CN201548520U - Metal magnetic memory diagnostic apparatus - Google Patents

Abstract

The utility model discloses a metal magnetic memory diagnostic apparatus, which comprises a detecting probe, a data processing module, an A/D converting module, a microprocessor, a display module, a range-measuring circuit and an alarming module. The detecting probe comprises four or eight magnetic field sensors and a multi-channel switch, wherein the magnetic field sensors are in array arrangement, an output end of the multi-channel switch is connected with the data processing module, an output end of the data processing module is connected with a microprocessor via the A/D converting module, and the microprocessor is further connected with the display module, the range-measuring circuit and the alarming module. The metal magnetic memory diagnostic apparatus can conveniently and accurately detect shortages or stress concentration areas inside metal workpieces.

Description

Metal magnetic memory diagnostic instrument

Technical field

The utility model relates to and detects the diagnostic device that metal stresses is concentrated, and is meant especially a kind ofly to utilize the magnetic memory effect and detect the diagnostic equipment of metal stresses concentration zones.

Background technology

Metal works is widely used in industrial and agricultural production and the life, particularly at main equipment such as workshop etc., its quality of stability directly affects manufacturing schedule and benefit, and for metal works, its inner defective that produces can't directly be judged by naked eyes, when having influence on the outside because of inherent vice, this moment, equipment often can not use, therefore as if finding rejected region early and handling, can save servicing time greatly, enhance productivity.

Detect the inherent vice of metal works at present, the defective of normally utilizing ferromagnetic component externally strong magnetic field action produces the principle of leakage field phenomenon down, its mechanism is defective meeting under strong magnetic field action " passively " generation " magnetic dispersion ", thereby allow magneto sensor " easily " capture, and then judge the size of its defective and character etc.Yet this method must adopt heavy magnetizing equipment, and power consumption is big, detecting often needs parts are demagnetized later, to some at labour equipment, parts, the perhaps parts of labyrinth, conventional leakage method often is difficult to carry out, and therefore need seek other detection approach.

As everyone knows, the earth exists south, the arctic, and earth magnetism is ubiquitous in people's living space, always has, and the ferromagnetism equipment of people's periphery, parts equally also are among " encirclement " of earth magnetism.Therefore, they also can be magnetized by the terrestrial magnetic field, and usually, people are unaware of " magnetic " of ferromagnetic component, be not have " magnetic ", but its magnetic intensity are more weak.In fact, under periodicity or vibratility loading condition, because the effect of magnetoelasticity and magneto-mechanical effect, the metal magnetization will significantly increase at the labour parts.Magnetic memory diagnostic techniques is exactly to utilize defective or defective to form microcell before to change under the effect of magnetic field of the earth, and " initiatively " sends such specific character of changes of magnetic field information, judges indirectly whether ferromagnetic component exists defective or area of stress concentration.

As everyone knows, in the ferromagnetic component processing hardening by cooling process, the hardening by cooling relatively place of fierceness may form the neck change, forms neck change place (section of Hp=0) at member the quick convergence of dislocation can take place, and cause micro-crack---form the originating point or the stress concentration line of member damage afterwards.When the stress concentration line is vertical with the direction of external load acting force, neck becomes the fracture of initiation member and must occur on the stress concentration line, if the stress concentration line distributes or stress when concentrating (Hp value change intensity) very little along member axis, the position of neck change does not often overlap with the fracture of member; Even so, still, the stress concentration line can occur and be offset to neck change place along with the increase of load force.Therefore, the stress concentration line that discloses in time at the labour hardware is very important.

The main root that component of machine and hardware are damaged is various microcosmic and macroscopical mechanical stress concentration.At region of stress concentration, the development of corrosion and fatigue and creep process is the fiercest.Mechanical stress has direct contact with the self-magnetization phenomenon and the residual magnetism situation of ferromagnetic material, and under the condition of ground magnetic action, the magnetoconductivity of fault location reduces, and the stray field of surface of the work increases, and this characteristic of ferrimagnet is called magneto-mechanical effect.Its lip-deep Distribution of Magnetic Field and component stress load have certain relation, the existence of magneto-mechanical effect makes the Surface field of ferromagnetic metal workpiece strengthen, the position that the defective of parts or stress are concentrated " is remembered " in this magnetic field that has strengthened, effect that Here it is " magnetic memory " therefore can be diagnosed component defect or stress concentrated position indirectly by the Distribution of Magnetic Field situation on detection part surface.

