Техническая информация Sumitomo - страница 6

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Technical Guidance Basics of Threading Turning Edition ■ Thread Cutting Methods Cutting Method Characteristics Radial Infeed Trailing · Most common threading technique, used mainly for small pitch threads. Leading Edge · Easy to change cutting conditions such as depth of cut, etc. Edge · Longer contact points lead to more chatter. · Difficult to control chip evacuation. · Damage on the trailing edge gets larger faster. Feed Dir. Direction of Cut Flank Infeed · Effective for large pitch threads and blemish-prone work material surfaces. · Chips evacuate from one side for good chip control. · The trailing edge side is worn, and therefore the flank is easily worn. Corrected Flank Infeed · Effective for large pitch threads and blemish-prone work material surfaces. · Chips evacuate from one side for good chip control. · Inhibits flank wear on trailing edge side. Alternating Flank Infeed · Effective for large pitch threads and blemish-prone work material surfaces. · Wears evenly on right and left cut edges. · Since both edges are used alternatively, chip control is sometimes difficult. ■ Troubleshooting for Threading Failure Cause Countermeasures Excessive Cutting Edge Wear · Tool material · Select a more wear-resistant grade · Decrease the cutting speed · Cutting condition · Optimise coolant flow and density · Change the number of passes. Cutting Edge Failure Uneven Wear on Right and Left · Check whether the cutting edge inclination angle is Sides · Insert attachment appropriate for the screw lead angle. · Check whether the tool is mounted properly. · Cutting condition · Change to corrected flank infeed or alternating flank infeed Chipping · Cutting condition · If caused by a built-up edge, increase cutting speed Breakage · Packing of chips · Supply enough amount of coolant to the cutting edge. · Cutting condition · Increase the number of passes while decreasing the depth of cut per pass. · Use different tools for roughing and finishing applications. · If blemished due to low-speed machining, increase the cutting speed. Poor Surface Roughness · Cutting condition · If chattering occurs, decrease the cutting speed. · If the depth of cut of the final pass is small, make it larger. N Shape and Accuracy · Tool material · Select a more wear-resistant grade Technical Guidance / · Inappropriate cutting · Select a correct shim to secure relief on the side of References edge inclination angle the insert. Inappropriate Thread Shape · Insert attachment · Check whether the tool is mounted properly. · Small depth of cut · Check cutting depth Shallow Thread Depth · Tool wear · Check damage to the cutting edge. N14