A welding process of a welding robot on site of a spherical tank, the spherical tank and welding equipment

Abstract

The application discloses a kind of welding processes of welding robot in the field of spherical tank, and welding robot includes first travel wheel and second travel wheel, first travel wheel and second travel wheel are separately arranged in the direction of welding robot to two sides;Welding process includes: sending welding instruction, control welding robot to carry out scanning on the weld of spherical tank, determine the welding path along weld;Determine the first travel distance of first travel wheel and the second travel distance of second travel wheel based on welding path;Determine travel distance difference, according to travel distance difference control welding time of welding robot, so that the welding filling amount of weld relative two sides is equal.The application also discloses a kind of spherical tank and welding equipment.The application is according to the travel distance difference value of travel wheel in the two sides of welding robot, adjusts the welding time of welding robot in the left and right sides of weld, balances the welding filling amount of left and right sides of weld, so that the forming thickness of left and right sides of weld is consistent.

Description

Technical Field

[0001] This application belongs to the field of pressure vessel welding technology, specifically relating to a welding process of a welding robot for on-site welding of spherical tanks, the spherical tank, and welding equipment. Background Technology

[0002] Existing spherical tanks typically include an upper electrode plate, an equatorial zone, and a lower electrode plate, with manholes also provided on the upper and lower electrode plates. In recent years, welding robots have been introduced into the field for welding spherical tanks. However, when using welding robots to weld the upper electrode plate, uneven filling of the weld seams (non-equatorial ring welds), such as the weld seams on both sides of the manhole and the square weld seams, occurs on the left and right sides of the weld seam. Summary of the Invention

[0003] The purpose of this application is to provide a welding process for a welding robot on-site for spherical tanks, so as to solve the problem of uneven filling on the left and right sides of the weld when the welding robot welds a ring-shaped weld.

[0004] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0005] According to one aspect of the embodiments of this application, this application provides a welding process for a welding robot on-site for spherical tanks. The welding robot includes a first traveling wheel and a second traveling wheel, which are respectively disposed on both sides of the direction of travel of the welding robot. The welding process is used for welding spherical tanks.

[0006] The welding process includes:

[0007] Send welding instructions to control the welding robot to scan the weld seam on the spherical tank and determine the welding path along the weld seam;

[0008] The first travel distance of the first traveling wheel and the second travel distance of the second traveling wheel are determined based on the welding path.

[0009] The travel distance difference is determined based on the first travel distance and the second travel distance, and the welding time of the welding robot is controlled according to the travel distance difference to make the welding filler amount on both sides of the weld seam equal.

[0010] The welding process described above includes a latitudinal seam distributed along the latitude of the spherical tank. The latitudinal seam includes a short annular surface and a long annular surface. The first traveling wheel is located on one side of the long annular surface, and the second traveling wheel is located on one side of the short annular surface.

[0011] The step of controlling the welding time of the welding robot based on the travel distance difference to ensure that the weld filler volume on both sides of the weld is equal includes:

[0012] The welding time difference between the long annular surface and the short annular surface is determined based on the travel distance difference, and the welding fill amount on one side of the long annular surface is increased according to the welding time difference.

[0013] The welding process, wherein the first travel distance is defined as L1, the second travel distance as L2, the single-pass weld thickness is h, the weld pool width is d, and the welding filler volume per unit time is m, satisfies:

[0014] The welding time difference

[0015] The welding process described herein, wherein the step of increasing the weld filler amount on one side of the long annular surface based on the welding time difference includes:

[0016] The dwell time of the welding robot's welding torch on one side of the long annular surface is increased according to the welding time difference;

[0017] The increased dwell time is combined with the welding filler amount per unit time to obtain the increment of welding filler amount on one side of the long annular surface.

