Precision Problem of Machining Slender Rod Type Tool in CNC Lathe

The improvement of the accuracy of the 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 chuck has a certain clamping precision (generally 0.002~0.005mm), before starting grinding,

The radial round jump at the cutting edge of the tool may have reached 0.005 mm to 0.01 mm (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.

The following is a simple analysis of the problem of tool accuracy when machining a slender rod-shaped tool with a CNC lathe.

First, the impact of CNC machining tools on tool accuracy. The influence of machine tool accuracy on tool accuracy When manufacturing any tool, the accuracy of the machine tool is the key to determining the tool accuracy.

Slender rod-shaped tools are no exception. The influence of the support block on the accuracy of the tool The support block equipped with the machine tool is mainly used for CNC machining of the slender rod-shaped tool. Its 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 low, the supporting force of the tool is insufficient, which will cause the sipe to form an inverted cone in the axial direction; if the support block is too high, the support block will hardly align with the tool, which 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.

CNC lathe machining

Second, the impact of CNC grinding machine grinding wheel on tool accuracy. All parameters of the tool are determined by the relative movement of the grinding wheel and the tool. Therefore, the diameter of the grinding wheel, the angle at which the grinding wheel directly participates in the cutting, the length of the flange of the grinding wheel shaft, the wear of the grinding wheel and the particle size of the grinding wheel all affect the accuracy of the tool.

Grinding wheel angle measurement or input accuracy The grinding wheel angle measurement or input may be inaccurate: the blade edge width does not match the requirements; the step tool step surface angle does not match the requirements;

There is an error in the position or angle of the back angle of the tool; there is an error in the groove angle of the chip flute.

Third, the cooling effect of the coolant on the grinding zone during the machining of the hardware parts will directly affect the accuracy of the tool.

Choosing a good performance coolant and proper cooling pressure will help the coolant to enter the grinding zone, taking the cutting heat and chips away in time, effectively reducing the surface roughness of the tool.