• Title/Summary/Keyword: 드릴 절삭 토크

Search Result 8, Processing Time 0.025 seconds

Cutting Torque Control in Drilling Part 2 : Drilling Torque Control Using Spindle Motor Current and Its Effect on Drill Flank Wear (드릴 공정시 절삭 토크 제어 제 2 편 : 주축 모터 전류를 이용한 드릴링 토크의 제어와 드릴 플랭크 마모에 대한 영향)

  • O, Yeong-Tak;Kim, Gi-Dae;Ju, Jong-Nam
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.18 no.8
    • /
    • pp.107-115
    • /
    • 2001
  • Drilling torque was measured indirectly using the spindle motor current and controlled in real time through feedrate manipulation in a machining center. The PID controller designed in the previous paper was applied to drilling torque control. A series of cutting experiments were performed for various cutting conditions. Experimental results showed that the drilling torque was well regulated at a given reference level by feedrate manipulation in all cutting conditions. The increase in the cutting torque and temperature according to the increase in machining depth was suppressed and the risk of the drill failure and the drill flank wear were reduced remarkably through cutting torque control. Moreover, the suggested cutting torque control system doesn\`t disturb the cutting process and is practical for industrial environment. Therefore, the proposed culling torque control system will contribute to productivity improvement in drilling process.

  • PDF

Analysis of multi-facet drill(MFD) performance and optimization of MFD geometry (다면 드릴의 성능 해석과 최적화)

  • 이상조;윤영식
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.14 no.6
    • /
    • pp.1523-1532
    • /
    • 1990
  • The objective of this study is to develope an optimized multi-facet drill (MFD). The principal factors that affect drilling performance are its geometry and the cutting conditions. In particular, the helix angle in the total twist angle of the twist drill, affects much morgen influence on the dynamic and static stiffness and on determining the characteristics of the chip disposal capacity of the drill. In this study, considering the helix angle as a major parameter, the model was developed. From this model, the deformation of transverse direction was simulated with the bending forces applied. The performance of a drill largely depends upon drilling forces. Comprehensive models for predicating the drilling thrust and torque are developed for the different drill geometries. The effects of MFD geometric parameters on thrust and torque are also deduced from the prediction models, from which an optimal drill geometry is found with the emphasis on minimum drilling forces.

Cutting Torque Control in Drilling Part 1 : Design of a Cutting Torque Controller (드릴 공정시 절삭 토크 제어 제 1 편 : 절삭 토크 제어기의 설계)

  • O, Yeong-Tak;Gwon, Won-Tae;Ju, Jong-Nam
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.18 no.8
    • /
    • pp.96-106
    • /
    • 2001
  • As the drilling depth increases, the cutting torque increases and fluctuates, which can lead to the machine tool vibration, severe tool wear, and catastrophic tool breakage. Hence, cutting torque control is very important to improve productivity in drilling. In this paper, a PID controller was designed to control the drilling torque. The plant including the feed drive system, cutting process and spindle drive system was modeled for controller design. The Ziegler-Nichols method was used to determine the controller gain and control action times and the root locus plot was used to tune the controller gain for a certain cutting condition. Also, suggested was a simple method to obtain the tuned controller gain for an arbitrary cutting condition not using the Ziegler-Nichols method and the root locus plot. The performance of the designed controller and the effect of controller gain tuning were verified from experiments.

  • PDF

Stabilization of the Drilling Process through Active Torque Control (능동적 토크제어를 통한 드릴공정의 안정화)

  • 김중배;이상조
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.17 no.9
    • /
    • pp.2234-2241
    • /
    • 1993
  • The torque variation in drilling process represents the problems of the efficient and stable machining. In order to cope with them, the active control method is adopted to drill the workpiece under the constant cutting torque though the cutting stiffness of the workpiece or the diameter of the drill bit changes. The cutting process is modeled in the geometric viewpoint related with the feed and the number of cutting lips. And the dynamic model is approximated to the first order system for the purpose of control. The adaptive PI control is used in computer simulations and experiments. The results of the study show the validity of the drilling method with torque control.

