Wooden mold real sample modeling method for large propeller

Abstract

The invention provides a large propeller wood mold real sample modeling method, which relates to the technical field of propeller manufacturing, and comprises the following manufacturing steps: firstly, according to finished product data and process parameters, establishing a three-dimensional model of a blade blank, performing layering treatment on a to-be-modeled propeller blade according to a model simulation result, and performing wood discharging according to a layering result, then, a steel framework is arranged on the propeller hub according to the shape of the propeller blade, all layers of wood are laid on the steel framework layer by layer and are bonded and fixed, manufacturing of the single-propeller-blade wood pattern is completed, and finally the surface of the wood pattern is polished and painted. The pressure surface and the suction surface of the blade are pounded by using the wood mold modeling, so that the manual error can be reduced, and the precision and the consistency of the blade allowance are obviously improved; in addition, the labor intensity is reduced, the modeling efficiency is improved, the labor and material cost is saved, after modeling precision control is achieved through a wood mold real sample, reverse deformation control and allowance reduction can be achieved by analyzing allowance data in manufacturing to adjust technological parameters, and the production cost is further reduced.

Description

Technical Field

[0001] This invention relates to the field of propeller manufacturing technology. Background Technology

[0002] Ship propellers, as crucial components of ships, play a vital role in their navigation efficiency and stability. Precision-cast propellers can significantly improve ship performance (including navigation efficiency, stability, and safety), enhancing my country's maritime strength and competitiveness. However, compared with international advanced levels, my country's research and application of ship propeller casting technology started relatively late. Ship propeller blades are currently produced using traditional sand casting methods, such as... Figure 1 As shown, the casting process is complicated and includes the following steps: pressure surface molding, making fake blade molds, pounding the mold, opening the mold, cleaning the fake blade molds, and grinding the blade root rounded corners. It has many problems such as many steps, long process, and difficulty in accurately controlling shape and performance, making it difficult to meet the urgent requirements of multiple varieties, short cycle, high precision, and high performance.

[0003] In the shipbuilding industry, the manufacturing quality of marine propellers with diameters exceeding 10 meters, weights exceeding 30 tons, and complex shapes directly affects the performance and reliability of the entire equipment. This means that the preparation of the blank requires correspondingly large-sized, high-quality sand molds. The molding efficiency and quality of the sand molds directly affect the efficiency and quality of casting, and thus the machining of the parts. However, errors in the casting sand molds in traditional casting processes can lead to a series of problems, such as the casting blanks being difficult to enclose the design model, significantly uneven machining allowances, and difficulty in analyzing the actual deformation patterns.

[0004] Currently, the casting molding of large propellers is still done manually, including manual sand scraping molding that combines blade cross-section templates with pitch gauge measurement points. This method relies heavily on worker experience. However, due to the large size requirements of large propellers, it generally suffers from low molding efficiency, difficulty in controlling surface roughness, and poor dimensional consistency. This results in insufficient sand mold size and precision, leading to poor blank dimensional accuracy. It is necessary to increase machining allowances to meet subsequent machining requirements, severely limiting the processing capacity of later stages and significantly reducing processing efficiency. Furthermore, the increased machining allowance removes the chilled, dense layer on the surface of the casting during machining, which also affects the casting quality of the propeller. Summary of the Invention

[0005] To overcome the problems of insufficient machining accuracy, low molding efficiency, and poor casting quality in traditional large propeller molding methods, this invention provides a method for molding large propeller wooden models.

[0006] The technical solution adopted by the present invention to achieve the above objectives includes the following steps: The wooden mold is constructed using a layer-by-layer bonding method. The specific construction method is as follows: Step S1: Create a 3D model of the blade blank; Step S2: Perform layered processing on the results of the 3D model simulation; Step S3: Lay out the timber according to the layering results, reserving space for the steel frame; Step S4: Lay each layer of wood onto the steel frame and glue and fix it in place. The wooden mold is now complete. Specifically, between step S2 and step S3, the following step is also included: a steel frame composed of multiple steel bars is arranged on the hub according to the shape of the blade; Specifically, between step S3 and step S4, the following step is also included: a steel frame composed of multiple steel bars is arranged on the rotor hub according to the shape of the rotor blade; Specifically, after step S4, the surface of the wooden mold is sanded and painted to complete the production of the single-blade wooden mold.

