Combination mold

Abstract

A combined mold includes a form-fitting mold and a supporting mold. The form-fitting mold includes a main body, a strengthening layer, a working surface and an assembly surface. The main body is pressed or printed with a granular material. A strengthening layer is arranged on the surface of the main body, or the strengthening layer penetrates into the surface of the main body. The side of the main body in contact with the sand mold cavity is the working surface, and the other side opposite is the assembly surface. The supporting mold is installed on one side of the main body assembly surface, and its shape matches the shape of the assembly surface. The form-fitting mold is printed or pressed using granular materials that are easy to shape. The advantage of the convenient molding of such granular materials is utilized. The strengthening layer with high tensile strength and hardness makes up for the disadvantage of insufficient hardness of the granular materials. The supporting mold is added as a filling material to solve the problems of overall tensile strength and hardness. At the same time, the overall mass can be made light. In this way, a combined mold that makes up for each other's shortcomings and integrates various advantages is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of casting moulds, in particular to a combined mould. Background Art

[0002] The bottleneck of new products in the foundry industry lies in mold development. The speed of mold development determines the length of the R&D cycle of new products. Existing molds have their own advantages and disadvantages. Traditional wooden molds are low in cost and can be used repeatedly, but have a long development cycle, especially for complex castings, which are more difficult to make and have poor repeatability; traditional lost foam molds are low in cost and require mechanical processing, but cannot be reused; traditional metal molds have a long production cycle and can be used repeatedly, but are not suitable for large parts and are costly; emerging FDM molds and SLA molds are all printed, with good results but too high a cost.

[0003] Therefore, molds that shorten mold development cycle, reduce mold manufacturing costs, can be used repeatedly, and can adapt to various complex structural designs are the most needed molds in the industry. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a combined mold. One aspect of the present invention solves the technical problems of long mold development cycle, high cost, non-reusability, and difficult processing of complex casting molds.

[0005] A technical solution adopted by the present invention to solve its technical problem is:

[0006] A combined mold comprises a form-fitting mold and a supporting mold. The form-fitting mold comprises a main body, a strengthening layer, a working surface and an assembly surface. The main body is formed by pressing or printing a granular material, a strengthening layer is arranged on the surface of the main body, or the strengthening layer penetrates into the surface of the main body, a side of the main body in contact with a sand mold cavity is a working surface, and the other opposite side is an assembly surface. The supporting mold is installed on one side of the main body assembly surface, and its shape matches the shape of the assembly surface.

[0007] Use granular materials that are easy to shape to print or press into a free-form mold. Take advantage of the easy molding of this granular material, use a reinforcement layer with high tensile strength and hardness to make up for the shortcomings of the granular material's insufficient hardness, and add a supporting mold as a filling material to solve the overall tensile strength and hardness problems. At the same time, the overall mass can be lightweight, so that a combined mold that compensates for each other's shortcomings and integrates all the advantages is obtained.

[0008] Preferably, the main body is made of a granular material of 5 to 2000 mesh, which can be at least one of silica sand, fused quartz, fused corundum particles, mullite particles, sillimanite particles, kaolinite clinker, refractory clay, zircon sand, rutile particles, spinel particles, magnesium oxide, calcium oxide, ceramsite sand, chromium ore sand, silicon carbide powder, silicon nitride powder, alumina powder, and starch.

[0009] The reason why granular materials are used is that they are easy to shape. All of the above granular materials can be shaped, and different materials can be selected to meet different needs. Currently, silica sand is the most commonly used. In addition, silica sand can be reused, which makes it particularly suitable for industrial production. However, some special industries or fine industries have different production requirements, so it is necessary to choose suitable materials as the granular materials for the main body of the mold.

[0010] Preferably, the strengthening layer is attached to the main body when in liquid state, and is in solid state after being cured. The hardness of the main body to which the strengthening layer is attached is not less than 85HD, and the tensile strength is not less than 15MPa.

[0011] The strengthening layer material is attached to the main body when it is in liquid state and can penetrate into the main body made of granular material. After solidifying into a solid state, it becomes one with the main body. The strengthening layer must be able to adhere to the main body and cannot be separated from the main body or easily peeled off from the main body, otherwise it will not play a strengthening role. The main body with the strengthening layer has the hardness and tensile strength that it should have as a mold, so that it can be shaped under a certain pressure.

