The treatment method of chip removal in deep hole machining is as follows:
In order to remove the chips smoothly, the iron chips need to come out as thin strips and bring out small pieces. At the same time, the coolant is easy to enter. The grinding method of the drill can adopt the grinding method created by Ni Zhifu, who has three points and seven edges (group drilling for the sake of not highlighting individuals in the Cultural Revolution). The simple grinding method of the deep hole of the mold is
1. Increase the included angle of the drilling edge to 130-140 degrees to increase the chip thickness and change the direction of chip discharge (the direction of chip discharge is perpendicular to the edge)
2. Grind the transverse edge to reduce the axial cutting tool and generate an angle at the cutting edge against the core to facilitate chip separation.
3. If the drilling diameter is large, the chip separating groove can be grinded on one side of the cutting edge, which should be one wider, so as to balance the cutting force of two cutting edges. If the diameter is large, the chip separating groove can be grinded on two cutting edges.
4. Make an angle of 1 mm 45 degrees at the outer corner of the cutting edge to reduce wear and improve the finish.
5. The drilling speed is slightly lower, and the feed amount should be larger, so that the chip thickens and is discharged in strips.
6. The nozzle of the coolant should face the hole inward so that the coolant can enter the cutting area,
Die deep hole manufacturers found that when the hole diameter ratio is more than 8 times larger, it’s best to drill on a special deep hole drilling machine, with very high efficiency. I once tried to produce lathe spindle diameter 32, length about 850mm, material 45 steel in only 13 minutes.
Deep hole drilling is divided into two types: external chip removal and internal chip removal;
For the smaller diameter, the external chip removal method is adopted, because the drill pipe is too small. For the larger diameter hole, the internal hole of drill pipe has enough space for chip removal. High pressure oil is pressed between the hole wall and the drill pipe to discharge the chip and heat from the rod. The drill bit is made of special general hard alloy, with two parts of the direction and chip edge, The height and width of the chip breaking groove depend on the material of the workpiece and the feed rate to ensure that the chip shape is tight and small C shape or tile shape is better.
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