• 제목/요약/키워드: End milling process

검색결과 257건 처리시간 0.026초

공구재종에 따른 엔드밀 가공의 절삭력에 관한 통계적해석 (Statistical Analysis of Cutting Force for End Milling with Different Cutting Tool Materials)

  • 최만성
    • 반도체디스플레이기술학회지
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    • 제15권4호
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    • pp.86-91
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    • 2016
  • End milling is an important and common machining operation because of its versatility and capability to produce various profiles and curved surfaces. This paper presents an experimental study of the cutting force variations in the end milling of SM25C with HSS(high speed steel) and carbide tool. This paper involves a study of the Taguchi design application to optimize cutting force in a end milling operation. The Taguchi design is an efficient and effective experimental method in which a response variable can be optimized, given various control and noise factors, using fewer resources than a factorial design. This study included feed rate, spindle speed and depth of cut as control factors, and the noise factors were different cutting tool in the same specification. An orthogonal array of $L_9(3^3)$ of ANOVA analyses were carried out to identify the significant factors affecting cutting force, and the optimal cutting combination was determined by seeking the best cutting force and signal-to-noise ratio. Finally, confirmation tests verified that the Taguchi design was successful in optimizing end milling parameters for cutting force.

자유곡면 볼엔드 밀링공정에서 CUSP PATTERN 조정

  • 심충건;양민양
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2001년도 추계학술대회 논문집
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    • pp.106-110
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    • 2001
  • The ball-end milling process is widely used in the die/mold industries, and it is very suitable for the machining of free-form surfaces. However, this process is inherently inefficient process to compared with the end-milling or face milling process, since it relays upon the machining at the cutter/surface contact point. The machined part is the result of continuous point-to-point machining on the free-form surface. And cusps (or scallops) remain at the machined part along the cutter paths and they give the geometrical roughness of the workpiece. Thus, for the good geometrical roughness of the workpiece, it is required very tightly spaced cutter paths in this ball-endmilling process. However, with the tight cutter paths, the geometrical roughness of the workpiece is not regular on the workpiece since the cusp height is variable in the previously developed ISO-parametric or Cartesian machining methods. This paper suggests a method of tool path generation which makes the geometrical roughness of workpiece be constant through the machined surface. In this method, Ferguson Surface design Model is used and cusp height is derived from the instantaneous curvatures. And, to have constant cusp height, an increment of parameter u or v is estimated along the reference cutter path. In ball-end milling experiments, the cusp pattern was examined, and it was proved that the geometrical roughness could be regular by suggested tool path generation method.

엔드밀 가공에서 형상 정밀도 향상을 위한 절삭 조건 선정 (Cutting Condition Selection for Geometrical Accuracy Improvement in End Milling)

  • 류시형;최덕기;주종남
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.1784-1788
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    • 2003
  • For the improvement of geometrical accuracy in end milling, cutting method and cutting condition selection are investigated in this paper. As machining processes are composed of several steps such as roughing, semi-finishing. and finishing, cutting forces and tool deflection are calculated considering surface shape generated by the previous cutting. The effects of tool teeth numbers, tool geometry, and cutting conditions on the form error are analyzed. Using the from error prediction method from tool deflection, cutting condition for geometrical accuracy improvement is discussed. The characteristics and the difference of generated surface shape in up and down milling are dealt with and over-cut free condition in up milling is presented. The form error reduction method by alternating up and down milling is also suggested. The effectiveness of the presented method is examined from a set of cutting tests under various cutting conditions. This research contributes to cutting process optimization for the geometrical accuracy improvement in die and mold manufacture.

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인코넬 718의 엔드밀링시 헬릭스각에 따른 절삭특성 변화 -(I) 상향엔드밀링 (Cutting Characteristics Variation of Inconel 718 in End Milling with different Helix Angles -(I) Up End Milling)

  • 태원익;이선호;최원식;양승한;이영문
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2000년도 추계학술대회 논문집
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    • pp.947-950
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    • 2000
  • The purpose of this paper is to investigate the effect of the helix angle of endmilling cutter on the cutting characteristics of inconel 718 in up endmilling. To this end cutters with helix angle of $20^\circ$, $30^\circ$, $40^\circ$ and $50^\circ$ degree have been prepared. And a modified cutting force model in up end milling process is presented. Using this cutting force components of 4-tooth endmills with various helix angles have been predicted. Predicted values of cutting force components are well coincide with the measured ones. As helix angle increases overlapping effects of the active cutting edges increase.

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미세형상 가공을 위한 Micro Slot 가공에서의 공구변형에 의한 가공오차 보상 (Machining Error Compensation for Tool Deflection in Micro Slot-Cutting Processes for Fabrication of Micro Shapes)

  • 손종인;윤길상;서태일
    • 한국공작기계학회논문집
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    • 제17권2호
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    • pp.121-127
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    • 2008
  • Micro end-milling has been becoming an important machining process to manufacture a number of small products such as micro-devices, bio-chips, micro-patterns and so on. Despite the importance of micro end-milling, many related researches have given grand efforts to micro end-milling phenomenon, for example, micro end-milling mechanism, cutting force modeling and machinability. This paper strongly concerned actual problem, micro tool deflection, which causes excessive machining errors on the workpiece. To solve this problem, machining error prediction method was proposed through a series of test micro cutting and analysis of their SEM images. An iterative algorithm was applied in order to obtain corrected tool path which allows reducing machining errors in spite of tool deflection. Experiments are carried out to validate the proposed approaches. In result, remarkable error reduction could be obtained.

