1304002 九、發明說明： 【發明所屬之技術領域】 本發明是有關於一種鑄造方法，特別是指一種具有内 流道鑄件之鑄造方法。 【先前技術】 習知用於成型具有内流道鑄件之鑄造方法，是先以木 模製作所需的原型（Pattern)與砂心模（Core)。當中的砂心模 是置於該原型之模穴内，以形成鑄件的内表面。在量產時 ，是以殼模法（Shell Mold Process)吹製所需砂心模，外模則 可採用金屬模。接著，將原型與砂心模組合，製作含有澆 道（Sprue)、冒口（Riser)之流路系統（Runner System)砂模 (Sand Mold)。而後，結合該金屬模並以重力鑄造（Pressure Casting)的方式將熔融金屬注入該砂模中，以形成鑄件。最 後，再將流路系統切除，即完成所需鑄件的製作。 然而，對於以此鑄造方法所成型的鑄件，在尺寸上、 複雜度上、製作時程上以及成本上有諸多的限制，並不適 合多樣少量之鑄件開發。 另一習知具有内流道鑄件之鑄造方法為利用包模鑄造 (Investment Casting)製程，又稱為脫蝶鑄造（Lost-wax Casting)製程。此鑄造方法是先製作一中空的模具組與砂心 模，該模具組的内部空間為符合欲成型之鑄件外型。接著 ，將砂心模結合於該模具組中，並將液態的蠟或塑膠材料 注入該模具組中，以形成蠟製的原型（蠟模）。而後，將該蠟 模與流路系統組合在一起（即組樹作業），再將之沾附泥漿與 Ι3Ό4002 淋 >、被覆，使其外表附著砂體，構成所謂的殼模（Shell1304002 IX. DESCRIPTION OF THE INVENTION: TECHNICAL FIELD 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 can be 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, molten metal is injected into the sand mold in combination with the metal mold and in a manner of pressure casting to form a casting. Finally, the flow path system is cut off to complete the production of the required casting. However, castings formed by this casting method have many limitations in terms of size, complexity, manufacturing time, and cost, and are not suitable for a variety of 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 and the Ι3Ό4002 leaching >, and the cover is attached to the surface to form a so-called shell mold (Shell)
Mold)。為能使殼模具有足夠的強度，通常會反覆數次進行 沾漿淋砂作業，以增加殼模的壁厚。接著，將該殼模進行 加熱，使内部的蠟模予以熔化流出。清除完殘蠟之後，就 可將熔融金屬注入於該殼模中，此程序稱之為澆鑄作業， 並待其冷卻。最後，將該殼模打破去除，即可獲得所需的 鑄件。 然而，此鑄造方法於製作該殼模之前置作業會花費較 夕寺門因為必須先加工成型該殼模的模具組。特別是對 於所欲成型之鑄件的形狀複雜並包含有内流道者而言，需 要更多的時間進行該模具組的製作，而此所造成的影響將 會大幅降低廠商的競爭力。 針對上述需要較多時間製作殼模的缺點，目前已有廠 商提出改善對策，如美國3D System公司改用立體印刷之成 型設備（Stereo Lithography Apparatus，SLA)取代脫蠟鑄造之 蠟模，達到快速完成該殼模。該公司稱之為Quick㈤tm 製程。以一般的鑄件的製作為例，Quick Cast製程約可在 10〜14天内完成，相較於傳統之鑄造方法需要18〜2〇週 (126〜140天）而言，可節省大量的時間，藉此縮短製程時間 ，增加競爭力。 但是，對於Quick Cast ™製程來說，為了能確保殼模 的強度’仍需要反覆地進行沾聚淋砂作業，即—層沾附聚 液層¥粒，以形成層次狀的殼模，也需要較多的處理時 間。更重要的問題是，對於具有複雜内流道之禱件，如内 Ι3Ό4002 部具有水冷系統的汽缸頭（Cylinder Head)，此水冷系統即為 環繞在該汽缸頭的内流道。在進行沾漿淋砂時，因為砂粒 的關係，而使得製液並不容易流填於該内流道，而且，洗 鑄之後’其殼模亦不容易清除。基於上述的理由，QuickMold). 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 wax mold. After the residual wax is removed, molten metal can be injected into the shell mold. This process is called a casting operation and is allowed to cool. 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 the manufacturer. 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 wax mold with dewax casting by using a Stereo Lithography Apparatus (SLA). The shell mold. The company calls it the Quick (five) tm process. Taking the production of general castings as an example, the Quick Cast process can be completed in about 10 to 14 days, which saves a lot of time compared to the traditional casting method requiring 18 to 2 weeks (126 to 140 days). This shortens the process time and increases 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, the layer is coated with the liquid layer to form a layered shell mold, and also needs More processing time. A more important issue is that for a prayer piece with a complex internal flow path, such as a cylinder head with a water cooling system, the water cooling system is the inner flow path surrounding the cylinder head. In the case of sand blasting, 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 washing. For the above reasons, Quick
