• Journal of the Korean Society of Industry Convergence
• /
• v.7 no.4
• /
• pp.419-424
• /
• 2004

In order to increase the efficiency of the sawdust machine, the helical type drums with an oblique cutting condition (3D) were developed. The preexisting drums have an orthogonal cutting condition (2D) considering of a saw cutter and a wood cutting pattern. Unfortunately, the disadvantages of this type drum are the big cutting resistance, the high cost of a cutting power and the extreme occurrence of a vibration. To improve this shortcoming, the helical type drum with an oblique cutting condition was developed. Therefore, this type drum decreased the vibration and the cutting resistance of the sawdust machine, and also improved the productivity of 30% or more and the porosity of the sawdust.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2004.04a
• /
• pp.88-92
• /
• 2004

We developed a helical type drum with an oblique cutting condition for sawdust machine. The existing drum has an orthogonal cutting(2D) condition considering of saw cutter and wood cutting pattern. Additional disadvantage of this type include big cutting resistance, high cost of cutting power and extreme occurrence of vibrations. To improve this shortcoming, we developed a helical type drum with an oblique cutting(3D) condition, therefore, this type drum decreased the vibration and cutting resistance of sawdust machine, and also improved productivity and sawdust porosity.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.18 no.7
• /
• pp.1643-1653
• /
• 1994

To facilitate the manufacturing of dull using CNC grinding machine, the simulation of helical groove machining with given wheel profile and setting condition is necessary. Considering the wheel as a collection of thin disks, the flute configuration is predicted in a cross section perpendicular to the axis and the grinding wheel profile is also predicted to machine the desired helical groove with given setting conditions. Two programs for these processes are developed. Using programs interactively, the helical groove machining process can be predicted more accurately. By clarifying the geometrical relation between the shape of cutting edge and the flute configuration in the cross section which is perpendicular to drill axis, it becomes possible to predict the necessary cross sectional shape of wheel for desired drill cutting edge shape. Some factors for the software are considered concerning prediction of accuracy and computing time.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.10a
• /
• pp.608-611
• /
• 2002

We developed low resistance drum that is used in sawdust machine in this research. The existent drum have two dimensional cutting form(orthogonal cutting) when see cutting pattern of saw cutter and wood, cutting resistance is big and cutting power is cost much, and also, vibration happens extremely. To improve this shortcoming, we developed helical type low cutting resistance drum for three dimensional cutting possible, decreased vibration and cutting resistance of sawdust machine, and improve productivity and sawdust ventilation. Also, a developed drum is mounting in sawdust machine, it is sold by product.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.253-254
• /
• 2006

In this investigation, the authors propose a novel method of Enveloping Helical gear generation by shaping operation and a math model to simulate its manufacturing process. The tooth geometry of the Enveloping Helical Gear is analytically determined by simulating the conjugate motion between the workpiece(Enveloping Helical gear) and cutting tool(shaper cutter) in the generation process. It is expected that such math modeling capability will give engineers an opportunity to correct manufacturing related issues in the design phase and thereby reduce the developing period.

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.6
• /
• pp.40-47
• /
• 1998

Drilling is an indispensable process in manufacturing of the die and mould and the other mechanical parts which needs high dimensional and surface accuracy. In this paper, a new type of drilling method was proposed in order to improve both processing efficiency and accuracy. Specifically, the helical motion using ball end mill tools, instead of normal drilling method, was applied to perform an effective hole machining. In this paper, an theoretical background of the new type of drilling method was established, and the feasibility of the proposed theory was proved by experiments, where proposed drilling process in the paper gave a different machining specification than general method did.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2009.05a
• /
• pp.139-142
• /
• 2009

As important mechanical elements, gears have been used widely in power transferring systems such as automobile transmission and there have been several researches trying to make gear parts with cold or warm forging in order to reduce cost and time required to gear manufacturing process. Although forging processes of spur and bevel gears have been developed as practical level owing to active previous researches in Korea, the manufacturing of helical gear has been still depended on traditional gear cutting processes such as hobbing, deburring and shaving. In order to manufacture helical gears with cold forging process, a research project supported by government has been conducted by Daegu university, KIMS and TAK and this paper deals with effects of back pressure forming technique to cold forging of helical gear as a fundamental research.

• Transactions of Materials Processing
• /
• v.20 no.7
• /
• pp.485-490
• /
• 2011

The application of helical gears in crucial parts of automotive transmissions has been steadily increasing due to their higher power transfer performance compared to spur gears. However, the traditional gear manufacturing methods such as hobbing and deburring require large cycle times with expensive production lines so that there have been intensive efforts trying to manufacture gears via forging processes. Although forging processes for spur and bevel type gears have been developed on the practical level, the manufacturing of helical gears is still dependent on the traditional cutting process. Therefore, this paper seeks to develop a cold forward extrusion process for the helical gear with the pitch diameter of 43.5mm and a helix angle of $18.4^{\circ}$. A forward extrusion process was used due to the relatively small diameter of the target geometry. The material deforming behavior influenced by the die geometry was examined by using CAE analysis. Finally, it was found that the helical gear manufactured by the developed extrusion process satisfied the dimensional accuracy and mechanical characteristics for automotive transmissions.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.3
• /
• pp.445-451
• /
• 2016

General fuse elements of solution for fast acting operation characteristics made using silver or silver alloy, those are not able to dominate cost competition to the advanced global leaders that have not only high technology but competitive price. In this study, the method that compose the fuse elements manufactured solution of fast acting operation characteristics by using precision multi-layer thin film plating and helical cutting process from low-priced copper metal. Furthermore, in order to move rated current line of fuse due to the heat loses, the manufacture construction method of fixed resistor is introduced, and then Ni-P plating layer and Sn plating layer are introduced multiply for controling fine opening time characteristics. So this study can establish the high productive and low-priced production method.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.17 no.4
• /
• pp.95-103
• /
• 2008

Diamond core drills are applied to drill difficult-to-cut materials. This paper proposes basic understanding of ceramic drilling mechanics and characteristics of main factors affecting tool life, tool wear, cutting force, and chipping thickness. In contrast to conventional drilling, the core drilling process make deep grooves on the workpiece. One difficulty of it is the evacuation of chips from the drilled groove. As the drilling depth increases, an increased amount of chips tend to cluster together and clog the groove. Eventually severe wear develops and diamond grits are separated from the drill body. To relieve the clogging problem and to evacuate chips from the groove easily, the helical drilling process is applied for the core drilling process. To analyze drilling characteristics and derive optimal drilling conditions, tool life, tool wear, cutting force, and chipping thickness are quantified through the monitoring system and the Taguchi method. Mathematical models for the tool life and chipping thickness are derived from the response surface method. Optimal drilling database has been constructed through the experimental models.