Six-axis giants for presses up to 5500 tons, and new in-cycle holding-pressure control.

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Engel (U.S. office in York, Pa.) has added new sizes to its easix six-axis articulated robot series, allowing them to be used on its presses up to 5500 metric tons. Engel made this announcement during its June 2015 Symposium in Austria, where it also debuted a new version of its shot-weight control software and new technology to mold liquid metal (see Close-Up).

Because of extended reach (3900 mm) and higher load capacity (up to 240 kg/529 lb), the robots can be used for molding large parts like bumpers, instrument panels, and trash bins. Engel’s partner in this new series is Kuka Roboter GmbH in Germany (Kuka Robotics Corp., Shelby Township, Mich.).

Controls for the easix robots are integrated into the Engel press control, just as for Engel’s three-axis viper linear robots. The control unit provides different user levels, from a simple view to a fully object-oriented visualization of the sequence. Engel says many tasks that previously required calling in a programmer can now be managed by the machine operators themselves, such as synchronization of the robot movements with the ejectors.

Engel also showcased new functions of its iQ weight control software. In addition to automatically adjusting the injection switchover point and the injection-speed profile, the holding pressure now can also be automatically readjusted during the cycle. The iQ weight control automatically recognizes deviations and compensates for them in the same shot.

To achieve this, the software breaks down the pressure profile in real time during the injection process and compares the measured values with a reference cycle online. Based on these results, the switchover point and the injection profile are adapted to the current conditions, which keep the injected volume constant during the entire production run. The effects of viscosity fluctuations in on mold filling, especially when the switchover point depends on the injection pressure, can also be compensated.

The new version of the software goes one step further. The automatic holding-pressure correction now compensates for fluctuations in viscosity even after the injection phase has been completed by adjusting the holding-pressure profile.

The new feature opens up a wider range of applications for iQ weight control. While automatic readjustment of the injection parameters increases weight consistency, especially in molding thin-wall parts, it is the holding-pressure phase that has a crucial impact on quality in production of thick-walled parts.

The iQ weight control is available for all Engel machines with electric injection units and is integrated into the CC300 control.

(For a feature-length discussion of iQ weight control, click here.)