Cast™製程實際上不適合製造具有複雜内流道之禱件。 【發明内容】 士因此，本發明之目的，即在提供一種具有内流道鑄件 之鑄造方法，可用於製作内部具有複雜内流道鑄件的鑄造 方法。 於是，本發明之具有内流道鑄件之鑄造方法，包含一 f夬速ie模步驟、一補強步驟、一沾附步驟、一燒失步驟、 -洗鑄步驟，以及-去除步驟。該快速造模步驟是以快速 造，技術製造内部形成有至少一内流道的原型，該補強步 驟是在該原型中需要補強支撐強度的位置處放置支撐管， 該沾附步驟是將-可硬化的耐火漿液沾附並包覆該原型， 且流填於該内流道中，待耐火漿液乾燥硬固之後，即形成 一包覆有該原型的殼模，所使用的耐火漿液是選自下列材 料之·石T粉加水混合、陶瓷粉與水解矽酸乙酯加硬化 劑之混合。該澆鑄步驟是將熔融金屬液體澆入該殼模中； 該去除步驟是等待該熔融金屬凝固成固體後，便將該殼模 敲碎去除，即獲得一具内流道之鑄件。 本發明之功效在於利用可硬化之耐火漿液流動性佳並 且可快速硬化的性質，加上無需淋砂之作業，可讓該耐火 名液fe易地充填流入於内流道中，不會被砂粒卡住。而且 1304002 ，在該去除步驟時，該耐火漿液製成的殼模是可以輕易地 被清除，適合製造内部具有複雜内流道之類型的鑄件。 【實施方式】 有關本發明之前述及其他技術内容、特點與功效，在 以下配合參考圖式之一個較佳實施例的詳細說明中，將可 清楚的呈現。 如圖1、2所示，本發明具有内流道鑄件之鑄造方法的 較佳實施例，適用於製作内部具有一複雜内流道21的鑄件 2，如汽車之汽缸頭鑄件，該汽缸頭内部形成有一形狀複雜 的循環水路，即為内流道21，用以冷卻汽缸的溫度。該鑄 造方法包含一快速造模步驟11、一補強步驟12、一沾附步 驟13、一脫氣步驟14、一燒失步驟15、一澆鑄步驟16, 以及一去除步驟17。 配合圖3,該快速造模步驟n是以快速造模技術製造 一内部形成有一内流道21，的原型2，。快速造模（Rapid Prototyping，RP)技術，主要是將欲製造的實品，先以電腦 繪圖軟體建構3D模型，再經軟體處理切成2D的切片。利 用快速造模設備全自動將各切片層層堆疊，以迅速製作出 仿製實品的原型。在該較佳實施例中，所使用的快速造模 技術是立體印刷之成型技術（SLA)，也可以是雷射擇區燒結 成型技術（Selective Laser sintering，SLS)。應說明的是，該 原型2’的外觀形狀應與欲成型之鑄件2相仿，為方便說明 ’圖3以後所呈現的原型2,僅為示意之用。The CastTM process is actually not suitable for making prayers 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. Thus, the casting method of the present invention having an inner flow passage casting includes a f idle speed die step, a reinforcing step, an adhering step, a burn-off step, a washing step, and a removing step. The rapid molding step is to rapidly produce a prototype in which at least one inner flow path is formed inside, and the reinforcing step is to place a support tube at a position in the prototype where reinforcement strength is required, and the adhesion step is to The hardened refractory slurry adheres and coats the prototype, and flows into the inner flow channel. After the hardened slurry is dried and hardened, a shell mold coated with the prototype is formed, and the refractory slurry used is selected from the following Mixture of material, stone T powder, water, ceramic powder and hydrolyzed ethyl citrate plus hardener. 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 invention has the advantages of utilizing the property that the hardenable refractory slurry has good fluidity and can be hardened quickly, and the operation without sanding can make the fire-resistant name liquid easy to fill and flow into the inner flow channel without being stuck by the sand card. live. Moreover, 1304002, in the removal step, the shell mold made of the refractory slurry can be easily removed, and is suitable for the manufacture of castings of a type having a complicated internal flow passage inside. The above and other technical contents, features, and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments. As shown in Figures 1 and 2, a preferred embodiment of the present invention has a casting method for an inner runner casting suitable for use in making a casting 2 having a complex inner flow passage 21 therein, such as