Coil Bar Research Articles

Design and Implementation of Spring Cable Shaping Method Based on Fuzzy Control

In order to improve the production efficiency and elastic quality of spring cable, and meet the market demand of automatic mass production, based on the market research and experimental analysis of common spring cable shaping methods, a rapid shaping method of coil bar current heating spring cable is innovatively proposed. After the spring cable is wound on the coil bar once, the coil bar is directly heated to realize the spring wire temperature rising and setting. The process temperature is input from the man-machine interface, and the temperature control is based on a fuzzy algorithm, which is automatically adjusted by PLC. The experimental results show that, compared with the traditional sizing method, the current heating method proposed in this paper can greatly shorten the product sizing time and has good sizing effect, which can well meet the market requirement of high-quality mass production of spring cable.

Robustness of retrospective weighted control charts

This study considers the construction of control charts when outliers could occur in the data. Simply increasing the width of control limits will make it more difficult to detect an out-of-control signal. This study aims to determine weights for each observation by measuring their respective distances to the average. The study proposes a retrospective weighted average and weighted inter-quartile range (WIQR) control chart based on the normal distribution that accounts for the false alarm rate, special causes, outliers, and a combination of special causes and outliers that might exist within the process. In addition to validating the detection effectiveness of the proposed control charts, this study also compares various average-type and range-type control charts for detecting the outliers and special causes. The proposed control charts show superior detection effectiveness in four tested scenarios compared to other types of control charts. Finally, the study also illustrates the practical application of the control charts for measuring the tensile strength of a deformed bar in coil. [Received 10 February 2014; Revised 21 August 2015; Revised 3 November 2015; Accepted 14 December 2015]

Potential distribution on stress grading of inverter-fed rotating machines under DC biased voltage

The erosion of the stress grading system of converter-fed rotating machines may occur by partial discharges and heat generation. There remain unclear issues in the formation of the potential and temperature distributions along the stress grading system of coils. In this paper, the potential distributions on the stress grading system of the model coil bar are measured under the application of 1 kHz square wave voltages of 10 kV in peak to peak value with/without 5 kV DC biased voltage. It turns out that DC bias voltage has little effect on potential distribution on a coil surface.

철근공사의 코일철근(Bar in Coil) 적용타당성 분석

The proportion of rebar factory manufacturing which has been settled down in Korea recently seems to increase because of their strength such as high decreasing rate of rebar loss and manufacturing accuracy and the external factors such as an increase of downtown projects and a decrease of skilled workers. However, factory manufacturing using straight rebars causes a certain amount of rebar loss and an environmental problem including emissions. To solve these problems, Bar in coil (BIC) has been introduced; however its application is very rare because it has not been produced so far in Korea and manufacturing machines of BIC are very expensive. Also, although BIC`s application is expected to expand due to its strengths, few analysis of its application has been conducted. Therefore in this study, analysis of the BIC`s characteristics and the influence to the rebar manufacturing industry are conducted for the advancement of rebar work as a basic research. To achieve this, inquiry on the present condition of rebar manufacturing industry in Korea is implemented. Then, the validation of BIC`s applications by aspects of industry and the analysis of stakeholders` economical profit and loss are conducted.

Testing of Partial Discharges in Generator Coil Bars with the Help of Calibrated Acoustic Emission Method

Investigation results of acoustic emission signals coming from partial discharges within chosen generator coil bar, in relation to measurement results of apparent charge introduced by partial discharges sources, are presented in the article. Analysis is based on amplitude distributions calculated for acoustic emission signals, ordered at difierent measuring points for difierent values of the supply voltage. In order to assign acoustic emission signal to its advance degree a descriptor named by an acronym ADP (deflned by authors) is calculated for each amplitude distribution. Descriptor families describing acoustic emission signals measured at particular measuring points (for difierent supply voltages) are presented in relation to apparent charge introduced by acoustic emission sources. These families concerning acoustic emission signals, measured at difierent measuring points for identical supply voltage, enable us to locate acoustic emission sources with maximum activity.

Real-time vision-based defect inspection for high-speed steel products

In the steel-making industry, both the quality and quantity of the products are critical. This work presents a real-time defect detection method for high-speed steel bar in coil (BIC). For good performance characteristics, the detection algorithm must be robust to problems associated with the cylindrical shape of BICs, the presence of noise and nonuniform brightness distribution of images, the various types of defects, and so on. Furthermore, because the target speed is very high, it should have a fast processing time. Therefore, a defect detection algorithm should satisfy the two conflicting requirements of reducing the processing time and improving the efficiency of defect detection. This work proposes an effective real-time defect detection algorithm that can satisfy these conditions. Moreover, to reduce cost, the proposed algorithm is implemented on a PC-based real-time defect detection system without a professional digital signal processing (DSP) board. Experimental results show that the proposed algorithm guarantees both real-time processing and accurate detection.

Real-Time Defects Detection Algorithm for High-Speed Steel Bar in Coil

Real-Time Defects Detection Algorithm for High-Speed Steel Bar in Coil

CFM raises the bar in coil coating: New process enhances performance level for electrogalvanizing and prepainting of steel products

CFM raises the bar in coil coating: New process enhances performance level for electrogalvanizing and prepainting of steel products

2098 冷間直線加工高強度異形鉄筋の時効性に関する研究

2098 冷間直線加工高強度異形鉄筋の時効性に関する研究