• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.370-375
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• 2004

This paper presents an accurate cutting simulation and feedrate scheduling system for CNC machining. This system is composed of a cutting simulation part and a feedrate scheduling part. The cutting simulation part computes the geometric informations and calculates the cutting forces in CNC machining. The cutting force model using cutting-condition-independent coefficients was introduced for flat end milling and ball end milling. The feedrate scheduling part divides original blocks of NC code into smaller ones with optimized feedrates to adjust the peak value of cutting forces to reference forces. Some machining examples show that the developed system can control the cutting force at desired levels.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.26 no.4
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• pp.402-409
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• 2017

Selection of optimal cutting conditions is important for improving productivity and implementing efficient process control in metal machining. In this study, improvement of cutting conditions in machining using end-mills is studied by using deep-layered neural networks, which comprise an input layer, output layer, and two hidden layers. System networks are designed with inputs as cutting conditions, and they output the cutting force. A pseudo-inverse network is designed that has the adjustable cutting condition as output and cutting force and other cutting conditions as input. The combination of the system network and pseudo-inverse network enables selection or improvement of cutting conditions that results in the expected cutting force.

• Journal of Biomedical Engineering Research
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• v.44 no.2
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• pp.109-117
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• 2023

In this study, the effect of the shape of the specimen and the feedrate of the dental ultrasonic surgical instrument on the cutting force and surface roughness of the specimen is analyzed. Experimental specimens were made of SAWBONES artificial bone materials in square and spherical specimens. In addition, the cutting feedrate of the surgical instrument was controlled through the developed moving system. The cutting force generated when cutting the specimen was measured through a force sensor. After the experiment, the cutting surface of the specimen was observed through a three-dimensional optical microscope and the surface roughness was measured. Through one-way ANOVA, the effect of each specimen shape and feed rate on surface roughness was analyzed. As a result of the experiment, the cutting force increased proportionally in the initial feed rate increase stage, but the increase in cutting force decreased as the feed rate continued to increase. Also, the cutting force showed a difference according to the shape of the specimen. The spherical specimen with a relatively small cutting surface area had less cutting force than the square specimen. However, as a result of one-way ANOVA, it was found that the specimen shape and feed rate did not affect the surface roughness. In future studies, it is expected to be used for comparative analysis of ultrasonic surgical instruments and correlation analysis between cutting factors.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.6
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• pp.133-140
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• 2001

This paper suggests another system for a cutting force measuring tool in a milling process. Generally, tool dynamometer is taken into account for the most appropriate cutting force measuring tool in the analysis of cutting mechanism. However, high price and limited space make it difficult to be in-situ system for controllable milling process. Although an alternative method using AC current of servo-motor has been suggested, it is unsuitable for cutting force control because of small upper frequency limit and noise. The cutting force measuring system is composed of two load cells placed between the moving table bracket and the nut flange part of ballscrew. It has many advantages such as low cost and wide range measurement than tool dynamometer because of the built-in moving table and the low cost load cell. The static and dynamic model of the measuring system using imbeded load cell is introduced. Various Experiments are carried out to validate both models. By comparing the cutting forces from a series of end milling experiments on the tool dynamometer and the system developed in this paper, the accuracy of the cutting force measuring system is verified. Upper frequency limit is measured by the experiment of dynamic characteristics.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.12
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• pp.151-157
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• 1996

The tool condition monitoring is one of the most important aspects to improve productivity and quality of workpiece. In this study, the wear of ceramic tool (A1$_{2}$0$_{3}$-TiC Series) cutting the hardened die material(SKD11) was investigated. Flank wear was more dominant than crater wear. Therefore the modeling of cutting force related to flank wear has been performed. The cutting force model was construct- ed by an assumption that the stress distribution on the tool face is affected by tool wear. The relationship between characteristics as cutting force and tool wear can be suggested by machining parameters depending on cutting conditions. Experiments were performed under the various cutting conditions to ensure the validity of force models. The theoretical predictions on the flank wear are approximately in good agreement with experimental results.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.1
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• pp.28-37
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• 2004

An on-line monitoring system of endmill failure such as weal, chipping, and fracture is developed using AE, cutting force Characteristic variations of AE and cutting force signals due to endmill failure are identified as follows. When endmill fracture occurs, AE count rate shows a rapid Increase in conjunction with a subsequent decrease while a standard deviation of the principal cutting force Increases significantly. The increase of AE count rate precedes the Increase of standard deviation of principal cutting force. Chipping results in relatively small increase and decrease of AE count rate without any significant variation of the cutting force Gradual increase of AE count rate and mean principal cutting force are Identified to be related with the wear of cutter. A cutter fracture detection algorithm is developed based on the present results. The signals me normalized to enhance the applicability of the algorithm to Wide those of fresh cutters, and qualitative characteristics of AE signals encountered at the moment of fracture are employed. It is demonstrated that the algorithm can detect the cutter fracture successfully.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.155-160
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• 2001

In the use of glass fiber reinforced plastics(GFRP) it is often necessary to cut the components, but the cutting of GFRP is often made difficult by the delamination of the compositions and short tool life. Experimental investigation was conducted to evaluate the chip formation of the glass fiber reinforced plastics during orthogonal cutting. The chip formation process, cutting force, and thrust force were studied. The chip formation processes were studied through the use of quick-stop device. Chip-tool contact areas were obtained with the use of the quick-stop device, and observed using optical microscopy after polishing. Cutting force and thrust force were measured through the use of the tool dynamometer.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.220-224
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• 2001

High-speed machining is one of the most effective technologies to improve productivity. Because of the high speed and high feedrate, high-speed machining can give great advantages for the machining of dies and molds. To perform efficient high-speed machining, evaluation of high speed machinability must be studied preferentially and it can be identified by investigation of cutting force. To measure cutting force in high-speed machining, dynamometer has to have high natural frequency. In this paper, The dynamometer which has high natural frequency used to measure the cutting force in various cutting conditions. High-speed machining characteristics are evaluated by the cutting force, FFT analysis of the cutting force and chip formation.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.257-262
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• 1999

On End Milling Process predict the cutting force is important. Dynamics the shear stress is the main parameter influencing the energy requirement in machining. It is well known that a nonzero force is obtained when cutting forces measured at different feed rates but otherwise constant cutting conditions are extrapolated to zero feed rate. In this paper, the cutting force measured in end-milling is compared with the simulated force models. The result show that stress measured in cutting is consistent with that stresses predicted.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.141-146
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• 2002

Real-time monitoring and control of the cutting force is essential for unmanned cutting process. Although the cutting force can be measured directly using tool dynamometers, their implementation is not feasible in industry due to high cost. Alternative approach is the cutting force estimation based on spindle drive models, but it requires the knowledge of their characteristics with the spindle speed variation. This paper investigates the power-factor and frictional characteristics of three-phase induction motors and determines its characteristics below and above the base speed, respectively. In order to realize the proposed cutting force monitoring system, a stand-alone DSP board was utilized. Its monitoring and control performance is evaluated in a CNC lathe.