A molding die for a sand core assembly for winding a pressure vessel

Abstract

The present invention belongs to the technical field of composite material molding, and relates to a molding die for a sand core assembly for winding a pressure vessel, which is composed of a sand core male mold and a sand core female mold, both of which include a core shaft (1), a locking nut (2), a flap mold assembly (3), and each of which includes a group of metal rings, each of which is composed of an inner metal ring and an outer metal ring; two groups of metal rings with different diameters are used in combination with a flap mold to form a female mold and a male mold with different end face shapes, the end faces of the female mold and the male mold are matched and overlapped, and the dimensional accuracy is high after assembly, which solves the problem of poor dimensional accuracy caused by the rotation of the sand core assembly during winding and machining in the prior art; at the same time, the manufacturing process is simplified, and the molding of the sand core male mold and the female mold can be realized by using a set of flap molds in combination with metal rings. The mold is suitable for winding molding of composite material shells of rotating bodies.

Description

Technical Field

[0001] The invention belongs to the technical field of composite material molding, and in particular relates to a molding die for a sand core assembly for winding a pressure vessel. Background Art

[0002] In recent years, with the development of high-performance fibers, it has been widely used in the field of winding pressure vessel products due to its advantages of light weight and high strength. At present, the molding molds for pressure vessel winding mainly include metal or wooden flap molds, sand core molds, etc. Compared with metal molds, sand core molds have the advantages of light weight and simple structure. Especially for large aspect ratio composite pressure vessel products, the metal mold structure is relatively complex, and the use of sand core mold molding has obvious advantages. At present, the existing sand core mold molding mostly adopts such Figure 1 The tooling shown in the figure includes a core shaft, a locking nut and a flap mold combination. When in use, the mortar is filled into the cavity formed by the core shaft and the flap mold combination and compacted. After solidification and demoulding, the end surface of the sand core mold is first machined flat, and then assembled one by one into a whole, such as Figure 2 shown.

[0003] This production method has the following disadvantages: 1) Since each sand core mold is assembled into one body in the form of end-face contact, the components of the assembly are prone to rotation during the fiber winding process, affecting the normal winding; 2) The end faces of each sand core mold need to be machined, the surface roughness of the end faces is poor, and the dimensional accuracy of the sand core mold assembly after assembly is poor; 3) There are many processes in the production of the core mold and the cycle is long. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a molding die for a sand core assembly for winding a pressure vessel, which adopts two sets of metal rings of different diameters in combination with a flap mold to form a female mold and a male mold with different end face shapes. The end faces of the female mold and the male mold are matched and overlapped, which solves the problem of poor dimensional accuracy caused by component rotation and machining process during winding and simplifies the production process. The molding of the sand core male mold and the female mold can be achieved by using a set of flap molds in combination with metal rings. The mold has strong designability and is easy to operate.

[0005] The purpose of the present invention is achieved in this way: threaded holes are processed on the core shaft 1 and the flap mold combination 3 respectively, through holes are provided on the two groups of metal rings, and the core shaft 1, the flap mold combination 3 and the metal rings are fixedly connected by screws or pins to achieve the purpose of forming the required cavity of the sand core male mold and the female mold; by matching and using two groups of metal rings with different diameters, female molds and male molds with different end face shapes are formed, and the female mold and the male mold are matched and overlapped to achieve an integrated combination of the female mold and the male mold, which not only solves the problem of component rotation during the winding molding process, but also greatly improves the accuracy of the size of the sand core mold assembly; when demolding, the threaded holes set on the outer metal ring can be used to demold the outer metal ring with screws, and the demolding method is simple and quick. Finally, the core shaft, the flap mold combination and the inner metal ring are demolded to obtain the sand core male mold and the female mold. Figure 3-1 , 3-2 , as shown in 4 to 12.

