• Journal of Welding and Joining
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• v.31 no.4
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• pp.13-16
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• 2013

In this research, laser cladding characteristics were investigated for various filler metal feeding methods such as powder, cold wire, and hot wire feeding. Appropriate parameter window, deposition rate, material efficiency and dilution for each filler feeding method were evaluated with same laser power and cladding speed range. Laser powder cladding has wider process parameter window but higher material efficiency and lower dilution were achieved by laser wire cladding. Among these feeding methods, laser hot-wire cladding showed best efficiency in material usage and deposition rate.

• International Journal of Precision Engineering and Manufacturing
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• v.7 no.1
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• pp.18-23
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• 2006

Cutting by a high speed laser cutting machine is one of most effective technologies to improve productivity. This paper has presented the cutting characteristics and optimal cutting conditions in a high speed feeding type laser cutting machine by using Tacuchi method in the design of experiment. An L9(34) orthogonal array is adopted to study the effect of adjustment parameters. The adjustment parameters consist of cutting speed, laser power, laser output duty and assistant gas pressure. The surface roughness of sheet metal is regarded as a quality feature. Analysis of variance is performed in order to evaluate the effect of adjustment parameters on the quality feature of laser cutting process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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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.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.464-469
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• 1998

In the conventional wire feeder drives of welding machine, one thyristor or MOSFET device was used for half-wave phase control circuit and direct EMF measurement was used for sensing the wire feed rate. But the method using one switching device has poor response for sudden disturbance and it has latent speed ripple. It can affect some welding performance such as spatter generation and irregular bead formming. Therefore, the welding performance using full-bridge PWM speed control scheme was compared with conventional driving scheme was compared with conventional driving scheme and experimented in this paper. The results of experiment confirm the posibility of welding performance improvement by proposed constant speed control scheme in wire feeding drive of welding machine.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.6
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• pp.77-83
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• 2004

Cutting by a high speed laser cutting machine is one of most effective technologies to improve productivity. This paper has studied to obtain the cutting characteristics and optimal cutting conditions in a high speed feeding type laser cutting machine by Tacuchi method in design of experiments. A Lf(34) orthogonal array is adopted to study the effect of adjustment parameter. The adjustment parameters consist of cutting speed, laser power, laser output duty and assistant gas pressure. And the quality feature is selected as surface roughness of sheet metal. Variance analysis is performed in order to evaluate the effect of adjustment parameters on the quality feature of laser cutting process.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.2
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• pp.271-277
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• 2004

The purpose of this experiment was to study the feeding behavior and running speed under various feed deprivation lengths and social environments. Three trials were conducted. Trial 1: ten pigs were trained individually to run a course and eat their feed at the end of the course. The pigs were deprived feed for 1, 5, 10 or 20 h. Trial 2: 1. Two pigs ran and ate together. Both pigs had 5 h of feed deprivation before the run (D5). 2. Two pigs ran and ate alone, but both pigs had 5 h of feed deprivation before the run (S5). 3. Two pigs ran and ate together. Both had 1 h of feed deprivation before the run (D1). 4. Two pigs ran and ate alone and both pigs had 1 h of feed deprivation before the run (S1). 5. Two pigs ran together, one had 5 h of feed deprivation, and the other had 1 h of feed deprivation before the run (51). Trial 3: 1. On the 1st day 5 pairs of pigs had 5 h feed deprivation and could eat feed together at (B) point (D1). 2. On the 2nd day the pigs ran and ate alone at (B) point after 5 h of feed deprivation. Feed was obtainable (D2). On the 3rd to 6th days, the pigs ran in pairs after 5 h of feed deprivation and only the dominant pig ate feed at point (B). The inferior pig was chased back to room and fed there. This stage was continued for four consecutive days, d 3 to 6. In trial 1, the running speed of pigs increased with the length of feed deprivation until 10 h, then being stable afterwards. Total feeding time increased with the length of feed deprivation (p<0.001). Eating speed did not increase with the length of feed deprivation (p>0.05). In trial 2, nine of ten pigs in treatment D5 ran faster than those in S5. Seven of the ten pigs in treatment S1 ran faster than those in treatment D1. The pigs in treatment D5 had significantly higher feed intake (p<0.001) and eating speed (p<0.05) than the pigs in other treatments. In trial 3, there were significant differences on running speed between D1 and D6 (p<0.01) and between D2 and D1, D3, D4 and D5. The inferior pig ran faster in D2 but from 3 to 6 it was the dominant pig that showed the greatest speed in completing the whole course. The results demonstrated that the pigs with low feeding motivation may cause low running speed to feed and low feed intake of the neighbor when compared with pigs kept individually.

