Axial flow type guide vane for water turbine and manufacturing method of axial flow type guide vane
By dividing the axial flow guide vane into multiple components and adjusting the weld position, the large problems of quality and processing allowance of the traditional overall casting structure are solved, and more efficient manufacturing and performance optimization are achieved.
Patent Information
- Application Number
- CN202511101074.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-06
- Publication Date
- 2025-09-05
AI Technical Summary
The traditional axial flow guide vane is an integral casting structure, with defects such as heavy quality, large processing allowance and slag inclusion, which affects the performance and manufacturing efficiency of the guide vane.
The axial flow guide vane is divided into upper shaft head, lower shaft head, shell plate, tail plate and cover plate. Through casting and welding connection, the weld position moves from the overflow surface to the end surface, reducing welding deformation and optimizing welding position.
It reduces welding deformation, reduces processing allowance, improves the manufacturing efficiency and performance of the guide vane, maintains the integrity of the overflow surface, and avoids interference from the welds on the tail line.
Smart Images
Figure CN120592786A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an axial flow guide vane for a water turbine and also relates to a method for manufacturing the axial flow guide vane for a water turbine. Background Art
[0002] Axial guide vanes include a rotatable main body, with upper and lower spindle heads fixedly connected to the main body defining an axis of rotation. Rotation of the axial guide vanes allows the opening of the flow channel between adjacent axial guide vanes to be varied. To close the flow channel, the leading seal overlap line of each axial guide vane rotates to abut against the trailing seal overlap line of the adjacent axial guide vane, completely blocking flow within the channel.
[0003] Traditional guide vanes are mostly integrally cast. This not only results in heavy weight and large machining allowances, but also presents defects such as slag inclusions, which impact guide vane quality. In recent years, engine manufacturers have generally adopted a cast-and-weld structure to improve overall guide vane performance.
[0004] Therefore, it is hoped that the performance of the axial flow guide vane can be improved and the efficiency of the axial flow guide vane manufacturing can be increased by appropriately dividing the axial flow guide vane into a plurality of parts that can be welded together. Summary of the Invention
[0005] 20. The repairing kit for automotive dents, according to claim 19, wherein the foot stand comprises a through-hole, and the two foot pieces comprise two bosses, wherein the bosses comprise a through-hole, a screw bolt, and a nut. The through-hole, the bosses comprise a through-hole, a screw bolt, and a nut. The through-hole, the bosses comprise a through-hole, a screw bolt, and a nut. The bottom edge of the second shell plate respectively has a bottom concave edge complementary to the top shape of the lower shaft head and recessed in the area of the first shell plate and the second shell plate, wherein the bottom end of the upper shaft head and the top concave edges of the first shell plate and the second shell plate are welded to each other, and the top end of the lower shaft head and the bottom concave edges of the first shell plate and the second shell plate are welded to each other; a tail plate, the front edge of the tail plate is respectively welded to the tail edge of the first shell plate on the water-facing surface and to the tail edge of the second shell plate on the water-receiving surface, so that the tail plate forms the tail end of the axial flow guide vane; a plurality of upper cover plates and a lower cover plate, the upper cover plate and the lower cover plate are respectively welded to the areas on the top and bottom edges of the first and second shell plates that are not welded to the upper and lower shaft heads to completely enclose the top and bottom ends of the axial flow guide vane.
[0006] The number of upper and lower cover plates is not limited to one. For example, if the upper shaft head is not positioned near the rear end of the axial guide vane but rather in the central region of the axial guide vane, upper cover plates may be provided on both the front and rear sides of the upper shaft head. If the lower shaft head is located at the rear end of the axial guide vane, only a complete lower cover plate is required on the front side.
[0007] In the prior art, the welds between the upper and lower shaft heads and the main body of the axial-flow guide vane are located within the flow surface. In contrast, in the present invention, the upper and lower cover plates are welded to the top and bottom edges of the first and second shell plates, moving the welds from the flow surface to the upper and lower end surfaces. The welds between the upper and lower shaft heads and the first and second shell plates on the flow surface occur only within the limited concave edges of the top and bottom sides. This maintains the integrity of the flow surface and reduces the possibility of cavitation on the flow surface during unit operation.
