Variable diameter nozzle and welding apparatus and welding method using the same, welding robot

Abstract

The application discloses a variable-diameter nozzle and a welding device and welding method and welding robot adopting the same, which adopts a conductive nozzle, a first nozzle, a second nozzle and a third nozzle which are sequentially sleeved from inside to outside, the conductive nozzle is drivingly connected with a rotary driving member, the first nozzle is fixedly connected with the conductive nozzle, the second nozzle is threadedly connected with the first nozzle, the third nozzle is threadedly connected with the second nozzle, a positioning device is arranged on the inner surfaces of the second nozzle and the third nozzle, a chamfer is arranged outside the lower end surface of the first nozzle, a positioning clamping groove is arranged on the outer surface of the second nozzle, and in the driving rotation process of the rotary driving member, any one of the three nozzles is driven to extend out through the cooperation of the positioning device and the positioning clamping groove or the cooperation with the chamfer, the automatic conversion of nozzles of different sizes is realized, the welding efficiency and the welding quality are improved, the on-off of the airflow channels of the three nozzles can be controlled, the protective gas can be provided when the nozzles of different sizes extend out, and the nozzles are prevented from being blocked in the welding process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of robot welding, in particular, to a variable-diameter nozzle, and further, to a welding device and welding method using the variable-diameter nozzle and a welding robot. BACKGROUND

[0002] The welding nozzle, also known as a welding gun nozzle, is a key component in a welding device, and its main function is to allow the protective gas required in the welding process to flow in a uniform and laminar manner, so as to ensure that the electric arc and the welding pool obtain constant protective gas coverage relative to the atmosphere. In MIG / MAG welding, the nozzle is responsible not only for guiding the compressed gas flow into the welding process, but also for protecting the electric arc from the surrounding atmosphere, ensuring proper gas flow and protective gas coverage during the welding process.

[0003] In the welding process, the welding nozzle has different sizes of diameters, corresponding to different grooves. In the welding process, a small-size nozzle can ensure that the welding wire reaches the root of the welding position smoothly, thereby ensuring the welding quality. However, the small-size nozzle is easily blocked by welding spatter during the welding process. In the gas shielded welding process, since the molten pool surface is not covered by slag, the protective gas has a strong cooling effect, causing the molten pool metal to solidify relatively quickly. If the gas cannot escape in time during the gas shielded welding process, pores are likely to be generated in the weld, affecting the quality and strength of the weld. Although a large-size nozzle can reduce the risk of blockage, it is difficult to reach the root of the weld. Therefore, in the welding process, a small-size nozzle is first used to fill the root of the welding wire, and then a large-size nozzle is used for welding. However, in the robot automatic welding process, due to the fast welding speed, it is difficult to replace the small-size nozzle with the large-size nozzle in time in most cases, which will result in blockage of the small-size nozzle and difficulty in achieving the required welding quality. SUMMARY

[0004] The present application provides a variable-diameter nozzle and a welding device and welding method using the same, and a welding robot, which can automatically switch between different size nozzles, improve welding efficiency and welding quality, and provide protective gas when different nozzles are extended, preventing the nozzle from being blocked during the welding process.

[0005] According to one aspect of the present application, a variable diameter nozzle is provided, comprising a conductive nozzle, a first nozzle, a second nozzle and a third nozzle which are sequentially sleeved from inside to outside, the upper end of the conductive nozzle is connected with a rotary driving member for performing a rotary telescopic action under the driving of the rotary driving member, a wire feeding hole is formed in the center of the conductive nozzle for automatically feeding wire during welding, at least one gas outlet hole is formed in the upper part of the conductive nozzle for providing protective gas during welding, the first nozzle is fixedly connected with the conductive nozzle and a gap exists between them, the lower end surface of the first nozzle protrudes from the lower end surface of the conductive nozzle, the second nozzle and the third nozzle are connected through threads, positioning devices are arranged on the inner surfaces of the second nozzle and the third nozzle, a chamfer is arranged on the outer side of the lower end surface of the first nozzle, a positioning clamping groove is arranged on the outer surface of the second nozzle, and gas flow channels are formed in the first nozzle, the second nozzle and the third nozzle, during the rotary telescopic action of the conductive nozzle, the limiting between the first nozzle and the second nozzle and between the second nozzle and the third nozzle is realized through the cooperation of the positioning devices and the positioning clamping groove or the cooperation with the chamfer, any one of the first nozzle, the second nozzle and the third nozzle is driven to extend out, and the on-off control between the gas flow channels of the three nozzles is realized, so that protective gas can be provided when different nozzles extend out.

[0006] Further, the gas flow channel of the first nozzle comprises a first through hole, the gas flow channel of the second nozzle comprises a second through hole, a first gas path and a first gas outlet hole, and the gas flow channel of the third nozzle comprises a blind hole, a second gas path and a second gas outlet hole, the first through hole, the second through hole and the blind hole are all radially formed, the first gas path and the second gas path are both axially formed, the second through hole and the first gas outlet hole are respectively the gas inlet and outlet of the first gas path, and the blind hole and the second gas outlet hole are respectively the gas inlet and outlet of the second gas path.

