Sand mold 3D printing mold core placing tool and assembling method and storage and transportation system thereof

Abstract

The invention discloses a sand mold 3D printing mold core placing tool and a configuration method thereof. The tool is of a reconfigurable modular four-layer structure and comprises a universal base with array T-shaped grooves, height supporting modules with various standard heights and capable of being arranged in a two-dimensional mode, and a shape follow-up attaching bearing piece which is precisely complementary with the shape of a mold core supporting face through Boolean reverse calculation and reserves uniform gaps. The replaceable buffer layer is laid on the surface of the bearing part; during configuration, the height and the position of a supporting point are analyzed according to the three-dimensional model of the mold core, the supporting modules are selected, matched and arranged, the shape follow-up attaching bearing part is generated and manufactured, and finally assembling and forming are conducted. High-precision flexible fitting of the tool and the surface of a complex mold core is achieved, supporting is uniform, a protruding structure can be avoided, the universal base and the supporting module can be repeatedly used, the tool can adapt to different mold cores only by replacing a low-cost shape follow-up bearing piece, the breakage rate and tool cost are remarkably reduced, and the tool is particularly suitable for multi-variety and small-batch flexible production.

Description

TECHNICAL FIELD

[0001] The present application relates to additive manufacturing and casting auxiliary equipment, in particular to a sand mold 3D printing core placement tool and its assembly method and sand mold 3D printing core storage and transportation system. BACKGROUND

[0002] Sand mold 3D printing technology is usually applied to complex structure, containing multiple precision cavities or bosses, and large wall thickness span of casting core, and such castings are more and more used in sand mold 3D printing technology production, 3D printing technology appeared in the mid-1990s, which is basically the same as ordinary printing principle, the printer is equipped with furan resin, which is connected with the computer, and the sand is laid layer by layer while the furan resin is sprayed according to the set shape under the control of the computer, so that the sand particles are bonded and stacked, and finally the blueprint on the computer is changed into a real object core.

[0003] The printed core is usually fragile in surface structure and overall structure due to its complex structure, and it is difficult to withstand vibration and collision during storage and transportation, and it cannot be directly placed on the ground or general rack plane. To solve the problem of placement and transportation, there are two common methods: 1. Use wooden boxes, put a certain thickness of loose sand in the wooden boxes, and place the sand core on the loose sand. The loose sand is used for buffering. In this way, it is difficult to manage the loose sand, pollute the site environment, and it is difficult to clean the loose sand in the complex structure sand core. The sand core is easily damaged during operation, resulting in scrap of the sand core. 2. Customized partial random placement racks of various materials, which are in contact with the sand core through several supporting surfaces to stabilize the placement of the sand core. However, this method has two disadvantages: first, the types of printed sand cores are various and the shapes vary greatly, so the cost of customizing random placement racks is high, the land occupation is large, and the number of uses is small, resulting in a large amount of waste. Second, the random placement racks are usually manufactured by conventional methods, and the curve fitting degree is low, so the sand core is easily damaged by uneven force or sliding and vibration.

[0004] The above two traditional sand core placement methods cannot meet the needs of 3D printing production line for efficient, safe storage and transportation of multiple types of sand cores, therefore, it has become a technical problem to be solved in the industry to develop a placement tool with strong universality, good fitting degree, controllable cost and low sand core damage rate. SUMMARY

[0005] To solve the problems in the prior art, the sand mold 3D printing core placing tool and the assembling method thereof and the sand mold 3D printing core storage and transportation system are provided, a four-fold composite structure of a general base layer + a support height layer + a conformal fitting layer + a surface buffer layer is adopted, a core placing tool for stably placing a printed sand core can be quickly obtained through free combination, and when the printed sand core changes, the core placing tool can be disassembled and replaced to be combined into a new core placing tool.The tool occupies less land, is suitable for placing various sand cores, and has good sand core fitting degree, thereby being beneficial to saving the manufacturing and storage costs of placing racks under multiple types of printing tasks, reducing the sand core damage and rejection rate and the casting rejection rate, and enabling the core placing rack designed and manufactured through the method to better meet the needs of a 3D printing production line and producers.