[0008] Compared to the prior art, the tail end of the axial-flow guide vane according to the present invention is no longer formed by directly welding the shell plates of the upstream and downstream surfaces. Instead, a tail plate is added. The advantage of this improved structure is that the weld seam at the tail end of the axial-flow guide vane no longer includes the tail end of the axial-flow guide vane. Instead, it is moved forward on the upstream and downstream surfaces to the front edge of the tail plate. This allows the tail end of the axial-flow guide vane to avoid the weld seam location of traditional welded guide vanes, correspondingly reducing or eliminating welding deformation at the tail plate end (i.e., the tail end of the axial-flow guide vane). Due to the reduced welding deformation, less post-weld machining allowance can be reserved during the tail plate blanking process, thereby reducing the overall post-weld machining effort and the amount of profiling required at the tail end of traditional welded guide vanes.
[0009] It is particularly preferred to design the tail plate length so that the tail seal overlap line of the water-facing surface of the axial guide vane falls within the tail plate. In this way, due to the forward position of the weld seam on the front edge of the tail plate, the tail seal overlap line falls entirely within the tail plate area where machining is required to remove only machining allowance. This facilitates the use of a smaller machining allowance during blanking and prevents the weld seam from interfering with the tail seal line.
[0010] Preferably, the weld seam between the front edges of the first and second shell plates and the build-up weld position of the sealing overlap line of the axial flow guide vane are close enough to be completed in a single welding operation. This not only eliminates the need for pre-processing of the build-up weld position, but also allows the sealing overlap line to be processed and the excess portion of the weld seam between the first and second shell plates to be removed in a single post-welding process, thereby reducing process steps, time, and labor costs.
[0011] According to a preferred embodiment of the axial-flow guide vane of the present invention, the lower shaft head is arranged near the tail end of the axial-flow guide vane body, with a portion of the upper end surface of the lower shaft head welded to the bottom end of the tail plate, and the remaining portion of the upper end surface and the front end surface adjacent to the upper end surface are welded to the bottom concave edges of the first and second shell plates. As an alternative or supplementary embodiment, the upper shaft head can also be arranged near the tail end of the axial-flow guide vane body, with a portion of the lower end surface of the upper shaft head welded to the top end of the tail plate, and the remaining portion of the lower end surface and the front end surface adjacent to the lower end surface are welded to the top concave edges of the first and second shell plates.
[0012] In the prior art, the upper and lower shaft heads are cast, cylindrical, and relatively large. These castings are welded to the flow panel sheet material with an appropriate machining allowance. According to the preferred embodiment of the axial-flow guide vane of the present invention, to prevent the presence of numerous welds near the shaft head at the tail end of the axial-flow guide vane, the guide vane tail end is partially cast simultaneously with the upper or lower shaft head near the guide vane tail end during casting, forming a single integral unit. This reduces the amount of welding and, in turn, reduces welding deformation at this location.
[0013] Preferably, the axial flow guide vane body further comprises a rib plate, which is welded to the inner side of the first shell plate, wherein a corresponding plug welding hole is provided on the second shell plate, and the rib plate is plug welded to the second shell plate through the plug welding hole on the outer side of the second shell plate.
[0014] Preferably, several of the upper cover plates and / or the lower cover plates are provided with exhaust holes for discharging welding heat inside the axial flow guide vane body, and the exhaust holes are suitable for being welded and sealed after welding inside the axial flow guide vane body is completed.
[0015] According to a preferred embodiment of the axial flow guide vane of the present invention, the axial flow guide vane body includes a continuous rib extending along the rotation axis of the axial flow guide vane. However, the ribs may also be discontinuous, as long as they all extend along the rotation axis of the axial flow guide vane.
[0016] According to a preferred embodiment of the axial flow guide vane of the present invention, the axial flow guide vane body includes one or multiple parallel continuous or discontinuous ribs that are symmetrical in shape with respect to the rotation axis of the axial flow guide vane.
