냉각수(冷却水) 용량(容量)이 소형(小型) 디젤기관(機關)의 성능(性能)에 미치는 영향(影響)

명병수,김성래,Myung, Byung Soo,Kim, Soung Rai 충남대학교 농업과학연구소 1986 Korean Journal of Agricultural Science Vol.13 No.2

동력경운기(動力耕耘機) 탑재용(塔載用) 6kW 수냉식(水冷式) 디젤기관(機關)의 성능향상(性能向上)을 도모(圖謀)하기 위(爲)하여 현존(現存)의 냉각장치(冷却裝置)는 그대로 이용(利用)하고 냉각수(冷却水) 용량(容量)만을 2700cc에서 2800cc, 2900cc, 3000cc, 3100cc 로 4수준(水準)으로 변화(變化)시키면서 기관(機關)의 출력(出力), 연료소비율(燃料消費率), Torque, 냉각수(冷却水) 및 윤활유(潤滑油)의 온도(溫度)와 기관(機關)의 마찰손실(摩擦損失)을 D.C. dynamometer를 이용(利用)하여 측정(測定)한 결과(結果)는 다음과 같은 결론(結論)을 얻었다. 1. 공시기관(供試機關)의 출력성능(出力性能)은 한국공업표준규격범위(韓國工業標準規格範圍)에는 들었으나 정격표시마력(定格表示馬力)이 실험결과(實驗結果)보다 약(約) 10% 정도(程度) 낮게 표기(表記)되어 있으며 연료소비율(燃料消費率)은 297.78g/kW-h 로 약간(若干) 높은 수준(水準)이었으며 냉각수(冷却水) 온도(溫度)는 $101^{\circ}C$로 SAE기준(基準)인 $88^{\circ}C$보다는 $13^{\circ}C$ 정도(程度)가 높았다. 2. 공시기(供試機)의 마찰손실(摩擦損失)은 정격상용회전(定格常用回轉)인 2200rpm에서 3.65kW 이었으며 기보고(旣報告)된 측정치(測定値)보다 약간(若干) 높은 범위(範圍)이었다. 3. 냉각수(冷却水) 용량(容量)을 2700cc에서 3100cc로 14.8% 증가(增加)시켰을 때 출력(出力)은 6.7kW에서 7.13kW로 0.43kW의 6.3%가 증가(增加)하였다. Torque도 냉각수(冷却水) 용량(容量) 2700cc일 때 28.85N.m에서 3100cc일 때 30.706N.m로 6.39%가 증가(增加)하는 경향(傾向)을 보였다. 4. 냉각수(冷却水) 용량(容量) 2700cc에서 3100cc로 증가(增加)시켰을 때 연료소비율(燃料消費率)은 310.85g/kW-h에서 304.14g/kW-h로 6.69g/kW-h가 감소(減少)하였으며 30분간(分間) 전하중운전시(全荷重運轉時) 냉각수(冷却水)의 온도(溫度)는 냉각수(冷却水) 용량(容量)이 2700cc에서 $101^{\circ}C$였고 냉각수(冷却水) 용량(容量)이 3100cc에서 $88^{\circ}C$로 $13^{\circ}C$가 감소하여 3100cc일 때는 SAE 표준(標準)과 같았고 윤활유(潤滑油) 온도(溫度)는 냉각수(冷却水) 용량(容量)이 2700cc일 때, $76.7^{\circ}C$였으며 냉각수(冷却水) 용량(容量)이 3100cc에서는 $70.4^{\circ}C$로 $6.4^{\circ}C$가 감소하였다. 5. 기계효율(機械效率)은 냉각수(冷却水) 용량(容量)이 2700cc에서 70.08%였고 냉각수(冷却水) 용량(容量)이 3100cc일 때는 71.08%로 0.95%가 증가(增加)하였다. This study was attempted to improve the thermal efficiency of 6 kW water-cooled diesel engine on power tiller. The engine performance tests were conducted to find out the effect of cooling water capacity of 2700cc, 2800cc, 2900cc, 3000cc, 3100cc on power, brake specific fuel consumption (BSFC), torque, temperature of cooling water and lubricating oil and friction losses of the engine with D. C. dynamometer. The results obtained in the study are summarized as follows: 1. The performance of the engine tested was adequated to Korea Industrial Standard but actual economy power was 10% higher than the labeled rated power of the engine. The BSFC of the engine tested 297.8g/kW-h which is belong a little higher level than hreign products. The temperature of cooling water was $101^{\circ}C$ which is higher than SAE standard ($88^{\circ}C$) 2. The friction losses of engine tested was 3.656 kW at 2200 rpm of rated rpm (piston speed 6.97m/sec) and is higher than those of foreign products. 3. When the cooling water capacity was increased from 2700cc to 3100cc the power output of the engine was increased from 6.7 kW to 7.13 kW at the rate of 6.4% and also the torque of the engine was increased from 28.85 N.m to 30.76 N.m at the rate of 6.39%. 4. When the cooling water capacity was increased from 2700cc to 3100cc, the BSFC was decreased 6.9g/kW-h from 310.9g/kW-h to 304.1g/kW-h, and after one half hour operation with full load, the temperature of cooling water was decreased $13^{\circ}C$ from $101^{\circ}C$ to $88^{\circ}C$ and also the temperature of lubricant oil was decreased $6.4^{\circ}C$ from $76.7^{\circ}C$ to $70.4^{\circ}C$. 5. The mechanical efficiency was increased from 70.08% to 71.08% when the cooling water capacity was increased from 2700cc to 3100cc.

