CN115890055A - Welding experimental frame and method for exploring the relationship between molten pool and welding quality - Google Patents

Abstract

The invention discloses a welding experiment frame and a method for exploring the correlation rule between molten pool and welding quality, and relates to the technical field of welding quality. The invention comprises a fixed plate, a driving mechanism, a positioning mechanism and a visual module are installed on the top of the fixed plate, the positioning mechanism is located at the top of the driving mechanism, and the visual module is located at one end of the driving mechanism; the driving mechanism includes a positioning frame, a stepping motor and a transmission screw , the top of the fixed plate is fixed with a positioning frame, and then the position of the driving mechanism can be fixed, and one end of the positioning frame is fixed with a stepping motor, and the output end of the stepping motor is connected with a transmission screw, so that the transmission screw can be quickly driven turn. The present invention can stably adjust the welding position, welding angle and welding speed of the welding torch through the cooperation of the driving mechanism, the positioning mechanism and the vision module, and the quality of the welding can be photographed by the vision module, so that the quality of the welding can be easily checked Make an evaluation.

Description

Welding experimental frame and method for exploring the correlation law between molten pool and welding quality

technical field

The invention belongs to the technical field of welding quality, and in particular relates to a welding experiment frame and a method for exploring the correlation law between molten pool and welding quality.

Background technique

During manual welding, it is difficult to control the accuracy and stability of the working angle of the welding torch, welding distance and welding speed during the welding process, resulting in unstable welding quality. And the strong arc light, high temperature, smoke, dust, splash, and poisonous gas produced in the welding process have caused great harm to the health of welding workers. Therefore, welding robots with advantages of high efficiency, replaceability and no fatigue are gradually being developed. At present, the intelligent welding robot on the market has the problem of single function in the control of welding quality. It can only detect the quality of weld formation after welding, and repair welding for the defective part of the weld. This process greatly reduces the efficiency of welding construction. The repair welding process of the weld defect is not only time-consuming and laborious, but also may affect the strength of the repaired joint or be scrapped due to invalid correction. If the welding quality can be controlled in real time during the welding process, the work efficiency will be greatly improved and the safety hazards caused by the secondary rework of workers will be reduced.

With the development of machine vision technology, welding robots have begun to widely use visual inspection technology to judge welding quality. Among them, the size and temperature distribution of the molten pool can determine the quality of the molten pool, and the quality control of the molten pool will determine the welding quality. The size of the molten pool and the temperature distribution of the molten pool during the welding process are the key issues affecting the welding quality, so it is particularly important to explore the relationship between the molten pool and the welding quality. The welding robot is equipped with a welding vision module featuring a large amount of information, intuitive observation and high real-time performance, which can establish a correlation platform between the molten pool and the welding quality. During the welding process, the vision module at the end of the welding torch obtains the image information of the front molten pool, and the current molten pool size and temperature distribution of the molten pool can be obtained by using the image processing method. The size of the molten pool can visually determine the current welding quality, but it cannot clearly analyze whether bubbles and slag are generated inside the molten pool. The temperature distribution of the molten pool can detect key information inside the molten pool, and the combination of the two will greatly ensure the accuracy of judging the quality of the molten pool.

Therefore, it is urgent to design a monitoring welding test bench with double feedback of molten pool size and molten pool temperature distribution, so as to control the quality of weld formation in real time.

Contents of the invention

The purpose of the present invention is to provide a welding test frame and method for exploring the relationship between molten pool and welding quality, so as to solve the problems raised in the above-mentioned background technology.

In order to solve the problems of the technologies described above, the present invention is achieved through the following technical solutions:

The present invention is a welding experiment frame for exploring the correlation law between molten pool and welding quality, which includes a fixed plate, a driving mechanism and a positioning mechanism are installed on the top of the fixed plate, and the positioning mechanism is located at the top of the driving mechanism;

The driving mechanism includes a positioning frame, a stepping motor and a transmission lead screw. The top of the fixing plate is fixed with a positioning frame, and one end of the positioning frame is fixed with a stepping motor, and the output end of the stepping motor is connected with a transmission lead screw.