A Study on the optimal machinability cutting conditions of the micro-drilling (미세구멍 가공의 최적 절삭력을 위한 절삭조건에 관한 연구)

  • 이병열;안중환;오정욱;김상준;이응숙
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1993.10a
    • /
    • pp.131-135
    • /
    • 1993
  • 오늘날 전자산업, 광학기계,미세노즐 및 오리피스, 정밀공구,게이지, 고밀도 PCB 기판등 각종 산업에서 미세구멍 가공기술이 요구되고 있다. 이러한 구멍 가공에 사용될 수 있는 기술로는 드릴 가공의 기계적 가공방식 이외에 레이져가공,전자빔가공, 방전가공등의 열적가공방식과 전해가공,전해연마,화학부식의 화학적가공 방식이 있겠으나 생산성, 가공표면의 정도, 심혈가공의 어려움 등의 이유로 미세드릴을 이용한 기계적인 가공방법이 선호되고 있다. 본 연구에서는 미세구멍/가공시 가공토크에 미치는 중요 변수들의 영향을 실험을 통하여 조사하여 높은 절삭성을 발휘하는 동시에 공구의 파손도 피할 수 있는 조건을 제시하였다.

  • PDF

A Study for Predicting Rotational Cutting Torque from Electrical Energy Required for Ground Drilling (지반절삭 전기에너지를 활용한 회전굴착토크 예측에 관한 연구)

  • Choi, Chang-Ho;Cho, Jin-Woo;Lee, Yong-Soo;Chung, Ha-Ik;Park, Yong-Boo
    • Journal of the Korean Geotechnical Society
    • /
    • v.23 no.7
    • /
    • pp.57-64
    • /
    • 2007
  • This study proposes a method to estimate drilling torque during ground boring with an aid of electrical energy required for rotating a boring-auger. Ground boring is commonly used in geotechnical engineering such as preboring precast pile installation, soil-cement grouting, ground exploration and so forth. In order to understand the correlation between required electrical energy to rotate the boring auger and the drilling torque, a small laboratory apparatus was designed and a pilot study was performed. The apparatus rotates common drill bits of $D=5{\sim}25mm$ in CBR specimens. The velocity of a bit is 19 RPM and predefined using a reduction gear which connects a main rotation axis to a 25 Watts AC electrical motor shaft. In the middle of drilling the motor current increments and the drilling torque were measured and the correlation between the current and the torque was obtained through linear square fits. Based on the correlation the acquired motor current during drilling was applied to predict the drilling torque in consequent testing and the prediction results were compared to the measured torque. The comparison leads a conclusion that the motor current during drilling using electrical power may be a good indicator to estimate/determine strength characteristics of the ground.

A Study on Monitoring Drilling using Torque from Main Spindle Based on PLC in CNC Machine Tools (PLC 기반 주축 모터의 토크에 의한 드릴링 절삭상태 감시에 관한 연구)

  • Yoon, Sang-hwan;Moon, Sung-min;Lyu, Sung-ki
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.17 no.3
    • /
    • pp.7-15
    • /
    • 2018
  • Drilling processes require a cutting monitoring function that can be analyzed and gives feedback about strange conditions, tool collision and tool wear in real time. In this study, we proposed a drill monitor using the torque from the main spindle in CNC machine tools and a PROFIBUS network as a PLC-based interface. This paper studied drilling torque changes depending on drill size, the repetition cutting of the drilling and the drill's wear in the same cutting conditions. The material of the drills was high speed steel (HSS) and uncoated. The drills chosen were 2.7 mm, 6.7 mm, and 10.0 mm in diameter. These drills were selected because they had basic holes for their taps.

A Study on Cutting Performance of the BTA Drilling (BTA드릴가공의 절삭성능에 관한 연구)

  • 장성규;김순경;전언찬
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.15 no.10
    • /
    • pp.65-72
    • /
    • 1998
  • The BTA drilling chip is better for deep hole drilling than other self-piloting with pad drilling chips because the large length to diameter ratio allows a unique cutting force dispersion and better supplies the high pressure fluid. Therefore the BTA is useful for many tasks, such as coolant hole drilling of large scale dies, as well as tube seat drilling, which is essential for the heat exchanger, and variable component drilling for automobiles. Deep hole drilling has several significant problems, such as hole deviation, hole over-size, circularity, straightness, and surface roughness. The reasons for these problems, which often result in quality short comings, are an alignment of the BTA drilling system and the unbalance of cutting force by work piece and tool shape. This paper analyzes the properties through an experiment which com¬pared single-edge BTA drills with multiple-edge BTA drills, as well as the shapes of the tools to cause an unbalance of cutting force, and its effect on the precision of the worked hole. Conclusions are as follows. 1) In SMSSC drilling, 60m/min of BTA with single and multi-edged tools proved the best cutting condition and the lowest wear character. 2) The roundness got a little worse as cutting speed was increased, but surface roughness was hot affected. 3) It was proved that the burnishing torque of both drills approached 26%. which is almost the same as the 24% insisted on by Griffiths, and the dispersion characteristic of the multi-edged BTA drill proved better than the single-edge BTA drill.

  • PDF