A Generic and Efficient Approach to Determining Locations and Orientations of Complex Standard and Worn Wheels for Cutter Flute Grinding Using Characteristics of Virtual Grinding Curves

Abstract

As an important feature of cutting tools, flutes determine rake faces of their cutting edges, their rigidity, chip breaking, and chip space. In industry, flutes are often ground with standard wheels of simple shape (e.g., 1A1 or 1V1 wheels), resulting in flutes without much variation. To make flutes of more complex shape, standard wheels of complex shape (e.g., 1B1, 1E1, 1F1, and 4Y1 wheels), compared to the current ones, should be used. Unfortunately, current commercial software cannot calculate the locations and orientations of these wheels; this is why they are not used to machine flutes. Moreover, grinding wheels are gradually worn out in use, and the flutes lose accuracy accordingly. Therefore, locations and orientations of the worn wheels should be recalculated or compensated in machining; however, no such technique is currently available. To address this challenge, a generic and efficient approach to determining the locations and orientations of complex standard and worn wheels for cutter flute grinding is proposed in this work. First, a parametric equation of the generic wheel surface and its kinematic equation in five-axis flute grinding are rendered. Second, virtual grinding curves are proposed and defined to directly represent the relationships between wheel location and orientation and the flute profile in a geometric way. Then, the characteristics of the virtual grinding curves are investigated and formulated, and a new model of the generic wheel location and orientation is established. Compared to the existing comparative model, this model significantly increases solution liability and computation efficiency. Finally, three practical cases are studied and discussed to validate this approach. This approach can be used to make flutes of more complex shape and can increase flute accuracy by compensating the locations and orientations of worn wheels in machining.

Research on grinding wheel wear measurement methods: Current status and future perspectives

“…图 15 分形维数计数过程示意图 [214] Figure 15 Schematic diagram of the fractal dimension counting process [214] Copyright © 2019, Elsevier 砂轮磨损预测方法也为砂轮磨削过程中砂轮磨 损的实时补偿提供了依据. 如图 16 所示, Habibi [216] 等人建立了虚拟磨削曲线, 用于磨削过程中对砂轮 磨损的补偿. Zhang [217] 等利用光学 CCD 对修磨后的 砂轮轮廓进行了定位测量, 研究了砂轮磨损形式, 并 基于此提出了合理的砂轮磨损补偿办法.…”

Wheel path planning for flute grinding of non-cylindrical solid end-mills based on circular arc projection

“…proposed iteration-based methods to search the wheel position for traditional flute [8] and "closed" flute [9] that needs two-pass grinding, and they also applied the method to determine the wheel position after the wheel wear [10]. Based on analytic geometry, some researchers [11,12] established the mathematical relationship between the wheel position and the flute parameters by a group of highly complex nonlinear equations. However, calculating the wheel position by solving the equations numerically is time-consuming and the solution is sensitive to the initial value.…”

A novel wheel path generation approach for grinding taper end-mills subject to adaptive cross-section

“…By setting the grinding wheel to move spirally relative to the blank step by step, and each step can be regarded as subtraction calculation, the method can get the 3D model of the flute. In sum, the direct method can get the exact geometry of the flute, but the geometric characteristics of the flute can not be controlled and it is greatly limited by standard grinding wheel [18]. Moreover, the grinding process is inefficient and time-consuming.…”