Further, the positioning mechanism includes a support base, a vertical shaft, a transverse shaft, a vertical clamp and a horizontal clamp, the support base is screwed to the outside of the drive screw, the top of the support base is fixed with a vertical shaft, A vertical clip is arranged outside the vertical shaft, a horizontal clip is fixed at one end of the vertical clip, and a horizontal shaft is arranged inside the horizontal clip.

Further, a fixing clip is provided on one side of the transverse axis, a welding torch is arranged on the inner side of the fixing clip, and a welding pipe is arranged at one end of the welding torch.

Further, the top of the fixing plate is also provided with a welding base material.

Further, a visual module for detection is installed on the outside of the welded pipe, the visual module includes a binocular camera and a connecting frame, the top of the binocular camera is fixed with a connecting frame, and the top of the connecting frame is connected to the welded pipe Sliding connection, the top of the connecting frame is also screw-connected with a clamping plate.

A method for exploring the welding test frame of the correlation law between molten pool and welding quality, which is used for any of the above items, and the steps are as follows:

S1: Start the stepper motor 3 to allow the support base 5 to move;

S2: adjust the positions of the vertical clamp 12 and the horizontal clamp 13;

S3: adjusting the angle of the fixing clip 14;

S4: The welding torch 6 is energized to weld the welding base metal 8;

S5: The vision module detects the welding position in the fourth step.

Further, the detection of the visual module is based on the following steps:

Ⅰ. Through the function of light reduction mirror and filter, the outline of molten pool is relatively clear, which is divided into molten pool during welding and molten pool during cooling;

Ⅱ. Real-time extraction of molten pool contour edge;

Ⅳ. Take out the "melt pool during welding" part separately and compare it with the edge standard in real time, and judge whether it is necessary to adjust the current and voltage or adjust the welding torch angle and welding speed.

The present invention has the following beneficial effects:

1. The present invention can stably adjust the welding position, welding angle and welding speed of the welding torch through the cooperation of the driving mechanism, the positioning mechanism and the vision module, and the quality of the welding can be photographed through the vision module, so that it can facilitate the welding quality is evaluated.

2. The present invention can control the rotation speed of the transmission screw by driving the rotation of the transmission screw through the stepping motor through the cooperation of the positioning frame, the stepping motor, the transmission screw and the support seat, and can control the movement of the welding torch through the support seat. So as to realize the precise and uniform movement of the welding torch.

3. The present invention allows the adjustment of the horizontal clamp to control the angle of the welding torch through the cooperation of the vertical axis, the horizontal axis, the vertical clamp, the horizontal clamp and the fixed clamp, and adjusts the extension distance of the welding torch through the cooperation of the horizontal axis and the horizontal clamp , adjust the up and down distance of the welding torch through the vertical axis and the vertical clamp.

4. The present invention detects the quality of welding through a binocular camera, and can monitor the quality of the molten pool after the welding torch works on the welding base material, and feed back to the computer to make adjustments.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings that are required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. Those of ordinary skill in the art can also obtain other drawings based on these drawings without any creative effort.

Fig. 1 is the overall structural representation of the present invention;

Fig. 2 is the overall back view of the present invention;

Fig. 3 is the structural representation of binocular camera of the present invention;

4 is a schematic diagram of the working principle of the vision system of the present invention;

Fig. 5 is the molten pool image that the present invention outputs to computer through vision system;

Fig. 6 is a schematic diagram of the image processing and its feedback process of the present invention;

Fig. 7 is a schematic diagram of the edge standard of the present invention.

