What are the reasons for the breakage of the drill bit of the CNC drilling machine

  CNC drilling machines are widely used in many factories and enterprises in our country, because they have advantages that ordinary drilling machines do not have, such as convenient operation, flexibility, wide application range, typicality, etc. are widely used reason. As a common machine tool, it is inevitable to encounter some problems during operation.

When the drill bit breaks, the main reasons are:

1. The drill bit is blunt, but continues to drill.

2. The spiral groove of the drill bit is blocked by chips, and the chips are not discharged in time.

3. When the hole is drilled quickly, the feed rate is not reduced or the maneuver is changed to manual feed.

4. When drilling soft metals such as brass, the rear angle of the drill bit is too large, and the front angle is not ground, resulting in the drill bit automatically screwing in.

5. The sharpening of the drill edge is too sharp, resulting in chipping, but the knife cannot be withdrawn quickly.

    Effective ways to avoid bit breakage:

(1) Before drilling, be sure to turn the end face of the workpiece flat, without leaving a protrusion in the center, and put the drill bit into the tailstock sleeve, and align the axis of the drill bit to coincide with the rotation axis of the workpiece.

(2) In order to prevent the radial runout of the drill bit, an iron stopper can be added to the tool holder to support the head of the drill bit and help the centering of the drill bit.

(3) When drilling small and deep holes, the center hole should be drilled with a center drill first to avoid drilling the hole crookedly. It is important to withdraw the drill bit frequently to remove iron chips during drilling.

 (4) When the drill bit just touches the end surface of the workpiece and the through hole is about to drill through the workpiece, because the chisel edge penetrates first, the axial resistance increases and the drill bit is easy to break, so the feed rate must be slowed down.

(5) During the drilling process, it is necessary to pay attention to frequently withdrawing the drill and lifting the drill bit in time. At the same time, it is also an opportunity to enter coolant, or to cool in the air. By adopting the above method, the breakage of the drill bit can be reduced, so as to save materials, improve production efficiency and improve the processing quality of workpieces.

(6) When the small-diameter drill is drilling, due to poor chip removal, the drill and temperature rise rapidly. In order to reduce the cutting temperature, reduce the friction coefficient between the chip, the workpiece and the tool contact surface, and improve the life of the small-diameter drill For the purpose of cooling, it must be fully cooled. Generally, it is better to use transparent anti-rust water as the cooling liquid. In addition, it is also possible to coat a layer of molybdenum disulfide on the groove of the drill bit, or lubricate it with low-viscosity mechanical oil or vegetable oil, which can get better results.

  To sum up, in order to obtain a satisfactory drilling effect, the above aspects should be paid attention to during the use of the CNC drilling machine bit, and due to the limitations of different conditions such as workpiece material, quality requirements, and drilling positions, The technical measures taken have to be changed accordingly.

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