Numerical control scribing and positioning process method of seat ring fixed guide vane

Abstract

The invention discloses a numerical control scribing and positioning process method for a fixed guide vane of a seat ring, which is characterized by comprising the following steps of: 1, generating a fixed guide vane azimuth contour line based on a three-dimensional model, and mapping the contour line to the surface of a lower ring plate of the seat ring; 2, a numerical control machine tool is used for scribing an azimuth contour line on the lower annular plate, and the scribing depth is 0.1 mm-0. 3 mm; and 3, a limiting block is welded along the scribed line, and accurate positioning of the fixed guide vane is achieved through the limiting block. Guide vane contour data are generated through three-dimensional modeling, accurate azimuth lines are carved on the lower ring plate through a numerical control machine tool, and a limiting block is welded to achieve quick positioning of the guide vane. The method solves the problems of large accumulative error, low efficiency and the like of a traditional process, remarkably improves the assembly precision and the production efficiency, and is suitable for manufacturing the large hydropower station seat ring.

Description

Technical Field

[0001] The invention relates to the technical field of hydro-generator set manufacturing, and in particular to a numerical control marking positioning process method for a seat ring fixing guide vane. Background Art

[0002] In a hydro-turbine generator set, the seat ring, as a core component, must withstand axial loads, ensure water flow uniformity, and transmit structural weight and water pressure. Traditional methods for positioning guide vanes rely on riveters manually drawing ground patterns and determining their positions using distribution circles and angles. However, this method has the following drawbacks:

[0003] Large cumulative errors: Manual operation can easily lead to dimensional deviations, especially in unevenly distributed guide vanes or large-diameter seat rings, where the errors are significantly superimposed.

[0004] Inefficiency: Drawing site samples requires a large area of land, is time-consuming and labor-intensive, and cannot meet the rapid delivery requirements of modern hydropower projects.

[0005] Insufficient precision: The positioning accuracy of complex linear guide vanes (such as asymmetric structures) is difficult to ensure, affecting the overall performance of the unit. Summary of the Invention

[0006] The present invention aims to provide a CNC-guided positioning method for seat ring fixed guide vanes, aiming to address the large cumulative errors, low efficiency, and insufficient precision inherent in conventional fixed guide vane positioning methods. By combining 3D modeling with CNC machining technology, a CNC-guided positioning process based on CNC guidance is proposed, achieving precise guide vane positioning, improving production efficiency and reducing labor intensity.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A numerical control scoring positioning process method for a seat ring fixed guide vane comprises the following steps:

[0009] Step 1: Generate a fixed guide vane azimuth contour line based on the three-dimensional model, and map the contour line to the surface of the seat ring lower ring plate;

[0010] Step 2: Use a CNC machine tool to carve an azimuth contour line on the lower ring plate, with a depth of 0.1 mm to 0.3 mm;

[0011] Step 3: Weld the limit blocks along the engraved lines, and use the limit blocks to achieve precise positioning of the fixed guide vanes.

[0012] In some embodiments, the CNC machine tool is a gantry milling machine, the engraving accuracy is ±0.1 mm, and the engraving shape is a V-groove or a U-groove.

[0013] In some embodiments, the welding method of the limiting block is continuous welding or intermittent spot welding, and the welding spacing error is controlled within ±0.5 mm.

[0014] In some embodiments, the 3D model in Step 1 is generated by CAD or CAE software and includes the data of the fixed guide vane profile with non-uniform distribution.

[0015] In some embodiments, before the scribing process, the surface of the lower ring plate needs to be cleaned and pre-treated for rust prevention to ensure that there are no impurities in the scribing area.

[0016] In some embodiments, the limiting block is made of high-strength alloy steel, and its height matches the installation clearance of the fixed guide vane, with an error range not exceeding ±0.3 mm.

[0017] In some embodiments, after scribing, laser scanning detection is carried out to ensure that the deviation of the scribing position is less than ±0.1 mm.

[0018] In some embodiments, the process is applicable to stay rings with a diameter greater than 10 meters and an asymmetric distribution structure with 10 - 20 guide vanes.