• Journal of Welding and Joining
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• v.24 no.1
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• pp.43-49
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• 2006

This paper describes the friction surface modification which has been successfully developed with the friction stir welding recently There are several problems including just position control and backlash in conventional friction surface modification system. Therefore it has been developed the friction surface modification system which has been controlled precisely both position and force by driving hydraulic cylinder in this paper. The mechtrode rotation speed(N) and feeding speed(Vz), travel speed(Vx,y) are of critical importance for the width and thickness of the coating in friction surfacing process. But there is no theoretical method of determining interrelations between process parameters affect the coating width and thickness. As a result of DOE(design of experiment) with developed system, the coating thickness and width seemed to decrease according to increase the mechtrode rotation speed(N) and traveling speed(Vx,y), to decrease feeding speed(Vz) apparently. However as the result of regression analysis the main effect was only the mechtrode rotation speed in the coating thickness.

• Journal of Mechanical Science and Technology
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• v.14 no.8
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• pp.851-860
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• 2000

Temperature field and cooling rate are important parameters to influence the properties of clad layer and the heat affected zone. In this paper the temperature field and cooling rate of laser cladding are studied by a two-dimensional time-dependent finite element model. Experiment has been carried out by Nd:YAG laser cladding with wire feeding. Research results indicate that at the beginning of cladding, the width and depth of melt pool increase with cladding time. The cooling rate is related to position, cladding time, cladding speed, and preheating temperature. The temperature near melt pool changes rapidly while the temperature far from melt pool changes slowly. With the increase of cladding time, cooling rate decreases. The further the distance from the melt pool, the lower the temperature and the slower the cooling rate. The faster the cladding speed, the faster the cooling rate. The higher the preheating temperature, the slower the cooling rate. The FEM results coincide well with the experiment results.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.569-572
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• 2005

In many machines handling lightweight and flexible media, such as automated teller machines(ATM) and printers etc., the media must transit an open space. In the paper feeding mechanism, it is important to feed the sheet without jamming under any conditions. To avoid sheet jamming, first we need to predict the behavior of the sheet exactly. The nonlinear theory of the dynamic elastica has often been used to a nonlinear dynamic deflection model. In this paper, the governing equation is derived and simulated by the finite difference method. The analysis has to include aerodynamic effect for more exact behavior analysis. For verification of the numerical simulation, the experiments were performed using high-speed camera and feeding mechanism. The experimental results show good agreement with the numerical simulations.

• Journal of Biosystems Engineering
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• v.43 no.2
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• pp.119-127
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• 2018

Purpose: Fermented feedstuffs have been found to improve productivity, reduce manure odor, and increase immunity. However, because there is not a commercialized pelletizing system for fermented total mixed ration (TMR) for pig feeding in Korea, a pelletizing system using TMR fermented feed was developed. Methods: The particle size, density, and volumetric density of the TMR feeds used in the test were measured. The pellet durability index (PDI, %) value of the pelletized TMR feed based on its moisture content, and the amount of pellet production based on the rotation speed of the compression roller were measured. Results: The test materials, TMR1 and TMR2, were approximately compressed to 387 kg/m3 with 18.2% (w.b.) and 544 kg/m3 with 22.2% (w.b.), respectively. Throughout this pellet molding test, the moisture content from 15 to 20% (w.b.) of mixture feedstuffs, including fermented forage, could be used for pellet molding. Based on the results, a small-scale pellet molding system of fermented TMR was designed and manufactured for pig farms. As rotation speed increased, the throughput increased, whereas the moisture content decreased by approximately 2% (w.b.) because of pellet molding. The best yield of pellets with 94.2% PDI was of 536 kg/h at 135 rpm rotation speed. Conclusions: Although the throughput of the prototype increased as the rotation speed increased, it was difficult to operate because of the greater noise and the lower PDI (%) at the higher rotation speed of the pellet molding rotor. It was found that the best production of pellets using the prototype was 536 kg/h having a PDI of 94.2% or more at a rotation speed of 135 rpm.