• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.20 no.6
• /
• pp.799-804
• /
• 2011

CFRP(Carbon Fiber Reinforced Plastics) has been used many industries aerospace, automobile, medical device and building material industries, etc. Because it is lighter than other metals and has good properties, such as rigidity, strength and wear. CFRP may be cured integrity. However, it needs postprocessing similar to drilling or endmilling for shape cutting and combination of various material. In this paper, tool dynamometer and accelerometer used to signal analysis for machining properties under various cutting conditions and tool shape changes. In addition, microscope used to verify the machined CFRP surface. As the results, it was found that the cutting force and the vibration were decreased in the increasing of cutting edge (2-flute < 4-flute < composite tool), and the good machined surface can be obtained in this experiments.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2000.10a
• /
• pp.274-278
• /
• 2000

Ball end milling process is widely used in the die and mould manufacturing because of suitableness for the machining of free form surface. But, as ball end mill is long and thin, it is easily deflected by cutting force. In this study, Cutting force, tool deflection and surface precision was measured according to the change of depth and cutting location. Cutting force was acquired with tool dynamometer and a couple of eddy-current sensor measured tool deflection in x-y direction each. After machining, surface precision was measured with roundness tester and coordination measuring machine for sculptured surface angle change and cutting depth.

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.4
• /
• pp.105-110
• /
• 1998

In this study, statistical and neural network methods were used to recognize the cutting tool states. This system employed the tool dynamometer and cutting force signals which are processed from the tool dynamometer sensor using linear discriminent function. To learn the necessary input/output mapping for turning operation diagnosis, the weights and thresholds of the neural network were adjusted according to the error back propagation method during off-line training. The cutting conditions, cutting force ratios and statistical values(standard deviation, coefficient of variation) attained from the cutting force signals were used as the inputs to the neural network. Through the suggested neural network a cutting tool states may be successfully diagnosed.

• Transactions of Materials Processing
• /
• v.18 no.2
• /
• pp.144-149
• /
• 2009

Recently, the monitoring technology of machining process is very important to improve productivity and quality in manufacturing filed. Such monitoring technology has been performed to measurement using vibration signal, acoustic emission signal and tool dynamometer. However, micro machining is limited small-scale parts machining because micro tool is very small and weakness to generate signal in micro machining process. Therefore, this study has efficient sensing technology for real monitoring system in micro machine that is proposed to supplement a disadvantage of single-sensor by multi sensor. From experimental result, it was evaluated tool wear and cutting situation according to repetitive slot cutting condition and changing cutting condition, and it was performed monitoring spindle rpm and condition according to compare acceleration signal with current signal.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.05a
• /
• pp.373-377
• /
• 2002

In the end milling operation the deflection of the cutter is an important factor affecting the accuracy of machining with implications on the selection of cutting parameters and economics of the operation. The deflection of the end mill was studied both experimentally with strain gauge, tool dynamometer, laser measuring apparatus and on a finite element model of the cutting using ANSYS software. The deflection of machining tool with various helix angles was studied with FEM simulation and experiment. ANSYS analysis performed on the finite element model of the end mill provides deflection results which agree within 15.0% with the experimental ones.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2001.10a
• /
• pp.225-230
• /
• 2001

Small diameter drilling which take high precision in cutting work is needed more small hole and high speed working. Especially, small hole deep drilling is one of the most important machining types and its necessity and importance become more and more increasing in the whole field of industry. This paper shows the limit depths with small diameter drills using experimental analysis. The results are gained by tool dynamometer and Labview system and obtained during small diameter twist drilling system on SM45C steel for different machining conditions. The machine and tools are the CNC machining center and twist drill of diameter 1.5mm. And additionally, tool microscope show the relationship between shapes of chips and breakage shapes of small diameter drills.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2001.04a
• /
• pp.275-280
• /
• 2001

Recently, the trends of industrial products grow more miniaturization, variety and mass production. Micro drilling which take high precision in cutting work is requested more micro hole and high speed working. Especially, Micro deep hole drilling is becoming more important in a wide spectrum of precision production industries, ranging from the production of automotive fuel injection nozzle, watch and camera parts, medical needles, and thick multi-layered Printed Circuit Boards(PCB) that are demanded for very high density electric circuitry. This paper shows the tool monitoring results of micro drill with tool dynamometer. And additionally, microscope with built-in monitor inspection show the relationship between burr in workpiece and chip form of micro drill machining.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2001.04a
• /
• pp.89-94
• /
• 2001

A cylindrical capacitance-type spindle displacement sensor was designed and tested in the hard turning as a way to develop a sensor that can estimate cutting forces without using a tool dynamometer. The displacement sensor was installed between the face of spindle cover and the chucking element, and measured pure radial motion of the spindle. Ceramic inserts and tool steel workpieceof 65 Rc were used during the hard turning tests. The signals from the sensor showed the same pattern of cutting force variations as those from the tool dynamometer. The research results showed that the developed sensor could be utilized as an effective and cheap on-line sensing device to estimate cutting forces.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1999.10a
• /
• pp.11-15
• /
• 1999

Monitoring of the cutting force signals in cutting process has been well emphasized in machine tool communities. Although the cutting force can be directly measured by a tool dynamometer, this method is not always feasible because of high cost and limitations in setup. In this paper an indirect cutting force monitoring system is developed so that the cutting force in turning process is estimated based on a AC spindle drive model. This monitoring system considers the cutting force as a disturbance input to the spindle drive and estimates the cutting force based on the inverse dynamic model. The inverse dynamic model represents the dynamic relation between the cutting force, the motor torque and the motor power. The proposed monitoring system is realized on a CNC lathe and its estimation performance is evaluated experimentally.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2002.10a
• /
• pp.104-110
• /
• 2002

In this study, the prediction on the quality of tools after coating process has been investigated. Under different coating conditions, cutting resistances have been obtained and analyzed with a tool dynamometer to provide optimized coating conditions. The optimized coating condition has been computed with the most effective factors found by S/N ratio of Taguchi method. To evaluate the influence of the factors on cutting efficiency through the minimum of number of experiment times, the way of neural network design using Taguchi method has been employed.