Mold for resin molding, method for manufacturing resin molded products, and resin molding apparatus

Abstract

A mold for resin molding that can reliably fill the mold even without high temperature and high pressure. The present invention provides a method for manufacturing resin molded products and a resin molding apparatus. [Solution] A resin molding mold comprising a container 10 having a container space 22 formed by a bottom 18 and side 20, an outer cylinder 12 whose outer shape closely fits the side 20 of the container 10 and is provided to be insertable into the container space 22, and a molding member 14 fixed inside the outer cylinder 12 and having a molded product space 28 corresponding to the resin molded product to be molded, and an insertion means for inserting the molding mold 16 into the container space 22 of the container 10, wherein the molded product space 28 has openings on both sides in the insertion direction of the outer cylinder 12, and the outer cylinder 12 opposite the container 10 has a suction port 30 connected to a vacuum device for reducing the pressure in the molded product space 28. Also, a method for manufacturing a resin molded product using this resin molding mold, and a resin molding apparatus having a resin molding mold and a vacuum device.

Description

Technical Field

[0005] , ,

[0004] , , , ,

[0001] The present invention relates to a mold for resin molding, a method for manufacturing a resin molded product, and a resin molding apparatus.

Background Art

[0002] When performing injection molding of a resin, after injecting the resin at high temperature and high pressure and filling it into a metal mold, it is cured to form a molded product. For example, Patent Document 1 describes a method of injecting a heated and melted resin at high pressure into a cavity of a mold device and forming the resin into a thin-walled shape. Further, Patent Document 2 describes a method of manufacturing a hollow molded product by applying heat so as to maintain a molten state at a high temperature and low viscosity and applying an internal pressure by blow molding.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

[0006] This invention has been made in view of these circumstances, and aims to provide a resin molding mold that can reliably fill with resin even without high temperature and high pressure, a method for manufacturing a resin molded product using this resin molding mold, and a resin molding apparatus. [Means for solving the problem]

[0007] The inventors of this invention conducted intensive research to solve the above problems and discovered that the problems can be solved by reducing the pressure inside the resin molding mold and filling it with resin using the pressure difference, leading to the present invention. In other words, the present invention is as follows. [1] A mold for resin molding comprising: a container having a container space formed by a bottom and sides; an outer cylinder having an outer shape that closely conforms to the sides of the container and is provided to be insertable into the container space; a molding member fixed inside the outer cylinder and having a molded product space inside corresponding to a resin molded product to be molded; and an insertion means for inserting the mold into the container space of the container, wherein the molded product space has openings on both sides in the insertion direction of the outer cylinder, and the outer cylinder has a suction port on the side opposite the container that is connected to a vacuum device for reducing the pressure in the molded product space. [2] The molding member is a resin molding mold according to [1], having a plurality of molded product spaces. [3] The mold for resin molding according to [1] or [2], wherein the shape of the molded product space is cylindrical and comprises a shaft portion corresponding to the hollow portion of the resin molded product that is molded within the molded product space. [4] The resin molding mold according to any one of [1] to [3], wherein the area of ​​the opening of the molded product space on the opposite side of the container is smaller than the area of ​​the opening on the container side. [5] A resin molding mold according to any one of [1] to [4], wherein the container space, the outer cylinder, and the molding member are cylindrical in shape. A method for manufacturing a resin molded product using a resin molding mold described in any of [6] [1] to [5], comprising: a molding mold preparation step of filling the container space of the container with a fluid resin and inserting a part of the molding mold into the container space; a filling step of filling the molded product space with resin by depressurizing the molded product space from the suction port of the outer cylinder of the molding mold using a depressurizing device and inserting the molding mold into the container space using the insertion means; and a curing step of forming a resin molded product by curing the resin after filling the molded product space. A resin molding apparatus comprising a resin molding mold as described in any of [7][1] to [5], and a vacuum device. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a resin molding mold that can reliably fill with resin even without high temperature and high pressure, a method for manufacturing a resin molded product using this resin molding mold, and a resin molding apparatus. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view showing one embodiment of a mold for resin molding. [Figure 2] This is a cross-sectional view of the resin molding mold shown in Figure 1, along the line II-II. [Figure 3] This is a cross-sectional view of the resin molding mold shown in Figure 1, along the line III-III. [Figure 4] This is a cross-sectional view of a disassembled mold for resin molding. [Figure 5] This is a plan view showing the entrance to the molding section of a molding mold. [Figure 6] This is a plan view showing the exit of the molding section of a molding mold. [Figure 7] It is a schematic diagram of a resin molding apparatus. [Figure 8] It is a diagram for explaining a method of manufacturing a resin molded product. [Figure 9] It is a diagram for explaining a method of manufacturing a resin molded product. [Figure 10] It is a diagram for explaining a method of manufacturing a resin molded product. [Figure 11] It is a cross-sectional view showing another embodiment of a mold for resin molding. [Embodiments for Carrying Out the Invention]

