Method for manufacturing resin mold

Abstract

The invention provides a technology capable of manufacturing a resin mold with improved strength. A method for manufacturing a resin mold, which is used when manufacturing a product by plastic working, comprises the steps of: (a) preparing a first molding mold having a first molding chamber therein that follows the outer shape of the resin mold; (b) preparing a structure cast inside the resin mold; (c) arranging a structure in the first molding chamber; (d) injecting a resin into the first molding chamber, and molding a resin mold having a structure therein; and (e) removing the resin mold by dissolving the first molding mold.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a resin mold. Background Technology

[0002] Previously, a technique for manufacturing resin molds was known that reduced the disadvantages of poor durability compared to metal molds (Patent Document 1). In this technique, a layered molded article composed of multiple resin layers is formed by repeatedly irradiating a photocurable resin with ultraviolet light to cure it using a 3D printer. Then, the stepped surfaces are smoothed by covering the stepped surfaces created by the offset of the ends of the multiple resin layers constituting the integral molded article, thereby manufacturing a resin mold with improved strength.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2017-124594 Summary of the Invention

[0004] Depending on the shape of the resin mold, stress may sometimes concentrate in a part of the mold, such as at the corners created by stepped surfaces. When stress is concentrated in a part of the resin mold, even with smooth stepped surfaces, the mold's strength may be insufficient, and there is a possibility of mold breakage.

[0005] The present invention can be implemented in the following ways.

[0006] (1) According to one aspect of the present invention, a method for manufacturing a resin mold is provided. The method comprises the steps of: (a) preparing a first molding die having a first molding chamber having an external shape along the body portion of the resin mold; (b) preparing a structure to be cast inside the resin mold; (c) arranging the structure inside the first molding chamber; (d) injecting resin into the first molding chamber to form the resin mold having the structure inside; and (e) removing the resin mold by dissolving the first molding die. According to this method, a resin mold with increased strength due to the structure can be manufactured. Therefore, the possibility of resin mold breakage can be reduced when manufacturing articles by plastic processing.

[0007] (2) According to the above method, in step (a), the first molding die can be formed by photocuring molding, which cures a photocurable resin by irradiating it with ultraviolet light. According to this method, the first molding die can be easily formed by photocuring molding.

[0008] (3) According to the above method, in step (b), the structure can be formed by injecting a compound material made of metal powder and binder into the second molding chamber of the second molding mold having a second molding chamber along the outer shape of the structure, and then dissolving the second molding mold. According to this method, by making the structure metal, it is possible to manufacture resin molds with further increased strength. Therefore, when manufacturing articles by plastic processing, the possibility of resin mold breakage can be further reduced.

[0009] (4) According to the above method, when manufacturing the article, the resin mold is subjected to external forces from at least two directions, namely a first direction and a second direction intersecting the first direction. The structure is a lattice structure with a periodically repeating lattice structure composed of a first component and a second component intersecting the first component. In step (c), the structure can be arranged in the first molding chamber such that the first component is along the first direction and the second component is along the second direction. According to this method, when manufacturing the article by plastic processing, the structure can be arranged inside the resin mold in an orientation corresponding to the direction of the external force acting on the resin mold. As a result, the overall strength of the resin mold can be improved. Therefore, when manufacturing the article by plastic processing, the possibility of resin mold breakage can be further reduced.

[0010] (5) According to the above method, the following steps may also be included: (f) preparing a reinforcing frame that is installed on at least a portion of the outer peripheral surface of the main body to improve the strength of the resin mold; and (g) installing the reinforcing frame on the outer peripheral surface of the main body. According to this method, it is possible to manufacture a resin mold whose strength is further improved by reinforcing the main body of the resin mold with a structure and a reinforcing frame. Therefore, when manufacturing articles by plastic processing, the possibility of resin mold breakage can be further reduced.

[0011] This invention can be implemented in various ways other than the resin mold manufacturing method described above. For example, it can be implemented by means of a manufacturing apparatus for manufacturing resin molds by the manufacturing method described above, and resin molds manufactured by the manufacturing method described above. Attached Figure Description

[0012] Figure 1 This diagram illustrates an example of a manufacturing method that produces an article through plastic processing.

[0013] Figure 2 This is a diagram showing an example of a resin mold.

[0014] Figure 3 This is a flowchart illustrating the method for manufacturing the resin mold in the first embodiment.

