An automatic welding apparatus and a welding method thereof

Abstract

The application provides an automatic welding device and a welding method thereof, and the automatic welding device comprises a line laser sensor, a contact sensor, an arc sensor, a control system and an automatic welding device. The welding instruction generation method is as follows: a bevel interface profile of a bevel is obtained by scanning a to-be-welded profile opening through the laser sensor; the welding instruction is generated according to the bevel interface profile; the bevel interface profile of the bevel is obtained by scanning the to-be-welded profile opening through the laser sensor; and the welding instruction is generated according to the bevel interface profile, which helps to solve the technical problem that the multi-layer multi-pass welding device and the welding method are blank.

Description

Technical fields:

[0001] This invention relates to the field of welding, and in particular to an automatic welding device and a welding method thereof. Background technology:

[0002] Currently, steel structure construction in various industries involves butt joints on planes and curved surfaces at different locations. For multi-layer, multi-pass welding of these butt joints, the theoretical position of the welding torch is determined by setting an offset. However, due to uneven bevel straightness and welding deformation during the welding process, the position of the welding torch must be adjusted in real-time according to the changes in the bevel.

[0003] Welding operations in various manufacturing industries involve multi-layer, multi-pass gas metal arc welding (GMAW). Currently, the automated welding equipment used in engineering cannot complete automated multi-pass welding while tracking the welding process. Summary of the Invention:

[0004] In one embodiment, the present invention provides an automatic welding device. The laser sensor scans the bevel to be welded to obtain the bevel interface contour. Based on the bevel interface contour, relevant information such as the bevel surface center, root center, depth, surface width, and weld layer width is obtained. The control system controls the welding machinery to adjust the welding torch position according to the information, ensuring that the welding position meets welding requirements. This helps to solve the technical problem of the lack of multi-layer, multi-pass welding equipment and methods.

[0005] The automatic welding equipment includes a line laser sensor, a contact sensor, an arc sensor, a control system, and the automatic welding equipment itself.

[0006] The line laser sensor and welding torch are mounted on the same motion device;

[0007] Contact sensors are used to adjust the position of the welding torch based on the contact points on both sides of the bevel edge.

[0008] The arc sensor is used to detect the actual welding current during the welding process, compare the difference between the actual welding current and the preset current, and adjust the distance (welding gun height) between the welding gun and the bevel.

[0009] The control system receives real-time data from the line laser sensor, the contact sensor, and the arc sensor, and sends welding commands based on the real-time data.

[0010] The method for generating welding instructions is as follows:

[0011] The laser sensor is used to scan the section to be welded to obtain the bevel interface contour.

[0012] Based on the bevel interface contour, relevant information such as the bevel surface center, root center, depth, surface width, and weld layer width are obtained. The control system controls the welding machinery to adjust the welding torch position according to the information to ensure that the welding position meets the welding requirements.

[0013] The automatic welding equipment is used to perform welding according to the welding instructions of the control system.

[0014] In one embodiment, the contact sensor and the arc sensor are disposed in a control cabinet.

[0015] In one embodiment, the distance between the line laser sensor and the welding torch is 60 to 120 millimeters.

[0016] In one embodiment, the present invention provides a welding method using an automatic welding device, wherein the welding method using the automatic welding device includes:

[0017] The line laser sensor scans the bevel to be welded to obtain the bevel interface profile, wherein the bevel interface profile is...

[0018] After scanning, the welding torch is cleaned and the wire is trimmed. The distance is set according to the bevel depth to ensure the welding extension length. The welding torch position is adjusted by touching both sides of the bevel edge using the contact sensing system to ensure that it is in the same position as the bevel center. If it is a filler layer weld or a capping layer weld, in addition to touching the bevel surface, it is also necessary to touch downward in the height direction to adjust the position of the welding torch in the height direction.

[0019] The automatic welding equipment uses a laser sensor to scan and acquire current weld bevel information in real time during the welding process.

[0020] Multi-layer, multi-pass welds are divided into root pass, fill pass, and cover pass. If the gap or weld layer width is greater than the predetermined value, the weld starts to be divided into passes. The welding parameters and offsets in the database are called up, and the offset is added to the weld position data obtained by the line laser sensor to compensate for the position of the welding gun, so as to realize automatic weld separation under the premise of online laser weld tracking.

