Welding seam crack nondestructive testing device

Abstract

A nondestructive testing device for weld cracks relates to the technical field of nondestructive testing of cracks by a direct-current potential difference method, and can realize rapid detection of cracks of a weld and a heat affected zone nearby the weld by the direct-current potential difference method. In the nondestructive testing device for the weld crack, an upper computer display system is installed on a tablet computer, a lower computer control system is built based on an STM32 chip, and a voltage measurement system is composed of a multichannel analog-to-digital conversion chip and an auxiliary circuit thereof and is used for measuring the potential difference between two detection probes and converting an analog signal into a digital signal. Meanwhile, the measurement result is obtained by the lower computer control system through the voltage measurement system and is sent to the upper computer display system to be displayed and stored; the probe fixing device is used for fixing and mounting the detection probe and driving the whole nondestructive detection device to move at the weld joint, and meanwhile, the detection probe is placed on the surface of the detected metal weld joint for current input and potential difference measurement.

Description

Technical Field

[0001] The utility model relates to the technical field of non-destructive crack detection using a DC potential difference method, in particular to a non-destructive detection device for weld cracks. Background Art

[0002] Welding is a manufacturing process and technology that uses heat, high temperature, or high pressure to join metals or other thermoplastic materials (such as plastics). Welding is the primary method for connecting metal structures. The weld and the surrounding heat-affected zone are weak areas in the metal connection, making them prone to crack damage.

[0003] Weld cracks are a highly detrimental defect. Besides reducing the load-bearing capacity of welded joints, the sharp notches at the ends of the cracks can cause severe stress concentration, prompting crack expansion and ultimately damaging the weld structure, rendering the product scrapped or even causing serious accidents. Generally, cracks are considered a serious defect in welded joints and, upon discovery, should be completely removed and repaired with welding.

[0004] Currently, the most commonly used nondestructive testing methods for weld cracks include ultrasonic, radiographic, and magnetic particle testing. Ultrasonic and radiographic testing techniques are primarily used to detect internal cracks in welds, while magnetic particle testing is used to detect surface cracks. However, the prevalence of weld reinforcement, weld lines, and fusion lines in welds can significantly interfere with test results. Consequently, these methods suffer from low efficiency, high operator experience requirements, and poor recordability and repeatability of test results.

[0005] Therefore, how to provide a non-destructive detection device for weld cracks that can effectively improve the detection efficiency of butt welds and enhance the recordability and repeatability of detection results has become a technical problem that technical personnel in this field urgently need to solve. Utility Model Content

[0006] The purpose of the utility model is to provide a nondestructive detection device for weld cracks, which can realize rapid detection of cracks in a weld and its adjacent heat-affected zone by adopting a DC potential difference method.

[0007] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0008] A nondestructive detection device for weld cracks, comprising: a host computer display system, the host computer display system being installed on a tablet computer and being used to display and store weld crack detection results in real time;

[0009] The lower computer control system is built based on the STM32 chip and is used to control the voltage acquisition of the voltage measurement system and is responsible for synchronous signal communication with the upper computer display system;

[0010] A voltage measurement system, which consists of a multi-channel analog-to-digital conversion chip and its auxiliary circuits, is used to measure the potential difference between the two detection probes and convert the analog signal into a digital signal. At the same time, the measurement result is obtained by the lower computer control system through the voltage measurement system and sent to the upper computer display system for display and storage;

[0011] A power supply system, comprising a lithium-ion battery, a charge and discharge control circuit, and a voltage conversion circuit, for providing power to the lower control system, the voltage measurement system, and the detection probe;

[0012] The probe fixing device is used to fix and install the detection probe and drive the entire non-destructive testing device to move at the weld. At the same time, the detection probe is placed on the surface of the metal weld to be tested for current input and potential difference measurement.

[0013] In actual application, the detection probe includes: a probe shell, and an upper cover and a lower cover that match and dock with the probe shell; the upper cover is provided with a probe connector, and the probe connector is provided with a built-in electrode; an electromagnet is provided inside the probe shell, and the power cord of the electromagnet is connected to the built-in electrode of the probe connector; a plug is provided at the center hole of the lower cover, and the plug is used to prevent the probe from falling; the probe can pass through the center hole of the lower cover and be connected to the built-in electrode through a connecting wire; a rubber pad is provided at one end of the probe adjacent to the electromagnet, and a compression spring is provided on the outside of the probe below the rubber pad.