In the accompanying drawings, the list of parts represented by each label is as follows:

1. Fixed plate; 2. Positioning frame; 3. Stepping motor; 4. Transmission screw; 5. Support seat; 6. Welding torch; 7. Binocular camera; 8. Welding base material; Vertical axis; 11. Transverse axis; 12. Vertical clip; 13. Horizontal clip; 14. Fixing clip; 15. Connecting frame.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Embodiment one:

Please refer to Figs. 1-7, the present invention is a welding experiment frame for exploring the relationship between molten pool and welding quality, including a fixed plate 1, a driving mechanism, a positioning mechanism and a visual module are installed on the top of the fixed plate 1, The positioning mechanism is located at the top of the driving mechanism, and the vision module is located at one end of the driving mechanism;

The driving mechanism includes a positioning frame 2, a stepping motor 3 and a transmission screw 4. The top of the fixed plate 1 is fixed with a positioning frame 2, and then the position of the driving mechanism can be fixed. One end of the positioning frame 2 is fixed with a stepping motor 3, The output end of the stepping motor 3 is connected with a transmission screw 4, so that the transmission screw 4 can be quickly driven to rotate;

Preferably, the driving mechanism further includes a control panel, so that the electrical components can be controlled through the control panel, and the moving speed of the driving mechanism can be seen.

The positioning mechanism includes a support seat 5, a vertical shaft 10, a transverse shaft 11, a vertical clamp 12 and a transverse clamp 13. The support seat 5 is threaded on the outside of the drive screw 4, and the support seat 5 is slidably connected with the positioning frame 2, so that The rotation of the support base 5 can drive the transmission screw 4 to move, the top of the support base 5 is fixed with a vertical shaft 10, the outside of the vertical shaft 10 is provided with a vertical clamp 12, and one end of the vertical clamp 12 is fixed with a horizontal clamp 13 , the inner side of the transverse clamp 13 is provided with a transverse shaft 11; and the axial movement direction of the support seat 5 and the movement speed (4mm-8mm/s) can be controlled by the rotation of the transmission screw 4;

Preferably, both the vertical clamp 12 and the horizontal clamp 13 are compressed by bolts.

Preferably, the inside of the vertical clamp 12 is provided with a first gear, and the first gear is meshed with the vertical shaft 10 , so that the rotation of the first gear can drive the vertical clamp 12 to move up and down outside the vertical shaft 10 .

Preferably, the inner side of the transverse clamp 13 is provided with a second gear, and the second gear is meshed with the transverse shaft 11 , so that the transverse clamp 13 can be driven to move outside the transverse shaft 11 by the rotation of the second gear.

One side of the transverse shaft 11 is provided with a fixed clip 14, and the fixed clip 14 is compressed by bolts, so that the fixed clip 14 can rotate with the transverse shaft 11 and can be locked and fixed after rotation, so that the fixed clip 14 can be rotated To adjust the angle, the inside of the fixing clip 14 is provided with a welding torch 6, so that the position of the welding torch 6 can be fixed, and one end of the welding torch 6 is provided with a welding pipe;

Preferably, a positioning post is fixed inside one side of the transverse shaft 11, and a positioning groove slightly smaller than the diameter of the positioning post is provided inside the fixing clip 14, and the fixing clip 14 and the transverse shaft 11 are rotationally connected through the positioning post and positioned after the rotational connection .

The top of the fixed plate 1 is also provided with a welding base material 8, and the inner side of the welding base material 8 and the position in contact with the welding torch 6 form a molten pool 9;

In this embodiment, the welding torch 6 is an existing and mature structure, which will not be described in detail one by one.

During use, the welding speed has a great correlation with the melting and coverage of the molten pool 9, which in turn affects the welding quality. Therefore, it is particularly important to accurately control the movement of the driving screw 4 at an average speed of (4mm-8mm/s). The stepper motor 3 controller can program its speed.

The outside of the welded pipe is equipped with a vision module for detection, the vision module includes a binocular camera 7 and a connecting frame 15, the top of the binocular camera 7 is fixed with a connecting frame 15, and the top of the connecting frame 15 is slidably connected with the welded pipe, so that the binocular The camera 7 can move on the outside of the welded pipe, and the top of the connecting frame 15 is also screwed with a clamping plate, and then the binocular camera 7 can be fixed on the outside of the welded pipe through the connection between the clamping plate and the connecting frame 15, thereby being able to visually The module detects the state of the molten pool 9 during the welding experiment, the shape of the molten pool 9 and the temperature of the molten pool 9, and captures image information.

In this embodiment, the binocular camera 7 is an existing and mature structure, which will not be described in detail here.