[0017] According to another aspect of the present invention, a method for manufacturing an axial flow guide vane is provided, the method comprising: providing an upper shaft head and a lower shaft head by casting, wherein the upper shaft head and the lower shaft head are respectively rotatable around a rotation axis of the axial flow guide vane; Providing a first shell plate as a water-facing surface of the axial-flow guide vane, wherein the first shell plate has a top concave edge complementary to the shape of the upper shaft head and a bottom concave edge complementary to the shape of the lower shaft head; Providing a second shell plate as the back water surface of the axial flow guide vane, wherein the second shell plate has a top concave edge complementary to the shape of the upper shaft head and a bottom concave edge complementary to the shape of the lower shaft head; Welding the front edge of the first shell plate and the front edge of the second shell plate to each other to form the front end of the axial flow guide vane; Welding the front edge of the tail plate to the tail edge of the first shell plate on the water-facing surface and to the tail edge of the second shell plate on the water-repelling surface, respectively, so that the tail plate forms the tail end of the axial flow guide vane and a machining allowance is reserved; Welding the upper shaft head to the concave edges of the top sides of the first shell plate and the second shell plate; Welding the lower shaft head to the concave edges of the bottom sides of the first shell plate and the second shell plate; Providing an upper cover plate as the top surface of the axial flow guide vane, and welding the upper cover plate to all areas of the top side edges of the first shell plate and the second shell plate that are not welded to the upper shaft head; Providing a lower cover plate as the bottom surface of the axial flow guide vane, and welding the lower cover plate to all areas of the bottom side edges of the first shell plate and the second shell plate that are not welded to the upper shaft head; The welding position at the front end and the reserved machining allowance position at the rear end of the axial flow guide vane are machined respectively.
[0018] According to a preferred embodiment of the method for manufacturing an axial flow guide vane according to the present invention, the method further comprises: providing a rib plate before welding the front edge of the first shell plate to the front edge of the second shell plate; welding the rib plate to the inner side of the first shell plate; and then, before or after welding the front edge of the first shell plate to the front edge of the second shell plate, plug welding the rib plate to the second shell plate from the outer side of the second shell plate through corresponding plug welding holes provided in the second shell plate. In other words, the order of splicing the front edge of the first shell plate to the front edge of the second shell plate and plug welding the rib plate to the second shell plate can be arbitrarily selected.
[0019] Preferably, the manufacturing method of the axial flow guide vane according to the present invention further includes: providing exhaust holes on the provided upper cover plate and / or the lower cover plate, and after welding the upper cover plate to the top side edges of the first shell plate and the second shell plate and welding the lower cover plate to the bottom side edges of the first shell plate and the second shell plate, sealing the exhaust holes on the upper cover plate and / or the lower cover plate by welding, wherein the exhaust holes are designed to discharge welding heat inside the axial flow guide vane body.
[0020] It should be understood that the exhaust holes may be provided on all upper and lower cover plates at the same time, or may be provided on only a part of them, for example, only on the upper cover plate. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the accompanying drawings: Figure 1 Schematically shows an exploded perspective view of an axial flow guide vane according to the present invention; Figure 2A Schematically shows the main structure of the axial flow guide vane according to the present invention; Figure 2B The weld structure of the axial flow guide vane according to the present invention is schematically shown in a three-dimensional view; Figure 3 The lower shaft head of the axial flow guide vane according to the present invention and the partial axial flow guide vane body connected thereto are schematically shown in a side view; Figure 4 The figure schematically illustrates in cross section the welding connection of the tail end of the axial flow guide vane according to the prior art; Figure 5A The upper shaft head of the axial flow guide vane and the partial axial flow guide vane body connected thereto are schematically shown in a side view according to the present invention; Figure 5B The figure schematically shows the welding connection between the upper shaft head of the axial flow guide vane and the first shell and the second shell in the prior art in a side view; Figure 6A The welded connection between the first shell and the second shell of the axial flow guide vane according to the present invention at the front end is schematically shown in a cross-sectional view; Figure 6B A schematic cross-sectional view shows the final shape of the first shell and the second shell of the axial flow guide vane according to the present invention after the front end is welded and connected and further machined; Figure 7A and Figure 7B The welding grooves between the first and second shells and the tail plate of the axial flow guide vane according to the present invention are schematically shown in longitudinal and transverse cross-sectional views respectively; Figure 8 The welded connection between the ribs of the axial flow guide vane and the inner sides of the first shell and the second shell is schematically shown in a partially exploded perspective view.
