JP2018176201A - Casting model and manufacturing method of casting using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To judge the quality of a casting from its appearance and to obtain a casting model which can determine whether a chiller has been placed on a sand mold to form the casting or not.SOLUTION: The casting model has an opening and a recess communicating with the opening at a position where a chiller is disposed. When the chiller is disposed at a normal position, the opening is formed at a position and a size such that the opening is blocked without any gaps by the chiller. The opening is formed in a size such that at least a part of the opening is exposed when the position of the chiller is arranged at an abnormal position.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a model used to manufacture a casting using a sand mold and a method of manufacturing the same.

  Conventionally, a chiller is disposed in a sand mold used for casting (see, for example, Patent Documents 1 and 2). The cooling metal is buried in sand forming a sand mold, absorbs the heat of the molten metal poured into the sand mold, and reduces the temperature of the molten metal appropriately. And while preventing that a shrinkage cavity generate | occur | produces in a casting, the structure which comprises a casting is refined | miniaturized and the quality of a casting is ensured. Moreover, what arrange | positions using an automatic molding machine as a method of arrange | positioning a cooling metal to a sand mold is known (for example, refer patent document 3, 4).

JP, 2010-227965, A Patent No. 3401765 Patent No. 3112213 gazette Patent No. 3112215 gazette

  When the chiller is placed in a sand mold, the chiller is placed on a framed model, sand is filled in the frame, and the chiller is embedded in the sand mold. In the case of small castings, sand molds are often produced automatically using a molding machine, but in the case of large castings, workers sometimes produce sand molds manually. When the worker manufactures a sand mold, the worker arranges a chiller.

  When a less experienced worker manufactures a sand mold, problems such as misalignment of the chiller and forgetting to place the chiller may occur. When a casting is manufactured using a sand mold with a cold metal misplacement and a sand mold without a cold metal, the strength necessary for the casting can not be obtained, and shrinkage defects may occur inside the casting. is there. However, castings formed by such a sand mold are hardly different in appearance from normal castings, and thus it is difficult to visually separate them. Therefore, it was difficult to determine from the appearance of the casting whether or not the chill was placed in the sand mold on which the casting was formed.

  The present invention has been made to solve the problems as described above, and the quality of the casting can be judged from the appearance of the casting, and a chill is placed in the sand mold on which the casting is formed. It is possible to obtain a casting model which can be judged whether it has been used or not.

  An opening and a recess communicating with the opening are formed at a position where the chiller of the casting model is disposed. The opening is formed at a position and a size such that the opening is closed without a gap by the cooling metal when the cooling metal is placed at a normal position. Then, the size of the opening is formed such that at least a part of the opening is exposed when the position of the cooling metal is arranged at an abnormal position.

  The casting model according to the present invention makes it possible to distinguish from the appearance of the casting that the placement position of the cold metal is shifted and that the cold metal is forgotten to be placed on the casting model when forming the sand mold. It is. Thus, the quality of the casting can be easily determined based on the appearance of the casting, and it is possible to prevent the outflow of the defective casting as a product.

FIG. 1 is a perspective view showing a casting cast according to Embodiment 1 of the present invention. It is a figure which shows the state which arrange | positions the casting model of FIG. 1 on the surface plate, and encloses in a metal frame. It is a figure which shows the state which arrange | positioned the cooling metal to the casting model of FIG. It is a top view of the casting model of FIG. It is a figure which shows the cross section of the casting model in alignment with the VV line | wire of FIG. It is a figure which shows a cross section. It is a figure which shows the state which arrange | positioned the cooling metal to the casting model of FIG. It is a figure which shows the state which has arrange | positioned the sand for sand mold formation around the casting model of FIG. It is a figure which shows the state which isolate | separated the sand mold from the state of FIG. It is a figure which shows the casting which formed the sand mold of FIG. 8, and this sand mold. It is a figure which shows the state which arrange | positioned the sand for sand mold formation, without arrange | positioning a cooling metal on the casting model of FIG. It is a figure which shows the state which isolate | separated the sand mold from the casting model of FIG. It is a figure which shows the casting which formed the sand mold of FIG. 11, and this sand mold. It is a figure which shows the state which arrange | positioned the sand for sand mold formation in the state which the cooling metal arrange | positioned to the casting model of FIG. 5 has shifted | deviated. It is a figure which shows the state which isolate | separated the sand mold from the casting model of FIG. It is a figure which shows the sand mold of FIG. 14, and the casting formed using this sand mold. FIG. 10 is a top view showing a first modification of a casting model according to the first embodiment. It is sectional drawing of the casting model in alignment with the XIV-XIV line of FIG. FIG. 16 is a cross-sectional view showing a second modification of the casting model according to the first embodiment. FIG. 7 is a cross-sectional view showing a casting cast according to Embodiment 2; FIG. 10 is a cross-sectional view showing a casting cast according to Embodiment 3; FIG. 18 is a cross-sectional view showing a modification of a casting model according to Embodiment 3; FIG. 20 is a cross-sectional view showing a casting cast according to Embodiment 4;

