What should I do if the drill bit always breaks during processing? Today we will talk about application problems and measures.
1. Abrasion of the drill point
The reason:
1. The workpiece will move down under the action of the drill bit’s penetration force, and the drill will bounce back after drilling through.
2. Insufficient machine rigidity.
3. The material of the drill bit is not strong enough.
4. The drill bit jumps too much.
5. The clamping rigidity is not enough and the drill bit slips.
Measures:
1. Reduce the cutting speed.
2. Increase the feed rate.
3. Adjust the cooling direction (internal cooling).
4. Add a chamfer.
5. Check and adjust the coaxiality of the drill bit.
6. Check whether the rear angle is reasonable.
2. Edge burst
The reason:
1. The workpiece will move down under the action of the drill bit’s penetration force, and the drill will bounce back after drilling through.
2. Insufficient machine rigidity.
3. The material of the drill bit is not strong enough.
4. Large eccentricity tolerance
5. The clamping rigidity is not enough and the drill bit slips.
Measures:
1. Choose a drill with a larger back cone.
2. Check the eccentricity tolerance range of the spindle drill bit (＜0.02mm).
3. Use a pre-center drill to make the top hole.
4. Use a more rigid drill bit, a hydraulic chuck with a neck sleeve or a heat shrink kit.
3. Build-up edge
The reason:
Caused by the chemical reaction between the cutting material and the workpiece material (low carbon steel with higher carbon content).
Measures:
1. Improve lubricant and increase oil or additive content.
2. Increase the cutting speed, reduce the feed rate and reduce the contact time.
3. If you are drilling aluminum, you can use a drill with a polished surface and no coating.
4. Break
The reason:
1. The spiral groove of the drill is blocked by cutting, and the chips are not discharged in time.
2. When the hole is fast drilling, the feed amount is not reduced or the maneuvering is changed to manual feed.
3. When drilling soft metals such as brass, the rear angle of the drill bit is too large, and the front angle is not trimmed, so that the drill bit is automatically screwed in.
4. The sharpening of the drill blade is too sharp, resulting in the phenomenon of edge chipping, and the blade cannot be withdrawn quickly.
Measures:
1. Shorten the cycle of changing tools.
2. Improve the installation and fixation, such as increasing the supporting area and increasing the clamping force.
3. Check the spindle bearing and sliding groove.
4. Use high-precision tool holders, such as hydraulic tool holders.
5. Use tougher materials.