• 한국산업융합학회 논문집
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• 제12권2호
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• pp.79-83
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• 2009

In this study, actual state of operation of rotary tillage was surveyed in the central part of Korea which includes 29 rural community around Asan city, Choongnam principal. 29 heads of the village and 44 farmers were surveyed at the field with a questionnaire on the operation of rotary tillage with farm tractors. Power requirement of rotary tillage operation was measured at the field of each farmers during rotary tilling operation in the central part of Korea. Summaries of this study are summarized as follows. 1) Operations of tillage and land preparation were found to be carried out with farm tractors by 98 percents which are results of the survey on 29 heads of the village and 44 farmers. 2) More than half of the farms had tractors with horsepower more than 38 kW which states that most tractors were supplied in middle and large size. 3) The case of applying secondary tillage after the first primary tillage were 79 percent among the most of operations of tillage and field preparation. Rotary tillage were carried out on the most of wet paddy fields and only 14 percent of dry fields were cultivated with rotary tillage. 4) 63.6 percent of farm tractors were surveyed to meet the recommended field capacity on tillage operation by the government which were ranged from 15.1 to 34.9 ha. And the field capacity of these farm tractors were greater than that of annual total area of operation field, 13.2ha (data from Information of agricultural machinery, National agricultural products quality service, Korea), which states the utilization of agricultural machinery was high in the area surveyed. 5) 46 percent of farmers changed the blade of rotary implement when they used it over the field capacity of rotary blade of 33 ha which is the area of field for rotary operation per a blade change. 55 percent of farmers changed the rotary blade more than once per two years. 6) The required power for rotary operation of each farm tractors were measured as 17.206 kW at untilled paddy field and 34.989 kW at untilled dry field on the average, respectively. The required power for rotary operation was measured as 28.248 kW on the average at the paddy field which had been plowed once and 28.015 at the paddy field that had rotary tillage operation. Untilled dry field showed the highest value of the required power for rotary operation.

• Journal of Biosystems Engineering
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• 제32권4호
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• pp.215-222
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• 2007

In the study, the cone index, the cohesion and the internal friction angle of soil were measured before and after tillage in order to suggest relative improvement in soil properties by comparing the two measured values before and after tillage. The tillage methods tested in the study were five combinations of plowing and rotovating; one plow tillage operation, one plow followed by one rotary, one plow followed by two rotary, one rotary without plow and two rotary without plow. The experiments were performed in a soil bin in Sunggyunkwan Univ. and in four selected test fields in Yeoju, Seodun-Dong, Suwon (especially, two different fields) and Chungju. In general, the internal friction angle and cohesion of soil increased with the increase of soil compaction. After applying the tillage operations, the internal friction angle reduced by 14 degree and the cohesion decreased up to about $2.2N/cm^2$ on the soil bin in comparison with those before tillage. The two values, however, reduced by 9 degree and up to about $1.0N/cm^2$ on the tested fields. The CIs for all the tillage operations on the soil bin and on 4 different test fields were decreased by 800 kPa in comparison with those before tillage. The best combination of tillage operations for decreasing the CIs of soil was one plow operation followed by one rotary. The CIs for one plow operation followed by two rotary were slightly higher than that for one plow operation followed by one rotary because one plow operation followed by two rotary crushed down the soil excessively, so that the porosity of soil decreased.

• Journal of Biosystems Engineering
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• 제43권2호
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• pp.83-93
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• 2018

Purpose: This study derived the consumed power and load characteristics of a tillage operation performed in an upland field located in Seomyeon, Chuncheon, Rep. Korea, where potatoes and cabbages were cultivated in two crops. Methods: A plow and rotavator were mounted on a tractor with 23.7 kW of rated power to perform the tillage operation. The work conditions were determined, considering the actual working speed of the tillage operation performed by the local farmers. The power consumption of the rear axle, engine, and power take-off (PTO), PTO torque, and tractive force were measured under each work condition. The consumed power and load characteristics were analyzed using their average values. Results: The rotary-tillage operation consumed more engine power than the plow operation for the same tractor-transmission gear condition. The PTO in the rotary-tillage operation and the rear axle in the plow operation consumed the most power. The power consumption of the engine and the PTO for the rotary-tillage operation tended to increase as the transmission gears of the tractor and the PTO became higher. In contrast, the rear-axle power consumption was insignificant. In addition, the PTO torque tended to rise as the tilling pitch increased. For the plow operation, the drawbar power and the rear axle power accounted for 68-90% of the engine power. The engine and rear axle power, drawbar power, and tractive force tended to rise as the working speed increased. Conclusions: The power consumption and load characteristics differed for the plow and rotary-tillage operations. They may also differ depending on the soil conditions. Therefore, the power consumption and load characteristics in various work environments and regions should be analyzed, and reflected in the design of tractors and working implements. The results derived from this study can be used as a reference for such designs.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.570-573
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• 1996

