Mold Equipment

Abstract

To provide a molding device that is able to prevent a core from sticking to a movable mold.SOLUTION: A molding device 1 according to the present embodiment, which is a molding device 1 for manufacturing a core, includes: a movable mold 10 having a parting surface 11; and a fixed mold 20 having a parting surface 21 and a recessed portion 22 formed in the parting surface 21, wherein the parting surface 11 and the parting surface 21 are brought into contact to use the recessed portion 22 as a cavity; wherein the fixed mold 20 has a groove 24 to server as an injection hole 25 for core sand 31, in the parting surface 21 between an end surface 23, intersecting the parting surface 21 apart from the recessed portion 22, and the recessed portion 22; wherein the groove 24 becomes narrower toward a bottom of the groove 24; and wherein, in the movable mold 10, a portion opposite the groove 24 is flush with the parting surface 11.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a die apparatus. [Background technology]

[0002] Patent Document 1 describes a manufacturing method for molding a core by injecting core sand into an injection molding die equipped with a fixed die and a movable die. The manufactured core is removed from the fixed die and the movable die by opening the die. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-131288 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the injection molding die of Patent Document 1, when the fixed die and the movable die are joined to form a cavity, the injection hole leading to the cavity is formed along the parting surface of the fixed die and the movable die to the end surface. Therefore, the opening of the injection hole is circular with the parting surface as the center. In that case, it is considered that part of the core formed in the injection hole will stick to the movable die when the die is opened.

[0005] The present invention has been made to solve such problems, and provides a mold apparatus that can prevent a core from sticking to a movable mold. [Means for solving the problem]

[0006] The die apparatus according to the present embodiment is a die apparatus for manufacturing a core, and includes a movable die having a first parting surface, and a fixed die having a second parting surface and a recess formed in the second parting surface, the recess becoming a cavity when the first parting surface and the second parting surface are brought into contact with each other, the fixed die has an end face intersecting the second parting surface and spaced from the recess, and a groove serving as an injection hole for core sand on the second parting surface between the end face intersecting the second parting surface and the recess, the groove narrowing toward the bottom of the groove, and the portion of the movable die facing the groove being flush with the first parting surface. With this configuration, it is possible to prevent the core from sticking to the movable die.

[0007] In the above mold apparatus, the cross section of the groove perpendicular to the direction in which the groove extends may be trapezoidal. This configuration also makes it possible to prevent the core from sticking to the movable die.

[0008] Furthermore, in the above die apparatus, a cross section of the groove perpendicular to the direction in which the groove extends may have a shape surrounded by an elliptical arc and a chord. This configuration also makes it possible to prevent the core from sticking to the movable die. Effect of the Invention

[0009] According to this embodiment, it is possible to provide a mold apparatus that can prevent the core from sticking to the movable mold. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a top view illustrating the mold device according to the first embodiment. [Diagram 2] 1 is a cross-sectional view illustrating a mold device according to a first embodiment. [Diagram 3] FIG. 2 is a perspective view illustrating a movable mold and a fixed mold of the mold device according to the first embodiment. [Figure 4] 1A to 1C are cross-sectional views illustrating steps in a method for producing a core according to the first embodiment. [Diagram 5] 1A to 1C are cross-sectional views illustrating steps in a method for producing a core according to the first embodiment. [Figure 6]1A to 1C are cross-sectional views illustrating steps in a method for producing a core according to the first embodiment. [Figure 7] 3 is a top view illustrating an example of an opening of an injection hole of the mold device according to the first embodiment. FIG. [Figure 8] FIG. 11 is a top view illustrating a mold device according to a comparative example. [Figure 9] 5A to 5C are cross-sectional views illustrating steps in a method for manufacturing a core according to a comparative example. [Figure 10] FIG. 11 is a top view illustrating an opening of a mold device according to a second embodiment. [Figure 11] 13 is a top view illustrating an opening of a mold device according to another example of the second embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will be described below through embodiments of the invention, but the invention according to the claims is not limited to the following embodiments. In addition, not all of the configurations described in the embodiments are necessarily essential means for solving the problems. For clarity of explanation, the following description and drawings are omitted and simplified as appropriate. In each drawing, the same elements are given the same reference numerals, and repeated explanations are omitted as necessary.

