A casting mold for producing wind turbine main shaft by using iron mold covered with sand and stacked boxes

Abstract

The utility model discloses a casting mold for producing a wind turbine main shaft by using an iron mold covered with sand and stacked boxes, including an iron mold covered with sand box, an iron mold covered with sand core, a casting system iron mold for making a casting system, and a cover box iron mold for forming the top surface of a main shaft casting. A plurality of iron mold covered with sand cores and an iron mold covered with sand boxes are alternately stacked on the casting system iron mold from bottom to top, and the cover box iron mold is covered on the iron mold covered with sand box on the top layer to form a main shaft casting cavity. A pouring cup and a plurality of shrinkage feeding risers are provided on the cover box iron mold. The pouring cup is connected to the casting system, and a plurality of shrinkage feeding risers are arranged in a circular array around the pouring cup. The utility model can extend the service life of the tooling and improve the process yield, improve the performance of the casting, improve the production efficiency, and shorten the processing cycle.

Description

Technical Field

[0001] The utility model belongs to the technical field of casting, and in particular relates to a casting mould for producing a wind turbine main shaft by stacking iron moulds covered with sand. Background Art

[0002] In the production of wind turbine main shaft castings, there are two main popular processes in the industry: self-hardening resin sand process and metal mold process.

[0003] The advantages of the self-hardening resin sand process are high sand strength, slow cooling after molten iron pouring, high elongation of castings but low tensile strength, and the tensile strength is difficult to break through 400MPa or above. The tensile strength can only be slightly improved by adding precious alloys. There is little room for weight reduction and cost reduction, and it is only suitable for the production of all-ferrite matrix ductile iron castings. The disadvantages are: the casting process is complicated, a large amount of cold iron needs to be placed at the hot section of the casting, the workload of cleaning and polishing the casting is large, and the production efficiency is low; the amount of casting sand used is large, the sand-to-iron ratio is generally 3:1 or above, the environmental pressure is high, and the production cost is high; the sand box is large in size and high in cost; the insulation time after molten iron pouring is long, and it takes more than 7 days after pouring to unpack the casting, and the tooling turnover time is long; it is necessary to rely on multiple risers for shrinkage compensation, and the casting yield rate is low.

[0004] The advantages of the metal mold process are simple modeling and high efficiency in assembly; the cooling speed of molten iron is fast, which reduces the amount of cold iron used and improves the tensile strength of the casting; the rigid casting reduces the number of shrinkage feeders and improves the process output rate. The disadvantages are: the production cost of the metal mold is high, the service life is generally 20-30 times, and the inner cavity needs to be reprocessed every 3 times. After many uses, a decarburized layer appears on the surface, the surface quality of the casting is poor, and the cost is high; in order to demold, the process will increase the draft angle of the vertical surface of the casting, the processing allowance is large, the processing cycle is long, and the parts with better surface performance of the casting will be removed; after pouring, there is a major quality risk that the metal mold and the casting are adhered to each other, resulting in the inability to unpack; the insulation time after the molten iron is poured is long, and it takes more than 3 days after pouring to unpack the casting, and the tooling turnover time is long. Utility Model Content

[0005] In view of the problems existing in the above-mentioned prior art, the utility model provides a casting mold for producing wind turbine main shafts by using iron molds covered with sand and stacked boxes. The purpose is to reduce the cost by reducing the amount of casting sand, extending the service life of tooling and improving the process yield; to improve the performance of castings by providing good casting cooling conditions; to improve production efficiency by opening the box in a short time; and to shorten the processing cycle by reducing the casting processing allowance.

[0006] In order to achieve the above purpose, the specific scheme of the utility model is as follows:

[0007] The iron mold covered with sand stacking box is used to produce a casting mold for a wind turbine main shaft, comprising an iron mold covered with sand box, an iron mold covered with sand core, a casting system iron mold for making a casting system and a cover box iron mold for forming the top surface of a main shaft casting. A plurality of iron mold covered with sand cores and an iron mold covered with sand boxes are alternately stacked on the casting system iron mold from bottom to top, so that the plurality of iron mold covered with sand cores form the inner cavity shape of the main shaft casting, and the plurality of iron mold covered with sand boxes form the outer cavity shape of the main shaft casting. The cover box iron mold is covered on the iron mold covered with sand box on the top layer to form the main shaft casting cavity. A pouring cup and a plurality of shrinkage feeding risers are provided on the cover box iron mold. The pouring cup is connected to the pouring system, and the plurality of shrinkage feeding risers are arranged in a circular array around the pouring cup.

