Page 25 - MetalForming July/August 2009

A common method for mounting end-of-arm tooling is use of a common plate located on the bars—which includes several fixed finger stations—shown here mounted on the inside face of the transfer rail of a front- and rear-mounted transfer system.
his own key personnel. This process sets a tone from the start that finger pointing, once the project gets under- way, will not be tolerated. This is the time to identify early-on any potential problems that might occur, and to account for them. From this meeting should come a set of master task lists and schedules, to be shared with the team and updated throughout the project.
No vendor can work in isolation from the others. High among the con- cerns of the companies developing the transfer system and tooling are the motion profiles, tooling interference curves, and motion strokes for optimum tool design and transfer performance. Working together, the vendors must avoid any interference from pins, cam drivers, heel blocks, etc. with the finger tooling during the stamping process.
Other key issues to address include transfer-finger designs and clearances for the end-of-arm tooling in the dies. Perform a transfer-interference analysis and run-at-rate analysis to identify, address and rectify any potential issues during the tool-design phase. Waiting until later in the project to perform these studies can prove very costly. The use of internet-based meetings and
part width;
• Less flexibility with respect to the
independent motion of the front-to- back rails;
• Often, the press window must be enlarged, which can add cost to a new press;
• Often not well suited to the retro- fit market;
• Can be difficult to adapt for take- over transfer work, possibly requiring significant modifications to the tooling and transfer fingers.
Front- and Rear-mount— Advantages
• Mounts on any style of press, including presses lacking windows;
• Fully independent head control— front rail can run a completely different motion profile to the rear rails;
• Typically has a larger range of motion than a window-mount system, with infinite passline adjustment and no restrictions due to window size;
• Can be easily adapted to accept emergency or takeover work, using bars and fingers from other transfer systems;
• Deflection rates tend to be less than with a window system, because the trans- fer rails are held at points in the center;
• Robust design capabilities allow heavy payloads to run at maximum rates.
Front- and Rear-mount— Disadvantages
• Takes up more room on the front and rear of a press, which can be a dis-
advantage with rolling bolsters and dur- ing die changes performed with an over- head crane. Longer tracks are needed to ensure that the bolsters extend past the transfer’s footprint.
Teamwork, from Start to Finish
All successful projects start with a room full of the key players selected for the project being on the same page. The metalformer should ask the ques- tion, “What can go wrong,” of the press supplier, transfer source, die shop and the feed-equipment vendor, as well as
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METALFORMING / JULY/AUGUST 2009 23
A servo-transfer system mounted on this 250-ton gap-frame press automates stamping of deep-drawn components.