Molding apparatus and control method

Abstract

To miniaturize a molding device for forming a molding body by fusing foamable particles by a micro wave.SOLUTION: A molding device for forming a molding body by fusing resin particles with formability, contains: a movement side unit of which an internal part is a hollow, and that contains a movement side type member on a front surface; a fixing side unit of which the internal part is the hollow, and that contains a fixing side type member at a position faced to the movement side type member of the front surface; a filling device that fills the rising particles in a filling space formed between the fixing side type member and the movement side type member; and a generation device that is provided into a space of the internal part of the fixing side unit and heats the resin particles by ejecting the micro wave into the filling space. The generation device contains: a generator that generates the micro wave; and a waveguide that transmits the micro wave to the filling space.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a molding apparatus for forming a molded article by fusing expandable resin particles. [Background technology]

[0002] Molded articles made of expandable resin particles (hereinafter referred to as "molded foam articles") are used in a variety of applications, such as packaging materials for industrial products and foods, automotive interior materials, and building materials. Various methods have been proposed for forming expanded molded articles by heating expandable resin particles (hereinafter referred to as "expandable particles") to fuse them together.

[0003] For example, Patent Document 1 discloses a method of forming a foamed molded article by fusing expandable particles with steam heating (so-called bead expansion molding). Specifically, a foamable resin is filled into the gap between two opposing molds, and steam heating is supplied into the space to fuse the foamable resins together. However, the technology of Patent Document 1, which fuses the expandable resin with steam heating, has a problem in that an excess or deficiency of steam causes poor fusion, making it impossible to obtain a good foamed molded article.

[0004] Therefore, techniques for fusing expandable resins using methods other than steam heating have also been proposed. For example, Patent Document 2 discloses a method for fusing expandable particles by irradiating them with microwaves. Specifically, two molds for forming a foamed molded body are placed in the internal space of a reactor (container) that blocks microwaves, and expandable particles are filled into the gap between the two molds. Microwaves are then generated by a magnetron installed outside the reactor, and the microwaves are irradiated into the interior of the reactor via a waveguide. When the expandable particles are irradiated with microwaves that have passed through the two molds, the expandable particles are fused together. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-080545 [Patent Document 2] Special Publication No. 2014-531352 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the technology of Patent Document 2 has the problem that the device for fusing expandable particles with microwaves becomes large because it requires a reactor for accommodating two molds and a magnetron and an introduction pipe outside the reactor. In consideration of the above circumstances, the present invention aims to miniaturize a molding device for fusing expandable particles with microwaves to form a foamed molded article. [Means for solving the problem]

[0007] In order to solve the above problems, the molding apparatus of the present invention is a molding apparatus for forming a molded body by fusing foamable resin particles, and is equipped with a movable unit which is hollow inside and includes a movable mold member on its surface, a fixed unit which is hollow inside and includes a fixed mold member at a position on its surface opposite the movable mold member, a filling device which fills the resin particles into a filling space formed between the fixed mold member and the movable mold member, and a generator which is provided in the internal space of the fixed unit and heats the resin particles by emitting microwaves into the filling space, and the generator includes an oscillator which generates the microwaves and a waveguide which transmits the microwaves to the filling space. [Effects of the Invention]

[0008] According to a preferred embodiment of the molding device of the present invention, it is possible to reduce the size of the molding device for forming a foamed molded article by fusing expandable particles with microwaves. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of a molding device according to a first embodiment. [Figure 2] 1 is a cross-sectional view of a molding device according to a first embodiment. [Figure 3] FIG. 2 is a plan view of a moving unit according to the first embodiment. [Figure 4] FIG. 2 is a plan view of the fixed side unit according to the first embodiment. [Figure 5] FIG. 2 is a cross-sectional view of the molding device according to the first embodiment in a state where it is filled with expanded beads. [Figure 6] FIG. 1 is a configuration diagram of a generating device according to a first embodiment. [Figure 7] FIG. 6 is a cross-sectional view of a molding device according to a second embodiment. [Figure 8] FIG. 10 is a schematic diagram for explaining the position at which the stirring mechanism according to the second embodiment is installed. [Figure 9] FIG. 10 is a plan view of a passing section (configuration (1)) according to the second embodiment. [Figure 10] FIG. 10 is a plan view of a passing section (configuration (2)) according to the second embodiment. [Figure 11] FIG. 10 is a plan view of a passing section (configuration (3)) according to the second embodiment. [Figure 12] FIG. 10 is a plan view of a passing section (configuration (4)) according to the second embodiment. [Figure 13] FIG. 10 is a plan view of a passing section (structure (5)) according to the second embodiment. [Figure 14] FIG. 10 is a plan view of a passing section (structure (6)) according to the second embodiment. [Figure 15] FIG. 10 is a perspective view of a stirring mechanism (structure (A)) according to a second embodiment. [Figure 16] FIG. 10 is a perspective view of the stirring mechanism (configuration (B)) according to the second embodiment. [Figure 17] FIG. 10 is a perspective view of a stirring mechanism (configuration (C)) according to a second embodiment. [Figure 18] FIG. 10 is a perspective view of the stirring mechanism (configuration (D)) according to the second embodiment. [Figure 19] FIG. 10 is a perspective view of the stirring mechanism (structure (E)) according to the second embodiment. [Figure 20] FIG. 10 is a perspective view of a stirring mechanism (structure (F)) according to a second embodiment. [Figure 21] FIG. 10 is a perspective view of the stirring mechanism (structure (G)) according to the second embodiment. [Figure 22] FIG. 10 is a configuration diagram illustrating functions of a control unit according to a second embodiment. [Figure 23] 10 is a flowchart (method (a)) of a process executed by a control unit according to the second embodiment. [Figure 24] 10 is a flowchart (method (b)) of a process executed by a control unit according to the second embodiment. [Figure 25] 10 is a flowchart (method (b)) of a process executed by a control unit according to the second embodiment. [Figure 26] FIG. 10 is a configuration diagram illustrating functions of a control unit according to a third embodiment. [Figure 27] FIG. 10 is a schematic view of a mold member according to a fourth embodiment. [Figure 28] 10A and 10B are schematic views illustrating the configuration of a slit according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] [First embodiment] 1 is a cross-sectional view of a molding apparatus 100 according to a first embodiment of the present invention. The molding apparatus 100 is an apparatus for forming a molded article (hereinafter referred to as a "molded foam article") made of expandable resin particles (hereinafter referred to as "expandable particles"). The molded foam article is used for various purposes, such as automotive interior materials, building materials, and packaging materials.

[0011] In general, a foam molded article is formed by filling the internal space (hereinafter referred to as the "filling space") of a molding die with expandable particles and then fusing the expandable particles. The molding die of the first embodiment is composed of a movable mold member 211 and a fixed mold member 311 that correspond to each other, as will be described later. The molding apparatus 100 according to the present invention is an apparatus that includes a molding die. In the first embodiment, it is assumed that a box-shaped foam molded article is to be formed.

[0012] Specifically, the molding apparatus 100 includes a movable unit 20 (a portion where a movable mold member 211 is provided), a fixed unit 30 (a portion where a fixed mold member 311 is provided), a filling device 40, and a generating device 50. As illustrated in FIG. 1, the movable unit 20 and the fixed unit 30 are provided in positions facing each other. In the following description, the direction in which the movable unit 20 and the fixed unit 30 are arranged is referred to as the X direction, the direction perpendicular to the X direction is referred to as the Y direction, and the direction perpendicular to the XY plane is referred to as the Z direction.

[0013] The movable unit 20 is movable in a direction toward (the negative side of the X direction) and a direction away (the positive side of the X direction) from the fixed unit 30. Fig. 2 is a cross-sectional view of the molding apparatus 100 when the movable unit 20 is closest to the fixed unit 30. As illustrated in Fig. 2, when the movable unit 20 approaches the fixed unit 30, a filling space U is formed between the movable mold member 211 and the fixed mold member 311.

