TW200533436A - Process for producing cast item - Google Patents

Abstract

The present invention discloses a process for producing a cast item with the use of a mold capable of easily crumbling. The process comprises the step of mixing together a granular aggregate, at least one type of water-soluble binder and water to thereby obtain an aggregate mixture and agitating the aggregate mixture to thereby effect foaming. This aggregate mixture is capable of suppressing undesirable gas generation at the time of mold formation or melt casting. Further, the present invention also provides a process comprising the step of filling a space for mold formation with the foamed aggregate mixture and evaporating water from the charged aggregate mixture to thereby solidify the aggregate mixture, thus accomplishing mold formation; the step of assembling the mold with another mold into a final mold; the step of casting a melt in the final mold; the step of, during the period of cooling of cast item after melt solidification, removing the mold from the cast item; and the step of performing heat treatment of the cast item.

Description

200533436 IX. Description of the invention: [Technical field to which the invention belongs] This description relates to a method for manufacturing a casting;; Replace the prayer piece of the conventional shell mold method with an easy-to-remove mold = L 凡 刖 raft] Opening agents will be filled in the known manufacturing methods of light alloy castings, such as

22: 1: Shell-mold method described in 嶋. Knot of the Shell Mold

WwPhenQ1_fQrmaldehydeU Γ bound sand is blown to a heated mold for metal molds ^ The bonding agent covered on the filled sand is hardened with the heat of the metal changer [Explanation of the invention] A⑺ & a double-branch method 'the sand after pouring The core mold is relatively hard. Therefore, the known mold must be disintegrated and removed from the casting, so it must be known, that is, a force v + hole ## is applied to the sand core mold. In order to perform the knock-down process, the casting is sufficiently cooled before the heat treatment of the casting. In addition, even if a large impact force of 1 MPa is continuously applied to the casting at 10 Hz or more. More than 2 seconds' still can only remove about 70 ~ 80¾ evening π mountain stone), so during and after the heat treatment, the residue of the sand core mold after dissolution is c # check that the sand core sand and sand core block still remain in _ Pieces. Therefore, when the above-mentioned shell crickets and women are gone, the sand core sand and sand core blocks must be removed again. In addition, in order to regenerate the y ~ pieces of the masonry cloud removed from the casting, firing must be performed frequently. Furthermore, the shell mold method involves the generation of ik volatile gas when the binder is hardened by the heat of the genus ‘Meng’. ^ Volatile gas, accompanied by uncomfortable six gas, of which formaldehyde, phenol, and crossbow gas have adverse effects on the human body. 5 200533436 Shell mold method for easy mold removal. Therefore, it is hoped that there can be a method for manufacturing castings that eliminates and suppresses the generation of volatile gases in order to replace the conventional invention. The present invention refers to silica sand, wrong stone, mullite sand, and artificial sand. "Particulate aggregate" is composed of one or more of sand, mullite sand, chromite sand, and alumina sand. Means that the melt solidifies differently.

