Asymmetric boring increases productivity, reduces costs

A geometric leap forward, asymmetric line boring accentuates the advantages of reaming and line boring of items such as engine blocks, while eliminating disadvantages.

Normal guide diameters are of full material, or built of three or more guide pads, providing no degree of freedom from the bore wall while feeding in and out. The asymmetric solution supports guide pads in a setup similar to a typical guide pad reamer, but the guide pad – normally located 180° to the cutting edge – is rotated so the resulting design provides freedom to enter and exit the guide part even passing through the raw bores. This geometry allows feeding the bar through raw bores on an eccentric path.

Asymmetric line boring offers precision bores and support on both ends of the tool and eliminates expensive lift functions, obstructive counter bearings, or critical mechanisms inside the tool. Complete feed-in and feed-out moves can be done at increased feed rates on conventional machining centers.

Indexable, high-precision RI8 inserts with eight pre-defined, back taper cutting edges allow for high feed rates. The diameter can be adjusted to 1µm, and the high of the conical clamp screw avoids any settling effects.

Both inserts and the asymmetric boring bar are designed so the inserts clamp directly into the boring bar body, eliminating the need for cartridges.
 

Asymmetric solution

• A pilot reamer is fed in and finishes journal 5
• The component (or machine table) rotates 180°
• The asymmetric boring bar is fed in off- center using the machining center’s X-Y axis
• The tool is moved to the center and finishes journals 1 through 4 simultaneously
• The tool is retracted off-center with fast feed out

Kennametal Inc.
www.kennametal.com