[0014] Fig. 3 is a plan view of the moving unit 20 (as viewed from the negative side in the X direction). Fig. 4 is a plan view of the fixed unit 30 (as viewed from the positive side in the X direction). Figs. 1 and 2 are cross-sectional views of the moving unit 20 taken along line aa in Fig. 3 and the fixed unit 30 taken along line bb in Fig. 4.

[0015] Specifically, the movable unit 20 is a hollow structure. As illustrated in Figures 1 and 3, for example, the movable unit 20 includes a movable mold member 211, a support plate 213, a frame portion 215, and a back plate portion 217. The back plate portion 217 is a flat plate-like member that is parallel to the YZ plane. For example, the back plate portion 217 is formed in an elongated shape when viewed from above in the X direction.

[0016] The frame portion 215 is a member that protrudes along the periphery of the back plate portion 217 to the negative side in the X direction (toward the fixed side unit 30). The frame portion 215 is formed around the entire periphery of the back plate portion 217. In other words, the frame portion 215 is formed in a ring shape in a plan view. The method of connecting the frame portion 215 to the back plate portion 217 is arbitrary. For example, the back plate portion 217 and the frame portion 215 are connected by fasteners (e.g., bolts) or by welding.

[0017] The movable mold member 211 is one of two members that make up the molding die. In the first embodiment, as shown in FIG. 3, a configuration in which the movable unit 20 is equipped with four movable mold members 211 is exemplified. The movable mold member 211 is formed into a shape corresponding to the molded body. The planar shape of the movable mold member 211 is typically rectangular.

[0018] 1 and 3, a recess G recessed from the surface is formed in each movable-side mold member 211. Specifically, an annular recess G is formed according to the planar shape of the movable-side mold member 211. The movable-side mold member 211 is supported by a frame portion 215 via a support plate 213.

[0019] 1, the frame portion 215 includes a protrusion N1 at an end opposite to the back plate portion 217. The protrusion N1 is a portion of the frame portion 215 that protrudes in the Y direction toward the space enclosed by the frame portion 215. For example, the protrusion N1 is formed around the entire periphery of the frame portion 215.

[0020] The support plate 213 is a plate-like member parallel to the back plate portion 217 and is connected to the frame portion 215. Specifically, the support plate 213 is connected to the side of the frame portion 215 opposite the back plate portion 217. That is, the back plate portion 217 is located on the positive side of the frame portion 215 in the X direction, and the support plate 213 is located on the negative side of the X direction. The support plate 213 is connected to the frame portion 215 around its entire periphery. Specifically, a protrusion N1 of the frame portion 215 is connected to the periphery of the support plate 213. Note that any method may be used to connect the support plate 213 to the frame portion 215. For example, the frame portion 215 and the support plate 213 are connected by fasteners (e.g., bolts) or by welding.

[0021] 1, through holes H corresponding to the respective movable-side mold members 211 are formed in the support plate 213. The periphery of the movable-side mold member 211 is connected to the support plate 213 in a state in which the recesses G of the movable-side mold member 211 are inserted into the through holes H. The movable-side mold member 211 is provided so as to be spaced apart from the back plate portion 217.

[0022] The movable unit 20 has an internal space R1 formed therein, which is composed of the movable mold member 211, the support plate 213, the frame portion 215, and the back plate portion 217. As can be understood from the above explanation, the movable unit 20 is an element that is hollow inside and includes the movable mold member 211 on its surface. Note that a support member K1 for supporting the movable mold member 211 and the support plate 213 in the internal space R1 is provided on the back plate portion 217.

[0023] A plurality of spacers S are provided on the surface of the movable side unit 20 opposite the back plate portion 217. As illustrated in FIG. 2, the spacers S are portions that come into contact with the surface of the fixed side unit 30 when the movable side unit 20 approaches the fixed side unit 30. For example, the spacers S are provided on the surface of the movable side mold member 211 (the surface opposite the internal space R1) or the surface of the support plate 213 (the surface opposite the internal space R1). The spacers S are provided in areas of each movable side mold member 211 other than the portion that forms the filling space U, and in areas of the support plate 213 that do not overlap with the movable side mold member 211. However, the position, number, and shape of the spacers S are arbitrary.

[0024] The moving unit 20 is supported by a moving plate 23. The moving plate 23 is connected to the surface of the back plate 217 opposite to the frame 215.

[0025] The fixed-side unit 30 is a hollow structure. As illustrated in Fig. 1 and Fig. 4, for example, the fixed-side unit 30 includes a fixed-side mold member 311, a support plate 313, a frame portion 315, and a back plate portion 317. The back plate portion 317 is a flat plate-like member that is parallel to the YZ plane. For example, the back plate portion 317 is formed in an elongated shape when viewed from above in the X direction.

[0026] The frame portion 315 is a member that protrudes along the periphery of the back plate portion 317 toward the positive side in the X direction (toward the moving unit 20). The frame portion 315 is formed around the entire periphery of the back plate portion 317. In other words, the frame portion 315 is formed in a ring shape in a plan view. The method of connecting the frame portion 315 to the back plate portion 317 is arbitrary. For example, the back plate portion 317 and the frame portion 315 are connected by fasteners (e.g., bolts) or by welding.

[0027] 1, the frame portion 315 includes a protrusion N2 at an end opposite to the back plate portion 317. The protrusion N2 is a portion of the frame portion 315 that protrudes in the Y direction toward the space enclosed by the frame portion 315. For example, the protrusion N2 is formed around the entire periphery of the frame portion 315.

[0028] The support plate 313 is a plate-like member parallel to the back plate portion 317 and is connected to the frame portion 315. Specifically, the support plate 313 is connected to the frame portion 315 on the side opposite to the back plate portion 317. That is, the back plate portion 317 is located on the negative side of the frame portion 315 in the X direction, and the support plate 313 is located on the positive side of the X direction. The support plate 313 is connected to the frame portion 315 along the entire periphery. Specifically, the protrusion N2 of the frame portion 315 is connected to the periphery of the support plate 313. Note that the method for connecting the support plate 313 to the frame portion 315 is arbitrary. For example, the frame portion 315 and the support plate 313 are connected by fasteners (e.g., bolts) or by welding.

[0029] The fixed-side mold member 311 is a member of the molding die that corresponds to the movable-side mold member 211. The same number (four) of fixed-side mold members 311 as the movable-side mold members 211 are provided in the fixed-side unit 30. One foam molded body is formed in a molding die configured as a pair of the movable-side mold member 211 and the fixed-side mold member 311. That is, four foam molded bodies are formed in the molding device 100 of the first embodiment. The number of molding dies is arbitrary.

[0030] Specifically, the fixed-side mold member 311 is formed in a shape corresponding to the movable-side mold member 211. In the first embodiment, the fixed-side mold member 311 is formed in a shape corresponding to the inner region of the outer periphery of the recess G of the movable-side mold member 211 in a plan view. For example, the fixed-side mold member 311 is formed in a rectangular shape in a plan view. Each fixed-side mold member 311 is provided at a position facing the movable-side mold member 211 on the surface of the support plate 313.

[0031] The fixed-side unit 30 has an internal space R2 formed therein, which is composed of the fixed-side mold member 311, the support plate 313, the frame portion 315, and the back plate portion 317. As can be understood from the above explanation, the fixed-side unit 30 is an element that is hollow inside and includes the fixed-side mold member 311 on its surface. Note that a support member K2 for supporting the fixed-side mold member 311 and the support plate 313 in the internal space R2 is provided on the back plate portion 317.

[0032] The fixed unit 30 is supported by a fixed plate 33. The fixed plate 33 is connected to the surface of the back plate 317 opposite to the frame portion 315.

