Laminated mold and its clamping machine

Abstract

To enable stable molding while realizing sufficient degassing and fluidity when molding a molding material such as a resin, especially a biomass powder material.SOLUTION: A lamination mold 1 for compression molding has a split mold structure that can be divided in a direction different from a lamination direction Z, being constructed by laminating a plurality of metallic thin sheets 20 in a decomposable state, and compression-molds a molding material under pressure from a pressure pin in the lamination direction Z. The lamination mold 1 may have an insertion part through which a positioning pin 30 is inserted.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a laminate mold and a mold clamping device thereof. [Background technology]

[0002] In recent years, there has been an increasing demand for high-mix, low-volume products, which has led to a strong demand for reduced costs and shorter delivery times related to mold manufacturing. Conventional molds are typically produced by cutting cast metal or steel blocks. However, in the case of cast metal, the production of the casting requires time, and in the case of cutting steel blocks, the processing is time-consuming and costly. In response to these demands, the concept of laminated molds has emerged. This involves forming a three-dimensional mold by stacking thin plates of different shapes. For example, mold shapes are created by stacking metal plates that have been precisely cut by laser processing (see, for example, Patent Document 1).

[0003] While there are various resin molding methods using molds, such as injection molding and compression molding, the majority of conventional laminate molds are designed for injection molding, and many are designed to easily incorporate cooling channels to improve the mold's cooling function. This requires joining of the laminated parts and subsequent machining. Compression molding is the oldest plastic molding method, 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] Japanese Patent Application Laid-Open No. 2006-069084 Summary of the Invention [Problem to be solved by the invention]

[0005] In both injection and compression molding, the gas generation and material flow characteristics during molding are important issues to consider when using resin molding. Gas management is particularly important. For example, thermosetting resins are divided into two types: condensation polymerization and addition polymerization, depending on the reaction state during curing. Condensation polymerization resins generate volatile components such as water, ammonia, phenol, and formalin when heated and with the addition of reaction accelerators. Addition polymerization resins generate almost no volatile components because the resins react directly with each other to form larger molecules. However, air and moisture present in the gaps between the materials exist as gas, resulting in gas generation, just like condensation polymerization resins. This is also true when molding biomass powder materials, such as those mentioned above. For example, when using powder materials containing lacquer, the volatile components of the lacquer, the moisture contained in the wood powder material, and the air present in the gaps exist as gas, making adequate degassing a challenge. Furthermore, powder materials containing lacquer have poor material flow characteristics, which can significantly affect molding conditions, making stable molding difficult using conventional molds.

[0006] Therefore, the present invention aims to provide a laminated mold and a mold clamping machine thereof that are structured to enable stable molding while achieving sufficient degassing and fluidity when molding molding materials such as resins, particularly biomass powder materials. [Means for solving the problem]

[0007] One aspect of the present invention is a laminated mold for compression molding, which has a split mold structure that can be separated in a direction different from the stacking direction and is constructed by stacking multiple metal thin plates in a disassembled state, and which compression molds a molding material by applying pressure from a pressure pin in the stacking direction.

[0008] With the above-described laminated mold, gas is vented between the stacked metal sheets (in other words, gas venting occurs throughout the entire mold), making it easier to achieve sufficient gas venting during the compression molding process (see Figure 20). Furthermore, the fact that sufficient gas venting is achieved with the laminated mold leads to improved fluidity and moldability of the material due to the liquid leakage effect. This is particularly noticeable when molding biomass powder materials, and contributes to the stable molding of such powder materials.

[0009] In the above-described laminated mold, the thin metal plates may be processed by laser cutting.

[0010] The above-described lamination mold may have an insertion portion for inserting a positioning pin.

[0011] In the laminated mold as described above, the thin metal plate may be provided with a chamfered portion inclined with respect to the molded product in a portion that forms the undercut portion of the molded product or a portion adjacent to the undercut.

[0012] In the above-described laminate mold, the cross section of the undercut may have a polygonal shape.

[0013] In the laminate mold as described above, the chamfered portion may be composed of a plurality of curved surfaces provided at equal intervals in the circumferential direction.

