TW200812726A - Casting method of casting member having inner passageway - Google Patents

Abstract

A casting method of casting member having inner passageway is disclosed, comprises the steps of: a rapid prototyping step in which a rapid prototyping means is adopted to fabricate a pattern having at least one inner passageway, a filling step in which a curable refractory slurry is poured in the pattern and covers the pattern, an ignition lost step in which a shell mold in which the pattern is provided is processed with a thermal treatment so the pattern melts and flows out of the shell mold, a casting step in which a melted metal liquid is poured into the shell mold and a removing step. The removing step is that after the melted metal is solidified, the shell mold is smashed and removed so a casting member having an inner passageway is obtained. The feature of good fluidity of the curable refractory slurry allows the slurry easily flow into inner passageways, and the shell mold is easy to be removed in the removing step, so is suitable for fabricating a casting member having a complex inner passageway.

Description

200812726 IX. Description of the invention: - [Technical field to which the invention pertains] The present invention relates to a casting method, and more particularly to a casting method having an inner flow passage casting. [Prior Art] Conventionally, a casting method for molding an inner flow passage casting is to first produce a desired pattern and a core mold in a wood mold. The sand core mold is placed in the cavity of the prototype to form the inner surface of the casting. In mass production, the required sand core mold is blown by the Shell Mold Process, and the outer mold is a metal mold. Next, the prototype is combined with a sand core mold to produce a Runner System sand mold (Sand Mold) containing a sprue and a riser. Then, the metal mold is combined and molten metal is injected into the sand core in a manner of Pressure Casting to form each piece. After the most, the flow path system is removed, that is, the required castings are completed. However, the castings formed by this casting method have many limitations in terms of size, complexity, production time and cost, and are not developed by various castings. Another conventional casting method with an inner runner casting is to utilize an Investment Casting process, also known as a Lost-wax Casting process. The casting method is to first make a hollow mold set and a sand core mold, and the inner space of the mold set is in conformity with the shape of the casting to be formed. Next, a sand core mold is bonded to the mold set, and a liquid wax or plastic material is injected into the mold set to form a wax prototype (wax mold). Then, the wax mold is combined with the flow path system (that is, the group tree operation), and then the mud is attached to the mud and the sand body is attached to the outer surface to form a so-called shell mold. In order to make the shell mold have sufficient strength, it is usually repeated several times to carry out the sanding operation to increase the wall thickness of the shell mold. Next, the shell mold is heated to melt and flow the inner mold. After the residue is removed, the refining 24 metal can be injected into the shell mold. This procedure is called a washing operation and is to be cooled. Finally, the shell mold is broken and removed to obtain the desired casting. However, this casting method takes place in the pre-operation of the shell mold because the mold set of the shell mold must be processed first. In particular, for those who have a complex shape and have an inner runner, it takes more time to make the mold set, and the impact will greatly reduce the competitiveness of Weishang. In view of the above-mentioned shortcomings of requiring more time to make a shell mold, manufacturers have proposed improvement measures. For example, the US 3D System Company replaced the Stereo Lithography Apparatus (SLA) with the two-mode dewaxing casting to achieve the final speed. Yuan into the shell mold. The company calls the Quick Cast TM A process as an example. The Quick Cast process can be completed in about 10 to 14 days, compared to the traditional casting method, which takes 18 to 2 weeks (126 to 140 days). ), it can save a lot of time, thereby shortening the process time and increasing competitiveness. However, for the Quick Cast tm process, in order to ensure the strength of the shell mold, it is still necessary to carry out the sanding operation repeatedly, that is, a layer of sand layer adhered to the slurry layer to form a layered shell mold, and also requires more A more important issue in the handling of the door is 'for castings with complex internal flow paths, such as the cylinder head with a water-cooled line in 200812726, which is the inner flow path around the cylinder head. When the dip (four) sand is applied, the liquid is not easily filled in the inner flow path due to the relationship of the sand particles, and the shell mold is not easily removed after the casting. For the above reasons, Qui:

