Dressing method of grinding wheel for spiral gear form grinding

The tooth profile accuracy of grinding wheel is relatively high, such as grinding high-precision gear, screw, worm, spline and so on. Diamond roller CNC wheel dresser brings great convenience for dressing complex profile. It is not only simple to operate, flexible to trim, convenient to change trimming profile, but also easy to trim complex profile without relying on experience.

After using the grinding wheel for a while, three possible conditions will occur. One is that the abrasive loses its acute angle and becomes blunt; the other is that the grinding wheel becomes blunt because the abrasive chips are inserted into the gap; the third is that the grinding wheel changes its shape and reduces its dimensional accuracy. At this time, if the grinding wheel continues to be used, its cutting capacity and grinding efficiency will be reduced, grinding heat will be increased, and then the surface roughness of the workpiece will be significantly reduced, the workpiece will be deformed or even cracked, and the workpiece precision will not meet the processing requirements. At this time, the grinding wheel needs to be trimmed in time. Grinding wheel dressing includes two processes: dressing and sharpening. Dressing is to make the grinding wheel have a certain geometry, while sharpening is to make the grinding wheel sharp. If the binder is loose, the general dressing and sharpening can be completed at one time, such as multi porosity ceramic bonded diamond wheel; if the binder is dense, the dressing and sharpening need to be carried out in sequence, such as resin and metal bonded wheel.

The most common dressing methods of grinding wheel are turning, forming diamond rolling and grinding

(1) Turning dressing

Turning method is the most commonly used, generally using single diamond pen, diamond dressing tools to achieve the purpose of dressing. But because the tip of the diamond pen is affected by continuous and concentrated heat and force, resulting in severe wear and unstable dressing quality, the state of the grinding wheel surface is difficult to meet the grinding requirements, so turning method has been widely used in the mechanical wheel dresser.

(2) Finishing by rolling

The rolling method is to make the forming surface of the diamond roller into the shape opposite to the concave and convex of the grinding surface of the required grinding wheel. The dressing of the forming grinding wheel is realized by the relative movement between the roller and the grinding wheel to be trimmed. During the rolling dressing, the rotation of the roller is driven by a lower speed grinding wheel. However, due to the extrusion pressure between the repaired grinding wheel and the roller, the abrasive particles will be broken or fall off. Although the dressing efficiency and roller durability of this dressing method are very high, and the grinding wheel can maintain good cutting performance, but the manufacturing cost of the diamond roller is high, the surface roughness of the grinding wheel, the process is relatively complex, and the surface roughness of the workpiece grinding is large, so this method is suitable for dressing the grinding wheel with large batch and special profile.

(3) Grinding dressing

Grinding dressing is to grind the diamond roller with the grinding wheel. The servo motor drives the dressing wheel and the grinding wheel respectively to realize forward and reverse rotation and stepless speed regulation, so as to meet the requirements of the roller for reverse dressing (reverse speed of the contact point between the roller and the dressing wheel) and forward dressing (same speed of the contact point between the roller and the dressing wheel). Diamond roller is a new type of NC dressing tool for grinding wheel. It can avoid the condition that the dressing tool will affect the profile accuracy due to the excessive wear of the dressing tool, and can get a relatively good profile of the grinding wheel. This kind of trimming tool is easy to operate and has a short repairing time. It can trim some complex surfaces which can not be realized by profiling trimming, and can keep the stability of mass parts quality for a long time. Based on the above advantages, the diamond roller has been widely used in the form grinding at home and abroad.