Variable-diameter nozzle, welding equipment adopting variable-diameter nozzle, welding method and welding robot

Abstract

The invention discloses a variable-diameter nozzle and welding equipment, a welding method and a welding robot adopting the variable-diameter nozzle, a contact tube, a first nozzle, a second nozzle and a third nozzle which are sequentially sleeved from inside to outside are adopted, the contact tube is in driving connection with a rotary driving part, the first nozzle is fixedly connected with the contact tube, and the second nozzle is fixedly connected with the third nozzle. The second nozzle is in threaded fit with the first nozzle, the third nozzle is in threaded fit with the second nozzle, 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 face of the first nozzle, and a positioning clamping groove is formed in the outer surface of the second nozzle. The positioning device is matched with the positioning clamping groove or the chamfer to drive any one of the three nozzles to stretch out, automatic switching of the nozzles of different sizes is achieved, the welding efficiency and the welding quality are improved, connection and disconnection of airflow channels of the three nozzles can be controlled, protective gas can be provided when the different nozzles stretch out, and the welding quality is improved. And the nozzle is prevented from being blocked in the welding process.

Description

Technical Field

[0001] The present invention relates to the technical field of robot welding, and in particular, to a variable diameter nozzle. In addition, the present invention also particularly relates to a welding device and a welding method, and a welding robot using the variable diameter nozzle. Background Art

[0002] The welding nozzle, also known as the welding gun nozzle, is a key component in welding equipment. Its main function is to allow the shielding gas required for the welding process to flow in a uniform and laminar manner, thereby ensuring that the arc and the weld pool obtain constant shielding gas coverage relative to the atmosphere. In MIG / MAG welding, the nozzle is not only responsible for directing the compressed gas flow into the welding process, but also protects the arc from the surrounding atmosphere, ensuring proper gas flow and shielding gas coverage during the welding process.

[0003] During the welding process, the welding nozzle has different sizes of calibers, corresponding to different grooves. During the welding process, the small-sized nozzle can ensure that the welding wire reaches the root of the welding position smoothly, thereby ensuring the welding quality. However, the small-sized nozzle is easily blocked by welding spatter during the welding process. During the gas shielded welding process, since there is no slag covering the surface of the molten pool, the shielding gas has a strong cooling effect, which makes the molten pool metal solidify faster. If there is no time to escape during the gas shielded welding process, it is easy to produce pores in the weld, affecting the quality and strength of the weld. Although the large-sized nozzle can reduce the risk of nozzle blockage, it is difficult for the large-sized nozzle to reach the root of the weld. Therefore, during the welding process, it is necessary to fill the root of the welding wire with a small-sized nozzle first, and then change to a large-sized nozzle for welding. However, during the robot automatic welding process, due to the high welding speed, it is difficult to replace the large and small nozzles in time in most cases, which will cause the small-sized nozzle to be blocked and the welding quality is difficult to meet the requirements. Summary of the invention

[0004] The present invention provides a variable-diameter nozzle and welding equipment, welding method and welding robot using the same, which can realize automatic conversion of nozzles of different sizes, improve welding efficiency and welding quality, and can provide protective gas when different nozzles are extended to prevent the nozzle from being blocked during welding.

[0005] According to one aspect of the present invention, 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 the inside to the outside, the upper end of the conductive nozzle is connected to a rotary drive member, and is used to perform a rotational telescopic action under the drive of the rotary drive member, a wire feeding hole is provided at the center of the conductive nozzle, which is used to automatically feed the wire during welding, at least one air outlet is provided at the upper part of the conductive nozzle, which is used to provide a shielding gas during welding, the first nozzle is fixedly connected to the conductive nozzle and there is a gap between the two, the lower end surface of the first nozzle protrudes from the lower end surface of the conductive nozzle, the second nozzle is connected to the first nozzle, and the third nozzle is connected to the second nozzle through Threaded connection, positioning devices are provided on the inner surfaces of the second nozzle and the third nozzle, a chamfer is provided on the outer side of the lower end surface of the first nozzle, a positioning slot is provided on the outer surface of the second nozzle, and air flow channels are provided on the first nozzle, the second nozzle and the third nozzle. During the rotation and extension of the conductive nozzle, the positioning device cooperates with the positioning slot or with the chamfer to achieve positioning between the first nozzle and the second nozzle, and between the second nozzle and the third nozzle, thereby driving any one of the first nozzle, the second nozzle and the third nozzle to extend, and realizing on-off control between the air flow channels of the three nozzles, so that protective gas can be provided when different nozzles are extended.

