Problems Existing in Tool Setting in Thread Turning
1) The first turning and clamping tool for thread processing
When the thread cutter is clamped for the first time, there will be unequal heights between the tip of the thread cutter and the rotation of the workpiece. It is generally common in welding knives. Due to the rough manufacture, the size of the tool holder is not accurate, and the middle height needs to be adjusted by adding shims. Affects the actual geometry angle after tool turning. When the tool is installed, the angle of the tip of the tool is deviated, which is easy to cause an error in the angle of the thread profile, resulting in a skewed tooth profile. If the thread cutter protrudes too long, the cutter will vibrate during processing, which will affect the surface roughness of the thread.
2) Rough and fine turning tool setting
In the process of machining high-precision threads and trapezoidal threads, two thread cutters are required to separate the rough and fine turns, and the large offset between the two cutters (especially in the Z direction) will cause the pitch diameter of the thread to become larger and be scrapped.
3) Repair the workpiece and set the tool
Due to the secondary clamping of the workpiece, the repaired helix and the one-turn signal of the encoder have changed, and random buckles will occur when the repair is performed again.
Way of Solving the Problem
1) The tip of the threading tool should be kept at the same height as the middle of the workpiece rotation. After the tool is sharpened, use the tool setting template to lean against the axis of the workpiece for tool setting to keep the tool tip angle installed correctly. If the CNC machine is used to clamp the tool, due to the high manufacturing precision of the tool bar, generally it is only necessary to close the tool bar to the side of the tool holder.
2) The tool setting of the thread cutter for rough and fine machining adopts a certain point as the reference point, and the tool setting can be done by the usual method. In the actual tool setting process, the trial cutting method only needs to adjust the tool compensation a little.
3) In thread processing, if the tool wears or breaks, the tool needs to be re-sharpened and then set. If the workpiece is not removed for repair, it is only necessary to overlap the position where the thread tool was installed with the position before it was removed. It is equivalent to processing with the same turning tool.
4) If the workpiece has been dismantled, the repairing work can only be carried out after determining the starting point of processing. How to determine the starting point of processing and the signal position of one revolution, first use the test rod to carry out thread turning with a surface depth of 0.05~0.1mm (all parameters Same as the thread parameters to be processed), Z value is the integer thread lead distance value from the right end face of the starting point of the thread, a helix is carved on the surface to determine the starting point of thread turning, and a marking is made on the corresponding position of the chuck circle surface (even if the marking line and In the same axial section as the screw starting point on the test bar).
Post time: May-23-2016