[0007] When the first nozzle extends to the position, the first through hole is not in communication with the second through hole, and protective gas is only sprayed from the gap between the first nozzle and the conductive nozzle; when the second nozzle extends to the position, the first through hole is in communication with the second through hole, and the second through hole is not in communication with the blind hole, and protective gas is simultaneously sprayed from the gap between the first nozzle and the conductive nozzle and the first gas outlet hole; when the third nozzle extends to the position, the first through hole is in communication with the second through hole, and the second through hole is in communication with the blind hole, and protective gas is simultaneously sprayed from the gap between the first nozzle and the conductive nozzle, the first gas outlet hole and the second gas outlet hole.

[0008] Further, when the rotary driving member is rotated forward, the driving electrically conductive nozzle and the first nozzle are rotated forward and extended together, when the first nozzle is extended to the chamfer and abuts against the positioning device of the inner surface of the second nozzle, the second nozzle and the third nozzle are driven to move relatively, when the positioning device of the inner surface of the third nozzle is clamped in the positioning clamping groove of the outer surface of the second nozzle, the second nozzle and the third nozzle stop relative movement, and the rotary driving member continues to rotate forward, the chamfer of the first nozzle extrudes the positioning device of the second nozzle and then continues to extend.

[0009] Further, when the rotary driving member is reversed, the driving electrically conductive nozzle and the first nozzle are reversed and retracted together, so that the second nozzle is relatively extended.

[0010] Further, when the rotary driving member continues to reverse, the driving electrically conductive nozzle and the first nozzle continue to reverse and retract, when the first nozzle is retracted to the end of the thread and cannot continue to move, the positioning clamping groove on the outer surface of the second nozzle extrudes the positioning device on the inner surface of the third nozzle, and the two move relatively, the second nozzle is retracted, and the third nozzle is relatively extended.

[0011] In addition, the present application also provides a welding device, which comprises a camera, a motor, a control module and the variable-diameter nozzle as described above, the camera is installed on the variable-diameter nozzle and used to collect images of a position to be welded, the motor is in driving connection with the variable-diameter nozzle and used to drive any nozzle of the variable-diameter nozzle to extend, and the control module is in electrical connection with the camera and the motor respectively and used to identify a welding form according to the images of the position to be welded, and control the working state of the motor according to the identified welding form, so as to drive the nozzle with an appropriate size to extend.

[0012] Further, when the welding form is identified as a fillet weld, the third nozzle is driven to extend, when the welding form is identified as a groove weld, a groove image is collected, the boundary of the groove is determined according to the groove image, and the nozzle conversion position is determined according to the circumscribed figure of the boundary of the groove.

[0013] Further, for a V-shaped groove, the nozzle conversion position is determined based on the following formula:

[0014]

[0015]

[0016]

[0017]

[0018] Wherein, A represents the included angle of the V-shaped groove, a, b and c respectively represent the side length of the three sides of the circumscribed isosceles triangle of the V-shaped groove boundary, a is the base, b and c are the legs, L represents the dry elongation, S represents the welding wire filling thickness, n1, n2 and n3 respectively represent the outer diameter of the first nozzle (2), the second nozzle (3) and the third nozzle (4), when the welding wire filling thickness reaches S2, the second nozzle (3) is driven to extend out, and when the welding wire filling thickness reaches S3, the third nozzle (4) is driven to extend out.

[0019] In addition, the present application also provides a welding method, using the welding equipment as described above, comprising the following contents:

[0020] Collecting the image of the position to be welded;

[0021] Identifying the welding form according to the image of the position to be welded;

[0022] Controlling the extension of the nozzle with adaptive size according to the welding form.

[0023] In addition, the present application also provides a welding robot, the execution end of the welding robot uses the welding equipment as described above.

[0024] The present application has the following beneficial effects:

[0025] The variable-diameter nozzle of the present application adopts the conductive nozzle, the first nozzle, the second nozzle and the third nozzle which are sequentially sleeved from inside to outside, the conductive nozzle is drivingly connected with the rotary driving member, the first nozzle is fixedly connected with the conductive nozzle, the second nozzle is threadedly connected with the first nozzle, the third nozzle is threadedly connected with the second nozzle, the positioning device is arranged on the inner surface of the second nozzle and the third nozzle, the chamfer is arranged on the outer side of the lower end surface of the first nozzle, and the positioning clamping groove is arranged on the outer surface of the second nozzle. In the driving rotation process of the rotary driving member, the positioning device cooperates with the positioning clamping groove or cooperates with the chamfer to realize the limiting between the first nozzle and the second nozzle and between the second nozzle and the third nozzle, so that any one of the first nozzle, the second nozzle and the third nozzle is driven to extend out, thereby realizing the automatic conversion of different size nozzles, improving the welding efficiency and the welding quality, and the on-off of the air flow passages between the three nozzles can be controlled, so that the protective gas can be provided when different nozzles extend out, preventing the nozzles from being blocked during welding.

[0026] In addition, the welding equipment of the present application can capture the image of the position to be welded, identify the welding form based on image recognition technology, and automatically control the working state of the motor according to the identified welding form to drive the nozzle with adaptive size to extend out, thereby realizing the intelligent control of nozzle replacement and greatly improving the welding efficiency and the welding quality.

[0027] In addition, the welding method and the welding robot of the present application also have the above-mentioned advantages.