[0014] The end area of the probe adjacent to the electromagnet is made of carbon steel, and the remaining area is made of copper, and the carbon steel area and the copper area are connected by welding;

[0015] The overall structure of the probe is a cylinder, and the outer surface of the probe has a draft angle.

[0016] Specifically, the upper cover and the lower cover are respectively connected to the probe housing via threads; and the probe connector is bonded to the upper cover via glue.

[0017] Furthermore, the rubber pad is made of rubber material, and has a through hole in the center thereof and is used to be sleeved on the probe, and the probe and the rubber pad are connected by an interference fit;

[0018] The plug is made of rubber and is inserted into the center hole of the lower cover by interference fit to prevent the probe from falling out of the center hole of the lower cover and being damaged during assembly and non-measurement periods.

[0019] In actual application, the probe fixing device includes: a probe cover, and the probe cover has a plurality of positioning holes distributed in a matrix, the outer surface of the probe shell has an external thread and is screwed into the positioning holes of the probe cover through the external thread; a cover and a handle are provided on the top outer side of the probe cover; the probe cover is provided with an external connector, and an electrode is provided inside the external connector, and the electrode is used to connect the wire of the detection probe; a walking mechanism is provided at the bottom ends of both sides of the probe cover.

[0020] Wherein, the walking mechanism includes: a support shaft and a support wheel connected to the support shaft; the support shaft is connected to the probe cover through a fastening nut.

[0021] Specifically, the probe cover is connected to the probe sleeve by fastening screws, and the handle is connected to the probe sleeve by welding; the external connector and the probe cover are connected by gluing.

[0022] Furthermore, the probe housing, the upper cover, the lower cover, the probe connector, the probe cover, the probe outer cover, the handle, the outer connector, the support shaft, the fastening nut and the support wheel are all made of stainless steel.

[0023] A method for using a weld crack nondestructive detection device comprises the following steps:

[0024] Start the power supply system, the lower computer control system and the upper computer display system. At this time, the electromagnets in each detection probe are in a charged state. The electromagnets have the magnetism to absorb the carbon steel on the upper part of the probe, so that the probe can be extended and retracted inside the probe housing.

[0025] Lift the handle and place the nondestructive testing device on the weld to be tested, pull out the plug and press the test button. At this time, the electromagnet is powered off, and the probe falls under the action of gravity and passes through the center hole of the lower cover. The compression spring is pressed down to the lower cover, and the compression spring is in a compressed state, driving the rubber pad to act as a buffer for the probe to prevent the probe from colliding with the weld to be tested and damaging the probe.

[0026] Signal measurement is performed at the crack-free location of the weld, and if necessary, magnetic particle inspection is performed on this location first to confirm that no crack damage exists. An excitation voltage is applied to the two left and right detection probes in each row, and the potential difference between the middle detection probe and the detection probe at either end is measured to serve as the benchmark for subsequent crack detection. The host computer display system automatically records and displays this detection benchmark. After completing the benchmark potential difference measurement, the end measurement button is pressed, the electromagnet is energized again, and the probe is retracted into the probe housing using the elastic force of the compression spring and the magnetic force of the electromagnet on the carbon steel at the upper end of the probe.

[0027] Lift the handle and place the nondestructive testing device on the weld to be tested. Pull out the plug and press the test button. The electromagnet is powered off and the probe falls under the action of gravity and passes through the center hole of the lower cover to start testing. After completing the test of one position, press the end measurement button, the electromagnet is powered on and the probe is retracted into the probe housing. At this time, push the handle to the new test position and start measuring again. During the entire test process, the host computer display system continuously displays and records the measurement results of the potential difference at different positions.

[0028] After completing all measurements, press the end measurement button, the electromagnet is energized, the probe is retracted into the inside of the probe housing, and the plug is inserted into the center hole of the lower cover; at this time, the reference potential difference and the potential difference at different detection positions are stored in the upper computer display system, and the upper computer display system, lower computer control system and power supply system are turned off in sequence.

