Dressing Kinematics

Dressing comprises the establishment of both the grinding wheel’s shape (profil­ing) and the grinding wheel’s cutting ability (sharpening). Depending on the grinding wheel bond, the profiling process can not only produce the desired tool geometry, but also sharp edges and sufficient chip space. In practice, this is most commonly the case, which is why the terms of profiling and dressing are used synonymously. In rare cases, separate processes have to be carried out for profil­ing and sharpening.

The dressing strategy used depends on qualitative and economic requirements and on the machine concept at hand. The abrasive material, the bond type and the grinding wheel shape determine the possible dressing tools and methods.

Generally, an automated dressing process is preferable. However, reproducible dressing results are a prerequisite for this; dressing tool wear has to be predictable, so that the dressing amounts and results remain definable. Moreover, the grinding wheel should stay on the spindle in order to limit non-productive times and clamp­ing errors.

Dressing methods can be categorised according to various aspects and criteria. One criterion is the method’s kinematics. We distinguish between rotating and non-rotating dressing tools.

The dressing tool materials can also be used as an ordering criterion. In order to obtain a defined machining of the grinding material during the dressing process, the dressing tools should be harder than the abrasive material. Thus, tools with diamonds are primarily used for dressing. Other equally or less hard materials are seldom used, as this leads for the most part to high dressing tool wear. This pre­cludes defined dressing of profiled grinding wheels. One can thus differentiate be­tween diamond and diamond-free media.

The operating principle is another potential aspect which can be considered in classifying dressing methods. In this context, the mechanisms of chip removal, separating the bond and material removal are significant. Chip removal is used by diamond dressing tools that sever the grits and the grinding wheel bond. The mechanism of separation, on the other hand, describes an isolated influence on the grinding wheel bond. Electrochemical or spark-erosive operating principles can be summarised under the category of material removal (see Manufacturing Processes Volume 3).

A dressing effect can however not only be achieved by machining the grinding wheel surface, but also by overloading the grinding wheel structure. For example, grinding very hard materials under extreme cutting conditions creates large cutting forces at the grits, which causes splintering or breakaway of the grits from the bond structure.

Updated: 24.03.2016 — 12:06