In this specification, "after the molten liquid is solidified", after the melting. The temperature at this time depends on the manufacturing process and the material of the molten liquid, and in the booklet, "During the cooling period of the casting", it means that the cold part is cooled to a degree that does not cause deformation than the casting (a period lower than the temperature when the mold is removed For example, in the T6 treatment of Shao alloy, it refers to the period from cold standby casting to 3GGt. The temperature 3Q (rc is lower than the solution heat treatment (about 520 °), but the temperature is lower than usual. It is also a high temperature from 70 to 111. According to one aspect of the present invention, it is a method for manufacturing a casting, which includes the following processes ... "Know at least one kind of particulate aggregate, at least one kind of water-soluble binder and water mixing The aggregate mixture is formed, and the aggregate mixture is stirred and foamed. The foamed aggregate mixture is filled in the space for mold making, and the moisture in the filled aggregate mixture is evaporated to solidify the aggregate mixture. A casting mold is made from the shaped aggregate; a casting made from the particulate aggregate is made: a mold is combined with a facing recording mold to make a complete casting mold; a molten liquid is poured into the complete casting mold; 6 200533436 The casting is removed in During the cooling period of the molten solidified casting, the mold is cast; the casting is heat-treated. The mold prayer mold made of particulate aggregate is preferably a sand core prayer mold. In this case, the opposite The mold (main mold) can be a metal mold or a sand mold. In this book, "Complete Prayer Mold" is a tool that can be used to inject molten solution. The main mold and particle bone At least] mold cores (Saishi heart molds) are made from materials. Therefore, the constituent elements of a complete mold, in addition to the main mold and the sand core mold, can also include the necessary components for washing. The manufacturing method of the classic Mao Ming's castings may further include a process of recovering the particulate moon material and a process of regenerating the recovered particulate aggregate. It is best to use the recovered and recycled particulate aggregate again in the mold making According to one embodiment of the present invention, the process of recovering and regenerating granular aggregates is mechanical recycling. 7 pieces of 仏 ming alloy castings, magnesium alloy castings, copper alloy castings, etc. The heat treatment is T6 treatment or T7 treatment. < " According to the invention In one embodiment, the process of removing the mold is a process of casting ^ \ vibration. For example, within 5 minutes to 20 minutes after pouring, less than 30 seconds is applied to the mold at a frequency of less than 30 Hz. ^ The manufacturing method of the cast of anomalous grievances includes the following processes: Mixing particles Zhuang, # 制 ^, ^ '枓, at least one water-soluble binder and water to form an aggregate mixture; moon compound Stir and foam, fill the foamed aggregate mixture-200533436 in the space for mold making, evaporate the water in the filled aggregate mixture to solidify the aggregate mixture to create a sand core mold; make the sand core mold and A metal mold is used to synthesize a complete mold; a molten aluminum alloy is poured into the complete mold; the sand core mold is removed from the casting during the cooling of the molten aluminum alloy after it is solidified; and the aluminum alloy casting is subjected to T6 or T7 heat treatment . At least one water-soluble binding agent is at least one of polyvinyl alcohol and its derivatives, or at least one of dianfan and its derivatives. [Embodiment] The shape of the house after the invention of rabbit jfe Fig. 1 is a process diagram schematically showing each process of the method for manufacturing a casting of the present invention. The principle of the method for manufacturing a casting according to the present invention will be explained first according to this process chart. In FIG. 1, first, at least one particulate aggregate, at least one water-soluble binder, and water are mixed to form an aggregate mixture, and the mixture is stirred and foamed (first (preparation) process 1). Second, the aggregate mixture foamed in the previous process is filled in the molding space to be solidified, and a mold composed of granular aggregates is produced (second (molding) process) 2). Thirdly, at least one of the mold making molds (sand core iron molds) and the opposite casting mold (main mold) are combined to produce a complete scale mold (third (assembly) process 3). Fourth, a molten liquid is poured into the complete mold (fourth (casting) cake 4). 8 200533436 No. 5, the mold is removed from the core after the solidification of the molten metal, and the mold is released (No. 5 (mold release) No. 6) The casting is subjected to heat treatment (No. Process 5 :). Part 6 (heat treatment) Process 6), the process of Figure 1 will be described in more detail. In the first (modulation) process 1, the granular aggregates are made of stone sand, wrong stone, sand At least one kind of sand, smelt sand, chromite sand, alumina sand, λ4 sand, artificial sand, etc.

