JP6691649B2 - Electromagnetic induction heating type resin molding die and method of manufacturing resin molding using the die - Google Patents

Description

  The present invention relates to an electromagnetic induction heating type resin molding die and a method for manufacturing a resin molding using the metal mold. More specifically, an electromagnetic induction heating type resin molding die that enables temperature gradient heating by local heating of a resin molded body by electromagnetic induction local heating by a cassette type coil that can be easily attached and detached, and temperature gradient cooling by local cooling, and this metal mold. The present invention relates to a method for producing a resin molded product that enables high cycle molding by locally heating and locally cooling a mold.

  Examples of the resin molding method in which a mold is used for molding include an injection molding method, a compression molding method, and a blow molding method. In these methods, a molten raw material resin is charged into a mold, and then heat is transferred to shape and solidify the resin. As a method for heating the mold, a method using an electric heater, a method using a heat medium such as steam or oil, and a method using high-frequency electromagnetic induction heating are known. A resin molding die that uses this high-frequency electromagnetic induction as a heating means does not require a heat medium, and therefore is excellent in terms of equipment costs and operating costs, and has recently attracted attention. Such heating of the mold is an essential technique for weldless molding and high transfer molding.

  As a conventional technique for such weldless molding and high transfer molding, for example, in Japanese Patent No. 4052600, a mold nest is divided into a nest front member having a cavity surface and a nest back member having no cavity surface. Then, there is disclosed a mold in which a groove passing through a portion in the vicinity of the surface of the cavity is provided in this nesting surface member, and an electric heater is housed in this groove. However, in this configuration, since the weld line generation point is different for each mold, it is necessary to design a groove for accommodating the electric heater, and it is difficult to handle a wide variety of molded products. It was

  Further, in the patent No. 5261283 of the same applicant, with the same configuration, it has a groove for accommodating the electric heater, and the electric heater is installed in a plurality of systems separately, and different temperature control is performed for each control zone. There is disclosed a structure for preventing the occurrence of a weld line. However, this structure also has a drawback that it is difficult to deal with a wide variety of molded products, like the above-mentioned reference.

  Further, in Japanese Patent Laid-Open No. 2007-8035, a pair of relatively openable mold plates, a cavity side mold and a core side mold which are respectively embedded in the pair of mold plates, and a cavity side mold are installed inside the mold plate. There is disclosed a molding die device which houses a heat source body for heating the cavity side die to a temperature higher than the thermal deformation temperature of the resin to prevent the occurrence of weld lines. However, even with this structure, the basic structure for accommodating the heat source body in the mold is still the same as the above-mentioned reference, and thus there is a drawback that it is difficult to deal with a wide variety of molded products.

  Similar configurations are disclosed in Japanese Patent Application Laid-Open Nos. 2007-8036, 2007-223168, and 2009-226778, all of which are filed by the same applicant, but in any configuration, the heat source is housed inside the mold. The basic structure is the same as the above-mentioned reference, and thus this structure has a drawback that it is difficult to deal with a wide variety of molded products.

  Next, as a resin molding die using high-frequency electromagnetic induction as a heating means, Japanese Patent Publication No. 2007-535786 has means for applying an electromagnetic field to an intermediate element arranged between an inductor and a material to be heated. A mold is disclosed. However, this configuration has a drawback that heating energy is wasted because the entire die is heated and not only the minimum necessary range is heated according to the shape of the die.

  Further, Japanese Patent Publication No. 2006-546570 by the same applicant also discloses a mold in which a plurality of cavities surround the field winding. However, with this configuration, the size of the field winding cannot be easily changed according to the shape of the part to be molded or deformed, and there is a drawback that the heating energy is wasted as in the above-mentioned reference.

