Resistance Welding Machine Research Articles

Гибридные энергонакопители на основе аккумуляторов и суперконденсаторов для контактной микросварки

Micro resistance welding is an effective way to reliably join small-scale parts. It is widely used in electronics and instrument-making. The important particularities of micro resistance welding are pulse character of energy consumption, non-linear load and special form of current pulses. So, these particularities of welding process cause negative influence on the mains. One of the known ways to avoid it is to use autonomous power supplies for micro resistance welding machines. The important task for building autonomous power supplies is to choose effective energy storages, which have high capacity and small internal resistance, and which are capable to be charged and deliver energy to load very quickly. The solution of this task is seen in using hybrid energy storages, which include accumulators and ultracapacitors. The accumulators are able to provide high energy capacitance and the ultracapacitors are able to provide fast energy delivery. The possibility of application of hybrid energy storages, based on accumulator batteries and ultracapacitors, in micro resistance welding machines is confirmed with computer simulation. Two variants of hybrid energy storages are proposed. These hybrid energy storages have high power and dynamic characteristics, which are sufficient to generate current pulses for welding according to necessary settings.

A method for measuring current in resistance welding

This paper describes a method of current measurement on resistance welding machines which provides for current measurement from the side of the primary winding and pulse duration from the side of the secondary coil of the welding transformer. The method also provides subsequent calculations according to the snap formula. The requirements for the hardware environment of method realization are formed, the results of tests of the experimental specimen are presented.

Using sodium in resistance welding machines

Special features of designing the secondary circuit for resistance welding machines are considered. It is shown that the replacement of aluminium and copper by sodium reduces the mass and cost of the elements of the secondary circuit.

Joining lithium–ion batteries into packs using small-scale resistance spot welding

This paper presents selected problems of small scale resistance spot welding in the construction and usage of lithium–ion batteries. A few ready-made battery packs were examined with the help of reverse engineering. The chemical composition of selected elements was investigated and the joints underwent metallographic examination (both macro- and microscopic). A prototype of a small-scale resistance welding machine was designed for joining batteries into packs and the prototype was tested. A series of sample joints were made and tested for resistance and strength. A similar course of tests was administered to the original pack. It was found that there is a difference between the sample and the original joints in their diameter and levels of resistance. Suggestions are made for further developments in the welding machine's control system to improve the quality of the joints.

Testing and Modeling of Mechanical Parameters in Resistance Welding Machines

The dynamic mechanical responses of resistance welding machine,which is mainly governed by the mechanical parameters of the machine, is very important to the weld quality especially in projection welding when collapse or deformation of work piece occurs. In this paper, a mathematical model for characterizing the dynamic mechanical response of resistance welding machine and a special test set-up called breaking test set-up have been developed. Based on the model and the test results, the mechanical parameters of the machine were identified, including the equivalent mass, the damping coefficient, and the stiffness for both electrode systems.

Research on the Forming Mechanism of Micro-Moulds Based on Laminated Slip-Welding of Ultrathin Stainless Steel Foils

To address the mainstream technology of UV-LIGA combined with micro-electroforming which could only fabricate micro-moulds cavity with vertical wall structure and low depth-to-width ratio, a new forming process based on femtosecond laser combined with laminated slip-welding was proposed in the paper. The forming process was achieved through experiment and it proved that the forming process could be a useful method for the process of micro-moulds with high depth-to-width ratio and complex structures. Work-pieces which were 0Cr18Ni9 stainless steel foils whose thickness was 20μm were welded by resistance welding machine and the microstructure of welding-zone was observed in detail. It was found that the welding-zone was composed of nugget zone, fusion zone and heat affected zone. Through the study of welding mechanism, the cooling rate of nugget zone was 3.99×104K/s and there was dynamic recrystallization in nugget zone. For further study, through the X-ray diffraction (XRD) test, it was found there were no chromium carbide and iron-copper eutectic alloy in nugget zone.