[0012] Preferably, the strengthening layer is made of furan resin, polyurea resin, modified polyurea resin, polyurethane resin, phenolic resin, urea-formaldehyde resin, melamine-formaldehyde resin, epoxy resin, polyurethane modified silicone resin, xanthan gum, polyvinyl acetate emulsion, polyacrylamide, ethyl silicate, silica sol, sulfate, rosin, syrup, Tianqing gum, coal tar, asphalt, polyvinyl acetal, ethylene-vinyl acetate copolymer, phenolic-nitrile glue, phenolic-chloroprene glue, phenolic-polyurethane glue, epoxy-nitrile glue, unsaturated polyester, acrylic resin, polyimide The invention is prepared from at least one of amine, polybenzimidazole, phenolic-polyvinyl acetal, phenolic-polyamide, epoxy-polyamide, olefin polymer, polyvinyl acetate, polyvinyl alcohol, perchlorethylene, polyisobutylene, polyester, polyether, polyamide, polyacrylate, a-cyanoacrylate, epoxy-polysulfide glue, silicone resin, furan resin, perchlorethylene, polyisobutylene, polyester, polyether, polyamide, polyacrylate, a-cyanoacrylate, polyvinyl acetal, epoxy resin AB glue, epoxy-polyamide AB glue and phenolic-epoxy resin AB glue.

[0013] Using any of the above materials can meet the requirements of the previous item, can be attached to the main body, and the cured hardness can meet the requirements. In addition, the above materials all have a characteristic that they are liquid before curing, which is convenient for brushing, spraying or soaking so that they can penetrate into the granular material. After reaching a certain temperature and curing, they can maintain the cured state at room temperature. They have high hardness and strength, which is convenient for industrial production and processing, and can meet the requirements of tensile strength and hardness.

[0014] Preferably, the strengthening layer penetrates at least 2 mm into the surface of the main body.

[0015] From the above, it can be seen that the reason for choosing granular materials is that there are gaps between the granular materials, allowing the strengthening layer to penetrate and thus achieve the effect. Whether the particles are too dense or the strengthening layer cannot penetrate, it will lead to failure to meet the requirements. Therefore, the penetration depth is also a guarantee of tensile strength and hardness. In theory, the deeper the penetration, the better the effect, but in fact, when the penetration reaches 2 mm, it can meet the initial tensile strength and hardness requirements, so the strengthening layer penetrates at least 2 mm.

[0016] Preferably, the main body includes a splicing body and a connecting block, and the main body is formed by splicing at least two splicing bodies; the connecting block is simultaneously connected to at least two adjacent splicing bodies to relatively fix at least two splicing bodies; optimally, the connecting block is butterfly-shaped or flower-shaped.

[0017] The theme is decomposed into several splicing bodies to facilitate making large molds. When making some large castings, the corresponding molds are also huge. They are designed to be spliced ​​to reduce the production volume. At the same time, the later assembly and molding are also convenient for the transfer and transportation of the mold. The adjacent splicing bodies are connected by connecting blocks, so that the adjacent splicing bodies are relatively fixed and there is no relative displacement. Finally, the complete main body is assembled. The connecting blocks are generally set horizontally.

[0018] Preferably, the splicing bodies further include slots, and adjacent splicing bodies are respectively provided with protruding or recessed slots that match each other, that is, adjacent splicing bodies are spliced ​​into shape by placing the protrusions in the recesses.

[0019] The connecting blocks are generally arranged horizontally, so the vertical direction generally uses protrusions or depressions to connect the splicing bodies, which limits the horizontal movement of the two splicing bodies and makes the connection between the splicing bodies more stable.

[0020] Preferably, the main body further includes reinforcing ribs, the main body is a double-layer or multi-layer structure with a cavity in the interlayer, and reinforcing ribs are arranged between the two-layer structure, the two ends of the reinforcing ribs are respectively connected to the two-layer structure, and the double-layer or multi-layer structure and the reinforcing ribs are integrally formed.

[0021] If you want to increase the hardness of the main body printed out of granular materials, you have to increase the thickness, which will increase the mass of the entire mold, which is inconvenient for handling and assembly. Therefore, the main body is designed to be double-layered or multi-layered, and the cavity in the middle is made of reinforcing ribs, which can both increase the hardness and reduce the mass, killing two birds with one stone. Adding a strengthening layer will increase the overall hardness and tensile strength of the main body, so this double or multi-layer will not only not reduce the overall strength, but also increase the overall hardness and reduce the thickness of the main body due to the layer frame of the strengthening layer area.

