Spherical mirror grinding and chamfering

A. Grinding and chamfering

Corresponding to the centering method, there are optical centering grinder, mechanical centering grinder, automatic centering grinder and so on. Among them, the mechanical centering machine is the most widely used equipment at present.

1. Edge grinding

The main grinding methods are parallel grinding, inclined grinding, face grinding, vertical grinding and combined profile wheel grinding, as shown in Figure 11-12 and Figure 11-14.

(1) Parallel grinding. Parallel grinding refers to the grinding wheel axis parallel to the lens axis, which is the most common grinding method because of its high grinding efficiency and easy adjustment. Figure 11-13 shows the grinding edge of parallel grinding.

(2) Tilt grinding. Adjust the grinding wheel at an angle to improve the force on the part and prevent it from falling off due to excessive thrust from the grinding wheel.

(3) Endface grinding. The use of grinding wheel end grinding glass, there is no force to make the parts off, high grinding efficiency; disadvantage is easy to grind the tapered or non-columnar surface.

(4) Vertical grinding. This type of grinding also does not dislodge the part, and it is easier to feed the tool.

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The chamfering of optical parts can be divided into two main categories, namely protective chamfering and design chamfering.

Protective chamfering is to prevent the sharp edges of the parts from being touched during assembly and to prevent the workers from cutting their hands. The contact between the grinding wheel and the lens is not very uniform when grinding the edge of the lens, so after grinding the edge, there are always small and large broken edges, chamfering can remove some small broken edges.

1) Forming diamond wheel chamfering

The use of molding diamond grinding wheel grinding edge and chamfering as shown in Figure 11-14. This method is first grinding edge, then grinding wheel relative to the lens left and right axial movement of a small distance grinding lens angle. This method requires the diameter of the joint D’ should be smaller than the diameter of the lens D, the relationship is

D’ = D-(0.5 + 2δ). Where, δ is the height of the chamfered part of the diamond grinding wheel.

2) Grinding wheel chamfering

By turning the grinding wheel or the workpiece by a certain angle, the chamfering can follow after the grinding. This is shown in Figure 11-15(a).

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3) Chamfering die chamfering

For chamfering, use diamond chamfering die with vacuum adsorption. For large lens and hard glass material, use W40 abrasive; for small lens and soft glass material, use W20 abrasive. As shown in Figure 11-15 (b).

4) Chamfer width

The chamfer width is related to the part diameter and part type, and the specific dimensions are shown in Table 11-3.

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Post time: Jun-21-2022