A welding process for steel pipe and flange

Abstract

The present invention relates to the field of welding technology, and in particular to a welding process for steel pipes and flanges, comprising the steps of installing flanges, recording parameters, trial production of samples, and formal production. During the welding process of the first set of flanges and steel pipes, the deformation of the flanges caused by welding is converted into a vertical upward force applied to a moving component, wherein the deformation during the welding of the first weld is converted into stress F1, and the deformation caused by the second weld and the deformation caused by the first weld accumulate to F2, until the final weld accumulates to Fn. After recording by a control device, during the welding process of the second set of flanges and steel pipes, the control device drives the fixing device to apply a force in the opposite direction to the flange, wherein the magnitude of the force applied during the welding of the first weld is F1, and the magnitude of the force applied at the beginning of the second weld is Fx, thereby offsetting the stress of the weld received by the flange during the welding process and reducing the possibility of deformation occurring after the welding of the steel pipe and the flange.

Description

Technical Field

[0001] The present invention relates to the technical field of welding, and in particular to a welding process for a steel pipe and a flange. Background Art

[0002] In industrial production, flanges are often placed on the outer surface of steel pipe ends and then welded together. In conventional direct welding processes, due to the large residual stress within the weld, the flanges are subject to the risk of significant angular deformation due to the rigid constraints imposed on the flange and pipe. This often requires flange correction, machining, or even scrapping. Summary of the Invention

[0003] Based on this, the present invention provides a welding process for a steel pipe and a flange, which reduces deformation occurring after welding the steel pipe and the flange.

[0004] The technical solution of the present invention is: a welding process for a steel pipe and a flange, comprising a base, a control device, and a fixing device for fixing the flange and the steel pipe, wherein the fixing device is fixed to the base, and the fixing device comprises a positioning column, a moving assembly, a clamping assembly, and a pressure gauge assembly, wherein the positioning column is fixed to the base, the fixed portion of the moving assembly is mounted on the positioning column, the clamping assembly is fixed to the moving portion of the moving assembly for clamping the flange, the pressure gauge assembly is mounted on the clamping assembly or the moving assembly for measuring the stress applied by the flange to the fixing device, and the pressure gauge assembly and the moving assembly are both electrically connected to the control device;

[0005] The welding process based on the above fixture includes the steps of flange installation, parameter recording, sample trial production and formal production, among which:

[0006] Installing the flange includes placing the flange on the base, driving the moving assembly to push the flange to a preset position through the control device, and then fixing the flange with the clamping assembly.

[0007] The parameter recording includes: after setting the steel pipe, automatically welding the steel pipe and the flange, during the welding process, the flange is deformed and forms a vertical upward stress on the fixing device, and the force applied to the fixing device during each weld pass measured by the pressure gauge assembly is recorded by the control device, wherein the average pressure applied to the fixing device during the first weld pass is F1, and the average pressure applied to the fixing device during the nth weld pass is Fn. After the welding is completed, the first set of steel pipes and flanges are removed.

[0008] The sample trial includes: after installing the second set of flanges and steel pipes, automatically welding the steel pipes and flanges, and at the same time, driving the moving assembly through the control device to apply a vertical downward force to the flanges, wherein the force applied during the first weld is F1, and starting from the second weld,

[0009] Fx=Fn-F(n-1),

[0010] Fx is the vertical downward force applied by the moving assembly to the flange during the nth weld pass, F(n-1) is the average pressure exerted on the fixture during the (n-1)th weld pass, and Fn is the average pressure exerted on the fixture during the nth weld pass.

[0011] Formal production includes testing the products obtained from sample trial production. After confirming that the welding strength is normal, the sample trial production process is repeated.

[0012] Optionally, the fixing device further includes an infrared light emitting component mounted on the positioning column, and the infrared light emitting component is electrically connected to the control device.

[0013] Optionally, the infrared light emitting component is rotatably connected to the positioning column.