[0018] The welding process described herein further includes:

[0019] Determine the posture of the welding robot on the spherical tank, including flat welding posture, flat climbing posture, overhead welding posture, overhead climbing posture and vertical welding posture;

[0020] Based on the posture, a working mode switching instruction is generated, which includes switching between flat welding mode, flat ramp mode, overhead welding mode, overhead ramp mode, and vertical welding mode.

[0021] In the flat welding mode, the swing amplitude of the welding torch is set to X1; in the flat ramp mode, the swing amplitude of the welding torch is set to X2; in the vertical welding mode, the swing amplitude of the welding torch is set to X3; in the overhead ramp mode, the swing amplitude of the welding torch is set to X4; and in the overhead welding mode, the swing amplitude of the welding torch is set to X5. Therefore, the following condition is satisfied: X1 > X2 > X3 > X4 > X5.

[0022] The welding process described herein, wherein the welding robot includes an attitude sensor, and the step of determining the attitude of the welding robot on the spherical tank includes:

[0023] The welding robot is controlled to acquire its posture on the spherical tank via the posture sensor; or

[0024] The welding robot is controlled to acquire remote posture commands, and the posture of the welding robot on the spherical tank is controlled based on the remote posture commands.

[0025] The welding process described herein includes a weld seam that is distributed along the longitude of the spherical tank. The longitude seam includes a first welding section, a second welding section, and a third welding section. The first welding section is located at the upper part of the spherical tank, the third welding section is located at the lower part of the spherical tank, and the second welding section is located between the first welding section and the third welding section.

[0026] The welding process includes:

[0027] Determine that the welding robot is located in the first welding section, and control the welding robot to move from the lower end to the upper end of the first welding section and weld;

[0028] Determine that the welding robot is located in the second welding section, and control the welding robot to move from the lower end to the upper end of the second welding section and weld;

[0029] The welding robot is located in the third welding section, and the welding robot is controlled to move from the lower end to the upper end of the third welding section and weld.

[0030] The welding process, prior to the step of controlling the welding robot to move from the lower end to the upper end of the first welding segment and weld, further includes: setting the welding gun swing amplitude of the welding robot to Y1 and the welding speed to Z1.

[0031] Before the step of controlling the welding robot to move from the lower end to the upper end of the second welding section and weld, the method further includes: setting the welding gun swing amplitude of the welding robot to Y2 and the welding speed to Z2.

[0032] Before the step of controlling the welding robot to move from the lower end to the upper end of the third welding segment and weld, the method further includes: setting the welding gun swing amplitude of the welding robot to Y3 and the welding speed to Z3.

[0033] Among them, Y1>Y2>Y3 and Z1>Z2>Z3 are satisfied.

[0034] In a second aspect of the present invention, a spherical tank is welded using any of the welding processes described in the first aspect above. The spherical tank includes a lower latitude seam, the bevel of which includes an upper bevel angle and a lower bevel angle, wherein the upper bevel angle is greater than the lower bevel angle.

[0035] In a third aspect of the invention, there is a welding apparatus comprising a welding robot and a control terminal, wherein the welding robot is configured to receive welding instructions from the control terminal and execute the welding process of any of the on-site welding robots for spherical tanks as described in the first aspect.

[0036] The present invention has the following beneficial effects:

[0037] As the welding robot moves along the welding path, the welding time on both sides of the weld is controlled by the difference in the travel distance of the two travel wheels on either side of the welding robot during the oscillating welding process. By adjusting the welding time, the amount of welding filler on both sides of the weld is balanced, making the forming thickness on both sides of the weld more consistent. This solves the problem of uneven filler on both sides of the weld when welding a ring-shaped weld in the prior art.

