Processing characteristics of deep hole drill:
1.The tool bar is limited by the hole diameter, the diameter is small, the length is big, the rigidity is bad, the strength is low, when cutting, easy to produce the vibration, the ripple, the taper, but affects the deep hole straightness and the Surface roughness.
2. During drilling and reaming, it is difficult to input the cooling lubricant into the cutting zone without special equipment, which reduces the tool durability and chips removal.
3.During the processing of deep holes, the cutting conditions of the cutting tools can not be observed directly, and only the sound of cutting, the chips, the vibration of the workpiece and the temperature of the workpiece, the oil pressure meter and the electric meter can be observed according to the working experience, to determine whether the cutting process is normal.
4.It is difficult to remove chip, we must use reliable means to break chip and control the length and shape of chip, in order to remove chip smoothly and prevent chip clogging.
5.In order to guarantee the deep hole processing smoothly and achieve the required processing quality, we should add the chip removal device inside and outside the cutter, the cutter guiding and supporting device, and the high-pressure cooling and lubricating device. Generally the hole depth is more than 5 times the hole diameter is called the deep hole, its difficulty is in the discharge chip and the cooling, the drill hole depth is smaller may use the twist drill, in order to discharge the chip smoothly, the iron filings must become the thin strip straight to come out and take out the smaller fragment, and the coolant is easy to get into. The grinding method of the diamond head can be a relatively simple one:
1.Increase the angle of the drill blade to 130-140 degrees to increase the thickness of the chip and change the direction of the chip discharge (the direction of the chip discharge is perpendicular to the edge)
2.Trim the edge to reduce the axial cutting tool and cut the edge to produce a corner-cutting favorable chip near the drill core.
3.Reverse 1 mm to 45 degree on the outside of the blade to reduce wear and improve finish.
4.The rotation speed of the drilling hole is slightly lower, and the feed amount should be larger, so that the chip thickens and is discharged in strips.
5.The coolant nozzle should be directed inward toward the hole to allow the coolant to enter the cutting area.
Common Problems and solutions edit hole surface roughness
1.Chip Bonding: Reduce cutting speed; avoid cutting edge collapse; change the extreme pressure of high cutting fluid, and improve the filtration situation; increase the cutting fluid pressure, flow.
2.Bad coaxiality: adjust the coaxiality of machine tool spindle and drill sleeve; adopt suitable diameter of drill sleeve.
3.Cutting speed is too low, feed is too large or uneven: use the appropriate cutting amount.
4.Improper tool geometry: change the geometry angle of the cutting edge and the shape of the guide block
The orifice is shaped like a trumpet
COAXIALITY is not good: adjust the coaxiality of machine tool spindle, drill sleeve and supporting sleeve; adopt proper drill sleeve diameter, replace the worn drill sleeve in time.
1. Chip breaking is not good, chip can not be discharged: change the size of the chip breaking groove, avoid too long, too shallow; timely detection of Broken Edge, and replacement; increase the pressure of cutting fluid, flow; the use of material organization uniform workpiece.
2.Feed too large, too small or uneven: The use of appropriate cutting dosage.
3.Excessive wear of drill bit: replace drill bit regularly to avoid excessive wear.
4.The cutting fluid is not suitable: select the appropriate cutting fluid and improve the filtration.
chips are banded: The geometry of chip breaker is not suitable; the geometry of cutting edge is not suitable; the feed quantity is too small; the material structure of workpiece is not uniform: change the geometry of chip breaker and cutting edge; increase the feed quantity; Work piece with Uniform Material Organization.
Chip too small: Chip Breaker is too short or too deep;
Chip Breaker Radius is too small: Change chip breaker geometry.
Chip too large: Chip breaker too long or too shallow;
chip breaker radius too large: change the geometry of chip breaker.