[0006] Further, the air flow channel of the first nozzle includes a first through hole, the air flow channel of the second nozzle includes a second through hole, a first air path and a first air outlet, the air flow channel of the third nozzle includes a blind hole, a second air path and a second air outlet, the first through hole, the second through hole and the blind hole are all opened in the radial direction, the first air path and the second air path are both opened in the axial direction, the second through hole and the first air outlet are respectively the air inlet and the air outlet of the first air path, and the blind hole and the second air outlet are respectively the air inlet and the air outlet of the second air path;

[0007] When the first nozzle is extended into place, the first through hole and the second through hole are not connected, and the shielding gas is ejected only from the gap between the first nozzle and the conductive nozzle; when the second nozzle is extended into place, the first through hole and the second through hole are connected, and the second through hole and the blind hole are not connected, and the shielding gas is ejected from the gap between the first nozzle and the conductive nozzle and the first air outlet at the same time; when the third nozzle is extended into place, the first through hole and the second through hole, and the second through hole and the blind hole are all connected, and the shielding gas is ejected from the gap between the first nozzle and the conductive nozzle, the first air outlet, and the second air outlet at the same time.

[0008] Furthermore, when the rotary drive member rotates forward, the conductive nozzle and the first nozzle are driven to rotate forward and extend together. When the first nozzle is extended until the chamfer abuts against the positioning device on the inner surface of the second nozzle, the second nozzle and the third nozzle are driven to move relative to each other. When the positioning device on the inner surface of the third nozzle is stuck in the positioning groove on the outer surface of the second nozzle, the second nozzle and the third nozzle stop relative movement, the rotary drive member continues to rotate forward, and the chamfer of the first nozzle squeezes the positioning device of the second nozzle and then continues to extend.

[0009] Furthermore, when the rotary drive member is reversed, the conductive nozzle and the first nozzle are driven to reverse and retract together, so that the second nozzle is relatively extended.

[0010] Furthermore, when the rotary drive member continues to reverse, the driving conductive nozzle and the first nozzle continue to reverse and retract. When the first nozzle retracts to the end of the thread and cannot move further, the positioning groove on the outer surface of the second nozzle squeezes the positioning device on the inner surface of the third nozzle, and the two move relative to each other. The second nozzle retracts to allow the third nozzle to extend relatively.

[0011] In addition, the present invention also provides a welding device, including a camera, a motor, a control module and the variable diameter nozzle as described above, wherein the camera is installed on the variable diameter nozzle and is used to collect images of the position to be welded, the motor is connected to the variable diameter nozzle driving device and is used to drive any one of the variable diameter nozzles to extend, and the control module is electrically connected to the camera and the motor, respectively, and is used to identify the welding form according to the image of the position to be welded, and control the working state of the motor according to the identified welding form to drive the nozzle of an adapted size to extend.

[0012] Furthermore, 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, the groove image is collected, and the groove boundary is determined based on the groove image, and then the nozzle conversion position is determined based on the circumscribed figure of the groove boundary.

[0013] Furthermore, for the V-groove, the nozzle switching position is determined based on the following formula:

[0014]

[0015]

[0016]

[0017]

[0018] Wherein, A represents the angle of the V-shaped groove, a, b and c represent the lengths of the three sides of the circumscribed isosceles triangle of the boundary of the V-shaped groove, a represents the base, b and c represent the waist, L represents the dry extension length, S represents the welding wire filling thickness, 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 welding wire filling thickness reaches S2, the second nozzle (3) is driven to extend, and when the welding wire filling thickness reaches S3, the third nozzle (4) is driven to extend.

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

[0020] Acquire an image of the location to be welded;

[0021] Identify the welding form based on the image of the position to be welded;

[0022] The nozzle extension is controlled to the appropriate size according to the welding form.