[0014] Optionally, the step before installing the flange further includes the step of determining the position, wherein:

[0015] Position determination includes inputting the dimensions of the flange and the steel pipe into the control device, and the control device driving the infrared light emitting component to operate so that the preset position of the flange is displayed on the side of the base close to the flange.

[0016] Optionally, the moving assembly includes a horizontal hydraulic cylinder and a vertical hydraulic cylinder, the fixed end of the horizontal hydraulic cylinder is fixed to the positioning column, the fixed end of the vertical hydraulic cylinder is fixed to the moving end of the horizontal hydraulic cylinder, and the clamping assembly is installed at the moving end of the vertical hydraulic cylinder.

[0017] Optionally, the number of the fixing devices is at least two, and the two fixing devices are evenly distributed along the outer circumference of the flange.

[0018] Optionally, there are two fixing devices, and the two fixing devices are symmetrically distributed along the axial direction of the flange.

[0019] Optionally, the clamping assembly further includes a clamping block, wherein one end of the clamping block close to the flange is provided with a stepped portion, and an outer side of the stepped portion is in contact with an outer peripheral surface of the flange.

[0020] Optionally, a sloped portion is provided on a side of the clamping block away from the horizontal hydraulic cylinder, and the sloped portion is connected to the stepped portion.

[0021] Optionally, the steps for installing the flange also include the following:

[0022] The control device drives the moving assembly to make the inclined portion abut against the outer peripheral surface of the flange, and the clamping block and the flange are squeezed to make the flange move along the inclined portion, driving the horizontal hydraulic cylinder and the vertical hydraulic cylinder to move so that the outer peripheral surface of the flange abuts against the stepped portion.

[0023] Optionally, between the step of installing the flange and the step of recording the parameters, a step of applying prestressing force may be included:

[0024] Applying the prestress includes moving the moving assembly in a vertical direction so that a prestress F0 exists between the clamping assembly and the flange, and recording F0 by the control device.

[0025] Optionally, the direction of the prestress F0 is vertically upward, with vertically upward as the positive direction, and F0>0.

[0026] Compared with the prior art, the implementation of the present invention has the following beneficial effects:

[0027] The welding process of the steel pipe and the flange of the present invention converts the deformation of the flange caused by welding into a vertical upward force applied to the movable component during the welding process of the first set of flanges and the steel pipe, wherein the deformation during the welding of the first weld bead is converted into stress F1, and the deformation caused by the second weld bead and the deformation caused by the first weld bead are accumulated to F2, until the final weld bead is accumulated to Fn. After being recorded by the control device, during the welding process of the second set of flanges and the steel pipe, the control device drives the fixing device to apply a force in the opposite direction to the flange, wherein the magnitude of the force applied during the welding of the first weld bead is F1, and the magnitude of the force applied at the beginning of the second weld bead is Fx, thereby offsetting the stress of the weld bead received by the flange during the welding process and reducing the possibility of deformation occurring after the welding of the steel pipe and the flange. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of the welding process of a steel pipe and a flange according to an embodiment of the present invention.

[0029] Figure 2 It is a structural schematic diagram of the fixing device described in an embodiment of the present invention.

[0030] Figure 3 It is a structural schematic diagram of the vertical hydraulic cylinder and the clamping assembly according to an embodiment of the present invention.

[0031] Description of reference numerals:

[0032] 100, base,

[0033] 200, control device,

[0034] 300, flange,

[0035] 400, steel pipe,

[0036] 500. Fixing device, 1. Positioning column, 2. Moving assembly, 21. Horizontal hydraulic cylinder, 22. Vertical hydraulic cylinder, 3. Clamping assembly, 31. Step portion, 32. Inclined portion, 4. Pressure gauge assembly, 5. Infrared light emitting assembly,

[0037] 600. Welding bead. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0039] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" and the like to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0040] Furthermore, the present invention uses terms such as "first" and "second" to describe various types of information, but such information should not be limited to these terms. These terms are merely used to distinguish information of the same type from one another. For example, "first" information could also be referred to as "second" information, and similarly, "second" information could also be referred to as "first" information without departing from the scope of the present invention.