An engineering method of calculating the critical thickness of the discs of the windings of transformers for resistance-welding machines

It is established that resistance welding machine's transformer winding discs thicknesses growth higher than certain critical value causes loss increase and excessive consumption of the winding copper. An analytical calculation of this value is given. Relative units' application in analytic expressions considerably simplifies disc critical thickness calculation.

Automatic Control System of Copper Pipe and Aluminum Pipe Butt Resistance Welding Machine

It becomes a tendency that the application of copper pipe and aluminum pipe welding joints in the field of refrigeration. Based on analysis of Cu-Al pipe welding process, a PLC automatic control system was developed to accurately control the resistance welding machine. The executive mechanism is composed of pneumatic components and controlled by the PLC system to complete the Cu-Al pipe welding process. Under the PLC control, the welding time parameter can be changed, according to the pip size. And the time error of the control system is limited in 0.01s. When the coil temperature rises up to 90°C or the network voltage fluctuates more than ±10%, the control system alarms the operator and the welding process can not be started.

Switching of thyristors in AC voltage relay-pulsed control circuits

Switching processes are considered and their parameters are calculated for two circuits for ac voltage relay-pulsed control. A comparative analysis of these circuits is conducted for their use in a resistance welding machine.

Joining characteristics of β-titanium wires with electrical resistance welding

The goal of this research was to investigate the effects of different conditions for electrical resistance welding of beta-titanium orthodontic wires. Three electrode types were used with a range of power settings on an electrical resistance welding machine to join beta-titanium wires (Resolve, GAC International). Forces that caused bond failures for joined specimens were obtained with tensile loading, and the values were compared using one-way ANOVA and the Tukey test (alpha = 0.05). Metallurgical phases in the joint region were determined by micro-X-ray diffraction. Mean tensile forces for bond failure ranged from 5 to 20 kgf for the eight specimen groups and were dependent on electrode type and power setting. All X-ray diffraction peaks in the joint region were indexed to beta-titanium. Superior bond strength was achieved with the use of wide electrodes. The absence of phases other than beta-titanium in the joint area suggests that the electrical resistance welding may not adversely affect clinically important mechanical properties. Scanning microscope observations indicated that the localized permanent deformation and the formation of an undesirable equiaxed grain structure occurred with the use of narrow electrodes.

Metrological facilities for measuring the current of the secondary circuit of resistance welding machines

Metrological facilities for measuring the current of the secondary circuit of resistance welding machines

Influence of Electrode Pressure and Welding Conditions on the Maximum Tensile Shear Load-Study on the Development of Electrode Force Changeable Lap Resistance Spot Welding Machine and Characteristics of Welds (Report 2)-

Lap resistance spot welding was performed on cold rolled steel (SPCC) with an electrode force changeable lap resistance welding machine the authors had developed. We evaluated the welds by ultrasonic testing (immersion method, C-scope representation) and a tensile shear test, and compared the results for this method with those by the conventional method. It was useful to apply the ultrasonic testing to evaluate the welds. Usually plug-type fracture was observed in the tensile shear test and the maximum tensile shear load was larger than those estimated using the value of the minimum strength (290 MPa) of SPCC specified by the Japanese Industrial Standard, though some specimens fractured along the weld interface. Regression analysis was performed by setting the maximum tensile shear load as a dependent variable, and setting the initial electrode force, the welding current, the initial electrode force timing and the latter electrode force as independent variables. The result shows that only the initial electrode force and the welding current were significant. The maximum tensile shear strength increased by increasing the welding current and decreasing the initial electrode force. It was made clear that we could obtain better spot welds by using the process we developed than the conventional spot welds.

溶接電源の正しい選択と据えつけ方 抵抗溶接機

溶接電源の正しい選択と据えつけ方 抵抗溶接機

Mechanical properties of resistance (especially spot and projection) welding machines∗

Mechanical properties of resistance (especially spot and projection) welding machines∗

European Developments in Resistance Welding

The United States has played and still plays the leading role in the development of the resistance welding technique. Spot welding of both structural steel in heavy construction and light alloys are mentioned in the early thirties. The first mercury-rectifier controlled resistance welding machine was shown in Europe about the same time. Control techniques have developed along the same lines as in the United States. Some unusual techniques of non-destructive testing, presently being developed in Europe, are outlined. Details of a flash-butt welding machine, said to be the world's biggest, are given. The cooperation of welding societies and research bodies within Europe and the European contribution to the International Institute of Welding are explained.