[0015] Figure 4 This is a schematic diagram illustrating the manufacturing method of the resin mold in the first embodiment.

[0016] Figure 5 This is a schematic diagram representing the first molding die.

[0017] Figure 6 This is a flowchart illustrating an example of a method for manufacturing a structure.

[0018] Figure 7 This is a schematic diagram illustrating an example of a method for manufacturing a structure.

[0019] Figure 8 This is a schematic diagram representing the second molding die.

[0020] Figure 9 This is a flowchart illustrating the method for manufacturing the resin mold in the second embodiment.

[0021] Figure 10 This is a schematic diagram illustrating the manufacturing method of the resin mold in the second embodiment. Detailed Implementation

[0022] A. Implementation Method 1:

[0023] Figure 1 This diagram illustrates an example of a manufacturing method that produces an article through plastic processing. Figure 1 The illustration depicts a case where a coil W is manufactured as an article by plastically deforming a coil material WM using multiple processing molds 10 to 30. The first processing mold 10 is a fixed type. For example, the first processing mold 10 is fixed to a base plate. The second processing mold 20 is a movable type that moves towards the first processing mold 10 in a first direction D1. The third processing mold 30 is a movable type that moves towards both the first processing mold 10 and the second processing mold 20 in a second direction D2. Figure 1 In the example shown, during the manufacturing of coil W, firstly, with the coil material WM to be processed placed on the opposing surface 110 of the first processing mold 10, which is opposite to the second processing mold 20, the second processing mold 20 descends along the first direction D1. As a result, the coil material WM is pressed against the opposing surface 110 of the first processing mold 10 and the opposing surface 210 of the second processing mold 20, causing a planar bend along the short side of the cross-section of the coil material WM. Next, the third processing mold 30 moves along the second direction D2, and the protrusion 310 of the third processing mold 30 is inserted between the opposing surface 110 of the first processing mold 10 and the opposing surface 210 of the second processing mold 20. As a result, a lateral bend along the length of the cross-section of the coil material WM occurs, thereby forming the coil W.

[0024] In this case, when the processing molds 10 to 30 are metal molds (hereinafter, metal molds), manufacturing the processing molds 10 to 30 requires cost and lead time. Therefore, for example, by making the first processing mold 10 or the second processing mold 20 a resin mold (hereinafter, resin mold), compared to making the processing molds 10 and 20 metal molds, the cost and lead time required to manufacture the processing molds 10 and 20 can be reduced. However, the strength of resin is sometimes lower than that of metal. Therefore, depending on the shape of the resin mold, when manufacturing an article by plastic processing, the stress generated by the external force applied to the resin mold is concentrated in a part of the resin mold, resulting in insufficient strength of the resin mold and the possibility of resin mold breakage. Therefore, in this embodiment, the resin mold is configured as follows to improve its strength.

[0025] Figure 2 This is a diagram showing an example of a resin mold 40. Figure 2 In this example, the resin mold 40 is illustrated as a first processing mold 10. The resin mold 40 has a structure 50 inside its resin main body 410. The structure 50 is a reinforcing member used to improve the strength of the resin mold 40. In this embodiment, the structure 50 is a metallic lattice structure whose lattice structure is periodically repeated by the first member 510 and a second member 520 intersecting the first member 510.

[0026] Figure 3 This is a flowchart illustrating the manufacturing method of the resin mold 40 in the first embodiment. Figure 4 This is a schematic diagram illustrating the manufacturing method of the resin mold 40 in the first embodiment. Figure 4 The example illustrates a manufacturing method for manufacturing the first processing mold 10, which serves as a resin mold 40.

[0027] In step S1, a process is performed to prepare a first molding die 60 having an internal space that is the shape of a first molding chamber 610 along the main body 410 of the resin mold 40. Figure 5 This is a schematic diagram showing a first molding die 60 having a first molding chamber 610 with an external shape following the first processing die 10. Figure 5 The diagram also illustrates the structure of the first processing mold 10. In this embodiment, the first molding mold 60 is formed using a 3D printer by photocuring, which cures a photocurable resin by irradiating it with ultraviolet light.

[0028] like Figure 3 and Figure 4 As shown, in step S2, the process of preparing the structure 50 to be cast inside the resin mold 40 is performed. Figure 6 This is a flowchart illustrating an example of a manufacturing method for structure 50. Figure 7 This is a schematic diagram illustrating an example of a manufacturing method for structure 50.

