CN221199546U - Storage tank bottom plate fillet weld defect detection device - Google Patents
Storage tank bottom plate fillet weld defect detection device Download PDFInfo
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- CN221199546U CN221199546U CN202322848048.5U CN202322848048U CN221199546U CN 221199546 U CN221199546 U CN 221199546U CN 202322848048 U CN202322848048 U CN 202322848048U CN 221199546 U CN221199546 U CN 221199546U
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- 238000005516 engineering process Methods 0.000 abstract description 6
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Abstract
The utility model belongs to the field of electromagnetic nondestructive detection, and particularly relates to a device for detecting a fillet weld defect of a bottom plate of a storage tank. The device comprises a travelling mechanism, a detection mechanism and a control terminal, wherein the detection mechanism and the control terminal are arranged on the travelling mechanism; the detection mechanism comprises a laser side distance sensor and a weak magnetic sensor which are respectively connected with the control terminal; the travelling mechanism comprises a guide mechanism and a distance maintaining mechanism. According to the technical scheme, the detection accuracy can be ensured by controlling the detection distance between the sensor and the fillet weld; and evaluating the fillet weld defect equivalent by using a weak magnetic technology. Detect convenient quick accurate: the developed detection device can be manually operated by an operator in a standing manner, and the distance between the sensor and the fillet weld is accurately controlled: the device is provided with the laser ranging sensor, and the distance between the bottom plate and the side plate is precisely controlled, so that the distance between the detection sensor and the fillet weld is precisely controlled, and the requirement of high-precision detection is met.
Description
Technical Field
The utility model belongs to the field of electromagnetic nondestructive detection, and particularly relates to a device for detecting a fillet weld defect of a bottom plate of a storage tank.
Background
The current storage tank is affected by adverse factors of natural environment and internal media in the long-term use process, and can be corroded to different degrees. In order to ensure reliable operation, the storage tank needs to be detected, evaluated and maintained. The related data show that in the corrosion failure of the storage tank, the corrosion of the bottom plate of the storage tank accounts for about 80 percent, and the conventional nondestructive detection method for the corrosion defect of the bottom plate of the petroleum storage tank mainly comprises the following steps: magnetic flux leakage detection, ultrasonic detection, magnetic powder detection, acoustic emission detection and the like, wherein the detection efficiency of the magnetic flux leakage detection, the ultrasonic detection and the magnetic powder detection is low; the acoustic emission detection needs more complicated external conditions, and has high noise and difficult signal analysis. In recent years, a rapid detection technology-a weak magnetic detection technology which can conveniently realize certain lift-off under the condition of no need of coupling and no need of external magnetization is available. The weak magnetic detection technology is a nondestructive detection technology which is based on a natural geomagnetic field, scans the surface of a sample through a magnetic signal acquisition instrument, acquires the changes of magnetic induction intensity in different directions so as to judge whether defects exist on the surface of the detected sample and in a certain depth range, and judges the positions and the sizes of the defects in the detected sample through data processing. The weak magnetic nondestructive detection technology does not need a magnetization process, can avoid adverse effects of workpieces caused by residual magnetism, has the advantages of simple operation, high detection speed and accurate positioning, can detect surface and internal defects, is easy to find tiny perforation, corrosion and crack, and can evaluate the discontinuity, stress concentration and places where defects are easy to generate of materials.
The defects in the bottom plate of the storage tank and the welding seam of the bottom plate are well known, but the detection of the welding seam of the bottom corner of the storage tank is close to the edge, so that the space is narrow and the detection becomes a blind area.
Therefore, it is necessary to provide a new device and a method for detecting the fillet weld defect of the bottom plate of the storage tank to solve the technical problem of nondestructive weld defect detection.
Disclosure of utility model
The utility model provides a storage tank bottom plate fillet weld defect detection device which comprises a running mechanism, a detection mechanism and a control terminal, wherein the detection mechanism and the control terminal are arranged on the running mechanism; the detection mechanism comprises a laser ranging sensor and a weak magnetic sensor which are respectively connected with the control terminal; the travelling mechanism comprises a guide mechanism and a distance maintaining mechanism.
Further, the travelling mechanism comprises a bottom plate and side plates, the bottom plate is provided with rollers, one side of the side plate, which is close to the bottom plate, is vertically arranged with the bottom plate longitudinally, the side plate is provided with a spacing maintaining mechanism, and the spacing maintaining mechanism is a sideslip auxiliary wheel.
Still further, guiding mechanism includes push rod, cardan shaft and mounting panel, the mounting panel is located on the bottom plate, push rod one end has the grab handle, the push rod other end passes through the cardan shaft with the mounting panel rotatable coupling.
Still further, control terminal is the industrial computer, the industrial computer still include with the optical signal line that laser rangefinder sensor is connected and with the magnetism signal line that weak magnetic sensor is connected.
