Features

• Novel pick and place mechanism to manipulate precut plies
• Integrated forming
• Automated assembly of stringers
• Automated manufacture and insertion of roving (noodle) material
• Higher throughput than manual operation
• Consistent quality

Situation:

A major rotorcraft OEM experiences an increase in unit orders quadrupling production requirements from one unit per month to four.

Problem:

The rotorcraft fuselage incorporates co-cured T & Z stiffener/stringers which are all currently made by hand. As the part is already qualified, no changes can be made to the materials and the current process must be automated as the current manual manufacturing method cannot keep up.

Implication:

The OEM must choose between increasing manpower, physical production space, training etc or look to an automation solution.

Solution:

Accudyne performed an extensive analysis of the current process as it began the task of developing the automation to manufacture this part.

The stiffener construction consists of two prelaminated ply packs that are folded and mated to form the required shape. In addition, a shaped prepreg roving is formed and placed in a crevis created by the mated ply packs. Typically, this manual process takes between one half and one hour. Inconsistencies in the stiffeners’ dimensional integrity and scrap are problems due to the difficulty in aligning the ply packs by hand.

The T&Z Stiffener Forming Machine automates this process and processes each part exactly the same with a cycle time of approximately 10 minutes. Over 160 different stiffener geometries are stored in recipes that can be selected by an operator. Prelaminated Ply Packs are loaded in the machine. A vacuum chuck picks up the ply pack and correctly positions it on one of four forming mandrels. Folds in the ply packs are made by preheating and bending the laminate into shape, with an inflatable bladder insuring a sharp corner and laminate compaction. The shaped prepreg roving is made automatically and inserted into the stiffener using a roller.