Volume Seven Transfer Technology Systems By Dennis Boerger, Product Manager AIDA-America Corporation Why Use A Transfer System? Today’s manufacturing trends particularly in the automotive industry, require metalformers to produce complex parts from thinner yet stronger materials. To meet this requirement modern press builders have designed transfer technology capable of stamping very complex parts. These systems are flexible, allowing metalformers to manipulate the part during production and reducing material waste when compared to progressive die, coil-fed applications. In addition to dedicated transfer presses, straightside presses and gap frame presses can be used as transfer systems. Deciding Which Transfer System To Use Deciding on which transfer system is appropriate depends on two basic criteria; part complexity and production volume. It is also important to find a press builder that can act as a single source for the press, the automation, the ancillary equipment, the integration services, the installation, the runoff and the post-installation support. Transfer Presses Transfer presses are most commonly used for large complex parts or just-intime-manufacturing demands which require production of a maximum number of parts in a limited time frame. Transfer presses are also used for the production of complete assemblies. Figure 1- A transfer press should have the capability to eliminate production problems so the operator does not have to stop the press. When selecting a transfer press, there are a number of elements to consider. A transfer press should have the capability to eliminate production problems so that it is not necessary to stop the press (Figure 1). Equally important is the capability to enhance the work ratio and increase unit/time productivity by reducing the time it takes to change the die. Certain press features can also help achieve these objectives. A blank feeding device can increase productivity by sensing and correcting double-blank misfeeds and reloading the blank feeder without requiring the operator to stop the press. The blank feeding device should be able to automatically discharge extra blanks when a double-blank is detected. Blank hold devices allow blanks to be automatically held while the next blank stacker is changed eliminating the need for the operator to stop the press when the supply of blanks is low. A data bank formula device can also raise productivity by making it possible to perform die changes more quickly. Copyright © 2004 AIDA-America Corporation. ALL RIGHTS RESERVED. 1

Volume Seven If a transfer press lacks a servo transfer mechanism, the press will not have the ability to change the motion profile for the transfer pitch, the transfer bar clamp motion and the lift motion. A transfer press equipped with an electronic servo transfer mechanism can deliver increased production speeds and greater efficiency because all three profiles can be adjusted and retimed for each part or each job to achieve optimal operating speed. In addition, once job programs have been written, they can be stored in the job memory eliminating the need to constantly reprogram the press....

Volume Seven Figure 3 – In a two or more press system, a straightside press can be run individually or as a single large transfer press by initiating the intermediate stage between the presses for continuous, synchronized operation. Transfer system programming can optimize the acceleration/deceleration curves for maximum productivity and strokes per minute. A free programmable dimension in 3-axes capability (transfer pitch, clamp pitch and lift pitch) can increase flexibility. High rigidity and low bed deflection are essential to part quality and accuracy. Other press features should include...

Volume Seven successfully run on a gap press line. (Figure 4). The advantages of a gap frame transfer system can help determine if this choice is appropriate. Higher material yields are possible because blanks are used. Gap transfer presses do not require one end of the product to be consistently connected to the coil during the forming process. This feature delivers greater freedom when handling complex forming operations. Because the part is conveyed in mid-air between stations without touching the dies, die structure is simpler and less expensive. With the ability to connect as many gap presses...