Questions about the accuracy of the slender rod type cutter

The improvement of the accuracy of the slender rod-shaped tool has always been a difficult point in the manufacture of the tool. The main reason is that the effective part of the tool is too long, and the cutting edge of the tool is too far away from the clamping portion during manufacture. Since the cutting edge is too far from the clamping part and the clamping head has a certain clamping precision (generally 0.002~0.005mm), the radial rounding at the cutting edge of the tool may have been reached before the grinding starts. 0.005mm to 0.01mm (or even larger). Due to the strong grinding process when grinding the tool, especially the grinding of the sipe, the grinding force is large, and the elastic deformation of the tool is large. Many problems arise during the machining process, such as the asymmetry of the tool groove, the outer circle size of the tool, Blade parameters and shape errors do not meet the requirements, and even when the tool is broken, the tool is broken. In order to solve these problems and meet the requirements of high precision and high efficiency of the manufacturing industry, Shanghai Tool Factory Co., Ltd. introduced a TGX five-axis CNC tool grinding machine manufactured by Australian ANCA Company for processing slender rod-shaped tools. The following is a simple analysis of the problem of tool accuracy when machining the slender rod-like tool with this machine tool.

1. The influence of machining machine tools on tool accuracy

The influence of machine accuracy on tool accuracy When manufacturing any tool, the accuracy of the machine tool is the key to determining the accuracy of the tool. Slender rod-shaped tools are no exception. The CNC tool grinding machine produced by Australian ANCA company has five axes, namely three axes of X, Y and Z and two rotating axes of A and C (in addition to a P axis for loading and unloading special workpieces). The accuracy of each axis is very high. The positioning accuracy of the three axes of X, Y and Z can reach 0.001mm, and the positioning accuracy of the two rotating axes of A and C can reach 0.001°. The two grinding wheel axes of the machine tool are arranged vertically. When machining different parts of the tool, not only different grinding wheels but also different grinding wheel shafts can be selected. When the wheel axle needs to be changed, it can be automatically replaced by the program control. The repeatability of the two axes is very high, which can fully meet the precision requirements when processing the slender rod-shaped tool.

Effect of detection data on tool accuracy The machine is equipped with a detection device (with two shapes of probes), and the measured data is directly related to the accuracy of the tool. Since the degree of tightness of the probe's contact with the workpiece during the detection is manually controlled, the measured data contains human error. The grinding wheel machining parameters can be compensated and corrected by the probe data and tool parameter compensation program to meet the accuracy requirements of the tool being machined.

The influence of the support block on the accuracy of the tool The support block equipped with the machine is mainly used for processing slender rod-shaped tools. The position can be adjusted in the horizontal and vertical directions, and can be positioned according to the actual situation. If the position of the support block in the lateral direction (ie, the axial direction of the tool) is unreasonable, a qualified elongated rod-shaped tool cannot be machined. If the support block is too far from the cutting edge of the tool, the edge of the grinding edge will not offset or compensate for the grinding force caused by the strong grinding, the support will be lost; if the cutting edge is too close, the edge will be sharpened. The grinding wheel is easy to grind to the support block. The positioning of the support block in the longitudinal direction (ie the radial direction of the tool) is also important: the support block is too low, the support force for the tool is not enough, which will cause the sipe to form an inverted cone in the axial direction; if the support block is too high, the support block hard top The tool will cause the sipe to form a straight cone in the axial direction. Therefore, the accurate positioning of the support block is also important for the accuracy of the tool.