[0038] It should be understood in this application that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this application. Attached Figure Description

[0039] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0040] Figure 1 The schematic diagram illustrates the welding process of a welding robot for on-site welding of a spherical tank according to this application;

[0041] Figure 2 The schematic diagram illustrates step S120 of the welding process of a welding robot for on-site welding of a spherical tank according to this application;

[0042] Figure 3 The schematic diagram illustrates step S122 of the welding process of a welding robot for on-site welding of a spherical tank according to this application;

[0043] Figure 4 This illustration shows a schematic diagram of the working mode switching of a welding process of a welding robot at a spherical tank site according to this application;

[0044] Figure 5 This illustration shows a longitudinal seam welding diagram of a welding robot used in the on-site welding of a spherical tank, as described in this application.

[0045] Figure 6This illustration shows a schematic diagram of the longitude seam welding process of a welding robot used in the on-site welding of a spherical tank according to this application.

[0046] Figure 7 The schematic diagram illustrates a bevel structure of a spherical tank according to this application.

[0047] The annotations in the attached figures are explained as follows:

[0048] a) First welding section; b) Second welding section; c) Third welding section;

[0049] α, angle of the upper slope face; β, angle of the lower slope face. Detailed Implementation

[0050] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0051] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0052] It should be noted that terms such as "upper," "lower," "left," and "right" are used only for distinction and convenience of description, and do not impose any positional limitations on the embodiments of the present invention. For example, "upper" in practice can refer to "lower," "left," or "right." In this invention, unless otherwise explicitly specified and limited, terms such as "assembly" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0053] In the description of this specification, references to terms such as "some embodiments," "exemplarily," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0054] In a first aspect, a welding process for a welding robot used on-site for welding spherical tanks is provided. The welding robot includes a first traveling wheel and a second traveling wheel, which are respectively located on both sides of the direction in which the welding robot moves. The welding process is used for welding spherical tanks.

[0055] The welding process, such as Figure 1 As shown, it includes:

[0056] S100: Sends welding instructions to control the welding robot to scan the weld seam on the spherical tank and determine the welding path along the weld seam;

[0057] S110: Determine the first traveling distance of the first traveling wheel and the second traveling distance of the second traveling wheel based on the welding path;

[0058] S120: Determine the travel distance difference based on the first travel distance and the second travel distance, and control the welding time of the welding robot according to the travel distance difference to make the welding filling amount on both sides of the weld seam equal.

[0059] The welding robot described in this application can be a trackless, all-position crawling welding robot (such as the BOT-WTA10-421 welding robot from Boqing Technology, or other welding robots capable of performing the welding process described in this application), equipped with solid welding wire and argon-rich mixed gas shielded welding (MAG) to complete the all-position automated welding of the three-dimensional weld seam of the spherical tank. Specifically, the welding material used is solid welding wire with a diameter of 1.2mm, conforming to the ER50-6 standard. The shielding gas is a mixed gas with a composition of 80% Ar + 20% CO2, wherein the purity of Ar gas is >99.99%, the purity of CO2 gas is >99.96%, and the gas flow rate is 20-25L / min. A ceramic gasket can be attached to the back of the bevel, and a round bar-shaped ceramic gasket is used for X-shaped bevels.

[0060] This welding robot uses permanent magnet adsorption technology and can crawl on the spherical tank by using the traveling wheels on both sides to drive the track system. The welding robot achieves automated welding by swinging the welding torch back and forth.

[0061] When the welding robot receives a welding command, it uses laser scanning to track the weld bevel, records and uploads the three-dimensional coordinates of the bevel information, and adjusts the welding position of the welding robot in real time by controlling the different walking speeds of the two tracks, so as to track the weld and determine the welding path of the weld.

[0062] If there is a difference in the travel distance between the first and second traveling wheels on the left and right sides of the welding path (i.e., one side moves faster and the other slower), considering that the oscillation process of the welding robot is usually symmetrical, the thickness of the weld layer (root weld / fill layer / capping layer) on the slower-moving side of the weld bevel will be larger, while the thickness of the weld layer on the faster-moving side will be smaller, resulting in unevenness on both sides of the weld. This problem exists when using a welding robot to weld spherical tanks, but does not exist in manual welding. Therefore, in this embodiment, the travel distance difference is determined based on the first travel distance of the first traveling wheel and the second travel distance of the second traveling wheel of the welding robot. The welding time of the welding robot on the left and right sides of the weld bevel is then controlled according to this travel distance difference to ensure that the weld layer thickness on both sides of the weld bevel is basically the same (i.e., from the perspective of the weld cross-section, the weld filler volume is equal on both sides). The value of the weld filler volume corresponds to a unit of volume.