[0041] Reference Figures 1 to 3This embodiment provides a steel pipe and flange welding process 100, including a base 100, a control device 200, and a fixing device 500 for fixing a flange 300 and a steel pipe 400. The fixing device 500 is fixed to the base 100. The fixing device 500 includes a positioning column 1, a moving component 2, a clamping component 3 and a pressure gauge component 4. The positioning column 1 is fixed to the base 100, the fixed part of the moving component 2 is installed on the positioning column 1, the clamping component 3 is fixed to the moving part of the moving component 2 for clamping the flange 300, the pressure gauge component 4 is installed on the clamping component 3 or the moving component 2 for measuring the stress applied by the flange 300 to the fixing device 500, and the pressure gauge component 4 and the moving component 2 are both electrically connected to the control device 200.

[0042] The welding process based on the fixture 500 includes the steps of installing the flange 300, recording parameters, making samples and formal production, wherein:

[0043] The installation of the flange 300 includes placing the flange 300 on the base 100 , driving the moving assembly 2 by the control device 200 to push the flange 300 to a preset position, and then fixing the flange 300 by the clamping assembly 3 .

[0044] The parameter recording includes: after setting the steel pipe 400, automatically welding the steel pipe 400 and the flange 300. During the welding process, the flange 300 is deformed and forms a vertical upward stress on the fixture 500. The control device 200 records the force applied to the fixture 500 during each weld 600 measured by the pressure gauge assembly 4, wherein the average pressure applied to the fixture 500 during the first weld 600 is F1, and the average pressure applied to the fixture 500 during the nth weld 600 is Fn. After the welding is completed, the first group of steel pipes 400 and flanges 300 are removed.

[0045] The sample trial includes installing the second set of flanges 300 and steel pipes 400, and then automatically welding the steel pipes 400 and flanges 300. During the welding, the control device 200 drives the moving assembly 2 to apply a vertical downward force to the flanges 300. The force applied during the first weld bead 600 is F1. Starting from the second weld bead 600,

[0046] Fx=Fn-F(n-1),

[0047] Fx is the vertical downward force applied by the moving assembly 2 to the flange 300 when the n-th weld bead 600 is welded, F(n-1) is the average pressure exerted on the fixture 500 during the (n-1)-th weld bead 600, and Fn is the average pressure exerted on the fixture 500 during the n-th weld bead 600.

[0048] Formal production includes testing the products obtained from sample trial production. After confirming that the welding strength is normal, the sample trial production process is repeated.

[0049] During the welding process of the first set of flanges 300 and the steel pipe 400, the deformation of the flange 300 caused by welding is converted into a vertical upward force applied to the moving component 2, wherein the deformation during the welding of the first weld bead 600 is converted into stress F1, and the deformation caused by the second weld bead 600 and the deformation caused by the first weld bead 600 are accumulated as F2, until the welding of the last weld bead 600 is accumulated as Fn. After being recorded by the control device 200, during the welding process of the second set of flanges 300 and the steel pipe 400, the control device 200 drives the fixing device 500 to apply a force in the opposite direction to the flange 300, wherein the magnitude of the force applied during the welding of the first weld bead 600 is F1, and the magnitude of the force applied at the beginning of the second weld bead 600 is Fx, thereby offsetting the stress of the weld bead 600 received by the flange 300 during the welding process, and reducing the possibility of deformation after the welding of the steel pipe 400 and the flange 300.

[0050] Better, Figure 1 and Figure 2 In this embodiment, the fixture 500 further includes an infrared light emitting assembly 5 mounted on the positioning post 1. The infrared light emitting assembly 5 is electrically connected to the control device 200. The specifications of the flange 300 to be welded are input into the control device 200. After calculation, the control device 200 controls the infrared light emitting assembly 5 to emit infrared light to mark the preset position of the flange 300. The operator can determine whether the flange 300 is in the preset position under the action of the moving assembly 2 by observing the relative position of the infrared light mark and the flange 300.

