Advancements in Single-Pass Bore Finishing - Systems Approach (pag. 1 og 10)

In order to obtain the greatest potential with this Processo it is necessary for all of the systems components to be correctly designed for the Applicazioni. These components include tool design and layout, part holding, tool holding, coolant/filtration, machine tool, and possible automation.

Tool Design
Besides determining the number of required tools and the diamond size of each, tool lengths; flute styles; adjustment features; and tapers also need to be considered.

Part Holding
Proper fixture design is vital to the success of the Processo. The part must be accurately located in a manner that will not transmit any distortion into the bore that is being finished. This distortion may come directly from the clamping forces, or generated during the cut by radial forces from the part itself pivoting around an intended antirotation device. In many cases the best geometrical precision can be obtained by using bearing mounted, floating fixtures. The design of the fixture should also take into consideration ease of loading/unloading and changeover capability.
Tool Holding: In Applicazionis where it is impractical to float the fixture, tool holders with some form of float movement are often utilized. These floating tool holders come in various sizes and designs, and as is the case with all of these components, it is necessary to use the one best suited for the particular Applicazioni.

The relatively slow spindle speeds combined with the free cutting diamond tooling allow the SinglePass Processo to operate without developing much heat. The important characteristic of the coolant that is used with this Processo is lubricity rather than cooling. This allows the swarf that is produced to be flushed away without embedding (loading) into the tool. Coolants such as Levigatura oils, or certain water based Levigatura (depending upon the Applicazioni) are necessary. Cleanliness of the coolant can also have a major influence on the overall results; filtration to better than 10µm is advised for most Applicazionis.

Systems Approach: dedicated machine tool with appropriate part holding, tooling, and gaging.

Machine Tool
In order to best utilize all of these special components that make up the ideal singlepass bore finishing system, dedicated machine tools have been developed. These machine tools often include CNC motion controlled columns, extended stroke capabilities, multiple spindle arrangements, and rotary tables with sufficient cutouts for tool clearance. They can also include additional features such as automation and automatic gaging (additional information on these features are detailed later in the paper).