Auxiliary assembly tool and installation method of outer bucket of impulse turbine

Abstract

The invention relates to the technical field of impulse water turbine generators, and discloses an auxiliary assembly tool and a mounting method of an outer water bucket of an impulse water turbine. According to the auxiliary assembly tool provided by the invention, the auxiliary assembly tool is additionally arranged and is used for reducing the assembly error of the outer water bucket, so that the welding deviation is reduced. Specifically, at least one of the front mold and the rear mold is provided with a hub water bucket fixing surface matched with the molded surface of the hub water bucket, at least one of the front mold and the rear mold is provided with an outer water bucket fixing surface matched with the molded surface of the outer water bucket, and when the outer water bucket is assembled on the top of the hub water bucket, all the fixing surfaces are attached to the corresponding molded surfaces, so that the outer water bucket is assembled on the top of the hub water bucket. And the front mold and the rear mold are fixed by using the connecting structure, so that accurate assembly of the outer water bucket in the assembly process can be ensured, and the assembly accuracy and stability are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of impulse hydrogenerators, and particularly to an auxiliary assembly tooling and an installation method for an outer water bucket of an impulse water turbine. Background Art

[0002] With the continuous and rapid development of China's economy, the energy demand shows an increasing trend. Against this background, large-capacity impulse hydroelectric generating units, as efficient and clean energy conversion equipment, have become an important choice to meet the country's energy demand. Such units can not only improve the power generation efficiency of hydropower stations, but also effectively reduce the impact on the environment, which is in line with China's concept of green and sustainable development.

[0003] As the core component of a hydro-generator set, the performance of the runner is directly related to the operating efficiency and stability of the entire unit. With the continuous increase in the unit capacity, the size and weight of the runner have increased sharply, which undoubtedly poses more stringent requirements for the manufacturing process and material selection of the runner. Currently, the industry generally adopts the forging and welding manufacturing process to manufacture the runner. Specifically, the runner hub and the outer water bucket are respectively made of forgings and processed separately, and then the runner hub and the outer water bucket are connected and fixed through precise welding technology.

[0004] However, during the process of assembling the outer water bucket of the runner to the end face of the runner hub, the accuracy of the assembly positioning is directly related to the profile size of the runner after welding. If the assembly welding deviation of the outer water bucket is too large, it will lead to a significant reduction in the hydraulic efficiency of the runner and cannot meet the hydraulic design requirements of the runner. This will not only affect the power generation efficiency of the unit, but may also cause a series of operating failures and safety hazards. Summary of the Invention

[0005] In view of this, the present invention provides an auxiliary assembly tooling and an installation method for an outer water bucket of an impulse water turbine to solve the problem of excessive assembly welding deviation of the outer water bucket.

[0006] In a first aspect, the present invention provides an auxiliary assembly tooling, which includes a front mold, a rear mold and a connection structure. At least one of the front mold and the rear mold is provided with a hub water bucket fixing surface, and at least one of the front mold and the rear mold is provided with an outer water bucket fixing surface. The hub water bucket fixing surface is adapted to the hub water bucket profile, and the outer water bucket fixing surface is adapted to the outer water bucket profile. When the hub water bucket fixing surface is attached to the hub water bucket profile and the outer water bucket fixing surface is attached to the outer water bucket profile, the front mold and the rear mold are fixed through the connection structure, and the root of the outer water bucket is accurately fixed on the top of the hub water bucket.

[0007] Beneficial effects: By adding an auxiliary assembly tooling, it is used to reduce the assembly error of the outer water bucket, thereby reducing the welding deviation. Specifically, by providing at least one of the front mold and the rear mold with a hub water bucket fixing surface adapted to the hub water bucket profile surface, and at least one of the front mold and the rear mold with an outer water bucket fixing surface adapted to the outer water bucket profile surface. When the outer water bucket is assembled on the top of the hub water bucket, through the fitting of each fixing surface with the corresponding profile surface and using the connecting structure to fix the front mold and the rear mold, it can ensure the precise assembly of the outer water bucket during the assembly process, improving the accuracy and stability of the assembly. At the same time, through the setting of the auxiliary assembly tooling, during operation, the maintenance personnel only need to align and fix the front mold and the rear mold with the corresponding water bucket profile surfaces, and then the assembly can be quickly completed, which can simplify the assembly process, reduce the time for manual adjustment, and lower the difficulty of manual adjustment, thereby improving the production efficiency. In addition, since the hub water bucket fixing surface in the tooling is adapted to the hub water bucket profile surface and the outer water bucket fixing surface is adapted to the outer water bucket profile surface, it can be adjusted according to different models and specifications of the outer water bucket, making the tooling highly flexible.

[0008] In an alternative embodiment, when the hub water bucket fixing surface is fitted with the hub water bucket profile surface and the outer water bucket fixing surface is fitted with the outer water bucket profile surface, the connection between the outer water bucket and the hub water bucket forms a weld seam; at least one of the front mold and the rear mold is provided with a welding through-hole, and the welding through-hole is used for the local welding area of the weld seam to communicate with the external environment.