마이크로컴퓨터를 이용한 기관의 진동계측시스템 및 분석프로그램 개발

명병수,김성래 ( B . S . Myung,S . R . Kim ) 한국농업기계학회 1993 바이오시스템공학 Vol.18 No.4

冷却水 容量이 小型 디젤機關의 性能에 미치는 影響

明炳洙,金聲來 충남대학교 농업과학연구소 1986 農業技術硏究報告 Vol.13 No.2

This study was attempted to improve the thermal efficiency of 6 kW water-cooled diesel engine on power tiller. The engine performance tests were conducted to find out the effect of cooling water capacity of 2700cc, 2800cc, 2900cc, 3000cc, 3100cc on power, brake specific fuel consumption(BSFC), torque, temperature of cooling water and lubricating oil and friction losses of the engine with D.C. dynamometer. The results obtained in the study are summarized as follows: 1. The performance of the engine tested was adequated to Korea Industrial Standard but actual economy power was 10% higher than the labeled rated power of the engine. The BSFC of the engine tested 297.8g/kW-h which is belong a little higher level than foreign products. The temperature of cooling water was 101℃ which is higher than SAE standard (88℃) 2. The friction losses of engine tested was 3.656kW at 2200rpm of rated rpm (piston speed 6.97m/sec) and is higher than those of foreign products. 3. When the cooling water capacity was increased from 2700cc to 3100cc the power output of the engine was increased from 6.7kW to 7.13kW at the rate of 6.4% and also the torque of the engine was increased from 28.85N.m to 30.76N.m at the rate of 6.39%. 4. When the cooling water capacity was increased from 2700cc to 3100cc, the BSFC was decreased 6.9g/kW -h from 310.9g/kW-h to 304.1g/kW -h, and after one half hour operation with full load, the temperature of cooling water was decreased 13℃ from 101℃ to 88℃ and also the temperature of lubricant oil was decreased 6.4℃ from 76.7℃ to 70.4℃. 5. The mechanical efficiency was increased from 70.08% to 71.08% when the cooling water capacity was increased from 2700cc to 3100cc.