[0051] Preferably, in this embodiment, the infrared light emitting assembly 5 is rotatably connected to the positioning column 1. By rotating the infrared light emitting assembly 5, the angle of the infrared light emitting assembly 5 is changed, so that infrared marks of different sizes can be drawn and applied to flanges 300 of different specifications and sizes.

[0052] Preferably, in this embodiment, the step of installing the flange 300 further includes a step of position determination, wherein:

[0053] Position determination includes inputting the dimensions of the flange 300 and the steel pipe 400 into the control device 200 , and the control device 200 drives the infrared light emitting assembly 5 to operate so that the preset position of the flange 300 is displayed on the side of the base 100 close to the flange 300 .

[0054] Better, refer to Figure 2In this embodiment, the moving assembly 2 includes a horizontal hydraulic cylinder 21 and a vertical hydraulic cylinder 22. The fixed end of the horizontal hydraulic cylinder 21 is fixed to the positioning column 1, and the fixed end of the vertical hydraulic cylinder 22 is fixed to the moving end of the horizontal hydraulic cylinder 21. The clamping assembly 3 is mounted on the moving end of the vertical hydraulic cylinder 22. The horizontal position of the clamping assembly 3 is adjusted by the horizontal hydraulic cylinder 21, and the vertical position of the clamping assembly 3 is adjusted by the vertical hydraulic cylinder 22.

[0055] Better, refer to Figure 1 In this embodiment, there are at least two fixtures 500, and the two fixtures 500 are evenly distributed along the outer periphery of the flange 300. Specifically, in this embodiment, there are two fixtures 500, and the two fixtures 500 are symmetrically distributed along the axis of the flange 300. By uniformly displacing the fixtures 500 in all directions, the center of the flange 300 is ensured to coincide with the preset center after the flange 300 is clamped, reducing the possibility of errors during the welding process.

[0056] Better, refer to Figures 1 to 3 In this embodiment, the clamping assembly 3 further includes a clamping block, and a stepped portion 31 is formed on one end of the clamping block near the flange 300. The outer side of the stepped portion 31 is in contact with the outer circumference of the flange 300. The stepped portion 31 is clamped to the flange 300 to achieve precise positioning of the flange 300.

[0057] Better, refer to Figure 3 In this embodiment, a chamfered portion 32 is provided on a side of the clamping block away from the horizontal hydraulic cylinder 21, and the chamfered portion 32 is in communication with the stepped portion 31. The step of installing the flange 300 further includes: driving the moving assembly 2 via the control device 200 to bring the chamfered portion 32 into contact with the outer circumference of the flange 300, squeezing the clamping block against the flange 300 so that the flange 300 moves along the chamfered portion 32, and driving the horizontal hydraulic cylinder 21 and the vertical hydraulic cylinder 22 to move so that the outer circumference of the flange 300 comes into contact with the stepped portion 31. By bringing the chamfered portion 32 into contact with the outer circumference of the flange 300 via the moving assembly 2 and causing the flange 300 to move along the chamfered portion 32, the accuracy of the outer wall of the flange 300 being engaged with the stepped portion 31 can be ensured.

[0058] Preferably, in this embodiment, the step of applying prestress is further included between the step of installing the flange 300 and the step of recording the parameters, wherein:

[0059] Applying prestress involves moving the mobile assembly 2 vertically to create a prestress F0 between the clamping assembly 3 and the flange 300, and recording F0 via the control device 200. The prestress F0 is directed vertically upward, with the vertical upward direction being the positive direction, and F0 > 0. This ensures sufficient contact between the clamping assembly 3 and the flange 300, reduces the gap between the flange 300 and the base 100, and mitigates the possibility of errors during welding.

[0060] This embodiment provides a welding process for a steel pipe 400 and a flange 300. The dimensions of the flange 300 and the steel pipe 400 are input into the control device 200. The control device 200 drives the infrared light emitting component 5 to operate so that the preset position of the flange 300 is displayed on the side of the base 100 close to the flange 300.

