An automated penetrant testing device for welds

Abstract

This utility model discloses an automated weld penetration testing device, comprising a device body, a pressing mechanism, a wiping mechanism, a walking mechanism, and a control system. The front of the device body has three placement slots, and the pressing mechanism has three sets corresponding to these slots. Each pressing mechanism includes a power rod, a connecting rod, and a force-amplifying lever. The rear end of the power rod is connected to a first driving device, and the power rod slides on the device body. The two ends of the connecting rod are connected to the power rod and the force-amplifying lever, respectively. A pressing block is located at the front end of the force-amplifying lever, pressing down on the reagent spray can to achieve spraying. The wiping mechanism is located at the front of the device body, and the walking mechanism is located at the bottom of the device body. The control system controls the action status, sequence, and interval time of each mechanism. This utility model achieves automatic and controllable pressing of the reagent spray can through the pressing mechanism, and, in conjunction with the wiping mechanism, walking mechanism, and control system, automates the weld penetration testing operation, improving the reliability of the test results and personnel safety.

Description

Technical Field

[0001] This utility model belongs to the field of non-destructive testing technology for weld defects, and specifically relates to an automated penetrant testing device for welds of large workpieces. Background Technology

[0002] Penetrant testing of welds is one of the most commonly used non-destructive testing methods for weld surface defects. Existing penetrant testing equipment mainly falls into three categories: the first category consists of large, complex, fixed equipment that uses a immersion method to penetrate the workpiece; the second category comprises specialized, large-capacity equipment suitable for one or several special types of parts, ideal for batch testing of small-sized parts; and the third category consists of simple, manually operated, portable equipment that can be easily moved as needed and is suitable for testing any type of workpiece. The first two types of testing equipment are typically limited by the size of the immersion tank and suffer from high reagent costs, usually used in conjunction with mass production lines. However, when testing large workpieces such as vehicle frames or tank truck bodies, these two types of equipment have significant limitations, therefore most companies use the third type of testing equipment.

[0003] Currently, portable devices typically use spray-type reagents, relying on manual pressing during testing. This presents challenges due to the difficulty in controlling the pressure applied to the nozzle, resulting in significant unpredictability in the uniformity and amount of reagent sprayed. This not only leads to low processing efficiency but also compromises the reliability and accuracy of test results. Furthermore, the aerosol added to the spray can has an irritating odor and is flammable. Especially in enclosed spaces or poorly ventilated areas, the mist-like reagent spreading in the surrounding air poses a health hazard to testing personnel. Utility Model Content

[0004] The purpose of this invention is to propose an automated weld penetration testing device to solve the problem that existing portable testing equipment relies on manual operation, resulting in low processing efficiency, low reliability and accuracy of test results, and threats to the health of testing personnel.

[0005] This utility model is achieved through the following technical solution:

[0006] This utility model proposes an automated weld penetration testing device, including a device body, a pressing mechanism, a wiping mechanism, a walking mechanism, and a control system. The front side of the device body has three placement slots: a cleaning agent placement slot, a penetrant placement slot, and a developer placement slot. The pressing mechanism has three sets corresponding to the placement slots. Each set of the pressing mechanism includes a power rod, a connecting rod, and a force-amplifying lever. The rear end of the power rod is connected to a first driving device. The power rod is slidably mounted on the device body. One end of the connecting rod is connected to the front end of the power rod, and the other end is connected to the rear end of the force-amplifying lever. The force-amplifying lever supports… The lever is fixed to the main body of the device. A pressing block is provided at the front end of the lever, which is positioned opposite the center of the placement groove. When a reagent needs to be sprayed, the power rod slides forward, and the connecting rod drives the front end of the lever to press down on the reagent spray can to achieve spraying. The wiping mechanism is located on the front side of the main body of the device and is used to remove excess reagent from the weld surface after the settling time is reached. The walking mechanism is located at the bottom of the main body of the device and is used to control the movement of the main body of the device. The control system is used to control the action status, action sequence and interval time of the pressing mechanism, the wiping mechanism and the walking mechanism.