a cylinder head casting of an automobile, the cylinder head interior A circulating water path having a complicated shape, that is, an inner flow path 21, is formed to cool the temperature of the cylinder. The casting method comprises a rapid molding step 11, a reinforcing step 12, an adhering step 13, a degassing step 14, a burn-off step 15, a casting step 16, and a removing step 17. Referring to Fig. 3, the rapid molding step n is a prototype 2 in which an inner flow path 21 is formed by a rapid molding technique. Rapid Prototyping (RP) technology is mainly to build a 3D model with computer graphics software, and then cut into 2D slices by software processing. The rapid prototyping equipment is used to fully stack the layers of each slice to quickly prototype 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, and the prototype 2 presented later in Fig. 3 is for illustrative purposes only.
圖3是顯示立體石板印刷成型技術之原理示意圖。SLA 1304002 . A屬於液態製程類型，是以光化學聚合物之液體受光照而 硬化的原理製作成特定之產品形狀。實際操作上，是在一 桶槽内放置光硬化樹脂液32，同時，亦於該桶槽31中 置入-可垂直昇降的平台33。一開始讓該平台33靠近液面 ，匕再以紫外線34照射該平台33上的光硬化樹脂液32,被 紫外線34照射的液體會即刻硬化騎為固態。透過控制紫 :卜線34的移動，並配合該平台33逐漸下降，使固態狀的 樹脂逐層堆疊，以建構成型出該原型2,。 如圖4所示，是顯示雷射擇區燒結成型技術（sls)之原 理不思圖。SLS是屬於粉末製程類型，使用雷射光照射粉末 狀材料而使之燒結在一起，以製作成特定之產品形狀。實 示操作日守’疋將金屬粉末或是塑膠粉末以薄層的型態平舖 在可垂直升降的圓筒41上，利用雷射光42照射該圓筒 41上的粉末，使之熔融而燒結成固體。隨著該圓筒41的下 移，同時反覆補充薄層粉末與控制雷射光42的移動，即可 使材料逐層堆疊以形成該原型2,。 而快速造模技術除了上述成型方式較為常見之外，尚 有光化學加工、熔融擠製沉積成型法（Fused Deposition Modeling)，及固基光敏液相法（s〇ndFig. 3 is a schematic view showing the principle of a three-dimensional stencil printing molding technique. SLA 1304002 . A is a liquid process type that is made into a specific product shape by the principle that the liquid of the photochemical polymer is hardened by light. In actual operation, the photo-curing resin liquid 32 is placed in a tank, and at the same time, a platform 33 which can be vertically raised and lowered is placed in the tank 31. The platform 33 is initially brought close to the liquid surface, and the light-hardening resin liquid 32 on the stage 33 is irradiated with ultraviolet rays 34, and the liquid irradiated by the ultraviolet rays 34 is immediately hardened and rided to a solid state. By controlling the movement of the purple line 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, it is a schematic diagram showing the laser selective sintering technique (sls). SLS is a powder process type that uses laser light to illuminate a powdered material and sinter it together to produce a specific product shape. The operation of the Japanese Guardian's 金属 金属 metal powder or plastic powder is laid in a thin layer on the vertically movable cylinder 41, and the powder on the cylinder 41 is irradiated with the laser light 42 to be melted and burned. Form a solid. As the cylinder 41 is moved downward, while replenishing the thin layer of powder and controlling the movement of the laser light 42, the materials are stacked layer by layer to form the prototype 2. In addition to the above-mentioned forming methods, the rapid modeling technology is still photochemical processing, Fused Deposition Modeling, and solid-based photosensitive liquid phase method (s〇nd).