[0033] 2, when the movable unit 20 approaches the fixed unit 30 until the spacer S of the movable unit 20 abuts against the support plate 313 of the fixed unit 30, a filling space U is formed between the movable mold member 211 and the fixed mold member 311. The movable mold member 211 and the fixed mold member 311 are formed from various metals such as aluminum.

[0034] The filling device 40 is an injector for filling the filling space U with expandable particles. In the first embodiment, the filling device 40 is provided in the fixed side unit 30. A filling device 40 is provided for each fixed side mold member 311 (filling space U). The filling device 40 is provided so as to penetrate the back plate portion 317, the support plate 313, and the fixed side mold member 311. The filling device 40 discharges expandable particles toward the positive side in the X direction.

[0035] FIG. 5 is a cross-sectional view of the molding apparatus 100 in a state where the filling space U is filled with expandable particles. The molding apparatus 100 fills the filling space U with expandable particles. The filling apparatus 40 is a so-called injector. The filling apparatus 40 is connected to a raw material tank (not shown) that accommodates expandable particles. In practice, when the expandable particles are filled into the filling space U, the filling port (the end on the positive side in the X direction) of the filling apparatus 40 moves toward the fixed unit 30. The number of filling apparatuses 40 for each filling space U and the positions at which the filling apparatus 40 is provided are arbitrary.

[0036] The expandable particles are formed by impregnating particles made of a thermoplastic resin such as a polystyrene resin, a polyolefin resin, a polyolefin, a polyamide resin, or a polyester resin with a foaming agent. The expandable particles may be formed by mixing two or more of these resins. Expandable particles whose surfaces are coated with various flame retardants may also be used. The filling space U may be filled with various other materials (e.g., closed-cell foam particles, copolymers such as polypropylene or polyethylene) in addition to the expandable particles. Furthermore, in order to improve the conductivity of the filling space U, salt water or the like may be filled.

[0037] Any known method may be employed as the method for filling the expandable particles into the filling space U. For example, a method (pressure filling method) in which the expandable particles are pressurized with pressurized gas to impart a predetermined internal pressure to the expandable particles and then filled into the filling space U, a method (compression filling method) in which the expandable particles are compressed with pressurized gas and filled into the pressurized filling space U, and then the pressure in the filling space U is released, or a method (cracking filling method) in which the expandable particles are filled into the filling space U while leaving a small gap between the movable-side mold member 211 and the fixed-side mold member 311, and then the movable-side mold member 211 and the fixed-side mold member 311 are completely closed to mechanically compress the expandable particles, etc. may be employed.

[0038] The generator 50 is a device for heating the expandable particles by emitting microwaves E of a predetermined frequency band into the filling space U. The generator 50 of the first embodiment is provided in the internal space R2 of the fixed side unit 30. The generator 50 of the present invention is used to fuse the expandable particles filled in the filling space U. The expandable particles filled in the filling space U are heated by being irradiated with the microwaves E generated by the generator 50, and the expandable particles with softened surfaces fuse to each other. Then, when the fused expandable particles are cooled, a foamed molded article is formed.

[0039] In addition, in the molding apparatus 100 of the first embodiment, in order to promote the fusion of the expandable particles, a configuration is also adopted in which copper pipes through which liquid at a constant temperature flows are brought into close contact with the movable side mold member 211 and the fixed side mold member 311, thereby controlling the heat of the movable side mold member 211 and the fixed side mold member 311.

[0040] The frequency band of the microwaves E generated by the generator 50 is, for example, the 2450 MHz band, which is the "frequency band designated for use as an ISM fundamental frequency" defined by J Standard J55011 (H27). However, the frequency band of the microwaves is not limited to the above examples. For example, it can be changed as appropriate depending on the material of the expandable particles and the size of the foamed molded body. Furthermore, the microwaves are irradiated so that the temperature reaches, for example, 80°C to 180°C (however, this temperature is not limited).

[0041] 6 is a configuration diagram (schematic diagram) showing an example of a generator 50. The generator 50 includes, for example, an oscillator 51, a waveguide 53, an isolator 55, a power monitor 57, and a tuner 59. The oscillator 51 (magnetron: output 300 W to 10 kW) is a device that generates microwaves E. The waveguide 53 is connected to the oscillator 51 and is a member that transmits the microwaves E generated by the oscillator 51 to the filled space.

[0042] An isolator 55, a power monitor 57, and a tuner 59 are provided in the waveguide 53. Microwaves E are irradiated into the filled space U through the waveguide 53. The isolator 55 is a device that absorbs reflected waves from the filled space U. The power monitor 57 is a device that detects the power of the forward wave and the power of the reflected wave of the microwaves E propagating within the waveguide 53. Note that the power monitor 57 can detect not only the power of the reflected wave, but also the amplitude and phase of the reflected wave. The tuner 59 is a device that adjusts the power of the reflected wave.

[0043] In the first embodiment, for example, the portion of the waveguide 53 beyond the tuner 59 is branched toward each fixed-side mold member 311. Specifically, as illustrated in Fig. 6, the waveguide 53 includes the same number of branch portions 531 as the number of fixed-side mold members 311 at the end opposite the oscillator 51. That is, in the first embodiment, four branch portions 531 are included. For convenience, only a cross section of the branch portion 531 is shown in the generator 50 of Fig. 1.

[0044] In the following explanation, the explanation will be focused on one fixed side mold member 311, but the other three fixed side mold members 311 have the same configuration.

[0045] The branching portion 531 is connected to the fixed-side mold member 311. As illustrated in FIGS. 1, 4, and 6, a through hole T for connecting the branching portion 531 is formed in each fixed-side mold member 311. Specifically, the end (opening portion) of the waveguide 53 opposite the oscillator 51 is connected to the through hole T from the opposite side to the movable-side mold member 211. In the first embodiment, the end of the branching portion 531 of the waveguide 53 is connected to the through hole T.

[0046] Incidentally, the support plate 313 also has an insertion hole formed therein at a position corresponding to the through hole T, through which the branch portion 531 is inserted. That is, each branch portion 531 of the waveguide 53 is connected to the through hole T while being inserted through the support plate 313. The position at which the through hole T is formed in the fixed-side mold member 311 is arbitrary. The branch portion 531 is connected to the through hole T so that its tip does not protrude from the surface of the fixed-side mold member 311.

[0047] The opening of the through-hole T on the movable mold member 211 side (the filling space U side) is closed by a lid member 532. The lid member 532 is formed in a thin plate shape from a material that transmits microwaves E. Examples of materials that transmit microwaves E include resins such as polypropylene, polyethylene, polyetherimide, and polytetrafluoroethylene, and ceramics such as alumina, mullite, and pyrophyllite. However, the microwave-transmitting material is not limited to the above examples. The microwaves E transmitted from the branching portion 531 pass through the lid member 532 and are irradiated onto the expandable particles in the filling space U. Note that a tuner 59 may be provided for each branching portion 531. Furthermore, if the through-hole T is large enough to allow microwaves to pass through and not allow the expandable particles to enter, the lid member 532 is not essential.

[0048] In the first embodiment, it is preferable that the elements of the movable side unit 20 and the fixed side unit 30 are configured to prevent microwave E from leaking outside the molding apparatus 100. For example, the elements of the movable side unit 20 and the fixed side unit 30 are formed of a material that blocks microwaves. For example, the movable side mold member 211 and the fixed side mold member 311 are formed of various metals such as aluminum, copper, or iron. However, it is not necessary to form all the elements of the movable side unit 20 and the fixed side unit 30 from a material that blocks microwaves. The configuration of the generator 50 is not limited to the example shown in FIG. 6 as long as it can generate microwaves in a predetermined frequency band.