[0021] In one embodiment, the bevel interface profile includes two feature points: the bevel surface and the root weld, to obtain the center positions of the bevel surface and the root weld surface, the bevel depth, the bevel surface width, the root gap, and the weld layer width.

[0022] In one embodiment, the bevel gap is set in the sensor system control cabinet, or the width of the current layer weld bevel is greater than 16mm to start multi-pass welding.

[0023] In one embodiment, when the gap width between the root pass and the filler weld is less than or equal to 16 mm, the welding torch offset is 0, and the welding is a single-layer, single-pass welding.

[0024] In one embodiment, if the gap width is greater than a predetermined value, the weld seam begins to separate into channels. The welding parameters and offset from the database are retrieved, and the offset is added to the weld seam position data acquired by the line laser sensor to compensate for the welding torch position. After the automatic weld seam separation step under the premise of online laser weld seam tracking is achieved, the method further includes:

[0025] The welding torch position can be adjusted in real time according to the current bevel condition.

[0026] In one embodiment, after the welding torch position can be adjusted in real time according to the current bevel state, the method further includes:

[0027] Each weld is welded in a cycle of 3-8 steps. Welding is completed when the weld reinforcement is ≥3mm. Attached image description:

[0028] Figure 1 This is a schematic diagram of a multi-layer, multi-pass welding process in one embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram showing the positional relationship between the bevel and the welding torch in another embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of a welding node in another embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of the hardware architecture of an automatic welding device according to another embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of the linear laser sensor arrangement in another embodiment of the present invention;

[0033] Figure 6 This is a schematic diagram of the connection relationship of the sensing system in another embodiment of the present invention;

[0034] Figure 7 This is a schematic diagram of weld types in another embodiment of the present invention;

[0035] Figure 8 This is a schematic diagram of the linear laser scanning process in another embodiment of the present invention;

[0036] Figure 9 This is a schematic diagram of contact positioning in another embodiment of the present invention;

[0037] Figure 10 This is a schematic diagram of the distance between the welding torch and the weld seam in another embodiment of the present invention. Detailed implementation method:

[0038] Multi-layer, multi-pass welding is an important welding method in manufacturing. Currently, experienced welding professionals are mostly used for welding, and some automated equipment is also used to assist welding, but none of them can completely automate the welding process.

[0039] For example, in the offset processing of multi-layer, multi-pass welding, a software preset method is used, which retrieves bevel information and calls parameters from a database before welding. The offset is related to the welding process's current and voltage, bevel angle, and gap plate thickness. The offset corresponds one-to-one with the welding node and welding parameters. In engineering applications, this method requires high precision in bevel setting. Moreover, the weld seam is affected by the welding temperature field during the welding process, causing welding deformation, which reduces the accuracy of the preset offset and leads to weld misalignment. During the welding process, an arc sensor is used to adjust the welding position. The working principle of the arc sensor is to detect the changes in the arc during the arc oscillation process and adjust the welding gun position according to the difference between the arcs on both sides to avoid weld misalignment. Although this solution has high arc sensor tracking accuracy and can adjust the welding gun position in real time according to the changes in the bevel, the arc sensor can only perform multi-layer, single-pass welding and cannot be applied to multiple passes within the same layer, etc.

[0040] In other words, the offset of multi-layer and multi-pass welds requires manual input and human intervention. Before each weld in a multi-layer and multi-pass weld, the position of the welding torch needs to be adjusted manually. The process of adjusting the position of the welding torch is the operation of the operator setting the offset according to experience. This method requires a high level of skill from the operator and human intervention, and cannot achieve fully automatic welding.

[0041] This invention proposes a technical solution for automatic layered routing of multi-layer, multi-pass welds in butt joint grooves. The automatic butt joint welding equipment realizes automatic layered routing welding without human intervention. The offset of the weld is obtained by line laser scanning of the groove to ensure accuracy.

