Casting mould structure of wind power nodular cast iron main shaft casting

Abstract

The casting mould structure of the wind power nodular cast iron main shaft casting comprises a sand box, a sand core, a pouring system and an auxiliary box pressing device, the sand box is a random sand-saving sand box, the sand thickness reserved on the periphery of the sand box is small, and a sand-saving baffle is further arranged in a partial area with the large sand thickness, so that the production cost is reduced, and the production efficiency is improved. The sand box comprises an upper sand box body, a middle sand box body and a lower sand box body which are connected in a matched mode, and sand filling operation and casting size control are facilitated through the three-box-box technology during molding. The sand core is arranged in the sand box and matched with the sand box to form a casting mold cavity, the pouring gate penetrates through the sand core from top to bottom, extends into the casting mold cavity and is communicated with the upper sand box, the middle sand box and the lower sand box to form a pouring system, a vertical bottom pouring mode is adopted, the flow speed of molten iron is conveniently controlled, casting defects are reduced, and meanwhile the occupied area in the main shaft molding stage is effectively reduced; the auxiliary box pressing device is arranged outside the sand box and pressed above the sand box, and box lifting is effectively prevented, so that the quality of castings and the stability of the production process are guaranteed.

Description

Technical Field

[0001] This utility model belongs to the field of wind turbine ductile iron main shaft casting technology, specifically relating to a mold structure for wind turbine ductile iron main shaft castings. Background Technology

[0002] With the rapid development of renewable energy, wind energy, as an important clean energy source, is gradually being widely used. Previously, wind turbine main shafts were typically forged, with the shaft blank formed through forging. The material was mainly high-quality alloy steel, resulting in heavy components and high procurement costs. As large-megawatt-level units gradually enter the market, cast main shafts offer numerous advantages, such as ease of forming, high production efficiency, and suitability for mass production, significantly reducing costs. Therefore, optimizing the main shaft blank forming method from forging to casting has become an inevitable trend. However, during the casting of thick-walled main shafts, the large temperature difference between the inside and outside of the molten iron leads to uneven heat dissipation, easily causing casting defects such as cracks, porosity, slag inclusions, and shrinkage cavities. These defects result in castings that fail to meet expected quality requirements, making conventional casting processes insufficient to meet the quality requirements of such thick-walled wind turbine main shafts. Utility Model Content

[0003] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a mold structure for wind turbine ductile iron main shaft castings. By adjusting the overall structure of the gating system and the placement of chills and risers, the casting process is optimized. At the same time, the use of resin sand is reduced by designing a conformal sand-saving box and an auxiliary pressure box structure. Under the premise of ensuring the quality of the main shaft, production efficiency is improved and production costs are reduced.

[0004] To achieve the above and other related objectives, this utility model provides a mold structure for a wind turbine ductile iron main shaft casting, comprising:

[0005] The sand box, from top to bottom, includes an upper sand box, a middle sand box, and a lower sand box that are connected to each other.

[0006] A sand core is placed inside the sand box, and each sand box and the sand core cooperate to form a casting cavity;

[0007] The gating channel runs from top to bottom through the sand core and extends into the mold cavity, connecting the upper sand box, the middle sand box, and the lower sand box to form a gating system.

[0008] In an optional embodiment of this utility model, the sand core is provided with multiple risers.

[0009] In an optional embodiment of the present invention, the casting system further includes a pouring cup disposed on the upper sand box, the direct pouring port of the gating system is located at the center of the sand core and penetrates the sand core, and the pouring cup is connected to the end of the direct pouring port near the upper sand box.

[0010] In an optional embodiment of this utility model, the medium sand box is divided into an upper medium sand box and a lower medium sand box, the upper medium sand box is connected to the upper sand box, and the lower medium sand box is connected to the lower sand box.

[0011] In an optional embodiment of this utility model, a transition connection part is provided at one end of the lower intermediate sand box near the lower sand box, and the lower intermediate sand box is connected to the lower sand box through the transition connection part. Multiple inclined plate reinforcing ribs are provided on the outer side of the lower intermediate sand box along the circumferential direction above the transition connection part.