The binocular camera 7 is composed of a camera and a composite filter system, which successfully overcomes the interference of excessive arc light and collects a clear image of the molten pool. It is possible to directly use the camera for information collection without any processing, and the final image will be flooded with strong arc light, and the geometric information of the molten pool we need cannot be obtained. Therefore, the core problem of the molten pool vision is that the industrial camera adopts appropriate light reduction and filtering operations to remove the interference of excessive arc light on the imaging area of the molten pool, so as to obtain high-quality image information. The infrared camera is to capture the text file information of the temperature matrix and transmit it to the computer, and process it into a temperature map through the program. A visual system with double feedback is formed.

The welding test bench is mainly composed of a driving mechanism that drives the welding torch to move, a positioning mechanism that adjusts the position and angle of the welding torch, and a vision module. As an important part of the vision module, the sensor system uses industrial cameras and infrared cameras to detect the status information of the welding process in real time, namely the shape of the molten pool and the temperature distribution of the molten pool, and feeds back the acquired information to the computer in real time, so as to realize the real-time monitoring of the welding process. Pool quality control. The driving mechanism and positioning mechanism not only play the role of moving the welding torch, but also can be used to adjust its welding parameters, welding speed, welding angle and welding distance, so as to explore the relationship between molten pool and welding quality;

The size and temperature of the molten pool during the welding process are the key issues affecting the quality of the weld seam. The welding parameters such as the working angle, walking angle and welding speed of the welding torch during the welding process can be adjusted through the control module of the welding test bench. The vision module monitors the molten pool size and molten pool temperature parameters in the welding process, and then realizes the intelligent welding technology solution for monitoring the molten pool parameters and feedback control welding parameters, so as to improve the welding of the main arch of long-span arch bridges in extreme environments. The welding efficiency of the robot ensures the welding quality.

The driving mechanism and positioning mechanism are used to adjust the welding parameters such as welding speed, welding distance and welding angle of the welding machine, explore the influence of welding parameters on the molten pool during the welding process, and evaluate the welding quality, so as to clarify the relationship between the molten pool and the welding process during the welding process. Welding quality correlation law, in order to achieve the purpose of controlling welding parameters to adjust molten pool characteristics to control welding quality. Firstly, the stepper motor in the driving mechanism drives the rotation of the transmission screw to control the rotation speed of the transmission screw, thereby driving the positioning mechanism above the support seat to move, thereby realizing the precise movement of the welding torch on the positioning mechanism. Then, the extension distance of the welding torch is adjusted through the rack and pinion between the transverse shaft and the transverse clamp, and the up and down distance of the welding torch is adjusted by the vertical axis and the vertical clamp. Second, let the transverse clip and fixed clip complete the welding angle of the welding torch. During the working process of the welding gun moving, the visual module component collects the image information of the molten pool during the welding process, and extracts the shape size and temperature distribution of the molten pool in the molten pool image in real time. Finally, the weld quality was evaluated by non-destructive testing of weld internal defects. The process control of welding quality is realized by exploring the relationship between welding parameters-welding pool-welding quality.

Embodiment two:

On the basis of above-mentioned embodiment 1, disclose its using method

The first step: start the stepper motor 3, let the support base 5 move;

The second step: adjust the positions of the vertical clamp 12 and the horizontal clamp 13;

The third step: adjust the angle of the fixing clip 14;

The fourth step: the welding torch 6 is energized to weld the welding base metal 8;

Step 5: The vision module detects the welding position in the fourth step;

Preferably, the detection of the vision module is according to the following steps:

Ⅰ. In the original image: the outline of the molten pool is relatively clear through the action of the light reducing mirror and the filter, which is divided into the molten pool during welding (refer to Figure 6) and the molten pool during cooling (refer to Figure 5);

Ⅱ. During edge detection: use the program to extract the edge of the molten pool contour in real time;

Ⅲ. Distinguishing the molten pool: because we mainly focus on the contour edge of the molten pool when the welding wire melts, it is necessary to distinguish between "cooling molten pool" and "welding molten pool";

Ⅳ. In the process of molten pool differentiation: the "weld pool" part is taken out separately and compared with the edge standard in real time, and fed back to the computer, and the computer determines whether it is necessary to adjust the current and voltage, or adjust parameters such as welding torch angle and welding speed;

During the feedback process: Before the computer feedbacks the molten pool, the computer needs a large number of molten pool images for machine learning.

