• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.3
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• pp.877-885
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• 1995

Cold forging die for metal scissor is made by electric discharge machine. The impression of female die is made by electric discharge machine, the heat treatment is applied, and the impression is polished. When we forge goods by using this kind of die, the abrasion is severe and the crack occurs after forging about 240 strokes. Because the die should be frequently produced in the case, the cost rises, the work is delayed, and the precesion of goods is not good. Therefore, the electric discharge machine was not used in this study. Main die was produced by making hob, installing the hob to cold hobbing press, indenting the die material, and cold hobbing the impression. The die life was increased to 5,000-6,000 strokes in this case. In the future study, the die life will be increased to 10,000 strokes by changing the following : (1) the pre-treatment of slug, (2) the structure of die block, (3) the heat treatment of die material

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.363-364
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• 2012

• Journal of the Korea Convergence Society
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• v.2 no.2
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• pp.27-34
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• 2011

This study is making a product for the development of one process worm wheel of making a shape for gear for worm wheel without hobbing manufacturing process. Because of removing a hobbing process, plastic worm wheel for increased productivity and equivalent quality is produced in the result. As the result, this product is selling to Hyundai Mobis, Mando, TRW, KOYO/NSK/Showa(Japan), Delphai(America). The core technology and different strategy are as follows. The technology protection for molding of worm whee is currently patent process "Molding process of helical gear(No. 10-2008-0105908). Further patent procedure for "molding system for positioning decision of inserting boss is currently prepared. As gear molding procedure in hobbing machine without gear machining procedure, most of all, core development technology which is making a gear tooth is main topic. So that, in case of currently developed worm wheel, because core and mold base are not developed in the first procedure, gear is machining in hobbing M/C as the second procedure. In the later, patent for mold base structure will be prepared in this study results.

• IE interfaces
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• v.5 no.2
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• pp.87-100
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• 1992

This paper presents FMC prototypes developed to propagate manufacuting automation for small and medium sized enterprises in Korea. The system consists of two cells used to machine oil pump drive gears, turing cell and hobbing cell. Characteristics and processes of the fears are anaylzed for the cell design. The system configuration and functions of individual component machines are described. Furthermore, the developed system is compared with the current manual system in terms of manpower and cost reduction and productivity increase.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.1
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• pp.20-25
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• 2016

Recently, the requirements for high precision and efficiency machining are gradually increased to raise international competitiveness at the industrial fields of automotive and gears. This trend had made effects on the industrial fields in Korea and which needs further studying of high accuracy and efficiency machining. This study is to investigate the effects of Jig type chuck for roundness improvement in CNC turning machining of high stage speed gear. After hobbing machining, Dimensional change before and after heat treatment was very largely generated. In order to solve this problem was to develop a jig type chuck. After the heat treatment, the operation of the chuck which was the most distinguished equipment among Jig type chuck(0.006mm), Scroll type chuck(0.05mm) and Bolt type chuck(0.04mm). Therefore, Jig type chuck was satisfied the requirement from the actual field(0.02mm).

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.3
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• pp.56-62
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• 2022

The tank engine clutch flange constitutes a tank on which the engine and transmission of the tank are mounted. The engine clutch flange is fabricated using a difficult-to-cut material that exhibits high strength and hardness. It is difficult to process and requires considerable processing expertise. In addition, the engine clutch flange for the tank requires high machining precision because it is a system in which the connection is detachable. Because it requires high processing precision, the measurement of products equally important as processing. However, productivity is low owing to the significant amount of time required to measure each product using a three-dimensional coordinate measuring machine. Hence, this study is conducted to improve the productivity of the female tank engine clutch flange. Dedicated hobs and jigs are designed and manufactured to convert the existing end-mill cutting processing into hobbing cutting processing. An engine clutch for the tanks is manufactured using the manufactured dedicated hob and jig, and the shortening time is verified by measuring the processing time. In addition, a jig for inspection is designed and manufactured to measure the precision of the product. To verify the inspected product, the product precision is measured using a contact-type three-dimensional coordinate measuring machine and a surface roughness measuring instrument. The study confirmed that the productivity of the engine clutch flange product for tanks can be improved by simplifying the process, reducing the processing time, and simplifying product inspection.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.10a
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• pp.242-247
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• 1998

The conventional closed-die forging processes had been applied to forging of the spur gears. But this type process requires high pressure. The commercial finite element analysis code ANSYS for the stress and elastic deformation of non-axisymmetric die was adopted in this study. In the non-axisymmetric die such as gear forging, maximum stresses were imposed on the tip of the gear tooth. When the stress exceeds yield strength of insert die, many approaches were attemped to prevent the die failure. Good shaped products are forged successfully. This type process could by used as an advanced technique to replace conventional hobbing process of gear.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.5
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• pp.54-59
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• 2012

This study dealt with effect of the grinding in SCM420H planetary gears. The hardness, tooth profile, lead and roughness of the gear surface can be improved by grinding process. Therein, the grinding techniques are widely used especially as one of the physical surface improvement methods. As the results, the gear grinding process reduced vibration and noise, and increased the life of the gear. And the gear grinding improved the surface of gear tooth in a short time and low cost, thus, it is a very important process in manufacturing industry. But nowadays, it is hard to find the detail information of gear grinding process. The test piece is a planetary gear which is used in the industrial machine. The manufacture process of the test piece contains hobbing, shaving, carburizing and grinding. This study investigated the effect of the grinding process to the physiognomy and the fatigue strength of test piece which was made by SCM420H.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.2
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• pp.100-107
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• 2014

Currently, there are many power transmission devices, including gears, friction wheels, chains, and belts. Because the power transmission of gears is most certainin these devices, gears are widely used in different power transmission fields and environments. In accordance with the gear shape, gears can be classified as cylindrical gears and conical gears. A cylindrical gear, which provides a means of power transmission under parallel axis and skewed axis conditions, contains a spur gear, a helical gear and a worm gear. A conical gear, which can be used on a skewed axis as well as parallel and crossed axes, includes a bevel gear(e.g., straight bevel, spiral bevel, hypoid gear) and a conical involute gear(or a bevel oid gear). In this paper, a conical involute gear which utilizes the fabrication method of other involute gears such as spur and helical gears using a CNC hobbing machine is discussed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.471-477
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• 2012

SCM420 steel tempered after performing gear hove PACVD carbide coating on the surface after the cutting surface hardness was high. Difficult-to-cut, without coating is classified as mild as large, including materials like mild, high strength that improves tool life and productivity have limited availability. Drive to improve it in the TiCN-coated carbide call for war to the finish coating on cutting a hob skiving good workability, tool wear less, 2.5-fold increase in tool life results were obtained. Experiments using CNC Skiving hobbing machine with wet cutting conditions, cutting speed and feed rate to apply a variety of the tool wear and surface roughness data were obtained. Results from condition 2 (V = 200m/min F = 0.7mm/rev) cutting speed feed mark the cutting surface microstructure and surface roughness Rmax $4.7{\mu}m$(Ra $1.19{\mu}m$) of the data was obtained.