[0010] Hereinafter, a mold for resin molding, a method of manufacturing a resin molded product, and a resin molding apparatus according to the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments.

[0011] [Mold for Resin Molding] FIG. 1 is a perspective view showing an embodiment of a mold for resin molding. FIG. 2 is a cross-sectional view taken along line II-II of the mold for resin molding shown in FIG. 1, and FIG. 3 is a cross-sectional view taken along line III-III of the mold for resin molding shown in FIG. 1. Note that FIG. 3 is a diagram for explaining the configuration of the pushing bolts of the outer cylinder, and the internal structure of the molding mold is omitted. FIG. 4 is a cross-sectional view of the mold for resin molding disassembled.

[0012] The mold 100 for resin molding of the present invention includes a container 10 having a container space 22 formed by a bottom portion 18 and side portions 20, an outer cylinder 12 whose outer shape is in close contact with the side portions 20 of the container 10 and is provided so as to be insertable into the container space 22, and a molding member 14 fixed inside the outer cylinder 12 and having a molding product space 28 corresponding to the resin molding product to be molded, and a molding mold 16 composed of these, and an insertion means for inserting the molding mold 16 into the container space 22 of the container 10. The molding product space 28 has openings 48 and 50 on both sides in the insertion direction of the outer cylinder 12, and on the opposite side of the container of the outer cylinder 12, it has a suction port 30 connected to a decompression device for decompressing the molding product space 28.

[0013] As shown in FIGS. 1 to 4, the mold 100 for resin molding of the present invention includes a container 10, a molding mold 16 composed of an outer cylinder 12 and a molding member 14. The container 10 has a container space 22 formed by a bottom portion 18 and a side portion 20. When manufacturing a resin molded product, a resin having fluidity as a material for the resin molded product is filled into the container space 22. The shape of the container space 22 is not particularly limited as long as the outer shape of the outer cylinder 12 of the molding mold 16 described later is in close contact therewith, but a cylindrical shape is preferable from the viewpoint of productivity.

[0014] The molding mold 16 is composed of an outer cylinder 12 and a molding member 14. The outer cylinder 12 has an outer shape that closely contacts the side portion 20 of the container 10 and is provided so as to be insertable into the container space 22 of the container 10. An elastic member 24 such as a packing is provided on the outer periphery of the tip side in the insertion direction of the container space 22 of the outer cylinder 12. By the close contact between the elastic member 24 and the side portion 20 of the container 10, gas leakage from the container space 22 is prevented, and the inside of the container space can be depressurized. Further, it is possible to prevent the resin having fluidity in the container space 22 from leaking between the side portion 20 of the container 10 and the outer cylinder 12.

[0015] Further, the inside of the outer cylinder 12 has a molding member space 26, and the molding member 14 is installed in the molding member space 26. The molding member 14 has an outer shape that closely contacts the side surface of the molding member space 26, and prevents the resin having fluidity from leaking between the side surface of the molding member space 26 and the molding member 14. The molding member 14 is fixed to the outer cylinder 12 by inserting the molding member 14 into the molding member space 26 of the outer cylinder 12 and sandwiching it between a convex portion 38 provided at the lower part of the molding member space 26 and a lid portion 36 fitted into the upper part. The molding member 14 has a molded product space 28 corresponding to the resin molded product to be molded. In the molding member 14 shown in FIG. 2, the resin molded product to be molded has a cylindrical shape and has a cylindrical hollow portion extending in the longitudinal direction inside. Therefore, the molded product space 28 has a cylindrical shape and has a shaft portion 29 corresponding to the hollow portion inside. With respect to the insertion direction of the outer cylinder 12 into the container space 22, the length of the molded member space 26 is formed to be longer than that of the molded member 14, so that when the molded member 14 is fixed to the outer cylinder 12, a space 26a is provided on the side opposite to the container 10. By providing space 26a, any excess fluid resin that has been filled into the molded product space 28 of the molded member 14 can flow into space 26a, thereby ensuring that the resin is reliably filled into the molded product space 28.