[0009] Beneficial effects: When the hub water bucket fixing surface is fitted with the hub water bucket profile surface and the outer water bucket fixing surface is fitted with the outer water bucket profile surface, the connection between the outer water bucket and the hub water bucket forms a weld seam. At this time, by providing a welding through-hole, it is convenient for the welder to approach the weld seam for local welding, improving the efficiency and accuracy of welding. At the same time, by welding the local area of the weld seam at the welding through-hole, it helps to complete the positioning work of the outer water bucket and the hub water bucket. In addition, since the welding area communicates with the external environment, it helps the heat, smoke, and harmful gases generated during the welding process to be discharged in a timely manner, which is beneficial for the welder to control the weld quality, reduce welding defects, and reduce the damage to the welding equipment caused by heat, smoke, and harmful gases, and extend the service life of the welding equipment.

[0010] In an alternative embodiment, the welding through-hole is provided with an avoidance notch for the welding end of the welding equipment to move.

[0011] Beneficial effects: By providing an avoidance notch in the welding through-hole, it helps the welding end of the welding equipment to approach the weld seam, reducing the difficulty of the welding end moving to the weld seam due to space limitations, and helping to optimize the welding process, enabling the welder to accurately complete the welding task.

[0012] In an alternative embodiment, the connection structure includes a first connection hole, a second connection hole, and a connecting member. The first connection hole and the second connection hole are respectively formed in the front mold and the rear mold. Among the first connection hole and the second connection hole, one of them is a through hole, and the other is an internal threaded hole. The connecting member is provided with an external thread that passes through the through hole and then screws into the internal threaded hole.

[0013] Advantages: By providing the first connection hole, the second connection hole, and the connecting member, during installation, only need to pass the external thread of the connecting member through the through hole and screw it into the internal threaded hole, then the relative fixation of the front mold and the rear mold can be completed, without the need to additionally use complex tools or connection methods. At the same time, through the threaded connection, a tight and stable connection is formed between the connecting member and the front mold and the rear mold. This connection method has high tensile strength and shear strength, which can ensure that the connection between the front mold and the rear mold will not loosen or fail during assembly and use. In addition, since the connecting member is screwed into the internal threaded hole through the thread, when disassembly is required, only need to rotate the connecting member in the reverse direction and take it out, which is convenient for subsequent disassembly by the auxiliary assembly tooling and reuse.

[0014] In an alternative embodiment, the auxiliary assembly tooling further includes a guiding and positioning structure. The guiding and positioning structure includes a first guiding hole, a second guiding hole, and a guiding member. The first guiding hole and the second guiding hole are respectively formed in the front mold and the rear mold. The first guiding hole and the second guiding hole are communicated, and the guiding member passes through one of the first guiding hole and the second guiding hole and extends towards the other.

[0015] Advantages: By providing the first guiding hole, the second guiding hole, and the guiding member, after the guiding member is installed, it can provide a relatively accurate guide for the connection structure, ensuring a high-precision connection process when the connection structure is connected, avoiding displacement, reducing the stress on the connecting member, and thus ensuring the assembly quality. At the same time, it helps to enhance the stability of the overall structure of the auxiliary assembly tooling, facilitating the improvement of the ability of the auxiliary assembly tooling to resist external force interference during the assembly process, so that the auxiliary assembly tooling has a relatively stable installation state. In addition, through the setting of the guiding and positioning structure, the assembly process becomes more stable and simple. The operator only needs to perform the assembly according to the guidance of the guiding hole, without the need to additionally perform complex adjustment and calibration work.

[0016] Second aspect, the present invention also provides a method for installing the outer water bucket of an impulse turbine, which is applied to the auxiliary assembly tooling described in the first aspect. The method for installing the outer water bucket of the impulse turbine includes the following steps: Precision machining: Precision machine the hub water bucket surface at the hub water bucket, precision machine the outer water bucket surface at the outer water bucket, and precision machine the hub water bucket fixing surface adapted to the hub water bucket surface and the outer water bucket fixing surface adapted to the outer water bucket surface at the auxiliary assembly tooling; Positioning welding: Complete the assembly of the auxiliary assembly tooling, the hub water bucket and the outer water bucket, and weld the local area of the weld seam at the through-welding part; Full welding: Remove the auxiliary assembly tooling and complete all welding work on the weld seam.

[0017] Beneficial effects: By precisely machining the corresponding surfaces at the hub water bucket and the outer water bucket, and machining the fixing surfaces adapted to these surfaces at the auxiliary assembly tooling, it ensures the precise fit of the auxiliary assembly tooling with the hub water bucket and the outer water bucket, helps reduce assembly errors, and improves the overall assembly quality. At the same time, after the assembly is completed, first welding the local area of the weld seam at the through-welding part helps fix the hub water bucket and the outer water bucket, providing stable support for the subsequent full welding. Also, after removing the auxiliary assembly tooling, then performing all welding work on the weld seam constitutes a step-by-step welding method, which not only helps ensure the welding quality, but also can reduce the thermal stress during the welding process, reduce welding deformation, and achieve optimized welding process and improved welding quality. In addition, the high-precision assembly process helps ensure the overall quality of the impulse turbine runner, which can not only improve the service life of the product, but also reduce the failure rate caused by assembly problems.

[0018] In an optional implementation manner, before precision machining, the following step should also be carried out: Prefabrication: Separately forge the hub water bucket and the outer water bucket.

[0019] Beneficial effects: Through the separate forging technology, the utilization rate of raw materials can be improved, and material waste can be reduced. At the same time, by setting the hub water bucket and the outer water bucket separately, compared with the integrated design of the hub water bucket and the outer water bucket, it is convenient to reduce the parameters of the equipment used for moving this part of the components, thus saving costs.

[0020] In an optional implementation manner, after completing the positioning welding step, and / or after completing the full welding step, the following step should also be carried out: Measurement and inspection: Use a laser scanner to scan and measure the outer water bucket surface with the hub water bucket as the reference, and compare the scanned data with the theoretical digital model of the runner.

[0021] Beneficial effects: By using a laser scanner to scan and measure the outer water bucket surface after one or both of the positioning welding and full welding steps are completed, the assembly quality can be visually evaluated, which helps to promptly detect defects such as cracks and slag inclusions in the welds, and timely adjust the welding process parameters to prevent the occurrence of defects during the assembly process, ensuring that the overall assembly quality meets the design requirements.

[0022] In an alternative embodiment, when performing the measurement and inspection step after completing the positioning welding step, the defined surface deviation is ≤2 mm; and / or when performing the measurement and inspection step after completing the full welding step, the defined surface deviation is ≤3 mm.

[0023] Beneficial effects: By setting the surface deviation, it helps to promptly detect and correct deviations during the welding process, avoid larger deviations after welding is completed, reduce rework caused by unqualified welding quality, contribute to reducing production costs, and improve production efficiency.

[0024] In an alternative embodiment, when performing the full welding step, a gas metal arc welding equipment is used to weld the weld formed between the outer water bucket and the hub water bucket. The yield strength R p0.2 of the wire deposited metal is 580 - 700 MPa, and the tensile strength R m is 780 - 900 MPa. The welding shielding gas is 95% Ar + 5% CO 2 , the welding preheating temperature T 0 ≥80 °C, and the interpass temperature T 1 is 80 - 150 °C; or when performing the full welding step, a gas tungsten arc welding equipment is used to weld the weld formed between the outer water bucket and the hub water bucket. The yield strength R p0.2 of the wire deposited metal is 580 - 700 MPa, and the tensile strength R m is 780 - 900 MPa. The welding shielding gas is 99.99% Ar, the welding preheating temperature T 0 ≥50 °C, and the interpass temperature T 1 is 50 - 150 °C.

[0025] Beneficial effects: By precisely controlling the welding parameters and processes, the rework phenomenon caused by unqualified weld quality can be greatly reduced, further reducing production costs. Specifically: By using a wire deposited metal with a yield strength R p0.2 of 580 - 700 MPa and a tensile strength R m of 780 - 900 MPa, it ensures that the weld has high mechanical properties such as load-bearing capacity after welding. Also, by using a welding shielding gas of 95% Ar + 5% CO 2Or 99.99% Ar can effectively prevent the weld seam from being contaminated by harmful gases such as oxygen and nitrogen in the air during the welding process, thereby improving the purity and quality of the weld seam. At the same time, when choosing gas metal arc welding according to the actual situation, it can have the advantage of fast welding speed, or choosing gas tungsten arc welding can improve the weld quality. In addition, by setting reasonable preheating temperature (T 0 ≥80 °C or T 0 ≥50 °C) and interpass temperature (80 - 150 °C or 50 - 150 °C), the generation of welding stress and cracks can be effectively reduced, and the toughness and fatigue resistance of the weld seam can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the specific embodiments of the present invention, the following will briefly introduce the drawings required for use in the description of the specific embodiments. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 It is a schematic structural diagram of the disassembled auxiliary assembly tooling provided by the embodiment of the present invention;

[0028] Figure 2 It is a schematic structural diagram of the disassembled outer water buckets and hub water buckets of the runner provided by the embodiment of the present invention;

[0029] Figure 3 It is a schematic structural diagram of the disassembled outer water buckets and hub water buckets of the runner provided by the embodiment of the present invention;

[0030] Figure 4 It is an assembly schematic diagram of the outer water buckets of the runner and the hub water buckets through the auxiliary assembly tooling provided by the embodiment of the present invention;

[0031] Figure 5 It is another perspective assembly schematic diagram of the outer water buckets of the runner and the hub water buckets through the auxiliary assembly tooling provided by the embodiment of the present invention;

[0032] Figure 6 It is a schematic flow diagram of the installation method of the outer water bucket of the impulse turbine provided by the embodiment of the present invention.

[0033] Description of the reference numerals:

[0034] 1. Front mold;

[0035] 2. Rear mold; 21. Hub water bucket fixing surface; 22. Outer water bucket fixing surface; 23. Welding-through part; 24. Avoidance notch;

[0036] 3. Connection structure; 31. First connection hole; 32. Second connection hole; 33. Connector;

[0037] 4. Guide and positioning structure; 41. First guide hole; 42. Second guide hole; 43. Guide;

[0038] 5. Hub bucket; 51. Hub bucket profile;

[0039] 6. Outer bucket; 61. Outer bucket profile;

[0040] 7. Weld seam. Detailed implementation mode

[0041] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0042] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "top", "bottom", "inside", "outside", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0043] The terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise specified, the meaning of "plurality" is two or more.

[0044] In the description of the present application, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0045] As a highly efficient and clean energy conversion device, large-capacity impulse hydroelectric generating units have become an important option to meet the country's energy needs. The runner, as the core component of the hydroelectric generating unit, its performance is directly related to the operating efficiency and stability of the entire unit.

[0046] With the continuous increase in the unit capacity, the size and weight of the runner have increased sharply, which undoubtedly poses more stringent requirements for the manufacturing process and material selection of the runner. Currently, the industry generally adopts the forging and welding manufacturing process to manufacture the runner. Specifically, the runner hub and the outer water buckets are respectively made of forgings and processed separately, and then the runner hub and the outer water buckets are connected and fixed through precise welding technology.

[0047] However, during the process of assembling the outer water buckets to the end face of the runner hub, the accuracy of the assembly positioning is directly related to the profile dimensions of the runner after welding. If the assembly and welding deviation of the outer water buckets is too large, it will lead to a significant reduction in the hydraulic efficiency of the runner and cannot meet the hydraulic design requirements of the runner. This will not only affect the power generation efficiency of the unit but may also cause a series of operating failures and safety hazards.

[0048] Therefore, the present invention improves the accuracy during the assembly of the outer water buckets by adding an auxiliary assembly tooling, thereby reducing the assembly difficulty.

[0049] The following Figures 1 to 6 , describes the embodiments of the present invention.

[0050] According to an embodiment of the present invention, in a first aspect, there is provided an auxiliary assembly tooling for accurately installing the root of the outer water bucket 6 on the top of the hub water bucket 5 in a fixed posture and disassembling it when the outer water bucket 6 and the hub water bucket 5 are initially welded.

[0051] As Figures 1 to 5 shown, the auxiliary assembly tooling includes a front mold 1, a rear mold 2, and a connection structure 3.

[0052] Wherein, at least one of the front mold 1 and the rear mold 2 is provided with a hub water bucket fixing surface 21, and at least one of the front mold 1 and the rear mold 2 is provided with an outer water bucket fixing surface 22. The hub water bucket fixing surface 21 is adapted to the hub water bucket profile 51, and the outer water bucket fixing surface 22 is adapted to the outer water bucket profile 61. When the hub water bucket fixing surface 21 is attached to the hub water bucket profile 51 and the outer water bucket fixing surface 22 is attached to the outer water bucket profile 61, the front mold 1 and the rear mold 2 are fixed through the connection structure 3, and the root of the outer water bucket 6 is accurately fixed on the top of the hub water bucket 5.

[0053] With such a setting, by adding an auxiliary assembly tooling, it is used to reduce the assembly error of the outer water bucket 6, thereby reducing the welding deviation. Specifically, by providing at least one of the front mold 1 and the rear mold 2 with a hub water bucket fixing surface 21 adapted to the hub water bucket profile surface 51, and providing at least one of the front mold 1 and the rear mold 2 with an outer water bucket fixing surface 22 adapted to the outer water bucket profile surface 61. When the outer water bucket 6 is assembled on the top of the hub water bucket 5, by fitting each fixing surface with the corresponding profile surface and using the connecting structure 3 to fix the front mold 1 and the rear mold 2, it can ensure that the outer water bucket 6 is accurately assembled during the assembly process, improving the accuracy and stability of the assembly.

[0054] At the same time, through the setting of the auxiliary assembly tooling, during operation, the maintenance personnel only need to align and fix the front mold 1 and the rear mold 2 with the corresponding water bucket profile surfaces, and then the assembly can be quickly completed. This can simplify the assembly process, reduce the time for manual adjustment, and lower the difficulty of manual adjustment, thereby improving the production efficiency.

[0055] In addition, since the hub water bucket fixing surface 21 in the tooling is adapted to the hub water bucket profile surface 51 and the outer water bucket fixing surface 22 is adapted to the outer water bucket profile surface 61, it can be adjusted according to different models and specifications of the outer water bucket 6, making the tooling highly flexible.

[0056] It can be noted that in this application, the number of the through-welding parts 23 is not specifically limited.

[0057] In one embodiment, when the hub water bucket fixing surface 21 is fitted with the hub water bucket profile surface 51 and the outer water bucket fixing surface 22 is fitted with the outer water bucket profile surface 61, the connection part between the outer water bucket 6 and the hub water bucket 5 forms a weld seam 7; at least one of the front mold 1 and the rear mold 2 is provided with a through-welding part 23, and the through-welding part 23 is used to connect the local welding area of the weld seam 7 with the external environment.