[0014] In the above-described stacking mold, after the stacked metal sheets are disassembled, the positions in the stacking direction of the metal sheets for forming the undercut and the metal sheets provided with the chamfered portions may be changeable.

[0015] In the laminated mold as described above, the joining surfaces of the split molds may be non-flat.

[0016] In the above-described stacking mold, the joining surface may be formed in a non-linear shape when viewed in a plan view along the stacking direction.

[0017] Another aspect of the present invention is a mold clamping machine for clamping the above-described laminate mold, an upper plate and a lower plate that sandwich the lamination mold; a clamping means for applying a clamping pressure to the upper plate and the lower plate; This is a mold clamping machine equipped with the above.

[0018] The above-described mold clamping device may further include side panels for holding down both sides of the laminate mold in the split mold direction.

[0019] In the above-described mold clamping device, an upper engaging portion that engages with the upper engaged portion of the side panel may be formed on the upper plate, and a lower engaging portion that engages with the lower engaged portion of the side panel may be formed on the lower plate.

[0020] In the above-described mold clamping machine, at least one of the upper engaging portion and the upper engaging portion, and at least one of the lower engaging portion and the lower engaging portion, may have an inclined portion formed thereon that generates a component force of the mold clamping pressure and applies a force toward the stacking mold to the side panel.

[0021] The above-described mold clamping device may further include a core that makes a part of the molded product have a concave shape.

[0022] In the above-described mold clamping machine, a pressure through hole through which a pressure pin of a compression molding device can be inserted may be provided in the upper plate. [Effects of the Invention]

[0023] According to the present invention, it is possible to provide a laminated mold and a mold clamping machine thereof that are structured to enable stable molding while achieving sufficient degassing and fluidity when molding molding materials such as resins, particularly biomass powder materials. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 2 is a plan view showing an example of a metal thin plate constituting a laminate mold in one embodiment of the present invention. [Figure 2] FIG. 2 is a view showing a cross section of the metal thin plate taken along line II-II in FIG. [Figure 3] 2 is an enlarged view of a part (encircled part) of the thin metal plate shown in FIG. 1. FIG. [Figure 4] FIG. 1 shows (A) a metal sheet that has not been modified in shape, and (B) a metal sheet that has been modified in shape by providing a chamfered portion inclined with respect to the central axis of the molded product in the portion that forms the undercut portion of the molded product or the portion adjacent to the undercut. [Figure 5] FIG. 10 is a perspective view showing a state in which a metal sheet that has not been subjected to shape modification and a metal sheet that has been subjected to shape modification are arranged one above the other. [Figure 6] 6 is a perspective view showing a state in which the thin metal plates shown in FIG. 5 are stacked one on top of the other. FIG. [Figure 7] FIG. 1 is a perspective view showing an example of a laminated mold formed by stacking a predetermined number of thin metal plates. [Figure 8] FIG. 1 is a front view showing an example of a laminated mold formed by stacking a predetermined number of thin metal plates. [Figure 9] FIG. 2 is a perspective view showing the mold clamping machine in a state before the laminated mold is inserted. [Figure 10] FIG. 10 is a perspective view showing the mold clamping machine in a state after inserting a laminate mold and clamping the mold. [Figure 11] FIG. 10 is a plan view showing the mold clamping machine in a state after inserting a laminate mold and clamping the mold. [Figure 12] FIG. 10 is a side view showing the mold clamping machine in a state after inserting a laminate mold and clamping the mold. [Figure 13] 13 is a cross-sectional view of a mold clamping device and the like taken along line XIII-XIII in FIG. 11. [Figure 14] 10A to 10C are images of a sake cup as an example of a molded product, with undercuts at different positions. [Figure 15] FIG. 1 is a plan view showing an example of a sake cup as a molded product. [Figure 16] FIG. 1 is a front view showing an example of a sake cup as a molded product. [Figure 17] 17 is a diagram showing a cross-sectional shape of the sake cup taken along line XVII-XVII in FIG. 16. FIG. [Figure 18] 18 is a diagram showing a cross section of the sake cup taken along line XVIII-XVIII in FIG. 15. [Figure 19] (A) is an image showing a molded product with a chip in part of the undercut, and (B) is an image showing a molded product without any chip in the undercut, which was molded using a shape-modified metal sheet. [Figure 20] (A) A schematic cross-sectional view of a lamination mold in one embodiment of the present invention, showing how gas is released from between the stacked metal sheets, and (B) a cross-sectional view of a conventional lamination mold, showing how gas is released only from between the core and the mold. [Figure 21] FIG. 1 is a diagram showing the configuration of an experimental device for verifying how the amount of gas leakage during compression molding changes when the thickness t of the metal thin plates and the number of layers are changed. [Figure 22] 1 is a graph showing the results of an experiment conducted to verify how the amount of gas leakage during compression molding changes when the thickness t of the metal thin plate and the number of layers are changed. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, preferred embodiments of a laminated mold and its clamping device according to the present invention will be described in detail with reference to the drawings (see FIG. 1, etc.).

