An important weld-preparation operation before weld-joining the thin sheet metal components is to remove the wrinkles and bulges from the welding zone and create an even surface for leak-proof weld-joints. Roller planishing is a simple, inexpensive and skill-free operation. When the sheet metal edges are fed through two rollers, a smooth & bulge-free surface is created. It relieves the stresses and the welded joints will be stronger. Welding after planishing ensures almost zero leakage from the joints.

Shenoy Engg Pvt Ltd, a Bangalore based SPM manufacturers, have developed the Roller Planishing SPM. The bottom roller is a driven roller and receives the drive from a VFD controlled drive unit. The drive unit consists of a motor and a worm reduction gear box. The step-less rotational speed of the roller is from 1 RPM to 20 RPM. The driven roller is connected to the drive unit through a spindle, which is rigidly supported by a pair of pre-loaded taper roller bearings. The top roller is an idle roller, having 50 mm adjustable up and down stroke through a Ø 150 mm pneumatic cylinder (5 bar / 900 kg). The up and down arm movement is guided through hardened LM guide ways. The top drive roller is also supported by a separate spindle unit and angular contact bearings. Both the drive and driven rollers are detachable and hardened & ground.

When the foot operated switch is pressed, the timer controlled driven roller rotation starts; simultaneously the top roller gets pushed down towards the driven roller. The edge of the job is fed through the rollers, following the required job contours. On completing the planishing operation, the foot switch is released; the top roller retracts to the home position and the driven roller stops rotating.

An automatic lubrication system lubricates the sliding and rotating parts of the machine at the regular intervals. A digital display is provided in the console which indicates the RPM of the drive roller. All other operational controls are provided in the console.

SEAM WELD ROLLER PLANISHING MACHINE

Case Study:

Customer’s Requirement:

A client, who has a fabrication shop received an order to make seam welded tubes. The client’s fabrication processes like cutting, rolling and welding were well established. But they did not have a solution to get flat level surface on a weld bead. They approached us for a solution.

Our Solution:

We offered a custom made machine to planish the component. This machine was specifically designed and built for this application. The machine has a scissor type arrangement with a hydraulic cylinder actuating the arm. At the end of the arms, hardened roller are mounted to flatten the weld bead on the component. One roller is idler roller, where as the other roller is a driven roller. The driven roller is powered by a 1hp AC induction motor coupled to a worm reduction gearbox. The motor is routed through a variable frequency drive to vary the roller speeds.

Conclusion: