A spherical head welding structure and a welding method

Abstract

The present invention relates to the technical field of pressure vessel manufacturing, and specifically to a welding structure for a spherical head. It includes two relatively arranged bases, on each of which a turning tire is provided. A support cylinder is rotatably connected to the turning tire. An upper head and a lower head are arranged between the two support cylinders. The upper head and the lower head are connected by multiple first connecting plates. A first weld seam is arranged on the outer side of the upper head, and a second weld seam is arranged on the outer side of the lower head. A welding machine opposite to the first weld seam or the second weld seam is arranged on the outer side of the support cylinder. In the present invention, by arranging a first weld seam on the outer side of the upper head and a second weld seam on the outer side of the lower head, the first weld seam and the second weld seam are located on the same arc surface, and the center line of the arc surface coincides with the center line of the support cylinder. Under the action of the turning tire, the support cylinder causes the first weld seam and the second weld seam to rotate around the axis of the support cylinder, and welding of the first weld seam and the second weld seam is achieved under the action of the welding machine.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure vessel manufacturing, and particularly to a welding structure and a welding method for a spherical head. Background Art

[0002] With the development of the large-scale pressure vessels, the wall thickness of the spherical head of the pressure vessel and the size of the slab are getting larger and larger. Given the limitations of the steel plate manufacturing capabilities of domestic and foreign steel mills, the forming equipment capabilities of the head forming manufacturers cannot achieve integral forming, and for some materials, there are no welding consumables that can still meet the equipment performance requirements after corresponding quenching and tempering treatments, such as spherical heads made of vanadium-added steel materials. Therefore, currently, large thick-walled heads are usually manufactured by splicing the slab before forming, and then replacing all the splicing welds on the head with new weld metal after forming and quenching and tempering. As Figure 1 shown, first, two slab materials are assembled and welded into a whole circular plate, and after hot forming and quenching and tempering treatments, a spherical head is formed. However, at this time, the performance of the splicing welds on the head cannot meet the manufacturing technical requirements. Therefore, it is necessary to remove the original splicing welds and the heat-affected zones on the head, and then refill the welds with welding consumables (at this time, the welds have not experienced hot forming and quenching and tempering treatments, and their performance can meet the manufacturing technical requirements). Since the surface of the spherical head is curved, after forming and quenching and tempering, replacing the weld metal on the head can only be carried out by manual welding. And by manual welding, to meet the appropriate welding conditions (such as the inclination angle requirements of the electrode and the welding position, the observation requirements for the bead formation during welding, etc.), the groove needs to be opened very large, resulting in a large amount of weld filling, a long corresponding manufacturing cycle, and it is not easy to guarantee the weld quality, and the production efficiency is low. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a welding structure and a welding method for a spherical head, which can improve the assembly accuracy and the forming quality of the welds, and shorten the processing cycle.

[0004] The technical solution adopted by the present invention to solve its technical problems is a welding structure for a spherical head, including two relatively arranged bases, on each of the two bases, there is a turning tire, a support cylinder is rotatably connected to the turning tire, between the two support cylinders, there are an upper head and a lower head, the upper head and the lower head are arranged up and down and are respectively fixedly connected to the support cylinder, the upper head and the lower head are connected by a plurality of first connecting plates, the plurality of first connecting plates are arranged along the circumference of the upper head, a first weld is arranged on the outer side of the upper head, a second weld is arranged on the outer side of the lower head, the first weld and the second weld are located on the same arc surface, and the center line of the arc surface coincides with the center line of the support cylinder, and a welding machine opposite to the first weld or the second weld is arranged on the outer side of the support cylinder.

[0005] Further, a starting and stopping arc plate is arranged between the first weld and the second weld.

[0006] Further, the circular arc radius corresponding to the arc-shaped drawing-in plate is the same as the circular arc surface radius where the first weld seam and the second weld seam are located.

[0007] Further, a plurality of second connecting plates are arranged on the outer side of the supporting cylinder along the circumferential direction of the supporting cylinder, and the second connecting plates are connected to the upper head or the lower head.

[0008] Further, the first weld seam is connected through a third connecting plate, the third connecting plate is arranged inside the upper head, the second weld seam is connected through a fourth connecting plate, and the fourth connecting plate is arranged inside the lower head.

[0009] Further, the groove shapes of the first weld seam and the second weld seam are U-shaped or I-shaped.

[0010] A spherical head welding method, adopting a spherical head welding structure, includes the following steps.

[0011] S1: Splice two arc-shaped blank plates to form an upper head, and a first weld seam is formed between the two arc-shaped blank plates; form a lower head with the two arc-shaped blank plates, and a second weld seam is formed between the two arc-shaped blank plates; the first weld seam and the second weld seam are located on the same circular arc surface, and the center line of the circular arc surface coincides with the center line of the supporting cylinder.

