Stacked mold for injection molding, and cassette mold system

Abstract

To provide a stacked mold for injection molding and a cassette mold system capable of allowing change of the stacking order of metal thin-plates and allowing partial exchange with another metal thin-plate even after the stacked mold has once been assembled, and relatively easy in laser processing.SOLUTION: A stacked mold 100 for injection molding configured by stacking a plurality of metal thin-plates 10 with a plate thickness of a prescribed value has clamping means 130 and 131 for clamping the stacked metal thin-plates 10 in a stacking direction while they can be disassembled. Peripheral molding surfaces 111 and 121 of the metal thin-plate 10 having the peripheral molding surfaces 111 and 121 for molding peripheral surfaces 510 and 520 of a molded article 500 have no daft angles.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a laminate mold and cassette mold system for injection molding. [Background technology]

[0002] In recent years, there has been an increasing demand for a wide variety of products in small quantities, and this has led to strong demand for cost reduction and delivery time reduction in mold manufacturing. Conventional molds are manufactured by cutting casts or steel blocks, which takes time to manufacture casts and costs a lot of time and money to machine steel blocks. In response to this demand, the idea of ​​a laminated mold has emerged. This is a method of forming a three-dimensional mold by laminating thin plates of different shapes. For example, the mold shape is created by laminating thin metal plates that have been precisely cut by laser processing (see, for example, Patent Document 1).

[0003] By the way, there are injection molding and compression molding methods for resin molding using molds, but the majority of conventional laminated molds are suitable for injection molding, and many of them are designed to easily install cooling channels to improve the cooling function of the mold. For this reason, joining of the laminated parts and subsequent machining are required. Compression molding is the oldest method of plastic molding, and is a typical molding method for thermosetting resins in particular. This molding method is also used for biomass powder materials. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-082096 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-mentioned conventional techniques, if a fluid is to be circulated in the lamination die to adjust the molding temperature of the die, the lamination dies must be integrated by adhesion or welding to prevent leakage of the fluid. Therefore, once the lamination die is assembled, the order of lamination of the metal sheets cannot be changed, and it is not possible to partially replace them with other metal sheets. In addition, the draft angle is given to each sheet to be laminated, and processing cannot be easily performed by laser.

[0006] Therefore, an object of the present invention is to provide a laminated mold and cassette mold system for injection molding that allows the order of stacking of metal sheets to be changed or partially replaced with other metal sheets even after the laminated mold has been assembled, and that is relatively easy to laser process. [Means for solving the problem]

[0007] One aspect of the present invention is a laminated die for injection molding, which is configured by laminating a plurality of thin metal plates each having a predetermined plate thickness T, a fastening means for fastening the stacked metal sheets in a stacking direction in a disassemblable state; This is a laminated mold in which no draft angle is provided on the forming peripheral surface of the metal sheet having a forming peripheral surface that forms the outer or inner surface of the molded product.

[0008] Unlike conventional lamination dies that had to be integrated by gluing or welding, in the lamination die of this embodiment, the laminated metal sheets are clamped in the lamination direction in a disassembled state, so that even after the lamination die is assembled, it is possible to change the lamination order of the metal sheets or to partially replace them with other metal sheets. In addition, since no draft is provided on the shaping peripheral surface of the laminated metal sheets, the metal sheets can be processed relatively easily by two-dimensional laser processing.

[0009] In the above-described stacking mold, at least a portion of the metal sheets may be formed into a different shape so that a step is formed in which the molding peripheral surface of each adjacent metal sheet successively widens or narrows in the stacking direction.

[0010] In the laminated mold as described above, the sheet thickness T in the lamination direction of the thin metal plate having the shaping peripheral surface may be 1 mm to 3 mm.

[0011] In the above-mentioned lamination mold, bolts may be used as the fastening means.

[0012] The laminated mold as described above may be composed of a cavity for forming the outer peripheral surface of the molded product, and a core for forming the inner peripheral surface of the molded product.