[0049] In order to prevent sparks from occurring in the filling space U due to the microwaves E, it is preferable to provide a safety device (earth) in the filling space U to allow the microwaves E to escape.

[0050] In Comparative Example 1 (e.g., Patent Document 1), in which the foamable resin is fused with heated steam, there is a problem in that an excess or deficiency of heated steam causes poor fusion, making it impossible to obtain a good foamed molded article. In contrast, according to the molding apparatus 100 of the present invention, the foamable resin is fused using microwaves, which has the advantage that poor fusion is less likely to occur than in the configuration of Comparative Example 1.

[0051] Furthermore, in Comparative Example 2 (e.g., Patent Document 2), in which microwaves are supplied from a generator provided outside a housing that houses the entire movable unit and fixed unit, the molding apparatus becomes large. In contrast, with the molding apparatus 100 of the first embodiment, in which the generator 50 is built into the internal space R2 of the fixed unit 30 and microwaves are irradiated onto the expandable resin from the internal space R2, it is possible to reduce the size of the molding apparatus 100 for fusing the expandable particles with microwaves compared to Comparative Example 2.

[0052] Furthermore, in Comparative Example 2, in order to irradiate the foamable resin with microwaves, the majority of the entire movable unit and fixed unit must be made of a material that transmits microwaves. In other words, it is difficult to form the movable unit and fixed unit from metal, which blocks microwaves. Therefore, in Comparative Example 2, the materials from which the movable unit and fixed unit can be formed are limited, resulting in low design freedom. In contrast, in the first embodiment, microwaves E are transmitted to the filling space U through the waveguide 53 of the generator 50 provided inside the internal space R2, so it is also possible to form each element of the movable unit 20 and fixed unit 30 from metal. Consequently, compared to Comparative Example 2, this embodiment has the advantage of providing greater design freedom for the movable unit 20 and fixed unit 30.

[0053] Furthermore, in Comparative Example 2, microwaves are generated outside the moving unit and the fixed unit, making it difficult to predict the direction in which the microwaves will travel. Therefore, it is difficult to properly irradiate the expandable granules filled in the filling space with microwaves. This ultimately leads to problems such as uneven fusion, which can lead to errors in the quality of the molded product. In contrast, the first embodiment has the advantage of properly irradiating the expandable granules with microwaves E via the waveguide 53 of the generator 50 installed in the internal space R2.

[0054] [Second embodiment] A second embodiment will be described. In the following examples, elements that have the same functions as those in the first embodiment will be designated by the same reference numerals as those in the first embodiment, and detailed descriptions thereof will be omitted where appropriate.

[0055] 7 is a cross-sectional view of a molding apparatus 100 according to a second embodiment. The molding apparatus 100 according to the second embodiment has a configuration in which a stirring mechanism 60 is provided in addition to the molding apparatus 100 according to the first embodiment. The stirring mechanism 60 is a mechanism for stirring the microwaves in the filling space U, thereby irradiating the microwaves over the entire expandable particles in the filling space U. A stirring mechanism 60 is provided for each filling space U.

[0056] Fig. 8 is a schematic diagram illustrating the position where the stirring mechanism 60 is installed. As illustrated in Fig. 8, the stirring mechanism 60 is installed on the surface of at least one of the fixed-side mold member 311 and the movable-side mold member 211 (the surface opposite the filling space U). Note that Fig. 7 illustrates the case where the stirring mechanism 60 is installed on the surface of the movable-side mold member 211. However, a configuration in which the stirring mechanism 60 is installed on the surface of the fixed-side mold member 311 or on the surfaces of both the fixed-side mold member 311 and the movable-side mold member 211 may also be adopted.

[0057] In the following description, the surface of the fixed-side mold member 311 and the movable-side mold member 211 on which the stirring mechanism 60 is provided will be referred to as the installation surface F. Furthermore, when there is no need to distinguish between the fixed-side mold member 311 and the movable-side mold member 211, they will simply be referred to as mold members.

[0058] 8, the installation surface F is provided with a passing section D through which microwaves in the filling space U can pass. The stirring mechanism 60 changes the amplitude and phase of the microwaves that have passed through the passing section D from the filling space U, and emits the microwaves with the changed amplitude and phase from the passing section D into the filling space U, thereby stirring the microwaves (electromagnetic field distribution) in the filling space U.

[0059] Specifically, the stirring mechanism 60 includes a housing 601. The housing 601 is, for example, a structure having an opening O and is made of a metal that does not allow microwaves to pass through. In the second embodiment, a cylindrical housing 601 having a square bottom is exemplified. That is, the opening O is on the side of the housing 601 opposite the bottom. The housing 601 is provided on the installation surface F so that the passing portion D is located inside the opening O of the housing 601. In other words, the housing 601 is provided on the installation surface F so as to cover the passing portion D. Microwaves enter the internal space R3 of the housing 601 from the filling space U through the passing portion D.

[0060] The shape of the casing 601 is arbitrary as long as microwaves can pass between the internal space R3 of the casing 601 and the filling space U via the passage D and can block microwaves. For example, the casing 601 may be formed so as to cover the entire surface of the mold member on which the stirring mechanism 60 is provided. The specific configuration of the stirring mechanism 60 other than the casing 601 will be described later.

[0061] Various configurations can be adopted for the passing section D as long as microwaves can pass through without the expandable particles in the filling space U leaking out. For example, the following configurations (1)-(6) can be adopted as the passing section D. Figures 9-14 are diagrams of the passing section D relating to configurations (1)-(6) when viewed from the W direction in Figure 8 (a direction perpendicular to the installation surface F).

[0062] <Configuration (1)> As illustrated in FIG. 9, the passage D of the configuration (1) includes a long slit D1 (an example of a first slit). The slit D1 penetrates the installation surface F. That is, the filling space U and the internal space R3 of the housing 601 communicate with each other via the slit D1. The direction in which the slit D1 extends is a direction that intersects with the direction of oscillation of the electric field of the microwaves emitted by the generator 50. FIG. 9 illustrates a case in which the slit D1 extends in a direction perpendicular to the direction of oscillation of the electric field of the microwaves emitted by the generator 50.

[0063] From the viewpoint of allowing microwaves to pass through appropriately, the length L of the slit D1 is, for example, equal to or greater than half the wavelength of the microwaves emitted by the generator 50. The width W of the slit D1 is set to be smaller than, for example, the diameter of the expandable particles in the filling space U in order to prevent the expandable particles from leaking into the internal space R3 through the slit D1.

[0064] <Configuration (2)> As illustrated in Fig. 10, the passing portion D of the configuration (2) includes two or more slits D1 arranged at a distance T from each other. The distance T is set to, for example, ¼ or more of the wavelength of the microwaves in order to suppress electromagnetic coupling between the slits D1 and reduce heat loss in the slits D1. The configuration (2) allows microwaves to pass through more efficiently than the configuration (1).

[0065] <Configuration (3)> 11, the passing portion D of the configuration (3) is a slit D2 (an example of a first slit). However, the slit D2 of the configuration (3) extends in a direction different from that of the slit D1. Specifically, the slit D2 of the configuration (3) extends in a direction inclined at an angle other than 90 degrees (for example, about 45 degrees) with respect to the direction of oscillation of the electric field of the microwave emitted by the generating device 50.

[0066] By adopting configuration (3), it becomes possible to change the direction of oscillation (polarization) of the magnetic field of microwaves entering and exiting through the passage D. In other words, the passage D (slit D2) of configuration (3) functions as a polarizer. Therefore, compared to configuration (1), it becomes possible to generate microwaves polarized on multiple axes within the filled space U. Ultimately, there is a significant effect of being able to irradiate microwaves throughout the entire filled space U. The angle at which the slit D2 is inclined can be any angle as long as it can function as a polarizer.