[0007] Based on the above technical solutions, the pressing force and accuracy of the pressing head are amplified by the design of the pressing mechanism and its force-enhancing lever, realizing automatic and controllable pressing of each reagent spray can. The wiping mechanism realizes automatic removal of reagents, and the walking mechanism allows the device body to be moved to any welding position of the workpiece. The control system realizes the setting and precise control of process conditions such as the action sequence of each mechanism and the settling time, thereby realizing the automated operation of weld penetration testing, reducing reliance on manual labor, improving the reliability of the testing process and results, and avoiding close contact between personnel and reagents, thus reducing the health risks of testing personnel.

[0008] Preferably, the developer placement tank is a semi-open tank structure with openings at the front and top. The rear end of the developer placement tank is provided with an anti-precipitation structure, which includes a receiving frame, a servo motor, and a push rod assembly. The receiving frame is movably disposed within the developer placement tank, and an anti-detachment structure is provided within the receiving frame. The front end of the push rod assembly is connected to the receiving frame via the servo motor, and the rear end is connected to the first driving device. The first driving device is used to push the receiving frame outwards from the developer placement tank, and the servo motor is used to drive the receiving frame to swing to mix the developer. The purpose of this design is to mix the developer before spraying, avoiding errors in the detection results caused by reagent precipitation.

[0009] Preferably, the first driving device includes a drive motor, a transmission assembly, and a helical feeding mechanism. The transmission assembly includes an intermittently meshing incompletely geared driving wheel and a fully geared driven wheel. The helical feeding mechanism includes a guide sleeve, a pin, and a limiting sleeve. The guide sleeve is fixedly connected to the driven wheel and has a helical groove. The pin is movably fitted inside the guide sleeve and has a fixing rod embedded in the helical groove. The front end of the pin is connected to the power rod or the push rod assembly. The limiting sleeve is fitted outside the guide sleeve and has a straight groove in its inner cavity. The straight groove is opposite to the fixing rod and is used to limit the rotation of the fixing rod. When the driven wheel rotates, the fixing rod slides along the helical groove and is limited by the straight groove, thereby driving the pin to move forward in a straight line. The purpose of this structural design is to achieve precise control of the movement and dwell time of the power rod or push rod assembly through the incompletely geared transmission assembly and the helical feeding mechanism, thereby more precisely controlling the pressing pressure and spraying amount.

[0010] Preferably, the first driving device is provided in two sets. The pressing mechanism for pressing the cleaning agent and the penetrant is connected to one set of the first driving device, and the pressing mechanism for pressing the developer and the push rod assembly of the anti-settling structure are connected to the other set of the first driving device. This design reduces the number of driving devices based on the incomplete gear transmission assembly, thereby simplifying the overall structure of the device.

[0011] Preferably, a first reset spring is provided between the front end of the power rod and the device body. The first reset spring is used to reset the force-increasing lever. A second reset spring is provided between the push rod assembly and the screw feed mechanism. The second reset spring is used to reposition the receiving frame into the developer placement tank. This design achieves automatic reset of the pressing mechanism after the reagent is pressed by setting the first reset spring, and achieves rapid and accurate reset of the developer to the pressing position for spraying after it is shaken evenly by setting the second reset spring, thereby ensuring the continuity and accurate control of the process.

[0012] Preferably, a weighing sensor is provided at the bottom of the placement tank, and the weighing sensor is connected to an alarm device. When the weighing sensor detects that the weight of the reagent in the placement tank is lower than a threshold, it will trigger the alarm device to issue an alarm signal. The purpose of this design is to visually determine the remaining amount of reagent before each spraying, so as to ensure that the amount of reagent sprayed each time is sufficient, reduce the error in the operation process, and improve the reliability of the test results.

[0013] Preferably, the traveling mechanism includes a guide rail, a slider, and a second driving device. The guide rail is arranged along the workpiece to be inspected, and the second driving device controls the slider to move along the guide rail to a designated position. The device body is disposed on the slider.

