Study on the Sharpening Characteristics of Single Crystal Diamond Tools (3)

Through the comparison of the various sharpening conditions, it is determined that the main cutting edge and the minor cutting edge are more reasonable. The direction of the grinding wheel should be directed to the direction of the blade pressing direction and form an angle of 15-30o. According to the machine tool data and considering the material removal rate and grinding ratio, the recommended grinding wheel speed is 8~65m/s. It is found through experiments that the grinding effect is best when the grinding wheel speed is 22~28m/s; the Rt value of the cutting edge is the smallest when the speed is 15m/s. Therefore, in the actual sharpening process, the cutter head is placed in the area around the grinding disc φ140, the grinding wheel speed is selected to be 2100 rev/min during rough grinding, and the grinding wheel speed is selected to be 1000 rev/min during fine grinding to ensure coarse grinding. The grinding wheel speed is about 23m/s, and it is about 15 m/s in fine grinding. The reciprocating swing amplitude of the main shaft should not be too large, generally it is slightly wider than the sharpening edge, and the swing frequency should not be too fast.

In order to obtain an economical sharpening effect, the grinding contact pressure needs to increase as the blade length increases. In rough grinding, as the contact pressure increases, a positive abrupt change in material removal rate occurs. In super-fine grinding, the material removal rate increases gradually with the increase of contact pressure. When the contact pressure increases to 180N, the material removal rate gradually decreases. When the contact pressure between the cutter and the grinding disc during fine polishing is 12 to 14N, it is most beneficial to ensure the surface finish of the sharpening surface. Therefore, the tool should have proper contact force with the surface of the grinding wheel during sharpening. When rough grinding, try to use the pressure control of the machine tool. After the tool is clamped, the tool should be applied as soon as possible, and press the machine position shifting lever (the lever is used to manipulate the table to convert between the working position and the measuring position) to ensure Large contact force is required to avoid causing machine tool vibration to cause chipping.

5 Conclusion

For the anisotropy of diamond crystals, accurate crystal orientation is required before sharpening. At the same time, the temperature, machine vibration, grinding wheel granularity, rotation speed and reciprocating speed should be strictly controlled during the sharpening process. Grinding equipment with high rotation precision and grinding disc with high plane precision should be selected to avoid the hard and brittleness and poor heat of diamond crystal. Unnecessary grinding and damage due to stability. In addition, the problem of manual pressure can not be solved to ensure the stability of the pressure, and the detection method and the detection instrument matched with the sharpening process are matched to ensure the quality stability of the sharpening.

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