[0026] In this embodiment, a plurality of metal sheets 20 for compression molding are prepared, stacked and assembled in a predetermined order to form a stacking mold 10 having a split mold structure, and then this stacking mold 10 is fixed to a clamping machine 100 to perform compression molding. Below, we will first explain the stacking mold, then explain the clamping machine 100, and then explain compression molding performed using this and the molded product thereby formed.

[0027] [Lamination mold] The stacking mold 10 of this embodiment is a mold that compresses and molds a molding material such as resin by receiving pressure in the stacking direction (indicated by the symbol Z in the drawing) from a plunger 220 while being fixed by a mold clamping device 100. In this embodiment, a stacking mold 10 is used that has a split mold structure that can be separated in a direction different from the stacking direction and is configured by stacking a plurality of thin metal plates in a disassemblable state (see FIGS. 7, 13, etc.).

[0028] The thin metal sheets 20 are made of plate material that is provided so that a plurality of them are stacked to form a laminated mold 10 (see Figures 1, 7, etc.). The shape of the thin metal sheets 20 is not particularly limited, but in this embodiment, thin sheets that are approximately square in plan view are used. A molding surface 21 that functions as a mold for shaping the outer peripheral surface of the molded product is provided in the center of the thin metal sheets 20. A cavity 12 that serves as a gap for compressing a molding material such as resin to form a molded product 500 is formed between each molding surface 21 of the stacked thin metal sheets 20 and the core 150 (see Figure 13).

[0029] In this embodiment, a single metal sheet 20 is constructed by joining a pair of opposing thin plate components (referred to as split dies in this specification) 20L, 20R, which can be separated in a direction perpendicular to the stacking direction, at a joining surface 24 (see FIG. 1, etc.). Hereinafter, the direction in which the opposing split dies 20L, 20R are separated and joined will be referred to as the left-right direction for convenience and represented by the symbol X (see FIG. 2, etc.). The shape and structure of the joining surfaces 24 of the split dies 20L, 20R are not particularly limited and may be planar or non-planar. In this embodiment, the joining surface 24 is formed by mountain-shaped or valley-shaped irregularities in a plan view and is a broken line extending in a direction perpendicular to the left-right direction X (hereinafter, for convenience, this will be referred to as the front-rear direction and represented by the symbol Y) (see FIGS. 1, 3, etc.). By forming the joining surfaces 24 into such a predetermined uneven shape in advance, it is possible to form the thin metal sheets 20 in a state in which it is easy to align them with precision when joining and combining the pair of opposing split molds 20L, 20R (see FIG. 1, etc.). Furthermore, forming the joining surfaces 24 into a bent (non-linear) shape that is bent midway rather than a shape that extends linearly in this way is advantageous in that it increases the contact area between the opposing joining surfaces 24, thereby appropriately suppressing leakage of gas in the front-to-rear direction Y from between the contact areas of these joining surfaces 24 during compression molding, and as a result, gas is released from between the stacked thin metal sheets 20, allowing gas venting to occur throughout the entire mold.