  Further, Japanese Patent Publication No. 2009-507674 by the same applicant discloses a configuration that enables local heating by high-frequency electromagnetic induction unlike the above-mentioned reference. That is, a network of inductors electrically connected to the current generator is arranged around the mold casings, a shielding layer is provided on a part of the outer surface of each mold casing, and the two mold casings face each other. A part of the surface is covered to enable local heating. The non-magnetic material used for this shielding layer is, for example, copper or aluminum, which has a low resistivity to limit energy loss. However, even with this configuration, it is not possible to locally heat even the shape of the resin molded body, and there is a drawback that the heating energy is wasted as in the case of the above-mentioned reference.

Next, as a resin molding die that uses high-frequency electromagnetic induction as a heating means, Japanese Patent Laid-Open No. 2012-214040 discloses that a cavity surface is formed in two molds, and a magnetic metal is formed in each portion having a cavity surface. There is disclosed an electromagnetic induction heating type mold device for resin molding, which is configured so that a plurality of induction coils are arranged on the outer surface of the magnetic metal portion within a predetermined range from the outer peripheral edge of the cavity. However, even in this structure, an induction coil must be provided for each mold, and the structure is limited to electromagnetic induction whole surface heating instead of electromagnetic induction local heating by a cassette type coil and whole surface cooling instead of local cooling. With such a configuration, heating / cooling energy is likely to be wasted. Further, since the induction coil is arranged with a fixed gap from the outer peripheral edge of the cavity, it is difficult to give a temperature gradient to each part of the mold cavity surface.

Finally, in JP-A-2013-226810, in a continuous resin-molded product manufacturing cycle using an electromagnetic induction heating mold having a configuration similar to that of the above-mentioned reference, a resin-molded product that stably reduces the time required Is disclosed. However, the electromagnetic induction heating mold used here has not yet reached the technical idea of forming a cassette of local heating and heating coils as described above, and has the drawback of not being an efficient method for producing a resin molded body. Have

Japanese Patent No. 4052600 Japanese Patent No. 5261283 JP 2007-8035 JP 2007-8036 JP 2007-223168 JP JP 2009-226778 JP Special Table 2007-535786 Publication Special Table 2006-546570 Publication Special Table 2009-507674 Publication JP 2012-214040 A JP 2013-226810 JP

  The problem to be solved is the structure of whole surface heating and whole surface cooling in the conventional electromagnetic induction heating type mold, and it corresponds to the weld line generation part and the transfer imperfect part which are different depending on the shape of each resin molding. However, it has a drawback that it cannot efficiently perform local heating and local cooling. In other words, it has a structure in which the entire surface is unnecessarily heated and the entire surface is unnecessarily cooled, and there is a drawback that energy cannot be used efficiently. Further, the induction heating coil for electromagnetic induction heating is integrally formed with the mold, and there is a drawback that the electromagnetic induction coil cannot be easily replaced for each shape of each resin molding. Further, due to the structure in which the gap between the die / die cavity surface and the induction heating coil is fixed, there is a drawback that a slight temperature gradient cannot be applied to the die cavity surface.

  The electromagnetic induction heating type resin molding die according to the present invention is a coil cassette for induction heating which can be easily attached and detached according to the shape of the resin molded body to be molded, and is configured to perform temperature gradient heating by local heating. The coil cassette is composed of a coil holding plate and an induction heating coil attached to the coil holding plate. Any number of induction heating coils can be attached according to the shape of the resin molded body to be molded, and the gap between each induction heating coil and the coil holding plate can be adjusted individually. The coil cassette can be attached and adjusted by providing an arbitrary gap from the heating surface of the die body. Regarding mold cooling as well, temperature gradient cooling is performed by local cooling corresponding to the location of local heating. Further, the coil cassette is not parallel to the cavity surface of the mold, but is appropriately inclined, so that a slight temperature gradient is imparted to the cavity surface of the mold. The temperature gradient may be imparted by arranging an additional magnetic material (soft ferrite) or the like close to each induction heating coil.

