Assembly In Action: Advanced Presses Automate Fastener Installation
"In certain chassis that we manu-facture," says Bert Santucci, vice president of operations, "75 pieces of hardware are installed in each unit. This high, constant volume led us to the conclusion that an automated press would best serve most of our needs."
The company currently uses more than a half-dozen of Penn Engineering (Danboro, PA) Pemserter Series 2000 automated presses, a Series 4 manual press and a Series P3 portable hand press. The automated presses are positioned in a row and run constantly during two shifts every day. Clinch nuts are automatically fed to the presses at rapid rates. Santucci notes that the press' 24-inch throat depth is more than enough to handle the workpieces, which are typically within standard industry dimensions of 30-inch cubes.
The shape of a workpiece directly influences the decision to choose a manual or automated fastener installation machine. If the workpiece has any unusual installation requirements, such as back flanges or hidden recesses, then a manual press, with open access, would likely be used. However, if fastener volume is significant enough and the mounting hole for installation is not too difficult to reach, then automatic bottom-feed clinch-nut installation tooling may be used.
Fastener sizes and types installed by the company tend to be the same for most of its customer applications. This consistency in hardware facilitates automated installation, adds Santucci.
In cases where only a handful of nuts or studs are installed, a Series 4 manual press has proved sufficient for the shorter production runs. If additional fasteners are required in an assembly after final inspection of a workpiece, a Series P3 portable hand press is used.
Operator safety was another reason that the company's older equipment was replaced with new automated presses. The Series 2000 automated press is equipped with the Lightstream safety system, which ensures that ram force is only applied to fasteners for installation. A pair of infrared beams immediately detects when the main ram contacts any object (metallic or nonmetallic) that should not be in its path. This optimizes operator confidence, reduces potential accidents and injuries, avoids workpiece damage, and ensures rapid and accurate fastener installation.
A menu-driven touch screen guides an operator through a 15-second set- up, and the program is retained for consistent operation even when the worker shift changes. The touch screen also allows the operator to adjust in-stallation variables, such as dwell time and installation force, and automatically alerts and directs the operator to any safety or system faults for quick diagnosis.
The press performs at cycle rates ranging from 2,750 to 3,600 strokes per hour and delivers a ram force of 400 to 16,000 pounds.
Updating the older equipment with a combination of automated and manual presses has helped the company maintain its high volume of chassis manu-facture, along with maintaining its employees' safety.
For more information on auto- mated presses, call the Pemserter Systems Div. of Penn Engineering at 215-766-8853, visit www.pemnet.com.