摘要
为研究直角自由切削松木过程中,切削厚度和刀具前角对切削力和切削区温度的影响,选用马尾松为切削材料,在牛头刨床上进行切削试验。采用石英三向测力仪和红外热成像仪分别测量了切削力和切削区温度,并用高速相机拍摄了切削动态过程,分析切削厚度、刀具前角以及切屑形成对切削力和切削区温度的影响。结果表明:从切削力变化的总趋势来看,平行于切削方向的水平分力F_x和垂直于切削方向的垂直分力Fy均随着切削厚度的增加而增大,随着刀具前角的增大而减小;在切削厚度为0.3 mm,刀具前角为40°和50°时,切屑为折断型切屑,其形成过程中所产生的超越裂缝可能导致切削分力F_x出现下降,这不仅可以减少刀具前刀面的磨损,也可以提高刀具的切削性能和使用寿命;而折断型切屑形成过程中所产生的超越裂缝对切削区温度并没有明显影响。此外,25°前角时的切削力和切削温度均高于40°和50°前角时,且25°前角时的切削力增加速率高于40°和50°前角时,25°前角时切削区温度的增加速率与40°和50°前角时大致相同。因此,小前角刀具对切削力的影响程度高于对切削温度的影响程度,对切削质量和切削过程的稳定性影响较大。在保证刀具切削性能和稳定性的前提下,切削加工应选择较大前角的刀具。
This paper presented a study regarding the effects of rake angle and cutting thickness on cutting force and cutting zone temperature in the process of orthogonal cutting parallel to grain.Pine(Pinus massoniana)was used as a cutting material and was conducted on a shaper,where a quartz three-component dynamometer and an infrared thermographic technique were used to measure the cutting forces and the cutting zone temperature respectively.In addition,a high-speed camera was used to catch the wood cutting dynamic process.Through the analysis of the experimental data and the general trend of cutting force,it was found that the cutting forces(horizontal force F x and vertical force F y)and cutting temperature decreased as the increase of rake angle and decrease of cutting thickness.However,the cutting force decreased under the cutting condition of 0.3 mm thickness of cut with 40°and 50°rake angles due to the cleavage failure parallel to grain.This can not only reduce the wear of the tool rake face,but also improve the cutting performance and service life of the tool.In contrast,the split chip type had no obvious effect on the cutting zone temperature.In addition,the cutting forces(horizontal force F x and vertical force F y)and cutting temperature of 25°rake angle were higher than those by cutters with 40°and 50°rake angles.The increase rate of the cutting forces of 25°rake angle was higher than that of 40°and 50°rake angles,and the increase rate of cutting zone temperature of the 25°rake angle was approximately the same as that of 40°and 50°rake angles.Therefore,the influence of small rake angle on cutting forces was higher than that on cutting temperature,and it had great influence on the surface quality and the stability of the processing.On the premise of ensuring the cutting performance and processing stability,the tools with a large rake angle should be chosen for the cutting.
作者
鲍旭
郭晓磊
曹平祥
邓敏思
王金鑫
BAO Xu;GUO Xiaolei;CAO Pingxiang;DENG Minsi;WANG Jinxin(College of Materials Science and Engineering,Nanjing Forestry University,Nanjing 210037,China)
出处
《林业工程学报》
北大核心
2018年第6期117-121,共5页
Journal of Forestry Engineering
基金
国家自然科学基金(31500480)
江苏高校优势学科建设工程资助项目(PAPD)