  In the present invention, the induction heating coil is formed into a cassette to minimize the heat capacity by local heating, and at the same time, local cooling is performed corresponding to the location of local heating, so that defective parts such as weld lines on the surface of the resin molding can be efficiently treated. It can be resolved well. Further, by such local heating and local cooling, there are advantages that high cycle molding can be achieved, and die cost can be reduced and workability can be improved. Further, by providing the induction heating coil cassette with an appropriate inclination with respect to the mold cavity surface, there is an advantage that the temperature of the mold cavity surface can be finely adjusted by freely giving a temperature inclination. Especially, unlike the conventional whole surface heating configuration, only the vicinity where the induction heating coil is attached can be locally heated, and by cooling this part locally, an efficient mold heating / cooling process can be performed. It becomes possible to configure. Further, in the coil cassette of the present invention, the gap between the coil holding plate and the heating surface of the mold body can be adjusted, and the gap between each induction heating coil and the coil holding plate can be adjusted, so that the shape of the resin molded body to be molded can be adjusted. Accordingly, by flexibly heating and cooling, energy can be efficiently used.

FIG. 1 is a schematic connection diagram of an electromagnetic induction heating type resin molding apparatus in which an electromagnetic induction heating type resin molding die according to the present invention is housed and installed in a resin molding machine. FIG. 2 is a sectional view of an electromagnetic induction heating type resin molding die of the present invention. FIG. 3 is a plan view in which the coil cassette is installed in the design surface mold. FIG. 4 is a plan view showing another embodiment in which soft ferrite is arranged near the induction heating coil.

  FIG. 1 is a schematic connection diagram of an electromagnetic induction heating type resin molding apparatus 1 in which an electromagnetic induction heating type resin molding die 100 according to the present invention is housed and installed in a resin molding machine 200. An electromagnetic induction heating device 300 and a cooling mechanism 400 are connected to a resin molding machine 200 accommodating the electromagnetic induction heating type resin molding die 100 for supplying heating power and cooling water and air, respectively. The structure itself is the same as that of the conventional electromagnetic induction heating type resin molding device, and therefore its details are omitted. The most basic configuration required for induction heating is a high-frequency transmitting unit (inverter), a heating coil (inductor), and a substance to be heated. However, the present invention further includes a transformer and a capacitor called a matching unit, which are not shown. This makes it possible to optimize the shape of the heating coil in a wide range, and it is configured to realize local heating and temperature gradient control by a plurality of heating coils and soft ferrite.

  2 is a cross-sectional view of the electromagnetic induction heating type resin molding die 100 of the present invention, and FIG. 3 is a plan view in which the coil cassette 30 is installed on the design surface die 100b. That is, the mold 100 is composed of a non-design surface side mold 100a on the left side in FIG. 2 and a design surface side mold 100b on the right side. Between the non-design surface side mold 100a and the design surface side mold 100b, a mold cavity 100c having an arbitrary shape for molding a resin molded body is provided. The former non-design surface side die 100a is integrally attached to the attachment plate 10 like the die according to the related art, and a plurality of cooling holes 50 and the ejector 11 are provided inside for cooling. A design surface side mold 100b is provided on the right side of the mold 100 with a molding mold cavity 100c interposed therebetween. A coil cassette 30 for electromagnetic induction heating is attached to the design surface side mold 100b in the coil cassette housing portion 20 having a predetermined depth. Further, a plurality of cooling holes 50 through which the cooling medium from the cooling mechanism flows are also provided in the heated metal portion 40 on the mold cavity 100c side with respect to the coil cassette 30.

  Here, the coil cassette 30 has a heat-resistant temperature of 100 ° C. or higher, a coil holding plate 31 having a thickness of about 1 to 30 mm due to insulation and heat resistance, and a non-magnetic mounting plate (not shown). An induction heating coil 33 is attached to the coil holding plate 31 with an induction heating coil mounting screw 34. However, the mounting method is not particularly limited, such as sandwiching the coil from the outside. The reason for limiting the thickness to about 1 to 30 mm is that it is considered to be optimum from the viewpoint of mechanical strength while considering the insulating property and heat resistance. If it exceeds 30 mm, eddy current is less likely to be generated in the heated metal portion 40, and induction heating is less likely to occur.

