TWI595945B - Using 3D printing shell mold sand molding method - Google Patents

Description

Sand filling modeling method using 3D printing shell mold

The invention relates to a casting method, in particular to a complicated and cumbersome process for replacing the dewaxed ceramic mold by using the 3D printer, and exhibits the precision of the dewaxing casting, and supports the mold with the sand mold casting method to reduce the mold. To the cumbersome process, to further reduce the method of consumables and pollution.

According to casting, casting is a metal thermal processing technology that has been mastered by humans for a long time. It has a history of about 6,000 years. Prehistoric humans in China have entered the heyday of bronze castings between 1700 and 1000 BC. Achieve a fairly high level.

Casting refers to a substance that becomes a liquid after heating. When it is melted, it is poured into a pre-made casting mold, and after it is cooled and solidified, it is taken out to obtain a desired casting. The material to be cast is mostly solid, but heated to a liquid metal (eg copper, iron, aluminum, tin, lead, etc.), and the material of the mold can be sand, metal or even ceramic. The method used will vary depending on the requirements.

In the casting, sand casting method and dewaxing casting method are more required according to the demand, and the sand mold casting method uses high heat-resistant enamel sand as a molding material, and the advantage is lower cost because the sand used in the mold can be reused. The disadvantage is that the casting is time-consuming, and the mold itself cannot be reused, and the finished product can be obtained after being destroyed. In addition, the dewaxing casting method first copies the objects to be cast with wax. Then immersed in a ceramic-containing cell and allowed to dry, so that the waxed replica is covered with a ceramic outer film, and the steps are repeated until the outer film is sufficient to support the casting process (between about 4 mm and 8 mm), and then in the melting mold. Wax and draw away from the mold. After that, the mold needs to be heated for many times, and the hardness can be used for casting. This method has good accuracy, but the manufacturing process requires multiple complicated processing, and the current dewaxing casting method is in the sintering treatment and sand cleaning treatment. At the same time, the shell mold is also very complicated to produce, which directly affects the low production efficiency.

On the other hand, 3D printing, also known as incremental manufacturing and grassroots manufacturing, has seen a variety of different 3D printing methods in the late 1970s, and with the advancement of the times, many incremental technologies have gradually been put into use. The main difference between the different incremental processes is the lamination method and the materials used. Some processes are layered by melting or softening materials, such as selective laser melting techniques or direct metal laser sintering, selective laser sintering, fused deposition modeling, or fuse fabrication.

There are also processes that use different techniques to process liquid materials, such as stereolithography (SLA). Under layered solid manufacturing techniques, raw materials (paper, polymers, metals, etc.) are layered for recombination. Each incremental process has its own advantages and disadvantages, so some companies are beginning to supply both powder and polymer raw materials for different process options.

However, as far as the above-mentioned conventional knowledge is concerned, the mold cast by the sand casting method can be known, although the material used is inexpensive, the production is time-consuming and labor-intensive, and the dewaxing casting method needs to copy the object to be cast by the wax, and the copying is completed. When the object to be replicated needs to be modified as a whole, it is immersed in a ceramic-containing pool and dried, so that the wax-made replica is covered with a ceramic outer film, and is always heavy. The steps are repeated until the outer film is sufficient to support the casting process, between about 4 mm and 8 mm, the overall process is lengthy and complicated, then the wax in the mold is melted and drawn away from the mold. After that, the mold needs to be heated for a plurality of times, and the hardness can be used for casting. Therefore, the manufacturing process requires multiple complicated processing, so the cost is quite expensive, time-consuming and laborious, and it is quite inconvenient, and needs to be improved.

The main purpose of the invention is to replace the complicated and cumbersome process of the dewaxed ceramic mold with its 3D printer, and to exhibit the precision of the dewaxing casting, and support the mold with the sand mold casting method, so as to reduce the cumbersome Process, a method to further reduce consumables and pollution.