[0006] To solve the above technical problems, the present application adopts the following technical solutions: The sand mold 3D printing core placing tool comprises: A general base, the upper surface of the general base is provided with standardized and arrayed T-shaped grooves; A plurality of height-adjustable support blocks, the bottom of each support block is respectively provided with a first connecting part capable of being slidably connected with and positioned in the T-shaped groove of the general base, and the top of each support block is provided with a second connecting part; A conformal fitting bearing part, the lower surface of the conformal fitting bearing part is provided with a third connecting part capable of being detachably connected with the second connecting part of the support block, and the upper surface of the conformal fitting bearing part has a bearing cavity which is complementary to the shape of the support surface of the core to be placed and has a reserved buffer gap; A replaceable surface buffer layer, which is laid on the surface of the bearing cavity.

[0007] Further, the support blocks are standardized and serialized rigid blocks, each support block has a different preset standard height, and different height support modules are selected and combined to match the height differences of the support surface of the core.

[0008] Further, the support blocks can be arranged in a discrete position in a two-dimensional plane along the T-shaped groove array of the general base, and for the local protruding structure of the bottom of the core, a support module or a disconnected support module is arranged at the corresponding T-shaped groove position to form an avoiding space.

[0009] Further, the surface of the bearing cavity of the conformal fitting bearing part is formed by performing a Boolean reverse operation on a three-dimensional model of the support surface of the core to generate a negative curved surface, and the negative curved surface and the support surface of the core are kept at a uniform gap of 0.2mm to 0.5mm.

[0010] Further, the conformal fitting bearing part is made of a sand mold 3D printing process, and the material of the conformal fitting bearing part is the same as or compatible with the material of the core to be placed.

[0011] Further, the universal base, the support module and the conformal bearing piece are detachably mechanically connected through the cooperation of T-shaped grooves and T-shaped sliding blocks, and the connection interfaces between the layers are standardized and consistent.

[0012] The application also discloses a configuration method of the sand mold 3D printing core placing tool. S1. Analysis and positioning: a three-dimensional model of a core to be placed is obtained, and a support contact area required by the core and the height of each area relative to a reference plane are determined. S2. Modular configuration: S2.1. According to the planar projection of the support contact area, support point positions are planned on the T-shaped groove array of the universal base. S2.2. According to the height data of each support point, corresponding models are selected from a series of support blocks with standard heights, and the support blocks are configured at the planned support point positions. S2.3. For the protruding structure of the bottom of the core, the "vacancy" or "disconnection" configuration of the support module is performed at the corresponding positions. S3. Digital fitting: based on the support surface data of the core three-dimensional model, a digital model of the conformal bearing piece is generated through three-dimensional Boolean reverse calculation and gap offset. S4. Integrated manufacturing and assembly: the conformal bearing piece is manufactured, and the conformal bearing piece is assembled to the top of the support module through the third connecting part, and finally a surface buffer layer is laid in the bearing cavity.

[0013] Further, in step S4, the manufacturing of the conformal bearing piece and the sand mold 3D printing of the core are completed synchronously in the same manufacturing cycle and the same equipment.

[0014] In addition, the application also discloses a sand mold 3D printing core storage and transportation system, comprising: A plurality of sand mold 3D printing core placing tools; And a standardized storage rack or transfer trolley matched with the universal base, wherein the storage rack or transfer trolley is provided with a positioning mechanism matched with the T-shaped groove or edge structure of the universal base.

[0015] The universal base is a base with a length of 500 mm, a width of 500 mm, a lifting lug and a groove.

[0016] The four-layer composite structure is a four-layer composite structure composed of a universal base layer, a support height layer, a conformal layer and a surface buffer layer.

