• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.227-238
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• 1993

IRRI Engineering Division has developed a well drilling rig attachment that matched power tiller or hand tractor. It was designed in response to the growing demand for ground water utilization for small-scale irrigation, especially in drought-sticken and rained farms in Asian countries. The power tiller-driven rig can drill 30 meters of 100mm well in an unconsolidated formation in one day and can be rapidly converted from rotary to jetting or to the percussion method of drilling to suit different soil and rock formation. In addition, the power tiller can be quickly installed or removed from the rig frame and can be used for transporting the rig to other sites. The rig can be dismantled into smaller sub-assemblies for carrying by hand into less accessible areas. One manufacturer in Central luzon Philippines has started to produce the rig for well drillers in Central Luzon. The Department of Agriculture in the Philippines have procured thirty three(33) units of these machines f r their Shallow Tubewell program.

• Journal of Biosystems Engineering
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• v.9 no.2
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• pp.1-7
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• 1984

The engines mounted on power-tillers are used as power source in various kinds of works such as plowing, harrowing, transporting, spraying, water pumping and threshing, etc. But the engines have not been used effectively from a standpoint of fuel consumption because of lack of proper power transmission system and lack of understanding of fuel consumption characteristics of the engines. Therefore, this study was attempted to establish proper power transmission system between the power-tiller engines and various implements. In order to accomplish the above objective, firstly, power requirement and pulley sizes for various implements, which are driven by the power-tiller engines, were investigated to find out whether the power transmission system is proper. Secondly, partload variable engine-speed test was conducted for 3 different sizes of diesel engines to measure to specific fuel consumption. Thirdly, the present power transmission systems were analyzed in terms of specific fuel consumption, and proper power transmission systems were suggested for various implements. The results of this study are summarized as follows: 1. Power requirement for each fixed-type implement of power-tiller varied from 1.5 ps to 11 ps according to its type and operating conditions, but generally in the range of 2.5 ps to 7 ps. 2. Each power tiller and implement were equipped with only one size of pully with few exeptions. With the present power transmission systems, the engines can't be utilized effectively in terms of fuel economy. The pulley size of engine or implement should be diversified to provide the optimum engine speed for different implements. 3. For a diesel eninge with the rated power output of 6 ps, the optimum engine speed to minimize specific fuel consumption was 2200 rpm for the power reguirement in the range of 6 ps or more, 1700 rpm in the range of 4 to 6 ps, and 1200 rpm in the range of 4 ps or less. 4. For a diesel engine with the rated power output of 8 ps, the optimum engine speed was 2200 rpm for the power requirement in the range of 7 ps or more, 1700 rpm in the range of 4.8 to 7 ps, and 1200 rpm in the range of 4.8 ps or less. 5. For a diesel engine with the rated power output of 10 ps, the optimum engine speed was 2200 rpm for the power requirement in the range of 8.4 ps or more, 1700 rpm in the range of 5.4 ps to 8.4 ps, and 1200 rpm in thr range of 5.4 ps or less. 6. Provided the existing implements are dirven by 8 ps diesel engines, the optimum size of engine pulley should be larger than 120mm for the works of requiring less than 4 ps and 90-110mm for the works requiring 4.5-6.5 ps in order to minimize fuel consumption.

• Journal of Chest Surgery
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• v.14 no.1
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• pp.83-86
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• 1981

Eight cases by power tiller accidents experienced for 3 years from Jan. 1978 to Dec. 1980 were studied clinically. The results are as follows: 1. The most of the patients were thirties to fifties, and the incidence rate of male to female 7:1. 2. The common injuries were hemopneumothorax and multiple rib fractures [respectively and the other associated injuries were hepatic and delayed splenic ruptures, and fractures of the another sites. 3. The accident forms were overturning [50.0%], falling down from the power tiller [37.5%], and collision against the power tiller [12.5%]. 4. All of the drivers and 75% of the passengers in the patients were drunken states at the accident time. 5. The common methods of treatment were closed thoracostomy [62.5%], conservative treatment [37.5%], and exploratory laparotomy [25.0%].

• Journal of the Korean Society of Tobacco Science
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• v.15 no.1
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• pp.57-62
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• 1993

Ridger and vinyl mulcher for 8-10 PS power tiller which were distributed at the rate of one out of 2.3 farm households in Korea, was developed to ease the labor shortage of tobacco production. Devices wheel shaft extension by 30cm at both sides improved the stability of straight drive and enabled to save required labor hours by 50% for ridging at sloping field. Screw type blades were attached on center drive rotavator shaft, gear set was deviled to reverse the rotavator, and it was good at need to adjust the width and height for ridge. As the results, required labor hours for ridging and vinyl mulching could be saved by 90% as compared to conventional manual method after cattle plowing, and by 50% as compared to conventional power tiller method.