[0012] (Embodiment 1) A die apparatus according to a first embodiment will be described. The die apparatus according to this embodiment is a die apparatus used, for example, in manufacturing a core. FIG. 1 is a top view illustrating the die apparatus according to the first embodiment. FIG. 2 is a cross-sectional view illustrating the die apparatus according to the first embodiment, showing a cross section along line II-II in FIG. 1. FIG. 3 is a perspective view illustrating a movable die and a fixed die of the die apparatus according to the first embodiment. As shown in FIGS. 1 to 3, the die apparatus 1 includes a movable die 10 and a fixed die 20.

[0013] Here, an XYZ orthogonal coordinate system is introduced for the convenience of explanation of the mold device 1. The direction perpendicular to the mating surface when the movable mold 10 and the fixed mold 20 are mated is defined as the X-axis direction, and two perpendicular directions in a plane parallel to the mating surfaces are defined as the Y-axis direction and the Z-axis direction.

[0014] The movable die 10 has a parting surface 11. The parting surface is also called a mating surface. A recess 12 may be formed in the parting surface 11 of the movable die 10. Depending on the shape of the core to be formed, a protrusion may be formed in the parting surface 11. The shape of the recess 12 is omitted in FIG. 3.

[0015] The movable mold 10 is, for example, rectangular parallelepiped. Note that the shape of the movable mold 10 is not limited to rectangular parallelepiped as long as it has a parting surface 11. The movable mold 10 has, for example, an end surface 13. The end surface 13 intersects with the parting surface 11. For example, the end surface 13 is perpendicular to the parting surface 11. For example, the end surface 13 faces the +Z axis direction. When a recess 12 is formed in the parting surface 11, the end surface 13 is separated from the recess 12.

[0016] The fixed die 20 has a parting surface 21. The fixed die 20 has a recess 22 formed in the parting surface 11. When the parting surface 11 of the movable die 10 and the parting surface 21 of the fixed die 20 are brought into contact with each other, the recess 22 becomes a cavity. When the recess 12 is formed in the movable die 10, the recess 22 and the recess 12 become a cavity.

[0017] The fixed mold 20 has, for example, a rectangular parallelepiped shape. Note that the shape of the fixed mold 20 is not limited to a rectangular parallelepiped shape as long as it has a parting surface 21. The fixed mold 20 has, for example, an end surface 23. The end surface 23 intersects with the parting surface 21 spaced apart from the recess 22. For example, the end surface 23 is perpendicular to the parting surface 21. For example, the end surface 23 faces the +Z axis direction.

[0018] The fixed mold 20 has a groove 24. The groove 24 is formed on the parting surface 21 between the end surface 23 and the recess 22. The groove 24 extends in the Z-axis direction. The groove 24 serves as an injection hole 25 for the core sand. The groove 24 is narrower toward the bottom of the groove 24. That is, the length of the groove 24 in the Y-axis direction perpendicular to the Z-axis direction increases toward the parting surface 21. That is, the length of the groove 24 in the Y-axis direction increases toward the -X-axis direction. When the parting surface 11 of the movable mold 10 and the parting surface 21 of the fixed mold 20 are brought into contact with each other, it is desirable that the end surface 13 and the end surface 23 are flush with each other. As a result, the opening 26 of the injection hole 25 is formed on a surface including the end surface 13 and the end surface 23. This facilitates the arrangement of an injection mechanism for injecting the core sand.