[0022] Preferably, the supporting mold is made of at least one material selected from the group consisting of wood, metal, and resin.

[0023] If the conformal mold is hollow, it will have higher requirements for tensile strength and hardness. Therefore, it is necessary to use materials with certain tensile strength and hardness to make the supporting mold and fill the cavity on one side of the conformal mold assembly surface, so that the tensile strength and hardness of the entire mold are improved.

[0024] Preferably, the supporting mold is hollow or grid-shaped.

[0025] At the same time, the quality of the supporting mold must be considered. Flowers that are too heavy are not convenient to flip, carry and use. Therefore, under the condition of appropriate tensile strength and hardness, the mass should be reduced as much as possible to obtain a lightweight supporting mold.

[0026] Preferably, the outer contour of the supporting mold is consistent with the outer contour of a three-dimensional shape composed of at least one cube and / or at least one cuboid.

[0027] This requires that the support mold is easy to make and will not rotate relative to the conformal mold. A simple cube or rectangular parallelepiped can be obtained using long strips or plates of material without having to be processed into arcs, circles and other shapes. This reduces the difficulty of processing the support mold, improves processing efficiency, and allows the support mold to be obtained faster and better. It is even possible to mass-produce the same type of support molds and match them with conformal molds of different types to achieve a quick assembly effect.

[0028] Preferably, the assembly surface is in complete contact with the supporting mold, and the surface of the supporting mold in contact with the assembly surface is a flat plane.

[0029] This is to prevent gaps or cavities between the assembly surface and the support surface, which would create weak points. By designing the shape of the assembly surface and covering the outside of the support mold with a flat plate, full contact between the assembly surface and the support surface can be achieved, thereby improving the overall hardness and reducing the force per unit area.

[0030] Preferably, the assembly surface includes a mounting structure A, and the supporting mold includes a mounting structure B. The mounting structure A of the assembly surface is protruding or recessed, and the mounting structure B on the corresponding supporting mold is correspondingly recessed or protruding. The assembly surface and the supporting mold are relatively fixed by placing the protrusion in the recess.

[0031] The use of this protrusion stuck in the recess to relatively fix the assembly surface and the support mold is easy to manufacture and convenient to assemble on the one hand, and on the other hand, it increases the assembly area, improves stability, and prolongs the service life. Preferably, a concave trapezoid is designed on the assembly surface, and a correspondingly protruding trapezoid is designed on the outside of the support mold. The trapezoid is small at the top and large at the bottom. After installation, the relative movement of the conformable mold and the support mold in the vertical direction is limited, which is more stable.

[0032] Preferably, it also includes a rivet rod, which penetrates the conformable mold and the supporting mold at the same time to relatively fix the conformable mold and the supporting mold.

[0033] Preferably, the rivet rod comprises a cap body at an upper end and a rod body at a lower end, the cross-sectional area of ​​the cap body is larger than the cross-sectional area of ​​the rod body, and the cap body is arranged in the conformable mold.

[0034] The rivet rods are used to fix multiple free-form molds or support molds at the same time, which improves the overall wedging degree, facilitates the operation and assembly, and improves the overall stability.

[0035] Preferably, the main body further includes a rivet hole, the main body is a double-layer or multi-layer with a cavity in the interlayer, the rivet hole is arranged in the cavity of the double-layer or multi-layer or the rivet hole passes through the main body, and the rivet rod is arranged in the rivet hole.

[0036] The rivet rod is accommodated in the cavity of the sandwich, which increases the contact surface and facilitates the design. It is also more convenient to assemble, and does not protrude from the surface, thereby improving the structural stability and making it easier to relatively fix the main bodies of different layers.

[0037] Preferably, it also includes a base plate, on which the form-fitting mold and the supporting mold are arranged, the supporting mold is fixed to the base plate, and the rivet rod simultaneously passes through the form-fitting mold, the supporting mold and the base plate.

[0038] Designing a base plate for the mold is convenient for later modeling work and for lifting and transportation. With the base plate, the mold, supporting mold and base plate are fixed together, making the integrated type better and more convenient for transportation and use.

[0039] Preferably, it further comprises a hanger, wherein two protruding hangers are respectively arranged on both sides of the conformable mold, and the intersection points of all the hangers coincide with the center of gravity.