Further, the bottom plate and the side plates are provided with penetrating holes for the laser ranging sensors, and the laser ranging sensors are arranged in the penetrating holes; the bottom plate at least comprises one penetrating hole, and the side plate at least comprises one penetrating hole.
Further, two penetrating holes are formed in the side plate, and one penetrating hole is formed in the bottom plate; the penetrating hole is positioned in the area below the sideslip auxiliary wheel; and three weak magnetic mounting holes are formed in one end, close to the side plate, of the lower surface of the bottom plate, and each weak magnetic mounting hole is internally provided with a weak magnetic sensor.
A method for detecting the defects of the fillet weld of a bottom plate of a storage tank comprises the following steps:
step one, starting a detection device and a control terminal;
step two, arranging the device on the surface of the bottom plate workpiece, so that the weak magnetic sensor stably moves above the surface of the welding line at a constant speed;
Step three, synchronously feeding back the acquired signals to a control terminal to perform judgment;
step four, obtaining a defect position according to the signal diagram;
and fifthly, carrying out the second step again on the position shown in the fourth step to obtain the final defect position.
Further, in the fourth step, the judgment basis is executed:
The probability that the random variable ζ falls within the interval (μ -aσ, μ+aσ) interval is: when a=1.96, the confidence level is 95%, and an upper threshold line and a lower threshold line of a region with the confidence level of 95% are obtained; setting three acquisition points, wherein the differential value is y i,j＝xi,j+1-xi,j, i=1, 2, …, n j =1, 2; and xi and y i,j are detected as defects only when signals exceeding the threshold value are simultaneously present, otherwise, the signals are not considered as defect signals.
According to the technical scheme, the detection accuracy can be ensured by controlling the detection distance between the sensor and the fillet weld; and evaluating the fillet weld defect equivalent by using a weak magnetic technology. Detect convenient quick accurate: the developed detection device can be manually operated by an operator in a standing manner, and the distance between the sensor and the fillet weld is accurately controlled: the device is provided with the laser ranging sensor, and the distance between the bottom plate and the side plate is precisely controlled, so that the distance between the detection sensor and the fillet weld is precisely controlled, and the requirement of high-precision detection is met.
Drawings
FIG. 1 is a front view of a detection device;
FIG. 2 is a rear view of the detection device;
FIG. 3 is a top view of the detection device;
FIG. 4 is a bottom view of the detection device;
FIG. 5 is a magnetic field gradient signal diagram;
Reference numerals: 11 push rod, 12 cardan shaft, 13 mounting plate, 21 curb plate, 22 bottom plate, 24 sideslip auxiliary wheel, 25 laser ranging sensor, 26 field weakening detection sensor, 31 optical signal line, 32 magnetic signal line, 4 control terminal.
Detailed Description
The following description of the embodiments of the present utility model will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the utility model are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.
The following description of the embodiments of the present utility model will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the utility model are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model. In the description of the present utility model, it should be understood that the terms "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the drawings, are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model.
Furthermore, the terms "first," "second," a, b, c, d, e, f, etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.
Example 1
Referring to fig. 1 to 4, the present embodiment presents a device for detecting a fillet weld defect of a tank bottom plate, comprising a traveling mechanism, and a detecting mechanism and a control terminal 4 provided on the traveling mechanism; the detection mechanism comprises a laser ranging sensor 25 and a weak magnetic sensor 26 which are respectively connected with the control terminal; the travelling mechanism comprises a guide mechanism and a distance maintaining mechanism.
The travelling mechanism comprises a bottom plate 22 and a side plate 21, wherein the bottom plate 22 is provided with rollers, one side of the side plate 21 close to the bottom plate 22 is vertically and longitudinally arranged with the bottom plate 22, and the side plate 22 is provided with a spacing maintaining mechanism which is a sideslip auxiliary wheel 24. The sideslip auxiliary wheel is used for keeping a distance from the region to be detected, prevents the device and the wall of the region to be detected, such as detecting a weld on the inner side of a ship body or detecting a weld in an aircraft cabin, and is not suitable for being directly contacted with the region to be detected. Avoiding scratch. If necessary, an additional layer is additionally arranged on the sideslip auxiliary wheel, and the sideslip auxiliary wheel can be corrosion-resistant, heat-insulating or buffer-increasing.
The guiding mechanism comprises a push rod 11, a universal shaft 12 and a mounting plate 13, wherein the mounting plate is arranged on a bottom plate 22, one end of the push rod 11 is provided with a grab handle, and the other end of the push rod 11 is rotatably connected with the mounting plate 13 through the universal shaft 12.
The control terminal 4 is an industrial personal computer, and the industrial personal computer further comprises an optical signal line 31 connected with the laser ranging sensor 25 and a magnetic signal line 32 connected with the weak magnetic sensor 26. The travelling mechanism can be composed of a wheel body, a crawler belt structure or an air cushion matched with the propeller which are arranged below the bottom plate.