[0019] The beneficial effects brought by the numerical control scribing positioning process method for the stay ring fixed guide vane disclosed in this application include but are not limited to:

[0020] High-precision positioning: The numerical control scribing accuracy can reach ±0.1 mm, significantly reducing the cumulative error, especially suitable for guide vanes with non-uniform distribution.

[0021] Efficiency improvement: The step of manually drawing the ground pattern is eliminated, saving about 30% - 40% of the working hours and reducing the site requirement by more than 50%.

[0022] Reduced labor intensity: The riveter only needs to weld the limiting block according to the scribing, with simplified operation and high error tolerance. Detailed implementation manners

[0023] In order to make the purpose, technical solutions and advantages of this application clearer, the following further details this application in conjunction with embodiments. It should be understood that the specific embodiments described here are only used to explain this application and are not used to limit this application.

[0024] On the contrary, this application covers any alternatives, modifications, equivalent methods and solutions made on the essence and scope of this application defined by the claims. Further, in order to enable the public to have a better understanding of this application, some specific details are described in detail in the following detailed description of this application. Those skilled in the art can fully understand this application without the description of these details.

[0025] Embodiment 1: Manufacture of the stay ring for the Luang Prabang Hydropower Station in Laos

[0026] Project Background

[0027] The stay ring has a diameter of 14.8 meters, a height of 5.9 meters, and weighs 237 tons, including 14 asymmetrically distributed stay vanes (8 different profiles).

[0028] Traditional processes use riveters to draw ground patterns for positioning, which have problems such as large cumulative errors and low efficiency, and need to be improved to numerical control line engraving processes.

[0029] Detailed Description of Process Steps

[0030] (1) 3D Modeling and Data Mapping

[0031] Use SolidWorks software to establish a 3D model of the stay ring, including the azimuth contour data of the non-uniform stay vanes.

[0032] Map the stay vane contour line to the surface of the lower ring plate to generate the G-code required for numerical control machining.

[0033] (2) Pretreatment of the Lower Ring Plate

[0034] Sandblast and clean the surface of the lower ring plate to remove the oxide layer and impurities, and spray anti-rust primer to ensure the cleanliness of the line engraving area.

[0035] (3) Numerical Control Line Engraving Machining

[0036] Use a five-axis numerical control gantry milling machine (model: XK2740) to engrave the V-groove contour line with a depth of 0.2mm×0.2mm and a line engraving accuracy of ±0.1mm.

[0037] After line engraving, use a LaserTrack LS-1000 laser scanner to detect the deviation of the line engraving position (the measured deviation ≤ 0.08mm).

[0038] (4) Welding of Limit Blocks

[0039] The material of the limit block is Q345B high-strength alloy steel, and its height matches the installation clearance of the stay vane (the designed value is 12mm, with an error of ±0.2mm).

[0040] Adopt continuous welding along the engraved line, and control the welding spacing error within ±0.3mm to ensure that the position of the limit block is consistent with the contour line.

[0041] (5) Assembly and Verification of Stay Vanes

[0042] Lift and fix the stay vane into the limit block, and measure the deviation of the stay vane position through a laser locator (the measured maximum deviation is 0.9mm, meeting the design requirement of ≤1mm).

[0043] The overall stay ring was reinspected by a coordinate measuring machine (CMM), and the dimensional tolerances conform to the ISO 2768-m standard.

[0044] Implementation effect

[0045] The cumulative error was reduced from ±3 mm in the traditional process to ±0.8 mm, and the guide vane positioning accuracy was improved by 72%.

[0046] The manufacturing cycle was shortened from 45 days to 30 days, and the floor space occupation was reduced by 70%.

[0047] The labor intensity of riveters was reduced by 60%, and the welding rework rate was reduced from 15% to 2%.

[0048] Example 2: Case - Manufacturing of the stay ring for a large pumped-storage power station

[0049] Project background

[0050] The stay ring has a diameter of 18 m, a height of 7.2 m, and a weight of 350 tons, and includes 20 asymmetric fixed guide vanes (12 types of profiles).