[0040] Preferably, it also includes a lifting hole. The top surface of the conformable mold is provided with a lifting hole. The lifting hole has a circular cavity, and an elongated opening is provided on the upper part of the cavity. The length of the elongated opening is consistent with the diameter of the circular cavity. The sling is an inverted T-shape. After the bottom end is placed into the cavity from the elongated opening, the sling is rotated 90° so that it is stuck in the cavity, thereby lifting the conformable mold.

[0041] The lifting handle and lifting holes designed at the back are used to facilitate the transfer of the combination mold. If a large sand mold is to be made, the corresponding combination mold is also huge, so it must be easy to transport. If it is light, use the lifting hole, and if it is heavy, use the lifting handle or use the base plate for transportation.

[0042] It can be seen from the above technical scheme that one of the beneficial effects brought by one aspect of the present invention is that it is preferred to use silica sand to make the main body. By adding a strengthening layer, the disadvantage of the low hardness of the sand mold itself is overcome, so that the sand mold meets the hardness requirements of the mold, and the cost is low. The silica sand can be recycled and reused repeatedly. The speed of sand mold design printing or pressing molding is fast, the cycle is short, simple structures can be quickly pressed and molded, and complex structures can be printed and molded at one time by additive printing. The manufacturing is high in precision and convenient and fast, that is, the advantage of the easy plasticity of the sand mold is used. On the other hand, wood, metal or resin is used as a supporting mold, and this material with a certain hardness and tensile strength is used to make a hollow or grid shape to obtain a lightweight and hard supporting mold as a support. The advantages of these materials in terms of hardness are utilized, and they are made into grids and hollows to reduce weight. There are advantages in various aspects. Finally, a new type of mold with light weight, sufficient hardness and high appearance precision is obtained, which has the advantages of short development cycle, low cost, repeated use, and complex molds can still be quickly processed and manufactured. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Attached Figure 1 It is a schematic structural diagram of a combined mold according to an embodiment disclosed in the present invention with one splicing body hidden.

[0044] Attached Figure 2 Yes Figure 1 sectional view of .

[0045] Attached Figure 3 It is a structural schematic diagram of a conformable mold of a combined mold according to an embodiment disclosed in the present invention.

[0046] Attached Figure 4 Yes Figure 3 A cross-sectional view of the structure shown.

[0047] Attached Figure 5 Yes Figure 3 A cross-sectional view of the structure shown from another angle.

[0048] Attached Figure 6 Yes Figure 3 Bottom view of the structure shown.

[0049] Attached Figure 7 It is a schematic structural diagram of a supporting mold of a combined mold according to an embodiment disclosed in the present invention.

[0050] Attached Figure 8 Yes Figure 7 Elevation view of the structure shown.

[0051] Attached Fig. 9 Yes Figure 7 A cross-sectional view of the structure shown.

[0052] Attached Fig.10 It is a schematic structural diagram of a supporting mold of a combined mold according to an embodiment disclosed in the present invention.

[0053] Attached Fig.11 It is a structural schematic diagram of a conformable mold of a combined mold according to an embodiment disclosed in the present invention.

[0054] Attached Fig.12 Yes Fig.11 Bottom view of the structure shown.

[0055] Attached Fig.13 Yes Fig.10 and attached Fig.11 Schematic diagram of the combined mold structure in which the structures shown are assembled together.

[0056] In the figure: the form-fitting mold 10, the main body 11, the splicing body 110, the connecting block 111, the slot 112, the reinforcing rib 113, the rivet hole 114, the strengthening layer 12, the working surface 13, the assembly surface 14, the mounting structure A140, the supporting mold 20, the mounting structure B21, the rivet rod 30, the bottom plate 40, the lifting handle 50, and the lifting hole 60. DETAILED DESCRIPTION

[0057] In conjunction with the accompanying drawings of the present invention, a technical solution of an embodiment of the invention is further elaborated in detail.

