• 제목/요약/키워드: Dynamic Cutting

검색결과 271건 처리시간 0.024초

자기회귀 벡터모델을 이용한 정면밀링의 동절삭력 모델해석 (An Analysis of Dynamic Cutting Force Model for Face Milling Using Modified Autoregressive Vector Model)

  • 백대균;김정현;김희술
    • 대한기계학회논문집
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    • 제17권12호
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    • pp.2949-2961
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    • 1993
  • Dynamic cutting process can be represented by a closed-loop0 system consisted of machine tool structure and pure cutting process. On this paper, cutting system is modeled as a six degrees of freedom system using MARV(Modified Autoregressive Vector) model in face milling, and the modeled dynamic cutting process is used to predict dynamic cutting force component. Based on the double modulation principle, a dynamic cutting force model is developed. From the simulated relative displacements between tool and workpiece the dynamic force domponents can be calculated, and the dynamic force can be obtained by superposition of the static force and dynamic force components. The simulated dynamic cutting forces have a good agreement with the measured cutting force.

채터진동에서의 동적 절삭력의 모델링과 안정성 해석 (A modeling of dynamic cutting force and analysis of stability in chatter vibration)

  • 김정석;강명창
    • 한국정밀공학회지
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    • 제10권2호
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    • pp.161-169
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    • 1993
  • The elimination of chatter vibration is necessary to improve the precision and the productivity of the cutting operation. A new mathematical model of chatter vibration is presented in order to predict the dynamic cutting force from the static cutting data. The dynamic cutting force is analytically expressed by the static cutting coefficient and the dynamic cutting coefficient which can be determined from the cutting mechanics. The stability analysis is carried out by a two degree of freedom system. The chatter experiments are conducted by exciting the cutting tool with an impact hammer during an orthogonal cutting. A good agreement is shown between the stability limits predicted by theory and the critical width of cut determined by experiments.

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저강성 공구를 이용한 절삭에서의 채터 진동 (The chatter vibration in metal cutting using the low stiffness tool)

  • 김정석;이병호
    • 대한기계학회논문집
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    • 제13권3호
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    • pp.424-432
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    • 1989
  • 본 연구에서는 정적절삭실험으로 결정될수 있는 절삭변수로 표현되는 동적 절삭력을 해석적으로 구한다. 이 모델은 3차원 절삭형태에도 적용될 수 있는 특성을 갖는다. 새로이 제안된 절삭 과정의 모델은 동적절삭상태에서 절삭력 합력의 변화를 고려한 절삭기구를 통해 이루어지며, 해석적으로 한계절삭폭을 구한다. 실험적 규명 은 채터진동이 발생하지 않는 한계절삭 공작물에 비해 공구의 강성이 상대적으로 적은 보링(boring)작업에서 발생하는 것을 대상으로 하였다.

볼 엔드밀 경사면 가공의 동적 모델 (Dynamic Model in Ball End Milling of Inclined Surface)

  • 김성윤;김병희;주종남;이영수
    • 한국정밀공학회지
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    • 제23권3호
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    • pp.39-46
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    • 2006
  • In this work a dynamic cutting force model in ball end milling of inclined surface is introduced. To represent the complex cutting geometry in ball end milling of inclined surface, workpiece is modeled with Z-map method and cutting edges are divided into finite cutting edge elements. As tool rotates and vibrates, a finite cutting edge element makes two triangular sub-patches. Using the number of nodes in workpiece which are in the interior of sub-patches, instant average uncut chip thickness is derived. Instant dynamic cutting forces are computed with the chip thickness and cutting coefficients. The deformation of cutting tool induced by cutting farces is also computed. With iterative computation of these procedures, a dynamic cutting force model is generated. The model is verified with several experiments.

평균 비절삭저항을 이용한 정면 밀리의 동절삭력 모델 개발 (Development of Dynamic Cutting Force Model by Mean Specific Cutting Pressure in Face Milling Process)

  • 이병철;백대균;김희술
    • 한국정밀공학회지
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    • 제12권8호
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    • pp.39-52
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    • 1995
  • In order to design and improve a new machine tool, there is a need for a better understanding of the dynamic cutting force. In this paper, the computer programs were developed to predict the dynamic cutting force by the mean specific cutting pressure in the face milling process. The simulated cutiing forces in X, Y, Z directions resulted from the developed dynamic cutting force model are compared with the measured cutiing forces in the time and frequency domains. The simulated cutting force model have a good agreement with the measured forces in comparison with those resulted from the existing cutting force model.

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절삭력의 동적 성분을 이용한 플랭크마모의 평가(I) (Flank Wear Estimation Using Dynamic Cutting Force(l))

  • Kwon, Y.K.;Oh, S.H.;Seo, N.S.
    • 한국정밀공학회지
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    • 제14권8호
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    • pp.115-121
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    • 1997
  • The in-process detection of the tool wear is one of the most important technologies in completely auto- matic operation of machine tool. In this research, using the tools having flank wear, the dynamic compo- nent of cutting forces is considered to be available for identifying the cutting process. In order to investi- gate this relation in detail, the cutting forces in turning of workpiece made of aluminum were measured by dynamometer of piezoelectric type, and the dynamic components of cutting force were analyzed. The fre- quency analysis, probability density analysis and RMS analysis of the dynamic components were carried out independently. Through the experiments, the characteristics of the tool system have a large effect on the dynamic component of cutting forces. As a result, it is shown that the dynamic cutting force was able to detect flank wear accurately.