[0029] Compared with the prior art, the weld crack nondestructive detection device described in the present invention has the following advantages:

[0030] In the weld crack nondestructive detection device provided by the present invention, since the host computer display system is installed on the tablet computer and is used to display and store the detection results of the weld crack in real time, the lower computer control system is built based on the STM32 chip and is used to control the voltage acquisition of the voltage measurement system, and is responsible for synchronous signal communication with the upper computer display system. The voltage measurement system is composed of a multi-channel analog-to-digital conversion chip and its auxiliary circuit and is used to measure the potential difference between the two detection probes and convert the analog signal into a digital signal. At the same time, the measurement result is obtained by the lower computer control system through the voltage measurement system and sent to the upper computer display system for display and storage. The power supply system includes a lithium ion battery, The charge and discharge control circuit and the voltage conversion circuit are used to provide power for the lower computer control system, the voltage measurement system, and the detection probe. The probe fixing device is used to fix and install the detection probe and drive the entire non-destructive testing device to move at the weld. At the same time, the detection probe is placed on the surface of the metal weld to be tested for current input and potential difference measurement. Therefore, the weld crack non-destructive testing device provided by the utility model uses the DC potential difference method to pass a certain value of DC current through the test piece to be tested. When a crack exists in the weld, the potential distribution is different compared to the case without cracks. By measuring this potential distribution difference caused by the presence of the crack, rapid detection of the crack can be effectively achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of the system framework structure of a weld crack nondestructive detection device provided by an embodiment of the present utility model;

[0032] Figure 2 A schematic diagram of the overall assembly structure of a weld crack nondestructive detection device provided by an embodiment of the present invention from a first perspective;

[0033] Figure 3 A schematic diagram of the overall assembly structure of the weld crack nondestructive detection device provided by an embodiment of the present utility model from a second perspective;

[0034] Figure 4 A schematic diagram of the internal assembly structure of a weld crack nondestructive detection device provided by an embodiment of the present utility model;

[0035] Figure 5 A schematic diagram of the assembly structure of a detection probe in a weld crack nondestructive detection device provided by an embodiment of the present utility model;

[0036] Figure 6 A schematic diagram of the explosion structure of a detection probe in a weld crack nondestructive detection device provided by an embodiment of the present utility model;

[0037] Figure 7 This is a schematic diagram of the layout distribution of detection probes in the weld crack non-destructive detection device provided by an embodiment of the utility model.

[0038] Reference numerals:

[0039] 1-Detection probe; 2-Probe cover; 3-Probe cover; 4-Handle; 5-External connector; 6-Fasten screw; 7-Support shaft; 8-Fasten nut; 9-Support wheel;

[0040] 10-probe housing; 11-upper cover; 12-probe connector; 13-electromagnet; 14-rubber pad; 15-probe; 16-compression spring; 17-lower cover; 18-plug. DETAILED DESCRIPTION

[0041] For ease of understanding, the weld crack nondestructive detection device provided by the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings.

[0042] The present invention provides a nondestructive detection device for weld cracks. Figures 1-6 As shown, it includes: a host computer display system, which is installed on a tablet computer and is used to display and store the detection results of weld cracks in real time;

[0043] The lower computer control system is built based on the STM32 chip and is used to control the voltage acquisition of the voltage measurement system. It is also responsible for synchronous signal communication with the upper computer display system.

[0044] The voltage measurement system consists of a multi-channel analog-to-digital conversion chip (such as AD5940, AD5590, etc.) and its auxiliary circuits. It is used to measure the potential difference between the two detection probes and convert the analog signal into a digital signal. At the same time, the measurement result is obtained by the lower-level control system through the voltage measurement system and sent to the upper-level display system for display and storage;

[0045] The power supply system includes a lithium-ion battery, a charge and discharge control circuit, and a voltage conversion circuit, and is used to provide power for the lower computer control system, voltage measurement system, and detection probe;

[0046] The probe fixing device is used to fix and install the detection probe 1 and drive the entire non-destructive testing device to move at the weld. At the same time, the detection probe 1 is placed on the surface of the metal weld to be tested for current input and potential difference measurement;

[0047] According to the width of the weld and weld heat-affected zone to be inspected, the number of detection probes 1 in each row and the total number of rows can be determined. In this application, it is preferred to have 3 probes in each row, with a total of 3 rows. Multiple rows are set in order to cover multiple detection points along the weld direction while staying at the same detection position, thereby further improving the detection efficiency.