[0013] The lamination mold as described above may be provided with ejection pins to eject the molded article and release it from the lamination mold.

[0014] The lamination mold as described above may be provided with an insertion portion for inserting an ejection pin therethrough.

[0015] In the laminated mold as described above, the core may be provided with an insertion portion.

[0016] The laminated mold as described above may be provided with a recess-forming protrusion for forming a portion including a recess in a part of the molded product.

[0017] In the laminated mold as described above, the portion including the recess may be a boss rib.

[0018] In the laminated mold as described above, the recess-forming convex portion may be a core pin which is a separate member from the thin metal plate.

[0019] In the laminated mold as described above, the core pin may be a straight core pin having a constant outer diameter.

[0020] In the laminated mold as described above, the core pin may include a tapered portion whose outer diameter changes.

[0021] One aspect of the present invention is a cassette mold system including a laminated mold as described above, a mold jig in which the laminated mold is mounted at a predetermined position, and a cassette mold in which the mold jig is mounted at a predetermined position.

[0022] In the cassette mold system as described above, a filling passage for molding material may be provided in a state in which the stack mold, the mold jig, and the cassette mold are in communication with each other. Effect of the Invention

[0023] According to the present invention, it is possible to provide a laminated mold and cassette mold system for injection molding, which allows the order of lamination of metal sheets to be changed or partially replaced with other metal sheets even after the laminated mold has been assembled, and which is relatively easy to laser process. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is an exploded perspective view showing an example of the configuration of a cassette mold system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view of a cassette mold system. [Diagram 3] FIG. 1 is a diagram illustrating an example of the configuration of a cassette mold system. [Figure 4] FIG. 2 is a diagram showing a laminated mold and a resin molded product after injection molding. [Diagram 5] 1A to 1C are diagrams illustrating an example of a procedure for releasing a resin molded product from a laminated mold. [Figure 6] 1A is a perspective view showing an example of a boss rib of a resin molded product, and FIG. 1B is a partial cross-sectional view. [Figure 7] FIG. 13 is an enlarged view of a part of a laminated die using a straight core pin as an example of a protrusion for forming a recess. [Figure 8]FIG. 1A is a diagram showing an example of a metal sheet having steps formed so that the forming peripheral surface of each adjacent metal sheet successively widens or narrows along the stacking direction, and FIG. 1B is a diagram showing another example. [Figure 9] FIG. 1A is a diagram showing an outline of a molded product made by a laminate mold according to one embodiment of the present invention, and FIG. 1B is a diagram showing an outline of a molded product made by a conventional mold having a draft angle on the molding surface. [Figure 10] FIG. 1 is a reference diagram showing a conventional mold and a resin molded product after injection molding. [Figure 11] 1A to 1C are reference diagrams for explaining an example of a procedure for releasing a resin molded product from a conventional mold. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, preferred embodiments of a laminate mold and a cassette mold system for injection molding according to the present invention will be described in detail with reference to the drawings (see FIG. 1, etc.).

[0026] The cassette mold system 1 in this embodiment is a system including a stacking mold 100, a nest (mold jig) 200, and a cassette mold 300, and is configured to perform injection molding after setting the stacking mold 100 at a predetermined position on the nest 200 and attaching the nest 200 to a predetermined position on the cassette mold 300 (see Figs. 1, 2, etc.). Below, the stacking mold 100 and the metal sheet 10 that constitutes it will first be described, followed by the nest 200 and the cassette mold 300.

