New assembly solutions for chair frames manufacturing

Customer’s need

Automatic assembly of 4 components of plastic chairs. Each component has a number of tightening points located at different heights also deep into holes.

The solutions has to provide:

• manual load

• reliability of each rundown

• the possibility of future retrofit

Solution

Fiam has manufactured 4 semi-automatic tightening units. Each one, managed by an operator, includes:

- Component customized jig, for its manual load/unload, including sensor detecting component presence

- Control panel to set and check in real time machine working parameters, displaying error messages for rapid intervention

- Self-feeding tightening module made of a double stroke fastening slide housing a DC electric (current control) brushless nutrunner motor

- The module moves along 3 linear axis X, Y and Z equipped with servo motors: this solution allows reaching all needed tightening points with the nosepiece

- Parameters of the tightening process are managed by TCS-B controller that displays torque and angle values discriminating the ok/ng rundowns. You can set among 5 different control strategies for each of 4 programs

- Special screw heads that hold the screw from the head rather than the shank: they allow the head to insert inside deep and tight tightening spots

- Screw feeding and escapement system

Solution advantages

100% control of the assembly process

If the component to be assembled is changed, we will just need to redesign the jig and re-program the machine for new sequences of assembly

Being manufactured using high-tech DC electric motors, the assembled product is a very high quality one and requires no post process quality check

Scrap elimination

Continuous screw feeding and high bowl feeder capacity: allow faster and more efficient assembly operations