[0017] Compared with the prior art, the technical effects of the application are as follows: 1. The tooling is decomposed into a standardized universal base, a serialized height support block, a customized conformal fitting layer, and a consumable surface cushion layer. Through flexible combination and partial replacement of modules, a set of system is adapted to various sand cores, significantly improving the universality and reuse rate of the tooling.

[0018] 2. The conformal fitting layer, which can be 3D printed, realizes high-precision shape matching with the sand core surface (through difference algorithm and gap control), ensuring the uniformity of the support. Combined with the flexible cushion layer on the top, it not only provides rigid positioning support, but also effectively absorbs micro-vibration and impact, forming a "rigid positioning, flexible contact" protection mechanism.

[0019] 3. The conformal fitting layer can be manufactured synchronously with the original sand mold 3D printing equipment and materials, without the need to introduce new special processing equipment, reducing manufacturing cost and cycle, and realizing closed-loop optimization of production process.

[0020] 4. Through the arrangement and combination of support blocks of different thicknesses, and the design of splitting the support blocks on the same guide rail to accommodate the protruding part of the sand core, the discrete and accurate support of complex three-dimensional curved surfaces in the height direction is realized, solving the problem of difficult adjustment of traditional integral support frame.

[0021] 5. Using the above manufacturing method, and making the overall design scheme reasonable and easy to operate, using a four-fold composite structure, suitable for placing various sand cores, with good sand core fitting, not only saving the production and storage cost of the placing rack under multiple types of printing tasks, but also reducing the sand core damage and rejection rate and the casting rejection rate, so that the core placing rack designed and produced by this method can better meet the needs of 3D printing production line and producers. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0023] Fig. 1 It is an assembly diagram of the sand mold 3D printing core placing tooling of the present application.

[0024] Fig. 2 It is a component diagram of the sand mold 3D printing core placing tooling of the present application. DETAILED DESCRIPTION

[0025] In order to make the technical means, creative features, purposes and effects realized by the present application easy to understand, the following will further describe the present application combined with specific drawings.

[0026] Reference Figs. 1-2 As shown in the figure, a design and manufacturing method of a sand mold 3D printing core placement tool is given, and the rapid manufacturing method steps are as follows: First step, design and manufacture of universal base 100: Size design: according to the maximum projection size of the sand core to be stored, determine the specification of the universal base 100.

[0027] Structural design: uniformly open T-shaped groove on the upper part of the universal base 100 along the length and width direction; the groove width and depth of the T-shaped groove need to be adapted to the connection structure of the subsequent support height layer (recommended groove width 15-20mm, groove depth 20-25mm), to ensure stable connection and easy disassembly; symmetrically design four lifting shafts at the four corners of the base, the lifting shaft adopts a cylindrical structure with a diameter ≥20mm and a height ≥50mm, a lifting hole (hole diameter ≥10mm) is opened at the center of the lifting shaft for lifting and transporting the base, and the lifting shaft is integrally printed with the base to ensure the connection strength.

[0028] Printing and manufacturing: import the designed universal base three-dimensional model into the 3D printing equipment, set the printing layer height to 0.1-0.2mm, adjust the printing speed according to the standard process parameters of the equipment, ensure the surface of the base is smooth, the T-shaped groove structure is accurate, and the lifting shaft is not deformed, and after printing, clean the surface, remove burrs, residual sand particles and other impurities, check the smoothness of the inner wall of the T-shaped groove to avoid affecting the subsequent assembly.

[0029] Second step, design and manufacture of support height layer 200: Thickness parameter: the thickness of all height support blocks 200 is uniform, and the support block itself has enough structural strength to withstand the weight of the sand core and external force impact during transportation.