[0014] Preferably, a spacing adjustment mechanism is provided between the walking mechanism and the device body. The spacing adjustment mechanism includes a distance sensor, a support block, and a lead screw motor. The distance sensor is used to measure the distance between the device body and the workpiece to be tested and to control the movement of the lead screw motor. The support block is screwed onto the lead screw motor, and the device body is fixedly connected to the support block. When the lead screw motor moves, the relative position between the device body and the workpiece to be tested is adjusted by the support block. The purpose of this design is to adjust the spacing between the device body and the workpiece to be tested, thereby placing them at the optimal spraying distance and improving the quality of reagent spraying.

[0015] Preferably, a grinding mechanism is also provided on the front side of the device body. The grinding mechanism, the wiping mechanism and the placement groove are arranged in sequence along the moving direction of the device body. The grinding mechanism is used to pre-treat the surface of the workpiece weld before the reagent is sprayed. The purpose of this design is to remove the surface oxide layer before spraying, thereby ensuring that the effect of the reagent on the weld surface is improved.

[0016] Preferably, an image acquisition device is provided between the penetrant placement tank and the developer placement tank to acquire images of the weld surface after development, so as to realize automatic acquisition of the developed images and provide basic data for back-end image analysis.

[0017] Beneficial effects

[0018] One of the above technical solutions has the following advantages or beneficial effects:

[0019] (1) By setting up a pressing mechanism with a force-increasing lever in a corresponding cleaning agent placement tank, penetrant placement tank and developer placement tank, and combining the wiping mechanism, walking mechanism and control system, the sequential automatic spraying control of each reagent is realized, thereby realizing the automation of the entire penetrant detection operation, reducing human operation error, avoiding close contact between personnel and reagents, reducing the health risk of testing personnel, and ensuring the reliability of the testing process and results, thereby ensuring the quality reliability of the tested products.

[0020] (2) By designing a container and anti-precipitation structure for the developer, the developer is mixed before spraying to eliminate precipitation and avoid deviation in test results caused by developer precipitation.

[0021] (3) By adopting a transmission assembly including an incomplete toothed driving wheel and a fully toothed driven wheel, as well as a spiral feeding mechanism between the driven wheel and the pressing mechanism or anti-precipitation structure, a single motor controls two sets of action mechanisms and converts the motor's rotational motion into linear motion, thereby achieving precise motion control of each reagent pressing and the developer anti-precipitation mechanism, and ultimately ensuring the accuracy of the test results.

[0022] (4) By setting up the spacing adjustment mechanism, grinding mechanism, image acquisition device, and first and second reset springs, the entire process of penetrant testing is automated, the parameters of each process are precisely controlled, and finally highly reliable development images are obtained, providing a basis for evaluating welding quality. Attached Figure Description

[0023] Other features, objects, and advantages of this invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0024] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0025] Figure 2 This is a schematic diagram of the structure of the present invention. Figure 1 (Remove the device body);

[0026] Figure 3 This is a schematic diagram of the structure of the present invention. Figure 2 (Remove the device body);

[0027] Figure 4 This is a schematic diagram of the spiral feed mechanism of this utility model;

[0028] Figure 5 This is a schematic diagram of the spacing adjustment mechanism of this utility model;

[0029] In the diagram: Device body 1; Placement tank 11; Cleaning agent placement tank 1101; Penetrant placement tank 1102; Developer placement tank 1103; Pressing mechanism 2; Power rod 21; First return spring 22; Connecting rod 23; Force amplifying lever 24; Pressing block 25; Grinding mechanism 3; Wiping mechanism 4; Image acquisition device 5; Walking mechanism 6; Guide rail 61; Slider 62; First driving device 7; Drive motor 71; Transmission assembly 72; Driving wheel 721; Driven wheel 722; Spiral feed mechanism 73; Guide bushing 731; Spiral groove 7311; Pin 732; Fixing rod 7321; Limiting sleeve 733; Spacing adjustment mechanism 8; Distance sensor 81; Support block 82; Lead screw motor 83; Anti-settling structure 9; Receiving frame 91; Anti-detachment structure 911; Servo motor 92; Push rod assembly 93; Second return spring 94. Detailed Implementation

[0030] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.