The evaluation test for the operation of rotary type surface mounters which consist of the reel axis, the index table and the X-Y table, has been performed by comparing the new method with the old one in only fields. Because the problem seeking for the optimal operation of rotary type surface mounters, is NP complete, it is almost impossible to get the optimal solutions of large problems. This paper deals with a dynamic network modeling, which can reduce the effort, the cost, and the time used for the performance test of rotary type surface mounters.

• Journal of Biosystems Engineering
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• 제36권6호
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• pp.397-406
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• 2011

In this study, surveys on operation status of the 73 tractors with rated power of over 75 kW from six provinces in Korea were performed to obtain basic data required for development and efficient use of the high-power and high-performance tractors. And types of tractors and implements, operation crops, types of operations, annual operation areas, annual operation days, annual operation hours, operation speeds and widths, and problems and improvements in use were investigated. Most (91.7%) of the tractor surveyed were operated for forage and silage crops such as rice straw, whole barley, rye grass, reed canary grass, sudan grass, and the remains were operated for upland crops such as ginseng, sweet potato, potato, chinese cabbage, radish. Main operations of the tractors were cutting, baling, and wrapping for forage crops, plow tillage, rotary tillage, and manure spreading. About half (47.9%) of the tractors were used exclusively for forage crop harvesting such as forage crop cutting, forage baling, and bale wrapping, 24.5% of the tractors were used exclusively for plow or rotary tillage, and 27.4% of the tractors were used for both forage crop harvesting, and plow or rotary tillage. For the tractors with power ranges of 75~83, 89~94, 98~101, 113, 124 kW, average annual operation areas per tractor for plow tillage, rotary tillage, forage crop harvesting (cutting, baling, wrapping), and manure spreading operations were analyzed as 112.6. 144.8, 158.9. 390.0. 215.6 ha, respectively. and total average annual operation area per tractor was 171.3 ha. Average annual operation days per tractor for those operations were analyzed as 24.1, 28.9, 38.3, 55.4, 33.4, respectively, and total average annual operation days per tractor was 33.6. Average annual operation hours per tractor for them were analyzed as 260.0, 321.6, 408.1, 664.8, 413.8, respectively, and total average annual operation hours per tractor for the all tractors was 377.1. Ranges of operation widths of plow tillage, rotary tillage, forage crop cutting, forage baling, bale wrapping, and manure spreading operations were shown as 1.5~2.6, 2.3~3.0, 1.8~3.2, 1.8~2.0, 1.8~2.3, 3.1~6.6 m, respectively. Ranges of operation speed of plow tillage, rotary tillage, forage crop cutting, forage baling, bale wrapping, and manure spreading were shown as 6~9, 4~11, 9~16, 8~15, 8~17, 12~16 km/h, respectively.

• Structural Engineering and Mechanics
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• 제10권3호
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• pp.277-288
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• 2000

The present paper, deals with the dynamic analysis of a thin-walled tower with varying cross-section and additional masses. It, especially, deals with the effect of the rotary inertia of those masses, which have been neglected up to now. Using Galerkin's method, we can find the spectrum of the eigenfrequencies and, also, the shape functions. Finally, we can solve the equations of the problem of the forced vibrations, by using Carson-Laplace's transformation. Applying this method on a tall mast with 2 concentrated masses, we can examine the effect of the rotary inertia and the diaphragmatic operation of the above masses, on the 3 first eigenfrequencies.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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• pp.75-78
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• 2012

Rotary kiln furnace is one of the most widely used reactors in industrial field. In this paper, 0-dimensional heat and mass balance for direct coal flame rotary kiln was performed preferentially, then a simplified 1-dimensional model was developed based on 0-dimensional analysis data to proceed additional thermal analysis. Compared the results with the currently operating rotary kiln data to validate 1-dimensional model. Through this procedure, it can help to derive fundamental idea for design and operation of rotary kiln.