In the description of this specification, descriptions with reference to the terms "one embodiment", "example", "specific example" and the like mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment of the present invention. In an embodiment or example. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The preferred embodiments of the invention disclosed above are only to help illustrate the invention. The preferred embodiments are not exhaustive in all detail, nor are the invention limited to specific embodiments described. Obviously, many modifications and variations can be made based on the contents of this specification. This description selects and specifically describes these embodiments in order to better explain the principle and practical application of the present invention, so that those skilled in the art can well understand and utilize the present invention. The invention is to be limited only by the claims, along with their full scope and equivalents.

Claims (7)

1. A welding experiment frame for exploring association rules of a molten pool and welding quality comprises a fixing plate (1), and is characterized in that: the top of the fixed plate (1) is provided with a driving mechanism, a positioning mechanism and a vision module, the positioning mechanism is positioned at the top end of the driving mechanism, and the vision module is positioned at one end of the driving mechanism;

actuating mechanism includes locating rack (2), step motor (3) and drive screw (4), the top of fixed plate (1) is fixed with locating rack (2), the one end of locating rack (2) is fixed with step motor (3), the output of step motor (3) is connected with drive screw (4).

2. The welding experiment frame for researching the association rule of the molten pool and the welding quality as claimed in claim 1, wherein the positioning mechanism comprises a supporting seat (5), a vertical shaft (10), a transverse shaft (11), a vertical clamp (12) and a transverse clamp (13), the supporting seat (5) is in threaded connection with the outer side of the transmission screw (4), the vertical shaft (10) is fixed to the top of the supporting seat (5), the vertical clamp (12) is arranged on the outer side of the vertical shaft (10), the transverse clamp (13) is fixed to one end of the vertical clamp (12), and the transverse shaft (11) is arranged on the inner side of the transverse clamp (13).

3. A welding experiment frame for researching the relation rule between the molten pool and the welding quality according to the claim 2 is characterized in that one side of the transverse shaft (11) is provided with a fixing clamp (14), the inner side of the fixing clamp (14) is provided with a welding gun (6), and one end of the welding gun (6) is provided with a welding pipe.

4. A welding experiment frame for researching the relation rule between the molten pool and the welding quality according to the claim 1 is characterized in that the top of the fixed plate (1) is also provided with a welding parent metal (8).

5. The welding experiment frame for researching association law of the molten pool and the welding quality as claimed in claim 3, wherein a vision module for detection is installed on the outer side of the welding pipe, the vision module comprises a binocular camera (7) and a connecting frame (15), the connecting frame (15) is fixed to the top of the binocular camera (7), the top of the connecting frame (15) is in sliding connection with the welding pipe, and a clamping plate is further connected to the top of the connecting frame (15) through screws.

6. A method of a welding bench for exploring the correlation law of a molten pool and welding quality, which is used for the building demolition apparatus according to any one of claims 1 to 5, characterized by the steps of:

s1: starting the stepping motor 3 to move the supporting seat 5;

s2: adjusting the positions of the vertical clamp 12 and the transverse clamp 13;

s3: adjusting the angle of the retaining clip 14;

s4: welding the welding torch 6 to weld the welding parent metal 8 by electrifying;

s5: and the vision module detects the welding position in the fourth step.

7. The method of claim 6, wherein the visual module detects the weld according to the following steps:

the method comprises the following steps that I, under the action of a light reduction mirror and a light filter, the outline of a molten pool is clear, and the molten pool is divided into a molten pool and a cooling molten pool during welding;

II, extracting the contour edge of the molten pool in real time;

and IV, independently taking out the part of the molten pool during welding, comparing the part with an edge standard in real time, and judging whether current and voltage need to be adjusted or the angle and the welding speed of a welding gun need to be adjusted.

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