[0006] The present invention relates to a molding die for a sand core assembly for winding a pressure vessel, which is composed of a sand core male mold and a sand core female mold, both of which include a core shaft 1, a locking nut 2, and a flap mold assembly 3, wherein the core shaft 1 is located inside the flap mold assembly 3, the two are coaxially arranged, and a locking nut 2 is used to achieve a fixed connection, and the characteristics are: the sand core male mold and the sand core female mold also each include a group of metal rings, each group of metal rings is composed of an inner metal ring and an outer metal ring; the outer metal ring Ⅰ4 of the sand core male mold is the same as the sand core The outer diameter of the outer metal ring Ⅱ5 of the female mold is the same, the inner diameter of the outer metal ring Ⅰ4 is the same as the outer diameter of the inner metal ring Ⅱ8 of the sand core female mold, the outer diameter of the inner metal ring Ⅰ7 of the sand core male mold is the same as the outer diameter of the core shaft 1, and the inner diameter of the outer metal ring Ⅱ5 is the same as the inner diameter of the middle cavity of the flap mold combination 3; the inner metal ring is fixedly connected to the core shaft 1, the outer metal ring is fixedly connected to the flap mold combination 3, and the connection between the flap mold combination 3 and the core shaft 1 has a molding surface that matches the core shaft 1; the core shaft 1, the flap mold combination 3 and the metal rings together form the cavity of the sand core mold.

[0007] Preferably, the core shaft 1 and one end of the petal mold assembly 3 are respectively provided with three evenly distributed threaded holes; the inner metal ring is provided with three evenly distributed through holes, which match the threaded holes on the core shaft, and the inner metal ring is connected to the core shaft by screws; the outer metal ring is provided with three evenly distributed through holes, which match the threaded holes on the petal mold assembly 3, and the outer metal ring is connected to the petal mold assembly 3 by screws;

[0008] Preferably, three evenly distributed blind holes are respectively provided at one end of the core shaft 1 and the flap mold combination 3; three evenly distributed through holes are provided on the inner metal ring, which match the blind holes on the core shaft 1, and the inner metal ring and the core shaft 1 are tightly connected by pins; three evenly distributed through holes are provided on the outer metal ring, which match the blind holes on the flap mold combination 3 and are tightly connected by pins.

[0009] Preferably, the end face of the flap mold assembly 3 is stepped, divided into a first end face and a second end face, and the second end face is provided with three evenly distributed threaded holes, which match the through holes on the outer metal ring, and the outer metal ring is fixed to the second end face of the flap mold assembly 3 by fastening screws. The stepped end face is designed to prevent the outer metal ring from shifting, better fix the outer metal ring, and further improve the end face dimensional accuracy of the male mold and the female mold. Figure 5 shown.

[0010] Preferably, the end face of the flap mold assembly 3 is stepped, divided into a first end face and a second end face, and the second end face is provided with three evenly distributed blind holes, which match the through holes on the outer metal ring, and the outer metal ring is fixed to the second end face of the flap mold assembly 3 by a pin tight fit.

[0011] Furthermore, the outer metal ring is provided with three evenly distributed threaded holes, the threaded holes and the through holes are arranged alternately, and the outer metal ring is pushed out by screws through the arranged threaded holes to achieve the purpose of separation.

[0012] The present invention relates to a molding die for a sand core assembly for winding a pressure vessel, which uses two sets of metal rings to realize the molding of a sand core male mold and a female mold. The end faces of the two are matched and overlapped, and no machining is required. The overlap surface is guaranteed by the mold, and the dimensional accuracy is high after assembly, which solves the problem of poor dimensional accuracy caused by the rotation of the sand core assembly during winding and machining in the prior art; at the same time, the manufacturing process is simplified, and the molding of the sand core male mold and female mold can be realized by using a set of petal molds in combination with metal rings. The mold is suitable for winding molding of composite material shells of rotating bodies. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a conventional sand core mold forming tool.

[0014] Figure 2 This is a schematic diagram of a conventional sand core mold after assembly.

[0015] Figure 3-1 It is a schematic diagram of assembling the male mold involved in the present invention.