[0067] <Configuration (4)> As illustrated in Fig. 12, the passing portion D of the configuration (4) includes two or more slits D2 arranged at a distance T from each other. As in the case of the configuration (2), the distance T is set to, for example, ¼ or more of the wavelength of the microwave in order to suppress electromagnetic coupling between the slits D2 and reduce heat loss in the slits D2. The configuration (4) allows microwaves to pass through more efficiently than the configuration (3).

[0068] <Configuration (5)> As illustrated in Fig. 13, the passing portion D of the configuration (5) is a transmitting member D3 that transmits microwaves. The material of the transmitting member D3 is arbitrary, but examples of suitable materials include glass, quartz, ceramic, and Teflon (registered trademark), which have a low degree of microwave loss (low dielectric tangent). A through-hole is formed in the installation surface F, and the transmitting member is provided to close the through-hole. The size of the transmitting member D3 is arbitrary.

[0069] In the configuration (5), microwaves can be transmitted more efficiently than in the configurations (1) to (4). On the other hand, in the configurations (1) to (4), the transparent member D3 is not required, and therefore the configuration of the passing section D can be simplified compared to the configuration (5).

[0070] <Configuration (6)> As illustrated in FIG. 14, the passing section D of the configuration (6) includes a polarizer B in addition to the transmitting member D3 of the configuration (5). The polarizer B is a long member formed of a metal that reflects microwaves. For example, the polarizer B is installed on the surface of the transmitting member D3 (the surface on the filling space U side or the surface on the stirring mechanism 60 side). Specifically, the polarizer B is formed so as to extend in a direction inclined at an angle other than 90 degrees (for example, about 45 degrees) with respect to the direction of oscillation of the electric field of the microwaves emitted by the generator 50. The angle at which the polarizer B is inclined is arbitrary as long as it can function as a polarizer.

[0071] By adopting the configuration (6), it is possible to change the direction of oscillation (polarization) of the electric field of the microwaves that enter and exit through the passing section D (transparent member D3). Therefore, compared to the configuration (5), it is possible to generate microwaves polarized on multiple axes within the filled space U. Consequently, there is a remarkable effect that microwaves can be irradiated throughout the entire filled space U.

[0072] However, the configuration of the passage section D is not limited to configurations (1)-(6) as long as microwaves can pass between the internal space R3 of the housing section 601 and the filling space U via the passage section D and the expandable particles in the filling space U do not leak out.

[0073] The stirring mechanism 60 may have a variety of configurations as long as it is capable of changing the amplitude and phase of the microwaves that have passed through the passage D. For example, the following configurations (A) to (G) are exemplified. Figures 15 to 21 are schematic perspective views of configurations (A) to (G). The stirring of the microwaves by the stirring mechanism 60 is controlled by a control unit, which will be described later.

[0074] <Configuration (A)> 15, the stirring mechanism 60 of configuration (A) has a screw unit 602 including a plurality of blades that rotate around a rotation axis, in an internal space R3 of a housing unit 601. The rotating screw unit 602 changes the amplitude and phase of the microwave. The specific configuration of the screw unit 602 (for example, the shape of the blades, the position of the rotation axis, etc.) is set appropriately so that the amplitude and phase of the microwave changes.

[0075] <Configuration (B)> As illustrated in FIG. 16 , the stirring mechanism 60 of configuration (B) has a configuration in which the housing 601 itself is extendable and retractable. The configuration for extending and retracting the housing 601 is arbitrary. For example, the housing 601 is configured with a cylindrical first member 611 that is open at both ends and a cylindrical second member 612 that is open at only one end and has a bottom. One open side of the first member 611 is placed on the installation surface F so that the passing section D is located inside, and the other open side of the first member 611 is inserted into the second member 612. With the first member 611 inserted inside, the second member 612 can move both toward and away from the passing section D. The extension and retraction of the housing 601 changes the amplitude and phase of the microwaves.

[0076] <Configuration (C)> As illustrated in FIG. 17 , the stirring mechanism 60 of configuration (C) includes a metal shaft member 603 that can move within the internal space R3 of the housing 601. The number of shaft members 603 is arbitrary, but FIG. 17 illustrates a case in which there are two shaft members 603. One of the shaft members 603 is arranged, for example, in the internal space R3 so as to align with the direction of oscillation of the electric field of the microwaves emitted from the generator 50, and is movable along the same direction as the direction of oscillation of the electric field. The other shaft member 603 is arranged, for example, in the internal space R3 so as to align with the direction of oscillation of the magnetic field of the microwaves emitted from the generator 50, and is movable along the same direction as the direction of oscillation of the magnetic field. The movement of the shaft member 603 changes the amplitude and phase of the microwaves. However, the number and orientation of the shaft members 603 are not limited to those illustrated above.

[0077] <Configuration (D)> As illustrated in FIG. 18, the stirring mechanism 60 of configuration (D) is configured such that the housing 601 is rotatable. Specifically, the housing 601 rotates around an axis passing through the center of the opening O of the housing 601. Any specific configuration can be used to rotate the housing 601. The stirring mechanism 60 of configuration (D) also functions as a polarizer. The rotation of the housing 601 changes the amplitude and phase of the microwave.

[0078] <Configuration> As illustrated in FIG. 19 , the stirring mechanism 60 of the configuration (E) is configured to be able to open and close an opening O in a housing unit 601. The stirring mechanism 60 includes, for example, a plate-shaped shielding unit 604 for opening and closing the opening O. The shielding unit 604 is made of, for example, metal and is provided so as to be positioned between the end of the housing unit 601 on the opening O side and the installation surface F. For example, two shielding units 604A are provided that are movable along the same direction as the oscillation direction of the magnetic field of the microwaves emitted from the generator 50, and two shielding units 604B are provided that are movable along the same direction as the oscillation direction of the electric field of the microwaves emitted from the generator 50. The two shielding units 604A are located on opposite sides of the opening O, and the two shielding units 604B are similarly located on opposite sides of the opening O. Each shielding unit 604A and each shielding unit 604B is movable in a direction to open and close the opening O. It is to be noted that only one of shielding portion 604A and shielding portion 604B may be provided. The amplitude and phase of the microwave change when opening / closing opening O of housing portion 601. However, the configuration of shielding portion 604 is not limited to the above example.

[0079] <Configuration> As illustrated in Figure 20, the stirring mechanism 60 of configuration (F) includes a probe 605 installed in the internal space R3 of the housing 601. In configuration (F), the impedance of the load connected to the probe 605 is changed. By changing the impedance of the load connected to the probe 605, the length of the probe 605 functions to expand and contract. As a result, the amplitude and phase of the microwave change.

[0080] The configuration for changing the impedance of the load connected to the probe 605 is arbitrary, but for example, the following configurations (F1) to (F3) are adopted.

[0081] The configuration (F1) is a configuration in which one of a plurality of loads having different impedances is selectively connected to the probe 605. The loads are switched by a switch.

[0082] Configuration (F2) is a configuration in which the impedance is changed by phase control using a phase shifter (for example, a line stretcher). The impedance of the load is changed by changing the phase of the microwaves transmitted through the line stretcher by expanding or contracting the line stretcher. Note that a digital phase shifter may be used as the phase shifter, and the method of phase change is not important.

[0083] The configuration (F3) is a configuration using an element whose impedance changes by voltage control. Specifically, the impedance of the load connected to the probe 605 is changed by changing the voltage applied to the element. Examples of elements whose impedance changes under voltage control include a variable capacitor and a PIN diode.

[0084] <Configuration (G)> As shown in FIG. 21, stirring mechanism 60 of configuration (G) includes coil 606 (helical antenna) made of a linear conductor wound into a spiral. Coil 606 is installed in internal space R3 of housing 601. Rotating coil 606 with motor 607 makes it possible to equivalently control the phase of microwaves entering and emitting from coil 606. Rotating coil 606 changes the amplitude and phase of the microwaves.