[0028] In addition to the objects, features and advantages of the present application described above, there is a further object, feature, and advantage of the present application that will be apparent from the following description. The above and other objects, features and advantages of the present application will become more apparent from the following description when taken in conjunction with the accompanying drawings, in which: BRIEF DESCRIPTION OF DRAWINGS

[0029] The accompanying drawings, which form a part of this specification, are included to provide a further understanding of the application and are incorporated by reference herein. The drawings illustrate preferred embodiments of the present application and, together with the description, serve to explain the application. In the drawings:

[0030] Figure 1 is a cross-sectional structure schematic diagram of the first nozzle of the variable-diameter nozzle of the preferred embodiment of the present application when the nozzle is extended.

[0031] Figure 2 is a cross-sectional structure schematic diagram of the second nozzle of the variable-diameter nozzle of the preferred embodiment of the present application when the nozzle is extended.

[0032] Figure 3 is a cross-sectional structure schematic diagram of the third nozzle of the variable-diameter nozzle of the preferred embodiment of the present application when the nozzle is extended.

[0033] Figure 4 is a structure schematic diagram of the conductive nozzle of the preferred embodiment of the present application.

[0034] Figure 5 is a structure schematic diagram of the conductive nozzle fixedly connected with the first nozzle of the preferred embodiment of the present application.

[0035] Figure 6 is a structure schematic diagram of the positioning device of the preferred embodiment of the present application.

[0036] Figure 7 is Figure 1 is an enlarged schematic diagram of the position I.

[0037] Figure 8 is a structure schematic diagram of the positioning device clamped in the positioning groove of the preferred embodiment of the present application.

[0038] Figure 9 is a cross-sectional schematic diagram of the gas path structure when the first nozzle of the variable-diameter nozzle of the preferred embodiment of the present application is extended.

[0039] Figure 10 is a cross-sectional schematic diagram of the gas path structure when the second nozzle of the variable-diameter nozzle of the preferred embodiment of the present application is extended.

[0040] Figure 11 is a cross-sectional schematic diagram of the gas path structure when the third nozzle of the variable-diameter nozzle of the preferred embodiment of the present application is extended.

[0041] Figure 12 is Figure 11 is an enlarged schematic diagram of the position II.

[0042] Figure 13 is a schematic view of a structure of a welding device mounted at the end of a welding robot according to another embodiment of the present application.

[0043] Figure 14 is Figure 13 is an enlarged schematic view of the position III in FIG. 1.

[0044] Figure 15 is a schematic view of a principle of a welding device according to another embodiment of the present application when switching a nozzle for calculating a V-shaped groove.

[0045] Figure 16 is a schematic view of a welding device according to another embodiment of the present application when welding by using a first nozzle.

[0046] Figure 17 is a schematic view of a welding device according to another embodiment of the present application when automatically switching a second nozzle for welding at a position S2.

[0047] Figure 18 is a schematic view of a welding device according to another embodiment of the present application when automatically switching a second nozzle for welding at a position S3.

[0048] Figure 19 is a schematic view of a welding method according to another embodiment of the present application.

[0049] BRIEF DESCRIPTION OF DRAWINGS

[0050] 1, conductive nozzle; 2, first nozzle; 3, second nozzle; 4, third nozzle; 5, positioning device; 6, positioning slot; 11, wire feeding hole; 12, gas outlet hole; 21, first through hole; 31, second through hole; 32, first gas path; 33, first gas outlet hole; 41, blind hole; 42, second gas path; 43, second gas outlet hole; 51, spherical ball; 52, elastic member; 100, camera; 200, motor. DETAILED DESCRIPTION

[0051] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0052] Reference will now be made to Figures 1 to 5As shown, the preferred embodiment of the present application provides a variable diameter nozzle, which comprises a conductive nozzle 1, a first nozzle 2, a second nozzle 3 and a third nozzle 4 which are sequentially sleeved from inside to outside, the upper end of the conductive nozzle 1 is connected with a rotary driving member for performing a rotary telescopic action under the driving of the rotary driving member, wherein the rotary driving member can adopt a motor or an electric motor, preferably an electric motor. The center of the conductive nozzle 1 is provided with a wire feeding hole 11 for automatically feeding welding wire during welding, and the upper part of the conductive nozzle 1 is provided with at least one gas outlet hole 12 for providing shielding gas during welding, wherein the internal gas circuit of the conductive nozzle 1 is also connected with an external shielding gas source, and the shielding gas provided by the shielding gas source is sprayed from the gas outlet hole 12. The first nozzle 2 is fixedly connected with the conductive nozzle 1 and there is a gap between them, and the lower end surface of the first nozzle 2 protrudes from the lower end surface of the conductive nozzle 1 to protect the conductive nozzle 1. The second nozzle 3 and the third nozzle 4 are connected by threads, specifically, the outer surface of the first nozzle 2 and the second nozzle 3 is provided with external threads, and the inner surface of the second nozzle 3 and the third nozzle 4 is provided with internal threads. The inner surface of the second nozzle 3 and the third nozzle 4 is provided with a positioning device 5, the lower end surface of the first nozzle 2 is provided with a chamfer, the outer surface of the second nozzle 3 is provided with a positioning clamping groove 6, and the first nozzle 2, the second nozzle 3 and the third nozzle 4 are all provided with a gas flow channel. During the rotary telescopic action of the conductive nozzle 1, through the cooperation of the positioning device 5 and the positioning clamping groove 6 or the cooperation with the chamfer, the limiting between the first nozzle 2 and the second nozzle 3 and between the second nozzle 3 and the third nozzle 4 is realized, so that any one of the first nozzle 2, the second nozzle 3 and the third nozzle 4 is driven to extend out, and the on-off control between the gas flow channels of the three nozzles is realized, so that the shielding gas can be provided when different nozzles extend out, protection is performed during welding, and the nozzles can also be prevented from being blocked during welding. Specifically, when the first nozzle 2 extends out, the shielding gas is only sprayed from the gap between the first nozzle 2 and the conductive nozzle 1, when the second nozzle 3 extends out, the shielding gas is sprayed from the gap between the first nozzle 2 and the conductive nozzle 1 and the gas flow channel of the second nozzle 3, and when the third nozzle 4 extends out, the shielding gas is sprayed from the gap between the first nozzle 2 and the conductive nozzle 1 and the gas flow channels of the second nozzle 3 and the third nozzle 4.