[0019] When the parting surface 11 of the movable die 10 and the parting surface 21 of the fixed die 20 are brought into contact with each other, the portion of the movable die 10 facing the groove 24 is flush with the parting surface 11 and is on the same plane as the parting surface 11. In other words, no groove that serves as an injection hole is formed in the parting surface 11 of the movable die 10. Therefore, it is possible to prevent the core from sticking to the movable die 10.

[0020] Next, a method for manufacturing a core using the mold apparatus 1 of this embodiment will be described. Figures 4 to 6 are cross-sectional views illustrating steps in the method for manufacturing a core according to embodiment 1. Figure 7 is a top view illustrating an opening 26 of an injection hole 25 of the mold apparatus 1 according to embodiment 1.

[0021] As shown in Fig. 4, first, the movable mold 10 is aligned with the fixed mold 20 so that the parting surface 11 of the movable mold 10 and the parting surface 21 of the fixed mold 20 are in contact with each other. As a result, the recess 22 of the fixed mold 20 becomes a cavity. The groove 24 of the fixed mold 20 becomes an injection hole 25. An opening 26 is formed on a surface including the end surface 13 and the end surface 23.

[0022] 5, an injection mechanism 30 is placed on the end face 13 and the end face 23. The injection mechanism 30 holds core sand 31. The injection mechanism 30 injects the held core sand 31 into the cavity of the mold device 1 through the opening 26 and the injection hole 25.

[0023] As shown in FIG. 7, when viewed from the direction in which the groove 24 extends, i.e., the Z-axis direction, the cross section of the groove 24 and the shape of the opening 26 are trapezoidal. For example, the angle between the bottom side and the side of the trapezoid is 70°. In addition, the bottom side is longer than the top side of the trapezoid. Meanwhile, the shape of the injection port 33 of the injection mechanism 30 is circular. Also, when viewed from the Z-axis direction, the area occupied by the opening 26 is larger than the area occupied by the injection port 33 of the injection mechanism 30, and it is desirable that the injection port 33 is disposed within the opening 26. This allows the core sand 31 to be injected into the cavity without resistance. Also, it is possible to suppress molding defects of the core due to insufficient pressing.

[0024] After the cavity is filled with the core sand 31, the core sand 31 is solidified within the cavity, thereby forming a core.

[0025] 6, the movable die 10 and the fixed die 20 are separated, and the solidified core 32 is taken out. In this manner, the die device 1 can manufacture the core 32.

[0026] Next, before describing the effects of this embodiment, a comparative example will be described. FIG. 8 is a top view illustrating a mold device according to a comparative example. FIG. 9 is a process cross-sectional view illustrating a method for manufacturing a core according to a comparative example. As shown in FIGS. 8 and 9, a mold device 101 of the comparative example includes a movable mold 110 and a fixed mold 120. The movable mold 110 has a groove 114 on a parting surface 111 between an end face 113 and a recess 112. The fixed mold 120 has a groove 124 on a parting surface 121 between an end face 123 and a recess 122. Thus, an injection hole 125 is formed by the groove 114 and the groove 124. A circular opening 126 is formed on the end face 113 and the end face 123, with the parting surfaces 111 and 121 of the movable mold 110 and the fixed mold 120 as centers.

[0027] In the comparative example, as shown in Fig. 9, a defect occurs in which part of core 132 sticks to movable die 110 during demolding. If the stuck part of core 132 is not released, the opening area of ​​opening 126 is reduced to half in the production of the next core 132. This causes operational disruption such as insufficient pressing, resulting in molding defects of core 132 and core sand that is not pressed in remaining on end faces 113 and 123. As described above, in the comparative example, the shape of injection hole 125 is also formed in movable die 110, so demolding resistance occurs and a sticking defect occurs.

[0028] Next, the effects of this embodiment will be described. In the mold apparatus 1 of this embodiment, a groove 24 that serves as an injection hole 25 is formed in the fixed mold 20, and the portion of the movable mold 10 that faces the groove 24 is flush with the parting surface 11. Therefore, when the mold is opened, a holding force that holds the core 32 is generated in the fixed mold 20, so that it is possible to prevent the core 32 from sticking to the movable mold 10. Therefore, by reducing sticking to the movable mold 10, it is possible to reduce sticking defects of the core plan. This makes it possible to prevent operational interruptions in the manufacture of the core 32.

