TYROLIT – Abrasives manufacturer TYROLIT tailors the ToolScope assistance system to specific grinding requirements. The system provides a transparent view of the condition of the machine and the operating and process data. As well as complete process stability, this helps the operator get the most out of grinding tools and minimise machining times.

Even in the age of Industry 4.0, a provider cannot do away with explaining what an assistant system is, everything it can do and how it is useful for the operator. TYROLIT, an abrasive materials producer in Schwaz, Austria, does this with a simple analogy: ToolScope is a navigation system for production operations.

Just like GPS navigation systems inform a driver of the fastest way to get from A to B, in production operations, assistance is about reducing cycle times and achieving the machining objective in the shortest possible time. To this end, the system monitors the entire process in order to gather the necessary data. As well as pure speed, this also makes for safer processes. Everything that has to be monitored, controlled, evaluated and documented depends on the specific requirements of the individual operator, who can tailor the system to their own requirements.

When TYROLIT’s ToolScope system made its public debut at the Grindtec fair in March, the company had the advantage of the assistance system having already been launched on the market as an Industry 4.0 solution for machining with defined cutting edges. The system was originally developed by the Brinkhaus start-up. In 2012, Brinkhaus was integrated into Komet Group, which was acquired by Ceratizit this year. This partnership has made it possible to monitor all machining processes and prepare individual assistance strategies. TYROLIT’s system is one of the ToolScope variants that were developed for grinding. Much of it resembles the assistance systems that Ceratizit has maintained for turning, drilling and milling. Nevertheless, many requirements fundamentally differently from each other, given that grinding tools behave differently in use.

Dr. Markus Weiss, Head of Abrasive Technology at TYROLIT, explains the significance of ToolScope being run in over 1,000 manufacturing plants: ‘The underlying structure for the operation of our system does not differ from one to the next, and so many operators are now familiar with this assistance system. The teething troubles that occur mainly in new software have been resolved and we are able to concentrate fully on the abrasive technology.’ The assistance system also fits well with the corporate philosophy of the Tyrol-based family-owned company, which is also a member of the Swarovski Group: TYROLIT is one of the world’s leading manufacturers of grinding and dressing tools. The company’s portfolio also includes a number of special products that leverage its strengths but often draw on the process experience of its application engineers.

Buffers to be redundant

ToolScope provides further enhancement of the machine after the experienced application engineer has set up a process and completed the operational start-up on site. The system collects information and has the capability to respond to fluctuations and optimise machines, process flows and tool use. With continuous monitoring, many safety buffers will become redundant, as ToolScope takes care of the necessary process transparency.

As explained by Markus Weiss, the goal is not to create a fully autonomous grinding process, but to achieve a changeover from manual data analysis to an ‘assistant’ for process managers in a first step on the road to Industry 4.0. The system processes the data to enable the operator to start out with the aid of additional information and to assist the operator in optimising the process, enhancing its design or in monitoring. ‘In the medium-term, there is no substitute for people who have an instinctive feel for grinding,’ says TYROLIT’s Abrasive Technology department. ‘However, we can support them in their job. The aim is to have informed users who make decisions based on facts.’

ToolScope analyses the data that already exists in the machine. ‘Everything that a machine requires for control can be used to set up a monitoring strategy,’ explains Weiss. The core element of ToolScope is a single hardware item: a rail module built into the machine and connected by PLC to the machine via the profibus. The engineers in Schwaz simply refer to this ToolScope hardware unit as ‘the little box’. The actual know-how of the system is contained in the software. Twelve apps monitor the machine and the process, perform various help functions and analyse data.

The logged values are saved for further analysis as required by the user, whether on the local device, in an existing ERP system, on the corporate network or in the Cloud. The user is also able to choose how the data is visualised: on the machine display, an external monitor or a tablet, or on a PC in the planning office.

