Solution in a box

Valves are among the most important components of an internal combustion engine: they ensure the intake of the air-fuel mixture into the combustion chamber and at the same time provide a controlled exhaust of the gas. This requires the valves to be hermetically sealed and reliably close the openings of the combustion chamber. This is achieved by elaborate polishing of the valve seat in particular, so that it achieves a precise smoothness.

Testing critical surfaces

Eaton Automotive Systems Sp. z o.o. in Bielsko-Biała / Poland therefore regularly checks the quality of the valve seats before, during and after production. "These surfaces are essential for the functioning of a valve in the engine and are classified as highly critical by our customers," explains Wojciech Liro, Measurement Systems Specialist at Eaton. In addition to vehicle and aircraft components, the global engineering company also develops and sells systems for mobile and industrial hydraulics, power distribution and electrical systems.

Intuitive measurement with the MarSurf M 310

Eaton's valves are made of special valve steels such as EMS-1 or EMS-296, and in order to accurately measure the roughness of their valve seats, Wojciech Liro's 2020 team was looking for the right measurement technology. "Our focus was clearly on precision, a long service life for the device, and saving as much time as possible," explains Liro. Since they already use many Mahr devices at the plant and are very satisfied with them, the request to Sales Engineer Jacek Bartoszek from Mahr Poland was obvious. "He has already provided us with excellent advice on metrological problems many times," Liro emphasizes. Bartoszek suggested the new MarSurf M 310 mobile roughness measuring device to the Eaton team. It features easy operation and a highly robust design. A large, high-resolution and backlit 4.3-inch TFT display ensures that all measurement results are accurately displayed. "The MarSurf M 310 is operated intuitively via the touch-enabled screen - just as we are used to from smartphones today. Another benefit is that users can reliably determine roughness parameters with the MarSurf M 310 even without specialist knowledge or training," Bartoszek explains the flexible measuring device.

Enclosure and scanner make errors impossible

Since July 2021, the MarSurf M 310 has now been used at Eaton to measure the roughness on the stem surface as well as the valve seat. The measurements are performed by the production line operator. "The plan is to extend the roughness measurements to valve tip, valve head and other geometric features of the valve in the future," reports the Eaton measurement engineer. Initially, quality inspectors at the Bielsko-Biała plant in southern Silesia had to manually select the respective program from the control unit menu for the measurements. This was time-consuming and entailed the risk of unintentionally changing the parameters. However, Bartoszek came up with the idea of placing the control unit in a separate box that separates it from the harsh production environment – and thus from the oil and oil mist on the factory floor, which can penetrate the device and slowly destroy its electronics. With this box, the operator is now separated from the control unit and no longer has to touch it. Instead, he simply scans a QR code with the barcode scanner connected to the MarSurf M 310, which triggers the corresponding measuring program. "So the operator no longer has to spend a long time searching for a program in the menu, but now has very easy access to it," explains quality manager Liro with satisfaction.

Conclusion: The MarSurf M 310 now puts the valve seats through their paces. The measurements deliver precise results with amazingly simple handling, and sources of error are largely eliminated. Only if the surface finish is within the permissible tolerances does the component pass the strict quality controls at Eaton Automotive Systems. And in the future, it will bring combustion engines up to full speed.

Questions about the device? Martin Adler, Product Manager MarSurf, will be happy to answer your questions and provide further information by phone at +49 551 / 7073-99321 or by email:  Martin.Adler@mahr.de.

Info: MarComProf supports internal controlling

With the MarSurf M 310, Eaton is also able to send measurement results data from the M 310 to the internal SPC analysis program via MarComProf software without touching the computer keyboard or manually rewriting the results – "this was not possible with our previous instruments," Liro says. This process eliminates the possibility of errors, saves a lot of time and allows operators to focus on their work, he said. His team also uses MarComProf to collect wirelessly data from Mahr's digital indicators attached to the M 310's measuring station and send it to the SPC program as well – unifying the measuring station.