• Journal of Korean Society of Environmental Engineers
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• v.28 no.10
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• pp.1016-1023
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• 2006

The water content of dewatered cake produced from belt press dewatering equipment was about 75 wt% which was some high to handle it, so the equipment contained a limit at the economical and environmental aspect. The thermal dewatering equipment built as an alternative to overcome several problems was set up at the sludge treatment field and estimated some feasibility as comparison with the dewatering performance of belt press. First, dewatering properties of waterworks sludge was analyzed by monthly. The sludge of a water shortage season contained a high organic content which led to be difficult to dewater the cake, the other side the sludge of rainwater season was ease to dewater because of low organic content. According to the results to analysis the water content of dewatered cake produced from two equipments on the base of the seasonal dewatering properties, the water content of dewatered cake produced from thermal dewatering for sludge of water shortage season was $41.6{\sim}48.3$ wt% and $71{\sim}84$ wt% from belt press. In the case of rainwater season, the water content of dewatered cake produced from thermal dewatering was $34{\sim}37.7$ wt% and $57{\sim}70$ wt% from belt press. It was understood that thereduction of water content of cake by thermal dewatering was larger than belt press. The economical aspect for two equipments was evaluated on considering the reduction of cake treatment amount as the decrease of water content of cake. When putting the cost index of thermal dewatering into 100, belt press was 121. This meant that thermal dewater was more economical than belt press by about 20% in the side of construction and operation. In conclusion, thermal dewatering equipment was estimated by producing the low water content dewatered cake as well as being operated with low coat.

• 연구논문집
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• s.22
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• pp.65-74
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• 1992

This paper aims at calculating optimum design dimensions to minimize the weight satisfied strain and stress intensity of the frame while loading maximum weight into a mechanical press in the static condition. Analysis of the frame was carried out by using the FEM, then the optimum condition was obtained by using these data. As modeling in the finite element analysis has great impact on the reliablity of analysis results, the analyzed object was selected a 150-ton mechanical press of J Company, the part little affected to structural rigidity was simplified, the load condition was considered in the only maximum load, the boundary condition was used by giving symmetric displacement due to symmetric boundary condition, the finite element was applied a linear membrane element. An intermediate processor program applied the normal ANSYS to analyze finite elements was developed, and the design sensitivity was calculated. This program was applied to the optimum design.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.7 no.2
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• pp.66-71
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• 2008

The data of the deformation and the stress according to time are studied at upper model of press and lower model of the blanking plate applied by press with the width, length and height of 0.4 m and 0.6 m respectively. The press is pushing downward on the plate fixed at the lower floor. These data are compared and investigated through this study. By using these results, there is the maximum deformation at 4 corners in the lower plate model of aluminium alloy fixed at lower floor. This deformation incase of elapsed time of 0.6 second becomes 4 times as much as in case of elapsed time of 0.2 second. The quantity of deformation at the lower plate model becomes more than at the upper press model to the extent of 10%. At the lower plate model of aluminium alloy, there is the maximum Von-Mises equivalent stress at 4 corners and both sides of middle area on the lower plate model of aluminium alloy. This stress in case of elapsed time of 0.6 second becomes 6 times as much as in case of elapsed time of 0.2 second. The Von-Mises equivalent stress of lower plate model becomes 2 times as much as that of upper press mode.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3
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• pp.356-363
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• 2013

Mechanical molding press which is used for transformation process during semiconductor manufacturing process has structural deformations by pressure. If these deformations have over limit range, life of the press itself can be reduced and it will be exerted on a bad effect for quality of the semiconductor. In this research, the main plates and links of a press are analyzed in relation to the structural deformations caused by pressure excluding thermal deformations. After modifying the modeling, the analysis is performed again to determine optimal design of the press, and this design is introduced to ensure that most of the stresses on the main plates are within safe allowable limits. As a result, an optimal design method for the structure is investigated to produce the desired pressure even when the size of the main structure is minimized.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.1
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• pp.190-198
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• 1989