[0058] With such a setting, when the hub water bucket fixing surface 21 is fitted with the hub water bucket profile surface 51 and the outer water bucket fixing surface 22 is fitted with the outer water bucket profile surface 61, the connection part between the outer water bucket 6 and the hub water bucket 5 forms a weld seam 7. At this time, by providing the through-welding part 23, it is convenient for the welding personnel to approach the weld seam 7 for local welding, improving the welding efficiency and accuracy.

[0059] At the same time, by welding the local area of the weld seam 7 at the through-welding part 23, it helps to complete the positioning work of the outer water bucket 6 and the hub water bucket 5.

[0060] In addition, since the welding area is connected to the external environment, it helps the heat, smoke and harmful gases generated during the welding process to be discharged in time, which is beneficial for the welding personnel to control the quality of the weld seam 7, reduce welding defects, and reduce the damage to the welding equipment caused by the heat, smoke and harmful gases, prolonging the service life of the welding equipment.

[0061] That is, when there is one through-welding part 23, the through-welding part 23 is arranged on the front mold 1 or the rear mold 2; when the number of through-welding parts 23 is two or more, one or both of the front mold 1 and the rear mold 2 are processed with through-welding parts 23.

[0062] In one embodiment, the through-welding part 23 is provided with an avoidance notch 24 for the welding end of the welding equipment to move.

[0063] With such a setting, by providing the avoidance notch 24 in the through-welding part 23, it helps the welding end of the welding equipment to approach the weld 7, reduces the difficulty for the welding end to move to the weld 7 due to space limitations, helps to optimize the welding process, and enables the welder to accurately complete the welding task.

[0064] In one embodiment, the connection structure 3 includes a first connection hole 31, a second connection hole 32, and a connecting member 33. The first connection hole 31 and the second connection hole 32 are respectively opened on the front mold 1 and the rear mold 2. Among the first connection hole 31 and the second connection hole 32, one of them is a through hole and the other is an internal thread hole. The connecting member 33 is provided with an external thread that passes through the through hole and is screwed into the internal thread hole.

[0065] With such a setting, by providing the first connection hole 31, the second connection hole 32, and the connecting member 33, during installation, only need to pass the external thread of the connecting member 33 through the through hole and screw it into the internal thread hole, then the relative fixation of the front mold 1 and the rear mold 2 can be completed, without the need to use additional complex tools or connection methods.

[0066] At the same time, through threaded connection, a tight and stable connection is formed between the connecting member 33 and the front mold 1 and the rear mold 2. This connection method has high tensile strength and shear strength, and can ensure that the connection between the front mold 1 and the rear mold 2 will not loosen or fail during assembly and use.

[0067] In addition, since the connecting member 33 is screwed into the internal thread hole by thread, when it needs to be disassembled, only need to rotate the connecting member 33 in the reverse direction and take it out, which is convenient for subsequent disassembly by the auxiliary assembly tooling and reuse.

[0068] It can be stated that the connecting member 33 is preferably a bolt.

[0069] In one embodiment, the auxiliary assembly tooling further includes a guiding and positioning structure 4. The guiding and positioning structure 4 includes a first guiding hole 41, a second guiding hole 42, and a guiding member 43. The first guiding hole 41 and the second guiding hole 42 are respectively opened on the front mold 1 and the rear mold 2. The first guiding hole 41 and the second guiding hole 42 are communicated, and the guiding member 43 passes through one of the first guiding hole 41 and the second guiding hole 42 and extends towards the other.

[0070] With such a setting, by providing the first guiding hole 41, the second guiding hole 42 and the guiding member 43, after the guiding member 43 is installed, a relatively precise guidance can be provided for the connecting structure 3, ensuring a high-precision connection process when the connecting structure 3 is connected, avoiding displacement, reducing the stress on the connecting member 33, and thus ensuring the assembly quality.

[0071] Meanwhile, it helps to enhance the stability of the overall structure of the auxiliary assembly tooling, facilitating the improvement of the ability of the auxiliary assembly tooling to resist external force interference during the assembly process, so that the auxiliary assembly tooling has a relatively stable installation state.

[0072] In addition, through the setting of the guiding and positioning structure 4, the assembly process becomes more stable and simple. The operator only needs to perform the assembly according to the guidance of the guiding holes, without the need for additional complex adjustment and calibration work.

[0073] It can be noted that the guiding member 43 is preferably a cylindrical pin for easy positioning.

[0074] According to an embodiment of the present invention, on the other hand, an installation method for the outer water bucket 6 of an impulse water turbine is also provided, which is applied to the auxiliary assembly tooling in the previous aspect.

[0075] As Figure 6 shown, the installation method for the outer water bucket 6 of the impulse water turbine includes steps such as precise machining, positioning welding, and full welding.