• Journal of Biosystems Engineering
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• 제36권3호
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• pp.163-170
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• 2011

Analysis of load on major parts of the tractor power drive line is critical for efficient and optimum design of a tractor. The purpose of this study was to evaluate severeness of the tractor PTO driving axle during rotary tillage operation. First, S-N (stress vs. number of cycle) curve of a PTO driving gear was obtained through the fatigue life test using a PTO dynamometer. Second, PTO severeness was evaluated during rotary tillage operation. Torque measurement system was constructed with strain-gauge sensors to measure torque of a PTO axle, an I/O interface to acquire the sensor signals, and an embedded system to calculate severeness. The severeness of PTO was analyzed using measured torque data during rotary tillage. In the PTO gear life fatigue test, breakage time and bending stress of the gear were measured by tooth widths and torque change during the fatigue life test. The S-N curve showed a good linear relationship between bending stress and number of cycle (life) with a coefficient of determination of 0.97. For PTO severenss evaluation, rotary tillage operations were conducted at two PTO rotational speeds (level-1, level-2) under different paddy and upland field sites with different soil conditions. Results of averaged relative severeness for PTO level-1 and PTO level-2 were 1.96 and 3.34, respectively, at paddy field sites, and they were 1.36 and 2.51, respectively, at upland field sites. The results showed that the PTO driving axle experienced more severe load during rotary tillage at paddy fields than at upland sites, and relative severeness was greater at the higher PTO rotational speed under all of the soil conditions.

• 농업과학연구
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• 제11권2호
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• pp.264-269
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• 1984

단면(單面)의 로우터리 경운(耕耘)날이 양면(兩面)보다 경운소요(耕耘所要)토오크를 절감(節減)시키는 데 효과적(效果的)이란 결과(結果)에 대(對)하여는 앞서의 연구(硏究)에서 보고(報告)한 바 있으며, 본(本) 연구(硏究)는 경운작업(耕耘作業)에 의(依)한 날의 마모과정중(磨耗過程中) 양(兩), 단면(單面) 형상(形狀)의 경운(耕耘)날이 경운소요(耕耘所要)토오크의 절감효과(節減效果)가 지속(持續)되는가를 구명(究明)하기 위(爲)하여 포장실험(圃場實驗)을 실시(實施)하였다. 양(兩), 단면(單面)의 공시(供試)날은 동일(同一) 로우터리 축(軸)에 부착(附着)시켜 미경운토양(未耕耘土壤)에서 포장작업(圃場作業)을 실시(實施)하여 매(每) 3시간(時間)마다 마모량(磨耗量)을 측정(測定)하였으며, 계량(計量)한 날의 경운소요(耕耘所要)토오크는 실험실(實驗室)에서 Soil bin system 을 이용(利用)하여 측정(測定)하였으며, 분석(分析) 결과(結果)를 요약(要約)하면 다음과 같다. 1. 로우터리 경운작업(耕耘作業)을 실시(實施)하는 동안 날의 단면형상(斷面形狀)의 원형(原形)은 변화(變化)하지 않았으며, 단면(單面)인 날이 양면(兩面)보다 전(全) 내용시간(耐用時間) 동안 최대경운소요(最大耕耘所要)토오크는 5~10%, 평균경운소요(平均耕耘所要)토오크는 3~15% 절감(節減)하는 것으로 분석(分析)되었다. 2. 일반적(一般的)으로, 경운소요(耕耘所要)토오크는 경운(耕耘)날의 형상(形狀)이 유지(維持)되는 12시간(時間)까지는 감소(減少)하였으나, 그 후(後)에는 날의 tip형상(形狀)의 변형(變形)에 의(依)하여 증가(增加)하는 것으로 나타났다. 이것은 날의 tip형상(形狀)이 경운소요(耕耘所要)토오크에 영향(影響)을 미치는 요인(要因)이라고 분석(分析)할 수 있으며, 이에 대(對)한 연구(硏究)는 계속(繼續)되어져야 할 것으로 사료(思料)된다.

• 한국정밀공학회지
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• 제12권8호
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• pp.106-113
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• 1995

Surface mounters are used to mount the parts of electronic products on PCB(Printed Circuit Board. Those machines rely on high precision, high productivity, and software for accomodation of use. In this paper, two algorithms and a software which can give the users the acco-modation and high productivity for rotary type surface mounters are presented. The algo- rithms for development of of the software consider all factors which affect the effeciency of the operation. And the interface between user and machine for the accomodation of use can be achieved through the developed software.