[0085] Note that a configuration in which the coil 606 has circular polarization characteristics (characteristics in which the vibration direction of the incident and emitted microwaves rotates over time) may also be adopted. For example, by designing the coil 606 as described in "Balanis, Constantine A. Antenna theory: analysis and design. John Wiley & Sons, 2015.", the coil 606 can be given circular polarization characteristics. Therefore, the microwaves incident and emitted from the coil 606 have circular polarization characteristics. This makes it possible to excite microwaves with polarization on multiple axes even within the filled space U. As described above, the stirring mechanism 60 of configuration (G) also functions as a polarizer.

[0086] In configuration (F), changing the impedance requires switching the switch an enormous number of times, which makes the switch susceptible to wear. This is expected to shorten the life of the stirring mechanism 60. In contrast, configuration (G) is easier to implement than configuration (F), and is also expected to extend the life of the stirring mechanism 60.

[0087] The microwaves whose amplitude and phase have been changed by the stirring mechanism 60 are emitted into the filling space U through the passage D. The configuration of the stirring mechanism 60 is not limited to configurations (A)-(G) as long as it is possible to change the amplitude and phase of the microwaves incident from the passage D. A drive device (not shown) for driving the stirring mechanism 60 is appropriately mounted on the molding machine.

[0088] The molding apparatus 100 of the second embodiment includes a control unit 70 for controlling the stirring mechanism 60. The control unit 70 is a computer system including one or more processing circuits such as a CPU (Central Processing Unit), and controls the stirring mechanism 60 in an integrated manner.

[0089] Here, microwave loss decreases in the portion of the filling space U where the heating of the expandable granules progresses and the moisture content decreases. When microwave loss decreases, reflected waves naturally decrease as well. In other words, if the stirring mechanism 60 is controlled so as to reduce reflected waves, it can be assumed that heating is progressing appropriately throughout the expandable granules in the filling space U.

[0090] Taking the above into consideration, the control unit 70 controls the stirring mechanism 60 so as to reduce reflection. Specifically, the control unit 70 changes the stirring state (hereinafter referred to as the "stirring state") of the stirring mechanism 60 so as to reduce reflection (i.e., reduce the power of the reflected wave). The stirring state can also be expressed as the state of the amplitude and phase of the microwave.

[0091] Fig. 22 is a configuration diagram illustrating the function of the control unit 70. As illustrated in Fig. 22, the control unit 70 controls the stirring mechanism 60 in accordance with information P of the reflected wave detected by the power monitor 57 (hereinafter referred to as "reflected wave information").

[0092] The manner in which the stirring state is changed differs depending on which of the configurations (A) to (F) is adopted. For example, in the case of configuration (A), the stirring state can be changed by changing the rotation speed of the screw portion 602 or the position of the blade portion of the screw portion 602; in the case of configuration (B), the degree and speed of extension and contraction can be changed; in the case of configuration (C), the movement speed and position of the shaft member 603 can be changed; in the case of configuration (D), the angular velocity and rotation angle can be changed; in the case of configuration (E), the degree and speed of the opening can be changed; in the case of configuration (F), the impedance of the load can be changed; and in the case of configuration (E), the angular velocity and rotation angle of the coil can be changed.

[0093] Hereinafter, methods (a) and (b) in which the control unit 70 controls the stirring mechanism 60 will be exemplified.

[0094] <Method (a)> In the method (a), the reflected wave information P detected by the power monitor 57 is exemplified by the power of the reflected wave.

[0095] Fig. 23 is a flowchart showing an example of processing executed by the control unit 70 according to method (a). The processing in Fig. 23 is started, for example, when the generator 50 starts operating (heating starts). When the processing in Fig. 23 starts, first, the control unit 70 acquires the power of the reflected wave (reflected wave information P) from the power monitor 57 (Sa1). The power of the reflected wave is repeatedly acquired at predetermined intervals.

[0096] Next, the control unit 70 determines whether the power of the reflected wave has decreased (Sa2). For example, the control unit 70 compares the power of the reflected wave acquired in step Sa1 with the power of the reflected wave acquired previously. Note that the power of the reflected wave acquired previously may be, for example, the power of the reflected wave acquired immediately before step Sa1 (the previous point in time) or the power of the reflected wave acquired at a point in time over a predetermined period of time (for example, several seconds to several minutes ago).

[0097] If it is determined that the power of the reflected wave has not decreased (i.e., the power of the reflected wave is maintained or increased) (Sa2; NO), it can be assumed that the heating is not proceeding properly. In other words, it can be assumed that the current stirring state of the stirring mechanism 60 is not appropriate. Therefore, the control unit 70 changes the stirring state (Sa4). Then, after changing the stirring state, the process returns to step Sa1.

[0098] On the other hand, if it is determined that the power of the reflected wave is decreasing (Sa2; YES), it can be assumed that the heating is proceeding appropriately. That is, it can be assumed that the stirring state of the stirring mechanism 60 is appropriate. In this case, the control unit 70 determines whether a predetermined time has elapsed since the start of heating (for example, the time at which it can be assumed that heating has been completed over the entire filling space U) (Sa3).

[0099] If the predetermined time has elapsed since the start of heating (Sa3; YES), the process of Fig. 23 ends. On the other hand, if the predetermined time has not elapsed since the start of heating (Sa3; NO), the process returns to step Sa1.

[0100] In step Sa2, for example, it may be determined whether the power of the reflected wave has decreased by determining whether the rate of decrease (rate of change) of the power of the reflected wave exceeds a predetermined threshold, or by determining whether the value of the power of the reflected wave is below a predetermined threshold. Furthermore, in step Sa3, the specific process for determining whether heating has been completed throughout the filling space U is not limited to the above example. As can be understood from the above explanation, the method by which the control unit 70 controls the stirring mechanism 60 in method (a) is not limited to the above example. Method (a) can be adopted in any of configurations (A) to (F).

[0101] <Method (b)> In the method (b), the control unit 70 uses the power and phase of the reflected wave as the reflected wave information P acquired from the power monitor 57. The method (b) is employed in, for example, the configuration (F).

[0102] Fig. 24 is a flowchart showing an example of processing executed by the control unit 70 according to the method (b). In the configuration (F), the load is set to an arbitrary impedance in advance. The processing of Fig. 24 is started, for example, when the generator 50 starts operating (heating starts).

[0103] 24 starts, the control unit 70 sets the impedance of the load (Sb1). Specifically, the control unit 70 sets the impedance of the load so that reflection is reduced. Fig. 25 is a detailed flowchart of the process of Sb1.

[0104] First, the control unit 70 acquires the power and phase of the reflected wave (an example of reflected wave information P) from the power monitor 57 (Sb11). Note that in step Sb1, the amplitude of the reflected wave may be used instead of the power of the reflected wave. The control unit 70 repeats step Sb11 until the power and phase of the reflected wave are acquired for a plurality of different impedances (e.g., three) (Sb12; NO).

[0105] When the acquisition of the power and phase of the reflected wave for each of the plurality of impedances is completed (Sb12; YES), the control unit 70 determines the relationship between the reflection level and the load impedance (hereinafter referred to as "reflection characteristics") from the power and phase of the reflected wave determined for each of the plurality of impedances (Sb13). Note that any known technique (e.g., "Receiver-Feedback-Free Cavity Resonant Wireless Power Transfer Based on In Situ S-Parameter Estimation Using a Parasitic Antenna," IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. 20, NO. 10, OCTOBER 2021) is used to estimate the reflection characteristics.

