Study on Tools with Restricted Tool-Chip Contact Length (Part 7)
Study on Tools with Restricted Tool-Chip Contact Length (Part 7)
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刀具与切屑接触长度受限的刀具研究（第7部分）
DOI：
10.2493/jjspe1933.34.161
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发表时间：
1968
影响因子：
--
通讯作者：
E. Usui
中科院分区：
文献类型：
--
作者：
K. Hoshi;E. Usui
对不同类型的硬质合金刀具在间歇加工碳钢时的磨损特性和刀具寿命曲线进行了临界比较。在伴有强烈冲击的间歇加工中，切削刀具似乎一般比传统刀具弱。刀具-切屑接触长度的减小，虽然减少了后刀面和前刀面的连续磨损，但促进了刀具刃口的切屑或折断。一次前角越大，接触长度越短，倾向越严重。碎屑似乎是由不规则的冲击应力引起的，这是由于粘连在一起的边缘或金属碎片粘在切割边缘造成的。因此，切割刀的弱点可以归因于它们在更高的切割速度下保持积刃的强烈倾向以及由于刃口形状而导致的机械弱点。刀具寿命特性可以用前述的积刃效应很好地解释。然而，与传统刀具相比，具有负前倾角和较长接触长度的切割刀具仍有可能获得更长的刀具寿命。在中等切割速度下尤其如此，因为在此速度范围内切屑倾向较小。
Critical comparisons of wear characteristics and tool-life curves for various types of carbide cut-away tools in intermittent machining of a carbon steel are presented. Cut-away tools appear generally to be weaker than conventional tools in intermittent machining accompanied with strong shocks. Chipping or breaking-off of cutting edge are promoted by the reduction of tool-chip contact length although continuous wear in flank and rake faces are decreased. The larger the first rake angle and the shorter the contact length are used, the more serious the tendency becomes. The chipping appears to be caused by an irregular impact stress due to adhered built-up edge or metal debris to the cutting edge. The weakness of cut-away tools, therefore, can be attributed to their strong tendency to maintain built-up edge up to higher cuting speeds as well as their mechanical weakness due to edge-shape. The tool-life characteristics are well explained by the aforementioned effect of built-up edge. It is still possible, however, to obtain longer tool-life with cut-away tools having negative rake angle and long contact length than with conventional tools. This is especially true in medium cutting speeds because of less tendency of chipping in this speed range.