[0016] Figure 3-2 It is a schematic diagram of the female mold assembly involved in the present invention.

[0017] Figure 4 It is a schematic diagram of the core shaft structure involved in the present invention.

[0018] Figure 5 It is a schematic diagram of the flap mold combination structure involved in the present invention.

[0019] Figure 6 It is a schematic structural diagram of an outer metal ring I and an inner metal ring I involved in the present invention.

[0020] Figure 7It is a schematic diagram of the structure of the outer metal ring II and the inner metal ring II involved in the present invention.

[0021] Figure 8 It is a schematic diagram of the male mold according to the present invention ejecting the outer metal ring I.

[0022] Fig. 9 It is a schematic diagram of the female mold according to the present invention when ejecting the outer metal ring II.

[0023] Fig.10 Schematic diagram of the formed sand core positive mold.

[0024] Fig.11 Schematic diagram of the formed sand core negative mold.

[0025] Fig.12 This is a schematic diagram of the assembled positive and negative molds of the formed sand core.

[0026] Among them: 1-core shaft, 2-locking nut, 3-petal mold assembly, 4-outer metal ring I; 5-outer metal ring II; 6-fixing mechanism, 7-inner metal ring I; 8-inner metal ring II. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with specific implementation modes and drawings, but this does not limit the technical solution.

[0028] Example 1

[0029] Take the sand core male mold with an outer diameter of 150mm and a length of 200mm, the sand core female mold with an outer diameter of 150mm and a length of 200mm, the sand core assembly with an outer diameter of 150mm and a length of 400mm after assembly, and the sand core female and male molds with a length of 20mm as an example. Figure 3-1 , 3-2 shown.

[0030] The mandrel 1 is a variable-section cylinder with a total length of 254 mm. The dimensions from top to bottom are: outer diameter 120 mm × 165 mm (height direction), outer diameter 50 mm × 15 mm (height direction), outer diameter 40 mm × 30 mm (height direction). In order to reduce the weight of the component, a hole with an inner diameter of 90 mm × 150 mm (height direction) is opened inside the mandrel 1. Three evenly distributed M8 threaded holes are preset on the upper end surface of the mandrel 1. The lower part of the mandrel 1 is processed with an M40 × 1.5 mm external thread with a thread length of 30 mm. The structure is as follows: Figure 4 shown.

[0031] The flap mold combination 3 is composed of a left flap mold and a right flap mold. The left flap mold and the right flap mold are symmetrical structures. The top end surfaces of the left and right flap molds are stepped and divided into a first end surface and a second end surface. The width of the first end surface is 10mm, the width of the second end surface is 20mm, and the height difference between the first end surface and the second end surface is 20mm. The total height of the left and right flap molds is 230mm. After the combination, the outer diameter of the flap mold is 210mm and the height is 230mm. Three cavities with different inner diameters and heights are formed inside, namely, upper, middle and lower cavities. The dimensions of the cavities are φ190mm×20mm (height direction), φ150mm×180mm (height direction), and φ40mm×30mm (wall thickness), respectively. The inner wall of the flap mold combination 3 has a molding surface that matches the outer wall of the sand core mold. The connection between the left and right flap molds and the core shaft 1 has a molding surface that matches the core shaft 1. After the left and right flap molds are combined, a through hole (φ40mm) with the same outer diameter as the core shaft 1 is formed at the bottom thereof, which is matched and connected with the core shaft 1. Two M12 threaded holes are preset at the intersection of the left and right flap molds 100mm away from the bottom and 95mm away from the rotation center line. The left and right flap molds are connected by screws to form flap mold combination 3. The flap mold combination 3 has three evenly distributed M10 threaded holes preset at the second end face. Its structure is as follows Figure 5 shown.

[0032] The outer metal ring Ⅰ4 has an inner diameter of 134mm, an outer diameter of 190mm, a thickness of 20mm, 3 evenly distributed through holes with a diameter of 12mm, and 3 cross-distributed M10 threaded holes. Its structure is as follows: Figure 6 As shown in the left picture.

