• Journal of Biosystems Engineering
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• 제20권1호
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• pp.13-21
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• 1995

This study was conducted to investigate the cutting mechanism of reciprocating knife of combine harvester. The cutting operation of reciprocating knife with the arrangement of the low-cutting and the double-cutting was demonstrated through cutting pattern diagram which was drawn by computer graphics. Various kinds and dimensions of reciprocating knives were analyzed using the developed program. The results are summarized as follows (1) The low-cutting type reciprocating knife was represented similar cutting characteristics to the standard type, but the maximum stalk-deflection was decreased as 1/2 level of the standard type. And the first ledger plate should be designed shorter than the second ledger plate. (2) The bunching area and the maximum stalk-deflection for the double cutting knife almost were not changed since cutting velocity ratio of 0.6, but the secondary cut were occurred at ratio of 0.8 and increased rapidly over these ratio. (3) The double cutting knife was recommended for the high speed combine, because its bunching area and the maximum stalk-deflection were decreased as 1/2 level of the standard type. (4) In order to maintain the proper cutting mechanism characterized by the bunching area, the maximum stalk-deflection and the secondary cutting length etc., the adequate cutting velocity at forward speed of 0.5㎧ to 1.2㎧ was from 0.3㎧ to 0.96㎧ for the double cutting knives.

• Journal of the Korean Society of Industry Convergence
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• 제7권4호
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• pp.419-424
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• 2004

In order to increase the efficiency of the sawdust machine, the helical type drums with an oblique cutting condition (3D) were developed. The preexisting drums have an orthogonal cutting condition (2D) considering of a saw cutter and a wood cutting pattern. Unfortunately, the disadvantages of this type drum are the big cutting resistance, the high cost of a cutting power and the extreme occurrence of a vibration. To improve this shortcoming, the helical type drum with an oblique cutting condition was developed. Therefore, this type drum decreased the vibration and the cutting resistance of the sawdust machine, and also improved the productivity of 30% or more and the porosity of the sawdust.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.88-92
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• 2004

We developed a helical type drum with an oblique cutting condition for sawdust machine. The existing drum has an orthogonal cutting(2D) condition considering of saw cutter and wood cutting pattern. Additional disadvantage of this type include big cutting resistance, high cost of cutting power and extreme occurrence of vibrations. To improve this shortcoming, we developed a helical type drum with an oblique cutting(3D) condition, therefore, this type drum decreased the vibration and cutting resistance of sawdust machine, and also improved productivity and sawdust porosity.

• Journal of Biosystems Engineering
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• 제4권1호
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• pp.48-57
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• 1979

In order to obtain a standard reference for designing an adequate power rice transplanter, the cutting forces depending upon variety of seedling, sowing density, seedling age and soil moisture content of mat-type seedling were measured by the rice transplanter installed with force measuring device of dynamic strain gage system in the laboratory. The result of this study are summarized as follows : 1. Cutting velocity and acceleration transplanting hoe obtained from jinematic analysis of planting mechanism was 1.32m/sec and 81.5m/$sec^2$ when planting crank-shaft rpm was 160. 2. Little difference between cutting forces on 30-days old seelings of japonica and Indica type was observed, as the cutting forces determined were 2.0kg per hill for Japonica type and 2.1kg per hill for Indica type. 3. Cutting forces determined on 40-days old seedlings were 2.5kg, 2.3kg, 3.1kg and 2.9kg per hill for Milyang No.15, Tongil, Akibare and Milyang No.23 compared to the other varieties. 4. The cutting force was not greatly affected by the sowing densities , only five percent of differences were observed epending upon the sowing densities. 5. Cutting forces were 2.7kg and 2.0kg per hill on 40-days old seedlings and 30-days old seedlings respectively. About 38 percent of more forces was required in cutting 40-days old seedling than in cutting 30-days old seedlings. 6. More cutting forces were required as soil moisture content of mat-type seedling was decreased. 7. Root length after cutting by the planting hoe and their relationships with soil moisture content on 30-days old seedlings, are as follows ; $y=4.147-11.384x+ 28.854x^2$ where , $y$=root length after cutting. (cm) , $x$=soil ture content of mat type seedlings.(%, d.b.) 8. Cutting forces were varied with the width of cuttings ; those on 40-days old mat type seedlings were 2.7kg and 2.2kg per hill when cutting with 14 mm and 10mm of width respectively, about 32 percent of more forces was required when cuting with 14mm of width compared to 10mm of width.