[0106] Then, the control unit 70 identifies the impedance of the load at which reflection is reduced from the reflection characteristics identified in step Sb13 (Sb14). For example, the control unit 70 identifies the impedance at which the reflection level is minimized in the reflection characteristics. Then, the control unit 70 sets the impedance of the load to the identified impedance. That is, the stirring state changes.

[0107] When the process of step Sb1 is completed, the process of steps Sa1-Sa3 is executed in the same manner as in method (a). However, if it is determined that the power of the reflected wave has not decreased (Sa2; NO), the process returns to step Sb1. That is, the impedance of the load is set again.

[0108] Note that method (b) can also be applied to configurations other than configuration (F). For example, in configuration (G), it is possible to obtain the power and phase of the reflected wave when the coil is fixed at a plurality of different rotation angles, and estimate the reflection characteristics.

[0109] As can be understood from the above explanation, stirring mechanism 60 and tuner 59 are controlled in accordance with reflected wave information P. Examples of reflected wave information P include at least one of the power, amplitude, and phase of the reflected wave. However, the method for controlling stirring mechanism 60 is not limited to method (a) and method (b).

[0110] In the second embodiment, the stirring mechanism 60 is controlled in accordance with the reflected wave information P, so that it is possible to sufficiently irradiate the expandable particles filled in the filling space U with microwaves while reducing the reflected waves.

[0111] [Third embodiment] FIG. 26 is a configuration diagram showing the functions of the control unit 70 according to the third embodiment.

[0112] Here, the reflected waves are not consumed within the filled space U, but are lost as wasted heat energy in the isolator 55. Therefore, the control unit 70 of the third embodiment further reduces the reflected waves by controlling the tuner 59 to remove the reflected waves remaining after controlling the stirring mechanism 60. That is, in addition to controlling the stirring mechanism 60, the control unit 70 also controls the tuner 59 in accordance with the reflected wave information P detected by the power monitor 57.

[0113] Specifically, the control unit 70 sets the impedance in the tuner 59 to an impedance that reduces reflection. The control unit 70 may specify the impedance by any method. For example, the control unit 70 may specify (search for) an impedance that reduces reflection based on a sweep or probabilistic method in accordance with the power of the reflected wave detected by the power monitor 57 (an example of the reflected wave information P), or may specify (search for) a unique impedance that reduces reflection in accordance with the power and phase of the reflected wave detected by the power monitor 57 (an example of the reflected wave information P). The specified impedance is then set in the tuner 59.

[0114] The method for uniquely identifying the impedance that reduces reflection involves determining in advance, through experiments, simulations, etc., the impedance that allows tuner 59 to reduce reflection for any "power and phase of the reflected wave," thereby identifying the relationship between the impedance and the reflection characteristics. Then, the impedance that corresponds to the "power and phase of the reflected wave" detected by power monitor 57 in the relationship between the impedance and the reflection characteristics is uniquely identified as the impedance that reduces reflection.

[0115] In the third embodiment, the tuner 59 is also controlled in addition to the stirring mechanism 60, which makes it possible to further reduce reflected waves. Note that a configuration in which only the tuner 59 is controlled without assuming control of the stirring mechanism 60 may also be employed.

[0116] [Fourth embodiment] The mold member of the fourth embodiment has a slit (an example of a second slit). The configuration of the fourth embodiment may be provided in any of the molding apparatuses 100 of the first to third embodiments.

[0117] 27 is a schematic diagram of a mold member (211, 311) according to the fourth embodiment. A slit (through hole) is provided at any corner J (corner) of the mold member. The corner J is a portion where different surfaces of the mold member (211, 311) intersect and connect with each other.

[0118] Here, electromagnetically, only an electric field perpendicular to the surface of a conductor is excited. Therefore, an electric field is difficult to generate at the corner J of the mold member. In other words, there is a problem that microwaves are difficult to agitate at the corner J.

[0119] Therefore, in the fourth embodiment, the electric field is trapped in a slit provided in the corner J (the electric field is brought close to the slit without leaking out from the slit), thereby exciting the electric field in the corner J. Consequently, it becomes possible to sufficiently stir the microwaves even in the corner J.

[0120] Various configurations are employed for the slit. Fig. 28 is a schematic diagram illustrating the configuration of the slit. Fig. 28 shows slits (elongated white portions) according to configurations (I)-(VI). Fig. 28 shows a corner J where two intersecting (orthogonal) faces F1 and F2 are connected.

[0121] 28 is set to, for example, ¼ or less (preferably ⅛ or less) of the wavelength of the microwave emitted by the generator 50, in order to prevent the microwave from leaking from the slit. The width (length in the lateral direction) of the slit is set to be smaller than the diameter of the expandable particles, in order to prevent the expandable particles from leaking from the slit.

[0122] The configuration (I) includes a slit 71 provided along the side at the corner J (that is, the boundary line where two faces connect).

[0123] The configuration (II) includes a slit 72 provided at the corner J so as to be perpendicular to the side.

[0124] The configuration (III) includes a slit 71 and a slit 72 that are provided so as to be perpendicular to each other.

[0125] Configuration (IV) includes a slit 73 provided so as to form a predetermined angle (less than 90 degrees) with respect to the side of corner J. For example, the slit 73 is provided so as to form an angle of approximately 45 degrees with respect to the side of corner J. Furthermore, two slits 73 may be provided so as to intersect with each other and form a predetermined angle with respect to the side of corner J.

[0126] Configuration (V) includes slits 74 and 75 in addition to slits 71 and 72. Slits 71 and 72 are provided at different positions (i.e., not at positions perpendicular to each other). Slit 74 is provided at an end of slit 72 so as to be perpendicular to slit 72. Slit 75 is provided at an end of slit 71 so as to be perpendicular to slit 71.

[0127] Like the configuration (V), the configuration (IV) includes slits 71, 72, 74, and 75. However, in the configuration (IV), the slits 71 and 72 are provided at positions perpendicular to each other, and then the slits 74 and 75 are provided.

[0128] Note that, in structures (I)-(VI), it is preferable that the slits provided on surfaces F1 and F2 are provided symmetrically about the side at corner J, as illustrated in Fig. 28. In particular, at a corner where three surfaces intersect among corner J (for example, corner Jz illustrated in Fig. 27), it is preferable that the slits are provided with corner Jz as the center, as illustrated in Fig. 28. However, the slits provided at the corners are not limited to structures (I)-(VI).

[0129] According to the configuration of the fourth embodiment, it is possible to sufficiently agitate the microwaves even at the corners J.

[0130] <Modification> The above-described embodiments can be modified in various ways. Specific examples of modifications are shown below. Two or more embodiments selected from the following examples can be combined as appropriate.

[0131] (1) In each of the above-described embodiments, the movable unit 20 may have any specific configuration as long as it has an internal space R1 and includes a movable mold member 211 on its surface. Similarly, the fixed unit 30 may have any specific configuration as long as it has an internal space R2 and includes a movable mold member 211 on its surface.

[0132] (2) In the above-described embodiments, the generator 50 is disposed in the internal space R2 of the fixed unit 30, but the generator 50 may be disposed in the internal space R1 of the mobile unit 20. Furthermore, the generator 50 may be provided in both the internal space R1 of the mobile unit 20 and the internal space R2 of the fixed unit 30.

[0133] (3) In each of the above-described embodiments, the shapes of the movable-side mold member 211 and the fixed-side mold member 311 are arbitrary. For example, it is possible to use a movable-side mold member 211 having a convex portion formed thereon that protrudes toward the fixed-side unit 30, and a fixed-side mold member 31 having a concave portion that corresponds to the convex portion of the movable-side mold member 211. In addition, the filling device 40 may be provided in the fixed-side unit 30.

