Machining Enterprises, Inc, in Saginaw, MI, performs a cubing operation on engine blocks and heads for new engines that power several sport utility vehicles. This operation involves machining on various surfaces, including the combustion chamber, the intake face, and the exhaust face. Cubing is necessary for validating the castings before they are shipped to a major automotive company''s engine plant. With the help of robots from Fanuc Robotics interfaced to GE Fanuc''s CIMPLICITY® Machine Edition software running on Control Station NTs, Machining Enterprises plays a key role in the engine manufacturing process. Machining Enterprises is able to identify problems early in the production process, providing early feedback to the major automotive manufacturer for problem solving and process adjustments.
Firing On All Cylinders
The Machining Enterprises plant floor features three machining work cells, each of which contains four Niigata horizontal machining centers. Two machines that run blocks are located side by side, and two that run heads are also side by side. A pair of Fanuc M-710iT six-axis overhead rail-mounted robots services each cell, a major cost and space savings benefit for Machining Enterprises.
"Typically, one robot services two machines, but two of our three cells are flexible, so one robot can perform two different tasks such as manufacturing blocks and heads side by side," says Brian Verzinski, manufacturing process engineer at Machining Enterprises. A robot traverses between two centers, working on one part, then stopping and changing its end-of-arm tool (EOAT) to work on the other part, then stopping and changing the tool again, and so on.
GE Fanuc''s CIMPLICITY Machine Edition software, running on Control Station NT industrial computers, interfaces between the robots and the Niigata machining centers. A single Control Station controls the two flexible cells, each of which is equipped with two additional Control Station NTs that serve as operator interfaces. The third cell uses one Control Station NT for control and one as an operator interface. CIMPLICITY Machine Edition transmits information received from the machining centers to the robot.
"A number of conditions must be met before a robot can execute a command; for example, determining whether a part is present, whether the light curtain is clear, and whether the robot has completed the previous task," Verzinski says.
Each controller has two separate I/O channels. One channel of Series 90™-30 I/O interfaces via Ethernet with the robots, and one channel of DeviceNet interfaces with conveyors using VersaMax® I/O. These conveyor transfer lines shuttle parts between the machining centers.
Solid Performance
"This is a complex robotic operation. This new solution has provided both manufacturing and enhanced process advantages," Verzinski says.
Speed was one of Machining Enterprises'' major concerns. The goal was to perform a unique "A" and "B" load on each machining center within the machining cycle time. Fanuc demonstrated this by creating a computer simulation model prior to equipment build. This simulation was later proven by an equipment trial run on Fanuc''s factory floor. The CIMPLICITY Machine Edition interface was able to keep pace with this demanding requirement while providing the required level of reliability.
Installing and commissioning the system went "extremely well," according to Verzinski. "We wanted a 4-hour fault-free run the first time out, and we got it. We made a few minor I/O changes once we saw how the robot was processing the parts, but that''s about it."
Given the complexity of this manufacturing environment, the graphical interface has a relatively simple screen layout to simplify the operation. "It takes about a month for new employees to learn how to run it, but that''s reasonable based on the application," Verzinski says. GE Fanuc provided initial training, and internal staff now teach new employees.
The overhead rail-mounted FANUC robots save valuable floor space, machine tool access and investment for Machining Enterprises, since one robot can service two machining centers. "In addition," Verzinski says, "designing and building a safety interlock system was easier with the overhead robot than it would have been on any other type."
"Working with Fanuc Robotics and GE Fanuc has been a good experience," says Verzinski. "They have provided a fine engineering team, expert program management and local technical support throughout this project."