Welding tool for right-angle joint of large-size transformer oil tank
By using welding fixtures with external arc plates during the welding process of transformer tanks, the problem of sharp corner pits caused by welding slag was solved, the standardization and aesthetics of the rounded corners at the weld were achieved, the safety performance of the transformer was improved, and the processing technology was simplified.
Patent Information
- Application Number
- CN202422818566.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-19
- Publication Date
- 2026-02-17
- Estimated Expiration
- 2034-11-19
AI Technical Summary
During the welding process of large-volume transformer tanks, welding slag is prone to sticking to sharp corners, causing pits, resulting in electric field concentration, which affects transformer safety. In addition, traditional grinding methods are time-consuming, labor-intensive, and difficult to guarantee quality.
A new type of welding fixture is adopted, which uses an outer arc plate to cut and unfold the round tube at the weld seam into an outer arc plate, and fixes it by laser welding, so as to achieve a rounded transition without grinding, simplify the processing technology and improve safety performance.
It achieves standardization and aesthetics in the rounded corners of welds, reduces sharp-corner discharge caused by weld slag, improves the safety performance of transformers, simplifies the processing technology, and reduces labor intensity.
Smart Images
Figure CN223916976U_ABST
Abstract
Description
Technical Field
[0001] This article belongs to the technical field of right-angle butt welding of tank bodies, specifically involving a welding fixture for right-angle joints of large-volume transformer tanks. Background Technology
[0002] The transformer tank is the outer casing of an oil-immersed transformer, with the transformer body placed inside a tank filled with transformer oil. The transformer tank serves two purposes: firstly, it acts as an insulating medium; secondly, it serves as a heat dissipation medium, transferring heat dissipated from the windings and core to the tank walls, radiators, or coolers through the circulation of the transformer oil. Transformer tanks are all welded from steel plates.
[0003] In oil-immersed transformers, sharp corners and burrs inside the tank, such as those on the tank wall and the weld seam where two steel plates are joined together near the riser, can easily cause weld slag to adhere to the sharp corners of the weld seam during the welding process. Due to their position on the edge, these weld slag spots cannot be removed individually. Simply removing the weld slag can easily cause pits on the edge. Both weld slag and pits can cause electric field concentration, which can easily lead to partial discharge in the transformer during subsequent use, seriously endangering the normal operating condition of the transformer.
[0004] Due to the sealing and pressure requirements of the fuel tank itself, the welding of long strip joints cannot be done using highly automated and high-precision laser welding, as this would lead to a decrease in strength and inability to withstand pressure. Therefore, gas-shielded arc welding with manually added welding rods is required. However, weld slag cannot be avoided during the arc welding process.
[0005] Therefore, during the manufacturing process of the fuel tank, after welding is completed, the sharp corners of the weld seam inside the fuel tank need to be ground rounded to eliminate sharp corner burrs on the metal parts, and also to ensure the stability of the electric field by providing a smooth transition.
[0006] The conventional practice is to use an angle grinder to round the weld after welding. However, when the oil tank is large and the weld is too long, this traditional method is too time-consuming and labor-intensive. Moreover, different operators have different grinding techniques and experience, which cannot guarantee the quality of the rounded corners and may pose a safety hazard to the final transformer product. Utility Model Content
[0007] To address the aforementioned issues, this paper proposes a welding fixture for right-angle joints in large-volume transformer tanks. The transformer tank comprises several steel plates joined and welded together. Each steel plate includes horizontal and vertical plates, with their sides joined together. A weld is welded to the outer side of the joint between the horizontal and vertical plates. An outer arc plate, which is a vertically cut circular tube, is then wrapped around the weld. Both ends of the outer arc plate are fitted with end caps. The two sides of the outer arc plate are tangentially welded to the surfaces of the horizontal and vertical plates. The central axis of the inner surface of the arc plate aligns with the joint edge of the horizontal and vertical plates. The length of the circular tube is the same as the weld length. This novel arc electrode fabrication fixture improves the roundness of the weld joints inside the tank, significantly simplifying the manufacturing process and resulting in more standardized and aesthetically pleasing roundness. It also greatly reduces the sharp-angle discharge phenomenon caused by weld slag on the inner wall of the tank, thereby improving the safety performance of the transformer.
[0008] The outer arc plate is a tangential arc plate formed by shearing and unfolding a circular tube. The circular tube is a straight, thin-walled tube with vertical slits on its surface. The tube unfolds symmetrically on both sides based on these slits. The two sides of the outer protective plate are tangent to the central arc. The bottom surfaces of the two sides of the outer protective plate are fitted to the outer surfaces of the horizontal and vertical plates. Both ends of the outer protective plate are fitted with end caps that cover the edges of the horizontal and vertical plates. The outer contour shape of the end caps is consistent with the outer protective plate. The outer contours of the plates are the same. The outer arc plate is connected to the horizontal and vertical plates by laser welding. By directly cutting the round tube and unfolding it into the form of the outer arc plate, the rounded corner transition of the oil tank can be achieved without the need for rounded corner grinding. Moreover, the required length of round tube can be selected according to the required edge length. The manufacturing is simple and convenient. Since the thickness of the outer arc plate is small, the tangential plane contacts the surface of the horizontal and vertical plates and there is no high strength requirement for it, which enables automated laser strip welding.