[0042] Figure 1 This is a schematic diagram of a multi-layer, multi-pass welding process in one embodiment of the present invention; Figure 2 This is a schematic diagram showing the positional relationship between the bevel and the welding torch in another embodiment of the present invention; Figure 3 This is a schematic diagram of a welding node in another embodiment of the present invention; Figure 4 This is a schematic diagram of the hardware architecture of an automatic welding device according to another embodiment of the present invention; Figure 5 This is a schematic diagram of the linear laser sensor arrangement in another embodiment of the present invention; Figure 6 This is a schematic diagram of the connection relationship of the sensing system in another embodiment of the present invention; Figure 7 This is a schematic diagram of weld types in another embodiment of the present invention; Figure 8 This is a schematic diagram of the linear laser scanning process in another embodiment of the present invention; Figure 9 This is a schematic diagram of contact positioning in another embodiment of the present invention; Figure 10This is a schematic diagram illustrating the distance between the welding torch and the weld seam in another embodiment of the present invention. In one embodiment, the present invention provides an automatic welding device, which includes a line laser sensor, a contact sensor, an arc sensor, a control system, and the automatic welding equipment itself.

[0043] A line laser sensor is mounted on the welding torch;

[0044] Contact sensors are used to adjust the position of the welding torch based on the contact points on both sides of the bevel edge.

[0045] The arc sensor is used to detect the actual welding current during the welding process and adjust the welding torch height according to the predetermined current value;

[0046] The control system receives real-time data from the line laser sensor, the contact sensor, and the arc sensor, and controls the mechanical device to adjust the position of the welding torch based on the real-time data.

[0047] The method for generating welding instructions is as follows:

[0048] The laser sensor is used to scan the groove to be welded to obtain the groove interface contour.

[0049] The welding command is generated based on the bevel interface profile.

[0050] The automatic welding equipment is used to perform welding according to the welding instructions of the control system.

[0051] This embodiment provides a specific implementation of an automatic welding equipment, which can be used for fully automated welding. The present invention requires the installation of a sensing system on the automatic welding equipment, including a contact sensor, an arc sensor, and a 3D line laser sensor. These three sensing systems work together to accurately sense the weld positions of different workpieces and obtain the offset coordinates of multi-layer, multi-pass welding. The contact sensing module uses the welding wire as the conductive part of the sensing circuit and is equipped with a high-voltage power supply (conventionally the welding machine, but can also be added separately). The arc sensing module is equipped with an arc sensor, and the laser sensing module is equipped with a 3D line laser sensor. The arc and contact sensors, along with other auxiliary accessories, are integrated in the control cabinet of the sensing system. All sensing functions are equipped with algorithm software, configuring corresponding parameters to control the movement of the equipment to achieve automatic pass welding.

[0052] In one embodiment, the contact sensor and the arc sensor are disposed in a control cabinet.

[0053] This embodiment provides a specific hardware structure for installing the contact sensor and the arc sensor in a control cabinet.

[0054] In one embodiment, the distance between the line laser sensor and the welding torch is 60 to 120 millimeters.

[0055] The line laser sensor is mounted in front of the welding torch in the welding direction, with a spacing of 60-120mm between them. The high-voltage power supply is generally the welding power supply, but an additional high-voltage power supply can also be installed for contact sensing. The contact sensor and arc sensor are placed in the control cabinet. The welding torch is connected to the high-voltage power supply, and the line laser sensor communicates with the control cabinet, the high-voltage power supply, and the contact sensor within the control cabinet.

[0056] In one embodiment, the present invention provides a welding method using an automatic welding device, wherein the welding method using the automatic welding device includes:

[0057] S101, the line laser sensor scans the bevel to be welded to obtain the bevel interface profile, wherein the bevel interface profile;

[0058] S102, After the scanning is completed, the welding torch is cleaned and the wire is cut. The distance is set according to the bevel depth to ensure the welding extension length. The welding torch position is adjusted by touching both sides of the bevel edge using the contact sensing system to ensure that it is in the same position as the bevel center.

[0059] After the pre-scan is completed, the welding torch is cleaned and the wire is trimmed. The torch is then lowered a certain distance according to the bevel depth to ensure the welding extension length. The position of the welding torch is adjusted by touching both sides of the bevel edge with a contact sensor system to align with the center position of the bevel.

[0060] The equipment is started and welding begins. During the welding process, the laser sensor scans in real time to obtain the current weld bevel information.

[0061] S103, the automatic welding equipment uses a laser sensor to scan and obtain the current weld groove information in real time during the welding process, and divides the multi-layer, multi-pass weld into root filler and cover weld.

[0062] Multi-layer, multi-pass welds are divided into three types: root pass, filler pass, and cover pass. Welding begins when the bevel gap is set in the sensor system control cabinet or when the width of the current layer weld is greater than 16mm.