[0007] Specifically, after the wooden mold is made, two hub lifting columns are symmetrically set at both ends of the large end face of the hub, 80-100mm from the edge, and two blade lifting columns are set at both ends of the blade 0.8R centerline, 270-300mm from the edge.

[0008] Specifically, in the steel frame composed of multiple steel bars, the second steel bar near the blade tip and guide edge has a 180-220mm protrusion at the guide edge, and a 20mm diameter through hole with a 24mm diameter to accommodate the threaded rod and matching nut is opened in the protrusion to fix the blade part of the wooden mold.

[0009] Specifically, after the wooden mold is made, two symmetrical propeller hub lifting columns are set at about 100mm from the edge at both ends of the large end face of the propeller hub, and two propeller blade lifting columns are set at about 300mm on both sides of the 0.8R center line of the propeller blade, to ensure that the wooden mold can be lifted and transported stably.

[0010] Preferably, the steel frame consists of 4-7 steel bars of varying lengths connected to the outer surface of the propeller hub.

[0011] Preferably, the steel frame comprises six steel bars of varying lengths.

[0012] Specifically, the layering process is based on a thickness of 20mm. The propeller blank model is disassembled layer by layer into three-dimensional models using a three-dimensional model, and the maximum projected area of ​​each cross section is selected as the three-dimensional model of the wood.

[0013] The beneficial effects of this invention are as follows: 1. Using wooden molds to shape the pressure and suction surfaces of the paddles can reduce human error, improve product precision, and significantly improve the precision and consistency of the paddle allowance compared to hand-shaping.

[0014] 2. Direct sand pounding and molding using the paddle blades can reduce molding difficulty, reduce labor intensity, directly improve molding efficiency, and save 1-2 workers.

[0015] 3. Using wooden molds for actual modeling instead of manual sandblasting can effectively control the accuracy of allowances, thereby saving material costs, reducing subsequent processing time, and lowering production costs, based on feedback from subsequent processing data. For the same product, using wooden molds for actual modeling can improve subsequent machining efficiency by approximately 13%. Depending on the propeller size, the cost of casting copper material can be reduced by approximately 0.5-1.5 million yuan per unit.

[0016] 4. After controlling the modeling accuracy through the wooden mold sample, the blade allowance and actual casting deformation can be analyzed based on the allowance data during production. By adjusting the process parameters, reverse deformation control and allowance reduction can be achieved, further reducing production costs. Attached Figure Description

[0017] Figure 1 It is a flowchart of the existing manual shaping process; Figure 2 This is a structural diagram of the internal steel frame of the wooden mold according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the bonding of the steel frame and the single-layer wooden mold according to an embodiment of the present invention; Figure 4 This is a perspective view of a single-blade wooden model according to an embodiment of the present invention; Figure 5 This is a schematic diagram of a single-blade layered adhesive wooden mold according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the hoisting points and fixing points according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the wooden mold sample shaping and positioning according to an embodiment of the present invention; Figure 8 This is an overall structural diagram of the embodiment of the present invention.

[0018] The markings in the diagram are: 1. Propeller hub; 2. Steel frame; 3. Propeller hub hoisting column; 4. Propeller blade hoisting column; 5. Wooden formwork fixing column; 6. Propeller blade fixing point; 7. Threaded rod fixing point; 8. Channel steel reference point; 9. Propeller blade; 10. Channel steel; 11. Support plate. Detailed Implementation

[0019] The present invention will be further explained and described below with reference to the accompanying drawings and embodiments.

[0020] The large propellers mentioned in this invention refer to marine propellers with a diameter exceeding 10 meters and a weight exceeding 30 tons.

[0021] like Figure 1-5As shown, the specific method for making a large propeller wooden model is as follows: First, a three-dimensional model of a single blade blank (9) is established. Based on the simulation results of the three-dimensional model, it is subjected to conformal layering. Wood is then laid out according to the layering results, reserving space for the steel frame 2. Next, a steel frame 2 composed of six steel bars is laid on the hub 1 according to the shape of the blade. Then, each layer of wood is laid on the steel frame 2 and bonded in place. Finally, the surface of the wooden model is sanded and painted to complete the production of the wooden model. The other blades connected to the hub are then made using the same method.