In line with aforementioned thought, the design people studies improvement to the device that detects metal inside defective or area of stress concentration now, and this case produces thus.

The utility model content

Fundamental purpose of the present utility model is to provide a kind of metal magnetic memory diagnostic instrument, and it can detect the defective or the area of stress concentration of metal works inside easily and accurately.

In order to reach above-mentioned purpose, solution of the present utility model is:

A kind of metal magnetic memory diagnostic instrument comprises detection probe, data processing module, A/D modular converter, microprocessor, display module, range-measuring circuit and alarm module; Detection probe comprises four or eight by the magnetic field sensor of arrayed and the multi-way switch that is attached thereto, and the output terminal of multi-way switch connects data processing module; The output terminal of data processing module connects microprocessor via the A/D modular converter, and this microprocessor also connects display module, range-measuring circuit and alarm module.

Above-mentioned data processing module comprises detecting circuit, amplifying circuit, differential amplifier circuit, gain adjustment circuit and the filtering circuit that connects successively.

Above-mentioned microprocessor also is connected with RS232 interface or USB interface.

Above-mentioned display module is LCD display circuit or LED light.

Above-mentioned microprocessor also is connected with keyboard.

After adopting such scheme, the utility model is by utilizing the magnetic memory effect, by detecting the Distribution of Magnetic Field situation on metal works surface, can make things convenient for defective or the area of stress concentration of judging workpiece inside exactly, provide the early diagnosis of equipment fatigue damage, thereby can carry out respective handling as early as possible, after damaging fully, the equipment that prevents repairs or replaces again, the continuity that keeps production reduces maintenance cost, enhances productivity.

Description of drawings

Fig. 1 is a structural representation of the present utility model;

Fig. 2 is the arrangement synoptic diagram of magnetic field sensor in the utility model;

Fig. 3 is the tangential and normal component synoptic diagram in metal material magnetic field;

Fig. 4 is the function synoptic diagram of the fatigue crack of tested metal material.

Embodiment

Below in conjunction with drawings and the specific embodiments structure of the present utility model and principle of work are elaborated.

At first with reference to shown in Figure 1, it is the structural representation of a kind of metal magnetic memory diagnostic instrument provided by the utility model, it comprises detection probe 1, data processing module 2, A/D modular converter 3, microprocessor 4, display module 5, range-measuring circuit 6, alarm module 7, interface circuit and keyboard 9, below is introduced respectively.

Detection probe 1 comprises 4 or 8 magnetic field sensors 11 (adopting 4 in the present embodiment) and multi-way switch 12, described magnetic field sensor 11 all adopts arrayed, form orthohormbic structure, can be simultaneously with reference to shown in Figure 2, wherein sensors A, C are responsible for the metal material Distribution of Magnetic Field of " level " direction and the detection of dynamic of magnetic field value, and sensor B, D are responsible for the metal material Distribution of Magnetic Field of " vertically " direction and the detection of dynamic of magnetic field value; The input end number of multi-way switch 12 and the number of magnetic field sensor 11 coupling be connected with each magnetic field sensor 11 respectively, and output terminal connect data processing module 2, the wherein a certain road of may command gating detection signal.

Data processing module 2 is used for the aforementioned detected signal initial stage of carrying out is handled, but make it to reach the standard of calculation process, specifically, described data processing module 2 comprises detecting circuit 21, amplifying circuit 22, differential amplifier circuit 23, gain adjustment circuit 24 and the filtering circuit 25 that connects successively, detection signal is carried out detection, amplification and filtering successively, send into A/D modular converter 3 again, the part analog signal conversion is microprocessor 4 discernible digital signals, sends in the microprocessor 4.