[0027] [Laminated molds and thin metal sheets] The laminated mold 100 is a mold formed by laminating thin metal sheets 10 (see FIG. 3, etc.). The laminated mold 100 of this embodiment is composed of a cavity 110 having a recess for forming an outer peripheral surface (side surface) 510 of a molded product 500, and a core 120 having a protrusion for forming an inner peripheral surface 520 of the molded product. A molding space 600 for injection molding is formed between the cavity 110 and the core 120 (see FIG. 4, etc.). A portion of the cavity 110 constituting the inner peripheral surface (referred to as a "molding peripheral surface" in this specification and indicated by reference numeral 111) forms the outer peripheral surface 510 of the molded product 500 (see FIG. 5, etc.). A portion of the core 120 constituting the outer peripheral surface (also referred to as a "molding peripheral surface" in this specification and indicated by reference numeral 121) forms the inner peripheral surface 520 of the molded product 500 (see FIG. 5, etc.).

[0028] The metal sheets 10 are formed to form the above-mentioned cavity 110 or core 120 when stacked (see FIG. 5, etc.). In this embodiment, the metal sheets 10 are formed in slightly different shapes so that the forming peripheral surfaces 111, 121 of the adjacent metal sheets 10 are stepped so that they are successively expanded or narrowed along the stacking direction (see FIG. 5, etc.). However, in this embodiment, the forming peripheral surfaces 111, 121 formed by stacking the metal sheets 10 are not provided with a draft. In other words, the inner and outer peripheral surfaces of the metal sheets 10 that form the forming peripheral surfaces 111, 121 are not provided with a slope (see FIG. 5, etc.). In this case, the molded product is easier to release from the mold than when a mold has a draft, but the cutting process for forming the metal sheets 10 into a predetermined shape can be performed relatively easily by two-dimensional laser processing. That is, if a draft gradient is provided in the lamination die, a gradient must be provided for each laminated thin plate, which requires time and effort for processing, but the lamination die 100 of this embodiment eliminates such time and effort, making processing easier. It is of course possible to two-dimensionally process the thin metal plate 10 by means other than laser processing, such as water jet processing or general drill cutting, but for example, if the thin metal plate 10 is laser processed based on predetermined data such as CAD data, it is possible to process with high precision in a short time.

[0029] The laminated thin metal sheets 10 are fastened in the stacking direction in a disassembled state by fastening means. In this embodiment, the cavity 110 and the core 120 formed by stacking the thin metal sheets 10 are fastened in the stacking direction by fastening means consisting of bolts 130 and necessary nuts 131 (see FIG. 5). Unlike a conventional lamination die (see FIG. 10 and FIG. 11; some members are indicated by symbols with a prime (') in FIG. 10 and the like) in which the thin metal sheets constituting the lamination die had to be integrated with each other by adhesion or welding, in the lamination die 100 of this embodiment as described above, the laminated thin metal sheets 10 are fastened in the stacking direction in a disassembled state, so that even after the lamination die 100 is assembled, it is possible to change the order of stacking the thin metal sheets 10 or partially replace them with other thin metal sheets 10. It should be noted that the bolts 130 and nuts 131 are merely preferred examples of fastening means, and any other fastening means can be used as long as it can fasten the stacked thin metal plates 10 in the stacking direction while allowing them to be disassembled.

[0030] If the metal sheets 10 to be laminated have the same thickness T, it is preferable that all the metal sheets 10 can be easily laser-processed based on predetermined data, and that the same material can be processed into metal sheets 10 of different shapes. However, this is merely a preferable example, and it is not necessary that all the metal sheets 10 have the same thickness T. As an example, in this embodiment, the metal sheets 10 having the forming peripheral surfaces 111 and 121 have the same thickness T in principle, and the other metal sheets (specifically, the metal sheets to be formed in contact with the top surface, bottom surface, edge portion, etc. of the formed product 500, and are indicated by the symbols 10a, 10b, and 10c in the figure) are the metal sheets 10a and 10c having a thicker thickness than the metal sheets 10a and 10c, or the metal sheets 10b having a thinner thickness than the metal sheets 10a and 10c (see FIG. 5, etc.).

