摘要
功率超声珩磨技术在发动机缸套的精密加工中能够得到较好的表面质量,其中珩磨力的大小与超声振动特点有关,是影响工件材料去除、磨削热及表面质量的重要因素之一。基于超声珩磨材料去除机理,考虑了油石表面磨粒分布规律,建立了包括材料切屑变形和磨粒与工件摩擦两种情况的超声珩磨力学模型。由力学模型仿真结果可知:功率超声珩磨磨削力与加工参数及加工过程中材料物理变化均有关,特别是材料应变率效应更加明显;在相同加工条件下,超声珩磨磨削力比普通珩磨平均降低50%以上,并且法向力与切向力比值增大,有利于材料的去除;超声振动能够减小磨粒与工件的平均动态摩擦系数,从而减小平均切向摩擦力大小,有利于提高工件表面质量;珩磨深度较主轴转速对珩磨力影响更大,当主轴转速高于620 r/min时,珩磨力开始逐渐减小。
It will be able to get a better surface quality in the precision honing of the engine cylinder liner with the technology of power ultrasonic machining. The grinding force is related to the ultrasonic vibration,which affects the material removal,grinding heat and the surface quality. Based on the material removal mechanism of ultrasonic honing and the grain distribution on the surface of oilstone,the ultrasonic honing force model was established,which included material chip deformation and friction situation between grain and workpiece. With the simulation results obtained by using the established force model it can be found that the grinding force is affected by the processing parameters and the physical change of materials; the ultrasonic honing force is decreased by more than 50%compared with the traditional honing under the same processing condition,and the ratio of normal force to tangential force is also increased; the average dynamic friction coefficient decreases under ultrasonic vibration,leading to the reducing of average tangential force; the honing depth is more significant to affect the honing force than the spindle speed,and the honing force begin to decrease gradually when the spindle speed is higher than 620 r /min.
出处
《机械科学与技术》
CSCD
北大核心
2014年第6期858-863,共6页
Mechanical Science and Technology for Aerospace Engineering
基金
国家自然科学基金项目(50975265
51275490)
山西省太原市大学生科技创新项目(120164060)资助
关键词
超声珩磨
磨粒分布
摩擦系数
磨削力
仿真
calculations
computer simulation
discriminant analysis
friction coefficient
friction
grain distribution
grinding（machining）
grinding force
honing
machining
normal distribution
processing
schematic diagrams
simulation
strain rate
surface properties
ultrasonic machining
ultrasonics
velocity
vibrations（mechanical）
