Page 40 - MetalForming March 2012

High-Pressure Lube System
cubic inch of available press space, measures 140 in. long by 38 in. wide, and stands 4 ft. tall. “With the high viscosity of the lube, combined with the limited space available in the die, we could not obtain a wide enough spray pattern with three nozzles to cover the area,” says Walker Tool & Die project manager Jim Rickner. Hence the addi- tions of a fourth nozzle in each of the two draw stations.
Spraying in Tight Space
The tight confines of the press not only posed a challenge to designing and installing the lube system, but also impacted the development of the transfer system (engineered and built by Linear Transfer Systems). A con- cern during transfer-system develop- ment was the limited space—a mere 5⁄8 in. of clearance from the top of the part to the top of the die in the press—
in which to lift and transfer the deep- drawn parts.
To optimize the transfer cycle and maximize cycle time, Bettcher opted to have the press rewired and pro- grammed (by Enprotech Mechanical Services) to operate in the single-cycle demand mode. Here, the press stops momentarily at the top of each stroke to allow enough time for the transfer system to index.
Gripping the blanks—17.25- to 18.5- in. dia., and weighing as much as 14 lb.—laden with a thick, slippery coating challenged Linear Transfer, Walker and Bettcher to develop a solution to keep the system running at its rated speed of 8 to 9 strokes/min. and 20-in. pitch
“The parts are heavy and slippery,” says James. “At one point during try- out we could actually push the parts out of the grippers. Linear Transfer was able to upgrade the tooling— shovel-style and friction grippers— with soft-rubber end effectors to alle- viate the problem, and now they’re working on a third-generation of mag- netic tooling for us.”
Parts Making an Untimely Exit
Retrofitting the Bliss press for this job, which has been running since July 2011 and consumes 60 percent of the press’s capacity, says James, also required some unique die engineering by Walker. First, since the press had typically run coil-fed progressive dies, a full feed line resides on one end. Now, a blank feeder (a Linear Transfer unit) resides on the opposite end of the press. To avoid having to move out the coil line when blank feeding the deep- draw job, to enable efficient removal of the finished parts Walker had to engi- neer the die to allow the parts to exit from the front of the press rather than through the window.
“We had to cut the corner off of the die,” says Walker Tool & Die engineer- ing manager Mark Sytsma, “to allow the parts to exit in front of the post. We then integrated a conveyor to index the parts back toward the center of the press so that an operator can handle them.” MF
38 MetalForming/March 2012
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