[0031] like Figure 1 , Figure 2As shown, this utility model provides an automated penetrant testing device for welds, including a device body 1, a pressing mechanism 2, a wiping mechanism 4, a traveling mechanism 6, and a control system (not shown in the figures). The pressing mechanism 2 is located on the upper surface of the device body 1 and is used to automatically spray the reagents required for testing. The wiping mechanism 4 is located on the front side of the device body 1 and is used to remove excess reagents from the weld surface after reaction. The traveling mechanism 6 is located below the device body 1 and is used to adjust the position of the device body 1 relative to the workpiece. The control system is used to control the action status, action sequence, and action interval of the pressing mechanism 2, the wiping mechanism 4, the traveling mechanism 6, and other moving parts (such as the grinding mechanism 3, the image acquisition device 5, etc.).

[0032] Specifically, the front side of the device body 1 is provided with three placement slots 11, which are designated as cleaning agent placement slot 1101, penetrant placement slot 1102 and developer placement slot 1103, respectively corresponding to placing cleaning agent spray cans, penetrant spray cans and developer spray cans;

[0033] The pressing mechanism 2 is provided in three sets corresponding to the cleaning agent placement tank 1101, the penetrant placement tank 1102, and the developer placement tank 1103, such as... Figure 2 , 3 As shown, each pressing mechanism 2 includes a power rod 21, a connecting rod 23, and a force-amplifying lever 24. The rear end of the power rod 21 is connected to a first driving device 7. The power rod 21 is slidably mounted on the device body 1. One end of the connecting rod 23 is connected to the front end of the power rod 21, and the other end is connected to the rear end of the force-amplifying lever 24. The fulcrum of the force-amplifying lever 24 is fixed on the device body 1. The front end of the force-amplifying lever 24 is provided with a pressing block 25 facing downward. The pressing block 25 is set relative to the center of the placement groove 11. That is, when the corresponding reagent spray can is placed in the placement groove 11, the pressing block 25 is located above the nozzle of the reagent spray can. When a certain reagent needs to be sprayed, the power rod 21 slides forward, the connecting rod 23 drives the rear end of the force-amplifying lever 24 to move upward, and the front end presses down on the reagent spray can to achieve spraying.

[0034] Furthermore, such as Figure 1 As shown, the developer placement tank 1103 is a semi-open tank structure with openings at the front and top, and the rear end of the developer placement tank 1103 is provided with an anti-precipitation structure 9, such as... Figure 2As shown, the anti-precipitation structure includes a receiving frame 91, a servo motor 92, and a push rod assembly 93. The receiving frame 92 is movably disposed within the developer placement tank 1103. The receiving frame 91 is provided with an anti-detachment structure 911. The front end of the push rod assembly 93 is connected to the receiving frame 91 via the servo motor 92, and the rear end is connected to the first driving device 7. The first driving device 7 is used to push the receiving frame 91 outward from the developer placement tank 1103. The servo motor 92 is used to drive the receiving frame 91 to swing to mix the developer.