Cast clothing is not suitable for the manufacture of castings with complex internal flow paths. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a casting method having an inner runner casting that can be used to make a casting method having a complex internal runner casting therein. In the present invention, a casting method for an inner flow passage casting of the present invention comprises a rapid molding step, an adhering step, a burn-off step, a casting step, and a removing step. The rapid molding step is a rapid prototyping process for producing a prototype having at least one inner flow path formed therein, the adhering step is to adhere and coat a hardenable refractory slurry, and fill the inner flow. In the middle of the road, after the refractory slurry is dried and hardened, the shell mold coated with the prototype is formed, and the refractory slurry used is one selected from the following materials: gypsum powder plus water mixing, ceramic powder and hydrolyzed ethyl citrate and hardening Mixture of agents. The casting step is to pour a molten metal liquid into the shell mold; the removing step is to wait for the molten metal to solidify into a solid, and then the shell mold is crushed and removed, thereby obtaining a casting having an inner flow passage. The utility model has the advantages of utilizing the property of the hardenable refractory slurry to have good fluidity and rapid hardening, and the operation without sanding, so that the virgin slurry can be easily filled into the inner flow passage without being stuck by the sand. . Moreover, in the removal step, the shell mold made of the refractory slurry can be easily removed 7 200812726, and is suitable for the manufacture of a casting having a complicated internal flow path type 〇

The foregoing and other technical features, features and advantages of the invention are set forth in the <RTIgt; As shown in Fig. i'2, the preferred embodiment of the casting method of the present invention having an inner flow member is adapted to produce a prayer piece 2 having a complex internal flow path, such as a cylinder head casting of a car. A circulating water path having a complicated shape is formed inside, that is, the inner flow path 21 for cooling the temperature of the steam. The method of prayer includes a rapid modeling step u, a reinforcing (four) 12, a __adhesion step 13, a degassing step 14, a burn-out step 15, a prayer step, and a removal step 17. In conjunction with Fig. 3, the rapid molding step u is a prototype 2 in which an inner flow path 21 is formed by rapid modeling. Rapid modeling (Rapid

Pr〇t〇iyPing, RP) technology, mainly to build a real product, first construct a 3D model with computer graphics software, and then cut into 2D slices by software processing. Use fast k-mode. It is also fully automated to stack the layers of each slice to quickly create a prototype of the imitation. In the preferred embodiment, the rapid prototyping technique used is a three-dimensional printing molding technique (SLA) or a selective laser sintering (SLS) technique. It should be noted that the shape of the prototype 2' should be similar to that of the casting 2 to be formed. For convenience of explanation, the prototype 2 presented later in Fig. 3 is for illustrative purposes only. Fig. 3 is a schematic view showing the principle of a three-dimensional stencil printing molding technique. Sla is a type of liquid sorrow process, which is made by the principle that the liquid of the photochemical polymer is lighted by the light of 2008/0726. In actual operation, a light stone worry #4月曰液32' is placed in a tank 31, and a platform 33 which can be vertically raised and lowered is also placed in the tank 31. At the beginning, the platform is placed close to the liquid surface, and then the light-hardened resin liquid w on the slanting table 33 is irradiated to the solid state. By controlling the movement of the ultraviolet ray 34 and gradually descending with the platform 33, the solid resin is stacked layer by layer to construct the prototype 2.

_ as shown in Fig. 4 is the original display of the laser selective sintering technology (SLS). Figure SLS® is of the powder process type, which uses laser light to illuminate the powdered material and sinter it together to make a specific product shape. In actual operation, the metal powder or the plastic powder is laid in a thin layer on the cylinder 41 which can be vertically lifted, and the powder on the cylinder 41 is irradiated with the laser light 42 to be melted and sintered. solid. As the cylinder ο is moved down while replenishing the thin layer of powder and controlling the movement of the laser light 42, the material can be stacked layer by layer to form the prototype 2. In addition to the above-mentioned forming methods, rapid prototyping technology has photochemical processing, Fused Dep〇siti〇n Modeling, and solid-based photoactive liquid phase method (s〇lk} Gr〇 The process of und Cudng), etc., can also be applied to the present invention 'it should not be limited to the scope of the patent application of the present invention. As shown in FIG. 5, and in conjunction with FIG. i, the reinforcing step 12 is to place the support tube 22 at a position where the reinforcing support strength is required in the prototype 2', mainly to avoid thinning or bearing due to the thickness of some parts. The larger the weight, it is easy to cause collapse and damage during handling to ensure its integrity. For large castings 9 200812726 = production, this is the case. In the preferred embodiment, the branch used is: a pottery tube made of terracotta terracotta material, which is because the hardness of the pottery is high and can withstand high temperatures, and the thermal expansion of the shell mold The service coefficient is equivalent, which can effectively improve the poor permeability of the shell mold 23 (see Fig. 6). As shown in Fig. 6 and in conjunction with Fig. i, the attaching step 13 is to make a hardenable pair of the prototype 2 and fill the inner flow passage 21, and at the same time, the prototype 2' After the refractory slurry is dried and hardened, a shell mold 23 coated with/without 2 is formed. In the preferred embodiment, the used fuel slurry is a mixture of gypsum powder and water (that is, gypsum solution), or a mixture of ceramic powder and hydrolyzed ethyl vinegar and a hardener (that is, ceramics). . The prototype 2 is first combined with the primary road system 24 prior to the application of the refractory slurry. The group tree) is then adhered to form a flow path for the (four) metal material. Since the adhered refractory slurry has better fluidity, it is important that it does not need to be sanded again and is not obstructed by larger sand particles. Therefore, the refractory slurry can easily flow into the inner flow passage 21 , medium, and can make the manufacturing space can be shortened, and the structural strength can be strengthened by the setting of the ceramic tube. The degassing step 14 is performed by evacuating to remove the gas that is entrained during the execution of the holding step 13 to prevent the gas from being mixed into the shell mold 23, thereby causing the defect to affect the strength. Of course, it is also possible to perform a vacuuming operation while the agitating refractory slurry is prepared in the attaching step 13, and to extract the gas entrained during the mixing process. In the preferred embodiment, since the present invention is simply a gypsum liquor or a ceramic pulp, the drying speed is relatively fast. Of course, it is also possible to apply a heat treatment to dry and add 10 200812726 to accelerate the dry hardening. Fire II is shown in Figure 7, and in conjunction with Figure 6', the burnout step is to be after the endurance ^^ solid, then the shell mold 23 coated with the prototype 2, H (four) 'm (4) type 2 'Melting and flowing out of the shell mold U. When using the slurry as the gypsum solution, the maximum loss of 苴 、 , , , 0. π. 〇 ^ loss is the C, the full burning time. If the refractory liquid used is terracotta, the loss on ignition is mere, and the complete loss on time is 6 hours. Finally