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

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

[0025] The variable diameter nozzle of the present invention adopts a conductive nozzle, a first nozzle, a second nozzle and a third nozzle which are sequentially sleeved from the inside to the outside, the conductive nozzle is driven and connected to the rotary driving member, the first nozzle is fixedly connected to the conductive nozzle, the second nozzle is threadedly matched with the first nozzle, and the third nozzle is threadedly matched with the second nozzle, and a positioning device is provided on the inner surface of the second nozzle and the third nozzle, a chamfer is provided on the outer side of the lower end surface of the first nozzle, and a positioning groove is provided on the outer surface of the second nozzle. During the driving and rotating process of the rotary driving member, the positioning device cooperates with the positioning groove or with the chamfer to achieve the limitation between the first nozzle and the second nozzle, and between the second nozzle and the third nozzle, so as to drive any one of the first nozzle, the second nozzle and the third nozzle to extend, thereby realizing the automatic conversion of nozzles of different sizes, improving the welding efficiency and welding quality, and controlling the on-off of the air flow channels of the three nozzles, so that protective gas can be provided when different nozzles are extended, and the nozzles are prevented from being blocked during welding.

[0026] In addition, the welding equipment of the present invention can identify the welding form based on image recognition technology by taking an image of the welding position, and automatically control the working state of the motor according to the identified welding form to drive the nozzle of the appropriate size to extend, thereby realizing intelligent control of nozzle replacement and greatly improving welding efficiency and welding quality.

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

[0028] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

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

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

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

[0033] Figure 4 It is a schematic structural diagram of a conductive nozzle according to a preferred embodiment of the present application.

[0034] Figure 5 It is a schematic structural diagram of a preferred embodiment of the present application in which the conductive nozzle is fixedly connected to the first nozzle.

[0035] Figure 6 It is a structural schematic diagram of a positioning device according to a preferred embodiment of the present application.

[0036] Figure 7 yes Figure 1 Enlarged schematic diagram of point Ⅰ in the middle.

[0037] Figure 8 It is a structural schematic diagram of the positioning device of the preferred embodiment of the present application being stuck in the positioning groove.

[0038] Fig. 9 It 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] Fig.10 It 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] Fig.11 It 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] Fig.12 yes Fig.11 Enlarged schematic diagram of point II in the middle.

[0042] Fig.13 This is a structural schematic diagram of another embodiment of the present application in which a welding device is installed at the end of a welding robot.

[0043] Fig.14 yes Fig.13 Enlarged schematic diagram of point III in the middle.

[0044] Fig.15 It is a schematic diagram of the principle of a welding device according to another embodiment of the present application when calculating the nozzle conversion position of a V-groove.

[0045] Fig.16 It is a schematic diagram of a welding device according to another embodiment of the present application using a first nozzle for welding.

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

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

[0048] Fig.19 It is a schematic flow chart of a welding method according to another embodiment of the present application.

[0049] Description of Reference Numerals

[0050] 1. Conductive nozzle; 2. First nozzle; 3. Second nozzle; 4. Third nozzle; 5. Positioning device; 6. Positioning slot; 11. Wire feeding hole; 12. Air outlet; 21. First through hole; 31. Second through hole; 32. First air path; 33. First air outlet; 41. Blind hole; 42. Second air path; 43. Second air outlet; 51. Ball; 52. Elastic member; 100. Camera; 200. Motor. DETAILED DESCRIPTION