[0008] Furthermore, the pouring system iron mold includes an upper iron mold for a pouring system, a lower iron mold for a pouring system, an upper mold for a pouring system for covering the upper iron mold for a pouring system with sand, and a lower mold for a pouring system for covering the lower iron mold for a pouring system with sand. The upper mold for the pouring system and the upper iron mold for the pouring system are combined to form an upper sand layer for the pouring system. The upper sand layer for the pouring system is filled with self-hardening resin sand, so that the self-hardening resin sand is bonded to the upper iron mold for the pouring system to form an upper casting mold for the pouring system. The lower mold for the pouring system and the lower iron mold for the pouring system are combined to form a lower sand layer for the pouring system. The lower sand layer for the pouring system is filled with self-hardening resin sand, so that the self-hardening resin sand is bonded to the lower iron mold for the pouring system to form a lower casting mold for the pouring system. The upper casting mold for the pouring system and the lower casting mold for the pouring system are combined to form a pouring system cavity. A foam ceramic filter is provided between the upper casting mold for the pouring system and the lower casting mold for the pouring system.

[0009] Furthermore, the pouring system includes a sprue, a ceramic connecting pipe, a slag collecting bag and an inner gate ceramic tube, the sprue is connected to the pouring cup, a plurality of slag collecting bags are connected to the sprue through ceramic connecting pipes, a foam ceramic filter is arranged in the slag collecting bag, and the bottom ends of the plurality of inner gate ceramic tubes are respectively connected between the foam ceramic filter and the bottom of the slag collecting bag.

[0010] Furthermore, the ceramic connecting tube is composed of a ceramic main body 1 connected to the straight runner and six cross runners 1 connected to the ceramic main body 1 in a circumferential array, and the bottom end of the ceramic main body 1 is sealed. The inner gate ceramic tube is composed of a ceramic main body 2 and a cross runner 2 connected to one side of the bottom of the ceramic main body 2, and the bottom end of the ceramic main body 2 is sealed.

[0011] Furthermore, the outer sides of the iron mold of the pouring system, the sand box covering the iron mold, and the cover box iron mold are respectively provided with hanging shafts.

[0012] Advantages of the utility model

[0013] The utility model uses an iron mold covered with sand stacking box to produce a casting mold for a wind turbine main shaft. The outer cavity of the main shaft casting adopts an iron mold covered with sand box, and the inner cavity of the main shaft casting adopts an iron mold covered with sand core, which replaces the traditional self-hardening resin sand process or metal mold process to produce the main shaft casting. The iron mold covered with sand core and the iron mold covered with sand box both adopt the stacking box process, which reduces the difficulty of modeling and core making, improves production efficiency, and reduces costs. It can reduce the amount of casting sand and reduce costs; it can provide good casting cooling conditions and improve casting performance; it can be opened in a short time and improve production efficiency; it can reduce the casting processing allowance and shorten the processing cycle; it can extend the service life of the tooling and reduce the mold cost; it can improve the process output rate and reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic cross-sectional view of a casting mold for producing wind turbine main shafts using iron molds covered with sand and stacked boxes.

[0015] Figure 2 for Figure 1 Stereoscopic diagram.

[0016] Figure 3 for Figure 1 Schematic diagram of the structure of the iron mold of the casting system.

[0017] Figure 4 for Figure 3 Schematic diagram of the structure of the iron mold on the casting system.

[0018] Figure 5 for Figure 3 Schematic diagram of the structure of the mold on the casting system.

[0019] Figure 6 for Figure 3 Schematic diagram of the structure of the iron mold under the pouring system.

[0020] Figure 7 for Figure 3 Schematic diagram of the structure of the mold under the pouring system.

[0021] Figure 8 for Figure 3 Schematic diagram of the cross-sectional connection of the sprue, ceramic connector, slag bag, and ingate ceramic tube.

[0022] Fig. 9 for Figure 8 Schematic diagram of the structure of the ceramic connector.

[0023] Fig.10 for Figure 8 Schematic diagram of the structure of the ingate ceramic tube.