It is best to use a water-soluble binder at room temperature. At room temperature, the water-soluble binder that can be made in water can form an aggregate mixture without heating, so it can save the time and energy required to heat the binder and particulate aggregate. This is an advantage of the present invention over the production of coated sand by the conventional shell mold method. The water-soluble binding agent used in the present invention is preferably one or both of polyvinyl alcohol or a derivative thereof and starch or a derivative thereof as a water-soluble binding agent, but is not limited thereto. This water-soluble binder can be easily volatilized or horned. Therefore, in the subsequent fifth (mold release) process 5, the casting core that can be solidified from the molten liquid is easy to remove the sand core mold. The water-soluble binder is preferably 0.1 to 5.0% by weight based on the particulate aggregate. The at least one water-soluble binder, at least one particulate aggregate, and water are mixed to form an aggregate mixture. The mixture is stirred and foamed, and the aggregate mixture becomes a whipping cream. In the second (molding) process 2, if the water in the aggregate mixture filled in the space for molding is evaporated to solidify the aggregate mixture, the aggregate will be made of particulate aggregate due to the foaming of the previous process. Hollow Sand Core Mold (Sand Core Casting 9 200533436 mold) factory. The porosity of the hollow mold was 60%. In addition, if the medium is 4 °-', the water-soluble binder has a mold surface layer between ι0-deep. That is, in the hollow mold made of foaming moon material / combination, the eight dead bodies M are made of square and knife in the aggregate mixture! The moisture contained in the bubbles and the binding agent is concentrated in the center of the mold, so, : By evaporating this water, the packing density of the aggregate in the center of the mold will change to h 3 (assembly) process 3 'at least one combinable main mold (composite prayer mold) composed of granular aggregate and Make up a complete prayer pattern. No. 2: Wu Ben: Metal molds can also be made of, for example, η ^ lack of coupling of particulate aggregates. Metal molds are known for low reflection. However, if metal molds are used, the method of the present invention, then "Unlimited pure f casting" can also be applied to back pressure casting, die casting, other processes such as gravity metal mold forming. In the 4th (casting) process 4, the molten liquid material poured into the complete mold, in this embodiment is Aluminum alloy, but not limited to this, may also be other light metal alloys or non-ferrous alloys (such as town alloys or copper alloys). In addition, cast iron, cast steel, or iron-based metal alloys may also be used. However, if used For iron-based metals, it is desirable to apply a coating material to a sand core mold. "During the 5th (mold release) spear showing 5, ^ during the cooling period (cooling the fastener to a temperature lower than the temperature of the pound after cooling) During this period, the degree of cooling will not be caused; the casting will be deformed when the mold is removed from the mold.) The sand core casting branch is removed from the casting. Here, "in the cooling period" when the material of the molten liquid in the fourth (pouring) process 4 is an aluminum alloy, for example, cooling the casting to 300. During the period of 〇, 10 200533436, the temperature 300 ° C is lower than the solid solution treatment temperature (about 520 ° C) of T6 treatment of aluminum alloy, but higher than the usual cooling temperature 7 (rcs 111. (: higher temperature). In the case of Shao alloy, the heat treatment of the 6th (heat treatment) process 6 is T6 treatment, T7 treatment, and other heat treatments. Since the water-soluble binder uses polyvinyl alcohol or its derivative or Yodichi or its derivative, No unpleasant odor occurred during the preparation process 1 for kneading the particulate aggregate mixture containing the binder, and during the molding process 2 for making the sand core mold. Furthermore, the produced sand core mold was melted by pouring. In the liquid casting process 4, even if the bonding agent is heated by the heat of the molten liquid, no odor and undesired volatile gas from the sand core casting are found. As shown in Fig. 1, this In the manufacturing method of the invention, the following process can be further added as necessary after the β (heat treatment) process 6: That is, the particulate aggregate (sand core sand) and core block of the sand core mold are recovered. Recycling process 7, crushed sand Block crushing process 8 and mechanical recycling process 9 for regenerating the recovered particulate aggregates mechanically. The recovered and regenerated powdery aggregates can be re-used in the molding of sand core molds. ^ Refer to Figure 1 The process drawing illustrates the special feature of the method for manufacturing the casting of the present invention: the application form. However, the material names appearing here are only used as examples and do not limit the present invention. 1 process (modulation process) i, # 2 kinds of aggregate mixtures a and b.

Table 1 Aggregate Mixture A 11 200533436 Particulate aggregate: Shi Xisha (Flatali Sand: 100% by weight) Water-soluble binder: Polyvinyl alcohol (jp_05 jApAN VAM & P0VAL CO., LTD.) ) Weight 0.8 weight parts of cross-linking agent: butane tetracarboxylic acid (Rikashid BT _ w Shinyoshimoto Chemical Co., Ltd.) 0.2 weight parts will appear in the aggregate mixture composed of the composition shown in Table 1 丨0 parts by weight and 6 parts by weight of water were mixed, stirred, and kneaded until foaming, to obtain a stirred creamy aggregate mixture A. Table 2 Aggregate Mixture B Teeth: Crescent Moon Moonite • Silica C (Flatali Sand) i 〇 〇