[0029] In step S21, a process is performed to prepare a second molding die 70 having an internal space that is an internal space that is an external space along the shape of the structure 50, in the second molding chamber 710. Figure 8 This is a schematic diagram showing a second molding die 70 having a second molding chamber 710 inside, with the shape of the second molding chamber 710 following the outline of the structure 50 in the first embodiment. Figure 8 The diagram also illustrates the structure of structure 50. In this embodiment, the second molding die 70 is formed using a 3D printer via photopolymerization.

[0030] like Figure 6 and Figure 7 As shown, in step S22, a process is performed in which a compound material MM, which is a mixture of metal powder and binder, is injected into the second molding chamber 710 to form a semi-finished product 55 of the structure 50. In step S22, for example, a compound material MM, which is a mixture of powdered metal powder such as stainless steel or tool steel and binder, is injected into the second molding chamber 710 and held for a predetermined time, thereby forming a semi-finished product 55 of the structure 50.

[0031] In step S23, a process is performed to remove the semi-finished product 55 of the structure 50 by dissolving the second molding die 70. The second molding die 70 is dissolved, for example, using a solvent capable of dissolving the photocurable resin constituting the second molding die 70.

[0032] In step S24, a process is performed to manufacture a degreased structure 50 by heating and sintering a semi-finished product 55 of the structure 50. The adhesive is removed from the semi-finished product 55 of the structure 50, for example, during the heating and sintering process.

[0033] like Figure 3 and Figure 4 As shown, in step S3, the process of arranging the structure 50 within the first molding chamber 610 is performed. In step S3, for example, the structure 50 is arranged inside the resin mold 40 with an orientation corresponding to the directions D1 and D2 of the external forces acting on the resin mold 40 during plastic processing. In this embodiment, as... Figure 1 As shown, during the manufacturing of coil W, the first processing mold 10 is subjected to external forces from at least two directions: a first direction D1 and a second direction D2 intersecting the first direction D1. Therefore, as Figure 4 As shown, the structure 50 is arranged in the first molding chamber 610 with the first component 510 along the first direction D1 and the second component 520 along the second direction D2.

[0034] like Figure 3 and Figure 4 As shown, in step S4, a process is performed in which resin RM is injected into the first molding chamber 610 to form a resin mold 40 having a structure 50 inside. In step S4, for example, resin RM having a strength equivalent to polyether ether ketone (PEEK) is injected into the first molding chamber 610 and held for a predetermined time, thereby forming a resin mold 40 with the structure 50 cast from resin RM.

[0035] In step S5, the process of removing the resin mold 40 by dissolving the first molding mold 60 is performed. The first molding mold 60 is dissolved, for example, using a solvent capable of dissolving the photocurable resin constituting the first molding mold 60.

[0036] According to the first embodiment described above, by setting the processing molds 10 and 20 as resin molds 40, compared to setting the processing molds 10 and 20 as metal molds, the manufacturing cost and lead time required for the processing molds 10 and 20 can be reduced. However, as... Figure 2 and Figure 5 As shown, on the opposing surface 110 of the first processing mold 10, there is a stepped surface 150 where the coil material WM is pressed when the third processing mold 30 moves along the second direction D2 and bends the side of the coil material WM. Through this stepped surface 150, there is a corner 155 with a predetermined radius R on the opposing surface 110 of the first processing mold 10. The smaller the radius R of the corner 155, the easier it is for stress to concentrate at the corner 155. Thus, depending on the shape of the resin mold 40, stress may sometimes concentrate on a part of the resin mold 40. In the case of stress concentration on a part of the resin mold 40, when manufacturing products such as coil W by plastic processing, there is a possibility that the resin mold 40 will crack. In contrast, according to the first embodiment described above, it is possible to manufacture a resin mold 40 having a structure 50 inside the resin body part 410. That is, it is possible to manufacture a resin mold 40 whose strength is increased by reinforcing the body part 410 by the structure 50. Therefore, when manufacturing products through plastic processing, the possibility of resin mold 40 cracking can be reduced.