[0024] Fig.11 for Figure 1Schematic diagram of the main shaft casting obtained by pouring the casting mold for producing the wind turbine main shaft with iron mold covered with sand and stacked boxes.

[0025] In the figure:

[0026] 1. Casting system iron mold; 2. Cover box iron mold; 3. Pouring cup; 4. Shrinkage feeding riser; 5. Iron mold sand box; 6. Iron mold sand core; 7. Ingate ceramic tube; 8. Foam ceramic filter; 9. Cross runner 1; 10. Straight runner; 11. Ceramic connecting pipe; 12. Cross runner 2; 13. Slag collecting bag; 14. Ceramic main pipe 1; 15. Ceramic main pipe 2; 16. Casting system upper iron mold; 17. Casting system upper mold; 18. Casting system lower iron mold; 19. Casting system lower mold; 20. Casting system upper sand layer; 21. Casting system lower sand layer; 22. Spindle casting. DETAILED DESCRIPTION

[0027] The present invention is further explained below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that this specific embodiment is not intended to limit the scope of rights of the present invention.

[0028] like Figures 1 to 11 As shown, the casting mold for producing wind turbine main shaft by using iron mold covered with sand and stacked boxes provided in this specific embodiment includes an iron mold covered with sand box 5, an iron mold covered with sand core 6, a casting system iron mold 1 for making the casting system, and a cover box iron mold 2 for forming the top surface of the main shaft casting 22.

[0029] Specifically, the casting system iron mold 1 includes a casting system upper iron mold 16, a casting system lower iron mold 18, a casting system upper mold 17 for covering the casting system upper iron mold 16 with sand, and a casting system lower mold 19 for covering the casting system lower iron mold 18 with sand. The casting system upper mold 17 and the casting system upper iron mold 16 are combined to form a casting system upper covering sand layer 20 with a thickness of 20 to 30 mm. The casting system upper covering sand layer 20 is filled with self-hardening resin sand, so that the self-hardening resin sand and the casting system upper mold 16 are connected. The iron mold 16 is bonded to form an upper casting mold of the pouring system, and the lower mold 19 of the pouring system and the lower iron mold 18 of the pouring system are combined to form a lower sand covering layer 21 of the pouring system with a thickness of 20 to 30 mm. The lower sand covering layer 21 of the pouring system is filled with self-hardening resin sand, so that the self-hardening resin sand and the lower iron mold 18 of the pouring system are bonded to form a lower casting mold of the pouring system. The upper casting mold of the pouring system and the lower casting mold of the pouring system are combined to form a casting system cavity, and a foam ceramic filter plate 8 is provided between the upper casting mold of the pouring system and the lower casting mold of the pouring system.

[0030] The pouring system includes a sprue 10, a ceramic connecting pipe 11, a slag collecting bag 13 and an inner gate ceramic tube 7. The ceramic connecting pipe 11 is composed of a ceramic main body 14 connected to the sprue 10 and six cross runners 9 connected to the ceramic main body 14 in a circumferential array. The bottom end of the ceramic main body 14 is sealed. The inner gate ceramic tube 7 is composed of a ceramic main body 2 15 and a cross runner 2 12 connected to one side of the bottom of the ceramic main body 2 15. The bottom end of the ceramic main body 2 15 is sealed. The sprue 10 is connected to the pouring cup 3. A plurality of slag collecting bags 13 are respectively connected to the sprue 10 through the ceramic connecting pipes 11. A foam ceramic filter sheet 8 is arranged in the slag collecting bag 13. The bottom ends of the plurality of inner gate ceramic tubes 7 are respectively connected between the foam ceramic filter sheet 8 and the bottom of the slag collecting bag 13. The working principle of the pouring system is as follows: the molten iron enters the slag ladle 13 through the six cross runners 9 through the ceramic connecting pipe 11 through the straight runner 10, and then enters the cavity connected to the lower part of the slag ladle 13 and the inner gate ceramic tube 7 after being filtered by the foam ceramic filter sheet 8 of the slag ladle 13. The molten iron then enters the casting mold from the inner gate ceramic tube 7, fills the mold cavity, and finally forms the main shaft casting. The outside of the casting system iron mold 1, the iron mold sand box 5, and the cover box iron mold 2 are respectively provided with hanging shafts.

