• 대한기계학회논문집
• /
• 제16권12호
• /
• pp.2216-2225
• /
• 1992

본 연구에서는 제약조건중 절삭조건 뿐만 아니라 작업 가공 목표, 즉 현장에 서 중요시하는 표면조도를 제약조건에 첨가하여 가공조건의 최적화를 꾀하였다. 또 한 앞의 논문들에서 적응제어나 R-T-F의 개념으로 경제성으로 고려한 최적 절삭 조건 을 구하였으나 본 논문에서는 국내 업체의 노무비 및 간접비로 최소 가공비를 구하고, 이에 대응하는 최적 절삭 속도 및 최대 생산율을 검토하였다. 그리고 이송변화에 따 른 최적 절삭 속도의 영향을 검토하여 생산 가공의 경제성을 제고하였다. 또한 각 업체의 선삭작업에 해당하는 입력 데이터만으로 경제성을 고려한 최적 절삭 조건의 자 동 설정을 하기 위한 프로그램을 구축하였다. 그러므로 이와같은 방법으로 현재 업 체의 장비와 인원만으로 기계 가공의 최적 조건 선정을 자동화 하므로써 생산성 향상 과 원가 절감의 효과를 극대화 할 수 있을 것으로 기대된다.

• 산업공학
• /
• 제9권3호
• /
• pp.283-297
• /
• 1996

The 'flat-bar' is a stiffener which is a component of ships. It is basically a long rectangle and has 'end-cut' shapes at both sides. The paper describes a fast nesting algorithm of the flat-bar, and a procedure to generate cutting path of gas/plasma torch, which is operated by a NC (numerically controlled) gas/plasma cutting machine. Proposed procedures are written in C-language and executable on VAX machine with Open VMS operating system.

• Journal of Biosystems Engineering
• /
• 제28권3호
• /
• pp.209-216
• /
• 2003

Red pepper calyx cutting devices using a impacting force by a rotational cutter were devised and tested to obtain the fundamental data for development of a calyx removal unit. Fresh red peppers with 80∼87%(w.b.) of initial moisture contents were used as experimental materials. Square and wire type of rotational cutters were used to cut the red pepper calyx and the fresh red peppers were fed into the device both manually and automatically. Three rotational speeds of 250, 500, 700rpm were selected for a square, and 1000, 1500, 1800rpm for a wire type cutter respectively. Four types of red pepper fixing unit were used in manual feeding. The cutting rate of the square type cutter was over 50% regardless the shape and specification of the cutter. For the wire type cutter, the copper wire and nylon chord could not be applied to cut the red pepper calyx because of the low cutting rate. But for the fine wire, the cutting rate was higher and the cutting mechanism was more steady than copper wire and nylon chord. The cutting rate of automatic feeding and wire type cutting unit was about 70% for all levels of the rotational speed. The cutting rate was highly related to the impacting point of red pepper in carrier box. To increase the cutting rate using the rotational cutter, a proper device and mechanism was required to keep the impacting point consistently.

• 기술사
• /
• 제21권4호
• /
• pp.6-11
• /
• 1988

The study on the progress of automatic machining system has been active centering at the CNC machine tools recently to lead the applied production technology like unmaned machining to the practical level, and to make these application more efficient, they require detective method for tool wear and breakage while machining. In this study chiefly on turning, first derive cutting force about the tool surface by the cutting resistant sensor and with which change into electric signal and compare with the standards to make the tool life detection system to let know the tool life and study its application; the cutting resistance detected by the cutting resistant sensor has increased to the level of standards, the measuring system which can decide whether we change tools on the basis of comperative circuit is shown to be very reliable model for cutting tool life detection system.

• Journal of Mechanical Science and Technology
• /
• 제18권5호
• /
• pp.753-761
• /
• 2004

In this paper, an efficient method for generating 5-axis cutting data for a turbine blade is presented. The interference elimination of 5-axis cutting currently is very complicated, and it takes up a lot of time. The proposed method can generate an interference-free tool path, within an allowance range. Generating the cutting data just point to the cutting process and using it to obtain NC data by calculating the feed rate, allows us to maintain the proper feed rate of the 5-axis machine. This paper includes the algorithms for: (1) CL data generation by detecting an interference-free heel angle, (2) finding the optimal tool path interval considering the cusp-height, (3) finding the adaptive feed rate values for each cutter path, and (4) the inverse kinematics depending on the structure of the 5-axis machine, for generating the NC data.