[0033] The inner metal ring I7 has an inner diameter of 90 mm, an outer diameter of 120 mm, a thickness of 20 mm, and three through holes with a diameter of 9 mm are evenly distributed. Its structure is as follows Figure 6 As shown in the picture on the right.

[0034] The outer metal ring II5 has an inner diameter of 150 mm, an outer diameter of 190 mm, a thickness of 20 mm, and is evenly distributed with 3 through holes of 12 mm in diameter and 3 M10 threaded holes evenly distributed crosswise. Its structure is as follows: Figure 7 As shown in the left picture.

[0035] The inner metal ring II8 has an inner diameter of 90 mm, an outer diameter of 134 mm, a thickness of 20 mm, and three through holes with a diameter of 9 mm are evenly distributed. Its structure is as follows Figure 7 As shown in the picture on the right.

[0036] 1. Mold assembly is carried out in the following order:

[0037] (a) Assembly when forming the sand core male mold

[0038] 1. Connect the two halves of the mold by screws to form a halves mold assembly 3.

[0039] 2. Place the core shaft 1 into the flap mold assembly 3 and lock the bottom with the locking nut 2.

[0040] 3. The outer metal ring Ⅰ4 is connected and fixed to the second end face of the flap mold assembly 3 by fastening screws or pins, and the inner metal ring Ⅰ7 is fixed and connected to the top of the core shaft 1 by fastening screws or pins to form the required cavity when forming the sand core male mold, such as Figure 3-1 shown.

[0041] 4. Place the mortar into the above cavity, compact it, and place it in an oven to cure.

[0042] (b) Assembly when forming the sand core female mold

[0043] 1. Connect the two halves of the mold by screws to form a halves mold assembly 3.

[0044] 2. Place the core shaft 1 into the flap mold assembly 3 and lock the bottom with the locking nut 2.

[0045] 3. The outer metal ring II5 is fixedly connected to the second end face of the flap mold assembly 3 by fastening screws or pins, and the inner metal ring II8 is fixedly connected to the top of the core shaft 1 by fastening screws or pins to form the cavity required for forming the sand core female mold, such as Figure 3-2 shown.

[0046] 4. Place the mortar into the above cavity, compact it, and place it in an oven to cure.

[0047] (ii) Demolding after molding is carried out in the following order:

[0048] (a) Demolding of the sand core male mold

[0049] 1. Loosen the locking nut of the mandrel 1 with a wrench. 2. Hit the bottom of the mandrel 1 with a copper rod and remove the mandrel 1 together with the inner metal ring Ⅰ7.

[0050] 2. Use a wrench to loosen and remove the fastening screws or pins of the flap mold assembly 3 and the outer metal part Ⅰ4.

[0051] 3. Take three M10 screws and install them into the threaded holes of the outer metal ring Ⅰ4, and push out the outer metal ring Ⅰ4. Figure 8 shown.

[0052] 4. Loosen and remove the connecting screws of the flap mold assembly 3 with a wrench, and then separate the two flap molds to obtain the sand core positive mold, such as Fig.10 shown.

[0053] (b) Demolding during sand core molding

[0054] 1. Loosen the locking nut of the mandrel 1 with a wrench. 2. Hit the bottom of the mandrel 1 with a copper rod and remove the mandrel 1 together with the inner metal ring II 8.

[0055] 2. Use a wrench to loosen and remove the fastening screws or pins of the flap mold assembly 3 and the outer metal part II 5.

[0056] 3. Take three M10 screws and install them into the threaded holes of the outer metal part Ⅱ5, and push the outer metal part Ⅱ5 out. Fig. 9 shown.

[0057] 4. Loosen and remove the connecting screws of the flap mold assembly 3 with a wrench, and then separate the two flap molds to obtain the sand core female mold, such as Fig.11 shown.

[0058] (III) Assembly of sand core male and female molds:

[0059] The sand core male mold and female mold prepared above are assembled into one to obtain a sand core assembly for winding a pressure vessel, such as Fig.12 shown.