[0051] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0052] Reference Figures 1 to 5As shown, a preferred embodiment of the present application provides a variable diameter nozzle, which includes a conductive nozzle 1, a first nozzle 2, a second nozzle 3 and a third nozzle 4 which are sequentially sleeved from the inside to the outside, the upper end of the conductive nozzle 1 is connected to a rotary drive member, and is used to perform a rotational telescopic action under the drive of the rotary drive member, wherein the rotary drive member can be a motor or an electric motor, preferably a motor. A wire feeding hole 11 is provided at the center of the conductive nozzle 1, which is used to automatically feed the welding wire during the welding process, and at least one gas outlet 12 is provided at the upper part of the conductive nozzle 1, which is used to provide a shielding gas during the welding process, wherein the internal gas path of the conductive nozzle 1 is also connected to an external shielding gas source, and the shielding gas provided by the shielding gas source is ejected from the gas outlet 12. The first nozzle 2 is fixedly connected to the conductive nozzle 1 and there is a gap between the two, 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 is connected to the first nozzle 2, and the third nozzle 4 is connected to the second nozzle 3 by threads. Specifically, the outer surfaces of the first nozzle 2 and the second nozzle 3 are provided with external threads, and the inner surfaces of the second nozzle 3 and the third nozzle 4 are provided with internal threads. Positioning devices 5 are provided on the inner surfaces of the second nozzle 3 and the third nozzle 4. The outer side of the lower end surface of the first nozzle 2 is provided with a chamfer, and the outer surface of the second nozzle 3 is provided with a positioning slot 6. The first nozzle 2, the second nozzle 3 and the third nozzle 4 are all provided with air flow channels. 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 achieve the limit between the first nozzle 2 and the second nozzle 3, and between the second nozzle 3 and the third nozzle 4, so as to drive any one of the first nozzle 2, the second nozzle 3 and the third nozzle 4 to extend, and realize the on-off control between the air flow channels of the three nozzles, so that protective gas can be provided when different nozzles are extended, protection is provided during the welding process, and the nozzles can be prevented from being blocked during the welding process. Specifically, when the first nozzle 2 is extended, the shielding gas is ejected only from the gap between the first nozzle 2 and the conductive nozzle 1; when the second nozzle 3 is extended, the shielding gas is ejected from both the gap between the first nozzle 2 and the conductive nozzle 1 and the air flow channel of the second nozzle 3; when the third nozzle 4 is extended, the shielding gas is ejected from both the gap between the first nozzle 2 and the conductive nozzle 1 and the air flow channels of the second nozzle 3 and the third nozzle 4.

[0053] It can be understood that the variable diameter nozzle of the present embodiment adopts a conductive nozzle 1, a first nozzle 2, a second nozzle 3 and a third nozzle 4 which are sequentially sleeved from the inside to the outside, the conductive nozzle 1 is driven and connected to the rotary drive member, the first nozzle 2 is fixedly connected to the conductive nozzle 1, the second nozzle 3 is threadedly engaged with the first nozzle 2, and the third nozzle 4 is threadedly engaged with the second nozzle 3, and a positioning device 5 is provided on the inner surface of the second nozzle 3 and the third nozzle 4, a chamfer is provided on the outer side of the lower end surface of the first nozzle 2, and a positioning groove 6 is provided on the outer surface of the second nozzle 3. During the driving and rotating process of the rotary drive member, the positioning device 5 cooperates with the positioning groove 6 or with the chamfer to achieve the limit between the first nozzle 2 and the second nozzle 3, and between the second nozzle 3 and the third nozzle 4, so as to drive any one of the first nozzle 2, the second nozzle 3 and the third nozzle 4 to extend, thereby realizing the automatic conversion of nozzles of different sizes, improving the welding efficiency and welding quality, and controlling the on-off of the air flow channels of the three nozzles, so that protective gas can be provided when different nozzles are extended to prevent the nozzles from being blocked during welding.

[0054] It is understandable that Figures 6 to 8 As shown, the positioning device 5 includes a ball 51 and an elastic member 52. A mounting hole is provided on the inner surface of the second nozzle 3 and the third nozzle 4. The 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 ball 51. When the ball 51 is not under pressure, the elastic member 52 is in a free state, and the ball 51 slightly protrudes from the inner surface of the second nozzle 3 and the third nozzle 4. When the ball 51 is squeezed, the elastic member 52 is in a compressed state, and the ball 51 is tangent to the inner surface of the second nozzle 3 and the third nozzle 4. Among them, two positioning devices 5 are provided on the inner surface of the second nozzle 3, and four positioning devices 5 are provided on the inner surface of the third nozzle 4. The number of the positioning slots 6 matches the number of the positioning devices 5 on the inner surface of the third nozzle 4.

[0055] It can be understood that when the rotary drive member rotates forward, since the conductive nozzle 1 is connected to the rotary drive member and the first nozzle 2 is fixedly connected to the conductive nozzle 1, the conductive nozzle 1 and the first nozzle 2 are driven to rotate forward and extend together. When the first nozzle 2 extends to the point where its chamfer abuts against the positioning device 5 on the inner surface of the second nozzle 3, the ball 51 of 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 ball 51 of 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 is pressed into the mounting hole and tangent to the inner surface of the third nozzle 4. 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 relative to the first nozzle 2 and the third nozzle 4, and the 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 stuck in the positioning slot 6 on the outer surface of the second nozzle 3, there is a limit between the second nozzle 3 and the third nozzle 4, and the second nozzle 3 and the third nozzle 4 stop relative movement. Since the positioning device 5 on the third nozzle 4 has four locations without chamfers, while the positioning device 5 on the second nozzle 3 has only two locations with chamfers, the rotational force can more easily drive the thread between the first nozzle 2 and the second nozzle 3 to rotate. When the rotary drive continues to rotate forward, it will drive the first nozzle 2 to continue to extend. The chamfer on the first nozzle 2 will squeeze the ball 51 of the positioning device 5 on the inner surface of the second nozzle 3 and continue to extend. After the rotary drive rotates forward for a preset number of times, the first nozzle 2 extends into place.