[0022] In one embodiment of the present invention, a wooden model of a 99K propeller is fabricated. Specifically, firstly, based on parameters such as the height of the hub 1, the pitch, roll, and strut of the blades 9, a suitable position for the steel frame 2 is designed. Using a thickness of 20mm as a baseline, the propeller blank model is disassembled layer by layer into three-dimensional models using a three-dimensional model. The maximum projected area of ​​each cross-section is selected as the three-dimensional model of the wood. Based on the three-dimensional models of each layer of wood, the actual wood for each layer is fabricated using a feeding machine, and the position for the steel frame 2 is reserved. Then, the steel frame 2 is connected to the hub 1, and each layer of wood is laid on the steel frame 2 one by one. The wood is then fixed using adhesive and bolts. After laying, excess wood is milled using a precision machining tool. Finally, the surface of the wooden model is sanded and painted to complete the fabrication of the wooden model.

[0023] In another embodiment of the present invention, a wooden model of a 7000PCTC ship-shaped propeller is produced. First, based on the height of the hub 1, the pitch, roll, and other parameters of the blades 9, a suitable position for the steel frame 2 is designed. Using a thickness of 20mm as a reference, the propeller blank model is disassembled layer by layer into three-dimensional models of each layer through a three-dimensional model. Then, the steel frame 2 is connected to the hub 1, and the maximum projected area of ​​each cross section is selected as the three-dimensional model of the wood. Based on the three-dimensional models of each layer of wood, the actual wood for each layer is produced by a feeding machine, and the position of the steel frame 2 is reserved. Subsequently, each layer of wood is laid on the steel frame 2, and the wood is fixed with adhesive and bolts. After the laying is completed, the excess wood is milled by a precision machining tool. Finally, the surface of the wooden model is sanded and painted to complete the production of the wooden model.

[0024] This method of using wooden molds to model actual objects has been applied to the production of propellers for ships of various sizes, including 82000T, 84500T, 85000T, 99000m3, and 210000T.

[0025] like Figure 4 and Figure 5As shown, after the wooden mold is made, to facilitate the hoisting of the propeller, two hub hoisting columns 3 are symmetrically set at both ends of the large end face of the hub 1, about 100mm from the edge, and two blade hoisting columns 4 are set at both ends of the 0.8R centerline of the blade 9, about 300mm from the edge, to ensure that the wooden mold can be hoisted stably. The second steel frame 2, near the blade tip and guide edge, has a protrusion of about 200mm at the guide edge, and a 24mm diameter through hole is drilled here. A 20mm diameter threaded rod and matching nut are used to fix the blade part of this wooden mold.

[0026] like Figures 2-7 The method for making a large wooden model of a propeller, as shown, involves shaping each blade 9 of the entire propeller individually based on the wooden model, including the following steps: (1) First, make the No. 1 blade by laying the base sand and scraping it with a base sand scraper until the base sand is flat; (2) Hoist the wooden mold to the bottom surface to contact the sand mold of the casting system using the shaft. Under the premise of ensuring that the sand intake of the edge and pressure surface is appropriate, adjust the wooden mold to the appropriate position on the support plate 11. (3) Slide the pitch gauge onto the shaft, hoist it to a suitable position above the wooden mold, and determine the measurement elevation and benchmark based on the waistline of the hub 1 and the radial reference line of the blade 9; (4) Correcting the position of the wooden mold: Use a pitch gauge to measure the position deviation of blade 9 #1, and then adjust the position of blade 9 #1 to ≤2mm according to the deviation data by using the pitch gauge and blade fixing point 6. (5) Weld the positioning channel steel reference point 8, and use a pitch gauge to record the coordinates of the positioning channel steel reference point 8; (6) Weld positioning channel steel 10 sequentially onto the remaining pallets 11 according to the data recorded by the pitch gauge; (7) Remove the pitch gauge used for measurement and complete the position correction of the wooden mold; (8) Pound sand on the pressure surface of blade 9; (9) After the lower box has hardened, pound the upper box; (10) Open the box, reset the pitch gauge, and re-inspect it; (11) Grind the blade shape. When grinding, make sure the wooden mold does not come off the shaft. (12) Lift the wooden mold and transfer it to the next pallet. Position and fix the wooden mold according to the position of the positioning channel steel 10. Shape the #2 blade 9 according to the above steps. Continue in this manner to complete the shaping of all the wooden molds of the blades 9 according to the actual shaping requirements.