[0030] Each of the plurality of metal sheet metals 20 that are stacked to form the stacking mold 10 is provided with an insertion portion 25 for inserting a positioning pin 30 therethrough (see FIGS. 1, 7, etc.). By inserting the positioning pins 30 into the insertion portion 25, it is possible to align the positions of all of the stacked plurality of metal sheet metals 20 in the left-right direction X and the front-rear direction Y (see FIG. 8, etc.). The positions and number of the insertion portions 25 are not particularly limited, but in this embodiment, two insertion portions 25 are provided in each of the split molds 20L, 20R so as to be symmetrically positioned at the four corners of the rectangular metal sheet metal 20 (see FIG. 1, etc.).

[0031] The side portions 28 of each metal sheet 20 in the left-right direction X (the side portions in the direction in which the split dies 20L, 20R are joined or separated) are formed so that when the metal sheets 20 are stacked, the surfaces are aligned and flush with each other (see FIGS. 6 to 8, etc.). During compression molding, the stacking mold 10 is compressed in the left-right direction via these side portions 28 by the side panels 130 of the mold clamping device 100 (see FIG. 13, etc.).

[0032] In the laminate mold 10 of this embodiment, which is configured as described above to stack a plurality of sheet metals 20 and form a cavity 12 between each molding surface 21 of the sheet metals 20 and the core 150, it is easy to mold molded products of different shapes by combining sheet metals 20 having different molding surfaces 21 (in other words, the degree of freedom in mold shape is increased). For example, when molding a cup-shaped container 300 (hereinafter, a container referred to as a "sake cup") as an example of a molded product, if a partially constricted concave undercut 310 is to be provided on the outer periphery of the sake cup 300, the undercut 310 can be molded only in the portion corresponding to the undercut 310 by disposing a sheet metal (i.e., a sheet metal for undercut molding) 20u having a molding surface (undercut molding surface 21u) different in shape and diameter from the molding surfaces 21 of the remaining portions of the sheet metal 20 (see FIGS. 5 and 6), in that portion (see FIGS. 14(A), 16, etc.). Furthermore, by appropriately rearranging the sheet metals 20 and changing the position of the sheet metals 20u for forming the undercut, it is possible to easily form sake cups 300 having undercuts 310 in different positions (see FIGS. 14(B) and (C)), and such arrangements and applications are extremely easy with the stacking mold 10 of this embodiment, which is structured to stack multiple sheet metals 20. Moreover, even if it is desired to change the shape of only a portion of the undercut 310, or if some of the multiple sheet metals 20 are defective, this can be addressed by replacing only the sheet metals 20 in that portion, making it extremely easy to use.

[0033] Furthermore, by appropriately changing the shape of undercut forming surface 21u of thin metal sheet 20u for undercut forming, it is possible to make the cross-sectional shape of undercut 310 of sake cup 300 either circular or non-circular. For example, by making undercut forming surface 21u of thin metal sheet 20u for undercut forming polygonal, only the undercut 310 portion has a polygonal cross-sectional shape and the other portions have a circular cross-sectional shape, thereby making it possible to form sake cup 300 that is excellent in practicality, such as ease of holding, and has an elegant design (see Figures 6, 17, etc.).

[0034] When the undercut 310 is formed as described above, a step occurs at the boundary between the undercut 310 and the remaining portion. Depending on the shape, the step may be large or sharp. While this is not a problem in itself, when forming a biomass powder material, particularly a powder material containing lacquer, chipping may occur or become more likely to occur at the step in the sake cup (molded product) 300 (see FIG. 19(A)). In consideration of this, in this embodiment, a chamfered portion 22 is provided in the metal sheet 20 at the portion of the undercut 310 of the sake cup 300 or the portion adjacent to the undercut 310 (see FIGS. 4 to 6, etc.).

