• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.6
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• pp.52-60
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• 2012

Minimizing the cylinder wear and the consumption rate of cylinder oil in a large two-stroke diesel engine is of great economic importance. A motor-driven cylinder lubricator for Sulzer RT-flex large two-stroke diesel engines developed by authors is in need of modifying the lubricating system to lubricate cylinder parts optimally by an electronically controlled quill device according to changes of engine load and revolution speed. In order to apply the developed accumulating distributor to an integrated cylinder lubricator by the electronically controlled system as the third research stage, the lubricating system is improved in the electronically controlled quill device with a solenoid valve. In this study, the effects of lubricator revolution speed, driving pressure and cylinder back pressure on oil feed rate, maximum discharge and delivery pressures are experimentally investigated by using the integrated cylinder lubricator system with an accumulated distribution by the electronic control. It is found that the oil feed rate of the developed integral cylinder lubricator system is less than that of the motor-driven cylinder lubricator by the electronically controlled quill system equipped with an accumulating distributor because of the decrease of delivery speed by increasing the maximum delivery pressure in the same experimental condition.

• Membrane Journal
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• v.13 no.3
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• pp.174-181
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• 2003

In this study the formation of the particle layer near the membrane surface was observed for the crossflow micro filtration module by the high speed video system. The microfiltration membrane of 0.2 {\mu}m$ nominal pore size and the 0.05 wt% solution of the polyacryl-copolymer particle distributed between 100 and 180 {\mu}m$ were used for the experiment. The feed rates were changed to 0.5, 0.75, 1.0, 1.25 and 1.5 cm/sec while the permeate rates were maintained at $20{\pm}3%$ of the feed rates, respectively, It was observed that the particles were accumulated rapidly on the membrane surface as the feed flow rate increased, but the particles were not accumulated at 0.5 cm/sec, Also, it was confirmed that almost all of the particles in the layer already formed during filtration were removed within 30 seconds as the feed flow rate increased to 1.88 cm/sec.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.7 no.3
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• pp.55-60
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• 2008

Until a recent date, the surface finish generated in turning by the conventional cutting tool is directly related to the feed rate and the size of the tool nose radius. With this tool a large feed rate will give poorer surface finish and a large nose radius will generate a better surface finish. Recently a new concept in the tool design is introduced to achieve a better surface finish at a higher feed rate. This is the wiper tool, which has the portion of nose with infinite radius. This can remove the ridges left when the conventional tool is used. In this study two series of cutting tests with the wiper tool and the conventional tool are carried out under the various cutting conditions of cutting depth, feed rate and cutting speed. The effects of the wiper design and the cutting conditions on the surface roughness resulted are carefully examined and compared.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.5
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• pp.510-515
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• 2012

Feed drive systems are used to position the machine tool components carrying the cutting tool and workpiece to the desired location. Hence, their positioning accuracy and speed determine the quality and productivity of machine tools. In this paper, technical trend of machine tools feed drive systems are analyzed by patent mapping. And this paper suggested future development direction of feed drive systems. The analysis is carried out by using problem solution map (PSM) for the applied patent during January 2000 and December 2009 in Korea, Japan, EU and U.S.A.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.5
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• pp.729-737
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• 2009

This paper introduces the machine tools feed system, which can be optimized the control's performance through simulation and the adjustment of the mechanical components. One method simulates the frequency response of the speed-loop with the design value using the MATLAB application, so that all of the interpolation axis can be equal to the response bandwidth, resulting in a high accuracy rate. The other method sees the mechanical component being adjusted by analyzing the results of various experiments. Lastly, this client's program is able to change the parameters that are related to the FFD, as well as the parameters in the friction compensation of the OPEN-CNC.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.1
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• pp.73-79
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• 2013

In this study, NIMAX material has been processed using the three-dimensional measuring instrument and white light interferometer. they were tested to roundness and surface roughness and results are as follows: As for a cutting characteristic, it indicated that F4 showed a lower result than 2F showed due to the high hardness of the material and showed a good result when spindle rotation speed and tool feed were low. As for the measurement of roundness through 3-Dimensional measuring machine, it indicated that 4F showed a good result like the condition of cutting component and that roundness showed a good result when spindle rotation speed of 1,700 rpm and tool feed speed of 85 mm/min were applied. As for the surface roughness of processing surface, Surface roughness showed better 4F than 2F and conditions of spindle rotation speed 1,700 rpm, tool feed rate 55 mm/min showed good results in the Ra $0.4025{\mu}m$.

