Tapping machine is a type of machine tool that uses taps to manufacture internal threads, and it is the most widely used type of internal thread machine tool. Due to the different states of each tap in the tapping machine, it is common for some taps to wear out and break due to increased torque, resulting in the scrapping of the workpiece. Sometimes even those workpieces that have undergone various precision processes for a long time are scrapped due to the breakage of the tap during the tapping machine process, resulting in a large amount of waste. Below is a brief introduction to the solutions to common faults of tapping machines:
(1) Due to the wear and passivation of the cutting edge of the tap, the tapping torque continues to increase to a certain extent. If the tap is not withdrawn in time, the tap will break.
(2) During the tapping process, if chips block the tap and the additional tapping torque increases sharply, if the chips cannot be further discharged and the tap does not reverse and exit, the tap will break due to excessive torque.
(3) Uneven hardness of the workpiece material results in local hard grains. When the tap touches, the torque increases. If the tapping torque exceeds a certain value, the tap needs to reverse and exit, otherwise it will break. Under normal circumstances, the tap can break through this part of the material and continue tapping.
(4) The tapping oil performance does not meet the process requirements. Using non specialized oils such as engine oil and vegetable oil as tapping oil can easily lead to defects such as burrs, and the lifespan of the tap can also be greatly reduced.
(5) Too fast feed speed leads to excessive torque. It is recommended that when using a regular tap to machine threads, the speed of the tapping machine should not be too fast.
(6) The bottom hole diameter does not match the tap. The part that needs to be cut by the tap during tapping will inevitably increase, causing the tap to break. It is recommended to choose the correct diameter of the bottom hole based on the type of tap and the material of the workpiece. If there is no drill bit that fully meets the requirements, a larger one can be chosen.
(7) Improper operation. When threading blind holes, when the tap is about to contact the bottom of the hole, it is still fed at the tapping speed before reaching the bottom of the hole, or forcibly fed in when chip removal is not smooth, causing the tap to break.
(8) The concentricity is insufficient. At the beginning of tapping, the starting position of the tap is incorrect, that is, the axis of the tap is not concentric with the centerline of the bottom hole, resulting in excessive torque during the tapping process, which is the main reason for the tap to break.
(9) Improper tapping steps. When tapping high hardness workpieces or deep holes, graded tapping should be carried out to avoid a seamless process.
The above are solutions to common faults of tapping machines. While ensuring the process, materials, and equipment conditions, the operator's positioning of the workpiece, control of machine tapping speed, and operation process methods are key to ensuring quality.