[0027] like Figure 7 and Figure 8As shown, when correcting the position of the wooden mold, a section of channel steel 10 is vertically welded onto the support plate 11 approximately 50mm outward from where the steel protrudes from the guide edge of the wooden mold. The height of the upper plane of the protruding steel is marked on the channel steel 10, and the height value is recorded using a pitch gauge. The pitch gauge is then rotated sequentially onto the remaining support plates 11. Based on the position coordinates of the channel steel 10, the positioning channel steel 10 is first welded onto the support plate 11. Then, based on the height and angle coordinates of the channel steel 10, the centerline position is marked on the positioning channel steel 10. The wooden mold is subsequently corrected using the position of the positioning channel steel 10 as a reference during the shaping of each blade.

[0028] This invention has been described through embodiments. Those skilled in the art will understand that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of this invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, this invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this invention.

Claims

1. A method for creating a large propeller using a wooden model, characterized in that, The production process includes the following steps: Step S1: Establish a three-dimensional model of the blade (9) blank; Step S2: Based on the results of the 3D model simulation, the propeller blades (9) to be shaped are processed into layers; Step S3: Lay out the timber according to the layering results, and reserve the position for the steel frame (2); Step S4: Lay each layer of wood onto the steel frame (2) and fix it in place. The wood mold is now complete.

2. The method for creating a large propeller wooden model according to claim 1, characterized in that: Between step S2 and step S3, the following steps are also included: a steel frame composed of multiple steel bars is laid on the hub according to the shape of the blade (2).

3. The method for creating a large propeller wooden model according to claim 1, characterized in that: Between steps S3 and S4, the following steps are also included: a steel frame (2) composed of multiple steel bars is laid on the hub (1) according to the shape of the blade (9).

4. The method for creating a large propeller wooden model according to any one of claims 1-3, characterized in that... It also includes the following steps: After step S4, the surface of the wooden mold is sanded and painted.

5. The method for creating a large propeller wooden model according to any one of claims 1-3, characterized in that... The following steps are also included: After the wooden mold is made, two hub hoisting columns (3) are symmetrically set at both ends of the large end face of the hub (1) near the edge at 80-100mm, and two blade hoisting columns (4) are set at 270-300mm on both sides of the blade 0.8R center line.

6. The method for creating a large propeller wooden model according to any one of claims 2 or 3, characterized in that... It also includes the following steps: When laying out a steel frame (2) composed of multiple steel bars, the second steel bar near the blade tip and guide edge has a protruding part of 180-220mm at the guide edge, and a through hole of 24mm diameter for a threaded rod with a matching diameter of 20mm and a matching nut is opened in the protruding part.

7. The method for creating a large propeller wooden model according to claim 5, characterized in that... The following steps are also included: After the wooden mold is made, two hub hoisting columns (3) are symmetrically set at the two ends of the large end face of the hub (1) near the edge of 100mm, and two blade hoisting columns (4) are set at the two sides of the 0.8R center line of the blade about 300mm apart.

8. The method for creating a large propeller wooden model according to any one of claims 1-3, characterized in that: The steel frame (2) includes 4-7 steel bars of varying lengths, which are connected to the outer surface of the propeller hub (1).

9. The method for creating a large propeller wooden model according to claim 8, characterized in that: The steel frame (2) consists of 6 steel bars of different lengths.

10. The method for creating a large propeller wooden model according to claim 1, characterized in that: The layering process is based on a thickness of 20mm. The propeller blank model is disassembled layer by layer into three-dimensional models using a three-dimensional model, and the maximum projected area of ​​each cross section is selected as the three-dimensional model of the wood.

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