[0051] The requirement for the guide vane positioning error is ≤0.5 mm, and the traditional process cannot meet the accuracy requirements.

[0052] Process optimization

[0053] Selection of the engraved line shape: For guide vanes with complex profiles, U-shaped grooves (depth 0.25 mm × 0.25 mm) are used for engraving to enhance the fit between the limit block and the engraved line.

[0054] Adjustment of the welding method: Intermittent spot welding (spacing 50 mm) is used, and the welding thermal deformation is reduced by 30%.

[0055] Detection upgrade: Industrial CT scanning is introduced to monitor the welding position of the limit block in real time to ensure the error ≤±0.2 mm.

[0056] Implementation effect

[0057] The guide vane positioning deviation is ≤0.4 mm, and the accuracy is improved by 80%.

[0058] The manufacturing cycle is compressed to 25 days, meeting the urgent delivery requirements of the project.

[0059] Example 3: General application description

[0060] Scope of application

[0061] Large stay rings with a diameter of 10 - 20 m, 10 - 20 guide vanes, applicable to hydropower stations, pumped-storage power stations, and tidal generating units.

[0062] Particularly applicable to complex structures with asymmetric guide vane distribution and multi-profile guide vanes.

[0063] Flexible Parameter Adjustment

[0064] Engraving Depth: Adjust the engraving depth according to the weight of the guide vane (0.1 mm - 0.3 mm). For heavy guide vanes, deep grooves are used to enhance the limit stability.

[0065] Material of the Limit Block: 316L stainless steel is used in marine environments to improve corrosion resistance.

[0066] Detection Method: For small stay rings, an optical projector can be used instead of laser scanning to reduce costs.

[0067] Summary of Technical Effects

[0068] As can be seen from the above embodiments, the present invention has the following advantages:

[0069] Precisely Adapt to Complex Structures: By combining three-dimensional modeling and numerical control engraving, the problem of non-uniform guide vane positioning is effectively solved.

[0070] High Process Flexibility: Supports the adaptation of various engraving shapes, welding methods, and detection means to meet the requirements of different projects.

[0071] Strong Industrial Promotion: Applicable to the manufacture of stay rings of various specifications, with the potential for large-scale production.

[0072] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A numerical control scribing positioning process method for stay vanes of stay ring, characterized in that, It includes the following steps: Step 1: Generate the fixed guide vane azimuth contour line based on the 3D model, and map the contour line to the surface of the lower ring plate of the stay ring; Step 2: Use a numerically controlled machine tool to scribe the azimuth contour line on the lower ring plate, and the scribing depth is 0.1 mm - 0.3 mm; Step 3: Weld the limit blocks along the scribed lines, and achieve the precise positioning of the fixed guide vanes through the limit blocks.

2. The process method according to claim 1, wherein The numerically controlled machine tool is a gantry milling machine, the scribing accuracy is ±0.1 mm, and the scribing shape is a V-shaped groove or a U-shaped groove.

3. The process method according to claim 1, characterized in that, The welding method of the limit blocks is continuous welding or intermittent spot welding, and the welding spacing error is controlled within ±0.5 mm.

4. The process method according to claim 1, wherein In the said Step 1, the 3D model is generated by CAD or CAE software and contains the data of the fixed guide vane profile line with non-uniform distribution.

5. The process method according to claim 1, characterized in that, Before the scribing process, the surface of the lower ring plate needs to be cleaned and pre-treated for rust prevention to ensure that there are no impurities in the scribing area.

6. The process method according to claim 1, wherein The limit blocks are made of high-strength alloy steel, and their height matches the installation clearance of the fixed guide vanes, and the error range does not exceed ±0.3 mm.

7. The process method according to claim 1, characterized in that, After the scribing is completed, laser scanning detection is carried out to ensure that the scribing position deviation is less than ±0.1 mm.

8. The process method according to claim 1, characterized in that, The said process is applicable to the stay ring with a diameter greater than 10 meters and the asymmetric distribution structure with 10 - 20 guide vanes.