Definition of Internal Grinding:
Internal grinding is a finishing method of inner holes, which can process through holes, non-through holes, stepped holes and end faces of parts. Internal grinding can also process hardened workpieces, so it is widely used in machining. Internal grinding generally achieves higher dimensional accuracy.
About the application of internal grinding wheel:
1. The diameter of the inner grinding wheel should not be too large or too small
When grinding the inner hole, if the diameter of the grinding wheel is too large, the contact arc between the grinding wheel and the workpiece increases, which increases the grinding heat and makes it difficult to cool and remove. If the diameter of the grinding wheel is too small, it is difficult to achieve the ideal grinding speed (30m/s~50m/s), which increases the grinding thickness, increases the friction of the abrasive particles, and is easy to blunt, which increases the surface roughness of the inner hole. , the production efficiency is reduced.
In order to obtain a good grinding effect, the diameter of the grinding wheel and the diameter of the inner hole should maintain an appropriate ratio, which is usually between 0.5 and 0.9. When the hole diameter is small, as long as the problem is that the peripheral speed of the grinding wheel is low, a large ratio should be taken at this time; when the hole spacing is small, the main problem is the difficulty of cooling and chip removal, and a small ratio should be used at this time. Please refer to the table below for the selection of the diameter of the internal grinding wheel.
The diameter of the hole to be ground/mm | Wheel diameter/mm | The diameter of the hole to be ground/mm | Wheel diameter/mm |
| 12-17 | 10 | 45-55 | 40 |
| 17-22 | 15 | 55-70 | 50 |
| 22-27 | 20 | 70-80 | 65 |
| 27-32 | 25 | 80-100 | 75 |
| 32-35 | 30 |
2. The width of the inner grinding wheel should not be too wide or too narrow
During internal grinding, if the width of the grinding wheel is too narrow, the grinding wheel is easy to wear, which is not conducive to improving the production efficiency and reducing the surface roughness; if the grinding wheel is too wide, the grinding force will increase, which will easily cause the bending deformation of the long axis of the grinding wheel. Therefore, when grinding the inner hole, the appropriate grinding wheel width should be selected. Within the range allowed by the rigidity of the extension axis and the power of the machine tool, the width of the grinding wheel can be selected according to the length of the workpiece, as shown in the table below.
| Grinding length/mm | Wheel width/mm | Grinding length/mm | Wheel width/mm |
| 14 | 10 | 45 | 32 |
| 30 | 25 | >50 | 40 |