  The induction heating coil 33 has an inner dimension radius R of 50 mm or less, for example. The inner radius R is set to be 50 mm or less so that the inner diameter of the coil of the metal to be heated is evenly heated, and the temperature gradient heating can be performed by locally heating the metal to be heated 40. Becomes That is, if the inner radius R is set to such a small diameter that the induced magnetic flux is perpendicular to the heated metal portion 40, the energy can be evenly concentrated at the portion where the temperature is to be raised, and the inner diameter is This is because if the thickness is 50 mm or more, a portion having a sparse magnetic flux density is formed in the coil inner diameter portion, and the temperature of the projection surface onto the heating surface of the coil inner diameter portion becomes low. The inner radius R may be appropriately determined according to the shape and size of the resin molded body in the mold cavity. In addition, the induction heating coil 33 is installed at a position near the place where the weld line of the resin molded body is likely to occur and the place where the defective molding such as incomplete transferability is likely to occur. The induction heating coil 33 may be freely arranged on the holding plate 31. For example, as shown in FIG. 3, it is in the vicinity of the convex portion 90 of the resin molded body, and is a portion on the downstream side of the molten resin with respect to the convex portion 90. In such a place, the divided molten resins join together to reduce the flow velocity, and they are not sufficiently fused to easily cause a weld line. Therefore, by locally heating such a part, unlike the whole surface heating, it is possible to effectively prevent the generation of a weld line. The size (outer diameter) of the induction heating coil 33 is also set to the minimum necessary size corresponding to the size of the convex portion 90 and the size / shape of the molded body, and the number of induction heating coils 33 is also defective such as a weld line. It is possible to minimize the heating power by adjusting the number of occurrence points. Further, the thickness of the coil holding plate 31 may be appropriately changed depending on the number of induction heating coils 33 and the like.

  The coil cassette 30 is planarly attached to the heated metal portion 40 as shown in FIG. 2 by the coil cassette attachment screw 32 shown in FIG. The mounting gap with the metal part 40 to be heated may be adjusted by the coil / cassette mounting screw 32, and the adjusted mounting gap may be used for heating adjustment. Further, the coil cassette 30 can be freely adjusted, for example, by adjusting the coil cassette mounting screws 32 provided at the four corners so as to have an appropriate inclination angle with respect to the heated metal portion 40 (simultaneously with the mold cavity 100c). A temperature gradient may be applied. This allows fine adjustment of heating. Unlike the mold according to the conventional example, such a temperature gradient can be provided only by using the coil cassette 30 which is a case different from the main body of the design surface mold 100b as in the present invention.

  More specifically, the coil cassette 30 will be described in detail. The induction heating coils 33 are attached to the coil holding plate 31 with the induction heating coil attachment screws 34. The heating coil mounting screw 34 may be adjusted by sandwiching a spacer or the like so that the gap with the heated metal portion 40 can be finely adjusted. The method of attaching the induction heating coil 33 to the coil holding plate 31 is not limited to the configuration of attaching the induction heating coil attachment screw 34 at the center of the coil as described above, and the attachment method such as sandwiching the coil from the outside is particularly preferable. Not limited. Further, the induction heating coil 33 can be attached in an arbitrary number according to the shape of the resin molded body to be molded, and the gap between the individual induction heating coil 33 and the coil holding plate 31 can be adjusted by the induction heating coil mounting screw 34. Can be adjusted individually. By constructing the coil cassette 30 in this way, it is possible to efficiently use energy by flexibly heating and cooling according to the shape of the resin molded body to be molded. Therefore, by forming the coil into a cassette, it becomes possible to give a temperature gradient more freely than the conventional configuration in which the coil is fixedly installed on the mold body.

  Further, the heated metal portion 40 shown in FIG. 2 may be an alloy having a different Curie temperature or a composite material thereof to control the temperature. In particular, this configuration is effective when controlling the upper limit of the heating temperature.