[0063] In this embodiment, when the welding robot moves along the welding path of the weld seam, the welding time on the left and right sides of the weld seam is controlled according to the difference in the travel distance of the travel wheels on both sides of the welding robot during the oscillating welding process. By adjusting the welding time, the welding filling amount on the left and right sides of the weld seam is balanced, making the forming thickness on the left and right sides of the weld seam more consistent. This solves the problem of uneven filling on the left and right sides of the weld seam when the welding robot is welding a ring-shaped weld seam in the prior art.

[0064] In some embodiments, the weld seam includes a latitudinal seam distributed along the latitude of the spherical tank, the latitudinal seam including a short annular surface and a long annular surface, the first traveling wheel being located on one side of the long annular surface and the second traveling wheel being located on one side of the short annular surface;

[0065] The step of controlling the welding time of the welding robot based on the travel distance difference to ensure that the weld filler amount on both sides of the weld is equal, such as... Figure 2 As shown, it includes:

[0066] S121: Determine the welding time difference between the long annular surface and the short annular surface based on the travel distance difference;

[0067] S122: Increase the amount of welding filler on one side of the long annular surface according to the welding time difference.

[0068] The latitude seam can be a circumferential weld between strip plates, between a strip plate and an electrode plate, or a square circumferential weld on an electrode plate. The long annular surface refers to the bevel surface on the side with the longer diameter (or circumference) of the latitude seam, and the short annular surface refers to the bevel surface on the side with the shorter diameter (or circumference) of the latitude seam. Assume the first traveling wheel crawls on the long annular surface and the second traveling wheel on the short annular surface. When the welding robot oscillates to weld the latitude seam, the first traveling wheel travels a greater distance than the second traveling wheel in the same time t. Assuming the welding filler volume m of the welding torch remains constant per unit time, to maintain the consistency of the weld formation on the long and short annular surfaces, compensation for the welding filler volume on the long annular surface is required. Since the actual crawling time of the two traveling wheels is the same during welding, compensation for the welding filler volume needs to be achieved by changing the welding time difference Δt between the welding torch on the long and short annular surfaces of the weld.

[0069] Regarding the welding time difference Δt, specifically, we can define the first travel distance as L1, the second travel distance as L2, the single-pass weld thickness as h, the weld pool width as d, and the welding filler volume per unit time as m, then the following conditions are met:

[0070] Welding time difference

[0071] The weld filler gap caused by the extra travel distance on one side of the long annular surface can be calculated from the weld pool width d, the single-pass weld thickness h, and the travel distance difference L1-L2. This weld filler gap and the weld filler amount m per unit time can be used to calculate the extra welding time difference that the welding robot's welding torch should stay on one side of the long annular surface.

[0072] In some embodiments, the step of increasing the amount of weld filler on one side of the long annular surface based on the welding time difference is as follows: Figure 3 As shown, it specifically includes:

[0073] S1221: Increase the dwell time of the welding robot's welding torch on one side of the long annular surface according to the welding time difference;

[0074] S1222: Combine the increased dwell time with the welding filler amount per unit time to obtain the increment of welding filler amount on one side of the long annular surface.

[0075] In this embodiment, considering that the welding time of the welding robot on either side of the weld bevel can be divided into the oscillation time of the welding torch on that side and the dwell time (when oscillating to the farthest end), the welding time difference Δt can include the oscillation time difference and the dwell time difference of the welding torch. In this embodiment, the dwell time of the welding torch on the long annular surface is increased to increase the welding filler volume on the long annular surface.