[0053] It can be understood that the variable-diameter nozzle of the embodiment adopts the conductive nozzle 1, the first nozzle 2, the second nozzle 3 and the third nozzle 4 which are sequentially sleeved from inside to outside, the conductive nozzle 1 is drivingly connected with the rotary driving member, the first nozzle 2 is fixedly connected with the conductive nozzle 1, the second nozzle 3 is threadedly matched with the first nozzle 2 and the third nozzle 4 is threadedly matched with the second nozzle 3, the positioning device 5 is arranged on the inner surfaces of the second nozzle 3 and the third nozzle 4, the chamfer is arranged on the outer side of the lower end surface of the first nozzle 2, the positioning clamping groove 6 is arranged on the outer surface of the second nozzle 3, and in the driving rotation process of the rotary driving member, the limiting between the first nozzle 2 and the second nozzle 3 and between the second nozzle 3 and the third nozzle 4 is realized through the cooperation of the positioning device 5 and the positioning clamping groove 6 or the cooperation with the chamfer, so that any one of the first nozzle 2, the second nozzle 3 and the third nozzle 4 is driven to protrude, thereby realizing the automatic conversion of the nozzles of different sizes, improving the welding efficiency and the welding quality, and the on-off between the airflow channels of the three nozzles can be controlled, so that the protective gas can be provided when the nozzles of different sizes protrude, thereby preventing the nozzles from being blocked during the welding process.

[0054] It can be understood that, as shown in Figures 6 to 8 , the positioning device 5 includes a spherical ball 51 and an elastic member 52, the mounting hole is formed on the inner surfaces of the second nozzle 3 and the third nozzle 4, the spherical ball 51 and the elastic member 52 are placed in the mounting hole, one end of the elastic member 52 abuts against the hole wall of the mounting hole and the other end abuts against the spherical ball 51. When the spherical ball 51 is not pressed, the elastic member 52 is in a free state, and the spherical ball 51 slightly protrudes from the inner surfaces of the second nozzle 3 and the third nozzle 4. When the spherical ball 51 is pressed, the elastic member 52 is in a compressed state, and the spherical ball 51 is tangent to the inner surfaces of the second nozzle 3 and the third nozzle 4. Among them, two positioning devices 5 are arranged on the inner surface of the second nozzle 3, four positioning devices 5 are arranged on the inner surface of the third nozzle 4, and the number of the positioning clamping grooves 6 is matched with the number of the positioning devices 5 on the inner surface of the third nozzle 4.

[0055] It can be understood that when the rotating driving member is rotated forward, the electrically conductive nozzle 1 and the first nozzle 2 are driven to rotate forward and extend together due to the driving connection between the electrically conductive nozzle 1 and the rotating driving member and the fixed connection between the first nozzle 2 and the electrically conductive nozzle 1. When the first nozzle 2 extends to the position where the chamfer thereof abuts against the positioning device 5 on the inner surface of the second nozzle 3, the positioning device 5 on the inner surface of the second nozzle 3 protrudes from the inner surface of the second nozzle 3, thereby limiting the first nozzle 2. At this time, the positioning device 5 on the inner surface of the third nozzle 4 is pressed by the outer surface of the second nozzle 3, and the ball 51 of the positioning device 5 is pressed in the mounting hole and tangent to the inner surface of the third nozzle 4, so that there is no limit between the second nozzle 3 and the third nozzle 4. Therefore, under the action of the thread between the first nozzle 2 and the second nozzle 3, the second nozzle 3 moves relatively with respect to the first nozzle 2 and the third nozzle 4, and the electrically conductive nozzle 1 and the first nozzle 2 stop extending at this time. With the relative movement between the second nozzle 3 and the third nozzle 4, when the ball 51 of the positioning device 5 on the inner surface of the third nozzle 4 is clamped in the positioning clamping groove 6 on the outer surface of the second nozzle 3, the second nozzle 3 and the third nozzle 4 are limited, and the second nozzle 3 and the third nozzle 4 stop moving relatively. Since the positioning device 5 on the third nozzle 4 has four positions and no chamfer, and the positioning device 5 on the second nozzle 3 has only two positions and a chamfer, the rotating force is more likely to drive the thread between the first nozzle 2 and the second nozzle 3 to rotate. When the rotating driving member continues to rotate forward, the first nozzle 2 continues to extend, and the chamfer on the first nozzle 2 continues to extend after pressing the ball 51 of the positioning device 5 on the inner surface of the second nozzle 3. When the rotating driving member rotates forward by a predetermined number of turns, the first nozzle 2 extends to the position.

