• Journal of the Korean Society for Precision Engineering
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• v.18 no.9
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• pp.89-95
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• 2001

Ceramic tool has to equip with not only high toughness and strength but also low thermal expansion and good thermal conductivity which leads to the high thermal shock resistance. These characteristics make it have longer tool life under thermal stress condition. In this study, commercial Si$_3$N$_4$ceramic cutting tool and home-made SiC based ceramic cutting tools which have different sintering time and chemical composition are tested under various cutting speed and the feed rate increase, the cutting force and the flank wear growth ratio increase, too. The performance of home-made SiC based ceramic cutting tool shows the possibility to be a new ceramic tool.

• Journal of the Korean Wood Science and Technology
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• v.16 no.4
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• pp.61-69
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• 1988

Recently the automization of wood manufacturing and the development of CNC machine tools becomes the center of interest. Cutting mechanism, tool wear and the roughness of machined surface have been studied. In the studies about wood for special uses, concrete data of cutting is desired. While Pinus densiflora is characterized that heartwood develops as age increases, Chunyang District has the characteristic of strength, red color, relatively regular chap and high heartwood - percentage. But there is no data about cutting this wood, Chunyang District. In this study face milling by sintered carbide tool was excuted to Chunyang District. Cutting force, Surface roughness and states were investigated with regard to cutting speed. Example results were as follows; 1) Mean cutting resistance against lateral component force and longitudinal component force decreased rapidly up to cutting speed of 155 m/min, and remains constant above this speed. 2) The surface roughness of cutting surface lowered as cutting speed increased, regardless of fiber formation. Radial rougness of fiber is larger than lineal surface roughness. 3) Increase in Cutting speed made machining mark restrained. Down-milling showed larger marks than up-milling.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.934-938
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• 2000

Built-up edge affects the surface integrity of the machined surface and tool wear. Tool geometry and cutting conditions are very important factors to remove BUE. In this paper, we optimized the geometry of the metal slitting saw .1nd cutting conditions to remove BUE by the experiment. In general, the metal slitting saw is plain milling cutter with thickness less of a 3/16 inch. This is used for cutting workpiece where high dimensional accuracy and surface finish are necessary. The experiment was planned with Taguchi method that is based on the orthogonal array of design factors(coating, rake angle, number of tooth, cutting speed, feed rate). Response table was made by the value of the surface roughness, the optimized tool geometry and cutting conditions through response table could be determined. In addition. the relative effect of factors were identified by the variance analysis. filially. coating and cutting speed turned out important factors.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.9
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• pp.62-67
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• 1999

In milling, cutting tool ins directly attached to spindle and this tells that spindle can provide very useful information on the cutting tool condition such as wear or breakage. Since spindle is rotating at a high speed, measuring spindle velocity using a noncontacting measurement system gives the best information which can be obtained. Due to the force applied to spindle through cutting tool, velocity of spindle changes. And any change in cutting tool condition affects cutting force and consequently spindle vibration. With the intent of continuously monitoring cutting tool condition in intermittent machining operations in a benign manner, a noncontacting velocity measurement system using a laser Doppler velocimeter was assembled to measure spindle torsional vibration. Spindle vibration was measured and analysis of it in the frequency domain yielded a measure which corresponded to amount of cutting tool wear in milling.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.5
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• pp.108-114
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• 2007

A new cutting force estimating approach and machining state monitoring examples are presented which uses a cylindrical displacement sensor built into the spindle. To identify the tool-spindle system dynamics with frequency up to 2 kHz, a home-built electro-magnetic exciter is used. The result is used to build an algorithm to extract the dynamic cutting force signal from the spindle error motion; because the built-in spindle sensor signal contains both spindle-tool dynamics and tool-workpiece interactions. This sensor is very sensitive and can measure broadband signal without affecting the system dynamics. The main characteristic is that it is designed so that the measurement is irrelevant to the geometric errors by covering the entire circumferential area between the target and sensor. It is also very simple to be installed. Usually the spindle front cover part is copied and replaced with a new one with this sensor added. It gives valuable information about the operating condition of the spindle at any time. It can be used to monitor cutting force and chatter vibration, to predict roughness and to compensate the form error by overriding spindle speed or feed rate. This approach is particularly useful in monitoring a high speed machining process.