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Machining Center에서의 Drill가공시 절삭저항과 그 동적성분에 관한 연구 (제1보) -SM45C 중심으로- (A Study on Static and Dynamic Cutting Force in Drilling Process for Machining Center (1st report) -SM45C-)

  • 전언찬;제정신;이동의;남궁척
    • 한국정밀공학회지
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    • 제3권2호
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    • pp.91-101
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    • 1986
  • This paper deals with the effect of static and dynamic cuttig force and the behaviour of drill life in drilling process. The experiments are performed with cemented carbide drills and high speed steel drills of 10mm in diameter and in an annealed SM45C. The conclusions are as follows (1) Dynamic cutting force is varied with the dept of hole. (2) Dynamic cutting forces of torque and thrust are increase with the increase in feed and cutting speed. (3) Chipping influence the dynamic cutting force of thrust than torque, and in the case of thrust, the amplitude is 3-7 times large than ordinary cutting state. (4) Prediction of drill life can be obtained from more easily the amplitude of static cutting force than that of dynamic cutting force.

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엔드밀 가공시 동적 절삭력 모델에 의한 절삭력 및 표면형상 예측 (The Prediction of Cutting Force and Surface Topography by Dynamic Force Model in End Milling)

  • 이기용;강명창;김정석
    • 한국정밀공학회지
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    • 제14권4호
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    • pp.38-45
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    • 1997
  • A new dynamic model for the cutting process inb the end milling process is developed. This model, which describes the dynamic response of the end mill, the chip load geometry including tool runout, the dependence of the cutting forces on the chip load, is used to predict the dynamic cutting force during the end milling process. In order to predict accurately cutting forces and tool vibration, the model which uses instantaneous specific cutting force, inclueds both regenerative effect and penetration effect, The model is verified through comparisons of model predicted cutting force with measured cutting force obtained from machining experiments.

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절삭저항의 동적성분에 미치는 절삭조건의 영향에 관한 연구(II) (A Study on the Influence of Cutting Conditions on the Dynamic Component of Cutting Resistance(ll))

  • 전언찬
    • 한국정밀공학회지
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    • 제1권2호
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    • pp.58-68
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    • 1984
  • In this study, the static and dynamic components of cutting resistance were measured with tool dynamometer (Swiss, pieso-electric type) when S45C, A1-alloy and brass were drilled under the some variable conditions. The results obtained are as follows; 1) The dynamic components of these cutting resistance are not related to the depth of drilled hole. 2) The static and dynamic components of cutting resistance are increased in accordance with the increase of feed and drill diameter. 3) The dynamic components of thrust force are increased in accordance with the increase of spindle speed. 4) The rate of the dynamic component to the static component is 0.3 .approx. 0.5 in torque, 0.1 .approx. 0.2 in thrust force. 5) The characteristic of the tool system is affected in dynamic component of cutting resistance, and the creasted frequency and amplitude of the chip are determined by the crilled materials. 6) The maximum amplitude of the dynamic component is increased proportionally in accordance with the feed rate and the spindle speed.

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선삭가공에 있어서 절삭저항의 동적성분에 관한 연구 [I] -동적성분에 의한 Chip배출상태의 인식- (A Study on the Dynamic Component of Cutting Force in Turning[1] -Recognition of Chip Flow by the Dynamic Cutting Force Component-)

  • 정의식
    • 한국정밀공학회지
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    • 제5권1호
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    • pp.84-93
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    • 1988
  • The on-line detection of the chip flow is one of the most important technologies in com- pletly automatic operation of machine tool, such as FMS and Unmanned Factories. This problem has been studied by many researchers, however, it is not solved as yet. For the recognition of chip flow in this study, the dynamic cutting force components due to the chip breaking were measured by dynamometer of piezo-electric type, and the frequency components of cutting force were also analyzed. From the measured results, the effect of cutting conditions and tool geometry on the dynamic cutting force component and chip formation were investigated in addition to the relationships between frequency of chip breaking (fB) and side serrated crack (fC) of chip. As a result, the following conclusions were obtaianed. 1) The chip formations have a large effect on the dynamic cutting force components. When chip breaking takes place, the dynamic cutting force component greatly increases, and the peridoic components appear, which correspond to maximum peak- frequency. 2) The crater wear of tool has a good effect on the chip control causing the chiup to be formed as upward-curl shape. In this case, the dymamic cutting force component greatly increases also 3) fB and fC of chip are closely corelated, and fC of chips has a large effect on the change of the situation of chip flow and dynamic cutting force component. 4) Under wide cutting conditions, the limit value (1.0 kgf) of dynamic cutting force component exists between the broken and continuous chips. Accordingly, this value is suitable for recognition of chip flow in on-line control of the cutting process.

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