[0056] In addition, when it is necessary to switch to the extension of the second nozzle 3, the rotating driving member is controlled to reverse, and the positioning device 5 on the inner surface of the second nozzle 3 is in a compressed state, that is, there is no limit between the first nozzle 2 and the second nozzle 3, and the positioning device 5 on the inner surface of the third nozzle 4 is in a non-compressed state, that is, there is a limit between the second nozzle 3 and the third nozzle 4. At this time, the thread between the first nozzle 2 and the second nozzle 3 is more likely to move relatively, and the rotating driving member drives the electrically conductive nozzle 1 and the first nozzle 2 to reverse and retract together, so that the second nozzle 3 extends relatively. When the rotating driving member reverses by a predetermined number of turns, the second nozzle 3 extends to the position.

[0057] In addition, when it is required to switch to the extension of the third nozzle 4, the control of the rotation driving member to continue the reverse rotation will drive the conductive nozzle 1 and the first nozzle 2 to continue the reverse retraction, and when the first nozzle 2 cannot continue to move after being retracted to the end of the thread, the rotation force will overcome the limit between the positioning device 5 and the positioning slot 6 on the outer surface of the second nozzle 3, the spherical ball 51 of the positioning device 5 on the inner surface of the third nozzle 4 will be extruded, so that the relative movement occurs between the two, and the second nozzle 3 is driven to retract, so that the third nozzle 4 is relatively extended, and when the rotation driving member is reversed for a predetermined number of turns, the third nozzle 4 is extended to the position. It can be understood that the extension of the third nozzle 4 is a relative extension, that is, after the first nozzle 2 and the second nozzle 3 are retracted, the third nozzle 4 is in an extended state relative to the first nozzle 2 and the second nozzle 3.

[0058] It can be understood that, as shown in Figures 9 to 12 The gas flow channel of the first nozzle 2 includes a first through hole 21, the gas flow channel of the second nozzle 3 includes a second through hole 31, a first gas path 32 and a first gas outlet 33, and the gas flow channel of the third nozzle 4 includes a blind hole 41, a second gas path 42 and a second gas outlet 43. The first through hole 21, the second through hole 31 and the blind hole 41 are all radially arranged, the first gas path 32 and the second gas path 42 are both axially arranged, the second through hole 31 and the first gas outlet 33 are respectively the gas inlet and the gas outlet of the first gas path 32, and the blind hole 41 and the second gas outlet 43 are respectively the gas inlet and the gas outlet of the second gas path 42. When the first nozzle 2 is extended to the position, the first through hole 21 is not communicated with the second through hole 31, that is, the first through hole 21 is misaligned with the second through hole 31, and the protective gas cannot flow from the first through hole 21 into the gas flow channel of the second nozzle 3. After the protective gas is sprayed from the gas outlet of the conductive nozzle 1, it is filled in the cavity between the conductive nozzle 1 and the first nozzle 2, and is only sprayed from the gap between the first nozzle 2 and the conductive nozzle 1. When the second nozzle 3 is extended to the position, the first through hole 21 is communicated with the second through hole 31, and the second through hole 31 is not communicated with the blind hole 41, that is, the first through hole 21 is aligned with the second through hole 31, and the second through hole 31 is misaligned with the blind hole 41. The protective gas flows from the first through hole 21 into the gas flow channel of the second nozzle 3, but cannot continue to flow into the gas flow channel of the third nozzle 4. The protective gas is simultaneously sprayed from the gap between the first nozzle 2 and the conductive nozzle 1, the first gas outlet 33 and the second gas outlet 43. When the third nozzle 4 is extended to the position, the first through hole 21 is communicated with the second through hole 31, and the second through hole 31 is communicated with the blind hole 41, that is, the first through hole 21, the second through hole 31 and the blind hole 41 are all aligned. The protective gas flows from the first through hole 21 into the gas flow channels of the second nozzle 3 and the third nozzle 4 in sequence. The protective gas is simultaneously sprayed from the gap between the first nozzle 2 and the conductive nozzle 1, the first gas outlet 33 and the second gas outlet 43.

[0059] In addition, as shown in Figure 13 and Figure 14As shown, another embodiment of the present application also provides a welding device, which comprises a camera 100, a motor 200, a control module and a variable diameter nozzle as described above, the camera 100 is mounted on the variable diameter nozzle for collecting images of the position to be welded, the motor 200 is drivingly connected with the variable diameter nozzle for driving any one of the nozzles in the variable diameter nozzle to extend, and the control module is electrically connected with the camera 100 and the motor 200 respectively, for identifying the welding form according to the image of the position to be welded, and controlling the working state of the motor 200 according to the identified welding form, so as to drive the nozzle of the appropriate size to extend. Wherein, the welding device can be used as the execution end of the welding robot, or be installed on other automatic welding devices, so as to automatically switch the nozzle size.

