Eddy current sensor with hamburger type structure

Abstract

The utility model provides an eddy current sensor with a hamburger type structure, which comprises an insulating support, a cylindrical detection coil, a rose-shaped excitation coil and a cylindrical excitation coil, and the cylindrical detection coil, the rose-shaped excitation coil and the cylindrical excitation coil are coaxially fixed on the insulating support with a three-layer bolt structure; the rose-shaped excitation coils are four uniformly distributed and mutually independent coils, the excitation current directions are the same, and excitation magnetic fields are superposed; the insulating support can be sleeved, and the coil can be sleeved on the support. And the upper detection coil is used for picking up an induced voltage signal, and when a defect exists in the test piece, the induced eddy current density in the tested piece is also changed, so that the voltage signal of the detection coil is changed, and further defect detection is realized. Compared with a conventional cylindrical pulse eddy current detection sensor, the sensor has higher defect detection sensitivity, and has important significance for industrial production.

Description

TECHNICAL FIELD

[0001] The utility model relates to nondestructive testing field, concretely is a hamburger formula structure eddy current sensor, be especially suitable for the detection of all kinds of metal material surface, subsurface defect, and detection sensitivity is high. BACKGROUND

[0002] Metal materials are widely used in industrial production and life, however, due to the influence of processing technology or long-term service and other factors, cracks, grooves and other defects often occur on the surface or inside of the material during production and use, and continuously deteriorate with the extension of service time, resulting in the decline of product quality and performance, affecting the service life, and even leading to major production accidents. Therefore, realizing the nondestructive testing of internal and surface defects of metal materials has great significance for preventing structural failure and ensuring social safety.

[0003] Pulsed eddy current testing technology is a kind of nondestructive testing technology improved for traditional eddy current testing technology, and its advantage compared with traditional eddy current testing technology is that it uses a pulse signal with wide frequency spectrum as excitation, so its response signal can carry more information. The pulsed eddy current detection probe is an essential part of realizing pulsed eddy current detection, and the detection sensitivity of the pulsed eddy current detection probe is directly related to the detection accuracy of the pulsed eddy current detection technology. Therefore, studying a detection probe with high sensitivity has great significance for promoting the development of pulsed eddy current detection technology and the application of engineering technology. SUMMARY

[0004] To achieve the above purpose, the utility model provides a hamburger formula structure eddy current sensor with three-layer structure can effectively realize the rapid, accurate detection of metal material surface, subsurface defect, and has higher detection sensitivity, and has important engineering application value for realizing defect detection.

[0005] To achieve the above purpose, the utility model adopts the following technical scheme: a hamburger formula structure eddy current sensor, comprising coaxial upper, middle and lower three layers of coils and insulating support, characterized by: the upper layer and the lower layer are respectively one cylindrical detection coil 2 and cylindrical excitation coil 4 with different sizes, the middle layer is four evenly distributed and same size rose type excitation coil 3, the insulating support 1 is a plug structure with three layers with size adapting to the size of each part of the coil, the support itself can be flexibly taken, and the coil can also be flexibly taken on the support.

[0006] The rose type excitation coil 3 and the cylindrical excitation coil 4 are connected with the output end of the data acquisition and transmission instrument, and the pulse excitation signal with the same current direction is connected, a superimposed magnetic field is generated, and an induced eddy current is generated in the tested piece.

[0007] The cylindrical detection coil 2 is connected with the input end of a data acquisition and transmission instrument, receives the induced signal generated by the test piece in the eddy current field and displays on the PC end.

[0008] The insulating support 1 is a three-layer bolt structure, characterized in that: the three layers are connected in the form of a bolt, and the first layer, the second layer and the third layer respectively sleeve the cylindrical detection coil 2, the rose-shaped excitation coil 3 and the cylindrical excitation coil 4.

[0009] Compared with the conventional cylindrical pulse eddy current detection probe, the utility model has the following advantages: the rose-shaped excitation coil and the cylindrical excitation coil are combined, the rose-shaped excitation coil generates a more concentrated eddy current field in the test piece, the double-layer excitation makes the eddy current density of the test piece at the same depth larger, can effectively inhibit the influence of the lift-off effect on the detection sensitivity, and has higher detection sensitivity. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 is a three-dimensional schematic view of a hamburger structure eddy current sensor of the utility model;

[0011] Figure 2 is a three-dimensional schematic view of an insulating support of a hamburger structure eddy current sensor of the utility model;

[0012] Figure 3 is a top view of a hamburger structure eddy current sensor of the utility model;

[0013] Figure 4 is a three-dimensional schematic view of all coils of a hamburger structure eddy current sensor of the utility model;

[0014] Figure 5 is a top view of all coils of a hamburger structure eddy current sensor of the utility model;

[0015] Figure 6 is a three-dimensional schematic view of a rose-shaped excitation coil of a hamburger structure eddy current sensor of the utility model. DETAILED DESCRIPTION

[0016] The following is a further detailed description of the utility model in combination with the drawings and specific embodiments:

[0017] As Figure 1 shown, the insulating support 1 has A, B, C three layers, and is a bolt structure, so that the coil can be sleeved flexibly.

[0018] As Figure 3 shown, the upper layer is a cylindrical detection coil 2, which is sleeved on the A layer of the insulating support 1 during detection; the middle layer is a rose-shaped excitation coil 3, which is sleeved on the B layer of the insulating support 1 during detection; the lower layer is a cylindrical excitation coil 4, which is sleeved on the C layer of the insulating support 1 during detection, thereby forming a complete hamburger-shaped pulsed eddy current detection probe.

[0019] Further, in the above embodiment, the probe is placed above the defective test piece for detection, and during the detection process, the rose-shaped excitation coil 3 and the cylindrical excitation coil 4 are applied with pulsed signals in the same direction as excitation, so that the double-layer excitation coil generates stronger induced eddy current at the same depth in the test piece; the cylindrical detection coil 2 receives the induced signal change caused by the defect and converts it into a voltage signal.

[0020] In the above embodiment, the probe can generate stronger eddy current field than the conventional cylindrical detection probe, which has important advantages in eliminating the adverse effects of lift-off effect on the detection accuracy of defects; at the same time, it has higher detection sensitivity than the conventional cylindrical detection probe, which has great value for promoting the application of nondestructive testing technology in engineering.

Claims

1. A hamburger configuration eddy current sensor characterized by: It comprises an insulating support (1), a cylindrical detection coil (2), a rose-shaped excitation coil (3) and a cylindrical excitation coil (4); the cylindrical detection coil (2), the rose-shaped excitation coil (3) and the cylindrical excitation coil (4) are coaxially fixed on the insulating support (1); the rose-shaped excitation coil (3) is four coils which are uniformly distributed and independent of each other, the excitation current directions are the same, and the excitation magnetic fields are superposed.

2. A burger configuration eddy current sensor according to claim 1, characterized in that: The insulating support (1) is a three-layer bolt structure with a size suitable for the size of the coil, the support itself can be sleeved, and the coil can be sleeved on the support.

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