[0076] In one embodiment, a hub water bucket profile 51 is precisely machined at the hub water bucket 5, and an outer water bucket profile 61 is precisely machined at the outer water bucket 6.

[0077] Specifically, the end face of the hub water bucket 5 for connecting the outer water bucket 6 is defined as the water bucket split interface, and the hub water bucket profile 51 and the outer water bucket profile 61 within 20 mm on both sides of the water bucket split interface are precisely machined as the assembly reference for the outer water bucket 6.

[0078] Furthermore, an auxiliary assembly tooling is designed and manufactured according to the dimensions of the hub water bucket profile 51 and the outer water bucket profile 61. An outlet hub water bucket fixing surface 21 adapted to the outlet hub water bucket profile 51 and an outer water bucket fixing surface 22 adapted to the outer water bucket profile 61 are precisely machined at the auxiliary assembly tooling.

[0079] It should be noted that since the hub water bucket profile 51 is machined at the hub water bucket 5 and the outer water bucket profile 61 is machined at the outer water bucket 6, therefore, it is thickened by 1 mm in advance to connect and transition the weld 7 between the outer water bucket 6 and the hub water bucket 5, so that the root materials of the outer water bucket 6 and the hub water bucket 5 will not be thinned during the grinding of the weld 7, thus avoiding the phenomenon that the outer water bucket 6 detaches from the hub water bucket 5 during the use of the runner.

[0080] Furthermore, a milling CNC machining method is selected to complete the precision machining step.

[0081] In one embodiment, before precision machining, the following steps should also be carried out: Prefabrication: The hub water bucket 5 and the outer water bucket 6 are forged separately.

[0082] In one embodiment, during prefabrication, it also includes: machining the auxiliary assembly tooling.

[0083] It should be noted that a welding-through part 23 is provided on the front mold 1 and / or the rear mold 2.

[0084] Furthermore, an avoidance notch 24 is machined on the welding-through part 23.

[0085] Preferably, as Figure 1 shown, an avoidance notch 24 is machined at the top of the welding-through part 23.

[0086] In one embodiment, after completing the precision machining, the assembly of the auxiliary assembly tooling, the hub water bucket 5 and the outer water bucket 6 is completed.

[0087] Specifically, the auxiliary assembly tooling is placed at the end of the hub water bucket 5 close to the outer water bucket 6, that is, the front mold 1 and the rear mold 2 of the auxiliary assembly tooling are sequentially installed at the end of the hub water bucket 5 close to the outer water bucket 6, and the outer water bucket 6 is placed into the auxiliary assembly tooling. Then, a cylindrical pin is used to penetrate the first guide hole 41 and the second guide hole 42, and then a bolt is used. The external thread of the bolt is passed through the through hole and screwed into the internal thread hole until it is tightened.

[0088] It can be noted that when installing the outer water bucket 6, a hoisting method is selected.

[0089] It can be noted that the installation order of the outer water bucket 6 and the auxiliary assembly tooling is not specifically limited. It only needs to avoid interference problems during installation. The specific installation order depends on actual needs. The installation of the outer water bucket 6 can be completed after the assembly of the auxiliary assembly tooling; or the installation of the auxiliary assembly tooling can be completed after the installation of the outer water bucket 6; of course, it can also be: after completing the assembly of one of the front mold 1 and the rear mold 2, then complete the installation of the outer water bucket 6, and finally complete the assembly of the other of the front mold 1 and the rear mold 2.

[0090] It can be noted that the standard for judging whether the auxiliary assembly tooling is installed in place is: the hub water bucket fixing surface 21 is in contact with the hub water bucket surface 51, and the outer water bucket fixing surface 22 is in contact with the outer water bucket surface 61.

[0091] Furthermore, the fitting gap between the hub water bucket fixing surface 21 and the hub water bucket surface 51 should be less than or equal to 1 mm, and the fitting gap between the outer water bucket fixing surface 22 and the outer water bucket surface 61 should be less than or equal to 1 mm.

[0092] Finally, weld the local area of the weld seam 7 at the through-welding part 23 to complete the positioning welding process of the outer water bucket 6 and the hub water bucket 5.

[0093] Among them, the positioning welding is completed by using a gas metal arc welding equipment. During the use, the gas metal arc welding equipment moves from the avoidance notch 24 at the through-welding part 23 to the area to be welded of the weld seam 7 and performs welding.

[0094] When the positioning welding step is completed, the full welding step is carried out.

[0095] Specifically, first remove the auxiliary assembly tooling, and then complete all the welding work of the weld seam 7.

[0096] It should be noted that the sequence of steps for removing the auxiliary assembly tooling is opposite to the sequence of steps for installing the auxiliary assembly tooling.

[0097] With such a setting, by precisely machining the corresponding profiles at the hub water bucket 5 and the outer water bucket 6, and machining the fixing surfaces adapted to these profiles at the auxiliary assembly tooling, it is ensured that the auxiliary assembly tooling is precisely matched with the hub water bucket 5 and the outer water bucket 6, which helps to reduce the assembly error and improve the overall assembly quality.

