Calculation of the Energy of Capacitors for a Spot Welding Apparatus by a Numerical Method

This article provides information on the development of an adjustable spot welder implemented on the basis of the capacitor principle without a transformer. Also the scientific work considers the calculation of the energy of the capacitors for a spot welding apparatus using modern methods of numerical simulation and programming. The method of calculation is given, as well as a mathematical solution tool. The calculation results are compared with the experiment. Based on the data obtained, according to the results of calculations, work was carried out on a prototype, the result of which was an adjustable spot welder. It allows you to accurately and quickly weld nickel plates to lithium cells, creating full-fledged batteries from them, which are widely used in modern technology, including promising vehicles. The presence of sensors and a screen allows the operator to control the charging process and the direct operation of the unit, which simplifies the use of the device.

A study on spot welding quality judgment based on hidden Markov model

Aiming at the influencing factors of spot welding quality and the shortcomings of the method of judging the spot welding quality based on the monitoring waveform curves: it is impossible to deeply analyze the differences between the corresponding monitoring waveform curves and spot welding qualities. In this study, according to the monitoring waveform curves of the welding current, inter-electrode voltage, electrode pressure and other signals when the spot welder executes the process parameters, by establishing the HMM model to realize the judgment of spot welding quality. The proposed method was also applied to the experiments of spot welding quality judgment for verifying the algorithm effectiveness.

A Novel Design of Automatic Welding System for White Watermarks

Watermarks, which are often used as security features of banknotes to prevent counterfeiting, are made onto the banknote paper using the dandy roll that is a roller of copper net with white watermarks accurately welded on it. The positioning accuracy of the white watermarks on the copper net is critical. However, the current technologies are inefficient, inaccurate and/or expensive. Therefore, in this paper a novel design of automatic system for white watermark is proposed. It is realized by thorough analysis of the welding procedure of the white watermark, design of a novel mechanical structure for the automatic feeding and accurate positioning of the white watermark to its welding position on the copper net and integration with the available spot welder. Compared with the current technologies, the proposed design could greatly improve the efficiency and accuracy for welding the white watermarks, and its total cost is low. Therefore, the proposed design could be adopted in the banknote printing industry to realize the automatic welding of the white watermarks.

Characteristics of Electrode Displacement and Force in Resistance Spot Welding

The behaviors of electrode displacement and force during spot welding were studied. Tests were conducted on a 170KVA MFDC spot welder. Data were collected via a multi-channel high speed data acquisition system, and were analyzed with MATLAB. Behaviors of 5182 aluminium and mild steel in spot welding were compared. Results showed that nugget expansion rate did not reach zero for aluminium as it did for mild steel as nugget grew to a certain size. An electrode force peak was observed and was believed relevant to sufficient nugget size.