[0022] In the drawings, identical or functionally similar components are represented by the same reference numbers for clarity. DETAILED DESCRIPTION
[0023] Figure 1 An exploded perspective view of an axial flow guide vane 1 according to the present invention is schematically shown. Figure 2A Schematically shows the main structure of the axial flow guide vane according to the present invention. Figure 2BThe weld structure of an axial guide vane according to the present invention is schematically illustrated in a three-dimensional view. The axial guide vane 1 for a hydraulic turbine includes an upper shaft head 10, a lower shaft head 20, and an axial guide vane body 30. The upper shaft head 10 and the lower shaft head 20 are each arranged to rotate about the rotation axis of the axial guide vane 1. The upper shaft head 10 and the lower shaft head 20 are each formed by casting and connected to the axial guide vane body 30 by welding. The axial guide vane body 30 includes a first shell plate 310 located on the water-facing side of the axial guide vane 1, a second shell plate 320 located on the water-facing side of the axial guide vane 1, a tail plate 330, and several upper and lower cover plates 340 and 350. The front edges of the first and second shell plates 310 and 320 are welded together to form the front end of the axial guide vane 1. The top edges 313 and 323 of the first and second shell plates 310 and 323 respectively have concave top edges 3131 and 3231 that complement the shape of the bottom end of the upper shaft head and are recessed into the regions of the first and second shell plates. The bottom edges 314 and 324 of the first and second shell plates 310 and 320 respectively have concave bottom edges 3141 and 3241 that complement the shape of the top end of the lower shaft head and are recessed into the regions of the first and second shell plates. The bottom end 104 of the upper shaft head is welded to the top concave top edges 3131 and 3231 of the first and second shell plates 310 and 320, and the top end of the lower shaft head is welded to the bottom concave bottom edges 3141 and 3241 of the first and second shell plates. The front edge 331 of the tail plate 330 is welded to the tail edge 312 of the first shell plate on the water-facing surface and to the tail edge 322 of the second shell plate on the water-repelling surface, so that the tail plate forms the tail end 302 of the axial flow guide vane. Figure 1 The front end, top end, and bottom end of the axial guide vane are shown with reference numerals 301, 303, and 304, respectively. The upper cover plate 340 and the lower cover plate 350 are welded to the top edges 313, 323 and bottom edges 314, 324 of the first shell plate 310 and the second shell plate 320, respectively, in the areas not welded to the upper shaft head 10 and the lower shaft head 20, thereby completely enclosing the top and bottom ends of the axial guide vane 1.
[0024] Figure 2A Schematically shows the main structure of the axial flow guide vane according to the present invention. Figure 2B FIG. 2 schematically shows the weld structure of the axial flow guide vane according to the present invention.
[0025] Figure 1The upper cover plate 340 and the lower cover plate 350 are also provided with exhaust holes 341 and 351. The exhaust holes 341 and 351 are designed to discharge the welding heat inside the axial flow guide vane body, especially to discharge the heat generated when welding the ribs. After the upper cover plate 340 is welded to the top edges of the first and second shell plates and the lower cover plate 350 is welded to the bottom edges of the first and second shell plates 310 and 320, the exhaust holes 341 and 351 on the upper and / or lower cover plates are sealed by welding. Figure 8 As shown, exhaust holes are also provided on the rib plate 360 to balance the temperature and air pressure on both sides of the rib plate.
