• Journal of the Korean Society for Precision Engineering
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• v.17 no.11
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• pp.115-121
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• 2000

In this paper, track tension estimation methods are developed for tracked vehicles which are subject to various maneuvering tasks such as turning and pivoting on flat road. The information of the track tension is very important for the tracked vehicles because the track tension is closely related to the maneuverability and the durability of the tracked vehicles. Kinetic models for the six road-wheels are obtained and used for calculating the track tension around the sprocket. This method does not require the tuning of the turning resistance, which makes it difficult to estimate the track tension in turning. The tension estimation performance of the proposed methods is verified through the simulation of the Multi-body Dynamics tool. The simulation results demonstrate the effectiveness of the proposed method under steering and pivoting of the tracked vehicles.

• Journal of the Korean Institute of Gas
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• v.26 no.3
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• pp.54-59
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• 2022

This paper is a purpose to study and analyze the failure examples for timing belt, camshaft position sensor and ignition coil of LPG automotive engine. The first example, whe the service man install the front case bracket of engine, he excessively tightened up a 12mm bolt for being fixed of brackct. As a results, the bolt was separated from joint part so that it was put in between the crankshaft sprocket. Therefore the belt was broken off because of interference between timing belt and sprocket tooth. The second example, it verified the disharmony phenenomen of engine that the gap of the camshaft position sensor and camshaft senseing point assembled on cylinder head part was small more than iregular value so that the it was generated senseing damage phenomenon by pulse signal misconduct. The third example, it was found the engine disharmony phenomenon that the fire in the ignition coil was leaked by inner damage of Number 2 ignition coil.Therefore, the the manager of a car throughtly have to inspect not in order to arise the failure symptoms.

• Journal of the Korean Society for Precision Engineering
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• v.34 no.3
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• pp.211-215
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• 2017

This research analyzes bucket elevator roller chain pins by finite element (FE) analysis and static structural analysis for a lightweight pin design. The stress distribution of light weight roller chain pins under static load is analyzed for safety factors and damping effect. The results show that the stress distribution is higher on the plate than on the bush pin. In order to compare experimental and FE analysis results, a light weight design approach was used to produce a prototype base pin. Because the inner diameter of the pin was different, the impact damping effect was most appropriate when the inner diameter was 34.05 mm, and it is used as basic research data on the impact of the roller chain and sprocket.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.76-81
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• 2002

The characteristics of the track are important concerning the mobility of tracked vehicles. It can be represented in terms of the track tension and maintaining the track tension adequately guarantees the stable and improved driving of the tracked vehicles. The track tension must be known in order to be controlled and it needs to be estimated in real-time because it is difficult to be measured. The tension around idler and sprocket can be controlled by the frizzy logic control system base on the estimated values. Dynamic Track Tensioning System(DTTS) which is estimating and controlling the track tension. In this paper, simulation tool is developed in order to apply the DTTS to real battle tanks. To construct the simulation tool, the Modeling the tracked vehicle, constructing estimation system, and designing controller should be achieved first and then all subsystem should be organized in one. The simulation tool make the RecurDyn model of tracked vehicle, which is plant model, and the control system exchange their data simultaneously. Simulation with many kinds of driving conditions and road conditions is carried out and the results are interpreted. The interpretation provides necessary information to apply the DTTS to real battle tanks.

• Agricultural and Biosystems Engineering
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• v.4 no.1
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• pp.34-38
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• 2003

A mathematical model was developed for estimating the mechanical interrelation between characteristics of soil and main design factors of a tracked vehicle, and predicting the tractive performance of the tracked vehicle. Based on the mathematical model, a computer simulation program (TPPMTV) was developed in the study. The model considered the continuous change in tension for the whole track of a tracked vehicle, the analysis of shape and tension of the track segment between sprocket and first roadwheel, and the side thrust on both sides of grouser by the active earth pressure theory in predicting the tractive performance of a tracked vehicle. Also, the model contained not only sinkage depth of the track but the pressure distribution under the track in analyzing the side thrust. The effectiveness of the developed model was verified by performing the draw bar pull tests with a tracked vehicle reconstructed for test in loam soil with moisture content of 18.92％. The predicted drawbar pulls by the model were well matched to the measured ones. Such results implied that the model developed in the study could estimate the drawbar pulls well at various soil conditions, and would be very useful as a simulation tool for designing a tracked vehicle and predicting its tractive performance.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.11
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• pp.919-925
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• 2016

In this study, multibody dynamic and mechanical analyses were conducted for the structure of roller chain bucket elevator system. The fatigue life of the roller chain elevator system was determined under static and fatigue loadings. Results of multibody dynamic analysis suggested that the maximum contact force occurred at the drive sprocket engagement point with the roller chain due to maximum tension. Fatigue analysis results suggest that the high load roller chain system is durable and safe because its life time is more than 700,000 cycles, close to its designed value (1,000,000 cycle). However, the contact portion of plate and pin needed a safety factor. The dynamic analysis of the heavy load roller chain was conducted with a multibody dynamic analysis program. The results obtained in this study can be utilized for dynamic analysis of roller chain systems in all industries.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.5 s.182
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• pp.177-183
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• 2006

A tape feeder is an important feeding device to supply micro-chips such as 1005 and 0603 components to PCB in SMT process. Traditionally, tape feeding methods using sprocket wheel mechanism has been used for the pickup system of chip-mounters. However, there is growing needs for new feeding mechanism with high accuracy and confidence as electric components are getting much smaller. Thus, recently, a tape feeder using cam-slider mechanism is developed to meet such requirements. The major advantages of developed system are; significantly reduced indexing and backlash errors, slim and compact design, and improved repetitive capacity compared to existing system. In this paper, the performance evaluation criteria for the developed tape feeder are suggested. Stability against induced vibration, positioning accuracy, cycle time, durability and supply error rate are estimated using developed self testers. As a result, the excellence of developed tape feeding mechanism is validated using the effective rating methods.