Microprocessor 4 is built-in with storer, is used to store the digital signal that receives, aforementioned data is carried out calculation process after, send into corresponding module again, particular content is as follows:

It is concentrated that the micro-crack that metal material produces owing to tired, creep can cause fault location stress to occur, Distribution of Magnetic Field on its parts surface and component stress load have certain relation, therefore can indirectly component defect or stress concentrated position be diagnosed by the Distribution of Magnetic Field situation on detection part surface.Tangential component Hp in ferromagnetic component defective or region of stress concentration magnetic field (x) and normal component Hp (y) have maximal value, and with reference to shown in Figure 3, wherein the black oblique line is represented the stress concentration line.

Operating personnel hand detection probe 1, move along the surface of metal works in certain initial point (can set up on their own) beginning according to actual conditions, microprocessor 4 is according to " level " direction that receives and the magnetic field value of " vertical " direction, and the formula below utilizing calculates the derivative value of a certain period.

K _X=(D _HX1-D _HX0)/(D _T1-t0) K _XMagnetic field derivative value for horizontal direction

K _Y=(D _HY1-D _HY0)/(D _T1-t0) K _YMagnetic field derivative value for horizontal direction

Utilize the principle of magnetic field orthotropic then, calculate the derivative value of magnetic vector:

$K=\sqrt{K_{\mathrm{<figure-callout\; id="2"\; label="X"\; filenames="H2009201812148E00011.png"\; state="\{\{state\}\}">X</figure-callout>}}^2+{\mathrm{<figure-callout\; id="2"\; label="K\; Y"\; filenames="H2009201812148E00011.png"\; state="\{\{state\}\}">K</figure-callout>}}_Y^{}}$

Check the fatigue crack table that plant metal material then, judge that whether K is greater than a certain value K ₀(can obtain by destructive test) in the laboratory, as shown in Figure 4, when find K greater than the time, illustrate that metal material is in stress at this moment and concentrates distress phase, this moment, range-measuring circuit 6 was measured the distance of this moment apart from initial point simultaneously, and send in the microprocessor 4, microprocessor 4 sends to display module 5 with corresponding data and shows, show information such as concrete data, position by LCD display circuit 51, and LED light 52 is corresponding luminous, cause operating personnel's attention, control warning module 7 is sent alerting signal simultaneously.

In addition, microprocessor 4 also is connected with keyboard 9, and operating personnel can pass through keyboard 9 input informations or order, regulates default value or controls.But microprocessor 4 is the connecting interface circuit also, comprises RS232 interface 81 and USB interface 82 among this embodiment, with reference to shown in Figure 1, so both can carry out telecommunication by RS232 interface 81, also can pass through USB interface 82 derived datas.

Above embodiment only is explanation technological thought of the present utility model; can not limit protection domain of the present utility model with this; every according to the technological thought that the utility model proposes, any change of being done on the technical scheme basis all falls within the utility model protection domain.

Claims (5)

1. a metal magnetic memory diagnostic instrument is characterized in that: comprise detection probe, data processing module, A/D modular converter, microprocessor, display module, range-measuring circuit and alarm module; Detection probe comprises four or eight by the magnetic field sensor of arrayed and the multi-way switch that is attached thereto, and the output terminal of multi-way switch connects data processing module; The output terminal of data processing module connects microprocessor via the A/D modular converter, and this microprocessor also connects display module, range-measuring circuit and alarm module.

2. metal magnetic memory diagnostic instrument as claimed in claim 1 is characterized in that: described data processing module comprises detecting circuit, amplifying circuit, differential amplifier circuit, gain adjustment circuit and the filtering circuit that connects successively.

3. metal magnetic memory diagnostic instrument as claimed in claim 1 is characterized in that: described microprocessor also is connected with RS232 interface or USB interface.

4. metal magnetic memory diagnostic instrument as claimed in claim 1 is characterized in that: described display module is LCD display circuit or LED light.

5. metal magnetic memory diagnostic instrument as claimed in claim 1 is characterized in that: described microprocessor also is connected with keyboard.

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