3相低周波式抵抗熔接電流の測定について

At present the most difficult problem in the three phase frequency converter type resistance welding machine is secondary current measurement.In this paper we discussed some questions on next two typical measuring methods, which seem to be most useful up to date, series resistance voltage drop method and toroidal coil method.Results obtained are as follows ;(1) For series resistance use, the height of pulsating component measured is higher than actual current. For toroidal coil use, (2) the influence of coupling position between welder lower arm and coil does not appear.(3) current magnitude is measured smaller than actual current value, and the errer is approximately proportional to welding time.

Design of transformers for resistance welding machines

A DISCUSSION OF transformer design and characteristics would have been a rather controversial subject 15 years ago, as in those days the name-plate kilovolt-ampere rating of the transformer meant little other than that it was printed in English. Oftentimes in the early years, if the power companies limited the maximum connected kilovolt-amperes for a particular installation, a machine was supplied with this name-plate kilovolt-ampere rating, regardless of the actual load drawn by the machine. It was rather common practice to use excessive amounts of copper in the secondaries and a very small amount of primary copper. There was no logical reason for this except perhaps that the secondaries could be seen while the primaries were covered. In general, confusion existed, no standard ratings were used, and it was extremely difficult for power companies or users to determine actual ratings and demand figures. This condition of course could not continue and several years ago the AIEE and the Resistance Welder Manufacturers' Association (RWMA) drew up specifications for the standardization of welding transformer ratings.

Design of transformers for resistance welding machines

A discussion of transformer design and characteristics would have been a rather controversial subject 15 years ago, as in those days the name-plate kilovolt-ampere rating of the transformer meant little other than that it was printed in English. Oftentimes in the early years, if the power companies limited the maximum connected kilovolt-amperes for a particular installation, a machine was supplied with this name-plate kilovolt-ampere rating, regardless of the actual load drawn by the machine. It was rather common practice to use excessive amounts of copper in the secondaries, and a very small amount of primary copper. There was no logical reason for this except perhaps that the secondaries could be seen, while the primaries were covered. In general, confusion existed, no standard ratings were used, and it was extremely difficult for power companies or users to determine actual ratings and demand figures. Of course, this condition could not continue, and several years ago the AIEE and the Resistance Welder Manufacturers' Association (RWMA) drew up specifications for the standardization of welding-transformer ratings.

ON A THREE PHASE RESISTANCE WELDING MACHINE PMM 4TC-300-60 ROLLSPOT AND SEAM WELDER AND ITS OPERATIONAL RESULTS

The three phase resistance welding machine recently imported by The Nippon Aluminium Mfg. Co., Ltd. from Soiaky Bros. Inc. is called PMM 4TC-300-60 rollspot and seam welder (300KVA at 50% duty cycle, short circuit secondary current, max. 130, 000 Amps.) and guranteed to satisfy U. S. Army-Navy Specification AN-W-30.We are going to report on sequence of various control panels, comparison between 3 phase and single phase welder, weling capacity of this welder, parameters of controls for spot welding two equal thickness of aluminum alloys and mild steel or 18-8 stainless steel, and the joint efficiency of seam-welded joints by this welder compared with that by a Japan made seam welder.

Selection of Fuses for Resistance Welding Machines

This paper covers: 1. An analysis of available fuse data with special reference to the data's applicability for resistance welding machines. 2. A proposed method of analysis of fuse characteristics. 3. Discussion of these fuse characteristics. 4. Use of these characteristics in welding applications. 5. The application of fuses as it is practiced in the industry today. The data that are presented are based only on 250-volt fuses. Six-hundred-volt fuses were checked and found to have characteristics substantially the same as 250-volt fuses. Consequently, any system of rating of 250-volt fuses applies also to other fuses.