• Design & Manufacturing
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• 제17권2호
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• pp.22-26
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• 2023

As Light-Emitting Diodes(LEDs) continue to advance in performance, their application in automotive lamps is increasing. Automotive LEDs utilize light guides not only for aesthetics but also to control light quantity and direction. Light guides employ patterns of a few hundred micrometers(㎛) to regulate the light, and the surface roughness(Ra) of these patterns can reach tens of nanometers(nm). Given that these light guides are produced through injection molding, mold processing technology with high surface quality micro-patterns is required. This study serves as a preliminary investigation into the development of high surface quality micro-pattern processing technology. It examines the surface roughness of the workpiece based on the cutting direction of the pattern and the cutting fluid type when cutting micro-patterns on STAVAX steel using cubic Boron Nitride(cBN) tools. The experiments involved machining a step-shaped micro-pattern with a height of 60 ㎛ and a pitch of 400 ㎛ in a 22×22 mm area under identical cutting conditions, with only the cutting direction and cutting fluid type being varied. The machining results of four cases were compared, encompassing two cases of cutting direction(parallel to the pattern, orthogonal to the pattern) and two cases of cutting fluid type (flood, mist). Consequently, the Ra value was found to be the highest(Ra 128.33 nm) when machining with the flood type in parallel to the pattern, while it was the lowest(Ra 95.22 nm) when machining with the mist type orthogonal to the pattern. These findings confirm that there is a difference of up to 25.8 % in the Ra value depending on the cutting direction and cutting fluid type.

• Transactions of the Korean Society of Mechanical Engineers A
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• 제28권2호
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• pp.196-205
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• 2004

The cutting characteristics and the deformed layer of nitrogen(N)-added type 316LN stainless steel were comparatively investigated to type 316L stainless steel. The cutting force, the surface roughness(Ra) and the tool wear in face milling works were measured with cutting conditions, and the deformed layers were obtained from micro-hardness testing method. The cutting resistance of type 316LN was similar to type 316L in spite of its high strength. The surface roughness of type 316LN was superior to type 316L for all the cutting conditions. In particular, in the high cutting speed above 345m/min, the surface roughness of the two stainless steels was closely same. The deformed layer thickness of the two stainless steels was generated in the 150$\mu\textrm{m}$-300$\mu\textrm{m}$ ranges, and its value of type 316LN was lower than that of type 316L. This is due to the high strength properties by nitrogen effect. It was found that type 316LN was higher in the tool wear than that type 316L, and flank wear was dominant to crater wear. In face milling works of type 316LN steel, tool wear is regarded as a important problem.

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

• Journal of The Korean Society of Grassland and Forage Science
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• 제20권4호
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• pp.237-242
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• 2000

This study was conducted to investigate the effects of cutting frequency on dry matter yield and nutritive value between heading and headless varieties of sorghumxsudangrass hybrid in 1998. Treatments were var. TE hay grazer(heading type) and Jumbo(headless type) as main plot, and 1, 2, and 3 cutting times per a year as sub plot. Although plant height of sorghumxsudangrass hybrid was no significant difference among treatments, headless type was very slightly higher than that of heading type, and both of variety decreased with 1, 2, and 3 cutting times in order. Also, dry matter yield of sorghum~sudangrass hybrid was no significant difference between heading and headless type. Dry matter yield of first cutting plot in heading type and in headless type was the higher than those of second and third cutting plot. Acid detergent fiber and neutral detergent fiber of headless type were slightly higher than that of heading type. Acid detergent fiber of sorghumxsudangrass hybrid was highest at first cutting plot in both varieties. Neutral detergent fiber of second cutting plot in heading type and first cutting plot in headless type were the highest respectively. In vitro dry matter digestibility of headless type was very slightly higher than that of heading type. And in vitro dry matter digestibility of second cutting plot was the highest in both varieties. In vitro digestible dry matter of sorghumxsudangrass hybrid was no significant difference among treatments. The results demonstrated that although there was not significant difference, cultivation of headless type and first cutting plot per a year were very good for nutritive value and DM yield of sorghumxsudangrass hybrid as summer forage crops in Korea. (Key words : Heading, Headless type, Cutting frequency, Sorghum X Sudangrass Hybrid)

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.223-238
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• 2002

This paper presented on an environment estimation of cutting fluid which is a mouse model of acute bacterial rhinosinusitis using cutting fluid in grinding and cutting. Above results will be remarked the necessity of friendly environmental cutting skill when it had used in workshop. The results of a mouse experimental using cutting fluid showed that it are occurred to the respiratory organs sickness. Also cutting fluid are occurred to hurtfulness a person when it used to grinding and cutting in workshop. Also, the results of grinding experiments in avitation materials showed that surface roughness are superior to more emulsion type oil than vegetable type oil according to increase of the depth of cut. Grinding force are similar to both emulsion type oil and vegetable type oil.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1820-1823
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• 2003

A high speed feeding type laser cutting M/C is developed for precise cutting of sheet metal. This paper has been carried out to obtain cutting characteristics and optimal cutting conditions of the developed high speed feeding type laser cutting M/C by a design of experiments. Cutting speed. laser power. laser duty and gas pressure are control factors for the surface roughness. The major factors affecting the surface roughness and the optimum cutting conditions are studied with minimum experiments using Taguchi method.