  Next, in the electromagnetic induction heating type resin molding die 100 according to the present invention, as shown in FIG. 2, a plurality of cooling holes 50 are provided in the non-design surface side die 100a on the left side and the design surface side die 100b on the right side in the figure. (A, b, c, d) are arranged respectively. In particular, a plurality of cooling holes 50 provided in the design surface side mold 100b on the right side are provided in the heated metal portion 40 on the mold cavity 100c side of the coil cassette 30. On the other hand, the conventional mold of the type heated by the electric heater has a drawback that the cooling efficiency is low because the cooling hole is provided apart from the cavity with the electric heater interposed therebetween. However, the present invention has an advantage that the cooling efficiency is good because the cooling hole 50 is provided at a position closer to the mold cavity 100c. This is possible because the coil cassette 30 is configured in a housing separate from the heated metal portion 40. Each cooling hole 50 is configured such that the control unit (not shown) can control the injection and discharge of the cooling medium. In this embodiment, two induction heating coils 33 are attached to the design surface mold 100b in the vicinity of the cooling holes 50a and 50c for temperature gradient heating by local heating. Therefore, the induction heating coil 33 performs local temperature gradient heating and injects the molten resin, and then injects the cooling medium only into the cooling holes 50a and 50c arranged in the vicinity of the induction heating coil 33 for cooling. In other words, the cooling medium is not injected into the cooling holes 50b and 50d arranged in the vicinity where local heating is not performed, or the amount of the cooling medium is reduced as compared with 50a and 50c. In this way, according to the present invention, not only the heating and cooling of the entire surface but also the entire surface cooling is not performed, but local heating and local cooling are performed, so that not only the energy consumption can be minimized but also the molding process can be shortened to achieve high cycle molding. Is configured to be possible. Further, the air purging of the cooling mechanism 400 in FIG. 1 prevents energy loss of heating the cooling medium by replacing air inside the cooling holes after cooling and before the heating step.

  FIG. 4 is a plan view showing another embodiment in which a plurality of soft ferrites are arranged near the induction heating coil 33. Typical examples of this soft ferrite are manganese zinc ferrite, nickel zinc ferrite, and copper zinc ferrite. Since it has a high magnetic permeability and a high electric resistance, it causes little eddy current loss in the high frequency region, and is therefore used as a magnetic core material for high frequency inductors and transformers called "ferrite cores". By arranging such soft ferrite, the magnetic flux is controlled to increase the magnetic flux density, and as a result, the current density of the eddy current is also increased, so that the heating efficiency of the heated metal portion 40 of the mold shown in FIG. 2 is increased. It is possible. If necessary, a metal such as a copper plate having a low electric resistance and relatively hard to be induction-heated may be arranged around the induction heating coil. That is, the skin effect of the eddy current on the copper plate is used to electromagnetically shield the metal part 40 to be heated, which makes it possible to finely adjust the temperature of the part where heating by the induction coil is low. .. In other words, a copper plate or the like, which is a non-magnetic conductive material having a sufficiently low electric resistance and a thickness equal to or greater than the skin depth, is arranged near the induction heating coil 33, thereby lowering the magnetic flux density and reducing the need for heating. By substantially magnetically shielding the portion, the heating temperature of the heated metal portion 40 can be finely adjusted. In any case, by arranging ferrite or a copper plate in the vicinity of the induction heating coil 33, there is an advantage that temperature gradient heating can be performed by more efficient local heating. (A) is the one in which the soft ferrite is arranged inside the induction heating coil 33, (b) is the one outside the induction heating coil 33, and (c) is the one above it. Since the temperature gradient heating is measured, it is preferable to determine each arrangement according to the shape of the resin molded body and the like.

  Note that the size (outer diameter) of the induction heating coil 33 may be changed to change the degree of concentration of heating energy with respect to the heating portion, and the temperature of local heating may be controlled. Naturally, if the size of the coil is made small, the degree of concentration of heating energy is improved, and local heating at high temperature becomes possible.