• Journal of Biosystems Engineering
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• v.25 no.4
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• pp.257-264
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• 2000

A tractor attached TMR(model 430) mixer has been developed in a previous study. However, the mixer was found to be improved through field applications in its capacity, manufacturing cost, ergonomic design and power-train requirement. The TMR mixer was modified into a model TMR500, approved by Institute of Agricultural Mechanization, as follows : 1. Roughage cutting system was seperated from the mixer, resulting in the 33% reduction of manufacturing cost. 2. Enlarged hopper capacity enabled to feed 60 heads at a batch. 3. Hydraulically controlled gate system saved ergonomic man power. 4. Power transmission system was changed from a chain-sprocket system(27:1) to the gear-train reduction system(38.6:1) to satisfy the recommended use of 540rpm PTO input.

• Journal of Drive and Control
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• v.20 no.1
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• pp.16-26
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• 2023

Although the upland field area of Korea is high as 44.8%, the platform optimized for the upland field is insufficient. It is necessary to develop an optimized platform for the upland field because the upland field environment is an irregular environment with many slopes. In addition, due to the characteristic of agricultural operations, the traction power and torque of the platform have to be sufficient. Therefore, in this study, a simulation model that can predict the traction power and driving torque of a crawler-type platform for the upland field was developed and validated using the specifications of the crawler platform. The simulation model was developed using Amesim (19.1, Siemens, Germany). The development of the model was conducted using the specifications of the platform. A measurement system was developed to validate the simulation model. The traction power data of the simulation model was validated with the traction force and vehicle speed. The driving torque data of the simulation model was validated with the torque of the sprocket on the crawler system. As a result of the analysis, the error between measurement and simulation results occurred within 10%, and it was determined that the traction power and driving torque prediction of the crawler platform using this model was possible.

• Journal of Biosystems Engineering
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• v.3 no.1
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• pp.20-36
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• 1978

The effect of binder kicking forces on the shattering losses of paddy rice, which has been widely understood as an outstanding loss factor in harvesting with a binder, were experimentally assessed in this thesis.Through the field tests the optimum time of harvest, in terms of grain moisture contents, was found by considering harvesting losses for two rice varieties, harvested by two different binders, at four or five grain moisture levels.A device was designed and manufactured to apply various kicking forces to the bundles and was used in the bundle kicking tests. It was intended to find out the optimum range of kicking force to minimize the kicking losses. Based on the study, modification of the existing binder kicking mechanism was suggested. The following is a summary of the results of this thesis. 1. In Suweon 258 variety, as the grain moisture content is reduced, so the cutting loss and the kicking loss increase. The grain losses range from 0.77 to 0.82 percent of total field yield for the cutting loss, from 1.83 to 2.01 percent for the kicking loss, and from 2.60 to 2.83 percent for the field loss, when the moisture content is about 22 percent. 2. In Jinheung variety , the field losses increased as the grain moisture content decreased . When the moisture content was 20 percent, the field loss, cutting loss and kicking loss was 0.42-0.49 % , 0.30-0.35, and 0.12 -0.14% of the total field yield, respectively. 3. The difference in the field loss , cutting loss, and kicking loss for the two binders was 0.23% , 0.05% and 0.18% respectively in Suweon 258 variety, and 0.07% , 0.02% and 0.05% respectively ini Jinheung variety. The grain losses for binder B were slightly higher than those for binder A. 4. In the statistical analysis of each variety , the kicking force and the moisture content of the grain, and its interaction were all highly significant at 1% level by T test .The optimum kicking force was found to be in the 3.0-0.4kg range. This does not interrupt the binder operation, while ioses are kept to an acceptale level. 5. To reduce the kicking force of the eXlstmg binder mechanism, the speed of rotation of the kicking arm needs to be redued by increasing the number of driving sprocket teeth, and the position and gear ratio of the knotter-bill and driving bevelgear have to be change to give a !motter-bill speed of 1110 rpm. It is also desirable to attach a belt conveyor which smoothly carries the bundle to the ground. 6. The optimum harvesting time cased on maximum field yield was found to be at a grain moisture content of around 22 percent for Suweon 258 variety, and 20 percent for Jinheung variety. Tota] field yield and field yield at the time amounted to 9, 812.5 kg/ha, 9, 302. 5kg/ha respectively for the Suweon 258, and 7, 819.5 kg/ ha, 7, 158.7 kg/ha respectively for the Jinheung variety.