[0056] In addition, when it is necessary to switch to extending the second nozzle 3, the rotary drive member is controlled to reverse. Since 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, the threads between the first nozzle 2 and the second nozzle 3 are more likely to move relative to each other. The rotary drive member will drive the conductive nozzle 1 and the first nozzle 2 to reverse and retract together, so that the second nozzle 3 is relatively extended. After the rotary drive member reverses a preset number of times, the second nozzle 3 is extended into place.

[0057] In addition, when it is necessary to switch to the extension of the third nozzle 4, the control of the rotary drive member continues to reverse, which will drive the conductive nozzle 1 and the first nozzle 2 to continue to reverse and retract. When the first nozzle 2 retracts to the end of the thread and cannot continue to move, the rotational force will overcome the limit between the positioning device 5 and the positioning slot 6. The positioning slot 6 on the outer surface of the second nozzle 3 will squeeze the ball 51 of the positioning device 5 on the inner surface of the third nozzle 4, so that the two move relative to each other, driving the second nozzle 3 to retract so that the third nozzle 4 extends relatively. After the rotary drive member reverses the preset number of circles, the third nozzle 4 extends into place. It can be understood that the extension of the third nozzle 4 is relative, 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 is understandable that Figures 9 to 12 As shown, the air flow channel of the first nozzle 2 includes a first through hole 21, the air flow channel of the second nozzle 3 includes a second through hole 31, a first air path 32 and a first air outlet 33, and the air flow channel of the third nozzle 4 includes a blind hole 41, a second air path 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 in the radial direction, the first air path 32 and the second air path 42 are both opened in the axial direction, the second through hole 31 and the first air outlet 33 are respectively the air inlet and the air outlet of the first air path 32, and the blind hole 41 and the second air outlet 43 are respectively the air inlet and the air outlet of the second air path 42. When the first nozzle 2 is extended to the full position, the first through hole 21 is not connected to the second through hole 31, that is, the first through hole 21 and the second through hole 31 are misaligned, and the shielding gas cannot flow from the first through hole 21 into the air flow channel of the second nozzle 3. The shielding gas is ejected from the air outlet of the conductive nozzle 1 and fills the cavity between the conductive nozzle 1 and the first nozzle 2, and is ejected only from the gap between the first nozzle 2 and the conductive nozzle 1. When the second nozzle 3 is extended to the full position, the first through hole 21 is connected to the second through hole 31, and the second through hole 31 and the blind hole 41 are not connected, that is, the first through hole 21 and the second through hole 31 are aligned, and the second through hole 31 and the blind hole 41 are misaligned. The shielding gas flows from the first through hole 21 into the air flow channel of the second nozzle 3, but does not continue to flow into the air flow channel of the third nozzle 4. The shielding gas is ejected from the gap between the first nozzle 2 and the conductive nozzle 1 and the first air outlet 33 at the same time. When the third nozzle 4 is extended into place, the first through hole 21 and the second through hole 31, as well as the second through hole 31 and the blind hole 41 are all connected, that is, the first through hole 21, the second through hole 31 and the blind hole 41 are aligned, and the shielding gas flows into the air flow channels of the second nozzle 3 and the third nozzle 4 in sequence through the first through hole 21, and the shielding gas is simultaneously ejected from the gap between the first nozzle 2 and the conductive nozzle 1, the first air outlet 33 and the second air outlet 43.

[0059] In addition, if Fig.13 and Fig.14As shown, another embodiment of the present invention further provides a welding device, which includes a camera 100, a motor 200, a control module and the variable diameter nozzle as described above, wherein the camera 100 is installed on the variable diameter nozzle for collecting images of the position to be welded, the motor 200 is connected to the variable diameter nozzle driving, and is used to drive any nozzle of the variable diameter nozzle to extend, and the control module is electrically connected to the camera 100 and the motor 200 respectively, and is used to identify the welding form according to the image of the position to be welded, and control the working state of the motor 200 according to the identified welding form, so as to drive the nozzle of the adapted size to extend. Among them, the welding device can be used as the execution end of a welding robot, or installed on other automatic welding devices, so as to automatically switch the nozzle size.

