Automated Cleaning of Powertrain Parts

May 12, 2015
Dürr Ecoclean introduced a SCARA manipulator to replace the standard, 6-axis jointed-arm robot for a part-cleaning work cell for powertrain components.

DÜRR ECOCLEAN introduced a SCARA (“Selective Compliance Articulated Robot Arm”) manipulator to replace the standard, 6-axis jointed-arm robot for a part-cleaning work cell — designed to improve process reliability and quality, energy efficiency and availability rates for pre-cleaning and final cleaning of powertrain components.

In the pre- and final cleaning of powertrain parts (including cylinder heads, engine blocks and crankcases), robot cells not only improve flexibility: They allow parts to be cleaned in short cycles, which makes them an indispensable asset in advanced engine and transmission manufacturing lines. The Dürr Ecoclean EcoCFlex 3 cell is available in two sizes, 3M and 3L.

An essential part of equipment is the robot, which is normally a modified standard type. However, despite extensive adaptations, these units cannot always cope with the demanding conditions encountered in cleaning applications, e.g., moisture, high temperatures and use of chemicals. As a result, unscheduled breakdowns and costly repairs occur time and again.

The EcoCFlex 3 introduces a scara manipulator developed by Dürr Ecoclean in place of the standard commercial 6-axis jointed-arm robot. Purpose-designed for use in a robot cell, this handling system is made entirely of high-strength aluminium and stainless steel. It needs neither paintwork nor a protective suit. Thanks to its IP69 protection rating, Dürr Ecoclean's scara manipulator is resistant to high-pressure water jets and to immersion, in addition to withstanding booth temperatures up to 65°C (150°F). The cleaning chemicals employed may range from pH 6 to pH 10 and need no external robot manufacturer's approval to be used or replaced.

Furthermore, the EcoCFlex 3 overcomes issues associated with the use of different control systems. One joint CNC control unit for the scara manipulator and the cleaning machine replaces the PLC and robot controller, simplifying and accelerating the programming, operation, maintenance, and start-up after a change in parts to be treated. The sensor system for calibrating the scara manipulator is integrated already.

The EcoCFlex 3 uses a water knife to direct the water jet in a focused pattern onto the areas to be cleaned, unlike a conventional round nozzle. Moreover, the machine is fitted with a so-called hybrid nozzle having a variable mixing chamber. Thanks to this configuration, both high-pressure and low-pressure treatments – in addition to injection flood washing – can be flexibly performed in one cleaning station. All cleaning operations, including high-pressure deburring, take place below the bath surface, which helps to reduce the noise level to just 72 dB(A).

The idling times needed for part handling in the work chamber are likewise markedly reduced with this new process technology. Thus, in conjunction with the modular vestibule design, it is possible to obtain 'on-spec' cleaning results in cycles starting from as little as 30 seconds.

The EcoCFlex 3 consumes only 30 kWh of energy, and demand can be supervised via the optional energy monitoring system.

With its reduced footprint of only 32 m², the EcoCFlex again sets a new standard for robot cells. This low floorspace requirement also reflects the fact that no space is 'wasted' for drying with compressed air. Instead, drying is performed in the EcoCDry system, a newly developed high-efficiency vacuum drier which uses no upstream compressed air blow-off stage. As a result, the part will cool down only slightly before the vacuum drying step. Thanks not least to this low temperature loss and the complete elimination of compressed air, the EcoCDry needs approx. 65 percent less energy than a vacuum dryer with upstream air blowing (based on a calculated compressed air consumption of 2 Nm³ per part). The vacuum is generated in the pressure vessel during non-productive times. This results in about 50% shorter cycle times compared to a system with compressed air blowing and vacuum drying. The new EcoCDry vacuum drier can also be retrofitted to existing robot cells.