[0026] Figure 3 The lower shaft head of the axial flow guide vane according to the present invention and the partial axial flow guide vane body connected thereto are schematically shown in a side view. It should be understood that the embodiment in which the lower shaft head is arranged close to the tail end of the axial flow guide vane is used as an example. Obviously, an embodiment in which the upper shaft head is arranged close to the tail end of the axial flow guide vane can also be considered. In the latter case, the lower shaft head is arranged in the central area of the bottom edge. Figure 3 As shown in , the lower shaft head is provided integrally with a partial area extending into the guide vane body to prevent the weld between the lower shaft head and the body of the axial flow guide vane from being too close to the tail end of the axial flow guide vane. Figure 3 In the figure, the front end face 201 of the lower shaft head is welded to the tail side edges 312 and 322 of the first shell 310 and the second shell 320, and the front half of the upper end face 203 of the lower shaft head is welded to the top concave edges 3141 and 3241 of the first shell plates of the first shell 310 and the second shell 320, and the rear half is welded to the tail plate 330.
[0027] Figure 7B The tail plate of the axial flow guide vane according to the present invention is schematically shown in a cross-sectional view. The tail plate has an integrated and complete structure, avoiding deformation caused by welding, so that less machining allowance H can be left when cutting. As a comparison, Figure 4 A schematic cross-section illustrates the welded connection at the tail end of an axial-flow guide vane using conventional technology. The primary difference lies in the use of a separate tail plate in the present invention, where the weld connection is no longer located at the tail end of the axial-flow guide vane but instead moved forward to the leading edge of the tail plate. This minimizes weld deformation and reduces the amount of profiling required on the tail plate. During blanking, the required machining allowance H for the tail plate is also significantly smaller than that used in conventional technology.
[0028] Figure 5A The upper shaft head of an axial flow guide vane according to the present invention and the partial axial flow guide vane body connected thereto are schematically shown in a side view. The upper cover plate 340 is welded to the axial flow guide vane body at welding position C shown in the figure and around the bottom end 104 of the upper shaft head. The figure also shows the front sealing overlap line at reference numeral 305. For comparison, Figure 5B The welding connection between the upper shaft head of the axial flow guide vane and the first shell and the second shell under the prior art is schematically shown in a side view, that is, welding position B. Obviously, Figure 5A In the embodiment of the invention shown, the majority of the weld does not pass through the wetted surfaces.
[0029] Figure 6A The welded connection of the first and second shells of an axial flow guide vane according to the present invention at the front end is schematically shown in a sectional view. Figure 6B A schematic cross-sectional view illustrates the final shape of the first and second shells of an axial-flow guide vane according to the present invention, after being welded together at the front ends and further machined. The weld seam between the front edges of the first and second shell plates and the build-up weld position of the front seal overlap line on the back surface of the axial-flow guide vane are so close together that they can be completed in a single weld. Therefore, when the first and second shells are welded together, the weld can simultaneously cover the location where the front seal overlap line 305 is to be machined, thereby conveniently completing the pre-machining process before build-up welding is performed on this location. Subsequently, after the weld seam and build-up welding are completed, the surface of the second shell is finished by finishing, and the weld seam and build-up weld position can be machined in a single step.
[0030] Figure 7A and Figure 7B The weld groove G between the first and second casings of an axial-flow guide vane and the tail plate according to the present invention is schematically illustrated in longitudinal and transverse cross-sectional views. This illustrates a single-sided groove method. Because the tail plate already requires pre-fabrication before welding, the single-sided groove can be incorporated into the tail plate and fabricated simultaneously, eliminating the need for beveling the two flow panels.
[0031] Figure 8 A partially exploded perspective view schematically illustrates the welded connection between the ribs of an axial-flow guide vane and the inner sides of the first and second shells according to the present invention. First, before welding the front edge 311 of the first shell plate and the front edge 321 of the second shell plate, a rib 360 is provided; the rib 360 is welded to the inner side of the first shell plate 310; then, before or after welding the front edge 311 of the first shell plate 310 and the front edge 321 of the second shell plate 320, a plug welding hole ( Figure 2B and Figure 8 The rib plate 360 is plug welded to the second shell plate 320 (the corresponding plug weld is shown by reference numeral 315 in the figure).
[0032] Although some embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various combinations, changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and purpose of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.