[0076] Alternatively, increasing the oscillation time of the welding torch on one side of the long toroidal surface can be considered to increase the amount of weld filler on that side. In other words, the oscillation speed of the welding torch on one side of the long toroidal surface can be reduced. Then, based on the oscillation amplitude of the welding torch combined with the oscillation speed before and after the reduction, the oscillation time difference can be calculated. Finally, using the oscillation time difference and the amount of weld filler per unit time (m), the increase in the amount of weld filler on the long toroidal surface can be obtained. This can also increase the amount of weld filler on the long toroidal surface.

[0077] In some embodiments, such as Figure 4 As shown, the welding process further includes:

[0078] S200: Determine the posture of the welding robot on the spherical tank, including flat welding posture, flat climbing posture, overhead welding posture, overhead climbing posture and vertical welding posture.

[0079] S210: Generates working mode switching instructions based on posture. The working mode switching instructions include switching between flat welding mode, flat ramp mode, overhead welding mode, overhead ramp mode, and vertical welding mode.

[0080] In the flat welding mode, the swing amplitude of the welding torch is set to X1; in the flat ramp mode, the swing amplitude of the welding torch is set to X2; in the vertical welding mode, the swing amplitude of the welding torch is set to X3; in the overhead ramp mode, the swing amplitude of the welding torch is set to X4; and in the overhead welding mode, the swing amplitude of the welding torch is set to X5. Then the following condition is met: X1 > X2 > X3 > X4 > X5.

[0081] The welding robot's posture on the spherical tank can be categorized into several postures, including flat welding, flat ramp welding, overhead welding, overhead ramp welding, and vertical welding. Flat ramp welding refers to a transitional posture between conventional flat welding and vertical welding, while overhead ramp welding refers to a transitional posture between conventional overhead welding and vertical welding. When the robot's posture is detected as flat welding, a working mode switching command switches it to flat welding mode; when the robot's posture is detected as flat ramp welding, the working mode switching command switches it to flat ramp welding mode; when the robot's posture is detected as overhead welding, the working mode switching command switches it to overhead ramp welding mode; when the robot's posture is detected as overhead ramp welding, the working mode switching command switches it to overhead ramp welding mode; and when the robot's posture is detected as vertical welding, the working mode switching command switches it to vertical welding mode. For the oscillating welding of the welding robot on the spherical tank, the closer the welding robot is to the North Pole, the closer its posture is to flat welding; the closer it is to the South Pole, the closer its posture is to overhead welding. After extensive experimentation and comparison of welding parameters, the inventors discovered that the required oscillation amplitude for the weld varies depending on the welding position. For example, in a flat welding posture, the oscillation amplitude can be set to its maximum, and the welding speed to its fastest. When the molten pool filling direction is the same as the gravity direction (i.e., a flat-climbing posture), the oscillation amplitude can be relatively large, the welding speed relatively fast, and welding parameters such as current correspondingly higher. In a vertical welding posture, the oscillation amplitude and welding speed are relatively smaller. In an overhead-climbing posture, the oscillation amplitude and welding speed are even smaller, and in an overhead welding state, the oscillation amplitude and welding speed are at their minimum. According to experimental data, for a 2000M... 3 For spherical tanks, the swing width (i.e., twice the swing amplitude) of the vertical weld seam can be 20mm, which can cover a bevel width of up to 24mm; in a horizontal climbing posture, the swing width can be 24mm, which can cover a bevel width of 28mm; in an upward climbing posture, the swing width can be 17mm, which can cover a maximum bevel width of 20mm. When the bevel width of the weld seam exceeds this width, the weld layer needs to be divided into two passes, with each pass consisting of two passes on the left and right.