[0035] The chamfered portion 22 is provided to eliminate the sharp edges at the top and bottom of the concave undercut 310 described above, creating a gentler shape (this may be referred to as "shape modification" in this specification). While the specific shape of the chamfered portion 22 is not particularly limited as long as it has such a shape, in this embodiment, the chamfered portion 22 is formed by a surface inclined with respect to the central axis of the sake cup 300 (indicated by reference numeral 300C in FIGS. 18 and 6). More specifically, the polygonal molding surface 21 of the metal sheet 20, located at the boundary between the undercut 310 and the non-undercut 310 portion, is provided with multiple curved surfaces at equal intervals in the circumferential direction to form the chamfered portion 22 (see FIGS. 5, 6, etc.). This chamfered portion 22 allows the stepped portions around the undercut 310 of the sake cup 300 to be chamfered and rounded during molding to modify the shape, resulting in a gentler shape without sharp edges. Sake cup 300 formed in this way, especially one formed from a powder material such as lacquer, will not chip at the step, and will have a shape in which undercut 310 is smoothly connected to the rest of the body, resulting in a texture that does not feel angular when held in the hand and a uniquely elegant design (see Figure 19(B), etc.). As mentioned above, sake cups 300 with different positions of undercut 310 can be easily formed by disassembling stacked thin metal sheets 20 and appropriately changing the stacking direction positions of thin metal sheets 20u for forming undercut 310 and thin metal sheets 20 with chamfered portions 22.

[0036] There is no particular limitation on the means for manufacturing the above-described thin metal plates 20. As an example, in this embodiment, each thin metal plate 20 is processed by laser cutting, which is advantageous in terms of cutting thin plates and cutting complex contour shapes, but of course other means may be used.

[0037] [Mold clamping machine] The mold clamping device 100 is a device configured with a mold clamping mold base for clamping and fixing the laminated mold 10. The mold clamping device 100 of this embodiment includes an upper plate 110, a lower plate 120, a side panel 130, a clamp handle 140, a core 150, and the like (see FIGS. 9 to 13).

[0038] The upper plate 110 and the lower plate 120 are plate-shaped members that sandwich the laminated mold 10 from above and below (see FIG. 9, etc.). The upper plate 110 is provided with a pressurizing through-hole 116 through which a plunger 220 of a compression molding device 200 is inserted (see FIG. 13, etc.). The upper plate 110 is also formed with an upper engagement groove 111 that engages with an upper engaged portion 131 of a side panel 130. The lower plate 120 is also formed with a lower engagement groove 122 that engages with a lower engaged portion 132 of the side panel 130 (see FIG. 13, etc.). The upper engagement groove 111 and the lower engagement groove 122 are formed with inclined portions 111s, 122s that generate a component force along the left-right direction X when a mold clamping pressure along the stacking direction Z is applied, and that apply a force toward the laminated mold 10 to the side panel 130 (see FIG. 13, etc.).

[0039] The side panels 130 are a pair of members provided to press down on both sides of the laminate die 10 along the split mold direction (along the left-right direction X in this embodiment) from the surface where the side portions 28 of the metal sheet 20 are located (see FIG. 10, etc.). An upper engaged portion 131 that engages with the upper engaging groove 111 of the upper plate 110 is formed on the upper part of the side panel 130. A lower engaged portion 132 that engages with the lower engaging groove 122 of the lower plate 120 is formed on the lower part of the side panel 130 (see FIG. 13, etc.). The upper engaged portion 131 and the lower engaged portion 132 are formed with inclined portions 131s, 132s that generate a component force along the left-right direction X when a mold clamping pressure along the stacking direction Z is applied, and that apply a force directed toward the laminate die 10 to the side panel 130 (see FIG. 13, etc.). In this embodiment, the inclination angles of these inclined portions 131s, 132s are made equal to the inclination angles of the inclined portion 111s of the upper engagement groove 111 and the inclined portion 122s of the lower engagement groove 122, so that each portion is in surface contact with the other (see FIG. 13, etc.). However, making the inclination angles of each portion equal to each other in this manner is merely a preferred example, and the specific embodiment is not limited to the example shown here, as long as a component force in the left-right direction X is generated by the wedge action when mold clamping pressure is applied in the stacking direction Z, and a force directed toward the stacking mold 10 is applied to the side panel 130.