[0031] The metal sheet 10 having the molding peripheral surfaces 111, 121 may have a thin plate thickness T within a predetermined range, for example, a plate thickness T of about 1 mm to 3 mm. As described above, in this embodiment, no draft is provided on the molding peripheral surfaces 111, 121 of the metal sheet 10. However, when releasing the molded product 500, the molded product 500 can be easily removed from the laminated mold 100 by shifting the molded product 500 in the lamination direction from the cavity 110 or the core 120 by the amount of the thin plate thickness T (see FIG. 5).

[0032] The laminated mold 100 is provided with an ejection pin 140 that ejects the molded product 500 and releases it from the laminated mold 100 (see FIG. 3, etc.). The laminated mold 100 is also provided with a through hole (insertion portion) 122 for inserting the ejection pin 140. In the laminated mold 100 of this embodiment, a plurality of through holes 122 are provided in the core 120 of the laminated mold 100 (see FIG. 4 and FIG. 5). When releasing the molded product 500 from the laminated mold 100, first, the cavity 110 and the core 120 are separated along the lamination direction to remove the molded product 500 from the cavity 110, and then the ejection pin 140 is ejected and the molded product 500 is removed from the core 120 (see FIG. 5). If the diameter of the through hole 122 is 0.2 mm larger than the diameter of the ejection pin 140, the ejection pin 140 can be ejected more smoothly. Conversely, if the difference is less than 0.2 mm, the ejector pin 140 may get caught on the thin metal sheet 10b, causing deformation of the thin metal sheet 10b, and if the difference is too large, the resin of the molding material may get into the gap, causing burrs.

[0033] In addition, when a portion including a recess (for example, boss rib 530) is molded in a part of the molded product 500 (see FIG. 6), a recess forming convex portion is provided on the laminated die 100, and the recess forming convex portion can be used to mold the portion including the recess. For example, in this embodiment, a core pin 400, which is a separate member from the thin metal plate 10, is used as a recess forming convex portion, so that a portion including a recess such as the boss rib 530 can be molded (see FIG. 7). A through hole (recess) 160 is provided in the portion of the thin metal plate 10 where the core pin 400 is provided so that a part of the core pin 400 can be accommodated therein. The core pin 400 may be a straight core pin with a constant outer diameter, or may be one including a tapered portion 402 with a variable outer diameter (see FIG. 7).

[0034] The lamination die 100 is provided with a filling passage 150 for the molding material. In this embodiment, through holes are provided in parts of the metal sheets 10, and when these metal sheets 10 are laminated, the through holes are connected to each other to form the filling passage 150 (see FIG. 3).

[0035] [Nested] The insert (mold jig) 200 is a mold jig to which the stacking mold 100 is attached at a predetermined position (see Figs. 1 to 3). The insert 200 in the cassette mold system 1 of this embodiment is composed of an upper mold 210 and a lower mold 220 that can be separated in the stacking direction of the metal sheet 10 (see Fig. 1, etc.). For example, the upper mold 210 of the insert 200 has a filling passage 250 for the molding material formed so as to communicate with the filling passage 150 of the stacking mold 100 (see Fig. 3). Even if the metal sheet 10 is rearranged, the same insert 200 can be used as long as the external shape of the stacking mold 100 is the same or similar.

[0036] [Cassette mold] The cassette mold 300 is a mold in which the insert 200 is attached at a predetermined position (see Figs. 1 to 3). In the cassette mold 300, a filling passage 350 for molding material is formed so as to communicate with the filling passage 250 of the insert 200 (see Fig. 3). Although not particularly shown, a cooling device is provided in the cassette mold 300 or the insert 200 of this embodiment, and the stacking mold 100 can be indirectly cooled using the cooling device. Therefore, in the cassette mold system 1 of this embodiment, it is not necessary to provide the stacking mold 100 with a fluid flow path for adjusting the molding temperature.

[0037] [Injection device] An injection device (not shown) is provided in the cassette mold system 1. The injection device injects molding material into the molding space 600 through the filling path 350 of the cassette mold 300, the filling path 250 of the insert 200, and the filling path 150 of the laminate mold 100.