[0009] Beneficial effects:
[0010] A novel arc electrode manufacturing tooling is used to improve the rounded corners of the weld seams inside the oil tank, greatly simplifying the processing technology, making the rounded corners of the weld seams more standard and aesthetically pleasing, and significantly reducing the sharp-corner discharge phenomenon caused by weld slag on the inner wall of the oil tank, thereby improving the safety performance of the transformer.
[0011] It is easy to produce and process, and can effectively reduce the workload of grinding the internal welds during the manufacturing process of transformer oil tank, and reduce the phenomenon of sharp-angle discharge inside the transformer.
[0012] By directly cutting the round tube and unfolding it into an outer arc plate, the rounded corner transition of the oil tank can be achieved without the need for rounded corner grinding. Furthermore, the required length of the round tube can be selected according to the required edge length. The manufacturing process is simple and convenient. Since the outer arc plate is relatively thin, the tangential plane contacts the surface of the horizontal and vertical plates, and there is no high strength requirement for it, thus enabling automated laser strip welding. Attached Figure Description
[0013] Figure 1 This is a cross-sectional schematic diagram of a welding fixture used for right-angle joints in a large-volume transformer tank;
[0014] In the diagram: 1. Horizontal plate, 2. Vertical plate, 3. Outer arc plate, 4. End sealing plate. Detailed Implementation
[0015] To enhance understanding of this utility model, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. These embodiments are only used to explain the present utility model and do not constitute a limitation on the scope of protection of the present utility model.
[0016] Horizontal plate 1, vertical plate 2, outer arc plate 3, end sealing plate 4.
[0017] like Figure 1 As shown;
[0018] A welding fixture for right-angle joints in a large-volume transformer tank. The transformer tank comprises several steel plates spliced and welded together. Each steel plate includes a horizontal plate 1 and a vertical plate 2. The sides of the horizontal plate 1 and the vertical plate 2 are joined together. A weld is welded to the outer side of the joint between the horizontal plate 1 and the vertical plate 2. An outer arc plate 3 is provided on the outer side of the weld. The outer arc plate 3 is a vertically cut, unfolded circular tube. Both ends of the outer arc plate 3 have end caps 4. The two sides of the outer arc plate 3 are tangentially welded to the surfaces of the horizontal plate 1 and the vertical plate 2. The central axis of the inner surface of the central arc of the outer arc plate 3 is in contact with the joint edge of the horizontal plate 1 and the vertical plate 2. The length of the circular tube is the same as the length of the weld. The outer arc plate 3 is a circular arc plate that is tangent to the circular tube by shearing and unfolding. The circular tube is a straight thin-walled circular tube with vertical slits on its surface. The circular tube unfolds symmetrically on both sides with the slits as the reference. The two sides of the outer protective plate are tangent to the central arc. The bottom surfaces of the two sides of the outer protective plate are attached to the outer surfaces of the horizontal plate 1 and the vertical plate 2. Both ends of the outer protective plate are attached to and covered by end sealing plates 4. The end sealing plates 4 are attached to and connected to the edges of the horizontal plate 1 and the vertical plate 2. The outer contour shape of the end sealing plates 4 is the same as the outer contour shape of the outer protective plate. The outer arc plate 3 is connected to the horizontal plate 1 and the vertical plate 2 by laser welding.
[0019] Implementation example;
[0020] When treating critical welds inside the oil tank, a 40mm diameter round tube is cut vertically and directly welded to the weld. This significantly reduces the amount of work required for rounding the corners. Furthermore, because the outer surface of the tube is a perfectly rounded surface, the electric field distribution is very uniform, thus reducing the occurrence of discharge phenomena during later transformer operation and effectively improving the transformer's safety performance.
[0021] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. A welding fixture for right-angle joints in a large-volume transformer tank, wherein the transformer tank comprises several steel plates spliced and welded together, characterized in that... The steel plate includes a horizontal plate and a vertical plate. The sides of the horizontal and vertical plates are joined together. A weld is welded on the outer side of the joint between the horizontal and vertical plates. An outer arc plate is provided on the outer side of the weld. The outer arc plate is a circular tube that is cut vertically on one side and unfolded. Both ends of the outer arc plate are provided with end caps. The two sides of the outer arc plate are tangentially welded to the surfaces of the horizontal and vertical plates. The central axis of the inner surface of the middle arc of the outer arc plate is in contact with the joint edge of the horizontal and vertical plates. The length of the circular tube is the same as the length of the weld.
2. The welding fixture for right-angle joints in large-volume transformer tanks according to claim 1, characterized in that, The outer arc plate is a circular arc plate with tangential arc shape, which is a sheared and unfolded circular tube. The circular tube is a straight thin-walled circular tube with vertical slits on its surface. The circular tube unfolds symmetrically on both sides with the slits as the reference.
3. The welding fixture for right-angle joints in large-volume transformer tanks according to claim 1, characterized in that, The two sides of the outer arc plate are tangent to the central arc, and the bottom surfaces of the two sides of the outer arc plate are fitted to the outer surfaces of the horizontal and vertical plates.
4. The welding fixture for right-angle joints in large-volume transformer tanks according to claim 1, characterized in that, Both ends of the outer arc plate are fitted with end caps, which are connected to the edges of the horizontal and vertical plates. The outer contour shape of the end caps is the same as that of the outer arc plate.
5. The welding fixture for right-angle joints in large-volume transformer tanks according to claim 1, characterized in that, The outer arc plate is connected to the horizontal and vertical plates by laser welding.