• Title/Summary/Keyword: Workpiece Vibration

Search Result 103, Processing Time 0.024 seconds

Kinematical Characteristics of Vibration Assisted Cutting Device Constructed with Parallel Piezoelectric Stacked Actuators (평행한 적층 압전 액추에이터로 구성된 진동절삭기의 기구학적 특성 고찰)

  • Loh, Byoung-Gook;Kim, Gi-Dae
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.21 no.12
    • /
    • pp.1185-1191
    • /
    • 2011
  • The kinematic characteristics of cutting device significantly affects cutting performance in 2-dimensional elliptical vibration cutting(EVC) where the cutting tool cuts workpiece, traversing a micro-scale elliptical trajectory in a trochoidal motion. In this study, kinematical characteristics of EVC device constructed with two parallel stacked piezoelectric actuators were analytically modeled and compared with the experimental results. The EVC device was subjected to step and low-frequency(0.1 Hz) sinusoidal inputs to reveal only its kinematical displacement characteristics. Hysteresis in the motion of the device was observed in the thrust direction and distinctive skew of the major axis of the elliptical trajectory of the cutting tool was also noticed. Discrepancy in the voltage-to-displacement characteristics of the piezoelectric actuators was found to largely contribute to the skew of the major axis of the elliptical trajectory of the cutting tool. Analytical kinematical model predicted the cutting direction displacement within 10 % error in magnitude with no phase error, but in estimating the thrust direction displacement, it showed a $27^{\circ}$ of phase-lag compared with the measured displacement with no magnitude error.

Development of a GUI Program for the Design of a Vibration Control Boring Bar with a Tube-Type Structure (튜브 타입 제진용 보링바 구조설계를 위한 GUI 프로그램 개발)

  • Guo, Yang-Yang;Park, Jong-Kweon;Hong, Jun-Hee;Song, Doo-Sang
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.25 no.4
    • /
    • pp.295-300
    • /
    • 2016
  • In the design of passive and active boring bars, the structural dimensions and shape of the vibration control boring bar are modified depending on the diameter and depth of the workpiece, which changes the dynamic behavior. Thus, the natural frequency, effective mass, and stiffness for the main structure of a tube-type boring bar need to be reset for each vibration control case. However, commercial finite element method (FEM) software and experimental modal analysis are mostly used at present despite being too time-consuming. To overcome the weaknesses of the two methods currently used for vibration control, we realized a graphical user interface (GUI) program for the modal analysis of a modified tube-type damping structure. The analysis results with the GUI program were compared to those with commercial FEM software in order to confirm the effectiveness of the former.

Improvement of Micro-hole EDM Efficiency using Vibration Flushing (진동기구를 이용한 미세구멍 방전가공의 효율향상)

  • Son, Seong-Min
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.12 no.2
    • /
    • pp.623-628
    • /
    • 2011
  • Micro EDM(Electric Discharge Machining) is one of the most powerful technologies which are capable of fabricating micro-structure without any problems from high cutting force. However, there is a significant defect in the part machining with deep holes or pockets, because debris which are generated by electric discharging may frequently cause a short circuit between an electrode and workpiece material. Vibration flushing can reduce the undesirable phenomena with dynamic flow of EDM fluid in a deep and choked area. In this study, Vibration flushing with solenoid is suggested and the results show that the method can generate a remarkable EDM efficiency with high amplitude at a low frequency in comparison with current vibration flushing methods with high frequency using piezo actuators.

Evaluation of Pre-estimation Model to the Inprocess Surface Roughness for Grinding Operations

  • Kim, Gun-Hoi
    • International Journal of Precision Engineering and Manufacturing
    • /
    • v.3 no.4
    • /
    • pp.24-30
    • /
    • 2002
  • In grinding operations, one of the most important problems is to increase efficiency of process. In order to achieve this purpose, it is necessary to administer the tool lift of grinding wheel and to optimize grinding conditions. Frequently dressing result in lowering the process efficiency remarkably and makes production cost high. On the other hand, grinding with a worn wheel causes the workpiece surface roughness to increase and often results in the occurrence of such troubles as chatter vibration and homing.

Evaluation of Pre-estimation Model to the Inprocess Surface Roughness for Grinding Operations (연삭가동용 Inprocess 표면조도 예측모델의 평가)

  • 김건희
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
    • /
    • 1998.03a
    • /
    • pp.11-18
    • /
    • 1998
  • In grinding operations, one of the most important problems is to increase efficiency of process. In order to achive this purpose, it is necessary to administer the tool life of grinding wheel and to optimize grinding conditions. Frequently dressing result in lowering the process efficiency remarkably and makes production cost high. On the other hand, grinding with a worn wheel causes the workpiece surface roughness to increase and often results in the occurrence of such troubles as chatter vibration and burning.