[0029] (Embodiment 2) Next, a mold device according to embodiment 2 will be described. In the mold device of this embodiment, the cross section of the groove perpendicular to the groove extension direction is a shape surrounded by an elliptical arc and a chord. Fig. 10 is a top view illustrating an opening of the mold device according to embodiment 2.

[0030] As shown in Fig. 10, in the mold device 2 of this embodiment, the cross section of the groove 44 formed in the parting surface 41 of the fixed mold 40 has a shape with a curved bottom. For example, the cross section of the groove 44 has a shape surrounded by an elliptical arc and a chord. Even in such a cross section of the groove 44, the width of the groove 44 narrows toward the bottom of the groove 44. Therefore, when the mold is opened, a holding force that holds the core 32 is generated in the fixed mold 40, so that it is possible to prevent the core 32 from sticking to the movable mold 10 side.

[0031] FIG. 11 is a top view illustrating an opening of a mold device according to another example of the second embodiment. As shown in FIG. 11, in the mold device 2a of the other example, the cross section of the groove 54 formed in the parting surface 51 of the fixed mold 50 is trapezoidal. In the trapezoid in the cross section of the groove 14 of the fixed mold 20 described above, the height is greater than the length of the upper side. On the other hand, in the trapezoid in the cross section of the groove 54 of the fixed mold 50, the length of the upper side is greater than the height. Therefore, when viewed from the Z-axis direction, when the circular injection port 33 of the injection mechanism 30 is disposed in the opening 56, the area occupied by the opening 56 is much larger than the area occupied by the injection port 33, and the opening 56 is open on both sides of the injection port 33 in the Y-axis direction. Even in such a cross section of the groove 54, the width of the groove 54 becomes narrower toward the bottom of the groove 54. Therefore, when the mold is opened, a holding force that holds the core 32 is generated toward the fixed mold 50, so that the core 32 can be prevented from sticking to the movable mold 10 side. Furthermore, the core sand 31 can be injected into the cavity without resistance, and defects in molding of the core due to insufficient press-fitting can be suppressed. Other configurations of this embodiment than those described above are the same as those of the first embodiment.

[0032] The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit and scope of the present invention. For example, a combination of the configurations of the first and second embodiments is also included in the scope of the technical idea of ​​the present embodiment. [Explanation of symbols]

[0033] 1, 2, 2a Mold equipment 10 Movable type 11 Parting Surface 12 Recess 13 End face 20, 40, 50 fixed type 21, 41, 51 Parting surface 22 Recess 23 End face 24, 44, 54 grooves 25 Injection hole 26 Aperture 30 Injection mechanism 31 Core sand 32 Core 33 Injection port 101 Mold equipment 110 Movable type 111 Parting surface 112 Recess 113 End face 114 Groove 120 Fixed type 121 Parting Surface 122 Recess 123 End face 124 Groove 125 Injection hole 126 Aperture 132 Core

Claims

1. A die apparatus for manufacturing a core, comprising: A movable mold having a first parting surface; a fixed mold having a second parting surface and a recess formed in the second parting surface, the recess becoming a cavity by bringing the first parting surface into contact with the second parting surface; Equipped with the fixed die has an end face intersecting the second parting face spaced from the recess and a groove serving as an injection hole for core sand on the second parting face between the end face and the recess, The groove is narrower toward the bottom of the groove, In the movable die, a portion facing the groove is flush with the first parting surface. Mold equipment.

2. A cross section of the groove perpendicular to the direction in which the groove extends is trapezoidal. The mold apparatus according to claim 1 .

3. A cross section of the groove perpendicular to the direction in which the groove extends is a shape surrounded by an elliptical arc and a chord. The mold apparatus according to claim 1 .

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