[0048] The present invention further provides a method for using a weld crack nondestructive detection device, comprising the following steps:

[0049] Start the power supply system, the lower computer control system, and the upper computer display system. At this time, the electromagnet 13 in each detection probe 1 is in a charged state, and the electromagnet 13 has the magnetic ability to absorb the carbon steel on the upper part of the probe 15, so that the probe 15 can be extended and retracted inside the probe housing 10;

[0050] Lift the handle 4 and place the nondestructive testing device on the weld to be tested. Pull out the plug 18 and press the test button. At this time, the electromagnet 13 is powered off, and the probe 15 falls under the action of gravity and passes through the center hole of the lower cover 17. The compression spring 16 is pressed down to the lower cover 17. The compression spring 16 is in a compressed state and drives the rubber pad 14 to act as a buffer for the probe 15 to prevent the probe 15 from colliding with the weld to be tested and damaging the probe 15.

[0051] Signal measurement is performed at a crack-free location on the weld, and if necessary, magnetic particle inspection is first performed on this location to confirm that no crack damage exists. An excitation voltage is applied to the two left and right detection probes 1 in each row, and the potential difference between the middle detection probe 1 and the detection probe 1 at either end is measured to serve as a reference for subsequent crack detection. The host computer display system automatically records and displays this detection reference. After completing the reference potential difference measurement, the end measurement button is pressed, and the electromagnet 13 is energized again. The probe 15 is retracted into the probe housing 10 using the elastic force of the compression spring 16 and the magnetic force of the electromagnet 13 on the carbon steel at the upper end of the probe 15.

[0052] Lift the handle 4 and place the nondestructive testing device on the weld to be tested. Pull out the plug 18 and press the test button. At this time, the electromagnet 13 is de-energized, and the probe 15 falls under the action of gravity and passes through the center hole of the lower cover 17 to start testing. After completing the test of one position, press the end measurement button, the electromagnet 13 is energized, and the probe 15 is retracted into the probe housing 10. At this time, push the handle 4 to the new test position and start measuring again. During the entire test process, the host computer display system continuously displays and records the measurement results of the potential difference at different positions.

[0053] After all measurements are completed, press the end measurement button, the electromagnet 13 is energized, the probe 15 is retracted into the interior of the probe housing 10, and the plug 18 is inserted into the center hole of the lower cover 17; at this time, the reference potential difference and the potential difference at different detection positions are stored in the upper computer display system, and the upper computer display system, the lower computer control system and the power supply system are turned off in sequence.

[0054] Compared with the prior art, the weld crack nondestructive detection device described in the embodiment of the present invention has the following advantages:

[0055] In the weld crack nondestructive detection device provided by the embodiment of the present invention, since the host computer display system is installed on the tablet computer and is used to display and store the detection results of the weld crack in real time, the lower computer control system is built based on the STM32 chip and is used to control the voltage acquisition of the voltage measurement system, and is responsible for synchronous signal communication with the host computer display system. The voltage measurement system is composed of a multi-channel analog-to-digital conversion chip and its auxiliary circuit and is used to measure the potential difference between the two detection probes and convert the analog signal into a digital signal. At the same time, the measurement result is obtained by the lower computer control system through the voltage measurement system and sent to the host computer display system for display and storage. The power supply system includes a lithium ion battery, The charge and discharge control circuit and the voltage conversion circuit are used to provide power for the lower computer control system, the voltage measurement system, and the detection probe. The probe fixing device is used to fix and install the detection probe and drive the entire non-destructive testing device to move at the weld. At the same time, the detection probe is placed on the surface of the metal weld to be tested for current input and potential difference measurement. Therefore, the weld crack non-destructive testing device provided by the embodiment of the present invention uses the DC potential difference method to pass a certain value of DC current through the test piece to be tested. When there is a crack in the weld, the potential distribution is different from that in the case without cracks. By measuring this potential distribution difference caused by the presence of the crack, rapid detection of the crack can be effectively achieved.