Ground Curing)···等製 私’亦可應用於本發明之中，不應以此侷限本發明之申請 專利範圍。 如圖5所示，並配合圖1，該補強步驟12是在該原型 2’中需要補強支撐強度的位置處放置支撐管22,主要是為 避免因某些部位的壁厚較薄或是承受較大之重量，在搬運 1304002 時容易造成發生崩塌毁壞，以確保其完整。對於大型鑄件 之生產更需如此做法。在該較佳實施例中，所使用的支撐 管22是以中空的陶瓷材料所製成的陶瓷管，這是因為陶2 管的硬度較高並且能耐高溫，與耐火殼模之熱膨脹係數相 當，能有效改善殼模23(見圖6)透氣性不佳的現象。 如圖6所示，並配合圖丨，該沾附步驟13是讓一可硬 化之耐火漿液流入該原型2,並填滿於該内流道21，中，同時 包覆該原型2’，待耐火漿液乾燥硬固之後，即形成一包覆 有该原型2’之-體型的殼模23。在該較佳實施例中，所使 用的耐火漿液是石膏粉加水混合（即為石膏液），也可以是使 用陶瓷粉加水解矽酸乙酯和硬化劑的混合（即為陶漿）。在沾 覆該耐火漿液之前，該原型2,是先與一流路系統24組合（組 樹），之後才進行沾附，以形成供熔融金屬澆鑄的流道。 由於所沾附的耐火漿液具有較佳的流動性，重要的是 並不需再進行淋砂，不會被較大的砂粒阻礙流動，因此， 耐火漿液可以容易地流入於該内流道21，中，並且可使得製 私時間上可以更為縮短，並且可藉由陶瓷管的設置，使結 構強度上獲得補強。 ^ 、該脫氣步驟U是利用抽真空的方式，以脫除在執行該 沾附步驟13時被捲人的氣體，以避免氣體混人該殼模23 中，而造成缺陷影響強度。當然：，也可以在執行該沾附步 驟13中凋製攪拌耐火漿液的時候，同時進行抽真空作業， 將攪拌過程中所捲入的氣體予以抽離。 在該較佳實施例中，因為本發明是單純使用石膏液或 10 1304002 也可施以烘乾加 疋陶桌’其乾固的速度已相當快。當然 熱處理，加速其乾固硬化。 如圖7所示，並配合圖1、6，該燒失步驟15是待到耐 火漿液乾固之後，即可對該包覆有該原型2,的殼模23施以 加熱處理’使該原$ 2’熔融並流出該殼才莫23。當使用的耐 火紫液為石膏液時，其燒失之最高溫度為7帆，完整的燒 失時間為24小時。若使用的耐火漿液為陶漿時則其燒= 之最高溫度為120(TC，完整的燒失時間$ 6小時。最^可 再以高壓空氣將殘餘其中的碎屑吹出。 如圖8所示，並配合圖！，該洗禱步驟16是先對該殼 模23進行預熱，使該殼模23的溫度提高，再將熔融金屬 液體洗入該殼模23中。預熱之目的在於提高料金屬於該 殼模23的流動性，避免初始流人該殼模23的㈣金屬因 溫降較大而開始凝固，阻礙了後續熔融金屬的流動。Ground Curing), etc. may also be applied to the present invention and should not be construed as limiting the scope of the invention. As shown in FIG. 5, and in conjunction with FIG. 1, 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 when handling 1304002 to ensure its integrity. This is especially true for the production of large castings. In the preferred embodiment, the support tube 22 used is a ceramic tube made of a hollow ceramic material because the ceramic tube 2 has a high hardness and can withstand high temperatures, and has a thermal expansion coefficient equivalent to that of the refractory shell mold. It can effectively improve the poor permeability of the shell mold 23 (see Fig. 6). As shown in FIG. 6, and in conjunction with the drawing, the adhering step 13 is to let a hardenable refractory slurry flow into the prototype 2, fill the inner flow passage 21, and cover the prototype 2' at the same time. After the refractory slurry is dried and hardened, a shell mold 23 coated with the prototype 2' is formed. In the preferred embodiment, the refractory slurry used is a mixture of gypsum powder and water (i.e., gypsum), or