Water-soluble binding agent: Polyvinyl alcohol (Ji-G5 Satoshi N VAM & P0VAL ', LTD.) 0.2 parts by weight, starch (dextrin ND-s Nikatsu Chemical Co., Ltd.) ^ 〇 parts by weight, and lemon Acid (made by Fuso Chemicals) 0.4 parts by weight The dry aggregate mixed with the composition shown in Table 2 was mixed with 6 parts by weight of water knife, water #, and oily aggregate mixture B. "Stirring the milk, in the process of the resin mold of the method of the preparation process of the present embodiment, the resin-coated sand y & A must not only make a conventional shell to remove the cause of the tree 2: the heat device, but also does not need a U-tree It is produced by the heating of the month, and the oblique is only 7. The deodorizing device of the lice body. The mold of the eighth mold cavity (not R-, using the Meng mold (not shown)) is molded to the mold maintained at 250 C. V Hetu not) internally pressurized one by one 埴) kinds of stirring cream / ° ° 2 obtained in the week clothing process 1, said humanoid moon family mixtures A and B, in the juice-holding composition owed a, hold for 1 minute, After the water of the aggregate is aluminized and solidified, the sand core mold (the second (molding) process 2) is taken out of the mold cavity of the drawing mold 12 200533436. As described above, this mold and another- The mold is assembled into a complete mold (3rd (assembly) process 3). Here, right Taimei # in the process of assembling evil in this kappa # 3, the metal mold of the main mold of the low-voltage if device is jealous. ) ~ • Take a complete mold and complete the preparation for pouring. ′ Wash and pour the melt into the complete mold (4th (washing) process 4). This implementation The form 'is a low-pressure casting device (not shown) ㈣ alloy castings, and the molten solution (temperature 72 (TC) from the bottom. Note: the molten solution? 2 0. 0 temperature makes the binder volatilize or decompose.' Easy to remove—the sand core prayer mold of the manufacturing process. During the cooling of the casting after the molten liquid has solidified, the sand core mold is removed from the casting (No. 5 (脱模) 制 # 作 5). The conventional shell mold method, $ ^ Since the sand core mold is disintegrated and removed from the casting, a large impact force must be applied to the mold after the casting is sufficiently cooled. If the method of the present invention is used, since a disintegrated sand core mold is used, there is no need to sand in the past. The core mold is removed from the casting with sufficient cooling and large subsequent impact forces. Therefore, the sand core mold can be removed by a simple method, such as light vibration described below. In the demolding process 5 of this embodiment, Yao About 10 minutes after the start of injection, the solidified molten solution was taken out as a casting. Immediately afterwards, an impact force of 1 MPa or less was applied to the casting at a temperature of 35 ° t with a light vibration of 20Ηζ for less than 20 seconds to remove sand. This can completely remove the sand core mold In addition, according to the experimental results, in the demoulding process 5, within 5 minutes to 20 minutes after casting, an impact force of less than 30 MPa is applied at a frequency of less than 30 MPa for 30 seconds to remove sand, and the sand core can be completely removed from the casting. Removal of the _ pieces of the washing path 'remove the burr of the casting, and then heat-treat the casting 13 200533436 (6th (heat treatment) process 6). The removal of the runner and burr of the casting, in this embodiment is in the casting The heat treatment is performed before, but it may be performed after the heat treatment. In this embodiment, the core sand recovery process 7, the crushing process 8, and the mechanical regeneration shown in FIG. 1 may be added after the sixth (heat treatment) process 6. Process 11 〇. Using a metal mold casting method, only the granular aggregates and sand core blocks from the sand core mold are recovered, so the recovered and recycled particulate aggregate can be easily reused in the mold making. Fig. 2 (conventional technique) used for comparison is a flowchart of a method for manufacturing a conventional casting using the shell mold method described in Japanese Patent Application Laid-Open No. 5-261261. The known method of FIG. 2 uses resin-coated sand. Generally, the resin-coated sand is manufactured and sold by a different supplier from the casting manufacturer. Therefore, the process (11) of manufacturing the resin-coated sand is different from the casting manufacturing site ^. Therefore, even if the resin-coated sand is recovered and the sand is regenerated, compared with the method of the present invention, it is still difficult to reuse the sand for mold making. According to the conventional method of FIG. 2, the casting manufacturer heats the commercially available resin-coated sand to produce a sand core mold 02), assembles the produced sand core mold with another mold, and manufactures a complete mold (13), The complete mold is poured (14). Secondly, the sand core is removed from the sand furnace (15), and the casting (16) is sufficiently cooled, and then the casting sand is completely removed by the knock-down process (17), and the casting is heat-treated (18). Furthermore, the core sand containing the core block is recovered from the knock-down process 17, the heat treatment process = and subsequent processes (9). The recovered sand core sand is produced in a resin-coated sand manufacturing site, that is, in another place different from the place where the return = 14 200533436 process 19 is usually performed, and the core block roasting 21 and the mechanical regeneration 22 are performed. 20 ′ # The method of manufacturing the casting of the present invention, which is different from that of the method, can reduce the number of processes. For example, the method of the present invention (Figure 5 (except model) Le I Chakou r #) For example, the use of the light two of the two ::: friend solution is easy 'so it can be achieved by the simple method of the second, r: n 'In contrast, the mold is not easy to disintegrate the removal 15, the charge of the shipment " Λ removal weights' must be cooled by the method of removing sand furnace, and the knock-down process 17'. Recycling of conventional methods 2 Roasting 6 (^ 理 ^ Shows the 5th (demolding) process 5 and the 5th heat treatment of the embodiment of the present invention) Figure 6 (Xiaotou ^ degrees) The graph of the relationship between ^. It is used to compare the processing process pair :: 2) The same graph of the broader & Baizhi process. After that, after entering the above-mentioned process of sufficiently cooling the casting, the sand removal process using the knock-down process (the process in Fig. 2) takes a long time to cool down, I: processing, and reheating. Therefore, as shown in "4 As shown in Fig. 3, the time and energy to be used for reheating for heat treatment. 衣衣 私 5 removes the molten core from the sand core scale mold. Therefore, immediately after removing the pieces, cool the casting f Kou De ^ must be fully processed in order to remove the sand core mold). Because of: Large impact, you can immediately start the solution treatment (heat, so it can shorten the additional time required for cooling A /. Θ can also reduce the number of heat treatment. Bindings are not :: " energy consumption, It can also reduce the process to be cooled to 100 ° C, and the cooling to _ can also obtain the energy-saving effect of 15 200533436. The above embodiment is only an example of the present invention, and does not limit the scope of the present invention. The technical field to which the present invention belongs Those with ordinary knowledge 'can make various and deformations without exceeding the purpose and subject recorded in the scope of patent application. [Brief Description of the Drawings] Figure 1 is a process drawing of the manufacturing method of the casting of the present invention. Figure 2' It is a manufacturing process drawing of a conventional casting manufacturing method using a shell mold method. Fig. 3 'is a graph showing the relationship between the temperature and time of the parts in the mold removal and heat treatment process of this embodiment. Fig. 4' System disk_ 〇. ../, bj 3 corresponds to the manufacturing process. The same graph shown in Figure 3 is shown in the manufacturing process using the conventional technique of the shell mold method. [Description of main component symbols] η "