[0033] Reference Signs List 1 Axial flow guide vanes 10 Upper spindle head 20 Lower spindle head 30 Axial flow guide vane body 301 Front end of axial flow guide vane 302 The tail end of the axial flow guide vane; 303 Top of the axial flow guide vane 304 Bottom end of axial flow guide vane 305 Sealing overlap line of axial flow guide vanes 310 First Shell Plate 320 Second Shell Plate 330 tailgate 311 Front edge of first shell plate 312 Aft edge of first shell plate 313 Top edge of the first shell plate 314 Bottom edge of the first shell plate 321 Front edge of the second shell 322 Aft edge of the second shell 323 Top edge of the second shell plate 324 Bottom edge of the second shell plate 331 Front edge of tailgate 104 Bottom end of upper shaft head 201 front end face of lower shaft head 203 Upper end face of lower shaft head 3131 Concave edge of top side of first shell plate 3141 Concave edge of bottom side of first shell plate 3231 Concave edge of top side of second shell plate 3241 Concave edge of bottom side of second shell 340 upper cover 350 lower cover 360 ribs 315 plug weld 341 exhaust vent 351 exhaust vent F Waterside A Welding position B Welding position C welding position D Welding position E Welding position G Welding position K welding position L plug welding H machining allowance.
Claims
1. An axial flow guide vane for a water turbine, the axial flow guide vane comprising an upper shaft head, a lower shaft head, and an axial flow guide vane body, wherein: The upper shaft head and the lower shaft head are arranged to be rotatable around the rotation axis of the axial flow guide vane, respectively. The upper shaft head and the lower shaft head are respectively formed by casting and connected to the axial flow guide vane body by welding. It is characterized in that the axial flow guide vane body comprises: a first shell plate, the first shell plate being located on a water-facing surface of the axial-flow guide vane; The second shell plate is located on the back water surface of the axial flow guide vane, wherein the front side edges of the first shell plate and the second shell plate are welded to each other to form the front end of the axial flow guide vane, wherein the top side edges of the first shell plate and the second shell plate respectively have a top side concave edge complementary to the bottom end shape of the upper shaft head and recessed into the area of the first shell plate and the second shell plate, and the bottom side edges of the first shell plate and the second shell plate respectively have a bottom side concave edge complementary to the top end shape of the lower shaft head and recessed into the area of the first shell plate and the second shell plate, wherein the bottom end of the upper shaft head and the top side concave edges of the first shell plate and the second shell plate are welded to each other, and the top end of the lower shaft head and the bottom side concave edges of the first shell plate and the second shell plate are welded to each other; a tail plate, wherein the front edge of the tail plate is welded to the tail edge of the first shell plate on the water-facing surface and to the tail edge of the second shell plate on the water-repelling surface, so that the tail plate forms the tail end of the axial flow guide vane; A plurality of upper cover plates and lower cover plates are respectively welded to the areas on the top and bottom edges of the first and second shell plates that are not welded to the upper shaft head and the lower shaft head to completely enclose the top and bottom ends of the axial flow guide vane.
2. The axial flow guide vane according to claim 1, characterized in that: The tail sealing overlap line of the water-facing surface of the axial flow guide vane is within the range of the tail plate.
3. The axial flow guide vane according to claim 2, characterized in that: The weld positions of the front edges of the first and second shell plates are close to the surfacing positions of the front sealing overlap lines of the back water surface of the axial flow guide vane to the extent that they can be completed in one welding operation.
4. The axial flow guide vane according to claim 3, characterized in that: The lower shaft head is arranged close to the tail end of the axial flow guide vane body, and the lower shaft head is welded to the bottom end of the tail plate with a portion of the upper end surface, and the remaining portion of the upper end surface and the front end surface adjacent to the upper end surface are welded to the bottom concave edges of the first shell plate and the second shell plate.
5. The axial flow guide vane according to claim 3, characterized in that: The upper shaft head is arranged close to the tail end of the axial flow guide vane body, and the upper shaft head is welded to the top end of the tail plate with a portion of the lower end surface, and the remaining portion of the lower end surface and the front end surface adjacent to the lower end surface are welded to the top side concave edges of the first shell plate and the second shell plate.