• Journal of Biosystems Engineering
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• v.9 no.1
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• pp.5-10
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• 1984

Using the renewal theory based on the Weibull distribution, an estimation was made on the number of replacement parts annually required for the after-service of some major parts of power tiller at the local repair shops or dealers. The production requirements of the parts were also estimated for the service in the next 5 years following the sales of power tillers.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.3
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• pp.222-230
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• 1995

This study was canied out to ddermine optimum areas for various sizes of land coverage of the farm machinery utilization in 1993-1994. A kind of machinery size and work systems were classed as the power tiller of 10HP+man power, the tractor of 35~46HP (tractor of 64~86HP and attachment were leased to harvest work), 64-86HP+ attachment and 90- 105HP+ attachment, respectively. \ulcornerhe results are summarized as follows: 1. The optimum areas of tractors of 90~105HP, 64~86HP and the power tiller of lOHP were estimated as 21.9 (corn-rye cropping system)- 26.9ha (sorghum $\times$ sudangrass - rye cropping system), 14.7 - 22.8ha and 1.2 - 1.61ha, respectively. The break-even-point areas of the tractors of 90-105HP. 64-86HP and the power tiller of lOHP were 16.6 (corn-rye cropping system)- 19.9ha (sorghum $\times$ sudangrass - rye cropping system), 12.5 - 16.lha and 0.12-0.13ha, respectively. 2. The optimum areas (land sizes, annual field capacity) for 50 cows by feeding rate(%) of roughage to concentrate were 6.8ha, 13.6ha in the 4060, 8.5ha, 17.0ha in the 5050 and 10.2ha, 20.4ha in the 60:40, and in case of 30 cows, it were 4.lha, 8.2ha in the 40:60, respectively. In the former case for the form of work system was the trador of 90-105HP+attachment and 64~86HP+ attachment, and the latter was the tractor of 35~46HP (tractor of 64~86HP and attachment were leased to harvest work) and 64-86HP+ attachment. 3. Productiori cost for corn-rye cropping system reducted to 51.8% in 102.9 wonkg dry matter the tractor of 90~ 105HP+ attachment with 213.4 wonkg dry matter the power tiller of 10HP+ man power.

• Journal of Biosystems Engineering
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• v.26 no.5
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• pp.423-430
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• 2001

The purpose of this study is to develop high-speed rotary tillage system for a power tiller by improving the rotary blade and the power train of transmission. Mechanical structure of gear train of rotary drive of conventional power tiller was simplified so that power can be transmitted directly from second shaft to tilling speed change shaft by rotating freely the transfer gear which changes the direction of rotation of shafts using needle bearing installed into middle shaft. A new gear train suitable for the single-edged rotary blade and high-speed rotary drive was developed with the rotational speed of rotary shaft faster than 7.5% at 1st-speed and 1.4% at 2nd-speed the one of conventional system by changing the numbers of teeth of gears of middle shaft, tilling speed change shaft and PTO shaft. Using the developed gear train for high-speed rotary drive, field tests were performed to compare tillage performances by the developed single-edged blade and by the conventional double-edged blade. The results showed that the performances by the single-edged blade compared with the one by the double-edged blade was improved about 18% in field capacity, about 34% in fuel consumption, and 9.4% in soil crushing ratio. Therefore, it may be concluded that tillage performance by the single-edged blade was improved compared to the one by the conventional blade. Evaluation of the developed system consisting of single-edged blade and gear train for high-speed rotary drive in field revealed that tillage performance of the developed system was similar to the one of field test conducted using the system consisting of single-edged blade and gear train for rotary drive of conventional power tiller However, considering the higher cone index of the upland field where evaluation was carried out compare to the one of the ordinary paddy field, it may be concluded that tillage performance of the developed rotary tilling system better than the one of conventional system.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11b
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• pp.446-459
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• 2000

This study was carried out in order to find out an effective machinery utilization strategy by conducting a survey on utilization and maintenance of agricultural machinery. The survey showed that the no. of utilization hours for power tiller in a year was 190.2hrs, 208.6hrs for tractor, 59.1hrs for rice transplanter, 74.0 hrs for combine, 44.6 cultivator and 254.4hrs for 4.4hrs for grain dryer. The period covered the time the machine was until it became unserviceable. The results are as follows: 10.0yrs for power tiller, 7.5yrs for tractor, 7.4yrs for rice transplanter and 5.4yrs for combine. This indicate that the actual period of use for power tiller and rice transplanter was longer than the expected period of duration years so there is a need for adjustment. The factors considered by the farmers for purchasing agricultural machine were: farm size(32%), machine operation (26.0%), performance(l4.0%) and post or after sales service(12.6%), according to the survey. It showed that repair cost rate in a year was classified into major agricultural machine; 4.8% for combine; 3.9% for tractor; 3.5% for rice transplanter; 2.0% for power tiller; 1.6% for grain dryer; and 1.2% for cultivator. The reasons for poor maintenance were insufficient after sales service(25%) and difficulty in buying parts(75%) because of the unavailability of parts in local shops(55%), imported models(30%) and outmoded model(15%).