[0030] Height design: according to the height range of the support surface of the sand core to be stored relative to the reference surface, design a set of height support blocks 200 arranged at certain intervals (for example, 10mm, 15mm, 20mm……50mm, etc.), forming a height-adjustable support system to meet the height adaptation requirements of different parts; Connection structure design: the bottom surface of the height support block is designed with a T-shaped boss adapted to the T-shaped groove of the universal base, and the size of the T-shaped boss is ≤0.5mm larger than the gap of the T-shaped groove, to ensure smooth sliding and no looseness; the top surface of the support block is designed with a T-shaped groove adapted to the conformal layer, and the specification is consistent with the T-shaped groove on the upper part of the base to ensure the universality of the connection. The height support block can be placed at intervals as needed in the length and width directions to adapt to the shape of the sand core.

[0031] Third step, design and manufacture of conformal layer 300: Shape design: Obtain the shape of the fitting surface that completely matches the contact surface of the sand core, ensure the fitting degree of the fitting layer and the surface of the sand core; reserve a gap of 0.30mm between the fitting surface and the surface of the sand core, which can effectively avoid the damage of the sand core due to thermal expansion and contraction or assembly error, while ensuring the stability of the sand core after placement.

[0032] Size design: The thickness of the conformal fitting layer is consistent with the thickness of the height support block (35-40mm), and the height direction size is ≥40mm, which ensures the structural strength of the fitting layer itself and avoids deformation caused by the weight of the sand core or external force; the overall contour size of the fitting layer needs to match the arrangement range of the support height layer to ensure that all the top surfaces of the support blocks can effectively contact the bottom surface of the fitting layer and bear force evenly.

[0033] Connection structure design: Design a T-shaped boss on the bottom surface of the fitting layer that matches the T-shaped groove on the top surface of the support height layer, and the boss position corresponds to the top surface of the support block one by one, with a size error of ≤0.2mm to ensure stable connection.

[0034] Fourth step, tool assembly and surface buffer layer laying: The general base layer, support height layer and conformal fitting layer are installed into the core holder through the T-shaped groove and connection structure, and a layer of soft cloth or foam paper is placed on the surface of the core holder as a surface buffer layer 400, forming a four-layer composite structure composed of general base layer + support height layer + conformal fitting layer + surface buffer layer.

[0035] Fifth step, tool disassembly and reassembly: When the stored sand core needs to be replaced, follow the following procedures: Disassembly process: First remove the surface buffer layer (which can be recycled and reused, or replaced if damaged); then slide the conformal fitting layer along the T-shaped groove direction and detach it from the support height layer, identify and store the conformal fitting layer according to the type of the old sand core for subsequent reuse of similar sand cores; finally, disassemble the positioning pins or locking bolts of the support height layer and remove the height support blocks from the T-shaped groove of the general base, and store them according to the height specifications.

[0036] Reassembly: Repeat the first to fourth steps above according to the parameters of the new sand core, only the conformal fitting layer needs to be redesigned and manufactured to adapt to the new sand core, the general base layer can be directly reused, and the support height layer can be recombined according to the height requirements of the new sand core without the need for overall replacement, achieving quick switching and adaptation.

[0037] The embodiment adopts a four-fold composite structure of a general base layer + a support height layer + a conformal fitting layer + a surface buffer layer, is suitable for placing various sand cores, and has good sand core fitting degree, is beneficial to saving the manufacturing and storage cost of the placing frame under multiple types of printing tasks, simultaneously reduces the sand core breakage and rejection rate and the casting rejection rate, and can make the core placing frame designed and manufactured by the method better meet the requirements of the 3D printing production line and the producer.

[0038] In conclusion, the application adopts the manufacturing method, has reasonable overall design scheme and convenient operation, adopts the four-fold composite structure, is suitable for placing various sand cores, has good sand core fitting degree, is beneficial to saving the manufacturing and storage cost of the placing frame under multiple types of printing tasks, simultaneously reduces the sand core breakage and rejection rate and the casting rejection rate, and can make the core placing frame designed and manufactured by the method better meet the requirements of the 3D printing production line and the producer.

