CN105588878A

CN105588878A - Eddy current array testing device for metal defects

Info

Publication number: CN105588878A
Application number: CN201610009792.8A
Authority: CN
Inventors: 张卫民; 岳明明; 秦峰; 庞炜涵; 陈国龙
Original assignee: Beijing Institute of Technology BIT
Current assignee: Beijing Institute of Technology BIT
Priority date: 2016-01-07
Filing date: 2016-01-07
Publication date: 2016-05-18

Abstract

The invention relates to an eddy current array testing device for metal defects and belongs to the technical field of electromagnetic eddy current testing in the nondestructive testing. Eddy current testing is an important branch of eddy current nondestructive testing, has the advantage of non-contact testing of the traditional testing method and combines advantages of proneness of large-area and rapid testing of the array testing method. According to the novel eddy current testing device scheme, an air bag, a stepping motor and the like are organically combined with an array sensor, and small-curvature curved surface damage can be effectively tested. The device is not necessarily higher than a single-probe testing device in accuracy, but has the advantages of rapidness and high efficiency, has certain adaptability to curved surface defects and has unique advantages in testing large-area damage such as corrosion, thinning and the like.

Description

A kind of eddy current array detection metal defect device

Technical field

The invention belongs to electromagnetic eddy technical field of nondestructive testing, relate to a kind of novel sensor array structure. Have detection piece surface, have certain curve surface adaptive, can realize automation, convenient, efficient feature, wish to replace in current actual production, artificial interdependency is high, the detection mode of inefficiency.

Background technology

In machine-building, a lot of crucial strength members, before final assembly, need to detect conventionally one by one. On actual production line, still mostly adopt at present magnetic detection mode, artificial interdependency is large, is unfavorable for realizing automation. Relatively be hopeful to replace manual method and realize automation, mainly contain ultrasonic and electromagnetic detection mode, but ultrasound detection is insensitive to piece surface damage, the appearance of some crackle, first start from surface often, therefore surface defects of parts is detected and be can not be ignored. In Electromagnetic Testing Technology, typical method eddy current detection method, need not be coupled, and detection efficiency is high, is that a kind of surface defects of parts that can be used in checks, more promising method.

The present invention proposes a kind of novel array architecture eddy current sensor, this sensor construction is flexible and rigidity combination, can not only detection plane part, and curved surface part is also had to certain adaptability.

The object of the invention is to provides a kind of novel eddy current sensor construction and device for detecting strength member blemish.

Summary of the invention

In the present invention, sensor array structure is made up of coil and flexible rubber cushion, air bag, stepper motor, pickup wire loop mechanism forms differential series, intermediate coil is for detecting, around coil does differential excitation, air bag is pressed on cell winding on tested part surface, this structure also has certain adaptability to small curve curved surface part, and stepper motor is delivered to sensor construction to need detection position, detects thereby realize.

Beneficial effect:

The present invention has designed a kind of New-type Vortex Sensor array structure and checkout gear, detects with the surface damage of effectively realizing machine components. This sensor construction and detection mode can effectively solve the test problems of small curve curved surface part, for replacing the detection mode falling behind in actual production, significant.

Brief description of the drawings:

Fig. 1: sensor array sonde configuration pictorial diagram;

Fig. 2: air bag pictorial diagram, in figure, spherical part is;

Fig. 3: stepper motor feeding part;

Fig. 4: multiplexed signal sampling system;

Fig. 5: air pump and air-channel system;

Fig. 6: checkout gear outside drawing;

Fig. 7: crack defect, material is aluminium alloy, Crack Parameters: width 2mm, degree of depth 3mm, length 10mm;

Fig. 8: testing result figure, in figure, circular black part is divided into crack position.

Detailed description of the invention

For objects and advantages of the present invention are described better, below in conjunction with the drawings and specific embodiments, the present invention will be further described.

In embodiment, select an aluminium alloy small curve curved surface part, process the crack-like defect that is of a size of (wide × long × dark, larger) 2mm × 10mm × 3mm in the above with mechanical means.

Sensor array is moved to defective locations, can observe signal amplitude undergo mutation at defective locations, signal is further processed by low pass filter etc., get final product the clear flaw indication that extracts, as shown in Figure 8, crack defect signal is black part in figure.

The present embodiment is only for a kind of test specimen of material detects. The present invention can detect multiple conductive material, and wire circle, the wire diameter etc. of sensor can be adjusted.

Claims

1. an eddy current array detection metal defect scanning equipment, detects eddy current by array-type flexible and visitsHead, gasbag-type device, stepper motor, multi-channel signal acquiring device, computer composition. SoftProperty array eddy current sensor is equidistantly fixed on flexible rubber pad by 30 groups of rigidity coils to be made,Each unit coil structure is consistent. Rubber blanket has certain flexibility, can meet little songThe detection demand of rate curved surface part. Gasbag-type device inflation when detection, by array eddy current probeBe pressed on piece surface, stepper motor drives can realize detection anywhere by assurance device.Multi-channel signal acquiring device can gather at most 48 road signals, in computer, carry out imaging placeReason.

2. array-type flexible detects an eddy current probe, and when work, centre position sensor rises to detect and doesWith, around neighboring sensors is done differential wave, plays incentive action. In detecting, do not run into defectTime, not too large variation of detection signal, in the time there is defect in tested part surface, this detection letterNumber change larger, utilize this relation, just can detect on part whether have defect.

3. high-speed sampling device, is case structure, owing to there is no similar structures on market, for independently grindingSend out and form. It is positive and negative 10V that this device can gather at most 48 tunnels, every road 500KHz, amplitudeAlternating signal, and can amplify as required and filtering processing.

4. the general principle of eddy current signal exciting circuit and signal processing circuit is as follows.

Main circuit will be divided into two parts, exciting circuit and signal processing circuit. Wherein driver unitAs function generation chip, produce amplitude, sinusoidal excitation signal that frequency is adjustable by ICL8038,After voltage follower, signal is divided into two-way. The phase shifter of wherein leading up to is realized and anotherThe 90 degree phase differences on road. So far realize the excitation work that two pairs of coil windings phases phasic difference 90 is spentDo.

The primary signal of being picked up by magnetic test coil needs treatment circuit to be further processed. SignalFirst by amplifier, dry through phase discriminator filtering alternating component and part after tentatively amplifyingDisturb, retain the flip-flop that comprises flaw size information. Final through twice amplification filtering againRealize signal and export computer to.