[0016] Furthermore, the outer cylinder 12 has a suction port 30 on the side opposite to the direction of insertion into the container space 22, which is connected to a pressure reducing device 310 (see Figure 7) that reduces the pressure in the molded product space 28 of the molding member 14. In Figures 1 to 4, it is provided on the lid portion 36. By drawing suction from the suction port 30 and reducing the pressure in the molding member space 26 and the molded product space 28, the fluid resin filled in the container space 22 can be moved to the molded product space 28 due to the pressure difference, thereby filling the molded product space 28 with resin.

[0017] Furthermore, the resin molding mold 100 includes a stopper bolt 32 and a push bolt 34 as insertion means for adjusting the amount the molding mold 16 is inserted into the container space 22 of the container 10. By adjusting the stopper bolt 32, the insertion amount of the molding mold 16 can be adjusted. The stopper bolt 32 is provided on a flange portion 40 provided around the outer cylinder 12, and the tip of the stopper bolt 32 is provided in contact with the wall portion 44 that constitutes the side portion 20 of the container 10. With this configuration, by loosening the stopper bolt 32, the molding mold 16 can be inserted into the container space 22, and by pushing in the fluid resin, the molded product space 28 of the molded member 14 can be filled with resin. Furthermore, as shown in Figures 1 and 3, the flange portion 40 is equipped with a push bolt 34. By tightening the push bolt 34 into the hole 46 provided in the wall portion 44 of the container 10, the front end of the molding mold 16 can be further pushed into the container 10. This allows the fluid resin to be further pushed into the molded product space 28, and the resin can be filled.

[0018] Next, the molding member 14 provided inside the outer cylinder 12 of the molding mold 16 will be described. Figure 5 is a plan view showing the inlet side of the molded product space of the molding member, and Figure 6 is a plan view showing the outlet side of the molded product space. The molding member 14 has a molded product space 28 inside and is configured to be separable so that the resin molded product formed in the molded product space 28 can be easily removed. The molding member 14 shown in Figures 2 and 4 consists of a space member 14a having a molded product space 28, a first holding member 14b and a second holding member 14c provided on the inlet and outlet sides of the space member 14a, respectively, which hold a shaft portion 29 corresponding to the hollow part of the resin molded product, and a shaft portion receiving member 14d provided on the outside of the second holding member 14c, which contacts the longitudinal end of the shaft portion 29. The fluid resin to be filled into the container 10 flows into the molding member 14 from an opening provided in the first holding member 14b of the molding member 14 and flows into the space member 14a from the opening 48 on the inlet side of the space member 14a. In this embodiment, a space can be provided between the first holding member 14b for holding the shaft portion 29 and the space member 14a. This space becomes a resin reservoir, making it easier for the resin to flow into the molded product space 28 of the space member 14a. After the molded product space 28 of the space member 14a is filled with resin, the resin passes through the second holding member 14c and the bearing member 14d, and flows out from the outlet opening 50 of the bearing member 14d (the outlet opening 50 of the molded member 14). In this embodiment, the resin flows into the molded product space 28 from the opening on the container 10 side and flows out from the opening on the opposite side of the container 10. Therefore, the opening on the container 10 side corresponds to the inlet opening 48, and the opening on the opposite side of the container 10 corresponds to the outlet opening 50. Furthermore, although the molded member 14 shown in Figure 2 is described as being composed of four members, the number of members is not limited as long as the molded resin product can be removed. For example, if the resin product does not have a hollow portion, the shaft portion 29 is unnecessary, and therefore the first holding member 14b and the second holding member 14c do not need to be provided.