[0098] At the same time, after the assembly is completed, first welding the local area of the weld seam 7 at the through-welding part 23 helps to fix the hub water bucket 5 and the outer water bucket 6 and provides stable support for the subsequent full welding.

[0099] Moreover, after removing the auxiliary assembly tooling, then carrying out all the welding work of the weld seam 7 constitutes a step-by-step welding method, which not only helps to ensure the welding quality, but also can reduce the thermal stress during the welding process, reduce the welding deformation, and achieve the optimization of the welding process and the improvement of the welding quality.

[0100] In addition, the high-precision assembly process helps to ensure the overall quality of the impulse turbine runner, which can not only improve the service life of the product, but also reduce the failure rate caused by assembly problems.

[0101] With such a setting, through the split forging technology, the utilization rate of raw materials can be improved and material waste can be reduced. At the same time, by setting the hub water bucket 5 and the outer water bucket 6 separately, compared with the integral design method of the hub water bucket 5 and the outer water bucket 6, it is convenient to reduce the parameters of the equipment used for moving this part of the components, thus saving costs.

[0102] In one embodiment, after the positioning welding step is completed, the following steps should also be carried out: measurement and inspection: use a laser scanner to scan and measure the profile 61 of the outer water bucket with the hub water bucket 5 as the reference, and compare the scanned data with the theoretical digital model of the runner.

[0103] In one embodiment, after the positioning welding step is completed and the measurement and inspection step is carried out, the defined profile deviation is ≤2 mm.

[0104] With such a setting, by setting the profile deviation, it is helpful to detect and correct deviations in a timely manner during the welding process, avoid larger deviations after welding is completed, reduce rework caused by unqualified welding quality, help reduce production costs, and improve production efficiency.

[0105] In one embodiment, after the full welding step is completed, the measurement and inspection step should be carried out again, and at this time the defined profile deviation is ≤3 mm.

[0106] With such a setting, by using a laser scanner to scan and measure the outer water bucket profile 61 after one or both of the positioning welding and full welding steps are completed, the assembly quality can be visually evaluated, which helps to detect defects such as cracks and slag inclusions in the weld 7 in a timely manner, and by adjusting the welding process parameters in a timely manner, prevent the occurrence of defects during the assembly process, and ensure that the overall assembly quality meets the design requirements.

[0107] In one embodiment, when carrying out the full welding step, a gas metal arc welding equipment is used to weld the weld 7 formed between the outer water bucket 6 and the hub water bucket 5, and the yield strength R of the deposited metal of the welding wire p0.2 is 580 - 700 MPa, and the tensile strength R m is 780 - 900 MPa, the welding shielding gas is 95% Ar + 5% CO 2 , the welding preheating temperature T 0 ≥80 °C, and the interpass temperature T 1 is 80 - 150 °C.

[0108] In one embodiment, when carrying out the full welding step, a gas tungsten arc welding equipment can also be used to weld the weld 7 formed between the outer water bucket 6 and the hub water bucket 5, and the yield strength R of the deposited metal of the welding wire p0.2 is 580 - 700 MPa, and the tensile strength R m is 780 - 900 MPa, the welding shielding gas is 99.99% Ar, the welding preheating temperature T 0 ≥50 °C, and the interpass temperature T 1 is 50 - 150 °C.

[0109] With such a setting, by precisely controlling the welding parameters and processes, the rework phenomenon caused by unqualified weld 7 quality can be greatly reduced, and the production cost can be further reduced.

[0110] Specifically: by using a yield strength R p0.2 of 580 - 700 MPa and a tensile strength R mIt is 780 - 900 MPa to ensure that the weld 7 has high mechanical properties such as load-bearing capacity after welding.

[0111] Also, by using a welding shielding gas of 95% Ar + 5% CO 2 or 99.99% Ar, it can effectively prevent the weld 7 from being contaminated by harmful gases such as oxygen and nitrogen in the air during welding, thereby improving the purity and quality of the weld 7.

[0112] Meanwhile, when choosing gas metal arc welding according to the actual situation, it can have the advantage of fast welding speed, or choosing gas tungsten arc welding can improve the quality of the weld 7.

[0113] In addition, by setting a reasonable preheating temperature for welding (T 0 ≥80°C or T 0 ≥50°C) and interpass temperature (80 - 150°C or 50 - 150°C), it can effectively reduce the generation of welding stress and cracks, and improve the toughness and fatigue resistance of the weld 7.

[0114] It should be noted that when using a gas tungsten arc welding equipment to weld the weld 7 between the outer water bucket 6 and the hub water bucket 5, since the welding shielding gas uses Ar with a purity of 99.99%, it is equivalent to a mixed shielding gas of 95% Ar + 5% CO2, which can effectively reduce the contents of element O and element C in the weld metal, thereby increasing the impact toughness value of the weld metal.