  Note that the present invention also discloses a method for manufacturing a resin molded body using the electromagnetic induction heating type resin molding apparatus 1. That is, first, with the mold 100 open, the induction heating coil 33 is energized to locally heat the mold cavity 100c to perform temperature gradient heating, and a gradient temperature is applied to raise the temperature to a predetermined temperature. Next, the mold 100 is closed to fill the resin into the mold cavity 100c, the pressure is maintained, and after a lapse of a predetermined time, the cooling mechanism 400 connected to the mold 100 locally cools only the vicinity of the locally heated portion. Alternatively, the resin molded body may be taken out after the completion of the temperature reduction. In this case, a soft ferrite may be arranged inside or outside the induction heating coil 33 or on the upper side thereof, and the surface temperature of the mold cavity 100c may be inclined at 10 ° C. to 200 ° C. to raise the temperature to a predetermined temperature. Good.

  As described above, in the electromagnetic induction heating type resin molding die 100 according to the present invention, since the induction heating coil cassette 30 is used, it is possible to easily change the location of local heating according to the shape of the resin molded body and the like. Is possible. Further, since the structure is such that only the portion corresponding to the local heating is locally cooled, it is possible to minimize the cooling energy. Further, by changing the position setting of the induction heating coil 33 according to the shape of the resin molded body, it is possible to use the same coil cassette 30 for various molds, which is advantageous in that the mold manufacturing becomes easy. Have. Further, by finely adjusting the gap between the heated metal part 40 and the induction heating coil cassette 30 or the gap between the coil holding plate 31 and the individual induction heating coils 33, the temperature can be locally heated on the surface of the mold cavity 100c. There is also an advantage that inclination can be imparted. Further, by arranging ferrite, which is a magnetic material, for the purpose of concentrating the magnetic flux in the vicinity of the induction heating coil, there is an advantage that the temperature of local heating can be controlled.

100 Electromagnetic Induction Heating Resin Mold 20 Coil / Cassette Storage Section 30 Coil / Cassette 31 Coil Holding Plate 32 Coil / Cassette Mounting Screw 33 Induction Heating Coil 34 Induction Heating Coil Mounting Screw 40 Heated Metal Part 50 Cooling Hole

Claims (15)