[0058] Molds are very important in the casting industry. Existing molds have their own advantages and disadvantages. The development of molds is very slow because there are not many particularly suitable ones, so traditional molds still occupy the vast majority. With the development of technology, 3DP molding technology is one of the most widely used additive manufacturing technologies. It mainly adopts the method of laying powder materials layer by layer and then printing and forming by spraying adhesives. The powder materials can be silica sand, ceramic powder, metal powder, sand, etc. Now it is mainly printed out by sand. Additive manufacturing has a significant advantage, that is, complex shapes can still be quickly designed through software, but if it is used as a mold, it has a fatal disadvantage, that is, it cannot meet the hardness and tensile strength requirements of the mold. Therefore, additive manufacturing has always printed sand molds, and no one has ever considered using additively manufactured products as molds. Consider the mold cost, reduce costs, improve quality and increase efficiency. The printing cost of 3DP sand molds is 0.6-0.7 times that of wooden molds. The use of 3DP sand molds can greatly reduce mold costs and improve production efficiency.

[0059] In order to solve the problem of insufficient surface hardness and tensile strength of the sand mold, a strengthening layer 12 is set on the surface of the sand mold, so that the surface hardness and tensile strength are doubled, meeting the requirements of the mold and ensuring a sufficient number of repeated uses. The granular material that is easy to shape is printed or pressed into a free-form mold. The advantage of the convenient molding of this granular material is utilized, and the strengthening layer 12 with high tensile strength and hardness makes up for the disadvantage of insufficient hardness of the granular material. In addition, the supporting mold 20 is used as a filling material to solve the problem of overall tensile strength and hardness. At the same time, the overall mass can be lightweight, so as to obtain a combined mold that makes up for each other's shortcomings and integrates various advantages.

[0060] Embodiment 1:

[0061] A combined mold includes a mold-following mold 10, a supporting mold 20 and a rivet rod 30. The mold-following mold 10 includes a main body 11, a strengthening layer 12, a working surface 13 and an assembly surface 14. The main body 11 is pressed or printed by granular materials. The strengthening layer 12 is arranged on the surface of the main body 11, or the strengthening layer 12 penetrates into the surface of the main body 11. The side of the main body 11 in contact with the sand mold cavity is the working surface 13, and the other side opposite to the main body 11 is the assembly surface 14. The supporting mold 20 is installed on one side of the assembly surface 14 of the main body 11, and its shape matches the shape of the assembly surface 14. Because some molds are used to form the external structure of the casting, such as the attachment Figure 10-13 As shown, some are for forming the inner cavity structure of the casting, such as the attached Figure 1-9 As shown, there will be some differences, but in general, the working surface 13 of the conformable mold 10 is the side in contact with the sand mold cavity, and the other opposite side is the assembly surface 14, which is connected to the supporting mold 20.

[0062] Refer to the attached Figure 7 and attached Figure 5As shown, the assembly surface 14 includes a mounting structure A140, and the supporting mold 20 includes a mounting structure B21. The mounting structure A140 of the assembly surface 14 is protruding or recessed, and the mounting structure B21 on the corresponding supporting mold 20 is correspondingly recessed or protruding. The assembly surface 14 and the supporting mold 20 are relatively fixed by protruding and being placed in the recess.

[0063] See attached Figure 1 and attached Figure 2 The rivet rod 30 penetrates the conformable mold 10 and the supporting mold 20 at the same time to fix the conformable mold 10 and the supporting mold 20 relatively. The rivet rod 30 includes a cap body at the upper end and a rod body at the lower end. The cross-sectional area of ​​the cap body is larger than the cross-sectional area of ​​the rod body. The cap body is arranged in the conformable mold.

[0064] The main body 11 is made of at least one granular material selected from the group consisting of silica sand, fused quartz, fused corundum particles, mullite particles, sillimanite particles, kaolinite clinker, refractory clay, zircon sand, rutile particles, spinel particles, magnesium oxide, calcium oxide, ceramsite sand, chromium sand, silicon carbide powder, silicon nitride powder, aluminum oxide powder, and starch, and the granular material is 5 to 2000 mesh, and the best is made of granular material of 70 to 800 mesh.

[0065] The reinforcement layer 12 is attached to the main body 11 when it is in liquid state. Because the main body 11 is granular, it is convenient for the reinforcement layer 12 to adhere to the main body 11 by at least 2 mm or penetrate into the main body 11 by at least 2 mm. The reinforcement layer 12 is solid after curing. The hardness of the main body 11 attached with the reinforcement layer 12 is not less than 85HD, and the tensile strength is not less than 15MPa.