[0115] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. An auxiliary assembly tool, characterized in that: The auxiliary assembly tool comprises a front mold (1), a rear mold (2) and a connecting structure (3); at least one of the front mold (1) and the rear mold (2) is provided with a hub water bucket fixing surface (21); and at least one of the front mold (1) and the rear mold (2) is provided with an outer water bucket fixing surface (22); the hub water bucket fixing surface (21) is configured to fit the hub water bucket profile (51); and the outer water bucket fixing surface (22) is configured to fit the outer water bucket profile (61); when the hub water bucket fixing surface (21) and the hub water bucket profile (51) are configured to fit and the outer water bucket fixing surface (22) and the outer water bucket profile (61) are configured to fit, the front mold (1) and the rear mold (2) are fixed by the connecting structure (3), and the root of the outer water bucket (6) is accurately fixed to the top of the hub water bucket (5).

2. The auxiliary assembly tool according to claim 1, characterized in that: When the hub water bucket fixing surface (21) and the hub water bucket profile surface (51) are arranged in abutment with each other and the outer water bucket fixing surface (22) and the outer water bucket profile surface (61) are arranged in abutment with each other, the connection between the outer water bucket (6) and the hub water bucket (5) forms a weld (7); At least one of the front mold (1) and the rear mold (2) is provided with a through-welding portion (23), and the through-welding portion (23) is used to connect a local welding area of ​​the weld (7) with the external environment.

3. The auxiliary assembly tool according to claim 2, characterized in that: The through-welding portion (23) is provided with an avoidance notch (24) for the welding end portion of the welding equipment to move.

4. The auxiliary assembly tool according to any one of claims 1 to 3, characterized in that: The connection structure (3) comprises a first connection hole (31), a second connection hole (32) and a connection piece (33); the first connection hole (31) and the second connection hole (32) are respectively provided in the front mold (1) and the rear mold (2); one of the first connection hole (31) and the second connection hole (32) is a through hole and the other is an internal threaded hole; the connection piece (33) is provided with an external thread which is penetrated through the through hole and then screwed into the internal threaded hole.

5. The auxiliary assembly tool according to any one of claims 1 to 3, characterized in that: The invention also comprises a guiding and positioning structure (4), wherein the guiding and positioning structure (4) comprises a first guiding hole (41), a second guiding hole (42) and a guiding member (43), wherein the first guiding hole (41) and the second guiding hole (42) are respectively provided in the front mold (1) and the rear mold (2), the first guiding hole (41) and the second guiding hole (42) are communicated with each other, and the guiding member (43) is passed through one of the first guiding hole (41) and the second guiding hole (42) and extends toward the other.

6. A method for installing an outer bucket of an impulse turbine, applied to the auxiliary assembly tool according to any one of claims 1 to 5, characterized in that: The method for installing the outer bucket (6) of the impulse turbine comprises the following steps: Precision machining: Precision machining a hub bucket profile (51) at the hub bucket (5), precision machining an outer bucket profile (61) at the outer bucket (6), and precision machining an outer hub bucket fixing surface (21) matching the outer hub bucket profile (51) and an outer bucket fixing surface (22) matching the outer bucket profile (61) at the auxiliary assembly tooling; Positioning welding: completing the assembly of the auxiliary assembly tooling, the wheel hub bucket (5) and the outer bucket (6), and welding the local area of ​​the weld (7) at the through-weld portion (23); Full welding: Remove the auxiliary assembly tooling and complete all welding work of the weld (7).

7. The method for installing the outer bucket of an impulse turbine according to claim 6, characterized in that: The following steps should be performed before precision machining: Prefabrication: The wheel hub water tank (5) and the outer water tank (6) are forged separately.

8. The method for installing the outer bucket of an impulse turbine according to claim 6, characterized in that: After completing the tack welding step, and / or after completing the full welding step, the following steps should be performed: Measurement and inspection: A laser scanner is used to scan and measure the outer bucket surface (61) with the hub bucket (5) as a reference, and the scanned data is compared with the theoretical digital model of the runner.

9. The method for installing the outer bucket of an impulse turbine according to claim 8, characterized in that: After completing the positioning welding step, during the measurement and inspection step, the profile deviation is defined as ≤ 2mm; and / or After completing the comprehensive welding step, during the measurement and inspection step, the profile deviation is defined as ≤3mm.

10. The method for installing the outer bucket of an impulse turbine according to claim 6, characterized in that: During the full welding step, the weld (7) formed between the outer bucket (6) and the hub bucket (5) is welded using a metal arc welding device, and the yield strength of the deposited metal of the welding wire is R p0.2 580~700MPa, tensile strength R m 780~900MPa, welding shielding gas is 95%Ar+5%CO2, welding preheating temperature T0≥80℃, interlayer temperature T1 is 80~150℃; or During the full welding step, the weld (7) formed between the outer bucket (6) and the wheel hub bucket (5) is welded using a non-melting inert gas shielded welding device. The yield strength R of the deposited metal of the welding wire is p0.2 580~700MPa, tensile strength R m The welding pressure is 780~900MPa, the welding shielding gas is 99.99% Ar, the welding preheating temperature T0≥50℃, and the interlayer temperature T1 is 50~150℃.

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