[0031] A plurality of iron mold sand-coated sand cores 6 and an iron mold sand-coated sand box 5 are alternately superimposed on the iron mold 1 of the pouring system from bottom to top, so that the plurality of iron mold sand-coated sand cores 6 form the inner cavity shape of the main shaft casting, and the plurality of iron mold sand-coated sand boxes 5 form the outer cavity shape of the main shaft casting. The cover box iron mold 2 is covered on the iron mold sand-coated sand box 5 on the top layer, and the cover box iron mold 2 is covered on the iron mold sand-coated sand box 5 on the top layer to form the main shaft casting cavity. The main shaft casting outer shape adopts the iron mold sand-coated sand box 5, and the main shaft casting inner shape adopts the iron mold sand-coated sand core 6, which replaces the traditional self-hardening resin sand process or metal mold process to produce the main shaft casting. The cover box iron mold 2 is provided with a pouring cup 3 and a plurality of shrinkage feeding risers 4, which play the role of pouring, shrinkage feeding and exhaust. The pouring cup 3 is connected to the pouring system, and the plurality of shrinkage feeding risers 4 are arranged in a circular array around the pouring cup 3.

[0032] Working principle:

[0033] When in use, the ceramic connecting tube 11 and the ingate ceramic tube 7 are pressed Figure 4 , 5, 6, 7, and 8 are placed on the upper and lower molds 17 and 19 of the pouring system, and then the upper and lower iron molds 16 and 18 of the pouring system are placed on the upper and lower molds 17 and 19 of the pouring system. The upper and lower iron molds 16 and 18 of the pouring system and the upper and lower molds 17 and 19 of the pouring system are positioned respectively by positioning pins and pin holes. After placement, fill with sand to bury the slag bag 13 mold and the ceramic connecting pipe 11, and scrape it flat after solidification. The upper and lower iron molds 16 and 18 of the pouring system are lifted up after demoulding. The self-hardening sand leaves the upper and lower molds 17 and 19 of the pouring system together with the iron mold 1 of the pouring system. The slag bag of the upper and lower iron molds 16 and 18 of the pouring system is formed by the mold to form a slag bag cavity. The self-hardening sand wraps the ceramic connecting tube 11. The ceramic connecting tube 11 and the cavity of the slag bag 13 are connected to allow molten iron to flow in and out. It flows from the straight runner 10 through the ceramic connecting tube 11 into the slag bag 13, passes through the foam ceramic filter 8 into the lower cavity of the slag bag 13, and then passes through the inner gate ceramic tube 7 into the inner cavity of the main shaft casting. After demoulding, the upper and lower iron molds 16 and 18 of the pouring system are turned over and painted, and the foam ceramic filter sheet 8 is placed. Then, the lower iron mold 18 of the pouring system is stacked on the upper iron mold 16 of the pouring system. At this point, the molten iron is made. Figure 3 The gating system iron mold 1 shown in the figure. After the level of the placed gating system iron mold 1 is measured by a spirit level, a bottom iron mold sand core 6 is installed, followed by an iron mold sand box 5, and then another iron mold sand core 6 is installed. The iron mold sand core 6 and the iron mold sand box 5 are alternately stacked in sequence, and all the iron mold sand cores 6 and the iron mold sand boxes 5 are assembled. Finally, the cover box iron mold 2 is covered. During pouring, the molten iron flows from the pouring cup 3 into the straight runner 10 and six cross runners 9 in sequence, and then enters the inner gate ceramic tube 7 after being filtered through the slag collecting bag 13, and enters the inner cavity of the main shaft casting. After solidification, the main shaft casting 22 is formed. Fig.11 shown.

[0034] The use of the above-mentioned iron mold covered with sand stacking box to produce a wind turbine main shaft mold casting wind turbine main shaft casting mold has the following advantages:

[0035] 1. The casting mold for producing wind turbine main shaft castings by the iron mold covered with sand and stacked boxes in this embodiment can realize the production of large wind turbine castings by segmented molding using a general iron mold covered with sand molding main machine and a hot core box core shooting machine, which can shorten the unpacking time to less than 4 hours. The unpacking time for each main shaft production can be saved by more than 2 days, which significantly improves the production efficiency.