[0056] It should be noted here that the principle of measuring cracks using the DC potential difference method is to apply a constant current to both ends of the specimen, generating a constant electric field in the thickness direction of the specimen; as the crack length increases, the crack cross-section continues to shrink and the resistance continues to increase; under a constant current, the potential or voltage drop at both ends of the crack surface increases with the increase in crack size.

[0057] In actual application, such as Figures 1-6 As shown, the above-mentioned detection probe 1 may include: a probe housing 10, and an upper cover 11 and a lower cover 17 that match and dock with the probe housing 10; the upper cover 11 may be provided with a probe connector 12, and the probe connector 12 may be provided with a built-in electrode; an electromagnet 13 may be provided inside the probe housing 10, and the power cord of the electromagnet 13 is connected to the built-in electrode of the probe connector 12; a plug 18 may be provided at the center hole of the lower cover 17, and the plug 18 can be used to prevent the probe 15 from falling; the probe 15 can pass through the center hole of the lower cover 17 (the compression spring 16 and the rubber pad 14 cannot pass through the center hole) and be connected to the built-in electrode through a connecting wire; a rubber pad 14 may be provided at one end of the probe 15 adjacent to the electromagnet 13, and a compression spring 16 may be provided on the outside of the probe 15 below the rubber pad 14. The material of the compression spring 16 may be stainless spring steel wire, and the outer surface is coated with insulating paint.

[0058] Among them, such as Figures 1-6As shown, the end area of the probe 15 adjacent to the electromagnet 13 can be made of carbon steel, and the remaining area can be made of copper, and the carbon steel area and the copper area can be connected by welding;

[0059] The overall structure of the probe 15 may preferably be a cylinder, and the outer surface of the probe 15 may have a draft angle.

[0060] Specifically, if Figures 1-6 As shown, the upper cover 11 and the lower cover 17 can be respectively connected to the probe housing 10 through threads; the probe connector 12 and the upper cover 11 can be bonded together by glue.

[0061] Furthermore, if Figures 1-6 As shown, the rubber pad 14 can be made of rubber material, and the center of the rubber pad 14 can have a through hole and be used to be sleeved on the probe 15. At the same time, the probe 15 and the rubber pad 14 can be connected by an interference fit.

[0062] The plug 18 can be made of rubber and inserted into the center hole of the lower cover 17 by interference fit to prevent the probe 15 from falling out of the center hole of the lower cover 17 and being damaged during assembly and non-measurement periods.

[0063] The assembly process of the detection probe 1 is as follows: one end of the connecting wire is connected to the upper end of the probe 15 by welding, and the other end of the connecting wire is passed through the center hole of the probe housing 10, the electromagnet 13, and the upper cover 11 in sequence, and the other end of the connecting wire is connected to the built-in electrode of the probe connector 12 by welding; the rubber pad 14 is inserted onto the probe 15 from the bottom of the probe 15 by interference fit, and the compression spring 16 is installed from the bottom of the probe 15. The assembled probe 15, rubber pad 14 and compression spring 16 are installed into the cavity of the lower half of the probe housing 10; the lower cover 17 is connected to the probe housing 10 by threading; the plug 18 is inserted into the center hole of the lower cover 17; the power line of the electromagnet 13 is connected to the built-in electrode of the probe connector 12 by welding, and the electromagnet 13 is placed in the cavity of the upper half of the probe housing 10; the upper cover 11 is tightly connected to the probe connector 12 using strong glue; and the upper cover 11 is connected to the probe housing 10 by threading.

[0064] In actual application, such as Figures 1-6As shown, the above-mentioned probe fixing device may include: a probe cover 2, and the probe cover 2 may have a plurality of positioning holes distributed in a matrix, the outer surface of the probe housing 10 may have an external thread and be screwed into the positioning hole of the probe cover 2 through the external thread to achieve the fixation of the detection probe 1; the top outer side of the probe cover 2 may be provided with a cover head cover 3 and a handle 4 (for moving and placing the entire set of non-destructive testing equipment); the probe cover 3 (for protecting the probe from external collision damage during the detection process) may be provided with an external connector 5, and the inside of the external connector 5 may be provided with an electrode, which can be used to connect the wire of the detection probe 1; the bottom ends of both sides of the probe cover 2 may be provided with a walking mechanism for enabling the entire set of non-destructive testing equipment to move quickly along the weld direction on the weld surface.