Some Developments in computer aided procedures for cold forging process and tool design of rotationally symmetric cup shape parts are described. The developed system enables appropriate forging sequence to be determined automatically, together with details of corresponding preform, die and punch design. The computer program developed is interactive and written in BASIC. This system not only assist the heavy work of designers but greatly shorten the time of design.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.7
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• pp.64-71
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• 2008

Burr generated on plate holder should be removed through additional process, because it has an influence on the function of automotive seat recliner. The process layout to perform simultaneously embossing and half blanking of plate holder has been developed in this study in order to minimize the influence of burr formation. The optimal process condition to satisfy the required dimensional accuracy of plate holder has been determined using Taguchi method and finite element analysis. It has been shown from experimental results that the proposed method is decidedly superior to the previous FCF method from the aspect of sheared surface, roll-over, flatness and burr height.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.6
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• pp.52-59
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• 2013

In this study, strength and durability are investigated using structural and vibration analyses on models 1 and 2 of a press in common use. Model 1 has a structure in which a punch is applied from the upper part to the lower part; however, model 2 a structure in which a punch is applied from the lower part to the upper part. Maximum displacements of models 1 and 2 are 0.018184 mm and 0.025498 mm, respectively. Maximum equivalent stresses of models 1 and 2 are 14.144 MPa and 18.58 MPa respectively. Maximum displacements are shown for the punches of both models; model 1 has less deformation than model 2. Model 1 has more durability than model 2, as determined by an investigation of the structural strength. Using natural frequency analysis, model 1 was found to have maximum deformation in the upper part of punch. Mode1 2 has its maximum deformation in the column part of the body and the upper part of the fixed pin. Using harmonic stress analysis, the maximum deformations were found on the punch part and column part of the body in the cases of models 1 and 2, respectively. As the maximum total deformation and equivalent stress in the case of model 2 are shown to become 40 times those values of model 1, the vibration durability of model 2 can be seen to be weaker than that of model 1.

• Journal of Power System Engineering
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• v.17 no.1
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• pp.97-103
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• 2013

Press machine has advantages over other manufacturing machine which can produce large quantities of products in short time so it is widely used in lots of industrial sectors. To obtain the vehicle's weight lightening and rigidity of the body-frame by applying 'Hot stamping' technique is increasing in the automotive field. In this paper, to improve the irregular vibration arose by 800Ton hot stamping press, the research was continued. Bed, slide and main frame are the key part of working precision, so perform structural analysis was conducted, and based on the analyzing results, structural changes were done on the parts where structural deformation occurred.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.7
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• pp.55-63
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• 2008

Fine blanking is a process of press shearing which makes it possible to produce the thick sheet metal of the finished surface and the close dimensional accuracy over the whole material thickness in the single blanking operation. In this paper, a plate holder of automotive seat recliner is manufactured by FCF(Flow Control Forming) method using the conventional mechanical press instead of the fine blanking press. Main processes for manufacturing of the plate holder by FCF method are embossing, half blanking and trimming processes. Optimal clearance, stripper force and counter force to increase the dimensional accuracy of the plate holder have been investigated by FE-analysis. As a result of FE-analysis, the clearance for both embossing and half blanking processes was -2%t and the forces of stripper and counter were 25ton and 15ton, respectively. After manufacturing the plate holder by FCF method, the measured dimensional characteristics have been compared with the required specifications as the final product. Although the dimensional accuracy of the plate holder manufactured by FCF method was a little inferior to that by fine blanking process, it was satisfactory in a general sense.

• Transactions of Materials Processing
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• v.29 no.6
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• pp.362-369
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• 2020

In this study, elastoplastic finite element analysis with multi-body treatment was used to elucidate the mechanical phenomena occurring from pre-stressing of die-system. A finite element analysis model with detailed conditions is proposed. The effects of die pre-stressing slope on the circumferential components of the pre-stressed die inserts were evaluated. The role of tight fitting between the supporter and die case was also emphasized because it has a significant effect on the undesirable change in the target slope of machined inner surface of the die case around the die insert. The two mechanical problems include the one between die-insert and die case and the other between supporter and die case, and their correlation is minimized to establish the optimum design in the die structural design stage because it cannot be quantitatively controlled owing to various factors affecting the die structural behavior during die pre-stressing.