[0040] The clamp handle 140 is provided as an example of a clamping means for applying clamping pressure to the upper plate 110 and the lower plate 120 along the stacking direction Z (see FIGS. 9 and 10, etc.). The clamp handle 140 of this embodiment is rotatably connected to a rotation shaft 142a at the upper end of a clamping rod 142 whose lower end is engaged with the lower plate 120, and is provided so as to gradually increase the pressure applied to the upper plate 110 via a substantially spiral-shaped abutment surface 144 whose diameter (distance) from the rotation shaft 142a gradually increases as the clamp handle 140 is rotated (see FIG. 13). In this embodiment, four clamp handles 140 and corresponding clamping rods 142 are arranged at the four corners of the upper plate 110, so that pressure can be applied evenly without bias (see FIGS. 11 and 12, etc.). As described above, the clamp handle 140 is merely one example of a configuration that can be used as mold clamping means, and it goes without saying that other fastening members such as bolts and nuts can also be used as mold clamping means.

[0041] The core 150 is a part that serves as an inner mold for forming a portion of the molded product into a concave shape. In this embodiment, the core 150 has an upwardly convex, tapered shape and is provided on the lower plate 120, so that the inner surface of the sake cup 300 conforms to the shape of the core 150 during molding (see FIG. 13, etc.). In this embodiment, the core 150 is designed to be detachable from the lower plate 120. In such cases, the core 150 alone can be replaced with one of a different shape depending on the inner shape of the sake cup 300 to be molded.

[0042] In the above-described mold clamping machine 100, the mold clamping pressure by the clamp handle (mold clamping means) 140 is preferably set based on the results calculated by CAE simulation in order to achieve good gas venting.

[0043] [Compression molding equipment] The compression molding device 200 is a device that uses a plunger (pressure pin) 220 to pressure-mold the powder material filled in the cavity 12 of the laminate mold 10. The compression molding device 200 itself may be a known device that has been used for a long time. Note that in the drawing, only the plunger 220 and the plate 230 to which the plunger 220 is attached are shown of the compression molding device 200, and the entire device is not shown (see FIG. 13, etc.).

[0044] With the above-described laminated mold 10, gas can be vented from between the laminated thin metal sheets 20, thereby enabling gas venting throughout the entire mold (see FIG. 20 ). Generally, when molding a biomass powder material, such as a powder material containing lacquer (for example, a biomass powder material prepared by heating and kneading lacquer, which is the sap of the urushi tree, with plant fibers such as cedar wood flour, or similar naturally derived materials), the volatile components of the lacquer, the moisture contained in the wood flour material, and the air present in the gaps between them exist as gases, which can cause poor material fluidity and significantly affect molding conditions, making sufficient gas venting a challenge. However, the laminated mold 10 of this embodiment makes it easy to discharge the volatile components, gases, and liquid components generated in the molding material. For this reason, even in situations where stable molding is difficult with conventional molds, the use of this laminate mold 10 makes it possible to improve the fluidity of the material, and by sufficiently venting gas, it is possible to suppress the occurrence of molding defects in the molded product and poor appearance such as "blisters," "cracks," and "cloudiness," thereby making it possible to achieve stable molding.

[0045] Furthermore, with a stacking mold 10 such as that of this embodiment, by changing the stacking order of metal sheet metals 20 of different shapes, it is possible and easy to mold molded products of different shapes, or to change the design by changing the stacking order of metal sheet metals 20, as shown in the example of changing the position of the undercut 310 in the above-mentioned embodiment (see Figure 14).

[0046] Furthermore, when molding materials such as biomass powder, it is difficult to take measures to prevent molding defects in advance due to differences in the shapes to be molded, but the laminate mold 10 of this embodiment realizes a disassembly mold that can be disassembled each time and replaced with a different shaped metal sheet 20, which means that it can be manufactured at low cost and easily verified. In fact, when molding lacquerware and other lacquer products, there are challenges such as the wide variety of sizes and shapes, the time-consuming finishing process, and the difficulty of determining the mold shape at the product prototype stage. In addition, to commercialize molded products such as the sake cup 300, molds are required from the prototype stage, and mold depreciation costs can increase depending on the production volume. However, the use of the laminate mold 10 of this embodiment makes it easy to address these challenges.