An electromagnetic induction heating type resin molding die used in the resin molding machine of the electromagnetic induction heating type resin molding apparatus (1) including the resin molding machine (200), the electromagnetic induction heating device (300) and the cooling mechanism (400) ( 100);
A coil cassette (30) for local induction heating constituted by a coil holding plate (31) and one or a plurality of induction heating coils (33) attached to the coil holding plate, the coil cassette comprising: , The coil / cassette housing (20) is easily attached to the metal part (40) to be heated and detached, and the metal part to be heated is subjected to temperature gradient heating by local heating by a predetermined high frequency power controlled by the electromagnetic induction heating device. Configured to do;
Further, a plurality of cooling holes (50) through which a cooling medium from the cooling mechanism flows are provided in the heated metal part (40) between the coil cassette and the mold cavity surface, and the induction heating coil locally serves. An electromagnetic induction heating type resin molding die characterized in that a cooling medium is caused to flow only through a cooling hole provided in the vicinity of a heated metal part to be locally cooled to perform temperature gradient cooling.   The induction heating coil (33) of the coil cassette (30) is arranged in an arbitrary number in the vicinity of a place where there is a high probability that defective molding will occur, and the induction heating coil (33) can be freely arranged on the coil holding plate (31). The electromagnetic induction heating type resin molding die according to claim 1, wherein   The induction heating coil cassette (30) can be mounted and adjusted by placing an arbitrary gap from the heating surface of the heated metal portion (40) and making it parallel or inclined to the heated metal portion. 2. The electromagnetic induction heating type resin molding die according to claim 1, wherein the heating surface is allowed to have a temperature gradient freely.   Each of the one or more induction heating coils (33) attached to the induction heating coil cassette (30) can be attached with an arbitrary gap from the coil holding plate (31). 2. The electromagnetic induction heating type resin molding die according to claim 1, wherein the heating surface is provided with a temperature gradient by different gaps.   The induction heating coil (33) is made of a copper wire or a copper tube and is arranged so that the gap between the heated surface of the heated metal part (40) is 30 mm or less and the inner radius R is 50 mm or less. 2. The coil inner diameter portion is heated uniformly by the heating means, whereby the temperature gradient heating can be performed by local heating without lowering the temperature of the coil inner diameter portion projection surface of the heated metal portion. Electromagnetic induction heating type resin molding die.   The coil holding plate (31) has a heat resistant temperature of 100 ° C. or higher, is arranged between the heating surface of the heated metal part (40) and the induction heating coil (33), and has a thickness of 1 to 30 mm. The electromagnetic induction heating type resin molding die according to claim 1, wherein the temperature gradient heating can be performed by local heating. A plurality of soft ferrites are arranged inside or outside the induction heating coil (33) or above the induction heating coil (33) to control the magnetic flux to control the temperature of local heating of the metal part (40) to be heated. The electromagnetic induction heating type resin molding die according to claim 1, wherein Further, a non-magnetic conductive material having a sufficiently low electric resistance and a thickness equal to or larger than the skin depth is arranged in the vicinity of the induction heating coil (33) to reduce the magnetic flux density and to substantially magnetize the portion where heating is low. The electromagnetic induction heating resin molding die according to claim 7 , wherein the shielding is used to control the temperature of local heating of the heated metal portion (40). The electromagnetic induction heating type resin molding die according to claim 8 , wherein the non-magnetic conductive material having a sufficiently low electric resistance and a thickness equal to or greater than the skin depth is a copper plate . The size (outer diameter) of the induction heating coil (33) is changed to change the degree of concentration of heating energy with respect to a heating portion, and the temperature of local heating is controlled. 1. The electromagnetic induction heating type resin molding die described in 1.   2. The electromagnetic induction heating according to claim 1, wherein the heated metal portion (40) is made of an alloy having a different Curie temperature or a composite material thereof to control the temperature of local heating. Resin mold. The mold cavity (100c) is heated by energizing the induction heating coil (33) with high frequency from the electromagnetic induction heating device (300) with the electromagnetic induction heating type resin molding mold (100) according to claim 1 being opened. Then, temperature gradient heating by local heating to a predetermined temperature,
Fill the mold cavity with resin and hold the pressure,
After a lapse of a predetermined time, of the plurality of cooling holes (50) through which the cooling medium supplied from the cooling mechanism (400) connected to the mold flows, only the cooling holes provided near the locally heated portion are cooled. A method for producing a resin molded body, in which temperature gradient cooling is performed by local cooling by controlling the medium to flow, and the resin molded body is taken out after completion of cooling. In the step of temperature gradient heating, the surface temperature of the mold cavity is controlled to 10 ° C to 200 ° C by arranging a soft ferrite inside or outside the induction heating coil (33) or controlling the magnetic flux. 13. The method for producing a resin molded product according to claim 12, further comprising the step of increasing the temperature to a predetermined temperature by providing an inclination. Further, in the temperature gradient heating step, it is necessary to dispose a non-magnetic conductive material having a sufficiently low electric resistance and a thickness not less than the skin depth in the vicinity of the induction heating coil (33) to lower the magnetic flux density and perform heating. 14. A step of raising the surface temperature of the mold cavity to a predetermined temperature by providing a slope of 10 [deg.] C. to 200 [deg.] C. by substantially magnetically shielding a portion having a low property is included. The method for producing a resin molded body according to claim 1. The method for producing a resin molded product according to claim 14 , wherein the non-magnetic conductive material having a sufficiently low electric resistance and a thickness equal to or greater than the skin depth is a copper plate .