[0060] It can be understood that the welding equipment of the present invention can identify the welding form based on image recognition technology by taking an image of the position to be welded, and automatically control the working state of the motor 200 according to the identified welding form to drive the nozzle of the appropriate size to extend, thereby realizing intelligent control of nozzle replacement and greatly improving welding efficiency and welding quality.

[0061] It can be understood that the control module stores a trained neural network model, and the captured image of the position to be welded is input into the neural network model, so that the welding form can be automatically identified. Specifically, a number of historical photos of the position to be welded are first obtained, and the historical photos of the position to be welded include different welding forms, wherein the welding forms include: fillet welds and groove welds, and the groove welds include V-shaped grooves, U-shaped grooves, X-shaped grooves, K-shaped grooves, J-shaped grooves, etc. The historical photos of the position to be welded are subjected to noise reduction processing to remove the noise in the image and improve the image quality. Specifically, the noise reduction processing can be performed by means of mean filtering, Gaussian filtering, and median filtering. In addition, the image after the noise reduction processing is normalized, the image data is scaled to a uniform range, the image data is standardized, the differences between the images are eliminated, and the images are more suitable for comparison and analysis. Specifically, the normalization processing can be performed by methods such as logarithmic normalization and decimal calibration normalization. Then, the normalized picture is resized to a uniform size, thereby determining the pre-processed photo. Finally, the pre-processed photos are divided into training set, validation set and test set according to a preset ratio to train the neural network model. The neural network model can use ResNet-50 network or Swin Transformer network to extract features through convolutional neural network model.

[0062] It can be understood that the neural network model specifically includes an input layer, a convolution layer, a pooling layer, a fully connected layer, and an output layer. The input layer is used to input training set images. The image data can be a uniform size of 64×64×3. The formula of the convolution layer is: Oij is an element of the convolutional layer output feature map, I is the input image, K is the convolution kernel or filter, b is the bias term, and m and n are the spatial sizes of the convolution kernel. The convolution layer receives the image data of the input layer and contains 16 5×5 convolution kernels. Each convolution kernel can perform a convolution operation on the input image data and output 16 60×60 feature maps. Specifically, the first convolution layer performs the first convolution operation on the input image data, using 16 convolution kernels of size 5×5 to obtain 16 feature maps of size 60×60. There are 416 parameters and 576,000 connections in total. The formula for the pooling layer is: ij =max(I 2i:2i+1,2j:2j+1 ), O ij is an element of the feature map output by the pooling layer, I is the input image, and illustratively, a 4×4 maximum pooling operation is performed on the convolutional feature map to obtain 16 30×30 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×I+b, O is an element of the fully connected layer output, W is the weight matrix, I is the input vector, and b is the bias vector. After the above process, each image in the input training data set is flattened into a one-dimensional vector (16×30×30=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 a softmax operation so that the sum of all elements of the output vector is 1, so that each element can be regarded as the predicted probability of the corresponding category, that is, the probability that the preprocessed image corresponds to the groove type or fillet weld. The images of determined welding forms in the training data set are input into the convolutional neural network model for training, and the model parameters are continuously optimized to obtain the trained convolutional neural network model; the trained neural network model is then evaluated and optimized through the validation set, and the hyperparameters are adjusted in time to avoid overfitting to determine the verified neural network; the verified neural network model is tested through the test set to determine the final neural network model.

[0063] It can be understood that after the image of the position to be welded is input into the trained neural network model, the welding form of the position to be welded can be identified. When the welding form is identified as a fillet weld, the third nozzle 4 is driven to extend, and the maximum size nozzle is directly used for welding. When the welding form is identified as a groove weld, it is necessary to collect the groove image, determine the groove boundary based on the groove image, and then determine the nozzle conversion position based on the external graphic of the groove boundary.