[0066] The strengthening layer 12 includes at least one of epoxy resin AB glue, epoxy-polyamide AB glue, phenolic-epoxy resin AB glue, phenolic resin, urea-formaldehyde resin, melamine-formaldehyde resin, epoxy resin, silicone resin, furan resin, unsaturated polyester, acrylic resin, polyimide, polybenzimidazole, phenolic-polyvinyl acetal, phenolic-polyamide, epoxy-polyamide, vinyl polymer, polyester, polyether, polyamide, polyacrylate, a-cyanoacrylate, polyvinyl acetal, ethylene-vinyl acetate copolymer, phenolic-nitrile glue, phenolic-chloroprene glue, phenolic-polyurethane glue, epoxy-nitrile glue, and epoxy-polysulfide glue.

[0067] See attached Figure 7-9 As shown, the support mold 20 is made of at least one material of wood, metal, and resin in a hollow or grid shape. This can reduce weight and meet support requirements. The thickness of the raw material plate of the support mold 20 is 80-120 mm, and the grid spacing of the support mold 20 is 150-250 mm, which reduces the material consumption and stabilizes the structure.

[0068] The above is an assembly mold formed in one piece with the mold 10, which is suitable for molds with smaller volumes. It utilizes the advantage of granular materials being easy to form, and combines the hardness and high tensile strength of the reinforcement layer 12 to form a shell-like structure that meets the mold needs and matches the shape of the cavity. It is filled with a hollow support mold 20, which is stronger in hardness and lightweight, to obtain an assembly mold.

[0069] Embodiment 2:

[0070] Based on Example 1, Figure 3-6 As shown, the main body 11 also includes a reinforcing rib 113. The main body 11 is made into a double layer, and the main body 11 is a double layer or a multi-layer structure with a cavity in the interlayer, and a reinforcing rib 113 is arranged between the two layers. The two ends of the reinforcing rib 113 are respectively connected to the two layers, and the double layer or the multi-layer structure is integrally formed with the reinforcing rib 113. The wall thickness of each layer is 20-50 mm. The spacing between the reinforcing ribs 113 is 100-300 mm.

[0071] After the main body 11 is made into a double-layer or multi-layer, a strengthening layer 12 is attached to or infiltrated on the surface to obtain a conformable mold 10. This reduces the weight of the main body 11 and increases the area of ​​the strengthening layer 12, thereby increasing the overall hardness and tensile strength of the conformable mold 10, resulting in a conformable mold 10 that is lighter in weight and higher in strength and hardness.

[0072] Embodiment 3:

[0073] On the basis of Example 1 or Example 2, the main body 11 includes a splicing body 110, a connecting block 111, and a slot 112. The main body 11 is formed by splicing at least two splicing bodies 110; the connecting block 111 is simultaneously connected to at least two adjacent splicing bodies 110 to relatively fix at least two splicing bodies 110. Adjacent splicing bodies 110 are respectively provided with mutually matching protruding or concave slots 112, that is, adjacent splicing bodies 110 are spliced ​​and formed by placing the protruding in the concave.

[0074] Refer to the attached Figure 1 and attached Figure 3 As shown, adjacent splicing bodies 110 are connected together by connecting blocks 111 or slots 112 so that the splicing bodies 110 become a whole. Generally, butterfly-shaped or flower-shaped connecting blocks 111 are horizontally arranged to connect the splicing bodies 110. Vertically, the splicing bodies 110 are connected by protruding and recessed slots 112. In this way, the splicing bodies 110 are limited from all directions so that the splicing bodies 110 become a whole.

[0075] Embodiment 4:

[0076] On the basis of embodiments 1-3, it also includes a bottom plate 40, a hanger 50 and a lifting hole 60. The bottom plate 40 is provided with the form-fitting mold 10 and the supporting mold 20. The supporting mold 20 is fixed on the bottom plate 40. The rivet rod 30 simultaneously penetrates the form-fitting mold 10, the supporting mold 20 and the bottom plate 40. The hangers 50 are provided with two protruding hangers 50 on both sides of the form-fitting mold. The hangers 50 protrude about 50 mm, and the end faces are designed as anti-slip bosses. The intersection points of all the hangers 50 coincide with the center of gravity. The lifting hole 60 is provided on the top surface of the form-fitting mold 10. The lifting hole 60 has a circular cavity, and a long strip opening is provided on the upper part of the cavity. The length of the long strip opening is consistent with the diameter of the circular cavity. The hanger is an inverted T-shaped. After the bottom end is placed into the cavity from the long strip opening, the hanger rotates 90°, so that it is stuck in the cavity, thereby lifting the form-fitting mold 10.