• 제어로봇시스템학회논문지
• /
• 제12권10호
• /
• pp.1029-1034
• /
• 2006

In this paper, the tracking control of an automatic pipe cutting robot, called APCROM, with a magnetic binder is studied. Using magnetic force APCROM, a wheeled robot, binds itself to the pipe and executes unmanned cutting process. The gravity effect on the movement of APCROM varies as it rotates around the pipe laid in the gravitational field. In addition to the varying gravity effect other types of nonlinear disturbances including backlash in the driving system and the slip between the wheels of APCROM and the pipe also cause degradation in the cutting process. To maintain a constant velocity and consistent cutting performance, the authors adopt a repetitive learning controller (MRLC), which learns the required effort to cancel the tracking errors. An angular-position estimation method based on the MEMS-type accelerometer is also used in conjunction with MRLC to compensate the tracking error caused by slip at the wheels. Experimental results verify the effectiveness of the proposed control scheme.

• 한국생산제조학회지
• /
• 제7권6호
• /
• pp.90-96
• /
• 1998

The ductile cast iron is austempered at 300, 350 and 40$0^{\circ}C$ temperature in order to investigate the basic factors for monitoring drill wear in automatic production process, and cutting force and AE RMS signals are measured with changing cutting condition for ADI(Austempered Ductile Cast Iron) with different mechanical properties. The signals of cutting force were influenced by cutting speed and feedrate greatly. On the other hand AE RMS signals are influenced by cutting speed where as it is not related with feedrate. As the depth of drilling increases, cutting force shows a slow increase and the value of AE RMS increases until the range of h/d=4. But over the range it increases greatly due to an amount of chip discharge and friction with inner wall of drilling hole, etc. As the drill diameter increases at a constant depth of drilling. Cutting force increases linearly, but the level of AE RMS does not increases linearly due to circumferential velocity and great influence of h/d.

• 한국정밀공학회지
• /
• 제16권12호
• /
• pp.222-229
• /
• 1999

In order to regulate cutting torque in milling, monitoring system should be set to a certain threshold. Radial immersion ratio is an important factor to determine the threshold and should be estimated in process for automatic regulation. In this paper, on-line estimation of the radial immersion ration using spindle motor current in face milling is presented. When a tooth finishes sweeping, a sudden drop of cutting torque occurs. This torque drop is equal to cutting torque acting on a single tooth at the swept angle of cut and can be acquired form cutting torque signals. Average cutting torque per revolution can also be calculate form cutting torque signals. The ratio of cutting torque acting on a single tooth at the swept angle of cut to the average cutting torque per revolution is a function of the swept angle of cut and the number of teeth. Using the magnitude of this ratio, the radial immersion ratio is estimated. Identical algorithm is adopted to estimate the immersion ratio based on the spindle motor current measurement. The experiments performed under different cutting conditions show that the radial immersion ratio can be estimated within 10% error range by the proposed method using spindle motor current.

• 한국공작기계학회논문집
• /
• 제10권1호
• /
• pp.1-9
• /
• 2001

The development of flexible automation in the manufacturing industry is concerned with production activities performed by unmanned machining system A major topic relevant to metal-cutting operations is monitoring toll wear, which affects process efficiency and product quality, and implementing automatic toll replacements. In this paper, the measurement of the cutting force components has been found to provide a method for an in-process detection of tool wear. The static com-ponents of cutting force have been used to detect flank wear. To eliminate the influence of variations in cutting conditions, tools, and workpiece materials, the force modeling is performed for various cutting conditions. The normalized force dis-parities are defined in this paper, and the relationships between normalized disparity and flank were are established. Final-ly, artificial neural network is used to learn these relationships and detect tool wear. According to proposed method, the static force components could provide the effective means to detect flank wear for varying cutting conditions in turning operation.

• 한국생산제조학회지
• /
• 제9권6호
• /
• pp.57-64
• /
• 2000

In order to regulate cutting torque in milling, monitoring system should be set to a certain threshold. Radial immersion ratio is an important factor to determine the threshold and should be estimated in process for automatic regulation. In this paper, on-line estimation of the radial immersion ratio using spindle motor current in face milling is presented. When a tooth finishes sweeping, a sudden drop of cutting torque occurs. This torque drop is equal to the cutting torque acting on a single tooth at the swept angle of cut and can be acquired from cutting torque signals. Average cutting torque per revolution can also be calculated from cutting torque signals. The ratio of cutting torque acting on a single tooth at the swept angle of cut to the average cutting torque per revolution is a function of the swept angle of cut and the number of teeth. Using the magnitude of this ratio, the radial immersion ratio is estimated. Identical algorithm is adopted to estimate the immersion ratio based on the spindle motor current measurement. The experiments performed under different cutting conditions show that the radial immersion ratio can be estimated within 10% error range by the proposed method using spindle motor current. Varying immersion ratio is also estimated well using the presented algorithm.