Spotwelding in a Robotic Press Brake Cell....

INTRODUCTION :

A couple of years ago, Ripley Engineering Limited - based in Basingstoke, installed a robot loaded CNC press brake sheet metal forming cell.

Recent additions to their customers product range caused a re-think of the manufacturing processes in one particular area - how to secure a folded flange to the remaining panel.

Compound bends around the front edge of the cabinet could allow the flange to vibrate against the cabinet side during operation, unless the flange is secured.

After some discussion, Robotix was contracted to design and manufacture a suitable spot welding machine, capable of attaching the flange to the side panel - with no visible marking to the outside of the panel.

Strategically positioned within the press brake cell, the robot offers the flanged edge of the panel to the spot welder. The spot welding gun has two working positions, allowing the robot to complete the spot welding in one operation.

( The photograph shows the spot welding machine in our loading bay - ready for delivery to the customers works. )

SOLUTION :


Robotix selectd an 18.0 kVA spot weld gun supplied by Sureweld Limited - Northampton for the job ( the self contained unit, complete with weld timer and robot interface is show in the photograph below ).

To elliminate unsightly marks, a flat swivel pad electrode is used on the outside of the panel. This electrode, together with precise control of the weld conditions ensures that the panel remains in perfect condition.

A guided rodless pneumatic cylinder allows the spot welding gun to travel between its two working positions.

Integral solenoid valves, speed controllers and hydraulic shock absorbers ensure that the motion of the heavy spot weld gun ( weighing in at 55 Kg ) is always smooth. A counter-balance weight running inside the hollow column and connected to the spotweld gun carriage by roller chain, elliminates any risk of 'run away' should the air supply fail.

Sequencing of the spot welder and pneumatic slide are under the control of the program in the ABB robot controller.

Sliding spotweld gun :