[0037] Furthermore, according to the first embodiment described above, by using a resin mold 40 having a structure 50 inside the main body 410 and manufacturing the product through plastic processing, the possibility of the resin mold 40 breaking can be reduced. Here, when manufacturing the resin mold 40 by repeatedly stacking multiple resin layers using a 3D printer and performing the operation of forming resin layers through photopolymerization, depending on the shape of the structure 50, sometimes the strength of the resin mold 40 cannot be sufficiently increased by the structure 50. For example, when the structure 50 is as follows... Figure 2In the case of the lattice structure shown, when forming the resin layer by photopolymerization, the resin RM sometimes fails to penetrate the cavity portion 530 of the structure 50. In this case, since a gap is generated between the main body portion 410 and the structure 50, it is sometimes impossible to sufficiently increase the strength of the resin mold 40 through the structure 50. Therefore, in the first embodiment described above, as... Figure 4 As shown, instead of using a 3D printer for photopolymerization, the resin mold 40 is manufactured by freeform injection molding (FIM). Specifically, a pre-prepared structure 50 is placed in the first molding chamber 610 of a first molding mold 60 having a first molding chamber 610 that follows the shape of the resin mold 40. After resin RM is injected into the first molding chamber 610 and molded, the resin mold 40 is manufactured by dissolving the first molding mold 60. In this way, the first molding chamber 610 can be filled with resin RM while the structure 50 is placed inside, thus reducing the possibility of gaps forming between the main body 410 and the structure 50. As a result, a resin mold 40 with increased strength due to the structure 50 can be manufactured.

[0038] Furthermore, according to the first embodiment described above, the first molding die 60 and the second molding die 70 can be easily formed using a 3D printer via photopolymerization. This further reduces the lead time required for manufacturing the molds 10 and 20. Additionally, the first molding die 60 and the second molding die 70 can also be formed using methods other than photopolymerization.

[0039] Furthermore, according to the first embodiment described above, such as Figure 7 As shown, a metal structure 50 can be formed by combining Metal Injection Molding (MIM) and FIM. Specifically, after injecting a compound material MM, which is a mixture of metal powder and binder, into the second molding chamber 710 of the second molding die 70 having a second molding chamber 710 along the shape of the structure 50, and molding it, the metal structure 50 can be formed by dissolving the second molding die 70. Thus, as... Figure 4 As shown, a resin mold 40 with a metal structure 50 inside can be manufactured. That is, a resin mold 40 with increased strength can be manufactured by making the structure 50 metal. Therefore, the possibility of the resin mold 40 breaking can be further reduced when manufacturing articles by plastic processing. In addition, the structure 50 can also be a structure other than metal. Furthermore, the structure 50 can also be formed by methods other than the above-described method of combining MIM and FIM.

[0040] Furthermore, according to the first embodiment described above, such as Figure 2 and Figure 4 As shown, when manufacturing an article by plastic processing, the structure 50, which is a lattice structure, can be arranged inside the resin mold 40 with an orientation corresponding to the directions D1 and D2 of the external forces acting on the resin mold 40. This improves the overall strength of the resin mold 40. Therefore, the possibility of the resin mold 40 breaking can be further reduced when manufacturing an article by plastic processing. Furthermore, the arrangement of the structure 50 is not limited to the above. The arrangement of the structure 50 can be appropriately determined, for example, based on the shape of the structure 50 or the directions D1 and D2 of the external forces acting on the resin mold 40.

[0041] B. Second Implementation Method:

[0042] Figure 9 This is a flowchart illustrating the manufacturing method of the resin mold 40a in the second embodiment. Figure 10 This is a schematic diagram illustrating the manufacturing method of the resin mold 40a in the second embodiment. Figure 10 The example illustrates a manufacturing method for manufacturing the first processing mold 10, which serves as the resin mold 40a. In this embodiment, after step S5, steps S6 and S7 are performed sequentially. Each step from S1 to S5 is similar to... Figure 3 The first embodiment shown is the same.

[0043] In step S6, a process is performed to prepare a reinforcing frame 90 that is mounted on at least a portion of the outer peripheral surface 410a of the main body 410 to increase the strength of the resin mold 40a. In this embodiment, the reinforcing frame 90 is formed using a 3D printer by photopolymerization.

[0044] In step S7, the process of installing the reinforcing frame 90 onto the outer peripheral surface 410a of the main body 410 is performed. The reinforcing frame 90 can be installed by fixing it to the main body 410 with adhesive, or by using a snap-fit ​​mechanism or a fixing component such as screws.

