Why the diameter of the internal grinding wheel should not be too large or too small？

When grinding inner holes, if the diameter of internal grinding wheel is too large, the contact arc between grinding wheel and workpiece will increase, which will increase the grinding heat and make it difficult to cool and row. If the grinding wheel diameter is too small, it is difficult to achieve the ideal grinding speed (30m/s~50m/s), which will increase the grinding thickness, increase the compliance of the abrasive particles, and easily blunt, which will increase the surface roughness of the inner hole and reduce the production efficiency.

In order to obtain good grinding effect, the diameter of the grinding wheel and the diameter of the inner hole should be kept an appropriate ratio, which is usually between 0.5 and 0.9. When the aperture is small, as long as the problem is that the circular speed of grinding wheel is low, a large ratio should be taken. When the hole spacing is small, the main problem is the difficulty of cooling and chip removal, so a smaller ratio should be removed.

Refer to the following table for diameter selection of the internal grinding wheel：

Why shouldn't the width of inner wheel be too wide or too narrow?

If the width of grinding wheel is too narrow, the grinding wheel is easy to wear, which is not conducive to improve the production efficiency and reduce the surface roughness. If the grinding wheel is too wide, the grinding force will increase, which will easily cause the bending deformation of the grinding wheel connecting the long shaft. Therefore, appropriate width of grinding wheel should be selected when grinding inner hole. The grinding wheel width can be selected according to the workpiece length within the allowable range of the rigidity of the connecting shaft and the power of the machine tool, as shown in the table below.

How to choose grinding wheel for CNC internal grinding machine?

The grinding quality of CNC internal grinder also depends on the grinding wheel to a large extent. Grinding wheel plays a key role in the quality of CNC grinding machine grinding, we often use electroplating grinding wheel, resin grinding wheel, ceramic grinding wheel, CBN grinding wheel, so we should choose what kind of grinding wheel is the most suitable for us?

1. Shape of diamond grinding wheel for CNC internal grinding machine

CNC grinder commonly used two kinds of wheel shapes: cylindrical and cup grinding wheel . Cylindrical grinding wheel mainly grinding through hole, cup grinding wheel mainly grinding inside hole, can also grind the end face of step hole.

2. Diameter of CNC grinder grinding wheel: 

In order to obtain the ideal grinding speed in the grinding process, it is generally best to choose a grinding wheel close to the aperture, but when the grinding wheel diameter increases, the contact arc between the grinding wheel and the workpiece also increases, resulting in the increase of grinding heat, which makes chip removal and cooling more difficult. In order to achieve better results, there is an appropriate ratio between the diameter of the grinding wheel and the aperture of the workpiece being ground, usually between 0.5-0.9.

3. Width of grinding wheel

CNC grinding machine adopts wider grinding wheel, which is beneficial to reduce workpiece surface roughness value and improve production efficiency, and can reduce grinding wheel wear. However, the grinding wheel should not be too wide, which will increase the grinding force and cause the bending deformation of the grinding wheel connecting the long shaft. The width of the grinding wheel can be selected according to the length of the workpiece within the allowable range of the rigidity of the grinding wheel connecting the long shaft and the power of the machine tool.

Moresuperhard can provide diamond&CBN internal grinding wheel for hole machining,we can provide 1A8, 1A1W, 1A1 type internal grinding wheel to achieve high workpiece precision.

----EDITOR: Doris Hu

---POST: Doris Hu