[0061] The flange 300 is placed on the base 100, and the control device 200 drives the moving component 2 to make the inclined portion 32 abut against the outer peripheral surface of the flange 300. The clamping block and the flange 300 are squeezed to make the flange 300 move along the inclined portion 32, driving the horizontal hydraulic cylinder 21 and the vertical hydraulic cylinder 22 to move so that the outer peripheral surface of the flange 300 abuts against the stepped portion 31, and the clamping component 3 fixes the flange 300.

[0062] After the steel pipe 400 is set, the mobile assembly 2 moves vertically, creating a prestressed force F0 between the clamping assembly 3 and the flange 300. This force is recorded by the control device 200. The steel pipe 400 and the flange 300 are automatically welded. During the welding process, the flange 300 deforms, exerting a vertical upward stress on the fixture 500. The force exerted on the fixture 500 during each weld bead 600, as measured by the pressure gauge assembly 4, is recorded by the control device 200. After welding is completed, the first set of steel pipes 400 and flanges 300 are removed.

[0063] After the second set of flanges 300 and steel pipes 400 are installed, the steel pipes 400 and flanges 300 are automatically welded. During welding, the control device 200 drives the moving assembly 2 to apply a vertical downward force to the flanges 300. The magnitude of the force applied during the welding of the first weld bead 600 is F1. Starting from the second weld bead 600,

[0064] Fx=Fn-F(n-1),

[0065] Fx is the vertical downward force applied by the moving assembly 2 to the flange 300 when the n-th weld bead 600 is welded, F(n-1) is the average pressure exerted on the fixture 500 during the (n-1)-th weld bead 600, and Fn is the average pressure exerted on the fixture 500 during the n-th weld bead 600.

[0066] The products obtained from the sample trial are tested. After confirming that the welding strength is normal, the sample trial process is repeated to start production.

[0067] The welding process of the steel pipe 400 and the flange 300 of this embodiment has the following beneficial effects:

[0068] 1. During the welding process of the first set of flanges 300 and the steel pipe 400, the deformation of the flange 300 caused by welding is converted into a vertical upward force applied to the moving component 2, wherein the deformation during the welding of the first weld bead 600 is converted into stress F1, and the deformation caused by the second weld bead 600 and the deformation caused by the first weld bead 600 are accumulated as F2, until the last weld bead 600 is accumulated as Fn. After being recorded by the control device 200, during the welding process of the second set of flanges 300 and the steel pipe 400, the control device 200 drives the fixing device 500 to apply a force in the opposite direction to the flange 300, wherein the magnitude of the force applied during the welding of the first weld bead 600 is F1, and the magnitude of the force applied at the beginning of the second weld bead 600 is Fx, thereby offsetting the stress of the weld bead 600 received by the flange 300 during the welding process, and reducing the possibility of deformation after the steel pipe 400 and the flange 300 are welded.

[0069] 2. The specifications of the flange 300 to be welded are input into the control device 200. After calculation, the control device 200 controls the infrared light emitting component 5 to emit infrared light to mark the preset position of the flange 300. The operator can judge whether the flange 300 is in the preset position under the action of the moving component 2 by observing the relative position of the infrared light mark and the flange 300.

[0070] 3. By moving the component 2 so that the inclined portion 32 abuts against the outer peripheral surface of the flange 300 and the flange 300 moves along the inclined portion 32, the accuracy of the outer wall of the flange 300 being engaged with the stepped portion 31 can be ensured, and the stepped portion 31 can be engaged with the flange 300 to form a precise positioning of the flange 300.

