A drilling jig for thin-walled ring parts

During machining, holes are often drilled on thin-walled ring parts. Because the axis of this type of parts is hollow, it is not easy to align the center. For example, the conventional methods of scribing, proofing, punching and drilling are used to process, the processing accuracy is difficult to guarantee, and the parts are prone to deformation during drilling. On the basis of the structural characteristics of ring parts, the author designed a set of simple drilling dies, which successfully solved the drilling problem of this type of parts on a common drilling machine, avoided the deformation of the parts in the processing process, ensured the processing accuracy and reduced The processing cost.

The structural characteristics of thin-walled ring parts include:

1) The wall of this type of part is thin, and it is easy to deform during the drilling process, which will cause machining errors: 2) The axis of this type of part is hollow, and it is not easy to find the center. If the part is directly fixed on the index plate to mark Line, will produce indexing errors, resulting in the hole spacing of the processing hole does not meet the design requirements of the drawing.

For this reason, the drilling jig designed by the author must meet the following requirements:

1) When drilling with a jig, the deformation of the parts during the drilling process must be controlled; 2) the position accuracy of each hole on the circumference of the jig must be guaranteed by a machining center with higher machining accuracy; 3) the drill sleeve must be quenched Handling, simple structure, fast processing, easy to change history when the bottom hole of the drill sleeve is out of tolerance

The structure of the jig

According to the structural characteristics of thin-walled ring-like parts, the author designed a set of special drilling molds, and the structure diagram is shown in Figure 1.

The drill mold is mainly composed of a drill mold body, a drill sleeve, a baffle, a pressure plate locking bolt and a wing nut. Considering the good consistency of the outer circle of the ring-like parts, I dare to use the outer circle of the part as the positioning reference when designing the drill mold, and design the gap between the inner hole of the drill mold body and the outer circle of the part to be 0.05~0.10 mm, the accuracy of the inner hole size is level 6, in order to reduce the positioning error between the drilling mold and the part, and at the same time avoid the deformation of the part during the drilling process. All holes on the circumference of the main body of the drill die are completed on a machining center with high precision, which can ensure the position accuracy of each hole. Since the bottom hole of the drill sleeve will gradually become larger after repeated use, the author chooses wear-resistant tool steel T10A as the material direction, and the quenching hardness is HRC (58~62). The outer circle of the drill sleeve and the inner hole of the drill die The matching accuracy is K6/H7, and the outer circle and inner hole of the drill sleeve are processed on a high-precision lathe, thus ensuring the assembly accuracy of the drill sleeve and the main body of the drill mold.