[0045] According to the second embodiment described above, it is possible to manufacture a resin mold 40a in which a reinforcing frame 90 is mounted on the outer peripheral surface 410a of the main body 410 of the resin mold 40. Therefore, it is possible to manufacture a resin mold 40a whose strength is further increased by reinforcing the main body 410 with the structure 50 and the reinforcing frame 90. Thus, the possibility of the resin mold 40a breaking can be further reduced when manufacturing articles by plastic processing. Furthermore, the shape of the reinforcing frame 90 or the method of mounting it to the main body 410 is not limited to the above.

[0046] Furthermore, according to the second embodiment described above, the reinforcing frame 90 can be easily formed using a 3D printer via photopolymerization. Therefore, even when the reinforcing frame 90 is mounted on the main body 410 of the resin mold 40a, the increase in lead time required for manufacturing the processing molds 10 and 20 can be suppressed. Additionally, the reinforcing frame 90 can also be formed using methods other than photopolymerization.

[0047] C. Other implementation methods:

[0048] Structure 50 can be, in addition to Figure 2 The structure 50 is a structure other than a lattice structure. For example, the structure 50 can be a truss structure or a honeycomb structure. When the structure 50 has an internal cavity 530, as in a lattice structure, truss structure, or honeycomb structure, and the structure 50 is disposed within the first molding chamber 610 and resin RM is injected, it is preferably shaped and arranged such that the resin RM flows into the cavity 530. That is, when the structure 50 is disposed within the first molding chamber 610 and resin RM is injected, it is preferably shaped and arranged such that the cavity 530 does not become an isolated island where resin RM does not flow. However, it is not necessary for the structure 50 to have a cavity 530.

[0049] This invention is not limited to the embodiments described above, and can be implemented in various configurations without departing from its spirit. For example, in order to address some or all of the above-described issues, or to achieve some or all of the above-described effects, the technical features of the embodiments corresponding to the technical features in the various forms described in the summary section of the invention can be appropriately replaced or combined. Furthermore, if a technical feature is not required to be described in this specification, it can be appropriately deleted.

[0050] Symbol Explanation

[0051] 10 - First processing mold, 20 - Second processing mold, 30 - Third processing mold, 40, 40a - Resin mold, 50 - Structure, 55 - Semi-finished product, 60 - First molding mold, 70 - Second molding mold, 90 - Reinforcing frame, 110 - Opposite surface of the first processing mold, 150 - Stepped surface, 155 - Corner, 210 - Opposite surface of the second processing mold, 310 - Protrusion, 410 - Main body, 410a - Outer peripheral surface, 510 - First component, 520 - Second component, 530 - Cavity, 610 - First molding chamber, 710 - Second molding chamber, D1 - First direction, D2 - Second direction, MM - Mixed material, R - Radius, RM - Resin, W - Coil, WM - Coil material.

Claims

1. A method for manufacturing a resin mold, the resin mold being used in manufacturing articles by plastic processing, the method for manufacturing the resin mold being characterized by comprising the following steps: (a) A first molding mold having a first molding chamber having an external shape along the body portion of the resin mold inside; (b) A structure to be cast inside the resin mold; (c) The structure is arranged in the first molding chamber; (d) Injecting resin into the first molding chamber to form the resin mold having the structure therein; and (e) The resin mold is removed by dissolving the first molding mold.

2. The method for manufacturing a resin mold according to claim 1, characterized in that, In step (a), the first molding die is formed by photocuring the photocurable resin by irradiating it with ultraviolet light.

3. The method for manufacturing a resin mold according to claim 1, characterized in that, In step (b), the structure is formed as follows: After molding by injecting a compound material made of metal powder and binder into the second molding chamber of the second molding mold, which has a second molding chamber that follows the shape of the structure, the second molding mold is dissolved.

4. The method for manufacturing a resin mold according to claim 1, characterized in that, During the manufacture of the article, the resin mold is subjected to external forces from at least two directions, namely a first direction and a second direction intersecting the first direction. The structure is a periodically repeating lattice structure composed of a first component and a second component that intersects with the first component. In the process (c), the structure is arranged in the first molding chamber such that the first component is along the first direction and the second component is along the second direction.

5. The method for manufacturing a resin mold according to claim 1, characterized in that, It also has the following processes: (f) Preparing a reinforcing frame for mounting on at least a portion of the outer peripheral surface of the main body to improve the strength of the resin mold; and (g) The reinforcing frame is installed on the outer peripheral surface of the main body.

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