[0065] Among them, such as Figures 1-6 As shown, the walking mechanism may include: a support shaft 7 and a support wheel 9 connected to the support shaft 7 ; and the support shaft 7 may be connected to the probe cover 2 via a fastening nut 8 .

[0066] Specifically, if Figures 1-6 As shown, the probe cover 3 can be connected to the probe sleeve 2 by fastening screws 6, and the handle 4 can be connected to the probe sleeve 2 by welding; the external connector 5 and the probe cover 3 can be connected by gluing.

[0067] Furthermore, if Figures 1-6 As shown, the probe housing 10, upper cover 11, lower cover 17, probe connector 12, probe cover 2, probe outer cover 3, handle 4, outer connector 5, support shaft 7, fastening nut 8 and support wheel 9 can all be made of stainless steel.

[0068] The assembly process of the entire non-destructive testing device is as follows: install the support shaft 7, fastening nut 8, support wheel 9 and probe cover 2, place the support wheel 9 on the left and right ends of the lower bottom surface of the probe cover 2, align the center hole of the support wheel 9 with the mounting hole of the probe cover 2, insert the support shaft 7, and screw the fastening nut 8 into the left and right ends of the support shaft 7 to fix the support wheel 9; screw the detection probe 1 into the threaded hole on the upper surface of the probe cover 2 to fix the detection probe 1; use connecting wires to connect the probe connector 12 of the detection probe 1 to the built-in electrode of the external connector 5 respectively; use fastening screws 6 to achieve fixed connection between the probe cover 3 and the probe cover 2; use connecting wires to connect the external connector 5 to the power supply system and voltage measurement system.

[0069] In this application, the detection probes 1 are arranged in a 3x3 pattern, with a total of 9. During the inspection, it is necessary to fully cover the cracks on the paths between the detection network formed by the 9 detection probes 1. When the probe group moves on the surface of the weld to be inspected under the drive of the probe cover 2 and stops at a detection position, it can quickly realize the rapid detection of weld cracks in various extension directions of the area, with high detection efficiency and detection coverage; in other application scenarios, the number and arrangement of the detection probes 1 can be flexibly set according to the width of the weld, the structural form of the weld, and the location where weld cracks are likely to occur.

[0070] like Figure 7 As shown, corresponding to the setting method of this application, when detecting cracks between the columns along the longitudinal direction of the weld, connect the 1# probe to the detection voltage +12V, the 7# probe to the ground, and measure the voltage of the 4# probe to the ground, that is, the voltage between the 4# probe and the 7# probe. Then, the voltage between the 1# probe and the 4# probe can be calculated. According to the magnitude of the voltage of the 4# probe to the ground, it can be inferred whether the distribution of the crack is between the 1# probe and the 4# probe, or between the 4# probe and the 7# probe. Similarly, connect the 2# probe to high voltage, connect the 8# probe to the ground, and measure the voltage of the 5# probe to the ground; connect the 3# probe to high voltage, connect the 9# probe to the ground, and measure the voltage of the 6# probe to the ground. When detecting the crack distribution between the rows of probes across the weld, connect the 1# probe to high voltage, connect the 3# probe to the ground, and measure the voltage of the 2# probe to the ground; connect the 4# probe to high voltage, connect the 6# probe to the ground, and measure the voltage of the 5# probe to the ground; connect the 7# probe to high voltage, connect the 9# probe to the ground, and measure the voltage of the 8# probe to the ground. The measurements of the probes in each column and row are not performed simultaneously, but are performed in sequence under the control of the measurement system control chip to avoid mutual interference.

[0071] Three CD4051 analog switch chips can be used to control the detection probes to connect to high voltage, ground, and measure respectively; the OUT pins of the CD4051 chip are respectively connected to the output leads of each detection probe, and the INH pin is connected to the IO pin of the control chip. The control chip outputs signals to control the opening and closing of each CD4051 chip; the A, B, and C pins of the three CD4051 chips are respectively connected to the IO pins of the control chip, and the control chip outputs high and low level signals through the IO pins to control the connection status of each detection probe respectively; the common output pin COM OUT of the three CD4051 chips is respectively connected to the +12V excitation voltage, the voltage measurement port OUT, and the ground port.