[0082] In this embodiment, considering that the molten pool on the spherical tank will be affected by gravity, in order to ensure that the weld thickness is relatively consistent, the welding robot is based on its position (or posture) on the spherical tank. The higher the position, the larger the swing amplitude and welding speed can be set during welding, and vice versa. The lower the position, the smaller the swing amplitude and welding speed should be set.

[0083] In some embodiments, the welding robot includes an attitude sensor, and the step of determining the attitude of the welding robot on the spherical tank includes:

[0084] The welding robot is controlled to acquire its posture on the spherical tank via the posture sensor; or

[0085] The welding robot is controlled to acquire remote posture commands, and the posture of the welding robot on the spherical tank is controlled based on the remote posture commands.

[0086] The posture of the welding robot on the spherical tank can generally be obtained in two ways. One is through the posture sensors built into the welding robot itself. The welding robot acquires posture data in various directions based on its posture sensors, and then comprehensively judges the posture and position of the welding robot on the spherical tank based on the posture data to further determine the welding method to be used. The other method is by receiving instructions from a remote control terminal to specify the current posture and confirm the welding method to be used.

[0087] In some embodiments, such as Figure 5 As shown, the weld seam includes a longitudinal seam distributed along the longitudinal direction of the spherical tank. The longitudinal seam includes a first welding segment a, a second welding segment b, and a third welding segment c. The first welding segment a is located at the upper part of the spherical tank, the third welding segment c is located at the lower part of the spherical tank, and the second welding segment b is located between the first welding segment and the third welding segment.

[0088] The welding process, such as Figure 6 As shown, it includes:

[0089] S300: Determine that the welding robot is located in the first welding section, and control the welding robot to move from the lower end to the upper end of the first welding section and weld;

[0090] S310: Determine that the welding robot is located in the second welding section, and control the welding robot to move from the lower end to the upper end of the second welding section and weld;

[0091] S320: Determine that the welding robot is located in the third welding section, and control the welding robot to move from the lower end to the upper end of the third welding section and weld.

[0092] In this embodiment, because the longitudinal seams on the spherical tank (especially the equatorial vertical welds) are often quite long, in order to control the amount of welding deformation, the longitudinal seams of the spherical tank are divided into three segments: a flat, sloping segment near the upper pole (corresponding to the first welding segment), a vertical welding segment near the middle (corresponding to the second welding segment), and an upward, sloping segment near the lower pole (corresponding to the third welding segment). Similarly, in order to control the amount of welding deformation, the welding robot is controlled to weld from bottom to top in all three welding segments, that is, first welding the first welding segment from bottom to top, then welding the second welding segment from bottom to top, and finally welding the third welding segment from bottom to top.

[0093] In some embodiments, before the step of controlling the welding robot to move from the lower end to the upper end of the first welding segment and to weld, the method further includes: setting the welding gun swing amplitude of the welding robot to Y1 and the welding speed to Z1;

[0094] Before the step of controlling the welding robot to move from the lower end to the upper end of the second welding section and weld, the method further includes: setting the welding gun swing amplitude of the welding robot to Y2 and the welding speed to Z2.

[0095] Before the step of controlling the welding robot to move from the lower end to the upper end of the third welding section and weld, the method also includes: setting the welding gun swing amplitude of the welding robot to Y3 and the welding speed to Z3.

[0096] Among them, Y1>Y2>Y3 and Z1>Z2>Z3 are satisfied.

[0097] Through extensive experimentation and comparison of welding parameters, the inventors discovered that the maximum required oscillation amplitude for the weld varies depending on the welding position when welding longitudinal seams. For example, when the molten pool filling direction is the same as the gravity direction (i.e., in a horizontal climbing posture), the oscillation amplitude can be set larger, the welding speed faster, and welding parameters such as current correspondingly higher. In a vertical welding posture, the oscillation amplitude and welding speed are set relatively smaller. And in an upward climbing posture, the oscillation amplitude and welding speed are minimized. Based on experimental data, for a 2000M... 3 For spherical tanks, the swing width (i.e., twice the swing amplitude) of the vertical weld can be 20mm, which can cover a bevel width of up to 24mm; when in a horizontal climbing posture, the swing width can be 24mm, which can cover a bevel width of 28mm; when in an upward climbing posture, the swing width can be 17mm, which can cover a maximum bevel width of 20mm.