[0063] S104 If the gap width is greater than the predetermined value, the weld seam begins to be divided into channels. The welding parameters and offsets in the database are called up, and the offsets are added to the weld seam position data obtained by the line laser sensor to compensate for the welding gun position, thereby realizing automatic weld seam channeling under the premise of online laser weld seam tracking.

[0064] This embodiment provides a specific implementation method for an automated welding method. The sensor system control cabinet communicates with the control device of the automated welding equipment, and the sensor system control cabinet can control the motion of the welding equipment. Multi-layer, multi-pass welds are categorized into three types: root pass / fill pass, and cover pass.

[0065] In one embodiment, the bevel interface profile includes two feature points: the bevel surface and the root weld, to obtain the center positions of the bevel surface and the root weld surface, the bevel depth, the bevel surface width, the root gap, and the weld layer width.

[0066] This sensor system initiates welding passes based on a bevel gap or the width of the current weld layer exceeding 16mm. A welding process database is established, with each weld gap, welding parameter, oscillation parameter, and offset corresponding to a specific condition. Once the automatic welding equipment moves or is moved near the weld, the laser sensor scans the bevel. With the laser line at its starting position, the welding equipment is controlled to initiate a pre-scan, with the scanning distance consistent with the distance between the welding torch and the laser. The line laser uses the laser triangulation principle to detect the weld bevel. The line laser beam is projected onto the bevel surface, producing diffuse reflection, which is received by the sensor to form a light spot. Based on the reflection angle, the bevel depth and laser line position are measured to obtain the bevel interface contour. Two feature points on the left and right sides of the bevel surface and root (weld) are identified, providing information such as the center position of the bevel surface and root (weld surface), bevel depth, bevel surface width, root gap, and weld layer width.

[0067] In one embodiment, the bevel gap is set in the sensor system control cabinet, or the width of the current layer weld bevel is greater than 16mm to start multi-pass welding.

[0068] When the gap width exceeds 16mm, the weld seam begins to branch. Welding parameters and offsets are retrieved from the database, and the offset is added to the weld seam position data acquired by the line laser sensor to compensate for the welding torch position. This achieves automatic weld seam branching under online laser weld seam tracking. Simultaneously, the welding torch position can be adjusted in real time according to the current bevel condition, avoiding problems such as weld seam misalignment.

[0069] During welding, the height of the welding torch is adjusted using an arc sensing system. The electrical characteristics of the welding power source are constant voltage, and the length of the arc affects the welding current. The arc sensor detects the actual welding current during the welding process, compares the actual current with the set current, and adjusts the torch height to ensure the distance between the torch and the weld surface.

[0070] In one embodiment, when the gap width between the root pass and the filler weld is less than or equal to 16 mm, the welding torch offset is 0, and the welding is a single-layer, single-pass welding.

[0071] In one embodiment, if the gap width or weld layer width is greater than a predetermined value, the weld begins to be divided into channels. The welding parameters and offsets from the database are retrieved, and the offset is added to the weld position data acquired by the line laser sensor to compensate for the welding torch position. After the automatic weld channel division step under the premise of online laser weld tracking is achieved, the method further includes:

[0072] The welding torch position can be adjusted in real time according to the current bevel condition.

[0073] In one embodiment, after the welding torch position can be adjusted in real time according to the current bevel state, the method further includes:

[0074] Each weld is welded in a cycle of 3-8 steps. Welding is completed when the weld reinforcement is ≥3mm.

[0075] Beneficial effects:

[0076] It reduces the amount of human intervention required during multi-layer, multi-pass welding of automatic welding equipment, and realizes fully automated welding process.

[0077] It solves the problem that the multi-layer, multi-pass welding parameters in the process database are not applicable under conditions such as welding deformation and poor bevel opening accuracy, and avoids welding defects such as misaligned welding.

[0078] With the premise of achieving weld seam tracking, the pre-weld offset is automatically offset to complete the layered layout of the weld seam, realizing fully automatic welding of multiple layers and multiple passes.

[0079] This solution adds arc sensing, contact sensing, and laser sensing devices to enable communication with automatic welding equipment. The weld data acquired during the welding process is combined with the process database, thereby achieving automatic layered routing of multi-layer, multi-pass welding of butt welds under the premise of weld tracking, and realizing automatic welding of butt welds.