[0019] Furthermore, in the molded member 14 of this embodiment, multiple molded product spaces 28 are provided so that multiple resin molded products can be formed. When multiple molded product spaces 28 are provided, for example, as shown in Figures 5 and 6, 10 molded product spaces 28 can be provided.

[0020] In the molding member 14, it is preferable that the area of ​​the outlet-side opening 50 of the molded product space 28 is smaller than the area of ​​the inlet-side opening 48. By making the area of ​​the outlet-side opening 50 smaller than the inlet-side opening 48, it is possible to reliably fill multiple molded product spaces 28 with fluid resin. By making the area of ​​the outlet-side opening 50 smaller, even after the resin has been filled into one molded product space 28, it is possible to make it difficult for the resin to flow out from the outlet-side opening 50. This makes it easier to move the resin from the inlet-side opening 48, which has a larger opening area, to the unfilled molded product spaces 28, and makes it easier to fill the unfilled molded product spaces 28 with resin.

[0021] In order to prevent the resin 42 from flowing out of the outlet opening 50 of the molded product space 28 solely due to the pressure difference, and to ensure that the molded product space 28 is filled with a fluid resin, the ratio of the area of ​​the outlet opening 50 to the area of ​​the inlet opening 48 is preferably 0.01 or more and 0.2 or less, and more preferably 0.01 or more and 0.1 or less. Furthermore, as shown in Figure 5, if the inlet opening 48 and the outlet opening 50 are circular, the diameter D1 of the inlet opening 48 is preferably 4 mm or more and 20 mm or less, and the diameter D2 of the outlet opening 50 is preferably 0.4 mm or more and 3 mm or less. Also, as shown in Figure 5, if the opening 48 has a shaft portion 29, the area of ​​this shaft portion 29 is not included in the opening.

[0022] [Resin molding equipment] Figure 7 is a schematic diagram showing the resin molding apparatus 300 of the present invention. The resin molding apparatus 300 includes a resin molding mold 100 and a pressure reducing device 310. The resin molding mold 100 can be any resin molding mold as described above. The pressure reducing device 310 is not particularly limited as long as it can reduce the pressure in the molded product space 28 of the resin molding mold 100, and examples include a compressor and a vacuum pump. The resin molding mold 100 and the pressure reducing device 310 are connected, for example, by piping 320. By operating the pressure reducing device 310, the pressure in the molded product space 28 of the resin molding mold 100 can be reduced.

[0023] [Method for manufacturing resin molded products] Next, a method for manufacturing a resin molded product using the resin molding mold 100 of the present invention will be described. Figures 8 to 10 illustrate the method for manufacturing a resin molded product. In Figures 8 to 10, in order to make the operation of the stopper bolt 32 and the push-in bolt 34 easier to understand, one is referred to as the stopper bolt 32 and the other as the push-in bolt 34, and will be described accordingly. The present invention provides a method for manufacturing a resin molded product, comprising: a mold preparation step of filling the container space 22 of a container 10 with a fluid resin 42 and inserting a part of a mold 16 into the container space 22; a filling step of filling the molded product space 28 by depressurizing the molded product space from the suction port 30 of the outer cylinder 12 with a depressurizing device and inserting the mold 16 into the container space 22 with an insertion means; and a curing step of forming a resin molded product by curing the resin 42 after filling the molded product space 28. Each step will be described below.

[0024] (Preparation process for molding molds) The molding mold preparation process involves filling the container space 22 of the container 10 with a fluid resin 42 and inserting a portion of the molding mold 16 into the container space 22. The molding mold preparation process begins with assembling the molding member 14. As described above, the molding member 14 is composed of multiple parts so that it can be disassembled to facilitate the removal of the molded resin product. Therefore, the molding member 14 is assembled first. Next, the molding member 14 is inserted into the molding member space 26 of the outer cylinder 12, and the molding member 14 is fixed in place by sandwiching it between the lid portion 36 from above and the protrusion 38 provided at the bottom of the molding member space 26. A stopper bolt 32 is tightened into a hole provided in the flange portion 40 of the outer cylinder 12.