[0077] The designed base plate 40, lifting handle 50 and lifting hole 60 are all used to facilitate the transfer of the combined mold. If a large sand mold is to be made, the corresponding combined mold is also huge, so it must be easy to transport. The lifting hole 60 is used for light ones, and the lifting handle 50 or the base plate 40 is used for transportation for heavy ones.

[0078] Embodiment 5:

[0079] The support mold 20 in any of the above embodiments is optimally designed so that the outer contour of the support mold 20 is consistent with the outer contour of a three-dimensional shape composed of at least one cube and / or at least one cuboid. At the same time, the assembly surface 14 is in full contact with the support mold 20, and the surface of the support mold 20 in contact with the assembly surface 14 is a flat surface. That is, the outermost skin of the upper grille or hollow support mold 20 has a thickness of about 12 mm.

[0080] The support mold 20 with an optimized design is formed by stacking simple cubes or cuboids, and can be expanded into simple three-dimensional shapes such as spheres, cylinders, cones, etc. in special cases, in order to facilitate production and assembly, simplify production difficulty, and improve efficiency. The assembly surface 14 is in full contact with the support mold 20 to prevent the gap from causing stress increase and becoming a weak point, thereby causing damage when the conformable mold 10 is subjected to excessive pressure.

[0081] During industrial production, some universal support molds 20 of different specifications can be assembled in batches. Support molds 20 of the same specification can be combined with flexible molds 10 of different specifications. The working surface 13 of the flexible mold 10 is designed according to the shape of the sand mold cavity. The assembly surface 14 of the flexible mold 10 within a certain range of size is of one specification and consistent with the support mold 20 of the corresponding specification. This can save time, achieve rapid combination, and improve work efficiency. Even in the case of limited support molds 20, one support mold 20 and multiple flexible molds 10 can be quickly combined as needed. Moreover, when the flexible mold 10 or the support mold 20 is damaged, the other one can be retained for high utilization.

[0082] In all the above embodiments, the conformable mold is made of a main body using granular material and then coated with a strengthening layer. Experiments were conducted on the hardness and tensile strength of the simple main body and the main body coated with the strengthening layer. The specific experimental results are as follows.

[0083] That is, using silica sand particles and obtaining a main body by 3D printing, a comparative experiment was conducted to compare the performance of a main body without a reinforcing agent (before treatment) and a main body with a reinforcing agent as described in this scheme (after treatment), and the results are shown below.

[0084] Table 1 Performance comparison before and after treatment

[0085]

[0086] It can be seen from Table 1 that the tensile strength and hardness of the model are greatly improved after treatment, especially the tensile strength is as high as 20Mpa, which is almost ten times that before treatment; the hardness is as high as 98HD. It is a good solution to the problem that the model is easy to break or damage during use, moving, handling or transportation due to its low hardness and hardness.

[0087] Therefore, it can be seen that the form-fitting mold can fully achieve the required tensile strength and hardness, and is capable of performing the work of the mold.

[0088] The specific design process of any of the above embodiments is as follows:

[0089] The specific assembly mold is designed according to the needs. When the mold is a large mold, the main body 11 of the free-standing mold 10 is shaped first, and then cut into several splicing bodies 110, and then the double layer or multi-layer is designed, and then the position of the reinforcing rib 113 is designed, and the position of the connecting block 111 is designed. At the same time, a depression matching the connecting block 111 is set on the corresponding splicing body 110. If it is printed, the rivet hole 114 in the double-layer cavity is designed and printed at the beginning, so that it is integrally formed, and the position and shape of the slot 112 between the upper and lower layers of the connecting body are designed, and the outer contour of the supporting mold 20 is designed at the same time.

[0090] According to the outer contour of the support mold 20 , the support mold 20 is designed, the spacing or size of the grid or hollowing is designed, and finally the skin on the side in contact with the assembly surface 14 is covered to ensure full contact with the assembly surface 14 .

[0091] The final step is to manufacture according to the design and then assemble it into shape.

[0092] The combined mold of the present invention can be used repeatedly under heavy loads while ensuring the tensile strength of the casting mold, and complex shapes can be easily obtained. The structure is light in weight, the mold cost is low, and it is easy to carry or flip on site. At the same time, because the assembly surface 14 of the form-fitting mold 10 is shell-shaped, the utilization rate of the material used for 3DP sand mold printing is effectively improved, the printing time is reduced, the entire molding production cycle is shortened, and the industrial application of the combined mold is promoted.