  Hereinafter, preferred embodiments of a casting model according to the present invention will be described with reference to the drawings.

Embodiment 1
FIG. 1 is a view showing a casting cast 10 according to a first embodiment of the present invention. FIG. 2 is a view showing a state in which the casting model 10 of FIG. 1 is disposed on a platen 20 and a metal frame 40 is attached. Moreover, FIG. 3 is the figure which arrange | positioned the cooling metal 50 to the casting model of FIG.

  As shown in FIG. 1, the casting model 10 is in the shape of a rectangular solid, and a recess 10B having a rectangular opening 10A is formed on the top surface. The casting model 10 is formed of wood, resin or metal, and the recess 10B is formed by cutting using a machine tool. In addition, the casting model 10 can also be formed by a lamination molding method using a 3D printer. By using the lamination molding method, the recess 10B can be formed without cutting. Therefore, compared with the case where it carries out cutting processing, it can form with few materials.

  The casting model 10 has the same shape as the product casting, and is used for producing a sand mold for casting the casting. The chiller 50 is buried in the sand when forming the sand mold. As shown in FIG. 2, the casting model 10 is disposed on a surface plate 20 and used in a state of being surrounded by a metal frame 40. The cooling metal 50 is disposed on the casting pattern 10 so as to close the opening 10A of the recess 10B formed in the casting pattern 10, as shown in FIG.

  Next, with reference to FIGS. 4-9, the procedure of manufacturing the casting 70 using the casting model 10 is demonstrated. 4 is a top view of the casting model 10 of FIG. 2, and FIG. 5 is a cross-sectional view taken along the line V-V of FIG. 6 to 9 show the same cross section as FIG.

  First, as shown in FIG. 4 and FIG. 5, the casting model 10 is disposed on the surface plate 20, and the periphery of the casting model 10 is surrounded by the metal frame 40. Next, as shown in FIG. 6, the cooling metal 50 is disposed so as to close the opening 10A of the recess 10B formed in the casting model 10.

  Next, as shown in FIG. 7, sand 90 is inserted without a gap between the metal frame 40 and the casting model 10. As shown in FIG. 7, since the opening 10A of the casting model 10 is closed by the cooling metal 50, the sand 90 does not enter into the recess 10B. After this, the sand 90 is solidified to form a sand mold 60. As a method of forming the sand mold 60, there are a forming method such as a green mold, a self-hardening type, and a gas-hardening type, but any method may be used.

  Next, the sand mold 60 is removed from the casting model 10 and the metal frame 40. As shown in FIG. 8, the sand mold 60 is formed with a recess 60 </ b> B having an opening 60 </ b> A. Then, the cooling metal 50 is embedded in the sand mold 60 in a state where the surface in contact with the casting model 10 is exposed to the bottom 60D of the recess 60B of the sand mold 60.

  Next, a molten metal is cast into the concave portion 60B of the formed sand mold 60 from the opening 60A to form a casting 70 as shown in FIG. Thus, the formation of the casting 70 using the casting model 10 is completed. The casting 70 formed by the sand mold 60 in which the cooling metal 50 is normally arranged has the same shape as the casting model 10, and the surface of the casting 70 has no unevenness.

  Here, when manufacturing the casting 70 using the casting model 10, the case where the cooling metal 50 is not arrange | positioned to the casting model 10 is demonstrated using FIGS. 10-12. 10 to 12 show the same cross section as FIG.