6. The axial flow guide vane according to claim 4 or 5, characterized in that: The axial flow guide vane body also includes a rib plate, which is welded to the inner side of the first shell plate, wherein corresponding plug welding holes are provided on the second shell plate, and the rib plate is plug welded to the second shell plate through the plug welding holes on the outer side of the second shell plate.
7. The axial flow guide vane according to claim 6, characterized in that: Several of the upper cover plates and / or the lower cover plates are provided with exhaust holes for discharging welding heat inside the axial flow guide vane body, and the exhaust holes are suitable for being welded and sealed after welding inside the axial flow guide vane body is completed.
8. The axial flow guide vane according to claim 6, characterized in that: The rib plate is provided with exhaust holes for balancing the temperature and air pressure on both sides of the rib plate.
9. The axial flow guide vane according to claim 7, characterized in that: The axial flow guide vane body includes a continuous or discontinuous rib extending along the rotation axis of the axial flow guide vane.
10. The axial flow guide vane according to claim 7, characterized in that: The axial flow guide vane body includes one or a plurality of parallel continuous or discontinuous ribs that are symmetrical in shape with respect to the rotation axis of the axial flow guide vane.
11. A method for manufacturing an axial flow guide vane, comprising: providing an upper shaft head and a lower shaft head by casting, wherein the upper shaft head and the lower shaft head are respectively rotatable around a rotation axis of the axial flow guide vane; Providing a first shell plate as a water-facing surface of the axial-flow guide vane, wherein the first shell plate has a top concave edge complementary to the shape of the upper shaft head and a bottom concave edge complementary to the shape of the lower shaft head; Providing a second shell plate as the back water surface of the axial flow guide vane, wherein the second shell plate has a top concave edge complementary to the shape of the upper shaft head and a bottom concave edge complementary to the shape of the lower shaft head; Welding the front edge of the first shell plate and the front edge of the second shell plate to each other to form the front end of the axial flow guide vane; Welding the front edge of the tail plate to the tail edge of the first shell plate on the water-facing surface and to the tail edge of the second shell plate on the water-repelling surface, respectively, so that the tail plate forms the tail end of the axial flow guide vane and a machining allowance is reserved; Welding the upper shaft head to the concave edges of the top sides of the first shell plate and the second shell plate; Welding the lower shaft head to the concave edges of the bottom sides of the first shell plate and the second shell plate; Providing an upper cover plate as the top surface of the axial flow guide vane, and welding the upper cover plate to all areas of the top side edges of the first shell plate and the second shell plate that are not welded to the upper shaft head; Providing a lower cover plate as the bottom surface of the axial flow guide vane, and welding the lower cover plate to all areas of the bottom side edges of the first shell plate and the second shell plate that are not welded to the upper shaft head; The welding position at the front end and the reserved machining allowance position at the rear end of the axial flow guide vane are machined respectively.
12. The method for manufacturing an axial flow guide vane according to claim 11, wherein: The manufacturing method of the axial flow guide vane further includes: Before welding the front edge of the first shell plate and the front edge of the second shell plate to each other, providing a rib plate; Welding the rib plate to the inner side of the first shell plate; Then, before or after welding the front side edge of the first shell plate and the front side edge of the second shell plate to each other, the rib plate is plug welded to the second shell plate through the corresponding plug welding holes on the outer side of the second shell plate.
13. The method for manufacturing an axial flow guide vane according to claim 11, wherein: The manufacturing method of the axial flow guide vane further includes: Provide an exhaust hole on the provided upper cover plate and / or the provided lower cover plate; After welding the upper cover plate to the top edges of the first and second shell plates and welding the lower cover plate to the bottom edges of the first and second shell plates, the exhaust holes on the upper cover plate and / or the lower cover plate are sealed by welding, wherein the exhaust holes are designed to discharge welding heat inside the axial-flow guide vane body.
14. The method for manufacturing an axial flow guide vane according to claim 12, wherein: The manufacturing method of the axial flow guide vane further includes: The provided rib plate is provided with exhaust holes for balancing the temperature and air pressure on both sides of the rib plate.