Fabrication Shop - PLC Programming, Industrial Controls, Machine And Tool Design

Bender Tooling

After Kenneth left an after market and OEM auto parts manufacturer, where he worked as a manufacturing engineer, he was contracted to design bender tooling for an F250 4x4 drag link. Steering linkages on light trucks and automobiles often require bends in their designs. These bends provide clearance for engine components when a vehicle is at full steering lock and at full jounce (when the suspension is at full compression). The bends can be put into the drag link either during the forging process or later during the manufacturing process. With the F250 drag link the bend was put in after the drag link was machined. The customer used two different presses to bend the various drag links they produced, the Rouselle and the Chicago. While Kenneth worked at the auto parts manufacturer, he had designed several bend dies for various different drag links.

SCOPE: Design a bend die for an F250 4x4 drag link with the following goals:

a.) bend the drag link in one stroke of the press

b.) use a positive locating device

c.) be able to use the bend die in either the Rouselle or Chicago presses

d.) eliminate any need to shim the tooling

e.) eliminate any need to adjust the ram height of the press

RESULTS: Again, Kenneth had designed several bend dies while he worked at the auto parts manufacturer. They had only one die in use when he had started working on the bend presses. This die was used to bend all of the various drag links that the customer produced. The set-up of this bend die was excessive and produced many scrap parts. This bend die was set up by changing different blocks (punches and dies) in the actual die set and then shimming them to the correct heights. The piece of tooling that located and oriented the drag link also had to be changed and adjusted. If the set-up was not correct either the drag link would have excessive marks or gouges on it or the part would simply be bent incorrectly. While he was working at the auto parts manufacturer, Kenneth designed individual bend dies for most of the drag links that the manufacturer produced. These dies had standardized die set heights and required very little ram adjustment to bend a part that was in tolerance. Each die also had a specific locator that would locate and orient the drag link so the bend was in the correct location and plane. The new dies also eliminated the need for shimming during a set-up.

Kenneth approached the design of the F250 bend die as he had the others. He established the working height and die set sizes of the other bend dies and then worked backward to arrive at the locator, punch and die dimensions. Kenneth also ensured that of the corners and surfaces of the punch and die were well blended so as not to mark the drag link when it was bent. The trick of designing the bend dies was to know how much to “over bend” the part to compensate for the different rod diameters, material properties and number of bends. Some of the parts required multiple bends either in the same plane or different planes. Kenneth supplied the customer with complete Auto-CAD drawings, plots, bill of materials and documentation for the F250 4x4 bend die.