[0012] S2: Weld a first connecting plate between the upper head and the lower head, and respectively weld and connect the upper head and the lower head to the supporting cylinders on both sides.

[0013] S3: Place the supporting cylinder on the turning tire, place a welding machine on the outer side of the supporting cylinder, and make the welding machine opposite to the first weld seam or the second weld seam.

[0014] S4: Turn on the welding machine, the turning tire drives the supporting cylinder to rotate, and the welding machine completes the welding of the first weld seam and the second weld seam.

[0015] Further, in step S2, weld an arc-shaped drawing-in plate between the first weld seam and the second weld seam, and remove the arc-shaped drawing-in plate after step S4.

[0016] Further, in step S2, a plurality of second connecting plates are arranged on the outer side of the supporting cylinder along the circumferential direction of the supporting cylinder, and the plurality of second connecting plates are connected to the upper head or the lower head.

[0017] Further, in step S2, the first weld seam is connected through a third connecting plate, the third connecting plate is arranged inside the upper head, the second weld seam is connected through a fourth connecting plate, the fourth connecting plate is arranged inside the lower head, and the arc-shaped drawing-in plate is removed after step S4.

[0018] The beneficial effects of the present invention are as follows: A first weld seam is provided on the outer side of the upper head, and a second weld seam is provided on the outer side of the lower head. The first weld seam and the second weld seam are located on the same circular arc surface, and the center line of the circular arc surface coincides with the center line of the support cylinder. Under the action of the turning tire, the support cylinder makes the first weld seam and the second weld seam rotate around the axis of the support cylinder, and the welding of the first weld seam and the second weld seam is realized under the action of the welding machine. The primary slab splicing process is reduced, the consumption of welding materials is reduced several times, the length of the weld seam is smaller, the welding filling amount is smaller, the overall performance of the head is better, the weld quality is better than that of manual welding, and the welding efficiency is higher. Moreover, this welding structure can be reused with a high utilization rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of the prior art;

[0020] Figure 2 is a schematic structural diagram of the present invention;

[0021] Figure 3 is a schematic diagram of the upper head;

[0022] Figure 4 is a schematic diagram of the lower head;

[0023] Figure 5 is a schematic diagram of the first weld seam;

[0024] Figure 6 is a schematic diagram of the second weld seam.

[0025] Reference numerals: 1 - base; 2 - turning tire; 3 - support cylinder; 301 - second connecting plate; 4 - upper head; 401 - first weld seam; 5 - lower head; 501 - second weld seam; 6 - first connecting plate; 7 - welding machine; 8 - arc starting and ending plate; 9 - third connecting plate; 10 - fourth connecting plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0027] As Figures 2 - 6As shown in the figure, a spherical head welding structure of the present invention includes two relatively arranged bases 1. A turning tire 2 is provided on each of the two bases 1. A support cylinder 3 is rotatably connected to the turning tire 2. An upper head 4 and a lower head 5 are provided between the two support cylinders 3. The upper head 4 and the lower head 5 are arranged up and down and are respectively fixedly connected to the support cylinder 3. The upper head 4 and the lower head 5 are connected by a plurality of first connecting plates 6. The plurality of first connecting plates 6 are arranged along the circumference of the upper head 4. A first weld 401 is provided on the outer side of the upper head 4. A second weld 501 is provided on the outer side of the lower head 5. The first weld 401 and the second weld 501 are located on the same arc surface, and the center line of the arc surface coincides with the center line of the support cylinder 3. A welding machine 7 opposite to the first weld 401 or the second weld 501 is provided on the outer side of the support cylinder 3.

[0028] Among them, the base 1 can be installed on the workshop floor. The height of the base 1 needs to have a gap between the lower head 5 and the upper head 4 after installation and the ground. The turning tire 2 is rotatably connected to the base 1, and the turning tire 2 can be driven to rotate by a servo motor; the support cylinder 3 is in a cylindrical shape and can drive the support cylinder 3 to rotate around its own axis during the rotation of the turning tire 2; the upper head 4 is respectively connected to the two support cylinders 3 by welding, and the lower head 5 is also respectively connected to the two support cylinders 3 by welding. The upper head 4 is located above the lower head 5. The outer surfaces of the upper head 4 and the lower head 5 are on the same spherical surface. The upper head 4 is formed by splicing two identical arc plates, and a first weld 401 is formed at the splicing place; the lower head 5 is also formed by splicing two identical arc plates, and a second weld 501 is formed at the splicing place; the first weld 401 and the second weld 501 are located on the same arc surface, and the center line of the arc surface coincides with the center line of the support cylinder 3. Such a setting enables the first weld 401 and the second weld 501 to rotate around the axis of the support cylinder 3 when the turning tire 2 drives the support cylinder 3 to rotate, and during the rotation, the welding height of the welding machine 7 will remain the same, which is convenient for welding the first weld 401 or the second weld 501. The welding machine 7 can be installed on the workshop floor.