• Journal of the Korean Society for Heat Treatment
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• v.6 no.1
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• pp.1-8
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• 1993

In this paper, the surface roughness influenced by Sm45C hardness in high frequency induction hardening and mechanical characteristics for the changed Hv 598 part and the unchanged hardness Hv 223 part by use of cermet and ceramic cutting tools was experimentally examined. Finally, we could be had some important results by processing surface roughness on cutting conditions such as cutting speed, feed rate, depth of cut and changes of tool nose radius. The results are summarized as follows. 1. In case of the same cutting condition, the hardness of workpiece was high and acquired the best processing surface roughness when the radius of the tool nose had 0.8 mm and feed rate was 0.04 mm/rev. 2. In case of the hardness of workpiece, though the cutting speed didn't have an effect on processing surface roughness, the less feed rate and the more processing surface roughness improved. On the other hand, the low inside the hardness of workpiece, the more cutting speed and the more feed rate increase, the processing surface of roughness improved. 3. Regardless of the hardness of workpiece, the change of the cutting depth didn't have great effect on the surface roughness. 4. On cutting the high surface hardness part with cutting tools of cermet and ceramic, it can be acquired the higher processing surface roughness because it hadn't been taken effect on cutting speed, In case of the cutting process of the low inside hardness part the two cutting tools have acquired the similar processing surface roughness.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.5
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• pp.102-107
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• 1999

In this paper hardened SCM440 material and annealed SCM440 material are for cutting experiments by the cutting con-dition which is chosen respectively by tool three components of cutting force are recorded using multicorder, Then the surface roughness for various force are measured by Roughness Tester. The results of the experiment are summarized as follow. The hardened material cut by ceramic tool(BX20) gives the highest radial component values among the cutting resistance radial components is increased higher for the higher cutting speed even though vertical component and axial component tend to decrease. But when the annealed material was cut increase in cutting speed results in the increase of three component forces. Since ceramic insert tip used the experiment hardly affect Built-up Edge and heat the cutting resistance decrease slightly regardless of the increased of cutting speed. The hardened material has higher three compo-nent force value than the annealed material because the material of high hardness is increased cutting resistance. The low-est cutting forces for hardened material and annealed material are shown in the cutting speed of 60m/min and 180m/min. respectively.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.258-263
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• 2000

Under the optimal cutting conditions, determined the machinability difference of cutting tools are by two major factors. One is the geometric shape of the cutting tool, and the other is the tool materials or heat treatment or coating of the cutting tool. In this research, we evaluated the machinability of cutting tools with conventional HSS and P/M(powder metallurgy) which was made from the different of materials and manufacture processes. Tool wear, surface roughness, cutting force and squareness of machined workpiece were evaluated.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.479-482
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• 2000

To complite the high speed cutting system, It should be solved some problems, to make light the weight of mechanism for feedrate, develop the Linear motor that bas more power, high speed control system, and high speed cutting tools, nowadays, although many high speed cutting machine is to be built by some machine maker ,they have same problems, in this study, developed the system ball screw type before the feedrate mechanism for linear motor ,so we make the basic system for Line Cents . through that, it is limited to reduce the weight of frame and their frame is to be designed differently each other to reach the purpose special material or strucutre should be contrived.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.458-468
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• 1996

The Oil Palm industry has developed tremendously with the increasing of planted area from 54,000 hectaresin 1960 to about 2.28 million hectares in 1995. This is expected to increase further to 2.5 million hectares by the year 2000. However, there has been an increasing difficulty in obtaining sufficient labour for the oil palm plantations. At present , harvesting of oil palm fresh fruit is facing an acute shortage of workforce as the workers are much more attracted to the better working environment and salary in the industrial sector. Harvesting of short palm is easily done by using a chisel attached to a short steel pole. Cutting is done by moving the tool at high speed to the target. The weight of the tool coupled with the speed of throwing will produce enough energy to cut the bunch stalk. In this cutting method, sharpness of the cutting device, weight of tool and the speed of throwing contribute to the efficiency of the tool . For the tall palms, a sickle attached to a ong pole is used and the job is more difficult compared to the short palms. Lifting of pole and cutting jobs require great effort and skills. This paper describes the basic design needs in developing an appropriate device that is practical for field use. A prototype design was developed and tested.