[0071] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A welding process for a steel pipe and a flange, characterized in that: The device comprises a base, a control device, and a fixing device for fixing a flange and a steel pipe, wherein the fixing device is fixed to the base, and the fixing device comprises a positioning column, a moving component, a clamping component, and a pressure gauge component. The positioning column is fixed to the base, the fixed portion of the moving component is mounted on the positioning column, the clamping component is fixed to the moving portion of the moving component for clamping the flange, the pressure gauge component is mounted on the clamping component or the moving component for measuring the stress applied by the flange to the fixing device, and the pressure gauge component and the moving component are both electrically connected to the control device; The welding process based on the above fixture includes the following steps: Installing the flange: placing the flange on the base, driving the moving assembly through the control device to push the flange to a preset position, and then fixing the flange with the clamping assembly; Parameter recording: After the steel pipe is set, the steel pipe and the flange are automatically welded to install a first set of steel pipes and flanges. During the welding process, the flange is deformed and forms a vertical upward stress on the fixture. The force applied to the fixture during each weld pass measured by the pressure gauge assembly is recorded by the control device, where the average pressure applied to the fixture during the first weld pass is F1, and the average pressure applied to the fixture during the nth weld pass is Fn. After welding is completed, the first set of steel pipes and flanges is removed; Sample trial: After installing the second set of flanges and steel pipes, the steel pipes and flanges are automatically welded. During welding, the control device drives the moving assembly to apply a vertical downward force to the flange. The force applied during the first weld is F1. Starting from the second weld, Fx=Fn-F(n-1), Fx is the vertical downward force exerted by the moving assembly on the flange during the nth weld pass, F(n-1) is the average pressure exerted on the fixture during the (n-1)th weld pass, and Fn is the average pressure exerted on the fixture during the nth weld pass; Formal production: Test the products obtained from the sample trial production. After confirming that the welding strength is normal, repeat the sample trial production process to start production.

2. The welding process for steel pipe and flange according to claim 1, characterized in that: The fixing device further comprises an infrared light emitting component mounted on the positioning column, and the infrared light emitting component is electrically connected to the control device.

3. The welding process for steel pipe and flange according to claim 2, characterized in that: The infrared light emitting component is rotatably connected to the positioning column.

4. The welding process for steel pipe and flange according to claim 2, characterized in that: The following steps are also included before installing the flange: Position determination: The dimensions of the flange and the steel pipe are input into the control device, and the control device drives the infrared light emitting component to operate so that the preset position of the flange is displayed on the side of the base close to the flange.

5. The welding process for steel pipe and flange according to claim 1, characterized in that: The moving assembly includes a horizontal hydraulic cylinder and a vertical hydraulic cylinder. The fixed end of the horizontal hydraulic cylinder is fixed to the positioning column, the fixed end of the vertical hydraulic cylinder is fixed to the moving end of the horizontal hydraulic cylinder, and the clamping assembly is installed on the moving end of the vertical hydraulic cylinder.

6. The welding process for steel pipe and flange according to claim 5, characterized in that: The number of the fixing devices is at least two, and the two fixing devices are evenly distributed along the outer circumference of the flange.

7. The welding process for steel pipe and flange according to claim 6, characterized in that: There are two fixing devices, and the two fixing devices are symmetrically distributed along the axial direction of the flange.

8. The welding process for steel pipe and flange according to claim 6, characterized in that: The clamping assembly further comprises a clamping block, wherein an end of the clamping block close to the flange is provided with a stepped portion, and an outer side of the stepped portion is in contact with an outer peripheral surface of the flange.

9. The welding process for steel pipe and flange according to claim 8, characterized in that: A sloped portion is provided on a side of the clamping block away from the horizontal hydraulic cylinder, and the sloped portion is communicated with the stepped portion.

10. The welding process for steel pipe and flange according to claim 9, characterized in that: The steps to install the flange also include the following: The control device drives the moving assembly to make the inclined portion abut against the outer peripheral surface of the flange, and the clamping block and the flange are squeezed to make the flange move along the inclined portion, driving the horizontal hydraulic cylinder and the vertical hydraulic cylinder to move so that the outer peripheral surface of the flange abuts against the stepped portion.

11. The welding process for steel pipe and flange according to claim 1, characterized in that: The following steps are included between the step of installing the flange and the step of recording the parameters: Applying prestress: the moving assembly moves in a vertical direction so that a prestress F0 exists between the clamping assembly and the flange, and F0 is recorded by the control device.

12. The welding process for steel pipe and flange according to claim 11, characterized in that: The direction of the prestress F0 is vertically upward, with vertically upward being the positive direction, and F0>0.

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