The invention provides a sand filling modeling method using a 3D printing shell mold, the method comprising the following steps: a) drawing a pattern step: drawing the view by computer according to requirements, and converting the file by a computer; b) printing the shell The modulating step: the converted file is transferred into the 3D ceramic printer by the step of drawing the pattern, and according to the converted file, the shrinkage ratio of the sintering is calculated, and the photosensitive material is used to print the ceramic material. The stereo shell mold is further sintered and solidified, and the shell mold thickness is between 0.2 mm and 7.0 mm to reduce the function of the consumables; c) the sand filling molding step: placing the solidified solid shell mold in a box, and Filling a casting sand on the outer side of the three-dimensional shell mold in the box, and the casting sand is selected to have a particle size ranging from 1 mesh to 1000 mesh, and the specific gravity of the casting sand oxide and the metal material is between 1 ~20, so that the foundry sand can be supported by the three-dimensional shell mold, and the casting sand can withstand the temperature resistance between 200 ° C ~ 2000 Between °C, and leave a filling port, then mechanically shake the box or vacuum suction to pull the air out of the box, so that the casting sand in the box is completely tightly compacted, greatly enhancing the solidity of the three-dimensional shell mold. d) decompression casting step: heating the metal raw material required to make it in a liquid state, and selecting an atmospheric furnace and a vacuum furnace for vacuum casting operation and atmospheric casting operation according to the required object, and pouring it into the filling port from the filling port The inside of the three-dimensional shell mold is cooled and solidified to produce a casting; e) the vibrating shell is opened: the solidified casting is taken out together with the three-dimensional shell mold, and the three-dimensional shell mold is vibrated by mechanical or manual means. Take out the inner casting and trim it to remove the excess material to obtain a finished product; and f) recover the foundry sand step: recycle the used foundry sand for use in the next casting, including magnetic casting The sand can be used to quickly separate the whole casting sand by electromagnetic attraction; wherein to the step 2), the ceramic material in the printing material includes: zirconia, alumina, tricalcium phosphate or hydroxyl Any one or a combination of the gray stones; wherein, in the step 4), the solid shell mold is further used for melt casting; wherein the foundry sand is selected from the group consisting of sand and chrome sand or a combination thereof The composition; wherein the foundry sand is represented by a circular, rectangular, triangular or polygonal geometry; wherein the 3D printer is selected from the group consisting of a ceramic material and a photosensitive resin mixture.

The sand filling modeling method using the 3D printing shell mold of the invention achieves the following functions: a) drawing the pattern step: drawing the view by computer according to requirements, and converting the file by computer; b) printing the shell mold step: By converting the completed file into the 3D ceramic printer, according to the file of the conversion, calculating the shrinkage ratio of the sintering, and printing a solid shell mold by using the photosensitive material mixed ceramic material. Further sintering and solidification, the thickness of the shell mold is between 0.2 mm and 7.0 mm to reduce the function of the consumables; c) the sand filling molding step: placing the solidified solid shell mold in a box and filling a casting Sand is used on the outside of the three-dimensional shell mold in the box, and the casting sand is selected to have a particle size ranging from 1 mesh to 1000 mesh, and the specific gravity of the casting sand oxide and the metal material is between 1 and 20 Therefore, the foundry sand can be supported by the three-dimensional shell mold, and the casting sand can withstand the temperature between 200 ° C and 2000 ° C, and leave a filling port, and then mechanically shake the box or vacuum suction Way to pump the air The box body causes the foundry sand in the box to be completely tightly compacted, and the solidity of the solid shell mold is greatly improved; d) the vacuum casting step: heating the metal material of the demand to make it liquid, according to the required object The atmospheric furnace and vacuum furnace are used for vacuum casting operation and atmospheric casting operation, and are poured into the solid shell mold from the filling port to cool and solidify, thereby producing castings; e) vibrating shell opening step: curing is completed The casting is taken out together with the three-dimensional shell mold, and the foundry sand is recovered, and the three-dimensional shell mold is vibrated by mechanical or manual means, and the inner casting is taken out. And trimming the excess material to obtain a finished product; and f) recovering the foundry sand step: recycling the used foundry sand for use in the next casting, wherein the magnetic casting sand is more usable Quickly separating the whole foundry sand by electromagnetic attraction; the above manufacturing process provides a molding method for replacing the dewaxing casting by the aforementioned 3D printer, and making it more perfect by sand casting By changing the way of making ceramic molds by 3D printer, the tedious steps of dewaxing ceramic molds are eliminated, and the thickness of the printed shell mold is reduced to 0.2 mm to 7.0 mm, reducing consumables, reducing pollution, and embedding The foundry sand is used to support the ceramic mold, and can be recycled after use, so that the ceramic mold can save more than the material in the 3D printer, and achieve the unique precision of the ceramic mold when the casting is completed. The foundry sands of these boxes can be recycled and reused, and the mold can be quickly produced, and the consumables and pollution can be reduced.