  As in the case of forming a normal casting 70, the casting model 10 is placed on the surface plate 20, and the periphery of the casting model 10 is surrounded by the metal frame 40. Then, as shown in FIG. 10, without disposing the cooling metal 50 on the casting model 10, sand 90 is inserted without a gap between the metal frame 40 and the casting model 10. At this time, as shown in FIG. 10, since the opening 10A of the casting model 10 is not blocked by the cooling metal 50, the sand 90 enters the recess 10B. After this, the sand 90 is solidified to form a sand mold 60.

  Next, the sand mold 60 is removed from the metal frame 40 and the casting model 10. At this time, as shown in FIG. 11, a convex portion 60 </ b> C is formed on the bottom portion 60 </ b> D of the concave portion 60 </ b> B of the sand mold 60.

  Next, a molten metal is cast into the concave portion 60B of the formed sand mold 60 from the opening 60A to form a casting 70 as shown in FIG. Then, the concave portion 70A is formed on the surface of the casting 70 by the convex portion 60C of the sand mold 60. Therefore, when the casting 70 has the recess 70A, the casting 70 is formed by the abnormal sand mold 60 and is a defective product.

  Further, as shown in FIG. 13, even if the cooling metal 50 is disposed on the casting model 10, if the arrangement position of the cooling metal 50 is shifted from the opening 10A of the casting model 10, The sand 90 enters the recess 10B from the gap of the opening 10A not closed by the cooling metal 50. And as shown in FIG. 14, convex part 60C is formed in bottom part 60D of concave part 60B of sand mold 60, and as shown in FIG. 15, concave part 70A is formed in casting 70. As shown in FIG. When the casting 70 has the recess 70A, the casting 70 is formed by the abnormal sand mold 60 and is a defective product.

  As described above, according to the casting model 10 of the first embodiment, the recess 10B having the opening 10A is formed on the upper surface of the casting model 10. Then, a cooling metal 50 is disposed to close the opening 10A to form a sand mold 60. When the cooling metal 50 is normally arranged in the sand mold 60, the surface of the casting 70 formed of the sand mold 60 facing the cooling metal 50 is flat.

  On the other hand, when the cooling metal 50 is not disposed in the sand mold 60, the recess 70B is formed on the surface of the casting 70 corresponding to the position of the cooling metal 50. Further, even if the cooling metal 50 is arranged on the casting model 10, if the arrangement position of the cooling metal 50 is deviated from the opening 10A of the casting model 10, the cooling metal of the casting 70 A recess 70B is formed on the surface corresponding to the position 50.

  Thus, according to casting model 10 of the first embodiment, casting 70 is formed of a normal sand mold 60 or an abnormal sand mold 60 by confirming the presence or absence of a recess 70B. It becomes possible to identify whether it is a defective product. Therefore, in the appearance inspection step, defective products of the casting 70 can be easily sorted out. Furthermore, it is possible to determine whether or not the cooling metal 50 has been properly disposed on the sand mold 60 in which the casting 70 is formed, depending on the presence or absence of the recess 70A.

  In the first embodiment, the shape of the casting model 10 is a rectangular parallelepiped, but the present invention is not limited to this. The casting model 10 is formed in various shapes according to the shape of the product, and may be any shape as long as the sand mold 60 can be formed. Further, the shapes of the opening 10A and the recess 10B are not limited to rectangular. For example, the shape of the opening 10A may be elliptical or polygonal. Furthermore, in the first embodiment, the shape of the cooling metal 50 is also a rectangular parallelepiped, but the present invention is not limited to this. For example, the shape of the cooling metal 50 may be cylindrical or polyhedron. Further, the surface of the cooling metal 50 exposed to the bottom portion 60D of the sand mold 60 is different depending on the shape of the casting 70 to be a product, and is not limited to a flat surface. For example, the surface of the cold metal 50 may be a curved surface.

  Moreover, in Embodiment 1, although the bottom of the recessed part of the cast pattern 10 was a plane, it does not restrict to this. For example, like the casting model 11 of the first modification shown in FIG. 17 which is a top view of FIG. 16 and a cross-sectional view taken along line XVII-XVII of FIG. It may be engraved. Then, when the cooling metal 50 is not disposed in the sand mold 60, the character 11C may be transferred to the sand mold 60 so that the character 11C is formed on the surface of the casting 70.