a mixture of ceramic powder and hydrolyzed ethyl citrate and a hardener (i.e., a ceramic slurry). Prior to the refractory slurry, the prototype 2 was first combined with the primary road system 24 (group tree) before being adhered to form a flow path for molten metal casting. Since the refractory slurry to be adhered has better fluidity, it is important that sand blasting is not required, and the flow is not hindered by the larger sand particles. Therefore, the refractory slurry can easily flow into the inner flow passage 21, Medium, and can make the manufacturing time shorter, and the structural strength can be strengthened by the setting of the ceramic tube. ^, the degassing step U is by vacuuming to remove the gas that is wound when the adhesion step 13 is performed 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 evacuating the agitated refractory slurry in the attaching step 13, and to extract the gas entrained during the stirring. In the preferred embodiment, since the present invention is simply a use of gypsum liquor or 10 1304002, the drying and kneading table can be applied. The drying speed is already quite fast. Of course, heat treatment accelerates its dry hardening. As shown in FIG. 7 and in conjunction with FIGS. 1 and 6, the burn-in step 15 is performed after the refractory slurry is dried, and the shell mold 23 coated with the prototype 2 is subjected to heat treatment to make the original $2' melts and flows out of the shell. When the fire-resistant purple liquid used is gypsum, the maximum temperature for burning loss is 7 sails, and the complete loss time is 24 hours. If the refractory slurry used is ceramic, the maximum temperature of the fire is 120 (TC, the complete loss time is $6 hours. The most can be blown out with high pressure air as shown in Figure 8. And in conjunction with the figure!, the washing step 16 is to preheat the shell mold 23 to increase the temperature of the shell mold 23, and then wash the molten metal liquid into the shell mold 23. The purpose of the preheating is to improve The fluidity of the metal in the shell mold 23 prevents the (iv) metal of the shell mold 23 from being initially solidified due to a large temperature drop, which hinders the flow of the subsequent molten metal.
