Centre for design & development offers a plc controlled plateau honing machine. Plateau honing is used in cylinders of internal combustion engines of diesel and petrol vehicles. Plateau honing involves flattening of the peaks produced in conventional honing to give the bore a surface finish similar to that achieved after many hours of running-in with a piston. It is divided into two phases and hence, requires a double expansion honing tool. The first phase is to improve the geometrical form accuracies of the bore, removal of material and obtain the basic surface structure with large hollow pockets and characteristic cross hatch pattern. In the second phase of plateau honing, the surface peaks are removed in a few seconds and small plateaus with good surface finish and high bearing areas are formed which give correct fit of runing engine. The roughing and finishing/plateau honing are done in a single spindle machine, with a double expansion system by the plc controls of the honz honing machine. If roughing and finishing are carried out on separate spindles, the plateau honing structure is irregular as the component distorts during clamping. The coaxial honing is made possible by a floating adaptor connection joining the machine spindle with the honing head. In-process plug sizing device controls the tolerance in roughing, and finishing is carried out with a built-in timer control. The spindle rotation is reversed during each roughing and finishing cycle, resulting in removal of high stocks with low contact pressures. Low pressures ensure honing without smeared surfaces or metal folding. Pulse feed system of honz honing machine, where alternate high pressure and low pressure pulses are generated, ensures that the stones do not get loaded and at the same time spark out at the end of each cycle ensures good form generation of the bore.