[0025] Furthermore, the container space 22 of the container 10 is filled with a fluid resin 42, which will be the material for the molded resin product. In this invention, the fluid resin preferably has a viscosity in the range of 0.001 Pa·s to 1500 Pa·s, and more preferably in the range of 50 Pa·s to 1500 Pa·s. The resin 42 can be heated to a temperature that does not affect the physical properties or quality of the molded resin product. The viscosity can also be adjusted to the above range by heating. Examples of resin 42 include rubber, natural resin, general-purpose plastic, engineering plastic, solid fuel, etc. In addition, it is preferable that the resin 42 contains a curing agent so that the resin hardens easily after being filled into the mold.

[0026] In the molding mold preparation process, as shown in Figures 8(a) and 9(b), the assembled molding mold 16 is inserted into the container 10, which is filled with a fluid resin 42 in the container space 22, until the stopper bolts 32 contact the wall portion 44 that forms the side of the container 10. Since the stopper bolts 32 are tightened at the flange portion 40, the stopper bolts 32 act as a stopper, limiting the amount the molding mold 16 can be inserted into the container 10. Furthermore, a decompression device 310 (see Figure 7) is connected to the suction port 30 provided on the outer cylinder 12.

[0027] (filling process) Next, after the molding mold preparation process is completed, the filling process is performed. The filling process involves depressurizing the molded product space 28 from the suction port 30 of the outer cylinder 12 of the molding mold 16 using a depressurizing device, and simultaneously inserting the molding mold 16 into the container space 22 using an insertion means, thereby filling the molded product space 28 with resin 42.

[0028] In the filling process, first, the molded product space 28 and the container space 22 are depressurized via the suction port 30 using a depressurization device. While depressurizing the molded product space 28 and the container space 22, the molding mold 16 is inserted into the container space 22 by loosening the stopper bolt 32. As shown in Figure 9(c), once the molding mold 16 is inserted into the container space 22, the inside of the molded product space 28 is under reduced pressure, and the resin 42 inside the container space 22 is filled into the molded product space 28 from the opening 48 on the inlet side of the molding member 14 due to the pressure difference.

[0029] Figure 10(d) shows the state after loosening the stopper bolt 32 and inserting the molding mold 16 into the container space 22. As shown in Figure 10(d), variations may occur in the filling state of the resin 42 in the multiple molded product spaces 28. In this embodiment, since the opening 50 on the outlet side of the molded product space 28 is narrower than the opening 48 on the inlet side, even if there are variations in the filling of the resin 42 into the multiple molded product spaces 28, the resin 42 can pass through the outlet side opening 50 of the molded product space 28 and move into space 26a, thereby filling the unfilled parts of the molded product space 28 with resin 42 and advancing the filling of the molded product space 28.

[0030] After the insertion of the molding mold 16 is completed by loosening the stopper bolt 32, the molding mold 16 is pushed into the container space 22 of the container 10 by tightening the push bolt 34 as shown in Figure 10(e). This pressurizes the container space 22 and the molded product space 28, which removes air bubbles from the resin in the molded product space 28, and allows for the production of a bubble-free resin molded product. Furthermore, the pressurization of the container space 22 and the molded product space 28 allows the resin 42 to flow out of the outlet opening 50 of the molded product space 28 into space 26a. By allowing the resin 42 to flow into space 26a, it can be confirmed that the molded product space 28 is reliably filled. After the resin 42 has flowed into space 26a, the depressurization from the suction port 30 is stopped. When the depressurization is stopped and the pressure is returned to atmospheric pressure, the liquid level of the resin 42 in space 26a drops. However, by allowing the resin 42 to flow out into space 26a, the molded resin product can be formed without any problems in shape, even if the liquid level of the resin 42 drops. In addition, by narrowing the opening 50 on the outlet side of the molded product space 28, it is possible to make it more difficult for the resin to return to the molded product space 28 when the pressure is returned to atmospheric pressure. By performing the next curing process in this state, it is possible to reliably manufacture resin molded products.

