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When e-chains carry

When e-chains carry sensors Thanks to smart plastics, unforeseen machine failures and imminent downtimes are detected in good time for an appropriate maintenance COMPONENTS AND SOFTWARE Intelligent energy chains and chainflex cables can inform you when they need to be replaced. A new series combine sensors with monitoring modules offer predictive maintenance for production. Unforeseen machine failures and imminent downtimes are detected, and appropriate maintenance can be initiated thus avoiding expensive production losses. The digital networking of machines and products makes it possible to continuously collect data about the status of machine components and integrate them with other systems. With preditive maintenance, production processes become simpler and safer, since the constant monitoring of all machines and components means that faults and wear are detected are predicted before failure. As a result, measures for the maintenance and repair of affected parts can be initiated at an early stage. This reduces expensive downtimes demanded by periodic maintenance. The predictive maintenance is therefore an important element within Industry 4.0. Manufacturers in the automotive industry in particular are asking for components for Production 4.0. Only the products are missing. Author: Harald Nehring, authorised officer for e-chainsystems, igus GmbH, Cologne, Germany Avoid machine downtimes: The isense principle At the Hannover Messe, igus presented smart plastics for the first time with the name ‘isense’ - intelligent components for the factory of the future. The isense series include various sensors and monitoring modules in or on the plastic components of the energy chain. Energy chains and the chainflex cables inside them supply energy and data to machines and plants. If these parts suddenly fail, the system would be stopped. An interrupted production run costs the plant operator dearly. It is understandable that plant managers want to prevent such possible failures. This is possible with the wear monitoring isense EC.W(ear): A sensor chip embedded in the opening crossbar of the e-chain continuously measures the status of the gliding e-chain during the travel. If the abrasion is so advanced that the end of the service life of the chain is near, the sensor reports by triggering a signal. A nearby antenna unit receives the data by radio and passes it on to a reader module. This processes the antenna signal and then reports it to the central communication unit called icom. The icom module prepares the data and forwards it to the plant system. In this way, the system operator does not experience a machine failure, but can include the replacement of the worn part into its maintenance process in a timely manner. The fact that there are no longer unforeseen downtimes increases the availability of its system. Conditioning monitoring products for plant safety A few years ago, igus introduced products for predictive maintenance: the PPDS push-pull detection system and the EMA diagnostic tool for identifying a chain-link break. Since then, these components have been gradually further developed and have been WORLD OF INDUSTRIES – INDUSTRIAL AUTOMATION 2/2017

integrated into the new isense family. Now, the unit for wear monitoring (EC.W) can be combined with other conditioning monitoring products - such as the isense break alarm EC.B (formerly EMA) and the pull/push force monitoring EC.P (formerly PPDS). In the case of the pull/push force monitoring, a load cell is installed in the mounting bracket of the e-chain, which monitors the displacement forces at the e-chain. For travel distances of more than 100 metres, the force sensor is integrated into the “floating moving end”, which compensates for lateral tolerances on the moving end of the travel: if a foreign body, for example a tool dropped into the travel path of the chain, blocks the movement of the e-chain, the displacement forces increase. From a defined threshold value, the sensor issues a signal - comparable to the abrasion monitoring - which is received by an evaluation box and is passed on to the icom communication module. If the permissible forces are exceeded, the system switches off the plant before it can cause major damage. Double safe: pull/push force and break monitoring The plant is double fail-proof with the break monitoring system, the isense EC.B module. Mechanical action or overloading of an e-chain can lead to a break in the side links. If this happens, a polymer sensor installed in special separators signals the information of the break to a sensor unit. The maintenance signal alerts the user who can initiate measures to prevent major damage. The replacement of a single damaged chain link is usually done in a few minutes. This prevents the second side part from breaking too, and the system will not come to a standstill due to major damage. Both signals can be read out via a reader module, since a readout unit can process up to four antennas. It would therefore be possible to connect up to four energy chains to one module. All data are processed in the icom communication unit and forwarded to the system of the plant. Fail-safe chainflex cables Even the safest e-chain is little use if the cables in it do not hold. And the challenges faced by e-chain cables are, as is well known, much higher than for cables in more general flexing applications. For this reason, igus has been developing its cables for moving applications for 25 years under the name of chainflex, ensuring excellent function and reliability of the cables in all moving applications, from stock. This too with a guarantee of up to 36 months. However, within the scope of isense, igus has also taken a step further with chainflex and developed a failure monitoring module for cables that are running continuously: isense CF.Q. Intelligent electrical conductor quality sensors continuously monitor measured values of the cables and indicate when the limits, based on empirical values from millions of results from the test laboratory, are exceeded. This means that the intelligent chainflex cable also informs the user about its remaining service life before a failure. The isense as a strategic means of maintenance Since the first use of polmyer energy chains more than four decades ago, the igus e-chain has evolved constantly: mechanically by continually researching ever better materials and designs that have made the e-chain ever lighter and quieter. As a result, not only linear motion but also movements in all directions and torsion have become possible. Now the e-chain has become smart: with the aid of intelligent sensors, it monitors itself continuously and warns of a failure in advance. Many thousands of test procedures already provide extensive data, on the basis of which the exact durability and service life of the e-chains are calculated and which are integrated in numerous online tools and apps. However, the use of sensors and ITbased data analysis has further developed the existing maintenance A sensor chip embedded in the opening crossbar of the e-chain measures the status of the e-chain in real operation strategies. By measuring the actual status of the e-chain in real operation, the smart plastics can detect the appearances of wear on time and maintenance can be initiated at an early stage. The key point is not to respond to failures, but to foresee them and plan accordingly. As a result, smart plastics are used as a strategic means to save costs in production: by the optimisation of resources in maintenance and spare parts logistics, or through higher response speeds within production processes. In addition, the avoidance of costly production stoppages from machine downtimes. The isense sensors in beta use The first assignments of the isense sensors were in the production plants of various German automotive manufacturers. However, they can be used wherever predictive maintenance is required for cost reasons or to increase plant efficiency and reduce energy consumption - for example, in e-chains on long travels in port facilities or crane systems. All isense products can be installed in a large range of products. Some of the isense products can even be retrofitted in existing plants. Application or cloud-based solution Simple digital I/O signals are still sent when a limit value is exceeded. The icom module passes the maintenance information about cables to the user’s systems. If, however, the data of many plants and production processes are brought together in a structured manner, more accurate analyses and more reliable predictions would be possible. A conceivable future solution would be one that not only evaluates local production data, but is also fed with data from other applications as well as the many test results from the igus database. Whether this is done in the form of an application by the user or cloud-based, ultimately the user could decide for himself. Photographs: Igus GmbH About Igus The igus GmbH is a leading manufacturer of energy chain systems and polymer plain bearings. The Cologne-based family business has offices in 35 countries and employs around 2,950 people around the world. In 2015, igus generated a turnover of 552 million euros with motion plastics, plastic components for moving applications. Igus operates the largest test laboratories and factories in its sector to offer customers quick turnaround times on innovative products and solutions tailored to their needs. WORLD OF INDUSTRIES – INDUSTRIAL AUTOMATION 2/2017