[0012] In an optional embodiment of this utility model, a sand-saving baffle is further provided on the inner side of the lower sand box and the transition connection part. The sand-saving baffle is parallel to the axial direction of the sand box and distributed along the circumference of the lower sand box. The inside of the sand-saving baffle is a sand-filling area, and the outside of the sand-saving baffle is a non-sand-filling area.

[0013] In an optional embodiment of this utility model, an overflow basin is also included, which is disposed in the upper sand box and communicates with the casting mold cavity.

[0014] In an optional embodiment of this utility model, a plurality of chills are distributed inside the sand core and inside the sand box.

[0015] In an optional embodiment of this utility model, the casting system further includes a filtering device. The end of the direct pouring port away from the pouring cup is connected to the filtering device and is connected to the ingate of the gating system through the filtering device. The ingate of the gating system is located in the lower sand box and is evenly distributed circumferentially.

[0016] In an optional embodiment of this utility model, an auxiliary pressing device is further included. The auxiliary pressing device includes an auxiliary sand box and a pressing iron. The auxiliary sand box is an octagonal sand box, which is placed outside the sand box. The pressing iron is placed above the octagonal sand box and the sand box to assist in pressing.

[0017] The technical advantages of this invention are as follows: the upper sand box, middle sand box, lower sand box, and sand core work together to form a casting cavity; the gating system is formed by the gating channel penetrating the sand core and connecting each sand box; the ingate is located in the lower sand box; and vertical bottom pouring is used for casting. Compared with the traditional horizontal casting and vertical pouring production method, this reduces the footprint of the main molding stage. A filter device is installed in the lower sand box to filter impurities before pouring, reducing casting defects. At the same time, risers are set inside the sand core, and chills are set in each sand box and sand core to ensure the quality of the casting in conjunction with the gating system. Each sand box is a mold-following sand-saving sand box, and inclined plates are set in areas with large sand intake to block sand, reducing the amount of resin sand used and lowering production costs. The overall structure is easy to operate and adjust, and can effectively ensure the quality of the casting. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the overall structure of the mold structure in one embodiment of the present utility model;

[0020] Figure 2 A schematic diagram of the mold structure after removing the auxiliary pressure box device in one embodiment of the present invention;

[0021] Figure 3 A schematic diagram of the overall structure of the sand box, sand core, and gating system in one embodiment of this utility model;

[0022] Figure 4 A cross-sectional view of the sand box, sand core, and gating system in one embodiment of this utility model;

[0023] Figure 5 A schematic diagram of the structure of the middle sand box, the lower sand box, the sand core, and the gating system in one embodiment of this utility model;

[0024] Figure 6 A schematic diagram of the lower sand box, sand core, and gating system in one embodiment of this utility model;

[0025] Figure 7 A schematic diagram of the lower sand box in one embodiment of this utility model;

[0026] Figure 8 A schematic diagram of the internal casting system of the sand box, the chill, and the casting in one embodiment of the present invention;

[0027] Figure 9 A schematic diagram of the connection structure between the gating channel and the filter device in one embodiment of this utility model.

[0028] Label Explanation:

[0029] 100. Sand box; 200. Sand core; 300. Casting system; 400. Auxiliary pressure box device; 500. Riser; 600. Chill; 700. Overflow basin; 800. Vent pipe;

[0030] 110. Upper sand box; 120. Middle sand box; 130. Lower sand box; 140. Sand-saving baffle;

[0031] 121. Transition connection; 122. Inclined plate reinforcing rib;

[0032] 210. Positioning tapered hole; 220. Positioning notch;

[0033] 310. Runner; 320. Pour cup; 330. Filter device; 311. Sprue; 312. Ingate;

[0034] 410. Auxiliary sand box; 420. Pressure box iron. Detailed Implementation

[0035] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0036] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0037] As large-megawatt wind turbine generator sets gradually enter the market, the cost reduction effect of cast spindles is significant due to their advantages such as ease of forming, high production efficiency, and suitability for mass production. Therefore, optimizing the spindle blank forming method from forging to casting is an inevitable trend. However, due to the special structure of the spindle, the shaft body is long and cylindrical, generally large in size, with a thick flange wall at the large end (usually around 200mm), while the shaft body is slender and thin, typically only 70-100mm thick. The significant gradient in wall thickness and the much slower cooling rate at the large end compared to the shaft body result in a high sand-to-iron ratio during traditional casting, easily leading to casting defects. Conventional casting processes are insufficient to meet the quality requirements of such thick-walled wind turbine generator spindles, and the need for heavy-duty cranes for unpacking further impacts the production efficiency of the molding workshop.