The bottom plate 22 and the side plate 21 are provided with penetrating holes for the laser ranging sensors 15, and the laser ranging sensors are arranged in the penetrating holes; the bottom plate 21 includes at least one through hole, and the side plate 21 includes at least one through hole.
Two through holes are formed in one side plate 21, one through hole is formed in the bottom plate 22, and the actual layout number can be dynamically adjusted according to cost, algorithm and detection point number; the penetrating hole is positioned in the area below the sideslip auxiliary wheel; three weak magnetic mounting holes are formed in the lower surface of the bottom plate 22 at one end close to the side plate, and a weak magnetic sensor 26 is arranged in each weak magnetic mounting hole.
The device is pushed or guided by an operator or machine along the area to be measured.
The system detection speed is the speed at which the operator walks. The device guarantees that the distance between the bottom plate of the storage tank to be detected and the distance between the side plate of the storage tank to be detected and the side edge of the storage tank are equal. When the measured value of any one laser ranging sensor is larger than 20mm, the device can be considered to be suspended, and the 20mm can be set and measured by itself according to actual conditions, so that the device is only used as an example. The weld was inspected at a 45 degree angle outward.
The laser ranging sensors are arranged in three circular holes on the bottom plate and the side plates and used for detecting whether the wheels of the device are suspended.
The laser ranging sensor is used for controlling the distance between the weak magnetic sensor and the fillet weld, and if the distance exceeds the range, an operator is required to adjust the movement direction of the device, so that the difference value of the ranging sensor is detected within a certain range.
The sensor is a main device carried by the device, is a detection device for tank bottom detection, and is designed to carry three sensors and is fixed in three cube hole sites of 13 x 13 shown in fig. 4, namely three weak magnetic mounting holes. The three holes are through holes above
The round hole penetrates through the upper surface of the device, so that connection of the sensor and the signal acquisition system is facilitated. The laser ranging sensor is arranged on the bottom plate and the side plate, one of the laser ranging sensors is arranged on the bottom plate, and the laser ranging sensor is arranged in the center of the bottom plate. And two side plates are respectively arranged right below the side wheels, and whether the two side wheels contact the wall surface is measured. The distance variation of each pulse is calculated. Let the resolution of the photoelectric encoder be N (number of pulses/turn), the actual linear travel S for each pulse be s=pi d/N (formula 1), where d is the diameter of the photoelectric encoder measurement wheel.
The distance of movement of the table per second was calculated. The movement distance V of the table per second is v=n×s×f (formula 2), where f is the frequency of the output signal of the photoelectric encoder.
Example 2
The embodiment is an elaboration of a method for detecting the defects of the fillet weld of the bottom plate of the storage tank, referring to fig. 5, the steps are as follows:
step one, starting a detection device and a control terminal;
step two, arranging the device on the surface of the bottom plate workpiece, so that the weak magnetic sensor stably moves above the surface of the welding line at a constant speed;
Step three, synchronously feeding back the acquired signals to a control terminal to perform judgment;
step four, obtaining a defect position according to the signal diagram;
and fifthly, carrying out the second step again on the position shown in the fourth step to obtain the final defect position.
And step four, executing judgment basis:
The probability that the random variable ζ falls within the interval (μ -aσ, μ+aσ) interval is: when a=1.96, the confidence level is 95%, and an upper threshold line and a lower threshold line of a region with the confidence level of 95% are obtained; setting three acquisition points, wherein the differential value is y i,j＝xi,j+1-xi,j, i=1, 2, …, n j =1, 2; and xi and y i,j are detected as defects only when signals exceeding the threshold value are simultaneously present, otherwise, the signals are not considered as defect signals.
The acquired non-stationary signal is a superposition of a magnetic induction intensity signal at the welding seam and a magnetic anomaly signal at the defect, the magnetic induction intensity signal of the welding seam can be understood to be a stationary background field signal, and the magnetic anomaly signal is an aperiodic disturbance signal with larger amplitude change and uncertain occurrence time, so that the change of the magnetic anomaly amplitude is considered to be compliant with normal distribution, if the defect is encountered in the detection process according to the normal distribution rule, the magnetic anomaly phenomenon is generated at the defect, the acquired magnetic field signal is represented as an anomaly point, the occurrence of the anomaly point belongs to a small probability event, a corresponding confidence interval can be calculated, a threshold value is set, and the anomaly signal generated by the defect is judged to be the anomaly signal generated by the defect.
Let the random variable ζ obey the normal distribution N (μ, σ 2), μ be the mathematical expectation, σ be the standard deviation.
