http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Design of Roll Profile for LM-Guide Block in Horizontal- Vertical Shape Rolling by 3D-EFA
이상진,이경훈,김병민 한국정밀공학회 2015 International Journal of Precision Engineering and Vol.16 No.4
In this paper, the design method for intermediate rolls has been developed to manufacture a linear motion (LM) guide block inhorizontal-vertical (H-V) shape rolling, based on the three-dimensional electric field analysis (3D-EFA). This design method canpredict appropriate cross-sections of roll profile at each pass based on the initial and final shapes. 3D-EFA simulations are performedseparately for the horizontal and vertical rolling passes to obtain roll profiles from equipotential lines. The roll profiles obtained basedon 3D-EFA are simulated by the commercial program Deform 3D, and are the reselected by compensating for the area of the errorfrom the equipotential lines. For convenience of field work and reducing strain concentration of the products, the roll profiles for thefirst and second passes are modified to be flat rolls because the roll profiles are almost rectangular. The effectiveness of the proposeddesign method is verified experimentally using AISI4120 steel for H-V shape rolling. From the experimental results, some over- andunder-filling ate the roll gap are observed for the final pass. However the dimensional errors are within ±0.3 mm, and no crackingor shearing is observed. The proposed design method will improve the efficiency of the design process by reducing time and costs.
Design of Roll Profile for Complex Shape in Shape Rolling by Combined 3D-EFA and BWT
이상진,이경훈,김병민 한국정밀공학회 2015 International Journal of Precision Engineering and Vol.16 No.2
A design method using three-dimensional electric field analysis (3D-EFA) and a backward tracing scheme (BWT) is proposed toimprove the dimensional accuracy for a complex shaped product in shape rolling. A complex door hinge used in the door hinge ofautomobile is taken as a case study. A shape rolling process for this hinge is designed using the proposed method, and a backwardtracing scheme is then applied to find a more suitable roll profile. 3D-EFA is carried out for this purpose, and the roll profiles ateach pass are selected based on the 3D-EFA results using the reduction ratio in the area per pass. In addition, a BWT is applied tothe selected roll profile in order to achieve the dimensions of the required product. The effectiveness of the proposed design methodis verified via FE-simulation and experimentation using plasticine. The results of FE-simulation and experiment show that theproposed design method can be used to effectively design the roll profile for the complex door hinge, leading to an accurate shapeand correct dimensions of the final within an allowable tolerance of ±0.5 mm. Therefore, it can be concluded that the proposed designmethod can be widely used to design roll profiles for producing a precise product.
Study on hot rolling process of the D51 large-diameter threaded bars
김정민,원성빈,김병민 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.4
The objective of this study is to design a hot rolling process for manufacturing large-diameter threaded bars. Threaded bars in which longitudinal ribs are eliminated and transverse ribs play a role as a screw thread can be used as rebars. To design the hot rolling process for the D51 threaded bar, the mean reduction and rolling pass numbers were determined. Calibers (box, oval and round caliber) were designed using the bar rolling theory. Six cases of the peanut caliber were designed by changing the main design parameters, namely caliber width (W) and center groove (R1), to analyze the shape of the threaded bar with respect to the shape of the peanut caliber. Furthermore, the rolling pass schedule including the average effective roll diameter (AERD) and rolling velocity was set. FE-simulation and artificial neural network (ANN) techniques were used to derive a combination of design parameter for the peanut caliber and rolling process of the D51 threaded bar. The rolling experiment was conducted using peanut caliber and rolling process derived by FEsimulation and ANN technique. After measuring cross-sectional area of the core part and transverse rib, the unfilled rate (U.R) of the core and transverse rib were compared and analyzed. The height of the transverse rib and cross-sectional area of the D51 threaded bar formed by rolling experiment was satisfied with the allowance tolerance of ±4 %. These results verified the reliability of the hot rolling process of the D51 threaded bar.