[0038] Please see Figures 1 to 9 This utility model proposes a mold structure for a ductile iron main shaft casting for wind turbines, including a sand box 120, a sand core 200, a gating system 300, and an auxiliary pressing device 400. The sand box 120 is a conformal sand-saving sand box, with a cylindrical main body adapted to the overall structure of the main shaft casting. The sand box 120, from top to bottom, includes an upper sand box 110, a middle sand box 120, and a lower sand box 130 that are connected to each other. The sand core 200 is disposed inside the sand box 120, and each sand box 120 cooperates with the sand core 200. A mold cavity is formed, and the gating system 300 is formed by the gating system 310 passing through the sand core 200 from top to bottom and extending into the mold cavity, connecting the upper sand box 110, the middle sand box 120 and the lower sand box 130. The main body of the spindle is made of QT400-18AL ductile iron. Molten iron is poured into the mold cavity, and after cooling and solidification, the spindle casting is formed. The auxiliary pressure box device 400 is set outside the sand box 100 and presses on top of the sand box 100 to provide pressure to prevent the sand box 120 from being lifted by buoyancy during the pouring process. The entire sand box 100 structure is designed to closely resemble the shape of the main shaft, with minimal pre-filled sand around its perimeter, reducing production costs. Simultaneously, the three-box process facilitates sand filling and control of casting dimensions during molding. The gating system 300 employs a vertical bottom-pouring method, with the flange connecting the main shaft and hub located on the bottom surface of the pouring surface. This allows for easy control of the molten iron flow rate, reducing casting defects. Compared to the traditional horizontal casting and vertical pouring production method, this effectively reduces the footprint of the main shaft molding stage. The auxiliary pressure box device 400 ensures that casting defects are not caused by the sand box 100 lifting during casting, guaranteeing casting quality and production process stability. Practical application has verified that the casting method using this mold structure can effectively improve production efficiency and reduce costs while ensuring main shaft quality.

[0039] Please see Figures 1 to 6In an optional embodiment of this utility model, the sand core 200 is disposed inside the sand box 100, and it cooperates with the sand box 100 to form a casting cavity. The structure of the sand core 200 is determined according to the internal shape of the casting and is used to form the inner hole of the main shaft and other structures. The bottom of the sand core 200 and the molding sand in the lower sand box 130 are respectively provided with positioning cone holes 210. The positioning sand cone is connected to the positioning cone hole 210 as a reference for mold assembly to ensure the accuracy of mold fitting. The bottom periphery of the sand core 200 is also provided with a positioning notch 220, which cooperates with the positioning sand cone to achieve fast and accurate positioning.

[0040] Please see Figures 1 to 6 In an optional embodiment of this utility model, the interior of the sand core 200 is further provided with multiple risers 500. These risers 500 can be evenly distributed circumferentially on the sides of the sand core 200. The risers 500 are primarily added to the inner cavity of the wind turbine ductile iron main shaft casting to prevent defects. The cavity of the riser 500 is a cavity for storing liquid metal, supplying metal during the formation of the wind turbine ductile iron main shaft casting, thus preventing shrinkage cavities, porosity, venting, and slag accumulation. Since the sand box 100 is a mold-following sand-saving sand box with a small sand capacity, it is inconvenient to place risers 500 on its sides. Therefore, the risers 500 are placed inside the sand core 200 to avoid casting defects. It should be noted that the shape, size, and position of the risers 500 inside the sand core 200 are not limited, but need to be set and adjusted according to the specific product in actual production to ensure the quality of the casting.

