To make the fine machining of the crankshaft bearing journals on a machining centre economical, line boring bars are often used. With an innovative concept, MAPAL has been able, in collaboration with a machine manufacturer, to optimise this processing in several ways: Compared with conventional line boring bars, quality can be increased, processing can be sped up, and tool service life can be increased, all thanks to the new line boring bars with compensation-enabled cutting edges.
The new line boring bars simultaneously act as actuating tools. The cutting edges are controlled to retract into the tool into the storage slots via an inner tie rod. Only in this way can all the separators of the crank shaft bearing lanes be machined simultaneously in one pulling cut. Without the control of the cutting edge, a collision of the work piece and the cutting edge upon retracting would be inevitable. The drawbar can be operated through different systems, such as the mechatronic systems (e.g. TOOLTRONIC), via a coolant pressure system or an in-house system of the machining centre.
A manual adjustment of the cutting inserts to compensate for wear causing with machine downtime is not necessary, thanks to the new implementation of the line boring bars. This is because according to each individual application, the cutting edges are measured directly in the machining centre with an integrated measuring rod or externally, and the actual value entered into the control of the machining centre. The cutting edges will be readjusted accordingly and the determined wear will automatically be compensated for.
Source: MAPAL Dr. Kress KG