Then, the residual debris is blown out by the south air. &lt;8&gt; and in conjunction with Figure i, step 16 of the process is to preheat the shell and crucible to increase the temperature of the shell mold 23 around the shell mold 23. The purpose of the pre-embarkation is to merge the genus of the genus of the genus... _ sex, to avoid the melting metal of the melamine metal in the 、 brother, the melon nucleus 23 began to condense m due to the large temperature drop, hindering the post-melting The flow of metal. =9, and in conjunction with Figure 2, the removal step ~ wait for the 7 cups to solidify into a solid, then the shell mold 23 and the branch tube (2) knock stone t are removed, and the flow path 24 is cut off _ Imitation of the original (four) shape of the casting 2 with the inner flow passage 21. It should be particularly noted that, because the shell mold 23 is simply made of gypsum or ceramics, and is used in conjunction with the use of the selective tube u, compared to the conventional shell mold of a layer of sand. According to the structure, the shell mold 23 of the present invention is easily removed after being crushed. During the knockout process, the shell mold debris present in the runner raft of the casting 2 can also be flushed by high dust air or water column. In summary, the casting method of the present invention has an inner flow passage casting method in which a hardenable refractory slurry is adhered to the prototype 2, and due to good fluidity, 11 200812726 can easily flow in and fill the complicated inner flow. In the 21st. Further, the support tube 22 is placed in the local position, so that the structure of the mold reduction η can obtain sufficient support and strength, and the air permeability of the shell mold 23 can be improved. In addition, since it is not necessary to repeatedly perform sand blasting as t, not only the process time can be shortened, but also the crushed shell mold chips can be easily removed, so that the object of the present invention can be achieved. The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a flow chart showing a preferred embodiment of a casting method of an inner flow passage casting of the present invention; and Fig. 2 is a perspective view showing a cylinder head which can be manufactured by the casting method of the present invention; 3 is a schematic diagram illustrating that the rapid molding step of the present invention may be to manufacture a prototype by using a three-dimensional printing molding technique (SLA); FIG. 4 is a schematic diagram showing that the rapid mold selection step of the present invention may also utilize a laser selection region. Sintering molding technology (SLS) manufacturing prototype; Figure 5 疋一制私思图' illustrates one of the reinforcement steps of the present invention, is to place the support tube in a prototype; Figure 6 is a schematic diagram of a process, illustrating a dip of the present invention The additional step is to adhere the hardenable refractory slurry to the combination of the prototype and the first-class road system to form a shell mold; 12 200812726 FIG. 7 is a schematic diagram of a process, illustrating a burn-in step of the present invention, which is the shell mold FIG. 8 is a schematic view showing a process of casting a molten metal into the shell mold; and FIG. 9 is a schematic view showing the present invention. A removal step, a knockdown of the shell mold, which can be obtained with the flow path of the casting.