Al 2024 합금의 측벽 엔드밀 가공 시 최적 가공조건 (Optimum Working Condition of Al 2024 Alloy in Side Wall End Milling)

  • 홍도관;안찬우;박진우;백황순
    • 한국기계가공학회지
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    • 제7권4호
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    • pp.37-43
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    • 2008
  • Working condition is one of the most important factors in precision working. In this study, we optimized the vibration acceleration level(VAL) of Al 2024 alloy to select optimum working condition of side wall end-milling using RSM(Response Surface Methodology). RSM was well adapted to make analytic model for minimizing vibration acceleration, created the objective function and saved a great deal of computational time. Therefore, it is expected that the proposed optimization procedure using RSM can be easily utilized to solve the optimization problem of working condition. The experimental results of the surface roughness and VAL showed the validity of the proposed working condition of side wall end-milling as it can be observed.

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경사면 가공에서 공구의 런아웃과 표면 형상과의 관계에 관한 연구 (A Study on the Relationship of Surface Shape and Tool Runout in the Ball-End Milling)

  • 박희범
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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    • pp.591-596
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    • 1999
  • Due to the development of CNC machining centers and the complexity of machined part geometry, the ball-end milling became the most widely used the cutting process. Generally, the tool runout defined as the eccentricity of a rotating tool set in the holder involved the spindle runout and the problem of tool runout generated to remove the workpiece is a main factor affecting the machining accuracy. In this paper, the relationship of tool runout(zero-to-peak, P-K) and surface shape on the change of cutting conditions is studied and it is proposed the probability of prediction of surface shape from the in-process tool runout measurements with high response displacement sensor in the ball-end milling

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플라스틱 소재의 표면가공 중 공정조건의 영향 (Effect of Processing Parameters in Surface Machining of Plastic Materials)

  • 한창모;이봉기
    • 한국기계가공학회지
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    • 제15권5호
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    • pp.1-7
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    • 2016
  • In the present study, a plastic surface end-milling was implemented to investigate the effects of processing parameters on surface quality. The end milling can be considered an efficient method for rapid prototyping of thermoplastic bio-systems since it exhibits several beneficial functions including short fabrication time and high dimensional accuracy. In this regard, putative biocompatible thermoplastic materials, such as PMMA, PET, and PC, were chosen as workpiece materials. Among the relevant processing parameters influencing the surface quality of the final product, depth of cut, feed rate, and spindle speed were considered in the present study. The roughness of surfaces machined under various conditions was measured to elucidate the effect of each parameter. We found that the cut depth was the most significant factor. Heat generation during machining also had a remarkable effect. From these investigations, an appropriate combination of processing conditions specific to each type of use and end-product could be found. This optimization can be useful in end-milling of thermoplastic bio-systems.

볼 엔드밀 가공의 유연 절삭력 모델에 관한 연구 (A Study on the Flexible Cutting Force Model in the Ball End Milling Process)

  • 최종근;강윤구;이재종
    • 한국공작기계학회논문집
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    • 제12권2호
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    • pp.44-52
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    • 2003
  • This research suggests a cutting force model for the ball end milling processes. This model includes the effect of tool run out and tool deflection. In the proposed model, the flutes of ball end mills are considered as series of infinitesimal elements and each cutting edge is assumed to be straight for the analysis of the oblique cutting process, in which the small cutting edge element has been analyzed as an orthogonal cutting process n the plane including the cutting velocity and the chip-flow vector. Therefor, the cutting forces can be calculated through the model using the orthogonal cutting data obtained from the orthogonal cutting test. In order to enhance the performance of the model, the flutes of ball end mill are defined to keep geometric consistency at the peak of the ball part and the junction with the end mill part. The divided infinitesimal cutting edges are regulated to be even lengths. Some experiments show the validity of the developed model in the various cutting coalitions.

볼 엔드밀링에서의 공구 정렬 오차에 의한 가공면의 이론적인 평가 (Theoretical Estimation of Machined Surface Profile by Tool Alignment Errors in Ball-End Milling)

  • 신영재;박경택;이종현;강병수
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2006년도 춘계학술대회 논문집
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    • pp.627-628
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    • 2006
  • High speed milling process is emerging as an important fabrication process benefits include the ability to fabricate micro and meso-scale parts out of a greater range of materials and with more varied geometry. It also enables the creation of micro and meso-scale molds for injection molding. Factors affecting surface roughness have not been studied in depth for this process. A series of experiments has been conducted in order to begin to characterize the factors affecting surface roughness and determine the range of attainable surface roughness values for the high speed milling process. It has previously been shown that run-out creates a greater problem for the dimensional accuracy of pans created by high speed milling process. And run-out also has a more significant effect on the surface quality of milled parts. The surface roughness traces reveal large peak to valley variations. This run-out is generated by spindle dynamics and tool geometry. In order to investigate the relationship between tool alignment errors and surface roughness the scallop generating mechanism in the ball-end milling with tool alignement errors has been studied and simulated. The results indicate that tool alignment errors have no significant effects ell the dimension of scallops in for flat planes.

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