Claims

1. A molding die for a sand core assembly for winding a pressure vessel, comprising a sand core male mold and a sand core female mold, both of which include a core shaft (1), a locking nut (2), and a flap mold assembly (3), wherein: The core shaft (1) is located inside the flap mold assembly (3), and the two are coaxially arranged. The flap mold assembly (3) and the bottom end of the core shaft (1) are fixedly connected by a locking nut (2). The sand core male mold and the sand core female mold each include a group of metal rings, each group of metal rings is composed of an inner metal ring and an outer metal ring, the inner metal ring is located inside the outer metal ring, the two are coaxially arranged and located in the same plane, and the thickness of the inner metal ring and the outer metal ring are both 20 mm; the outer diameter of the outer metal ring I (4) of the sand core male mold is the same as the outer diameter of the outer metal ring II (5) of the sand core female mold, and the inner diameter of the outer metal ring I (4) is the same as that of the sand core female mold. The outer diameter of the inner metal ring II (8) is the same as that of the core shaft (1), the outer diameter of the inner metal ring I (7) of the sand core male mold is the same as the outer diameter of the top end of the core shaft (1), the inner diameter of the outer metal ring II (5) is the same as the inner diameter of the middle cavity of the flap mold combination (3), and the inner diameter of the inner metal ring I (7) of the sand core male mold is the same as the inner diameter of the inner metal ring II (8) of the sand core female mold; the inner metal ring is fixedly connected to the top end of the core shaft (1), the outer metal ring is fixedly connected to the top end of the flap mold combination (3), and the connection between the flap mold combination (3) and the core shaft (1) has a profile that matches the core shaft (1); the core shaft (1), the flap mold combination (3) and the metal ring together form the cavity of the sand core mold.

2. The forming die of the sand core assembly for winding a pressure vessel according to claim 1, characterized in that: The core shaft (1) and the flap mold assembly (3) are respectively provided with three evenly distributed threaded holes at one end; the inner metal ring is provided with three evenly distributed through holes, which match the threaded holes on the core shaft (1), and the inner metal ring and the core shaft (1) are connected by screws; the outer metal ring is provided with three evenly distributed through holes, which match the threaded holes on the flap mold assembly (3), and the outer metal ring and the flap mold assembly (3) are connected by fastening screws.

3. The forming die of the sand core assembly for winding a pressure vessel according to claim 1, characterized in that: The core shaft (1) and one end of the flap mold assembly (3) are respectively provided with three evenly distributed blind holes; the inner metal ring is provided with three evenly distributed through holes, which match the blind holes on the core shaft (1), and the inner metal ring and the core shaft (1) are tightly connected by pins; the outer metal ring is provided with three evenly distributed through holes, which match the blind holes on the flap mold assembly (3), and are tightly connected by pins.

4. The forming die of the sand core assembly for winding a pressure vessel according to claim 2, characterized in that: The top end surface of the flap mold assembly (3) is stepped and is divided into a first end surface and a second end surface. The second end surface is provided with three evenly distributed threaded holes, which match the through holes on the outer metal ring. The outer metal ring is fixed to the second end surface of the flap mold assembly (3) by means of fastening screws, and the inner metal ring is fixed to the top end of the core shaft (1).

5. The forming die of the sand core assembly for winding a pressure vessel according to claim 3, characterized in that: The top end surface of the flap mold assembly (3) is stepped and is divided into a first end surface and a second end surface. The second end surface is provided with three evenly distributed blind holes, which match the through holes on the outer metal ring. The outer metal ring is fixed to the second end surface of the flap mold assembly (3) by a tight fit with pins, and the inner metal ring is fixed to the top end of the core shaft (1).

6. A forming die for a sand core assembly for winding a pressure vessel according to any one of claims 1 to 5, characterized in that: The outer metal ring is also provided with three evenly distributed threaded holes, and the threaded holes and the through holes are arranged alternately.

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