[0047] Furthermore, in recent years, as the move away from plastics has progressed in order to reduce the burden on the environment, naturally derived materials have been attracting attention. The laminated mold 10 and its mold clamping machine 100 of this embodiment can be adapted to these new materials, and therefore can also be said to contribute to reducing the burden on the environment.

[0048] The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto and various modifications are possible within the scope of the present invention. For example, in the above-described embodiment, a biomass powder material is specifically described as an example of a molding object, but it goes without saying that the present invention is not limited thereto and can be applied to all molding materials used in compression molding.

[0049] Furthermore, although the above-described embodiments have been described using expressions such as plan view, front view, left and right, it goes without saying that these are merely expedient expressions. For example, if the compression molding device is placed horizontally and compression is performed in the horizontal direction, it may be expressed as compression in the left and right direction, but it is clear that the content of the present invention is not limited to such superficial expressions. [Example]

[0050] An experiment was carried out using an experimental device 400 to verify how the amount of gas leakage during compression molding changes when the thickness t of the metal sheet 20 in the laminate mold 10 changes (see FIGS. 21 and 22).

[0051] The mold used for verification in the experimental device 400 had the same structure as the lamination mold 1 used in actual compression molding. This lamination mold 10 had a rectangular metal sheet 20 with a width (length in the left-right direction X) of 55 mm and a length (length in the front-back direction Y) of 50 mm. A 16 mm diameter hole was drilled in the center to form a circular molding surface 21, and 6 mm diameter insertion holes 25 were drilled on the left and right sides of the hole to pass positioning pins 30. A hole for liquid injection was drilled in the lower plate 120, and a coupler was attached to the 3 / 16 taper thread. A manual reciprocating pump 406 generating a pressure of 2.5 MPa was connected to the coupler via a hose (piping) 407 (see Figure 21). A glycerin solution with a viscosity similar to that of the lacquer solution was used. In FIG. 21, reference numeral 402 denotes a press, 403 denotes a mold temperature regulator, 404 denotes a pressure gauge (for mold clamping pressure), 405 denotes a pressure gauge (for liquid pressure), and 408 denotes a solution container.

[0052] (Specifications of experimental lamination mold) -Thickness of metal sheet: t=0.5mm, t=1.0mm, t=2.0mm, t=3.0mm, t=6.0mm, t=10mm -Metal sheet material: SUS304 Surface roughness of thin metal sheets: Ra0.2~0.4μm However, ordinary rolled plates were used for t=0.5 to 3.0, and t=6 mm and t=10 mm were machined. Each of the metal thin plates 20 was stacked in the following numbers (t=0.5: 60 sheets, t=1.0: 30 sheets, t=2.0: 15 sheets, t=3.0: 10 sheets, t=6.0: 5 sheets, t=10: 3 sheets) so that the height (thickness along the stacking direction Z) was 30 mm, and then the mold was clamped.

[0053] (Experimental conditions) Mold clamping force: 1000kg Mold temperature: 45℃ Mold injection liquid: Glycerin solution Injection pressure: 2.5MPa Hydraulic pressure time: 60 seconds

[0054] (Method for measuring gas leakage amount) The filter paper was cut into pieces 200 mm long and 29.5 mm wide, and the weight of the cut pieces was standardized. The filter paper was wrapped around the outer periphery of an experimental laminate mold 1 measuring 55 mm wide, 50 mm long, and 30 mm high, and the leaked liquid (glycerin) was absorbed and weighed.

[0055] The results of the above experiment are shown in Figure 22. The findings obtained from the differences in leakage amounts in the experiment are as follows. 1. The gap between the contact surfaces of overlapping thin metal plates 20 is related not only to the surface properties (surface roughness) but also to the plate thickness tolerance and flatness tolerance (surface waviness and warpage). 2. When the thickness (thickness t) of the thin metal plates 20 is thin, the strength of the plates is weak, so that the entire plates are deformed (elastically deformed) when the mold is clamped, reducing the gap between the thin metal plates 20 . 3. As the thickness (thickness t) of the thin metal plate 20 increases, the strength of the plate increases, the deformation (elastic deformation) of the entire plate decreases, and the warp and waviness (flatness) of the plate surface do not change, so the gap is maintained and the leakage amount increases. 4. As is clear from the graph (Fig. 22), when the thickness t was 6.0 mm and 10 mm, the leakage amount was extremely large. [Industrial Applicability]