[0029] In order to avoid defects such as pores and cracks when the welding machine 7 welds to the end of the first weld 401 or the second weld 501, further, see Figure 2, a shrinkage arc plate 8 is arranged between the first weld seam 401 and the second weld seam 501. By arranging the shrinkage arc plate 8 between the first weld seam 401 and the second weld seam 501, one end of the shrinkage arc plate 8 is connected to the first weld seam 401, and the other end of the shrinkage arc plate 8 is connected to the second weld seam 501. When the end of the first weld seam 401 or the second weld seam 501 moves to the welding machine 7, the arc starting part and the arc ending part, which are prone to defects such as pores and cracks on the first weld seam 401 and the second weld seam 501, are extended to the shrinkage arc plate 8, avoiding defects such as pores and cracks at both ends of the first weld seam 401 and the second weld seam 501.

[0030] In order to make the transition between the first weld seam 401 and the second weld seam 501 more uniform, further, the circular arc radius corresponding to the shrinkage arc plate 8 is the same as the circular arc surface radius where the first weld seam 401 and the second weld seam 501 are located.

[0031] In order to improve the connection stability between the support cylinder 3 and the upper head 4 and the lower head 5, further, see Figure 2 , a plurality of second connecting plates 301 are arranged on the outer side of the support cylinder 3 along the circumferential direction of the support cylinder 3, and the second connecting plates 301 are connected to the upper head 4 or the lower head 5. The connecting plates are welded on the support cylinder 3, and the end connected to the upper head 4 or the lower head 5 is a circular arc surface, and this circular arc surface is coplanar with the outer surface of the upper head 4 or the lower head 5.

[0032] In order to improve the stability of the upper head 4 and the lower head 5, further, see Figure 3 and Figure 4 , the first weld seam 401 is connected through a third connecting plate 9, the third connecting plate 9 is arranged inside the upper head 4, the second weld seam 501 is connected through a fourth connecting plate 10, and the fourth connecting plate 10 is arranged inside the lower head 5. Among them, a plurality of third connecting plates 9 are provided, which are arranged at intervals along the arrangement direction of the first weld seam 401, and the third connecting plates 9 are connected to the upper head 4 by welding; similarly, a plurality of fourth connecting plates 10 are provided, which are arranged at intervals along the arrangement direction of the second weld seam 501, and the fourth connecting plates 10 are connected to the lower head 5 by welding. With such an arrangement, the upper head 4 and the lower head 5 form an integral body, avoiding the deviation of the first weld seam 401 and the second weld seam 501 during the rotation process.

[0033] Further, see Figure 5 and Figure 6, the groove shapes of the first weld seam 401 and the second weld seam 501 are U-shaped or double-V-shaped. Taking a head with a plate thickness of 150 mm and an inner SR of 2210 mm of the head as an example, when using a U-shaped or double-V-shaped groove, the upper width of the groove is only 24 - 28 mm. If manual welding is used, the weld width is 60 mm and the welding cycle is 14 - 15 days. By using the method adopted in this patent and using the welding machine 7 for automatic welding, it only takes 3 days, greatly shortening the manufacturing cycle.

[0034] A spherical head welding method, adopting a spherical head welding structure, includes the following steps

[0035] S1: Splice two arc-shaped blanks to form the upper head 4, and a first weld seam 401 is formed between the two arc-shaped blanks; form the lower head 5 from the two arc-shaped blanks, and a second weld seam 501 is formed between the two arc-shaped blanks; the first weld seam 401 and the second weld seam 501 are located on the same circular arc surface, and the center line of the circular arc surface coincides with the center line of the support cylinder 3;

[0036] S2: Weld the first connecting plate 6 between the upper head 4 and the lower head 5, and respectively weld and connect the upper head 4 and the lower head 5 to the support cylinders 3 on both sides;

[0037] S3: Place the support cylinder 3 on the turning tire 2, place the welding machine 7 outside the support cylinder 3, and make the welding machine 7 face the first weld seam 401 or the second weld seam 501;

[0038] S4: Turn on the welding machine 7, the turning tire 2 drives the support cylinder 3 to rotate, and the welding machine 7 completes the welding of the first weld seam 401 and the second weld seam 501.

[0039] Further, in step S2, a welding lead-in and run-off plate 8 is welded between the first weld seam 401 and the second weld seam 501, and after step S4, the welding lead-in and run-off plate 8 is removed.