[0031] (hardening process) After the filling process is completed, a curing process is performed. The curing process involves filling the molded product space 28 with resin 42 and then curing it to form a resin molded product. The curing process can be carried out, for example, by leaving it at room temperature. After the filling of the resin 42 is complete, the molded member 14 can be removed from the mold 16, and the molded member 14 can be disassembled to obtain the resin molded product, thereby manufacturing the resin molded product.

[0032] According to the resin molding mold, resin molding method, and resin molding apparatus of the present invention, the time required for filling the mold with resin can be shortened by reducing the pressure inside the mold and filling the mold with resin. Therefore, even resins that harden at room temperature can be filled in a short time, and the filling of the mold can be reliably performed.

[0033] (Another embodiment) Figure 11 is a cross-sectional view showing another embodiment of a resin molding mold. The resin molding mold 200 shown in Figure 11 differs from the resin molding molds shown in Figures 1 to 4 in that the area of ​​the opening 148 on the inlet side of the molding member 114 within the molding mold 116 is the same as the area of ​​the opening 150 on the outlet side.

[0034] The resin molding mold 100 shown in Figures 1 and 2 prevents the formation of unfilled molded product spaces 28 among the multiple molded product spaces 28 by making the area of ​​the openings on the inlet side and the outlet side of the molding member 14 different. According to the resin molding mold 200 shown in Figure 11, the resin used as the material for the molded resin product to be manufactured has high fluidity, and even if the area of ​​the opening 148 on the inlet side and the opening 150 on the outlet side of the molding member 114 are the same, it is possible to manufacture a molded resin product as long as there are no unfilled molded product spaces 28 among the multiple molded product spaces 28. [Industrial applicability]

[0035] According to the present invention, since the mold can be reliably filled even without high temperature and high pressure, molding can be performed on materials that cannot be molded under high temperature and high pressure conditions. [Explanation of symbols]

[0036] 10 containers 12 Outer cylinder 14, 114 Molded members 14a Spatial member 14b First retaining member 14c Second retaining member 14d Bearing member 16, 116 Molding molds 18 Bottom 20 Side 22 Container space 24 Elastic members 26 Molded part space 26a Space 28 Molded product space 29 Shaft 30 Suction port 32 Stopper bolts 34 Push-in bolts 36 Lid 38 Convex part 40 Flange section 42 resin 44 Wall 46 holes 48, 148 Entrance side opening 50, 150 Exit side opening 100, 200 resin molding molds 300 Resin molding equipment 310 Pressure Reducing Device 320 piping

Claims

1. A container having a container space formed by the bottom and sides, A molding mold comprising: an outer cylinder whose outer shape closely conforms to the side of the container and is provided to be insertable into the container space; and a molding member fixed inside the outer cylinder and having a molded product space inside corresponding to the resin molded product to be molded; The system includes an insertion means for inserting the molding mold into the container space of the container, The molded product space has openings on both sides in the insertion direction of the outer cylinder, A resin molding mold having a suction port on the opposite side of the container of the outer cylinder, which is connected to a vacuum device for reducing the pressure in the molded product space.

2. The mold for resin molding according to claim 1, wherein the molding member has a plurality of molded product spaces.

3. The resin molding mold according to claim 1 or 2, wherein the shape of the molded product space is cylindrical, and the mold includes a shaft portion corresponding to the hollow portion of the resin molded product that is molded within the molded product space.

4. The resin molding mold according to claim 1 or 2, wherein the area of ​​the opening in the molded product space on the side opposite to the container is smaller than the area of ​​the opening on the container side.

5. The resin molding mold according to claim 1 or 2, wherein the container space, the outer cylinder, and the molding member are cylindrical in shape.

6. A method for manufacturing a resin molded product using a resin molding mold as described in claim 1 or 2, A molding mold preparation step involves filling the container space of the container with a fluid resin and inserting a part of the molding mold into the container space, A filling step in which the molded product space is filled with resin by reducing the pressure of the molded product space using a depressurizing device from the suction port of the outer cylinder of the molding mold, and by inserting the molding mold into the container space using the insertion means, A method for manufacturing a resin molded product, comprising a curing step of filling the molded product space with the resin and then curing it to form a resin molded product.

7. A resin molding apparatus comprising a resin molding mold according to claim 1 or 2, and a vacuum device.

Images