[0060] It can be understood that the welding device of the present application can identify the welding form based on image recognition technology by shooting the image of the position to be welded, and automatically control the working state of the motor 200 according to the identified welding form, so as to drive the nozzle of the appropriate size to extend, which realizes the intelligent control of nozzle replacement, and greatly improves the welding efficiency and welding quality.

[0061] It can be understood that the control module stores a trained neural network model, and the image of the position to be welded is input into the neural network model, so as to automatically identify the welding form. Specifically, a plurality of historical position-to-be-welded photos are obtained, the historical position-to-be-welded photos include different welding forms, wherein the welding forms include fillet weld and groove weld, and the groove weld includes V-shaped groove, U-shaped groove, X-shaped groove, K-shaped groove and J-shaped groove. The historical position-to-be-welded photos are processed by noise reduction to remove noise in the image and improve image quality, which can be processed by mean filtering, Gaussian filtering and median filtering. In addition, the image processed by noise reduction is normalized to scale the image data to a uniform range, standardize the image data, eliminate the difference between images, and make the image more suitable for comparison and analysis, which can be normalized by logarithmic normalization and decimal scaling normalization. Then, the normalized image is adjusted in size to a uniform size, so as to determine the preprocessed photo. Finally, the preprocessed photo is divided into a training set, a validation set and a test set according to a preset proportion, so as to train the neural network model. The neural network model can use ResNet-50 network or Swin Transformer network, and feature extraction is performed by a convolutional neural network model.

[0062] It can be understood that the neural network model specifically includes an input layer, a convolutional layer, a pooling layer, a fully connected layer and an output layer, wherein the input layer is used to input the training set image, the image data can be uniform 64x64x3 size, and the formula of the convolutional layer is: Oij For an element of the output feature map of the convolution layer, I is the input picture, K is the convolution kernel or filter, b is the bias term, and m and n are the spatial dimensions of the convolution kernel. The convolution layer receives the picture data of the input layer, contains 16 5x5 convolution kernels, each of which can perform convolution operation on the input picture data, and outputs 16 60x60 feature maps. Specifically, the first convolution layer performs the first convolution operation on the input picture data using 16 5x5 convolution kernels to obtain 16 60x60 feature maps, which have a total of 416 parameters and 576,000 connections. The formula of the pooling layer is: O ij = max(I 2i:2i+1,2j:2j+1 ), O ij is an element of the output feature map of the pooling layer, I is the input picture. Exemplarily, a 4x4 maximum pooling operation is performed on the feature map after convolution to obtain 16 30x30 feature maps. The pooling operation reduces the size of the feature map, making the model less susceptible to small spatial changes. The formula of the fully connected layer is: O = W x I + b, O is an element of the output of the fully connected layer, W is the weight matrix, I is the input vector, and b is the bias vector. After the above process, the picture in each input training data set is expanded into a one-dimensional vector (16x30x30 = 14400), and then input into a fully connected layer with 128 neurons. The role of the fully connected layer is to combine the learned "local" features into "global" features. The final output is processed by the softmax operation, so that the sum of all elements of the output vector is 1. Thus, each element can be regarded as the prediction probability of the corresponding category, i.e., the probability of the preprocessed picture corresponding to the groove type or the angle weld. The pictures of the welding form determined in the training data set are input into the convolution neural network model for training, and the model parameters are continuously optimized to obtain the trained convolution neural network model. The trained neural network model is then evaluated and optimized by the validation set to timely adjust the hyperparameters to avoid overfitting, and to determine the validated neural network. Based on the validated neural network model, the test set is tested to determine the final neural network model.

[0063] It can be understood that after the image of the to-be-welded position is input into the trained neural network model, the welding form of the to-be-welded position can be recognized. When the welding form is recognized as an angle weld, the third nozzle 4 is driven to extend, and a maximum size nozzle is directly used for welding. When the welding form is recognized as a groove weld, the groove image needs to be collected, and the groove boundary is determined according to the groove image. Then, the nozzle conversion position is determined according to the circumscribed figure of the groove boundary.

[0064] It can be understood that, before welding, the welding part is placed in the to-be-welded area, one end of the to-be-welded area is a welding starting position, the to-be-welded position is identified, when the welding form of the to-be-welded position is identified as a groove weld, the welding equipment is driven to move to the welding starting position, and the welding groove is photographed at the fixed position, wherein the welding groove is photographed at the fixed position to ensure the consistency of the photographed picture, thereby ensuring the accuracy of the calculation of the size of the welding groove. Then, the groove image is processed to determine the groove boundary. Specifically, the groove image is first binarized to obtain a binary image, then the external figure of the groove boundary is determined according to the binary image, and finally the size of the groove is calculated according to the external figure of the groove boundary, and the conversion position of the nozzle is determined.

