• 한국생산제조학회지
• /
• 제7권5호
• /
• pp.134-139
• /
• 1998

There have been so manu study in the ultra-precision mirror finishing. Already Using system of experiments extract factors effecting surface roughness and find optimal machining conditions in 40${\mu}{\textrm}{m}$, 30${\mu}{\textrm}{m}$, 15${\mu}{\textrm}{m}$ abrasive film. So in this study, Using Abrasive film of 12~3${\mu}{\textrm}{m}$ extract factors effecting surface roughness and results are follows; Factor A(film feed) in 12${\mu}{\textrm}{m}$ and 5${\mu}{\textrm}{m}$ abrasive film, Factor A(film feed) and B(applied force) in 9${\mu}{\textrm}{m}$ abrasive film, Factor C(grinding speed) in 3${\mu}{\textrm}{m}$ abrasive film are main factor effecting surface roughness.

• 한국생산제조학회지
• /
• 제21권6호
• /
• pp.871-877
• /
• 2012

New materials widely used for automobile related industry, aircraft, space development area are mostly high hardness materials. The hardness value of some hardened materials is over HRC45 and machining of this hardened materials is called as hard turning. Hard turning has its advantage on processing flexibility, cycle time and tool cost reduction. Also this process obtains high efficiency in processing and precise surface roughness through application of the CBN tools. In hard turning process with CBN tool, surface integrity is the important factor for considering the design of machine part and component under high stress and load conditions. A purpose of this study is to analyze optimal condition in hard turning process of AISI 52100 steel (HRC62) with high CBN and low CBN on turning characteristics, tool wear mechanism comparison and surface integrity.

• 한국정밀공학회지
• /
• 제28권4호
• /
• pp.416-421
• /
• 2011

Recently there has been increase in need for high precision and high speed machining due to economic and environmental reasons. It is a very important issue that determines the optimal preload that is to be applied to bearings in order to satisfy the performance required in bearings according to its operation conditions. This study introduces a variable preload device that can automatically adjust the preload applied in a machine tool spindle using centrifugal force as opposed in existing rubber instrument. In this study, the deformation of the rubber device by the centrifugal force is analyzed and it is discussed that the proposed device can be worked properly through changes of the collar density.

• 한국기계가공학회지
• /
• 제17권1호
• /
• pp.69-75
• /
• 2018

This study aims to provide ways to achieve structural improvements of the internal flow path of the discharge plenum of a swash plate piston pump valve block vulnerable to cracks. This paper corresponds to Part I, which consists of a structural analysis of the valve block, identification of the stress distribution and stress raisers, and creation of a Simple Model of the valve block to review the optimal design. Structural analysis was performed by assigning the same conditions as those found in the valve block model, and the design was reviewed by examining three different design improvement plans for the internal flow path of the discharge plenum.

• 한국기계가공학회지
• /
• 제9권1호
• /
• pp.19-24
• /
• 2010

The noise of an running industrial fan or blower depends on the type of a fan, the machining accuracy and assembled conditions of each element, and buffs. Many studies have been carried out to reduce the noise through silencer in blower. In this study, 3 types of buffs which have different hole are employed in pipe of blower to study the influence the number and arrangement of buffs on the noise reduction at inlet and outlet in pipe. Commercial engineering software ANSYS was employed to analyze the characteristics and reduction ratio of pressure. Experimental results shows that optimal one can reduce the reduction ratio of noise as much as 16 percents in the laboratory. Good agreement was found between the analysed ratio of noise reduction and those obtained from the experiments.

• 한국기계가공학회지
• /
• 제7권1호
• /
• pp.22-31
• /
• 2008

The operating window method is a novel approach in quality improvement. But it has not received deserved attention in academic research. If a critical factor for competing failure modes can be identified, the probability of failure can be reduced by widening the operating window of this factor. Traditional SN ratio for the operating window advocated by Taguchi has a critical shortcoming, which has been derived under the assumption that failure rates are determined by the operating window factor only. A new metric for robustness is given for the operating window method, which has relaxed the restrictive assumption of Taguchi's SN ratio. And procedures for determining optimal conditions based on the new metric is presented. The effectiveness of the proposed approach over the traditional practice is tested with the aid of a wave soldering process.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 1996년도 춘계학술대회 논문집
• /
• pp.124-131
• /
• 1996

The use of small hemispherical high-speed precision bearing has increased drastically these days in the field of computer disk driver, highteech devices as well as communication and electronic device drivers. It was suggested that the new polishing process adopting the diamond grinding wheel and polishing tool instead of multi stage lapping processes, which enables the mass production of the bearing by reduction of polishing time. Polishing mechanism was analysed and the results were applied to the design and manufacturing of the polishing system. Experiments for selection of optimal polishing conditions were carried out using the polishing system.

• 한국생산제조학회지
• /
• 제18권5호
• /
• pp.443-448
• /
• 2009

The roughness models have developed to describe the grinding behaviour and predict the final quality of workpiece. The model forms of the plunge grinding process are generally established with initial and steady state model form in accordance with the accumulated metal removal. The steady state roughness model form are based on the grinding condition and specific parameters are used to show the influence of it according to the grinding process such as the equivalent chip thickness and accumulated metal removal. However, the models have been developed in past are not considered the effect of changing the grinding conditions in the same batch. In this paper, the roughness model form to consider the effect of changing grinding condition is proposed and the performance of proposed model is evaluated based on the experimental results.

• 한국정밀공학회지
• /
• 제25권5호
• /
• pp.43-51
• /
• 2008

Generally a plastic injection molding is a manufacturing process used to produce the various parts of complicated shape at low cost. The objective of this study is to implement a new plastic injection molding process with inserted Aluminum sheet, which is highly durable, light and luminous. Moldflow analysis and simulation of plastic injection molding process with inserted Aluminum sheet were carried out in order to predict optimal molding operation conditions. The experimental results in the Al-inserted plastic injection molding process were compared with the simulation results by Moldflow. Durability and reliability test results for trial products were satisfied to adopt the Al-inserted plastic injection molding process developed as manufacturing of automobile interior parts.

• 한국기계가공학회지
• /
• 제18권10호
• /
• pp.34-41
• /
• 2019

Warpage and weld line are two major cosmetic defects in the injection molding process. These defects are very sensitive to uncontrollable parameters within the process. The optimization of the design variables can be treated with the use of robust designs. Therefore, in order to minimize the warpage and weld line, a special design method to diminish defects is required. In this study, a new robust design method using designer preference to achieve the optimal robust design conditions in the injection molding process is proposed. The effectiveness of the proposed method is shown with an example of the part of warpage and weld line.