Turning threads is one of the most common processes for turning parts, so this article is an example of a common fault and solution for turning threads. When turning threads, there are various reasons for problems in the movement between the spindle and the tool, which may cause a fault when turning threads and affect normal production, and should be resolved in a timely manner. The following is a list of common faults and solutions.
1、Rough surface of thread
Failure analysis: The main reason for this problem is that the cutting edge of the turning tool is not smooth enough, the cutting fluid and cutting speed do not match the processed material, or the vibration generated during the cutting process.
Solution: Fine study the tool with oil or grinding wheel, choose the matching cutting fluid and cutting speed, adjust the position of various parts, and ensure the accuracy of each guide gap, so as to prevent the vibration generated during cutting.
Failure analysis: mainly due to the incorrect location of the turning tool installation, either too high or too low, and the workpiece clamping is not solid, the turning tool wear is too large
Solution: adjust the height of the turning tool, so that the tool tip and the axis of the workpiece is equal to the height
Failure analysis: The reason is that when the screw rotates for a week, the workpiece is not installed over the whole number of turns and caused.
(1) When the ratio of lathe screw pitch and workpiece pitch is not an integer number, if the bed saddle is swung to the starting position by opening the opening and closing nut when the tool is retired, then when the opening and closing nut is closed again, the turning tool tip will not be in the spiral groove turned out by the previous tool, resulting in a messy buckle. The solution is to use the positive and negative turning method to return the tool, that is, at the end of the first stroke, do not lift the opening and closing nut, the tool along the radial exit, the spindle will be reversed, so that the turning tool along the longitudinal return, and then the second stroke, so that the reciprocating process, because the transmission between the spindle, screw and tool holder has not been separated, the turning tool is always in the original spiral groove, there will be no messy buckle.
(2) For threads where the ratio of the screw pitch to the workpiece pitch of the turning lathe is an integer number of times, the workpiece and the screw are rotating, and after lifting the opening and closing nut, at least wait for the screw to turn one turn before closing the opening and closing nut again, so that when the screw turns one turn, the workpiece turns an integer number of times, and the turning tool can enter the spiral groove turned out by the previous tool, so that there is no messy buckling. This way, you can open the opening and closing nuts and manually rewind the tool. This is a fast retreat, which is conducive to improving productivity and maintaining the accuracy of the screw, while the screw is also safer.
4、Pitch is not correct
Failure analysis and solutions.
(1) Improper matching of the hanging wheel or incorrect position of the handle of the feed box, resulting in incorrect thread length, can re-check the position of the handle of the feed box or check the hanging wheel.
(2) The local incorrectness is due to the local error of the pitch of the lathe screw itself, so the screw can be replaced or partially repaired.
5、The middle warp is not correct
Failure analysis: The reason is that the eating tool is too big and the dial is not allowed, and it is not measured in time.
Solution: Check in detail whether the dial is loose when finishing, the finishing margin should be appropriate, the cutting edge of the turning tool should be sharp, and it should be measured in time.