  Further, as in the casting model 12 of the second modified example shown in FIG. 18, the characters 12C may be convex. By making the characters 12C convex, the characters transferred to the sand mold 60 can be made concave. If the character 12C transferred to the sand mold 60 is convex, the character 12C may be missing because the sand mold 60 is fragile. By making the characters 12C concave, even small characters can be formed without missing. The concave character 12C may be formed directly on the surface of the casting model 12 without forming the recess 12B in the casting model 12.

  The characters 11C and 12C may be made meaningful by using numbers, alphabets, symbols or the like. For example, from the process of separating the sand mold 60 from the casting model 10 by casting a word representing a defective product such as "NG" into the sand mold 60, the process of coating the sand mold 60, the state of the sand mold 60 In the inspection process, the process of removing the sand burrs of the sand mold 60, and all the processes up to the pouring process, it is possible to notify the operator that the sand mold 60 is defective.

Second Embodiment
FIG. 19 is a view showing a casting model 13 according to the second embodiment. The second embodiment differs from the first embodiment in that the casting model 13 is formed of two parts. The other configuration is the same as that of the first embodiment.

  As shown in FIG. 19, the casting model 13 has an attaching / detaching portion 30 in the recess 13 </ b> B. The detachable portion 30 can be detached from the casting model 13 and replaced. The detachable portion 30 has an opening 30A, a recess 30B, and a convex character 30C. The structure for attaching the detachable portion 30 to the casting model 13 is, for example, by fastening using a screw or the like as in the case of a mold nest, and the detailed description is omitted.

  Since the detachable portion 30 is detachable from the casting model 13, the position, size and size of the recess 30B formed in the detachable portion 30 according to the position, size and shape change of the cooling metal 50. It becomes possible to replace with the attachment or detachment part 30 from which a shape differs. Thus, according to casting model 13 of the second embodiment, even if the position, size and shape of cooling metal 50 are changed, casting model 13 needs to be newly manufactured. Therefore, it is possible to reduce the production cost of the casting model 13 and shorten the production period.

  In addition, the casting 70 may be manufactured in a plurality of foreign countries. Even when manufacturing at a factory in Japan, workers of different nationalities may take turns in charge of manufacturing. In such a case, according to casting model 13 of the second embodiment, a plurality of detachable portions 30 are prepared in advance, and characters 30C of each detachable portion 30 are in the languages of a plurality of possible countries. It can be formed. Then, the detachable portion 30 in which the characters 30C are formed in a language corresponding to the manufacturing country and the nationality of the worker can be attached to the casting model 13. This makes it possible to notify workers of different nationalities that the sand mold 60 is defective.

  As a method of forming characters in the detachable portion 30 of the casting model 13, cutting by a machining center or the like is generally used, but if the material is wood, it is also possible to carve the characters by manual processing. If a material is resin, you may form using lamination modeling, such as 3D printer.

  In addition, the detachable portion 30 and the casting model 13 may be formed of different materials and manufacturing methods. For example, the casting model 13 can be formed by cutting wood or metal, and the attaching / detaching portion 30 can be precisely molded by a 3D printer using CAD data. This makes it possible to reduce the manufacturing cost and shorten the manufacturing period, taking advantage of different manufacturing methods such as processing by a machine tool and molding by a 3D printer.

Third Embodiment
FIG. 20 is a view showing a casting model 14 according to the third embodiment. The casting model 14 according to the third embodiment is different from the casting model 10 according to the first embodiment in that the recess 14B has an inverse tapered shape. The other configuration is the same as that of the first embodiment.

  As shown in FIG. 20, the recess 14B formed in the casting model 14 has a reverse taper shape from the opening 14A toward the inside of the casting model 14. Therefore, when the sand mold 60 is formed without arranging the cooling metal 50, a part of the sand mold 60 formed in the recess 14B does not come out of the casting model 14. If the sand mold 60 is forcibly pulled out in this state, the sand mold 60 around the recess 14B collapses, and the bottom portion 60D of the recess 60B of the sand mold 60 has an irregular concavo-convex shape. Then, on the surface of the casting 70 formed by the sand mold 60, an abnormal asperity shape is formed. Thereby, according to the cast pattern 14 of the third embodiment, by inspecting the appearance of the casting 70, it can be determined that the cooling metal 50 is not properly disposed on the sand mold 60. In addition, the formation of abnormal irregularities on the surface of the casting 70 facilitates the screening of defective products.