13 200812726 [Explanation of main component symbols] 11 Rapid prototyping step 22... Support tube 12 ..... Reinforcement step 23... Shell mold 13 - 'Adhesion step 24... Flow path system 14 · Degassing step 31... ...tank 15 ... χ ... burnout step 32 ... ... light hardening resin liquid 16 ... * ... wash every step 33 ... · ... platform 17 , ... remove step 34 ... ... ultraviolet 2 ' ... each piece 41 ... round Cartridge 2, ... prototype 42... ♦♦ laser light 21, 21' inner flow channel

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Claims (1)

200812726 X. Patent application scope: 1. A casting method with internal flow passage castings, comprising the following steps: - rapid modeling step, manufacturing of (four) shaped at least one inner flow path by rapid modeling technology; adhesion step, A hardenable refractory liquid is adhered and coated to the prototype: and the flow is filled in the inner flow passage. After the hardened slurry is dried and hardened, P forms a shell mold of the prototype, and the refractory slurry used is k. From the following materials - the gypsum powder is mixed with water, and the mixture of the ceramic i powder and the hydrolyzed ethyl citrate and the hardener; a burning loss step, the shell mold coated with the prototype is subjected to heat treatment to make the prototype Melting and flowing out of the shell mold; 70. The steam liquid metal is washed into the shell mold; and the removing step 'after the molten metal solidifies into a solid, the shell mold is broken and removed, that is, one is obtained. Castings with internal runners. 2. The casting method with the inner runner casting according to the scope of claim 1 further includes a reinforcing step between the rapid molding step and the adhering step. The reinforcing step requires reinforcement support in the prototype. Place the support tube at the location of the strength. 3. A casting method having an inner flow passage casting according to item 2 of the patent application scope. wherein, in the reinforcing step, the support tube used is a ceramic tube made of ceramic. 4: The casting method having the inner flow prayer piece according to claim 1 of the application patent scope further comprises a degassing step between the adhesion step and the burning loss step, wherein the degassing step is by vacuuming, To remove the gas that was entrained during the execution of the adhesion 15 200812726 procedure. 5. According to the application method of the first and eighth patents, the casting method with internal flow castings is 'in which' in the adhesion step, first (four) the H night is to be made uniform, while stirring, The way of true S is carried out to extract the gas entrained during the stirring process. 6. The casting method with an inner flow passage casting according to item i of the patent application scope, wherein in the rapid molding step, the rapid mold forming technique is selected from the following technologies: a three-dimensional printing molding technology , laser selection zone sintering technology. 7. The casting method of the inner flow passage casting according to claim 1, wherein in the burning loss step, the molten metal is poured into the shell mold, and the shell mold is preheated. To improve the fluidity of molten metal after casting. 8. The casting method with an inner flow passage casting according to item 7 of the patent application scope, wherein in the burning loss step, when the refractory slurry used is Shixi liquid, the maximum temperature of the loss of combustion is 740 t, burning The loss time is 24 hours 〇9. The method for sizing the inner flow passage casting according to item 7 of the patent application scope, wherein in the burning loss step, when the refractory slurry used is ceramic slurry, the loss is lost. The maximum temperature is 120 〇 ° C and the loss on ignition time is 6 hours. The method for praying an inner flow passage casting according to item 3 of the patent application scope further includes a degassing step between the adhering step and the burning loss step, wherein the degassing step is by vacuuming. To remove the gas that is entrained during the execution of the adhesion step. 16 200812726 η. A casting method having an inner flow passage casting according to item i of the patent application scope, wherein in the rapid molding step, the rapid molding technique used is one selected from the following technologies: Three-dimensional printing technology, laser selection sintering technology. 12. The casting method of the inner flow passage casting according to the first aspect of the patent application, wherein in the burning loss step, the first part of the shell mold is pre-processed before the molten metal is poured into the shell mold. Heat to increase the fluidity of the molten metal after casting. ® 13 · A casting method with an inner flow passage casting according to the scope of the patent application, in which the maximum temperature of the loss of combustion is 740 ° C when the refractory slurry used is gypsum. The burnout time is 24 hours. 14. The casting method with an inner flow passage casting according to the scope of claim 12, wherein in the burning loss step, when the refractory slurry used is ceramic, the maximum temperature of burning loss is 120 (TC, burning) The loss time is 6 hours. 15. The casting method with the inner runner casting φ according to the scope of claim 1, 13, or 14, wherein in the removing step, after the shell mold is broken, a high pressure can be used. The air is used to flush the pieces. 16. The casting method with the inner flow path casting according to the scope of claim 1, wherein the 'after crushing the shell mold' can be used in the water column. The pieces are washed away. 17