[0039] The basic principle, main features and advantages of the application are shown and described above. It should be understood by those skilled in the art that the application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principle of the application, and various changes and improvements can be made without departing from the spirit and scope of the application, and these changes and improvements all fall within the scope of the claimed application. The scope of protection of the application is defined by the appended claims and their equivalents.

Claims

1. A sand mold 3D printed core placement tooling, characterized by, The utility model relates to a kind of core support device, including: General base (100), the upper surface of which is provided with standardized, arrayed T-shaped groove; Multiple height-adjustable support blocks (200), the bottom of each support block is respectively provided with the first connecting part that can be connected with the T-shaped groove of the general base (100) and positioned, and the top is provided with the second connecting part; Conformal fitting carrier (300), the lower surface of which is provided with the third connecting part that can be detachably connected with the second connecting part of the support block (200), and the upper surface has load-bearing cavity that is complementary to the shape of the support surface of the core to be placed and has a buffer gap reserved; Replaceable surface buffer layer (400), laid on the surface of the load-bearing cavity.

2. The sand form 3D printed core placement tooling of claim 1, wherein, The support block (200) is a standardized, serialized rigid block, each support block has a different preset standard height, and the height difference of the core support surface is matched by selecting and combining support modules of different heights.

3. The sand form 3D printed core placement tooling of claim 2, wherein, The support block (200) can be arranged in a two-dimensional plane along the T-shaped groove array of the general base (100), and for the local protruding structure of the core bottom, the support module is arranged or the disconnected support module is arranged to form a avoiding space at the corresponding T-shaped groove position.

4. The sand- mold 3D-printed core placement tooling of claim 1, wherein, The surface of the load-bearing cavity of the conformal fitting carrier (300) is formed by performing Boolean reverse operation on the three-dimensional model of the core support surface to generate its negative surface, and maintaining a uniform gap of 0.2mm to 0.5mm between the negative surface and the core support surface.

5. The sand- mold 3D-printed core placement tooling of claim 4, wherein, The conformal fitting carrier (300) is made of sand mold 3D printing process, and the material is the same as or compatible with the material of the core to be placed.

6. The sand- pattern 3D-printed core placement tooling of claim 1, wherein, The general base (100), the support module (200) and the conformal fitting carrier (300) are detachably mechanically interconnected through the matching structure of T-shaped groove and T-shaped slider, and the connection interfaces between each layer are standardized and consistent.

7. A method for configuring a sand mold 3D printed core placement tooling based on any one of claims 1-6, characterized in that, The method comprises the following steps: S1. Analysis and positioning: obtain the three-dimensional model of the core to be placed, determine the required support contact area and the height of each area relative to the reference plane; S2. Modular configuration: S2.1 According to the planar projection of the support contact area, plan the support point position on the T-shaped groove array of the general base (100); S2.2 According to the height data of each support point, select the corresponding model from a series of standard height support blocks (200), and configure it at the planned support point position; S2.3 For the protruding structure of the core bottom, perform "vacancy” or "disconnection” configuration of support module at the corresponding position; S3. Digital fitting: based on the support surface data of the core three-dimensional model, generate the digital model of the conformal fitting carrier (300) through three-dimensional Boolean reverse operation and gap offset; S4. Integrated manufacturing and assembly: manufacture the conformal fitting carrier (300), and assemble it to the top of the configured support module (200) through the third connecting part, and finally lay the surface buffer layer (400) in the load-bearing cavity.

8. The configuration method of claim 7, wherein, In step S4, the manufacturing of the conformal fit carrier (300) is synchronously completed with the sand mold 3D printing of the core in the same manufacturing cycle, in the same equipment.

9. A sand mold 3D printed core handling system, characterized by, Comprise: A plurality of sand mold 3D printing core placement toolings according to any one of claims 1-6; And a standardized storage rack or transfer trolley matched with the universal base (100), wherein the storage rack or transfer trolley is provided with a positioning mechanism matched with the T-shaped groove or edge structure of the universal base (100).

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