[0072] The MAX1134 chip is an analog-to-digital conversion chip ADC. Its AIN pin is connected to the common output pin COM OUT of the second CD4051 chip, and the voltage measurement signal is input into its AIN pin; the CS#, DIN, SCLK, and DOUT pins are respectively connected to the IO pins of the control chip, and the control chip controls the voltage acquisition process of the MAX1134 chip; the MAX6126 chip is responsible for providing the reference voltage to the MAX1134 chip.

[0073] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A nondestructive testing device for weld cracks, characterized in that: include: A host computer display system, which is installed on a tablet computer and is used to display and store weld crack detection results in real time; The lower computer control system is built based on the STM32 chip and is used to control the voltage acquisition of the voltage measurement system and is responsible for synchronous signal communication with the upper computer display system; A voltage measurement system, which consists of a multi-channel analog-to-digital conversion chip and its auxiliary circuits, is used to measure the potential difference between the two detection probes and convert the analog signal into a digital signal. At the same time, the measurement result is obtained by the lower computer control system through the voltage measurement system and sent to the upper computer display system for display and storage; A power supply system, comprising a lithium-ion battery, a charge and discharge control circuit, and a voltage conversion circuit, for providing power to the lower control system, the voltage measurement system, and the detection probe; The probe fixing device is used to fix and install the detection probe and drive the entire non-destructive testing device to move at the weld. At the same time, the detection probe is placed on the surface of the metal weld to be tested for current input and potential difference measurement.

2. The weld crack nondestructive testing device according to claim 1, characterized in that: The detection probe includes: a probe housing, and an upper cover and a lower cover that match and dock with the probe housing; the upper cover is provided with a probe connector, and the probe connector is provided with a built-in electrode; an electromagnet is provided inside the probe housing, and the power cord of the electromagnet is connected to the built-in electrode of the probe connector; a plug is provided at the center hole of the lower cover, and the plug is used to prevent the probe from falling; the probe can pass through the center hole of the lower cover and be connected to the built-in electrode through a connecting wire; a rubber pad is provided at one end of the probe adjacent to the electromagnet, and a compression spring is provided on the outside of the probe below the rubber pad.

3. The weld crack nondestructive testing device according to claim 2, characterized in that: The end area of the probe adjacent to the electromagnet is made of carbon steel, and the remaining area is made of copper, and the carbon steel area and the copper area are connected by welding; The overall structure of the probe is a cylinder, and the outer surface of the probe has a draft angle.

4. The weld crack nondestructive testing device according to claim 2, characterized in that: The upper cover and the lower cover are respectively connected to the probe housing via threads; the probe connector and the upper cover are bonded via glue.

5. The weld crack nondestructive testing device according to claim 2, characterized in that: The rubber pad is made of rubber material, and has a through hole in the center thereof and is used to be sleeved on the probe, and the probe and the rubber pad are connected by an interference fit; The plug is made of rubber and is inserted into the center hole of the lower cover by interference fit to prevent the probe from falling out of the center hole of the lower cover and being damaged during assembly and non-measurement periods.

6. The weld crack nondestructive testing device according to any one of claims 2 to 5, characterized in that: The probe fixing device includes: a probe cover, and the probe cover has a plurality of positioning holes distributed in a matrix, the outer surface of the probe shell has an external thread and is screwed into the positioning holes of the probe cover through the external thread; a probe cover and a handle are provided on the top outer side of the probe cover; the probe cover is provided with an external connector, and an electrode is provided inside the external connector, and the electrode is used to connect the wire of the detection probe; a walking mechanism is provided at the bottom ends of both sides of the probe cover.

7. The weld crack nondestructive testing device according to claim 6, characterized in that: The walking mechanism includes: a support shaft and a support wheel connected to the support shaft; the support shaft is connected to the probe cover through a fastening nut.

8. The weld crack nondestructive testing device according to claim 6, characterized in that: The probe cover is connected to the probe sleeve by fastening screws, and the handle is connected to the probe sleeve by welding; the external connector and the probe cover are connected by gluing.

9. The weld crack nondestructive testing device according to claim 7, characterized in that: The probe housing, the upper cover, the lower cover, the probe connector, the probe sleeve, the probe outer cover, the handle, the outer connector, the support shaft, the fastening nut and the support wheel are all made of stainless steel.

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