[0041] Please see Figures 1 to 8 In an optional embodiment of this utility model, multiple chills 600 are distributed inside the sand core 200 and the sand box 100. During the casting process, the chills 600 can cooperate with structures such as the riser 500 to compensate for shrinkage in the casting, effectively preventing defects such as shrinkage cavities and ensuring the quality of the casting. Specifically, for example, multiple chills 600 are provided inside the sand core 200 at positions such as the side and bottom surfaces; conformal chills 600 are also provided inside the sand box 100 at corresponding positions on the side walls and flange structures according to the casting structure. For example, the conformal chills 600 can be arranged circumferentially at positions corresponding to the casting wall thickness and the flange end face, without affecting the casting process. It should be noted that the shape and distribution of the chills 600 can be configured in various ways. Space is left inside the sand box 100 to place the chills 600. The chills 600 can be adjusted and placed according to actual production requirements to reduce casting defects. For example, in actual production, multiple chills 600 can also be set along the circumference in the medium sand box 120 corresponding to the thin-walled part of the casting to avoid casting defects that occur at that location and ensure the overall quality of the casting.

[0042] Please see Figures 1 to 7In an optional embodiment of this utility model, the sand box 100 includes an upper sand box 110, a middle sand box 120, and a lower sand box 130 that are connected to each other. Each sand box 100 has multiple circumferentially aligned positioning pin holes to ensure accurate relative positioning of each sand box 100 during mold assembly. The interior of the sand box 100 is filled with resin sand and contains conformal chills 600, which, together with the internal sand core 200, form the mold cavity of the casting. The cavity structure is consistent with the casting structure. Molten metal is injected through the gating system 300 and fills the mold cavity. After cooling and solidification, the casting is formed. The sand box 100 is a conformal sand-saving sand box; the shape of each sand box 100 is adapted to the shape of the main shaft casting, with a small allowance for sand intake, thereby reducing the amount of resin sand used inside the box. Specifically, considering the overall shape and structure of the spindle, the outer diameter of the lower sand box 130 corresponding to the flange at the end of the spindle is relatively large, while the outer diameters of the upper sand box 110 and the middle sand box 120 are relatively small. The spindle casting process adopts a three-box process for mold separation and disassembly, and the bottom pouring method is used for casting. Compared with the traditional horizontal casting and vertical pouring production method, this reduces the area occupied during the spindle molding stage. The multi-layer sand box 100 facilitates sand filling operations, improves work efficiency, and facilitates local structural adjustments.

[0043] Please see Figures 1 to 8 In an optional embodiment of this utility model, an overflow basin 700 is provided on the top of the upper sand box 110. The overflow basin 700 is connected to the mold cavity and can communicate with the upper space of the casting during the casting process to observe whether the casting is full. The overflow basin 700 can collect the overflowing molten metal and also has the functions of venting and liquid feeding to improve the quality of the casting. The upper sand box 110 is also provided with multiple vent pipes 800, which are connected to the mold cavity for venting. The overflow basin 700 can be connected to the mold cavity through the vent pipes 800. When the mold is assembled, the upper sand box 110 and the middle sand box 120 are fitted together and cover the sand core 200. When the mold is closed, a gap of 3-5mm is left between the top of the upper sand box 110 and the top of the sand core 200 to prevent damage to the sand core 200. If the gap is too large after the mold is assembled, a steel plate can be added at the gap for support.

[0044] Please see Figures 1 to 5In an optional embodiment of this utility model, the internal cavity of the intermediate sand box 120 is mainly used to form the main structure of the spindle. Combined with the spindle casting structure, the intermediate sand box 120 is divided into two layers: an upper intermediate sand box 120 and a lower intermediate sand box 120. The upper intermediate sand box 120 is connected to the upper sand box 110, and the lower intermediate sand box 120 is connected to the lower sand box 130. This two-layer design of the intermediate sand box 120 reduces the height of each sand box 100, facilitating sand filling during molding. Furthermore, by replacing intermediate sand boxes 120 of different heights to match the casting frame dimensions, the structure of the mold can be easily adjusted to adapt to the production of different castings. In addition, it facilitates partial replacement in case of damage to the sand box 100, reducing costs.