Then the random variable ζ falls within the interval
The probability within the interval (μ -aσ, μ+aσ) is:
When a=1.96, then the confidence level is 95%, the random signal falls within the interval as a non-defective signal that is considered to be trusted, and the abnormal defect signal that falls outside the interval as an abnormal defect signal that is considered to be untrusted. Because the magnetic field is a vector signal, the measured actual signal is a magnetic induction intensity curve, the signals are in different levels, the magnetic field gradient signals can reflect the abrupt change condition of the magnetic signals, and the signals are in the same level, so that the magnetic field gradient signals are obtained by calculating the measured magnetic induction intensity signals, the upper threshold line and the lower threshold line with the confidence level of 95% interval are obtained by calculating the magnetic field gradient signals, and the position exceeding the threshold line can be judged as the abnormal signal caused by the defect.
When the fillet weld detection of the storage tank is carried out, the fillet weld detection adopts a single-sensor mode because the width of the weld is not large. However, in the direction along the trend of the welding seam (as shown in the drawing), a plurality of weak magnetic sensors are arranged to realize detection multiplexing, so that the reliability is improved.
In this example, 3 weak magnetic sensors are provided, and defect determination is performed by using a front-rear differential method.
Let the signal value that the sensor gathered be x i,1,xi,2,xi,3, represent the signal value that gathers of No. 1 sensor, the signal value that gathers of No. 2 sensor, the signal value that gathers of 3 sensor respectively.
The differential value is y i,j＝xi,j+1-xi,j, where i=1, 2, …, n j =1, 2
Y i,j and xi belong to the same kind of data, and the defect is judged by adopting the same data processing method.
The weld defect judging method comprises the following steps:
And xi and y i,j are detected as defects only when signals exceeding the threshold value are simultaneously present, otherwise, the signals are not considered as defect signals. (y i,1 and y i,2 can use either as sample data, and two sets of data are provided to improve the reliability of the instrument)
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present utility model, and are not limiting; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced with equivalents; such modifications and substitutions do not depart from the spirit of the technical solutions according to the embodiments of the present utility model.
Claims (6)
1. The device for detecting the fillet weld defect of the bottom plate of the storage tank is characterized by comprising a travelling mechanism, and a detecting mechanism and a control terminal which are arranged on the travelling mechanism; the detection mechanism comprises a laser ranging sensor and a weak magnetic sensor which are respectively connected with the control terminal; the travelling mechanism comprises a guide mechanism and a distance maintaining mechanism.
2. The device for detecting the fillet weld defect of the bottom plate of the storage tank according to claim 1, wherein the traveling mechanism comprises a bottom plate and a side plate, the bottom plate is provided with rollers, one side of the side plate, which is close to the bottom plate, is vertically arranged with the bottom plate in the longitudinal direction, the side plate is provided with the interval maintaining mechanism, and the interval maintaining mechanism is a sideslip auxiliary wheel.
3. The device for detecting the fillet weld defect of the bottom plate of the storage tank according to claim 2, wherein the guiding mechanism comprises a push rod, a universal shaft and a mounting plate, the mounting plate is arranged on the bottom plate, one end of the push rod is provided with a grab handle, and the other end of the push rod is rotatably connected with the mounting plate through the universal shaft.
4. The device for detecting the fillet weld defect of the bottom plate of the storage tank according to claim 2 or 3, wherein the control terminal is an industrial personal computer, and the industrial personal computer further comprises an optical signal wire connected with the laser ranging sensor and a magnetic signal wire connected with the weak magnetic sensor.
5. The device for detecting the fillet weld defect of the bottom plate of the storage tank according to claim 4, wherein the bottom plate and the side plate are provided with penetrating holes for the laser ranging sensors, and the laser ranging sensors are arranged in the penetrating holes; the bottom plate at least comprises one penetrating hole, and the side plate at least comprises one penetrating hole.
6. The device for detecting the fillet weld defect of the bottom plate of the storage tank according to claim 5, wherein two penetrating holes are formed in the side plate, and one penetrating hole is formed in the bottom plate; the penetrating hole is positioned in the area below the sideslip auxiliary wheel; and three weak magnetic mounting holes are formed in one end, close to the side plate, of the lower surface of the bottom plate, and each weak magnetic mounting hole is internally provided with a weak magnetic sensor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202322848048.5U CN221199546U (en) | 2023-10-23 | 2023-10-23 | Storage tank bottom plate fillet weld defect detection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202322848048.5U CN221199546U (en) | 2023-10-23 | 2023-10-23 | Storage tank bottom plate fillet weld defect detection device |
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| CN221199546U true CN221199546U (en) | 2024-06-21 |
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| CN202322848048.5U Active CN221199546U (en) | 2023-10-23 | 2023-10-23 | Storage tank bottom plate fillet weld defect detection device |
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| CN (1) | CN221199546U (en) |
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- 2023-10-23 CN CN202322848048.5U patent/CN221199546U/en active Active
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