[0134] (4) In each of the above-described embodiments, a configuration is adopted in which the waveguide 53 of one generator 50 is branched and connected to each fixed-side mold member 31, but the configuration for irradiating the expandable particles in the filling space U with microwaves E is not limited to the above example. For example, a generator 50 may be provided for each fixed-side mold member 31. The molding apparatus 100 may have any configuration as long as it is possible to irradiate the expandable particles with microwaves E via the waveguide 53 of the generator 50 provided in the internal space R2 (or internal space R1).

[0135] (5) In each of the above-described embodiments, it is preferable to form fine irregularities (microfabrication) on the surfaces of both the movable-side mold member 211 and the fixed-side mold member 31 on the filling space U side in order to diffusely reflect the microwaves E transmitted into the filling space U. Diffused reflection of the microwaves E in the filling space U makes it possible to effectively fuse the expandable particles.

[0136] (6) The stirring mechanism according to the second embodiment can be considered an independent feature, regardless of the specific configuration of the molding device. Specifically, the molding device can be considered as a molding device for forming a molded body by fusing expandable resin particles, comprising a mold member (mold) having a filling space into which the resin particles are filled, a generator that emits microwaves into the filling space to heat the resin particles, and a stirring mechanism that stirs the microwaves in the filling space, wherein the mold member has a passage through which the microwaves can pass, and the stirring mechanism is connected to the passage, changes the amplitude and phase of microwaves that pass through the passage from the filling space, and emits the microwaves after the amplitude and phase change from the passage to the filling space. In the molding device described above, the position of the generator and the specific configuration of the mold member are arbitrary.

[0137] The molding device described above can solve the problem of agitating microwaves in the filling space, and therefore can properly irradiate microwaves over the entire resin particles in the filling space.

[0138] (7) The control method for the stirring device according to the second embodiment can be considered as an independent feature, regardless of the specific configuration of the molding device. Specifically, the control method can be considered as a control method for a molding device for forming a molded body by fusing expandable resin particles, the molding device comprising: a mold member having a filling space into which the resin particles are filled; a generator that emits microwaves into the filling space to heat the resin particles; and a stirring mechanism that stirs the microwaves in the filling space, the generator including a power monitor that detects information on reflected waves (reflected wave information). In the above control method, the presence or absence of a passage and the specific configuration of the stirring mechanism are optional.

[0139] The above control method solves the problem of appropriately controlling the stirring mechanism in accordance with the information on the reflected waves, and ultimately makes it possible to appropriately irradiate microwaves over the entire resin particles filled in the filling space.

[0140] (8) The molding device with the slit according to the fourth embodiment can be considered as an independent feature, regardless of the specific configuration of the molding device other than the slit or the presence or absence of a stirring mechanism. Specifically, it is a device for forming a molded body by fusing expandable resin particles, and includes a mold member having a filling space into which the resin particles are filled, a generator that heats the resin particles by emitting microwaves into the filling space, and a slit (second slit) provided at a corner of the mold member.

[0141] The molding device described above can solve the problem of being able to properly irradiate microwaves even at corners of the mold members. [Explanation of symbols]

[0142] 20: Moving unit 23: Moving plate 30: Fixed unit 31: Fixed side mold member 33: Fixed side plate 40: Filling device 50: Generator 51: Oscillator 53: Waveguide 55: Isolator 57: Power monitor 59: Tuner 60: Stirring mechanism 70: Control unit 71: Slit 72: Slit 73: Slit 74: Slit 75: Slit 100: Molding equipment 211: Moving side mold member 213: Support plate 215: Frame section 217: Back plate 311: Fixed side mold member 313: Support plate 315: Frame section 317: Back plate 531: Branch 532: Lid member 601: Housing 602: Screw part 603: Shaft member 604: Shielding part 605: Probe 606: Coil 607: Motor 611: First member 612: Second member D: Passage section E: Microwave F: Installation surface G: Concave H:Through hole J: Corner K1: Support member K2: Support member N1:Protrusion N2:Protrusion P:Reflected wave information R1: Internal space R2: Internal space R3: Internal space S: Spacer T:Through hole U: Filling space

Claims

1. A molding apparatus for forming a molded body in which expandable resin particles are fused together, a movable unit having a hollow interior and including a movable mold member on its surface; a fixed-side unit having a hollow interior and including a fixed-side mold member at a position on the surface facing the movable-side mold member; a filling device that fills the resin particles into a filling space formed between the fixed-side mold member and the movable-side mold member; a microwave generator provided in the internal space of the fixed unit for emitting microwaves into the filling space to heat the resin particles; The generator includes an oscillator that generates the microwaves and a waveguide that transmits the microwaves to the filled space. Molding equipment.

2. a through hole is formed in the fixed-side mold member; an opening of the through hole on the movable mold member side is closed by a cover member made of a material that transmits microwaves; The end of the waveguide opposite to the oscillator is connected to the through hole from the side opposite to the movable mold member. The molding apparatus of claim 1.

3. the fixed-side mold member includes a plurality of fixed-side mold members, the movable-side mold member includes a plurality of movable-side mold members provided at positions facing the plurality of fixed-side mold members, respectively; The waveguide branches so as to connect to the through holes in the fixed-side mold members. The molding apparatus of claim 2.

4. A molding apparatus for forming a molded body in which expandable resin particles are fused together, a movable unit having a hollow interior and including a movable mold member on its surface; a fixed-side unit having a hollow interior and including a fixed-side mold member at a position on the surface facing the movable-side mold member; a filling device that fills the resin particles into a filling space formed between the fixed-side mold member and the movable-side mold member; a microwave generating device provided in the internal space of the moving unit for heating the resin particles in the filling space by microwaves; The generator includes an oscillator that generates the microwaves and a waveguide that transmits the microwaves to the filled space. Molding equipment.

5. a passage portion provided on at least one of the movable mold member and the fixed mold member, through which the microwaves can pass; a stirring mechanism connected to the passing part, which changes the amplitude and phase of microwaves that have passed through the passing part from the filling space, and emits the microwaves after the amplitude and phase changes from the passing part to the filling space. The molding apparatus according to any one of claims 1 to 4.

6. the passage portion includes one or more first slits, the width of the first slit is smaller than the diameter of the resin particle; The direction in which the first slit extends is a direction intersecting with the direction of oscillation of the electric field in the microwave emitted by the generator. The molding apparatus of claim 5.

7. The direction intersecting the direction of the vibration of the electric field is a direction intersecting the direction of the vibration of the electric field at an angle other than 90 degrees. The molding apparatus of claim 6.

8. the passage portion includes a plurality of first slits, The plurality of first slits are arranged at intervals of at least ¼ of the wavelength of the microwaves emitted by the generator. The molding apparatus according to claim 6 or 7.

9. The length of the first slit is equal to or greater than half the wavelength of the microwave emitted by the generator. The molding apparatus according to any one of claims 6 to 8.

10. The passing portion includes a transmitting member that transmits the microwave. The molding apparatus of claim 5.

11. A control unit for controlling the stirring mechanism is provided. the generator includes a power monitor that detects information about the reflected wave; The control unit controls the stirring mechanism in accordance with information on the reflected wave detected by the power monitor. The molding apparatus according to any one of claims 5 to 10.

12. The information on the reflected wave includes one or more of the power of the reflected wave, the amplitude of the reflected wave, and the phase of the reflected wave. The molding apparatus of claim 11.

13. The control unit controls the stirring mechanism so as to reduce reflected waves. The molding apparatus of claim 11 or 12.

14. a second slit provided at a corner of at least one of the movable mold member and the fixed mold member; the width of the second slit is smaller than the diameter of the resin particle; The length of the second slit is equal to or less than 1 / 4 of the wavelength of the microwave emitted by the generator. The molding apparatus of any one of claims 1 to 13.

15. A method for controlling a stirring mechanism in a molding apparatus according to claim 5, comprising: The stirring mechanism is controlled according to the information of the reflected wave. Control method.

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