Solutions to the failure of stainless steel turning parts

Turning the thread is one of the most common processes of stainless steel turning parts. This article takes the failures and solutions that are often encountered in turning threads as an example. When actually turning the thread, due to various reasons, there is a problem in one link of the movement between the spindle and the tool, which causes a problem when turning the thread and affects normal production. It should be resolved in time. Let's take a look at common faults and solutions:

1. The thread surface is rough

Failure analysis: The main reason for this problem is that the cutting edge of the turning tool is not smooth enough, the cutting fluid, cutting speed does not match the processing material, or the vibration caused by the cutting process.

Solution: Grind the tool with oil or grinding wheel, and select the matching cutting fluid and cutting speed, adjust the position of various parts, ensure the accuracy of the gap between the guide rails, and thus prevent the vibration during cutting.

2. Gnawing knife

Failure analysis: mainly due to the wrong installation position of the turning tool, either too high or too low, and the workpiece clamping is not firm, the turning tool wears too much;

Solution: Adjust the turning tool height so that the tool tip is at the same height as the workpiece axis.

3. Shuffle

Failure analysis: The reason is that when the screw rotates one revolution, the workpiece has not been installed with an integer rotation.

Solution:

(1) When the ratio between the screw pitch of the lathe and the pitch of the workpiece is not an integral multiple, if the opening and closing nut is used when the tool is retracted, the bed saddle is shaken to the starting position, then when the opening and closing nut is closed again, the turning tool The tip of the knife is not in the spiral groove pulled out by the previous knife, so that there is a mess. The solution is to use the positive and negative turning method to retract the tool, that is, at the end of the first stroke, without lifting the opening and closing nut, after the tool is retracted in the radial direction, the spindle is reversed to make the turning tool retract in the longitudinal direction The second stroke, so that during the reciprocating process, because the transmission between the main shaft, the screw and the tool holder has not been separated, the turning tool is always in the original spiral groove, and there will be no buckling.

(2) For stainless steel turning parts, the threaded workpiece and the screw of the screw pitch of the lathe and the workpiece pitch are multiples of the whole rotating, after lifting the opening and closing nut, at least wait for the screw to rotate once before closing the opening again Close the nut, so that when the screw rotates one turn, the workpiece rotates an integer number of times, the turning tool can enter the spiral groove of the previous tool turning, there will be no buckling, so you can use the opening and closing nut, manually Retreat. This allows the tool to be retracted quickly, which is beneficial to improving productivity and maintaining the accuracy of the lead screw, and the lead screw is also safer.

4. Wrong pitch

Failure analysis and solution:

(1) Improper combination of the hanging wheel or incorrect position of the feed box handle, resulting in an incorrect length of the thread, you can recheck the position of the feed box handle or check the hanging wheel.

(2) The part is incorrect. Due to the local error of the screw pitch of the lathe screw, the screw can be replaced or repaired locally.

5. The Chinese warp is wrong

Failure analysis: The reason is that the knife is too large, the dial is not accurate, and it is not measured in time.

Solution: Check carefully whether the dial is loose during finishing, the remaining amount of finishing is appropriate, the cutting edge of the turning tool should be sharp, and it should be measured in time.