[0098] In this embodiment, considering that the molten pool on the spherical tank will be affected by gravity, in order to ensure that the weld thickness is relatively consistent, the welding robot can be set to a larger swing amplitude and welding speed when welding the first welding segment at a higher position, and a smaller swing amplitude and welding speed should be set when welding the third welding segment at a lower position.

[0099] A second aspect of the invention is a spherical tank, such as Figure 7 As shown, the spherical tank is welded using any of the welding processes described in the first aspect. The spherical tank includes a lower latitude seam, and the outer side of the bevel of the lower latitude seam includes an upper bevel face angle α and a lower bevel face angle β, wherein the upper bevel face angle α is greater than the lower bevel face angle β.

[0100] In this case, the bevel angle of the latitude seam is equivalent to the sum of the upper bevel angle α and the lower bevel angle β. In existing spherical tank circumferential seams, the bevel angle α and the lower bevel angle β are equal. And because the weld bevels of spherical tanks are mainly X-type or V-type bevels (… Figure 7 The X-shaped bevel (as seen in the example) ensures fusion and symmetry of the weld on both sides of the vertical weld seam and the flat weld seam of the upper electrode plate in spherical tanks. However, at locations such as the manhole sides of the lower electrode plate, the circumferential weld seam of the lower electrode plate, and the square circumferential weld seam, the different curvatures can lead to inconsistent weld uniformity on both sides of the bevel during welding. Due to the influence of gravity, the weld pool tends to accumulate on the downward bevel surface. To ensure consistent height on both sides of each weld seam and prevent defects such as weld curling and incomplete fusion, the inventors, after extensive experimental data and on-site weld analysis, chose to design the weld bevel as a single-sided asymmetrical V-shaped or X-shaped bevel. This reduces the amount of filler in the bevel and also ensures the consistency of the weld seam on both sides of the bevel. Specifically, it can be set as follows: when the latitude seam (such as the circumferential seam) is in the lower half of the spherical tank, the upper bevel face angle α on the outside of the bevel can be set to be greater than the lower bevel face angle β; when the latitude is larger, the upper bevel face angle α can be set to be larger, while the lower bevel face angle β can be set to be smaller.

[0101] In a third aspect of the invention, there is a welding apparatus comprising a welding robot and a control terminal, wherein the welding robot is configured to receive welding instructions from the control terminal and execute welding processes as described in any of the welding robots used in the first aspect of the spherical tank site.

[0102] The welding robot can form a welding equipment with the control terminal, so that the various welding processes of the first aspect of the present invention can be realized remotely by sending welding instructions through the control terminal.

[0103] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0104] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A welding process for a welding robot on site of a spherical tank, characterized in that, The welding robot comprises a first travel wheel and a second travel wheel, which are arranged on two sides of the welding robot in a direction, and the welding process is used for welding a spherical tank; The welding process comprises: sending a welding instruction to control the welding robot to scan a weld on the spherical tank to determine a welding path along the weld; determining a first travel distance of the first travel wheel and a second travel distance of the second travel wheel based on the welding path; controlling a welding time of the welding robot according to a travel distance difference between the first travel distance and the second travel distance to make welding filling amounts on opposite sides of the weld equal; the weld comprises a latitude seam distributed along a latitude of the spherical tank, the latitude seam comprises a short annular surface and a long annular surface, the first travel wheel is located on one side of the long annular surface, and the second travel wheel is located on one side of the short annular surface; the step of controlling the welding time of the welding robot according to the travel distance difference to make the welding filling amounts on opposite sides of the weld equal comprises: determining a welding time difference between the long annular surface and the short annular surface based on the travel distance difference, and increasing the welding filling amount on one side of the long annular surface according to the welding time difference; defining the first travel distance as L1, the second travel distance as L2, a single-pass weld thickness of the weld as h, a weld pool width of the weld as d, and a welding filling amount per unit time as m, and the following conditions are met: The welding time difference .

