectric actuators were used to make an elliptical vibration cutting device. When harmonic voltages of $90^{\circ}$ out-of-phase are supplied to the EVC device, creation of an ideal elliptical trajectory whose major and minor axes are parallel to the cutting and thrust directions is anticipated from a kinematic analysis of the EVC device, however, the paths we experimentally observed showed significant distortions in its shape ranging from skew to excessive elongation of the major axis of the ellipse. To compensate distortions, an analytical model describing the elliptical path of the cutting tool was developed and verified with experimental results, and based on the analytical model, the distorted elliptical paths created at 100 Hz, 1 kHz, and 16 kHz were corrected for skew and elongation.

타원궤적 절삭기의 가진주파수에 따른 절삭 날 회전 진동 특성 (Characteristics of Rotational Vibration of Cutting Edge in Elliptical Vibration Cutting by Modulation of Excitation Frequency)

  • 노병국;김기대
    • 한국소음진동공학회논문집
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    • 제21권3호
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    • pp.258-263
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    • 2011
  • The direction of the cutting tool plays a critical role in elliptical vibration cutting(EVC) where the cutting tool cuts workpiece in a trochoidal motion. In this study, EVC cutting device was developed using two parallel piezoelectric materials and it was observed that the rotation direction of the tool reverses as the EVC device undergoes resonance at which either flexural(cutting direction) or longitudinal( thrust direction) mode shapes occurs. To analytically explain reversal of the rotation direction, kinematic motion analysis of the tool was modified to incorporate amplification of the vibration amplitude and phase introduced by resonance. It successfully demonstrated, through Matlab simulation, reversal of the rotation direction of the cutting tool as the excitation frequency increases beyond resonance frequencies at which either flexural or longitudinal vibration occurs.

타원궤적 진동절삭법을 이용한 미세 면선삭 (Micro Turning on Face using Elliptical Vibration Cutting)

  • 김기대;노병국
    • 한국정밀공학회지
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    • 제26권1호
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    • pp.82-88
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    • 2009
  • Ultra-precision turning is highly needed to manufacture molds for precision lens. In this study, micro-turning combined with elliptical vibration cutting (EVC), which is known to enhance micro- machining quality, was investigated by installing a rotary stage into the micro-grooving machine. From machining experiments involving materials of copper, brass, and aluminum and single and poly crystalline diamond tools, it was found that EVC produced thinner and curlier chips and that better surface finish could be achieved, compared with conventional turning, owing to prohibition of formation of burrs and built-up edges. Therefore, we found EVC micro turning could be readily utilized to manufacture precision mold.

초정밀 미세가공을 위한 궤적 변화에 따른 타원 궤적 진동 절삭 (Elliptical Vibration Cutting with Variable Trajectory for Ultra-precision Micro-Machining)

  • 김기대;노병국
    • 한국정밀공학회지
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    • 제24권11호
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    • pp.52-58
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    • 2007
  • A cutting device capable of generating various shapes of the cyclic elliptical trajectory of a cutting tool was proposed and micro v-grooving experiments were performed to investigate the characteristics of elliptical vibration cutting (EVC). The proposed cutting device is comprised of a pair of parallel piezoelectric actuators with which harmonic voltages of varying phase difference and magnitude are supplied, creating various shapes of the elliptical tool path. The attributes of the elliptical locus involving the direction of the axis of an ellipse, the rotational direction and amplitudes of a trajectory were fine-tuned for stable operation of the EVC. The EVC characteristics performed with brass and copper revealed reduction in the cutting resistance and suppression of burr formation, resulting in the enhancement of form accuracy of machined micro-features. While the effect of the EVC increases with the increase of excitation frequency and the amplitude, it is found that a change in the cutting force decreases as the amplitude of an elliptical locus increases.