[0045] Please see Figures 1 to 5 In an optional embodiment of this utility model, a transition connection 121 is provided at one end of the lower sand box 120 near the lower sand box 130. The lower sand box 120 is connected to the lower sand box 130 through the transition connection 121. Multiple inclined plate reinforcing ribs 122 are provided on the outer side of the lower sand box 120 along the circumferential direction above the transition connection 121. It should be noted that the external structure of the sand box 100 is consistent with the structure of the casting. Due to the large size difference between the bottom flange structure and the middle part of the main shaft casting, the flange structure of the mold cavity is located in the lower part of the lower intermediate sand box 120 and the lower sand box 130. The upper part of the lower intermediate sand box 120 and the outer diameter of the upper intermediate sand box 120 are consistent to achieve positioning and connection. The lower part of the lower intermediate sand box 120 and the outer diameter of the lower sand box 130 are consistent to facilitate connection. Therefore, the size difference between the upper and lower parts of the lower intermediate sand box 120 is large. Above the transition connection part 121 with a larger radial dimension, multiple inclined plate reinforcing ribs 122 are set on the outer side of the lower intermediate sand box 120 in the circumferential direction to connect and improve the strength of the sand box 100.

[0046] Please see Figures 1 to 7 In an optional embodiment of this utility model, a sand-saving baffle 140 is also provided on the inner side of the lower sand box 130 and the transition connection 121. The sand-saving baffle 140 is parallel to the axial direction of the sand box 100, that is, it is vertically arranged and distributed along the circumference of the lower sand box 130. The inside of the sand-saving baffle 140 is a sand-filling area, and the outside of the sand-saving baffle 140 is a non-sand-filling area. It is understandable that the transition connection 121 of the lower sand box 120 and the interior of the lower sand box 130 are flange cavities used to form the flange connecting the end of the main shaft to the hub. The area near the gating system 300 in the lower sand box 130 has a large sand intake. According to the special structure of the main shaft flange, multiple baffles can be set inside the sand box 100. For example, three inclined plates evenly distributed along the circumference can be set. The inclined plates are located between the flange connection parts, dividing the interior of the sand box 100 into multiple areas. The inside of the inclined plates is the sand-filling area, and the outside of the inclined plates is the non-sand-filling area. This reduces the amount of resin sand used and lowers the cost without affecting the casting quality.

[0047] Please see Figures 1 to 9 In an optional embodiment of this utility model, the gating system 300 includes a gating system 310, a pouring cup 320, and a filtering device 330. The gating system 310 extends from top to bottom through the sand core 200 and into the mold cavity, introducing externally injected molten metal into the bottom of the mold cavity and filling it. The sprue 311 of the gating system 310 is located at the center of the sand core 200 and extends through it. The end of the sprue 311 near the upper sand box 110 is connected to the pouring cup 320 on the upper sand box 110 to inject molten metal from the outside. The end of the sprue 311 away from the pouring cup 320 is connected to the filtering device 330 and is connected to the ingate 312 of the gating system 310 through the filtering device 330. The ingate 312 of the gating system 310 is located in the lower sand box 130 and is evenly distributed circumferentially. The filtering device 330 filters the molten metal before it is injected into the mold cavity to reduce casting defects. The molten metal is injected from the bottom using the gating system 300, and the speed at which the molten metal fills the mold and the time required to fill the mold are controlled to ensure that the molten metal enters the mold smoothly, avoiding turbulence and scouring of the mold. Impurities are filtered through the filtration system to reduce casting defects.

[0048] Specifically, the end of the sprue 311 furthest from the pouring cup 320 is connected to the bottom of the filter device 330 via multiple horizontal gating gates. The molten metal is injected into the sprue 311 through the pouring cup 320 and then diverted into the filter device 330 through the horizontal gating gates. One end of the ingate 312 is connected to the bottom of the filter device 330, and the other end is connected to the cavity of the lower sand box 130. Impurities in the molten metal are left in the filter device 330, and clean molten metal enters the cavity. Multiple sets of ingates 312 are distributed circumferentially, so that the molten metal is injected into the cavity smoothly. The filter device 330 filters impurities in the molten metal to reduce casting defects. At the same time, the filter system also plays a role in stabilizing the flow. The molten metal that has passed through the filter system is injected into the bottom of the cavity at a stable flow rate, thereby reducing impurities such as secondary oxidation and improving the quality of the casting.