Practical tests in the Tech Centre

TYROLIT provides practical demonstrations in the Technology Centre at the company headquarters in Schwaz. Here, TYROLIT has installed and tested the system on a machine produced by GST, an Austrian manufacturer, and a round grinding machine made by Emag. The latter company specialises in cylindrical machining, out-of-round machining, transmission shafts and camshafts. As such, it covers a major part of the spectrum of machining work required by customers. To be able to operate at a maximum speed range of about 200 metres per minute, TYROLIT has opted for a bench instead of the cylindrical grinding option preferred by the machine manufacturer. This, for example, enables insightful tests to be conducted for the turbine industry demonstrating that when peak power is reached during the process or peak levels of torque occur, it can provide warning of burning in the grinding process.

Tests are also performed on an old Emag cylindrical grinding machine, demonstrating that use of the assistance system is not only relevant for new machines. Here, the processes are simulated on wheel-shaped blanks with specific dimensions. In rare cases, the original customer process is replicated, but with the corresponding machining steps using exactly the same materials as those of the customer. To be able to set the appropriate limits in each case, a considerable volume of material will be machined. Working under constant conditions, the system will collect values for the processes and tools involved.

Here in the Technology Centre, the machining run is displayed on both the machine display and on a large monitor screen. This enables multiple parameters to be observed at the same time. A lot of information can be derived from the torque of the spindle, for example taking readings of recessing operations or the influence of lateral friction. Besides torque, the level of speed offers plenty of possibilities for optimising processes. In tests, median values and critical thresholds are both identified. In multiple runs, the curve in the diagram consistently shifts downwards, which serves as an indicator of the condition of the grinding wheel. Dressing processes are visible in jumps, and wheel changes can also be seen. At the Tech Centre, TYROLIT has also identified correlations between spindle torque and coarseness. After dressing, the wheel is smooth and this results in high torque. If the measured value falls below a certain threshold, the surface will become too rough and will have be re-dressed.

Programmable responses

For each project, the machine response for each particular event is programmed. This can be an alarm signal, bringing the machine to a stop or an adaptive control of the feed. An automated dressing process is also possible. The testing and modification of each PLC is carried out at Ceratizit in Hanover. It is this unrestricted configurability and adaptation to individual processing requirements that sets the ToolScope system apart from other solutions.

When deciding what values would be most suitable for monitoring a particular process, assistance is provided by TYROLIT technical sales support that draws on a tried-and-tested structure previously set up at Komet Brinkhaus. In Schwaz, Gabriel Huber bears this responsibility for the grinding assistance systems. First of all, he demonstrates to customers the potential of the system for individual projects. In most cases, ToolScope is installed on one machine to start with and then tested for a few months. As a rule, customers then want to use the system on other machines, having seen the advantages offered by the system.

There are many reasons to use ToolScope: excessive tool wear, overly-frequent dressing, too much scrap, strong variations in properties with grinding and greatly differing outcomes with components. TYROLIT’s application engineers identify problems like these at the customer’s premises and, while proposing changes in grinding tools and process parameters, also recommend the use of ToolScope. Components typically monitored in production include crankshafts, camshafts, transmission shafts and shaft-mounted tools for the tool manufacturing industry. The payoff from process optimising is especially visible in long run work.

For one year now, ToolScope has been employed by one of Germany’s major car manufacturers, where four grinding machines are used on two production lines to turn out transmission shafts in various designs. To begin with, the car manufacturer only used the system for process monitoring and logging. This meant differences in batches or the hardness of the source material that could affect the machinability of the material would be detected.

Given these kinds of variations that can result in different levels of wear in the tools involved, this is often highly relevant for grinding machines. VW has actually succeeded in identifying and overcoming these differences. In addition, the analysis has shown that there is room for optimising the process. TYROLIT engineers estimate that if time buffers are eliminated and the grinding wheels only dressed or replaced when necessary, this could achieve time savings of a good 20 per cent.

Machine and personnel costs account for about half of the costs of a produced workpiece. According to Dr. Markus Weiss, the greatest impact on reducing costs per finished component can be achieved by reducing cycle times, improving machine availability and preventing rework as much as possible. In this regard, the price of a high-quality tool makes little difference, because it serves as an enabler to make a process go faster. In addition, there will be savings in material costs if scrap is avoided. Using examples, TYROLIT can show how the costs for its assistance system can be recouped within half a year when used in industrial three-shift operations.

Source (German only): Maschine+Werkzeug