[0064] It can be understood that before welding, the weldment is first placed in the area to be welded, wherein one end of the area to be welded is the welding starting position, and the position to be welded is identified. When it is identified that the welding form of the position to be welded is a groove weld, the welding equipment is driven to move to the welding starting position, and the welding groove is photographed at a fixed position, wherein the groove is photographed at a fixed position to ensure the consistency of the photographs, thereby ensuring the accuracy of the groove size calculation. Then, the groove image is processed to determine the groove boundary. Specifically, the groove image is first binarized to obtain a binarized image, and then the circumscribed figure of the groove boundary is determined based on the binarized image. Finally, the groove size is calculated based on the circumscribed figure of the groove boundary, and the conversion position of the nozzle is determined.

[0065] Among them, Figures 15 to 18 As shown, 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, where 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, determine the length of the three sides of the isosceles triangle, and then combine the arccosine function to determine the groove angle A: A represents the angle of the V-groove, a, b and c represent the lengths of the three sides of the circumscribed isosceles triangle of the V-groove boundary, a is the base, i.e. P1P3, b and c are the waists, i.e. P1P2 and P2P3, and b=c. During the welding process, the welding wire will extend from the nozzle to the root of the groove, and the angle at which the welding wire extends is generally located at the position of the angle bisector of the groove angle. The length of the welding wire extending from the nozzle is called "dry extension length". The normal dry extension length is generally ≤12mm, which can ensure the welding quality of the weld. In the present invention, the preset dry extension length is 12mm, which can be set according to actual needs. Therefore, under the premise that the dry extension length is 12mm, S1 can be calculated in a right triangle with an angle of A / 2, and the calculation formula is: L represents the dry extension length, which is generally 12 mm, 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. In order to prevent interference, d1 needs to be slightly larger than the outer diameter n1 of the first nozzle 2. The deviation between d1 and n1 can be set according to actual needs, for example, 0.1 mm, 0.2 mm, 0.5 mm, etc. Of course, in an ideal case, d1 = n1.

[0066] In addition, according to similar triangles, we can calculate:

[0067]

[0068]

[0069] Among them, n1, n2 and n3 represent the outer diameters of the first nozzle 2, the second nozzle 3 and the third nozzle 4 respectively, S2 represents the waist length of the isosceles triangle formed by the extended position of the second nozzle 3 and the groove, and S3 represents the waist length of the isosceles triangle formed by the extended position of the third nozzle 4 and the groove. 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 the intelligent replacement of the nozzle size, 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, set to 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 invention can calculate the replacement position of the nozzle by calculating the size of the V-groove, thereby realizing intelligent replacement of the nozzle size and greatly improving the welding efficiency and welding quality.

[0071] In addition, if Fig.19 As shown, another embodiment of the present invention further provides a welding method, preferably using the welding device as described above, comprising the following contents:

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

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

[0074] Step S3: Control the nozzle of the appropriate size to extend according to the welding form.

[0075] It can be understood that the welding method of this embodiment, by taking an image of the position to be welded, identifies the welding form based on image recognition technology, and drives the nozzle of appropriate size to extend according to the identified welding form, thereby realizing intelligent control of nozzle replacement and greatly improving welding efficiency and welding quality.

[0076] In addition, another embodiment of the present invention further provides a welding robot, 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 into the control chip of the welding robot.

[0077] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned 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] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A variable diameter nozzle, characterized in that: The welding device comprises a conductive nozzle (1), a first nozzle (2), a second nozzle (3) and a third nozzle (4) which are sequentially sleeved from the inside to the outside. The upper end of the conductive nozzle (1) is connected to a rotary drive member and is used to perform a rotary telescopic action under the drive of the rotary drive member. A wire feeding hole (11) is provided at the center of the conductive nozzle (1) for automatically feeding wire during welding. At least one gas outlet hole (12) is provided at the upper part of the conductive nozzle (1) for providing protective gas during welding. The first nozzle (2) is fixedly connected to the conductive nozzle (1) with a gap therebetween. The lower end surface of the first nozzle (2) protrudes from the lower end surface 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. The second nozzle ( A positioning device (5) is provided on the inner surface of each of the first and second nozzles (3) and the third nozzle (4); a chamfer is provided on the outer side of the lower end surface of the first nozzle (2); a positioning slot (6) is provided on the outer surface of the second nozzle (3); and air flow channels are provided on each of 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 achieve position 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 on-off control between the air flow channels of the three nozzles, so that protective gas can be provided when different nozzles are extended.