[0065] As shown in Figures 15 to 18 For a V-shaped groove, the starting point P1, the root point P2 and the virtual point P3 of the groove are obtained according to the external figure of the groove boundary, wherein the virtual point P3 is determined according to the length of P1P2, and the length of P1P2 is equal to the length of P2P3, that is, the external figure of the V-shaped groove boundary is an isosceles triangle. Then, the lengths of the three sides of the isosceles triangle are determined, and the groove angle A is determined in combination with the inverse cosine function: A represents the included angle of the V-shaped groove, a, b and c respectively represent the lengths of the three sides of the external isosceles triangle of the V-shaped groove boundary, a is the base, that is, P1P3, b and c are the waist, that is, P1P2 and P2P3, and b=c. During welding, the welding wire will extend from the nozzle to the root of the groove, and the angle of the welding wire extending from the nozzle is generally located at the position of the angle bisector of the groove angle, and the length of the welding wire extending from the nozzle is called "dry extension", and the normal dry extension is generally ≤12mm, which can ensure the welding quality of the weld, and in the present application, the preset dry extension is 12mm, which can be set according to actual needs. Therefore, under the premise that the dry extension is 12mm, S1 can be calculated in the right triangle with an angle of A / 2, and the calculation formula is: L represents the dry extension, which is generally 12mm, and S1 represents the waist length of the isosceles triangle formed by the first nozzle 2 and the groove when the welding wire extends to the root of the groove. In addition, the ideal outer diameter d1 of the nozzle can also be calculated based on the Pythagorean theorem, and in order to prevent interference, d1 needs to be slightly larger than the outer diameter size n1 of the first nozzle 2, wherein the deviation between d1 and n1 can be set according to actual needs, for example, 0.1mm, 0.2mm, 0.5mm, etc., of course, in the ideal case, d1=n1.

[0066] In addition, according to similar triangles, the following can be calculated:

[0067]

[0068]

[0069] Wherein, n1, n2 and n3 respectively represent the outer diameter of the first nozzle 2, the second nozzle 3 and the third nozzle 4, S2 represents the waist length of the isosceles triangle formed by the second nozzle 3 and the bevel, and S3 represents the waist length of the isosceles triangle formed by the third nozzle 4 and the bevel. Therefore, when the nozzle moves to the S2 position, the second nozzle 3 is driven to extend, and when the nozzle moves to the S3 position, the third nozzle 4 is driven to extend, thereby realizing intelligent replacement of the nozzle size and greatly improving the welding efficiency and welding quality. In addition, d2 needs to be slightly larger than n2, and d3 needs to be slightly larger than n3. The specific deviation can be set according to actual needs, for example, 0.1mm, 0.2mm, 0.5mm, etc. Of course, in an ideal case, the two are equal.

[0070] It can be understood that the present application can calculate the replacement position of the nozzle by calculating the size of the V-shaped groove, thereby realizing intelligent replacement of the nozzle size and greatly improving the welding efficiency and welding quality.

[0071] In addition, as Figure 19 indicated, another embodiment of the present application also provides a welding method, preferably using the welding equipment as described above, comprising the following contents:

[0072] Step S1: collecting the image of the position to be welded;

[0073] Step S2: identifying the welding form according to the image of the position to be welded;

[0074] Step S3: controlling the extension of the nozzle with an adaptive size according to the welding form.

[0075] It can be understood that the welding method of the present embodiment realizes intelligent control of nozzle replacement by photographing the image of the position to be welded, identifying the welding form based on image recognition technology, and driving the nozzle with an adaptive size to extend according to the identified welding form, thereby greatly improving the welding efficiency and welding quality.

[0076] In addition, another embodiment of the present application also provides a welding robot, and the execution end of the welding robot adopts the welding equipment as described above, wherein the control module of the welding equipment can be integrated in the control chip of the welding robot.

[0077] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications to the embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0078] It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the spirit or scope of the application. Thus, it is intended that the present application cover modifications and variations of this application provided they come within the scope of the appended claims and their equivalents.

[0079] The preferred embodiments of the application are described above with reference to the accompanying drawings, and alternative embodiments of the application can be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