[0056] The present invention is suitable for application to a mold for compression molding and a mold clamping device therefor. [Explanation of symbols]

[0057] 10...Laminated mold 12...cavity 20…Thin metal plate 20L, 20R... Split mold (thin plate component) 20u...Metal sheet for undercut molding 21…molding surface 21u…molding surface 22...Beveled part 24...Split mold joint surface 25...Passage part 28...Side portion of thin metal plate in the split direction 30...Locating pin 100...Mold clamping machine 110...Upper plate 111...Upper engagement groove (upper engagement portion) 111s…Slope part 116...Pressure hole 120...Lower plate 122...lower engagement groove (lower engagement portion) 122s…Slope part 130...Side panel 131...Upper cover engagement part 131s…Slope part 132...Lower sheath engagement part 132s…Slope part 140...Clamp handle (mold clamping means) 142...Mold clamping rod 142a...rotation axis 144…Abutment surface 150...Core 200...Compression molding device 220...Plunger (pressure pin) 230...Plate 300... Sake cup (molded product) 300C...Central axis (of molded product) 310...Undercut 400...Experimental equipment 402...Press machine 403…Mold temperature controller 404...Pressure gauge (for mold clamping pressure) 405...Pressure gauge (for liquid pressure) 406...Manual pump 407...Hose (piping) 408...Solution container X…Left and right direction (split mold direction) Y: Front-rear direction Z…Stacking direction

Claims

1. The product has a split structure that can be separated in a direction different from the stacking direction and is constructed by stacking multiple thin metal plates in a disassemblable state. The metal sheet has a chamfered portion inclined with respect to the molded product at a portion of the metal sheet that forms an undercut portion of the molded product or a portion adjacent to the undercut, A laminated mold for compression molding, which compresses and molds the molding material by applying pressure from pressure pins in the stacking direction.

2. The laminated mold according to claim 1 , further comprising an insertion portion for inserting a positioning pin therethrough.

3. The laminate mold according to claim 1 or 2, wherein the cross section of the undercut has a polygonal shape.

4. The laminated mold according to claim 1 , wherein the chamfered portion is composed of a plurality of curved surfaces provided at equal intervals in the circumferential direction.

5. 5. A laminated mold according to claim 1, wherein the positions in the stacking direction of the metal sheet for forming the undercut and the metal sheet provided with the chamfered portion can be changed after the stacked metal sheets are disassembled.

6. The laminate mold according to claim 1 , wherein the joining surfaces of the split molds are non-flat.

7. The laminated mold according to claim 6 , wherein the joining surface is formed in a non-linear shape when viewed in a plan view along the lamination direction.

8. A mold clamping machine for clamping a laminated mold for compression molding, which has a split mold structure that can be split in a direction different from the stacking direction and is constructed by stacking multiple thin metal plates in a disassemblable state, and compresses and molds a molding material by receiving pressure from a pressure pin in the stacking direction, an upper plate and a lower plate that sandwich the lamination mold; a clamping means for applying a clamping pressure to the upper plate and the lower plate; Side panels that hold down both sides of the laminate mold in the split mold direction; Equipped with An upper engaging portion that engages with the upper engaged portion of the side panel is formed on the upper plate, and a lower engaging portion that engages with the lower engaged portion of the side panel is formed on the lower plate.

9. The mold clamping machine of claim 8, wherein at least one of the upper engaged portion and the upper engaging portion, and at least one of the lower engaged portion and the lower engaging portion, is formed with an inclined portion that generates a component force of the mold clamping pressure and applies a force toward the stack mold to the side panel.

10. A mold clamping machine as described in claim 8 or 9, further comprising a core that gives a portion of the molded product a concave shape.

11. 11. The mold clamping machine according to claim 8, wherein the upper plate is provided with a pressure through hole through which a pressure pin of a compression molding device can be inserted.

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