16

Claims (1)

200533436 10. Scope of patent application: 1. A method for manufacturing castings, which includes the following processes: Mixed seed granular aggregates, at least 1 type of water-soluble: binding agent and water: [to form a material mixture, and stir the aggregate mixture The foaming bone aggregate mixture is filled in the mold molding space to evaporate the water in the filling mouth to solidify the aggregate mixed aggregate to make a mold; the genius pair is made from the particulate aggregate. The molds, molds, and complete molds; and. Upward-facing · The molten mold is poured into the complete mold; during the cooling period of the finished material, it is removed from the town piece, and the < 2. For the method of manufacturing a casting according to item 1 of the scope of patent application, in bean, at least one molding mold made of the particulate aggregate is a sand core mold, and the opposite mold is a main mold. The method of manufacturing the castings of Youxiang, among them, the method of manufacturing castings of Xiang, 3. If the main scope of the patent application, the main mold is a metal mold. 4. If the scope of patent application is the first, the main mold casting mold is a sand mold. Any of the items from item 4 to item 4-a method of manufacturing a prayer piece, a process of recovering the particulate aggregate and a process of regenerating the recovered particulate aggregate. 6. If the method of manufacturing a casting according to item 1 of the scope of the patent application is to use the 17 200533436 mouth-recycled particulate aggregate again for mold making. 7. The method of casting according to item 5 of the scope of patent application. The process for recovering and regenerating the granular aggregates of 5th is mechanical recycling. Manufacturing = The casting of any one of the items 1 to 4 in the application scope, the casting is an aluminum alloy casting or a magnesium alloy casting. • The method for manufacturing a casting according to item 8 of the patent application scope, wherein the heat treatment is a T6 treatment or a T7 treatment. A [1 of the steel casting of the casting of any one of the items, or the casting of any one of the iron-based metal items. If the scope of the patent application is from item 1 to the manufacturing method 'wherein' the casting is made of cast iron Composition of castings. U, such as the method of applying for patents No. 1 to t, π 迨 method, wherein the casting is a copper alloy casting. Manufacturing: as in the method of applying any one of items i to 4 in the scope of patent application, where the method of removing the mold is to apply vibration to the mold. Section 13. The manufacturing method of the castings on the front page of the patent scope as described in the patent, wherein the riding mold applies vibration within 5 minutes to 2G minutes. Each mold applies an impact force of less than 1Mpa at a frequency less than 2 seconds. 14. A method for manufacturing a casting, comprising the following processes: mixing particulate aggregate, at least j kinds of water-soluble binders and water to form an aggregate mixture; ^ mixing and foaming the aggregate mixture, The aggregate mixture of foam is filled into the space for mold making, and the moisture in the filled aggregate mixture is evaporated to solidify the aggregate mixture to create a sand core mold. 18 200533436 The sand core mold and the metal mold module are integrated. Casting a mold; pouring a molten aluminum alloy into the complete mold; removing the sand core mold from the casting during cooling of the molten aluminum alloy after solidification; and applying T6 or T7 heat treatment to the aluminum alloy casting. 1 5. The method for manufacturing a casting according to any one of claims 1 to 4, and 14, in which the at least one water-soluble binder is at least one of polyvinyl alcohol and its derivatives One, or starch and its derivatives-, scheme: as in the next page ❿ 19