S1~S6‧‧‧ process steps

1‧‧‧ computer

2‧‧‧3D printer

3‧‧‧Three-dimensional shell mold

31‧‧‧ Filling port

4‧‧‧ cabinet

41‧‧‧ foundry sand

5‧‧‧Metal materials

6‧‧‧ castings

61‧‧‧ finished products

62‧‧‧Remaining materials

Fig. 1 is a flow chart showing a sand filling molding method using a 3D printing shell mold of the present invention.

Fig. 2 is a flow chart showing the detailed description of the sand filling molding method using the 3D printing shell mold of the present invention.

Fig. 3 is a schematic view showing the manufacture of the three-dimensional shell mold of the present invention.

Fig. 4 is a schematic view showing the steps of sand filling molding of the three-dimensional shell mold of the present invention.

Fig. 5 is a schematic view showing the step of decompression casting of the three-dimensional shell mold of the present invention.

Fig. 6 is a schematic view showing the step of opening the vibrating shell of the three-dimensional shell mold of the present invention.

Fig. 7 is a schematic view showing the dressing trimming of the vibrating case opening step of the present invention.

In order to enable the reviewer to have a better understanding of the purpose, features and effects of the present invention, the following is a detailed description of the [schematic description of the drawings] as follows: Please refer to Figures 1 to 2 for The present invention discloses a flow chart of a sand filling molding method using a 3D printing shell mold; wherein the method comprises the following steps: Step S1: drawing a pattern step: drawing the view using the computer 1 according to requirements, and using a computer Transferring the file to the 3D printer 2; Step S2: Printing the shell mold step: the file converted by the computer 1 by the step of drawing a pattern is transferred to the 3D printer 2, so that the file is completed according to the conversion, and is calculated The shrinkage ratio during sintering is adjusted, and a three-dimensional shell mold 3 is printed by using the photosensitive material mixed ceramic material, wherein when the three-dimensional shell mold 3 is printed, it can be further sintered or sintered after the printing is completed, so that the three-dimensional shell is made. The mold 3 is solidified and fixed, and the thickness of the three-dimensional shell mold 3 is between 0.2 and 7.0 mm, which has the function of reducing consumables, and has the precision of dewaxing molding, wherein the material of the 3D printer 2 The ceramic material comprises: alumina, zirconia, tricalcium phosphate or hydroxyapatite or a combination thereof; Step S3: sand filling molding step: placing the solidified stereo shell mold 3 in a box In the body 4, a casting sand 41 is filled outside the three-dimensional shell mold 3 in the box body 4, and the casting sand is selected from a mesh size of between 1 mesh and 1000 mesh, and the casting sand 41 is used. The specific gravity of the oxide and the metal is between 1 and 20, so that the foundry sand 41 can be supported by the solid shell mold 3 without The gap between the foundry sands 41 is too large to cast the three-dimensional shell mold 3 to be broken and deformed, and the casting sand 41 can withstand a temperature between 200 ° C and 2000 ° C to support the three-dimensional shell during casting. The mold 3 does not melt or soften due to excessive temperature, resulting in insufficient support force, and a filling port 31 is provided for casting the metal material 5 to flow through the filling port 31, and then mechanically shaking it. The casing 4 or the vacuum suction method draws air away from the casing 4, so that the foundry sand 41 in the casing 4 is more closely compacted, and the density of the foundry sand 41 is greatly increased to enhance the solid shell mold 3. Sturdy; Step S4: Pressure-reducing casting step: heating one of the metal materials 5 to be in a liquid state, and selecting an air furnace or a vacuum furnace for vacuum casting operation and atmospheric casting operation according to the desired object, and The filling port 31 is poured into the interior of the three-dimensional shell mold 3, so that it is cooled and solidified, thereby producing the casting 6; Step S5: the vibrating shell opening step: the solidified casting 6 together with the solid shell mold 3 from the tank 4 Take it out and use it mechanically or manually The shell mold 3 is shredded to open the mold, the inner casting 6 is taken out, and the excess remaining material 62 is trimmed to obtain a finished product 61; and step S6: the foundry sand is recovered: the used foundry sand 41 is recovered, For the next casting, the magnetic casting sand 41 can be used to quickly separate the whole casting sand 41 by electromagnetic attraction.