[0035] Furthermore, the first driving device 7 can be a linear driving device such as an electric push rod or an actuation push rod that corresponds one-to-one with the pressing mechanism 2 and the anti-settling structure 9. Preferably, such as... Figure 3 As shown, the first driving device 7 includes a drive motor 71, a transmission assembly 72, and a screw feed mechanism 73. The drive motor 71 is a stepper motor to improve control accuracy. The transmission assembly 72 includes an intermittently meshing incompletely toothed driving gear 721 and a fully toothed driven gear 722. Figure 4 As shown, the spiral feeding mechanism 73 includes a guide sleeve 731, a pin 732, and a limiting sleeve 733. The guide sleeve 731 is fixedly connected to the driven wheel 722. The guide sleeve 731 is provided with a spiral groove 7311. The pin 732 is movably sleeved in the guide sleeve 731. The pin 732 is provided with a fixing rod 7321 embedded in the spiral groove 7311. The front end of the pin 732 is connected to the power rod 21 or the push rod assembly 93. The guide sleeve 731 is provided with a limiting sleeve 733. The inner cavity of the limiting sleeve 733 is provided with a straight groove (not shown in the figure) to limit the rotation of the fixing rod 7321. In actual use, precise control of rotational motion is achieved by controlling the meshing state and rotation angle range of the incomplete gear drive wheel 721 and driven wheel 722; the fixed rod 7321 of the spiral feed mechanism 73 slides along the spiral groove 7311 and is restricted by the straight groove in the inner cavity of the limiting sleeve 733, driving the pin 732 to move forward linearly, converting rotational motion into linear movement, thereby precisely controlling the pressing force and dwell time of the pressing mechanism 2, and the push distance and shaking time of the anti-settling structure 9, ultimately achieving precise control of spraying quality. Preferably, based on the sequential use of the reagents required for penetrant testing, the first drive device 7 is provided with two sets. The pressing mechanism 2 for pressing the cleaning agent and penetrant is connected to one set of the first drive device 7, and the pressing mechanism 2 for pressing the developer and the push rod assembly 93 of the anti-settling structure 9 are connected to the other set of the first drive device 7. This realizes a single motor driving two sets of action mechanisms, reducing the number of drive motors 71 used, simplifying the device structure, and improving the overall portability of the device.

[0036] Further preferably, a first return spring 22 is provided between the front end of the power rod 21 and the device body 1. The first return spring 22 is used to reset the force-increasing lever 24. A second return spring 94 is provided between the push rod assembly 93 and the screw feed mechanism 73 to reposition the receiving frame 8 back into the developer placement tank 1103. Wherein, as... Figure 1 As shown, the structure of the first reset spring 22 can be as follows: the device body 1 is provided with a sliding groove (not shown in the attached figure) that matches the power rod 21, and the first reset spring 22 is also provided in the sliding groove, with one end fixed to the front end of the power rod 21 and the other end fixed to the wall of the sliding groove; the reset working method is as follows: when pressed, the transmission component 72 engages to provide power, the power rod 21 moves forward to compress the first reset spring 22, after the preset pressing time is reached, the transmission component 72 turns to the non-engaged state, the first reset spring 22 is restored to its initial state by the elastic force, driving the power rod 21 to move backward, the linkage 23 and the force-increasing lever 24 move, releasing the pressing of the reagent spray can and stopping the spraying. Among them, as shown in the attached figure, the first reset spring 22 is provided with a sliding groove (not shown in the attached figure) that matches the power rod 21, the first reset spring 22 moves forward to compress the first reset spring 22, after the preset pressing time is reached, the transmission component 72 turns to the non-engaged state, the first reset spring 22 is restored to its initial state by the elastic force, driving the power rod 21 to move backward, the linkage 23 and the force-increasing lever 24 move, releasing the pressing of the reagent spray can and stopping the spraying. Figure 2 As shown, the second return spring 94 can be sleeved on the rear end of the push rod of the push rod assembly 93 or on the front end of the pin 732 of the spiral feed mechanism 73. Both ends of the second return spring 94 are fixed to the limiting sleeves 733 of the push rod assembly 93 and the spiral feed mechanism 73, respectively. When performing the developer mixing operation, the transmission assembly 72 engages to provide power. When the developer spray can is pushed out, the second return spring 94 is stretched. When the transmission assembly 72 returns to a non-engaged state, the second return spring 94 is restored to its initial state by the elastic force, pulling the push rod assembly 93 back to the receiving frame 8 and returning it to the state within the developer placement slot 1103. When the first return spring 22 and the second return spring 94 reset, the fixing rod 7321 on the pin 732 simultaneously retracts along the spiral groove 7311 to its initial position.