  • PDF

A Study on the Precision Machining Characteristics in Heavy Cutting of Al-alloy (Al합금의 중절삭시 정밀가공 특성에 관한 연구)

  • 권용기;김동현
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
    • /
    • 2002.10a
    • /
    • pp.203-208
    • /
    • 2002
  • This paper deals with turning experiments of aluminium alloy using a single crystal diamond with round cutting edge. A face cutting was conducted using a special precision machine to study the characteristic phenomena in heavy cutting of aluminium alloy. In many cases, one of the most important matter on the surface integrity is about a damaged layer remaining just under the surface after machining. A machined surface roughness can be improved at a small geometrical surface roughness under special cutting conditions, even if a steady vibration exists between a tool and a workpiece.

  • PDF

Statistical analysis and modelization of tool life and vibration in dry face milling of AISI 52100 STEEL in annealed and hardened conditions

  • Benghersallah, Mohieddine;Medjber, Ali;Zahaf, Mohamed Zakaria;Tibakh, Idriss;Amirat, Abdelaziz
    • Advances in materials Research
    • /
    • v.9 no.3
    • /
    • pp.189-202
    • /
    • 2020
  • The objective of the present work is to investigate the effect of cutting parameters (Vc, fz and ap) on tool life and the level of vibrations velocity in the machined part during face milling operation of hardened AISI 52100 steel. Dry-face milling has been achieved in the annealed (28 HRc) and quenched (55 HRc) conditions using multi-layer coating micro-grain carbide inserts. Statistical analysis based on the Response surface methodology (RSM) and ANOVA analysis have been conducted through a plan of experiments methodology using a reduced Taguchi table (L9) in order to obtain engineering models for tool life and vibration velocity in the workpiece for both heat treatment conditions. The results show that the cutting speed has a dominant influence on tool life for both soft and hard part. Cutting speed and feed per tooth is the most significant parameters for vibration levels. Comparing the experimental values with those predicted by the developed engineering models of tool life and levels of vibrations velocity, a good correlation has been obtained (between 97% and 99%) in annealed and hard conditions.

Prediction of Surface Topography by Dynamic Model in High Speed End Milling (고속 엔드밀 가공시 동적 모델에 의한 표면형상 예측)

  • Lee, Gi-Yong;Ha, Geon-Ho;Gang, Myeong-Chang;Lee, Deuk-U;Kim, Jeong-Seok
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.24 no.7 s.178
    • /
    • pp.1681-1688
    • /
    • 2000
  • A dynamic model for the prediction of surface topography in high speed end milling process is developed. In this model the effect of tool runout, tool deflection and spindle vibration were taken in to account. An equivalent diameter of end mill is obtained by finite element method and tool deflection experiment. A modal parameter of machine tool is extracted by using frequency response function. The tool deflection, spindle vibration chip thickness and cutting force were calculated in dynamic cutting condition. The tooth pass is calculated at the current angular position for each point of contact between the tool and the workpiece. The new dynamic model for surface predition are compared with several investigated model. It is shown that new dynamic model is more effective to predict surface topography than other suggested models. In high speed end milling, the tool vibration has more effect on surface topography than the tool deflection.

A Study on the Machining Accuracy according to Vibration and Unbalance Decrease in Rotational Speed Domains of High Precision Machine Tools (정밀 공작기계의 회전 영역별 진동 및 불평형량 감소에 따른 가공 정밀도 영향에 관한 연구)

  • Son, Deok-Soo;Kim, Sang-Hwa;Park, Il-Hwan
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.12 no.2
    • /
    • pp.121-126
    • /
    • 2013
  • Precision machine tools for high dignity cutting are needed for efforts to improve machining accuracy. However, there are many factors to improve machining accuracy. This study investigated how machining accuracy changes when variation and unbalance amount in rotational speed domain is decreased. Machining accuracy of initial machine tools depends on manufacturing and assembly of parts such as bearing. And then, vibration and noise vary with volume of unbalance amount when it is rotation, so it effects unbalance amount. Also vibration and noise increased by unbalance shorten spindle's life and it especially makes worse boring accuracy. Therefore, this study studied the change of roundness and cylindricity of workpiece when it decreases variation and unbalance in rotational speed domain.

The Development of a new High Working Accuracy by Ultrasonic Vibration Cutting (초음파진동절삭을 이용한 새로운 고정밀가공법의 개발)

  • ;Shin, Bong-Seok
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.1 no.2
    • /
    • pp.89-94
    • /
    • 1977
  • So far, high accuracy in-process sensors have been used for controlling the cutting tool, but the method followed in this new system is guite different form previous processes. In this system, after the rough cut the mark indication the pasition of the finished size in put on the cutting surface of the workpiece by ultrasonic or vibration cutting. The cutting is then continued until the mark just disappears, This position being observed by the used of a simple in-proces sensor, The in-prosess sensor in used only to detect the existence or dis apperance of the mark.