플라이휠의 고무댐퍼가 기관의 진동에 미치는 영향

명병수,김성래 ( B . S . Myung,S . R . Kim ) 한국농업기계학회 1993 바이오시스템공학 Vol.18 No.3

디젤機關 플라이휠의 고무댐퍼 開發

明炳洙,金聲來 충남대학교 농업과학연구소 1993 농업과학연구 Vol.20 No.1

Data acquisition system and computer program developed in. this study could be well used in engine vibration analysis. The system and program developed were also operated to be able to control measuring interval, number of channels, number of data. The flywheel was specially studied to provide the proper weight with rubber damper for the engine design at low level of vibration. This study was conducted to obtain basic data which affect the engine vibration. The experiment of this study was performed on original weight flywheel. weight-reduced flywheel, weight-reduced and rubber-coated flywheel, weight-reduced and damper-attached flywheel. Avarage of peak value, maximum vibration, power spectrum density based on FFT analysis are major factors of this experiment. Results were obtained as follows: 1. When rubber was inserted in the flywheel rim of which weight was reduced from 32.2kgf to 24.4kgf, maximum vibration of the engine was decreased 48.3% at X axis, 35.5% at Y axis and 34.6% at Z axis in comparison with the flywheel of original weight. 2. When the flywheel of rubber damper was compared with the original flywheel, the average of absolute vibration for rubber damped flywheel was decreased at X. Y. Z axis and especially its decreasing rate was so high at X axis comparing with the other flywheel, which implied that rubber damper was very useful to reducing the vibration of the engine at X axis. 3. Hysteresis losses of X, Y. Z axis were greatly decreased in the flywheel with rubber damper on rim. 4. Damped oscillation effect on X and Y axis vibration above average peak vibration by the flywheel of rubber damper on rim was larger than those by the other flywheels. 5. Power spectrums of vibration at real and imagine y part were bi-mode type. The vibration frequency of rubber dampered flywheel which weight is decreased was slightly increased as compared with original flywheel.

플라이휠 重量이 디젤 機關의 振動에 미치는 影響

明炳洙,金聲來 충남대학교 농업과학연구소 1993 농업과학연구 Vol.20 No.2

Most of small size diesel engines are widely used with the same size and weight flywheel in the levels of 6.0kW and 7.5kW. This study was conducted to obtain basic data which affect the engine performance of the power tiller. The flywheel weight was considered as a major factor in this research. Basically, fuel consumption ratio. motoring loss, torque, vibration and mechanical efficiency of the engine were measured and analyzed on four levels of flywheel weight. 32.2, 29.4, 26.2 and 24.2kg_f, respectively. Results were obtained as follows: 1. The weights of flywheel were 23.7kg_f from design program of JSME and 24.5kg_f from ASME and SAE design criteria. Therefore, the flywheel weight of 32.2kg_f might be reduced about 8kg_f in 7.5kW engine. 2. The rated outputs of 6.0kW and 7.5kW engine were actually 7.43kW and 7.85kW, respectively. When flywheel weight was reduced from 32.2kg_f to 24.2kg_f, outputs were increased from 7.43kW to 7.70kW in 6.0kW engine and from 7.85kW to 8.25kW in 7.5kW engine, 3. When the flywheel weight was reduced from 32.2kg_f to 24.2kg_f, fuel consumption ratio was decreased from 300.8 to 296.8g/kW-hr in 6.0kW engine and also from 313.6 to 312.8g/kW-hr in 7.5 kW engine, respectively. 4. When the flywheel weight was reduced from 32.2kg_f to 24.2kg_f, mechanical efficiency of engine was increased from 76.1% to 76.8% in 6.0kW engine and also from 76.7% to 77.0% in 7.5kW engine, respectively. 5. When the flywheel weight was reduced from 32.2kg_f to 24.2kg_f, vibration was decreased at X-axis and Z-axis in 6.0kW engine, however, slightly increased at Y-axis in 6.0kW engine and at all axes in 7.5kW engine. 6. When the flywheel weight was reduced from 32.2kg_f to 24.4kg_f motoring loss was decreased from 2.33kW to 1.75kW in 6.0kW engine and also from 2.46kW to 1.84kW in 7.5kW engine