2. The welding process of claim 1, wherein, the step of increasing the welding filling amount on one side of the long annular surface according to the welding time difference comprises: increasing a dwell time of a welding torch of the welding robot on one side of the long annular surface according to the welding time difference; and combining the increased dwell time with the welding filling amount per unit time to obtain an increment of the welding filling amount on one side of the long annular surface.

3. The welding process of claim 1, wherein, The welding process further comprises: determining a posture of the welding robot on the spherical tank, the posture comprising a flat welding posture, a flat climbing posture, an overhead welding posture, an overhead climbing posture, and an upright welding posture; generating a working mode switching instruction according to the posture, the working mode switching instruction comprising switching between a flat welding mode, a flat climbing mode, an overhead welding mode, an overhead climbing mode, and an upright welding mode; wherein, in the flat welding mode, an oscillation amplitude of a welding torch of the welding robot is set as X1; in the flat climbing mode, the oscillation amplitude of the welding torch is set as X2; in the upright welding mode, the oscillation amplitude of the welding torch is set as X3; in the overhead climbing mode, the oscillation amplitude of the welding torch is set as X4; and in the overhead welding mode, the oscillation amplitude of the welding torch is set as X5; and the following conditions are met: X1>X2>X3>X4>X5.

4. The welding process of claim 3, wherein, The welding robot comprises a posture sensor, and the step of determining the posture of the welding robot on the spherical tank comprises: controlling the welding robot to acquire the posture on the spherical tank through the posture sensor; or controlling the welding robot to acquire a remote posture instruction and controlling the posture of the welding robot on the spherical tank based on the remote posture instruction.

5. The welding process of claim 1, wherein, The weld seam comprises a longitudinal seam longitudinally distributed along the spherical tank, the longitudinal seam comprises a first welding section, a second welding section and a third welding section, the first welding section is located at the upper part of the spherical tank, the third welding section is located at the lower part of the spherical tank, and the second welding section is located between the first welding section and the third welding section. The welding process comprises: determining that the welding robot is located at the first welding section, and controlling the welding robot to travel from the lower end to the upper end of the first welding section and weld; determining that the welding robot is located at the second welding section, and controlling the welding robot to travel from the lower end to the upper end of the second welding section and weld; determining that the welding robot is located at the third welding section, and controlling the welding robot to travel from the lower end to the upper end of the third welding section and weld.

6. The welding process of claim 5, wherein, Before the step of controlling the welding robot to travel from the lower end to the upper end of the first welding section and weld, the method further comprises setting the welding gun swing amplitude of the welding robot to Y1 and the welding speed to Z1; Before the step of controlling the welding robot to travel from the lower end to the upper end of the second welding section and weld, the method further comprises setting the welding gun swing amplitude of the welding robot to Y2 and the welding speed to Z2; Before the step of controlling the welding robot to travel from the lower end to the upper end of the third welding section and weld, the method further comprises setting the welding gun swing amplitude of the welding robot to Y3 and the welding speed to Z3; Wherein Y1>Y2>Y3, Z1>Z2>Z3.

7. A spherical tank welded by the welding process of any one of claims 1 to 6, the spherical tank comprising a lower latitude seam, the outer side of the lower latitude seam comprising an upper bevel face angle and a lower bevel face angle, wherein the upper bevel face angle is greater than the lower bevel face angle.

8. A welding device comprising a welding robot and a control terminal, the welding robot being configured to receive welding instructions from the control terminal and perform the welding process of the welding robot on site of a spherical tank as claimed in any one of claims 1 to 6.

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