• Journal of Biosystems Engineering
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• v.43 no.3
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• pp.185-193
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• 2018

Purpose: The purpose of this study was to analyze the performance factors of a rotary impact-type thresher to develop a sesame and perilla thresher, specifically to analyze the cut length of the stems and the threshing rates based on the relationship between the blade velocity and feeding speed. Methods: The materials were dried within a range of 12.3-13.0% to test the impact cut by bending. The cut lengths of the perilla and sesame stems were categorized in 6 ranges (~7.0, 7.1-10.0, 10.1-13.0, 13.1-16.0, 16.1-20.0, 20.1- (cm)). For testing the cut length and threshing rate, the upward-rotating blade velocity was varied as 11.0 m/s, 13.5 m/s, and 22.3 m/s. Feeding speeds were changed from 0.1 m/s to 2.2 m/s by the inverter connected to the feed motor. The feed rate and threshing rates without cover-casing were evaluated with the factors of thresher testing. Results: The mean cut length of the stem decreased as the blade velocity increased and/or the feeding speed decreased. As the feed rate increased up to 17.5 g/s, the cut length distributions showed no significant difference. The threshing rate was 98.9% for sesame, and flexible according to the blade velocity and feeding speed of the perilla. Conclusion: Feeding material too fast could produce longer cut stem segments, therefore, a feeding speed less than 2.2 m/s is recommended. A blade velocity of 13.5 m/s is preferable for both sesame and perilla with regard to cut length and threshing rate.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.4
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• pp.56-63
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• 1998

The purpose of this is to analyze experimentally how the change of cutting speed have effects on hole over size of cutting hole, surface roughness of workpiece and roundness during the deep hole machining of SM55C with solid BTA drill using BTA drilling system. Conclusion reached is as follows. (1) The diameter was expanded for 25$\mu$m at the first section and then was reduced 0$\mu$m and 15$\mu$m respectively at the 10m and 20m section comparing to the diameter of tool with respect to the variation of cutting length at 70m/min of cutting speed. 0.15mm/rev of feed. (2) It was proved that roughness was below 8.67$\mu$m for the whole section of cutting length. (3) The roundness has been below 12$\mu$m. Regarding the polygon phenomenon, it has been proved that not only uneven best at 70m/min of cutting speed. 0.15mm/rev of feed.

• Food Science and Biotechnology
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• v.16 no.3
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• pp.381-385
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• 2007

The objective of this experiment was to study the influence of feed moisture content on the degree of enzymatic hydrolysis of com starch in a twin screw extruder and the saccharification yield of the dried extrudate. The feed moisture content was set at 25, 30, and 35% and ${\alpha}$-amylase solution was directly injected into the feed section at a barrel temperature of $95^{\circ}C$ and screw speed of 250 rpm. Amyloglucosidase was used for the saccharification of the dried extrudate at a concentration of 0.055%(w/w). Expansion ratio and swelling factor of extrudates decreased with increasing the feed moisture content. Addition of ${\alpha}$-amylase during extrusion process raised reducing sugar content of extrudates which also increased with the feed moisture content. The saccharification yield of dried extrudate was higher for the extrudate with lower feed moisture content.

• Journal of Powder Materials
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• v.10 no.5
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• pp.349-352
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• 2003

This study examined the correlation of various operational factors including reaction temperature and the quantity of reductant and diluent with the characteristics of powder using $K_2$ TaF$_{7}$ as feed materials, Na as a reductant and KCl/KF as a diluent. Also to control the particle size and shape, external supply system developed, it can provide a feed material and a reductant at a fixed quantity and evaluated the characteristics of tantalum powder. When the external supply system was applied instead of the batch type process that charges feed material, reductant and diluent at the same time, it was possible to induce regular reduction reaction between feed material and reductant, which increased the recovery rate and reduced the mixture of impurities. In particular, the application of the external supply system enabled the control of reaction temperature and reaction speed according to the feeding rate of feed material during reduced reaction, and resultantly it enabled the manufacturing of granular-shaped powder with a regular granularity of 2∼3 ${\mu}{\textrm}{m}$ and purity of 99.5%.