  As a method of forming the reverse tapered shape of the concave portion 14B, it is preferable to use a 3D printer because machining is difficult in cutting with a machine tool. In this case, as in the casting model 15 of the modified example shown in FIG. 21, the recess 31 B of the reverse taper shape is formed in the detachable portion 31 of another component and attached to the recess 15 B of the casting model 15. Good. The processing cost can be reduced and the manufacturing period can be shortened by forming the reverse taper-shaped concave portion 31 B which is difficult to process in the detachable portion 31 of the separate part.

Fourth Embodiment
FIG. 22 is a view showing a casting model 16 according to the fourth embodiment. The casting model 16 according to the fourth embodiment is different from that of the first embodiment in that the recess 16B is formed not on the upper surface of the casting model 16 but on the side surface. The other configuration is the same as that of the first embodiment.

  As shown in FIG. 22, the casting pattern 16 has a recess 16B having an opening 16A on the side surface. Therefore, when the sand mold 60 is formed without arranging the cooling metal 50, a part of the sand mold 60 formed in the recess 16B does not come out of the casting model 16. In this state, if the sand mold 60 is forcibly pulled out, the sand mold 60 around the recess 16B collapses, and the inner wall of the recess 60B of the sand mold 60 has an irregular asperity shape. Then, an irregular asperity shape is formed on the side surface of the casting 70 formed by the sand mold 60. Thus, according to the casting model 14 of the fourth embodiment, by inspecting the appearance of the casting 70, it can be determined that the cooling metal 50 is not properly disposed on the sand mold 60. In addition, the formation of abnormal irregularities on the surface of the casting 70 facilitates the screening of defective products.

  Here, in the casting 70, generally, two sand molds of upper and lower molds or three upper and lower molds and an intermediate mold are formed to form a mold of one product by combining them. There is. The sand mold 60 described herein may be any of an upper mold, a lower mold and an intermediate mold.

  DESCRIPTION OF SYMBOLS 10-16 Casting model, 10A-16A opening, 10B-16B recessed part, 11C, 12C character, 20 surface plate, 30, 31 detachable part, 30A, 31A opening part, 30B, 31B recessed part, 30C character, 40 gold frame 50 chills, 60 sand molds (molds), 60A openings, 60B recesses, 60C protrusions, 60D bottoms, 70 castings, 70A recesses, 90 sand.

Claims (7)

It is a casting model used in the manufacture of a mold in which a cooling metal is embedded,
It has an opening and a recess communicating with the opening at a position where the chiller is disposed,
The opening is
When the cooling metal is placed in a normal position, the cooling metal forms the opening at a position and size that can be closed without any gap.
The size of the opening is
When the position of the cold metal is disposed at an abnormal position, at least a part of the opening is formed to be exposed.
Casting model. The recess is
At the bottom of the recess, the character has a concave shape,
A casting model according to claim 1. The recess is
Formed in reverse taper shape,
A casting model according to claim 1 or 2. It has a detachable removable part,
The recess is formed in the attaching / detaching portion.
The casting model according to any one of claims 1 to 3. A method of manufacturing a casting using a casting model according to any one of claims 1 to 4,
Forming a recess having an opening on the surface of the casting model;
A chill forms the sand mold in a state in which the opening is closed without any gap.
A method of manufacturing a casting using a casting model. A convex portion is formed on the sand mold by the concave portion formed in the casting model,
Depending on the presence or absence of the concave portion formed on the surface of the casting by the convex portion of the sand mold,
Determine the quality of the casting;
A method of manufacturing a casting using a casting model according to claim 5. A convex portion is formed on the sand mold by the concave portion formed in the casting model,
Depending on the presence or absence of the concave portion formed on the surface of the casting by the convex portion of the sand mold,
Determine the quality of the sand mold,
The manufacturing method of the casting using the cast pattern according to claim 5 or 6.

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