Line Boring Bar Enables Cutting Edge Retraction for Crankshaft Machining

Mapal’s line boring bar for the fine machining of crankshaft bearing journals is designed to optimize the process with compensation-enabled cutting edges that are said to increase quality, processing speed and tool life. The line boring bar simultaneously acts as an actuating tool. The cutting edges can be retracted into storage slots within the tool via an inner tie rod. This way, all the separators of the crankshaft bearing lanes can be machined simultaneously in one pulling cut. Without control of the cutting edge, a collision of the workpiece and the cutting edge upon retracting would be inevitable. The drawbar can be operated through different systems, including the mechatronic systems (such as the company’s Tooltronic drive system), a coolant pressure system or an in-house system on the machining center.

The line boring bar eliminates the need to manually adjust the cutting inserts to compensate for wear, thereby reducing machine downtime. This is because the cutting edges are measured directly in the machining center according to each individual application, and the actual value entered into the machine control. The cutting edges will be readjusted accordingly, automatically compensating for the determined wear.