[0040] Further, in step S2, a plurality of second connecting plates 301 are arranged on the outer side of the support cylinder 3 along the circumferential direction of the support cylinder 3, and the plurality of second connecting plates 301 are connected to the upper head 4 or the lower head 5.

[0041] Further, in step S2, the first weld seam 401 is connected by a third connecting plate 9, the third connecting plate 9 is arranged inside the upper head 4, the second weld seam 501 is connected by a fourth connecting plate 10, the fourth connecting plate 10 is arranged inside the lower head 5, and after step S4, the welding lead-in and run-off plate 8 is removed.

[0042] The embodiments of this specific implementation manner are all preferred embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A spherical head welding structure, comprising two oppositely arranged bases (1), and tyre rollers (2) are arranged on both of the two bases (1), characterized in that: A support cylinder body (3) is rotatably connected to the rolling tire (2). An upper head (4) and a lower head (5) are arranged between the two support cylinder bodies (3). The upper head (4) and the lower head (5) are arranged up and down and are respectively fixedly connected to the support cylinder body (3). The upper head (4) and the lower head (5) are connected by a plurality of first connecting plates (6). The plurality of first connecting plates (6) are arranged along the circumferential direction of the upper head (4). A first weld seam (401) is arranged on the outer side of the upper head (4). A second weld seam (501) is arranged on the outer side of the lower head (5). The first weld seam (401) and the second weld seam (501) are located on the same circular arc surface, and the center line of the circular arc surface coincides with the center line of the support cylinder body (3). A welding machine (7) opposite to the first weld seam (401) or the second weld seam (501) is arranged on the outer side of the support cylinder body (3); A starting and ending arc plate (8) is arranged between the first weld seam (401) and the second weld seam (501); The circular arc radius corresponding to the starting and ending arc plate (8) is the same as the circular arc surface radius where the first weld seam (401) and the second weld seam (501) are located.

2. The welded structure of a spherical head according to claim 1, wherein: A plurality of second connecting plates (301) are arranged along the circumferential direction of the outer side of the support cylinder body (3). The second connecting plates (301) are connected to the upper head (4) or the lower head (5).

3. A spherical head welding structure according to claim 1, characterized in that: The first weld seam (401) is connected by a third connecting plate (9). The third connecting plate (9) is arranged inside the upper head (4). The second weld seam (501) is connected by a fourth connecting plate (10). The fourth connecting plate (10) is arranged inside the lower head (5).

4. The spherical head welding structure according to claim 3, characterized in that: The groove shapes of the first weld seam (401) and the second weld seam (501) are U-shaped or II-shaped.

5. A method for welding a spherical head, adopting the spherical head welding structure according to any one of claims 1-4, characterized in that: It includes the following steps S1: Two arc-shaped plate blanks are spliced to form the upper head (4), and a first weld seam (401) is formed between the two arc-shaped plate blanks; Two arc-shaped plate blanks are formed into the lower head (5), and a second weld seam (501) is formed between the two arc-shaped plate blanks; The first weld seam (401) and the second weld seam (501) are located on the same circular arc surface, and the center line of the circular arc surface coincides with the center line of the support cylinder body (3); S2: The first connecting plate (6) is welded between the upper head (4) and the lower head (5), and the upper head (4) and the lower head (5) are respectively welded and connected to the support cylinder bodies (3) on both sides; S3: The support cylinder body (3) is placed on the rolling tire (2), and the welding machine (7) is placed on the outer side of the support cylinder body (3), and the welding machine (7) is made to be opposite to the first weld seam (401) or the second weld seam (501); S4: The welding machine (7) is turned on, the rolling tire (2) drives the support cylinder body (3) to rotate, and the welding machine (7) completes the welding of the first weld seam (401) and the second weld seam (501).

6. The method for welding a spherical head according to claim 5, characterized in that: In step S2, the starting and ending arc plate (8) is welded between the first weld seam (401) and the second weld seam (501). After step S4, the starting and ending arc plate (8) is removed.

7. A method for welding a spherical head as claimed in claim 5, characterized in that: In step S2, a plurality of second connecting plates (301) are arranged on the outer side of the support cylinder body (3) along the circumferential direction of the support cylinder body (3), and the plurality of second connecting plates (301) are connected to the upper end head (4) or the lower end head (5).

8. A method for welding a spherical head as claimed in claim 5, characterized in that: In step S2, the first weld seam (401) is connected through a third connecting plate (9), the third connecting plate (9) is arranged inside the upper end head (4), the second weld seam (501) is connected through a fourth connecting plate (10), the fourth connecting plate (10) is arranged inside the lower end head (5), and after step S4, the third connecting plate (9) and the fourth connecting plate (10) are removed.

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