[0037] The walking mechanism 6 can be a universal wheel located at the bottom of the device body 1, or it can include a guide rail 61, a slider 62, and a second drive device (not shown in the attached diagram). The second drive device is a DC motor. The guide rail 61 is set along the workpiece to be inspected. The second drive device controls the slider 62 to move along the guide rail 61 to a designated position. The device body 1 is mounted on the slider 62. Further, a spacing adjustment mechanism 8 is provided between the walking mechanism 6 and the device body 1, such as... Figure 5As shown, the spacing adjustment mechanism 8 includes a distance sensor 81, a support block 82, and a lead screw motor 83. The distance sensor 81 is located on the side of the spacing adjustment mechanism 8 closest to the workpiece and is used to measure the distance between the device body 1 and the workpiece to be inspected and to control the action of the lead screw motor 83. The support block 82 is screwed onto the lead screw motor 83, and the device body 1 is fixedly connected to the support block 82. When the lead screw motor 83 is activated, the relative position between the device body 1 and the workpiece to be inspected is adjusted by the support block 82 so that the two are at the optimal spraying distance.

[0038] Furthermore, the front side of the device body 1 is also provided with a grinding mechanism 3 for pre-treating the weld surface of the workpiece before reagent spraying to remove the oxide layer on the weld surface, ensuring the effect of the reagent on the weld surface, and an image acquisition device 5 for acquiring an image of the weld surface after development. The grinding mechanism 3, the wiping mechanism 4, and the placement tank 11 are arranged sequentially along the moving direction of the device body 1, and the image acquisition device 5 is located between the penetrant placement tank 1102 and the developer placement tank 1103.

[0039] Furthermore, a weighing sensor (not shown in the attached figure) is provided at the bottom of the placement tank 11 to obtain the remaining reagent amount before each spraying, thereby determining whether new reagent needs to be replaced. The weighing sensor is connected to an alarm device (not shown in the attached figure). When the weighing sensor detects that the reagent weight in the placement tank 11 is lower than a threshold, it triggers the alarm device to issue an alarm signal, visually prompting the testing personnel to judge the remaining reagent status, so as to ensure that the amount of reagent for each spraying is sufficient, reduce operational errors, and improve the reliability of test results.

[0040] This invention achieves automatic adjustment of the device's position relative to the workpiece through a walking mechanism 6 and a spacing adjustment mechanism, automatic pressing and spraying of various reagents through a pressing mechanism 2, automatic treatment of welds and excess reagents through a grinding mechanism 3 and a wiping mechanism 4, automatic acquisition of weld development images through an image acquisition device 5, and further confirmation of reagent status before spraying through anti-precipitation structure 9 and weighing sensors. All action mechanisms are coordinated and controlled by a control system, ultimately achieving automatic operation of the entire penetrant testing process. This effectively solves the problems of inaccurate control of pressing pressure, inaccurate reagent spraying amount, and health hazards caused by close-range operation that exist in manual operation. It features a high degree of automation, controllable and stable testing process, and reliable and accurate test results.

[0041] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the technical scope of the present utility model. Therefore, any minor modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall still fall within the protection scope of the present utility model.

Claims

1. A weld automated penetrant inspection apparatus, characterized by: The device includes a main body, a pressing mechanism, a wiping mechanism, a walking mechanism, and a control system. The front of the main body has three placement slots: a cleaning agent placement slot, a penetrant placement slot, and a developer placement slot. The pressing mechanism has three sets corresponding to the placement slots. Each set of the pressing mechanism includes a power rod, a connecting rod, and a lever. The rear end of the power rod is connected to a first driving device. The power rod is slidably mounted on the main body. One end of the connecting rod is connected to the front end of the power rod, and the other end is connected to the rear end of the lever. The fulcrum of the lever is fixed to the main body. The front end of the lever is provided with a pressing block facing downwards. The pressing block is positioned relative to the center of the placement groove. When a certain reagent needs to be sprayed, the power rod slides forward, and the connecting rod drives the front end of the lever to press down on the reagent spray can to achieve spraying. The wiping mechanism is located on the front side of the device body and is used to remove excess reagent from the weld surface after the settling time is reached. The walking mechanism is located at the bottom of the device body and is used to control the movement of the device body. The control system is used to control the action status, action sequence, and interval time of the pressing mechanism, the wiping mechanism, and the walking mechanism.