Claims

1. A combined mold, characterized in that: It includes a form-fitting mold and a supporting mold. The form-fitting mold includes a main body, a strengthening layer, a working surface and an assembly surface. The main body is pressed or printed by granular materials. The strengthening layer is arranged on the surface of the main body, or the strengthening layer penetrates into the surface of the main body. The side of the main body in contact with the sand mold cavity is the working surface, and the other side opposite to it is the assembly surface. The supporting mold is installed on one side of the main body assembly surface, and its shape matches the shape of the assembly surface. Hanging handles are arranged on both sides of the form-fitting mold. The top surface of the form-fitting mold is provided with a lifting hole. The main body includes a splicing body and a connecting block, and the main body is formed by splicing at least two splicing bodies; the connecting block is simultaneously connected to at least two adjacent splicing bodies to relatively fix the at least two splicing bodies; The main body further includes a reinforcing rib, the main body is a double-layer or multi-layer structure with a cavity in the interlayer, and a reinforcing rib is arranged between the two-layer structure, the two ends of the reinforcing rib are respectively connected to the two-layer structure, and the double-layer or multi-layer structure and the reinforcing rib are integrally formed; the main body further includes a rivet hole, the rivet hole is arranged in the cavity of the double-layer or multi-layer structure or the rivet hole passes through the main body; The supporting mold is made of at least one material selected from wood, metal, and resin; the supporting mold is in a hollow shape or a grid shape; The combined mold further comprises a rivet rod, which penetrates the conformable mold and the supporting mold at the same time to fix the conformable mold and the supporting mold relatively; The rivet rod comprises a cap body at the upper end and a rod body at the lower end, the cross-sectional area of ​​the cap body is larger than the cross-sectional area of ​​the rod body, and the cap body is arranged in the conformable mold; the rivet rod is arranged in the rivet hole.

2. The combined mold according to claim 1, characterized in that: The main body is made of 5-2000 mesh granular material.

3. The combined mold according to claim 1, characterized in that: The strengthening layer is attached to the main body when in liquid state, and is solid after being cured. The main body to which the strengthening layer is attached has a hardness of not less than 85HD, and a tensile strength of not less than 15MPa.

4. The combined mold according to claim 1, characterized in that: The strengthening layer includes at least one of epoxy resin AB glue, epoxy-polyamide AB glue, phenolic-epoxy resin AB glue, phenolic resin, urea-formaldehyde resin, melamine-formaldehyde resin, epoxy resin, silicone resin, furan resin, unsaturated polyester, acrylic resin, polyimide, polybenzimidazole, phenolic-polyvinyl acetal, phenolic-polyamide, epoxy-polyamide, vinyl polymer, polyester, polyether, polyamide, polyacrylate, a-cyanoacrylate, polyvinyl acetal, ethylene-vinyl acetate copolymer, phenolic-nitrile glue, phenolic-chloroprene glue, phenolic-polyurethane glue, epoxy-nitrile glue, and epoxy-polysulfide glue.

5. The combined mold according to claim 4, characterized in that: The strengthening layer penetrates at least 2 mm into the surface of the main body.

6. The combined mold according to claim 1, characterized in that: The splicing bodies further include slots, and adjacent splicing bodies are respectively provided with protruding or recessed slots that match each other, that is, adjacent splicing bodies are spliced ​​into shape by placing the protruding ones in the recesses.

7. The combined mold according to claim 1, characterized in that: The outer contour of the supporting mold is consistent with the outer contour of a three-dimensional shape composed of at least one cube and / or at least one cuboid.

8. The combined mold according to claim 1, characterized in that: The assembly surface is in complete contact with the supporting mold, and the surface where the supporting mold contacts the assembly surface is a flat plane.

9. The combined mold according to claim 1, characterized in that: The assembly surface includes a mounting structure A, and the supporting mold includes a mounting structure B. The mounting structure A of the assembly surface is convex or concave, and the mounting structure B on the corresponding supporting mold is a corresponding concave or convex. The assembly surface and the supporting mold are relatively fixed by placing the convexity in the concave.

10. The combined mold according to claim 1, characterized in that: It also includes a bottom plate, on which the conformable mold and the supporting mold are arranged, the supporting mold is fixed on the bottom plate, and the rivet rod simultaneously passes through the conformable mold, the supporting mold and the bottom plate.

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