Vertical double face grinder is widely used in plane grinding because of its good machining quality, high machining efficiency, non magnetism and many other advantages. The grinding principle is shown in the figure below. In the actual machining process, the diversity of workpieces often encounter the grinding of the two ends of the workpiece with asymmetrical interface. In the machining process, in addition to the conventional machining quality problems, the appearance quality is good Serious out of tolerance and out of alignment of datum plane and wear occurred.

1. Factors affecting appearance quality and datum plane Flatness:

Many factors, such as the directional friction force of the grinding wheel and the tilting moment of the opposite direction of the grinding force, lead to the irregular dynamic state of the ferrule when it passes through the grinding area.

2. Grinding deviation and edge sweeping

Because of the great difference between the area of the two end faces of the ferrule and the amount of material removal, the unit area grinding pressure of the non reference end face is very large, so the material is very easy to be removed. At the initial stage of grinding, the grinding pressure on the two end faces is basically the same, and the thickness of the material removed is also basically the same. With the continuous grinding, the contact area between the reference end face and the grinding wheel is getting larger and larger. At this time, the grinding pressure is decreasing. Therefore, the machining surface at the initial stage of grinding leaves the grinding wheel surface due to the movement of the ferrule. Finally, the meniscus trace is left on the reference surface.

3. Improvement measures

The adjustment of the vertical double face grinder, such as the parallel problem between the width of the feed path and the discharge path, the center line and the surface of the grinding wheel, the differential grinding, the relationship between the horizontal and vertical directions of the two grinding wheels, etc.

a. Distinguish grinding area

Under the condition of certain grinding allowance, the area for grinding the outermost material is the rough grinding area, the main task is to remove the redundant material; the area for grinding the workpiece out of the formed surface is the fine grinding area, which is mainly to obtain the dimensional accuracy, geometric accuracy and surface quality of the product.

b. Selection of grinding wheel

As the double face grinding belongs to continuous grinding, once the adjustment and trial grinding are completed and the first inspection is qualified, it is required to ensure the continuity of production, and it is not allowed to pause in the middle. At this time, the grinding wheel should have good deformation resistance performance to ensure that the working surface is not distorted as much as possible, so the first choice should be the appropriate hardness of the grinding wheel. If the cooling liquid is sufficient, it will not cause burn, and the effect will be better if the grinding wheel end face is slotted. Secondly, in order to ensure that the grinding depth of both sides is consistent, the characteristic parameters of the grinding wheel of the grinding reference plane should be changed relative to the other side.