2. A device for automated penetrant testing of welds as claimed in claim 1, wherein: The developer placement tank is a semi-open tank structure with openings at the front and top. The rear end of the developer placement tank is provided with an anti-precipitation structure. The anti-precipitation structure includes a receiving frame, a servo motor, and a push rod assembly. The receiving frame is movably disposed within the developer placement tank. The receiving frame is provided with an anti-detachment structure. The front end of the push rod assembly is connected to the receiving frame through the servo motor, and the rear end is connected to the first driving device. The first driving device is used to push the receiving frame outward from the developer placement tank. The servo motor is used to drive the receiving frame to swing to mix the developer.

3. A device for automated penetrant testing of welds as claimed in claim 2, wherein: The first driving device includes a drive motor, a transmission assembly, and a helical feeding mechanism. The transmission assembly includes an intermittently meshing incompletely toothed driving wheel and a fully toothed driven wheel. The helical feeding mechanism includes a guide sleeve, a pin, and a limiting sleeve. The guide sleeve is fixedly connected to the driven wheel and has a helical groove. The pin is movably fitted inside the guide sleeve and has a fixing rod embedded in the helical groove. The front end of the pin is connected to the power rod or the push rod assembly. The limiting sleeve is fitted outside the guide sleeve and has a straight groove in its inner cavity. The straight groove is opposite to the fixing rod and is used to limit the rotation of the fixing rod. When the driven wheel rotates, the fixing rod slides along the helical groove and is limited by the straight groove, thereby driving the pin to move forward in a straight line.

4. A device for automated penetrant testing of welds as claimed in claim 3, wherein: The first driving device is provided in two sets. The pressing mechanism for pressing the cleaning agent and the penetrant is connected to one set of the first driving device, and the pressing mechanism for pressing the developer and the push rod assembly of the anti-settling structure are connected to the other set of the first driving device.

5. The apparatus of claim 3, wherein: A first reset spring is provided between the front end of the power rod and the device body. The first reset spring is used to reset the force-increasing lever. A second reset spring is provided between the push rod assembly and the screw feed mechanism. The second reset spring is used to reposition the receiving frame into the developer placement tank.

6. The apparatus of claim 1, wherein: A weighing sensor is installed at the bottom of the placement tank. The weighing sensor is connected to an alarm device. When the weighing sensor detects that the weight of the reagent in the placement tank is lower than a threshold, it will trigger the alarm device to issue an alarm signal.

7. The apparatus of claim 1, wherein: The traveling mechanism includes a guide rail, a slider, and a second driving device. The guide rail is arranged along the workpiece to be inspected, and the second driving device controls the slider to move along the guide rail to a designated position. The device body is arranged on the slider.

8. A device for automated penetrant testing of welds as claimed in claim 1 or 7, wherein: A spacing adjustment mechanism is provided between the walking mechanism and the device body. The spacing adjustment mechanism includes a distance sensor, a support block, and a lead screw motor. The distance sensor is used to measure the distance between the device body and the workpiece to be inspected and to control the movement of the lead screw motor. The support block is screwed onto the lead screw motor, and the device body is fixedly connected to the support block. When the lead screw motor moves, the relative position between the device body and the workpiece to be inspected is adjusted through the support block.

9. The apparatus of claim 1, wherein: The front side of the device body is also provided with a grinding mechanism. Along the moving direction of the device body, the grinding mechanism, the wiping mechanism and the placement groove are arranged in sequence. The grinding mechanism is used to pre-treat the surface of the workpiece weld before the reagent is sprayed.

10. The apparatus of claim 1, wherein: An image acquisition device is provided between the penetrant placement tank and the developer placement tank to acquire images of the weld surface after development.

Images