By the above, the following further details: as in the foregoing step S2), the ceramic material in the material of the 3D printer 2 includes: zirconia, alumina, tricalcium phosphate or hydroxyapatite Any or a combination of them. Wherein, in the foregoing step S4), the solid shell mold 3 is further used for melt casting; the casting sand 41 is selected from any one of sand and chrome sand or a combination thereof; the casting sand 41, It is represented by a geometric shape of a circle, a rectangle, a triangle or a polygon; the aforementioned 3D printer 2 is selected from a 3D printer which can be used for a ceramic material and a photosensitive resin mixture; as described in the above method, please refer to the third FIG. 7 is a schematic view showing the implementation state of the “filling method for sand filling using a 3D printing shell mold” according to the present invention, and further clarifies the following: the view is drawn by using the computer 1 according to the casted article. The drawing soft system is selected by drawing software such as CAD, and the file is transferred to the 3D printer 2 (as shown in FIG. 3), wherein the 3D printer 2 is selected from a ceramic material and a photosensitive resin mixture. The 3D printer 2 is used, and the stereoscopic shell mold 3 is printed by using a ceramic material in combination with the photosensitive resin; the file of the patterning step is introduced into the 3D printer 2, so that the needle is further inserted according to the incoming data. Calculating the shrinkage rate of the material to be cast during the sintering, and printing the solid shell mold 3 by using the ceramic material and the plasticity of the photosensitive resin; and the stereo shell mold 3 is required to be by the 3D printer 2 or by other mechanical or The human body is sintered and formed, and the shaped photosensitive resin is melted and removed during sintering, so that the solid shell mold 3 is solidified by sintering of the ceramic material, and the thickness of the solid shell mold 3 is between 0.2 and 7.0 mm, and has dewaxing. The precision of molding; since the solidified solid shell mold 3 is still insufficient to support the process during casting, the solid is The shell mold 3 is placed in a box 4 and filled with a foundry sand 41 on the outside of the three-dimensional form 3 in the box 4. The casting sand 41 is selected from a mesh size of 1 to 1000 mesh. Between the oxides and the metal of the foundry sand 41, the specific gravity is between 1 and 20, so that the foundry sand can be supported by the solid shell mold 3. The excessive mesh size and specific gravity may result in insufficient support strength. If it is too small, the density may be insufficient to generate voids, so that the three-dimensional shell mold 3 is cracked or deformed during casting, and the gap between the casting sands 41 is not excessively large, so that the three-dimensional shell mold 3 is broken and deformed during casting. The casting sand 41 can withstand the temperature between 200 ° C and 2000 ° C, so that the three-dimensional shell mold 3 is not melted or softened due to excessive temperature during casting, resulting in insufficient support force and leaving a filling material. The port 31 is then mechanically shaken by the casing 4 or vacuum suctioned to evacuate the air from the casing 4, so that the casting sand 41 of the casing 4 is more tightly compacted, the density thereof is greatly increased, and the solid is raised. The robustness of the shell mold 3; heating the desired metal material 5 to make it liquid According to the required object, the atmospheric casting furnace and the vacuum furnace are used for the vacuum casting operation and the atmospheric casting operation, and the inside of the three-dimensional mold shell 3 is poured through the filling port 31 of the three-dimensional shell mold 3, so that it is cooled and solidified, thereby generating Casting 6; the solidified casting 6 is taken out from the box 4 together with the solid shell mold 3, and the solid shell mold 3 is vibrated by mechanical or manual means, and the inner casting 6 is taken out and trimmed. The material 62 is further polished according to the required surface smoothness to obtain a finished product 61; and the used foundry sand 41 is recovered for use in the next casting, wherein the magnetic casting sand is more electromagnetically attractive. The method is to quickly separate the whole foundry sand; thereby, the old technology is provided as a comparison, and the sand casting method is taken according to the demand in the casting. Wax casting method, etc., and the sand mold casting method uses high heat-resistant enamel sand as a molding material, the advantage is lower cost, because the sand used in the mold can be reused; the disadvantage is that the mold is time-consuming to manufacture, and the mold itself cannot be Repeated use, it must be destroyed before the finished product 61 can be obtained; and in the dewaxing casting method, the object to be cast is first copied with wax, then immersed in a ceramic-containing pool and dried, so that the wax-made replica is covered with a layer of ceramic The outer membrane is repeated until the outer membrane is sufficient to support the casting process (between about 4 mm and 8 mm), and the iterative process is time consuming and costly, followed by melting the wax in the mold and withdrawing it from the mold. After that, the mold needs to be heated for many times, and the hardness can be used for casting. This method has good accuracy, but the manufacturing process requires multiple complicated processing, and the production cost is too high, and the current dewaxing casting method is The amount of pollution generated during the sintering of the shell mold is large; at the same time, the shell mold is also very complicated to produce, which directly affects the low production efficiency.

