MACHINE TENDING – PRESS LOAD/UNLOAD
This manufacturer of sheet metal parts supplies hundreds of thousands of units to a very demanding, consumer driven market. This production demand surfaces in the plant in the form of an overall cost containment, the need for rugged and in some cases no frills equipment and absolute uptime.
Manually loading and unloading presses in this environment is a thankless and often dangerous job. The allowable part handling time is minimal. The plant processes are segmented by the allowable process times for each of the part types in the final product with the more commonly used parts pressed for shorter part-to-part times and the lesser used parts allowed some breathing room.
Many years ago this customer attempted to use robotic automation with little success, there was some resistance to the idea when TEC arrived on the scene to offer our services. With a short discussion about the advances in the capability of robots and a longer discussion about the need to partner with a reliable vendor/integrator, the decision was made to create a demonstration for management of a target application.
The customer supplied certain key process tooling and TEC supplied the demo robot, a tool and some basic programming. With the success of this demonstration, an agreement was reached.
The part variations in the cell are minor in this case. The critical elements for the success of the system included optimizing the handling cycle time, coordination with the press tooling vendor with regards to the addition of the proper automation friendly additions and confirming the overall success of the project through the use of 3 dimensional modeling and system development on the TEC shop floor.
System Requirements
-Seven-second takt time
-Direct labor savings
-Use one robot for two presses
-Load incoming parts as they come (presence of grease, nicks and possibly burrs)
-Meet the financial goals set by the customer
-Show it can be done
-Turnkey through on site start up and acceptance
Description of the Solution:
TEC designed and built a two-sided cell with one robot positioned on a manual two-position floor mounted slide. Each side of the cell is provided with a part-specific pick and place device, pneumatically driven and PLC controlled, that separates and prepares a part for pick up by the robot.
One robot end-of –arm tool is used for the range of parts. The programmed points are altered to load and unload the two presses in the cell.
The operator loads a stack of parts into one side of a two-sided magazine and presents the full side to the robot inside of the safety barrier. The robot, once in synchronous cycle, manipulates the parts in the press and loads one position in the press with a new part. Finished parts are dropped into TEC built flipper and transporter system for removal from the cell.
TEC used an ABB IRB140 robot mounted to a riser unit and TEC designed and built floor mounted manual slide. The custom end-of-arm tool uses a vacuum for part handling. Fanning magnets are used for sheet separation to assist the pick and place devices. An Allen-Bradley PLC and small HMI unit create an operator friendly environment.
Customer Benefits:
All of the stated and agreed to system requirements were met with these additions:
-Finally, an automation solution that works and makes sense
-We beat the seven-second takt time and we do it consistently
-No human touches of individual parts
-Safer work environment
-The indirect benefits outweigh the direct benefits
Palletizing and Packaging Equipment