• Journal of Biosystems Engineering
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• v.3 no.2
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• pp.35-61
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• 1978

To find out the power tiller's travel and tractive characteristics on the general slope land, the tractive p:nver transmitting system was divided into the internal an,~ external power transmission systems. The performance of power tiller's engine which is the initial unit of internal transmission system was tested. In addition, the mathematical model for the tractive force of driving wheel which is the initial unit of external transmission system, was derived by energy and force balance. An analytical solution of performed for tractive forces was determined by use of the model through the digital computer programme. To justify the reliability of the theoretical value, the draft force was measured by the strain gauge system on the general slope land and compared with theoretical values. The results of the analytical and experimental performance of power tiller on the field may be summarized as follows; (1) The mathematical equation of rolIing resistance was derived as $$Rh=\frac {W_z-AC \[1+ \frac{sl}{K} \(\varrho ^{-\frac{sl}{K}-1\)\] sin\theta_1}} {tan\phi \[1+ \frac{sl}{K} \(\varrho ^{-\frac{sl}{K}-1\)\]+\frac{tan\theta_1}{1}$$ and angle of rolling resistance as $$\theta _1 - tan^1\[ \frac {2T(AcrS_0 - T)+\sqrt (T-AcrS_0)^2(2T)^2-4(T^2-W_2^2r^2)\times (T-AcrS_0)^2 W_z^2r^2S_0^2tan^2\phi} {2(T^2-W_z^2r^2)S_0tan\phi}\] $$and the equation of frft force was derived as$$P=(AC+Rtan\phi)\[1+ \frac{sl}{K} \(\varrho ^{-\frac{sl}{K}-1\)\]cos\phi_1 \ulcorner \frac {W_z \ulcorner{AC\[ [1+ \frac{sl}{K} \(\varrho ^{-\frac{sl}{K}-1\)\]sin\phi_1 {tan\phi[1+ \frac{sl}{K} \(\varrho ^{-\frac{sl}{K}-1\]+ \frac {tan\phi_1} { 1} \ulcorner W_1sin\alpha $$The slip coefficient K in these equations was fitted to approximately 1. 5 on the level lands and 2 on the slope land. (2) The coefficient of rolling resistance Rn was increased with increasing slip percent 5 and did not influenced by the angle of slope land. The angle of rolling resistance Ol was increasing sinkage Z of driving wheel. The value of Ol was found to be within the limits of Ol =2\ulcorner "'16\ulcorner. (3) The vertical weight transfered to power tiller on general slope land can be estim ated by use of th~ derived equation: $$R_pz= \frac {\sum_{i=1}^{4}{W_i}} {l_T} { (l_T-l) cos\alpha cos\beta \ulcorner \bar(h) sin \alpha - W_1 cos\alpha cos\beta$$The vertical transfer weight $R_pz$ was decreased with increasing the angle of slope land. The ratio of weight difference of right and left driving wheel on slop eland,$\lambda= \frac { {W_L_Z} - {W_R_Z}} {W_Z} $, was increased from ,$\lambda$=0 to$\lambda$=0.4 with increasing the angle of side slope land ($\beta = 0^\circ~20^\circ) (4) In case of no draft resistance, the difference between the travelling velocities on the level and the slope land was very small to give 0.5m/sec, in which the travelling velocity on the general slope land was decreased in curvilinear trend as the draft load increased. The decreasing rate of travelling velocity by the increase of side slope angle was less than that by the increase of hill slope angle a, (5) Rate of side slip by the side slope angle was defined as $ S_r=\frac {S_s}{l_s} \times$ 100( %), and the rate of side slip of the low travelling velocity was larger than that of the high travelling velocity. (6) Draft forces of power tiller did not affect by the angular velocity of driving wheel, and maximum draft coefficient occurred at slip percent of S=60% and the maximum draft power efficiency occurred at slip percent of S=30%. The maximum draft coefficient occurred at slip percent of S=60% on the side slope land, and the draft coefficent was nearly constant regardless of the side slope angle on the hill slope land. The maximum draft coefficient occurred at slip perecent of S=65% and it was decreased with increasing hill slope angle $\alpha$. The maximum draft power efficiency occurred at S=30 % on the general slope land. Therefore, it would be reasonable to have the draft operation at slip percent of S=30% on the general slope land. (7) The portions of the power supplied by the engine of the power tiller which were used as the source of draft power were 46.7% on the concrete road, 26.7% on the level land, and 13~20%; on the general slope land ($\alpha = O~ 15^\circ ,\beta = 0 ~ 10^\circ$) , respectively. Therefore, it may be desirable to develope the new mechanism of the external pO'wer transmitting system for the general slope land to improved its performance.l slope land to improved its performance.