[0038] In the laminated mold 100 of this embodiment and the cassette mold system 1 equipped with it as described above, although there is no draft angle as in conventional molds (see Figures 10 and 11), by forming a low step equivalent to the thickness T (e.g., 1 mm to 3 mm) of the metal sheet in the portion that forms the peripheral surface of the molded product 500, a structure is realized in which the molded product 500 can be released from the mold by pushing out the molded product 500 by the amount of thickness T (see Figures 8 and 9).

[0039] The above-described embodiment is one example of a preferred embodiment of the present invention, but the present invention is not limited to this embodiment and can be modified in various ways without departing from the gist of the present invention. [Industrial Applicability]

[0040] The present invention is suitable for application to a laminate mold for injection molding and a cassette mold system including the same. [Explanation of symbols]

[0041] 1…Cassette mold system 10…Thin metal plate 10a, 10b, 10c...Metal sheets in contact with the top and bottom surfaces of the molded product 100...Laminated mold 110…Cavity 111...molded peripheral surface 120…Core 121…molded peripheral surface 122...Through hole (insertion part) 130...Bolt (fastening means) 131...Nut (fastening means) 140…Ejector pin 150...Molding material filling passage 160...Through hole that fits part of the core pin 200…Insert (mold jig) 210...Upper mold 220…lower mold 250…Molding material filling passage 300…Cassette mold 350…Molding material filling passage 400...Core pin (convex part for forming concave part) 402…Tapered section 500…molded product 510...Outer surface of molded product 520…Inner surface of molded product 530...Boss rib (including recess) 600…Molding space T: Thickness of thin metal plate

Claims

1. A laminated die for injection molding, which is configured by laminating a plurality of thin metal plates each having a predetermined plate thickness T, a fastening means for fastening the stacked thin metal plates in a stacking direction in a disassemblable state, A laminated mold, in which the metal sheet has a molding peripheral surface that forms the outer or inner surface of a molded product, and the molding peripheral surface does not have a draft angle.

2. 2. The laminated mold according to claim 1, wherein at least a portion of the metal sheets are formed into different shapes so that the forming peripheral surface of each of the adjacent metal sheets has a step that gradually widens or narrows along the stacking direction.

3. The laminated mold according to claim 1, wherein the sheet thickness T in the lamination direction of the thin metal plate having the molding peripheral surface is 1 mm to 3 mm.

4. 2. The laminated mold according to claim 1, wherein the fastening means is a bolt.

5. The laminated mold according to claim 1 , comprising a cavity for forming an outer peripheral surface of the molded product, and a core for forming an inner peripheral surface of the molded product.

6. The laminate mold according to claim 5 , further comprising an ejector pin for ejecting the molded product and releasing it from the laminate mold.

7. The laminated mold according to claim 6 , further comprising an insertion portion for inserting the ejection pin therethrough.

8. The laminated mold according to claim 7 , wherein the core is provided with the insertion portion.

9. The laminated mold according to claim 1 , further comprising a recess-forming protrusion for forming a portion including a recess in a part of the molded product.

10. The laminated mold according to claim 9 , wherein the portion including the recess is a boss rib.

11. The laminated die according to claim 9 , wherein the recess-forming protrusion is a core pin that is a separate member from the thin metal plate.

12. The laminated mold according to claim 11 , wherein the core pin is a straight core pin having a constant outer diameter.

13. The laminate mold according to claim 11 , wherein the core pin includes a tapered portion whose outer diameter changes.

14. A laminate mold according to any one of claims 1 to 13, a die jig on which the laminated die is attached at a predetermined position; a cassette mold in which the mold jig is attached at a predetermined position; A cassette mold system.

15. The cassette mold system according to claim 14 , wherein a filling passage for molding material is provided in a state in which the stack mold, the mold jig, and the cassette mold are in communication with each other.

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