So far, in the above description of the manufacturing process and the old technology, it is known that the effect is achieved by providing the 3D printer 2 to replace the mold-making procedure of the dewaxing casting, and by sand casting. The more perfect casting method, the 3D printer 2 changes the manufacturing mode of the ceramic mold, the cumbersome steps of the dewaxing ceramic mold manufacturing are omitted, and the thickness of the printed solid shell mold 3 is reduced, the consumables are reduced, and the consumables are reduced. Contamination, and embedded in the foundry sand 41, to support the ceramic mold, can be recycled after use, so that the ceramic mold can save more than the material in the 3D printer 2, and when the casting is completed The uniqueness of the ceramic mold, and the casting sand 41 of the box 4 can be recycled and reused, so as to achieve the rapid production of the mold, reduce the consumption of consumables and pollution.

In summary, when it is known that the present invention can be used for related industries, it is extremely progressive and novel, and the invention is not disclosed before the application, in accordance with the provisions of the Patent Law, and the invention patent application is filed according to law. It is a pray that the bureau has clearly examined and patented patents.

The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto; that is, the equivalent changes and modifications made by the scope of the present invention should still belong to the present invention. Within the scope of the patent.

S1~S6‧‧‧ process steps

Claims (6)

A sand filling modeling method using a 3D printing shell mold, the method comprising the following steps: a) drawing a pattern step: drawing the view by a computer according to requirements, and converting the file by a computer; b) printing the shell mold step: By converting the completed file into the 3D ceramic printer, according to the file of the conversion, calculating the shrinkage ratio of the sintering, and printing a solid shell mold by using the photosensitive material mixed ceramic material. Further sintering and solidification, the thickness of the shell mold is between 0.2 mm and 7.0 mm to reduce the function of the consumables; c) the sand filling molding step: placing the solidified solid shell mold in a box and filling a casting Sand is used on the outside of the three-dimensional shell mold in the box, and the casting sand is selected to have a particle size ranging from 1 mesh to 1000 mesh, and the specific gravity of the casting sand oxide and the metal material is between 1 and 20 Therefore, the foundry sand can be supported by the three-dimensional shell mold, and the casting sand can withstand the temperature between 200 ° C and 2000 ° C, and leave a filling port, and then mechanically shake the box or vacuum suction Way to air Leaving the box body, the casting sand in the box body is completely tightly compacted, and the solidity of the solid shell mold is greatly improved; d) the pressure casting step: heating the metal material required to make it liquid state, according to the required The object is selected from atmospheric furnace and vacuum furnace for vacuum casting operation and atmospheric casting operation, and is poured into the solid shell mold from the filling port to cool and solidify, thereby producing castings; e) vibrating shell opening step: curing is completed The casting is taken out together with the three-dimensional shell mold, and the three-dimensional shell mold is vibrated by mechanical or manual means, the inner casting is taken out, and the excess left material is trimmed to obtain a finished product; f) Recycling sand for casting: The used foundry sand is recovered for use in the next casting, and the magnetic casting sand can be used to quickly separate the whole casting sand by electromagnetic attraction. A sand filling molding method using a 3D printing shell mold according to claim 1, wherein the ceramic material in the printing material includes: zirconia, alumina, tricalcium phosphate or hydroxyapatite. Any or a combination of them. The sand filling molding method using a 3D printing shell mold as described in claim 1 wherein, in the step d), the solid shell mold is more useful for melt casting. A sand filling molding method using a 3D printing shell mold as claimed in claim 1, wherein the foundry sand is selected from the group consisting of sand and chrome sand or a combination thereof. A sand filling molding method using a 3D printed shell mold as described in claim 1, wherein the foundry sand is represented by a geometric shape of a circle, a rectangle, a triangle or a polygon. A sand filling molding method using a 3D printing shell mold as described in claim 1, wherein the 3D printer is selected from a 3D printer which can be used for a ceramic material and a photosensitive resin mixture.