When Cummins Inc. was facing the challenge of assembling a manufacturing system for the production of light duty diesel engine blocks and cylinder heads for a new engine program in its plant in Columbus, Ind., the company examined numerous bids from a number of American and international system suppliers. As the bids came in for the new systems for plant automation, parts cleaning and deburring, as well as centralized coolant filtration systems for its engine block and head production line, the company found that Dürr Ecoclean could handle all three tasks. Cummins eventually discovered that the Dürr system would help keep the company’s costs low, streamline the installation and minimize the headaches associated with commissioning a new engine plant.
Cummins converted an older building that had formerly been used for production of an engine line, which was taken out of service several years ago. Company management planned a hybrid manufacturing process that would allow for incremental capacity increases in the production of these duty diesel engine blocks.
Cummins wasn’t necessarily looking for one supplier to provide all of the systems required. Greg Langendorfer, the company LDD machining leader and project coordinator for the new plant, says, “Once we put together our list of potential suppliers, did our initial evaluations and put it up for competitive bids, we got our information back and evaluated it. As it turned out, Dürr was selected as the supplier for all those components.”
Not only was the Dürr system chosen because it was able to meet Cummins’ need for future flexibility and cost effectiveness, but the company only needed one product manager for the three systems rather than having to coordinate three separate suppliers.
“We worked with one individual for all three of Dürr’s products,” Mr. Langendorfer says. “This gave us one point of contact for all our engineering work, our manufacturing work, equipment run-off, shipment, installation, and so on. That was very significant, and it helped streamline the entire process.”
Automation for Optimized Workflow
Cummins required an extensive solution from Dürr for its automation process. This consisted of a system of gantries and over-aisle elevators, Dürr’s modular PZR (Powered Zone Roller) conveyor technology and a robotic buffer system to help manage part flow through the system.
The gantry system delivers components to and from approximately 34 CNC machines by means of an overhead rail and a traveling carriage to lift, move and lower components into the CNC machines for machining.
For transporting components such as blocks and heads between machining operations, the PZR’s modularity allows possible future changes in plant layout and the addition of further machining centers to take place easily and quickly, according to company management. The various “zones” of the PZR have its own bidirectional motor, which only moves components to the next zone when space is available. Since the motors do not run continuously as they do in conventional conveyors, both energy consumption and in-plant noise levels are reduced.
The conveying process also incorporates OGVs (Overhead Guided Vehicles) to transport parts across main aisles without interrupting operator or forklift flow. RIO (Robotic Input-Output) buffers help manage part flow through the process.
Cleaning Parts with Complex Geometries
Cummins relies on two Dürr EcoCTrans parts cleaners for cleaning, deburring and drying applications for its diesel engine blocks and heads. The parts cleaners for the block washing applications feature a solvent-based washing process with injection flooding and dedicated washing nozzles, as well as regenerative air blow-off and vacuum drying.
Cummins required a sophisticated system as part of its design specification for the cylinder head cleaning process. The cleaning process—performed by two additional EcoCTrans parts cleaners—is similar to that for the blocks, but with additional features and capabilities.
Also, the cylinder head would probably have the most potential for future proliferation, meaning that future requirements might lead to several different part numbers or machining configurations for different customers. A robot inside the parts cleaner can be programmed to accommodate different part numbers and address different features in terms of cleaning and deburring.
Meeting Coolant Filtration Needs
Since Cummins plans to expand beyond its current combination of more than 44 CNC and transfer machines for its metalcutting applications, there was a need for a filtration system that can handle not only the present number of machining centers, but also the anticipated future expansion. Dürr filled this need with a central coolant filtration system with two tanks, each with a holding capacity of 100,000 gallons and a pumping capacity of 17,000 gallons per minute.
The flexibility and modularity of the entire Dürr Ecoclean system provides the engine company the ability to easily expand in the future with additional equipment and machines, which was one of the most important points behind the decision to order this integrated system. Also, the future changes and expansions will be simplified because all the systems come from one source.