Drives and control specialist Bosch Rexroth has reduced downtime costs by 25 per cent at its factory in Homburg, Germany, after retrofitting production test rigs — some of them up to ten years old — with Rexroth’s latest IoT Gateway technology.
These test rigs were fitted with standard hardware and software, with each machine taking less than four hours to connect to the network. But now, the upgraded test rigs are able to provide documented data on status and process monitoring, replacing a complex manual analysis process and achieving a total return on investment in less than 18 months.
The Homburg plant is now retrofitting a further 22 test rigs with Bosch Rexroth’s IoT Gateway and sensors, with more machines in the Bosch Group to follow. The process is seen as successfully demonstrating the ability of Bosch Rexroth’s IoT Gateway technology to be retrofitted to older machines, without the need to update or modernise existing facilities.
Fabian Borowski, who leads the Industry 4.0 initiative at the Homburg plant, said: “In Industry 4.0 we are seeing the opportunity to prepare our plant for the future, to produce more efficiently and deliver customised products quickly and at a high quality. However, during the transition, we always need to keep an eye on cost-effectiveness. The overall equipment efficiency of the modernised test rigs has increased by five per cent — we also managed to reduce downtime costs by 25 per cent. Subsequent networking pays for itself within 18 months, and that’s without taking process improvement into account.”
Reduced engineering costs
Engineering costs were also reduced by around 90 per cent, says Borowski, as a prior knowledge of Programmable Logic Controller (PLC) is not required to install the IoT Gateway technology. He added: “Our specialists estimated that it would take at least one working week for the modernisation of the test rigs, including the connection of the sensors and interfaces to the classical PLC systems. However, with web-based configuration, an electrician can complete commissioning within half a day — no knowledge of PLC is required.”
The plant at Homburg manufactures hydraulic valves, alongside other components, that are used in mobile machinery such as tractors and fork trucks. After being drilled and milled in machining centres, individual components are cleaned and assembled. All valves are then tested for leaks, and the electronics are also tested and set up. This is achieved by connecting components to the hydraulics circuit of the test beds. The valves are then able to be tested with a specified working pressure.
Although the valves are thoroughly cleaned in advance before testing, metal particles, swarf and residual water can still be present. When the valve is connected to the test rig and cycled, the residual contaminants are released into the test rig oil supply. These can cause damage to the test rig, and even subsequent valves for testing. In order to avoid the costly downtime of the rig to flush out the contaminants, the filter media need to be changed at regular fixed intervals, which is then documented manually by a factory employee.
Using Bosch Rexroth’s new IoT Gateway, Borowski and his team have been able to implement comprehensive monitoring of the test rigs. The connected sensor system can now continuously monitor the filter and automate the maintenance schedule, which has so far reduced downtime costs by around 25 per cent.