• Journal of Biosystems Engineering
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• v.3 no.2
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• pp.34-34
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• 1978

To find out the power tiller's travel and tractive characteristics on the general slope land, the tractive p:nver transmitting system was divided into the internal an,~ external power transmission systems. The performance of power tiller's engine which is the initial unit of internal transmission system was tested. In addition, the mathematical model for the tractive force of driving wheel which is the initial unit of external transmission system, was derived by energy and force balance. An analytical solution of performed for tractive forces was determined by use of the model through the digital computer programme. To justify the reliability of the theoretical value, the draft force was measured by the strain gauge system on the general slope land and compared with theoretical values. The results of the analytical and experimental performance of power tiller on the field may be summarized as follows; (1) The mathematical equation of rolIing resistance was derived as $$Rh=\frac {W_z-AC \[1+ \frac{sl}{K} \(\varrho ^{-\frac{sl}{K}-1\)\] sin\theta_1}} {tan\phi \[1+ \frac{sl}{K} \(\varrho ^{-\frac{sl}{K}-1\)\]+\frac{tan\theta_1}{1}$$ and angle of rolling resistance as $$\theta _1 - tan^1\[ \frac {2T(AcrS_0 - T)+\sqrt (T-AcrS_0)^2(2T)^2-4(T^2-W_2^2r^2)\times (T-AcrS_0)^2 W_z^2r^2S_0^2tan^2\phi} {2(T^2-W_z^2r^2)S_0tan\phi}\] $$and the equation of frft force was derived as$$P=(AC+Rtan\phi)\[1+ \frac{sl}{K} \(\varrho ^{-\frac{sl}{K}-1\)\]cos\phi_1 ? \frac {W_z ?{AC\[ [1+ \frac{sl}{K} \(\varrho ^{-\frac{sl}{K}-1\)\]sin\phi_1 {tan\phi[1+ \frac{sl}{K} \(\varrho ^{-\frac{sl}{K}-1\]+ \frac {tan\phi_1} { 1} ? W_1sin\alpha $$The slip coefficient K in these equations was fitted to approximately 1. 5 on the level lands and 2 on the slope land. (2) The coefficient of rolling resistance Rn was increased with increasing slip percent 5 and did not influenced by the angle of slope land. The angle of rolling resistance Ol was increasing sinkage Z of driving wheel. The value of Ol was found to be within the limits of Ol =2? "'16?. (3) The vertical weight transfered to power tiller on general slope land can be estim ated by use of th~ derived equation: $$R_pz= \frac {\sum_{i=1}^{4}{W_i}} {l_T} { (l_T-l) cos\alpha cos\beta ? \bar(h) sin \alpha - W_1 cos\alpha cos\beta$$The vertical transfer weight $R_pz$ was decreased with increasing the angle of slope land. The ratio of weight difference of right and left driving wheel on slop eland,$\lambda= \frac { {W_L_Z} - {W_R_Z}} {W_Z} $, was increased from ,$\lambda$=0 to$\lambda$=0.4 with increasing the angle of side slope land ($\beta = 0^\circ~20^\circ) (4) In case of no draft resistance, the difference between the travelling velocities on the level and the slope land was very small to give 0.5m/sec, in which the travelling velocity on the general slope land was decreased in curvilinear trend as the draft load increased. The decreasing rate of travelling velocity by the increase of side slope angle was less than that by the increase of hill slope angle a, (5) Rate of side slip by the side slope angle was defined as $ S_r=\frac {S_s}{l_s} \times$ 100( %), and the rate of side slip of the low travelling velocity was larger than that of the high travelling velocity. (6) Draft forces of power tiller did not affect by the angular velocity of driving wheel, and maximum draft coefficient occurred at slip percent of S=60% and the maximum draft power efficiency occurred at slip percent of S=30%. The maximum draft coefficient occurred at slip percent of S=60% on the side slope land, and the draft coefficent was nearly constant regardless of the side slope angle on the hill slope land. The maximum draft coefficient occurred at slip perecent of S=65% and it was decreased with increasing hill slope angle $\alpha$. The maximum draft power efficiency occurred at S=30 % on the general slope land. Therefore, it would be reasonable to have the draft operation at slip percent of S=30% on the general slope land. (7) The portions of the power supplied by the engine of the power tiller which were used as the source of draft power were 46.7% on the concrete road, 26.7% on the level land, and 13~20%; on the general slope land ($\alpha = O~ 15^\circ ,\beta = 0 ~ 10^\circ$) , respectively. Therefore, it may be desirable to develope the new mechanism of the external pO'wer transmitting system for the general slope land to improved its performance.