2. The variable diameter nozzle according to claim 1, characterized in that: The air flow channel of the first nozzle (2) comprises a first through hole (21), the air flow channel of the second nozzle (3) comprises a second through hole (31), a first air path (32) and a first air outlet (33), the air flow channel of the third nozzle (4) comprises a blind hole (41), a second air path (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 in a radial direction, the first air path (32) and the second air path (42) are both opened in an axial direction, the second through hole (31) and the first air outlet (33) are respectively an air inlet and an air outlet of the first air path (32), and the blind hole (41) and the second air outlet (43) are respectively an air inlet and an air outlet of the second air path (42); When the first nozzle (2) is extended into position, the first through hole (21) and the second through hole (31) are not connected, and the protective gas is ejected only from the gap between the first nozzle (2) and the conductive nozzle (1); when the second nozzle (3) is extended into 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 ejected from the gap between the first nozzle (2) and the conductive nozzle (1) and the first gas outlet hole (33) at the same time; when the third nozzle (4) is extended into position, the first through hole (21) and the second through hole (31) and the second through hole (31) and the blind hole (41) are both connected, and the protective gas is ejected from the gap between the first nozzle (2) and the conductive nozzle (1), the first gas outlet hole (33) and the second gas outlet hole (43) at the same time.

3. The variable diameter nozzle according to claim 1, characterized in that: When the rotary drive member rotates forward, the conductive nozzle (1) and the first nozzle (2) are driven to rotate forward and extend together. When the first nozzle (2) extends to the point where the chamfer contacts the positioning device (5) on the inner surface of the second nozzle (3), the second nozzle (3) and the third nozzle (4) are driven to move relative to each other. When the positioning device (5) on the inner surface of the third nozzle (4) is stuck in the positioning groove (6) on the outer surface of the second nozzle (3), the second nozzle (3) and the third nozzle (4) stop moving relative to each other. The rotary drive member 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.

4. The variable diameter nozzle according to claim 3, characterized in that: When the rotary drive member is reversed, the conductive nozzle (1) and the first nozzle (2) are driven to reverse and retract together, so that the second nozzle (3) is relatively extended.

5. The variable diameter nozzle according to claim 4, characterized in that: When the rotary drive member continues to reverse, the conductive nozzle (1) and the first nozzle (2) are driven to continue to reverse and retract. When the first nozzle (2) retracts to the end of the thread and cannot move further, 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), and the two move relative to each other. The second nozzle (3) retracts, so that the third nozzle (4) extends relatively.

6. A welding device, characterized in that: The invention comprises a camera (100), a motor (200), a control module and a variable diameter nozzle as claimed in any one of claims 1 to 5, wherein the camera (100) is mounted on the variable diameter nozzle and is used to collect an image of a position to be welded, the motor (200) is connected to the variable diameter nozzle driving device and is used to drive any one of the variable diameter nozzles to extend, and the control module is electrically connected to the camera (100) and the motor (200) respectively and is used to identify a welding form according to the image of the position to be welded, and control the working state of the motor (200) according to the identified welding form, so as to drive a nozzle of an adapted size to extend.

7. The welding device according to claim 6, characterized in that When the welding form is identified as a fillet weld, the third nozzle (4) is driven to extend; when the welding form is identified as a groove weld, a groove image is collected, and the groove boundary is determined based on the groove image, and then the nozzle conversion position is determined based on the circumscribed figure of the groove boundary.

8. The welding device according to claim 7, characterized in that For V-grooves, the nozzle switching position is determined based on the following formula: Wherein, A represents the angle of the V-shaped groove, a, b and c represent the lengths of the three sides of the circumscribed isosceles triangle of the boundary of the V-shaped groove, a represents the base, b and c represent the waist, L represents the dry extension length, S1 represents the waist length of the isosceles triangle formed by the first nozzle (2) and the groove when the welding wire is extended to the root of the groove, S2 represents the waist length of the isosceles triangle formed by the extended position of the second nozzle (3) and the groove, S3 represents the waist length of the isosceles triangle formed by the extended 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.

9. A welding method, using the welding equipment according to any one of claims 6 to 8, characterized in that: Includes the following: Collecting images of the position to be welded; Identify the welding form based on the image of the position to be welded; The nozzle extension is controlled to the appropriate size according to the welding form.

10. A welding robot, characterized in that: The execution end of the welding robot adopts the welding equipment as described in any one of claims 6 to 8.

Images