Special magnetic detection machine for non-contact type tube coupling

Abstract

The invention provides a special magnetic detection machine for a non-contact type tube coupling. The special magnetic detection machine is characterized by comprising two longitudinal coils and a conductive magnetic bar passing through the longitudinal coils, wherein the conductive magnetic bar is axially arranged along the two longitudinal coils and can do telescopic motion along the direction under the driving of a gas cylinder, a workpiece bracket is arranged between the two longitudinal coils, and the pipe coupling is arranged on the workpiece bracket. Flaw detection is conducted by adopting a non-contact type sensing method so as to avoid electric arc discharge phenomenon. The distance of chucks does not need to be adjusted according to the different lengths of couplings, the usage reliability of the machine can be increased, and the working efficiency can be greatly improved.

Description

technical field [0001] The invention relates to a special magnetic particle flaw detector for detecting defects in various directions on the inner and outer surfaces of steel pipe couplings. Background technique [0002] In the actual production of oil and gas production casings, they need to be connected with couplings. In order to ensure its safety and reliability in use, flaw detection must be carried out on the casing and coupling during the manufacturing process. In the industry, ultrasonic, eddy current, magnetic flux leakage and other methods are used for flaw detection of casings, while magnetic particle flaw detection is used for couplings. [0003] At present, domestic coupling magnetic particle flaw detection mainly adopts the flaw detection method of passing through the rod with AC circumferential magnetization and DC coil longitudinal magnetization. The conductive copper tube of the circumferential magnetization device passes through a chuck shaft, passes thro...

AI Technical Summary

Problems solved by technology

Longitudinal magnetization actually uses the yoke method for flaw detection. The disadvantage of the yoke method is that the range of the magnetic field is limited. During the actual flaw detection process of the coupling, the longitudinal magnetic induction intensity in the middle is weaker than that at both ends, which makes it difficult to detect radial defects in the middle of the coupling.

In addition, in the actual flaw detection process, the clamps at both ends need to clamp the coupling. Therefore, the distance between the clamps at both ends must be adjusted according to the length of the coupling, which increases the workload of the operator in actual use.

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