[0049] Please see Figure 1In an optional embodiment of this utility model, the auxiliary pressing device 400 includes an auxiliary sand box 410 and a pressing iron 420. The auxiliary sand box 410 is an octagonal sand box 100, which is placed outside the sand box 100. The pressing iron 420 is placed above the octagonal sand box 100 and the sand box 100 to assist in pressing the sand box. The weight of the pressing iron 420 is calculated, verified, and determined according to actual production conditions. Multiple pressing irons 420 are placed above the auxiliary sand box 410 to ensure the stability of the sand box 100. It is understood that during the casting process, the buoyancy of the molten metal is about 3 to 5 times the weight of the casting. Under the action of a large buoyancy, the sand box 100 may be lifted, leading to casting defects or even scrap. The auxiliary sand box 410 and the pressing iron 420 press down the sand box 100 to prevent it from lifting and causing casting defects, thus ensuring the stability and reliability of the production process. The external auxiliary sand box 410 is structurally compatible with the internal sand box 100. The octagonal sand box 100 is easy to manufacture and process. The octagonal sand box 100 is used in conjunction with the pressure box iron 420 to press the box in place to prevent the box from lifting during pouring and causing casting defects, thus ensuring product quality.

[0050] Please see Figures 1 to 9 First, sand box 100 and sand core 200 are made according to the product's external dimensions, and risers 500 and chills 600 are arranged in appropriate positions. Then, the mold is closed, ensuring accurate fit between components. Specifically, sand core 200 is first placed in the lower sand box 130 and positioned using a positioning sand cone and a positioning notch. Then, two layers of middle sand box 120 are placed. The wall thickness of the casting is adjusted from the top of the middle sand box 120, and the inner cavity is checked for cleanliness to prevent eccentricity or sand blocks from falling in. When sand box 110 is closed, the main sand core is checked. Regarding the gap between the 200 and the sand box 100, if the gap is large, a 3-5mm steel plate should be inserted to fill it. After the sand boxes are closed, place the pouring cup 320 and the overflow basin 700 on top of the upper sand box 110. Place the octagonal sand box 100 on the outside of the sand box 100. Place the pressure box iron 420 above the auxiliary sand box 410 and the sand-saving sand box 100. The pressure box weight is adjusted according to the weight of the casting. Multiple pressure box irons 420 can be placed on the auxiliary sand box 410 until the casting meets the required pressure box weight. After completion, the casting can be poured.

[0051] In summary, the mold structure of the wind turbine ductile iron main shaft casting of this utility model has a sand box structure and gating system adapted to the main shaft structure. It adopts a vertical bottom-pouring method, which, compared to the traditional horizontal-to-vertical production method, reduces the footprint of the main shaft molding stage. The three-box process facilitates sand filling and control of casting dimensions. Riser, chills, and overflow basins are used to compensate for the casting's shrinkage. A filtration system removes impurities and ensures stable molten metal flow, effectively improving the casting's processing quality. An auxiliary pressing device prevents box lifting, ensuring casting quality and production process stability. The sand box structure uses a conformal sand-saving sand box, and sand-saving baffles are added in areas with high sand consumption near the lower gating system according to the main shaft structure, reducing the sand-to-iron ratio by approximately 70% and reducing resin usage. This improves production efficiency and reduces casting production costs while ensuring main shaft quality.

[0052] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

[0053] Throughout this description, numerous specific details, such as examples of components and / or methods, are provided to provide a complete understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention may be practiced without one or more of these specific details or by other devices, systems, components, methods, parts, materials, components, etc. In other instances, well-known structures, materials, or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

[0054] Throughout this specification, references to "an embodiment," "an embodiment," or "a specific embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention, but not necessarily in all embodiments. Therefore, the various representations of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout the specification do not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic of any specific embodiment of the present invention can be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the embodiments of the present invention described and illustrated herein may be based on the teachings herein and will be considered part of the spirit and scope of the present invention.

[0055] It should also be understood that one or more of the elements shown in the figures may be implemented in a more separate or more integrated manner, or may even be removed because they are inoperable in certain circumstances or provided because they may be useful for a particular application.

[0056] Furthermore, unless otherwise expressly stated, any arrows in the accompanying drawings should be considered illustrative only and not limiting. Additionally, unless otherwise stated, the term "or" as used herein is generally intended to mean "and / or". Where a term is anticipated to provide a separation or combination capability that is unclear, a combination of components or steps will also be considered as indicated.

[0057] As used herein and throughout the claims below, unless otherwise specified, “a” and “the” include the plural references. Similarly, as used herein and throughout the claims below, unless otherwise specified, “in” means “in” and “on”.

