Design and Fabrication of Fixture for Internal Grinding CNC Machine

The work carried out was on a special purpose grinding CNC machine- Meccanodora Cimat C-661, a 3axis PCbasedCNCcontrollerhavingmaximumspeedof40,000RPM.WhentheprojecttomodifytheCIMA TC-661ID grinder CNC machine tool was proposed, the machine tool, process and modification plan were studied. The company’s requirement was to grind the inner surface of the rotary sleeve valve in the ID grinder to a very high surface finish (0.5 – 0.6 Microns) and high precision, so a new ID grinder CNC was needed. As the new machine would be too expensive, the company considered modifying the existing ID grinding C-661CNC to a general-purpose ID grinding CNC, which makes itcost-effectiveandsuitableforgrindingrotarysleevevalvesand othercylindricalparts.Aspecialfixturedesignwas requiredfor holding the sleeve valve that would serve the requirement. Therefore, a collet type of fixture was designed which will self-lock the sleeve valve with the existing setup. The designed automatic clamping system with collet fixture reduced human intervention which were often prone to errors. Therefore, considering all the design aspect, the special purpose magnetic type of fixture made up ofchrome vanadium alloy spring steel 0.50%C was replaced with a collet type offixture.Thisinturn hasfoundtoreducethetotal costfornewmachine providingmaximum benefitsintermsof company and customer.