如圖9所示，並配合圖丨、2，該去除步驟17是等待該 熔融金屬凝固成固體之後，便將該殼模23與支撐管敲 碎去除’並切除該流路系統24，即可獲得一仿製該原型形 狀之具内流道21的鑄件2。要特別說明的是，因糾 23單純是以石膏或是陶瓷一體型所製成，並配合支撐管U 的使用，相較於習知以一層漿液一層砂粒的殼模結構，本 發明所使用的殼模23敲碎後容易清除。敲除過程^，也可 以藉由高壓空氣或是水柱將存在於該鑄件2之内流道21中 的殼模碎屑沖除。 歸納上述，本發明之具有内流道鎢件之鑄造方法，是 1304002 將可硬化之财火漿液沾附於該原$ 2，上，由於流動性佳， 可以容易地流人並填滿該複雜的内流道21中。再配合在局 部位置擺放支料22，使該賴23之結構可讀得㈣i 撐與強度，並可改善該殼模23透氣性不佳的現象。另外， 因為無須反覆進行淋砂作業，不但可以縮短製程時間，而 且還可使敲碎的殼模碎屑容易清除，故確實能達到本發明 之目的。 惟以上所述者，僅為本發明之較佳實施例而已，當不 能以此限定本發明實施之範圍’即大凡依本發明中請專利 範圍及發明說明内容所作之簡單的等效變化與修飾，皆仍 屬本發明專利涵蓋之範圍内。 【圖式簡單說明】 圖1是一流程圖，說明本發明具有内流道鑄件之鑄造 方法之較佳實施例； 圖2是一立體圖，說明可利用本發明之鑄造方法製造 的汽缸頭； 圖3是一原理示意圖，說明本發明之快速造模步驟可 以是利用立體印刷成型技術（SLA)製造原型； 圖4疋一原理示意圖，說明本發明之快速造模步驟也 可以是利用雷射擇區燒結成型技術（SLS)製造原型； 圖5疋一製私示意圖，說明本發明之一補強步驟，是 將支撐管置於一原型中； 圖6疋一製私示意圖，說明本發明之一沾附步驟，是 將可硬化对火漿液沾附該原型與一流路系統之組合，以形 12 1304002 成一殼模； 圖7是一製程示意圖，說明本發明之一燒失步驟，是 將該殼模中的原型燒失； 圖8是一製程示意圖，說明本發明之一澆鑄步驟，是 將熔融金屬倒入該殼模中；及 圖9是一製程示意圖，說明本發明之一去除步驟，是 敲除該殼模，即可獲得該具有内流道之鑄件。 13 1304002 【主要元件符號說明】 11 .… ♦快速造模步驟 22… ♦…支撐管 12…… •補強步驟 23… -…殼模 13…… …沾附步驟 24… -…流路糸統 14 …… β脱氣步驟 31… *…桶槽 15 ，… -燒失步驟 32… …♦光硬化樹脂液 16 * 。洗鑄步驟 33… •…平台 17…… 。去除步驟 34… 紫外線 2 «.*♦♦<· •鑄件 41… 圓筒 2， … *原型 42… 4…雷射光 21、21’ 内流道 14As shown in FIG. 9, in conjunction with FIG. 2, the removing step 17 is to wait for the molten metal to solidify into a solid, and then the shell mold 23 and the support tube are crushed and removed and the flow path system 24 is cut off. A casting 2 having the inner flow path 21 imitation of the prototype shape is obtained. It should be particularly noted that the correction 23 is simply made of gypsum or ceramic integrated type, and is used in conjunction with the support tube U, compared to the conventional shell mold structure with a layer of slurry of sand, which is used in the present invention. The shell mold 23 is easily removed after being broken. In the knockout process, the shell mold debris existing in the inner flow path 21 of the casting 2 can also be flushed by high pressure air or water column. In summary, the casting method of the tungsten material with internal flow channel of the present invention is 1304002, and the hardenable chemical slurry is adhered to the original $2, which can easily flow and fill the complex due to good fluidity. In the inner flow channel 21. In combination with the placement of the material 22 at the local location, the structure of the Lay 23 can be read (4) and the strength of the shell 23 can be improved. In addition, since the sand blasting operation is not required to be repeated, 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. However, the above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto. 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 modeling step of the present invention may also utilize a laser selection region. Sintering molding technology (SLS) manufacturing prototype; Figure 5 is a private schematic diagram illustrating one of the reinforcing steps of the present invention is to place the support tube in a prototype; Figure 6 is a private schematic diagram illustrating one of the inventions The step is to combine the prototype with the first-class road system by hardening the fire slurry, and form a shell mold with the shape 12 1304002; FIG. 7 is a schematic diagram of a process, illustrating a burning and losing step of the present invention, in 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 one of the processes of the present invention. In the removing step, the shell mold is knocked out to obtain the casting having the inner flow passage. 13 1304002 [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 ...... β degassing step 31... *...tank tank 15, ... - burnout step 32... ♦ light hardening resin liquid 16*. Washing step 33... •... Platform 17... Removal step 34... Ultraviolet light 2 «.*♦♦<· • Casting 41... Cylinder 2, ... *Prototype 42... 4...Laser light 21,21' Inner flow path 14