小型디젤機關의 負荷變動에 따른 振動特性 硏究

黃成萬,明炳洙 公州大學校 資源科學硏究所 1994 資源科學硏究論文集 Vol.2 No.-

This study was conducted to show the characteristics of vibration with small diesel engine at varied load and loaded. The engine used is the engine that is used to motor in rural areas and to powered tiller The results were summarized as follows: 1. The natural frequency of vibration with 7.5kW diesel engine was 49Hz in full load of net output. 2. The engine vibration was excessive at X-, Y-, and Z-axis in full load of net output. 3. When the loads was varied, the vibration was showed largely at 4.5 - 6.0kW loads. 4. From the FFT and statistical analysis, the type of vibration of engine was bi-mode in all loads. 5. The minimum hysteresis losses were showed in 2.8kW loads at X-axis, in 7.5kW loads at Y-axis and in 3.7kW loads at Z-axis and the maximum hysteresis losses were showed in 9.0kW loads at all axis. 6. The RMS of vibration was slightly increased at X-and Z-axis, and was not varied at Y-axis.

小型 機關의 消音器 設計를 위한 音響測定 및 分析 프로그램의 開發

명병수,노광모,최규홍,황성만,김성태 公州大學校 資源科學硏究所 1995 資源科學硏究論文集 Vol.3 No.-

To reduce the exessive noise from the engine of the farm machinery, the precise measuring equipments and analyzing apparatus are required. The exhaust noise of an engine varies continuously between several ranges, it can not be, therefore, measured accurately by the noise indicator commercially available. In this study, acoustic measuring and analyzing system with a high reproducibility of the exhaust noise were developed to investigate desingn paramenters of a muffler and to manufacture an effective silencer of the small farm diesel engine. The system consisted of a microcomputer, sound recognition board, A/D converter, FFT and PSD analysis programs, etc. The results of the experiments were summarized as follows; 1. At the experimental apparatus were produced with the resonance and abnormal sound induced at the rear of the speaker were absorbed, and playbacks of the recorded sound were set up as the original sound resources. The sound resources recorded on the engine removed muffer and were input and analyzed at the microcomputer. 2. The developed system with high sensitivity microphone and microcomputer could be applied as the range as 1㎑, and proved to be useful in the noise measurement and analysis for small diesel engines, and the result of statistical analysis showed a high significance below 1% between original and reproduced sound conditions.

중부지방에서의 로터리 경운작업 실태조사 및 경운부하

명병수(Byung-Su Myung),이현동(Hyun-Dong Lee) 한국산업융합학회 2009 한국산업융합학회 논문집 Vol.12 No.2

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 ㎾ 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, 13.2㏊ (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 ㎾ at untilled paddy field and 34.989 ㎾ at untilled dry field on the average, respectively. The required power for rotary operation was measured as 28.248 ㎾ 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.

자전거 편집설계를 위한 부품형상 정보 모델 기반 CAD 라이브러리 제어 방법

명병수(B.S. Myung),이재선(J. Lee),김병철(B.C. Kim),문두환(D. Mun),이한민(H. Lee),박성환(S. W. Park) 한국생산제조학회 2013 한국생산제조학회지 Vol.22 No.6

A library of parametric CAD models should be provided for the reuse of design data in configuration design. Mechanical products have many options and parameters, which in turn, require a large number of CAD models for configuration designs. Existing methods for library construction are limited in their ability to decrease the number of CAD models and ensureindependency between theconfiguration design system and the library. To solve these problems, we propose a method thatcontrolsa CAD library based on part-shape information model, and also present its technical details. To verify the proposed method, a CAD library for bicycles was constructed and design modification experiments usinga prototype part-shape controller were performed. From the experiments, we found that the proposed method can effectively decrease the required number of CAD models by reusingmodels for configuration designs.