[0080] Currently, the company's existing robotic arm automated welding equipment includes imported thin plate lines, deep-channel block lines, and sheet metal lines. These systems are currently unable to achieve automated butt welds, resulting in low equipment utilization. The application of this patent will help improve equipment utilization, achieve automated butt welds, increase welding automation, reduce labor costs, and promote the company's intelligent welding technology development.

[0081] This invention, when installed on existing robots, enables multi-layer, multi-pass welding of butt welds, improving equipment utilization. It can also be applied to currently tested trackless crawling robots, optimizing curved surface trackless crawling robot equipment to achieve automated welding of curved surface welds, effectively increasing the automation rate of ship welding and reducing labor costs.

[0082] This invention provides a new multi-layer, multi-pass welding solution for the company's existing robotic production lines and the automated welding equipment currently under testing. It addresses the company's challenges of low automation rates and high manual labor input in butt welds, not only improving welding efficiency and reducing manual labor input, thus helping the company improve efficiency and reduce costs, but also establishing the company's image as an innovative and technology-driven shipbuilder. This further enhances the company's influence in the shipbuilding industry and lays a solid technical foundation for the company to continue undertaking high-value-added ship types.

Claims

1. A welding method for an automatic welding equipment, characterized in that, Based on the aforementioned automatic welding equipment The automatic welding equipment includes: A single laser sensor is mounted on the same motion device as the welding torch. Upon contact with the sensor, the welding wire touches both sides of the bevel and the weld depth, adjusting the position of the welding torch. An arc sensor compares the difference between the actual welding current and the preset current to adjust the distance between the welding torch and the bevel. A control system receives real-time data from the line laser sensor, the contact sensor, and the arc sensor, and sends welding commands based on the real-time data. The method for generating welding instructions is as follows: The weld bevel profile is obtained by scanning the weld bevel using the line laser sensor. Based on the bevel interface contour, information related to the bevel surface center, root center, depth, surface width, and weld layer width is obtained. The control system controls the welding machinery to adjust the welding torch position according to the information to ensure that the welding position meets the welding requirements. The welding method of the automatic welding equipment includes: The line laser sensor scans the groove to be welded to obtain the groove interface profile, wherein the groove interface profile includes two feature points: the groove surface and the root weld. After scanning, the welding torch is cleaned and the wire is cut. The distance is set according to the bevel depth to ensure the welding extension length. The contact sensor is used to adjust the position of the welding torch by extending the welding wire to touch both sides of the bevel edge to ensure that it is in the same position as the bevel center. If it is a filler layer weld or a capping layer weld, in addition to touching the bevel surface, it is also necessary to touch downward in the height direction to adjust the position of the welding torch in the height direction. The automatic welding equipment uses a laser sensor to scan and acquire the current weld bevel information in real time during the welding process. Multi-layer, multi-pass welds are divided into root pass, fill pass, and cover pass. If the bevel gap or weld layer width is greater than the predetermined value, the weld starts to be separated into passes. The welding parameters and offsets in the database are called up, and the offset is added to the weld position data obtained by the line laser sensor to compensate for the position of the welding gun, so as to realize automatic weld separation under the premise of online laser weld tracking.

2. The welding method of the automatic welding equipment according to claim 1, characterized in that, The bevel interface profile is identified by two feature points: the bevel surface and the root weld. The center positions of the bevel surface and the root weld surface, the bevel depth, the bevel surface width, the root gap, and the weld layer width are obtained.

3. The welding method of the automatic welding equipment according to claim 2, characterized in that, Set the bevel gap in the sensor system control cabinet or start welding in stages when the width of the current layer weld is greater than 16mm.

4. The welding method of the automatic welding equipment according to claim 3, characterized in that, When the gap width between the root pass and the filler weld is less than or equal to 16mm, the welding torch offset is 0, and the welding is a single-layer, single-pass welding.

5. The welding method of the automatic welding equipment according to claim 4, characterized in that, If the bevel gap width is greater than a predetermined value, the weld begins to branch. The welding parameters and offset from the database are retrieved, and the offset is added to the weld position data acquired by the line laser sensor to compensate for the welding torch position. After the automatic weld branching step under the premise of online laser weld tracking is achieved, the method further includes: The welding torch position can be adjusted in real time according to the current bevel condition.

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