Claims

1. A variable diameter nozzle, characterized in that, The welding system includes a conductive nozzle (1), a first nozzle (2), a second nozzle (3), and a third nozzle (4) arranged sequentially from the inside out. The upper end of the conductive nozzle (1) is connected to a rotary drive component and is used to perform a rotary extension and retraction action under the drive of the rotary drive component. A wire feeding hole (11) is provided in the center of the conductive nozzle (1) for automatic wire feeding during the welding process. At least one vent hole (12) is provided in the upper part of the conductive nozzle (1) for providing protective gas during the welding process. The first nozzle (2) is fixedly connected to the conductive nozzle (1) and there is a gap between them. The lower end face of the first nozzle (2) protrudes from the lower end face of the conductive nozzle (1). The second nozzle (3) is connected to the first nozzle (2), and the third nozzle (4) is connected to the second nozzle (3) by threads. Positioning devices (5) are provided on the inner surfaces of the first nozzle (2) and the third nozzle (4). A chamfer is provided on the outer side of the lower end face of the first nozzle (2). A positioning slot (6) is provided on the outer surface of the second nozzle (3). An airflow channel is provided on the first nozzle (2), the second nozzle (3) and the third nozzle (4). During the rotation and extension of the conductive nozzle (1), the positioning device (5) cooperates with the positioning slot (6) or with the chamfer to realize the limiting between the first nozzle (2) and the second nozzle (3) and between the second nozzle (3) and the third nozzle (4), thereby driving any one of the first nozzle (2), the second nozzle (3) and the third nozzle (4) to extend, and realizing the on / off control between the airflow channels of the three nozzles so that protective gas can be provided when different nozzles extend. The airflow channel of the first nozzle (2) includes a first through hole (21), the airflow channel of the second nozzle (3) includes a second through hole (31), a first air passage (32) and a first air outlet (33), and the airflow channel of the third nozzle (4) includes a blind hole (41), a second air passage (42) and a second air outlet (43). The first through hole (21), the second through hole (31) and the blind hole (41) are all opened radially, the first air passage (32) and the second air passage (42) are both opened axially, the second through hole (31) and the first air outlet (33) are respectively the air inlet and air outlet of the first air passage (32), and the blind hole (41) and the second air outlet (43) are respectively the air inlet and air outlet of the second air passage (42). When the first nozzle (2) is extended to the position, the first through hole (21) and the second through hole (31) are not connected, and the protective gas is only sprayed out from the gap between the first nozzle (2) and the conductive nozzle (1); when the second nozzle (3) is extended to the position, the first through hole (21) and the second through hole (31) are connected, and the second through hole (31) and the blind hole (41) are not connected, and the protective gas is sprayed out from the gap between the first nozzle (2) and the conductive nozzle (1) and the first vent hole (33); when the third nozzle (4) is extended to the position, the first through hole (21) and the second through hole (31) and the second through hole (31) are connected, and the second through hole (31) and the blind hole (41) are connected, and the protective gas is sprayed out from the gap between the first nozzle (2) and the conductive nozzle (1), the first vent hole (33) and the second vent hole (43).

2. The variable diameter nozzle as described in claim 1, characterized in that, When the rotary drive rotates forward, the drive conductive nozzle (1) and the first nozzle (2) extend forward together. When the first nozzle (2) extends to the point where the chamfer abuts against the positioning device (5) on the inner surface of the second nozzle (3), the drive second nozzle (3) and third nozzle (4) move relative to each other. When the positioning device (5) on the inner surface of the third nozzle (4) is locked in the positioning slot (6) on the outer surface of the second nozzle (3), the second nozzle (3) and third nozzle (4) stop moving relative to each other. The rotary drive continues to rotate forward, and the chamfer of the first nozzle (2) squeezes the positioning device (5) of the second nozzle (3) and continues to extend.

3. The variable diameter nozzle as described in claim 2, characterized in that, When the rotating drive reverses, the drive conductive nozzle (1) and the first nozzle (2) retract together, so that the second nozzle (3) extends out relative to it.

4. The variable diameter nozzle as described in claim 3, characterized in that, When the rotating drive continues to reverse, the drive conductive nozzle (1) and the first nozzle (2) continue to reverse and retract. When the first nozzle (2) retracts to the end of the thread, it can no longer move. The positioning groove (6) on the outer surface of the second nozzle (3) squeezes the positioning device (5) on the inner surface of the third nozzle (4). The two then move relative to each other, and the second nozzle (3) retracts so that the third nozzle (4) extends relative to each other.

5. A welding device, characterized in that, The device includes a camera (100), a motor (200), a control module, and a variable diameter nozzle as described in any one of claims 1 to 4. The camera (100) is mounted on the variable diameter nozzle to acquire images of the position to be welded. The motor (200) is driven and connected to the variable diameter nozzle to drive any one of the nozzles in the variable diameter nozzle to extend. The control module is electrically connected to the camera (100) and the motor (200) respectively to identify the welding form based on the image of the position to be welded and to control the working state of the motor (200) based on the identified welding form to drive the nozzle of the appropriate size to extend.

6. The welding equipment as described in claim 5, characterized in that, When the welding type is identified as fillet weld, the third nozzle (4) is driven to extend; when the welding type is identified as groove weld, a groove image is acquired, and the groove boundary is determined according to the groove image, and then the nozzle switching position is determined according to the circumscribed shape of the groove boundary.

7. The welding equipment as described in claim 6, characterized in that, For a V-groove, the nozzle switching position is determined based on the following formula: Where A represents the included angle of the V-groove, a, b and c represent the side lengths of the three sides of the circumscribed isosceles triangle of the V-groove boundary, a is the base, b and c are the legs, L represents the extension length, S1 represents the leg length of the isosceles triangle formed by the first nozzle (2) and the groove when the welding wire extends to the root of the groove, S2 represents the leg length of the isosceles triangle formed by the extension position of the second nozzle (3) and the groove, S3 represents the leg length of the isosceles triangle formed by the extension position of the third nozzle (4) and the groove, n1, n2 and n3 represent the outer diameters of the first nozzle (2), the second nozzle (3) and the third nozzle (4) respectively. When the nozzle moves to the S2 position, the second nozzle (3) is driven to extend, and when the nozzle moves to the S3 position, the third nozzle (4) is driven to extend.

8. A welding method, employing the welding equipment as described in any one of claims 5 to 7, characterized in that, Includes the following: Acquire images of the area to be welded; The welding method is identified based on the image of the location to be welded; The nozzle extension is adjusted to the appropriate size according to the welding method.

9. A welding robot, characterized in that, The end effector of the welding robot uses the welding equipment described in any one of claims 5 to 7.

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