| A unique front cross-member assembly system that features special build-up fixtures, precise part holding, and an ergonomically-correct counterbalanced lifting device has been developed by Peak Industries, Inc., for use by Chrysler at two of its minivan manufacturing facilities. The front cross-member is a critical and complex component that serves as a mounting platform for the vehicles steering gear, sway bar, control arms, and reinforcement plate.
Assembly technique
Peak Industries' approach to cross-member assembly features special build-up fixtures each approximately four feet long and with 13 floating pockets that accommodate 13 nuts. These fixtures arrive at the cross-member assembly area on a conveyor. The first operator places the 13 nuts in their sockets and locates the aluminum cross-member into the fixture using an Ergo-Arm.
The next operator places the steering gear unit in position using a three-spindle nut runner to tighten three bolts. The sway bar is loaded in and bolted down by the next operator, followed by a fourth operator who mounts and bolts on two control arms.
In the final assembly step an operator puts a steel reinforcement plate across the top of the cross-member and bolts it into position, using multiple nut runners.
Part holding and ergonomics
What appears to be a relatively straightforward part-holding function, in effect requires a precise application of pressure to achieve the proper torque and avoid having any of the nuts hangup or lock in their sockets. An integral plunger device developed by Peak Industries' engineers releases the assembled cross-member with an 1/8 in. vertical travel.
After all of the bolts are tightened. The completed cross-member assembly is then lifted from the fixture via an ergonomically-correct handling system and placed on a delivery system to the final vehicle assembly line.
This last handling step is done with a Peak Industries' air operated, counterbalanced lifting device. It is mounted on an overhead carriage that moves on rails supported by a bridge-type structure. The company builds this versatile handling system in a variety of weight-lifting capacities.
Peak has delivered 16 front cross-member assembly fixtures to St Louis, No., plant and 20 to the Windsor, Ont., facility. Three others were delivered to a plant in Austria.
Peak Industries has been a supplier of custom automation and assembly components and special machines and systems for the automotive and other manufacturing industries since 1966.
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