[0036] 2. Use an iron mold covered with sand and stacked boxes in this embodiment to produce a wind turbine main shaft casting mold. Design a positioning pin sleeve on the upper parting surface of each iron mold, and design a positioning pin on the lower parting surface. The main shaft casting mold is made through stacking box molding to reduce the weight of the iron mold. Calculated at 60 tons for a single iron mold cast by a metal mold, the stacking process divides it into 5 layers or more, and the weight of each layer of the iron mold can be reduced to less than 15 tons, thereby reducing the specifications of the crane.

[0037] 3. The casting of this type obtained by using the casting mold of this embodiment will not be damaged throughout its life cycle. Compared with the metal mold which can only be used about 30 times, the life span is extended by more than 50 times, greatly reducing the mold cost.

[0038] 4. When using iron molds covered with sand and stacked boxes to produce wind turbine main shaft casting molds, there is no need to place a large amount of shrinkage-feeding chillers. Based on the shrinkage-feeding chiller time of 4 hours per piece and 2 employees, each production of a main shaft casting can save more than 8 working hours. Producing 300 main shaft castings per year can save 2,400 working hours.

Claims

1. Iron mold covered with sand stacking box production wind turbine main shaft casting mold, characterized in that: It includes an iron mold covered with sand box, an iron mold covered with sand core, a casting system iron mold for making a casting system and a cover box iron mold for forming the top surface of a main shaft casting. A plurality of iron mold covered with sand cores and iron mold covered with sand boxes are alternately stacked on the casting system iron mold from bottom to top, and the cover box iron mold is covered on the iron mold covered with sand box on the top layer to form a main shaft casting cavity. A pouring cup and a plurality of shrinkage feeding risers are provided on the cover box iron mold. The pouring cup is connected to the casting system, and the plurality of shrinkage feeding risers are arranged in a circular array around the pouring cup.

2. The casting mold for producing wind turbine main shaft by using iron mold covered with sand and stacked boxes according to claim 1 is characterized in that: The pouring system iron mold comprises an upper iron mold for a pouring system, a lower iron mold for a pouring system, an upper mold for a pouring system used for covering the upper iron mold for a pouring system with sand, and a lower mold for a pouring system used for covering the lower iron mold for a pouring system with sand. The upper mold for a pouring system and the upper iron mold for a pouring system are combined to form an upper sand layer for a pouring system. The upper sand layer for a pouring system is filled with self-hardening resin sand, so that the self-hardening resin sand is bonded to the upper iron mold for a pouring system to form an upper casting mold for a pouring system. The lower mold for a pouring system and the lower iron mold for a pouring system are combined to form a lower sand layer for a pouring system. The lower sand layer for a pouring system is filled with self-hardening resin sand, so that the self-hardening resin sand is bonded to the lower iron mold for a pouring system to form a lower casting mold for a pouring system. The upper casting mold for a pouring system and the lower casting mold for a pouring system are combined to form a casting system cavity. A foam ceramic filter is provided between the upper casting mold for a pouring system and the lower casting mold for a pouring system.

3. The casting mold for producing wind turbine main shaft by using iron mold covered with sand and stacked boxes according to claim 1 is characterized in that: The pouring system includes a sprue, a ceramic connecting pipe, a slag collecting bag and an inner gate ceramic pipe. The sprue is connected to the pouring cup. A plurality of slag collecting bags are respectively connected to the sprue through the ceramic connecting pipes. A foam ceramic filter is arranged in the slag collecting bag. The bottom ends of the plurality of inner gate ceramic pipes are respectively connected between the foam ceramic filter and the bottom of the slag collecting bag.

4. The casting mold for producing wind turbine main shaft by using iron mold covered with sand and stacked boxes according to claim 3 is characterized in that: The ceramic connecting tube is composed of a ceramic main body 1 connected to the straight runner and seven cross runners 1 connected to the ceramic main body 1 in a circumferential array, and the bottom end of the ceramic main body 1 is sealed. The inner gate ceramic tube is composed of a ceramic main body 2 and a cross runner 2 connected to one side of the bottom of the ceramic main body 2, and the bottom end of the ceramic main body 2 is sealed.

5. The casting mold for producing wind turbine main shaft by using iron mold covered with sand and stacked boxes according to claim 1 is characterized in that: The outer sides of the iron mold of the pouring system, the sand box covering the iron mold and the cover box iron mold are respectively provided with hanging shafts.

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