[0058] The above description of the embodiments shown in this utility model (including the content set forth in the abstract of the specification) is not intended to be an exhaustive enumeration or to limit the utility model to the precise forms disclosed herein. Although specific embodiments and examples of the utility model have been described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the utility model, as will be recognized and understood by those skilled in the art. As indicated, these modifications can be made to the utility model in accordance with the above description of the embodiments described herein, and such modifications will be within the spirit and scope of the utility model.

[0059] This document has generally described the systems and methods in detail to aid in understanding the present invention. Furthermore, various specific details have been set forth to provide a general understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention can be practiced without one or more specific details, or using other devices, systems, accessories, methods, components, materials, parts, etc. In other instances, well-known structures, materials, and / or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

[0060] Therefore, although the present invention has been described herein with reference to specific embodiments thereof, freedom of modification, various changes and substitutions are also within the scope of the above disclosure, and it should be understood that in some cases, certain features of the present invention may be adopted without departing from the scope and spirit of the invention and without corresponding use of other features. Thus, many modifications can be made to adapt a particular environment or material to the essential scope and spirit of the present invention. The present invention is not intended to be limited to the specific terms used in the following claims and / or the specific embodiments disclosed as the best mode of carrying out the present invention, but the present invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Therefore, the scope of the present invention will be determined only by the appended claims.

Claims

1. A mold structure for a wind turbine ductile iron main shaft casting, characterized in that, include: The sand box, from top to bottom, includes an upper sand box, a middle sand box, and a lower sand box that are connected to each other. A sand core is placed inside the sand box, and each sand box and the sand core cooperate to form a casting cavity; The gating channel runs from top to bottom through the sand core and extends into the mold cavity, connecting the upper sand box, the middle sand box, and the lower sand box to form a gating system.

2. The mold structure for the wind turbine ductile iron main shaft casting according to claim 1, characterized in that, The sand core has multiple risers inside.

3. The mold structure for the wind turbine ductile iron main shaft casting according to claim 1, characterized in that, The gating system also includes a pouring cup, which is disposed on the upper sand box. The direct pouring port of the gating system is located at the center of the sand core and penetrates the sand core. The pouring cup is connected to the end of the direct pouring port near the upper sand box.

4. The mold structure for the wind turbine ductile iron main shaft casting according to claim 1, characterized in that, The medium sand box is divided into an upper medium sand box and a lower medium sand box. The upper medium sand box is connected to the upper sand box, and the lower medium sand box is connected to the lower sand box.

5. The mold structure for the wind turbine ductile iron main shaft casting according to claim 4, characterized in that, The lower intermediate sand box is provided with a transition connection part at one end near the lower sand box. The lower intermediate sand box is connected to the lower sand box through the transition connection part. Multiple inclined plate reinforcing ribs are provided on the outer side of the lower intermediate sand box along the circumferential direction above the transition connection part.

6. The mold structure for the wind turbine ductile iron main shaft casting according to claim 5, characterized in that, A sand-saving baffle is also provided on the inner side of the lower sand box and the transition connection. The sand-saving baffle is parallel to the axial direction of the sand box and distributed along the circumference of the lower sand box. The inside of the sand-saving baffle is a sand-filling area, and the outside of the sand-saving baffle is a non-sand-filling area.

7. The mold structure for the wind turbine ductile iron main shaft casting according to claim 1, characterized in that, It also includes an overflow basin, which is disposed in the upper sand box and communicates with the mold cavity.

8. The mold structure for the wind turbine ductile iron main shaft casting according to claim 1, characterized in that, Multiple chills are distributed within the sand core and the sand box.

9. The mold structure for the wind turbine ductile iron main shaft casting according to claim 3, characterized in that, The gating system also includes a filtration device. The end of the direct gating port away from the gating cup is connected to the filtration device and is connected to the ingate of the gating system through the filtration device. The ingate of the gating system is located in the lower sand box and is evenly distributed circumferentially.

10. The mold structure for the wind turbine ductile iron main shaft casting according to claim 1, characterized in that, It also includes an auxiliary pressing device, which includes an auxiliary sand box and a pressing iron. The auxiliary sand box is an octagonal sand box, which is placed outside the sand box. The pressing iron is placed above the octagonal sand box and the sand box to assist in pressing.

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