Seamless titanium tube automatic flaw detection mechanical structure
Put the probe into a probe trolley, and use the method of two-stage tension spring push to make the detection probe always maintain a certain distance from the surface of the tested workpiece. From the test results, the follow-up of the probe is relatively strong, which basically ensures that the distance between the probe and the surface of the detected titanium tube is stable, and the flaw detection has also achieved good results. In general, the main methods to deal with the water coupling layer are: fixing the water tank and not messing with the water spray equipment. Due to the method of using the titanium tube to rotate the probe, the length of the seamless titanium tube is generally about 10m. Therefore, it is necessary to consider the use of non-disruptive water spray equipment, such as adding the diameter of the flow port, reducing the height of the flow port and the titanium tube, and reducing the water splash. The current conventional treatment method can only be like this, but the effect of the treatment is within the tolerable range.
Generally, the main methods to deal with the lift-off effect are: the mechanical tracking method of the probe, the bridge connection method of the probe coil, the change of the capacitance value of the LC loop of the detection coil, and the use of multi-frequency detection skills. In addition to the mechanical tracking method, several other treatment methods can be completed by improving the probe and the instrument, but the mechanical tracking can only improve the probe holder to avoid the change of the lift-off gap. In practical industrial applications, the probe mechanical tracking method is the most commonly used method to overcome the influence of the lift-off effect.
There are two common types of probe mechanical tracking:
One way is to use the combination of roller limit and cylinder or tension spring push to make the detection probe and the surface of the tested workpiece maintain a stable distance. Of course, this method can play a better role in restraining the lift-off effect, but together it will increase the oscillation noise.
Another way to choose the mechanical tracking of the probe is to use the ranging probe to timely measure the shaking condition of the detection probe lifted from the gap, and use the ranging signal to control and drive the stepping motor and other power equipment to move the detection probe. Ensure that the gap between the probe and the workpiece to be inspected is stable.
This method is suitable for flat scanning and flaw detection of plates or blanks. The defect is due to the slower reaction speed of mechanical measures and more complicated.
In active flaw detection, the lift-off effect and the effect of the undisturbed coupling layer on flaw detection are often the most difficult titles. In active flaw detection, the lift-off effect and the uninterrupted coupling layer are the main causes of missed detections and false alarms. Whether it is a missed detection or a false alarm, it affects the reliability of the detection.
For a long time, in the practical application of active flaw detection, the title of reduced detection reliability due to lifting and shaking may be due to the change in the thickness of the water coupling layer, which has been a “bottleneck” that puzzles the normal application of this skill.