EuroWire November 2023

Technology News

New surface fault detection algorithms for monitoring systems

and requires relatively low investment levels. Resistance welding is relatively straightforward – the operator simply pushes down the battery tab with a weld head, which is operated by a cable or footswitch, and starts the weld. The equipment can easily measure the welding process, including electrical parameters such as current, voltage, resistance and power, and mechanical parameters like force, height and movement of electrodes during welding. Laser welding is a non-contact process with a fast cycle time. The laser weld is formed as the intense laser light rapidly heats the material – typically calculated in milliseconds. Laser welders can join a wide range of steels, nickel alloys, titanium, aluminium and copper, and are suitable for applications where the components would deform under mechanical pressure. With laser welding, a larger connection area is possible, which lowers electrical resistance from the battery to the battery tab. One company that specialises in manu facturing batteries for passenger vehicles achieved 21 per cent more starting ener gy from a battery pack by switching from resistance to laser welding. profiles. Various models are available with between four and eight laser/ camera modules and different measuring field sizes to cover product dimensions from 5 to 720mm (0.2" to 28.3"). Product temperatures up to 1,200°C can be handled. including width, height, angle, radius and other geometric characteristics, are displayed in an operator-friendly graphical user interface. Changes in speed and twist within normal limits have no influence on the measurement precision. Benefits of the systems include 100 per cent inspection in real time, reduced start-up time, increased repeatability and precision of the end product, improved process control and reduced scrap. Process problems are detected at an early stage. All relevant dimensions,

Battery experienced in recent years, owing to power train electrification, cordless power tools, stationary energy storage products and electric vehicles. Tab-to-terminal connection is one of the key battery pack welding applications. Manufacturers need equipment, systems and automated lines that meet quality and production requirements for these products. The critical process step for battery pack welding is joining the individual batteries together using a collector plate, which consists of tabs for the individual cells to be welded to both the positive and negative terminals. involves considerations that include the materials to be joined, joint geometry, weld access, cycle time and budget, as well as manufacturing flow and production requirements. Several alternatives are available for battery tab to connector welding, such as resistance welding, laser welding, micro-arc welding (also known as pulse-arc) and ultrasonic welding. Resistance welding is the traditional welding technology used for battery pack manufacturing. The reliable tech- nology has been used for many years significant growth Selecting the appropriate technology battery pack welding Owing to the growing demand for surface inspection, Zumbach has launched two new features in the Profilemaster® SPS product range. The latest generation of high-speed cameras allow the acquisition of full product contours at a rate of 2,000 Hz. This allows a stable and reliable measurement even on very high line speeds and challenging products such as rebar. In addition, the new surface fault detection algorithm (software option “SFD”) benefits from the faster cameras, as smaller surface faults can be detected. It is also possible to inspect any kind of complex products, such as rails and profiles. Profilemaster monitoring systems have been used in the harsh environments of rolling mills for hot and cold steel rods, bars and Since their launch, pack manufacturing has

Profilemaster SPS 80 measuring unit

The systems are seamlessly integrated into networks or higher-level systems, and all production data is logged for quality control purposes. Zumbach Electronic AG www.zumbach.com

Choosing the right welding system for battery packs

Micro-arc tungsten inert gas (TIG) welding is an efficient, non-contact method for generating localised heat and is often used for welding conductive battery interconnects. A controlled and easily monitored current is passed into the elements to be welded. The heat is generated by the resistance of the electric arc and its associated current, and is independent of the product conductivity, providing a controlled method of developing localised welding temperatures that are suitable for joining materials up to 0.5mm in thickness onto conductive battery cans. In combination with custom TIG torches that provide electrical return contacts and arc shielding, micro TIG welding units can be configured for manual battery pack assembly or high-volume, multi-spot battery pack assembly with automatic step and repeat torch positioning. Ultrasonic welding was originally used in battery pack applications because of its ability to weld dissimilar metals, for ex ample welding aluminium to copper. As laser welding has also developed this ca pability, it has largely replaced ultrasonic welding for welding dissimilar metals.

Amada Weld Tech GmbH www.amadaweldtech.eu

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November 2023